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Sample records for optimized filtering step

  1. STEPS: A Grid Search Methodology for Optimized Peptide Identification Filtering of MS/MS Database Search Results

    SciTech Connect

    Piehowski, Paul D.; Petyuk, Vladislav A.; Sandoval, John D.; Burnum, Kristin E.; Kiebel, Gary R.; Monroe, Matthew E.; Anderson, Gordon A.; Camp, David G.; Smith, Richard D.

    2013-03-01

    For bottom-up proteomics there are a wide variety of database searching algorithms in use for matching peptide sequences to tandem MS spectra. Likewise, there are numerous strategies being employed to produce a confident list of peptide identifications from the different search algorithm outputs. Here we introduce a grid search approach for determining optimal database filtering criteria in shotgun proteomics data analyses that is easily adaptable to any search. Systematic Trial and Error Parameter Selection - referred to as STEPS - utilizes user-defined parameter ranges to test a wide array of parameter combinations to arrive at an optimal "parameter set" for data filtering, thus maximizing confident identifications. The benefits of this approach in terms of numbers of true positive identifications are demonstrated using datasets derived from immunoaffinity-depleted blood serum and a bacterial cell lysate, two common proteomics sample types.

  2. Structural notch filter optimization

    SciTech Connect

    Felton, R.; Burge, S.; Bradshaw, A.

    1995-09-01

    A modified algorithm for nonlinear constrained optimization of structural mode filters for an aeroelastic aircraft model is presented. The optimizer set-up and control is implemented in a MATLAB{trademark} graphical user interface environment. It is shown that the modified algorithm gives improved performance over existing nonlinear constrained optimization methods.

  3. Robust Spatiotemporal Quadrature Filter for Multiphase Stepping

    NASA Astrophysics Data System (ADS)

    Rivera, Mariano; Marroquin, Jose L.; Botello, Salvador; Servín, Manuel

    2000-01-01

    A robust algorithm for phase recovery from multi-phase-stepping images is presented. This algorithm is based on the minimization of an energy (cost) functional and is equivalent to the simultaneous application of a fixed temporal quadrature filter and a spatial adaptive quadrature filter to the phase-stepping pattern ensemble. The algorithm, believed to be new, is specially suited for those applications in which a large number of phase-stepping images may be obtained, e.g., profilometry with a computer-controlled fringe projector. We discuss the selection of parameter values and present examples of its performance in both synthetic and real image sequences.

  4. Optimal filtering and filter stability of linear stochastic delay systems

    NASA Technical Reports Server (NTRS)

    Kwong, R. H.-S.; Willsky, A. S.

    1977-01-01

    Optimal filtering equations are obtained for very general linear stochastic delay systems. Stability of the optimal filter is studied in the case where there are no delays in the observations. Using the duality between linear filtering and control, asymptotic stability of the optimal filter is proved. Finally, the cascade of the optimal filter and the deterministic optimal quadratic control system is shown to be asymptotically stable as well.

  5. Optimization of integrated polarization filters.

    PubMed

    Gagnon, Denis; Dumont, Joey; Déziel, Jean-Luc; Dubé, Louis J

    2014-10-01

    This study reports on the design of small footprint, integrated polarization filters based on engineered photonic lattices. Using a rods-in-air lattice as a basis for a TE filter and a holes-in-slab lattice for the analogous TM filter, we are able to maximize the degree of polarization of the output beams up to 98% with a transmission efficiency greater than 75%. The proposed designs allow not only for logical polarization filtering, but can also be tailored to output an arbitrary transverse beam profile. The lattice configurations are found using a recently proposed parallel tabu search algorithm for combinatorial optimization problems in integrated photonics. PMID:25360980

  6. OPTIMIZATION OF ADVANCED FILTER SYSTEMS

    SciTech Connect

    R.A. Newby; G.J. Bruck; M.A. Alvin; T.E. Lippert

    1998-04-30

    Reliable, maintainable and cost effective hot gas particulate filter technology is critical to the successful commercialization of advanced, coal-fired power generation technologies, such as IGCC and PFBC. In pilot plant testing, the operating reliability of hot gas particulate filters have been periodically compromised by process issues, such as process upsets and difficult ash cake behavior (ash bridging and sintering), and by design issues, such as cantilevered filter elements damaged by ash bridging, or excessively close packing of filtering surfaces resulting in unacceptable pressure drop or filtering surface plugging. This test experience has focused the issues and has helped to define advanced hot gas filter design concepts that offer higher reliability. Westinghouse has identified two advanced ceramic barrier filter concepts that are configured to minimize the possibility of ash bridge formation and to be robust against ash bridges should they occur. The ''inverted candle filter system'' uses arrays of thin-walled, ceramic candle-type filter elements with inside-surface filtering, and contains the filter elements in metal enclosures for complete separation from ash bridges. The ''sheet filter system'' uses ceramic, flat plate filter elements supported from vertical pipe-header arrays that provide geometry that avoids the buildup of ash bridges and allows free fall of the back-pulse released filter cake. The Optimization of Advanced Filter Systems program is being conducted to evaluate these two advanced designs and to ultimately demonstrate one of the concepts in pilot scale. In the Base Contract program, the subject of this report, Westinghouse has developed conceptual designs of the two advanced ceramic barrier filter systems to assess their performance, availability and cost potential, and to identify technical issues that may hinder the commercialization of the technologies. A plan for the Option I, bench-scale test program has also been developed based on the issues identified. The two advanced barrier filter systems have been found to have the potential to be significantly more reliable and less expensive to operate than standard ceramic candle filter system designs. Their key development requirements are the assessment of the design and manufacturing feasibility of the ceramic filter elements, and the small-scale demonstration of their conceptual reliability and availability merits.

  7. Fully optimal filter for ALLEGRO

    NASA Astrophysics Data System (ADS)

    Santostasi, Giovanni

    2004-03-01

    The FAST and SLOW filters are compared when applied to data from one-mode and two-mode resonant gravitational wave detectors. There is no substantial difference between the performance of two filters in the case of the one-mode detector. Notable reduction of the noise temperature is achieved for a two-mode detector when filtering the data with the FAST filter. We explain the principal reason for the better performance of the FAST filter with respect to the SLOW filter. We also observed that the performance of the FAST filter depends on the ratio Γ between the thermal narrow band noise and the SQUID amplifier white noise.

  8. OPTIMIZATION OF ADVANCED FILTER SYSTEMS

    SciTech Connect

    R.A. Newby; M.A. Alvin; G.J. Bruck; T.E. Lippert; E.E. Smeltzer; M.E. Stampahar

    2002-06-30

    Two advanced, hot gas, barrier filter system concepts have been proposed by the Siemens Westinghouse Power Corporation to improve the reliability and availability of barrier filter systems in applications such as PFBC and IGCC power generation. The two hot gas, barrier filter system concepts, the inverted candle filter system and the sheet filter system, were the focus of bench-scale testing, data evaluations, and commercial cost evaluations to assess their feasibility as viable barrier filter systems. The program results show that the inverted candle filter system has high potential to be a highly reliable, commercially successful, hot gas, barrier filter system. Some types of thin-walled, standard candle filter elements can be used directly as inverted candle filter elements, and the development of a new type of filter element is not a requirement of this technology. Six types of inverted candle filter elements were procured and assessed in the program in cold flow and high-temperature test campaigns. The thin-walled McDermott 610 CFCC inverted candle filter elements, and the thin-walled Pall iron aluminide inverted candle filter elements are the best candidates for demonstration of the technology. Although the capital cost of the inverted candle filter system is estimated to range from about 0 to 15% greater than the capital cost of the standard candle filter system, the operating cost and life-cycle cost of the inverted candle filter system is expected to be superior to that of the standard candle filter system. Improved hot gas, barrier filter system availability will result in improved overall power plant economics. The inverted candle filter system is recommended for continued development through larger-scale testing in a coal-fueled test facility, and inverted candle containment equipment has been fabricated and shipped to a gasifier development site for potential future testing. Two types of sheet filter elements were procured and assessed in the program through cold flow and high-temperature testing. The Blasch, mullite-bonded alumina sheet filter element is the only candidate currently approaching qualification for demonstration, although this oxide-based, monolithic sheet filter element may be restricted to operating temperatures of 538 C (1000 F) or less. Many other types of ceramic and intermetallic sheet filter elements could be fabricated. The estimated capital cost of the sheet filter system is comparable to the capital cost of the standard candle filter system, although this cost estimate is very uncertain because the commercial price of sheet filter element manufacturing has not been established. The development of the sheet filter system could result in a higher reliability and availability than the standard candle filter system, but not as high as that of the inverted candle filter system. The sheet filter system has not reached the same level of development as the inverted candle filter system, and it will require more design development, filter element fabrication development, small-scale testing and evaluation before larger-scale testing could be recommended.

  9. Optimal frequency domain textural edge detection filter

    NASA Technical Reports Server (NTRS)

    Townsend, J. K.; Shanmugan, K. S.; Frost, V. S.

    1985-01-01

    An optimal frequency domain textural edge detection filter is developed and its performance evaluated. For the given model and filter bandwidth, the filter maximizes the amount of output image energy placed within a specified resolution interval centered on the textural edge. Filter derivation is based on relating textural edge detection to tonal edge detection via the complex low-pass equivalent representation of narrowband bandpass signals and systems. The filter is specified in terms of the prolate spheroidal wave functions translated in frequency. Performance is evaluated using the asymptotic approximation version of the filter. This evaluation demonstrates satisfactory filter performance for ideal and nonideal textures. In addition, the filter can be adjusted to detect textural edges in noisy images at the expense of edge resolution.

  10. Steps Toward Optimal Competitive Scheduling

    NASA Technical Reports Server (NTRS)

    Frank, Jeremy; Crawford, James; Khatib, Lina; Brafman, Ronen

    2006-01-01

    This paper is concerned with the problem of allocating a unit capacity resource to multiple users within a pre-defined time period. The resource is indivisible, so that at most one user can use it at each time instance. However, different users may use it at different times. The users have independent, se@sh preferences for when and for how long they are allocated this resource. Thus, they value different resource access durations differently, and they value different time slots differently. We seek an optimal allocation schedule for this resource. This problem arises in many institutional settings where, e.g., different departments, agencies, or personal, compete for a single resource. We are particularly motivated by the problem of scheduling NASA's Deep Space Satellite Network (DSN) among different users within NASA. Access to DSN is needed for transmitting data from various space missions to Earth. Each mission has different needs for DSN time, depending on satellite and planetary orbits. Typically, the DSN is over-subscribed, in that not all missions will be allocated as much time as they want. This leads to various inefficiencies - missions spend much time and resource lobbying for their time, often exaggerating their needs. NASA, on the other hand, would like to make optimal use of this resource, ensuring that the good for NASA is maximized. This raises the thorny problem of how to measure the utility to NASA of each allocation. In the typical case, it is difficult for the central agency, NASA in our case, to assess the value of each interval to each user - this is really only known to the users who understand their needs. Thus, our problem is more precisely formulated as follows: find an allocation schedule for the resource that maximizes the sum of users preferences, when the preference values are private information of the users. We bypass this problem by making the assumptions that one can assign money to customers. This assumption is reasonable; a committee is usually in charge of deciding the priority of each mission competing for access to the DSN within a time period while scheduling. Instead, we can assume that the committee assigns a budget to each mission.This paper is concerned with the problem of allocating a unit capacity resource to multiple users within a pre-defined time period. The resource is indivisible, so that at most one user can use it at each time instance. However, different users may use it at different times. The users have independent, se@sh preferences for when and for how long they are allocated this resource. Thus, they value different resource access durations differently, and they value different time slots differently. We seek an optimal allocation schedule for this resource. This problem arises in many institutional settings where, e.g., different departments, agencies, or personal, compete for a single resource. We are particularly motivated by the problem of scheduling NASA's Deep Space Satellite Network (DSN) among different users within NASA. Access to DSN is needed for transmitting data from various space missions to Earth. Each mission has different needs for DSN time, depending on satellite and planetary orbits. Typically, the DSN is over-subscribed, in that not all missions will be allocated as much time as they want. This leads to various inefficiencies - missions spend much time and resource lobbying for their time, often exaggerating their needs. NASA, on the other hand, would like to make optimal use of this resource, ensuring that the good for NASA is maximized. This raises the thorny problem of how to measure the utility to NASA of each allocation. In the typical case, it is difficult for the central agency, NASA in our case, to assess the value of each interval to each user - this is really only known to the users who understand their needs. Thus, our problem is more precisely formulated as follows: find an allocation schedule for the resource that maximizes the sum ofsers preferences, when the preference values are private information of the users. We bypass this problem by making the assumptions that one can assign money to customers. This assumption is reasonable; a committee is usually in charge of deciding the priority of each mission competing for access to the DSN within a time period while scheduling. Instead, we can assume that the committee assigns a budget to each mission.

  11. Optimization of OT-MACH Filter Generation for Target Recognition

    NASA Technical Reports Server (NTRS)

    Johnson, Oliver C.; Edens, Weston; Lu, Thomas T.; Chao, Tien-Hsin

    2009-01-01

    An automatic Optimum Trade-off Maximum Average Correlation Height (OT-MACH) filter generator for use in a gray-scale optical correlator (GOC) has been developed for improved target detection at JPL. While the OT-MACH filter has been shown to be an optimal filter for target detection, actually solving for the optimum is too computationally intensive for multiple targets. Instead, an adaptive step gradient descent method was tested to iteratively optimize the three OT-MACH parameters, alpha, beta, and gamma. The feedback for the gradient descent method was a composite of the performance measures, correlation peak height and peak to side lobe ratio. The automated method generated and tested multiple filters in order to approach the optimal filter quicker and more reliably than the current manual method. Initial usage and testing has shown preliminary success at finding an approximation of the optimal filter, in terms of alpha, beta, gamma values. This corresponded to a substantial improvement in detection performance where the true positive rate increased for the same average false positives per image.

  12. Dual Adaptive Filtering by Optimal Projection Applied to Filter Muscle Artifacts on EEG and Comparative Study

    PubMed Central

    Peyrodie, Laurent; Szurhaj, William; Bolo, Nicolas; Pinti, Antonio; Gallois, Philippe

    2014-01-01

    Muscle artifacts constitute one of the major problems in electroencephalogram (EEG) examinations, particularly for the diagnosis of epilepsy, where pathological rhythms occur within the same frequency bands as those of artifacts. This paper proposes to use the method dual adaptive filtering by optimal projection (DAFOP) to automatically remove artifacts while preserving true cerebral signals. DAFOP is a two-step method. The first step consists in applying the common spatial pattern (CSP) method to two frequency windows to identify the slowest components which will be considered as cerebral sources. The two frequency windows are defined by optimizing convolutional filters. The second step consists in using a regression method to reconstruct the signal independently within various frequency windows. This method was evaluated by two neurologists on a selection of 114 pages with muscle artifacts, from 20 clinical recordings of awake and sleeping adults, subject to pathological signals and epileptic seizures. A blind comparison was then conducted with the canonical correlation analysis (CCA) method and conventional low-pass filtering at 30?Hz. The filtering rate was 84.3% for muscle artifacts with a 6.4% reduction of cerebral signals even for the fastest waves. DAFOP was found to be significantly more efficient than CCA and 30?Hz filters. The DAFOP method is fast and automatic and can be easily used in clinical EEG recordings. PMID:25298967

  13. Optimal filtering of constant velocity torque data.

    PubMed

    Murray, D A

    1986-12-01

    The purpose of this investigation was to implement an optimal filtering strategy for processing in vivo dynamometric data. The validity of employing commonly accepted analog smoothing methods was also appraised. An inert gravitational model was used to assess the filtering requirements of two Cybex II constant velocity dynamometers at 10 pre-set speeds with three selected loads. Speed settings were recorded as percentages of the servomechanism's maximum tachometer feedback voltage (10 to 100% Vfb max). Spectral analyses of unsmoothed torque and associated angular displacement curves, followed by optimized low-pass digital filtering, revealed the presence of two superimposed contaminating influences: a damped oscillation, representing successive sudden braking and releasing of the servomechanism control system; a relatively stationary oscillatory series, which was attributed to the Cybex motor. The optimal cutoff frequency for any data set was principally a positive function of % Vfb max. This association was represented for each machine by a different, but reliable, third order least-squares polynomial, which could be used to accurately predict the correct smoothing required for any speed setting. Unacceptable errors may be induced, especially when measuring peak torques, if data are inappropriately filtered. Over-smoothing disguises inertial artefacts. The use of Cybex recorder damping settings should be discouraged. Optimal filtering is a minimal requirement of valid data processing. PMID:3784873

  14. Desensitized Optimal Filtering and Sensor Fusion Toolkit

    NASA Technical Reports Server (NTRS)

    Karlgaard, Christopher D.

    2015-01-01

    Analytical Mechanics Associates, Inc., has developed a software toolkit that filters and processes navigational data from multiple sensor sources. A key component of the toolkit is a trajectory optimization technique that reduces the sensitivity of Kalman filters with respect to model parameter uncertainties. The sensor fusion toolkit also integrates recent advances in adaptive Kalman and sigma-point filters for non-Gaussian problems with error statistics. This Phase II effort provides new filtering and sensor fusion techniques in a convenient package that can be used as a stand-alone application for ground support and/or onboard use. Its modular architecture enables ready integration with existing tools. A suite of sensor models and noise distribution as well as Monte Carlo analysis capability are included to enable statistical performance evaluations.

  15. MEDOF - MINIMUM EUCLIDEAN DISTANCE OPTIMAL FILTER

    NASA Technical Reports Server (NTRS)

    Barton, R. S.

    1994-01-01

    The Minimum Euclidean Distance Optimal Filter program, MEDOF, generates filters for use in optical correlators. The algorithm implemented in MEDOF follows theory put forth by Richard D. Juday of NASA/JSC. This program analytically optimizes filters on arbitrary spatial light modulators such as coupled, binary, full complex, and fractional 2pi phase. MEDOF optimizes these modulators on a number of metrics including: correlation peak intensity at the origin for the centered appearance of the reference image in the input plane, signal to noise ratio including the correlation detector noise as well as the colored additive input noise, peak to correlation energy defined as the fraction of the signal energy passed by the filter that shows up in the correlation spot, and the peak to total energy which is a generalization of PCE that adds the passed colored input noise to the input image's passed energy. The user of MEDOF supplies the functions that describe the following quantities: 1) the reference signal, 2) the realizable complex encodings of both the input and filter SLM, 3) the noise model, possibly colored, as it adds at the reference image and at the correlation detection plane, and 4) the metric to analyze, here taken to be one of the analytical ones like SNR (signal to noise ratio) or PCE (peak to correlation energy) rather than peak to secondary ratio. MEDOF calculates filters for arbitrary modulators and a wide range of metrics as described above. MEDOF examines the statistics of the encoded input image's noise (if SNR or PCE is selected) and the filter SLM's (Spatial Light Modulator) available values. These statistics are used as the basis of a range for searching for the magnitude and phase of k, a pragmatically based complex constant for computing the filter transmittance from the electric field. The filter is produced for the mesh points in those ranges and the value of the metric that results from these points is computed. When the search is concluded, the values of amplitude and phase for the k whose metric was largest, as well as consistency checks, are reported. A finer search can be done in the neighborhood of the optimal k if desired. The filter finally selected is written to disk in terms of drive values, not in terms of the filter's complex transmittance. Optionally, the impulse response of the filter may be created to permit users to examine the response for the features the algorithm deems important to the recognition process under the selected metric, limitations of the filter SLM, etc. MEDOF uses the filter SLM to its greatest potential, therefore filter competence is not compromised for simplicity of computation. MEDOF is written in C-language for Sun series computers running SunOS. With slight modifications, it has been implemented on DEC VAX series computers using the DEC-C v3.30 compiler, although the documentation does not currently support this platform. MEDOF can also be compiled using Borland International Inc.'s Turbo C++ v1.0, but IBM PC memory restrictions greatly reduce the maximum size of the reference images from which the filters can be calculated. MEDOF requires a two dimensional Fast Fourier Transform (2DFFT). One 2DFFT routine which has been used successfully with MEDOF is a routine found in "Numerical Recipes in C: The Art of Scientific Programming," which is available from Cambridge University Press, New Rochelle, NY 10801. The standard distribution medium for MEDOF is a .25 inch streaming magnetic tape cartridge (Sun QIC-24) in UNIX tar format. MEDOF was developed in 1992-1993.

  16. Optimal time step for incompressible SPH

    NASA Astrophysics Data System (ADS)

    Violeau, Damien; Leroy, Agnès

    2015-05-01

    A classical incompressible algorithm for Smoothed Particle Hydrodynamics (ISPH) is analyzed in terms of critical time step for numerical stability. For this purpose, a theoretical linear stability analysis is conducted for unbounded homogeneous flows, leading to an analytical formula for the maximum CFL (Courant-Friedrichs-Lewy) number as a function of the Fourier number. This gives the maximum time step as a function of the fluid viscosity, the flow velocity scale and the SPH discretization size (kernel standard deviation). Importantly, the maximum CFL number at large Reynolds number appears twice smaller than with the traditional Weakly Compressible (WCSPH) approach. As a consequence, the optimal time step for ISPH is only five times larger than with WCSPH. The theory agrees very well with numerical data for two usual kernels in a 2-D periodic flow. On the other hand, numerical experiments in a plane Poiseuille flow show that the theory overestimates the maximum allowed time step for small Reynolds numbers.

  17. Optimal digital filtering for tremor suppression.

    PubMed

    Gonzalez, J G; Heredia, E A; Rahman, T; Barner, K E; Arce, G R

    2000-05-01

    Remote manually operated tasks such as those found in teleoperation, virtual reality, or joystick-based computer access, require the generation of an intermediate electrical signal which is transmitted to the controlled subsystem (robot arm, virtual environment, or a cursor in a computer screen). When human movements are distorted, for instance, by tremor, performance can be improved by digitally filtering the intermediate signal before it reaches the controlled device. This paper introduces a novel tremor filtering framework in which digital equalizers are optimally designed through pursuit tracking task experiments. Due to inherent properties of the man-machine system, the design of tremor suppression equalizers presents two serious problems: 1) performance criteria leading to optimizations that minimize mean-squared error are not efficient for tremor elimination and 2) movement signals show ill-conditioned autocorrelation matrices, which often result in useless or unstable solutions. To address these problems, a new performance indicator in the context of tremor is introduced, and the optimal equalizer according to this new criterion is developed. Ill-conditioning of the autocorrelation matrix is overcome using a novel method which we call pulled-optimization. Experiments performed with artificially induced vibrations and a subject with Parkinson's disease show significant improvement in performance. Additional results, along with MATLAB source code of the algorithms, and a customizable demo for PC joysticks, are available on the Internet at http:¿tremor-suppression.com. PMID:10851810

  18. GNSS data filtering optimization for ionospheric observation

    NASA Astrophysics Data System (ADS)

    D'Angelo, G.; Spogli, L.; Cesaroni, C.; Sgrigna, V.; Alfonsi, L.; Aquino, M. H. O.

    2015-12-01

    In the last years, the use of GNSS (Global Navigation Satellite Systems) data has been gradually increasing, for both scientific studies and technological applications. High-rate GNSS data, able to generate and output 50-Hz phase and amplitude samples, are commonly used to study electron density irregularities within the ionosphere. Ionospheric irregularities may cause scintillations, which are rapid and random fluctuations of the phase and the amplitude of the received GNSS signals. For scintillation analysis, usually, GNSS signals observed at an elevation angle lower than an arbitrary threshold (usually 15°, 20° or 30°) are filtered out, to remove the possible error sources due to the local environment where the receiver is deployed. Indeed, the signal scattered by the environment surrounding the receiver could mimic ionospheric scintillation, because buildings, trees, etc. might create diffusion, diffraction and reflection. Although widely adopted, the elevation angle threshold has some downsides, as it may under or overestimate the actual impact of multipath due to local environment. Certainly, an incorrect selection of the field of view spanned by the GNSS antenna may lead to the misidentification of scintillation events at low elevation angles. With the aim to tackle the non-ionospheric effects induced by multipath at ground, in this paper we introduce a filtering technique, termed SOLIDIFY (Standalone OutLiers IDentIfication Filtering analYsis technique), aiming at excluding the multipath sources of non-ionospheric origin to improve the quality of the information obtained by the GNSS signal in a given site. SOLIDIFY is a statistical filtering technique based on the signal quality parameters measured by scintillation receivers. The technique is applied and optimized on the data acquired by a scintillation receiver located at the Istituto Nazionale di Geofisica e Vulcanologia, in Rome. The results of the exercise show that, in the considered case of a noisy site under quiet ionospheric conditions, the SOLIDIFY optimization maximizes the quality, instead of the quantity, of the data.

  19. Constrained filter optimization for subsurface landmine detection

    NASA Astrophysics Data System (ADS)

    Torrione, Peter A.; Collins, Leslie; Clodfelter, Fred; Lulich, Dan; Patrikar, Ajay; Howard, Peter; Weaver, Richard; Rosen, Erik

    2006-05-01

    Previous large-scale blind tests of anti-tank landmine detection utilizing the NIITEK ground penetrating radar indicated the potential for very high anti-tank landmine detection probabilities at very low false alarm rates for algorithms based on adaptive background cancellation schemes. Recent data collections under more heterogeneous multi-layered road-scenarios seem to indicate that although adaptive solutions to background cancellation are effective, the adaptive solutions to background cancellation under different road conditions can differ significantly, and misapplication of these adaptive solutions can reduce landmine detection performance in terms of PD/FAR. In this work we present a framework for the constrained optimization of background-estimation filters that specifically seeks to optimize PD/FAR performance as measured by the area under the ROC curve between two FARs. We also consider the application of genetic algorithms to the problem of filter optimization for landmine detection. Results indicate robust results for both static and adaptive background cancellation schemes, and possible real-world advantages and disadvantages of static and adaptive approaches are discussed.

  20. Optimal edge filters explain human blur detection.

    PubMed

    McIlhagga, William H; May, Keith A

    2012-01-01

    Edges are important visual features, providing many cues to the three-dimensional structure of the world. One of these cues is edge blur. Sharp edges tend to be caused by object boundaries, while blurred edges indicate shadows, surface curvature, or defocus due to relative depth. Edge blur also drives accommodation and may be implicated in the correct development of the eye's optical power. Here we use classification image techniques to reveal the mechanisms underlying blur detection in human vision. Observers were shown a sharp and a blurred edge in white noise and had to identify the blurred edge. The resultant smoothed classification image derived from these experiments was similar to a derivative of a Gaussian filter. We also fitted a number of edge detection models (MIRAGE, N(1), and N(3)(+)) and the ideal observer to observer responses, but none performed as well as the classification image. However, observer responses were well fitted by a recently developed optimal edge detector model, coupled with a Bayesian prior on the expected blurs in the stimulus. This model outperformed the classification image when performance was measured by the Akaike Information Criterion. This result strongly suggests that humans use optimal edge detection filters to detect edges and encode their blur. PMID:22984222

  1. Program Computes SLM Inputs To Implement Optimal Filters

    NASA Technical Reports Server (NTRS)

    Barton, R. Shane; Juday, Richard D.; Alvarez, Jennifer L.

    1995-01-01

    Minimum Euclidean Distance Optimal Filter (MEDOF) program generates filters for use in optical correlators. Analytically optimizes filters on arbitrary spatial light modulators (SLMs) of such types as coupled, binary, fully complex, and fractional-2pi-phase. Written in C language.

  2. Stepped Impedance Resonators in Triple Band Bandpass Filter Design for Wireless Communication Systems

    SciTech Connect

    Eroglu, Abdullah

    2010-01-01

    Triple band microstrip tri-section bandpass filter using stepped impedance resonators (SIRs) is designed, simulated, built, and measured using hair pin structure. The complete design procedure is given from analytical stage to implementation stage with details The coupling between SIRs is investigated for the first time in detail by studying their effect on the filter characteristics including bandwidth, and attenuation to optimize the filter perfomance. The simulation of the filler is performed using method of moment based 2.5D planar electromagnetic simulator The filter is then implemented on RO4003 material and measured The simulation, and measured results are compared and found to be my close. The effect of coupling on the filter performance is then investigated using electromagnetic simulator It is shown that the coupling effect between SIRs can be used as a design knob to obtain a bandpass Idler with a better performance jar the desired frequency band using the proposed filter topology The results of this work can used in wireless communication systems where multiple frequency bandy are needed

  3. Metal finishing wastewater pressure filter optimization

    SciTech Connect

    Norford, S.W.; Diener, G.A.; Martin, H.L.

    1992-12-31

    The 300-M Area Liquid Effluent Treatment Facility (LETF) of the Savannah River Site (SRS) is an end-of-pipe industrial wastewater treatment facility, that uses precipitation and filtration which is the EPA Best Available Technology economically achievable for a Metal Finishing and Aluminum Form Industries. The LETF consists of three close-coupled treatment facilities: the Dilute Effluent Treatment Facility (DETF), which uses wastewater equalization, physical/chemical precipitation, flocculation, and filtration; the Chemical Treatment Facility (CTF), which slurries the filter cake generated from the DETF and pumps it to interim-StatuS RCRA storage tanks; and the Interim Treatment/Storage Facility (IT/SF) which stores the waste from the CTF until the waste is stabilized/solidified for permanent disposal, 85% of the stored waste is from past nickel plating and aluminum canning of depleted uranium targets for the SRS nuclear reactors. Waste minimization and filtration efficiency are key to cost effective treatment of the supernate, because the waste filter cake generated is returned to the IT/SF. The DETF has been successfully optimized to achieve maximum efficiency and to minimize waste generation.

  4. Metal finishing wastewater pressure filter optimization

    SciTech Connect

    Norford, S.W.; Diener, G.A.; Martin, H.L.

    1992-01-01

    The 300-M Area Liquid Effluent Treatment Facility (LETF) of the Savannah River Site (SRS) is an end-of-pipe industrial wastewater treatment facility, that uses precipitation and filtration which is the EPA Best Available Technology economically achievable for a Metal Finishing and Aluminum Form Industries. The LETF consists of three close-coupled treatment facilities: the Dilute Effluent Treatment Facility (DETF), which uses wastewater equalization, physical/chemical precipitation, flocculation, and filtration; the Chemical Treatment Facility (CTF), which slurries the filter cake generated from the DETF and pumps it to interim-StatuS RCRA storage tanks; and the Interim Treatment/Storage Facility (IT/SF) which stores the waste from the CTF until the waste is stabilized/solidified for permanent disposal, 85% of the stored waste is from past nickel plating and aluminum canning of depleted uranium targets for the SRS nuclear reactors. Waste minimization and filtration efficiency are key to cost effective treatment of the supernate, because the waste filter cake generated is returned to the IT/SF. The DETF has been successfully optimized to achieve maximum efficiency and to minimize waste generation.

  5. A hybrid method for optimization of the adaptive Goldstein filter

    NASA Astrophysics Data System (ADS)

    Jiang, Mi; Ding, Xiaoli; Tian, Xin; Malhotra, Rakesh; Kong, Weixue

    2014-12-01

    The Goldstein filter is a well-known filter for interferometric filtering in the frequency domain. The main parameter of this filter, alpha, is set as a power of the filtering function. Depending on it, considered areas are strongly or weakly filtered. Several variants have been developed to adaptively determine alpha using different indicators such as the coherence, and phase standard deviation. The common objective of these methods is to prevent areas with low noise from being over filtered while simultaneously allowing stronger filtering over areas with high noise. However, the estimators of these indicators are biased in the real world and the optimal model to accurately determine the functional relationship between the indicators and alpha is also not clear. As a result, the filter always under- or over-filters and is rarely correct. The study presented in this paper aims to achieve accurate alpha estimation by correcting the biased estimator using homogeneous pixel selection and bootstrapping algorithms, and by developing an optimal nonlinear model to determine alpha. In addition, an iteration is also merged into the filtering procedure to suppress the high noise over incoherent areas. The experimental results from synthetic and real data show that the new filter works well under a variety of conditions and offers better and more reliable performance when compared to existing approaches.

  6. Optimal design of AC filter circuits in HVDC converter stations

    SciTech Connect

    Saied, M.M.; Khader, S.A.

    1995-12-31

    This paper investigates the reactive power as well as the harmonic conditions on both the valve and the AC-network sides of a HVDC converter station. The effect of the AC filter circuits is accurately modeled. The program is then augmented by adding an optimization routine. It can identify the optimal filter configuration, yielding the minimum current distortion factor at the AC network terminals for a prespecified fundamental reactive power to be provided by the filter. Several parameter studies were also conducted to illustrate the effect of accidental or intentional deletion of one of the filter branches.

  7. Optimal filter bandwidth for pulse oximetry

    NASA Astrophysics Data System (ADS)

    Stuban, Norbert; Niwayama, Masatsugu

    2012-10-01

    Pulse oximeters contain one or more signal filtering stages between the photodiode and microcontroller. These filters are responsible for removing the noise while retaining the useful frequency components of the signal, thus improving the signal-to-noise ratio. The corner frequencies of these filters affect not only the noise level, but also the shape of the pulse signal. Narrow filter bandwidth effectively suppresses the noise; however, at the same time, it distorts the useful signal components by decreasing the harmonic content. In this paper, we investigated the influence of the filter bandwidth on the accuracy of pulse oximeters. We used a pulse oximeter tester device to produce stable, repetitive pulse waves with digitally adjustable R ratio and heart rate. We built a pulse oximeter and attached it to the tester device. The pulse oximeter digitized the current of its photodiode directly, without any analog signal conditioning. We varied the corner frequency of the low-pass filter in the pulse oximeter in the range of 0.66-15 Hz by software. For the tester device, the R ratio was set to R = 1.00, and the R ratio deviation measured by the pulse oximeter was monitored as a function of the corner frequency of the low-pass filter. The results revealed that lowering the corner frequency of the low-pass filter did not decrease the accuracy of the oxygen level measurements. The lowest possible value of the corner frequency of the low-pass filter is the fundamental frequency of the pulse signal. We concluded that the harmonics of the pulse signal do not contribute to the accuracy of pulse oximetry. The results achieved by the pulse oximeter tester were verified by human experiments, performed on five healthy subjects. The results of the human measurements confirmed that filtering out the harmonics of the pulse signal does not degrade the accuracy of pulse oximetry.

  8. Optimal Filter Systems for Photometric Redshift Estimation

    NASA Astrophysics Data System (ADS)

    Benítez, N.; Moles, M.; Aguerri, J. A. L.; Alfaro, E.; Broadhurst, T.; Cabrera-Caño, J.; Castander, F. J.; Cepa, J.; Cerviño, M.; Cristóbal-Hornillos, D.; Fernández-Soto, A.; González Delgado, R. M.; Infante, L.; Márquez, I.; Martínez, V. J.; Masegosa, J.; Del Olmo, A.; Perea, J.; Prada, F.; Quintana, J. M.; Sánchez, S. F.

    2009-02-01

    In the coming years, several cosmological surveys will rely on imaging data to estimate the redshift of galaxies, using traditional filter systems with 4-5 optical broad bands; narrower filters improve the spectral resolution, but strongly reduce the total system throughput. We explore how photometric redshift performance depends on the number of filters nf , characterizing the survey depth by the fraction of galaxies with unambiguous redshift estimates. For a combination of total exposure time and telescope imaging area of 270 hr m2, 4-5 filter systems perform significantly worse, both in completeness depth and precision, than systems with nf gsim 8 filters. Our results suggest that for low nf the color-redshift degeneracies overwhelm the improvements in photometric depth, and that even at higher nf the effective photometric redshift depth decreases much more slowly with filter width than naively expected from the reduction in the signal-to-noise ratio. Adding near-IR observations improves the performance of low-nf systems, but still the system which maximizes the photometric redshift completeness is formed by nine filters with logarithmically increasing bandwidth (constant resolution) and half-band overlap, reaching ~0.7 mag deeper, with 10% better redshift precision, than 4-5 filter systems. A system with 20 constant-width, nonoverlapping filters reaches only ~0.1 mag shallower than 4-5 filter systems, but has a precision almost three times better, δz = 0.014(1 + z) versus δz = 0.042(1 + z). We briefly discuss a practical implementation of such a photometric system: the ALHAMBRA Survey.

  9. Illumination system design with multi-step optimization

    NASA Astrophysics Data System (ADS)

    Magarill, Simon; Cassarly, William J.

    2015-08-01

    Automatic optimization algorithms can be used when designing illumination systems. For systems with many design variables, optimization using an adjustable set of variables at different steps of the process can provide different local minima. We present a few examples of implementing a multi-step optimization method. We have found that this approach can sometimes lead to more efficient solutions. In this paper we illustrate the effectiveness of using a commercially available optimization algorithm with a slightly modified procedure.

  10. Optimal Gain Filter Design for Perceptual Acoustic Echo Suppressor

    NASA Astrophysics Data System (ADS)

    Kim, Kihyeon; Ko, Hanseok

    This Letter proposes an optimal gain filter for the perceptual acoustic echo suppressor. We designed an optimally-modified log-spectral amplitude estimation algorithm for the gain filter in order to achieve robust suppression of echo and noise. A new parameter including information about interferences (echo and noise) of single-talk duration is statistically analyzed, and then the speech absence probability and the a posteriori SNR are judiciously estimated to determine the optimal solution. The experiments show that the proposed gain filter attains a significantly improved reduction of echo and noise with less speech distortion.

  11. Entropy-based optimization of wavelet spatial filters.

    PubMed

    Farina, Darino; Kamavuako, Ernest Nlandu; Wu, Jian; Naddeo, Francesco

    2008-03-01

    A new class of spatial filters for surface electromyographic (EMG) signal detection is proposed. These filters are based on the 2-D spatial wavelet decomposition of the surface EMG recorded with a grid of electrodes and inverse transformation after zeroing a subset of the transformation coefficients. The filter transfer function depends on the selected mother wavelet in the two spatial directions. Wavelet parameterization is proposed with the aim of signal-based optimization of the transfer function of the spatial filter. The optimization criterion was the minimization of the entropy of the time samples of the output signal. The optimized spatial filter is linear and space invariant. In simulated and experimental recordings, the optimized wavelet filter showed increased selectivity with respect to previously proposed filters. For example, in simulation, the ratio between the peak-to-peak amplitude of action potentials generated by motor units 20 degrees apart in the transversal direction was 8.58% (with monopolar recording), 2.47% (double differential), 2.59% (normal double differential), and 0.47% (optimized wavelet filter). In experimental recordings, the duration of the detected action potentials decreased from (mean +/- SD) 6.9 +/- 0.3 ms (monopolar recording), to 4.5 +/- 0.2 ms (normal double differential), 3.7 +/- 0.2 (double differential), and 3.0 +/- 0.1 ms (optimized wavelet filter). In conclusion, the new class of spatial filters with the proposed signal-based optimization of the transfer function allows better discrimination of individual motor unit activities in surface EMG recordings than it was previously possible. PMID:18334382

  12. Optimization-based tuning of LPV fault detection filters for civil transport aircraft

    NASA Astrophysics Data System (ADS)

    Ossmann, D.; Varga, A.

    2013-12-01

    In this paper, a two-step optimal synthesis approach of robust fault detection (FD) filters for the model based diagnosis of sensor faults for an augmented civil aircraft is suggested. In the first step, a direct analytic synthesis of a linear parameter varying (LPV) FD filter is performed for the open-loop aircraft using an extension of the nullspace based synthesis method to LPV systems. In the second step, a multiobjective optimization problem is solved for the optimal tuning of the LPV detector parameters to ensure satisfactory FD performance for the augmented nonlinear closed-loop aircraft. Worst-case global search has been employed to assess the robustness of the fault detection system in the presence of aerodynamics uncertainties and estimation errors in the aircraft parameters. An application of the proposed method is presented for the detection of failures in the angle-of-attack sensor.

  13. Geomagnetic modeling by optimal recursive filtering

    NASA Technical Reports Server (NTRS)

    Gibbs, B. P.; Estes, R. H.

    1981-01-01

    The results of a preliminary study to determine the feasibility of using Kalman filter techniques for geomagnetic field modeling are given. Specifically, five separate field models were computed using observatory annual means, satellite, survey and airborne data for the years 1950 to 1976. Each of the individual field models used approximately five years of data. These five models were combined using a recursive information filter (a Kalman filter written in terms of information matrices rather than covariance matrices.) The resulting estimate of the geomagnetic field and its secular variation was propogated four years past the data to the time of the MAGSAT data. The accuracy with which this field model matched the MAGSAT data was evaluated by comparisons with predictions from other pre-MAGSAT field models. The field estimate obtained by recursive estimation was found to be superior to all other models.

  14. Initial steps of inactivation at the K+ channel selectivity filter.

    PubMed

    Thomson, Andrew S; Heer, Florian T; Smith, Frank J; Hendron, Eunan; Bernèche, Simon; Rothberg, Brad S

    2014-04-29

    K(+) efflux through K(+) channels can be controlled by C-type inactivation, which is thought to arise from a conformational change near the channel's selectivity filter. Inactivation is modulated by ion binding near the selectivity filter; however, the molecular forces that initiate inactivation remain unclear. We probe these driving forces by electrophysiology and molecular simulation of MthK, a prototypical K(+) channel. Either Mg(2+) or Ca(2+) can reduce K(+) efflux through MthK channels. However, Ca(2+), but not Mg(2+), can enhance entry to the inactivated state. Molecular simulations illustrate that, in the MthK pore, Ca(2+) ions can partially dehydrate, enabling selective accessibility of Ca(2+) to a site at the entry to the selectivity filter. Ca(2+) binding at the site interacts with K(+) ions in the selectivity filter, facilitating a conformational change within the filter and subsequent inactivation. These results support an ionic mechanism that precedes changes in channel conformation to initiate inactivation. PMID:24733889

  15. Time-domain split-step method with variable step-sizes in vectorial pulse propagation by using digital filters

    NASA Astrophysics Data System (ADS)

    Farhoudi, R.; Mehrany, K.

    2010-06-01

    Finite impulse response (FIR) and infinite impulse response (IIR) digital filters are proposed to allow for time-domain simulation of optical pulse propagation by using the operator-splitting technique. These filters simulate polarization mode dispersion and chromatic dispersion effects with acceptable accuracy in time-domain. An analytical relation between the coefficients of these filters and the simulation step-size is established to accommodate the possibility of carrying out the time-domain split-step method with variable split-step length at virtually no computational burden. The superiority of the proposed method over the conventional frequency-domain technique is particularly demonstrated in wavelength-division multiplexing (WDM) applications.

  16. Optimal Sharpening of Compensated Comb Decimation Filters: Analysis and Design

    PubMed Central

    Troncoso Romero, David Ernesto

    2014-01-01

    Comb filters are a class of low-complexity filters especially useful for multistage decimation processes. However, the magnitude response of comb filters presents a droop in the passband region and low stopband attenuation, which is undesirable in many applications. In this work, it is shown that, for stringent magnitude specifications, sharpening compensated comb filters requires a lower-degree sharpening polynomial compared to sharpening comb filters without compensation, resulting in a solution with lower computational complexity. Using a simple three-addition compensator and an optimization-based derivation of sharpening polynomials, we introduce an effective low-complexity filtering scheme. Design examples are presented in order to show the performance improvement in terms of passband distortion and selectivity compared to other methods based on the traditional Kaiser-Hamming sharpening and the Chebyshev sharpening techniques recently introduced in the literature. PMID:24578674

  17. A family of variable step-size affine projection adaptive filter algorithms using statistics of channel impulse response

    NASA Astrophysics Data System (ADS)

    Shams Esfand Abadi, Mohammad; AbbasZadeh Arani, Seyed Ali Asghar

    2011-12-01

    This paper extends the recently introduced variable step-size (VSS) approach to the family of adaptive filter algorithms. This method uses prior knowledge of the channel impulse response statistic. Accordingly, optimal step-size vector is obtained by minimizing the mean-square deviation (MSD). The presented algorithms are the VSS affine projection algorithm (VSS-APA), the VSS selective partial update NLMS (VSS-SPU-NLMS), the VSS-SPU-APA, and the VSS selective regressor APA (VSS-SR-APA). In VSS-SPU adaptive algorithms the filter coefficients are partially updated which reduce the computational complexity. In VSS-SR-APA, the optimal selection of input regressors is performed during the adaptation. The presented algorithms have good convergence speed, low steady state mean square error (MSE), and low computational complexity features. We demonstrate the good performance of the proposed algorithms through several simulations in system identification scenario.

  18. State-space realizations of fractional-step delay digital filters with applications to array beamforming

    NASA Astrophysics Data System (ADS)

    Leung, S.-H.; Barnes, C. W.

    1984-04-01

    An approach to the design of fractional-step delay (FSD) digital filters based on a state-space formulation applicable to either finite impulse response (FIR) or infinite impulse response (IIR) is presented. FSD filters are single-rate, do not require sample rate changes, and are based on an offset impulse-invariant transformation of an interpolating filter design. Utilization of FIR or IIR FSD filters for beamforming effects spurious sidelobes in the array spatial beam pattern, but an appropriate design of the FSD filters magnitude response can suppress the sidelobes. Since the nonlinear phase characteristics of FSD filters do not influence spatial response of the array, computational efficiency and constraints on temporal phase distortion determine the choice of FIR or IIR implementation. Also determined is that FIR implementation is more efficient for FSD filters derived from interpolating filters with low transition ratios.

  19. Identifying Optimal Measurement Subspace for the Ensemble Kalman Filter

    SciTech Connect

    Zhou, Ning; Huang, Zhenyu; Welch, Greg; Zhang, J.

    2012-05-24

    To reduce the computational load of the ensemble Kalman filter while maintaining its efficacy, an optimization algorithm based on the generalized eigenvalue decomposition method is proposed for identifying the most informative measurement subspace. When the number of measurements is large, the proposed algorithm can be used to make an effective tradeoff between computational complexity and estimation accuracy. This algorithm also can be extended to other Kalman filters for measurement subspace selection.

  20. Optimal filtering methods to structural damage estimation under ground excitation.

    PubMed

    Hsieh, Chien-Shu; Liaw, Der-Cherng; Lin, Tzu-Hsuan

    2013-01-01

    This paper considers the problem of shear building damage estimation subject to earthquake ground excitation using the Kalman filtering approach. The structural damage is assumed to take the form of reduced elemental stiffness. Two damage estimation algorithms are proposed: one is the multiple model approach via the optimal two-stage Kalman estimator (OTSKE), and the other is the robust two-stage Kalman filter (RTSKF), an unbiased minimum-variance filtering approach to determine the locations and extents of the damage stiffness. A numerical example of a six-storey shear plane frame structure subject to base excitation is used to illustrate the usefulness of the proposed results. PMID:24453869

  1. Optimal Filtering Methods to Structural Damage Estimation under Ground Excitation

    PubMed Central

    Hsieh, Chien-Shu; Liaw, Der-Cherng; Lin, Tzu-Hsuan

    2013-01-01

    This paper considers the problem of shear building damage estimation subject to earthquake ground excitation using the Kalman filtering approach. The structural damage is assumed to take the form of reduced elemental stiffness. Two damage estimation algorithms are proposed: one is the multiple model approach via the optimal two-stage Kalman estimator (OTSKE), and the other is the robust two-stage Kalman filter (RTSKF), an unbiased minimum-variance filtering approach to determine the locations and extents of the damage stiffness. A numerical example of a six-storey shear plane frame structure subject to base excitation is used to illustrate the usefulness of the proposed results. PMID:24453869

  2. Design and performance optimization of fiber optic adaptive filters.

    PubMed

    Paparao, P; Ghosh, A; Allen, S D

    1991-05-10

    There is a great need for easy-to-fabricate and versatile fiber optic signal processing systems in which optical fibers are used for the delay and storage of wideband guided lightwave signals. We describe the design of the least-mean-square algorithm-based fiber optic adaptive filters for processing guided lightwave signals in real time. Fiber optic adaptive filters can learn to change their parameters or to process a set of characteristics of the input signal. In our realization we employ as few electronic devices as possible and use optical computation to utilize the advantages of optics in the processing speed, parallelism, and interconnection. Many schemes for optical adaptive filtering of electronic signals are available in the literature. The new optical adaptive filters described in this paper are for optical processing of guided lightwave signals, not electronic signals. We analyzed the convergence or learning characteristics of the adaptive filtering process as a function of the filter parameters and the fiber optic hardware errors. From this analysis we found that the effects of the optical round-off errors and noise can be reduced, and the learning speed can be comparatively increased in our design through an optimal selection of the filter parameters. A general knowledge of the fiber optic hardware, the statistics of the lightwave signal, and the desired goal of the adaptive processing are enough for this optimum selection of the parameters. Detailed computer simulations validate the theoretical results of performance optimization. PMID:20700365

  3. Optimal Recursive Digital Filters for Active Bending Stabilization

    NASA Technical Reports Server (NTRS)

    Orr, Jeb S.

    2013-01-01

    In the design of flight control systems for large flexible boosters, it is common practice to utilize active feedback control of the first lateral structural bending mode so as to suppress transients and reduce gust loading. Typically, active stabilization or phase stabilization is achieved by carefully shaping the loop transfer function in the frequency domain via the use of compensating filters combined with the frequency response characteristics of the nozzle/actuator system. In this paper we present a new approach for parameterizing and determining optimal low-order recursive linear digital filters so as to satisfy phase shaping constraints for bending and sloshing dynamics while simultaneously maximizing attenuation in other frequency bands of interest, e.g. near higher frequency parasitic structural modes. By parameterizing the filter directly in the z-plane with certain restrictions, the search space of candidate filter designs that satisfy the constraints is restricted to stable, minimum phase recursive low-pass filters with well-conditioned coefficients. Combined with optimal output feedback blending from multiple rate gyros, the present approach enables rapid and robust parametrization of autopilot bending filters to attain flight control performance objectives. Numerical results are presented that illustrate the application of the present technique to the development of rate gyro filters for an exploration-class multi-engined space launch vehicle.

  4. Improvements of Adaptive Filtering by Optimal Projection to filter different artifact types on long duration EEG recordings.

    PubMed

    Boudet, S; Peyrodie, L; Forzy, G; Pinti, A; Toumi, H; Gallois, P

    2012-10-01

    Adaptive Filtering by Optimal Projection (AFOP) is an automatic method for reducing ocular and muscular artifacts on electro-encephalographic (EEG) recordings. This paper presents two additions to this method: an improvement of the stability of ocular artifact filtering and an adaptation of the method for filtering electrode artifacts. With these improvements, it is possible to reduce almost all the current types of artifacts, while preserving brain signals, particularly those characterising epilepsy. This generalised method consists of dividing the signal into several time-frequency windows, and in applying different spatial filters to each. Two steps are required to define one of these spatial filters: the first step consists of defining artifact spatial projection using the Common Spatial Pattern (CSP) method and the second consists of defining EEG spatial projection via regression. For this second step, a progressive orthogonalisation process is proposed to improve stability. This method has been tested on long-duration EEG recordings of epileptic patients. A neurologist quantified the ratio of removed artifacts and the ratio of preserved EEG. Among the 330 artifacted pages used for evaluation, readability was judged better for 78% of pages, equal for 20% of pages, and worse for 2%. Artifact amplitudes were reduced by 80% on average. At the same time, brain sources were preserved in amplitude from 70% to 95% depending on the type of waves (alpha, theta, delta, spikes, etc.). A blind comparison with manual Independent Component Analysis (ICA) was also realised. The results show that this method is competitive and useful for routine clinical practice. PMID:22717094

  5. Optimization of filtering schemes for broadband astro-combs.

    PubMed

    Chang, Guoqing; Li, Chih-Hao; Phillips, David F; Szentgyorgyi, Andrew; Walsworth, Ronald L; Krtner, Franz X

    2012-10-22

    To realize a broadband, large-line-spacing astro-comb, suitable for wavelength calibration of astrophysical spectrographs, from a narrowband, femtosecond laser frequency comb ("source-comb"), one must integrate the source-comb with three additional components: (1) one or more filter cavities to multiply the source-comb's repetition rate and thus line spacing; (2) power amplifiers to boost the power of pulses from the filtered comb; and (3) highly nonlinear optical fiber to spectrally broaden the filtered and amplified narrowband frequency comb. In this paper we analyze the interplay of Fabry-Perot (FP) filter cavities with power amplifiers and nonlinear broadening fiber in the design of astro-combs optimized for radial-velocity (RV) calibration accuracy. We present analytic and numeric models and use them to evaluate a variety of FP filtering schemes (labeled as identical, co-prime, fraction-prime, and conjugate cavities), coupled to chirped-pulse amplification (CPA). We find that even a small nonlinear phase can reduce suppression of filtered comb lines, and increase RV error for spectrograph calibration. In general, filtering with two cavities prior to the CPA fiber amplifier outperforms an amplifier placed between the two cavities. In particular, filtering with conjugate cavities is able to provide <1 cm/s RV calibration error with >300 nm wavelength coverage. Such superior performance will facilitate the search for and characterization of Earth-like exoplanets, which requires <10 cm/s RV calibration error. PMID:23187265

  6. Optimal Filter Estimation for Lucas-Kanade Optical Flow

    PubMed Central

    Sharmin, Nusrat; Brad, Remus

    2012-01-01

    Optical flow algorithms offer a way to estimate motion from a sequence of images. The computation of optical flow plays a key-role in several computer vision applications, including motion detection and segmentation, frame interpolation, three-dimensional scene reconstruction, robot navigation and video compression. In the case of gradient based optical flow implementation, the pre-filtering step plays a vital role, not only for accurate computation of optical flow, but also for the improvement of performance. Generally, in optical flow computation, filtering is used at the initial level on original input images and afterwards, the images are resized. In this paper, we propose an image filtering approach as a pre-processing step for the Lucas-Kanade pyramidal optical flow algorithm. Based on a study of different types of filtering methods and applied on the Iterative Refined Lucas-Kanade, we have concluded on the best filtering practice. As the Gaussian smoothing filter was selected, an empirical approach for the Gaussian variance estimation was introduced. Tested on the Middlebury image sequences, a correlation between the image intensity value and the standard deviation value of the Gaussian function was established. Finally, we have found that our selection method offers a better performance for the Lucas-Kanade optical flow algorithm.

  7. Ares-I Bending Filter Design using a Constrained Optimization Approach

    NASA Technical Reports Server (NTRS)

    Hall, Charles; Jang, Jiann-Woei; Hall, Robert; Bedrossian, Nazareth

    2008-01-01

    The Ares-I launch vehicle represents a challenging flex-body structural environment for control system design. Software filtering of the inertial sensor output is required to ensure adequate stable response to guidance commands while minimizing trajectory deviations. This paper presents a design methodology employing numerical optimization to develop the Ares-I bending filters. The design objectives include attitude tracking accuracy and robust stability with respect to rigid body dynamics, propellant slosh, and flex. Under the assumption that the Ares-I time-varying dynamics and control system can be frozen over a short period of time, the bending filters are designed to stabilize all the selected frozen-time launch control systems in the presence of parameter uncertainty. To ensure adequate response to guidance command, step response specifications are introduced as constraints in the optimization problem. Imposing these constrains minimizes performance degradation caused by the addition of the bending filters. The first stage bending filter design achieves stability by adding lag to the first structural frequency to phase stabilize the first flex mode while gain stabilizing the higher modes. The upper stage bending filter design gain stabilizes all the flex bending modes. The bending filter designs provided here have been demonstrated to provide stable first and second stage control systems in both Draper Ares Stability Analysis Tool (ASAT) and the MSFC MAVERIC 6DOF nonlinear time domain simulation.

  8. Assessment of optimally filtered recent geodetic mean dynamic topographies

    NASA Astrophysics Data System (ADS)

    Siegismund, F.

    2013-01-01

    AbstractRecent geoids from the Gravity Recovery and Climate Experiment (GRACE) and the Gravity field and steady state Ocean Circulation Explorer satellite mission (GOCE) contain useful short-scale information for the construction of a geodetic ocean mean dynamic topography (MDT). The geodetic MDT is obtained from subtracting the geoid from a mean sea surface (MSS) as measured by satellite altimetry. A gainful use of the MDT and an adequate assessment needs an <span class="hlt">optimal</span> <span class="hlt">filtering</span>. This is accomplished here by defining a cutoff length scale dmax for the geoid and applying a Gaussian <span class="hlt">filter</span> with half-width radius r on the MDT. A series of MDTs (GRACE, GOCE, and combined satellite-only (GOCO) solutions) is tested, using different sets of <span class="hlt">filter</span> parameters dmax and r. <span class="hlt">Optimal</span> global and regional dependent <span class="hlt">filter</span> parameters are estimated. To find <span class="hlt">optimal</span> parameters and to assess the resulting MDTs, the geostrophic surface currents induced by the <span class="hlt">filtered</span> geodetic MDT are compared to corrected near-surface currents obtained from the Global Drifter Program (GDP). The global <span class="hlt">optimal</span> cutoff degree and order (d/o) dmax (half-width radius r of the spatial Gaussian <span class="hlt">filter</span>) is 160 (1.1°) for GRACE; 180 (1.1-1.2°) for 1st releases of GOCE (time- and space-wise methods) and GOCO models; and 210 (1.0 degree) for 2nd and 3rd releases of GOCE and GOCO models. The cutoff d/o is generally larger (smaller) and the <span class="hlt">filter</span> length smaller (larger) for regions with strong, small-scale (slow, broad scale) currents. The smallest deviations from the drifter data are obtained with the GOCO03s geoid model, although deviations of other models are only slightly higher.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PApGe.173..795M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PApGe.173..795M"><span id="translatedtitle"><span class="hlt">Step</span>-Edge Detection <span class="hlt">Filters</span> for the Interpretation of Potential Field Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ma, Guoqing; Huang, Danian; Liu, Cai</p> <p>2016-03-01</p> <p>Edge detection is a useful tool in the interpretation of potential field data, and the existing edge detection <span class="hlt">filters</span> are almost functions of first-order horizontal and vertical derivatives. We propose <span class="hlt">step</span>-edge detection <span class="hlt">filters</span> to improve the resolution of edge detection results, which use the functions of different-order derivatives to accomplish the edge detection task. We demonstrate the proposed <span class="hlt">filters</span> on synthetic potential field data, and the results show that the new methods can recognize the edges of the sources more precisely and clearly. We also discuss the application effect of different <span class="hlt">step</span>-edge detection <span class="hlt">filters</span>. Lastly, we apply the proposed <span class="hlt">filters</span> to real potential field data, and the recognized edges of the stratigraphic markers are more precise and clear.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19970023609&hterms=1609&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231609','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19970023609&hterms=1609&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231609"><span id="translatedtitle"><span class="hlt">Optimal</span> Correlation <span class="hlt">Filters</span> for Images with Signal-Dependent Noise</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Downie, John D.; Walkup, John F.</p> <p>1994-01-01</p> <p>We address the design of <span class="hlt">optimal</span> correlation <span class="hlt">filters</span> for pattern detection and recognition in the presence of signal-dependent image noise sources. The particular examples considered are film-grain noise and speckle. Two basic approaches are investigated: (1) deriving the <span class="hlt">optimal</span> matched <span class="hlt">filters</span> for the signal-dependent noise models and comparing their performances with those derived for traditional signal-independent noise models and (2) first nonlinearly transforming the signal-dependent noise to signal-independent noise followed by the use of a classical <span class="hlt">filter</span> matched to the transformed signal. We present both theoretical and computer simulation results that demonstrate the generally superior performance of the second approach in terms of the correlation peak signal-to-noise ratio.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4190536','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4190536"><span id="translatedtitle">Na-Faraday rotation <span class="hlt">filtering</span>: The <span class="hlt">optimal</span> point</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kiefer, Wilhelm; Löw, Robert; Wrachtrup, Jörg; Gerhardt, Ilja</p> <p>2014-01-01</p> <p>Narrow-band optical <span class="hlt">filtering</span> is required in many spectroscopy applications to suppress unwanted background light. One example is quantum communication where the fidelity is often limited by the performance of the optical <span class="hlt">filters</span>. This limitation can be circumvented by utilizing the GHz-wide features of a Doppler broadened atomic gas. The anomalous dispersion of atomic vapours enables spectral <span class="hlt">filtering</span>. These, so-called, Faraday anomalous dispersion optical <span class="hlt">filters</span> (FADOFs) can be by far better than any commercial <span class="hlt">filter</span> in terms of bandwidth, transition edge and peak transmission. We present a theoretical and experimental study on the transmission properties of a sodium vapour based FADOF with the aim to find the best combination of optical rotation and intrinsic loss. The relevant parameters, such as magnetic field, temperature, the related optical depth, and polarization state are discussed. The non-trivial interplay of these quantities defines the net performance of the <span class="hlt">filter</span>. We determine analytically the <span class="hlt">optimal</span> working conditions, such as transmission and the signal to background ratio and validate the results experimentally. We find a single global optimum for one specific optical path length of the <span class="hlt">filter</span>. This can now be applied to spectroscopy, guide star applications, or sensing. PMID:25298251</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009pcms.confE..89B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009pcms.confE..89B"><span id="translatedtitle">Sub-<span class="hlt">Optimal</span> Ensemble <span class="hlt">Filters</span> and distributed hydrologic modeling: a new challenge in flood forecasting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baroncini, F.; Castelli, F.</p> <p>2009-09-01</p> <p>Data assimilation techniques based on Ensemble <span class="hlt">Filtering</span> are widely regarded as the best approach in solving forecast and calibration problems in geophysics models. Often the implementation of statistical <span class="hlt">optimal</span> techniques, like the Ensemble Kalman <span class="hlt">Filter</span>, is unfeasible because of the large amount of replicas used in each time <span class="hlt">step</span> of the model for updating the error covariance matrix. Therefore the sub <span class="hlt">optimal</span> approach seems to be a more suitable choice. Various sub-<span class="hlt">optimal</span> techniques were tested in atmospheric and oceanographic models, some of them are based on the detection of a "null space". Distributed Hydrologic Models differ from the other geo-fluid-dynamics models in some fundamental aspects that make complex to understanding the relative efficiency of the different suboptimal techniques. Those aspects include threshold processes , preferential trajectories for convection and diffusion, low observability of the main state variables and high parametric uncertainty. This research study is focused on such topics and explore them through some numerical experiments on an continuous hydrologic model, MOBIDIC. This model include both water mass balance and surface energy balance, so it's able to assimilate a wide variety of datasets like traditional hydrometric "on ground" measurements or land surface temperature retrieval from satellite. The experiments that we present concern to a basin of 700 kmq in center Italy, with hourly dataset on a 8 months period that includes both drought and flood events, in this first set of experiment we worked on a low spatial resolution version of the hydrologic model (3.2 km). A new Kalman <span class="hlt">Filter</span> based algorithm is presented : this <span class="hlt">filter</span> try to address the main challenges of hydrological modeling uncertainty. The proposed <span class="hlt">filter</span> use in Forecast <span class="hlt">step</span> a COFFEE (Complementary Orthogonal <span class="hlt">Filter</span> For Efficient Ensembles) approach with a propagation of both deterministic and stochastic ensembles to improve robustness and convergence proprieties. After, through a P.O.D. Reduction from control theory, we compute a Reduced Order Forecast Covariance matrix . In analysis <span class="hlt">step</span> the <span class="hlt">filter</span> uses a LE (Local Ensemble) Kalman <span class="hlt">Filter</span> approach. We modify the LE Kalman <span class="hlt">Filter</span> assimilation scheme and we adapt its formulation to the P.O.D. Reduced sub-space propagated in forecast <span class="hlt">step</span>. Through this, assimilation of observations is made only in the maximum covariance directions of the model error. Then the efficiency of this technique is weighed in term of hydrometric forecast accuracy in a preliminary convergence test of a synthetic rainfall event toward a real rain fall event.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15285252','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15285252"><span id="translatedtitle">Degeneracy, frequency response and <span class="hlt">filtering</span> in IMRT <span class="hlt">optimization</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Llacer, Jorge; Agazaryan, Nzhde; Solberg, Timothy D; Promberger, Claus</p> <p>2004-07-01</p> <p>This paper attempts to provide an answer to some questions that remain either poorly understood, or not well documented in the literature, on basic issues related to intensity modulated radiation therapy (IMRT). The questions examined are: the relationship between degeneracy and frequency response of <span class="hlt">optimizations</span>, effects of initial beamlet fluence assignment and stopping point, what does <span class="hlt">filtering</span> of an <span class="hlt">optimized</span> beamlet map actually do and how could image analysis help to obtain better <span class="hlt">optimizations</span>? Two target functions are studied, a quadratic cost function and the log likelihood function of the dynamically penalized likelihood (DPL) algorithm. The algorithms used are the conjugate gradient, the stochastic adaptive simulated annealing and the DPL. One simple phantom is used to show the development of the analysis tools used and two clinical cases of medium and large dose matrix size (a meningioma and a prostate) are studied in detail. The conclusions reached are that the high number of iterations that is needed to avoid degeneracy is not warranted in clinical practice, as the quality of the <span class="hlt">optimizations</span>, as judged by the DVHs and dose distributions obtained, does not improve significantly after a certain point. It is also shown that the optimum initial beamlet fluence assignment for analytical iterative algorithms is a uniform distribution, but such an assignment does not help a stochastic method of <span class="hlt">optimization</span>. Stopping points for the studied algorithms are discussed and the deterioration of DVH characteristics with <span class="hlt">filtering</span> is shown to be partially recoverable by the use of space-variant <span class="hlt">filtering</span> techniques. PMID:15285252</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004PMB....49.2853L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004PMB....49.2853L"><span id="translatedtitle">Degeneracy, frequency response and <span class="hlt">filtering</span> in IMRT <span class="hlt">optimization</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Llacer, Jorge; Agazaryan, Nzhde; Solberg, Timothy D.; Promberger, Claus</p> <p>2004-07-01</p> <p>This paper attempts to provide an answer to some questions that remain either poorly understood, or not well documented in the literature, on basic issues related to intensity modulated radiation therapy (IMRT). The questions examined are: the relationship between degeneracy and frequency response of <span class="hlt">optimizations</span>, effects of initial beamlet fluence assignment and stopping point, what does <span class="hlt">filtering</span> of an <span class="hlt">optimized</span> beamlet map actually do and how could image analysis help to obtain better <span class="hlt">optimizations</span>? Two target functions are studied, a quadratic cost function and the log likelihood function of the dynamically penalized likelihood (DPL) algorithm. The algorithms used are the conjugate gradient, the stochastic adaptive simulated annealing and the DPL. One simple phantom is used to show the development of the analysis tools used and two clinical cases of medium and large dose matrix size (a meningioma and a prostate) are studied in detail. The conclusions reached are that the high number of iterations that is needed to avoid degeneracy is not warranted in clinical practice, as the quality of the <span class="hlt">optimizations</span>, as judged by the DVHs and dose distributions obtained, does not improve significantly after a certain point. It is also shown that the optimum initial beamlet fluence assignment for analytical iterative algorithms is a uniform distribution, but such an assignment does not help a stochastic method of <span class="hlt">optimization</span>. Stopping points for the studied algorithms are discussed and the deterioration of DVH characteristics with <span class="hlt">filtering</span> is shown to be partially recoverable by the use of space-variant <span class="hlt">filtering</span> techniques.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9411E..0PG','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9411E..0PG"><span id="translatedtitle"><span class="hlt">Optimal</span> color image restoration: Wiener <span class="hlt">filter</span> and quaternion Fourier transform</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grigoryan, Artyom M.; Agaian, Sos S.</p> <p>2015-03-01</p> <p>In this paper, we consider the model of quaternion signal degradation when the signal is convoluted and an additive noise is added. The classical model of such a model leads to the solution of the <span class="hlt">optimal</span> Wiener <span class="hlt">filter</span>, where the <span class="hlt">optimality</span> with respect to the mean square error. The characteristic of this <span class="hlt">filter</span> can be found in the frequency domain by using the Fourier transform. For quaternion signals, the inverse problem is complicated by the fact that the quaternion arithmetic is not commutative. The quaternion Fourier transform does not map the convolution to the operation of multiplication. In this paper, we analyze the linear model of the signal and image degradation with an additive independent noise and the <span class="hlt">optimal</span> filtration of the signal and images in the frequency domain and in the quaternion space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...820...51P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...820...51P"><span id="translatedtitle"><span class="hlt">Optimized</span> Beam Sculpting with Generalized Fringe-rate <span class="hlt">Filters</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Parsons, Aaron R.; Liu, Adrian; Ali, Zaki S.; Cheng, Carina</p> <p>2016-03-01</p> <p>We generalize the technique of fringe-rate <span class="hlt">filtering</span>, whereby visibilities measured by a radio interferometer are re-weighted according to their temporal variation. As the Earth rotates, radio sources traverse through an interferometer’s fringe pattern at rates that depend on their position on the sky. Capitalizing on this geometric interpretation of fringe rates, we employ time-domain convolution kernels to enact fringe-rate <span class="hlt">filters</span> that sculpt the effective primary beam of antennas in an interferometer. As we show, beam sculpting through fringe-rate <span class="hlt">filtering</span> can be used to <span class="hlt">optimize</span> measurements for a variety of applications, including mapmaking, minimizing polarization leakage, suppressing instrumental systematics, and enhancing the sensitivity of power-spectrum measurements. We show that fringe-rate <span class="hlt">filtering</span> arises naturally in minimum variance treatments of many of these problems, enabling <span class="hlt">optimal</span> visibility-based approaches to analyses of interferometric data that avoid systematics potentially introduced by traditional approaches such as imaging. Our techniques have recently been demonstrated in Ali et al., where new upper limits were placed on the 21 {cm} power spectrum from reionization, showcasing the ability of fringe-rate <span class="hlt">filtering</span> to successfully boost sensitivity and reduce the impact of systematics in deep observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26849867','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26849867"><span id="translatedtitle">Fourier Spectral <span class="hlt">Filter</span> Array for <span class="hlt">Optimal</span> Multispectral Imaging.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jia, Jie; Barnard, Kenneth J; Hirakawa, Keigo</p> <p>2016-04-01</p> <p>Limitations to existing multispectral imaging modalities include speed, cost, range, spatial resolution, and application-specific system designs that lack versatility of the hyperspectral imaging modalities. In this paper, we propose a novel general-purpose single-shot passive multispectral imaging modality. Central to this design is a new type of spectral <span class="hlt">filter</span> array (SFA) based not on the notion of spatially multiplexing narrowband <span class="hlt">filters</span>, but instead aimed at enabling single-shot Fourier transform spectroscopy. We refer to this new SFA pattern as Fourier SFA, and we prove that this design solves the problem of <span class="hlt">optimally</span> sampling the hyperspectral image data. PMID:26849867</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003SPIE.5117..245D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003SPIE.5117..245D"><span id="translatedtitle">System-level <span class="hlt">optimization</span> of baseband <span class="hlt">filters</span> for communication applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Delgado-Restituto, Manuel; Fernandez-Bootello, Juan F.; Rodriguez-Vazquez, Angel</p> <p>2003-04-01</p> <p>In this paper, we present a design approach for the high-level synthesis of programmable continuous-time Gm-C and active-RC <span class="hlt">filters</span> with optimum trade-off among dynamic range, distortion products generation, area consumption and power dissipation, thus meeting the needs of more demanding baseband <span class="hlt">filter</span> realizations. Further, the proposed technique guarantees that under all programming configurations, transconductors (in Gm-C <span class="hlt">filters</span>) and resistors (in active-RC <span class="hlt">filters</span>) as well as capacitors, are related by integer ratios in order to reduce the sensitivity to mismatch of the monolithic implementation. In order to solve the aforementioned trade-off, the <span class="hlt">filter</span> must be properly scaled at each configuration. It means that <span class="hlt">filter</span> node impedances must be conveniently altered so that the noise contribution of each node to the <span class="hlt">filter</span> output be as low as possible, while avoiding that peak amplitudes at such nodes be so high as to drive active circuits into saturation. Additionally, in order to not degrade the distortion performance of the <span class="hlt">filter</span> (in particular, if it is implemented using Gm-C techniques) node impedances can not be scaled independently from each other but restrictions must be imposed according to the principle of nonlinear cancellation. Altogether, the high-level synthesis can be seen as a constrained <span class="hlt">optimization</span> problem where some of the variables, namely, the ratios among similar components, are restricted to discrete values. The proposed approach to accomplish optimum <span class="hlt">filter</span> scaling under all programming configurations, relies on matrix methods for network representation, which allows an easy estimation of performance features such as dynamic range and power dissipation, as well as other network properties such as sensitivity to parameter variations and non-ideal effects of integrators blocks; and the use of a simulated annealing algorithm to explore the design space defined by the transfer and group delay specifications. It must be noted that such design space also includes most common approximation methods and network synthesis approaches as <span class="hlt">optimization</span> variables, in order to make as widespread as possible the search for optimum solutions. The proposed methodology has been partially developed in MATLAB, taking advantage of the routines available in the signal processing and control toolboxes, and C++. The validity of the methodology and companying software will be demonstrated at the Conference and reported in the paper, using as a tailoring example the design of a programmable bank of <span class="hlt">filters</span> for a high-performance powerline modem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996SPIE.2969...16D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996SPIE.2969...16D"><span id="translatedtitle"><span class="hlt">Optimization</span> <span class="hlt">steps</span> in a cuneiform inscription characterization process</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Demoli, Nazif; Dahms, Uwe; Gruber, Hartmut; Wernicke, Guenther K.</p> <p>1996-12-01</p> <p>Recently, an investigation of using holographically based techniques for the cuneiform inscription characterization has been reported in several publications. This paper provides an overview of the development of the experimental systems and techniques. Particularly, we describe the main <span class="hlt">optimization</span> <span class="hlt">steps</span> as well as the selected correlation results, and the general frame of the future work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960023550','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960023550"><span id="translatedtitle"><span class="hlt">Optimal</span> Signal Processing of Frequency-<span class="hlt">Stepped</span> CW Radar Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ybarra, Gary A.; Wu, Shawkang M.; Bilbro, Griff L.; Ardalan, Sasan H.; Hearn, Chase P.; Neece, Robert T.</p> <p>1995-01-01</p> <p>An <span class="hlt">optimal</span> signal processing algorithm is derived for estimating the time delay and amplitude of each scatterer reflection using a frequency-<span class="hlt">stepped</span> CW system. The channel is assumed to be composed of abrupt changes in the reflection coefficient profile. The <span class="hlt">optimization</span> technique is intended to maximize the target range resolution achievable from any set of frequency-<span class="hlt">stepped</span> CW radar measurements made in such an environment. The algorithm is composed of an iterative two-<span class="hlt">step</span> procedure. First, the amplitudes of the echoes are <span class="hlt">optimized</span> by solving an overdetermined least squares set of equations. Then, a nonlinear objective function is scanned in an organized fashion to find its global minimum. The result is a set of echo strengths and time delay estimates. Although this paper addresses the specific problem of resolving the time delay between the two echoes, the derivation is general in the number of echoes. Performance of the <span class="hlt">optimization</span> approach is illustrated using measured data obtained from an HP-851O network analyzer. It is demonstrated that the <span class="hlt">optimization</span> approach offers a significant resolution enhancement over the standard processing approach that employs an IFFT. Degradation in the performance of the algorithm due to suboptimal model order selection and the effects of additive white Gaussion noise are addressed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_3 --> <div id="page_4" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="61"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970003425','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970003425"><span id="translatedtitle"><span class="hlt">Optimal</span> Signal Processing of Frequency-<span class="hlt">Stepped</span> CW Radar Data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ybarra, Gary A.; Wu, Shawkang M.; Bilbro, Griff L.; Ardalan, Sasan H.; Hearn, Chase P.; Neece, Robert T.</p> <p>1995-01-01</p> <p>An <span class="hlt">optimal</span> signal processing algorithm is derived for estimating the time delay and amplitude of each scatterer reflection using a frequency-<span class="hlt">stepped</span> CW system. The channel is assumed to be composed of abrupt changes in the reflection coefficient profile. The <span class="hlt">optimization</span> technique is intended to maximize the target range resolution achievable from any set of frequency-<span class="hlt">stepped</span> CW radar measurements made in such an environment. The algorithm is composed of an iterative two-<span class="hlt">step</span> procedure. First, the amplitudes of the echoes are <span class="hlt">optimized</span> by solving an overdetermined least squares set of equations. Then, a nonlinear objective function is scanned in an organized fashion to find its global minimum. The result is a set of echo strengths and time delay estimates. Although this paper addresses the specific problem of resolving the time delay between the first two echoes, the derivation is general in the number of echoes. Performance of the <span class="hlt">optimization</span> approach is illustrated using measured data obtained from an HP-X510 network analyzer. It is demonstrated that the <span class="hlt">optimization</span> approach offers a significant resolution enhancement over the standard processing approach that employs an IFFT. Degradation in the performance of the algorithm due to suboptimal model order selection and the effects of additive white Gaussion noise are addressed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4416937','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4416937"><span id="translatedtitle">A Neural Network-Based <span class="hlt">Optimal</span> Spatial <span class="hlt">Filter</span> Design Method for Motor Imagery Classification</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yuksel, Ayhan; Olmez, Tamer</p> <p>2015-01-01</p> <p>In this study, a novel spatial <span class="hlt">filter</span> design method is introduced. Spatial <span class="hlt">filtering</span> is an important processing <span class="hlt">step</span> for feature extraction in motor imagery-based brain-computer interfaces. This paper introduces a new motor imagery signal classification method combined with spatial <span class="hlt">filter</span> <span class="hlt">optimization</span>. We simultaneously train the spatial <span class="hlt">filter</span> and the classifier using a neural network approach. The proposed spatial <span class="hlt">filter</span> network (SFN) is composed of two layers: a spatial <span class="hlt">filtering</span> layer and a classifier layer. These two layers are linked to each other with non-linear mapping functions. The proposed method addresses two shortcomings of the common spatial patterns (CSP) algorithm. First, CSP aims to maximize the between-classes variance while ignoring the minimization of within-classes variances. Consequently, the features obtained using the CSP method may have large within-classes variances. Second, the maximizing <span class="hlt">optimization</span> function of CSP increases the classification accuracy indirectly because an independent classifier is used after the CSP method. With SFN, we aimed to maximize the between-classes variance while minimizing within-classes variances and simultaneously <span class="hlt">optimizing</span> the spatial <span class="hlt">filter</span> and the classifier. To classify motor imagery EEG signals, we modified the well-known feed-forward structure and derived forward and backward equations that correspond to the proposed structure. We tested our algorithm on simple toy data. Then, we compared the SFN with conventional CSP and its multi-class version, called one-versus-rest CSP, on two data sets from BCI competition III. The evaluation results demonstrate that SFN is a good alternative for classifying motor imagery EEG signals with increased classification accuracy. PMID:25933101</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25933101','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25933101"><span id="translatedtitle">A neural network-based <span class="hlt">optimal</span> spatial <span class="hlt">filter</span> design method for motor imagery classification.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yuksel, Ayhan; Olmez, Tamer</p> <p>2015-01-01</p> <p>In this study, a novel spatial <span class="hlt">filter</span> design method is introduced. Spatial <span class="hlt">filtering</span> is an important processing <span class="hlt">step</span> for feature extraction in motor imagery-based brain-computer interfaces. This paper introduces a new motor imagery signal classification method combined with spatial <span class="hlt">filter</span> <span class="hlt">optimization</span>. We simultaneously train the spatial <span class="hlt">filter</span> and the classifier using a neural network approach. The proposed spatial <span class="hlt">filter</span> network (SFN) is composed of two layers: a spatial <span class="hlt">filtering</span> layer and a classifier layer. These two layers are linked to each other with non-linear mapping functions. The proposed method addresses two shortcomings of the common spatial patterns (CSP) algorithm. First, CSP aims to maximize the between-classes variance while ignoring the minimization of within-classes variances. Consequently, the features obtained using the CSP method may have large within-classes variances. Second, the maximizing <span class="hlt">optimization</span> function of CSP increases the classification accuracy indirectly because an independent classifier is used after the CSP method. With SFN, we aimed to maximize the between-classes variance while minimizing within-classes variances and simultaneously <span class="hlt">optimizing</span> the spatial <span class="hlt">filter</span> and the classifier. To classify motor imagery EEG signals, we modified the well-known feed-forward structure and derived forward and backward equations that correspond to the proposed structure. We tested our algorithm on simple toy data. Then, we compared the SFN with conventional CSP and its multi-class version, called one-versus-rest CSP, on two data sets from BCI competition III. The evaluation results demonstrate that SFN is a good alternative for classifying motor imagery EEG signals with increased classification accuracy. PMID:25933101</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016RAA....16e...4L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016RAA....16e...4L"><span id="translatedtitle">A high-contrast imaging polarimeter with a <span class="hlt">stepped</span>-transmission <span class="hlt">filter</span> based coronagraph</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Cheng-Chao; Ren, De-Qing; Zhu, Yong-Tian; Dou, Jiang-Pei; Guo, Jing</p> <p>2016-05-01</p> <p>The light reflected from planets is polarized mainly due to Rayleigh scattering, but starlight is normally unpolarized. Thus it provides an approach to enhance the imaging contrast by inducing the imaging polarimetry technique. In this paper, we propose a high-contrast imaging polarimeter that is <span class="hlt">optimized</span> for the direct imaging of exoplanets, combined with our recently developed <span class="hlt">stepped</span>-transmission <span class="hlt">filter</span> based coronagraph. Here we present the design and calibration method of the polarimetry system and the associated test of its high-contrast performance. In this polarimetry system, two liquid crystal variable retarders (LCVRs) act as a polarization modulator, which can extract the polarized signal. We show that our polarimeter can achieve a measurement accuracy of about 0.2% at a visible wavelength (632.8 nm) with linearly polarized light. Finally, the whole system demonstrates that a contrast of 10‑9 at 5λ/D is achievable, which can be used for direct imaging of Jupiter-like planets with a space telescope.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993gnc..conf.1740A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993gnc..conf.1740A"><span id="translatedtitle">Development of an <span class="hlt">optimized</span> LEB <span class="hlt">filter</span> and its application to INS/GPS test data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Antonini, Claudio D.</p> <p></p> <p>An <span class="hlt">optimized</span> linear-ellipsoidal-bounded (LEB) <span class="hlt">filter</span> has been developed and applied to data obtained from a ground test using a combined INS/GPS configuration. In this cascaded configuration, the <span class="hlt">filter</span> receives eight outputs from the INS (accelerations, velocity, angles, altitude) and six outputs from the GPS (velocities and positions). The GPS measurements have included the effect of SA of varying or unknown spectrum which, although likely to be estimated and compensated with some modelling techniques at the expense of including extra state variables, could also be dealt with the approach indicated in this article at much less effort. An <span class="hlt">optimized</span> formulation for the LEB <span class="hlt">filter</span> is presented in which the volume of the ellipsoid containing the estimation errors is minimized at every <span class="hlt">step</span> or at selected intervals. The SA effect is modelled as an unknown-but-bounded (UBB) noise process. Comparisons with an Extended Kalman <span class="hlt">filter</span> (KF) show that KF innovations are not white and the LEB <span class="hlt">filter</span> estimates are one order of magnitude smaller that those produced by the KF.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SPIE.7879E..0QC','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SPIE.7879E..0QC"><span id="translatedtitle">Web image annotation using two-<span class="hlt">step</span> <span class="hlt">filtering</span> on social tags</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cho, Sunyoung; Cha, Jaeseong; Byun, Hyeran</p> <p>2011-03-01</p> <p>Web image annotation has become an important issue with exploding web images and the necessity of effective image search. The social tags have recently utilized at image annotation because they can reflect the user's tagging tendency, and reduce the semantic gap. However, an effective <span class="hlt">filtering</span> procedure is required to extract the relevant tags since the user's subjectivity and noisy tags. In this paper, we propose a two-<span class="hlt">step</span> <span class="hlt">filtering</span> on social tags for image annotation. This method conducts the <span class="hlt">filtering</span> and verification tasks by analyzing the tags of visual neighbor images using voting method and co-occurrence analysis. Our method consists of the following three <span class="hlt">steps</span>: 1) the tag candidate set is founded by searching the visual neighbor images, 2) from a given tag candidate set, coarse <span class="hlt">filtering</span> is conducted by tag grouping and voting technique, 3) the dense <span class="hlt">filtering</span> is conducted by using similarity verification for coarse <span class="hlt">filtered</span> candidate tag set. To evaluate the performance of our approach, we conduct the experiments on a social-tagged image dataset obtained from Flickr. We compare the annotation accuracy between the voting method and our proposed method. Our experimental results show that our method has an improvement in image annotation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090008505','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090008505"><span id="translatedtitle">Multidisciplinary Analysis and <span class="hlt">Optimization</span> Generation 1 and Next <span class="hlt">Steps</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Naiman, Cynthia Gutierrez</p> <p>2008-01-01</p> <p>The Multidisciplinary Analysis & <span class="hlt">Optimization</span> Working Group (MDAO WG) of the Systems Analysis Design & <span class="hlt">Optimization</span> (SAD&O) discipline in the Fundamental Aeronautics Program s Subsonic Fixed Wing (SFW) project completed three major milestones during Fiscal Year (FY)08: "Requirements Definition" Milestone (1/31/08); "GEN 1 Integrated Multi-disciplinary Toolset" (Annual Performance Goal) (6/30/08); and "Define Architecture & Interfaces for Next Generation Open Source MDAO Framework" Milestone (9/30/08). Details of all three milestones are explained including documentation available, potential partner collaborations, and next <span class="hlt">steps</span> in FY09.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/672026','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/672026"><span id="translatedtitle">A multi-dimensional procedure for BNCT <span class="hlt">filter</span> <span class="hlt">optimization</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lille, R.A.</p> <p>1998-02-01</p> <p>An initial version of an <span class="hlt">optimization</span> code utilizing two-dimensional radiation transport methods has been completed. This code is capable of predicting material compositions of a beam tube-<span class="hlt">filter</span> geometry which can be used in a boron neutron capture therapy treatment facility to improve the ratio of the average radiation dose in a brain tumor to that in the healthy tissue surrounding the tumor. The <span class="hlt">optimization</span> algorithm employed by the code is very straightforward. After an estimate of the gradient of the dose ratio with respect to the nuclide densities in the beam tube-<span class="hlt">filter</span> geometry is obtained, changes in the nuclide densities are made based on: (1) the magnitude and sign of the components of the dose ratio gradient, (2) the magnitude of the nuclide densities, (3) the upper and lower bound of each nuclide density, and (4) the linear constraint that the sum of the nuclide density fractions in each material zone be less than or equal to 1.0. A local <span class="hlt">optimal</span> solution is assumed to be found when one of the following conditions is satisfied in every material zone: (1) the maximum positive component of the gradient corresponds to a nuclide at its maximum density and the sum of the density fractions equals 1.0 or, and (2) the positive and negative components of the gradient correspond to nuclides densities at their upper and lower bounds, respectively, and the remaining components of the gradient are sufficiently small. The <span class="hlt">optimization</span> procedure has been applied to a beam tube-<span class="hlt">filter</span> geometry coupled to a simple tumor-patient head model and an improvement of 50% in the dose ratio was obtained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhCS.659a2022H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.659a2022H"><span id="translatedtitle">Performance evaluation of iterated extended Kalman <span class="hlt">filter</span> with variable <span class="hlt">step</span>-length</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Havlík, Jindřich; Straka, Ondřej</p> <p>2015-11-01</p> <p>The paper deals with state estimation of nonlinear stochastic dynamic systems. In particular, the iterated extended Kalman <span class="hlt">filter</span> is studied. Three recently proposed iterated extended Kalman <span class="hlt">filter</span> algorithms are analyzed in terms of their performance and specification of a user design parameter, more specifically the <span class="hlt">step</span>-length size. The performance is compared using the root mean square error evaluating the state estimate and the noncredibility index assessing covariance matrix of the estimate error. The performance and influence of the design parameter, are analyzed in a numerical simulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PMB....54.7183A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PMB....54.7183A"><span id="translatedtitle">Comparison of IMRT planning with two-<span class="hlt">step</span> and one-<span class="hlt">step</span> <span class="hlt">optimization</span>: a strategy for improving therapeutic gain and reducing the integral dose</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abate, A.; Pressello, M. C.; Benassi, M.; Strigari, L.</p> <p>2009-12-01</p> <p>The aim of this study was to evaluate the effectiveness and efficiency in inverse IMRT planning of one-<span class="hlt">step</span> <span class="hlt">optimization</span> with the <span class="hlt">step</span>-and-shoot (SS) technique as compared to traditional two-<span class="hlt">step</span> <span class="hlt">optimization</span> using the sliding windows (SW) technique. The Pinnacle IMRT TPS allows both one-<span class="hlt">step</span> and two-<span class="hlt">step</span> approaches. The same beam setup for five head-and-neck tumor patients and dose-volume constraints were applied for all <span class="hlt">optimization</span> methods. Two-<span class="hlt">step</span> plans were produced converting the ideal fluence with or without a smoothing <span class="hlt">filter</span> into the SW sequence. One-<span class="hlt">step</span> plans, based on direct machine parameter <span class="hlt">optimization</span> (DMPO), had the maximum number of segments per beam set at 8, 10, 12, producing a directly deliverable sequence. Moreover, the plans were generated whether a split-beam was used or not. Total monitor units (MUs), overall treatment time, cost function and dose-volume histograms (DVHs) were estimated for each plan. PTV conformality and homogeneity indexes and normal tissue complication probability (NTCP) that are the basis for improving therapeutic gain, as well as non-tumor integral dose (NTID), were evaluated. A two-sided t-test was used to compare quantitative variables. All plans showed similar target coverage. Compared to two-<span class="hlt">step</span> SW <span class="hlt">optimization</span>, the DMPO-SS plans resulted in lower MUs (20%), NTID (4%) as well as NTCP values. Differences of about 15-20% in the treatment delivery time were registered. DMPO generates less complex plans with identical PTV coverage, providing lower NTCP and NTID, which is expected to reduce the risk of secondary cancer. It is an effective and efficient method and, if available, it should be favored over the two-<span class="hlt">step</span> IMRT planning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9034E..0BD','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9034E..0BD"><span id="translatedtitle">Neuromuscular fiber segmentation through particle <span class="hlt">filtering</span> and discrete <span class="hlt">optimization</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dietenbeck, Thomas; Varray, Franois; Kybic, Jan; Basset, Olivier; Cachard, Christian</p> <p>2014-03-01</p> <p>We present an algorithm to segment a set of parallel, intertwined and bifurcating fibers from 3D images, targeted for the identification of neuronal fibers in very large sets of 3D confocal microscopy images. The method consists of preprocessing, local calculation of fiber probabilities, seed detection, tracking by particle <span class="hlt">filtering</span>, global supervised seed clustering and final voxel segmentation. The preprocessing uses a novel random local probability <span class="hlt">filtering</span> (RLPF). The fiber probabilities computation is performed by means of SVM using steerable <span class="hlt">filters</span> and the RLPF outputs as features. The global segmentation is solved by discrete <span class="hlt">optimization</span>. The combination of global and local approaches makes the segmentation robust, yet the individual data blocks can be processed sequentially, limiting memory consumption. The method is automatic but efficient manual interactions are possible if needed. The method is validated on the Neuromuscular Projection Fibers dataset from the Diadem Challenge. On the 15 first blocks present, our method has a 99.4% detection rate. We also compare our segmentation results to a state-of-the-art method. On average, the performances of our method are either higher or equivalent to that of the state-of-the-art method but less user interactions is needed in our approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23796954','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23796954"><span id="translatedtitle"><span class="hlt">Optimization</span> of adenovirus 40 and 41 recovery from tap water using small disk <span class="hlt">filters</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McMinn, Brian R</p> <p>2013-11-01</p> <p>Currently, the U.S. Environmental Protection Agency's Information Collection Rule (ICR) for the primary concentration of viruses from drinking and surface waters uses the 1MDS <span class="hlt">filter</span>, but a more cost effective option, the NanoCeram® <span class="hlt">filter</span>, has been shown to recover comparable levels of enterovirus and norovirus from both matrices. In order to achieve the highest viral recoveries, filtration methods require the identification of <span class="hlt">optimal</span> concentration conditions that are unique for each virus type. This study evaluated the effectiveness of 1MDS and NanoCeram <span class="hlt">filters</span> in recovering adenovirus (AdV) 40 and 41 from tap water, and <span class="hlt">optimized</span> two secondary concentration procedures the celite and organic flocculation method. Adjustments in pH were made to both virus elution solutions and sample matrices to determine which resulted in higher virus recovery. Samples were analyzed by quantitative PCR (qPCR) and Most Probable Number (MPN) techniques and AdV recoveries were determined by comparing levels of virus in sample concentrates to that in the initial input. The recovery of adenovirus was highest for samples in unconditioned tap water (pH 8) using the 1MDS <span class="hlt">filter</span> and celite for secondary concentration. Elution buffer containing 0.1% sodium polyphosphate at pH 10.0 was determined to be most effective overall for both AdV types. Under these conditions, the average recovery for AdV40 and 41 was 49% and 60%, respectively. By <span class="hlt">optimizing</span> secondary elution <span class="hlt">steps</span>, AdV recovery from tap water could be improved at least two-fold compared to the currently used methodology. Identification of the <span class="hlt">optimal</span> concentration conditions for human AdV (HAdV) is important for timely and sensitive detection of these viruses from both surface and drinking waters. PMID:23796954</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016CNSNS..35..123Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016CNSNS..35..123Z"><span id="translatedtitle">On one-<span class="hlt">step</span> worst-case <span class="hlt">optimal</span> trisection in univariate bi-objective Lipschitz <span class="hlt">optimization</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Žilinskas, Antanas; Gimbutienė, Gražina</p> <p>2016-06-01</p> <p>The bi-objective Lipschitz <span class="hlt">optimization</span> with univariate objectives is considered. The concept of the tolerance of the lower Lipschitz bound over an interval is generalized to arbitrary subintervals of the search region. The one-<span class="hlt">step</span> worst-case <span class="hlt">optimality</span> of trisecting an interval with respect to the resulting tolerance is established. The theoretical investigation supports the previous usage of trisection in other algorithms. The trisection-based algorithm is introduced. Some numerical examples illustrating the performance of the algorithm are provided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.G33B0985D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.G33B0985D"><span id="translatedtitle"><span class="hlt">Optimal</span> <span class="hlt">Filtering</span> in Mass Transport Modeling From Satellite Gravimetry Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ditmar, P.; Hashemi Farahani, H.; Klees, R.</p> <p>2011-12-01</p> <p>Monitoring natural mass transport in the Earth's system, which has marked a new era in Earth observation, is largely based on the data collected by the GRACE satellite mission. Unfortunately, this mission is not free from certain limitations, two of which are especially critical. Firstly, its sensitivity is strongly anisotropic: it senses the north-south component of the mass re-distribution gradient much better than the east-west component. Secondly, it suffers from a trade-off between temporal and spatial resolution: a high (e.g., daily) temporal resolution is only possible if the spatial resolution is sacrificed. To make things even worse, the GRACE satellites enter occasionally a phase when their orbit is characterized by a short repeat period, which makes it impossible to reach a high spatial resolution at all. A way to mitigate limitations of GRACE measurements is to design <span class="hlt">optimal</span> data processing procedures, so that all available information is fully exploited when modeling mass transport. This implies, in particular, that an unconstrained model directly derived from satellite gravimetry data needs to be <span class="hlt">optimally</span> <span class="hlt">filtered</span>. In principle, this can be realized with a Wiener <span class="hlt">filter</span>, which is built on the basis of covariance matrices of noise and signal. In practice, however, a compilation of both matrices (and, therefore, of the <span class="hlt">filter</span> itself) is not a trivial task. To build the covariance matrix of noise in a mass transport model, it is necessary to start from a realistic model of noise in the level-1B data. Furthermore, a routine satellite gravimetry data processing includes, in particular, the subtraction of nuisance signals (for instance, associated with atmosphere and ocean), for which appropriate background models are used. Such models are not error-free, which has to be taken into account when the noise covariance matrix is constructed. In addition, both signal and noise covariance matrices depend on the type of mass transport processes under investigation. For instance, processes of hydrological origin occur at short time scales, so that the input time series is typically short (1 month or less), which implies a relatively strong noise in the derived model. On the contrary, study of a long-term ice mass depletion requires a long time series of satellite data, which leads to a reduction of noise in the mass transport model. Of course, the spatial pattern (and therefore, the signal covariance matrices) of various mass transport processes are also very different. In the presented study, we compare various strategies to build the signal and noise covariance matrices in the context of mass transport modeling. In this way, we demonstrate the benefits of an accurate construction of an <span class="hlt">optimal</span> <span class="hlt">filter</span> as outlined above, compared to simplified strategies. Furthermore, we consider both models based on GRACE data alone and combined GRACE/GOCE models. In this way, we shed more light on a potential synergy of the GRACE and GOCE satellite mission. This is important nor only for the best possible mass transport modeling on the basis of all available data, but also for the <span class="hlt">optimal</span> planning of future satellite gravity missions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4415408','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4415408"><span id="translatedtitle">Simultaneous learning and <span class="hlt">filtering</span> without delusions: a Bayes-<span class="hlt">optimal</span> combination of Predictive Inference and Adaptive <span class="hlt">Filtering</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kneissler, Jan; Drugowitsch, Jan; Friston, Karl; Butz, Martin V.</p> <p>2015-01-01</p> <p>Predictive coding appears to be one of the fundamental working principles of brain processing. Amongst other aspects, brains often predict the sensory consequences of their own actions. Predictive coding resembles Kalman <span class="hlt">filtering</span>, where incoming sensory information is <span class="hlt">filtered</span> to produce prediction errors for subsequent adaptation and learning. However, to generate prediction errors given motor commands, a suitable temporal forward model is required to generate predictions. While in engineering applications, it is usually assumed that this forward model is known, the brain has to learn it. When <span class="hlt">filtering</span> sensory input and learning from the residual signal in parallel, a fundamental problem arises: the system can enter a delusional loop when <span class="hlt">filtering</span> the sensory information using an overly trusted forward model. In this case, learning stalls before accurate convergence because uncertainty about the forward model is not properly accommodated. We present a Bayes-<span class="hlt">optimal</span> solution to this generic and pernicious problem for the case of linear forward models, which we call Predictive Inference and Adaptive <span class="hlt">Filtering</span> (PIAF). PIAF <span class="hlt">filters</span> incoming sensory information and learns the forward model simultaneously. We show that PIAF is formally related to Kalman <span class="hlt">filtering</span> and to the Recursive Least Squares linear approximation method, but combines these procedures in a Bayes <span class="hlt">optimal</span> fashion. Numerical evaluations confirm that the delusional loop is precluded and that the learning of the forward model is more than 10-times faster when compared to a naive combination of Kalman <span class="hlt">filtering</span> and Recursive Least Squares. PMID:25983690</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.B13C0189I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.B13C0189I"><span id="translatedtitle"><span class="hlt">Optimizing</span> Parameters of Process-Based Terrestrial Ecosystem Model with Particle <span class="hlt">Filter</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ito, A.</p> <p>2014-12-01</p> <p>Present terrestrial ecosystem models still contain substantial uncertainties, as model intercomparison studies have shown, because of poor model constraint by observational data. So, development of advanced methodology of data-model fusion, or data-assimilation, is an important task to reduce the uncertainties and improve model predictability. In this study, I apply the Particle <span class="hlt">filter</span> (or Sequential Monte Carlo filer) to <span class="hlt">optimize</span> parameters of a process-based terrestrial ecosystem model (VISIT). The Particle <span class="hlt">filter</span> is one of the data-assimilation methods, in which probability distribution of model state is approximated by many samples of parameter set (i.e., particle). This is a computationally intensive method and applicable to nonlinear systems; this is an advantage of the method in comparison with other techniques like Ensemble Kalman <span class="hlt">filter</span> and variational method. At several sites, I used flux measurement data of atmosphere-ecosystem CO2 exchange in sequential and non-sequential manners. In the sequential data assimilation, a time-series data at 30-min or daily <span class="hlt">steps</span> were used to <span class="hlt">optimize</span> gas-exchange-related parameters; this method would be also effective to assimilate satellite observational data. On the other hand, in the non-sequential case, annual or long-term mean budget was adjusted to observations; this method would be also effective to assimilate carbon stock data. Although there remain technical issues (e.g., appropriate number of particles and likelihood function), I demonstrate that the Partile <span class="hlt">filter</span> is an effective method of data-assimilation for process-based models, enhancing collaboration between field and model researchers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984isa..conf..577L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984isa..conf..577L"><span id="translatedtitle">Design of <span class="hlt">optimal</span> Nyquist and partial response FIR digital <span class="hlt">filters</span> using linear programming techniques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liang, J.-K.; Lu, F.-C.</p> <p></p> <p>The design of a Nyquist <span class="hlt">filter</span> for generating a band-limited pulse for data transmission zero intersymbol interference is formulated as a linear programming problem, and the Steinglitz (1979) program is modified and then used to design such pulse shaping <span class="hlt">filters</span>. Advantages of the new approach over other methods with regard to design speed and <span class="hlt">filter</span> <span class="hlt">optimality</span> are described and illustrated with examples.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016OptCo.358...59C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OptCo.358...59C"><span id="translatedtitle"><span class="hlt">Optimal</span> design of multichannel fiber Bragg grating <span class="hlt">filters</span> using Pareto multi-objective <span class="hlt">optimization</span> algorithm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Jing; Liu, Tundong; Jiang, Hao</p> <p>2016-01-01</p> <p>A Pareto-based multi-objective <span class="hlt">optimization</span> approach is proposed to design multichannel FBG <span class="hlt">filters</span>. Instead of defining a single <span class="hlt">optimal</span> objective, the proposed method establishes the multi-objective model by taking two design objectives into account, which are minimizing the maximum index modulation and minimizing the mean dispersion error. To address this <span class="hlt">optimization</span> problem, we develop a two-stage evolutionary computation approach integrating an elitist non-dominated sorting genetic algorithm (NSGA-II) and technique for order preference by similarity to ideal solution (TOPSIS). NSGA-II is utilized to search for the candidate solutions in terms of both objectives. The obtained results are provided as Pareto front. Subsequently, the best compromise solution is determined by the TOPSIS method from the Pareto front according to the decision maker's preference. The design results show that the proposed approach yields a remarkable reduction of the maximum index modulation and the performance of dispersion spectra of the designed <span class="hlt">filter</span> can be <span class="hlt">optimized</span> simultaneously.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EJASP2015...83Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EJASP2015...83Z"><span id="translatedtitle">Effect of embedded unbiasedness on discrete-time <span class="hlt">optimal</span> FIR <span class="hlt">filtering</span> estimates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Shunyi; Shmaliy, Yuriy S.; Liu, Fei; Ibarra-Manzano, Oscar; Khan, Sanowar H.</p> <p>2015-12-01</p> <p>Unbiased estimation is an efficient alternative to <span class="hlt">optimal</span> estimation when the noise statistics are not fully known and/or the model undergoes temporary uncertainties. In this paper, we investigate the effect of embedded unbiasedness (EU) on <span class="hlt">optimal</span> finite impulse response (OFIR) <span class="hlt">filtering</span> estimates of linear discrete time-invariant state-space models. A new OFIR-EU <span class="hlt">filter</span> is derived by minimizing the mean square error (MSE) subject to the unbiasedness constraint. We show that the OFIR-UE <span class="hlt">filter</span> is equivalent to the minimum variance unbiased FIR (UFIR) <span class="hlt">filter</span>. Unlike the OFIR <span class="hlt">filter</span>, the OFIR-EU <span class="hlt">filter</span> does not require the initial conditions. In terms of accuracy, the OFIR-EU <span class="hlt">filter</span> occupies an intermediate place between the UFIR and OFIR <span class="hlt">filters</span>. Contrary to the UFIR <span class="hlt">filter</span> which MSE is minimized by the <span class="hlt">optimal</span> horizon of N opt points, the MSEs in the OFIR-EU and OFIR <span class="hlt">filters</span> diminish with N and these <span class="hlt">filters</span> are thus full-horizon. Based upon several examples, we show that the OFIR-UE <span class="hlt">filter</span> has higher immunity against errors in the noise statistics and better robustness against temporary model uncertainties than the OFIR and Kalman <span class="hlt">filters</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016OptCo.358..132B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OptCo.358..132B"><span id="translatedtitle"><span class="hlt">Optimization</span> of the performances of correlation <span class="hlt">filters</span> by pre-processing the input plane</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bouzidi, F.; Elbouz, M.; Alfalou, A.; Brosseau, C.; Fakhfakh, A.</p> <p>2016-01-01</p> <p>We report findings on the <span class="hlt">optimization</span> of the performances of correlation <span class="hlt">filters</span>. First, we propound and validate an <span class="hlt">optimization</span> of ROC curves adapted to correlation technique. Then, analysis suggests that a pre-processing of the input plane leads to a compromise between the robustness of the adapted <span class="hlt">filter</span> and the discrimination of the inverse <span class="hlt">filter</span> for face recognition applications. Rewardingly, our technical results demonstrate that this method is remarkably efficient to increase the performances of a VanderLugt correlator.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_4 --> <div id="page_5" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="81"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/8497560','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/8497560"><span id="translatedtitle"><span class="hlt">Optimal</span> digital <span class="hlt">filters</span> for long-latency components of the event-related brain potential.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Farwell, L A; Martinerie, J M; Bashore, T R; Rapp, P E; Goddard, P H</p> <p>1993-05-01</p> <p>A fundamentally important problem for cognitive psychophysiologists is selection of the appropriate off-line digital <span class="hlt">filter</span> to extract signal from noise in the event-related brain potential (ERP) recorded at the scalp. Investigators in the field typically use a type of finite impulse response (FIR) <span class="hlt">filter</span> known as moving average or boxcar <span class="hlt">filter</span> to achieve this end. However, this type of <span class="hlt">filter</span> can produce significant amplitude diminution and distortion of the shape of the ERP waveform. Thus, there is a need to identify more appropriate <span class="hlt">filters</span>. In this paper, we compare the performance of another type of FIR <span class="hlt">filter</span> that, unlike the boxcar <span class="hlt">filter</span>, is designed with an <span class="hlt">optimizing</span> algorithm that reduces signal distortion and maximizes signal extraction (referred to here as an <span class="hlt">optimal</span> FIR <span class="hlt">filter</span>). We applied several different <span class="hlt">filters</span> of both types to ERP data containing the P300 component. This comparison revealed that boxcar <span class="hlt">filters</span> reduced the contribution of high-frequency noise to the ERP but in so doing produced a substantial attenuation of P300 amplitude and, in some cases, substantial distortions of the shape of the waveform, resulting in significant errors in latency estimation. In contrast, the <span class="hlt">optimal</span> FIR <span class="hlt">filters</span> preserved P300 amplitude, morphology, and latency and also eliminated high-frequency noise more effectively than did the boxcar <span class="hlt">filters</span>. The implications of these results for data acquisition and analysis are discussed. PMID:8497560</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002NIMPA.480..726C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002NIMPA.480..726C"><span id="translatedtitle"><span class="hlt">Optimal</span> measurement of signal over noise ratio with constrained <span class="hlt">filter</span> transfer functions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cattaneo, Paolo Walter</p> <p>2002-03-01</p> <p>The problem of <span class="hlt">optimal</span> measurement of a signal in presence of noise is treated in detail by Baldinger and Franzen (Adv. Electron. Electron Phys. 8 (1956) 225), Radeka and Karlovac (Nucl. Instr. and Meth. 52 (1967) 86) and Gatti and Manfredi (La Rivista Nuovo Cimento 9(1) (1986) 1), and the <span class="hlt">filter</span> transfer function <span class="hlt">optimizing</span> the signal over noise ratio is well known. These calculations deals with unconstrained <span class="hlt">optimization</span>, that is the <span class="hlt">filter</span> transfer function may assume any value. In this paper functional analysis techniques are applied to <span class="hlt">optimize</span> the <span class="hlt">filter</span> transfer function in presence of linear constraints.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Freq...68..227C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Freq...68..227C"><span id="translatedtitle">A Triple-band Bandpass <span class="hlt">Filter</span> using Tri-section <span class="hlt">Step</span>-impedance and Capacitively Loaded <span class="hlt">Step</span>-impedance Resonators for GSM, WiMAX, and WLAN systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chomtong, P.; Akkaraekthalin, P.</p> <p>2014-05-01</p> <p>This paper presents a triple-band bandpass <span class="hlt">filter</span> for applications of GSM, WiMAX, and WLAN systems. The proposed <span class="hlt">filter</span> comprises of the tri-section <span class="hlt">step</span>-impedance and capacitively loaded <span class="hlt">step</span>-impedance resonators, which are combined using the cross coupling technique. Additionally, tapered lines are used to connect at both ports of the <span class="hlt">filter</span> in order to enhance matching for the tri-band resonant frequencies. The <span class="hlt">filter</span> can operate at the resonant frequencies of 1.8 GHz, 3.7 GHz, and 5.5 GHz. At resonant frequencies, the measured values of S11 are -17.2 dB, -33.6 dB, and -17.9 dB, while the measured values of S21 are -2.23 dB, -2.98 dB, and -3.31 dB, respectively. Moreover, the presented <span class="hlt">filter</span> has compact size compared with the conventional open-loop cross coupling triple band bandpass <span class="hlt">filters</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006EJASP2006...30Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006EJASP2006...30Y"><span id="translatedtitle">The <span class="hlt">Optimal</span> Design of Weighted Order Statistics <span class="hlt">Filters</span> by Using Support Vector Machines</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yao, Chih-Chia; Yu, Pao-Ta</p> <p>2006-12-01</p> <p>Support vector machines (SVMs), a classification algorithm for the machine learning community, have been shown to provide higher performance than traditional learning machines. In this paper, the technique of SVMs is introduced into the design of weighted order statistics (WOS) <span class="hlt">filters</span>. WOS <span class="hlt">filters</span> are highly effective, in processing digital signals, because they have a simple window structure. However, due to threshold decomposition and stacking property, the development of WOS <span class="hlt">filters</span> cannot significantly improve both the design complexity and estimation error. This paper proposes a new designing technique which can improve the learning speed and reduce the complexity of designing WOS <span class="hlt">filters</span>. This technique uses a dichotomous approach to reduce the Boolean functions from 255 levels to two levels, which are separated by an <span class="hlt">optimal</span> hyperplane. Furthermore, the <span class="hlt">optimal</span> hyperplane is gotten by using the technique of SVMs. Our proposed method approximates the <span class="hlt">optimal</span> weighted order statistics <span class="hlt">filters</span> more rapidly than the adaptive neural <span class="hlt">filters</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JIEIB..94..285S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JIEIB..94..285S"><span id="translatedtitle">Teaching-learning-based <span class="hlt">Optimization</span> Algorithm for Parameter Identification in the Design of IIR <span class="hlt">Filters</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, R.; Verma, H. K.</p> <p>2013-12-01</p> <p>This paper presents a teaching-learning-based <span class="hlt">optimization</span> (TLBO) algorithm to solve parameter identification problems in the designing of digital infinite impulse response (IIR) <span class="hlt">filter</span>. TLBO based <span class="hlt">filter</span> modelling is applied to calculate the parameters of unknown plant in simulations. Unlike other heuristic search algorithms, TLBO algorithm is an algorithm-specific parameter-less algorithm. In this paper big bang-big crunch (BB-BC) <span class="hlt">optimization</span> and PSO algorithms are also applied to <span class="hlt">filter</span> design for comparison. Unknown <span class="hlt">filter</span> parameters are considered as a vector to be <span class="hlt">optimized</span> by these algorithms. MATLAB programming is used for implementation of proposed algorithms. Experimental results show that the TLBO is more accurate to estimate the <span class="hlt">filter</span> parameters than the BB-BC <span class="hlt">optimization</span> algorithm and has faster convergence rate when compared to PSO algorithm. TLBO is used where accuracy is more essential than the convergence speed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060028978&hterms=Kalman&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DKalman','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060028978&hterms=Kalman&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DKalman"><span id="translatedtitle">An <span class="hlt">optimal</span> modification of a Kalman <span class="hlt">filter</span> for time scales</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Greenhall, C. A.</p> <p>2003-01-01</p> <p>The Kalman <span class="hlt">filter</span> in question, which was implemented in the time scale algorithm TA(NIST), produces time scales with poor short-term stability. A simple modification of the error covariance matrix allows the <span class="hlt">filter</span> to produce time scales with good stability at all averaging times, as verified by simulations of clock ensembles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006SPIE.6159E..4KB','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006SPIE.6159E..4KB"><span id="translatedtitle">Farrow structure implementation of fractional delay <span class="hlt">filter</span> <span class="hlt">optimal</span> in Chebyshev sense</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blok, Marek</p> <p>2006-03-01</p> <p>In this paper the problem of variable delay <span class="hlt">filter</span> implementation based on the Farrow structure is discussed. The idea of such an implementation is to calculate, for each required delay, coefficients of fractional delay <span class="hlt">filter</span> impulse response using delay independent polynomials. This approach leads to significant decrease of computational costs in applications which require frequent delay changes. Achieved computational complexity reduction is especially important in case of recursive <span class="hlt">optimal</span> <span class="hlt">filters</span> design methods. In this paper we demonstrate that quality and properties of fractional delay <span class="hlt">filters</span> <span class="hlt">optimal</span> in Chebyshev sense can be retained even for low orders of the Farrow structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21608686','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21608686"><span id="translatedtitle">Optease Vena Cava <span class="hlt">Filter</span> <span class="hlt">Optimal</span> Indwelling Time and Retrievability</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rimon, Uri Bensaid, Paul Golan, Gil Garniek, Alexander Khaitovich, Boris; Dotan, Zohar; Konen, Eli</p> <p>2011-06-15</p> <p>The purpose of this study was to assess the indwelling time and retrievability of the Optease IVC <span class="hlt">filter</span>. Between 2002 and 2009, a total of 811 Optease <span class="hlt">filters</span> were inserted: 382 for prophylaxis in multitrauma patients and 429 for patients with venous thromboembolic (VTE) disease. In 139 patients [97 men and 42 women; mean age, 36 (range, 17-82) years], <span class="hlt">filter</span> retrieval was attempted. They were divided into two groups to compare change in retrieval policy during the years: group A, 60 patients with <span class="hlt">filter</span> retrievals performed before December 31 2006; and group B, 79 patients with <span class="hlt">filter</span> retrievals from January 2007 to October 2009. A total of 128 <span class="hlt">filters</span> were successfully removed (57 in group A, and 71 in group B). The mean <span class="hlt">filter</span> indwelling time in the study group was 25 (range, 3-122) days. In group A the mean indwelling time was 18 (range, 7-55) days and in group B 31 days (range, 8-122). There were 11 retrieval failures: 4 for inability to engage the <span class="hlt">filter</span> hook and 7 for inability to sheathe the <span class="hlt">filter</span> due to intimal overgrowth. The mean indwelling time of group A retrieval failures was 16 (range, 15-18) days and in group B 54 (range, 17-122) days. Mean fluoroscopy time for successful retrieval was 3.5 (range, 1-16.6) min and for retrieval failures 25.2 (range, 7.2-62) min. Attempts to retrieve the Optease <span class="hlt">filter</span> can be performed up to 60 days, but more failures will be encountered with this approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995ApOpt..34..346F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995ApOpt..34..346F"><span id="translatedtitle">Photorefractive two-beam coupling <span class="hlt">optimal</span> thresholding <span class="hlt">filter</span> for additive signal-dependent noise reduction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fu, Jack; Khoury, Jehad; Cronin-Golomb, Mark; Woods, Charles L.</p> <p>1995-01-01</p> <p>Computer simulations of photorefractive thresholding <span class="hlt">filters</span> for the reduction of artifact or dust noise demonstrate an increase in signal-to-noise ratio (SNR) of 70% to 95%, respectively, of that provided by the Wiener <span class="hlt">filter</span> for inputs with a SNR of approximately 3. These simple, nearly <span class="hlt">optimal</span> <span class="hlt">filters</span> use a spectral thresholding profile that is proportional to the envelope of the noise spectrum. Alternative nonlinear <span class="hlt">filters</span> with either 1/ nu or constant thresholding profiles increase the SNR almost as much as the noise-envelope thresholding <span class="hlt">filter</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NIMPA.808..150S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NIMPA.808..150S"><span id="translatedtitle"><span class="hlt">Optimized</span> digital <span class="hlt">filtering</span> techniques for radiation detection with HPGe detectors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salathe, Marco; Kihm, Thomas</p> <p>2016-02-01</p> <p>This paper describes state-of-the-art digital <span class="hlt">filtering</span> techniques that are part of GEANA, an automatic data analysis software used for the GERDA experiment. The discussed <span class="hlt">filters</span> include a novel, nonlinear correction method for ballistic deficits, which is combined with one of three shaping <span class="hlt">filters</span>: a pseudo-Gaussian, a modified trapezoidal, or a modified cusp <span class="hlt">filter</span>. The performance of the <span class="hlt">filters</span> is demonstrated with a 762 g Broad Energy Germanium (BEGe) detector, produced by Canberra, that measures γ-ray lines from radioactive sources in an energy range between 59.5 and 2614.5 keV. At 1332.5 keV, together with the ballistic deficit correction method, all <span class="hlt">filters</span> produce a comparable energy resolution of ~1.61 keV FWHM. This value is superior to those measured by the manufacturer and those found in publications with detectors of a similar design and mass. At 59.5 keV, the modified cusp <span class="hlt">filter</span> without a ballistic deficit correction produced the best result, with an energy resolution of 0.46 keV. It is observed that the loss in resolution by using a constant shaping time over the entire energy range is small when using the ballistic deficit correction method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008SPIE.6623E..21L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008SPIE.6623E..21L"><span id="translatedtitle">Implementation and <span class="hlt">optimization</span> of an improved morphological <span class="hlt">filtering</span> algorithm for speckle removal based on DSPs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Qitao; Li, Yingchun; Sun, Huayan; Zhao, Yanzhong</p> <p>2008-03-01</p> <p>Laser active imaging system, which is of high resolution, anti-jamming and can be three-dimensional (3-D) imaging, has been used widely. But its imagery is usually affected by speckle noise which makes the grayscale of pixels change violently, hides the subtle details and makes the imaging resolution descend greatly. Removing speckle noise is one of the most difficult problems encountered in this system because of the poor statistical property of speckle. Based on the analysis of the statistical characteristic of speckle and morphological <span class="hlt">filtering</span> algorithm, in this paper, an improved multistage morphological <span class="hlt">filtering</span> algorithm is studied and implemented on TMS320C6416 DSP. The algorithm makes the morphological open-close and close-open transformation by using two different linear structure elements respectively, and then takes a weighted average over the above transformational results. The weighted coefficients are decided by the statistical characteristic of speckle. This algorithm is implemented on the TMS320C6416 DSPs after simulation on computer. The procedure of software design is fully presented. The methods are fully illustrated to achieve and <span class="hlt">optimize</span> the algorithm in the research of the structural characteristic of TMS320C6416 DSP and feature of the algorithm. In order to fully benefit from such devices and increase the performance of the whole system, it is necessary to take a series of <span class="hlt">steps</span> to <span class="hlt">optimize</span> the DSP programs. This paper introduces some effective methods, including refining code structure, eliminating memory dependence, <span class="hlt">optimizing</span> assembly code via linear assembly and so on, for TMS320C6x C language <span class="hlt">optimization</span> and then offers the results of the application in a real-time implementation. The results of processing to the images blurred by speckle noise shows that the algorithm can not only effectively suppress speckle noise but also preserve the geometrical features of images. The results of the <span class="hlt">optimized</span> code running on the DSP platform show that the <span class="hlt">optimized</span> outcome realizes better instruction-level parallelism and pipeline operation and the program is proved to be reliable, effective and high real time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.5772..144G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.5772..144G"><span id="translatedtitle">Analysis and <span class="hlt">optimization</span> of the computational process of nonlinear discrete Kalman <span class="hlt">filtering</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gurov, Igor; Taratin, Mikhail; Zakharov, Alexey</p> <p>2005-06-01</p> <p><span class="hlt">Optimization</span> of nonlinear discrete Kalman <span class="hlt">filtering</span> computational process is considered in application to dynamic processing of interferometric signals in Optical Coherence Tomography. Processing speed of low-coherence fringe signals is assessed when using discrete nonlinear Kalman <span class="hlt">filtering</span> algorithm implemented by Intel Pentium 4 processor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25569031','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25569031"><span id="translatedtitle">Bio-desulfurization of biogas using acidic biotrickling <span class="hlt">filter</span> with dissolved oxygen in <span class="hlt">step</span> feed recirculation.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chaiprapat, Sumate; Charnnok, Boonya; Kantachote, Duangporn; Sung, Shihwu</p> <p>2015-03-01</p> <p>Triple stage and single stage biotrickling <span class="hlt">filters</span> (T-BTF and S-BTF) were operated with oxygenated liquid recirculation to enhance bio-desulfurization of biogas. Empty bed retention time (EBRT 100-180 s) and liquid recirculation velocity (q 2.4-7.1 m/h) were applied. H2S removal and sulfuric acid recovery increased with higher EBRT and q. But the highest q at 7.1 m/h induced large amount of liquid through the media, causing a reduction in bed porosity in S-BTF and H2S removal. Equivalent performance of S-BTF and T-BTF was obtained under the lowest loading of 165 gH2S/m(3)/h. In the subsequent continuous operation test, it was found that T-BTF could maintain higher H2S elimination capacity and removal efficiency at 175.6±41.6 gH2S/m(3)/h and 89.0±6.8% versus S-BTF at 159.9±42.8 gH2S/m(3)/h and 80.1±10.2%, respectively. Finally, the relationship between outlet concentration and bed height was modeled. <span class="hlt">Step</span> feeding of oxygenated liquid recirculation in multiple stages clearly demonstrated an advantage for sulfide oxidation. PMID:25569031</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/913143','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/913143"><span id="translatedtitle">Method for <span class="hlt">optimizing</span> output in ultrashort-pulse multipass laser amplifiers with selective use of a spectral <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Backus, Sterling J.; Kapteyn, Henry C.</p> <p>2007-07-10</p> <p>A method for <span class="hlt">optimizing</span> multipass laser amplifier output utilizes a spectral <span class="hlt">filter</span> in early passes but not in later passes. The pulses shift position slightly for each pass through the amplifier, and the <span class="hlt">filter</span> is placed such that early passes intersect the <span class="hlt">filter</span> while later passes bypass it. The <span class="hlt">filter</span> position may be adjust offline in order to adjust the number of passes in each category. The <span class="hlt">filter</span> may be <span class="hlt">optimized</span> for use in a cryogenic amplifier.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PASJ...64...47O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PASJ...64...47O"><span id="translatedtitle">Wide-Band Optical <span class="hlt">Filter</span> <span class="hlt">Optimized</span> for Deep Imaging of Small Solar System Bodies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Okumura, Shin-ichiro; Nishiyama, Kota; Urakawa, Seitaro; Sakamoto, Tsuyoshi; Takahashi, Noritsugu; Yoshikawa, Makoto</p> <p>2012-06-01</p> <p>This paper describes a newly designed wide-band optical <span class="hlt">filter</span>. It is <span class="hlt">optimized</span> for deep imaging of small solar-system bodies. The new <span class="hlt">filter</span>, which we denote as W i, is designed to reduce contamination by light pollution from street lamps, especially strong mercury and sodium emission lines. It is also useful for reducing unwanted scattered moonlight. Compared with the use of a commercially available long-wave cut wide-band <span class="hlt">filter</span>, the signal-to-noise ratios in the detection of asteroids are improved by about 6% by using the W i <span class="hlt">filter</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhB...48r5001Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhB...48r5001Z"><span id="translatedtitle"><span class="hlt">Optimization</span> of atomic Faraday <span class="hlt">filters</span> in the presence of homogeneous line broadening</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zentile, Mark A.; Keaveney, James; Mathew, Renju S.; Whiting, Daniel J.; Adams, Charles S.; Hughes, Ifan G.</p> <p>2015-09-01</p> <p>We show that homogeneous line broadening drastically affects the performance of atomic Faraday <span class="hlt">filters</span>. We study the effects of cell length and find that the behaviour of line-centre <span class="hlt">filters</span> are quite different from wing-type <span class="hlt">filters</span>, where the effect of self-broadening is found to be particularly important. We use a computer <span class="hlt">optimization</span> algorithm to find the best magnetic field and temperature for Faraday <span class="hlt">filters</span> with a range of cell lengths, and experimentally realize one particular example using a micro-fabricated 87Rb vapour cell. We find excellent agreement between our theoretical model and experimental data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PASP..125..838P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PASP..125..838P"><span id="translatedtitle">An Efficient and <span class="hlt">Optimal</span> <span class="hlt">Filter</span> for Identifying Point Sources in Millimeter/Submillimeter Wavelength Sky Maps</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perera, T. A.; Wilson, G. W.; Scott, K. S.; Austermann, J. E.; Schaar, J. R.; Mancera, A.</p> <p>2013-07-01</p> <p>A new technique for reliably identifying point sources in millimeter/submillimeter wavelength maps is presented. This method accounts for the frequency dependence of noise in the Fourier domain as well as nonuniformities in the coverage of a field. This <span class="hlt">optimal</span> <span class="hlt">filter</span> is an improvement over commonly-used matched <span class="hlt">filters</span> that ignore coverage gradients. Treating noise variations in the Fourier domain as well as map space is traditionally viewed as a computationally intensive problem. We show that the penalty incurred in terms of computing time is quite small due to casting many of the calculations in terms of FFTs and exploiting the absence of sharp features in the noise spectra of observations. Practical aspects of implementing the <span class="hlt">optimal</span> <span class="hlt">filter</span> are presented in the context of data from the AzTEC bolometer camera. The advantages of using the new <span class="hlt">filter</span> over the standard matched <span class="hlt">filter</span> are also addressed in terms of a typical AzTEC map.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992agcp.agar.....A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992agcp.agar.....A"><span id="translatedtitle">Multivariable frequency response methods for <span class="hlt">optimal</span> Kalman-Bucy <span class="hlt">filters</span> with applications to radar tracking systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arcasoy, C. C.</p> <p>1992-11-01</p> <p>The problem of multi-output, infinite-time, linear time-invariant <span class="hlt">optimal</span> Kalman-Bucy <span class="hlt">filter</span> both in continuous and discrete-time cases in frequency domain is addressed. A simple new algorithm is given for the analytical solution to the steady-state gain of the optimum <span class="hlt">filter</span> based on a transfer function approach. The algorithm is based on spectral factorization of observed spectral density matrix of the <span class="hlt">filter</span> which generates directly the return-difference matrix of the <span class="hlt">optimal</span> <span class="hlt">filter</span>. The method is more direct than by algebraic Riccati equation solution and can easily be implemented on digital computer. The design procedure is illustrated by examples and closed-form solution of ECV and ECA radar tracking <span class="hlt">filters</span> are considered as an application of the method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820033301&hterms=track+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dtrack%2Bfield','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820033301&hterms=track+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dtrack%2Bfield"><span id="translatedtitle">An <span class="hlt">optimal</span> numerical <span class="hlt">filter</span> for wide-field-of-view measurements of earth-emitted radiation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, G. L.; House, F. B.</p> <p>1981-01-01</p> <p>A technique is described in which all data points along an arc of the orbit may be used in an <span class="hlt">optimal</span> numerical <span class="hlt">filter</span> for wide-field-of-view measurements of earth emitted radiation. The statistical <span class="hlt">filter</span> design is derived whereby the <span class="hlt">filter</span> is required to give a minimum variance estimate of the radiative exitance at discrete points along the ground track of the satellite. An equation for the <span class="hlt">optimal</span> numerical <span class="hlt">filter</span> is given by minimizing the estimate error variance equation with respect to the <span class="hlt">filter</span> weights, resulting in a discrete form of the Wiener-Hopf equation. Finally, variances of the errors in the radiant exitance can be computed along the ground track and in the cross track directions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15524032','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15524032"><span id="translatedtitle">3 <span class="hlt">steps</span> for <span class="hlt">optimizing</span> self-pay outsourcing.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Seman, Maria H; Guyton, Elizabeth M</p> <p>2004-10-01</p> <p>Just because you outsource your self-pay receivables doesn't mean a dramatic improvement in return is inevitable. For <span class="hlt">optimal</span> results, providers need to be actively involved in the process by carefully screening the vendor, coordinating activities to allow for a seamless transition, and implementing a system that accurately and continually tracks results. PMID:15524032</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10148667','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10148667"><span id="translatedtitle">Linear adaptive noise-reduction <span class="hlt">filters</span> for tomographic imaging: <span class="hlt">Optimizing</span> for minimum mean square error</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sun, W Y</p> <p>1993-04-01</p> <p>This thesis solves the problem of finding the <span class="hlt">optimal</span> linear noise-reduction <span class="hlt">filter</span> for linear tomographic image reconstruction. The <span class="hlt">optimization</span> is data dependent and results in minimizing the mean-square error of the reconstructed image. The error is defined as the difference between the result and the best possible reconstruction. Applications for the <span class="hlt">optimal</span> <span class="hlt">filter</span> include reconstructions of positron emission tomographic (PET), X-ray computed tomographic, single-photon emission tomographic, and nuclear magnetic resonance imaging. Using high resolution PET as an example, the <span class="hlt">optimal</span> <span class="hlt">filter</span> is derived and presented for the convolution backprojection, Moore-Penrose pseudoinverse, and the natural-pixel basis set reconstruction methods. Simulations and experimental results are presented for the convolution backprojection method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25227085','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25227085"><span id="translatedtitle">Bandwidth <span class="hlt">optimization</span> for <span class="hlt">filter</span>-based fatigue index in different inter-electrode distances.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Jungyoon; Son, Jongsang; Kim, Youngho</p> <p>2014-01-01</p> <p>In this study, the bandwidth of the <span class="hlt">filter</span>-based fatigue index was determined by the comparison of <span class="hlt">optimized</span> cut-off frequencies in different inter-electrode distances. Sixty-one subjects participated in isometric knee extension, isotonic ankle dorsiflexion, and isotonic elbow extension exercises. Electromyography (EMG) signals were obtained from right rectus femoris, triceps brachii, and tibialis anterior muscles during exercises. The <span class="hlt">filter</span>-based fatigue index was compared with mean root-mean-square values, median frequency, Dimitrov spectral index, and Gonzalez-Izal wavelet index. <span class="hlt">Optimized</span> cut-off frequencies of the high-pass <span class="hlt">filter</span> for three different exercises and three different inter-electrode distances were about 350 Hz. Results from this study support that around 350 Hz high-pass <span class="hlt">filter</span> could be useful to determine cut-off frequency for fatigue prediction in general purposes. PMID:25227085</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19963573','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19963573"><span id="translatedtitle">An <span class="hlt">optimal</span> spatial <span class="hlt">filtering</span> electrode for brain computer interface.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Besio, W G; Kay, S M; Liu, X</p> <p>2009-01-01</p> <p>There are millions of people in the U.S. and many more worldwide who could benefit from a noninvasive-based electroencephalography (EEG) brain computer interface (BCI). A BCI is an alternative or augmentative communication method for people with severe motor disabilities. However, EEG suffers from poor spatial resolution and signal-to-noise ratio (SNR). To improve the spatial resolution and SNR many researchers have turned to implantable electrodes. We have previously reported on significant improvements in BCI recognition rates using tripolar concentric ring electrodes compared to disc electrodes. We now report on a <span class="hlt">optimal</span> method for combining the outputs from the independent elements of the tripolar concentric ring electrodes to improve the spatial resolution further. We used minimum variance distortionless look (MVDL), a beamformer, on simulated data to compare the spatial sensitivity of the <span class="hlt">optimal</span> combination to disc electrodes and the tripolar concentric ring electrode surface Laplacian. The <span class="hlt">optimal</span> combination shows the highest spatial sensitivity with the Laplacian a close second and disc electrodes resulting in a distant third. Further analysis is necessary with a more realistic computer model and then real signals. however it appears that the <span class="hlt">optimal</span> combination may improve the spatial resolution of EEG further which in turn can be utilized to improve noninvasive EEG-based BCIs. PMID:19963573</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26424837','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26424837"><span id="translatedtitle">Biologic efficacy <span class="hlt">optimization</span>-a <span class="hlt">step</span> towards personalized medicine.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kiely, Patrick D W</p> <p>2016-05-01</p> <p>This following is a review of the factors that influence the outcome of biologic agents in the treatment of adult RA and, when synthesized into the clinical decision-making process, enhance <span class="hlt">optimization</span>. Adiposity can exacerbate inflammatory diseases; patients with high BMI have worse outcomes from RA, including TNF inhibitors (TNFis), whereas the efficacy of abatacept and tocilizumab is unaffected. Smoking adversely affects TNFi outcomes but has less or no effect on the efficacy of rituximab and tocilizumab, and the effect on abatacept is unknown. Patients who are positive for ACPA and RF have better efficacy with rituximab and abatacept than those who are seronegative, whereas the influence of serotype is less significant for tocilizumab and more complex for TNFis. All biologics seem to do better when co-prescribed with MTX, whereas in monotherapy, tocilizumab is superior to adalimumab and prescription of a non-MTX DMARD has advantages over no DMARD for rituximab and adalimumab. Monitoring of TNFi drug levels is an exciting new field, correlating closely with efficacy in RA and PsA, and is influenced by BMI, adherence, co-prescribed DMARDs and anti-drug antibodies. The measurement of trough levels provides a potential tool for patients who are not doing well to determine early whether to switch within the TNFi class (if levels are low) or to a biologic with an alternative mode of action (if levels are normal or high). Conversely, the finding of supratherapeutic levels has the potential to enable individual patient selection for dose reduction without the risk of flare. PMID:26424837</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9654E..0BP','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9654E..0BP"><span id="translatedtitle">Design and <span class="hlt">optimization</span> of high reflectance graded index optical <span class="hlt">filter</span> with quintic apodization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Praveen Kumar, Vemuri S. R. S.; Sunita, Parinam; Kumar, Mukesh; Rao, Parinam Krishna; Kumari, Neelam; Karar, Vinod; Sharma, Amit L.</p> <p>2015-06-01</p> <p>Rugate <span class="hlt">filters</span> are a special kind of graded-index films that may provide advantages in both, optical performance and mechanical properties of the optical coatings. In this work, design and <span class="hlt">optimization</span> of a high reflection rugate <span class="hlt">filter</span> having reflection peak at 540nm has been presented which has been further <span class="hlt">optimized</span> for side-lobe suppression. A suitable number of apodization and matching layers, generated through Quintic function, were added to the basic sinusoidal refractive index profile to achieve high reflectance of around 80% in the rejection window for normal incidence. Smaller index contrast between successive layers in the present design leads to less residual stress in the thinfilm stack which enhances the adhesion and mechanical strength of the <span class="hlt">filter</span>. The <span class="hlt">optimized</span> results show excellent side lobe suppression achieved around the stopband.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26391486','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26391486"><span id="translatedtitle"><span class="hlt">Optimal</span> fractional delay-IIR <span class="hlt">filter</span> design using cuckoo search algorithm.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kumar, Manjeet; Rawat, Tarun Kumar</p> <p>2015-11-01</p> <p>This paper applied a novel global meta-heuristic <span class="hlt">optimization</span> algorithm, cuckoo search algorithm (CSA) to determine <span class="hlt">optimal</span> coefficients of a fractional delay-infinite impulse response (FD-IIR) <span class="hlt">filter</span> and trying to meet the ideal frequency response characteristics. Since fractional delay-IIR <span class="hlt">filter</span> design is a multi-modal <span class="hlt">optimization</span> problem, it cannot be computed efficiently using conventional gradient based <span class="hlt">optimization</span> techniques. A weighted least square (WLS) based fitness function is used to improve the performance to a great extent. FD-IIR <span class="hlt">filters</span> of different orders have been designed using the CSA. The simulation results of the proposed CSA based approach have been compared to those of well accepted evolutionary algorithms like Genetic Algorithm (GA) and Particle Swarm <span class="hlt">Optimization</span> (PSO). The performance of the CSA based FD-IIR <span class="hlt">filter</span> is superior to those obtained by GA and PSO. The simulation and statistical results affirm that the proposed approach using CSA outperforms GA and PSO, not only in the convergence rate but also in <span class="hlt">optimal</span> performance of the designed FD-IIR <span class="hlt">filter</span> (i.e., smaller magnitude error, smaller phase error, higher percentage improvement in magnitude and phase error, fast convergence rate). The absolute magnitude and phase error obtained for the designed 5th order FD-IIR <span class="hlt">filter</span> are as low as 0.0037 and 0.0046, respectively. The percentage improvement in magnitude error for CSA based 5th order FD-IIR design with respect to GA and PSO are 80.93% and 74.83% respectively, and phase error are 76.04% and 71.25%, respectively. PMID:26391486</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15603077','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15603077"><span id="translatedtitle">Two-stage hybrid <span class="hlt">optimization</span> of fiber Bragg gratings for design of linear phase <span class="hlt">filters</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zheng, Rui Tao; Ngo, Nam Quoc; Le Binh, Nguyen; Tjin, Swee Chuan</p> <p>2004-12-01</p> <p>We present a new hybrid <span class="hlt">optimization</span> method for the synthesis of fiber Bragg gratings (FBGs) with complex characteristics. The hybrid <span class="hlt">optimization</span> method is a two-tier search that employs a global <span class="hlt">optimization</span> algorithm [i.e., the tabu search (TS) algorithm] and a local <span class="hlt">optimization</span> method (i.e., the quasi-Netwon method). First the TS global <span class="hlt">optimization</span> algorithm is used to find a "promising" FBG structure that has a spectral response as close as possible to the targeted spectral response. Then the quasi-Newton local <span class="hlt">optimization</span> method is applied to further <span class="hlt">optimize</span> the FBG structure obtained from the TS algorithm to arrive at a targeted spectral response. A dynamic mechanism for weighting of different requirements of the spectral response is employed to enhance the <span class="hlt">optimization</span> efficiency. To demonstrate the effectiveness of the method, the synthesis of three linear-phase optical <span class="hlt">filters</span> based on FBGs with different grating lengths is described. PMID:15603077</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70015521','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70015521"><span id="translatedtitle"><span class="hlt">Optimal</span>-adaptive <span class="hlt">filters</span> for modelling spectral shape, site amplification, and source scaling</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Safak, Erdal</p> <p>1989-01-01</p> <p>This paper introduces some applications of <span class="hlt">optimal</span> <span class="hlt">filtering</span> techniques to earthquake engineering by using the so-called ARMAX models. Three applications are presented: (a) spectral modelling of ground accelerations, (b) site amplification (i.e., the relationship between two records obtained at different sites during an earthquake), and (c) source scaling (i.e., the relationship between two records obtained at a site during two different earthquakes). A numerical example for each application is presented by using recorded ground motions. The results show that the <span class="hlt">optimal</span> <span class="hlt">filtering</span> techniques provide elegant solutions to above problems, and can be a useful tool in earthquake engineering.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26906867','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26906867"><span id="translatedtitle"><span class="hlt">Optimized</span> design of N optical <span class="hlt">filters</span> for color and polarization imaging.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tu, Xingzhou; Pau, Stanley</p> <p>2016-02-01</p> <p>Designs of N optical <span class="hlt">filters</span> for color and polarization imaging are found by minimizing detector noise, photon shot noise, and interpolation error for the image acquisition in a division of focal plane configuration. To minimize interpolation error, a general tiling procedure and an <span class="hlt">optimized</span> tiling pattern for N <span class="hlt">filters</span> are presented. For multispectral imaging, a general technique to find the transmission band is presented. For full Stokes polarization imaging, the general design with <span class="hlt">optimized</span> retardances and fast angles of the polarizers is compared with the solution of the Thomson problem. These results are applied to the design of a three-color full Stokes imaging camera. PMID:26906867</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/7565389','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/7565389"><span id="translatedtitle">Simultaneous <span class="hlt">optimization</span> of dynamic multileaf collimation and scanning patterns or compensation <span class="hlt">filters</span> using a generalized pencil beam algorithm.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gustafsson, A; Lind, B K; Svensson, R; Brahme, A</p> <p>1995-07-01</p> <p>A very flexible iterative method for simultaneous <span class="hlt">optimization</span> of dynamic multileaf collimation, scanning patterns and compensation <span class="hlt">filters</span> has been developed. The algorithm can account for and <span class="hlt">optimize</span> almost all the degrees of freedom available in a modern radiation therapy clinic. The method has been implemented for three dimensional treatment planning. The algorithm has been tested for a number of cases where both traditional wedge <span class="hlt">filters</span> and block collimators, and modern equipment such as scanned beams and multileaf collimators are available. It is shown that the algorithm can improve heavily on traditional uniform dose plans with respect to the probability of achieving tumor control without causing severe complications (P+) simply by finding the <span class="hlt">optimal</span> beam weights and block collimator settings. By allowing more complex equipment to deliver the dose and by accounting for their increased flexibility during the <span class="hlt">optimization</span>, the dose plan can be substantially improved with respect to the applied objective functions. It is demonstrated that flexible lateral collimation combined with compensators or scanned beams in most cases allow close to <span class="hlt">optimal</span> dose delivery. Here both the calculation time and the amount of primary computer memory needed has been reduced by performing the dose calculations in a cone beam coordinate system allowing the use of approximately spatially invariant energy deposition kernels. A typical calculation time for <span class="hlt">optimization</span> of a two-field technique in a three dimensional volume is about 20 s per iteration <span class="hlt">step</span> on a Hewlett-Packard 735 workstation. A well converged solution is normally obtained within about 50-100 iterations or within 15-30 min. PMID:7565389</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.5797B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.5797B"><span id="translatedtitle">Improved design and <span class="hlt">optimization</span> of subsurface flow constructed wetlands and sand <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brovelli, A.; Carranza-Díaz, O.; Rossi, L.; Barry, D. A.</p> <p>2010-05-01</p> <p>Subsurface flow constructed wetlands and sand <span class="hlt">filters</span> are engineered systems capable of eliminating a wide range of pollutants from wastewater. These devices are easy to operate, flexible and have low maintenance costs. For these reasons, they are particularly suitable for small settlements and isolated farms and their use has substantially increased in the last 15 years. Furthermore, they are also becoming used as a tertiary - polishing - <span class="hlt">step</span> in traditional treatment plants. Recent work observed that research is however still necessary to understand better the biogeochemical processes occurring in the porous substrate, their mutual interactions and feedbacks, and ultimately to identify the <span class="hlt">optimal</span> conditions to degrade or remove from the wastewater both traditional and anthropogenic recalcitrant pollutants, such as hydrocarbons, pharmaceuticals, personal care products. <span class="hlt">Optimal</span> pollutant elimination is achieved if the contact time between microbial biomass and the contaminated water is sufficiently long. The contact time depends on the hydraulic residence time distribution (HRTD) and is controlled by the hydrodynamic properties of the system. Previous reports noted that poor hydrodynamic behaviour is frequent, with water flowing mainly through preferential paths resulting in a broad HRTD. In such systems the flow rate must be decreased to allow a sufficient proportion of the wastewater to experience the minimum residence time. The pollutant removal efficiency can therefore be significantly reduced, potentially leading to the failure of the system. The aim of this work was to analyse the effect of the heterogeneous distribution of the hydraulic properties of the porous substrate on the HRTD and treatment efficiency, and to develop an improved design methodology to reduce the risk of system failure and to <span class="hlt">optimize</span> existing systems showing poor hydrodynamics. Numerical modelling was used to evaluate the effect of substrate heterogeneity on the breakthrough curves of both a conservative tracer and a reactive organic compound. Random, spatially correlated hydraulic conductivity fields following a log-normal distribution were generated to represent the heterogeneous distribution of the hydraulic properties. The effect of the variance of the hydraulic conductivity distribution, as well as the aspect ratio of the correlation lengths were analyzed and compared to experimental findings. The proposed design methodology is based on the target hydraulic residence time, that is, the residence time required to achieve the degradation of the contaminants. The effect of the heterogeneity is accounted for using a Monte Carlo approach. From the analysis of the simulation results the probability of failure of the system can be estimated and used to design a new system or <span class="hlt">optimize</span> existing systems. The methodology was illustrated using a realistic test case with water contaminated with benzene.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120008933','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120008933"><span id="translatedtitle">Nonlinear Motion Cueing Algorithm: <span class="hlt">Filtering</span> at Pilot Station and Development of the Nonlinear <span class="hlt">Optimal</span> <span class="hlt">Filters</span> for Pitch and Roll</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zaychik, Kirill B.; Cardullo, Frank M.</p> <p>2012-01-01</p> <p>Telban and Cardullo have developed and successfully implemented the non-linear <span class="hlt">optimal</span> motion cueing algorithm at the Visual Motion Simulator (VMS) at the NASA Langley Research Center in 2005. The latest version of the non-linear algorithm performed <span class="hlt">filtering</span> of motion cues in all degrees-of-freedom except for pitch and roll. This manuscript describes the development and implementation of the non-linear <span class="hlt">optimal</span> motion cueing algorithm for the pitch and roll degrees of freedom. Presented results indicate improved cues in the specified channels as compared to the original design. To further advance motion cueing in general, this manuscript describes modifications to the existing algorithm, which allow for <span class="hlt">filtering</span> at the location of the pilot's head as opposed to the centroid of the motion platform. The rational for such modification to the cueing algorithms is that the location of the pilot's vestibular system must be taken into account as opposed to the off-set of the centroid of the cockpit relative to the center of rotation alone. Results provided in this report suggest improved performance of the motion cueing algorithm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23523646','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23523646"><span id="translatedtitle"><span class="hlt">Optimizing</span> the bandpass <span class="hlt">filter</span> for acoustic stimuli in recording ocular vestibular-evoked myogenic potentials.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Shou-Jen; Jaw, Fu-Shan; Young, Yi-Ho</p> <p>2013-05-10</p> <p>This study aimed to determine the <span class="hlt">optimal</span> bandpass <span class="hlt">filter</span> (BPF) setting for acoustic stimuli in recording the ocular vestibular-evoked myogenic potential (oVEMP). Twelve healthy volunteers underwent oVEMP tests using acoustic stimuli with various high-pass <span class="hlt">filters</span> (1, 10 and 100Hz) and low-pass <span class="hlt">filters</span> (500, 1000 and 2000Hz). Initially, various effects of high-pass <span class="hlt">filter</span> on the oVEMPs were examined under Conditions A (BPF of 1-1000Hz), B (BPF of 10-1000Hz) and C (BPF of 100-1000Hz). Of these conditions, Condition A showed 100% response rate and had larger nI-pI amplitude than Conditions B and C. Thus, Condition A was selected for subsequent analysis of the various effects of low-pass <span class="hlt">filter</span> on the oVEMPs. However, Condition A (BPF of 1-1000Hz) did not significantly differ from Conditions D (BPF of 1-500Hz) and E (BPF of 1-2000Hz) in terms of the latencies and amplitudes of oVEMPs. Condition A thus is supposed to be the <span class="hlt">optimal</span> recording condition for oVEMPs. In conclusion, the <span class="hlt">optimal</span> BPF setting for acoustic stimuli in recording oVEMPs is suggested to be between 1 and 1000Hz. PMID:23523646</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1706b0011L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1706b0011L"><span id="translatedtitle"><span class="hlt">Optimal</span> matched <span class="hlt">filter</span> design for ultrasonic NDE of coarse grain materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Minghui; Hayward, Gordon</p> <p>2016-02-01</p> <p>Coarse grain materials are widely used in a variety of key industrial sectors like energy, oil and gas, and aerospace due to their attractive properties. However, when these materials are inspected using ultrasound, the flaw echoes are usually contaminated by high-level, correlated grain noise originating from the material microstructures, which is time-invariant and demonstrates similar spectral characteristics as flaw signals. As a result, the reliable inspection of such materials is highly challenging. In this paper, we present a method for reliable ultrasonic non-destructive evaluation (NDE) of coarse grain materials using matched <span class="hlt">filters</span>, where the <span class="hlt">filter</span> is designed to approximate and match the unknown defect echoes, and a particle swarm <span class="hlt">optimization</span> (PSO) paradigm is employed to search for the <span class="hlt">optimal</span> parameters in the <span class="hlt">filter</span> response with an objective to maximise the output signal-to-noise ratio (SNR). Experiments with a 128-element 5MHz transducer array on mild steel and INCONEL Alloy 617 samples are conducted, and the results confirm that the SNR of the images is improved by about 10-20 dB if the <span class="hlt">optimized</span> matched <span class="hlt">filter</span> is applied to all the A-scan waveforms prior to image formation. Furthermore, the matched <span class="hlt">filter</span> can be implemented in real-time with low extra computational cost.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8401E..0RM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8401E..0RM"><span id="translatedtitle"><span class="hlt">Optimization</span> of high speed pipelining in FPGA-based FIR <span class="hlt">filter</span> design using genetic algorithm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meyer-Baese, Uwe; Botella, Guillermo; Romero, David E. T.; Kumm, Martin</p> <p>2012-06-01</p> <p>This paper compares FPGA-based full pipelined multiplierless FIR <span class="hlt">filter</span> design options. Comparison of Distributed Arithmetic (DA), Common Sub-Expression (CSE) sharing and n-dimensional Reduced Adder Graph (RAG-n) multiplierless <span class="hlt">filter</span> design methods in term of size, speed, and A*T product are provided. Since DA designs are table-based and CSE/RAG-n designs are adder-based, FPGA synthesis design data are used for a realistic comparison. Superior results of a genetic algorithm based <span class="hlt">optimization</span> of pipeline registers and non-output fundamental coefficients are shown. FIR <span class="hlt">filters</span> (posted as open source by Kastner et al.) for <span class="hlt">filters</span> in the length from 6 to 151 coefficients are used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AcMSn.tmp..113Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AcMSn.tmp..113Y"><span id="translatedtitle">Plate/shell topological <span class="hlt">optimization</span> subjected to linear buckling constraints by adopting composite exponential <span class="hlt">filtering</span> function</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ye, Hong-Ling; Wang, Wei-Wei; Chen, Ning; Sui, Yun-Kang</p> <p>2015-11-01</p> <p>In this paper, a model of topology <span class="hlt">optimization</span> with linear buckling constraints is established based on an independent and continuous mapping method to minimize the plate/shell structure weight. A composite exponential function (CEF) is selected as <span class="hlt">filtering</span> functions for element weight, the element stiffness matrix and the element geometric stiffness matrix, which recognize the design variables, and to implement the changing process of design variables from "discrete" to "continuous" and back to "discrete". The buckling constraints are approximated as explicit formulations based on the Taylor expansion and the <span class="hlt">filtering</span> function. The <span class="hlt">optimization</span> model is transformed to dual programming and solved by the dual sequence quadratic programming algorithm. Finally, three numerical examples with power function and CEF as <span class="hlt">filter</span> function are analyzed and discussed to demonstrate the feasibility and efficiency of the proposed method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhyA..447...49D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhyA..447...49D"><span id="translatedtitle">Performance <span class="hlt">optimization</span> of total momentum <span class="hlt">filtering</span> double-resonance energy selective electron heat pump</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ding, Ze-Min; Chen, Lin-Gen; Ge, Yan-Lin; Sun, Feng-Rui</p> <p>2016-04-01</p> <p>A theoretical model for energy selective electron (ESE) heat pumps operating with two-dimensional electron reservoirs is established in this study. In this model, a double-resonance energy <span class="hlt">filter</span> operating with a total momentum <span class="hlt">filtering</span> mechanism is considered for the transmission of electrons. The <span class="hlt">optimal</span> thermodynamic performance of the ESE heat pump devices is also investigated. Numerical calculations show that the heating load of the device with two resonances is larger, whereas the coefficient of performance (COP) is lower than the ESE heat pump when considering a single-resonance <span class="hlt">filter</span>. The performance characteristics of the ESE heat pumps in the total momentum <span class="hlt">filtering</span> condition are generally superior to those with a conventional <span class="hlt">filtering</span> mechanism. In particular, the performance characteristics of the ESE heat pumps considering a conventional <span class="hlt">filtering</span> mechanism are vastly different from those of a device with total momentum <span class="hlt">filtering</span>, which is induced by extra electron momentum in addition to the horizontal direction. Parameters such as resonance width and energy spacing are found to be associated with the performance of the electron system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19830033191&hterms=water+filter&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dwater%2Bfilter','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19830033191&hterms=water+filter&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dwater%2Bfilter"><span id="translatedtitle"><span class="hlt">Optimal</span> interpolation and the Kalman <span class="hlt">filter</span>. [for analysis of numerical weather predictions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cohn, S.; Isaacson, E.; Ghil, M.</p> <p>1981-01-01</p> <p>The estimation theory of stochastic-dynamic systems is described and used in a numerical study of <span class="hlt">optimal</span> interpolation. The general form of data assimilation methods is reviewed. The Kalman-Bucy, KB <span class="hlt">filter</span>, and <span class="hlt">optimal</span> interpolation (OI) <span class="hlt">filters</span> are examined for effectiveness in performance as gain matrices using a one-dimensional form of the shallow-water equations. Control runs in the numerical analyses were performed for a ten-day forecast in concert with the OI method. The effects of <span class="hlt">optimality</span>, initialization, and assimilation were studied. It was found that correct initialization is necessary in order to localize errors, especially near boundary points. Also, the use of small forecast error growth rates over data-sparse areas was determined to offset inaccurate modeling of correlation functions near boundaries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013IJEEP..14..477B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013IJEEP..14..477B"><span id="translatedtitle">Decoupled Control Strategy of Grid Interactive Inverter System with <span class="hlt">Optimal</span> LCL <span class="hlt">Filter</span> Design</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Babu, B. Chitti; Anurag, Anup; Sowmya, Tontepu; Marandi, Debati; Bal, Satarupa</p> <p>2013-09-01</p> <p>This article presents a control strategy for a three-phase grid interactive voltage source inverter that links a renewable energy source to the utility grid through a LCL-type <span class="hlt">filter</span>. An <span class="hlt">optimized</span> LCL-type <span class="hlt">filter</span> has been designed and modeled so as to reduce the current harmonics in the grid, considering the conduction and switching losses at constant modulation index (Ma). The control strategy adopted here decouples the active and reactive power loops, thus achieving desirable performance with independent control of active and reactive power injected into the grid. The startup transients can also be controlled by the implementation of this proposed control strategy: in addition to this, <span class="hlt">optimal</span> LCL <span class="hlt">filter</span> with lesser conduction and switching copper losses as well as core losses. A trade-off has been made between the total losses in the LCL <span class="hlt">filter</span> and the Total Harmonic Distortion (THD%) of the grid current, and the <span class="hlt">filter</span> inductor has been designed accordingly. In order to study the dynamic performance of the system and to confirm the analytical results, the models are simulated in the MATLAB/Simulink environment, and the results are analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1010409','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1010409"><span id="translatedtitle">Design <span class="hlt">Optimization</span> of Vena Cava <span class="hlt">Filters</span>: An application to dual filtration devices</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Singer, M A; Wang, S L; Diachin, D P</p> <p>2009-12-03</p> <p>Pulmonary embolism (PE) is a significant medical problem that results in over 300,000 fatalities per year. A common preventative treatment for PE is the insertion of a metallic <span class="hlt">filter</span> into the inferior vena cava that traps thrombi before they reach the lungs. The goal of this work is to use methods of mathematical modeling and design <span class="hlt">optimization</span> to determine the configuration of trapped thrombi that minimizes the hemodynamic disruption. The resulting configuration has implications for constructing an <span class="hlt">optimally</span> designed vena cava <span class="hlt">filter</span>. Computational fluid dynamics is coupled with a nonlinear <span class="hlt">optimization</span> algorithm to determine the <span class="hlt">optimal</span> configuration of trapped model thrombus in the inferior vena cava. The location and shape of the thrombus are parameterized, and an objective function, based on wall shear stresses, determines the worthiness of a given configuration. The methods are fully automated and demonstrate the capabilities of a design <span class="hlt">optimization</span> framework that is broadly applicable. Changes to thrombus location and shape alter the velocity contours and wall shear stress profiles significantly. For vena cava <span class="hlt">filters</span> that trap two thrombi simultaneously, the undesirable flow dynamics past one thrombus can be mitigated by leveraging the flow past the other thrombus. Streamlining the shape of thrombus trapped along the cava wall reduces the disruption to the flow, but increases the area exposed to abnormal wall shear stress. Computer-based design <span class="hlt">optimization</span> is a useful tool for developing vena cava <span class="hlt">filters</span>. Characterizing and parameterizing the design requirements and constraints is essential for constructing devices that address clinical complications. In addition, formulating a well-defined objective function that quantifies clinical risks and benefits is needed for designing devices that are clinically viable.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006SPIE.6360E..0LB','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006SPIE.6360E..0LB"><span id="translatedtitle"><span class="hlt">Optimal</span> band selection in hyperspectral remote sensing of aquatic benthic features: a wavelet <span class="hlt">filter</span> window approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bostater, Charles R., Jr.</p> <p>2006-09-01</p> <p>This paper describes a wavelet based approach to derivative spectroscopy. The approach is utilized to select, through <span class="hlt">optimization</span>, <span class="hlt">optimal</span> channels or bands to use as derivative based remote sensing algorithms. The approach is applied to airborne and modeled or synthetic reflectance signatures of environmental media and features or objects within such media, such as benthic submerged vegetation canopies. The technique can also applied to selected pixels identified within a hyperspectral image cube obtained from an board an airborne, ground based, or subsurface mobile imaging system. This wavelet based image processing technique is an extremely fast numerical method to conduct higher order derivative spectroscopy which includes nonlinear <span class="hlt">filter</span> windows. Essentially, the wavelet <span class="hlt">filter</span> scans a measured or synthetic signature in an automated sequential manner in order to develop a library of <span class="hlt">filtered</span> spectra. The library is utilized in real time to select the <span class="hlt">optimal</span> channels for direct algorithm application. The unique wavelet based derivative <span class="hlt">filtering</span> technique makes us of a translating, and dilating derivative spectroscopy signal processing (TDDS-SP (R)) approach based upon remote sensing science and radiative transfer processes unlike other signal processing techniques applied to hyperspectral signatures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26569247','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26569247"><span id="translatedtitle"><span class="hlt">Optimization</span> Algorithm for Kalman <span class="hlt">Filter</span> Exploiting the Numerical Characteristics of SINS/GPS Integrated Navigation Systems.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hu, Shaoxing; Xu, Shike; Wang, Duhu; Zhang, Aiwu</p> <p>2015-01-01</p> <p>Aiming at addressing the problem of high computational cost of the traditional Kalman <span class="hlt">filter</span> in SINS/GPS, a practical <span class="hlt">optimization</span> algorithm with offline-derivation and parallel processing methods based on the numerical characteristics of the system is presented in this paper. The algorithm exploits the sparseness and/or symmetry of matrices to simplify the computational procedure. Thus plenty of invalid operations can be avoided by offline derivation using a block matrix technique. For enhanced efficiency, a new parallel computational mechanism is established by subdividing and restructuring calculation processes after analyzing the extracted "useful" data. As a result, the algorithm saves about 90% of the CPU processing time and 66% of the memory usage needed in a classical Kalman <span class="hlt">filter</span>. Meanwhile, the method as a numerical approach needs no precise-loss transformation/approximation of system modules and the accuracy suffers little in comparison with the <span class="hlt">filter</span> before computational <span class="hlt">optimization</span>. Furthermore, since no complicated matrix theories are needed, the algorithm can be easily transplanted into other modified <span class="hlt">filters</span> as a secondary <span class="hlt">optimization</span> method to achieve further efficiency. PMID:26569247</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4701286','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4701286"><span id="translatedtitle"><span class="hlt">Optimization</span> Algorithm for Kalman <span class="hlt">Filter</span> Exploiting the Numerical Characteristics of SINS/GPS Integrated Navigation Systems</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hu, Shaoxing; Xu, Shike; Wang, Duhu; Zhang, Aiwu</p> <p>2015-01-01</p> <p>Aiming at addressing the problem of high computational cost of the traditional Kalman <span class="hlt">filter</span> in SINS/GPS, a practical <span class="hlt">optimization</span> algorithm with offline-derivation and parallel processing methods based on the numerical characteristics of the system is presented in this paper. The algorithm exploits the sparseness and/or symmetry of matrices to simplify the computational procedure. Thus plenty of invalid operations can be avoided by offline derivation using a block matrix technique. For enhanced efficiency, a new parallel computational mechanism is established by subdividing and restructuring calculation processes after analyzing the extracted “useful” data. As a result, the algorithm saves about 90% of the CPU processing time and 66% of the memory usage needed in a classical Kalman <span class="hlt">filter</span>. Meanwhile, the method as a numerical approach needs no precise-loss transformation/approximation of system modules and the accuracy suffers little in comparison with the <span class="hlt">filter</span> before computational <span class="hlt">optimization</span>. Furthermore, since no complicated matrix theories are needed, the algorithm can be easily transplanted into other modified <span class="hlt">filters</span> as a secondary <span class="hlt">optimization</span> method to achieve further efficiency. PMID:26569247</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23664450','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23664450"><span id="translatedtitle">Global localization of 3D anatomical structures by pre-<span class="hlt">filtered</span> Hough forests and discrete <span class="hlt">optimization</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Donner, René; Menze, Bjoern H; Bischof, Horst; Langs, Georg</p> <p>2013-12-01</p> <p>The accurate localization of anatomical landmarks is a challenging task, often solved by domain specific approaches. We propose a method for the automatic localization of landmarks in complex, repetitive anatomical structures. The key idea is to combine three <span class="hlt">steps</span>: (1) a classifier for pre-<span class="hlt">filtering</span> anatomical landmark positions that (2) are refined through a Hough regression model, together with (3) a parts-based model of the global landmark topology to select the final landmark positions. During training landmarks are annotated in a set of example volumes. A classifier learns local landmark appearance, and Hough regressors are trained to aggregate neighborhood information to a precise landmark coordinate position. A non-parametric geometric model encodes the spatial relationships between the landmarks and derives a topology which connects mutually predictive landmarks. During the global search we classify all voxels in the query volume, and perform regression-based agglomeration of landmark probabilities to highly accurate and specific candidate points at potential landmark locations. We encode the candidates' weights together with the conformity of the connecting edges to the learnt geometric model in a Markov Random Field (MRF). By solving the corresponding discrete <span class="hlt">optimization</span> problem, the most probable location for each model landmark is found in the query volume. We show that this approach is able to consistently localize the model landmarks despite the complex and repetitive character of the anatomical structures on three challenging data sets (hand radiographs, hand CTs, and whole body CTs), with a median localization error of 0.80 mm, 1.19 mm and 2.71 mm, respectively. PMID:23664450</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/6632838','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/6632838"><span id="translatedtitle">An <span class="hlt">optimal</span> linear <span class="hlt">filter</span> for the reduction of noise superimposed to the EEG signal.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bartoli, F; Cerutti, S</p> <p>1983-10-01</p> <p>In the present paper a procedure for the reduction of super-imposed noise on EEG tracings is described, which makes use of linear digital <span class="hlt">filtering</span> and identification methods. In particular, an <span class="hlt">optimal</span> <span class="hlt">filter</span> (a Kalman <span class="hlt">filter</span>) has been developed which is intended to capture the disturbances of the electromyographic noise on the basis of an a priori modelling which considers a series of impulses with a temporal occurrence according to a Poisson distribution as a noise generating mechanism. The experimental results refer to the EEG tracings recorded from 20 patients in normal resting conditions: the procedure consists of a preprocessing phase (which uses also a low-pass FIR digital <span class="hlt">filter</span>), followed by the implementation of the identification and the Kalman <span class="hlt">filter</span>. The performance of the <span class="hlt">filters</span> is satisfactory also from the clinical standpoint, obtaining a marked reduction of noise without distorting the useful information contained in the signal. Furthermore, when using the introduced method, the EEG signal generating mechanism is accordingly parametrized as AR/ARMA models, thus obtaining an extremely sensitive feature extraction with interesting and not yet completely studied pathophysiological meanings. The above procedure may find a general application in the field of noise reduction and the better enhancement of information contained in the wide set of biological signals. PMID:6632838</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25312927','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25312927"><span id="translatedtitle">Hair enhancement in dermoscopic images using dual-channel quaternion tubularness <span class="hlt">filters</span> and MRF-based multilabel <span class="hlt">optimization</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mirzaalian, Hengameh; Lee, Tim K; Hamarneh, Ghassan</p> <p>2014-12-01</p> <p>Hair occlusion is one of the main challenges facing automatic lesion segmentation and feature extraction for skin cancer applications. We propose a novel method for simultaneously enhancing both light and dark hairs with variable widths, from dermoscopic images, without the prior knowledge of the hair color. We measure hair tubularness using a quaternion color curvature <span class="hlt">filter</span>. We extract <span class="hlt">optimal</span> hair features (tubularness, scale, and orientation) using Markov random field theory and multilabel <span class="hlt">optimization</span>. We also develop a novel dual-channel matched <span class="hlt">filter</span> to enhance hair pixels in the dermoscopic images while suppressing irrelevant skin pixels. We evaluate the hair enhancement capabilities of our method on hair-occluded images generated via our new hair simulation algorithm. Since hair enhancement is an intermediate <span class="hlt">step</span> in a computer-aided diagnosis system for analyzing dermoscopic images, we validate our method and compare it to other methods by studying its effect on: 1) hair segmentation accuracy; 2) image inpainting quality; and 3) image classification accuracy. The validation results on 40 real clinical dermoscopic images and 94 synthetic data demonstrate that our approach outperforms competing hair enhancement methods. PMID:25312927</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20150009149&hterms=decompose&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Ddecompose','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20150009149&hterms=decompose&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Ddecompose"><span id="translatedtitle"><span class="hlt">Optimized</span> FPGA Implementation of Multi-Rate FIR <span class="hlt">Filters</span> Through Thread Decomposition</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zheng, Jason Xin; Nguyen, Kayla; He, Yutao</p> <p>2010-01-01</p> <p>Multirate (decimation/interpolation) <span class="hlt">filters</span> are among the essential signal processing components in spaceborne instruments where Finite Impulse Response (FIR) <span class="hlt">filters</span> are often used to minimize nonlinear group delay and finite-precision effects. Cascaded (multi-stage) designs of Multi-Rate FIR (MRFIR) <span class="hlt">filters</span> are further used for large rate change ratio, in order to lower the required throughput while simultaneously achieving comparable or better performance than single-stage designs. Traditional representation and implementation of MRFIR employ polyphase decomposition of the original <span class="hlt">filter</span> structure, whose main purpose is to compute only the needed output at the lowest possible sampling rate. In this paper, an alternative representation and implementation technique, called TD-MRFIR (Thread Decomposition MRFIR), is presented. The basic idea is to decompose MRFIR into output computational threads, in contrast to a structural decomposition of the original <span class="hlt">filter</span> as done in the polyphase decomposition. Each thread represents an instance of the finite convolution required to produce a single output of the MRFIR. The <span class="hlt">filter</span> is thus viewed as a finite collection of concurrent threads. The technical details of TD-MRFIR will be explained, first showing its applicability to the implementation of downsampling, upsampling, and resampling FIR <span class="hlt">filters</span>, and then describing a general strategy to <span class="hlt">optimally</span> allocate the number of <span class="hlt">filter</span> taps. A particular FPGA design of multi-stage TD-MRFIR for the L-band radar of NASA's SMAP (Soil Moisture Active Passive) instrument is demonstrated; and its implementation results in several targeted FPGA devices are summarized in terms of the functional (bit width, fixed-point error) and performance (time closure, resource usage, and power estimation) parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21413209','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21413209"><span id="translatedtitle"><span class="hlt">Optimal</span> configurations of <span class="hlt">filter</span> cavity in future gravitational-wave detectors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Khalili, F. Ya.</p> <p>2010-06-15</p> <p>Sensitivity of future laser interferometric gravitational wave detectors can be improved using squeezed light with frequency-dependent squeeze angle and/or amplitude, which can be created using additional so-called <span class="hlt">filter</span> cavities. Here we compare performances of several variants of this scheme, proposed during the last few years, assuming the case of a single relatively short (tens of meters) <span class="hlt">filter</span> cavity suitable for implementation already during the life cycle of the second-generation detectors, like Advanced LIGO. Using numerical <span class="hlt">optimization</span>, we show that the phase <span class="hlt">filtering</span> scheme proposed by Kimble et al [H. J. Kimble, Yu. Levin, A. B. Matsko, K. S. Thorne, and S. P. Vyatchanin, Phys. Rev. D 65, 022002 (2001).] looks like the best candidate for this scenario.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ITEIS.132.1066T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ITEIS.132.1066T"><span id="translatedtitle">Design of FIR <span class="hlt">Filters</span> with Discrete Coefficients using Ant Colony <span class="hlt">Optimization</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsutsumi, Shuntaro; Suyama, Kenji</p> <p></p> <p>In this paper, we propose a new design method for linear phase FIR (Finite Impulse Response) <span class="hlt">filters</span> with discrete coefficients. In a hardware implementation, <span class="hlt">filter</span> coefficients must be represented as discrete values. The design problem of digital <span class="hlt">filters</span> with discrete coefficients is formulated as the integer programming problem. Then, an enormous amount of computational time is required to solve the problem in a strict solver. Recently, ACO (Ant Colony <span class="hlt">Optimization</span>) which is one heuristic approach, is used widely for solving combinational problem like the traveling salesman problem. In our method, we formulate the design problem as the 0-1 integer programming problem and solve it by using the ACO. Several design examples are shown to present effectiveness of the proposed method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009ITEIS.129...59O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009ITEIS.129...59O"><span id="translatedtitle"><span class="hlt">Optimal</span> Design of CSD Coefficient FIR <span class="hlt">Filters</span> Subject to Number of Nonzero Digits</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ozaki, Yuichi; Suyama, Kenji</p> <p></p> <p>In a hardware implementation of FIR(Finite Impulse Response) digital <span class="hlt">filters</span>, it is desired to reduce a total number of nonzero digits used for a representation of <span class="hlt">filter</span> coefficients. In general, a design problem of FIR <span class="hlt">filters</span> with CSD(Canonic Signed Digit) representation, which is efficient one for the reduction of numbers of multiplier units, is often considered as one of the 0-1 combinational problems. In such the problem, some difficult constraints make us prevent to linearize the problem. Although many kinds of heuristic approaches have been applied to solve the problem, the solution obtained by such a manner could not guarantee its <span class="hlt">optimality</span>. In this paper, we attempt to formulate the design problem as the 0-1 mixed integer linear programming problem and solve it by using the branch and bound technique, which is a powerful method for solving integer programming problem. Several design examples are shown to present an efficient performance of the proposed method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4712810','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4712810"><span id="translatedtitle">Fishing for drifts: detecting buoyancy changes of a top marine predator using a <span class="hlt">step</span>-wise <span class="hlt">filtering</span> method</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gordine, Samantha Alex; Fedak, Michael; Boehme, Lars</p> <p>2015-01-01</p> <p>ABSTRACT In southern elephant seals (Mirounga leonina), fasting- and foraging-related fluctuations in body composition are reflected by buoyancy changes. Such buoyancy changes can be monitored by measuring changes in the rate at which a seal drifts passively through the water column, i.e. when all active swimming motion ceases. Here, we present an improved knowledge-based method for detecting buoyancy changes from compressed and abstracted dive profiles received through telemetry. By <span class="hlt">step</span>-wise <span class="hlt">filtering</span> of the dive data, the developed algorithm identifies fragments of dives that correspond to times when animals drift. In the dive records of 11 southern elephant seals from South Georgia, this <span class="hlt">filtering</span> method identified 0.8–2.2% of all dives as drift dives, indicating large individual variation in drift diving behaviour. The obtained drift rate time series exhibit that, at the beginning of each migration, all individuals were strongly negatively buoyant. Over the following 75–150 days, the buoyancy of all individuals peaked close to or at neutral buoyancy, indicative of a seal's foraging success. Independent verification with visually inspected detailed high-resolution dive data confirmed that this method is capable of reliably detecting buoyancy changes in the dive records of drift diving species using abstracted data. This also affirms that abstracted dive profiles convey the geometric shape of drift dives in sufficient detail for them to be identified. Further, it suggests that, using this <span class="hlt">step</span>-wise <span class="hlt">filtering</span> method, buoyancy changes could be detected even in old datasets with compressed dive information, for which conventional drift dive classification previously failed. PMID:26486362</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26486362','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26486362"><span id="translatedtitle">Fishing for drifts: detecting buoyancy changes of a top marine predator using a <span class="hlt">step</span>-wise <span class="hlt">filtering</span> method.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gordine, Samantha Alex; Fedak, Michael; Boehme, Lars</p> <p>2015-12-01</p> <p>In southern elephant seals (Mirounga leonina), fasting- and foraging-related fluctuations in body composition are reflected by buoyancy changes. Such buoyancy changes can be monitored by measuring changes in the rate at which a seal drifts passively through the water column, i.e. when all active swimming motion ceases. Here, we present an improved knowledge-based method for detecting buoyancy changes from compressed and abstracted dive profiles received through telemetry. By <span class="hlt">step</span>-wise <span class="hlt">filtering</span> of the dive data, the developed algorithm identifies fragments of dives that correspond to times when animals drift. In the dive records of 11 southern elephant seals from South Georgia, this <span class="hlt">filtering</span> method identified 0.8-2.2% of all dives as drift dives, indicating large individual variation in drift diving behaviour. The obtained drift rate time series exhibit that, at the beginning of each migration, all individuals were strongly negatively buoyant. Over the following 75-150 days, the buoyancy of all individuals peaked close to or at neutral buoyancy, indicative of a seal's foraging success. Independent verification with visually inspected detailed high-resolution dive data confirmed that this method is capable of reliably detecting buoyancy changes in the dive records of drift diving species using abstracted data. This also affirms that abstracted dive profiles convey the geometric shape of drift dives in sufficient detail for them to be identified. Further, it suggests that, using this <span class="hlt">step</span>-wise <span class="hlt">filtering</span> method, buoyancy changes could be detected even in old datasets with compressed dive information, for which conventional drift dive classification previously failed. PMID:26486362</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26724066','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26724066"><span id="translatedtitle">Design and <span class="hlt">optimization</span> of a harmonic probe with <span class="hlt">step</span> cross section in multifrequency atomic force microscopy.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cai, Jiandong; Wang, Michael Yu; Zhang, Li</p> <p>2015-12-01</p> <p>In multifrequency atomic force microscopy (AFM), probe's characteristic of assigning resonance frequencies to integer harmonics results in a remarkable improvement of detection sensitivity at specific harmonic components. The selection criterion of harmonic order is based on its amplitude's sensitivity on material properties, e.g., elasticity. Previous studies on designing harmonic probe are unable to provide a large design capability along with maintaining the structural integrity. Herein, we propose a harmonic probe with <span class="hlt">step</span> cross section, in which it has variable width in top and bottom <span class="hlt">steps</span>, while the middle <span class="hlt">step</span> in cross section is kept constant. Higher order resonance frequencies are tailored to be integer times of fundamental resonance frequency. The probe design is implemented within a structural <span class="hlt">optimization</span> framework. The <span class="hlt">optimally</span> designed probe is micromachined using focused ion beam milling technique, and then measured with an AFM. The measurement results agree well with our resonance frequency assignment requirement. PMID:26724066</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22482666','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22482666"><span id="translatedtitle">Design and <span class="hlt">optimization</span> of a harmonic probe with <span class="hlt">step</span> cross section in multifrequency atomic force microscopy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cai, Jiandong; Zhang, Li; Wang, Michael Yu</p> <p>2015-12-15</p> <p>In multifrequency atomic force microscopy (AFM), probe’s characteristic of assigning resonance frequencies to integer harmonics results in a remarkable improvement of detection sensitivity at specific harmonic components. The selection criterion of harmonic order is based on its amplitude’s sensitivity on material properties, e.g., elasticity. Previous studies on designing harmonic probe are unable to provide a large design capability along with maintaining the structural integrity. Herein, we propose a harmonic probe with <span class="hlt">step</span> cross section, in which it has variable width in top and bottom <span class="hlt">steps</span>, while the middle <span class="hlt">step</span> in cross section is kept constant. Higher order resonance frequencies are tailored to be integer times of fundamental resonance frequency. The probe design is implemented within a structural <span class="hlt">optimization</span> framework. The <span class="hlt">optimally</span> designed probe is micromachined using focused ion beam milling technique, and then measured with an AFM. The measurement results agree well with our resonance frequency assignment requirement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015RScI...86l5007C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015RScI...86l5007C"><span id="translatedtitle">Design and <span class="hlt">optimization</span> of a harmonic probe with <span class="hlt">step</span> cross section in multifrequency atomic force microscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cai, Jiandong; Wang, Michael Yu; Zhang, Li</p> <p>2015-12-01</p> <p>In multifrequency atomic force microscopy (AFM), probe's characteristic of assigning resonance frequencies to integer harmonics results in a remarkable improvement of detection sensitivity at specific harmonic components. The selection criterion of harmonic order is based on its amplitude's sensitivity on material properties, e.g., elasticity. Previous studies on designing harmonic probe are unable to provide a large design capability along with maintaining the structural integrity. Herein, we propose a harmonic probe with <span class="hlt">step</span> cross section, in which it has variable width in top and bottom <span class="hlt">steps</span>, while the middle <span class="hlt">step</span> in cross section is kept constant. Higher order resonance frequencies are tailored to be integer times of fundamental resonance frequency. The probe design is implemented within a structural <span class="hlt">optimization</span> framework. The <span class="hlt">optimally</span> designed probe is micromachined using focused ion beam milling technique, and then measured with an AFM. The measurement results agree well with our resonance frequency assignment requirement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009MSSP...23..652C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009MSSP...23..652C"><span id="translatedtitle"><span class="hlt">Optimal</span> <span class="hlt">filtering</span> of gear signals for early damage detection based on the spectral kurtosis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Combet, F.; Gelman, L.</p> <p>2009-04-01</p> <p>In this paper, we propose a methodology for the enhancement of small transients in gear vibration signals in order to detect local tooth faults, such as pitting, at an early stage of damage. We propose to apply the <span class="hlt">optimal</span> denoising (Wiener) <span class="hlt">filter</span> based on the spectral kurtosis (SK). The originality is to estimate and apply this <span class="hlt">filter</span> to the gear residual signal, as classically obtained after removing the mesh harmonics from the time synchronous average (TSA). This presents several advantages over the direct estimation from the raw vibration signal: improved signal/noise ratio, reduced interferences from other stages of the gearbox and easier detection of excited structural resonance(s) within the range of the mesh harmonic components. From the SK-based <span class="hlt">filtered</span> residual signal, called SK-residual, we define the local power as the smoothed squared envelope, which reflects both the energy and the degree of non-stationarity of the fault-induced transients. The methodology is then applied to an industrial case and shows the possibility of detection of relatively small tooth surface pitting (less than 10%) in a two-stage helical reduction gearbox. The adjustment of the resolution for the SK estimation appears to be <span class="hlt">optimal</span> when the length of the analysis window is approximately matched with the mesh period of the gear. The proposed approach is also compared to an inverse <span class="hlt">filtering</span> (blind deconvolution) approach. However, the latter turns out to be more unstable and sensitive to noise and shows a lower degree of separation, quantified by the Fisher criterion, between the estimated diagnostic features in the pitted and unpitted cases. Thus, the proposed <span class="hlt">optimal</span> <span class="hlt">filtering</span> methodology based on the SK appears to be well adapted for the early detection of local tooth damage in gears.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24388927','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24388927"><span id="translatedtitle">A two-<span class="hlt">step</span> crushed lava rock <span class="hlt">filter</span> unit for grey water treatment at household level in an urban slum.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Katukiza, A Y; Ronteltap, M; Niwagaba, C B; Kansiime, F; Lens, P N L</p> <p>2014-01-15</p> <p>Decentralised grey water treatment in urban slums using low-cost and robust technologies offers opportunities to minimise public health risks and to reduce environmental pollution caused by the highly polluted grey water i.e. with a COD and N concentration of 3000-6000 mg L(-1) and 30-40 mg L(-1), respectively. However, there has been very limited action research to reduce the pollution load from uncontrolled grey water discharge by households in urban slums. This study was therefore carried out to investigate the potential of a two-<span class="hlt">step</span> filtration process to reduce the grey water pollution load in an urban slum using a crushed lava rock <span class="hlt">filter</span>, to determine the main <span class="hlt">filter</span> design and operation parameters and the effect of intermittent flow on the grey water effluent quality. A two-<span class="hlt">step</span> crushed lava rock <span class="hlt">filter</span> unit was designed and implemented for use by a household in the Bwaise III slum in Kampala city (Uganda). It was monitored at a varying hydraulic loading rate (HLR) of 0.5-1.1 m d(-1) as well as at a constant HLR of 0.39 m d(-1). The removal efficiencies of COD, TP and TKN were, respectively, 85.9%, 58% and 65.5% under a varying HLR and 90.5%, 59.5% and 69%, when operating at a constant HLR regime. In addition, the log removal of Escherichia coli, Salmonella spp. and total coliforms was, respectively, 3.8, 3.2 and 3.9 under the varying HLR and 3.9, 3.5 and 3.9 at a constant HLR. The results show that the use of a two-<span class="hlt">step</span> filtration process as well as a lower constant HLR increased the pollutant removal efficiencies. Further research is needed to investigate the feasibility of adding a tertiary treatment <span class="hlt">step</span> to increase the nutrients and microorganisms removal from grey water. PMID:24388927</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25898578','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25898578"><span id="translatedtitle">[<span class="hlt">Optimization</span> of one-<span class="hlt">step</span> pelletization technology of Jiuwei Xifeng granules by response surface methodology].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Xiu-hai; Yang, Xu-fang; Fan, Ye-wen; Zhang, Yan-jun; Xu, Zhong-kun; Yang, Lin-yong; Wang, Zhen-zhong; Xiao, Wei</p> <p>2014-12-01</p> <p>Using the qualified rates of particles as the evaluation indexes, the impact tactors of one-<span class="hlt">step</span> pelletization technology of Jiuwei Xifeng granules were selected from six factors by the Plackett-Burman experimental design and the levels of non-significant factors were identified. According to the Plackett-Burman experimental design, choosing the qualified rates of particles and angle of repose as the evaluation indexes, three levels of the three factors were selected by Box-Behnken of central composite design to <span class="hlt">optimize</span> the experimental. The best conditions were as follows: the fluid extract was sprayed with frequency of 29 r . min-1, inlet air temperature was 90 °C, the frequency of fan was 34 Hz. Under the response surface methodology <span class="hlt">optimized</span> scheme, the average experimental results are similar to the predicted values, and surface methodology could be used in the <span class="hlt">optimization</span> of one-<span class="hlt">step</span> pelletization for Chinese materia medica. PMID:25898578</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950028531&hterms=discrimination&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddiscrimination','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950028531&hterms=discrimination&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddiscrimination"><span id="translatedtitle"><span class="hlt">Optimizing</span> binary phase and amplitude <span class="hlt">filters</span> for PCE, SNR, and discrimination</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Downie, John D.</p> <p>1992-01-01</p> <p>Binary phase-only <span class="hlt">filters</span> (BPOFs) have generated much study because of their implementation on currently available spatial light modulator devices. On polarization-rotating devices such as the magneto-optic spatial light modulator (SLM), it is also possible to encode binary amplitude information into two SLM transmission states, in addition to the binary phase information. This is done by varying the rotation angle of the polarization analyzer following the SLM in the optical train. Through this parameter, a continuum of <span class="hlt">filters</span> may be designed that span the space of binary phase and amplitude <span class="hlt">filters</span> (BPAFs) between BPOFs and binary amplitude <span class="hlt">filters</span>. In this study, we investigate the design of <span class="hlt">optimal</span> BPAFs for the key correlation characteristics of peak sharpness (through the peak-to-correlation energy (PCE) metric), signal-to-noise ratio (SNR), and discrimination between in-class and out-of-class images. We present simulation results illustrating improvements obtained over conventional BPOFs, and trade-offs between the different performance criteria in terms of the <span class="hlt">filter</span> design parameter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000053101','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000053101"><span id="translatedtitle">Multi-Bandwidth Frequency Selective Surfaces for Near Infrared <span class="hlt">Filtering</span>: Design and <span class="hlt">Optimization</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cwik, Tom; Fernandez, Salvador; Ksendzov, A.; LaBaw, Clayton C.; Maker, Paul D.; Muller, Richard E.</p> <p>1998-01-01</p> <p>Frequency selective surfaces are widely used in the microwave and millimeter wave regions of the spectrum for <span class="hlt">filtering</span> signals. They are used in telecommunication systems for multi-frequency operation or in instrument detectors for spectroscopy. The frequency selective surface operation depends on a periodic array of elements resonating at prescribed wavelengths producing a <span class="hlt">filter</span> response. The size of the elements is on the order of half the electrical wavelength, and the array period is typically less than a wavelength for efficient operation. When operating in the optical region, diffraction gratings are used for <span class="hlt">filtering</span>. In this regime the period of the grating may be several wavelengths producing multiple orders of light in reflection or transmission. In regions between these bands (specifically in the infrared band) frequency selective <span class="hlt">filters</span> consisting of patterned metal layers fabricated using electron beam lithography are beginning to be developed. The operation is completely analogous to surfaces made in the microwave and millimeter wave region except for the choice of materials used and the fabrication process. In addition, the lithography process allows an arbitrary distribution of patterns corresponding to resonances at various wavelengths to be produced. The design of sub-millimeter <span class="hlt">filters</span> follows the design methods used in the microwave region. Exacting modal matching, integral equation or finite element methods can be used for design. A major difference though is the introduction of material parameters and thicknesses that may not be important in longer wavelength designs. This paper describes the design of multi- bandwidth <span class="hlt">filters</span> operating in the 1-5 micrometer wavelength range. This work follows on a previous design. In this paper extensions based on further <span class="hlt">optimization</span> and an examination of the specific shape of the element in the periodic cell will be reported. Results from the design, manufacture and test of linear wedge <span class="hlt">filters</span> built using microlithographic techniques and used in spectral imaging applications will be presented.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20050123787&hterms=selective+surface&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dselective%2Bsurface','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20050123787&hterms=selective+surface&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dselective%2Bsurface"><span id="translatedtitle">Multi-Bandwidth Frequency Selective Surfaces for Near Infrared <span class="hlt">Filtering</span>: Design and <span class="hlt">Optimization</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cwik, Tom; Fernandez, Salvador; Ksendzov, A.; LaBaw, Clayton C.; Maker, Paul D.; Muller, Richard E.</p> <p>1999-01-01</p> <p>Frequency selective surfaces are widely used in the microwave and millimeter wave regions of the spectrum for <span class="hlt">filtering</span> signals. They are used in telecommunication systems for multi-frequency operation or in instrument detectors for spectroscopy. The frequency selective surface operation depends on a periodic array of elements resonating at prescribed wavelengths producing a <span class="hlt">filter</span> response. The size of the elements is on the order of half the electrical wavelength, and the array period is typically less than a wavelength for efficient operation. When operating in the optical region, diffraction gratings are used for <span class="hlt">filtering</span>. In this regime the period of the grating may be several wavelengths producing multiple orders of light in reflection or transmission. In regions between these bands (specifically in the infrared band) frequency selective <span class="hlt">filters</span> consisting of patterned metal layers fabricated using electron beam lithography are beginning to be developed. The operation is completely analogous to surfaces made in the microwave and millimeter wave region except for the choice of materials used and the fabrication process. In addition, the lithography process allows an arbitrary distribution of patterns corresponding to resonances at various wavelengths to be produced. The design of sub-millimeter <span class="hlt">filters</span> follows the design methods used in the microwave region. Exacting modal matching, integral equation or finite element methods can be used for design. A major difference though is the introduction of material parameters and thicknesses tha_ may not be important in longer wavelength designs. This paper describes the design of multi-bandwidth <span class="hlt">filters</span> operating in the I-5 micrometer wavelength range. This work follows on previous design [1,2]. In this paper extensions based on further <span class="hlt">optimization</span> and an examination of the specific shape of the element in the periodic cell will be reported. Results from the design, manufacture and test of linear wedge <span class="hlt">filters</span> built using micro-lithographic techniques and used ir spectral imaging applications will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22285081','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22285081"><span id="translatedtitle">Design and <span class="hlt">optimization</span> of <span class="hlt">stepped</span> austempered ductile iron using characterization techniques</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hernández-Rivera, J.L.; Garay-Reyes, C.G.; Campos-Cambranis, R.E.; Cruz-Rivera, J.J.</p> <p>2013-09-15</p> <p>Conventional characterization techniques such as dilatometry, X-ray diffraction and metallography were used to select and <span class="hlt">optimize</span> temperatures and times for conventional and <span class="hlt">stepped</span> austempering. Austenitization and conventional austempering time was selected when the dilatometry graphs showed a constant expansion value. A special heat color-etching technique was applied to distinguish between the untransformed austenite and high carbon stabilized austenite which had formed during the treatments. Finally, it was found that carbide precipitation was absent during the <span class="hlt">stepped</span> austempering in contrast to conventional austempering, on which carbide evidence was found. - Highlights: • Dilatometry helped to establish austenitization and austempering parameters. • Untransformed austenite was present even for longer processing times. • Ausferrite formed during <span class="hlt">stepped</span> austempering caused important reinforcement effect. • Carbide precipitation was absent during <span class="hlt">stepped</span> treatment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JBO....20e5003W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JBO....20e5003W"><span id="translatedtitle"><span class="hlt">Optimal</span> spectral <span class="hlt">filtering</span> in soliton self-frequency shift for deep-tissue multiphoton microscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Ke; Qiu, Ping</p> <p>2015-05-01</p> <p>Tunable optical solitons generated by soliton self-frequency shift (SSFS) have become valuable tools for multiphoton microscopy (MPM). Recent progress in MPM using 1700 nm excitation enabled visualizing subcortical structures in mouse brain in vivo for the first time. Such an excitation source can be readily obtained by SSFS in a large effective-mode-area photonic crystal rod with a 1550-nm fiber femtosecond laser. A longpass <span class="hlt">filter</span> was typically used to isolate the soliton from the residual in order to avoid excessive energy deposit on the sample, which ultimately leads to optical damage. However, since the soliton was not cleanly separated from the residual, the criterion for choosing the <span class="hlt">optimal</span> <span class="hlt">filtering</span> wavelength is lacking. Here, we propose maximizing the ratio between the multiphoton signal and the n'th power of the excitation pulse energy as a criterion for <span class="hlt">optimal</span> spectral <span class="hlt">filtering</span> in SSFS when the soliton shows dramatic overlapping with the residual. This <span class="hlt">optimization</span> is based on the most efficient signal generation and entirely depends on physical quantities that can be easily measured experimentally. Its application to MPM may reduce tissue damage, while maintaining high signal levels for efficient deep penetration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26517548','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26517548"><span id="translatedtitle">AFM tip characterization by using FFT <span class="hlt">filtered</span> images of <span class="hlt">step</span> structures.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yan, Yongda; Xue, Bo; Hu, Zhenjiang; Zhao, Xuesen</p> <p>2016-01-01</p> <p>The measurement resolution of an atomic force microscope (AFM) is largely dependent on the radius of the tip. Meanwhile, when using AFM to study nanoscale surface properties, the value of the tip radius is needed in calculations. As such, estimation of the tip radius is important for analyzing results taken using an AFM. In this study, a geometrical model created by scanning a <span class="hlt">step</span> structure with an AFM tip was developed. The tip was assumed to have a hemispherical cone shape. Profiles simulated by tips with different scanning radii were calculated by fast Fourier transform (FFT). By analyzing the influence of tip radius variation on the spectra of simulated profiles, it was found that low-frequency harmonics were more susceptible, and that the relationship between the tip radius and the low-frequency harmonic amplitude of the <span class="hlt">step</span> structure varied monotonically. Based on this regularity, we developed a new method to characterize the radius of the hemispherical tip. The tip radii estimated with this approach were comparable to the results obtained using scanning electron microscope imaging and blind reconstruction methods. PMID:26517548</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9034E..1AQ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9034E..1AQ"><span id="translatedtitle">Fast automatic estimation of the <span class="hlt">optimization</span> <span class="hlt">step</span> size for nonrigid image registration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qiao, Y.; Lelieveldt, B. P. F.; Staring, M.</p> <p>2014-03-01</p> <p>Image registration is often used in the clinic, for example during radiotherapy and image-guide surgery, but also for general image analysis. Currently, this process is often very slow, yet for intra-operative procedures the speed is crucial. For intensity-based image registration, a nonlinear <span class="hlt">optimization</span> problem should be solved, usually by (stochastic) gradient descent. This procedure relies on a proper setting of a parameter which controls the <span class="hlt">optimization</span> <span class="hlt">step</span> size. This parameter is difficult to choose manually however, since it depends on the input data, <span class="hlt">optimization</span> metric and transformation model. Previously, the Adaptive Stochastic Gradient Descent (ASGD) method has been proposed that automatically chooses the <span class="hlt">step</span> size, but it comes at high computational cost. In this paper, we propose a new computationally efficient method to automatically determine the <span class="hlt">step</span> size, by considering the observed distribution of the voxel displacements between iterations. A relation between the <span class="hlt">step</span> size and the expectation and variance of the observed distribution is then derived. Experiments have been performed on 3D lung CT data (19 patients) using a nonrigid B-spline transformation model. For all tested dissimilarity metrics (mean squared distance, normalized correlation, mutual information, normalized mutual information), we obtained similar accuracy as ASGD. Compared to ASGD whose estimation time is progressively increasing with the number of parameters, the estimation time of the proposed method is substantially reduced to an almost constant time, from 40 seconds to no more than 1 second when the number of parameters is 105.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SPIE.7490E..1IZ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SPIE.7490E..1IZ"><span id="translatedtitle">An <span class="hlt">optimized</span> item-based collaborative <span class="hlt">filtering</span> recommendation algorithm based on item genre prediction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, De-Jia</p> <p>2009-07-01</p> <p>With the fast development of Internet, many systems have emerged in e-commerce applications to support the product recommendation. Collaborative <span class="hlt">filtering</span> is one of the most promising techniques in recommender systems, providing personalized recommendations to users based on their previously expressed preferences in the form of ratings and those of other similar users. In practice, with the adding of user and item scales, user-item ratings are becoming extremely sparsity and recommender systems utilizing traditional collaborative <span class="hlt">filtering</span> are facing serious challenges. To address the issue, this paper presents an approach to compute item genre similarity, through mapping each item with a corresponding descriptive genre, and computing similarity between genres as similarity, then make basic predictions according to those similarities to lower sparsity of the user-item ratings. After that, item-based collaborative <span class="hlt">filtering</span> <span class="hlt">steps</span> are taken to generate predictions. Compared with previous methods, the presented collaborative <span class="hlt">filtering</span> employs the item genre similarity can alleviate the sparsity issue in the recommender systems, and can improve accuracy of recommendation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930004220','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930004220"><span id="translatedtitle">Implicit application of polynomial <span class="hlt">filters</span> in a k-<span class="hlt">step</span> Arnoldi method</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sorensen, D. C.</p> <p>1990-01-01</p> <p>The Arnoldi process is a well known technique for approximating a few eigenvalues and corresponding eigenvectors of a general square matrix. Numerical difficulties such as loss of orthogonality and assessment of the numerical quality of the approximations as well as a potential for unbounded growth in storage have limited the applicability of the method. These issues are addressed by fixing the number of <span class="hlt">steps</span> in the Arnoldi process at a prescribed value k and then treating the residual vector as a function of the initial Arnoldi vector. This starting vector is then updated through an iterative scheme that is designed to force convergence of the residual to zero. The iterative scheme is shown to be a truncation of the standard implicitly shifted QR-iteration for dense problems and it avoids the need to explicitly restart the Arnoldi sequence. The main emphasis of this paper is on the derivation and analysis of this scheme. However, there are obvious ways to exploit parallelism through the matrix-vector operations that comprise the majority of the work in the algorithm. Preliminary computational results are given for a few problems on some parallel and vector computers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ChPhC..39a8101L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ChPhC..39a8101L"><span id="translatedtitle"><span class="hlt">Optimization</span> of single-<span class="hlt">step</span> tapering amplitude and energy detuning for high-gain FELs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, He-Ting; Jia, Qi-Ka</p> <p>2015-01-01</p> <p>We put forward a method to <span class="hlt">optimize</span> the single-<span class="hlt">step</span> tapering amplitude of undulator strength and initial energy tuning of electron beam to maximize the saturation power of high gain free-electron lasers (FELs), based on the physics of longitudinal electron beam phase space. Using the FEL simulation code GENESIS, we numerically demonstrate the accuracy of the estimations for parameters corresponding to the linac coherent light source and the Tesla test facility.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.5485W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.5485W"><span id="translatedtitle">A Two-<span class="hlt">Step</span> Double <span class="hlt">Filter</span> Method to Extract Open Water Surfaces from Landsat ETM+ Imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Haijing; Kinzelbach, Wolfgang</p> <p>2010-05-01</p> <p>In arid and semi-arid areas, lakes and temporal ponds play a significant role in agriculture and livelihood of local communities as well as in ecology. Monitoring the changes of these open water bodies allows to draw conclusions on water use as well as climatic impacts and can assist in the formulation of a sustainable resource management strategy. The simultaneous monitoring of larger numbers of water bodies with respect to their stage and area is feasible with the aid of remote sensing. Here the monitoring of lake surface areas is discussed. Landsat TM and ETM+ images provide a medium resolution of 30m, and offer an easily available data source to monitor the long term changes of water surfaces in arid and semi-arid regions. In the past great effort was put into developing simple indices to extract water surfaces from satellite images. However, there is a common problem in achieving accurate results with these indices: How to select a threshold value for water pixels without introducing excessive subjective judgment. The threshold value would also have to vary with location, land features and seasons, allowing for inherent uncertainty. A new method was developed using Landsat ETM+ imaginary (30 meter resolution) to extract open water surfaces. This method uses the Normalized Difference of Vegetation Index (NDVI) as the basis for an objective way of selecting threshold values of Modified Normalized Difference of Water Index (MNDWI) and Stress Degree Days (SDD), which were used as a combined <span class="hlt">filter</span> to extract open water surfaces. We choose two study areas to verify the method. One study area is in Northeast China, where bigger lakes, smaller muddy ponds and wetlands are interspersed with agricultural land and salt crusts. The other one is Kafue Flats in Zambia, where seasonal floods of the Zambezi River create seasonal wetlands in addition to the more permanent water ponds and river channels. For both sites digital globe images of 0.5 meter resolution are available, which were taken within a few days of Landsat passing dates and which will serve here as ground truth information. On their basis the new method was compared to other available methods for extracting water pixels. Compared to the other methods, the new method can extract water surface not only from deep lakes/reservoirs and wetlands but also from small mud ponds in alkali flats and irrigation ponds in the fields. For the big and deep lakes, the extracted boundary of the lakes fits accurately the observed boundary. Five test sites in the study area in Northeast China with only shallow water surfaces were chosen and tested. The extracted water surfaces were compared with each site's digital globe maps, respectively to determine the accuracy of the method. The comparison shows that the method could extract all completely wet pixels (water area covering 100% of the pixel area) in all test sites. For partially wet pixels (50-100% of pixel area), the model can detect 91% of all pixels. No dry pixels were mistaken by the model as water pixels. Keywords: Remote sensing, Landsat ETM+ imaginary, Water Surface, NDVI, MNDWI, and SDD</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22413389','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22413389"><span id="translatedtitle">Novel tools for <span class="hlt">stepping</span> source brachytherapy treatment planning: Enhanced geometrical <span class="hlt">optimization</span> and interactive inverse planning</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dinkla, Anna M. Laarse, Rob van der; Koedooder, Kees; Petra Kok, H.; Wieringen, Niek van; Pieters, Bradley R.; Bel, Arjan</p> <p>2015-01-15</p> <p>Purpose: Dose <span class="hlt">optimization</span> for <span class="hlt">stepping</span> source brachytherapy can nowadays be performed using automated inverse algorithms. Although much quicker than graphical <span class="hlt">optimization</span>, an experienced treatment planner is required for both methods. With automated inverse algorithms, the procedure to achieve the desired dose distribution is often based on trial-and-error. Methods: A new approach for <span class="hlt">stepping</span> source prostate brachytherapy treatment planning was developed as a quick and user-friendly alternative. This approach consists of the combined use of two novel tools: Enhanced geometrical <span class="hlt">optimization</span> (EGO) and interactive inverse planning (IIP). EGO is an extended version of the common geometrical <span class="hlt">optimization</span> method and is applied to create a dose distribution as homogeneous as possible. With the second tool, IIP, this dose distribution is tailored to a specific patient anatomy by interactively changing the highest and lowest dose on the contours. Results: The combined use of EGO–IIP was evaluated on 24 prostate cancer patients, by having an inexperienced user create treatment plans, compliant to clinical dose objectives. This user was able to create dose plans of 24 patients in an average time of 4.4 min/patient. An experienced treatment planner without extensive training in EGO–IIP also created 24 plans. The resulting dose-volume histogram parameters were comparable to the clinical plans and showed high conformance to clinical standards. Conclusions: Even for an inexperienced user, treatment planning with EGO–IIP for <span class="hlt">stepping</span> source prostate brachytherapy is feasible as an alternative to current <span class="hlt">optimization</span> algorithms, offering speed, simplicity for the user, and local control of the dose levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.H23C0975L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.H23C0975L"><span id="translatedtitle">Daily Time <span class="hlt">Step</span> Refinement of <span class="hlt">Optimized</span> Flood Control Rule Curves for a Global Warming Scenario</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, S.; Fitzgerald, C.; Hamlet, A. F.; Burges, S. J.</p> <p>2009-12-01</p> <p>Pacific Northwest temperatures have warmed by 0.8 °C since 1920 and are predicted to further increase in the 21st century. Simulated streamflow timing shifts associated with climate change have been found in past research to degrade water resources system performance in the Columbia River Basin when using existing system operating policies. To adapt to these hydrologic changes, <span class="hlt">optimized</span> flood control operating rule curves were developed in a previous study using a hybrid <span class="hlt">optimization</span>-simulation approach which rebalanced flood control and reservoir refill at a monthly time <span class="hlt">step</span>. For the climate change scenario, use of the <span class="hlt">optimized</span> flood control curves restored reservoir refill capability without increasing flood risk. Here we extend the earlier studies using a detailed daily time <span class="hlt">step</span> simulation model applied over a somewhat smaller portion of the domain (encompassing Libby, Duncan, and Corra Linn dams, and Kootenai Lake) to evaluate and refine the <span class="hlt">optimized</span> flood control curves derived from monthly time <span class="hlt">step</span> analysis. Moving from a monthly to daily analysis, we found that the timing of flood control evacuation needed adjustment to avoid unintended outcomes affecting Kootenai Lake. We refined the flood rule curves derived from monthly analysis by creating a more gradual evacuation schedule, but kept the timing and magnitude of maximum evacuation the same as in the monthly analysis. After these refinements, the performance at monthly time scales reported in our previous study proved robust at daily time scales. Due to a decrease in July storage deficits, additional benefits such as more revenue from hydropower generation and more July and August outflow for fish augmentation were observed when the <span class="hlt">optimized</span> flood control curves were used for the climate change scenario.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9808E..3QL','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9808E..3QL"><span id="translatedtitle">Spatial join <span class="hlt">optimization</span> among WFSs based on recursive partitioning and <span class="hlt">filtering</span> rate estimation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lan, Guiwen; Wu, Congcong; Shi, Guangyi; Chen, Qi; Yang, Zhao</p> <p>2015-12-01</p> <p>Spatial join among Web Feature Services (WFS) is time-consuming for most of non-candidate spatial objects may be encoded by GML and transferred to client side. In this paper, an <span class="hlt">optimization</span> strategy is proposed to enhance performance of these joins by <span class="hlt">filtering</span> non-candidate spatial objects as many as possible. By recursive partitioning, the data skew of sub-areas is facilitated to reduce data transmission using spatial semi-join. Moreover <span class="hlt">filtering</span> rate is used to determine whether a spatial semi-join for a sub-area is profitable and choose a suitable execution plan for it. The experimental results show that the proposed strategy is feasible under most circumstances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26736755','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26736755"><span id="translatedtitle">Spatial <span class="hlt">filter</span> and feature selection <span class="hlt">optimization</span> based on EA for multi-channel EEG.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yubo Wang; Mohanarangam, Krithikaa; Mallipeddi, Rammohan; Veluvolu, K C</p> <p>2015-08-01</p> <p>The EEG signals employed for BCI systems are generally band-limited. The band-limited multiple Fourier linear combiner (BMFLC) with Kalman <span class="hlt">filter</span> was developed to obtain amplitude estimates of the EEG signal in a pre-fixed frequency band in real-time. However, the high-dimensionality of the feature vector caused by the application of BMFLC to multi-channel EEG based BCI deteriorates the performance of the classifier. In this work, we apply evolutionary algorithm (EA) to tackle this problem. The real-valued EA encodes both the spatial <span class="hlt">filter</span> and the feature selection into its solution and <span class="hlt">optimizes</span> it with respect to the classification error. Three BMFLC based BCI configurations are proposed. Our results show that the BMFLC-KF with covariance matrix adaptation evolution strategy (CMAES) has the best overall performance. PMID:26736755</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SCPMA..54.1083Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SCPMA..54.1083Z"><span id="translatedtitle">An algorithm for terrain-aided inertial navigation based on nonlinear <span class="hlt">optimal</span> <span class="hlt">filtering</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Long</p> <p>2011-06-01</p> <p>When the initial position error or the altimeter measurement noise is large, the BUAA Inertial Terrain-Aided Navigation (BITAN) algorithm based on extended Kalman <span class="hlt">filtering</span> can not be located accurately. To solve this problem, we propose a modified BITAN algorithm based on nonlinear <span class="hlt">optimal</span> <span class="hlt">filtering</span>. The posterior probability density correction is obtained by using the prior probability density of the system's state transition model and the most recent observations. Hence, the local unobservable system caused by the measurement equation through terrain linearization is avoided. This algorithm is tested by using the digital elevation model and flight data, and is compared with BITAN. Results show that the accuracy of the proposed algorithm is higher than BITAN, and the robustness of the system is improved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26993962','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26993962"><span id="translatedtitle">Transdermal film-loaded finasteride microplates to enhance drug skin permeation: Two-<span class="hlt">step</span> <span class="hlt">optimization</span> study.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ahmed, Tarek A; El-Say, Khalid M</p> <p>2016-06-10</p> <p>The goal was to develop an <span class="hlt">optimized</span> transdermal finasteride (FNS) film loaded with drug microplates (MIC), utilizing two-<span class="hlt">step</span> <span class="hlt">optimization</span>, to decrease the dosing schedule and inconsistency in gastrointestinal absorption. First; 3-level factorial design was implemented to prepare <span class="hlt">optimized</span> FNS-MIC of minimum particle size. Second; Box-Behnken design matrix was used to develop <span class="hlt">optimized</span> transdermal FNS-MIC film. Interaction among MIC components was studied using physicochemical characterization tools. Film components namely; hydroxypropyl methyl cellulose (X1), dimethyl sulfoxide (X2) and propylene glycol (X3) were <span class="hlt">optimized</span> for their effects on the film thickness (Y1) and elongation percent (Y2), and for FNS steady state flux (Y3), permeability coefficient (Y4), and diffusion coefficient (Y5) following ex-vivo permeation through the rat skin. Morphological study of the <span class="hlt">optimized</span> MIC and transdermal film was also investigated. Results revealed that stabilizer concentration and anti-solvent percent were significantly affecting MIC formulation. <span class="hlt">Optimized</span> FNS-MIC of particle size 0.93μm was successfully prepared in which there was no interaction observed among their components. An enhancement in the aqueous solubility of FNS-MIC by more than 23% was achieved. All the studied variables, most of their interaction and quadratic effects were significantly affecting the studied variables (Y1-Y5). Morphological observation illustrated non-spherical, short rods, flakes like small plates that were homogeneously distributed in the <span class="hlt">optimized</span> transdermal film. Ex-vivo study showed enhanced FNS permeation from film loaded MIC when compared to that contains pure drug. So, MIC is a successful technique to enhance aqueous solubility and skin permeation of poor water soluble drug especially when loaded into transdermal films. PMID:26993962</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000PhRvD..61j2001B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000PhRvD..61j2001B"><span id="translatedtitle">?2 testing of <span class="hlt">optimal</span> <span class="hlt">filters</span> for gravitational wave signals: An experimental implementation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baggio, L.; Cerdonio, M.; Ortolan, A.; Vedovato, G.; Taffarello, L.; Zendri, J.-P.; Bonaldi, M.; Falferi, P.; Martinucci, V.; Mezzena, R.; Prodi, G. A.; Vitale, S.</p> <p>2000-05-01</p> <p>We have implemented likelihood testing of the performance of an <span class="hlt">optimal</span> <span class="hlt">filter</span> within the online analysis of AURIGA, a sub-Kelvin resonant-bar gravitational wave detector. We demonstrate the effectiveness of this technique in discriminating between impulsive mechanical excitations of the resonant-bar and other spurious excitations. This technique also ensures the accuracy of the estimated parameters such as the signal-to-noise ratio. The efficiency of the technique to deal with nonstationary noise and its application to data from a network of detectors are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPRS..114...10W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPRS..114...10W"><span id="translatedtitle">Modified patch-based locally <span class="hlt">optimal</span> Wiener method for interferometric SAR phase <span class="hlt">filtering</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Yang; Huang, Haifeng; Dong, Zhen; Wu, Manqing</p> <p>2016-04-01</p> <p>This paper presents a modified patch-based locally <span class="hlt">optimal</span> Wiener (PLOW) method for interferometric synthetic aperture radar (InSAR) phase <span class="hlt">filtering</span>. PLOW is a linear minimum mean squared error (LMMSE) estimator based on a Gaussian additive noise condition. It jointly estimates moments, including mean and covariance, using a non-local technique. By using similarities between image patches, this method can effectively <span class="hlt">filter</span> noise while preserving details. When applied to InSAR phase <span class="hlt">filtering</span>, three modifications are proposed based on spatial variant noise. First, pixels are adaptively clustered according to their coherence magnitudes. Second, rather than a global estimator, a locally adaptive estimator is used to estimate noise covariance. Third, using the coherence magnitudes as weights, the mean of each cluster is estimated, using a weighted mean to further reduce noise. The performance of the proposed method is experimentally verified using simulated and real data. The results of our study demonstrate that the proposed method is on par or better than the non-local interferometric SAR (NL-InSAR) method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20775124','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20775124"><span id="translatedtitle">Continuous intensity map <span class="hlt">optimization</span> (CIMO): A novel approach to leaf sequencing in <span class="hlt">step</span> and shoot IMRT</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cao Daliang; Earl, Matthew A.; Luan, Shuang; Shepard, David M.</p> <p>2006-04-15</p> <p>A new leaf-sequencing approach has been developed that is designed to reduce the number of required beam segments for <span class="hlt">step</span>-and-shoot intensity modulated radiation therapy (IMRT). This approach to leaf sequencing is called continuous-intensity-map-<span class="hlt">optimization</span> (CIMO). Using a simulated annealing algorithm, CIMO seeks to minimize differences between the <span class="hlt">optimized</span> and sequenced intensity maps. Two distinguishing features of the CIMO algorithm are (1) CIMO does not require that each <span class="hlt">optimized</span> intensity map be clustered into discrete levels and (2) CIMO is not rule-based but rather simultaneously <span class="hlt">optimizes</span> both the aperture shapes and weights. To test the CIMO algorithm, ten IMRT patient cases were selected (four head-and-neck, two pancreas, two prostate, one brain, and one pelvis). For each case, the <span class="hlt">optimized</span> intensity maps were extracted from the Pinnacle{sup 3} treatment planning system. The CIMO algorithm was applied, and the <span class="hlt">optimized</span> aperture shapes and weights were loaded back into Pinnacle. A final dose calculation was performed using Pinnacle's convolution/superposition based dose calculation. On average, the CIMO algorithm provided a 54% reduction in the number of beam segments as compared with Pinnacle's leaf sequencer. The plans sequenced using the CIMO algorithm also provided improved target dose uniformity and a reduced discrepancy between the <span class="hlt">optimized</span> and sequenced intensity maps. For ten clinical intensity maps, comparisons were performed between the CIMO algorithm and the power-of-two reduction algorithm of Xia and Verhey [Med. Phys. 25(8), 1424-1434 (1998)]. When the constraints of a Varian Millennium multileaf collimator were applied, the CIMO algorithm resulted in a 26% reduction in the number of segments. For an Elekta multileaf collimator, the CIMO algorithm resulted in a 67% reduction in the number of segments. An average leaf sequencing time of less than one minute per beam was observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPhCS.645a2018C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPhCS.645a2018C"><span id="translatedtitle">Towards <span class="hlt">Optimal</span> <span class="hlt">Filtering</span> on ARM for ATLAS Tile Calorimeter Front-End Processing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cox, Mitchell A.</p> <p>2015-10-01</p> <p>The Large Hadron Collider at CERN generates enormous amounts of raw data which presents a serious computing challenge. After planned upgrades in 2022, the data output from the ATLAS Tile Calorimeter will increase by 200 times to over 40 Tb/s. Advanced and characteristically expensive Digital Signal Processors (DSPs) and Field Programmable Gate Arrays (FPGAs) are currently used to process this quantity of data. It is proposed that a cost- effective, high data throughput Processing Unit (PU) can be developed by using several ARM System on Chips in a cluster configuration to allow aggregated processing performance and data throughput while maintaining minimal software design difficulty for the end-user. ARM is a cost effective and energy efficient alternative CPU architecture to the long established x86 architecture. This PU could be used for a variety of high-level algorithms on the high data throughput raw data. An <span class="hlt">Optimal</span> <span class="hlt">Filtering</span> algorithm has been implemented in C++ and several ARM platforms have been tested. <span class="hlt">Optimal</span> <span class="hlt">Filtering</span> is currently used in the ATLAS Tile Calorimeter front-end for basic energy reconstruction and is currently implemented on DSPs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JHyd..514..249R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JHyd..514..249R"><span id="translatedtitle"><span class="hlt">Optimal</span> hydrograph separation <span class="hlt">filter</span> to evaluate transport routines of hydrological models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rimmer, Alon; Hartmann, Andreas</p> <p>2014-06-01</p> <p>Hydrograph separation (HS) using recursive digital <span class="hlt">filter</span> approaches focuses on trying to distinguish between the rapidly occurring discharge components like surface runoff, and the slowly changing discharge originating from interflow and groundwater. <span class="hlt">Filter</span> approaches are mathematical procedures, which perform the HS using a set of separation parameters. The first goal of this study is to minimize the subjective influence that a user of the <span class="hlt">filter</span> technique exerts on the results by the choice of such <span class="hlt">filter</span> parameters. A simple <span class="hlt">optimal</span> HS (OHS) technique for the estimation of the separation parameters was introduced, relying on measured stream hydrochemistry. The second goal is to use the OHS parameters to benchmark the performance of process-based hydro-geochemical (HG) models. The new HG routine can be used to quantify the degree of knowledge that the stream flow time series itself contributes to the HG analysis, using newly developed benchmark geochemistry efficiency (BGE). Results of the OHS show that the two HS fractions (“rapid” and “slow”) differ according to the HG substances which were selected. The BFImax parameter (long-term ratio of baseflow to total streamflow) ranged from 0.26 to 0.94 for SO4-2 and total suspended solids, TSS, respectively. Then, predictions of SO4-2 transport from a process-based hydrological model were benchmarked with the proposed HG routine, in order to evaluate the significance of the HG routines in the process-based model. This comparison provides valuable quality test that would not be obvious when using the traditional measures like r2 or the NSE (Nash-Sutcliffe efficiency). The process-based model resulted in r2 = 0.65 and NSE = 0.65, while the benchmark routine results were slightly lower with r2 = 0.61 and NSE = 0.58. However, the comparison between the two model resulted in obvious advantage for the process-based model with BGE = 0.15.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26575920','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26575920"><span id="translatedtitle">Automated Discovery of Elementary Chemical Reaction <span class="hlt">Steps</span> Using Freezing String and Berny <span class="hlt">Optimization</span> Methods.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Suleimanov, Yury V; Green, William H</p> <p>2015-09-01</p> <p>We present a simple protocol which allows fully automated discovery of elementary chemical reaction <span class="hlt">steps</span> using in cooperation double- and single-ended transition-state <span class="hlt">optimization</span> algorithms--the freezing string and Berny <span class="hlt">optimization</span> methods, respectively. To demonstrate the utility of the proposed approach, the reactivity of several single-molecule systems of combustion and atmospheric chemistry importance is investigated. The proposed algorithm allowed us to detect without any human intervention not only "known" reaction pathways, manually detected in the previous studies, but also new, previously "unknown", reaction pathways which involve significant atom rearrangements. We believe that applying such a systematic approach to elementary reaction path finding will greatly accelerate the discovery of new chemistry and will lead to more accurate computer simulations of various chemical processes. PMID:26575920</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009IJTPE.129..733K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009IJTPE.129..733K"><span id="translatedtitle">Determination Method for <span class="hlt">Optimal</span> Installation of Active <span class="hlt">Filters</span> in Distribution Network with Distributed Generation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kawasaki, Shoji; Hayashi, Yasuhiro; Matsuki, Junya; Kikuya, Hirotaka; Hojo, Masahide</p> <p></p> <p>Recently, the harmonic troubles in a distribution network are worried in the background of the increase of the connection of distributed generation (DG) and the spread of the power electronics equipments. As one of the strategies, control the harmonic voltage by installing an active <span class="hlt">filter</span> (AF) has been researched. In this paper, the authors propose a computation method to determine the <span class="hlt">optimal</span> allocations, gains and installation number of AFs so as to minimize the maximum value of voltage total harmonic distortion (THD) for a distribution network with DGs. The developed method is based on particle swarm <span class="hlt">optimization</span> (PSO) which is one of the nonlinear <span class="hlt">optimization</span> methods. Especially, in this paper, the case where the harmonic voltage or the harmonic current in a distribution network is assumed by connecting many DGs through the inverters, and the authors propose a determination method of the <span class="hlt">optimal</span> allocation and gain of AF that has the harmonic restrictive effect in the whole distribution network. Moreover, the authors propose also about a determination method of the necessary minimum installation number of AFs, by taking into consideration also about the case where the target value of harmonic suppression cannot be reached, by one set only of AF. In order to verify the validity and effectiveness of the proposed method, the numerical simulations are carried out by using an analytical model of distribution network with DGs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16293280','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16293280"><span id="translatedtitle">Development of a reliable alkaline wastewater treatment process: <span class="hlt">optimization</span> of the pre-treatment <span class="hlt">step</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Prisciandaro, M; Mazziotti di Celso, G; Vegliò, F</p> <p>2005-12-01</p> <p>Alkaline waters produced by caprolactam plants polymerizing the fibres of nylon-6 are characterized by a very high alkalinity, salinity and COD values, in addition to the presence of recalcitrant organic molecules. These characteristics make alkaline wastewaters very difficult to treat; so the development of the suitable sequence to carry out in a depuration process appears of great interest. The proposed general process consists of three main <span class="hlt">steps</span>: first, pre-treatment for the acidification of the polluted stream, second, a successive extraction of the bio-recalcitrant compound (noted as cycloexanecarboxysulphonic acid (CECS)) and a final biological treatment. In particular, this paper deals with the pre-treatment <span class="hlt">step</span>: it consists of an acidification process by means of sulphuric acid with the concomitant precipitation of black slurries in the presence of different substances, such as solvents, CaCl2, bentonite, several flocculants and coagulants. The aim of this study is to set an experimental procedure, which could minimize fouling problems during sludge filtration. The use of additives like bentonite seems to give the best results, because it allows good COD reductions and a <span class="hlt">filterable</span> precipitate, which avoids excessive fouling problems of the experimental apparatus. PMID:16293280</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26748662','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26748662"><span id="translatedtitle">Statistical efficiency and <span class="hlt">optimal</span> design for <span class="hlt">stepped</span> cluster studies under linear mixed effects models.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Girling, Alan J; Hemming, Karla</p> <p>2016-06-15</p> <p>In <span class="hlt">stepped</span> cluster designs the intervention is introduced into some (or all) clusters at different times and persists until the end of the study. Instances include traditional parallel cluster designs and the more recent <span class="hlt">stepped</span>-wedge designs. We consider the precision offered by such designs under mixed-effects models with fixed time and random subject and cluster effects (including interactions with time), and explore the <span class="hlt">optimal</span> choice of uptake times. The results apply both to cross-sectional studies where new subjects are observed at each time-point, and longitudinal studies with repeat observations on the same subjects. The efficiency of the design is expressed in terms of a 'cluster-mean correlation' which carries information about the dependency-structure of the data, and two design coefficients which reflect the pattern of uptake-times. In cross-sectional studies the cluster-mean correlation combines information about the cluster-size and the intra-cluster correlation coefficient. A formula is given for the 'design effect' in both cross-sectional and longitudinal studies. An algorithm for optimising the choice of uptake times is described and specific results obtained for the best balanced <span class="hlt">stepped</span> designs. In large studies we show that the best design is a hybrid mixture of parallel and <span class="hlt">stepped</span>-wedge components, with the proportion of <span class="hlt">stepped</span> wedge clusters equal to the cluster-mean correlation. The impact of prior uncertainty in the cluster-mean correlation is considered by simulation. Some specific hybrid designs are proposed for consideration when the cluster-mean correlation cannot be reliably estimated, using a minimax principle to ensure acceptable performance across the whole range of unknown values. © 2016 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd. PMID:26748662</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110012253','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110012253"><span id="translatedtitle"><span class="hlt">Optimal</span> Tuner Selection for Kalman-<span class="hlt">Filter</span>-Based Aircraft Engine Performance Estimation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Simon, Donald L.; Garg, Sanjay</p> <p>2011-01-01</p> <p>An emerging approach in the field of aircraft engine controls and system health management is the inclusion of real-time, onboard models for the inflight estimation of engine performance variations. This technology, typically based on Kalman-<span class="hlt">filter</span> concepts, enables the estimation of unmeasured engine performance parameters that can be directly utilized by controls, prognostics, and health-management applications. A challenge that complicates this practice is the fact that an aircraft engine s performance is affected by its level of degradation, generally described in terms of unmeasurable health parameters such as efficiencies and flow capacities related to each major engine module. Through Kalman-<span class="hlt">filter</span>-based estimation techniques, the level of engine performance degradation can be estimated, given that there are at least as many sensors as health parameters to be estimated. However, in an aircraft engine, the number of sensors available is typically less than the number of health parameters, presenting an under-determined estimation problem. A common approach to address this shortcoming is to estimate a subset of the health parameters, referred to as model tuning parameters. The problem/objective is to <span class="hlt">optimally</span> select the model tuning parameters to minimize Kalman-filterbased estimation error. A tuner selection technique has been developed that specifically addresses the under-determined estimation problem, where there are more unknown parameters than available sensor measurements. A systematic approach is applied to produce a model tuning parameter vector of appropriate dimension to enable estimation by a Kalman <span class="hlt">filter</span>, while minimizing the estimation error in the parameters of interest. Tuning parameter selection is performed using a multi-variable iterative search routine that seeks to minimize the theoretical mean-squared estimation error of the Kalman <span class="hlt">filter</span>. This approach can significantly reduce the error in onboard aircraft engine parameter estimation applications such as model-based diagnostic, controls, and life usage calculations. The advantage of the innovation is the significant reduction in estimation errors that it can provide relative to the conventional approach of selecting a subset of health parameters to serve as the model tuning parameter vector. Because this technique needs only to be performed during the system design process, it places no additional computation burden on the onboard Kalman <span class="hlt">filter</span> implementation. The technique has been developed for aircraft engine onboard estimation applications, as this application typically presents an under-determined estimation problem. However, this generic technique could be applied to other industries using gas turbine engine technology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16359687','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16359687"><span id="translatedtitle"><span class="hlt">Optimizing</span> the integrated pulsed amperometric multicycle <span class="hlt">step</span> waveform for the determination of tetracyclines.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cai, Yu-e; Cai, Yaqi; Shi, Yali; Mou, Shifen; Lu, Yiqiang</p> <p>2006-06-16</p> <p>A method of modified integrated pulsed amperometric detection with multicycle <span class="hlt">step</span> waveform (Multi-IPAD) following high-performance liquid chromatography (HPLC) was applied for the determination of tetracyclines (TCs) including dimethyltetracycline (DMTC), oxytetracycline (OTC) and tetracycline (TC). The key advantages of the Multi-IPAD are the abilities to enhance sensitivity and reproducibility and the ability to keep working electrode clean through the use of a high-frequent waveform alteration in integration <span class="hlt">step</span> and the use of a cleaning potential, which is quite different from conventional three-<span class="hlt">step</span> potential waveform. The analyses were carried out using the mobile phase of acetonitrile-water mixture solution (10:90, v/v) containing 1% perchloric acid on a C(18) column at a flow rate of 0.21 mL/min. The IPAD waveform parameters were <span class="hlt">optimized</span> to maximize the signal-to-noise ratio (S/N) and successfully applied for the sensitive detection of TCs. The detection limits (S/N=3, 20 microL injected) were 0.07 mg/L for DMTC, 0.08 mg/L for OTC and 0.05 mg/L for TC. The peak height relative standard deviations (RSDs) of every compound for replicate injection (n=15) determined were below 4.6%. PMID:16359687</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25675449','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25675449"><span id="translatedtitle">Graphics-processor-unit-based parallelization of <span class="hlt">optimized</span> baseline wander <span class="hlt">filtering</span> algorithms for long-term electrocardiography.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Niederhauser, Thomas; Wyss-Balmer, Thomas; Haeberlin, Andreas; Marisa, Thanks; Wildhaber, Reto A; Goette, Josef; Jacomet, Marcel; Vogel, Rolf</p> <p>2015-06-01</p> <p>Long-term electrocardiogram (ECG) often suffers from relevant noise. Baseline wander in particular is pronounced in ECG recordings using dry or esophageal electrodes, which are dedicated for prolonged registration. While analog high-pass <span class="hlt">filters</span> introduce phase distortions, reliable offline <span class="hlt">filtering</span> of the baseline wander implies a computational burden that has to be put in relation to the increase in signal-to-baseline ratio (SBR). Here, we present a graphics processor unit (GPU)-based parallelization method to speed up offline baseline wander <span class="hlt">filter</span> algorithms, namely the wavelet, finite, and infinite impulse response, moving mean, and moving median <span class="hlt">filter</span>. Individual <span class="hlt">filter</span> parameters were <span class="hlt">optimized</span> with respect to the SBR increase based on ECGs from the Physionet database superimposed to autoregressive modeled, real baseline wander. A Monte-Carlo simulation showed that for low input SBR the moving median <span class="hlt">filter</span> outperforms any other method but negatively affects ECG wave detection. In contrast, the infinite impulse response <span class="hlt">filter</span> is preferred in case of high input SBR. However, the parallelized wavelet <span class="hlt">filter</span> is processed 500 and four times faster than these two algorithms on the GPU, respectively, and offers superior baseline wander suppression in low SBR situations. Using a signal segment of 64 mega samples that is <span class="hlt">filtered</span> as entire unit, wavelet <span class="hlt">filtering</span> of a seven-day high-resolution ECG is computed within less than 3 s. Taking the high <span class="hlt">filtering</span> speed into account, the GPU wavelet <span class="hlt">filter</span> is the most efficient method to remove baseline wander present in long-term ECGs, with which computational burden can be strongly reduced. PMID:25675449</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24128476','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24128476"><span id="translatedtitle"><span class="hlt">Optimization</span> of a blanching <span class="hlt">step</span> to maximize sulforaphane synthesis in broccoli florets.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pérez, Carmen; Barrientos, Herna; Román, Juan; Mahn, Andrea</p> <p>2014-02-15</p> <p>A blanching <span class="hlt">step</span> was designed to favor sulforaphane synthesis in broccoli. Blanching was optimised through a central composite design, and the effects of temperature (50-70 °C) and immersion time in water (5-15 min) on the content of total glucosinolates, glucoraphanin, sulforaphane, and myrosinase activity were determined. Results were analysed by ANOVA and the <span class="hlt">optimal</span> condition was determined through response surface methodology. Temperature between 50 and 60 °C significantly increased sulforaphane content (p<0.05), whilst blanching at 70 and 74 °C diminished significantly this content, compared to fresh broccoli. The <span class="hlt">optimal</span> blanching conditions given by the statistical model were immersion in water at 57 °C for 13 min; coinciding with the minimum glucosinolates and glucoraphanin content, and with the maximum myrosinase activity. In the <span class="hlt">optimal</span> conditions, the predicted response of 4.0 μmol sulforaphane/g dry matter was confirmed experimentally. This value represents a 237% increase with respect to the fresh vegetable. PMID:24128476</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4658170','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4658170"><span id="translatedtitle">Reliably Detecting Clinically Important Variants Requires Both Combined Variant Calls and <span class="hlt">Optimized</span> <span class="hlt">Filtering</span> Strategies</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Field, Matthew A.; Cho, Vicky</p> <p>2015-01-01</p> <p>A diversity of tools is available for identification of variants from genome sequence data. Given the current complexity of incorporating external software into a genome analysis infrastructure, a tendency exists to rely on the results from a single tool alone. The quality of the output variant calls is highly variable however, depending on factors such as sequence library quality as well as the choice of short-read aligner, variant caller, and variant caller <span class="hlt">filtering</span> strategy. Here we present a two-part study first using the high quality ‘genome in a bottle’ reference set to demonstrate the significant impact the choice of aligner, variant caller, and variant caller <span class="hlt">filtering</span> strategy has on overall variant call quality and further how certain variant callers outperform others with increased sample contamination, an important consideration when analyzing sequenced cancer samples. This analysis confirms previous work showing that combining variant calls of multiple tools results in the best quality resultant variant set, for either specificity or sensitivity, depending on whether the intersection or union, of all variant calls is used respectively. Second, we analyze a melanoma cell line derived from a control lymphocyte sample to determine whether software choices affect the detection of clinically important melanoma risk-factor variants finding that only one of the three such variants is unanimously detected under all conditions. Finally, we describe a cogent strategy for implementing a clinical variant detection pipeline; a strategy that requires careful software selection, variant caller <span class="hlt">filtering</span> <span class="hlt">optimizing</span>, and combined variant calls in order to effectively minimize false negative variants. While implementing such features represents an increase in complexity and computation the results offer indisputable improvements in data quality. PMID:26600436</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26278994','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26278994"><span id="translatedtitle"><span class="hlt">Optimization</span> of hydrolysis and volatile fatty acids production from sugarcane <span class="hlt">filter</span> cake: Effects of urea supplementation and sodium hydroxide pretreatment.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Janke, Leandro; Leite, Athaydes; Batista, Karla; Weinrich, Sören; Sträuber, Heike; Nikolausz, Marcell; Nelles, Michael; Stinner, Walter</p> <p>2016-01-01</p> <p>Different methods for <span class="hlt">optimization</span> the anaerobic digestion (AD) of sugarcane <span class="hlt">filter</span> cake (FC) with a special focus on volatile fatty acids (VFA) production were studied. Sodium hydroxide (NaOH) pretreatment at different concentrations was investigated in batch experiments and the cumulative methane yields fitted to a dual-pool two-<span class="hlt">step</span> model to provide an initial assessment on AD. The effects of nitrogen supplementation in form of urea and NaOH pretreatment for improved VFA production were evaluated in a semi-continuously operated reactor as well. The results indicated that higher NaOH concentrations during pretreatment accelerated the AD process and increased methane production in batch experiments. Nitrogen supplementation resulted in a VFA loss due to methane formation by buffering the pH value at nearly neutral conditions (∼ 6.7). However, the alkaline pretreatment with 6g NaOH/100g FCFM improved both the COD solubilization and the VFA yield by 37%, mainly consisted by n-butyric and acetic acids. PMID:26278994</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8777E..1BE','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8777E..1BE"><span id="translatedtitle">Spectral <span class="hlt">filtering</span> <span class="hlt">optimization</span> of a measuring channel of an x-ray broadband spectrometer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Emprin, B.; Troussel, Ph.; Villette, B.; Delmotte, F.</p> <p>2013-05-01</p> <p>A new channel of an X-ray broadband spectrometer has been developed for the 2 - 4 keV spectral range. It uses a spectral <span class="hlt">filtering</span> by using a non-periodic multilayer mirror. This channel is composed by a <span class="hlt">filter</span>, an aperiodic multilayer mirror and a detector. The design and realization of the optical coating mirror has been defined such as the reflectivity is above 8% in almost the entire bandwidth range 2 - 4 keV and lower than 2% outside. The mirror is <span class="hlt">optimized</span> for working at 1.9° grazing incidence. The mirror is coated with a stack of 115 chromium / scandium (Cr / Sc) non-periodic layers, between 0.6 nm and 7.3 nm and a 3 nm thick top SiO2 layer to protect the stack from oxidization. To control thin thicknesses, we produced specific multilayer mirrors which consist on a superposition of two periodic Cr / Sc multilayers with the layer to calibrate in between. The mirror and subnanometric layers characterizations were made at the "Laboratoire Charles Fabry" (LCF) with a grazing incidence reflectometer working at 8.048 keV (Cu Kα radiation) and at the synchrotron radiation facility SOLEIL on the hard X-ray branch of the "Metrology" beamline. The reflectivity of the mirrors as a function of the photon energy was obtained in the Physikalisch Technische Bundesanstalt (PTB) laboratory at the synchrotron radiation facility Bessy II.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22917190','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22917190"><span id="translatedtitle">A modified statistically <span class="hlt">optimal</span> null <span class="hlt">filter</span> method for recognizing protein-coding regions.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Lei; Tian, Fengchun; Wang, Shiyuan</p> <p>2012-06-01</p> <p>Computer-aided protein-coding gene prediction in uncharacterized genomic DNA sequences is one of the most important issues of biological signal processing. A modified <span class="hlt">filter</span> method based on a statistically <span class="hlt">optimal</span> null <span class="hlt">filter</span> (SONF) theory is proposed for recognizing protein-coding regions. The square deviation gain (SDG) between the input and output of the model is used to identify the coding regions. The effective SDG amplification model with Class I and Class II enhancement is designed to suppress the non-coding regions. Also, an evaluation algorithm has been used to compare the modified model with most gene prediction methods currently available in terms of sensitivity, specificity and precision. The performance for identification of protein-coding regions has been evaluated at the nucleotide level using benchmark datasets and 91.4%, 96%, 93.7% were obtained for sensitivity, specificity and precision, respectively. These results suggest that the proposed model is potentially useful in gene finding field, which can help recognize protein-coding regions with higher precision and speed than present algorithms. PMID:22917190</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JaJAP..54hKA05T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JaJAP..54hKA05T"><span id="translatedtitle"><span class="hlt">Optimal</span> design of bandpass <span class="hlt">filters</span> to reduce emission from photovoltaic cells under monochromatic illumination</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Takeda, Yasuhiko; Iizuka, Hideo; Ito, Tadashi; Mizuno, Shintaro; Hasegawa, Kazuo; Ichikawa, Tadashi; Ito, Hiroshi; Kajino, Tsutomu; Higuchi, Kazuo; Ichiki, Akihisa; Motohiro, Tomoyoshi</p> <p>2015-08-01</p> <p>We have theoretically investigated photovoltaic cells used under the illumination condition of monochromatic light incident from a particular direction, which is very different from that for solar cells under natural sunlight, using detailed balance modeling. A multilayer bandpass <span class="hlt">filter</span> formed on the surface of the cell has been found to trap the light generated by radiative recombination inside the cell, reduce emission from the cell, and consequently improve conversion efficiency. The light trapping mechanism is interpreted in terms of a one-dimensional photonic crystal, and the design guide to <span class="hlt">optimize</span> the multilayer structure has been clarified. For obliquely incident illumination, as well as normal incidence, a significant light trapping effect has been achieved, although the emission patterns are extremely different from each other depending on the incident directions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015OptCo.349...31S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015OptCo.349...31S"><span id="translatedtitle">An <span class="hlt">optimized</span> strain demodulation method for PZT driven fiber Fabry-Perot tunable <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sheng, Wenjuan; Peng, G. D.; Liu, Yang; Yang, Ning</p> <p>2015-08-01</p> <p>An <span class="hlt">optimized</span> strain-demodulation-method based on piezo-electrical transducer (PZT) driven fiber Fabry-Perot (FFP) <span class="hlt">filter</span> is proposed and experimentally demonstrated. Using a parallel processing mode to drive the PZT continuously, the hysteresis effect is eliminated, and the system demodulation rate is increased. Furthermore, an AC-DC compensation method is developed to address the intrinsic nonlinear relationship between the displacement and voltage of PZT. The experimental results show that the actual demodulation rate is improved from 15 Hz to 30 Hz, the random error of the strain measurement is decreased by 95%, and the deviation between the test values after compensation and the theoretical values is less than 1 pm/??.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/10817828','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/10817828"><span id="translatedtitle"><span class="hlt">Filter</span>-feeding and cruising swimming speeds of basking sharks compared with <span class="hlt">optimal</span> models: they <span class="hlt">filter</span>-feed slower than predicted for their size.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sims</p> <p>2000-06-01</p> <p>Movements of six basking sharks (4.0-6.5 m total body length, L(T)) swimming at the surface were tracked and horizontal velocities determined. Sharks were tracked for between 1.8 and 55 min with between 4 and 21 mean speed determinations per shark track. The mean <span class="hlt">filter</span>-feeding swimming speed was 0.85 m s(-1) (+/-0.05 S.E., n=49 determinations) compared to the non-feeding (cruising) mean speed of 1.08 m s(-1) (+/-0.03 S.E., n=21 determinations). Both absolute (m s(-1)) and specific (L s(-1)) swimming speeds during <span class="hlt">filter</span>-feeding were significantly lower than when cruise swimming with the mouth closed, indicating basking sharks select speeds approximately 24% lower when engaged in <span class="hlt">filter</span>-feeding. This reduction in speed during <span class="hlt">filter</span>-feeding could be a behavioural response to avoid increased drag-induced energy costs associated with feeding at higher speeds. Non-feeding basking sharks (4 m L(T)) cruised at speeds close to, but slightly faster ( approximately 18%) than the optimum speed predicted by the Weihs (1977) [Weihs, D., 1977. Effects of size on the sustained swimming speeds of aquatic organisms. In: Pedley, T.J. (Ed.), Scale Effects in Animal Locomotion. Academic Press, London, pp. 333-338.] <span class="hlt">optimal</span> cruising speed model. In contrast, <span class="hlt">filter</span>-feeding basking sharks swam between 29 and 39% slower than the speed predicted by the Weihs and Webb (1983) [Weihs, D., Webb, P.W., 1983. <span class="hlt">Optimization</span> of locomotion. In: Webb, P.W., Weihs, D. (Eds.), Fish Biomechanics. Praeger, New York, pp. 339-371.] <span class="hlt">optimal</span> <span class="hlt">filter</span>-feeding model. This significant under-estimation in observed feeding speed compared to model predictions was most likely accounted for by surface drag effects reducing optimum speeds of tracked sharks, together with inaccurate parameter estimates used in the general model to predict <span class="hlt">optimal</span> speeds of basking sharks from body size extrapolations. PMID:10817828</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008SPIE.7140E..2ZU','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008SPIE.7140E..2ZU"><span id="translatedtitle">The first on-site evaluation of a new <span class="hlt">filter</span> <span class="hlt">optimized</span> for TARC and developer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Umeda, Toru; Ishibashi, Takeo; Nakamura, Atsushi; Ide, Junichi; Nagano, Masaru; Omura, Koichi; Tsuzuki, Shuichi; Numaguchi, Toru</p> <p>2008-11-01</p> <p>In previous studies, we identified <span class="hlt">filter</span> properties that have a strong effect on microbubble formation on the downstream side of the <span class="hlt">filter</span> membrane. A new Highly Asymmetric Polyarylsulfone (HAPAS) <span class="hlt">filter</span> was developed based on the findings. In the current study, we evaluated newly-developed HAPAS <span class="hlt">filter</span> in environmentally preferred non-PFOS TARC in a laboratory setting. Test results confirmed that microbubble counts downstream of the <span class="hlt">filter</span> were lower than those of a conventional HDPE <span class="hlt">filter</span>. Further testing in a manufacturing environment confirmed that HAPAS filtration of TARC at point of use was able to reduce defectivity caused by microbubbles on both unpatterned and patterned wafers, compared with a HDPE <span class="hlt">filter</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3930727','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3930727"><span id="translatedtitle"><span class="hlt">Optimization</span> of a One-<span class="hlt">Step</span> Heat-Inducible In Vivo Mini DNA Vector Production System</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wettig, Shawn; Slavcev, Roderick A.</p> <p>2014-01-01</p> <p>While safer than their viral counterparts, conventional circular covalently closed (CCC) plasmid DNA vectors offer a limited safety profile. They often result in the transfer of unwanted prokaryotic sequences, antibiotic resistance genes, and bacterial origins of replication that may lead to unwanted immunostimulatory responses. Furthermore, such vectors may impart the potential for chromosomal integration, thus potentiating oncogenesis. Linear covalently closed (LCC), bacterial sequence free DNA vectors have shown promising clinical improvements in vitro and in vivo. However, the generation of such minivectors has been limited by in vitro enzymatic reactions hindering their downstream application in clinical trials. We previously characterized an in vivo temperature-inducible expression system, governed by the phage λ pL promoter and regulated by the thermolabile λ CI[Ts]857 repressor to produce recombinant protelomerase enzymes in E. coli. In this expression system, induction of recombinant protelomerase was achieved by increasing culture temperature above the 37°C threshold temperature. Overexpression of protelomerase led to enzymatic reactions, acting on genetically engineered multi-target sites called “Super Sequences” that serve to convert conventional CCC plasmid DNA into LCC DNA minivectors. Temperature up-shift, however, can result in intracellular stress responses and may alter plasmid replication rates; both of which may be detrimental to LCC minivector production. We sought to <span class="hlt">optimize</span> our one-<span class="hlt">step</span> in vivo DNA minivector production system under various induction schedules in combination with genetic modifications influencing plasmid replication, processing rates, and cellular heat stress responses. We assessed different culture growth techniques, growth media compositions, heat induction scheduling and temperature, induction duration, post-induction temperature, and E. coli genetic background to improve the productivity and scalability of our system, achieving an overall LCC DNA minivector production efficiency of ∼90%.We <span class="hlt">optimized</span> a robust technology conferring rapid, scalable, one-<span class="hlt">step</span> in vivo production of LCC DNA minivectors with potential application to gene transfer-mediated therapeutics. PMID:24586704</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24586704','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24586704"><span id="translatedtitle"><span class="hlt">Optimization</span> of a one-<span class="hlt">step</span> heat-inducible in vivo mini DNA vector production system.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nafissi, Nafiseh; Sum, Chi Hong; Wettig, Shawn; Slavcev, Roderick A</p> <p>2014-01-01</p> <p>While safer than their viral counterparts, conventional circular covalently closed (CCC) plasmid DNA vectors offer a limited safety profile. They often result in the transfer of unwanted prokaryotic sequences, antibiotic resistance genes, and bacterial origins of replication that may lead to unwanted immunostimulatory responses. Furthermore, such vectors may impart the potential for chromosomal integration, thus potentiating oncogenesis. Linear covalently closed (LCC), bacterial sequence free DNA vectors have shown promising clinical improvements in vitro and in vivo. However, the generation of such minivectors has been limited by in vitro enzymatic reactions hindering their downstream application in clinical trials. We previously characterized an in vivo temperature-inducible expression system, governed by the phage λ pL promoter and regulated by the thermolabile λ CI[Ts]857 repressor to produce recombinant protelomerase enzymes in E. coli. In this expression system, induction of recombinant protelomerase was achieved by increasing culture temperature above the 37°C threshold temperature. Overexpression of protelomerase led to enzymatic reactions, acting on genetically engineered multi-target sites called "Super Sequences" that serve to convert conventional CCC plasmid DNA into LCC DNA minivectors. Temperature up-shift, however, can result in intracellular stress responses and may alter plasmid replication rates; both of which may be detrimental to LCC minivector production. We sought to <span class="hlt">optimize</span> our one-<span class="hlt">step</span> in vivo DNA minivector production system under various induction schedules in combination with genetic modifications influencing plasmid replication, processing rates, and cellular heat stress responses. We assessed different culture growth techniques, growth media compositions, heat induction scheduling and temperature, induction duration, post-induction temperature, and E. coli genetic background to improve the productivity and scalability of our system, achieving an overall LCC DNA minivector production efficiency of ∼ 90%.We <span class="hlt">optimized</span> a robust technology conferring rapid, scalable, one-<span class="hlt">step</span> in vivo production of LCC DNA minivectors with potential application to gene transfer-mediated therapeutics. PMID:24586704</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003PhDT........93T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003PhDT........93T"><span id="translatedtitle"><span class="hlt">Optimal</span> spatial <span class="hlt">filtering</span> for design of a conformal velocity sonar array</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Traweek, Charles M.</p> <p></p> <p>In stark contrast to the ubiquitous <span class="hlt">optimization</span> problem posed in the array processing literature, tactical hull sonar arrays have traditionally been designed using extrapolations of low spatial resolution empirical self noise data, dominated by hull noise at moderate speeds, in conjunction with assumptions regarding achievable conventional beamformer sidelobe levels by so-called Taylor shading for a time domain, delay-and-sum beamformer. That ad hoc process defaults to an extremely conservative (expensive and heavy) design for an array baffle as a means to assure environmental noise limited sonar performance. As an alternative, this dissertation formulates, implements, and demonstrates an objective function that results from the expression of the log likelihood ratio of the <span class="hlt">optimal</span> Bayesian detector as a comparison to a threshold. Its purpose is to maximize the deflection coefficient of a square-law energy detector over an arbitrarily specified frequency band by appropriate selection of array shading weights for the generalized conformal velocity sonar array under the assumption that it will employ the traditional time domain delay-and-sum beamformer. The restrictive assumptions that must be met in order to appropriately use the deflection coefficient as a performance metric are carefully delineated. A series of conformal velocity sonar array spatial <span class="hlt">filter</span> <span class="hlt">optimization</span> problems was defined using a data set characterized by spatially complex structural noise from a large aperture conformal velocity sonar array experiment. The detection performance of an 80-element cylindrical array was <span class="hlt">optimized</span> over a reasonably broad range of frequencies (from k0a = 12.95 to k 0a = 15.56) for the cases of broadside and off-broadside signal incidence. In each case, performance of the array using <span class="hlt">optimal</span> real-valued time domain delay-and-sum beamformer weights was much better than that achieved for either uniform shading or for Taylor shading. The result is an analytical engine with which to consider not only the tradeoff between <span class="hlt">optimality</span> and robustness in the definition of array baffle design requirements, but numerous other tradeoffs within the array design error budget allocation process as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040006352','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040006352"><span id="translatedtitle">An Explicit Linear <span class="hlt">Filtering</span> Solution for the <span class="hlt">Optimization</span> of Guidance Systems with Statistical Inputs</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stewart, Elwood C.</p> <p>1961-01-01</p> <p>The determination of optimum <span class="hlt">filtering</span> characteristics for guidance system design is generally a tedious process which cannot usually be carried out in general terms. In this report a simple explicit solution is given which is applicable to many different types of problems. It is shown to be applicable to problems which involve <span class="hlt">optimization</span> of constant-coefficient guidance systems and time-varying homing type systems for several stationary and nonstationary inputs. The solution is also applicable to off-design performance, that is, the evaluation of system performance for inputs for which the system was not specifically <span class="hlt">optimized</span>. The solution is given in generalized form in terms of the minimum theoretical error, the optimum transfer functions, and the optimum transient response. The effects of input signal, contaminating noise, and limitations on the response are included. From the results given, it is possible in an interception problem, for example, to rapidly assess the effects on minimum theoretical error of such factors as target noise and missile acceleration. It is also possible to answer important questions regarding the effect of type of target maneuver on optimum performance.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25514627','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25514627"><span id="translatedtitle">Selecting the <span class="hlt">optimal</span> anti-aliasing <span class="hlt">filter</span> for multichannel biosignal acquisition intended for inter-signal phase shift analysis.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Keresnyei, Rbert; Megyeri, Pter; Zidarics, Zoltn; Hejjel, Lszl</p> <p>2015-01-01</p> <p>The availability of microcomputer-based portable devices facilitates the high-volume multichannel biosignal acquisition and the analysis of their instantaneous oscillations and inter-signal temporal correlations. These new, non-invasively obtained parameters can have considerable prognostic or diagnostic roles. The present study investigates the inherent signal delay of the obligatory anti-aliasing <span class="hlt">filters</span>. One cycle of each of the 8 electrocardiogram (ECG) and 4 photoplethysmogram signals from healthy volunteers or artificially synthesised series were passed through 100-80-60-40-20?Hz 2-4-6-8th order Bessel and Butterworth <span class="hlt">filters</span> digitally synthesized by bilinear transformation, that resulted in a negligible error in signal delay compared to the mathematical model of the impulse- and <span class="hlt">step</span> responses of the <span class="hlt">filters</span>. The investigated <span class="hlt">filters</span> have as diverse a signal delay as 2-46?ms depending on the <span class="hlt">filter</span> parameters and the signal slew rate, which is difficult to predict in biological systems and thus difficult to compensate for. Its magnitude can be comparable to the examined phase shifts, deteriorating the accuracy of the measurement. As a conclusion, identical or very similar anti-aliasing <span class="hlt">filters</span> with lower orders and higher corner frequencies, oversampling, and digital low pass <span class="hlt">filtering</span> are recommended for biosignal acquisition intended for inter-signal phase shift analysis. PMID:25514627</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EL....10330007L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EL....10330007L"><span id="translatedtitle">One <span class="hlt">step</span> memory of group reputation is <span class="hlt">optimal</span> to promote cooperation in public goods games</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Aming; Wu, Te; Cong, Rui; Wang, Long</p> <p>2013-08-01</p> <p>Individuals' change of social ties has been observed to promote cooperation under specific mechanism, such as success-driven or expectation-driven migration. However, there is no clear criterion or information from players' instinctive memory or experience for them to consult as they would like to change their social ties. For the first time we define the reputation of a group based on individual's memory law. A model is proposed, where all players are endowed with the capacity to adjust interaction ambience involved if the reputation of their environment fails to satisfy their expectations. Simulation results show that cooperation decays as the increase of player's memory depth and one <span class="hlt">step</span> memory is <span class="hlt">optimal</span> to promote cooperation, which provides a potential interpretation for that most species memorize their reciprocators over very short time scales. Of intrigue is the result that cooperation can be improved greatly at an <span class="hlt">optimal</span> interval of moderate expectation. Moreover, cooperation can be established and stabilized within a wide range of model parameters even when players choose their new partners randomly under the combination of reputation and group switching mechanisms. Our work validates the fact that individuals' short memory or experience within a multi-players group acts as an effective ingredient to boost cooperation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000PhDT.......206L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000PhDT.......206L"><span id="translatedtitle">Rotor cascade shape <span class="hlt">optimization</span> with unsteady passing wakes using implicit dual time <span class="hlt">stepping</span> method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Eun Seok</p> <p>2000-10-01</p> <p>An improved aerodynamics performance of a turbine cascade shape can be achieved by an understanding of the flow-field associated with the stator-rotor interaction. In this research, an axial gas turbine airfoil cascade shape is <span class="hlt">optimized</span> for improved aerodynamic performance by using an unsteady Navier-Stokes solver and a parallel genetic algorithm. The objective of the research is twofold: (1) to develop a computational fluid dynamics code having faster convergence rate and unsteady flow simulation capabilities, and (2) to <span class="hlt">optimize</span> a turbine airfoil cascade shape with unsteady passing wakes for improved aerodynamic performance. The computer code solves the Reynolds averaged Navier-Stokes equations. It is based on the explicit, finite difference, Runge-Kutta time marching scheme and the Diagonalized Alternating Direction Implicit (DADI) scheme, with the Baldwin-Lomax algebraic and k-epsilon turbulence modeling. Improvements in the code focused on the cascade shape design capability, convergence acceleration and unsteady formulation. First, the inverse shape design method was implemented in the code to provide the design capability, where a surface transpiration concept was employed as an inverse technique to modify the geometry satisfying the user specified pressure distribution on the airfoil surface. Second, an approximation storage multigrid method was implemented as an acceleration technique. Third, the preconditioning method was adopted to speed up the convergence rate in solving the low Mach number flows. Finally, the implicit dual time <span class="hlt">stepping</span> method was incorporated in order to simulate the unsteady flow-fields. For the unsteady code validation, the Stokes's 2nd problem and the Poiseuille flow were chosen and compared with the computed results and analytic solutions. To test the code's ability to capture the natural unsteady flow phenomena, vortex shedding past a cylinder and the shock oscillation over a bicircular airfoil were simulated and compared with experiments and other research results. The rotor cascade shape <span class="hlt">optimization</span> with unsteady passing wakes was performed to obtain an improved aerodynamic performance using the unsteady Navier-Stokes solver. Two objective functions were defined as minimization of total pressure loss and maximization of lift, while the mass flow rate was fixed. A parallel genetic algorithm was used as an <span class="hlt">optimizer</span> and the penalty method was introduced. Each individual's objective function was computed simultaneously by using a 32 processor distributed memory computer. One <span class="hlt">optimization</span> took about four days.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993SPIE.1772..201F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993SPIE.1772..201F"><span id="translatedtitle">Performance of mixed-metric <span class="hlt">optimized</span> ternary correlation <span class="hlt">filters</span> on realistic binary and gray-scale imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Flannery, David L.; Phillips, William E., III; Goldstein, Dennis H.</p> <p>1993-01-01</p> <p>The ternary phase-amplitude <span class="hlt">filter</span> (TPAF) is by definition restricted to the modulation values -1, 0, and 1, thus comprising a binary phase-only <span class="hlt">filter</span> (BPOF) multiplied by a binary- amplitude pattern, i.e., a region of support. The TPAF offers an attractive combination of real-time implementation with available devices and good correlation performance. Smart (<span class="hlt">optimized</span> distortion-invariant) TPAF formulations have been developed. The TPAF enables <span class="hlt">filter</span> implementation with magneto-optic devices and these devices also can be used for image input if gray scale scenes can be binarized while preserving good correlation performance. We provide simulation results addressing the comparative performance of mixed-metric smart TPAF's using gray scale, edge-enhanced and binary images derived from identical original scenes. The variation of <span class="hlt">filter</span> performance with training set background intensity level is examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994OptEn..33.1767H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994OptEn..33.1767H"><span id="translatedtitle">Design and evaluation of three-level composite <span class="hlt">filters</span> obtained by <span class="hlt">optimizing</span> a compromise average performance measure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hendrix, Charles D.; Vijaya Kumar, B. V. K.</p> <p>1994-06-01</p> <p>Correlation <span class="hlt">filters</span> with three transmittance levels (+1, 0, and -1) are of interest in optical pattern recognition because they can be implemented on available spatial light modulators and because the zero level allows us to include a region of support (ROS). The ROS can provide additional control over the <span class="hlt">filter</span>'s noise tolerance and peak sharpness. A new algorithm based on <span class="hlt">optimizing</span> a compromise average performance measure (CAPM) is proposed for designing three-level composite <span class="hlt">filters</span>. The performance of this algorithm is compared to other three-level composite <span class="hlt">filter</span> designs using a common image database and using figures of merit such as the Fisher ratio, error rate, and light efficiency. It is shown that the CAPM algorithm yields better results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22413537','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22413537"><span id="translatedtitle"><span class="hlt">Optimization</span> of leaf margins for lung stereotactic body radiotherapy using a flattening <span class="hlt">filter</span>-free beam</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wakai, Nobuhide; Sumida, Iori; Otani, Yuki; Suzuki, Osamu; Seo, Yuji; Isohashi, Fumiaki; Yoshioka, Yasuo; Ogawa, Kazuhiko; Hasegawa, Masatoshi</p> <p>2015-05-15</p> <p>Purpose: The authors sought to determine the <span class="hlt">optimal</span> collimator leaf margins which minimize normal tissue dose while achieving high conformity and to evaluate differences between the use of a flattening <span class="hlt">filter</span>-free (FFF) beam and a flattening-<span class="hlt">filtered</span> (FF) beam. Methods: Sixteen lung cancer patients scheduled for stereotactic body radiotherapy underwent treatment planning for a 7 MV FFF and a 6 MV FF beams to the planning target volume (PTV) with a range of leaf margins (−3 to 3 mm). Forty grays per four fractions were prescribed as a PTV D95. For PTV, the heterogeneity index (HI), conformity index, modified gradient index (GI), defined as the 50% isodose volume divided by target volume, maximum dose (Dmax), and mean dose (Dmean) were calculated. Mean lung dose (MLD), V20 Gy, and V5 Gy for the lung (defined as the volumes of lung receiving at least 20 and 5 Gy), mean heart dose, and Dmax to the spinal cord were measured as doses to organs at risk (OARs). Paired t-tests were used for statistical analysis. Results: HI was inversely related to changes in leaf margin. Conformity index and modified GI initially decreased as leaf margin width increased. After reaching a minimum, the two values then increased as leaf margin increased (“V” shape). The <span class="hlt">optimal</span> leaf margins for conformity index and modified GI were −1.1 ± 0.3 mm (mean ± 1 SD) and −0.2 ± 0.9 mm, respectively, for 7 MV FFF compared to −1.0 ± 0.4 and −0.3 ± 0.9 mm, respectively, for 6 MV FF. Dmax and Dmean for 7 MV FFF were higher than those for 6 MV FF by 3.6% and 1.7%, respectively. There was a positive correlation between the ratios of HI, Dmax, and Dmean for 7 MV FFF to those for 6 MV FF and PTV size (R = 0.767, 0.809, and 0.643, respectively). The differences in MLD, V20 Gy, and V5 Gy for lung between FFF and FF beams were negligible. The <span class="hlt">optimal</span> leaf margins for MLD, V20 Gy, and V5 Gy for lung were −0.9 ± 0.6, −1.1 ± 0.8, and −2.1 ± 1.2 mm, respectively, for 7 MV FFF compared to −0.9 ± 0.6, −1.1 ± 0.8, and −2.2 ± 1.3 mm, respectively, for 6 MV FF. With the heart inside the radiation field, the mean heart dose showed a V-shaped relationship with leaf margins. The <span class="hlt">optimal</span> leaf margins were −1.0 ± 0.6 mm for both beams. Dmax to the spinal cord showed no clear trend for changes in leaf margin. Conclusions: The differences in doses to OARs between FFF and FF beams were negligible. Conformity index, modified GI, MLD, lung V20 Gy, lung V5 Gy, and mean heart dose showed a V-shaped relationship with leaf margins. There were no significant differences in <span class="hlt">optimal</span> leaf margins to minimize these parameters between both FFF and FF beams. The authors’ results suggest that a leaf margin of −1 mm achieves high conformity and minimizes doses to OARs for both FFF and FF beams.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3188653','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3188653"><span id="translatedtitle">Multisource modeling of flattening <span class="hlt">filter</span> free (FFF) beam and the <span class="hlt">optimization</span> of model parameters</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cho, Woong; Kielar, Kayla N.; Mok, Ed; Xing, Lei; Park, Jeong-Hoon; Jung, Won-Gyun; Suh, Tae-Suk</p> <p>2011-01-01</p> <p>Purpose: With the introduction of flattening <span class="hlt">filter</span> free (FFF) linear accelerators to radiation oncology, new analytical source models for a FFF beam applicable to current treatment planning systems is needed. In this work, a multisource model for the FFF beam and the <span class="hlt">optimization</span> of involved model parameters were designed. Methods: The model is based on a previous three source model proposed by Yang [“A three-source model for the calculation of head scatter factors,” Med. Phys. 29, 2024–2033 (2002)]. An off axis ratio (OAR) of photon fluence was introduced to the primary source term to generate cone shaped profiles. The parameters of the source model were determined from measured head scatter factors using a line search <span class="hlt">optimization</span> technique. The OAR of the photon fluence was determined from a measured dose profile of a 40×40 cm2 field size with the same <span class="hlt">optimization</span> technique, but a new method to acquire gradient terms for OARs was developed to enhance the speed of the <span class="hlt">optimization</span> process. The improved model was validated with measured dose profiles from 3×3 to 40×40 cm2 field sizes at 6 and 10 MV from a TrueBeam™ STx linear accelerator. Furthermore, planar dose distributions for clinically used radiation fields were also calculated and compared to measurements using a 2D array detector using the gamma index method. Results: All dose values for the calculated profiles agreed with the measured dose profiles within 0.5% at 6 and 10 MV beams, except for some low dose regions for larger field sizes. A slight overestimation was seen in the lower penumbra region near the field edge for the large field sizes by 1%–4%. The planar dose calculations showed comparable passing rates (>98%) when the criterion of the gamma index method was selected to be 3%∕3 mm. Conclusions: The developed source model showed good agreements between measured and calculated dose distributions. The model is easily applicable to any other linear accelerator using FFF beams as the required data include only the measured PDD, dose profiles, and output factors for various field sizes, which are easily acquired during conventional beam commissioning process. PMID:21626926</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23834855','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23834855"><span id="translatedtitle">Geometric <span class="hlt">optimization</span> of a <span class="hlt">step</span> bearing for a hydrodynamically levitated centrifugal blood pump for the reduction of hemolysis.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kosaka, Ryo; Yada, Toru; Nishida, Masahiro; Maruyama, Osamu; Yamane, Takashi</p> <p>2013-09-01</p> <p>A hydrodynamically levitated centrifugal blood pump with a semi-open impeller has been developed for mechanical circulatory assistance. However, a narrow bearing gap has the potential to cause hemolysis. The purpose of the present study is to <span class="hlt">optimize</span> the geometric configuration of the hydrodynamic <span class="hlt">step</span> bearing in order to reduce hemolysis by expansion of the bearing gap. First, a numerical analysis of the <span class="hlt">step</span> bearing, based on lubrication theory, was performed to determine the <span class="hlt">optimal</span> design. Second, in order to assess the accuracy of the numerical analysis, the hydrodynamic forces calculated in the numerical analysis were compared with those obtained in an actual measurement test using impellers having <span class="hlt">step</span> lengths of 0%, 33%, and 67% of the vane length. Finally, a bearing gap measurement test and a hemolysis test were performed. As a result, the numerical analysis revealed that the hydrodynamic force was the largest when the <span class="hlt">step</span> length was approximately 70%. The hydrodynamic force calculated in the numerical analysis was approximately equivalent to that obtained in the measurement test. In the measurement test and the hemolysis test, the blood pump having a <span class="hlt">step</span> length of 67% achieved the maximum bearing gap and reduced hemolysis, as compared with the pumps having <span class="hlt">step</span> lengths of 0% and 33%. It was confirmed that the numerical analysis of the <span class="hlt">step</span> bearing was effective, and the developed blood pump having a <span class="hlt">step</span> length of approximately 70% was found to be a suitable configuration for the reduction of hemolysis. PMID:23834855</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050239001','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050239001"><span id="translatedtitle">An <span class="hlt">Optimal</span> Orthogonal Decomposition Method for Kalman <span class="hlt">Filter</span>-Based Turbofan Engine Thrust Estimation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Litt, Jonathan S.</p> <p>2005-01-01</p> <p>A new linear point design technique is presented for the determination of tuning parameters that enable the <span class="hlt">optimal</span> estimation of unmeasured engine outputs such as thrust. The engine s performance is affected by its level of degradation, generally described in terms of unmeasurable health parameters related to each major engine component. Accurate thrust reconstruction depends upon knowledge of these health parameters, but there are usually too few sensors to be able to estimate their values. In this new technique, a set of tuning parameters is determined which accounts for degradation by representing the overall effect of the larger set of health parameters as closely as possible in a least squares sense. The technique takes advantage of the properties of the singular value decomposition of a matrix to generate a tuning parameter vector of low enough dimension that it can be estimated by a Kalman <span class="hlt">filter</span>. A concise design procedure to generate a tuning vector that specifically takes into account the variables of interest is presented. An example demonstrates the tuning parameters ability to facilitate matching of both measured and unmeasured engine outputs, as well as state variables. Additional properties of the formulation are shown to lend themselves well to diagnostics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20100042588&hterms=Kalman&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DKalman','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20100042588&hterms=Kalman&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DKalman"><span id="translatedtitle">An <span class="hlt">Optimal</span> Orthogonal Decomposition Method for Kalman <span class="hlt">Filter</span>-Based Turbofan Engine Thrust Estimation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Litt, Jonathan S.</p> <p>2007-01-01</p> <p>A new linear point design technique is presented for the determination of tuning parameters that enable the <span class="hlt">optimal</span> estimation of unmeasured engine outputs, such as thrust. The engine's performance is affected by its level of degradation, generally described in terms of unmeasurable health parameters related to each major engine component. Accurate thrust reconstruction depends on knowledge of these health parameters, but there are usually too few sensors to be able to estimate their values. In this new technique, a set of tuning parameters is determined that accounts for degradation by representing the overall effect of the larger set of health parameters as closely as possible in a least squares sense. The technique takes advantage of the properties of the singular value decomposition of a matrix to generate a tuning parameter vector of low enough dimension that it can be estimated by a Kalman <span class="hlt">filter</span>. A concise design procedure to generate a tuning vector that specifically takes into account the variables of interest is presented. An example demonstrates the tuning parameters ability to facilitate matching of both measured and unmeasured engine outputs, as well as state variables. Additional properties of the formulation are shown to lend themselves well to diagnostics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20080047455&hterms=Kalman&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DKalman','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20080047455&hterms=Kalman&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DKalman"><span id="translatedtitle">An <span class="hlt">Optimal</span> Orthogonal Decomposition Method for Kalman <span class="hlt">Filter</span>-Based Turbofan Engine Thrust Estimation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Litt, Jonathan S.</p> <p>2007-01-01</p> <p>A new linear point design technique is presented for the determination of tuning parameters that enable the <span class="hlt">optimal</span> estimation of unmeasured engine outputs, such as thrust. The engine s performance is affected by its level of degradation, generally described in terms of unmeasurable health parameters related to each major engine component. Accurate thrust reconstruction depends on knowledge of these health parameters, but there are usually too few sensors to be able to estimate their values. In this new technique, a set of tuning parameters is determined that accounts for degradation by representing the overall effect of the larger set of health parameters as closely as possible in a least-squares sense. The technique takes advantage of the properties of the singular value decomposition of a matrix to generate a tuning parameter vector of low enough dimension that it can be estimated by a Kalman <span class="hlt">filter</span>. A concise design procedure to generate a tuning vector that specifically takes into account the variables of interest is presented. An example demonstrates the tuning parameters ability to facilitate matching of both measured and unmeasured engine outputs, as well as state variables. Additional properties of the formulation are shown to lend themselves well to diagnostics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22453408','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22453408"><span id="translatedtitle"><span class="hlt">Optimizing</span> single mode robustness of the distributed modal <span class="hlt">filtering</span> rod fiber amplifier.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jørgensen, Mette Marie; Petersen, Sidsel Rübner; Laurila, Marko; Lægsgaard, Jesper; Alkeskjold, Thomas Tanggaard</p> <p>2012-03-26</p> <p>High-power fiber amplifiers for pulsed applications require large mode area (LMA) fibers having high pump absorption and near diffraction limited output. Photonic crystal fibers allow realization of short LMA fiber amplifiers having high pump absorption through a pump cladding that is decoupled from the outer fiber diameter. However, achieving ultra low NA for single mode (SM) guidance is challenging, thus different design strategies must be applied. The distributed modal <span class="hlt">filtering</span> (DMF) design enables SM guidance in ultra low NA fibers with very large cores, where large preform tolerances can be compensated during the fiber draw. Design <span class="hlt">optimization</span> of the SM bandwidth of the DMF rod fiber is presented. Analysis of band gap properties results in a fourfold increase of the SM bandwidth compared to previous results, achieved by utilizing the first band of cladding modes, which can cover a large fraction of the Yb emission band including wavelengths of 1030 nm and 1064 nm. Design parameters tolerating refractive index fabrication uncertainties of ± 10⁻⁴ are targeted to yield stable SM bandwidths. PMID:22453408</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18954974','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18954974"><span id="translatedtitle"><span class="hlt">Optimization</span> of medium components for increased production of C-phycocyanin from Phormidium ceylanicum and its purification by single <span class="hlt">step</span> process.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Singh, Niraj Kumar; Parmar, Asha; Madamwar, Datta</p> <p>2009-02-01</p> <p>Phycocyanin is a major protein produced by cyanobacteria, but very few phycocyanin-producing strains have been reported. In the present study, response surface methodology (RSM) involving a central composite design for four factors was successfully employed to <span class="hlt">optimize</span> medium components for increased production of phycocyanin from Phormidium ceylanicum. The production of phycocyanin and interactions between sodium nitrate, calcium chloride, trace metal mix and citric acid stock were investigated and modeled. Under <span class="hlt">optimized</span> condition P. ceylanicum was able to give 2.3-fold increase in phycocyanin production in comparison to commonly used BG 11 medium in 32 days. We have demonstrated the extraction, purification and characterization of C-phycocyanin using novel method based on filtration and single <span class="hlt">step</span> chromatography. The protein was extracted by repeated freeze-thaw cycles and the crude extract was <span class="hlt">filtered</span> and concentrated in stirred ultrafiltration cell (UFC). The UFC concentrate was then subjected to a single ion exchange chromatographic <span class="hlt">step</span>. A purity ratio of 4.15 was achieved from a starting value of 1.05. The recovery efficiency of C-phycocyanin from crude extract was 63.50%. The purity was checked by electrophoresis and UV-Vis spectroscopy. PMID:18954974</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21807026','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21807026"><span id="translatedtitle">Dimension reduction: additional benefit of an <span class="hlt">optimal</span> <span class="hlt">filter</span> for independent component analysis to extract event-related potentials.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cong, Fengyu; Leppänen, Paavo H T; Astikainen, Piia; Hämäläinen, Jarmo; Hietanen, Jari K; Ristaniemi, Tapani</p> <p>2011-09-30</p> <p>The present study addresses benefits of a linear <span class="hlt">optimal</span> <span class="hlt">filter</span> (OF) for independent component analysis (ICA) in extracting brain event-related potentials (ERPs). A <span class="hlt">filter</span> such as the digital <span class="hlt">filter</span> is usually considered as a denoising tool. Actually, in <span class="hlt">filtering</span> ERP recordings by an OF, the ERP' topography should not be changed by the <span class="hlt">filter</span>, and the output should also be able to be modeled by the linear transformation. Moreover, an OF designed for a specific ERP source or component may remove noise, as well as reduce the overlap of sources and even reject some non-targeted sources in the ERP recordings. The OF can thus accomplish both the denoising and dimension reduction (reducing the number of sources) simultaneously. We demonstrated these effects using two datasets, one containing visual and the other auditory ERPs. The results showed that the method including OF and ICA extracted much more reliable components than the sole ICA without OF did, and that OF removed some non-targeted sources and made the underdetermined model of EEG recordings approach to the determined one. Thus, we suggest designing an OF based on the properties of an ERP to <span class="hlt">filter</span> recordings before using ICA decomposition to extract the targeted ERP component. PMID:21807026</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4662124','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4662124"><span id="translatedtitle"><span class="hlt">Optimization</span> of a Multi-<span class="hlt">Step</span> Procedure for Isolation of Chicken Bone Collagen</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2015-01-01</p> <p>Chicken bone is not adequately utilized despite its high nutritional value and protein content. Although not a common raw material, chicken bone can be used in many different ways besides manufacturing of collagen products. In this study, a multi-<span class="hlt">step</span> procedure was <span class="hlt">optimized</span> to isolate chicken bone collagen for higher yield and quality for manufacture of collagen products. The chemical composition of chicken bone was 2.9% nitrogen corresponding to about 15.6% protein, 9.5% fat, 14.7% mineral and 57.5% moisture. The lowest amount of protein loss was aimed along with the separation of the highest amount of visible impurities, non-collagen proteins, minerals and fats. Treatments under optimum conditions removed 57.1% of fats and 87.5% of minerals with respect to their initial concentrations. Meanwhile, 18.6% of protein and 14.9% of hydroxyproline were lost, suggesting that a selective separation of non-collagen components and isolation of collagen were achieved. A significant part of impurities were selectively removed and over 80% of the original collagen was preserved during the treatments. PMID:26761863</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013aero.confE..97S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013aero.confE..97S"><span id="translatedtitle"><span class="hlt">Optimized</span> FIR <span class="hlt">filters</span> for digital pulse compression of biphase codes with low sidelobes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sanal, M.; Kuloor, R.; Sagayaraj, M. J.</p> <p></p> <p>In miniaturized radars where power, real estate, speed and low cost are tight constraints and Doppler tolerance is not a major concern biphase codes are popular and FIR <span class="hlt">filter</span> is used for digital pulse compression (DPC) implementation to achieve required range resolution. Disadvantage of low peak to sidelobe ratio (PSR) of biphase codes can be overcome by linear programming for either single stage mismatched <span class="hlt">filter</span> or two stage approach i.e. matched <span class="hlt">filter</span> followed by sidelobe suppression <span class="hlt">filter</span> (SSF) <span class="hlt">filter</span>. Linear programming (LP) calls for longer <span class="hlt">filter</span> lengths to obtain desirable PSR. Longer the <span class="hlt">filter</span> length greater will be the number of multipliers, hence more will be the requirement of logic resources used in the FPGAs and many time becomes design challenge for system on chip (SoC) requirement. This requirement of multipliers can be brought down by clustering the tap weights of the <span class="hlt">filter</span> by kmeans clustering algorithm at the cost of few dB deterioration in PSR. The cluster centroid as tap weight reduces logic used in FPGA for FIR <span class="hlt">filters</span> to a great extent by reducing number of weight multipliers. Since k-means clustering is an iterative algorithm, centroid for weights cluster is different in different iterations and causes different clusters. This causes difference in clustering of weights and sometimes even it may happen that lesser number of multiplier and lesser length of <span class="hlt">filter</span> provide better PSR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EJASP2014...95H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EJASP2014...95H"><span id="translatedtitle">Multiple local feature representations and their fusion based on an SVR model for iris recognition using <span class="hlt">optimized</span> Gabor <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>He, Fei; Liu, Yuanning; Zhu, Xiaodong; Huang, Chun; Han, Ye; Dong, Hongxing</p> <p>2014-12-01</p> <p>Gabor descriptors have been widely used in iris texture representations. However, fixed basic Gabor functions cannot match the changing nature of diverse iris datasets. Furthermore, a single form of iris feature cannot overcome difficulties in iris recognition, such as illumination variations, environmental conditions, and device variations. This paper provides multiple local feature representations and their fusion scheme based on a support vector regression (SVR) model for iris recognition using <span class="hlt">optimized</span> Gabor <span class="hlt">filters</span>. In our iris system, a particle swarm <span class="hlt">optimization</span> (PSO)- and a Boolean particle swarm <span class="hlt">optimization</span> (BPSO)-based algorithm is proposed to provide suitable Gabor <span class="hlt">filters</span> for each involved test dataset without predefinition or manual modulation. Several comparative experiments on JLUBR-IRIS, CASIA-I, and CASIA-V4-Interval iris datasets are conducted, and the results show that our work can generate improved local Gabor features by using <span class="hlt">optimized</span> Gabor <span class="hlt">filters</span> for each dataset. In addition, our SVR fusion strategy may make full use of their discriminative ability to improve accuracy and reliability. Other comparative experiments show that our approach may outperform other popular iris systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3791008','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3791008"><span id="translatedtitle">Globally <span class="hlt">Optimal</span> Multisensor Distributed Random Parameter Matrices Kalman <span class="hlt">Filtering</span> Fusion with Applications</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Luo, Yingting; Zhu, Yunmin; Luo, Dandan; Zhou, Jie; Song, Enbin; Wang, Donghua</p> <p>2008-01-01</p> <p>This paper proposes a new distributed Kalman <span class="hlt">filtering</span> fusion with random state transition and measurement matrices, i.e., random parameter matrices Kalman <span class="hlt">filtering</span>. It is proved that under a mild condition the fused state estimate is equivalent to the centralized Kalman <span class="hlt">filtering</span> using all sensor measurements; therefore, it achieves the best performance. More importantly, this result can be applied to Kalman <span class="hlt">filtering</span> with uncertain observations including the measurement with a false alarm probability as a special case, as well as, randomly variant dynamic systems with multiple models. Numerical examples are given which support our analysis and show significant performance loss of ignoring the randomness of the parameter matrices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/973636','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/973636"><span id="translatedtitle">Toward an <span class="hlt">Optimal</span> Position for IVC <span class="hlt">Filters</span>: Computational Modeling of the Impact of Renal Vein Inflow</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wang, S L; Singer, M A</p> <p>2009-07-13</p> <p>The purpose of this report is to evaluate the hemodynamic effects of renal vein inflow and <span class="hlt">filter</span> position on unoccluded and partially occluded IVC <span class="hlt">filters</span> using three-dimensional computational fluid dynamics. Three-dimensional models of the TrapEase and Gunther Celect IVC <span class="hlt">filters</span>, spherical thrombi, and an IVC with renal veins were constructed. Hemodynamics of steady-state flow was examined for unoccluded and partially occluded TrapEase and Gunther Celect IVC <span class="hlt">filters</span> in varying proximity to the renal veins. Flow past the unoccluded <span class="hlt">filters</span> demonstrated minimal disruption. Natural regions of stagnant/recirculating flow in the IVC are observed superior to the bilateral renal vein inflows, and high flow velocities and elevated shear stresses are observed in the vicinity of renal inflow. Spherical thrombi induce stagnant and/or recirculating flow downstream of the thrombus. Placement of the TrapEase <span class="hlt">filter</span> in the suprarenal vein position resulted in a large area of low shear stress/stagnant flow within the <span class="hlt">filter</span> just downstream of thrombus trapped in the upstream trapping position. <span class="hlt">Filter</span> position with respect to renal vein inflow influences the hemodynamics of <span class="hlt">filter</span> trapping. Placement of the TrapEase <span class="hlt">filter</span> in a suprarenal location may be thrombogenic with redundant areas of stagnant/recirculating flow and low shear stress along the caval wall due to the upstream trapping position and the naturally occurring region of stagnant flow from the renal veins. Infrarenal vein placement of IVC <span class="hlt">filters</span> in a near juxtarenal position with the downstream cone near the renal vein inflow likely confers increased levels of mechanical lysis of trapped thrombi due to increased shear stress from renal vein inflow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005PhyC..433..108W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005PhyC..433..108W"><span id="translatedtitle"><span class="hlt">Optimization</span> of <span class="hlt">step</span>-edge substrates for high- TC superconducting devices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, C. H.; Chen, M. J.; Hsu, M. H.; Chen, J. C.; Chen, K. L.; Chen, J. H.; Jeng, J. T.; Lai, T. S.; Horng, H. E.; Yang, H. C.</p> <p>2005-12-01</p> <p>To pursue <span class="hlt">step</span>-edge for high- TC superconducting grain boundary junctions or SQUIDs with high reproducibility and quality, we have developed two-<span class="hlt">step</span> procedures of fabricating very good <span class="hlt">step</span>-edge substrates. A protocol of precisely controlling <span class="hlt">step</span> angles for Josephson junctions has been established, with which we can predict the <span class="hlt">step</span> angles as well as get a better control of the fabrication process. The procedures can improve the <span class="hlt">step</span> ramp quality substantially. There are no needles, waves, trenches, cascade, or other flaws on these surfaces. The <span class="hlt">step</span> substrates present good uniformity with respect to any <span class="hlt">step</span> angle. We have characterized high- TC <span class="hlt">step</span>-edge dc SQUIDs connected in series. The I- V curves of SQUID arrays show the RSJ behavior. The enhanced modulation amplitude of 110 μV is achieved at 77 K with the <span class="hlt">step</span>-edge dc SQUID in series. The results clearly show the high uniformity and quality of the fabricated <span class="hlt">step</span>-edge Josephson junctions.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JMMM..394..361M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JMMM..394..361M"><span id="translatedtitle"><span class="hlt">Optimization</span> of synthesis and peptization <span class="hlt">steps</span> to obtain iron oxide nanoparticles with high energy dissipation rates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mérida, Fernando; Chiu-Lam, Andreina; Bohórquez, Ana C.; Maldonado-Camargo, Lorena; Pérez, María-Eglée; Pericchi, Luis; Torres-Lugo, Madeline; Rinaldi, Carlos</p> <p>2015-11-01</p> <p>Magnetic Fluid Hyperthermia (MFH) uses heat generated by magnetic nanoparticles exposed to alternating magnetic fields to cause a temperature increase in tumors to the hyperthermia range (43-47 °C), inducing apoptotic cancer cell death. As with all cancer nanomedicines, one of the most significant challenges with MFH is achieving high nanoparticle accumulation at the tumor site. This motivates development of synthesis strategies that maximize the rate of energy dissipation of iron oxide magnetic nanoparticles, preferable due to their intrinsic biocompatibility. This has led to development of synthesis strategies that, although attractive from the point of view of chemical elegance, may not be suitable for scale-up to quantities necessary for clinical use. On the other hand, to date the aqueous co-precipitation synthesis, which readily yields gram quantities of nanoparticles, has only been reported to yield sufficiently high specific absorption rates after laborious size selective fractionation. This work focuses on improvements to the aqueous co-precipitation of iron oxide nanoparticles to increase the specific absorption rate (SAR), by <span class="hlt">optimizing</span> synthesis conditions and the subsequent peptization <span class="hlt">step</span>. Heating efficiencies up to 1048 W/gFe (36.5 kA/m, 341 kHz; ILP=2.3 nH m2 kg-1) were obtained, which represent one of the highest values reported for iron oxide particles synthesized by co-precipitation without size-selective fractionation. Furthermore, particles reached SAR values of up to 719 W/gFe (36.5 kA/m, 341 kHz; ILP=1.6 nH m2 kg-1) when in a solid matrix, demonstrating they were capable of significant rates of energy dissipation even when restricted from physical rotation. Reduction in energy dissipation rate due to immobilization has been identified as an obstacle to clinical translation of MFH. Hence, particles obtained with the conditions reported here have great potential for application in nanoscale thermal cancer therapy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890004052','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890004052"><span id="translatedtitle"><span class="hlt">Optimization</span> by decomposition: A <span class="hlt">step</span> from hierarchic to non-hierarchic systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sobieszczanski-Sobieski, Jaroslaw</p> <p>1988-01-01</p> <p>A new, non-hierarchic decomposition is formulated for system <span class="hlt">optimization</span> that uses system analysis, system sensitivity analysis, temporary decoupled <span class="hlt">optimizations</span> performed in the design subspaces corresponding to the disciplines and subsystems, and a coordination <span class="hlt">optimization</span> concerned with the redistribution of responsibility for the constraint satisfaction and design trades among the disciplines and subsystems. The approach amounts to a variation of the well-known method of subspace <span class="hlt">optimization</span> modified so that the analysis of the entire system is eliminated from the subspace <span class="hlt">optimization</span> and the subspace <span class="hlt">optimizations</span> may be performed concurrently.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21032835','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21032835"><span id="translatedtitle">Dual-energy approach to contrast-enhanced mammography using the balanced <span class="hlt">filter</span> method: Spectral <span class="hlt">optimization</span> and preliminary phantom measurement</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Saito, Masatoshi</p> <p>2007-11-15</p> <p>Dual-energy contrast agent-enhanced mammography is a technique of demonstrating breast cancers obscured by a cluttered background resulting from the contrast between soft tissues in the breast. The technique has usually been implemented by exploiting two exposures to different x-ray tube voltages. In this article, another dual-energy approach using the balanced <span class="hlt">filter</span> method without switching the tube voltages is described. For the spectral <span class="hlt">optimization</span> of dual-energy mammography using the balanced <span class="hlt">filters</span>, we applied a theoretical framework reported by Lemacks et al. [Med. Phys. 29, 1739-1751 (2002)] to calculate the signal-to-noise ratio (SNR) in an iodinated contrast agent subtraction image. This permits the selection of beam parameters such as tube voltage and balanced <span class="hlt">filter</span> material, and the <span class="hlt">optimization</span> of the latter's thickness with respect to some critical quantity--in this case, mean glandular dose. For an imaging system with a 0.1 mm thick CsI:Tl scintillator, we predict that the <span class="hlt">optimal</span> tube voltage would be 45 kVp for a tungsten anode using zirconium, iodine, and neodymium balanced <span class="hlt">filters</span>. A mean glandular dose of 1.0 mGy is required to obtain an SNR of 5 in order to detect 1.0 mg/cm{sup 2} iodine in the resulting clutter-free image of a 5 cm thick breast composed of 50% adipose and 50% glandular tissue. In addition to spectral <span class="hlt">optimization</span>, we carried out phantom measurements to demonstrate the present dual-energy approach for obtaining a clutter-free image, which preferentially shows iodine, of a breast phantom comprising three major components - acrylic spheres, olive oil, and an iodinated contrast agent. The detection of iodine details on the cluttered background originating from the contrast between acrylic spheres and olive oil is analogous to the task of distinguishing contrast agents in a mixture of glandular and adipose tissues.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ApPhL.103i3702I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ApPhL.103i3702I"><span id="translatedtitle">Focusing time harmonic scalar fields in non-homogenous lossy media: Inverse <span class="hlt">filter</span> vs. constrained power focusing <span class="hlt">optimization</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iero, D. A. M.; Isernia, T.; Crocco, L.</p> <p>2013-08-01</p> <p>Two strategies to focus time harmonic scalar fields in known inhomogeneous lossy media are compared. The first one is the Inverse <span class="hlt">Filter</span> (IF) method, which faces the focusing task as the synthesis of a nominal field. The second one is the Constrained Power Focusing <span class="hlt">Optimization</span> (CPFO) method, which tackles the problem in terms of constrained mask constrained power <span class="hlt">optimization</span>. Numerical examples representative of focusing in noninvasive microwave hyperthermia are provided to show that CPFO is able to outperform IF, thanks to the additional degrees of freedom arising from the adopted power synthesis formulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26681183','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26681183"><span id="translatedtitle"><span class="hlt">Optimal</span> design of monitoring networks for multiple groundwater quality parameters using a Kalman <span class="hlt">filter</span>: application to the Irapuato-Valle aquifer.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Júnez-Ferreira, H E; Herrera, G S; González-Hita, L; Cardona, A; Mora-Rodríguez, J</p> <p>2016-01-01</p> <p>A new method for the <span class="hlt">optimal</span> design of groundwater quality monitoring networks is introduced in this paper. Various indicator parameters were considered simultaneously and tested for the Irapuato-Valle aquifer in Mexico. The <span class="hlt">steps</span> followed in the design were (1) establishment of the monitoring network objectives, (2) definition of a groundwater quality conceptual model for the study area, (3) selection of the parameters to be sampled, and (4) selection of a monitoring network by choosing the well positions that minimize the estimate error variance of the selected indicator parameters. Equal weight for each parameter was given to most of the aquifer positions and a higher weight to priority zones. The objective for the monitoring network in the specific application was to obtain a general reconnaissance of the water quality, including water types, water origin, and first indications of contamination. Water quality indicator parameters were chosen in accordance with this objective, and for the selection of the <span class="hlt">optimal</span> monitoring sites, it was sought to obtain a low-uncertainty estimate of these parameters for the entire aquifer and with more certainty in priority zones. The <span class="hlt">optimal</span> monitoring network was selected using a combination of geostatistical methods, a Kalman <span class="hlt">filter</span> and a heuristic <span class="hlt">optimization</span> method. Results show that when monitoring the 69 locations with higher priority order (the <span class="hlt">optimal</span> monitoring network), the joint average standard error in the study area for all the groundwater quality parameters was approximately 90 % of the obtained with the 140 available sampling locations (the set of pilot wells). This demonstrates that an <span class="hlt">optimal</span> design can help to reduce monitoring costs, by avoiding redundancy in data acquisition. PMID:26681183</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2956227','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2956227"><span id="translatedtitle">The Touro 12-<span class="hlt">Step</span>: A Systematic Guide to <span class="hlt">Optimizing</span> Survey Research with Online Discussion Boards</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ip, Eric J; Tenerowicz, Michael J; Perry, Paul J</p> <p>2010-01-01</p> <p>The Internet, in particular discussion boards, can provide a unique opportunity for recruiting participants in online research surveys. Despite its outreach potential, there are significant barriers which can limit its success. Trust, participation, and visibility issues can all hinder the recruitment process; the Touro 12-<span class="hlt">Step</span> was developed to address these potential hurdles. By following this <span class="hlt">step-by-step</span> approach, researchers will be able to minimize these pitfalls and maximize their recruitment potential via online discussion boards. PMID:20507843</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22254562','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22254562"><span id="translatedtitle">Improvement of hemocompatibility for hydrodynamic levitation centrifugal pump by <span class="hlt">optimizing</span> <span class="hlt">step</span> bearings.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kosaka, Ryo; Yada, Toru; Nishida, Masahiro; Maruyama, Osamu; Yamane, Takashi</p> <p>2011-01-01</p> <p>We have developed a hydrodynamic levitation centrifugal blood pump with a semi-open impeller for a mechanically circulatory assist. The impeller levitated with original hydrodynamic bearings without any complicated control and sensors. However, narrow bearing gap has the potential for causing hemolysis. The purpose of the study is to investigate the geometric configuration of the hydrodynamic <span class="hlt">step</span> bearing to minimize hemolysis by expansion of the bearing gap. Firstly, we performed the numerical analysis of the <span class="hlt">step</span> bearing based on Reynolds equation, and measured the actual hydrodynamic force of the <span class="hlt">step</span> bearing. Secondly, the bearing gap measurement test and the hemolysis test were performed to the blood pumps, whose <span class="hlt">step</span> length were 0 %, 33 % and 67 % of the vane length respectively. As a result, in the numerical analysis, the hydrodynamic force was the largest, when the <span class="hlt">step</span> bearing was around 70 %. In the actual evaluation tests, the blood pump having <span class="hlt">step</span> 67 % obtained the maximum bearing gap, and was able to improve the hemolysis, compared to those having <span class="hlt">step</span> 0% and 33%. We confirmed that the numerical analysis of the <span class="hlt">step</span> bearing worked effectively, and the blood pump having <span class="hlt">step</span> 67 % was suitable configuration to minimize hemolysis, because it realized the largest bearing gap. PMID:22254562</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005PMB....50.5509C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005PMB....50.5509C"><span id="translatedtitle"><span class="hlt">Optimal</span> <span class="hlt">filter</span> design for shielded and unshielded ambient noise reduction in fetal magnetocardiography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Comani, S.; Mantini, D.; Alleva, G.; Di Luzio, S.; Romani, G. L.</p> <p>2005-12-01</p> <p>The greatest impediment to extracting high-quality fetal signals from fetal magnetocardiography (fMCG) is environmental magnetic noise, which may have peak-to-peak intensity comparable to fetal QRS amplitude. Being an unstructured Gaussian signal with large disturbances at specific frequencies, ambient field noise can be reduced with hardware-based approaches and/or with software algorithms that digitally <span class="hlt">filter</span> magnetocardiographic recordings. At present, no systematic evaluation of <span class="hlt">filters</span>' performances on shielded and unshielded fMCG is available. We designed high-pass and low-pass Chebychev II-type <span class="hlt">filters</span> with zero-phase and stable impulse response; the most commonly used band-pass <span class="hlt">filters</span> were implemented combining high-pass and low-pass <span class="hlt">filters</span>. The achieved ambient noise reduction in shielded and unshielded recordings was quantified, and the corresponding signal-to-noise ratio (SNR) and signal-to-distortion ratio (SDR) of the retrieved fetal signals was evaluated. The study regarded 66 fMCG datasets at different gestational ages (22-37 weeks). Since the spectral structures of shielded and unshielded magnetic noise were very similar, we concluded that the same <span class="hlt">filter</span> setting might be applied to both conditions. Band-pass <span class="hlt">filters</span> (1.0-100 Hz) and (2.0-100 Hz) provided the best combinations of fetal signal detection rates, SNR and SDR; however, the former should be preferred in the case of arrhythmic fetuses, which might present spectral components below 2 Hz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890015778','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890015778"><span id="translatedtitle"><span class="hlt">Optimization</span> by decomposition: A <span class="hlt">step</span> from hierarchic to non-hierarchic systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sobieszczanski-Sobieski, Jaroslaw</p> <p>1989-01-01</p> <p>A new, non-hierarchic decomposition is formulated for system <span class="hlt">optimization</span> that uses system analysis, system sensitivity analysis, temporary decoupled <span class="hlt">optimizations</span> performed in the design subspaces corresponding to the disciplines and subsystems, and a coordination <span class="hlt">optimization</span> concerned with the redistribution of responsibility for the constraint satisfaction and design trades among the disciplines and subsystems, and a coordination <span class="hlt">optimization</span> concerned with the redistribution of responsibility for the constraint satisfaction and design trades among the disciplines and subsystems. The approach amounts to a variation of the well-known method of subspace <span class="hlt">optimization</span> modified so that the analysis of the entire system is eliminated from the subspace <span class="hlt">optimization</span> and the subspace <span class="hlt">optimizations</span> may be performed concurrently.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/981334','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/981334"><span id="translatedtitle">Near-Diffraction-Limited Operation of <span class="hlt">Step</span>-Index Large-Mode-Area Fiber Lasers Via Gain <span class="hlt">Filtering</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Marciante, J.R.; Roides, R.G.; Shkunov, V.V.; Rockwell, D.A.</p> <p>2010-06-04</p> <p>We present, for the first time to our knowledge, an explicit experimental comparison of beam quality in conventional and confined-gain multimode fiber lasers. In the conventional fiber laser, beam quality degrades with increasing output power. In the confined-gain fiber laser, the beam quality is good and does not degrade with output power. Gain <span class="hlt">filtering</span> of higher-order modes in 28 μm diameter core fiber lasers is demonstrated with a beam quality of M^2 = 1.3 at all pumping levels. Theoretical modeling is shown to agree well with experimentally observed trends.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SPIE.6789E..22W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SPIE.6789E..22W"><span id="translatedtitle"><span class="hlt">Optimal</span> features selection based on circular Gabor <span class="hlt">filters</span> and RSE in texture segmentation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Qiong; Liu, Jian; Tian, Jinwen</p> <p>2007-12-01</p> <p>This paper designs the circular Gabor <span class="hlt">filters</span> incorporating into the human visual characteristics, and the concept of mutual information entropy in rough set is introduced to evaluate the effect of the features extracted from different <span class="hlt">filters</span> on clustering, redundant features are got rid of, Experimental results indicate that the proposed algorithm outperforms conventional approaches in terms of both objective measurements and visual evaluation in texture segmentation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4818102','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4818102"><span id="translatedtitle">Robust Brain-Machine Interface Design Using <span class="hlt">Optimal</span> Feedback Control Modeling and Adaptive Point Process <span class="hlt">Filtering</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Carmena, Jose M.</p> <p>2016-01-01</p> <p>Much progress has been made in brain-machine interfaces (BMI) using decoders such as Kalman <span class="hlt">filters</span> and finding their parameters with closed-loop decoder adaptation (CLDA). However, current decoders do not model the spikes directly, and hence may limit the processing time-scale of BMI control and adaptation. Moreover, while specialized CLDA techniques for intention estimation and assisted training exist, a unified and systematic CLDA framework that generalizes across different setups is lacking. Here we develop a novel closed-loop BMI training architecture that allows for processing, control, and adaptation using spike events, enables robust control and extends to various tasks. Moreover, we develop a unified control-theoretic CLDA framework within which intention estimation, assisted training, and adaptation are performed. The architecture incorporates an infinite-horizon <span class="hlt">optimal</span> feedback-control (OFC) model of the brain’s behavior in closed-loop BMI control, and a point process model of spikes. The OFC model infers the user’s motor intention during CLDA—a process termed intention estimation. OFC is also used to design an autonomous and dynamic assisted training technique. The point process model allows for neural processing, control and decoder adaptation with every spike event and at a faster time-scale than current decoders; it also enables dynamic spike-event-based parameter adaptation unlike current CLDA methods that use batch-based adaptation on much slower adaptation time-scales. We conducted closed-loop experiments in a non-human primate over tens of days to dissociate the effects of these novel CLDA components. The OFC intention estimation improved BMI performance compared with current intention estimation techniques. OFC assisted training allowed the subject to consistently achieve proficient control. Spike-event-based adaptation resulted in faster and more consistent performance convergence compared with batch-based methods, and was robust to parameter initialization. Finally, the architecture extended control to tasks beyond those used for CLDA training. These results have significant implications towards the development of clinically-viable neuroprosthetics. PMID:27035820</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27035820','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27035820"><span id="translatedtitle">Robust Brain-Machine Interface Design Using <span class="hlt">Optimal</span> Feedback Control Modeling and Adaptive Point Process <span class="hlt">Filtering</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shanechi, Maryam M; Orsborn, Amy L; Carmena, Jose M</p> <p>2016-04-01</p> <p>Much progress has been made in brain-machine interfaces (BMI) using decoders such as Kalman <span class="hlt">filters</span> and finding their parameters with closed-loop decoder adaptation (CLDA). However, current decoders do not model the spikes directly, and hence may limit the processing time-scale of BMI control and adaptation. Moreover, while specialized CLDA techniques for intention estimation and assisted training exist, a unified and systematic CLDA framework that generalizes across different setups is lacking. Here we develop a novel closed-loop BMI training architecture that allows for processing, control, and adaptation using spike events, enables robust control and extends to various tasks. Moreover, we develop a unified control-theoretic CLDA framework within which intention estimation, assisted training, and adaptation are performed. The architecture incorporates an infinite-horizon <span class="hlt">optimal</span> feedback-control (OFC) model of the brain's behavior in closed-loop BMI control, and a point process model of spikes. The OFC model infers the user's motor intention during CLDA-a process termed intention estimation. OFC is also used to design an autonomous and dynamic assisted training technique. The point process model allows for neural processing, control and decoder adaptation with every spike event and at a faster time-scale than current decoders; it also enables dynamic spike-event-based parameter adaptation unlike current CLDA methods that use batch-based adaptation on much slower adaptation time-scales. We conducted closed-loop experiments in a non-human primate over tens of days to dissociate the effects of these novel CLDA components. The OFC intention estimation improved BMI performance compared with current intention estimation techniques. OFC assisted training allowed the subject to consistently achieve proficient control. Spike-event-based adaptation resulted in faster and more consistent performance convergence compared with batch-based methods, and was robust to parameter initialization. Finally, the architecture extended control to tasks beyond those used for CLDA training. These results have significant implications towards the development of clinically-viable neuroprosthetics. PMID:27035820</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19746797','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19746797"><span id="translatedtitle">Spectral <span class="hlt">optimization</span> for measuring electron density by the dual-energy computed tomography coupled with balanced <span class="hlt">filter</span> method.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Saito, Masatoshi</p> <p>2009-08-01</p> <p>Dual-energy computed tomography (DECT) has the potential for measuring electron density distribution in a human body to predict the range of particle beams for treatment planning in proton or heavy-ion radiotherapy. However, thus far, a practical dual-energy method that can be used to precisely determine electron density for treatment planning in particle radiotherapy has not been developed. In this article, another DECT technique involving a balanced <span class="hlt">filter</span> method using a conventional x-ray tube is described. For the spectral <span class="hlt">optimization</span> of DECT using balanced <span class="hlt">filters</span>, the author calculates beam-hardening error and air kerma required to achieve a desired noise level in electron density and effective atomic number images of a cylindrical water phantom with 50 cm diameter. The calculation enables the selection of beam parameters such as tube voltage, balanced <span class="hlt">filter</span> material, and its thickness. The <span class="hlt">optimized</span> parameters were applied to cases with different phantom diameters ranging from 5 to 50 cm for the calculations. The author predicts that the <span class="hlt">optimal</span> combination of tube voltages would be 80 and 140 kV with Tb/Hf and Bi/Mo <span class="hlt">filter</span> pairs for the 50-cm-diameter water phantom. When a single phantom calibration at a diameter of 25 cm was employed to cover all phantom sizes, maximum absolute beam-hardening errors were 0.3% and 0.03% for electron density and effective atomic number, respectively, over a range of diameters of the water phantom. The beam-hardening errors were 1/10 or less as compared to those obtained by conventional DECT, although the dose was twice that of the conventional DECT case. From the viewpoint of beam hardening and the tube-loading efficiency, the present DECT using balanced <span class="hlt">filters</span> would be significantly more effective in measuring the electron density than the conventional DECT. Nevertheless, further developments of low-exposure imaging technology should be necessary as well as x-ray tubes with higher outputs to apply DECT coupled with the balanced <span class="hlt">filter</span> method for clinical use. PMID:19746797</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18263022','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18263022"><span id="translatedtitle">Convergence acceleration of the Hopfield neural network by <span class="hlt">optimizing</span> integration <span class="hlt">step</span> sizes.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Abe, S</p> <p>1996-01-01</p> <p>In our previous work we have clarified global convergence of the Hopfield neural network and showed, by computer simulations, improvement of solution quality by gradually decreasing the diagonal elements of the coefficient matrix. In this paper, to accelerate convergence of the Hopfield network, at each time <span class="hlt">step</span> the integration <span class="hlt">step</span> size is determined dynamically so that at least one component of a variable vector reaches the surface of the hypercube. The computer simulation for the traveling salesman problem and an LSI module placement problem shows that convergence is stabilized and accelerated compared to integration by a constant <span class="hlt">step</span> size. PMID:18263022</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2974102','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2974102"><span id="translatedtitle">Generalized <span class="hlt">optimal</span> spatial <span class="hlt">filtering</span> using a kernel approach with application to EEG classification</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rutkowski, Tomasz M.; Zhang, Liqing; Cichocki, Andrzej</p> <p>2010-01-01</p> <p>Common spatial patterns (CSP) has been widely used for finding the linear spatial <span class="hlt">filters</span> which are able to extract the discriminative brain activities between two different mental tasks. However, the CSP is difficult to capture the nonlinearly clustered structure from the non-stationary EEG signals. To relax the presumption of strictly linear patterns in the CSP, in this paper, a generalized CSP (GCSP) based on generalized singular value decomposition (GSVD) and kernel method is proposed. Our method is able to find the nonlinear spatial <span class="hlt">filters</span> which are formulated in the feature space defined by a nonlinear mapping through kernel functions. Furthermore, in order to overcome the overfitting problem, the regularized GCSP is developed by adding the regularized parameters. The experimental results demonstrate that our method is an effective nonlinear spatial <span class="hlt">filtering</span> method. PMID:22132044</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22325161','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22325161"><span id="translatedtitle">SU-E-I-57: Evaluation and <span class="hlt">Optimization</span> of Effective-Dose Using Different Beam-Hardening <span class="hlt">Filters</span> in Clinical Pediatric Shunt CT Protocol</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gill, K; Aldoohan, S; Collier, J</p> <p>2014-06-01</p> <p>Purpose: Study image <span class="hlt">optimization</span> and radiation dose reduction in pediatric shunt CT scanning protocol through the use of different beam-hardening <span class="hlt">filters</span> Methods: A 64-slice CT scanner at OU Childrens Hospital has been used to evaluate CT image contrast-to-noise ratio (CNR) and measure effective-doses based on the concept of CT dose index (CTDIvol) using the pediatric head shunt scanning protocol. The routine axial pediatric head shunt scanning protocol that has been <span class="hlt">optimized</span> for the intrinsic x-ray tube <span class="hlt">filter</span> has been used to evaluate CNR by acquiring images using the ACR approved CT-phantom and radiation dose CTphantom, which was used to measure CTDIvol. These results were set as reference points to study and evaluate the effects of adding different <span class="hlt">filtering</span> materials (i.e. Tungsten, Tantalum, Titanium, Nickel and Copper <span class="hlt">filters</span>) to the existing <span class="hlt">filter</span> on image quality and radiation dose. To ensure <span class="hlt">optimal</span> image quality, the scanner routine air calibration was run for each added <span class="hlt">filter</span>. The image CNR was evaluated for different kVps and wide range of mAs values using above mentioned beam-hardening <span class="hlt">filters</span>. These scanning protocols were run under axial as well as under helical techniques. The CTDIvol and the effective-dose were measured and calculated for all scanning protocols and added filtration, including the intrinsic x-ray tube <span class="hlt">filter</span>. Results: Beam-hardening <span class="hlt">filter</span> shapes energy spectrum, which reduces the dose by 27%. No noticeable changes in image low contrast detectability Conclusion: Effective-dose is very much dependent on the CTDIVol, which is further very much dependent on beam-hardening <span class="hlt">filters</span>. Substantial reduction in effective-dose is realized using beam-hardening <span class="hlt">filters</span> as compare to the intrinsic <span class="hlt">filter</span>. This phantom study showed that significant radiation dose reduction could be achieved in CT pediatric shunt scanning protocols without compromising in diagnostic value of image quality.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120000816','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120000816"><span id="translatedtitle"><span class="hlt">Optimized</span> FPGA Implementation of Multi-Rate FIR <span class="hlt">Filters</span> Through Thread Decomposition</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kobayashi, Kayla N.; He, Yutao; Zheng, Jason X.</p> <p>2011-01-01</p> <p>Multi-rate finite impulse response (MRFIR) <span class="hlt">filters</span> are among the essential signal-processing components in spaceborne instruments where finite impulse response <span class="hlt">filters</span> are often used to minimize nonlinear group delay and finite precision effects. Cascaded (multistage) designs of MRFIR <span class="hlt">filters</span> are further used for large rate change ratio in order to lower the required throughput, while simultaneously achieving comparable or better performance than single-stage designs. Traditional representation and implementation of MRFIR employ polyphase decomposition of the original <span class="hlt">filter</span> structure, whose main purpose is to compute only the needed output at the lowest possible sampling rate. In this innovation, an alternative representation and implementation technique called TD-MRFIR (Thread Decomposition MRFIR) is presented. The basic idea is to decompose MRFIR into output computational threads, in contrast to a structural decomposition of the original <span class="hlt">filter</span> as done in the polyphase decomposition. A naive implementation of a decimation <span class="hlt">filter</span> consisting of a full FIR followed by a downsampling stage is very inefficient, as most of the computations performed by the FIR state are discarded through downsampling. In fact, only 1/M of the total computations are useful (M being the decimation factor). Polyphase decomposition provides an alternative view of decimation <span class="hlt">filters</span>, where the downsampling occurs before the FIR stage, and the outputs are viewed as the sum of M sub-<span class="hlt">filters</span> with length of N/M taps. Although this approach leads to more efficient <span class="hlt">filter</span> designs, in general the implementation is not straightforward if the numbers of multipliers need to be minimized. In TD-MRFIR, each thread represents an instance of the finite convolution required to produce a single output of the MRFIR. The <span class="hlt">filter</span> is thus viewed as a finite collection of concurrent threads. Each of the threads completes when a convolution result (<span class="hlt">filter</span> output value) is computed, and activated when the first input of the convolution becomes available. Thus, the new threads get spawned at exactly the rate of N/M, where N is the total number of taps, and M is the decimation factor. Existing threads retire at the same rate of N/M. The implementation of an MRFIR is thus transformed into a problem to statically schedule the minimum number of multipliers such that all threads can be completed on time. Solving the static scheduling problem is rather straightforward if one examines the Thread Decomposition Diagram, which is a table-like diagram that has rows representing computation threads and columns representing time. The control logic of the MRFIR can be implemented using simple counters. Instead of decomposing MRFIRs into subfilters as suggested by polyphase decomposition, the thread decomposition diagrams transform the problem into a familiar one of static scheduling, which can be easily solved as the input rate is constant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2583789','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2583789"><span id="translatedtitle"><span class="hlt">Optimality</span> of the Holm procedure among general <span class="hlt">step</span>-down multiple testing procedures</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Salzman, Peter</p> <p>2008-01-01</p> <p>We study the class of general <span class="hlt">step</span>-down multiple testing procedures, which contains the usually considered procedures determined by a nondecreasing sequence of thresholds (we call them threshold <span class="hlt">step</span>-down, or TSD, procedures) as a parametric subclass. We show that all procedures in this class satisfying the natural condition of monotonicity and controlling the family-wise error rate (FWER) at a prescribed level are dominated by one of them – the classical Holm procedure. This generalizes an earlier result pertaining to the subclass of TSD procedures (Lehmann and Romano, Testing Statistical Hypotheses, 3rd ed., 2005). We also derive a relation between the levels at which a monotone <span class="hlt">step</span>-down procedure controls the FWER and the generalized FWER (the probability of k or more false rejections). PMID:19759804</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=286120','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=286120"><span id="translatedtitle"><span class="hlt">Optimal</span> optical <span class="hlt">filters</span> of fluorescence excitation and emission for poultry fecal detection</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Purpose: An analytic method to design excitation and emission <span class="hlt">filters</span> of a multispectral fluorescence imaging system is proposed and was demonstrated in an application to poultry fecal inspection. Methods: A mathematical model of a multispectral imaging system is proposed and its system parameters, ...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006MNRAS.370.1713S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006MNRAS.370.1713S"><span id="translatedtitle">Detecting Sunyaev-Zel'dovich clusters with Planck - II. Foreground components and <span class="hlt">optimized</span> <span class="hlt">filtering</span> schemes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schäfer, B. M.; Pfrommer, C.; Hell, R. M.; Bartelmann, M.</p> <p>2006-08-01</p> <p>The Planck mission is the most sensitive all-sky cosmic microwave background (CMB) experiment currently planned. The High-Frequency Instrument (HFI) will be especially suited for observing clusters of galaxies by their thermal Sunyaev-Zel'dovich (SZ) effect. In order to assess Planck's SZ capabilities in the presence of spurious signals, a simulation is presented that combines maps of the thermal and kinetic SZ effects with a realization of the CMB, in addition to Galactic foregrounds (synchrotron emission, free-free emission, thermal emission from dust, CO-line radiation) as well as the submillimetric emission from celestial bodies of our Solar system. Additionally, observational issues such as the finite angular resolution and spatially non-uniform instrumental noise of Planck's sky maps are taken into account, yielding a set of all-sky flux maps, the autocorrelation and cross-correlation properties of which are examined in detail. In the second part of the paper, <span class="hlt">filtering</span> schemes based on scale-adaptive and matched <span class="hlt">filtering</span> are extended to spherical data sets, that enable the amplification of the weak SZ signal in the presence of all contaminations stated above. The theory of scale-adaptive and matched <span class="hlt">filtering</span> in the framework of spherical maps is developed, the resulting <span class="hlt">filter</span> kernel shapes are discussed and their functionality is verified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8783E..1EY','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8783E..1EY"><span id="translatedtitle">Research on improved mechanism for particle <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Jinxia; Xu, Jingmin; Tang, Yongli; Zhao, Qian</p> <p>2013-03-01</p> <p>Based on the analysis of particle <span class="hlt">filter</span> algorithm, two improved mechanism are studied so as to improve the performance of particle <span class="hlt">filter</span>. Firstly, hybrid proposal distribution with annealing parameter is studied in order to use current information of the latest observed measurement to <span class="hlt">optimize</span> particle <span class="hlt">filter</span>. Then, resampling <span class="hlt">step</span> in particle <span class="hlt">filter</span> is improved by two methods which are based on partial stratified resampling (PSR). One is that it uses the <span class="hlt">optimal</span> idea to improve the weights after implementing PSR, and the other is that it uses the <span class="hlt">optimal</span> idea to improve the weights before implementing PSR and uses adaptive mutation operation for all particles so as to assure the diversity of particle sets after PSR. At last, the simulations based on single object tracking are implemented, and the performances of the improved mechanism for particle <span class="hlt">filter</span> are estimated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/971914','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/971914"><span id="translatedtitle"><span class="hlt">Optimization</span> of a femtosecond Ti : sapphire amplifier using a acouto-optic programmable dispersive <span class="hlt">filter</span> and a genetic algorithm.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Korovyanko, O. J.; Rey-de-Castro, R.; Elles, C. G.; Crowell, R. A.; Li, Y.</p> <p>2006-01-01</p> <p>The temporal output of a Ti:Sapphire laser system has been <span class="hlt">optimized</span> using an acousto-optic programmable dispersive <span class="hlt">filter</span> and a genetic algorithm. In-situ recording the evolution of spectral phase, amplitude and temporal pulse profile for each iteration of the algorithm using SPIDER shows that we are able to lock the spectral phase of the laser pulse within a narrow margin. By using the second harmonic of the CPA laser as feedback for the genetic algorithm, it has been demonstrated that severe mismatch between the compressor and stretcher can be compensated for in a short period of time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MS%26E...69a2005B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MS%26E...69a2005B"><span id="translatedtitle">Numerical experiment <span class="hlt">optimization</span> to obtain the characteristics of the centrifugal pump <span class="hlt">steps</span> package</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boldyrev, S. V.; Boldyrev, A. V.</p> <p>2014-12-01</p> <p>The numerical simulation method of turbulent flow in a running space of the working-stage in a centrifugal pump using the periodicity conditions has been formulated. The proposed method allows calculating the characteristic indices of one pump <span class="hlt">step</span> at a lower computing resources cost. The comparison of the pump characteristics' calculation results with pilot data has been conducted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/1698470','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/1698470"><span id="translatedtitle"><span class="hlt">Optimizing</span> planar lipid bilayer single-channel recordings for high resolution with rapid voltage <span class="hlt">steps</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wonderlin, W F; Finkel, A; French, R J</p> <p>1990-08-01</p> <p>We describe two enhancements of the planar bilayer recording method which enable low-noise recordings of single-channel currents activated by voltage <span class="hlt">steps</span> in planar bilayers formed on apertures in partitions separating two open chambers. First, we have refined a simple and effective procedure for making small bilayer apertures (25-80 micrograms diam) in plastic cups. These apertures combine the favorable properties of very thin edges, good mechanical strength, and low stray capacitance. In addition to enabling formation of small, low-capacitance bilayers, this aperture design also minimizes the access resistance to the bilayer, thereby improving the low-noise performance. Second, we have used a patch-clamp headstage modified to provide logic-controlled switching between a high-gain (50 G omega) feedback resistor for high-resolution recording and a low-gain (50 M omega) feedback resistor for rapid charging of the bilayer capacitance. The gain is switched from high to low before a voltage <span class="hlt">step</span> and then back to high gain 25 microseconds after the <span class="hlt">step</span>. With digital subtraction of the residual currents produced by the gain switching and electrostrictive changes in bilayer capacitance, we can achieve a steady current baseline within 1 ms after the voltage <span class="hlt">step</span>. These enhancements broaden the range of experimental applications for the planar bilayer method by combining the high resolution previously attained only with small bilayers formed on pipette tips with the flexibility of experimental design possible with planar bilayers in open chambers. We illustrate application of these methods with recordings of the voltage-<span class="hlt">step</span> activation of a voltage-gated potassium channel. PMID:1698470</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016RScI...87bB136C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016RScI...87bB136C"><span id="translatedtitle"><span class="hlt">Optimization</span> of plasma parameters with magnetic <span class="hlt">filter</span> field and pressure to maximize H- ion density in a negative hydrogen ion source</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cho, Won-Hwi; Dang, Jeong-Jeung; Kim, June Young; Chung, Kyoung-Jae; Hwang, Y. S.</p> <p>2016-02-01</p> <p>Transverse magnetic <span class="hlt">filter</span> field as well as operating pressure is considered to be an important control knob to enhance negative hydrogen ion production via plasma parameter <span class="hlt">optimization</span> in volume-produced negative hydrogen ion sources. Stronger <span class="hlt">filter</span> field to reduce electron temperature sufficiently in the extraction region is favorable, but generally known to be limited by electron density drop near the extraction region. In this study, unexpected electron density increase instead of density drop is observed in front of the extraction region when the applied transverse <span class="hlt">filter</span> field increases monotonically toward the extraction aperture. Measurements of plasma parameters with a movable Langmuir probe indicate that the increased electron density may be caused by low energy electron accumulation in the <span class="hlt">filter</span> region decreasing perpendicular diffusion coefficients across the increasing <span class="hlt">filter</span> field. Negative hydrogen ion populations are estimated from the measured profiles of electron temperatures and densities and confirmed to be consistent with laser photo-detachment measurements of the H- populations for various <span class="hlt">filter</span> field strengths and pressures. Enhanced H- population near the extraction region due to the increased low energy electrons in the <span class="hlt">filter</span> region may be utilized to increase negative hydrogen beam currents by moving the extraction position accordingly. This new finding can be used to design efficient H- sources with an <span class="hlt">optimal</span> <span class="hlt">filtering</span> system by maximizing high energy electron <span class="hlt">filtering</span> while keeping low energy electrons available in the extraction region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1082192','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1082192"><span id="translatedtitle">Exploration of <span class="hlt">Optimization</span> Options for Increasing Performance of a GPU Implementation of a Three-dimensional Bilateral <span class="hlt">Filter</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bethel, E. Wes; Bethel, E. Wes</p> <p>2012-01-06</p> <p>This report explores using GPUs as a platform for performing high performance medical image data processing, specifically smoothing using a 3D bilateral <span class="hlt">filter</span>, which performs anisotropic, edge-preserving smoothing. The algorithm consists of a running a specialized 3D convolution kernel over a source volume to produce an output volume. Overall, our objective is to understand what algorithmic design choices and configuration options lead to <span class="hlt">optimal</span> performance of this algorithm on the GPU. We explore the performance impact of using different memory access patterns, of using different types of device/on-chip memories, of using strictly aligned and unaligned memory, and of varying the size/shape of thread blocks. Our results reveal <span class="hlt">optimal</span> configuration parameters for our algorithm when executed sample 3D medical data set, and show performance gains ranging from 30x to over 200x as compared to a single-threaded CPU implementation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/8063302','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/8063302"><span id="translatedtitle"><span class="hlt">Optimal</span> discrimination and classification of neuronal action potential waveforms from multiunit, multichannel recordings using software-based linear <span class="hlt">filters</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gozani, S N; Miller, J P</p> <p>1994-04-01</p> <p>We describe advanced protocols for the discrimination and classification of neuronal spike waveforms within multichannel electrophysiological recordings. The programs are capable of detecting and classifying the spikes from multiple, simultaneously active neurons, even in situations where there is a high degree of spike waveform superposition on the recording channels. The protocols are based on the derivation of an <span class="hlt">optimal</span> linear <span class="hlt">filter</span> for each individual neuron. Each <span class="hlt">filter</span> is tuned to selectively respond to the spike waveform generated by the corresponding neuron, and to attenuate noise and the spike waveforms from all other neurons. The protocol is essentially an extension of earlier work [1], [13], [18]. However, the protocols extend the power and utility of the original implementations in two significant respects. First, a general single-pass automatic template estimation algorithm was derived and implemented. Second, the <span class="hlt">filters</span> were implemented within a software environment providing a greatly enhanced functional organization and user interface. The utility of the analysis approach was demonstrated on samples of multiunit electrophysiological recordings from the cricket abdominal nerve cord. PMID:8063302</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25285187','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25285187"><span id="translatedtitle">A COMPARISON OF MODEL BASED AND DIRECT <span class="hlt">OPTIMIZATION</span> BASED <span class="hlt">FILTERING</span> ALGORITHMS FOR SHEARWAVE VELOCITY RECONSTRUCTION FOR ELECTRODE VIBRATION ELASTOGRAPHY.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ingle, Atul; Varghese, Tomy</p> <p>2013-04-01</p> <p>Tissue stiffness estimation plays an important role in cancer detection and treatment. The presence of stiffer regions in healthy tissue can be used as an indicator for the possibility of pathological changes. Electrode vibration elastography involves tracking of a mechanical shear wave in tissue using radio-frequency ultrasound echoes. Based on appropriate assumptions on tissue elasticity, this approach provides a direct way of measuring tissue stiffness from shear wave velocity, and enabling visualization in the form of tissue stiffness maps. In this study, two algorithms for shear wave velocity reconstruction in an electrode vibration setup are presented. The first method models the wave arrival time data using a hidden Markov model whose hidden states are local wave velocities that are estimated using a particle <span class="hlt">filter</span> implementation. This is compared to a direct <span class="hlt">optimization</span>-based function fitting approach that uses sequential quadratic programming to estimate the unknown velocities and locations of interfaces. The mean shear wave velocities obtained using the two algorithms are within 10%of each other. Moreover, the Young's modulus estimates obtained from an incompressibility assumption are within 15 kPa of those obtained from the true stiffness data obtained from mechanical testing. Based on visual inspection of the two <span class="hlt">filtering</span> algorithms, the particle <span class="hlt">filtering</span> method produces smoother velocity maps. PMID:25285187</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4180247','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4180247"><span id="translatedtitle">A COMPARISON OF MODEL BASED AND DIRECT <span class="hlt">OPTIMIZATION</span> BASED <span class="hlt">FILTERING</span> ALGORITHMS FOR SHEARWAVE VELOCITY RECONSTRUCTION FOR ELECTRODE VIBRATION ELASTOGRAPHY</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ingle, Atul; Varghese, Tomy</p> <p>2014-01-01</p> <p>Tissue stiffness estimation plays an important role in cancer detection and treatment. The presence of stiffer regions in healthy tissue can be used as an indicator for the possibility of pathological changes. Electrode vibration elastography involves tracking of a mechanical shear wave in tissue using radio-frequency ultrasound echoes. Based on appropriate assumptions on tissue elasticity, this approach provides a direct way of measuring tissue stiffness from shear wave velocity, and enabling visualization in the form of tissue stiffness maps. In this study, two algorithms for shear wave velocity reconstruction in an electrode vibration setup are presented. The first method models the wave arrival time data using a hidden Markov model whose hidden states are local wave velocities that are estimated using a particle <span class="hlt">filter</span> implementation. This is compared to a direct <span class="hlt">optimization</span>-based function fitting approach that uses sequential quadratic programming to estimate the unknown velocities and locations of interfaces. The mean shear wave velocities obtained using the two algorithms are within 10%of each other. Moreover, the Young’s modulus estimates obtained from an incompressibility assumption are within 15 kPa of those obtained from the true stiffness data obtained from mechanical testing. Based on visual inspection of the two <span class="hlt">filtering</span> algorithms, the particle <span class="hlt">filtering</span> method produces smoother velocity maps. PMID:25285187</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26362231','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26362231"><span id="translatedtitle">A multiobjective <span class="hlt">optimization</span> approach for combating Aedes aegypti using chemical and biological alternated <span class="hlt">step</span>-size control.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dias, Weverton O; Wanner, Elizabeth F; Cardoso, Rodrigo T N</p> <p>2015-11-01</p> <p>Dengue epidemics, one of the most important viral disease worldwide, can be prevented by combating the transmission vector Aedes aegypti. In support of this aim, this article proposes to analyze the Dengue vector control problem in a multiobjective <span class="hlt">optimization</span> approach, in which the intention is to minimize both social and economic costs, using a dynamic mathematical model representing the mosquitoes' population. It consists in finding <span class="hlt">optimal</span> alternated <span class="hlt">step</span>-size control policies combining chemical (via application of insecticides) and biological control (via insertion of sterile males produced by irradiation). All the <span class="hlt">optimal</span> policies consists in apply insecticides just at the beginning of the season and, then, keep the mosquitoes in an acceptable level spreading into environment a few amount of sterile males. The <span class="hlt">optimization</span> model analysis is driven by the use of genetic algorithms. Finally, it performs a statistic test showing that the multiobjective approach is effective in achieving the same effect of variations in the cost parameters. Then, using the proposed methodology, it is possible to find, in a single run, given a decision maker, the <span class="hlt">optimal</span> number of days and the respective amounts in which each control strategy must be applied, according to the tradeoff between using more insecticide with less transmission mosquitoes or more sterile males with more transmission mosquitoes. PMID:26362231</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740021420','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740021420"><span id="translatedtitle">Design of FIR digital <span class="hlt">filters</span> for pulse shaping and channel equalization using time-domain <span class="hlt">optimization</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Houts, R. C.; Vaughn, G. L.</p> <p>1974-01-01</p> <p>Three algorithms are developed for designing finite impulse response digital <span class="hlt">filters</span> to be used for pulse shaping and channel equalization. The first is the Minimax algorithm which uses linear programming to design a frequency-sampling <span class="hlt">filter</span> with a pulse shape that approximates the specification in a minimax sense. Design examples are included which accurately approximate a specified impulse response with a maximum error of 0.03 using only six resonators. The second algorithm is an extension of the Minimax algorithm to design preset equalizers for channels with known impulse responses. Both transversal and frequency-sampling equalizer structures are designed to produce a minimax approximation of a specified channel output waveform. Examples of these designs are compared as to the accuracy of the approximation, the resultant intersymbol interference (ISI), and the required transmitted energy. While the transversal designs are slightly more accurate, the frequency-sampling designs using six resonators have smaller ISI and energy values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014OptLE..54..141G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014OptLE..54..141G"><span id="translatedtitle"><span class="hlt">Optimization</span> of 3D laser scanning speed by use of combined variable <span class="hlt">step</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garcia-Cruz, X. M.; Sergiyenko, O. Yu.; Tyrsa, Vera; Rivas-Lopez, M.; Hernandez-Balbuena, D.; Rodriguez-Quiñonez, J. C.; Basaca-Preciado, L. C.; Mercorelli, P.</p> <p>2014-03-01</p> <p>The problem of 3D TVS slow functioning caused by constant small scanning <span class="hlt">step</span> becomes its solution in the presented research. It can be achieved by combined scanning <span class="hlt">step</span> application for the fast search of n obstacles in unknown surroundings. Such a problem is of keynote importance in automatic robot navigation. To maintain a reasonable speed robots must detect dangerous obstacles as soon as possible, but all known scanners able to measure distances with sufficient accuracy are unable to do it in real time. So, the related technical task of the scanning with variable speed and precise digital mapping only for selected spatial sectors is under consideration. A wide range of simulations in MATLAB 7.12.0 of several variants of hypothetic scenes with variable n obstacles in each scene (including variation of shapes and sizes) and scanning with incremented angle value (0.6° up to 15°) is provided. The aim of such simulation was to detect which angular values of interval still permit getting the maximal information about obstacles without undesired time losses. Three of such local maximums were obtained in simulations and then rectified by application of neuronal network formalism (Levenberg-Marquradt Algorithm). The obtained results in its turn were applied to MET (Micro-Electro-mechanical Transmission) design for practical realization of variable combined <span class="hlt">step</span> scanning on an experimental prototype of our previously known laser scanner.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100006914','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100006914"><span id="translatedtitle"><span class="hlt">Optimal</span> Tuner Selection for Kalman <span class="hlt">Filter</span>-Based Aircraft Engine Performance Estimation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Simon, Donald L.; Garg, Sanjay</p> <p>2010-01-01</p> <p>A linear point design methodology for minimizing the error in on-line Kalman <span class="hlt">filter</span>-based aircraft engine performance estimation applications is presented. This technique specifically addresses the underdetermined estimation problem, where there are more unknown parameters than available sensor measurements. A systematic approach is applied to produce a model tuning parameter vector of appropriate dimension to enable estimation by a Kalman <span class="hlt">filter</span>, while minimizing the estimation error in the parameters of interest. Tuning parameter selection is performed using a multi-variable iterative search routine which seeks to minimize the theoretical mean-squared estimation error. This paper derives theoretical Kalman <span class="hlt">filter</span> estimation error bias and variance values at steady-state operating conditions, and presents the tuner selection routine applied to minimize these values. Results from the application of the technique to an aircraft engine simulation are presented and compared to the conventional approach of tuner selection. Experimental simulation results are found to be in agreement with theoretical predictions. The new methodology is shown to yield a significant improvement in on-line engine performance estimation accuracy</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996SPIE.2765..110A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996SPIE.2765..110A"><span id="translatedtitle">Adaptive-<span class="hlt">filter</span>/feature-orthogonalization processing string for <span class="hlt">optimal</span> LLRT mine classfication in side-scan sonar imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aridgides, Tom; Libera, Peter; Fernandez, Manuel F.; Dobeck, Gerald J.</p> <p>1996-05-01</p> <p>An automatic, robust, adaptive clutter suppression, mine detection and classification processing string has been developed and applied to side-scan sonar imagery data. The overall processing string includes data pre-processing, adaptive clutter <span class="hlt">filtering</span> (ACF), 2D normalization, detection, feature extraction, and classification processing blocks. The data pre-processing block contains automatic gain control and data decimation processing. The ACF technique designs a 2D adaptive range-crossrange linear FIR <span class="hlt">filter</span> which is <span class="hlt">optimal</span> in the Least Squares sense, simultaneously suppressing the background clutter while preserving an average peak target signature (normalized shape) computed a priori using training set data. A multiple reference ACF algorithm version was utilized to account for multiple target shapes (due to different mine types, multiple target aspect angles, etc.). The detection block consists of thresholding, clustering of exceedances and limiting their number, and a secondary thresholding process. Following feature extraction, the classification block applies a novel transformation to the data, which orthogonalizes the features and enables an efficient application of the <span class="hlt">optimal</span> log-likelihood-ratio-test (LLRT) classification rule. The utility of the overall processing string was demonstrated with two side-scan sonar data sets. The ACF/feature orthogonalization based LLRT mine classification processing string provided average probability of correct mine classification and false alarm rate performance similar to that obtained when utilizing an expert sonar operator.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24895663','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24895663"><span id="translatedtitle">A multiobjective interval programming model for wind-hydrothermal power system dispatching using 2-<span class="hlt">step</span> <span class="hlt">optimization</span> algorithm.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ren, Kun; Jihong, Qu</p> <p>2014-01-01</p> <p>Wind-hydrothermal power system dispatching has received intensive attention in recent years because it can help develop various reasonable plans to schedule the power generation efficiency. But future data such as wind power output and power load would not be accurately predicted and the nonlinear nature involved in the complex multiobjective scheduling model; therefore, to achieve accurate solution to such complex problem is a very difficult task. This paper presents an interval programming model with 2-<span class="hlt">step</span> <span class="hlt">optimization</span> algorithm to solve multiobjective dispatching. Initially, we represented the future data into interval numbers and simplified the object function to a linear programming problem to search the feasible and preliminary solutions to construct the Pareto set. Then the simulated annealing method was used to search the <span class="hlt">optimal</span> solution of initial model. Thorough experimental results suggest that the proposed method performed reasonably well in terms of both operating efficiency and precision. PMID:24895663</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4034478','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4034478"><span id="translatedtitle">A Multiobjective Interval Programming Model for Wind-Hydrothermal Power System Dispatching Using 2-<span class="hlt">Step</span> <span class="hlt">Optimization</span> Algorithm</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jihong, Qu</p> <p>2014-01-01</p> <p>Wind-hydrothermal power system dispatching has received intensive attention in recent years because it can help develop various reasonable plans to schedule the power generation efficiency. But future data such as wind power output and power load would not be accurately predicted and the nonlinear nature involved in the complex multiobjective scheduling model; therefore, to achieve accurate solution to such complex problem is a very difficult task. This paper presents an interval programming model with 2-<span class="hlt">step</span> <span class="hlt">optimization</span> algorithm to solve multiobjective dispatching. Initially, we represented the future data into interval numbers and simplified the object function to a linear programming problem to search the feasible and preliminary solutions to construct the Pareto set. Then the simulated annealing method was used to search the <span class="hlt">optimal</span> solution of initial model. Thorough experimental results suggest that the proposed method performed reasonably well in terms of both operating efficiency and precision. PMID:24895663</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920001792','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920001792"><span id="translatedtitle">Maximized gust loads for a nonlinear airplane using matched <span class="hlt">filter</span> theory and constrained <span class="hlt">optimization</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Scott, Robert C.; Pototzky, Anthony S.; Perry, Boyd, III</p> <p>1991-01-01</p> <p>Two matched <span class="hlt">filter</span> theory based schemes are described and illustrated for obtaining maximized and time correlated gust loads for a nonlinear aircraft. The first scheme is computationally fast because it uses a simple 1-D search procedure to obtain its answers. The second scheme is computationally slow because it uses a more complex multi-dimensional search procedure to obtain its answers, but it consistently provides slightly higher maximum loads than the first scheme. Both schemes are illustrated with numerical examples involving a nonlinear control system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22391418','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22391418"><span id="translatedtitle">Rod-<span class="hlt">filter</span>-field <span class="hlt">optimization</span> of the J-PARC RF-driven H{sup −} ion source</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ueno, A. Ohkoshi, K.; Ikegami, K.; Takagi, A.; Yamazaki, S.; Oguri, H.</p> <p>2015-04-08</p> <p>In order to satisfy the Japan Proton Accelerator Research Complex (J-PARC) second-stage requirements of an H{sup −} ion beam of 60mA within normalized emittances of 1.5πmm•mrad both horizontally and vertically, a flat top beam duty factor of 1.25% (500μs×25Hz) and a life-time of longer than 1month, the J-PARC cesiated RF-driven H{sup −} ion source was developed by using an internal-antenna developed at the Spallation Neutron Source (SNS). Although rod-<span class="hlt">filter</span>-field (RFF) is indispensable and one of the most beam performance dominative parameters for the RF-driven H{sup −} ion source with the internal-antenna, the procedure to <span class="hlt">optimize</span> it is not established. In order to <span class="hlt">optimize</span> the RFF and establish the procedure, the beam performances of the J-PARC source with various types of rod-<span class="hlt">filter</span>-magnets (RFMs) were measured. By changing RFM’s gap length and gap number inside of the region projecting the antenna inner-diameter along the beam axis, the dependence of the H{sup −} ion beam intensity on the net 2MHz-RF power was <span class="hlt">optimized</span>. Furthermore, the fine-tuning of RFM’s cross-section (magnetmotive force) was indispensable for easy operation with the temperature (T{sub PE}) of the plasma electrode (PE) lower than 70°C, which minimizes the transverse emittances. The 5% reduction of RFM’s cross-section decreased the time-constant to recover the cesium effects after an slightly excessive cesiation on the PE from several 10 minutes to several minutes for T{sub PE} around 60°C.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730010134','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730010134"><span id="translatedtitle">Control system <span class="hlt">optimization</span> studies. Volume 2: High frequency cutoff <span class="hlt">filter</span> analysis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fong, M. H.</p> <p>1972-01-01</p> <p>The problem of digital implementation of a cutoff <span class="hlt">filter</span> is approached with consideration to word length, sampling rate, accuracy requirements, computing time and hardware restrictions. Computing time and hardware requirements for four possible programming forms for the linear portions of the <span class="hlt">filter</span> are determined. Upper bounds for the steady state system output error due to quantization for digital control systems containing a digital network programmed both in the direct form and in the canonical form are derived. This is accomplished by defining a set of error equations in the z domain and then applying the final value theorem to the solution. Quantization error was found to depend upon the digital word length, sampling rate, and system time constants. The error bound developed may be used to estimate the digital word length and sampling rate required to achieve a given system specification. From the quantization error accumulation, computing time and hardware point of view, and the fact that complex poles and zeros must be realized, the canonical form of programming seems preferable.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AdSpR..56.2248X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AdSpR..56.2248X"><span id="translatedtitle">EOP prediction using least square fitting and autoregressive <span class="hlt">filter</span> over <span class="hlt">optimized</span> data intervals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, XueQing; Zhou, YongHong</p> <p>2015-11-01</p> <p>This study firstly employs the calculation of base sequence with different length, in 1-90 day predictions of EOP (the UT1-UTC and polar motion), by the combined method of least squares and autoregressive model, and find the base sequence with best result for different prediction spans, which we call as "predictions over <span class="hlt">optimized</span> data intervals". Compared to the EOP predictions with fixed base data intervals, the "predictions over <span class="hlt">optimized</span> data intervals" performs better for the prediction of UT1-UTC, and shows a significant improvement for the prediction of polar motion, and particularly promotes our competitive level in the international activity of Earth Orientation Parameters Combination of Prediction Pilot Project.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JBO....18a6006T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JBO....18a6006T"><span id="translatedtitle">Two-<span class="hlt">step</span> reconstruction method using global <span class="hlt">optimization</span> and conjugate gradient for ultrasound-guided diffuse optical tomography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tavakoli, Behnoosh; Zhu, Quing</p> <p>2013-01-01</p> <p>Ultrasound-guided diffuse optical tomography (DOT) is a promising method for characterizing malignant and benign lesions in the female breast. We introduce a new two-<span class="hlt">step</span> algorithm for DOT inversion in which the optical parameters are estimated with the global <span class="hlt">optimization</span> method, genetic algorithm. The estimation result is applied as an initial guess to the conjugate gradient (CG) <span class="hlt">optimization</span> method to obtain the absorption and scattering distributions simultaneously. Simulations and phantom experiments have shown that the maximum absorption and reduced scattering coefficients are reconstructed with less than 10% and 25% errors, respectively. This is in contrast with the CG method alone, which generates about 20% error for the absorption coefficient and does not accurately recover the scattering distribution. A new measure of scattering contrast has been introduced to characterize benign and malignant breast lesions. The results of 16 clinical cases reconstructed with the two-<span class="hlt">step</span> method demonstrates that, on average, the absorption coefficient and scattering contrast of malignant lesions are about 1.8 and 3.32 times higher than the benign cases, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26273732','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26273732"><span id="translatedtitle">Reaction null-space <span class="hlt">filter</span>: extracting reactionless synergies for <span class="hlt">optimal</span> postural balance from motion capture data.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nenchev, D N; Miyamoto, Y; Iribe, H; Takeuchi, K; Sato, D</p> <p>2016-06-01</p> <p>This paper introduces the notion of a reactionless synergy: a postural variation for a specific motion pattern/strategy, whereby the movements of the segments do not alter the force/moment balance at the feet. Given an <span class="hlt">optimal</span> initial posture in terms of stability, a reactionless synergy can ensure <span class="hlt">optimality</span> throughout the entire movement. Reactionless synergies are derived via a dynamical model wherein the feet are regarded to be unfixed. Though in contrast with the conventional fixed-feet models, this approach has the advantage of exhibiting the reactions at the feet explicitly. The dynamical model also facilitates a joint-space decomposition scheme yielding two motion components: the reactionless synergy and an orthogonal complement responsible for the dynamical coupling between the feet and the support. Since the reactionless synergy provides the basis (a feedforward control component) for <span class="hlt">optimal</span> balance control, it may play an important role when evaluating balance abnormalities or when assessing <span class="hlt">optimality</span> in balance control. We show how to apply the proposed method for analysis of motion capture data obtained from three voluntary movement patterns in the sagittal plane: squat, sway, and forward bend. PMID:26273732</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JMagR.255...34H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JMagR.255...34H"><span id="translatedtitle"><span class="hlt">Optimized</span> selective lactate excitation with a refocused multiple-quantum <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holbach, Mirjam; Lambert, Jörg; Johst, Sören; Ladd, Mark E.; Suter, Dieter</p> <p>2015-06-01</p> <p>Selective detection of lactate signals in in vivo MR spectroscopy with spectral editing techniques is necessary in situations where strong lipid or signals from other molecules overlap the desired lactate resonance in the spectrum. Several pulse sequences have been proposed for this task. The double-quantum <span class="hlt">filter</span> SSel-MQC provides very good lipid and water signal suppression in a single scan. As a major drawback, it suffers from significant signal loss due to incomplete refocussing in situations where long evolution periods are required. Here we present a refocused version of the SSel-MQC technique that uses only one additional refocussing pulse and regains the full refocused lactate signal at the end of the sequence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21431590','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21431590"><span id="translatedtitle">Medical image processing using novel wavelet <span class="hlt">filters</span> based on atomic functions: <span class="hlt">optimal</span> medical image compression.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Landin, Cristina Juarez; Reyes, Magally Martinez; Martin, Anabelem Soberanes; Rosas, Rosa Maria Valdovinos; Ramirez, Jose Luis Sanchez; Ponomaryov, Volodymyr; Soto, Maria Dolores Torres</p> <p>2011-01-01</p> <p>The analysis of different Wavelets including novel Wavelet families based on atomic functions are presented, especially for ultrasound (US) and mammography (MG) images compression. This way we are able to determine with what type of <span class="hlt">filters</span> Wavelet works better in compression of such images. Key properties: Frequency response, approximation order, projection cosine, and Riesz bounds were determined and compared for the classic Wavelets W9/7 used in standard JPEG2000, Daubechies8, Symlet8, as well as for the complex Kravchenko-Rvachev Wavelets ψ(t) based on the atomic functions up(t),  fup (2)(t), and eup(t). The comparison results show significantly better performance of novel Wavelets that is justified by experiments and in study of key properties. PMID:21431590</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820013596&hterms=sar+image+quality&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsar%2Bimage%2Bquality','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820013596&hterms=sar+image+quality&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsar%2Bimage%2Bquality"><span id="translatedtitle"><span class="hlt">Optimal</span> spatial <span class="hlt">filtering</span> and transfer function for SAR ocean wave spectra</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Beal, R. C.; Tilley, D. G.</p> <p>1981-01-01</p> <p>The impulse response of the SAR system is not a delta function and the spectra represent the product of the underlying image spectrum with the transform of the impulse response which must be removed. A digitally computed spectrum of SEASAT imagery of the Atlantic Ocean east of Cape Hatteras was smoothed with a 5 x 5 convolution <span class="hlt">filter</span> and the trend was sampled in a direction normal to the predominant wave direction. This yielded a transform of a noise-like process. The smoothed value of this trend is the transform of the impulse response. This trend is fit with either a second- or fourth-order polynomial which is then used to correct the entire spectrum. A 16 x 16 smoothing of the spectrum shows the presence of two distinct swells. Correction of the effects of speckle is effected by the subtraction of a bias from the spectrum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23729235','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23729235"><span id="translatedtitle"><span class="hlt">Optimal</span> spatial <span class="hlt">filtering</span> for brain oscillatory activity using the Relevance Vector Machine.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Belardinelli, P; Jalava, A; Gross, J; Kujala, J; Salmelin, R</p> <p>2013-11-01</p> <p>Over the past decade, various techniques have been proposed for localization of cerebral sources of oscillatory activity on the basis of magnetoencephalography (MEG) or electroencephalography recordings. Beamformers in the frequency domain, in particular, have proved useful in this endeavor. However, the localization accuracy and efficacy of such spatial <span class="hlt">filters</span> can be markedly limited by bias from correlation between cerebral sources and short duration of source activity, both essential issues in the localization of brain data. Here, we evaluate a method for frequency-domain localization of oscillatory neural activity based on the relevance vector machine (RVM). RVM is a Bayesian algorithm for learning sparse models from possibly overcomplete data sets. The performance of our frequency-domain RVM method (fdRVM) was compared with that of dynamic imaging of coherent sources (DICS), a frequency-domain spatial <span class="hlt">filter</span> that employs a minimum variance adaptive beamformer (MVAB) approach. The methods were tested both on simulated and real data. Two types of simulated MEG data sets were generated, one with continuous source activity and the other with transiently active sources. The real data sets were from slow finger movements and resting state. Results from simulations show comparable performance for DICS and fdRVM at high signal-to-noise ratios and low correlation. At low SNR or in conditions of high correlation between sources, fdRVM performs markedly better. fdRVM was successful on real data as well, indicating salient focal activations in the sensorimotor area. The resulting high spatial resolution of fdRVM and its sensitivity to low-SNR transient signals could be particularly beneficial when mapping event-related changes of oscillatory activity. PMID:23729235</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25794715','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25794715"><span id="translatedtitle"><span class="hlt">Optimization</span> of conditions for the single <span class="hlt">step</span> IMAC purification of miraculin from Synsepalum dulcificum.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>He, Zuxing; Tan, Joo Shun; Lai, Oi Ming; Ariff, Arbakariya B</p> <p>2015-08-15</p> <p>In this study, the methods for extraction and purification of miraculin from Synsepalum dulcificum were investigated. For extraction, the effect of different extraction buffers (phosphate buffer saline, Tris-HCl and NaCl) on the extraction efficiency of total protein was evaluated. Immobilized metal ion affinity chromatography (IMAC) with nickel-NTA was used for the purification of the extracted protein, where the influence of binding buffer pH, crude extract pH and imidazole concentration in elution buffer upon the purification performance was explored. The total amount of protein extracted from miracle fruit was found to be 4 times higher using 0.5M NaCl as compared to Tris-HCl and phosphate buffer saline. On the other hand, the use of Tris-HCl as binding buffer gave higher purification performance than sodium phosphate and citrate-phosphate buffers in IMAC system. The optimum purification condition of miraculin using IMAC was achieved with crude extract at pH 7, Tris-HCl binding buffer at pH 7 and the use of 300 mM imidazole as elution buffer, which gave the overall yield of 80.3% and purity of 97.5%. IMAC with nickel-NTA was successfully used as a single <span class="hlt">step</span> process for the purification of miraculin from crude extract of S. dulcificum. PMID:25794715</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23863422','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23863422"><span id="translatedtitle">Microorganism inactivation by an ozonation <span class="hlt">step</span> <span class="hlt">optimized</span> for micropollutant removal from tertiary effluent.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schaar, H; Sommer, R; Schürhagl, R; Yillia, P; Kreuzinger, N</p> <p>2013-01-01</p> <p>This paper demonstrates the additional benefit of the microbicidal efficacy of an ozonation plant implemented for micropollutant removal from tertiary effluent. Due to the low amount of viruses and protozoa in the tertiary effluent, bacteriophage MS2 and spores of Bacillus subtilis were dosed as surrogates. At specific ozone consumptions of 0.6 and 0.9 g O3/g dissolved organic carbon (DOC) a 2-log colony forming unit (CFU) reduction was achieved for indigenous Escherichia coli and enterococci, and the limits of the European bathing water directive for the excellent quality of inland waters were met. Higher removal was impeded by the shielding effect of suspended solids in the effluent, which implies the combination of ozonation with a preceding filtration <span class="hlt">step</span> if higher microbicidal performances are required. The surrogate virus MS2 was reduced by 4-5 log while no significant inactivation was detected for B. subtilis spores. Additionally, the impact of ozonation on the biochemical oxygen demand (BOD) was studied. The BOD5 measurement was not adversely affected despite the reduced concentration of microorganisms after ozonation. The intrinsic increase in BOD5 averaged 15% at 0.6-0.7 g O3/g DOC. The impact of the projected increase on the surface water quality is generally not considered a problem but has to be assessed on a case-by-case approach. PMID:23863422</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26378868','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26378868"><span id="translatedtitle">Development of a Transcatheter Tricuspid Valve Prosthesis Through <span class="hlt">Steps</span> of Iterative <span class="hlt">Optimization</span> and Finite Element Analysis.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pott, Desiree; Kütting, Maximilian; Zhong, Zhaoyang; Amerini, Andrea; Spillner, Jan; Autschbach, Rüdiger; Steinseifer, Ulrich</p> <p>2015-10-01</p> <p>The development of a transcatheter tricuspid valve prosthesis for the treatment of tricuspid regurgitation (TR) is presented. The design process involves an iterative development method based on computed tomography data and different <span class="hlt">steps</span> of finite element analysis (FEA). The enhanced design consists of two self-expandable stents, one is placed inside the superior vena cava (SVC) for primary device anchoring, the second lies inside the tricuspid valve annulus (TVA). Both stents are connected by flexible connecting struts (CS) to anchor the TVA-stent in the orthotopic position. The iterative development method includes the expansion and crimping of the stents and CS with FEA. Leaflet performance and leaflet-stent interaction were studied by applying the physiologic pressure cycle of the right heart onto the leaflet surfaces. A previously implemented nitinol material model and a new porcine pericardium material model derived from uniaxial tensile tests were used. Maximum strains/stresses were approx. 6.8% for the nitinol parts and 2.9 MPa for the leaflets. Stent displacement because of leaflet movement was ≤1.8 mm at the commissures and the coaptation height was 1.6-3 mm. This led to an overall good performance of the prosthesis. An anatomic study showed a good anatomic fit of the device inside the human right heart. PMID:26378868</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013OptCo.289...33O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013OptCo.289...33O"><span id="translatedtitle"><span class="hlt">Optimized</span> pre-processing input plane GPU implementation of an optical face recognition technique using a segmented phase only composite <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ouerhani, Y.; Jridi, M.; Alfalou, A.; Brosseau, C.</p> <p>2013-02-01</p> <p>The key outcome of this work is to propose and validate a fast and robust correlation scheme for face recognition applications. The robustness of this fast correlator is ensured by an adapted pre-processing <span class="hlt">step</span> for the target image allowing us to minimize the impact of its (possibly noisy and varying) amplitude spectrum information. A segmented composite <span class="hlt">filter</span> is <span class="hlt">optimized</span>, at the very outset of its fabrication, by weighting each reference with a specific coefficient which is proportional to the occurrence probability. A hierarchical classification procedure (called two-level decision tree learning approach) is also used in order to speed up the recognition procedure. Experimental results validating our approach are obtained with a prototype based on GPU implementation of the all-numerical correlator using the NVIDIA GPU GeForce 8400GS processor and test samples from the Pointing Head Pose Image Database (PHPID), e.g. true recognition rates larger than 85% with a run time lower than 120 ms have been obtained using fixed images from the PHPID, true recognition rates larger than 77% using a real video sequence with 2 frame per second when the database contains 100 persons. Besides, it has been shown experimentally that the use of more recent GPU processor like NVIDIA-GPU Quadro FX 770M can perform the recognition of 4 frame per second with the same length of database.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9274E..07D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9274E..07D"><span id="translatedtitle">Long-range high spatial resolution optical frequency-domain reflectometry based on <span class="hlt">optimized</span> deskew <span class="hlt">filter</span> method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ding, Zhenyang; Du, Yang; Liu, Tiegen; Yao, X. Steve; Feng, Bowen; Liu, Kun; Jiang, Junfeng</p> <p>2014-11-01</p> <p>We present a long-range high spatial resolution optical frequency-domain reflectometry (OFDR) based on <span class="hlt">optimized</span> deskew <span class="hlt">filter</span> method. In proposed method, the frequency tuning nonlinear phase obtained from an auxiliary interferometer is used to compensate the nonlinear phase of the beating signals generated from a main OFDR interferometer using a deskew <span class="hlt">filter</span>. The method can be applied for the entire spatial domain of the OFDR signals at once with a high computational efficiency. In addition, we apply the methods of higher orders of Taylor expansion and cepstrum analysis to improve the estimation accuracy of nonlinear phase. We experimentally achieve a measurement range of 80 km and a spatial resolution of 20 cm and 80 cm at distances of 10 km and 80 km that is about 187 times enhancement when compared with that of the same OFDR trace without nonlinearity compensation. The improved performance of the OFDR with the high spatial resolution, long measurement range and short process time will lead to practical applications in real-time monitoring and measurement of the optical fiber communication and sensing systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23367417','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23367417"><span id="translatedtitle">An <span class="hlt">optimized</span> DSP implementation of adaptive <span class="hlt">filtering</span> and ICA for motion artifact reduction in ambulatory ECG monitoring.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Berset, Torfinn; Geng, Di; Romero, Iñaki</p> <p>2012-01-01</p> <p>Noise from motion artifacts is currently one of the main challenges in the field of ambulatory ECG recording. To address this problem, we propose the use of two different approaches. First, an adaptive <span class="hlt">filter</span> with electrode-skin impedance as a reference signal is described. Secondly, a multi-channel ECG algorithm based on Independent Component Analysis is introduced. Both algorithms have been designed and further <span class="hlt">optimized</span> for real-time work embedded in a dedicated Digital Signal Processor. We show that both algorithms improve the performance of a beat detection algorithm when applied in high noise conditions. In addition, an efficient way of choosing this methods is suggested with the aim of reduce the overall total system power consumption. PMID:23367417</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9622E..0UT','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9622E..0UT"><span id="translatedtitle">A novel track-before-detect algorithm based on <span class="hlt">optimal</span> nonlinear <span class="hlt">filtering</span> for detecting and tracking infrared dim target</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tian, Yuexin; Gao, Kun; Liu, Ying; Han, Lu</p> <p>2015-08-01</p> <p>Aiming at the nonlinear and non-Gaussian features of the real infrared scenes, an <span class="hlt">optimal</span> nonlinear <span class="hlt">filtering</span> based algorithm for the infrared dim target tracking-before-detecting application is proposed. It uses the nonlinear theory to construct the state and observation models and uses the spectral separation scheme based Wiener chaos expansion method to resolve the stochastic differential equation of the constructed models. In order to improve computation efficiency, the most time-consuming operations independent of observation data are processed on the fore observation stage. The other observation data related rapid computations are implemented subsequently. Simulation results show that the algorithm possesses excellent detection performance and is more suitable for real-time processing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26974772','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26974772"><span id="translatedtitle">Designing spectrum-splitting dichroic <span class="hlt">filters</span> to <span class="hlt">optimize</span> current-matched photovoltaics.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Miles, Alexander; Cocilovo, Byron; Wheelwright, Brian; Pan, Wei; Tweet, Doug; Norwood, Robert A</p> <p>2016-03-10</p> <p>We have developed an approach for designing a dichroic coating to <span class="hlt">optimize</span> performance of current-matched multijunction photovoltaic cells while diverting unused light. By matching the spectral responses of the photovoltaic cells and current matching them, substantial improvement to system efficiencies is shown to be possible. A design for use in a concentrating hybrid solar collector was produced by this approach, and is presented. Materials selection, design methodology, and tilt behavior on a curved substrate are discussed. PMID:26974772</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750005841','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750005841"><span id="translatedtitle">Shuttle <span class="hlt">filter</span> study. Volume 1: Characterization and <span class="hlt">optimization</span> of filtration devices</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1974-01-01</p> <p>A program to develop a new technology base for filtration equipment and comprehensive fluid particulate contamination management techniques was conducted. The study has application to the systems used in the space shuttle and space station projects. The scope of the program is as follows: (1) characterization and <span class="hlt">optimization</span> of filtration devices, (2) characterization of contaminant generation and contaminant sensitivity at the component level, and (3) development of a comprehensive particulate contamination management plane for space shuttle fluid systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6780L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6780L"><span id="translatedtitle">Influence of simulation time-<span class="hlt">step</span> (temporal-scale) on <span class="hlt">optimal</span> parameter estimation and runoff prediction performance in hydrological modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Loizu, Javier; Álvarez-Mozos, Jesús; Casalí, Javier; Goñi, Mikel</p> <p>2015-04-01</p> <p>Nowadays, most hydrological catchment models are designed to allow their use for streamflow simulation at different time-scales. While this permits models to be applied for broader purposes, it can also be a source of error in hydrological processes simulation at catchment scale. Those errors seem not to affect significantly simple conceptual models, but this flexibility may lead to large behavior errors in physically based models. Equations used in processes such as those related to soil moisture time-variation are usually representative at certain time-scales but they may not characterize properly water transfer in soil layers at larger scales. This effect is especially relevant as we move from detailed hourly scale to daily time-<span class="hlt">step</span>, which are common time scales used at catchment streamflow simulation for different research and management practices purposes. This study aims to provide an objective methodology to identify the degree of similarity of <span class="hlt">optimal</span> parameter values when hydrological catchment model calibration is developed at different time-scales. Thus, providing information for an informed discussion of physical parameter significance on hydrological models. In this research, we analyze the influence of time scale simulation on: 1) the <span class="hlt">optimal</span> values of six highly sensitive parameters of the TOPLATS model and 2) the streamflow simulation efficiency, while <span class="hlt">optimization</span> is carried out at different time scales. TOPLATS (TOPMODEL-based Land-Atmosphere Transfer Scheme) has been applied on its lumped version on three catchments of varying size located in northern Spain. The model has its basis on shallow groundwater gradients (related to local topography) that set up spatial patterns of soil moisture and are assumed to control infiltration and runoff during storm events and evaporation and drainage in between storm events. The model calculates the saturated portion of the catchment at each time <span class="hlt">step</span> based on Topographical Index (TI) intervals. Surface runoff is then calculated at rainfall events proportionally to the saturation degree of the catchment. Separately, baseflow is calculated based on the distance between catchment average water table depth and specific depth at each TI interval. This study focuses on the comparison of hourly and daily simulations for the 2000-2007 time period. An <span class="hlt">optimization</span> algorithm has been applied to identify the <span class="hlt">optimal</span> values of the following four soil properties: 1) Brooks-Corey pore size distribution index (β), 2) Bubbling pressure (ψc), 3) Saturated soil moisture (θs), 4) Surface saturated hydraulic conductivity (Ks), and two subsurface flow controlling parameters: 1) Subsurface flow at complete saturation (Q0), and 2) Exponential coefficient for TOPMODEL baseflow equation (f). The algorithm was set up to maximize Nash-Sutcliffe Efficiency (NSE) at the catchment outlet. Results presented include the <span class="hlt">optimal</span> values of each parameter at both hourly and daily time scale. These values provided valuable information to discuss the relative importance of each soil-related model parameter for enhanced streamflow simulation and adequate model response to both surface runoff and baseflow simulation. Catchment baseflow magnitude (Q0) and decay behavior (f) are also proved to require detailed analysis depending on the selected hydrological modeling purpose and corresponding selected time-<span class="hlt">step</span>. Obtained results showed that different time-scale simulations may require different parameter values for soil properties and catchment behavior characterization in order to properly simulate streamflow at catchment scale. Despite calibrated parameters were soil properties and water flow quantities with physical meaning and defined units, optimum values differed with time-scale and were not always similar to field observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22753308','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22753308"><span id="translatedtitle">Drying process <span class="hlt">optimization</span> for an API solvate using heat transfer model of an agitated <span class="hlt">filter</span> dryer.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nere, Nandkishor K; Allen, Kimberley C; Marek, James C; Bordawekar, Shailendra V</p> <p>2012-10-01</p> <p>Drying an early stage active pharmaceutical ingredient candidate required excessively long cycle times in a pilot plant agitated <span class="hlt">filter</span> dryer. The key to faster drying is to ensure sufficient heat transfer and minimize mass transfer limitations. Designing the right mixing protocol is of utmost importance to achieve efficient heat transfer. To this order, a composite model was developed for the removal of bound solvent that incorporates models for heat transfer and desolvation kinetics. The proposed heat transfer model differs from previously reported models in two respects: it accounts for the effects of a gas gap between the vessel wall and solids on the overall heat transfer coefficient, and headspace pressure on the mean free path length of the inert gas and thereby on the heat transfer between the vessel wall and the first layer of solids. A computational methodology was developed incorporating the effects of mixing and headspace pressure to simulate the drying profile using a modified model framework within the Dynochem software. A dryer operational protocol was designed based on the desolvation kinetics, thermal stability studies of wet and dry cake, and the understanding gained through model simulations, resulting in a multifold reduction in drying time. PMID:22753308</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011WRR....47.2529K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011WRR....47.2529K"><span id="translatedtitle">Many-objective groundwater monitoring network design using bias-aware ensemble Kalman <span class="hlt">filtering</span>, evolutionary <span class="hlt">optimization</span>, and visual analytics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kollat, J. B.; Reed, P. M.; Maxwell, R. M.</p> <p>2011-02-01</p> <p>This study contributes the Adaptive Strategies for Sampling in Space and Time (ASSIST) framework for improving long-term groundwater monitoring decisions across space and time while accounting for the influences of systematic model errors (or predictive bias). The new framework combines contaminant flow-and-transport modeling, bias-aware ensemble Kalman <span class="hlt">filtering</span> (EnKF), many-objective evolutionary <span class="hlt">optimization</span>, and visual analytics-based decision support. The ASSIST framework allows decision makers to forecast the value of investments in new observations for many objectives simultaneously. Information tradeoffs are evaluated using an EnKF to forecast plume transport in space and time in the presence of uncertain and biased model predictions that are conditioned on uncertain measurement data. This study demonstrates the ASSIST framework using a laboratory-based physical aquifer tracer experiment. In this initial demonstration, the position and frequency of tracer sampling was <span class="hlt">optimized</span> to (1) minimize monitoring costs, (2) maximize the information provided to the EnKF, (3) minimize failures to detect the tracer, (4) maximize the detection of tracer fluxes, (5) minimize error in quantifying tracer mass, and (6) minimize error in quantifying the centroid of the tracer plume. Our results demonstrate that the forecasting, search, and visualization components of the ASSIST framework represent a significant advance for observation network design that has a strong potential to innovate our characterization, prediction, and management of groundwater systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.H33B1130K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.H33B1130K"><span id="translatedtitle">Many-objective Groundwater Monitoring Network Design Using Bias-Aware Ensemble Kalman <span class="hlt">Filtering</span>, Evolutionary <span class="hlt">Optimization</span>, and Visual Analytics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kollat, J. B.; Reed, P. M.; Maxwell, R. M.</p> <p>2010-12-01</p> <p>This study contributes the ASSIST (Adaptive Strategies for Sampling in Space and Time) framework for improving long-term groundwater monitoring decisions across space and time while accounting for the influences of systematic model errors (or predictive bias). The new framework combines contaminant flow-and-transport modeling, bias-aware ensemble Kalman <span class="hlt">filtering</span> (EnKF), many-objective evolutionary <span class="hlt">optimization</span>, and visual analytics-based decision support. The ASSIST framework allows decision makers to forecast the value of investments in new observations for many objectives simultaneously. Information tradeoffs are evaluated using an EnKF to forecast plume transport in space and time in the presence of uncertain and biased model predictions that are conditioned on uncertain measurement data. This study demonstrates the ASSIST framework using a laboratory-based physical aquifer tracer experiment. In this initial demonstration, the position and frequency of tracer sampling was <span class="hlt">optimized</span> to: (1) minimize monitoring costs, (2) maximize the information provided to the EnKF, (3) minimize failures to detect the tracer, (4) maximize the detection of tracer fluxes, (5) minimize error in quantifying tracer mass, and (6) minimize error in quantifying the centroid of the tracer plume. Our results demonstrate that the forecasting, search, and visualization components of the ASSIST framework represent a significant advance for observation network design that has a strong potential to innovate our characterization, prediction, and management of groundwater systems.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JMagR.243....8H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JMagR.243....8H"><span id="translatedtitle"><span class="hlt">Optimized</span> multiple-quantum <span class="hlt">filter</span> for robust selective excitation of metabolite signals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holbach, Mirjam; Lambert, Jörg; Suter, Dieter</p> <p>2014-06-01</p> <p>The selective excitation of metabolite signals in vivo requires the use of specially adapted pulse techniques, in particular when the signals are weak and the resonances overlap with those of unwanted molecules. Several pulse sequences have been proposed for this spectral editing task. However, their performance is strongly degraded by unavoidable experimental imperfections. Here, we show that <span class="hlt">optimal</span> control theory can be used to generate pulses and sequences that perform almost ideally over a range of rf field strengths and frequency offsets that can be chosen according to the specifics of the spectrometer or scanner being used. We demonstrate this scheme by applying it to lactate editing. In addition to the robust excitation, we also have designed the pulses to minimize the signal of unwanted molecular species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11990038','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11990038"><span id="translatedtitle"><span class="hlt">Optimized</span>, one-<span class="hlt">step</span>, recovery-enrichment broth for enhanced detection of Listeria monocytogenes in pasteurized milk and hot dogs.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Knabel, Stephen J</p> <p>2002-01-01</p> <p>A one-<span class="hlt">step</span>, recovery-enrichment broth, <span class="hlt">optimized</span> Penn State University (oPSU) broth, was developed to consistently detect low levels of injured and uninjured Listeria monocytogenes cells in ready-to-eat foods. The oPSU broth contains special selective agents that inhibit growth of background flora without inhibiting recovery of injured Listeria cells. After recovery in the anaerobic section of oPSU broth, Listeria cells migrated to the surface, forming a black zone. This migration separated viable from nonviable cells and the food matrix, thereby reducing inhibitors that prevent detection by molecular methods. The high Listeria-to-background ratio in the black zone resulted in consistent detection of low levels of L. monocytogenes in pasteurized foods by both cultural and molecular methods, and greatly reduced both false-negative and false-positive results. oPSU broth does not require transfer to a secondary enrichment broth, making it less laborious and less subject to external contamination than 2-<span class="hlt">step</span> enrichment protocols. Addition of 150mM D-serine prevented germination of Bacillus spores, but not the growth of vegetative cells. Replacement of D-serine with 12 mg/L acriflavin inhibited growth of vegetative cells of Bacillus spp. without inhibiting recovery of injured Listeria cells. oPSU broth may allow consistent detection of low levels of injured and uninjured cells of L. monocytogenes in pasteurized foods containing various background microflora. PMID:11990038</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014HESS...18.1705C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014HESS...18.1705C"><span id="translatedtitle">A conceptual model of check dam hydraulics for gully control: efficiency, <span class="hlt">optimal</span> spacing and relation with <span class="hlt">step</span>-pools</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Castillo, C.; Pérez, R.; Gómez, J. A.</p> <p>2014-05-01</p> <p>There is little information in scientific literature regarding the modifications induced by check dam systems in flow regimes within restored gully reaches, despite it being a crucial issue for the design of gully restoration measures. Here, we develop a conceptual model to classify flow regimes in straight rectangular channels for initial and dam-filling conditions as well as a method of estimating efficiency in order to provide design guidelines. The model integrates several previous mathematical approaches for assessing the main processes involved (hydraulic jump, impact flow, gradually varied flows). Ten main classifications of flow regimes were identified, producing similar results when compared with the IBER model. An interval for <span class="hlt">optimal</span> energy dissipation (ODI) was observed when the steepness factor c was plotted against the design number (DN, ratio between the height and the product of slope and critical depth). The ODI was characterized by maximum energy dissipation and total influence conditions. Our findings support the hypothesis of a maximum flow resistance principle valid for a range of spacing rather than for a unique configuration. A value of c = 1 and DN ~ 100 was found to economically meet the ODI conditions throughout the different sedimentation stages of the structure. When our model was applied using the same parameters to the range typical of <span class="hlt">step</span>-pool systems, the predicted results fell within a similar region to that observed in field experiments. The conceptual model helps to explain the spacing frequency distribution as well as the often-cited trend to lower c for increasing slopes in <span class="hlt">step</span>-pool systems. This reinforces the hypothesis of a close link between stable configurations of <span class="hlt">step</span>-pool units and man-made interventions through check dams.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23086665','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23086665"><span id="translatedtitle"><span class="hlt">Optimization</span> of a refolding <span class="hlt">step</span> for a therapeutic fusion protein in the quality by design (QbD) paradigm.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bade, Pratap D; Kotu, Susmitha P; Rathore, Anurag S</p> <p>2012-11-01</p> <p>Production of biotech therapeutics in Escherichia coli involves protein expression as insoluble inclusion bodies that need to be denatured and the resulting protein refolded into the native structure. In this paper, we apply a Quality by Design approach using Design of Experiments for <span class="hlt">optimization</span> of the refolding process for a recombinant biotech therapeutic, granulocyte colony stimulating factor. First, risk analysis was performed to identify process parameters that require experimental examination. Next, the chosen parameters were examined using a fractional factorial screening design. Based on the results of this study, parameters that have significant effect on refold yield and product quality were identified and examined using a full factorial Design of Experiments for their interactions. The final model was statistically significant and delivered a refolding yield of 77%. Further, kinetics of refolding was evaluated under <span class="hlt">optimal</span> conditions and was found to be of first order with a rate constant of 0.132/min. Design space was established for the three parameters for a given permissible range of yield, protein concentration, and purity. The primary objective of this paper is to provide a roadmap for implementing Quality by Design for development of a protein refolding <span class="hlt">step</span>. PMID:23086665</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70014167','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70014167"><span id="translatedtitle">Moment tensor solutions estimated using <span class="hlt">optimal</span> <span class="hlt">filter</span> theory for 51 selected earthquakes, 1980-1984</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sipkin, S.A.</p> <p>1987-01-01</p> <p>The 51 global events that occurred from January 1980 to March 1984, which were chosen by the convenors of the Symposium on Seismological Theory and Practice, have been analyzed using a moment tensor inversion algorithm (Sipkin). Many of the events were routinely analyzed as part of the National Earthquake Information Center's (NEIC) efforts to publish moment tensor and first-motion fault-plane solutions for all moderate- to large-sized (mb>5.7) earthquakes. In routine use only long-period P-waves are used and the source-time function is constrained to be a <span class="hlt">step</span>-function at the source (??-function in the far-field). Four of the events were of special interest, and long-period P, SH-wave solutions were obtained. For three of these events, an unconstrained inversion was performed. The resulting time-dependent solutions indicated that, for many cases, departures of the solutions from pure double-couples are caused by source complexity that has not been adequately modeled. These solutions also indicate that source complexity of moderate-sized events can be determined from long-period data. Finally, for one of the events of special interest, an inversion of the broadband P-waveforms was also performed, demonstrating the potential for using broadband waveform data in inversion procedures. ?? 1987.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1062576','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1062576"><span id="translatedtitle">Metrics For Comparing Plasma Mass <span class="hlt">Filters</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Abraham J. Fetterman and Nathaniel J. Fisch</p> <p>2012-08-15</p> <p>High-throughput mass separation of nuclear waste may be useful for <span class="hlt">optimal</span> storage, disposal, or environmental remediation. The most dangerous part of nuclear waste is the fission product, which produces most of the heat and medium-term radiation. Plasmas are well-suited to separating nuclear waste because they can separate many different species in a single <span class="hlt">step</span>. A number of plasma devices have been designed for such mass separation, but there has been no standardized comparison between these devices. We define a standard metric, the separative power per unit volume, and derive it for three different plasma mass <span class="hlt">filters</span>: the plasma centrifuge, Ohkawa <span class="hlt">filter</span>, and the magnetic centrifugal mass <span class="hlt">filter</span>. __________________________________________________</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMNG21A1475L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMNG21A1475L"><span id="translatedtitle">Non-Gaussian <span class="hlt">Filtering</span> by Local Linear Approximation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lei, J.; Peter, B.</p> <p>2013-12-01</p> <p>We propose a new approach to nonlinear non-Gaussian <span class="hlt">filtering</span>, by explicitly mimicking the <span class="hlt">optimal</span> <span class="hlt">filter</span> using local linear approximation to the underlying dynamical system. At each time <span class="hlt">step</span>, instead of directly using the forecast ensemble as the forecast distribution as in the ensemble Kalman <span class="hlt">filter</span>, we find a suitable linear transformation that maps the previous updated ensemble to the current forecast ensemble, with small additive Gaussian noises. Once this linear transformation and the noise distribution are estimated, the <span class="hlt">optimal</span> <span class="hlt">filtering</span> can be approximated by a standard Kalman <span class="hlt">filtering</span>. Such a local linear approximation shall have good robustness against the highly nonlinear dynamics. It can also make use of temporal smoothness by borrowing information from recent time <span class="hlt">steps</span> using techniques such as weighted local averaging. Spatial smoothness can be taken into account by regularizing the estimated linear transformation and noise distribution. The method will be illustrated on several classical models of nonlinear dynamical systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MSSP...52..465T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MSSP...52..465T"><span id="translatedtitle">An <span class="hlt">optimal</span> modeling of multidimensional wave digital <span class="hlt">filtering</span> network for free vibration analysis of symmetrically laminated composite FSDT plates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tseng, Chien-Hsun</p> <p>2015-02-01</p> <p>The technique of multidimensional wave digital <span class="hlt">filtering</span> (MDWDF) that builds on traveling wave formulation of lumped electrical elements, is successfully implemented on the study of dynamic responses of symmetrically laminated composite plate based on the first order shear deformation theory. The philosophy applied for the first time in this laminate mechanics relies on integration of certain principles involving modeling and simulation, circuit theory, and MD digital signal processing to provide a great variety of outstanding features. Especially benefited by the conservation of passivity gives rise to a nonlinear programming problem (NLP) for the issue of numerical stability of a MD discrete system. Adopting the augmented Lagrangian genetic algorithm, an effective <span class="hlt">optimization</span> technique for rapidly achieving solution spaces of NLP models, numerical stability of the MDWDF network is well received at all time by the satisfaction of the Courant-Friedrichs-Levy stability criterion with the least restriction. In particular, optimum of the NLP has led to the <span class="hlt">optimality</span> of the network in terms of effectively and accurately predicting the desired fundamental frequency, and thus to give an insight into the robustness of the network by looking at the distribution of system energies. To further explore the application of the optimum network, more numerical examples are engaged in efforts to achieve a qualitative understanding of the behavior of the laminar system. These are carried out by investigating various effects based on different stacking sequences, stiffness and span-to-thickness ratios, mode shapes and boundary conditions. Results are scrupulously validated by cross referencing with early published works, which show that the present method is in excellent agreement with other numerical and analytical methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JHyd..529.1147T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JHyd..529.1147T"><span id="translatedtitle">On the difficulty to <span class="hlt">optimally</span> implement the Ensemble Kalman <span class="hlt">filter</span>: An experiment based on many hydrological models and catchments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thiboult, A.; Anctil, F.</p> <p>2015-10-01</p> <p>Forecast reliability and accuracy is a prerequisite for successful hydrological applications. This aim may be attained by using data assimilation techniques such as the popular Ensemble Kalman <span class="hlt">filter</span> (EnKF). Despite its recognized capacity to enhance forecasting by creating a new set of initial conditions, implementation tests have been mostly carried out with a single model and few catchments leading to case specific conclusions. This paper performs an extensive testing to assess ensemble bias and reliability on 20 conceptual lumped models and 38 catchments in the Province of Québec with perfect meteorological forecast forcing. The study confirms that EnKF is a powerful tool for short range forecasting but also that it requires a more subtle setting than it is frequently recommended. The success of the updating procedure depends to a great extent on the specification of the hyper-parameters. In the implementation of the EnKF, the identification of the hyper-parameters is very unintuitive if the model error is not explicitly accounted for and best estimates of forcing and observation error lead to overconfident forecasts. It is shown that performance are also related to the choice of updated state variables and that all states variables should not systematically be updated. Additionally, the improvement over the open loop scheme depends on the watershed and hydrological model structure, as some models exhibit a poor compatibility with EnKF updating. Thus, it is not possible to conclude in detail on a single ideal manner to identify an <span class="hlt">optimal</span> implementation; conclusions drawn from a unique event, catchment, or model are likely to be misleading since transferring hyper-parameters from a case to another may be hazardous. Finally, achieving reliability and bias jointly is a daunting challenge as the <span class="hlt">optimization</span> of one score is done at the cost of the other.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140009131','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140009131"><span id="translatedtitle">Model-Based Control of a Nonlinear Aircraft Engine Simulation using an <span class="hlt">Optimal</span> Tuner Kalman <span class="hlt">Filter</span> Approach</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Connolly, Joseph W.; Csank, Jeffrey Thomas; Chicatelli, Amy; Kilver, Jacob</p> <p>2013-01-01</p> <p>This paper covers the development of a model-based engine control (MBEC) methodology featuring a self tuning on-board model applied to an aircraft turbofan engine simulation. Here, the Commercial Modular Aero-Propulsion System Simulation 40,000 (CMAPSS40k) serves as the MBEC application engine. CMAPSS40k is capable of modeling realistic engine performance, allowing for a verification of the MBEC over a wide range of operating points. The on-board model is a piece-wise linear model derived from CMAPSS40k and updated using an <span class="hlt">optimal</span> tuner Kalman <span class="hlt">Filter</span> (OTKF) estimation routine, which enables the on-board model to self-tune to account for engine performance variations. The focus here is on developing a methodology for MBEC with direct control of estimated parameters of interest such as thrust and stall margins. Investigations using the MBEC to provide a stall margin limit for the controller protection logic are presented that could provide benefits over a simple acceleration schedule that is currently used in traditional engine control architectures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26092218','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26092218"><span id="translatedtitle">Detection and measurement of rheumatoid bone and joint lesions of fingers by tomosynthesis: a phantom study for reconstruction <span class="hlt">filter</span> setting <span class="hlt">optimization</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ono, Yohei; Kamishima, Tamotsu; Yasojima, Nobutoshi; Tamura, Kenichi; Tsutsumi, Kaori</p> <p>2016-01-01</p> <p>Rheumatoid arthritis (RA) is a systemic disease that is caused by autoimmunity. RA causes synovial proliferation, which may result in bone erosion and joint space narrowing in the affected joint. Tomosynthesis is a promising modality which may detect early bone lesions such as small bone erosion and slight joint space narrowing. Nevertheless, so far, the <span class="hlt">optimal</span> reconstruction <span class="hlt">filter</span> for detection of early bone lesions of fingers on tomosynthesis has not yet been known. Our purpose in this study was to determine an <span class="hlt">optimal</span> reconstruction <span class="hlt">filter</span> setting by using a bone phantom. We obtained images of a cylindrical phantom with holes simulating bone erosions (diameters of 0.6, 0.8, 1.0, 1.2, and 1.4 mm) and joint spaces by aligning two phantoms (space widths from 0.5 to 5.0 mm with 0.5 mm intervals), examining six reconstruction <span class="hlt">filters</span> by using tomosynthesis. We carried out an accuracy test of the bone erosion size and joint space width, done by one radiological technologist, and a test to assess the visibility of bone erosion, done by five radiological technologists. No statistically significant difference was observed in the measured bone erosion size and joint space width among all of the reconstruction <span class="hlt">filters</span>. In the visibility assessment test, reconstruction <span class="hlt">filters</span> of Thickness+- and Thickness-- were among the best statistically in all characteristics except the signal-to-noise ratio. The Thickness+- and Thickness-- reconstruction <span class="hlt">filter</span> may be <span class="hlt">optimal</span> for evaluation of RA bone lesions of small joints in tomosynthesis. PMID:26092218</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23201520','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23201520"><span id="translatedtitle">Production of algal biodiesel from marine macroalgae Enteromorpha compressa by two <span class="hlt">step</span> process: <span class="hlt">optimization</span> and kinetic study.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Suganya, Tamilarasan; Nagendra Gandhi, Nagarajan; Renganathan, Sahadevan</p> <p>2013-01-01</p> <p>In this investigation, Enteromorpha compressa algal oil with high free fatty acids (FFA) used as a feedstock for biodiesel production. Two <span class="hlt">step</span> process was developed and kinetic study executed to obtain reaction rate constant for the transesterification reaction. The acid esterification was carried out to reduce FFA from 6.3% to 0.34% with <span class="hlt">optimized</span> parameters of 1.5% H(2)SO(4), 12:1 methanol-oil ratio, 400 rpm at 60 °C and 90 min of reaction time. The maximum biodiesel yield 90.6% was achieved from base transesterification through optimum conditions of 1% NaOH, 9:1 methanol-oil ratio, 600 rpm and 60 °C temperature for 70 min. The algal biodiesel was characterized by GC-MS, HPLC and NIR. This transesterification follows first order reaction kinetics and the activation energy was determined as 73,154.89 J/mol. The biodiesel properties were analyzed and found to be within the limits of American standards. Hence, E. compressa serves as a valuable renewable raw-material for biodiesel production. PMID:23201520</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720021544','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720021544"><span id="translatedtitle">The use of linear programming techniques to design <span class="hlt">optimal</span> digital <span class="hlt">filters</span> for pulse shaping and channel equalization</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Houts, R. C.; Burlage, D. W.</p> <p>1972-01-01</p> <p>A time domain technique is developed to design finite-duration impulse response digital <span class="hlt">filters</span> using linear programming. Two related applications of this technique in data transmission systems are considered. The first is the design of pulse shaping digital <span class="hlt">filters</span> to generate or detect signaling waveforms transmitted over bandlimited channels that are assumed to have ideal low pass or bandpass characteristics. The second is the design of digital <span class="hlt">filters</span> to be used as preset equalizers in cascade with channels that have known impulse response characteristics. Example designs are presented which illustrate that excellent waveforms can be generated with frequency-sampling <span class="hlt">filters</span> and the ease with which digital transversal <span class="hlt">filters</span> can be designed for preset equalization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PMB....61N..35C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PMB....61N..35C"><span id="translatedtitle">Reducing radiation dose by application of <span class="hlt">optimized</span> low-energy x-ray <span class="hlt">filters</span> to K-edge imaging with a photon counting detector</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Choi, Yu-Na; Lee, Seungwan; Kim, Hee-Joung</p> <p>2016-01-01</p> <p>K-edge imaging with photon counting x-ray detectors (PCXDs) can improve image quality compared with conventional energy integrating detectors. However, low-energy x-ray photons below the K-edge absorption energy of a target material do not contribute to image formation in the K-edge imaging and are likely to be completely absorbed by an object. In this study, we applied x-ray <span class="hlt">filters</span> to the K-edge imaging with a PCXD based on cadmium zinc telluride for reducing radiation dose induced by low-energy x-ray photons. We used aluminum (Al) <span class="hlt">filters</span> with different thicknesses as the low-energy x-ray <span class="hlt">filters</span> and implemented the iodine K-edge imaging with an energy bin of 34-48 keV at the tube voltages of 50, 70 and 90 kVp. The effects of the low-energy x-ray <span class="hlt">filters</span> on the K-edge imaging were investigated with respect to signal-difference-to-noise ratio (SDNR), entrance surface air kerma (ESAK) and figure of merit (FOM). The highest value of SDNR was observed in the K-edge imaging with a 2 mm Al <span class="hlt">filter</span>, and the SDNR decreased as a function of the <span class="hlt">filter</span> thicknesses. Compared to the K-edge imaging with a 2 mm Al <span class="hlt">filter</span>, the ESAK was reduced by 66%, 48% and 39% in the K-edge imaging with a 12 mm Al <span class="hlt">filter</span> for 50 kVp, 70 kVp and 90 kVp, respectively. The FOM values, which took into account the ESAK and SDNR, were maximized for 8, 6 to 8 and 4 mm Al <span class="hlt">filters</span> at 50 kVp, 70 kVp and 90 kVp, respectively. We concluded that the use of an <span class="hlt">optimal</span> low-energy <span class="hlt">filter</span> thickness, which was determined by maximizing the FOM, could significantly reduce radiation dose while maintaining image quality in the K-edge imaging with the PCXD.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26733235','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26733235"><span id="translatedtitle">Reducing radiation dose by application of <span class="hlt">optimized</span> low-energy x-ray <span class="hlt">filters</span> to K-edge imaging with a photon counting detector.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Choi, Yu-Na; Lee, Seungwan; Kim, Hee-Joung</p> <p>2016-01-21</p> <p>K-edge imaging with photon counting x-ray detectors (PCXDs) can improve image quality compared with conventional energy integrating detectors. However, low-energy x-ray photons below the K-edge absorption energy of a target material do not contribute to image formation in the K-edge imaging and are likely to be completely absorbed by an object. In this study, we applied x-ray <span class="hlt">filters</span> to the K-edge imaging with a PCXD based on cadmium zinc telluride for reducing radiation dose induced by low-energy x-ray photons. We used aluminum (Al) <span class="hlt">filters</span> with different thicknesses as the low-energy x-ray <span class="hlt">filters</span> and implemented the iodine K-edge imaging with an energy bin of 34-48 keV at the tube voltages of 50, 70 and 90 kVp. The effects of the low-energy x-ray <span class="hlt">filters</span> on the K-edge imaging were investigated with respect to signal-difference-to-noise ratio (SDNR), entrance surface air kerma (ESAK) and figure of merit (FOM). The highest value of SDNR was observed in the K-edge imaging with a 2 mm Al <span class="hlt">filter</span>, and the SDNR decreased as a function of the <span class="hlt">filter</span> thicknesses. Compared to the K-edge imaging with a 2 mm Al <span class="hlt">filter</span>, the ESAK was reduced by 66%, 48% and 39% in the K-edge imaging with a 12 mm Al <span class="hlt">filter</span> for 50 kVp, 70 kVp and 90 kVp, respectively. The FOM values, which took into account the ESAK and SDNR, were maximized for 8, 6 to 8 and 4 mm Al <span class="hlt">filters</span> at 50 kVp, 70 kVp and 90 kVp, respectively. We concluded that the use of an <span class="hlt">optimal</span> low-energy <span class="hlt">filter</span> thickness, which was determined by maximizing the FOM, could significantly reduce radiation dose while maintaining image quality in the K-edge imaging with the PCXD. PMID:26733235</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003SPIE.5146..127L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003SPIE.5146..127L"><span id="translatedtitle">Selection vector <span class="hlt">filter</span> framework</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lukac, Rastislav; Plataniotis, Konstantinos N.; Smolka, Bogdan; Venetsanopoulos, Anastasios N.</p> <p>2003-10-01</p> <p>We provide a unified framework of nonlinear vector techniques outputting the lowest ranked vector. The proposed framework constitutes a generalized <span class="hlt">filter</span> class for multichannel signal processing. A new class of nonlinear selection <span class="hlt">filters</span> are based on the robust order-statistic theory and the minimization of the weighted distance function to other input samples. The proposed method can be designed to perform a variety of <span class="hlt">filtering</span> operations including previously developed <span class="hlt">filtering</span> techniques such as vector median, basic vector directional <span class="hlt">filter</span>, directional distance <span class="hlt">filter</span>, weighted vector median <span class="hlt">filters</span> and weighted directional <span class="hlt">filters</span>. A wide range of <span class="hlt">filtering</span> operations is guaranteed by the <span class="hlt">filter</span> structure with two independent weight vectors for angular and distance domains of the vector space. In order to adapt the <span class="hlt">filter</span> parameters to varying signal and noise statistics, we provide also the generalized <span class="hlt">optimization</span> algorithms taking the advantage of the weighted median <span class="hlt">filters</span> and the relationship between standard median <span class="hlt">filter</span> and vector median <span class="hlt">filter</span>. Thus, we can deal with both statistical and deterministic aspects of the <span class="hlt">filter</span> design process. It will be shown that the proposed method holds the required properties such as the capability of modelling the underlying system in the application at hand, the robustness with respect to errors in the model of underlying system, the availability of the training procedure and finally, the simplicity of <span class="hlt">filter</span> representation, analysis, design and implementation. Simulation studies also indicate that the new <span class="hlt">filters</span> are computationally attractive and have excellent performance in environments corrupted by bit errors and impulsive noise.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050212421','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050212421"><span id="translatedtitle">Nonlinear Attitude <span class="hlt">Filtering</span> Methods</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Markley, F. Landis; Crassidis, John L.; Cheng, Yang</p> <p>2005-01-01</p> <p>This paper provides a survey of modern nonlinear <span class="hlt">filtering</span> methods for attitude estimation. Early applications relied mostly on the extended Kalman <span class="hlt">filter</span> for attitude estimation. Since these applications, several new approaches have been developed that have proven to be superior to the extended Kalman <span class="hlt">filter</span>. Several of these approaches maintain the basic structure of the extended Kalman <span class="hlt">filter</span>, but employ various modifications in order to provide better convergence or improve other performance characteristics. Examples of such approaches include: <span class="hlt">filter</span> QUEST, extended QUEST, the super-iterated extended Kalman <span class="hlt">filter</span>, the interlaced extended Kalman <span class="hlt">filter</span>, and the second-order Kalman <span class="hlt">filter</span>. <span class="hlt">Filters</span> that propagate and update a discrete set of sigma points rather than using linearized equations for the mean and covariance are also reviewed. A two-<span class="hlt">step</span> approach is discussed with a first-<span class="hlt">step</span> state that linearizes the measurement model and an iterative second <span class="hlt">step</span> to recover the desired attitude states. These approaches are all based on the Gaussian assumption that the probability density function is adequately specified by its mean and covariance. Other approaches that do not require this assumption are reviewed, including particle <span class="hlt">filters</span> and a Bayesian <span class="hlt">filter</span> based on a non-Gaussian, finite-parameter probability density function on SO(3). Finally, the predictive <span class="hlt">filter</span>, nonlinear observers and adaptive approaches are shown. The strengths and weaknesses of the various approaches are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22412508','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22412508"><span id="translatedtitle"><span class="hlt">Optimizing</span> mini-ridge <span class="hlt">filter</span> thickness to reduce proton treatment times in a spot-scanning synchrotron system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Courneyea, Lorraine; Beltran, Chris Tseung, Hok Seum Wan Chan; Yu, Juan; Herman, Michael G.</p> <p>2014-06-15</p> <p>Purpose: Study the contributors to treatment time as a function of Mini-Ridge <span class="hlt">Filter</span> (MRF) thickness to determine the <span class="hlt">optimal</span> choice for breath-hold treatment of lung tumors in a synchrotron-based spot-scanning proton machine. Methods: Five different spot-scanning nozzles were simulated in TOPAS: four with MRFs of varying maximal thicknesses (6.15–24.6 mm) and one with no MRF. The MRFs were designed with ridges aligned along orthogonal directions transverse to the beam, with the number of ridges (4–16) increasing with MRF thickness. The material thickness given by these ridges approximately followed a Gaussian distribution. Using these simulations, Monte Carlo data were generated for treatment planning commissioning. For each nozzle, standard and stereotactic (SR) lung phantom treatment plans were created and assessed for delivery time and plan quality. Results: Use of a MRF resulted in a reduction of the number of energy layers needed in treatment plans, decreasing the number of synchrotron spills needed and hence the treatment time. For standard plans, the treatment time per field without a MRF was 67.0 ± 0.1 s, whereas three of the four MRF plans had treatment times of less than 20 s per field; considered sufficiently low for a single breath-hold. For SR plans, the shortest treatment time achieved was 57.7 ± 1.9 s per field, compared to 95.5 ± 0.5 s without a MRF. There were diminishing gains in time reduction as the MRF thickness increased. Dose uniformity of the PTV was comparable across all plans; however, when the plans were normalized to have the same coverage, dose conformality decreased with MRF thickness, as measured by the lung V20%. Conclusions: Single breath-hold treatment times for plans with standard fractionation can be achieved through the use of a MRF, making this a viable option for motion mitigation in lung tumors. For stereotactic plans, while a MRF can reduce treatment times, multiple breath-holds would still be necessary due to the limit imposed by the proton extraction time. To balance treatment time and normal tissue dose, the ideal MRF choice was shown to be the thinnest option that is able to achieve the desired breath-hold timing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3946449','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3946449"><span id="translatedtitle"><span class="hlt">Optimal</span> Cut-Off Points for Two-<span class="hlt">Step</span> Strategy in Screening of Undiagnosed Diabetes: A Population-Based Study in China</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ye, Zhen; Cong, Liming; Ding, Gangqiang; Yu, Min; Zhang, Xinwei; Hu, Ruying; Wu, Jianjun; Fang, Le; Wang, Hao; Zhang, Jie; He, Qingfang; Su, Danting; Zhao, Ming; Wang, Lixin; Gong, Weiwei; Xiao, Yuanyuan; Liang, Mingbin; Pan, Jin</p> <p>2014-01-01</p> <p>To identify <span class="hlt">optimal</span> cut-off points of fasting plasma glucose for two-<span class="hlt">step</span> strategy in screening of undiagnosed diabetes in Chinese people, data were selected from two cross-sectional studies of Metabolic Syndrome in Zhejiang Province of China, Zhejiang Statistical Yearbook (2010), and published literatures. Two-<span class="hlt">step</span> strategy was used among 17437 subjects sampled from population to screen undiagnosed diabetes. Effectiveness (proportion of cases identified), costs (including medical and non-medical costs), and efficiency (cost per case identified) of these different two-<span class="hlt">step</span> screening strategies were evaluated. This study found the sensitivities of all the two-<span class="hlt">step</span> screening strategies with further Oral Glucose Tolerance Test (OGTT) at different Fasting Plasma Glucose (FPG) cut-off points from 5.0 to 7.0 (mmol/L) ranged from 0.66 to 0.91. For the FPG point of 5.0 mmol/L, 91 percent of undiagnosed cases were identified. The total cost of detecting one undiagnosed diabetes case ranged from 547.1 to 1294.5 CNY/case, and the strategy with FPG at cut-off point of 6.1 (mmol/L) resulted in the least cost. Considering both sensitivity and cost of screening diabetes, FPG cut-off point at 5.4 mmol/L was <span class="hlt">optimized</span> for the two-<span class="hlt">step</span> strategy. In conclusion, different <span class="hlt">optimal</span> cut-off points of FPG for two-<span class="hlt">step</span> strategy in screening of undiagnosed diabetes should be used for different screening purposes. PMID:24609110</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20688130','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20688130"><span id="translatedtitle"><span class="hlt">Filters</span> for <span class="hlt">optimal</span> smoothing of acoustic and electric blink reflex EMG responses to determine blink response magnitude.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>van Boxtel, Anton</p> <p>2010-10-01</p> <p>The functional (i.e., kinematic) aspects of the blink reflex depend on the size of the integrated orbicularis oculi EMG response. Peak amplitude of smoothed rectified EMG is often used as an approximation of integrated EMG. A comparison was made between the outputs of 24 different smoothing <span class="hlt">filters</span>, correlating peak amplitude of acoustic or electric blink reflexes with integrated EMG. The coefficient of determination (R2) was largest (i.e., ≥.95 for acoustic and ≥.90 for electric blink reflexes) when using either (1) a first-order resistor-capacitor <span class="hlt">filter</span> with a time constant of 50 or 100 ms, (2) a boxcar <span class="hlt">filter</span> averaging 51 or 101 data points, or (3) an unequal-weight finite impulse response <span class="hlt">filter</span> with a cutoff frequency of 5 or 10 Hz. These <span class="hlt">filters</span> are thus recommended when determining peak amplitude. Applying a baseline correction on peak amplitude and integrated EMG produced slightly smaller values of R2 compared with uncorrected measures. PMID:20688130</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880004518','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880004518"><span id="translatedtitle">Investigation, development, and application of <span class="hlt">optimal</span> output feedback theory. Volume 3: The relationship between dynamic compensators and observers and Kalman <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Broussard, John R.</p> <p>1987-01-01</p> <p>Relationships between observers, Kalman <span class="hlt">Filters</span> and dynamic compensators using feedforward control theory are investigated. In particular, the relationship, if any, between the dynamic compensator state and linear functions of a discrete plane state are investigated. It is shown that, in steady state, a dynamic compensator driven by the plant output can be expressed as the sum of two terms. The first term is a linear combination of the plant state. The second term depends on plant and measurement noise, and the plant control. Thus, the state of the dynamic compensator can be expressed as an estimator of the first term with additive error given by the second term. Conditions under which a dynamic compensator is a Kalman <span class="hlt">filter</span> are presented, and reduced-order <span class="hlt">optimal</span> estimaters are investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760022072','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760022072"><span id="translatedtitle">Development of an <span class="hlt">optimal</span> automatic control law and <span class="hlt">filter</span> algorithm for steep glideslope capture and glideslope tracking</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Halyo, N.</p> <p>1976-01-01</p> <p>A digital automatic control law to capture a steep glideslope and track the glideslope to a specified altitude is developed for the longitudinal/vertical dynamics of a CTOL aircraft using modern estimation and control techniques. The control law uses a constant gain Kalman <span class="hlt">filter</span> to process guidance information from the microwave landing system, and acceleration from body mounted accelerometer data. The <span class="hlt">filter</span> outputs navigation data and wind velocity estimates which are used in controlling the aircraft. Results from a digital simulation of the aircraft dynamics and the control law are presented for various wind conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26803003','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26803003"><span id="translatedtitle"><span class="hlt">Stepped</span> MS(All) Relied Transition (SMART): An approach to rapidly determine <span class="hlt">optimal</span> multiple reaction monitoring mass spectrometry parameters for small molecules.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ye, Hui; Zhu, Lin; Wang, Lin; Liu, Huiying; Zhang, Jun; Wu, Mengqiu; Wang, Guangji; Hao, Haiping</p> <p>2016-02-11</p> <p>Multiple reaction monitoring (MRM) is a universal approach for quantitative analysis because of its high specificity and sensitivity. Nevertheless, <span class="hlt">optimization</span> of MRM parameters remains as a time and labor-intensive task particularly in multiplexed quantitative analysis of small molecules in complex mixtures. In this study, we have developed an approach named <span class="hlt">Stepped</span> MS(All) Relied Transition (SMART) to predict the <span class="hlt">optimal</span> MRM parameters of small molecules. SMART requires firstly a rapid and high-throughput analysis of samples using a <span class="hlt">Stepped</span> MS(All) technique (sMS(All)) on a Q-TOF, which consists of serial MS(All) events acquired from low CE to gradually <span class="hlt">stepped</span>-up CE values in a cycle. The <span class="hlt">optimal</span> CE values can then be determined by comparing the extracted ion chromatograms for the ion pairs of interest among serial scans. The SMART-predicted parameters were found to agree well with the parameters <span class="hlt">optimized</span> on a triple quadrupole from the same vendor using a mixture of standards. The parameters <span class="hlt">optimized</span> on a triple quadrupole from a different vendor was also employed for comparison, and found to be linearly correlated with the SMART-predicted parameters, suggesting the potential applications of the SMART approach among different instrumental platforms. This approach was further validated by applying to simultaneous quantification of 31 herbal components in the plasma of rats treated with a herbal prescription. Because the sMS(All) acquisition can be accomplished in a single run for multiple components independent of standards, the SMART approach are expected to find its wide application in the multiplexed quantitative analysis of complex mixtures. PMID:26803003</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20767048','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20767048"><span id="translatedtitle">Estimating model parameters for an impact-produced shock-wave simulation: <span class="hlt">Optimal</span> use of partial data with the extended Kalman <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kao, Jim . E-mail: kao@lanl.gov; Flicker, Dawn; Ide, Kayo; Ghil, Michael</p> <p>2006-05-20</p> <p>This paper builds upon our recent data assimilation work with the extended Kalman <span class="hlt">filter</span> (EKF) method [J. Kao, D. Flicker, R. Henninger, S. Frey, M. Ghil, K. Ide, Data assimilation with an extended Kalman <span class="hlt">filter</span> for an impact-produced shock-wave study, J. Comp. Phys. 196 (2004) 705-723.]. The purpose is to test the capability of EKF in <span class="hlt">optimizing</span> a model's physical parameters. The problem is to simulate the evolution of a shock produced through a high-speed flyer plate. In the earlier work, we have showed that the EKF allows one to estimate the evolving state of the shock wave from a single pressure measurement, assuming that all model parameters are known. In the present paper, we show that imperfectly known model parameters can also be estimated accordingly, along with the evolving model state, from the same single measurement. The model parameter <span class="hlt">optimization</span> using the EKF can be achieved through a simple modification of the original EKF formalism by including the model parameters into an augmented state variable vector. While the regular state variables are governed by both deterministic and stochastic forcing mechanisms, the parameters are only subject to the latter. The <span class="hlt">optimally</span> estimated model parameters are thus obtained through a unified assimilation operation. We show that improving the accuracy of the model parameters also improves the state estimate. The time variation of the <span class="hlt">optimized</span> model parameters results from blending the data and the corresponding values generated from the model and lies within a small range, of less than 2%, from the parameter values of the original model. The solution computed with the <span class="hlt">optimized</span> parameters performs considerably better and has a smaller total variance than its counterpart using the original time-constant parameters. These results indicate that the model parameters play a dominant role in the performance of the shock-wave hydrodynamic code at hand.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4364753','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4364753"><span id="translatedtitle"><span class="hlt">Optimal</span> Cut-Off Points of Fasting Plasma Glucose for Two-<span class="hlt">Step</span> Strategy in Estimating Prevalence and Screening Undiagnosed Diabetes and Pre-Diabetes in Harbin, China</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sun, Bo; Lan, Li; Cui, Wenxiu; Xu, Guohua; Sui, Conglan; Wang, Yibaina; Zhao, Yashuang; Wang, Jian; Li, Hongyuan</p> <p>2015-01-01</p> <p>To identify <span class="hlt">optimal</span> cut-off points of fasting plasma glucose (FPG) for two-<span class="hlt">step</span> strategy in screening abnormal glucose metabolism and estimating prevalence in general Chinese population. A population-based cross-sectional study was conducted on 7913 people aged 20 to 74 years in Harbin. Diabetes and pre-diabetes were determined by fasting and 2 hour post-load glucose from the oral glucose tolerance test in all participants. Screening potential of FPG, cost per case identified by two-<span class="hlt">step</span> strategy, and <span class="hlt">optimal</span> FPG cut-off points were described. The prevalence of diabetes was 12.7%, of which 65.2% was undiagnosed. Twelve percent or 9.0% of participants were diagnosed with pre-diabetes using 2003 ADA criteria or 1999 WHO criteria, respectively. The <span class="hlt">optimal</span> FPG cut-off points for two-<span class="hlt">step</span> strategy were 5.6 mmol/l for previously undiagnosed diabetes (area under the receiver-operating characteristic curve of FPG 0.93; sensitivity 82.0%; cost per case identified by two-<span class="hlt">step</span> strategy ¥261), 5.3 mmol/l for both diabetes and pre-diabetes or pre-diabetes alone using 2003 ADA criteria (0.89 or 0.85; 72.4% or 62.9%; ¥110 or ¥258), 5.0 mmol/l for pre-diabetes using 1999 WHO criteria (0.78; 66.8%; ¥399), and 4.9 mmol/l for IGT alone (0.74; 62.2%; ¥502). Using the two-<span class="hlt">step</span> strategy, the underestimates of prevalence reduced to nearly 38% for pre-diabetes or 18.7% for undiagnosed diabetes, respectively. Approximately a quarter of the general population in Harbin was in hyperglycemic condition. Using <span class="hlt">optimal</span> FPG cut-off points for two-<span class="hlt">step</span> strategy in Chinese population may be more effective and less costly for reducing the missed diagnosis of hyperglycemic condition. PMID:25785585</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9633E..21M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9633E..21M"><span id="translatedtitle">Pixelated <span class="hlt">filters</span> for spatial imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mathieu, Karine; Lequime, Michel; Lumeau, Julien; Abel-Tiberini, Laetitia; Savin De Larclause, Isabelle; Berthon, Jacques</p> <p>2015-10-01</p> <p>Small satellites are often used by spatial agencies to meet scientific spatial mission requirements. Their payloads are composed of various instruments collecting an increasing amount of data, as well as respecting the growing constraints relative to volume and mass; So small-sized integrated camera have taken a favored place among these instruments. To ensure scene specific color information sensing, pixelated <span class="hlt">filters</span> seem to be more attractive than <span class="hlt">filter</span> wheels. The work presented here, in collaboration with Institut Fresnel, deals with the manufacturing of this kind of component, based on thin film technologies and photolithography processes. CCD detectors with a pixel pitch about 30 μm were considered. In the configuration where the matrix <span class="hlt">filters</span> are positioned the closest to the detector, the matrix <span class="hlt">filters</span> are composed of 2x2 macro pixels (e.g. 4 <span class="hlt">filters</span>). These 4 <span class="hlt">filters</span> have a bandwidth about 40 nm and are respectively centered at 550, 700, 770 and 840 nm with a specific rejection rate defined on the visible spectral range [500 - 900 nm]. After an intense design <span class="hlt">step</span>, 4 thin-film structures have been elaborated with a maximum thickness of 5 μm. A run of tests has allowed us to choose the <span class="hlt">optimal</span> micro-structuration parameters. The 100x100 matrix <span class="hlt">filters</span> prototypes have been successfully manufactured with lift-off and ion assisted deposition processes. High spatial and spectral characterization, with a dedicated metrology bench, showed that initial specifications and simulations were globally met. These excellent performances knock down the technological barriers for high-end integrated specific multi spectral imaging.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22105751','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22105751"><span id="translatedtitle">Modeling <span class="hlt">filters</span> for formation of mono-energetic neutron beams in the research reactor IRT MEPhI and <span class="hlt">optimization</span> of radiation shielding for liquid-xenon detector</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ivakhin, S. V.; Tikhomirov, G. V.; Bolozdynya, A. I.; Efremenko, Y. V.; Akimov, D. Y.; Stekhanov, V. N.</p> <p>2012-07-01</p> <p>The paper considers formation of mono-energetic neutron beams at the entrance of experimental channels in research reactors for various applications. The problem includes the following <span class="hlt">steps</span>: 1. Full-scale mathematical model of the research IRT MEPhI was developed for numerical evaluations of neutron spectra and neutron spatial distribution in the area of experimental channels. 2. Modeling of <span class="hlt">filters</span> in the channel to shift neutron spectrum towards the required mono-energetic line was performed. 3. Some characteristics of neutron beams at the entrance of detector were evaluated. The <span class="hlt">filter</span> materials were selected. The calculations were carried out with application of the computer code based on the high-precision Monte-Carlo code MCNP. As a result, mathematical model was created for the <span class="hlt">filter</span> which is able to form mono-energetic (24 keV) neutron beam. The study was carried out within the frames of the research project on development of Russian emission detector with liquid noble gas to observe rare processes of neutrino scattering and particles of hypothetical dark matter in atomic nuclei. (authors)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22253223','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22253223"><span id="translatedtitle">Multiple time <span class="hlt">step</span> molecular dynamics in the <span class="hlt">optimized</span> isokinetic ensemble steered with the molecular theory of solvation: Accelerating with advanced extrapolation of effective solvation forces</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Omelyan, Igor E-mail: omelyan@icmp.lviv.ua; Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 2G8; Institute for Condensed Matter Physics, National Academy of Sciences of Ukraine, 1 Svientsitskii Street, Lviv 79011 ; Kovalenko, Andriy; Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 2G8 </p> <p>2013-12-28</p> <p>We develop efficient handling of solvation forces in the multiscale method of multiple time <span class="hlt">step</span> molecular dynamics (MTS-MD) of a biomolecule steered by the solvation free energy (effective solvation forces) obtained from the 3D-RISM-KH molecular theory of solvation (three-dimensional reference interaction site model complemented with the Kovalenko-Hirata closure approximation). To reduce the computational expenses, we calculate the effective solvation forces acting on the biomolecule by using advanced solvation force extrapolation (ASFE) at inner time <span class="hlt">steps</span> while converging the 3D-RISM-KH integral equations only at large outer time <span class="hlt">steps</span>. The idea of ASFE consists in developing a discrete non-Eckart rotational transformation of atomic coordinates that minimizes the distances between the atomic positions of the biomolecule at different time moments. The effective solvation forces for the biomolecule in a current conformation at an inner time <span class="hlt">step</span> are then extrapolated in the transformed subspace of those at outer time <span class="hlt">steps</span> by using a modified least square fit approach applied to a relatively small number of the best force-coordinate pairs. The latter are selected from an extended set collecting the effective solvation forces obtained from 3D-RISM-KH at outer time <span class="hlt">steps</span> over a broad time interval. The MTS-MD integration with effective solvation forces obtained by converging 3D-RISM-KH at outer time <span class="hlt">steps</span> and applying ASFE at inner time <span class="hlt">steps</span> is stabilized by employing the <span class="hlt">optimized</span> isokinetic Nosé-Hoover chain (OIN) ensemble. Compared to the previous extrapolation schemes used in combination with the Langevin thermostat, the ASFE approach substantially improves the accuracy of evaluation of effective solvation forces and in combination with the OIN thermostat enables a dramatic increase of outer time <span class="hlt">steps</span>. We demonstrate on a fully flexible model of alanine dipeptide in aqueous solution that the MTS-MD/OIN/ASFE/3D-RISM-KH multiscale method of molecular dynamics steered by effective solvation forces allows huge outer time <span class="hlt">steps</span> up to tens of picoseconds without affecting the equilibrium and conformational properties, and thus provides a 100- to 500-fold effective speedup in comparison to conventional MD with explicit solvent. With the statistical-mechanical 3D-RISM-KH account for effective solvation forces, the method provides efficient sampling of biomolecular processes with slow and/or rare solvation events such as conformational transitions of hydrated alanine dipeptide with the mean life times ranging from 30 ps up to 10 ns for “flip-flop” conformations, and is particularly beneficial for biomolecular systems with exchange and localization of solvent and ions, ligand binding, and molecular recognition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/24387356','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/24387356"><span id="translatedtitle">Multiple time <span class="hlt">step</span> molecular dynamics in the <span class="hlt">optimized</span> isokinetic ensemble steered with the molecular theory of solvation: accelerating with advanced extrapolation of effective solvation forces.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Omelyan, Igor; Kovalenko, Andriy</p> <p>2013-12-28</p> <p>We develop efficient handling of solvation forces in the multiscale method of multiple time <span class="hlt">step</span> molecular dynamics (MTS-MD) of a biomolecule steered by the solvation free energy (effective solvation forces) obtained from the 3D-RISM-KH molecular theory of solvation (three-dimensional reference interaction site model complemented with the Kovalenko-Hirata closure approximation). To reduce the computational expenses, we calculate the effective solvation forces acting on the biomolecule by using advanced solvation force extrapolation (ASFE) at inner time <span class="hlt">steps</span> while converging the 3D-RISM-KH integral equations only at large outer time <span class="hlt">steps</span>. The idea of ASFE consists in developing a discrete non-Eckart rotational transformation of atomic coordinates that minimizes the distances between the atomic positions of the biomolecule at different time moments. The effective solvation forces for the biomolecule in a current conformation at an inner time <span class="hlt">step</span> are then extrapolated in the transformed subspace of those at outer time <span class="hlt">steps</span> by using a modified least square fit approach applied to a relatively small number of the best force-coordinate pairs. The latter are selected from an extended set collecting the effective solvation forces obtained from 3D-RISM-KH at outer time <span class="hlt">steps</span> over a broad time interval. The MTS-MD integration with effective solvation forces obtained by converging 3D-RISM-KH at outer time <span class="hlt">steps</span> and applying ASFE at inner time <span class="hlt">steps</span> is stabilized by employing the <span class="hlt">optimized</span> isokinetic Nosé-Hoover chain (OIN) ensemble. Compared to the previous extrapolation schemes used in combination with the Langevin thermostat, the ASFE approach substantially improves the accuracy of evaluation of effective solvation forces and in combination with the OIN thermostat enables a dramatic increase of outer time <span class="hlt">steps</span>. We demonstrate on a fully flexible model of alanine dipeptide in aqueous solution that the MTS-MD/OIN/ASFE/3D-RISM-KH multiscale method of molecular dynamics steered by effective solvation forces allows huge outer time <span class="hlt">steps</span> up to tens of picoseconds without affecting the equilibrium and conformational properties, and thus provides a 100- to 500-fold effective speedup in comparison to conventional MD with explicit solvent. With the statistical-mechanical 3D-RISM-KH account for effective solvation forces, the method provides efficient sampling of biomolecular processes with slow and/or rare solvation events such as conformational transitions of hydrated alanine dipeptide with the mean life times ranging from 30 ps up to 10 ns for "flip-flop" conformations, and is particularly beneficial for biomolecular systems with exchange and localization of solvent and ions, ligand binding, and molecular recognition. PMID:24387356</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996SPIE.2662...24L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996SPIE.2662...24L"><span id="translatedtitle">Using adaptive genetic algorithms in the design of morphological <span class="hlt">filters</span> in textural image processing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Wei; Haese-Coat, Veronique; Ronsin, Joseph</p> <p>1996-03-01</p> <p>An adaptive GA scheme is adopted for the <span class="hlt">optimal</span> morphological <span class="hlt">filter</span> design problem. The adaptive crossover and mutation rate which make the GA avoid premature and at the same time assure convergence of the program are successfully used in <span class="hlt">optimal</span> morphological <span class="hlt">filter</span> design procedure. In the string coding <span class="hlt">step</span>, each string (chromosome) is composed of a structuring element coding chain concatenated with a <span class="hlt">filter</span> sequence coding chain. In decoding <span class="hlt">step</span>, each string is divided into 3 chains which then are decoded respectively into one structuring element with a size inferior to 5 by 5 and two concatenating morphological <span class="hlt">filter</span> operators. The fitness function in GA is based on the mean-square-error (MSE) criterion. In string selection <span class="hlt">step</span>, a stochastic tournament procedure is used to replace the simple roulette wheel program in order to accelerate the convergence. The final convergence of our algorithm is reached by a two <span class="hlt">step</span> converging strategy. In presented applications of noise removal from texture images, it is found that with the <span class="hlt">optimized</span> morphological <span class="hlt">filter</span> sequences, the obtained MSE values are smaller than those using corresponding non-adaptive morphological <span class="hlt">filters</span>, and the <span class="hlt">optimized</span> shapes and orientations of structuring elements take approximately the same shapes and orientations as those of the image textons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26123740','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26123740"><span id="translatedtitle">The Tenth <span class="hlt">Step</span> of the BFHI: What midwives need to know about <span class="hlt">optimal</span> support for mothers, post-discharge.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Thorley, Virginia</p> <p>2015-09-01</p> <p>This commentary discusses the 10th <span class="hlt">Step</span> of the Baby-Friendly Hospital Initiative (BFHI), the only <span class="hlt">step</span> that goes beyond the hospital to provide for the mother to receive breast-feeding support after she returns to the community. The reasons why such support is needed, and how this support has been provided in different settings, will be discussed. Post-discharge support for breast-feeding mothers takes many forms and is optimised when mothers can access both professional and peer support. The mother-baby dyad is best served by the right advice from the right person at the right time. Midwives who assist the new mother with information about easily accessible support in the community enable the care she has received during her short hospital stay and during any midwifery home visiting to continue when she is in an environment that may not be supportive of breast feeding. PMID:26123740</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26561726','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26561726"><span id="translatedtitle"><span class="hlt">Optimization</span>, physicochemical characterization and in vivo assessment of spray dried emulsion: A <span class="hlt">step</span> toward bioavailability augmentation and gastric toxicity minimization.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mehanna, Mohammed M; Alwattar, Jana K; Elmaradny, Hoda A</p> <p>2015-12-30</p> <p>The limited solubility of BCS class II drugs diminishes their dissolution and thus reduces their bioavailability. Our aim in this study was to develop and <span class="hlt">optimize</span> a spray dried emulsion containing indomethacin as a model for Class II drugs, Labrasol®/Transuctol® mixture as the oily phase, and maltodextrin as a solid carrier. The <span class="hlt">optimization</span> was carried out using a 2(3) full factorial design based on two independent variables, the percentage of carrier and concentration of Poloxamer® 188. The effect of the studied parameters on the spray dried yield, loading efficiency and in vitro release were thoroughly investigated. Furthermore, physicochemical characterization of the <span class="hlt">optimized</span> formulation was performed. In vivo bioavailability, ulcerogenic capability and histopathological features were assessed. The results obtained pointed out that poloxamer 188 concentration in the formulation was the predominant factor affecting the dissolution release, whereas the drug loading was driven by the carrier concentration added. Moreover, the yield demonstrated a drawback by increasing both independent variables studied. The <span class="hlt">optimized</span> formulation presented a complete release within two minutes thus suggesting an immediate release pattern as well, the formulation revealed to be uniform spherical particles with an average size of 7.5μm entrapping the drug in its molecular state as demonstrated by the DSC and FTIR studies. The in vivo evaluation, demonstrated a 10-fold enhancement in bioavailability of the <span class="hlt">optimized</span> formulation, with absence of ulcerogenic side effect compared to the marketed product. The results provided an evidence for the significance of spray dried emulsion as a leading strategy for improving the solubility and enhancing the bioavailability of class II drugs. PMID:26561726</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22339801','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22339801"><span id="translatedtitle">SU-E-T-23: A Novel Two-<span class="hlt">Step</span> <span class="hlt">Optimization</span> Scheme for Tandem and Ovoid (T and O) HDR Brachytherapy Treatment for Locally Advanced Cervical Cancer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sharma, M; Todor, D; Fields, E</p> <p>2014-06-01</p> <p>Purpose: To present a novel method allowing fast, true volumetric <span class="hlt">optimization</span> of T and O HDR treatments and to quantify its benefits. Materials and Methods: 27 CT planning datasets and treatment plans from six consecutive cervical cancer patients treated with 45 intracavitary T and O insertions were used. Initial treatment plans were created with a goal of covering high risk (HR)-CTV with D90 > 90% and minimizing D2cc to rectum, bladder and sigmoid with manual <span class="hlt">optimization</span>, approved and delivered. For the second <span class="hlt">step</span>, each case was re-planned adding a new structure, created from the 100% prescription isodose line of the manually <span class="hlt">optimized</span> plan to the existent physician delineated HR-CTV, rectum, bladder and sigmoid. New, more rigorous DVH constraints for the critical OARs were used for the <span class="hlt">optimization</span>. D90 for the HR-CTV and D2cc for OARs were evaluated in both plans. Results: Two-<span class="hlt">step</span> <span class="hlt">optimized</span> plans had consistently smaller D2cc's for all three OARs while preserving good D90s for HR-CTV. On plans with excellent CTV coverage, average D90 of 96% (range 91102), sigmoid D2cc was reduced on average by 37% (range 1673), bladder by 28% (range 2047) and rectum by 27% (range 1545). Similar reductions were obtained on plans with good coverage, with an average D90 of 93% (range 9099). For plans with inferior coverage, average D90 of 81%, an increase in coverage to 87% was achieved concurrently with D2cc reductions of 31%, 18% and 11% for sigmoid, bladder and rectum. Conclusions: A two-<span class="hlt">step</span> DVH-based <span class="hlt">optimization</span> can be added with minimal planning time increase, but with the potential of dramatic and systematic reductions of D2cc for OARs and in some cases with concurrent increases in target dose coverage. These single-fraction modifications would be magnified over the course of 45 intracavitary insertions and may have real clinical implications in terms of decreasing both acute and late toxicity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JCoPh.304..441T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JCoPh.304..441T"><span id="translatedtitle">Unconditionally energy stable time <span class="hlt">stepping</span> scheme for Cahn-Morral equation: Application to multi-component spinodal decomposition and <span class="hlt">optimal</span> space tiling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tavakoli, Rouhollah</p> <p>2016-01-01</p> <p>An unconditionally energy stable time <span class="hlt">stepping</span> scheme is introduced to solve Cahn-Morral-like equations in the present study. It is constructed based on the combination of David Eyre's time <span class="hlt">stepping</span> scheme and Schur complement approach. Although the presented method is general and independent of the choice of homogeneous free energy density function term, logarithmic and polynomial energy functions are specifically considered in this paper. The method is applied to study the spinodal decomposition in multi-component systems and <span class="hlt">optimal</span> space tiling problems. A penalization strategy is developed, in the case of later problem, to avoid trivial solutions. Extensive numerical experiments demonstrate the success and performance of the presented method. According to the numerical results, the method is convergent and energy stable, independent of the choice of time stepsize. Its MATLAB implementation is included in the appendix for the numerical evaluation of algorithm and reproduction of the presented results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/21144528','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/21144528"><span id="translatedtitle"><span class="hlt">Optimization</span> of pressurized liquid extraction and purification conditions for gas chromatography-mass spectrometry determination of UV <span class="hlt">filters</span> in sludge.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Negreira, N; Rodríguez, I; Rubí, E; Cela, R</p> <p>2011-01-14</p> <p>This work presents an effective sample preparation method for the determination of eight UV <span class="hlt">filter</span> compounds, belonging to different chemical classes, in freeze-dried sludge samples. Pressurized liquid extraction (PLE) and gas chromatography-mass spectrometry (GC-MS) were selected as extraction and determination techniques, respectively. Normal-phase, reversed-phase and anionic exchange materials were tested as clean-up sorbents to reduce the complexity of raw PLE extracts. Under final working conditions, graphitized carbon (0.5 g) was used as in-cell purification sorbent for the retention of co-extracted pigments. Thereafter, a solid-phase extraction cartridge, containing 0.5 g of primary secondary amine (PSA) bonded silica, was employed for off-line removal of other interferences, mainly fatty acids, overlapping the chromatographic peaks of some UV <span class="hlt">filters</span>. Extractions were performed with a n-hexane:dichloromethane (80:20, v:v) solution at 75°C, using a single extraction cycle of 5 min at 1500 psi. Flush volume and purge time were set at 100% and 2 min, respectively. Considering 0.5 g of sample and 1 mL as the final volume of the purified extract, the developed method provided recoveries between 73% and 112%, with limits of quantification (LOQs) from 17 to 61 ng g(-1) and a linear response range up to 10 μg g(-1). Total solvent consumption remained around 30 mL per sample. The analysis of non-spiked samples confirmed the sorption of significant amounts of several UV <span class="hlt">filters</span> in sludge with average concentrations above 0.6 μg g(-1) for 3-(4-methylbenzylidene) camphor (4-MBC), 2-ethylhexyl-p-methoxycinnamate (EHMC) and octocrylene (OC). PMID:21144528</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2651631','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2651631"><span id="translatedtitle">Biological/Biomedical Accelerator Mass Spectrometry Targets. 1. <span class="hlt">Optimizing</span> the CO2 Reduction <span class="hlt">Step</span> Using Zinc Dust</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2008-01-01</p> <p>Biological and biomedical applications of accelerator mass spectrometry (AMS) use isotope ratio mass spectrometry to quantify minute amounts of long-lived radioisotopes such as 14C. AMS target preparation involves first the oxidation of carbon (in sample of interest) to CO2 and second the reduction of CO2 to filamentous, fluffy, fuzzy, or firm graphite-like substances that coat a −400-mesh spherical iron powder (−400MSIP) catalyst. Until now, the quality of AMS targets has been variable; consequently, they often failed to produce robust ion currents that are required for reliable, accurate, precise, and high-throughput AMS for biological/biomedical applications. Therefore, we described our <span class="hlt">optimized</span> method for reduction of CO2 to high-quality uniform AMS targets whose morphology we visualized using scanning electron microscope pictures. Key features of our <span class="hlt">optimized</span> method were to reduce CO2 (from a sample of interest that provided 1 mg of C) using 100 ± 1.3 mg of Zn dust, 5 ± 0.4 mg of −400MSIP, and a reduction temperature of 500 °C for 3 h. The thermodynamics of our <span class="hlt">optimized</span> method were more favorable for production of graphite-coated iron powders (GCIP) than those of previous methods. All AMS targets from our <span class="hlt">optimized</span> method were of 100% GCIP, the graphitization yield exceeded 90%, and δ13C was −17.9 ± 0.3‰. The GCIP reliably produced strong 12C− currents and accurate and precise Fm values. The observed Fm value for oxalic acid II NIST SRM deviated from its accepted Fm value of 1.3407 by only 0.0003 ± 0.0027 (mean ± SE, n = 32), limit of detection of 14C was 0.04 amol, and limit of quantification was 0.07 amol, and a skilled analyst can prepare as many as 270 AMS targets per day. More information on the physical (hardness/color), morphological (SEMs), and structural (FT-IR, Raman, XRD spectra) characteristics of our AMS targets that determine accurate, precise, and high-hroughput AMS measurement are in the companion paper. PMID:18785761</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18785761','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18785761"><span id="translatedtitle">Biological/biomedical accelerator mass spectrometry targets. 1. <span class="hlt">optimizing</span> the CO2 reduction <span class="hlt">step</span> using zinc dust.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kim, Seung-Hyun; Kelly, Peter B; Clifford, Andrew J</p> <p>2008-10-15</p> <p>Biological and biomedical applications of accelerator mass spectrometry (AMS) use isotope ratio mass spectrometry to quantify minute amounts of long-lived radioisotopes such as (14)C. AMS target preparation involves first the oxidation of carbon (in sample of interest) to CO 2 and second the reduction of CO 2 to filamentous, fluffy, fuzzy, or firm graphite-like substances that coat a -400-mesh spherical iron powder (-400MSIP) catalyst. Until now, the quality of AMS targets has been variable; consequently, they often failed to produce robust ion currents that are required for reliable, accurate, precise, and high-throughput AMS for biological/biomedical applications. Therefore, we described our <span class="hlt">optimized</span> method for reduction of CO 2 to high-quality uniform AMS targets whose morphology we visualized using scanning electron microscope pictures. Key features of our <span class="hlt">optimized</span> method were to reduce CO 2 (from a sample of interest that provided 1 mg of C) using 100 +/- 1.3 mg of Zn dust, 5 +/- 0.4 mg of -400MSIP, and a reduction temperature of 500 degrees C for 3 h. The thermodynamics of our <span class="hlt">optimized</span> method were more favorable for production of graphite-coated iron powders (GCIP) than those of previous methods. All AMS targets from our <span class="hlt">optimized</span> method were of 100% GCIP, the graphitization yield exceeded 90%, and delta (13)C was -17.9 +/- 0.3 per thousand. The GCIP reliably produced strong (12)C (-) currents and accurate and precise F m values. The observed F m value for oxalic acid II NIST SRM deviated from its accepted F m value of 1.3407 by only 0.0003 +/- 0.0027 (mean +/- SE, n = 32), limit of detection of (14)C was 0.04 amol, and limit of quantification was 0.07 amol, and a skilled analyst can prepare as many as 270 AMS targets per day. More information on the physical (hardness/color), morphological (SEMs), and structural (FT-IR, Raman, XRD spectra) characteristics of our AMS targets that determine accurate, precise, and high-hroughput AMS measurement are in the companion paper. PMID:18785761</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26625415','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26625415"><span id="translatedtitle">Edge-Aware BMA <span class="hlt">Filters</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guang Deng</p> <p>2016-01-01</p> <p>There has been continuous research in edge-aware <span class="hlt">filters</span> which have found many applications in computer vision and image processing. In this paper, we propose a principled-approach for the development of edge-aware <span class="hlt">filters</span>. The proposed approach is based on two well-established principles: 1) <span class="hlt">optimal</span> parameter estimation and 2) Bayesian model averaging (BMA). Using this approach, we formulate the problem of <span class="hlt">filtering</span> a pixel in a local pixel patch as an <span class="hlt">optimal</span> estimation problem. Since a pixel belongs to multiple local patches, there are multiple estimates of the same pixel. We combine these estimates into a final estimate using BMA. We demonstrate the versatility of this approach by developing a family of BMA <span class="hlt">filters</span> based on different settings of cost functions and log-likelihood and log-prior functions. We also present a new interpretation of the guided <span class="hlt">filter</span> and develop a BMA guided <span class="hlt">filter</span> which includes the guided <span class="hlt">filter</span> as a special case. We show that BMA <span class="hlt">filters</span> can produce similar smoothing results as those of the state-of-the-art edge-aware <span class="hlt">filters</span>. Two BMA <span class="hlt">filters</span> are computationally as efficient as the guided <span class="hlt">filter</span> which is one of the fastest edge-aware <span class="hlt">filters</span>. We also demonstrate that the BMA guided <span class="hlt">filter</span> is better than the guided <span class="hlt">filter</span> in preserving sharp edges. A new feature of the BMA guided <span class="hlt">filter</span> is that the <span class="hlt">filtered</span> image is similar to that produced by a clustering process. PMID:26625415</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910001004','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910001004"><span id="translatedtitle">Computation of maximum gust loads in nonlinear aircraft using a new method based on the matched <span class="hlt">filter</span> approach and numerical <span class="hlt">optimization</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pototzky, Anthony S.; Heeg, Jennifer; Perry, Boyd, III</p> <p>1990-01-01</p> <p>Time-correlated gust loads are time histories of two or more load quantities due to the same disturbance time history. Time correlation provides knowledge of the value (magnitude and sign) of one load when another is maximum. At least two analysis methods have been identified that are capable of computing maximized time-correlated gust loads for linear aircraft. Both methods solve for the unit-energy gust profile (gust velocity as a function of time) that produces the maximum load at a given location on a linear airplane. Time-correlated gust loads are obtained by re-applying this gust profile to the airplane and computing multiple simultaneous load responses. Such time histories are physically realizable and may be applied to aircraft structures. Within the past several years there has been much interest in obtaining a practical analysis method which is capable of solving the analogous problem for nonlinear aircraft. Such an analysis method has been the focus of an international committee of gust loads specialists formed by the U.S. Federal Aviation Administration and was the topic of a panel discussion at the Gust and Buffet Loads session at the 1989 SDM Conference in Mobile, Alabama. The kinds of nonlinearities common on modern transport aircraft are indicated. The Statical Discrete Gust method is capable of being, but so far has not been, applied to nonlinear aircraft. To make the method practical for nonlinear applications, a search procedure is essential. Another method is based on Matched <span class="hlt">Filter</span> Theory and, in its current form, is applicable to linear systems only. The purpose here is to present the status of an attempt to extend the matched <span class="hlt">filter</span> approach to nonlinear systems. The extension uses Matched <span class="hlt">Filter</span> Theory as a starting point and then employs a constrained <span class="hlt">optimization</span> algorithm to attack the nonlinear problem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22858472','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22858472"><span id="translatedtitle">Pretreatment based on two-<span class="hlt">step</span> steam explosion combined with an intermediate separation of fiber cells--<span class="hlt">optimization</span> of fermentation of corn straw hydrolysates.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Yuzhen; Fu, Xiaoguo; Chen, Hongzhang</p> <p>2012-10-01</p> <p>Pretreatment is necessary for lignocellulose to achieve a highly efficient enzymatic hydrolysis and fermentation. However, coincident with pretreatment, compounds inhibiting microorganism growth are formed. Some tissues or cells, such as thin-walled cells that easily hydrolyze, will be excessively degraded because of the structural heterogeneity of lignocellulose, and some inhibitors will be generated under the same pretreatment conditions. Results showed, compared with one-<span class="hlt">step</span> steam explosion (1.2 MPa/8 min), two-<span class="hlt">step</span> steam explosion with an intermediate separation of fiber cells (ISFC) (1.1 Mpa/4 min-ISFC-1.2 MPa/4 min) can increase enzymatic hydrolyzation by 12.82%, reduce inhibitor conversion by 33%, and increase fermentation product (2,3-butanediol) conversion by 209%. Thus, the two-<span class="hlt">step</span> steam explosion with ISFC process is proposed to <span class="hlt">optimize</span> the hydrolysis process of lignocellulose by modifying the raw material from the origin. This novel process reduces the inhibitor content, promotes the biotransformation of lignocellulose, and simplifies the process of excluding the detoxification unit operation. PMID:22858472</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9412E..3PK','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9412E..3PK"><span id="translatedtitle">Multi-dimensional tensor-based adaptive <span class="hlt">filter</span> (TBAF) for low dose x-ray CT</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Knaup, Michael; Lebedev, Sergej; Sawall, Stefan; Kachelrie, Marc</p> <p>2015-03-01</p> <p>Edge-preserving adaptive <span class="hlt">filtering</span> within CT image reconstruction is a powerful method to reduce image noise and hence to reduce patient dose. However, highly sophisticated adaptive <span class="hlt">filters</span> typically comprise many parameters which must be adjusted carefully in order to obtain <span class="hlt">optimal</span> <span class="hlt">filter</span> performance and to avoid artifacts caused by the <span class="hlt">filter</span>. In this work we applied an anisotropic tensor-based adaptive image <span class="hlt">filter</span> (TBAF) to CT image reconstruction, both as an image-based post-processing <span class="hlt">step</span>, as well as a regularization <span class="hlt">step</span> within an iterative reconstruction. The TBAF is a generalization of the <span class="hlt">filter</span> of reference.1 Provided that the image noise (i.e. the variance) of the original image is known for each voxel, we adjust all <span class="hlt">filter</span> parameters automatically. Hence, the TBAF can be applied to any individual CT dataset without user interaction. This is a crucial feature for a possible application in clinical routine. The TBAF is compared to a well-established adaptive bilateral <span class="hlt">filter</span> using the same noise adjustment. Although the differences between both <span class="hlt">filters</span> are subtle, edges and local structures emerge more clearly in the TBAF <span class="hlt">filtered</span> images while anatomical details are less affected than by the bilateral <span class="hlt">filter</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920057751&hterms=1053&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231053','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920057751&hterms=1053&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231053"><span id="translatedtitle">An IIR median hybrid <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bauer, Peter H.; Sartori, Michael A.; Bryden, Timothy M.</p> <p>1992-01-01</p> <p>A new class of nonlinear <span class="hlt">filters</span>, the so-called class of multidirectional infinite impulse response median hybrid <span class="hlt">filters</span>, is presented and analyzed. The input signal is processed twice using a linear shift-invariant infinite impulse response <span class="hlt">filtering</span> module: once with normal causality and a second time with inverted causality. The final output of the MIMH <span class="hlt">filter</span> is the median of the two-directional outputs and the original input signal. Thus, the MIMH <span class="hlt">filter</span> is a concatenation of linear <span class="hlt">filtering</span> and nonlinear <span class="hlt">filtering</span> (a median <span class="hlt">filtering</span> module). Because of this unique scheme, the MIMH <span class="hlt">filter</span> possesses many desirable properties which are both proven and analyzed (including impulse removal, <span class="hlt">step</span> preservation, and noise suppression). A comparison to other existing median type <span class="hlt">filters</span> is also provided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003SPIE.5159..299T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003SPIE.5159..299T"><span id="translatedtitle">Refinement and generalization of the extension method of covariance matrix inversion by regularization for spectral <span class="hlt">filtering</span> <span class="hlt">optimization</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Twede, David R.; Hayden, Andreas F.</p> <p>2003-12-01</p> <p>Many spectral signature detection algorithms depend on numerically inverting covariance matrices. Hyperspectral data rarely span the full band space because of factors such as sensor noise, numerical round-off, sparse sampling, and band correlation inherent in the data or introduced by data processing. Processing the full order of the covariance matrix without regard to its useful rank leads to reduced detection performance. It was previously shown that the performance of inverse-covariance based detection algorithms can be improved by regularizing the covariance matrix inversion through extension of an <span class="hlt">optimally</span> chosen eigenvalue. The extension method provides a robust way to <span class="hlt">optimize</span> signal to clutter ratio (SCR) on data collected with a detector of uniform gain. The method of trusted eigenvalue extension has now been applied to data collected with a sensor with multiple gain regions. Multiple gain regions are used on wide spectral range sensors such as HYDICE and complicate the inversion of the covariance matrix over the full range of spectral bands. Further <span class="hlt">optimization</span> of the trusted eigenvalue is presented and compared against traditional regularization methods. Since the extension method is particularly intended for sparsely sampled data with high dimensionality, a comparison is presented between the extension method and band coaddition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004SPIE.5159..299T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004SPIE.5159..299T"><span id="translatedtitle">Refinement and generalization of the extension method of covariance matrix inversion by regularization for spectral <span class="hlt">filtering</span> <span class="hlt">optimization</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Twede, David R.; Hayden, Andreas F.</p> <p>2004-01-01</p> <p>Many spectral signature detection algorithms depend on numerically inverting covariance matrices. Hyperspectral data rarely span the full band space because of factors such as sensor noise, numerical round-off, sparse sampling, and band correlation inherent in the data or introduced by data processing. Processing the full order of the covariance matrix without regard to its useful rank leads to reduced detection performance. It was previously shown that the performance of inverse-covariance based detection algorithms can be improved by regularizing the covariance matrix inversion through extension of an <span class="hlt">optimally</span> chosen eigenvalue. The extension method provides a robust way to <span class="hlt">optimize</span> signal to clutter ratio (SCR) on data collected with a detector of uniform gain. The method of trusted eigenvalue extension has now been applied to data collected with a sensor with multiple gain regions. Multiple gain regions are used on wide spectral range sensors such as HYDICE and complicate the inversion of the covariance matrix over the full range of spectral bands. Further <span class="hlt">optimization</span> of the trusted eigenvalue is presented and compared against traditional regularization methods. Since the extension method is particularly intended for sparsely sampled data with high dimensionality, a comparison is presented between the extension method and band coaddition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=computer+AND+network+AND+security&pg=7&id=EJ711631','ERIC'); return false;" href="http://eric.ed.gov/?q=computer+AND+network+AND+security&pg=7&id=EJ711631"><span id="translatedtitle">Security: <span class="hlt">Step</span> by <span class="hlt">Step</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Svetcov, Eric</p> <p>2005-01-01</p> <p>This article provides a list of the essential <span class="hlt">steps</span> to keeping a school's or district's network safe and sound. It describes how to establish a security architecture and approach that will continually evolve as the threat environment changes over time. The article discusses the methodology for implementing this approach and then discusses the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JCrGr.315...74B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JCrGr.315...74B"><span id="translatedtitle">Characterization and <span class="hlt">optimization</span> of 2-<span class="hlt">step</span> MOVPE growth for single-mode DFB or DBR laser diodes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bugge, F.; Mogilatenko, A.; Zeimer, U.; Brox, O.; Neumann, W.; Erbert, G.; Weyers, M.</p> <p>2011-01-01</p> <p>We have studied the MOVPE regrowth of AlGaAs over a grating for GaAs-based laser diodes with an internal wavelength stabilisation. Growth temperature and aluminium concentration in the regrown layers considerably affect the oxygen incorporation. Structural characterisation by transmission electron microscopy of the grating after regrowth shows the formation of quaternary InGaAsP regions due to the diffusion of indium atoms from the top InGaP layer and As-P exchange processes during the heating-up procedure. Additionally, the growth over such gratings with different facets leads to self-organisation of the aluminium content in the regrown AlGaAs layer, resulting in an additional AlGaAs grating, which has to be taken into account for the estimation of the coupling coefficient. With <span class="hlt">optimized</span> growth conditions complete distributed feedback laser structures have been grown for different emission wavelengths. At 1062 nm a very high single-frequency output power of nearly 400 mW with a slope efficiency of 0.95 W/A for a 4 μm ridge-waveguide was obtained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22105810','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22105810"><span id="translatedtitle"><span class="hlt">Steps</span> towards verification and validation of the Fetch code for Level 2 analysis, design, and <span class="hlt">optimization</span> of aqueous homogeneous reactors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nygaard, E. T.; Pain, C. C.; Eaton, M. D.; Gomes, J. L. M. A.; Goddard, A. J. H.; Gorman, G.; Tollit, B.; Buchan, A. G.; Cooling, C. M.; Angelo, P. L.</p> <p>2012-07-01</p> <p>Babcock and Wilcox Technical Services Group (B and W) has identified aqueous homogeneous reactors (AHRs) as a technology well suited to produce the medical isotope molybdenum 99 (Mo-99). AHRs have never been specifically designed or built for this specialized purpose. However, AHRs have a proven history of being safe research reactors. In fact, in 1958, AHRs had 'a longer history of operation than any other type of research reactor using enriched fuel' and had 'experimentally demonstrated to be among the safest of all various type of research reactor now in use [1].' While AHRs have been modeled effectively using simplified 'Level 1' tools, the complex interactions between fluids, neutronics, and solid structures are important (but not necessarily safety significant). These interactions require a 'Level 2' modeling tool. Imperial College London (ICL) has developed such a tool: Finite Element Transient Criticality (FETCH). FETCH couples the radiation transport code EVENT with the computational fluid dynamics code (Fluidity), the result is a code capable of modeling sub-critical, critical, and super-critical solutions in both two-and three-dimensions. Using FETCH, ICL researchers and B and W engineers have studied many fissioning solution systems include the Tokaimura criticality accident, the Y12 accident, SILENE, TRACY, and SUPO. These modeling efforts will ultimately be incorporated into FETCH'S extensive automated verification and validation (V and V) test suite expanding FETCH'S area of applicability to include all relevant physics associated with AHRs. These efforts parallel B and W's engineering effort to design and <span class="hlt">optimize</span> an AHR to produce Mo99. (authors)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25145201','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25145201"><span id="translatedtitle"><span class="hlt">Optimization</span> of the performance of a thermophilic biotrickling <span class="hlt">filter</span> for alpha-pinene removal from polluted air.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Montes, M; Veiga, M C; Kennes, C</p> <p>2014-01-01</p> <p>Biodegradation of alpha-pinene was investigated in a biological thermophilic trickling <span class="hlt">filter</span>, using a lava rock and polymer beads mixture as packing material. Partition coefficient (PC) between alpha-pinene and the polymeric material (Hytrel G3548 L) was measured at 50 degrees C. PCs of 57 and 846 were obtained between the polymer and either the water or the gas phase, respectively. BTF experiments were conducted under continuous load feeding. The effect of yeast extract (YE) addition in the recirculating nutrient medium was evaluated. There was a positive relationship between alpha-pinene biodegradation, CO2 production and YE addition. A maximum elimination capacity (ECmax) of 98.9 g m(-3) h(-1) was obtained for an alpha-pinene loading rate of about 121 g m(-3) h(-1) in the presence of 1 g L(-1) YE. The ECmax was reduced by half in the absence of YE. It was also found that a decrease in the liquid flow rate enhances alpha-pinene biodegradation by increasing the ECmax up to 103 gm(-3) h(-1) with a removal efficiency close to 90%. The impact of short-term shock-loads (6 h) was tested under different process conditions. Increasing the pollutant load either 10- or 20-fold resulted in a sudden drop in the BTF's removal capacity, although this effect was attenuated in the presence of YE. PMID:25145201</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26357282','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26357282"><span id="translatedtitle">Systematic Biological <span class="hlt">Filter</span> Design with a Desired I/O <span class="hlt">Filtering</span> Response Based on Promoter-RBS Libraries.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hsu, Chih-Yuan; Pan, Zhen-Ming; Hu, Rei-Hsing; Chang, Chih-Chun; Cheng, Hsiao-Chun; Lin, Che; Chen, Bor-Sen</p> <p>2015-01-01</p> <p>In this study, robust biological <span class="hlt">filters</span> with an external control to match a desired input/output (I/O) <span class="hlt">filtering</span> response are engineered based on the well-characterized promoter-RBS libraries and a cascade gene circuit topology. In the field of synthetic biology, the biological <span class="hlt">filter</span> system serves as a powerful detector or sensor to sense different molecular signals and produces a specific output response only if the concentration of the input molecular signal is higher or lower than a specified threshold. The proposed systematic design method of robust biological <span class="hlt">filters</span> is summarized into three <span class="hlt">steps</span>. Firstly, several well-characterized promoter-RBS libraries are established for biological <span class="hlt">filter</span> design by identifying and collecting the quantitative and qualitative characteristics of their promoter-RBS components via nonlinear parameter estimation method. Then, the topology of synthetic biological <span class="hlt">filter</span> is decomposed into three cascade gene regulatory modules, and an appropriate promoter-RBS library is selected for each module to achieve the desired I/O specification of a biological <span class="hlt">filter</span>. Finally, based on the proposed systematic method, a robust externally tunable biological <span class="hlt">filter</span> is engineered by searching the promoter-RBS component libraries and a control inducer concentration library to achieve the <span class="hlt">optimal</span> reference match for the specified I/O <span class="hlt">filtering</span> response. PMID:26357282</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DFDD24004C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DFDD24004C"><span id="translatedtitle">Real-time Coupled Ensemble Kalman <span class="hlt">Filter</span> Forecasting & Nonlinear Model Predictive Control Approach for <span class="hlt">Optimal</span> Power Take-off of a Wave Energy Converter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cavaglieri, Daniele; Bewley, Thomas; Previsic, Mirko</p> <p>2014-11-01</p> <p>In recent years, there has been a growing interest in renewable energy. Among all the available possibilities, wave energy conversion, due to the huge availability of energy that the ocean could provide, represents nowadays one of the most promising solutions. However, the efficiency of a wave energy converter for ocean wave energy harvesting is still far from making it competitive with more mature fields of renewable energy, such as solar and wind energy. One of the main problems is related to the difficulty to increase the power take-off through the implementation of an active controller without a precise knowledge of the oncoming wavefield. This work represents the first attempt at defining a realistic control framework for <span class="hlt">optimal</span> power take-off of a wave energy converter where the ocean wavefield is predicted through a nonlinear Ensemble Kalman <span class="hlt">filter</span> which assimilates data from a wave measurement device, such as a Doppler radar or a measurement buoy. Knowledge of the future wave profile is then leveraged in a nonlinear direct multiple shooting model predictive control framework allowing the online <span class="hlt">optimization</span> of the energy absorption under motion and machinery constraints of the device.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26091782','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26091782"><span id="translatedtitle"><span class="hlt">Optimization</span> of an analytical methodology for the simultaneous determination of different classes of ultraviolet <span class="hlt">filters</span> in cosmetics by pressurized liquid extraction-gas chromatography tandem mass spectrometry.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vila, Marlene; Lamas, J Pablo; Garcia-Jares, Carmen; Dagnac, Thierry; Llompart, Maria</p> <p>2015-07-31</p> <p>A methodology based on pressurized liquid extraction (PLE) followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) has been developed for the simultaneous analysis of different classes of UV <span class="hlt">filters</span> including methoxycinnamates, benzophenones, salicylates, p-aminobenzoic acid derivatives, and others in cosmetic products. The extractions were carried out in 1mL extraction cells and the amount of sample extracted was only 100mg. The experimental conditions, including the acetylation of the PLE extracts to improve GC performance, were <span class="hlt">optimized</span> by means of experimental design tools. The two main factors affecting the PLE procedure such as solvent type and extraction temperature were assessed. The use of a matrix matched approach consisting of the addition of 10μL of diluted commercial cosmetic oil avoided matrix effects. Good linearity (R(2)>0.9970), quantitative recoveries (>80% for most of compounds, excluding three banned benzophenones) and satisfactory precision (RSD<10% in most cases) were achieved under the <span class="hlt">optimal</span> conditions. The validated methodology was successfully applied to the analysis of different types of cosmetic formulations including sunscreens, hair products, nail polish, and lipsticks, amongst others. PMID:26091782</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870024403&hterms=water+filter&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dwater%2Bfilter','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870024403&hterms=water+filter&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dwater%2Bfilter"><span id="translatedtitle">A Kalman <span class="hlt">filter</span> for a two-dimensional shallow-water model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Parrish, D. F.; Cohn, S. E.</p> <p>1985-01-01</p> <p>A two-dimensional Kalman <span class="hlt">filter</span> is described for data assimilation for making weather forecasts. The <span class="hlt">filter</span> is regarded as superior to the <span class="hlt">optimal</span> interpolation method because the <span class="hlt">filter</span> determines the forecast error covariance matrix exactly instead of using an approximation. A generalized time <span class="hlt">step</span> is defined which includes expressions for one time <span class="hlt">step</span> of the forecast model, the error covariance matrix, the gain matrix, and the evolution of the covariance matrix. Subsequent time <span class="hlt">steps</span> are achieved by quantifying the forecast variables or employing a linear extrapolation from a current variable set, assuming the forecast dynamics are linear. Calculations for the evolution of the error covariance matrix are banded, i.e., are performed only with the elements significantly different from zero. Experimental results are provided from an application of the <span class="hlt">filter</span> to a shallow-water simulation covering a 6000 x 6000 km grid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26706748','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26706748"><span id="translatedtitle"><span class="hlt">Optimization</span> and kinetic modeling of esterification of the oil obtained from waste plum stones as a pretreatment <span class="hlt">step</span> in biodiesel production.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kostić, Milan D; Veličković, Ana V; Joković, Nataša M; Stamenković, Olivera S; Veljković, Vlada B</p> <p>2016-02-01</p> <p>This study reports on the use of oil obtained from waste plum stones as a low-cost feedstock for biodiesel production. Because of high free fatty acid (FFA) level (15.8%), the oil was processed through the two-<span class="hlt">step</span> process including esterification of FFA and methanolysis of the esterified oil catalyzed by H2SO4 and CaO, respectively. Esterification was <span class="hlt">optimized</span> by response surface methodology combined with a central composite design. The second-order polynomial equation predicted the lowest acid value of 0.53mgKOH/g under the following <span class="hlt">optimal</span> reaction conditions: the methanol:oil molar ratio of 8.5:1, the catalyst amount of 2% and the reaction temperature of 45°C. The predicted acid value agreed with the experimental acid value (0.47mgKOH/g). The kinetics of FFA esterification was described by the irreversible pseudo first-order reaction rate law. The apparent kinetic constant was correlated with the initial methanol and catalyst concentrations and reaction temperature. The activation energy of the esterification reaction slightly decreased from 13.23 to 11.55kJ/mol with increasing the catalyst concentration from 0.049 to 0.172mol/dm(3). In the second <span class="hlt">step</span>, the esterified oil reacted with methanol (methanol:oil molar ratio of 9:1) in the presence of CaO (5% to the oil mass) at 60°C. The properties of the obtained biodiesel were within the EN 14214 standard limits. Hence, waste plum stones might be valuable raw material for obtaining fatty oil for the use as alternative feedstock in biodiesel production. PMID:26706748</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25454824','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25454824"><span id="translatedtitle">Modeling and <span class="hlt">optimization</span> of ultrasound-assisted extraction of polyphenolic compounds from Aronia melanocarpa by-products from <span class="hlt">filter</span>-tea factory.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ramić, Milica; Vidović, Senka; Zeković, Zoran; Vladić, Jelena; Cvejin, Aleksandra; Pavlić, Branimir</p> <p>2015-03-01</p> <p>Aronia melanocarpa by-product from <span class="hlt">filter</span>-tea factory was used for the preparation of extracts with high content of bioactive compounds. Extraction process was accelerated using sonication. Three level, three variable face-centered cubic experimental design (FCD) with response surface methodology (RSM) was used for <span class="hlt">optimization</span> of extraction in terms of maximized yields for total phenolics (TP), flavonoids (TF), anthocyanins (MA) and proanthocyanidins (TPA) contents. Ultrasonic power (X₁: 72-216 W), temperature (X₂: 30-70 °C) and extraction time (X₃: 30-90 min) were investigated as independent variables. Experimental results were fitted to a second-order polynomial model where multiple regression analysis and analysis of variance were used to determine fitness of the model and <span class="hlt">optimal</span> conditions for investigated responses. Three-dimensional surface plots were generated from the mathematical models. The <span class="hlt">optimal</span> conditions for ultrasound-assisted extraction of TP, TF, MA and TPA were: X₁=206.64 W, X₂=70 °C, X₃=80.1 min; X₁=210.24 W, X₂=70 °C, X₃=75 min; X₁=216 W, X₂=70 °C, X₃=45.6 min and X₁=199.44 W, X₂=70 °C, X₃=89.7 min, respectively. Generated model predicted values of the TP, TF, MA and TPA to be 15.41 mg GAE/ml, 9.86 mg CE/ml, 2.26 mg C3G/ml and 20.67 mg CE/ml, respectively. Experimental validation was performed and close agreement between experimental and predicted values was found (within 95% confidence interval). PMID:25454824</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19780057524&hterms=cascade+control+system&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcascade%2Bcontrol%2Bsystem','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19780057524&hterms=cascade+control+system&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcascade%2Bcontrol%2Bsystem"><span id="translatedtitle">Estimation and <span class="hlt">filter</span> stability of stochastic delay systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kwong, R. H.; Willsky, A. S.</p> <p>1978-01-01</p> <p>Linear and nonlinear <span class="hlt">filtering</span> for stochastic delay systems are studied. A representation theorem for conditional moment functionals is obtained, which, in turn, is used to derive stochastic differential equations describing the <span class="hlt">optimal</span> linear or nonlinear <span class="hlt">filter</span>. A complete characterization of the <span class="hlt">optimal</span> <span class="hlt">filter</span> is given for linear systems with Gaussian noise. Stability of the <span class="hlt">optimal</span> <span class="hlt">filter</span> is studied in the case where there are no delays in the observations. Using the duality between linear <span class="hlt">filtering</span> and control, asymptotic stability of the <span class="hlt">optimal</span> <span class="hlt">filter</span> is proved. Finally, the cascade of the <span class="hlt">optimal</span> <span class="hlt">filter</span> and the deterministic <span class="hlt">optimal</span> quadratic control system is shown to be asymptotically stable as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/865803','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/865803"><span id="translatedtitle">Disk <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Bergman, Werner</p> <p>1986-01-01</p> <p>An electric disk <span class="hlt">filter</span> provides a high efficiency at high temperature. A hollow outer <span class="hlt">filter</span> of fibrous stainless steel forms the ground electrode. A refractory <span class="hlt">filter</span> material is placed between the outer electrode and the inner electrically isolated high voltage electrode. Air flows through the outer <span class="hlt">filter</span> surfaces through the electrified refractory <span class="hlt">filter</span> media and between the high voltage electrodes and is removed from a space in the high voltage electrode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5409246','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/5409246"><span id="translatedtitle">Disk <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Bergman, W.</p> <p>1985-01-09</p> <p>An electric disk <span class="hlt">filter</span> provides a high efficiency at high temperature. A hollow outer <span class="hlt">filter</span> of fibrous stainless steel forms the ground electrode. A refractory <span class="hlt">filter</span> material is placed between the outer electrode and the inner electrically isolated high voltage electrode. Air flows through the outer <span class="hlt">filter</span> surfaces through the electrified refractory <span class="hlt">filter</span> media and between the high voltage electrodes and is removed from a space in the high voltage electrode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1089675','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1089675"><span id="translatedtitle">Next <span class="hlt">Step</span> for <span class="hlt">STEP</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wood, Claire; Bremner, Brenda</p> <p>2013-08-09</p> <p>The Siletz Tribal Energy Program (<span class="hlt">STEP</span>), housed in the Tribe’s Planning Department, will hire a data entry coordinator to collect, enter, analyze and store all the current and future energy efficiency and renewable energy data pertaining to administrative structures the tribe owns and operates and for homes in which tribal members live. The proposed data entry coordinator will conduct an energy options analysis in collaboration with the rest of the Siletz Tribal Energy Program and Planning Department staff. An energy options analysis will result in a thorough understanding of tribal energy resources and consumption, if energy efficiency and conservation measures being implemented are having the desired effect, analysis of tribal energy loads (current and future energy consumption), and evaluation of local and commercial energy supply options. A literature search will also be conducted. In order to educate additional tribal members about renewable energy, we will send four tribal members to be trained to install and maintain solar panels, solar hot water heaters, wind turbines and/or micro-hydro.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26342871','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26342871"><span id="translatedtitle">Synthesis and <span class="hlt">optimization</span> of wide pore superficially porous particles by a one-<span class="hlt">step</span> coating process for separation of proteins and monoclonal antibodies.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Wu; Jiang, Kunqiang; Mack, Anne; Sachok, Bo; Zhu, Xin; Barber, William E; Wang, Xiaoli</p> <p>2015-10-01</p> <p>Superficially porous particles (SPPs) with pore size ranging from 90Å to 120Å have been a great success for the fast separation of small molecules over totally porous particles in recent years. However, for the separation of large biomolecules such as proteins, particles with large pore size (e.g. ≥ 300Å) are needed to allow unrestricted diffusion inside the pores. One early example is the commercial wide pore (300Å) SPPs in 5μm size introduced in 2001. More recently, wide pore SPPs (200Å and 400Å) in smaller particle sizes (3.5-3.6μm) have been developed to meet the need of increasing interest in doing faster analysis of larger therapeutic molecules by biopharmaceutical companies. Those SSPs in the market are mostly synthesized by the laborious layer-by-layer (LBL) method. A one <span class="hlt">step</span> coating approach would be highly advantageous, offering potential benefits on process time, easier quality control, materials cost, and process simplicity for facile scale-up. A unique one-<span class="hlt">step</span> coating process for the synthesis of SPPs called the "coacervation method" was developed by Chen and Wei as an improved and <span class="hlt">optimized</span> process, and has been successfully applied to synthesis of a commercial product, Poroshell 120 particles, for small molecule separation. In this report, we would like to report on the most recent development of the one <span class="hlt">step</span> coating coacervation method for the synthesis of a series of wide pore SPPs of different particle size, pore size, and shell thickness. The one <span class="hlt">step</span> coating coacervation method was proven to be a universal method to synthesize SPPs of any particle size and pore size. The effects of pore size (300Å vs. 450Å), shell thickness (0.25μm vs. 0.50μm), and particle size (2.7μm and 3.5μm) on the separation of large proteins, intact and fragmented monoclonal antibodies (mAbs) were studied. Van Deemter studies using proteins were also conducted to compare the mass transfer properties of these particles. It was found that the larger pore size actually had more impact on the performance of mAbs than particle size and shell thickness. The SPPs with larger 3.5μm particle size and larger 450Å pore size showed the best resolution of mAbs and the lowest back pressure. To the best of our knowledge, this is the largest pore size made on SPPs. These results led to the <span class="hlt">optimal</span> particle design with a particle size of 3.5μm, a thin shell of 0.25μm and a larger pore size of 450Å. PMID:26342871</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020080938','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020080938"><span id="translatedtitle">Water <span class="hlt">Filters</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1993-01-01</p> <p>The Aquaspace H2OME Guardian Water <span class="hlt">Filter</span>, available through Western Water International, Inc., reduces lead in water supplies. The <span class="hlt">filter</span> is mounted on the faucet and the <span class="hlt">filter</span> cartridge is placed in the "dead space" between sink and wall. This <span class="hlt">filter</span> is one of several new filtration devices using the Aquaspace compound <span class="hlt">filter</span> media, which combines company developed and NASA technology. Aquaspace <span class="hlt">filters</span> are used in industrial, commercial, residential, and recreational environments as well as by developing nations where water is highly contaminated.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4559244','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4559244"><span id="translatedtitle">Two-speed phacoemulsification for soft cataracts using <span class="hlt">optimized</span> parameters and procedure <span class="hlt">step</span> toolbar with the CENTURION Vision System and Balanced Tip</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Davison, James A</p> <p>2015-01-01</p> <p>Purpose To present a cause of posterior capsule aspiration and a technique using <span class="hlt">optimized</span> parameters to prevent it from happening when operating soft cataracts. Patients and methods A prospective list of posterior capsule aspiration cases was kept over 4,062 consecutive cases operated with the Alcon CENTURION machine and Balanced Tip. Video analysis of one case of posterior capsule aspiration was accomplished. A surgical technique was developed using empirically derived machine parameters and customized setting-selection procedure <span class="hlt">step</span> toolbar to reduce the pace of aspiration of soft nuclear quadrants in order to prevent capsule aspiration. Results Two cases out of 3,238 experienced posterior capsule aspiration before use of the soft quadrant technique. Video analysis showed an attractive vortex effect with capsule aspiration occurring in 1/5 of a second. A soft quadrant removal setting was empirically derived which had a slower pace and seemed more controlled with no capsule aspiration occurring in the subsequent 824 cases. The setting featured simultaneous linear control from zero to preset maximums for: aspiration flow, 20 mL/min; and vacuum, 400 mmHg, with the addition of torsional tip amplitude up to 20% after the fluidic maximums were achieved. A new setting selection procedure <span class="hlt">step</span> toolbar was created to increase intraoperative flexibility by providing instantaneous shifting between the soft and normal settings. Conclusion A technique incorporating a reduced pace for soft quadrant acquisition and aspiration can be accomplished through the use of a dedicated setting of integrated machine parameters. Toolbar placement of the procedure button next to the normal setting procedure button provides the opportunity to instantaneously alternate between the two settings. Simultaneous surgeon control over vacuum, aspiration flow, and torsional tip motion may make removal of soft nuclear quadrants more efficient and safer. PMID:26355695</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997SPIE.3026..266B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997SPIE.3026..266B"><span id="translatedtitle">Multivariate granulometric <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Batman, Sinan; Dougherty, Edward R.</p> <p>1997-04-01</p> <p>As introduced by Matheron, granulometries depend on a single sizing parameter for each structuring element. The concept of granulometry has recently been extended in such a way that each structuring element has its own sizing parameter resulting in a <span class="hlt">filter</span> (Psi) t depending on the vector parameter t equals (t1..., tn). The present paper generalizes the concept of a parameterized reconstructive (tau) -opening to the multivariate setting, where the reconstructive <span class="hlt">filter</span> (Lambda) t fully passes any connected component not fully eliminated by (Psi) t. The problem of minimizing the MAE between the <span class="hlt">filtered</span> and ideal image processes becomes one of vector <span class="hlt">optimization</span> in an n- dimensional search space. Unlike the univariate case, the MAE achieved by the optimum <span class="hlt">filter</span> (Lambda) t is global in the sense that it is independent of the relative sizes of structuring elements in the <span class="hlt">filter</span> basis. As a consequence, multivariate granulometries provide a natural environment to study <span class="hlt">optimality</span> of the choice of structuring elements. If the shapes of the structuring elements are themselves parameterized, the expected error is a deterministic function of the shape and size parameters and its minimization yields the <span class="hlt">optimal</span> MAE <span class="hlt">filter</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26196621','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26196621"><span id="translatedtitle"><span class="hlt">Optimal</span> State Estimation for Cavity Optomechanical Systems.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wieczorek, Witlef; Hofer, Sebastian G; Hoelscher-Obermaier, Jason; Riedinger, Ralf; Hammerer, Klemens; Aspelmeyer, Markus</p> <p>2015-06-01</p> <p>We demonstrate <span class="hlt">optimal</span> state estimation for a cavity optomechanical system through Kalman <span class="hlt">filtering</span>. By taking into account nontrivial experimental noise sources, such as colored laser noise and spurious mechanical modes, we implement a realistic state-space model. This allows us to obtain the conditional system state, i.e., conditioned on previous measurements, with a minimal least-squares estimation error. We apply this method to estimate the mechanical state, as well as optomechanical correlations both in the weak and strong coupling regime. The application of the Kalman <span class="hlt">filter</span> is an important next <span class="hlt">step</span> for achieving real-time <span class="hlt">optimal</span> (classical and quantum) control of cavity optomechanical systems. PMID:26196621</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=treatment+AND+wastewater&pg=5&id=EJ191125','ERIC'); return false;" href="http://eric.ed.gov/?q=treatment+AND+wastewater&pg=5&id=EJ191125"><span id="translatedtitle">Biological <span class="hlt">Filters</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Klemetson, S. L.</p> <p>1978-01-01</p> <p>Presents the 1978 literature review of wastewater treatment. The review is concerned with biological <span class="hlt">filters</span>, and it covers: (1) trickling <span class="hlt">filters</span>; (2) rotating biological contractors; and (3) miscellaneous reactors. A list of 14 references is also presented. (HM)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020090806','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020090806"><span id="translatedtitle">Metallic <span class="hlt">Filters</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1985-01-01</p> <p>Filtration technology originated in a mid 1960's NASA study. The results were distributed to the <span class="hlt">filter</span> industry, an HR Textron responded, using the study as a departure for the development of 421 <span class="hlt">Filter</span> Media. The HR system is composed of ultrafine steel fibers metallurgically bonded and compressed so that the pore structure is locked in place. The <span class="hlt">filters</span> are used to <span class="hlt">filter</span> polyesters, plastics, to remove hydrocarbon streams, etc. Several major companies use the product in chemical applications, pollution control, etc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900024239&hterms=brushless+motor&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dbrushless%2Bmotor','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900024239&hterms=brushless+motor&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dbrushless%2Bmotor"><span id="translatedtitle">High accuracy motor controller for positioning optical <span class="hlt">filters</span> in the CLAES Spectrometer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thatcher, John B.</p> <p>1989-01-01</p> <p>The Etalon Drive Motor (EDM), a precision etalon control system designed for accurate positioning of etalon <span class="hlt">filters</span> in the IR spectrometer of the Cryogenic Limb Array Etalon Spectrometer (CLAES) experiment is described. The EDM includes a brushless dc torque motor, which has an infinite resolution for setting an etalon <span class="hlt">filter</span> to any desired angle, a four-<span class="hlt">filter</span> etalon wheel, and an electromechanical resolver for angle information. An 18-bit control loop provides high accuracy, resolution, and stability. Dynamic computer interaction allows the user to <span class="hlt">optimize</span> the <span class="hlt">step</span> response. A block diagram of the motor controller is presented along with a schematic of the digital/analog converter circuit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25577357','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25577357"><span id="translatedtitle">Analysis of plasticizers in poly(vinyl chloride) medical devices for infusion and artificial nutrition: comparison and <span class="hlt">optimization</span> of the extraction procedures, a pre-migration test <span class="hlt">step</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bernard, Lise; Cueff, Rgis; Bourdeaux, Daniel; Breysse, Colette; Sautou, Valrie</p> <p>2015-02-01</p> <p>Medical devices (MDs) for infusion and enteral and parenteral nutrition are essentially made of plasticized polyvinyl chloride (PVC). The first <span class="hlt">step</span> in assessing patient exposure to these plasticizers, as well as ensuring that the MDs are free from di(2-ethylhexyl) phthalate (DEHP), consists of identifying and quantifying the plasticizers present and, consequently, determining which ones are likely to migrate into the patient's body. We compared three different extraction methods using 0.1 g of plasticized PVC: Soxhlet extraction in diethyl ether and ethyl acetate, polymer dissolution, and room temperature extraction in different solvents. It was found that simple room temperature chloroform extraction under <span class="hlt">optimized</span> conditions (30 min, 50 mL) gave the best separation of plasticizers from the PVC matrix, with extraction yields ranging from 92 to 100% for all plasticizers. This result was confirmed by supplemented Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR) and gravimetric analyses. The technique was used on eight marketed medical devices and showed that they contained different amounts of plasticizers, ranging from 25 to 36% of the PVC weight. These yields, associated with the individual physicochemical properties of each plasticizer, highlight the need for further migration studies. PMID:25577357</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800020574','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800020574"><span id="translatedtitle">Smoothing <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lear, W. H.</p> <p>1980-01-01</p> <p>The improvement of accuracy in using the smoothing <span class="hlt">filter</span> instead of the Kalman <span class="hlt">filter</span> is discussed. Factors of improvement for velocity errors of up to four are shown for position measurements. Smoothing equations are presented, and it is shown that smoothing equations for the smoothing <span class="hlt">filter</span> appear to be stable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020087779','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020087779"><span id="translatedtitle">Water <span class="hlt">Filters</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1987-01-01</p> <p>A compact, lightweight electrolytic water <span class="hlt">filter</span> generates silver ions in concentrations of 50 to 100 parts per billion in the water flow system. Silver ions serve as effective bactericide/deodorizers. Ray Ward requested and received from NASA a technical information package on the Shuttle <span class="hlt">filter</span>, and used it as basis for his own initial development, a home use <span class="hlt">filter</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/4281796','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/4281796"><span id="translatedtitle"><span class="hlt">FILTER</span> TREATMENT</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Sutton, J.B.; Torrey, J.V.P.</p> <p>1958-08-26</p> <p>A process is described for reconditioning fused alumina <span class="hlt">filters</span> which have become clogged by the accretion of bismuth phosphate in the <span class="hlt">filter</span> pores, The method consists in contacting such <span class="hlt">filters</span> with faming sulfuric acid, and maintaining such contact for a substantial period of time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010APS..DFD.RJ006C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010APS..DFD.RJ006C"><span id="translatedtitle">Game-theoretic Kalman <span class="hlt">Filter</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Colburn, Christopher; Bewley, Thomas</p> <p>2010-11-01</p> <p>The Kalman <span class="hlt">Filter</span> (KF) is celebrated as the <span class="hlt">optimal</span> estimator for systems with linear dynamics and gaussian uncertainty. Although most systems of interest do not have linear dynamics and are not forced by gaussian noise, the KF is used ubiquitously within industry. Thus, we present a novel estimation algorithm, the Game-theoretic Kalman <span class="hlt">Filter</span> (GKF), which intelligently hedges between competing sequential <span class="hlt">filters</span> and does not require the assumption of gaussian statistics to provide a "best" estimate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/868447','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/868447"><span id="translatedtitle"><span class="hlt">Filtering</span> apparatus</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Haldipur, Gaurang B.; Dilmore, William J.</p> <p>1992-01-01</p> <p>A vertical vessel having a lower inlet and an upper outlet enclosure separated by a main horizontal tube sheet. The inlet enclosure receives the flue gas from a boiler of a power system and the outlet enclosure supplies cleaned gas to the turbines. The inlet enclosure contains a plurality of particulate-removing clusters, each having a plurality of <span class="hlt">filter</span> units. Each <span class="hlt">filter</span> unit includes a <span class="hlt">filter</span> clean-gas chamber defined by a plate and a perforated auxiliary tube sheet with <span class="hlt">filter</span> tubes suspended from each tube sheet and a tube connected to each chamber for passing cleaned gas to the outlet enclosure. The clusters are suspended from the main tube sheet with their <span class="hlt">filter</span> units extending vertically and the <span class="hlt">filter</span> tubes passing through the tube sheet and opening in the outlet enclosure. The flue gas is circulated about the outside surfaces of the <span class="hlt">filter</span> tubes and the particulate is absorbed in the pores of the <span class="hlt">filter</span> tubes. Pulses to clean the <span class="hlt">filter</span> tubes are passed through their inner holes through tubes free of bends which are aligned with the tubes that pass the clean gas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7235367','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/7235367"><span id="translatedtitle"><span class="hlt">Filtering</span> apparatus</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Haldipur, G.B.; Dilmore, W.J.</p> <p>1992-09-01</p> <p>A vertical vessel is described having a lower inlet and an upper outlet enclosure separated by a main horizontal tube sheet. The inlet enclosure receives the flue gas from a boiler of a power system and the outlet enclosure supplies cleaned gas to the turbines. The inlet enclosure contains a plurality of particulate-removing clusters, each having a plurality of <span class="hlt">filter</span> units. Each <span class="hlt">filter</span> unit includes a <span class="hlt">filter</span> clean-gas chamber defined by a plate and a perforated auxiliary tube sheet with <span class="hlt">filter</span> tubes suspended from each tube sheet and a tube connected to each chamber for passing cleaned gas to the outlet enclosure. The clusters are suspended from the main tube sheet with their <span class="hlt">filter</span> units extending vertically and the <span class="hlt">filter</span> tubes passing through the tube sheet and opening in the outlet enclosure. The flue gas is circulated about the outside surfaces of the <span class="hlt">filter</span> tubes and the particulate is absorbed in the pores of the <span class="hlt">filter</span> tubes. Pulses to clean the <span class="hlt">filter</span> tubes are passed through their inner holes through tubes free of bends which are aligned with the tubes that pass the clean gas. 18 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/774088','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/774088"><span id="translatedtitle">Kaon <span class="hlt">Filtering</span> For CLAS Data</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>McNabb, J.</p> <p>2001-01-30</p> <p>The analysis of data from CLAS is a multi-<span class="hlt">step</span> process. After the detectors for a given running period have been calibrated, the data is processed in the so called pass-1 cooking. During the pass-1 cooking each event is reconstructed by the program a1c which finds particle tracks and computes momenta from the raw data. The results are then passed on to several data monitoring and <span class="hlt">filtering</span> utilities. In CLAS software, a <span class="hlt">filter</span> is a parameterless function which returns an integer indicating whether an event should be kept by that <span class="hlt">filter</span> or not. There is a main <span class="hlt">filter</span> program called g1-<span class="hlt">filter</span> which controls several specific <span class="hlt">filters</span> and outputs several files, one for each <span class="hlt">filter</span>. These files may then be analyzed separately, allowing individuals interested in one reaction channel to work from smaller files than using the whole data set would require. There are several constraints on what the <span class="hlt">filter</span> functions should do. Obviously, the <span class="hlt">filtered</span> files should be as small as possible, however the <span class="hlt">filter</span> should also not reject any events that might be used in the later analysis for which the <span class="hlt">filter</span> was intended.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6231987','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6231987"><span id="translatedtitle">Database <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pramanik, S.</p> <p>1982-01-01</p> <p>Several hardware database-searchers for a large number of patterns or keys are presented. These searchers can be implemented by a random access memory and are suitable for VLSI implementation. Application of these searchers as database <span class="hlt">filters</span> is described; a <span class="hlt">filter</span> detects all the matched records in the database, as well as a few others. The percentage of unmatched records can be reduced to any arbitrary minimum value by using several <span class="hlt">filters</span> together, or passing the output records repeatedly through the same <span class="hlt">filters</span>. The performance of the <span class="hlt">filters</span> using the iterative approach depends very much on the regrouping algorithms of the patterns/keys. Several such algorithms are presented and their performances compared. A single pass is required if they are pipelined. Hardware organisation for different pipelined approaches are also studied. Experiments are performed for all the different hardware organisations mentioned above on an employee-name database. 25 references.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9477E..06G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9477E..06G"><span id="translatedtitle">Comparison of spatial domain <span class="hlt">optimal</span> trade-off maximum average correlation height (OT-MACH) <span class="hlt">filter</span> with scale invariant feature transform (SIFT) using images with poor contrast and large illumination gradient</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gardezi, A.; Qureshi, T.; Alkandri, A.; Young, R. C. D.; Birch, P. M.; Chatwin, C. R.</p> <p>2015-03-01</p> <p>A spatial domain <span class="hlt">optimal</span> trade-off Maximum Average Correlation Height (OT-MACH) <span class="hlt">filter</span> has been previously developed and shown to have advantages over frequency domain implementations in that it can be made locally adaptive to spatial variations in the input image background clutter and normalised for local intensity changes. In this paper we compare the performance of the spatial domain (SPOT-MACH) <span class="hlt">filter</span> to the widely applied data driven technique known as the Scale Invariant Feature Transform (SIFT). The SPOT-MACH <span class="hlt">filter</span> is shown to provide more robust recognition performance than the SIFT technique for demanding images such as scenes in which there are large illumination gradients. The SIFT method depends on reliable local edge-based feature detection over large regions of the image plane which is compromised in some of the demanding images we examined for this work. The disadvantage of the SPOTMACH <span class="hlt">filter</span> is its numerically intensive nature since it is template based and is implemented in the spatial domain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/631136','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/631136"><span id="translatedtitle">Hot-gas <span class="hlt">filter</span> manufacturing assessments: Volume 5. Final report, April 15, 1997</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Boss, D.E.</p> <p>1997-12-31</p> <p>The development of advanced filtration media for advanced fossil-fueled power generating systems is a critical <span class="hlt">step</span> in meeting the performance and emissions requirements for these systems. While porous metal and ceramic candle-<span class="hlt">filters</span> have been available for some time, the next generation of <span class="hlt">filters</span> will include ceramic-matrix composites (CMCs), intermetallic alloys, and alternate <span class="hlt">filter</span> geometries. The goal of this effort was to perform a cursory review of the manufacturing processes used by 5 companies developing advanced <span class="hlt">filters</span> from the perspective of process repeatability and the ability for their processes to be scale-up to production volumes. It was found that all of the <span class="hlt">filter</span> manufacturers had a solid understanding of the product development path. Given that these <span class="hlt">filters</span> are largely developmental, significant additional work is necessary to understand the process-performance relationships and projecting manufacturing costs. While each organization had specific needs, some common among all of the <span class="hlt">filter</span> manufacturers were access to performance testing of the <span class="hlt">filters</span> to aide process/product development, a better understanding of the stresses the <span class="hlt">filters</span> will see in service for use in structural design of the components, and a strong process sensitivity study to allow <span class="hlt">optimization</span> of processing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/956351','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/956351"><span id="translatedtitle">Stack <span class="hlt">filter</span> classifiers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Porter, Reid B; Hush, Don</p> <p>2009-01-01</p> <p>Just as linear models generalize the sample mean and weighted average, weighted order statistic models generalize the sample median and weighted median. This analogy can be continued informally to generalized additive modeels in the case of the mean, and Stack <span class="hlt">Filters</span> in the case of the median. Both of these model classes have been extensively studied for signal and image processing but it is surprising to find that for pattern classification, their treatment has been significantly one sided. Generalized additive models are now a major tool in pattern classification and many different learning algorithms have been developed to fit model parameters to finite data. However Stack <span class="hlt">Filters</span> remain largely confined to signal and image processing and learning algorithms for classification are yet to be seen. This paper is a <span class="hlt">step</span> towards Stack <span class="hlt">Filter</span> Classifiers and it shows that the approach is interesting from both a theoretical and a practical perspective.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2614560','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2614560"><span id="translatedtitle">Multiresolution Bilateral <span class="hlt">Filtering</span> for Image Denoising</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhang, Ming; Gunturk, Bahadir K.</p> <p>2008-01-01</p> <p>The bilateral <span class="hlt">filter</span> is a nonlinear <span class="hlt">filter</span> that does spatial averaging without smoothing edges; it has shown to be an effective image denoising technique. An important issue with the application of the bilateral <span class="hlt">filter</span> is the selection of the <span class="hlt">filter</span> parameters, which affect the results significantly. There are two main contributions of this paper. The first contribution is an empirical study of the <span class="hlt">optimal</span> bilateral <span class="hlt">filter</span> parameter selection in image denoising applications. The second contribution is an extension of the bilateral <span class="hlt">filter</span>: multiresolution bilateral <span class="hlt">filter</span>, where bilateral <span class="hlt">filtering</span> is applied to the approximation (low-frequency) subbands of a signal decomposed using a wavelet <span class="hlt">filter</span> bank. The multiresolution bilateral <span class="hlt">filter</span> is combined with wavelet thresholding to form a new image denoising framework, which turns out to be very effective in eliminating noise in real noisy images. Experimental results with both simulated and real data are provided. PMID:19004705</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1107790','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1107790"><span id="translatedtitle">High-resolution wave-theory-based ultrasound reflection imaging using the split-<span class="hlt">step</span> fourier and globally <span class="hlt">optimized</span> fourier finite-difference methods</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Huang, Lianjie</p> <p>2013-10-29</p> <p>Methods for enhancing ultrasonic reflection imaging are taught utilizing a split-<span class="hlt">step</span> Fourier propagator in which the reconstruction is based on recursive inward continuation of ultrasonic wavefields in the frequency-space and frequency-wave number domains. The inward continuation within each extrapolation interval consists of two <span class="hlt">steps</span>. In the first <span class="hlt">step</span>, a phase-shift term is applied to the data in the frequency-wave number domain for propagation in a reference medium. The second <span class="hlt">step</span> consists of applying another phase-shift term to data in the frequency-space domain to approximately compensate for ultrasonic scattering effects of heterogeneities within the tissue being imaged (e.g., breast tissue). Results from various data input to the method indicate significant improvements are provided in both image quality and resolution.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016OEJV..176...10Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OEJV..176...10Z"><span id="translatedtitle">PHOEBE - <span class="hlt">step</span> by <span class="hlt">step</span> manual</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zasche, P.</p> <p>2016-03-01</p> <p>An easy <span class="hlt">step-by-step</span> manual of PHOEBE is presented. It should serve as a starting point for the first time users of PHOEBE analyzing the eclipsing binary light curve. It is demonstrated on one particular detached system also with the downloadable data and the whole procedure is described easily till the final trustworthy fit is being reached.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ApCM...19..901L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ApCM...19..901L"><span id="translatedtitle"><span class="hlt">Step</span> Pultrusion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Langella, A.; Carbone, R.; Durante, M.</p> <p>2012-12-01</p> <p>The pultrusion process is an efficient technology for the production of composite material profiles. Thanks to this positive feature, several studies have been carried out, either to expand the range of products made using the pultrusion technology, or improve its already high production rate. This study presents a process derived from the traditional pultrusion technology named "<span class="hlt">Step</span> Pultrusion Process Technology" (SPPT). Using the <span class="hlt">step</span> pultrusion process, the final section of the composite profiles is obtainable by means of a progressive cross section increasing through several resin cure stations. This progressive increasing of the composite cross section means that a higher degree of cure level can be attained at the die exit point of the last die. Mechanical test results of the manufactured pultruded samples have been used to compare both the traditional and the <span class="hlt">step</span> pultrusion processes. Finally, there is a discussion on ways to improve the new <span class="hlt">step</span> pultrusion process even further.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18292001','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18292001"><span id="translatedtitle">Permutation weighted order statistic <span class="hlt">filter</span> lattices.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Arce, G R; Hall, T A; Barner, K E</p> <p>1995-01-01</p> <p>We introduce and analyze a new class of nonlinear <span class="hlt">filters</span> called permutation weighted order statistic (PWOS) <span class="hlt">filters</span>. These <span class="hlt">filters</span> extend the concept of weighted order statistic (WOS) <span class="hlt">filters</span>, in which <span class="hlt">filter</span> weights associated with the input samples are used to replicate the corresponding samples, and an order statistic is chosen as the <span class="hlt">filter</span> output. PWOS <span class="hlt">filters</span> replicate each input sample according to weights determined by the temporal-order and rank-order of samples within a window. Hence, PWOS <span class="hlt">filters</span> are in essence time-varying WOS <span class="hlt">filters</span>. By varying the amount of temporal-rank order information used in selecting the output for a given observation window size, we obtain a wide range of <span class="hlt">filters</span> that are shown to comprise a complete lattice structure. At the simplest level in the lattice, PWOS <span class="hlt">filters</span> reduce to the well-known WOS <span class="hlt">filter</span>, but for higher levels in the lattice, the obtained selection <span class="hlt">filters</span> can model complex nonlinear systems and signal distortions. It is shown that PWOS <span class="hlt">filters</span> are realizable by a N! piecewise linear threshold logic gate where the coefficients within each partition can be easily <span class="hlt">optimized</span> using stack <span class="hlt">filter</span> theory. Simulations are included to show the advantages of PWOS <span class="hlt">filters</span> for the processing of image and video signals. PMID:18292001</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120010515','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120010515"><span id="translatedtitle">Recursive Implementations of the Consider <span class="hlt">Filter</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zanetti, Renato; DSouza, Chris</p> <p>2012-01-01</p> <p>One method to account for parameters errors in the Kalman <span class="hlt">filter</span> is to consider their effect in the so-called Schmidt-Kalman <span class="hlt">filter</span>. This work addresses issues that arise when implementing a consider Kalman <span class="hlt">filter</span> as a real-time, recursive algorithm. A favorite implementation of the Kalman <span class="hlt">filter</span> as an onboard navigation subsystem is the UDU formulation. A new way to implement a UDU consider <span class="hlt">filter</span> is proposed. The non-<span class="hlt">optimality</span> of the recursive consider <span class="hlt">filter</span> is also analyzed, and a modified algorithm is proposed to overcome this limitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19840000095&hterms=nitrogen+plants&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dnitrogen%2Bplants','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19840000095&hterms=nitrogen+plants&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dnitrogen%2Bplants"><span id="translatedtitle">Aquatic Plants Aid Sewage <span class="hlt">Filter</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wolverton, B. C.</p> <p>1985-01-01</p> <p>Method of wastewater treatment combines micro-organisms and aquatic plant roots in <span class="hlt">filter</span> bed. Treatment occurs as liquid flows up through system. Micro-organisms, attached themselves to rocky base material of <span class="hlt">filter</span>, act in several <span class="hlt">steps</span> to decompose organic matter in wastewater. Vascular aquatic plants (typically, reeds, rushes, cattails, or water hyacinths) absorb nitrogen, phosphorus, other nutrients, and heavy metals from water through finely divided roots.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23567732','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23567732"><span id="translatedtitle">Microwave assisted biodiesel production from Jatropha curcas L. seed by two-<span class="hlt">step</span> in situ process: <span class="hlt">optimization</span> using response surface methodology.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jaliliannosrati, Hamidreza; Amin, Nor Aishah Saidina; Talebian-Kiakalaieh, Amin; Noshadi, Iman</p> <p>2013-05-01</p> <p>The synthesis of fatty acid ethyl esters (FAEEs) by a two-<span class="hlt">step</span> in situ (reactive) esterification/transesterification from Jatropha curcas L. (JCL) seeds using microwave system has been investigated. Free fatty acid was reduced from 14% to less than 1% in the first <span class="hlt">step</span> using H2SO4 as acid catalyst after 35 min of microwave irradiation heating. The organic phase in the first <span class="hlt">step</span> was subjected to a second reaction by adding 5 N KOH in ethanol as the basic catalyst. Response surface methodology (RSM) based on central composite design (CCD) was utilized to design the experiments and analyze the influence of process variables (particles seed size, time of irradiation, agitation speed and catalyst loading) on conversion of triglycerides (TGs) in the second <span class="hlt">step</span>. The highest triglycerides conversion to fatty acid ethyl esters (FAEEs) was 97.29% at the optimum conditions:<0.5mm seed size, 12.21 min irradiation time, 8.15 ml KOH catalyst loading and 331.52 rpm agitation speed in the 110 W microwave power system. PMID:23567732</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4102364','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4102364"><span id="translatedtitle">Modelling of diffraction grating based optical <span class="hlt">filters</span> for fluorescence detection of biomolecules</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kovačič, M.; Krč, J.; Lipovšek, B.; Topič, M.</p> <p>2014-01-01</p> <p>The detection of biomolecules based on fluorescence measurements is a powerful diagnostic tool for the acquisition of genetic, proteomic and cellular information. One key performance limiting factor remains the integrated optical <span class="hlt">filter</span>, which is designed to reject strong excitation light while transmitting weak emission (fluorescent) light to the photodetector. Conventional <span class="hlt">filters</span> have several disadvantages. For instance absorbing <span class="hlt">filters</span>, like those made from amorphous silicon carbide, exhibit low rejection ratios, especially in the case of small Stokes’ shift fluorophores (e.g. green fluorescent protein GFP with λexc = 480 nm and λem = 510 nm), whereas interference <span class="hlt">filters</span> comprising many layers require complex fabrication. This paper describes an alternative solution based on dielectric diffraction gratings. These <span class="hlt">filters</span> are not only highly efficient but require a smaller number of manufacturing <span class="hlt">steps</span>. Using FEM-based optical modelling as a design <span class="hlt">optimization</span> tool, three <span class="hlt">filtering</span> concepts are explored: (i) a diffraction grating fabricated on the surface of an absorbing <span class="hlt">filter</span>, (ii) a diffraction grating embedded in a host material with a low refractive index, and (iii) a combination of an embedded grating and an absorbing <span class="hlt">filter</span>. Both concepts involving an embedded grating show high rejection ratios (over 100,000) for the case of GFP, but also high sensitivity to manufacturing errors and variations in the incident angle of the excitation light. Despite this, simulations show that a 60 times improvement in the rejection ratio relative to a conventional flat absorbing <span class="hlt">filter</span> can be obtained using an <span class="hlt">optimized</span> embedded diffraction grating fabricated on top of an absorbing <span class="hlt">filter</span>. PMID:25071964</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850021138&hterms=GLA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DGLA','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850021138&hterms=GLA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DGLA"><span id="translatedtitle">Sigma <span class="hlt">Filter</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Balgovind, R. C.</p> <p>1985-01-01</p> <p>The GLA Fourth-Order model is needed to smooth the topography. This is to remove the Gibbs phenomenon. The Gibbs phenomenon occurs whenever we truncate a Fourier Series. The Sigma factors were introduced to reduce the Gibbs phenomenon. It is found that the smooth Fourier series is nothing but the original Fourier series with its coefficients multiplied by corresponding sigma factors. This operator can be applied many times to obtain high order sigma <span class="hlt">filtered</span> field and is easily applicable using FFT. It is found that this <span class="hlt">filter</span> is beneficial in deriving the topography.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020086719','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020086719"><span id="translatedtitle">Water <span class="hlt">Filters</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1988-01-01</p> <p>Seeking to find a more effective method of <span class="hlt">filtering</span> potable water that was highly contaminated, Mike Pedersen, founder of Western Water International, learned that NASA had conducted extensive research in methods of purifying water on board manned spacecraft. The key is Aquaspace Compound, a proprietary WWI formula that scientifically blends various types of glandular activated charcoal with other active and inert ingredients. Aquaspace systems remove some substances; chlorine, by atomic adsorption, other types of organic chemicals by mechanical filtration and still others by catalytic reaction. Aquaspace <span class="hlt">filters</span> are finding wide acceptance in industrial, commercial, residential and recreational applications in the U.S. and abroad.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5775397','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5775397"><span id="translatedtitle"><span class="hlt">Step</span> cell</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Epstein, J.; Marincic, N.</p> <p>1981-10-06</p> <p>A lithium/thionyl chloride electrochemical cell, particularly suitable for use in surgically implanted devices, is disclosed which exhibits a <span class="hlt">step</span> change in its output voltage sufficiently prior to full cell discharge to enable the timely replacement of the cell under non-critical circumstances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3431882','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3431882"><span id="translatedtitle"><span class="hlt">Optimization</span> of Xylanase Production from Penicillium sp.WX-Z1 by a Two-<span class="hlt">Step</span> Statistical Strategy: Plackett-Burman and Box-Behnken Experimental Design</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cui, Fengjie; Zhao, Liming</p> <p>2012-01-01</p> <p>The objective of the study was to <span class="hlt">optimize</span> the nutrition sources in a culture medium for the production of xylanase from Penicillium sp.WX-Z1 using Plackett-Burman design and Box-Behnken design. The Plackett-Burman multifactorial design was first employed to screen the important nutrient sources in the medium for xylanase production by Penicillium sp.WX-Z1 and subsequent use of the response surface methodology (RSM) was further <span class="hlt">optimized</span> for xylanase production by Box-Behnken design. The important nutrient sources in the culture medium, identified by the initial screening method of Placket-Burman, were wheat bran, yeast extract, NaNO3, MgSO4, and CaCl2. The <span class="hlt">optimal</span> amounts (in g/L) for maximum production of xylanase were: wheat bran, 32.8; yeast extract, 1.02; NaNO3, 12.71; MgSO4, 0.96; and CaCl2, 1.04. Using this statistical experimental design, the xylanase production under <span class="hlt">optimal</span> condition reached 46.50 U/mL and an increase in xylanase activity of 1.34-fold was obtained compared with the original medium for fermentation carried out in a 30-L bioreactor. PMID:22949884</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004NatMa...3..610S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004NatMa...3..610S"><span id="translatedtitle">Carbon nanotube <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Srivastava, A.; Srivastava, O. N.; Talapatra, S.; Vajtai, R.; Ajayan, P. M.</p> <p>2004-09-01</p> <p>Over the past decade of nanotube research, a variety of organized nanotube architectures have been fabricated using chemical vapour deposition. The idea of using nanotube structures in separation technology has been proposed, but building macroscopic structures that have controlled geometric shapes, density and dimensions for specific applications still remains a challenge. Here we report the fabrication of freestanding monolithic uniform macroscopic hollow cylinders having radially aligned carbon nanotube walls, with diameters and lengths up to several centimetres. These cylindrical membranes are used as <span class="hlt">filters</span> to demonstrate their utility in two important settings: the elimination of multiple components of heavy hydrocarbons from petroleum-a crucial <span class="hlt">step</span> in post-distillation of crude oil-with a single-<span class="hlt">step</span> <span class="hlt">filtering</span> process, and the filtration of bacterial contaminants such as Escherichia coli or the nanometre-sized poliovirus (~25 nm) from water. These macro <span class="hlt">filters</span> can be cleaned for repeated filtration through ultrasonication and autoclaving. The exceptional thermal and mechanical stability of nanotubes, and the high surface area, ease and cost-effective fabrication of the nanotube membranes may allow them to compete with ceramic- and polymer-based separation membranes used commercially.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15286755','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15286755"><span id="translatedtitle">Carbon nanotube <span class="hlt">filters</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Srivastava, A; Srivastava, O N; Talapatra, S; Vajtai, R; Ajayan, P M</p> <p>2004-09-01</p> <p>Over the past decade of nanotube research, a variety of organized nanotube architectures have been fabricated using chemical vapour deposition. The idea of using nanotube structures in separation technology has been proposed, but building macroscopic structures that have controlled geometric shapes, density and dimensions for specific applications still remains a challenge. Here we report the fabrication of freestanding monolithic uniform macroscopic hollow cylinders having radially aligned carbon nanotube walls, with diameters and lengths up to several centimetres. These cylindrical membranes are used as <span class="hlt">filters</span> to demonstrate their utility in two important settings: the elimination of multiple components of heavy hydrocarbons from petroleum-a crucial <span class="hlt">step</span> in post-distillation of crude oil-with a single-<span class="hlt">step</span> <span class="hlt">filtering</span> process, and the filtration of bacterial contaminants such as Escherichia coli or the nanometre-sized poliovirus ( approximately 25 nm) from water. These macro <span class="hlt">filters</span> can be cleaned for repeated filtration through ultrasonication and autoclaving. The exceptional thermal and mechanical stability of nanotubes, and the high surface area, ease and cost-effective fabrication of the nanotube membranes may allow them to compete with ceramic- and polymer-based separation membranes used commercially. PMID:15286755</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22163140','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22163140"><span id="translatedtitle">Influence of multi-<span class="hlt">step</span> heat treatments in creep age forming of 7075 aluminum alloy: <span class="hlt">Optimization</span> for springback, strength and exfoliation corrosion</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Arabi Jeshvaghani, R.; Zohdi, H.; Shahverdi, H.R.; Bozorg, M.; Hadavi, S.M.M.</p> <p>2012-11-15</p> <p>Multi-<span class="hlt">step</span> heat treatments comprise of high temperature forming (150 Degree-Sign C/24 h plus 190 Degree-Sign C for several minutes) and subsequent low temperature forming (120 Degree-Sign C for 24 h) is developed in creep age forming of 7075 aluminum alloy to decrease springback and exfoliation corrosion susceptibility without reduction in tensile properties. The results show that the multi-<span class="hlt">step</span> heat treatment gives the low springback and the best combination of exfoliation corrosion resistance and tensile strength. The lower springback is attributed to the dislocation recovery and more stress relaxation at higher temperature. Transmission electron microscopy observations show that corrosion resistance is improved due to the enlargement in the size and the inter-particle distance of the grain boundaries precipitates. Furthermore, the achievement of the high strength is related to the uniform distribution of ultrafine {eta} Prime precipitates within grains. - Highlights: Black-Right-Pointing-Pointer Creep age forming developed for manufacturing of aircraft wing panels by aluminum alloy. Black-Right-Pointing-Pointer A good combination of properties with minimal springback is required in this component. Black-Right-Pointing-Pointer This requirement can be improved through the appropriate heat treatments. Black-Right-Pointing-Pointer Multi-<span class="hlt">step</span> cycles developed in creep age forming of AA7075 for improving of springback and properties. Black-Right-Pointing-Pointer Results indicate simultaneous enhancing the properties and shape accuracy (lower springback).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770011363','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770011363"><span id="translatedtitle">Notch <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shelton, G. B. (Inventor)</p> <p>1977-01-01</p> <p>A notch <span class="hlt">filter</span> for the selective attenuation of a narrow band of frequencies out of a larger band was developed. A helical resonator is connected to an input circuit and an output circuit through discrete and equal capacitors, and a resistor is connected between the input and the output circuits.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://gallery.usgs.gov/photos/12_17_2012_d28Kb54AAu_12_17_2012_3','SCIGOVIMAGE-USGS'); return false;" href="http://gallery.usgs.gov/photos/12_17_2012_d28Kb54AAu_12_17_2012_3"><span id="translatedtitle">Phosphorus <span class="hlt">Filter</span></span></a></p> <p><a target="_blank" href=""></a></p> <p></p> <p></p> <p>Tom Kehler, fishery biologist at the U.S. Fish and Wildlife Service's Northeast Fishery Center in Lamar, Pennsylvania, checks the flow rate of water leaving a phosphorus <span class="hlt">filter</span> column. The USGS has pioneered a new use for acid mine drainage residuals that are currently a disposal challenge, usi...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070013790','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070013790"><span id="translatedtitle">Initial Ares I Bending <span class="hlt">Filter</span> Design</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jang, Jiann-Woei; Bedrossian, Nazareth; Hall, Robert; Norris, H. Lee; Hall, Charles; Jackson, Mark</p> <p>2007-01-01</p> <p>The Ares-I launch vehicle represents a challenging flex-body structural environment for control system design. Software <span class="hlt">filtering</span> of the inertial sensor output will be required to ensure control system stability and adequate performance. This paper presents a design methodology employing numerical <span class="hlt">optimization</span> to develop the Ares-I bending <span class="hlt">filters</span>. The <span class="hlt">filter</span> design methodology was based on a numerical constrained <span class="hlt">optimization</span> approach to maximize stability margins while meeting performance requirements. The resulting bending <span class="hlt">filter</span> designs achieved stability by adding lag to the first structural frequency and hence phase stabilizing the first Ares-I flex mode. To minimize rigid body performance impacts, a priority was placed via constraints in the <span class="hlt">optimization</span> algorithm to minimize bandwidth decrease with the addition of the bending <span class="hlt">filters</span>. The bending <span class="hlt">filters</span> provided here have been demonstrated to provide a stable first stage control system in both the frequency domain and the MSFC MAVERIC time domain simulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23943524','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23943524"><span id="translatedtitle">A high-throughput sample preparation method for cellular proteomics using 96-well <span class="hlt">filter</span> plates.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Switzar, Linda; van Angeren, Jordy; Pinkse, Martijn; Kool, Jeroen; Niessen, Wilfried M A</p> <p>2013-10-01</p> <p>A high-throughput sample preparation protocol based on the use of 96-well molecular weight cutoff (MWCO) <span class="hlt">filter</span> plates was developed for shotgun proteomics of cell lysates. All sample preparation <span class="hlt">steps</span>, including cell lysis, buffer exchange, protein denaturation, reduction, alkylation and proteolytic digestion are performed in a 96-well plate format, making the platform extremely well suited for processing large numbers of samples and directly compatible with functional assays for cellular proteomics. In addition, the usage of a single plate for all sample preparation <span class="hlt">steps</span> following cell lysis reduces potential samples losses and allows for automation. The MWCO <span class="hlt">filter</span> also enables sample concentration, thereby increasing the overall sensitivity, and implementation of washing <span class="hlt">steps</span> involving organic solvents, for example, to remove cell membranes constituents. The <span class="hlt">optimized</span> protocol allowed for higher throughput with improved sensitivity in terms of the number of identified cellular proteins when compared to an established protocol employing gel-filtration columns. PMID:23943524</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22885040','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22885040"><span id="translatedtitle"><span class="hlt">Optimization</span> of pressurized liquid extraction using a multivariate chemometric approach and comparison of solid-phase extraction cleanup <span class="hlt">steps</span> for the determination of polycyclic aromatic hydrocarbons in mosses.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Foan, L; Simon, V</p> <p>2012-09-21</p> <p>A factorial design was used to <span class="hlt">optimize</span> the extraction of polycyclic aromatic hydrocarbons (PAHs) from mosses, plants used as biomonitors of air pollution. The analytical procedure consists of pressurized liquid extraction (PLE) followed by solid-phase extraction (SPE) cleanup, in association with analysis by high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD). For method development, homogeneous samples were prepared with large quantities of the mosses Isothecium myosuroides Brid. and Hypnum cupressiforme Hedw., collected from a Spanish Nature Reserve. A factorial design was used to identify the <span class="hlt">optimal</span> PLE operational conditions: 2 static cycles of 5 min at 80 °C. The analytical procedure performed with PLE showed similar recoveries (∼70%) and total PAH concentrations (∼200 ng g(-1)) as found using Soxtec extraction, with the advantage of reducing solvent consumption by 3 (30 mL against 100mL per sample), and taking a fifth of the time (24 samples extracted automatically in 8h against 2 samples in 3.5h). The performance of SPE normal phases (NH(2), Florisil, silica and activated aluminium) generally used for organic matrix cleanup was also compared. Florisil appeared to be the most selective phase and ensured the highest PAH recoveries. The <span class="hlt">optimal</span> analytical procedure was validated with a reference material and applied to moss samples from a remote Spanish site in order to determine spatial and inter-species variability. PMID:22885040</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22293624','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22293624"><span id="translatedtitle">Testing Dual Rotary <span class="hlt">Filters</span> - 12373</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Herman, D.T.; Fowley, M.D.; Stefanko, D.B.; Shedd, D.A.; Houchens, C.L.</p> <p>2012-07-01</p> <p>The Savannah River National Laboratory (SRNL) installed and tested two hydraulically connected SpinTek{sup R} Rotary Micro-<span class="hlt">filter</span> units to determine the behavior of a multiple <span class="hlt">filter</span> system and develop a multi-<span class="hlt">filter</span> automated control scheme. Developing and testing the control of multiple <span class="hlt">filters</span> was the next <span class="hlt">step</span> in the development of the rotary <span class="hlt">filter</span> for deployment. The test stand was assembled using as much of the hardware planned for use in the field including instrumentation and valving. The control scheme developed will serve as the basis for the scheme used in deployment. The multi <span class="hlt">filter</span> setup was controlled via an Emerson DeltaV control system running version 10.3 software. Emerson model MD controllers were installed to run the control algorithms developed during this test. Savannah River Remediation (SRR) Process Control Engineering personnel developed the software used to operate the process test model. While a variety of control schemes were tested, two primary algorithms provided extremely stable control as well as significant resistance to process upsets that could lead to equipment interlock conditions. The control system was tuned to provide satisfactory response to changing conditions during the operation of the multi-<span class="hlt">filter</span> system. Stability was maintained through the startup and shutdown of one of the <span class="hlt">filter</span> units while the second was still in operation. The equipment selected for deployment, including the concentrate discharge control valve, the pressure transmitters, and flow meters, performed well. Automation of the valve control integrated well with the control scheme and when used in concert with the other control variables, allowed automated control of the dual rotary <span class="hlt">filter</span> system. Experience acquired on a multi-<span class="hlt">filter</span> system behavior and with the system layout during this test helped to identify areas where the current deployment rotary <span class="hlt">filter</span> installation design could be improved. Completion of this testing provides the necessary information on the control and system behavior that will be used in deployment on actual waste. (authors)</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/973849','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/973849"><span id="translatedtitle">Plasmonic <span class="hlt">filters</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Passmore, Brandon Scott; Shaner, Eric Arthur; Barrick, Todd A.</p> <p>2009-09-01</p> <p>Metal films perforated with subwavelength hole arrays have been show to demonstrate an effect known as Extraordinary Transmission (EOT). In EOT devices, optical transmission passbands arise that can have up to 90% transmission and a bandwidth that is only a few percent of the designed center wavelength. By placing a tunable dielectric in proximity to the EOT mesh, one can tune the center frequency of the passband. We have demonstrated over 1 micron of passive tuning in structures designed for an 11 micron center wavelength. If a suitable midwave (3-5 micron) tunable dielectric (perhaps BaTiO{sub 3}) were integrated with an EOT mesh designed for midwave operation, it is possible that a fast, voltage tunable, low temperature <span class="hlt">filter</span> solution could be demonstrated with a several hundred nanometer passband. Such an element could, for example, replace certain components in a <span class="hlt">filter</span> wheel solution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1982spin.rept...65.','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1982spin.rept...65."><span id="translatedtitle">Water <span class="hlt">Filter</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p></p> <p>1982-01-01</p> <p>A compact, lightweight electrolytic water sterilizer available through Ambassador Marketing, generates silver ions in concentrations of 50 to 100 parts per billion in water flow system. The silver ions serve as an effective bactericide/deodorizer. Tap water passes through <span class="hlt">filtering</span> element of silver that has been chemically plated onto activated carbon. The silver inhibits bacterial growth and the activated carbon removes objectionable tastes and odors caused by addition of chlorine and other chemicals in municipal water supply. The three models available are a kitchen unit, a "Tourister" unit for portable use while traveling and a refrigerator unit that attaches to the ice cube water line. A <span class="hlt">filter</span> will treat 5,000 to 10,000 gallons of water.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020087762','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020087762"><span id="translatedtitle">Eyeglass <span class="hlt">Filters</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1987-01-01</p> <p>Biomedical Optical Company of America's suntiger lenses eliminate more than 99% of harmful light wavelengths. NASA derived lenses make scenes more vivid in color and also increase the wearer's visual acuity. Distant objects, even on hazy days, appear crisp and clear; mountains seem closer, glare is greatly reduced, clouds stand out. Daytime use protects the retina from bleaching in bright light, thus improving night vision. <span class="hlt">Filtering</span> helps prevent a variety of eye disorders, in particular cataracts and age related macular degeneration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9353E..0WB','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9353E..0WB"><span id="translatedtitle">Microfabrication of three-dimensional <span class="hlt">filters</span> for liposome extrusion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baldacchini, Tommaso; Nuñez, Vicente; LaFratta, Christopher N.; Grech, Joseph S.; Vullev, Valentine I.; Zadoyan, Ruben</p> <p>2015-03-01</p> <p>Liposomes play a relevant role in the biomedical field of drug delivery. The ability of these lipid vesicles to encapsulate and transport a variety of bioactive molecules has fostered their use in several therapeutic applications, from cancer treatments to the administration of drugs with antiviral activities. Size and uniformity are key parameters to take into consideration when preparing liposomes; these factors greatly influence their effectiveness in both in vitro and in vivo experiments. A popular technique employed to achieve the <span class="hlt">optimal</span> liposome dimension (around 100 nm in diameter) and uniform size distribution is repetitive extrusion through a polycarbonate <span class="hlt">filter</span>. We investigated two femtosecond laser direct writing techniques for the fabrication of three-dimensional <span class="hlt">filters</span> within a microfluidics chip for liposomes extrusion. The miniaturization of the extrusion process in a microfluidic system is the first <span class="hlt">step</span> toward a complete solution for lab-on-a-chip preparation of liposomes from vesicles self-assembly to optical characterization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3985781','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3985781"><span id="translatedtitle">Holographic Photopolymer Linear Variable <span class="hlt">Filter</span> with Enhanced Blue Reflection</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2015-01-01</p> <p>A single beam one-<span class="hlt">step</span> holographic interferometry method was developed to fabricate porous polymer structures with controllable pore size and location to produce compact graded photonic bandgap structures for linear variable optical <span class="hlt">filters</span>. This technology is based on holographic polymer dispersed liquid crystal materials. By introducing a forced internal reflection, the optical reflection throughout the visible spectral region, from blue to red, is high and uniform. In addition, the control of the bandwidth of the reflection resonance, related to the light intensity and spatial porosity distributions, was investigated to <span class="hlt">optimize</span> the optical performance. The development of portable and inexpensive personal health-care and environmental multispectral sensing/imaging devices will be possible using these <span class="hlt">filters</span>. PMID:24517443</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9412E..1ML','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9412E..1ML"><span id="translatedtitle">Imaging task-based <span class="hlt">optimal</span> kV and mA selection for CT radiation dose reduction: from <span class="hlt">filtered</span> backprojection (FBP) to statistical model based iterative reconstruction (MBIR)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Ke; Gomez-Cardona, Daniel; Lubner, Meghan G.; Pickhardt, Perry J.; Chen, Guang-Hong</p> <p>2015-03-01</p> <p><span class="hlt">Optimal</span> selections of tube potential (kV) and tube current (mA) are essential in maximizing the diagnostic potential of a given CT technology while minimizing radiation dose. The use of a lower tube potential may improve image contrast, but may also require a significantly higher tube current to compensate for the rapid decrease of tube output at lower tube potentials. Therefore, the selection of kV and mA should take those kinds of constraints as well as the specific diagnostic imaging task in to consideration. For conventional quasi-linear CT systems employing linear <span class="hlt">filtered</span> back-projection (FBP) image reconstruction algorithm, the <span class="hlt">optimization</span> of kV-mA combinations are relatively straightforward, as neither spatial resolution nor noise texture has significant dependence on kV and mA settings. In these cases, zero-frequency analysis such as contrast-to-noise ratio (CNR) or normalized CNR by dose (CNRD) can be used for <span class="hlt">optimal</span> kV-mA selection. The recently introduced statistical model-based iterative reconstruction (MBIR) method, however, has introduced new challenges to <span class="hlt">optimal</span> kV and mA selection, as both spatial resolution and noise texture become closely correlated with kV and mA. In this work, a task-based approach based on modern signal detection theory and the corresponding frequency-dependent analysis has been proposed to perform the kV and mA <span class="hlt">optimization</span> for both FBP and MBIR. By performing exhaustive measurements of task-based detectability index through the technically accessible kV-mA parameter space, iso-detectability contours were generated and overlaid on top of iso-dose contours, from which the kV-mA pair that minimize dose yet still achieving the desired detectability level can be identified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011HESS...15.3237N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011HESS...15.3237N"><span id="translatedtitle">Applying sequential Monte Carlo methods into a distributed hydrologic model: lagged particle <span class="hlt">filtering</span> approach with regularization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Noh, S. J.; Tachikawa, Y.; Shiiba, M.; Kim, S.</p> <p>2011-10-01</p> <p>Data assimilation techniques have received growing attention due to their capability to improve prediction. Among various data assimilation techniques, sequential Monte Carlo (SMC) methods, known as "particle <span class="hlt">filters</span>", are a Bayesian learning process that has the capability to handle non-linear and non-Gaussian state-space models. In this paper, we propose an improved particle <span class="hlt">filtering</span> approach to consider different response times of internal state variables in a hydrologic model. The proposed method adopts a lagged <span class="hlt">filtering</span> approach to aggregate model response until the uncertainty of each hydrologic process is propagated. The regularization with an additional move <span class="hlt">step</span> based on the Markov chain Monte Carlo (MCMC) methods is also implemented to preserve sample diversity under the lagged <span class="hlt">filtering</span> approach. A distributed hydrologic model, water and energy transfer processes (WEP), is implemented for the sequential data assimilation through the updating of state variables. The lagged regularized particle <span class="hlt">filter</span> (LRPF) and the sequential importance resampling (SIR) particle <span class="hlt">filter</span> are implemented for hindcasting of streamflow at the Katsura catchment, Japan. Control state variables for <span class="hlt">filtering</span> are soil moisture content and overland flow. Streamflow measurements are used for data assimilation. LRPF shows consistent forecasts regardless of the process noise assumption, while SIR has different values of <span class="hlt">optimal</span> process noise and shows sensitive variation of confidential intervals, depending on the process noise. Improvement of LRPF forecasts compared to SIR is particularly found for rapidly varied high flows due to preservation of sample diversity from the kernel, even if particle impoverishment takes place.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930000688&hterms=John+Callas&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DJohn%2BCallas','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930000688&hterms=John+Callas&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DJohn%2BCallas"><span id="translatedtitle">Fuel And Oxidizer <span class="hlt">Filters</span> For The Galileo Spacecraft</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jan, Darrell L.; Guernsey, Carl S.; Callas, John L.</p> <p>1993-01-01</p> <p>Report describes experimental and theoretical studies of <span class="hlt">filters</span> in propellant streams of propulsion system in Galileo spacecraft. Studies contributed to base of information useful in <span class="hlt">optimizing</span> design of <span class="hlt">filters</span> in propulsion systems of future spacecraft.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/672502','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/672502"><span id="translatedtitle"><span class="hlt">Stepped</span> nozzle</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Sutton, G.P.</p> <p>1998-07-14</p> <p>An insert is described which allows a supersonic nozzle of a rocket propulsion system to operate at two or more different nozzle area ratios. This provides an improved vehicle flight performance or increased payload. The insert has significant advantages over existing devices for increasing nozzle area ratios. The insert is temporarily fastened by a simple retaining mechanism to the aft end of the diverging segment of the nozzle and provides for a multi-<span class="hlt">step</span> variation of nozzle area ratio. When mounted in place, the insert provides the nozzle with a low nozzle area ratio. During flight, the retaining mechanism is released and the insert ejected thereby providing a high nozzle area ratio in the diverging nozzle segment. 5 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/871699','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/871699"><span id="translatedtitle"><span class="hlt">Stepped</span> nozzle</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Sutton, George P.</p> <p>1998-01-01</p> <p>An insert which allows a supersonic nozzle of a rocket propulsion system to operate at two or more different nozzle area ratios. This provides an improved vehicle flight performance or increased payload. The insert has significant advantages over existing devices for increasing nozzle area ratios. The insert is temporarily fastened by a simple retaining mechanism to the aft end of the diverging segment of the nozzle and provides for a multi-<span class="hlt">step</span> variation of nozzle area ratio. When mounted in place, the insert provides the nozzle with a low nozzle area ratio. During flight, the retaining mechanism is released and the insert ejected thereby providing a high nozzle area ratio in the diverging nozzle segment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6994727','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6994727"><span id="translatedtitle">Nonlinear <span class="hlt">filtering</span> in oil/gas reservoir simulation: <span class="hlt">filter</span> design</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Arnold, E.M.; Voss, D.A.; Mayer, D.W.</p> <p>1980-10-01</p> <p>In order to provide an additional mode of utility to the USGS reservoir model VARGOW, a nonlinear <span class="hlt">filter</span> was designed and incorporated into the system. As a result, <span class="hlt">optimal</span> (in the least squares sense) estimates of reservoir pressure, liquid mass, and gas cap plus free gas mass are obtained from an input of reservoir initial condition estimates and pressure history. These <span class="hlt">optimal</span> estimates are provided continuously for each time after the initial time, and the input pressure history is allowed to be corrupted by measurement error. Preliminary testing of the VARGOW <span class="hlt">filter</span> was begun and the results show promise. Synthetic data which could be readily manipulated during testing was used in tracking tests. The results were positive when the initial estimates of the reservoir initial conditions were reasonably close. Further testing is necessary to investigate the <span class="hlt">filter</span> performance with real reservoir data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/220576','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/220576"><span id="translatedtitle">Ceramic <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Holmes, B.L.; Janney, M.A.</p> <p>1995-12-31</p> <p><span class="hlt">Filters</span> were formed from ceramic fibers, organic fibers, and a ceramic bond phase using a papermaking technique. The distribution of particulate ceramic bond phase was determined using a model silicon carbide system. As the ceramic fiber increased in length and diameter the distance between particles decreased. The calculated number of particles per area showed good agreement with the observed value. After firing, the papers were characterized using a biaxial load test. The strength of papers was proportional to the amount of bond phase included in the paper. All samples exhibited strain-tolerant behavior.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AIPC.1637..683M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AIPC.1637..683M"><span id="translatedtitle">Solution of two-dimensional electromagnetic scattering problem by FDTD with <span class="hlt">optimal</span> <span class="hlt">step</span> size, based on a semi-norm analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Monsefi, Farid; Carlsson, Linus; Rančić, Milica; Otterskog, Magnus; Silvestrov, Sergei</p> <p>2014-12-01</p> <p>To solve the electromagnetic scattering problem in two dimensions, the Finite Difference Time Domain (FDTD) method is used. The order of convergence of the FDTD algorithm, solving the two-dimensional Maxwell's curl equations, is estimated in two different computer implementations: with and without an obstacle in the numerical domain of the FDTD scheme. This constitutes an electromagnetic scattering problem where a lumped sinusoidal current source, as a source of electromagnetic radiation, is included inside the boundary. Confined within the boundary, a specific kind of Absorbing Boundary Condition (ABC) is chosen and the outside of the boundary is in form of a Perfect Electric Conducting (PEC) surface. Inserted in the computer implementation, a semi-norm has been applied to compare different <span class="hlt">step</span> sizes in the FDTD scheme. First, the domain of the problem is chosen to be the free-space without any obstacles. In the second part of the computer implementations, a PEC surface is included as the obstacle. The numerical instability of the algorithms can be rather easily avoided with respect to the Courant stability condition, which is frequently used in applying the general FDTD algorithm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22390800','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22390800"><span id="translatedtitle">Solution of two-dimensional electromagnetic scattering problem by FDTD with <span class="hlt">optimal</span> <span class="hlt">step</span> size, based on a semi-norm analysis</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Monsefi, Farid; Carlsson, Linus; Silvestrov, Sergei; Rančić, Milica; Otterskog, Magnus</p> <p>2014-12-10</p> <p>To solve the electromagnetic scattering problem in two dimensions, the Finite Difference Time Domain (FDTD) method is used. The order of convergence of the FDTD algorithm, solving the two-dimensional Maxwell’s curl equations, is estimated in two different computer implementations: with and without an obstacle in the numerical domain of the FDTD scheme. This constitutes an electromagnetic scattering problem where a lumped sinusoidal current source, as a source of electromagnetic radiation, is included inside the boundary. Confined within the boundary, a specific kind of Absorbing Boundary Condition (ABC) is chosen and the outside of the boundary is in form of a Perfect Electric Conducting (PEC) surface. Inserted in the computer implementation, a semi-norm has been applied to compare different <span class="hlt">step</span> sizes in the FDTD scheme. First, the domain of the problem is chosen to be the free-space without any obstacles. In the second part of the computer implementations, a PEC surface is included as the obstacle. The numerical instability of the algorithms can be rather easily avoided with respect to the Courant stability condition, which is frequently used in applying the general FDTD algorithm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4285650','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4285650"><span id="translatedtitle">The <span class="hlt">optimization</span> of essential oils supercritical CO2 extraction from Lavandula hybrida through static-dynamic <span class="hlt">steps</span> procedure and semi-continuous technique using response surface method</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kamali, Hossein; Aminimoghadamfarouj, Noushin; Golmakani, Ebrahim; Nematollahi, Alireza</p> <p>2015-01-01</p> <p>Aim: The aim of this study was to examine and evaluate crucial variables in essential oils extraction process from Lavandula hybrida through static-dynamic and semi-continuous techniques using response surface method. Materials and Methods: Essential oil components were extracted from Lavandula hybrida (Lavandin) flowers using supercritical carbon dioxide via static-dynamic <span class="hlt">steps</span> (SDS) procedure, and semi-continuous (SC) technique. Results: Using response surface method the optimum extraction yield (4.768%) was obtained via SDS at 108.7 bar, 48.5°C, 120 min (static: 8×15), 24 min (dynamic: 8×3 min) in contrast to the 4.620% extraction yield for the SC at 111.6 bar, 49.2°C, 14 min (static), 121.1 min (dynamic). Conclusion: The results indicated that a substantial reduction (81.56%) solvent usage (kg CO2/g oil) is observed in the SDS method versus the conventional SC method. PMID:25598636</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JPhD...46p5501A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JPhD...46p5501A"><span id="translatedtitle">Rapid synthesis of carbon nanoparticles with an <span class="hlt">optimized</span> combination of specific surface area and crystallinity by a plasma-assisted single-<span class="hlt">step</span> process</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aomoa, N.; Bhuyan, H.; Cabrera, A. L.; Favre, M.; Diaz-Droguett, D. E.; Rojas, S.; Ferrari, P.; Srivastava, D. N.; Kakati, M.</p> <p>2013-04-01</p> <p>This paper reports controlled synthesis of carbon nanoparticles by an expanded thermal plasma jet assisted technique through a single-<span class="hlt">step</span>, high-throughput process. The plasma discharge zone in the experimental reactor remained isolated from the particle nucleation/growth chamber through a supersonic nozzle, which allowed using the sample collection chamber pressure as an efficient control parameter to synthesize carbon nanostructures with tailored combination of some important properties. Low chamber pressure conditions produced samples with both good specific surface area and crystallinity, which may be ideal for use as an efficient catalyst support material as well as in batteries and super capacitors. This dominantly mesoporous sample was also found to have good hydrogen absorption properties. Another significant observation was that the average number of carbon nano-sheets stacked together inside the crumpled paper like layers increased with pressure in the sample collection chamber. Optical emission spectroscopic techniques were used to measure the effective cooling rates responsible for the particle nucleation process under different experimental conditions, which also indicated that C2 dimer molecules are the basic precursors behind the formation of these carbon nanostructures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760023889','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760023889"><span id="translatedtitle">The Lockheed alternate partial polarizer universal <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Title, A. M.</p> <p>1976-01-01</p> <p>A tunable birefringent <span class="hlt">filter</span> using an alternate partial polarizer design has been built. The <span class="hlt">filter</span> has a transmission of 38% in polarized light. Its full width at half maximum is .09A at 5500A. It is tunable from 4500 to 8500A by means of <span class="hlt">stepping</span> motor actuated rotating half wave plates and polarizers. Wave length commands and thermal compensation commands are generated by a PPD 11/10 minicomputer. The alternate partial polarizer universal <span class="hlt">filter</span> is compared with the universal birefringent <span class="hlt">filter</span> and the design techniques, construction methods, and <span class="hlt">filter</span> performance are discussed in some detail. Based on the experience of this <span class="hlt">filter</span> some conclusions regarding the future of birefringent <span class="hlt">filters</span> are elaborated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1174621','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1174621"><span id="translatedtitle">Sub-wavelength efficient polarization <span class="hlt">filter</span> (SWEP <span class="hlt">filter</span>)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Simpson, Marcus L.; Simpson, John T.</p> <p>2003-12-09</p> <p>A polarization sensitive <span class="hlt">filter</span> includes a first sub-wavelength resonant grating structure (SWS) for receiving incident light, and a second SWS. The SWS are disposed relative to one another such that incident light which is transmitted by the first SWS passes through the second SWS. The <span class="hlt">filter</span> has a polarization sensitive resonance, the polarization sensitive resonance substantially reflecting a first polarization component of incident light while substantially transmitting a second polarization component of the incident light, the polarization components being orthogonal to one another. A method for forming polarization <span class="hlt">filters</span> includes the <span class="hlt">steps</span> of forming first and second SWS, the first and second SWS disposed relative to one another such that a portion of incident light applied to the first SWS passes through the second SWS. A method for separating polarizations of light, includes the <span class="hlt">steps</span> of providing a <span class="hlt">filter</span> formed from a first and second SWS, shining incident light having orthogonal polarization components on the first SWS, and substantially reflecting one of the orthogonal polarization components while substantially transmitting the other orthogonal polarization component. A high Q narrowband <span class="hlt">filter</span> includes a first and second SWS, the first and second SWS are spaced apart a distance being at least one half an optical wavelength.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvA..92f2119T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvA..92f2119T"><span id="translatedtitle">Volterra <span class="hlt">filters</span> for quantum estimation and detection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsang, Mankei</p> <p>2015-12-01</p> <p>The implementation of <span class="hlt">optimal</span> statistical inference protocols for high-dimensional quantum systems is often computationally expensive. To avoid the difficulties associated with <span class="hlt">optimal</span> techniques, here I propose an alternative approach to quantum estimation and detection based on Volterra <span class="hlt">filters</span>. Volterra <span class="hlt">filters</span> have a clear hierarchy of computational complexities and performances, depend only on finite-order correlation functions, and are applicable to systems with no simple Markovian model. These features make Volterra <span class="hlt">filters</span> appealing alternatives to <span class="hlt">optimal</span> nonlinear protocols for the inference and control of complex quantum systems. Applications of the first-order Volterra <span class="hlt">filter</span> to continuous-time quantum <span class="hlt">filtering</span>, the derivation of a Heisenberg-picture uncertainty relation, quantum state tomography, and qubit readout are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010SPIE.7697E..0IS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010SPIE.7697E..0IS"><span id="translatedtitle">First-moment <span class="hlt">filters</span> for spatial independent cluster processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Swain, Anthony; Clark, Daniel E.</p> <p>2010-04-01</p> <p>A group target is a collection of individual targets which are, for example, part of a convoy of articulated vehicles or a crowd of football supporters and can be represented mathematically as a spatial cluster process. The process of detecting, tracking and identifying group targets requires the estimation of the evolution of such a dynamic spatial cluster process in time based on a sequence of partial observation sets. A suitable generalisation of the Bayes <span class="hlt">filter</span> for this system would provide us with an <span class="hlt">optimal</span> (but computationally intractable) estimate of a multi-group multi-object state based on measurements received up to the current time-<span class="hlt">step</span>. In this paper, we derive the first-moment approximation of the multi-group multi-target Bayes <span class="hlt">filter</span>, inspired by the first-moment multi-object Bayes <span class="hlt">filter</span> derived by Mahler. Such approximations are Bayes <span class="hlt">optimal</span> and provide estimates for the number of clusters (groups) and their positions in the group state-space, as well as estimates for the number of cluster components (object targets) and their positions in target state-space.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910010718','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910010718"><span id="translatedtitle">Rocket noise <span class="hlt">filtering</span> system using digital <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mauritzen, David</p> <p>1990-01-01</p> <p>A set of digital <span class="hlt">filters</span> is designed to <span class="hlt">filter</span> rocket noise to various bandwidths. The <span class="hlt">filters</span> are designed to have constant group delay and are implemented in software on a general purpose computer. The Parks-McClellan algorithm is used. Preliminary tests are performed to verify the design and implementation. An analog <span class="hlt">filter</span> which was previously employed is also simulated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22409672','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22409672"><span id="translatedtitle">TU-C-BRE-11: 3D EPID-Based in Vivo Dosimetry: A Major <span class="hlt">Step</span> Forward Towards <span class="hlt">Optimal</span> Quality and Safety in Radiation Oncology Practice</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mijnheer, B; Mans, A; Olaciregui-Ruiz, I; Rozendaal, R; Spreeuw, H; Herk, M van</p> <p>2014-06-15</p> <p>Purpose: To develop a 3D in vivo dosimetry method that is able to substitute pre-treatment verification in an efficient way, and to terminate treatment delivery if the online measured 3D dose distribution deviates too much from the predicted dose distribution. Methods: A back-projection algorithm has been further developed and implemented to enable automatic 3D in vivo dose verification of IMRT/VMAT treatments using a-Si EPIDs. New software tools were clinically introduced to allow automated image acquisition, to periodically inspect the record-and-verify database, and to automatically run the EPID dosimetry software. The comparison of the EPID-reconstructed and planned dose distribution is done offline to raise automatically alerts and to schedule actions when deviations are detected. Furthermore, a software package for online dose reconstruction was also developed. The RMS of the difference between the cumulative planned and reconstructed 3D dose distributions was used for triggering a halt of a linac. Results: The implementation of fully automated 3D EPID-based in vivo dosimetry was able to replace pre-treatment verification for more than 90% of the patient treatments. The process has been fully automated and integrated in our clinical workflow where over 3,500 IMRT/VMAT treatments are verified each year. By <span class="hlt">optimizing</span> the dose reconstruction algorithm and the I/O performance, the delivered 3D dose distribution is verified in less than 200 ms per portal image, which includes the comparison between the reconstructed and planned dose distribution. In this way it was possible to generate a trigger that can stop the irradiation at less than 20 cGy after introducing large delivery errors. Conclusion: The automatic offline solution facilitated the large scale clinical implementation of 3D EPID-based in vivo dose verification of IMRT/VMAT treatments; the online approach has been successfully tested for various severe delivery errors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21064241','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21064241"><span id="translatedtitle">Nonlinear <span class="hlt">Filtering</span> with Fractional Brownian Motion</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Amirdjanova, A.</p> <p>2002-12-19</p> <p>Our objective is to study a nonlinear <span class="hlt">filtering</span> problem for the observation process perturbed by a Fractional Brownian Motion (FBM) with Hurst index 1/2 <H<1 . A reproducing kernel Hilbert space for the FBM is considered and a 'fractional' Zakai equation for the unnormalized <span class="hlt">optimal</span> <span class="hlt">filter</span> is derived.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10124794','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10124794"><span id="translatedtitle">Late washing <span class="hlt">filter</span> cleaning cycle demonstration</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Meyer, M.L.; McCabe, D.J.</p> <p>1992-08-31</p> <p>The DWPF Late Washing Facility will <span class="hlt">filter</span> cesium and potassium tetraphenyl borate (TPB) solids using a Mott sintered metal <span class="hlt">filter</span>, identical to the <span class="hlt">filter</span> now used in the In-tank Precipitation Facility. The purpose of the late wash <span class="hlt">step</span> is primarily to remove the nitrite salts from the slurry prior to delivery to DWPF. Periodic chemical cleaning of the <span class="hlt">filter</span> will be required, presumably after each batch although the actual required frequency could not be determined on the lab-scale. Minimization of chemical cleaning solution volumes is key to maximizing the attainment of the Late Wash facility. This report summarizes work completed in experiments designed to identify minimum cleaning solution requirements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.C24B..02F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.C24B..02F"><span id="translatedtitle">The Next <span class="hlt">Step</span> in Ice Flow Measurement from Optical Imagery: Comprehensive Mapping Of Ice Sheet Flow in Landsat 8 Imagery Using Spatial Frequency <span class="hlt">Filtering</span>, Enabled by High Radiometric Sensitivity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fahnestock, M. A.; Scambos, T. A.; Klinger, M. J.</p> <p>2014-12-01</p> <p>The advent of large area satellite coverage in the visible spectrum enabled satellite-based tracking of ice sheet flow just over twenty years ago. Following this, rapid development of techniques for imaging radar data enabled the wide-area mapping and time series coverage that SAR has brought to the documentation of changing ice discharge. We report on the maturation of feature tracking in visible-band satellite imagery of the ice sheets enabled by the high radiometric resolution and accurate geolocation delivered by Landsat 8, and apply this to mapping ice flow in the interiors of Antarctica and Greenland. The high radiometric resolution of Landsat 8 enables one to track subtle patterns on the surface of the ice sheet, unique at spatial scales of a few hundred meters, between images separated by multiple orbit cycles. In areas with significant dynamic topography generated by ice flow, this requires use of simple spatial <span class="hlt">filtering</span> techniques first applied by Scambos et al. 1992. The result is densely sampled maps of surface motion that begin to rival the coverage available from SAR speckle tracking and interferometry. Displacement accuracy can approach one tenth of a pixel for reasonable chip sizes using conventional normalized cross-correlation; this can exceed the geolocation accuracy of the scenes involved, but coverage is sufficient to allow correction strategies based on very slow moving ice. The advance in radiometry, geo-location, and tracking tools is augmented by an increased rate of acquisition by Landsat 8. This helps mitigate the issue of cloud cover, as much of every 16-day orbit cycle over ice is acquired, maximizing the acquisition of clear-sky scenes. Using the correlation techniques common to IMCORR and later software, modern libraries, and single-cpu hardware, we are able to process full Landsat 8 scene pairs in a few minutes, allowing comprehensive analysis of ~1K available ice sheet image pairs in a few days.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003SPIE.4945...21I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003SPIE.4945...21I"><span id="translatedtitle">Continuously tunable InP-based multiple air-gap MOEMS <span class="hlt">filters</span> with ultrawide tuning range</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Irmer, Soeren; Daleiden, Juergen; Rangelov, Ventzeslav; Prott, Cornelia; Roemer, Friedhard; Strassner, Martin; Tarraf, Amer; Hillmer, Hartmut</p> <p>2003-03-01</p> <p>Continuously tunable Fabry-Perot <span class="hlt">filters</span> manufactured using multiple air-gap MOEMS technology are studied and presented. The InP/air-gap <span class="hlt">filters</span> <span class="hlt">optimized</span> for optical telecommunication systems using the third optical telecommunication window (1550nm) exhibit a wide tuning range of 142nm and an extremely wide stop-band of 550nm (1250nm-1800nm). The tuning is continuously adjustable requiring ultra-low actuation voltages between 0V (1599nm) and 3.2V (1457nm). The <span class="hlt">filters</span> are based on a relatively simple vertical structure which is fabricated by few surface micro machining <span class="hlt">steps</span>. No mirror alignment or subsequent micro mounting are necessary facilitating a compact batch process production.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080005023','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080005023"><span id="translatedtitle">Method and system for training dynamic nonlinear adaptive <span class="hlt">filters</span> which have embedded memory</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rabinowitz, Matthew (Inventor)</p> <p>2002-01-01</p> <p>Described herein is a method and system for training nonlinear adaptive <span class="hlt">filters</span> (or neural networks) which have embedded memory. Such memory can arise in a multi-layer finite impulse response (FIR) architecture, or an infinite impulse response (IIR) architecture. We focus on <span class="hlt">filter</span> architectures with separate linear dynamic components and static nonlinear components. Such <span class="hlt">filters</span> can be structured so as to restrict their degrees of computational freedom based on a priori knowledge about the dynamic operation to be emulated. The method is detailed for an FIR architecture which consists of linear FIR <span class="hlt">filters</span> together with nonlinear generalized single layer subnets. For the IIR case, we extend the methodology to a general nonlinear architecture which uses feedback. For these dynamic architectures, we describe how one can apply <span class="hlt">optimization</span> techniques which make updates closer to the Newton direction than those of a steepest descent method, such as backpropagation. We detail a novel adaptive modified Gauss-Newton <span class="hlt">optimization</span> technique, which uses an adaptive learning rate to determine both the magnitude and direction of update <span class="hlt">steps</span>. For a wide range of adaptive <span class="hlt">filtering</span> applications, the new training algorithm converges faster and to a smaller value of cost than both steepest-descent methods such as backpropagation-through-time, and standard quasi-Newton methods. We apply the algorithm to modeling the inverse of a nonlinear dynamic tracking system 5, as well as a nonlinear amplifier 6.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820034467&hterms=polarizing+michelson+interferometer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dpolarizing%2Bmichelson%2Binterferometer','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820034467&hterms=polarizing+michelson+interferometer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dpolarizing%2Bmichelson%2Binterferometer"><span id="translatedtitle">Tunable birefringent <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Title, A. M.; Rosenberg, W. J.</p> <p>1981-01-01</p> <p>This article reviews the types and capabilities of birefringent <span class="hlt">filters</span>. The general operating principles of Lyot (perfect polarizers), partial polarizing, and Solc (no internal polarizers) <span class="hlt">filters</span> are introduced. Appropriate techniques for tuning each <span class="hlt">filter</span> type are presented. Field of view of birefringent <span class="hlt">filters</span> is discussed and is compared to Fabry-Perot and interference <span class="hlt">filters</span>. The transmission and throughput advantages of birefringent <span class="hlt">filters</span> are shown. Finally, the current state of the art in practical <span class="hlt">filters</span> is reviewed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26149246','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26149246"><span id="translatedtitle">Organic solvent-free air-assisted liquid-liquid microextraction for <span class="hlt">optimized</span> extraction of illegal azo-based dyes and their main metabolite from spices, cosmetics and human bio-fluid samples in one <span class="hlt">step</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barfi, Behruz; Asghari, Alireza; Rajabi, Maryam; Sabzalian, Sedigheh</p> <p>2015-08-15</p> <p>Air-assisted liquid-liquid microextraction (AALLME) has unique capabilities to develop as an organic solvent-free and one-<span class="hlt">step</span> microextraction method, applying ionic-liquids as extraction solvent and avoiding centrifugation <span class="hlt">step</span>. Herein, a novel and simple eco-friendly method, termed one-<span class="hlt">step</span> air-assisted liquid-liquid microextraction (OS-AALLME), was developed to extract some illegal azo-based dyes (including Sudan I to IV, and Orange G) from food and cosmetic products. A series of experiments were investigated to achieve the most favorable conditions (including extraction solvent: 77μL of 1-Hexyl-3-methylimidazolium hexafluorophosphate; sample pH 6.3, without salt addition; and extraction cycles: 25 during 100s of sonication) using a central composite design strategy. Under these conditions, limits of detection, linear dynamic ranges, enrichment factors and consumptive indices were in the range of 3.9-84.8ngmL(-1), 0.013-3.1μgmL(-1), 33-39, and 0.13-0.15, respectively. The results showed that -as well as its simplicity, fastness, and use of no hazardous disperser and extraction solvents- OS-AALLME is an enough sensitive and efficient method for the extraction of these dyes from complex matrices. After <span class="hlt">optimization</span> and validation, OS-AALLME was applied to estimate the concentration of 1-amino-2-naphthol in human bio-fluids as a main reductive metabolite of selected dyes. Levels of 1-amino-2-naphthol in plasma and urinary excretion suggested that this compound may be used as a new potential biomarker of these dyes in human body. PMID:26149246</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22325165','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22325165"><span id="translatedtitle">SU-E-I-62: Assessing Radiation Dose Reduction and CT Image <span class="hlt">Optimization</span> Through the Measurement and Analysis of the Detector Quantum Efficiency (DQE) of CT Images Using Different Beam Hardening <span class="hlt">Filters</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Collier, J; Aldoohan, S; Gill, K</p> <p>2014-06-01</p> <p>Purpose: Reducing patient dose while maintaining (or even improving) image quality is one of the foremost goals in CT imaging. To this end, we consider the feasibility of <span class="hlt">optimizing</span> CT scan protocols in conjunction with the application of different beam-hardening filtrations and assess this augmentation through noise-power spectrum (NPS) and detector quantum efficiency (DQE) analysis. Methods: American College of Radiology (ACR) and Catphan phantoms (The Phantom Laboratory) were scanned with a 64 slice CT scanner when additional filtration of thickness and composition (e.g., copper, nickel, tantalum, titanium, and tungsten) had been applied. A MATLAB-based code was employed to calculate the image of noise NPS. The Catphan Image Owl software suite was then used to compute the modulated transfer function (MTF) responses of the scanner. The DQE for each additional <span class="hlt">filter</span>, including the inherent filtration, was then computed from these values. Finally, CT dose index (CTDIvol) values were obtained for each applied filtration through the use of a 100 mm pencil ionization chamber and CT dose phantom. Results: NPS, MTF, and DQE values were computed for each applied filtration and compared to the reference case of inherent beam-hardening filtration only. Results showed that the NPS values were reduced between 5 and 12% compared to inherent filtration case. Additionally, CTDIvol values were reduced between 15 and 27% depending on the composition of filtration applied. However, no noticeable changes in image contrast-to-noise ratios were noted. Conclusion: The reduction in the quanta noise section of the NPS profile found in this phantom-based study is encouraging. The reduction in both noise and dose through the application of beam-hardening <span class="hlt">filters</span> is reflected in our phantom image quality. However, further investigation is needed to ascertain the applicability of this approach to reducing patient dose while maintaining diagnostically acceptable image qualities in a clinical setting.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5375276','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5375276"><span id="translatedtitle"><span class="hlt">Filter</span> apparatus</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zahedi, K.; Alexander, J. C.; Zieve, P. B.</p> <p>1985-03-19</p> <p>Electrified <span class="hlt">filter</span> bed apparatus includes inner and outer cylindrical bed-retaining structures for confining a granular bed therebetween. The inner cylindrical structure may comprise a cage of superposed frusto-conical louvers and the outer structure may comprise a similar cage or a perforated cylindrical, liquid-drainage sheet. A cylindrical bed electrode for electrically charging the bed granules is suspended between the retaining structures. The tubular bed surrounds an internal gas passage from which polluted gas flows through the bed from the inside out. Gas enters the internal passage from above through an ionizer section of the apparatus. The ionizer section may include a disc-type ionizer assembly in an ionizer tube. The tube may form an extension of the inner louver cage. A corona discharge may be formed between the disc and the ionizer tube by providing electric current to the discs, whereby the corona discharge electrically charges particulate material within the gas stream. The discs may carry radially protruding needles defining circumferential corona discharge points. A blowdown system may be provided for cleaning the ionizer discs and the tube wall in the region of the discs. The apparatus may include means for avoiding blowout of bed granules from between the outer louvers, and a system for washing pollutant-coated bed granules.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040110662','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040110662"><span id="translatedtitle">Relative Navigation In Elliptical Orbits Using An Iterative Nonlinear <span class="hlt">Filter</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Garrison, James L.; Axelrad, Penina</p> <p>1997-01-01</p> <p>The two <span class="hlt">step</span> <span class="hlt">filter</span> is applied to process intersatellite radar measurements to determine the motion of one satellite relative to another in close elliptical orbits. This <span class="hlt">filter</span> breaks a nonlinear estimation problem into two state vectors. The 'first <span class="hlt">step</span>' state is chosen so as to have a linear measurement equation. This is nonlinearly related to the 'second <span class="hlt">step</span>' state which describes the dynamics. Two different forms are used. In one, the first <span class="hlt">step</span> state is the second <span class="hlt">step</span> state vector augmented by the measurement equation. In the other, the first <span class="hlt">step</span> and second <span class="hlt">step</span> state vectors are of equal dimension. The two <span class="hlt">step</span> <span class="hlt">filter</span> is compared against an iterated extended Kalman <span class="hlt">filter</span> and a Kalman <span class="hlt">filter</span> using a change of variables. Analytical differences between the two <span class="hlt">step</span> estimator and these conventional <span class="hlt">filters</span> are highlighted. Special concerns for initializing the first <span class="hlt">step</span> state covariance matrix and handling the possibility of numerically rank deficient covariance matrices are addressed. Numerical simulations are performed which show that the Two <span class="hlt">Step</span> estimator produces a lower estimation bias under two circumstances; large apriori initial error; and small dimension observation vectors which require a longer arc of measurements to generate observability of the state.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/827435','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/827435"><span id="translatedtitle">ADVANCED HOT GAS <span class="hlt">FILTER</span> DEVELOPMENT</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>E.S. Connolly; G.D. Forsythe</p> <p>2000-09-30</p> <p>DuPont Lanxide Composites, Inc. undertook a sixty-month program, under DOE Contract DEAC21-94MC31214, in order to develop hot gas candle <span class="hlt">filters</span> from a patented material technology know as PRD-66. The goal of this program was to extend the development of this material as a <span class="hlt">filter</span> element and fully assess the capability of this technology to meet the needs of Pressurized Fluidized Bed Combustion (PFBC) and Integrated Gasification Combined Cycle (IGCC) power generation systems at commercial scale. The principal objective of Task 3 was to build on the initial PRD-66 <span class="hlt">filter</span> development, <span class="hlt">optimize</span> its structure, and evaluate basic material properties relevant to the hot gas <span class="hlt">filter</span> application. Initially, this consisted of an evaluation of an advanced filament-wound core structure that had been designed to produce an effective bulk <span class="hlt">filter</span> underneath the barrier <span class="hlt">filter</span> formed by the outer membrane. The basic material properties to be evaluated (as established by the DOE/METC materials working group) would include mechanical, thermal, and fracture toughness parameters for both new and used material, for the purpose of building a material database consistent with what is being done for the alternative candle <span class="hlt">filter</span> systems. Task 3 was later expanded to include analysis of PRD-66 candle <span class="hlt">filters</span>, which had been exposed to actual PFBC conditions, development of an improved membrane, and installation of equipment necessary for the processing of a modified composition. Task 4 would address essential technical issues involving the scale-up of PRD-66 candle <span class="hlt">filter</span> manufacturing from prototype production to commercial scale manufacturing. The focus would be on capacity (as it affects the ability to deliver commercial order quantities), process specification (as it affects yields, quality, and costs), and manufacturing systems (e.g. QA/QC, materials handling, parts flow, and cost data acquisition). Any <span class="hlt">filters</span> fabricated during this task would be used for product qualification tests being conducted by Westinghouse at Foster-Wheeler's Pressurized Circulating Fluidized Bed (PCFBC) test facility in Karhula, Finland. Task 5 was designed to demonstrate the improvements implemented in Task 4 by fabricating fifty 1.5-meter hot gas <span class="hlt">filters</span>. These <span class="hlt">filters</span> were to be made available for DOE-sponsored field trials at the Power Systems Development Facility (PSDF), operated by Southern Company Services in Wilsonville, Alabama.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22340201','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22340201"><span id="translatedtitle">THE SLOAN DIGITAL SKY SURVEY STRIPE 82 IMAGING DATA: DEPTH-<span class="hlt">OPTIMIZED</span> CO-ADDS OVER 300 deg{sup 2} IN FIVE <span class="hlt">FILTERS</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jiang, Linhua; Fan, Xiaohui; McGreer, Ian D.; Green, Richard; Bian, Fuyan; Strauss, Michael A.; Buck, Zoë; Annis, James; Hodge, Jacqueline A.; Myers, Adam D.; Rafiee, Alireza; Richards, Gordon</p> <p>2014-07-01</p> <p>We present and release co-added images of the Sloan Digital Sky Survey (SDSS) Stripe 82. Stripe 82 covers an area of ∼300 deg{sup 2} on the celestial equator, and has been repeatedly scanned 70-90 times in the ugriz bands by the SDSS imaging survey. By making use of all available data in the SDSS archive, our co-added images are <span class="hlt">optimized</span> for depth. Input single-epoch frames were properly processed and weighted based on seeing, sky transparency, and background noise before co-addition. The resultant products are co-added science images and their associated weight images that record relative weights at individual pixels. The depths of the co-adds, measured as the 5σ detection limits of the aperture (3.''2 diameter) magnitudes for point sources, are roughly 23.9, 25.1, 24.6, 24.1, and 22.8 AB magnitudes in the five bands, respectively. They are 1.9-2.2 mag deeper than the best SDSS single-epoch data. The co-added images have good image quality, with an average point-spread function FWHM of ∼1'' in the r, i, and z bands. We also release object catalogs that were made with SExtractor. These co-added products have many potential uses for studies of galaxies, quasars, and Galactic structure. We further present and release near-IR J-band images that cover ∼90 deg{sup 2} of Stripe 82. These images were obtained using the NEWFIRM camera on the NOAO 4 m Mayall telescope, and have a depth of about 20.0-20.5 Vega magnitudes (also 5σ detection limits for point sources)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApJS..213...12J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApJS..213...12J"><span id="translatedtitle">The Sloan Digital Sky Survey Stripe 82 Imaging Data: Depth-<span class="hlt">optimized</span> Co-adds over 300 deg2 in Five <span class="hlt">Filters</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, Linhua; Fan, Xiaohui; Bian, Fuyan; McGreer, Ian D.; Strauss, Michael A.; Annis, James; Buck, Zoë; Green, Richard; Hodge, Jacqueline A.; Myers, Adam D.; Rafiee, Alireza; Richards, Gordon</p> <p>2014-07-01</p> <p>We present and release co-added images of the Sloan Digital Sky Survey (SDSS) Stripe 82. Stripe 82 covers an area of ~300 deg2 on the celestial equator, and has been repeatedly scanned 70-90 times in the ugriz bands by the SDSS imaging survey. By making use of all available data in the SDSS archive, our co-added images are <span class="hlt">optimized</span> for depth. Input single-epoch frames were properly processed and weighted based on seeing, sky transparency, and background noise before co-addition. The resultant products are co-added science images and their associated weight images that record relative weights at individual pixels. The depths of the co-adds, measured as the 5σ detection limits of the aperture (3.''2 diameter) magnitudes for point sources, are roughly 23.9, 25.1, 24.6, 24.1, and 22.8 AB magnitudes in the five bands, respectively. They are 1.9-2.2 mag deeper than the best SDSS single-epoch data. The co-added images have good image quality, with an average point-spread function FWHM of ~1'' in the r, i, and z bands. We also release object catalogs that were made with SExtractor. These co-added products have many potential uses for studies of galaxies, quasars, and Galactic structure. We further present and release near-IR J-band images that cover ~90 deg2 of Stripe 82. These images were obtained using the NEWFIRM camera on the NOAO 4 m Mayall telescope, and have a depth of about 20.0-20.5 Vega magnitudes (also 5σ detection limits for point sources).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013Geomo.190..112R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013Geomo.190..112R"><span id="translatedtitle">Generating an <span class="hlt">optimal</span> DTM from airborne laser scanning data for landslide mapping in a tropical forest environment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Razak, Khamarrul Azahari; Santangelo, Michele; Van Westen, Cees J.; Straatsma, Menno W.; de Jong, Steven M.</p> <p>2013-05-01</p> <p>Landslide inventory maps are fundamental for assessing landslide susceptibility, hazard, and risk. In tropical mountainous environments, mapping landslides is difficult as rapid and dense vegetation growth obscures landslides soon after their occurrence. Airborne laser scanning (ALS) data have been used to construct the digital terrain model (DTM) under dense vegetation, but its reliability for landslide recognition in the tropics remains surprisingly unknown. This study evaluates the suitability of ALS for generating an <span class="hlt">optimal</span> DTM for mapping landslides in the Cameron Highlands, Malaysia. For the bare-earth extraction, we used hierarchical robust <span class="hlt">filtering</span> algorithm and a parameterization with three sequential <span class="hlt">filtering</span> <span class="hlt">steps</span>. After each <span class="hlt">filtering</span> <span class="hlt">step</span>, four interpolations techniques were applied, namely: (i) the linear prediction derived from the SCOP++ (SCP), (ii) the inverse distance weighting (IDW), (iii) the natural neighbor (NEN) and (iv) the topo-to-raster (T2R). We assessed the quality of 12 DTMs in two ways: (1) with respect to 448 field-measured terrain heights and (2) based on the interpretability of landslides. The lowest root-mean-square error (RMSE) was 0.89 m across the landscape using three <span class="hlt">filtering</span> <span class="hlt">steps</span> and linear prediction as interpolation method. However, we found that a less stringent DTM <span class="hlt">filtering</span> unveiled more diagnostic micro-morphological features, but also retained some of vegetation. Hence, a combination of <span class="hlt">filtering</span> <span class="hlt">steps</span> is required for <span class="hlt">optimal</span> landslide interpretation, especially in forested mountainous areas. IDW was favored as the interpolation technique because it combined computational times more reasonably without adding artifacts to the DTM than T2R and NEN, which performed relatively well in the first and second <span class="hlt">filtering</span> <span class="hlt">steps</span>, respectively. The laser point density and the resulting ground point density after <span class="hlt">filtering</span> are key parameters for producing a DTM applicable to landslide identification. The results showed that the ALS-derived DTMs allowed mapping and classifying landslides beneath equatorial mountainous forests, leading to a better understanding of hazardous geomorphic problems in tropical regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006SPIE.6229E..0PS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006SPIE.6229E..0PS"><span id="translatedtitle">Adaptive particle <span class="hlt">filtering</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stevens, Mark R.; Gutchess, Dan; Checka, Neal; Snorrason, Magnús</p> <p>2006-05-01</p> <p>Image exploitation algorithms for Intelligence, Surveillance and Reconnaissance (ISR) and weapon systems are extremely sensitive to differences between the operating conditions (OCs) under which they are trained and the extended operating conditions (EOCs) in which the fielded algorithms are tested. As an example, terrain type is an important OC for the problem of tracking hostile vehicles from an airborne camera. A system designed to track cars driving on highways and on major city streets would probably not do well in the EOC of parking lots because of the very different dynamics. In this paper, we present a system we call ALPS for Adaptive Learning in Particle Systems. ALPS takes as input a sequence of video images and produces labeled tracks. The system detects moving targets and tracks those targets across multiple frames using a multiple hypothesis tracker (MHT) tightly coupled with a particle <span class="hlt">filter</span>. This tracker exploits the strengths of traditional MHT based tracking algorithms by directly incorporating tree-based hypothesis considerations into the particle <span class="hlt">filter</span> update and resampling <span class="hlt">steps</span>. We demonstrate results in a parking lot domain tracking objects through occlusions and object interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/10140625','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/10140625"><span id="translatedtitle">Active <span class="hlt">filter</span> application guide. Final report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Not Available</p> <p>1998-01-01</p> <p>Nonlinear loads interacting with a utility can cause harmonic currents and voltages. Nonlinear loads include arcing loads, power converters that use switching devices, and saturable transformers and reactors. When reactive loads interact with harmonic sources, the results can be harmonic distortion, malfunction of harmonic sensitive equipment, and capacitor overload. To solve these harmonic disturbances, most passive harmonic <span class="hlt">filters</span> must be custom designed to operate with site-specific conditions. Active <span class="hlt">filters</span>, on the other hand, offer the potential of a single black-box solution that is relatively independent of system parameters. Power quality problems attributable to harmonic voltages and currents are increasing. Traditionally, passive harmonic <span class="hlt">filters</span> have been used to solve these problems. A more recent approach for harmonic compensation uses active <span class="hlt">filters</span>. The Active <span class="hlt">Filter</span> Application Guide covers fundamentals of harmonics, discusses harmonic producing loads, presents harmonic <span class="hlt">filtering</span> principles (both active and passive), and provides a <span class="hlt">step-by-step</span> application guide for analyzing and specifying an active <span class="hlt">filter</span>. Also included in the Guide are two active-<span class="hlt">filter</span> case studies. Each demonstrates how the application guide can be used to select and specify solutions for both single harmonic load and multiple harmonic producing loads at a clustered site.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JKPS...62.1330C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JKPS...62.1330C"><span id="translatedtitle">Analytic study on the effects of the number of MLC segments and the least segment area on <span class="hlt">step</span>-and-shoot head-and-neck IMRT planning using direct machine parameter <span class="hlt">optimization</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheong, Kwang-Ho; Kang, Sei-Kwon; Lee, MeYeon; Kim, Haeyoung; Bae, Hoonsik; Park, SoAh; Hwang, Taejin; Kim, KyoungJu; Han, Taejin</p> <p>2013-05-01</p> <p>In this study, we present the concurrent effects of the number of segments (NS) and the least segment area (LSA) for <span class="hlt">step</span>-and-shoot head-and-neck intensity-modulated radiation therapy (IMRT) planning using the direct machine parameter <span class="hlt">optimization</span> (DMPO), on which basis we suggest the <span class="hlt">optimal</span> NS and LSA ranges. We selected three head-and-neck patients who had received IMRT via the simultaneous integrated boost (SIB) technique and classified them as easy, intermediate, and difficult cases. We formulated a benchmark plan and made 11 additional plans by re-<span class="hlt">optimizing</span> the benchmark by varying the NS and the LSA for each case. Clinical and physical plan-quality evaluation parameters were considered separately: the conformality index (CI), the homogeneity index (HI) and the maximum or mean doses for the organs-at-risk were the clinical factors, and these were summarized as plan-quality parameter, Q. The modulation index (MI), the total monitor units (MUs), and the final composite cost function F were employed as parameters in the evaluation of the physical aspects. A 2-way analysis of variance (2-way ANOVA) was used to determine the effects of the NS and the LSA concurrently. Pearson's correlations among the total MU, MI, F, and Q were examined as well. Overall plan-efficiency factor ɛ was defined to estimate the <span class="hlt">optimal</span> NS and LSA by considering the plan's quality and the beam delivery efficiency together. Plans with simple targets or a small number of beams (NB) were affected by the LSA whereas plans with complex targets or large NB were affected by the NS. Moreover, smaller NS and smaller LSA were advantageous for simple plans whereas larger NS and smaller LSA were beneficial for complex plans. When we consider the plan's quality and the beam delivery efficiency, {NS = 60-80, LSA = 8-12 cm2} are the proper ranges for head-and-neck IMRT planning with DMPO; however, the combination may differ based on the complexity of a given plan.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19910031204&hterms=types+polarization&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dtypes%2Bpolarization','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19910031204&hterms=types+polarization&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dtypes%2Bpolarization"><span id="translatedtitle">Polarization <span class="hlt">filtering</span> of SAR data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dubois, Pascale C.; Van Zyl, Jakob J.</p> <p>1989-01-01</p> <p>A theoretical analysis of polarization <span class="hlt">filtering</span> for the bistatic case is developed for optimum discrimination between two types of targets. The resulting method is half analytical and half numerical. Because it is based on the Stokes matrix representation, the targets of interest can be extended targets. The scattered field from such targets is partially polarized. This method is then applied to the monostatic case with numerical examples relying on the JPL (Jet Propulsion Laboratory) full-polarimetric L-band radar data. A matched <span class="hlt">filter</span> to maximize the power ratio between urban and natural targets is developed. The results show that the same <span class="hlt">filter</span> is <span class="hlt">optimal</span> for both ocean and forest targets as natural targets.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000052704','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000052704"><span id="translatedtitle">Genetically Engineered Microelectronic Infrared <span class="hlt">Filters</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cwik, Tom; Klimeck, Gerhard</p> <p>1998-01-01</p> <p>A genetic algorithm is used for design of infrared <span class="hlt">filters</span> and in the understanding of the material structure of a resonant tunneling diode. These two components are examples of microdevices and nanodevices that can be numerically simulated using fundamental mathematical and physical models. Because the number of parameters that can be used in the design of one of these devices is large, and because experimental exploration of the design space is unfeasible, reliable software models integrated with global <span class="hlt">optimization</span> methods are examined The genetic algorithm and engineering design codes have been implemented on massively parallel computers to exploit their high performance. Design results are presented for the infrared <span class="hlt">filter</span> showing new and <span class="hlt">optimized</span> device design. Results for nanodevices are presented in a companion paper at this workshop.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8450E..3SM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8450E..3SM"><span id="translatedtitle">Design of the J-PAS and J-PLUS <span class="hlt">filter</span> systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marín-Franch, A.; Chueca, S.; Moles, M.; Benitez, N.; Taylor, K.; Cepa, J.; Cenarro, A. J.; Cristobal-Hornillos, D.; Ederoclite, A.; Gruel, N.; Hernández-Fuertes, J.; López-Sainz, A.; Luis-Simoes, R.; Rueda-Teruel, F.; Rueda-Teruel, S.; Varela, J.; Yanes-Díaz, A.; Brauneck, U.; Danielou, A.; Dupke, R.; Fernández-Soto, A.; Mendes de Oliveira, C.; Sodré, L.</p> <p>2012-09-01</p> <p>J-PAS (Javalambre-PAU Astrophysical Survey) is a Spanish-Brazilian collaboration to conduct an innovative photometric survey of more than 8000 square degrees of northern sky using a system of 57 <span class="hlt">filters</span>, 54 narrow-band (FWHM=13.8 nm) <span class="hlt">filters</span> continuously populating the spectrum between 370 to 920 nm with 10.0 nm <span class="hlt">steps</span>, plus 3 broad-band <span class="hlt">filters</span>. Together with the main J-PAS survey, the collaboration is carrying out J-PLUS (the Javalambre Photometric Local Universe Survey), an all-sky survey using a set of 12 carefully <span class="hlt">optimized</span> broad- and narrow-band <span class="hlt">filters</span> that will be used to perform the calibration tasks for the main survey. The J-PAS survey will be carried out using JPCam, a 14-CCD mosaic camera using the new e2v 9.2k-by-9.2k, 10μm pixel detectors, mounted on the JST/T250, a dedicated 2.55-m wide-field telescope at the Observatorio Astrofísico de Javalambre (OAJ) in Teruel, Spain. J-PLUS, on the other hand, will be carried out using a wide field CCD camera (the T80Cam) equipped with a large format STA 1600 CCD (10.5k-by-10.5k, 9μm pixel) and mounted on the JAST/T80, a dedicated 0.83-m wide-field telescope at the OAJ. In both cases, the <span class="hlt">filters</span> will operate close to, but up-stream from the dewar window in a fast converging optical beam. This optical configuration imposes challenging requirements for the J-PLUS and J-PAS <span class="hlt">filters</span>, some of them requiring the development of new <span class="hlt">filter</span> design solutions. This paper describes the main requirements and design strategies for these two sets of <span class="hlt">filters</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16649562','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16649562"><span id="translatedtitle">An online novel adaptive <span class="hlt">filter</span> for denoising time series measurements.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Willis, Andrew J</p> <p>2006-04-01</p> <p>A nonstationary form of the Wiener <span class="hlt">filter</span> based on a principal components analysis is described for <span class="hlt">filtering</span> time series data possibly derived from noisy instrumentation. The theory of the <span class="hlt">filter</span> is developed, implementation details are presented and two examples are given. The <span class="hlt">filter</span> operates online, approximating the maximum a posteriori <span class="hlt">optimal</span> Bayes reconstruction of a signal with arbitrarily distributed and non stationary statistics. PMID:16649562</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/867499','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/867499"><span id="translatedtitle">Optical ranked-order <span class="hlt">filtering</span> using threshold decomposition</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Allebach, Jan P.; Ochoa, Ellen; Sweeney, Donald W.</p> <p>1990-01-01</p> <p>A hybrid optical/electronic system performs median <span class="hlt">filtering</span> and related ranked-order operations using threshold decomposition to encode the image. Threshold decomposition transforms the nonlinear neighborhood ranking operation into a linear space-invariant <span class="hlt">filtering</span> <span class="hlt">step</span> followed by a point-to-point threshold comparison <span class="hlt">step</span>. Spatial multiplexing allows parallel processing of all the threshold components as well as recombination by a second linear, space-invariant <span class="hlt">filtering</span> <span class="hlt">step</span>. An incoherent optical correlation system performs the linear <span class="hlt">filtering</span>, using a magneto-optic spatial light modulator as the input device and a computer-generated hologram in the <span class="hlt">filter</span> plane. Thresholding is done electronically. By adjusting the value of the threshold, the same architecture is used to perform median, minimum, and maximum <span class="hlt">filtering</span> of images. A totally optical system is also disclosed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6866284','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/6866284"><span id="translatedtitle">Optical ranked-order <span class="hlt">filtering</span> using threshold decomposition</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Allebach, J.P.; Ochoa, E.; Sweeney, D.W.</p> <p>1987-10-09</p> <p>A hybrid optical/electronic system performs median <span class="hlt">filtering</span> and related ranked-order operations using threshold decomposition to encode the image. Threshold decomposition transforms the nonlinear neighborhood ranking operation into a linear space-invariant <span class="hlt">filtering</span> <span class="hlt">step</span> followed by a point-to-point threshold comparison <span class="hlt">step</span>. Spatial multiplexing allows parallel processing of all the threshold components as well as recombination by a second linear, space-invariant <span class="hlt">filtering</span> <span class="hlt">step</span>. An incoherent optical correlation system performs the linear <span class="hlt">filtering</span>, using a magneto-optic spatial light modulator as the input device and a computer-generated hologram in the <span class="hlt">filter</span> plane. Thresholding is done electronically. By adjusting the value of the threshold, the same architecture is used to perform median, minimum, and maximum <span class="hlt">filtering</span> of images. A totally optical system is also disclosed. 3 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6377465','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6377465"><span id="translatedtitle">Optical ranked-order <span class="hlt">filtering</span> using threshold decomposition</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Allebach, J.P.; Ochoa, E.; Sweeney, D.W.</p> <p>1990-08-14</p> <p>This patent describes a hybrid optical/electronic system. It performs median <span class="hlt">filtering</span> and related ranked-order operations using threshold decomposition to encode the image. Threshold decomposition transforms the nonlinear neighborhood ranking operation into a linear space-invariant <span class="hlt">filtering</span> <span class="hlt">step</span> followed by a point-to-point threshold comparison <span class="hlt">step</span>. Spatial multiplexing allows parallel processing of all the threshold components as well as recombination by a second linear, space-invariant <span class="hlt">filtering</span> <span class="hlt">step</span>. An incoherent optical correlation system performs the linear <span class="hlt">filtering</span>, using a magneto-optic spatial light modulator as the input device and a computer-generated hologram in the <span class="hlt">filter</span> plane. Thresholding is done electronically. By adjusting the value of the threshold, the same architecture is used to perform median, minimum, and maximum <span class="hlt">filtering</span> of images. A totally optical system is also disclosed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10171262','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10171262"><span id="translatedtitle">HEPA <span class="hlt">filter</span> dissolution process</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Brewer, K.N.; Murphy, J.A.</p> <p>1992-12-31</p> <p>This invention is comprised of a process for dissolution of spent high efficiency particulate air (HEPA) <span class="hlt">filters</span> and then combining the complexed <span class="hlt">filter</span> solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent <span class="hlt">filters</span> which is an inefficient method of treating spent HEPA <span class="hlt">filters</span> for disposal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/866054','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/866054"><span id="translatedtitle">Recirculating electric air <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Bergman, Werner</p> <p>1986-01-01</p> <p>An electric air <span class="hlt">filter</span> cartridge has a cylindrical inner high voltage eleode, a layer of <span class="hlt">filter</span> material, and an outer ground electrode formed of a plurality of segments moveably connected together. The outer electrode can be easily opened to remove or insert <span class="hlt">filter</span> material. Air flows through the two electrodes and the <span class="hlt">filter</span> material and is exhausted from the center of the inner electrode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5381258','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/5381258"><span id="translatedtitle">Recirculating electric air <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Bergman, W.</p> <p>1985-01-09</p> <p>An electric air <span class="hlt">filter</span> cartridge has a cylindrical inner high voltage electrode, a layer of <span class="hlt">filter</span> material, and an outer ground electrode formed of a plurality of segments moveably connected together. The outer electrode can be easily opened to remove or insert <span class="hlt">filter</span> material. Air flows through the two electrodes and the <span class="hlt">filter</span> material and is exhausted from the center of the inner electrode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5210680','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/5210680"><span id="translatedtitle">HEPA <span class="hlt">filter</span> dissolution process</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Brewer, K.N.; Murphy, J.A.</p> <p>1994-02-22</p> <p>A process is described for dissolution of spent high efficiency particulate air (HEPA) <span class="hlt">filters</span> and then combining the complexed <span class="hlt">filter</span> solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent <span class="hlt">filters</span> which is an inefficient method of treating spent HEPA <span class="hlt">filters</span> for disposal. 4 figures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/869167','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/869167"><span id="translatedtitle">Hepa <span class="hlt">filter</span> dissolution process</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Brewer, Ken N.; Murphy, James A.</p> <p>1994-01-01</p> <p>A process for dissolution of spent high efficiency particulate air (HEPA) <span class="hlt">filters</span> and then combining the complexed <span class="hlt">filter</span> solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent <span class="hlt">filters</span> which is an inefficient method of treating spent HEPA <span class="hlt">filters</span> for disposal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SPIE.7495E..0OC','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SPIE.7495E..0OC"><span id="translatedtitle">Efficient particle <span class="hlt">filter</span> and its application in contour tracking</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Peng; Qian, Hui; Gao, Weisong; Zhu, Miaoliang</p> <p>2009-10-01</p> <p>In order to improve the real-time performance of particle <span class="hlt">filter</span>, this paper proposes an efficient particle <span class="hlt">filter</span> algorithm and evaluates its usage in object contour tracking application. This new <span class="hlt">filter</span> uses only one particle to predict next state in certain situations. As particle set size is one, there is no need to resample the particles before prediction. Therefore the real-time performance of particle <span class="hlt">filter</span> is improved. To maintain the performance of particle <span class="hlt">filter</span>, we use one particle sample only in prediction <span class="hlt">step</span> and only in situations where particles are close enough with each other. After prediction <span class="hlt">step</span>, the original number of particle samples is recovered. Experiment shows that the new particle <span class="hlt">filter</span> uses less time to process the particles while retain tracking performance comparable with the regular particle <span class="hlt">filter</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730023804','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730023804"><span id="translatedtitle">Properties of multilayer <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Baumeister, P. W.</p> <p>1973-01-01</p> <p>New methods were investigated of using optical interference coatings to produce bandpass <span class="hlt">filters</span> for the spectral region 110 nm to 200 nm. The types of <span class="hlt">filter</span> are: triple cavity metal dielectric <span class="hlt">filters</span>; all dielectric reflection <span class="hlt">filters</span>; and all dielectric Fabry Perot type <span class="hlt">filters</span>. The latter two types use thorium fluoride and either cryolite films or magnesium fluoride films in the stacks. The optical properties of the thorium fluoride were also measured.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/12636128','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/12636128"><span id="translatedtitle">Tap water <span class="hlt">filters</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p></p> <p>2003-02-01</p> <p>Moen PureTouch <span class="hlt">filters</span> remove impurities from tap water without removing fluoride. These carbon block <span class="hlt">filters</span> consist of finely powdered activated carbon that is combined with a plastic binder material and heated to form a hollow cylinder. The blocks are further wrapped with material to improve performance and reduce clogging. The <span class="hlt">filters</span> are available with different <span class="hlt">filtering</span> capabilities (Table 1). The <span class="hlt">filters</span> mount in the faucet spout or under the sink. PMID:12636128</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016OptCo.359..250X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OptCo.359..250X"><span id="translatedtitle">Metal-dielectric metameric <span class="hlt">filters</span> for optically variable devices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xiao, Lixiang; Chen, Nan; Deng, Zihao; Wang, Xiaozhong; Guo, Rong; Bu, Yikun</p> <p>2016-01-01</p> <p>A pair of metal-dielectric metameric <span class="hlt">filters</span> that could create a hidden image was presented for the first time. The structure of the <span class="hlt">filters</span> is simple and only six layers for <span class="hlt">filter</span> A and five layers for <span class="hlt">filter</span> B. The prototype <span class="hlt">filters</span> were designed by using the film color target <span class="hlt">optimization</span> method and the designed results show that, at normal observation angle, the reflected colors of the pair of <span class="hlt">filters</span> are both green and the color difference index between them is only 0.9017. At observation angle of 60°, the <span class="hlt">filter</span> A is violet and the <span class="hlt">filter</span> B is blue. The <span class="hlt">filters</span> were fabricated by remote plasma sputtering process and the experimental results were in accordance with the designs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JMSA....7..116H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JMSA....7..116H"><span id="translatedtitle">Comparison of robust H∞ <span class="hlt">filter</span> and Kalman <span class="hlt">filter</span> for initial alignment of inertial navigation system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hao, Yan-Ling; Chen, Ming-Hui; Li, Liang-Jun; Xu, Bo</p> <p>2008-06-01</p> <p>There are many <span class="hlt">filtering</span> methods that can be used for the initial alignment of an integrated inertial navigation system. This paper discussed the use of GPS, but focused on two kinds of <span class="hlt">filters</span> for the initial alignment of an integrated strapdown inertial navigation system (SINS). One method is based on the Kalman <span class="hlt">filter</span> (KF), and the other is based on the robust <span class="hlt">filter</span>. Simulation results showed that the <span class="hlt">filter</span> provides a quick transient response and a little more accurate estimate than KF, given substantial process noise or unknown noise statistics. So the robust <span class="hlt">filter</span> is an effective and useful method for initial alignment of SINS. This research should make the use of SINS more popular, and is also a <span class="hlt">step</span> for further research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20457535','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20457535"><span id="translatedtitle">3D early embryogenesis image <span class="hlt">filtering</span> by nonlinear partial differential equations.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Krivá, Z; Mikula, K; Peyriéras, N; Rizzi, B; Sarti, A; Stasová, O</p> <p>2010-08-01</p> <p>We present nonlinear diffusion equations, numerical schemes to solve them and their application for <span class="hlt">filtering</span> 3D images obtained from laser scanning microscopy (LSM) of living zebrafish embryos, with a goal to identify the <span class="hlt">optimal</span> <span class="hlt">filtering</span> method and its parameters. In the large scale applications dealing with analysis of 3D+time embryogenesis images, an important objective is a correct detection of the number and position of cell nuclei yielding the spatio-temporal cell lineage tree of embryogenesis. The <span class="hlt">filtering</span> is the first and necessary <span class="hlt">step</span> of the image analysis chain and must lead to correct results, removing the noise, sharpening the nuclei edges and correcting the acquisition errors related to spuriously connected subregions. In this paper we study such properties for the regularized Perona-Malik model and for the generalized mean curvature flow equations in the level-set formulation. A comparison with other nonlinear diffusion <span class="hlt">filters</span>, like tensor anisotropic diffusion and Beltrami flow, is also included. All numerical schemes are based on the same discretization principles, i.e. finite volume method in space and semi-implicit scheme in time, for solving nonlinear partial differential equations. These numerical schemes are unconditionally stable, fast and naturally parallelizable. The <span class="hlt">filtering</span> results are evaluated and compared first using the Mean Hausdorff distance between a gold standard and different isosurfaces of original and <span class="hlt">filtered</span> data. Then, the number of isosurface connected components in a region of interest (ROI) detected in original and after the <span class="hlt">filtering</span> is compared with the corresponding correct number of nuclei in the gold standard. Such analysis proves the robustness and reliability of the edge preserving nonlinear diffusion <span class="hlt">filtering</span> for this type of data and lead to finding the <span class="hlt">optimal</span> <span class="hlt">filtering</span> parameters for the studied models and numerical schemes. Further comparisons consist in ability of splitting the very close objects which are artificially connected due to acquisition error intrinsically linked to physics of LSM. In all studied aspects it turned out that the nonlinear diffusion <span class="hlt">filter</span> which is called geodesic mean curvature flow (GMCF) has the best performance. PMID:20457535</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/4337274','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/4337274"><span id="translatedtitle">ARRANGEMENT FOR REPLACING <span class="hlt">FILTERS</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Blomgren, R.A.; Bohlin, N.J.C.</p> <p>1957-08-27</p> <p>An improved <span class="hlt">filtered</span> air exhaust system which may be continually operated during the replacement of the <span class="hlt">filters</span> without the escape of unfiltered air is described. This is accomplished by hermetically sealing the box like <span class="hlt">filter</span> containers in a rectangular tunnel with neoprene covered sponge rubber sealing rings coated with a silicone impregnated pneumatic grease. The tunnel through which the <span class="hlt">filters</span> are pushed is normal to the exhaust air duct. A number of unused <span class="hlt">filters</span> are in line behind the <span class="hlt">filters</span> in use, and are moved by a hydraulic ram so that a fresh <span class="hlt">filter</span> is positioned in the air duct. The used <span class="hlt">filter</span> is pushed into a waiting receptacle and is suitably disposed. This device permits a rapid and safe replacement of a radiation contaminated <span class="hlt">filter</span> without interruption to the normal flow of exhaust air.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990aifs.book.....N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990aifs.book.....N"><span id="translatedtitle">Adaptive inverse <span class="hlt">filters</span> for stereophonic sound reproduction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nelson, P. A.; Hamada, H.; Elliott, S. J.</p> <p>1990-07-01</p> <p>A general theoretical basis for the design of adaptive digital <span class="hlt">filters</span> for the equalization of the response of multichannel sound reproduction systems is described. The formulation used was a generalization of the Atal-Shroeder cross talk canceller. The use of a least square approach to the digital <span class="hlt">filter</span> design, combined with appropriate modeling delays, allowed the effective equalization of nonminimum phase components in the transmission path. A stochastic gradient algorithm is presented which facilitates the adoption of the digital <span class="hlt">filters</span> to the <span class="hlt">optimal</span> solution, providing the possibility of the design of the <span class="hlt">filters</span> 'in situ' in a given listening space. Some experimental results appear at very low frequencies if the response of the <span class="hlt">filters</span> are an exponential form.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21064240','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21064240"><span id="translatedtitle">Stochastic Vorticity and Associated <span class="hlt">Filtering</span> Theory</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Amirdjanova, A.; Kallianpur, G.</p> <p>2002-12-19</p> <p>The focus of this work is on a two-dimensional stochastic vorticity equation for an incompressible homogeneous viscous fluid. We consider a signed measure-valued stochastic partial differential equation for a vorticity process based on the Skorohod-Ito evolution of a system of N randomly moving point vortices. A nonlinear <span class="hlt">filtering</span> problem associated with the evolution of the vorticity is considered and a corresponding Fujisaki-Kallianpur-Kunita stochastic differential equation for the <span class="hlt">optimal</span> <span class="hlt">filter</span> is derived.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900045064&hterms=improvement+continuous&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dimprovement%2Bcontinuous','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900045064&hterms=improvement+continuous&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dimprovement%2Bcontinuous"><span id="translatedtitle">Laboratory comparison of continuous vs. binary phase-mostly <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Monroe, Stanley E., Jr.; Knopp, Jerome; Juday, Richard D.</p> <p>1989-01-01</p> <p>Recent developments in spatial light modulators have led to devices which are capable of continuous phase modulation, even if only over a limited range. One of these devices, the deformable mirror device is used, to compare the relative merits of binary and partially-continuous phase <span class="hlt">filters</span> in a specific problem of pattern recognition by optical correlation. Each <span class="hlt">filter</span> was physically limited to only about a radiation of modulation. Researchers have predicted that for low input noise levels, continuous phase-only <span class="hlt">filters</span> should have a higher absolute correlator peak output than the corresponding binary <span class="hlt">filters</span>, as well as having a larger SNR. When continuous and binary <span class="hlt">filters</span> were implemented on the DMD and they exhibited the same performance; an ad hoc <span class="hlt">filter</span> <span class="hlt">optimization</span> procedure was developed for use in the laboratory. The <span class="hlt">optimized</span> continuous <span class="hlt">filter</span> gave higher correlation peaks than did an independently <span class="hlt">optimized</span> binary <span class="hlt">filter</span>. Background behavior in the correlation plane was similar for the two <span class="hlt">filters</span>, and thus the SNR showed the same improvement for the continuous <span class="hlt">filter</span>. A phasor diagram analysis and computer simulation have explained part of the <span class="hlt">optimization</span> procedure's success.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/doepatents/biblio/872975','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/doepatents/biblio/872975"><span id="translatedtitle">Rigid porous <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Chiang, Ta-Kuan (Morgantown, WV); Straub, Douglas L. (Morgantown, WV); Dennis, Richard A. (Morgantown, WV)</p> <p>2000-01-01</p> <p>The present invention involves a porous rigid <span class="hlt">filter</span> including a plurality of concentric filtration elements having internal flow passages and forming external flow passages there between. The present invention also involves a pressure vessel containing the <span class="hlt">filter</span> for the removal of particulates from high pressure particulate containing gases, and further involves a method for using the <span class="hlt">filter</span> to remove such particulates. The present <span class="hlt">filter</span> has the advantage of requiring fewer <span class="hlt">filter</span> elements due to the high surface area-to-volume ratio provided by the <span class="hlt">filter</span>, requires a reduced pressure vessel size, and exhibits enhanced mechanical design properties, improved cleaning properties, configuration options, modularity and ease of fabrication.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/458574','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/458574"><span id="translatedtitle"><span class="hlt">Filter</span> type gas sampler with <span class="hlt">filter</span> consolidation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Miley, H.S.; Thompson, R.C.; Hubbard, C.W.; Perkins, R.W.</p> <p>1997-03-25</p> <p>Disclosed is an apparatus for automatically consolidating a <span class="hlt">filter</span> or, more specifically, an apparatus for drawing a volume of gas through a plurality of sections of a <span class="hlt">filter</span>, where after the sections are subsequently combined for the purpose of simultaneously interrogating the sections to detect the presence of a contaminant. 5 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/870882','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/870882"><span id="translatedtitle"><span class="hlt">Filter</span> type gas sampler with <span class="hlt">filter</span> consolidation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Miley, Harry S.; Thompson, Robert C.; Hubbard, Charles W.; Perkins, Richard W.</p> <p>1997-01-01</p> <p>Disclosed is an apparatus for automatically consolidating a <span class="hlt">filter</span> or, more specifically, an apparatus for drawing a volume of gas through a plurality of sections of a <span class="hlt">filter</span>, whereafter the sections are subsequently combined for the purpose of simultaneously interrogating the sections to detect the presence of a contaminant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ITSP...61.3799R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ITSP...61.3799R"><span id="translatedtitle"><span class="hlt">Filter</span> Design With Secrecy Constraints: The MIMO Gaussian Wiretap Channel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reboredo, Hugo; Xavier, Joao; Rodrigues, Miguel R. D.</p> <p>2013-08-01</p> <p>This paper considers the problem of <span class="hlt">filter</span> design with secrecy constraints, where two legitimate parties (Alice and Bob) communicate in the presence of an eavesdropper (Eve), over a Gaussian multiple-input-multiple-output (MIMO) wiretap channel. This problem involves designing, subject to a power constraint, the transmit and the receive <span class="hlt">filters</span> which minimize the mean-squared error (MSE) between the legitimate parties whilst assuring that the eavesdropper MSE remains above a certain threshold. We consider a general MIMO Gaussian wiretap scenario, where the legitimate receiver uses a linear Zero-Forcing (ZF) <span class="hlt">filter</span> and the eavesdropper receiver uses either a ZF or an <span class="hlt">optimal</span> linear Wiener <span class="hlt">filter</span>. We provide a characterization of the <span class="hlt">optimal</span> <span class="hlt">filter</span> designs by demonstrating the convexity of the <span class="hlt">optimization</span> problems. We also provide generalizations of the <span class="hlt">filter</span> designs from the scenario where the channel state is known to all the parties to the scenario where there is uncertainty in the channel state. A set of numerical results illustrates the performance of the novel <span class="hlt">filter</span> designs, including the robustness to channel modeling errors. In particular, we assess the efficacy of the designs in guaranteeing not only a certain MSE level at the eavesdropper, but also in limiting the error probability at the eavesdropper. We also assess the impact of the <span class="hlt">filter</span> designs on the achievable secrecy rates. The penalty induced by the fact that the eavesdropper may use the <span class="hlt">optimal</span> non-linear receive <span class="hlt">filter</span> rather than the <span class="hlt">optimal</span> linear one is also explored in the paper.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20360832','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20360832"><span id="translatedtitle">Extended active optical lattice <span class="hlt">filters</span>: <span class="hlt">filter</span> synthesis.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dabkowski, Mieczyslaw; El Nagdi, Amr; Hunt, Louis R; Liu, Ke; Macfarlane, Duncan L; Ramakrishna, Viswanath</p> <p>2010-04-01</p> <p>In this paper, we study the synthesis of asymptotically stable <span class="hlt">filters</span> from a unit cell of a two-dimensional tunable lattice <span class="hlt">filter</span> architecture consisting of four four-port couplers and four waveguides containing semiconductor optical amplifiers. Upper bounds on the number of gains that will produce a <span class="hlt">filter</span> with a priori prescribed poles, for a specific system, are obtained. We also provide sufficient conditions on the reflection-type coefficients, characterizing each four-port coupler, which ensure that real-valued gains, taking values in [0,1], exist so that the <span class="hlt">filter</span> is asymptotically stable. Finally, we motivate the notion of a transmission zero of a <span class="hlt">filter</span> and discuss the possibility of simultaneously placing both poles and transmission zeros for the unit cell. PMID:20360832</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/2180633','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/2180633"><span id="translatedtitle">Adaptive <span class="hlt">filtering</span> in biological signal processing.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Iyer, V K; Ploysongsang, Y; Ramamoorthy, P A</p> <p>1990-01-01</p> <p>The high dependence of conventional <span class="hlt">optimal</span> <span class="hlt">filtering</span> methods on the a priori knowledge of the signal and noise statistics render them ineffective in dealing with signals whose statistics cannot be predetermined accurately. Adaptive <span class="hlt">filtering</span> methods offer a better alternative, since the a priori knowledge of statistics is less critical, real time processing is possible, and the computations are less expensive for this approach. Adaptive <span class="hlt">filtering</span> methods compute the <span class="hlt">filter</span> coefficients "on-line", converging to the <span class="hlt">optimal</span> values in the least-mean square (LMS) error sense. Adaptive <span class="hlt">filtering</span> is therefore apt for dealing with the "unknown" statistics situation and has been applied extensively in areas like communication, speech, radar, sonar, seismology, and biological signal processing and analysis for channel equalization, interference and echo canceling, line enhancement, signal detection, system identification, spectral analysis, beamforming, modeling, control, etc. In this review article adaptive <span class="hlt">filtering</span> in the context of biological signals is reviewed. An intuitive approach to the underlying theory of adaptive <span class="hlt">filters</span> and its applicability are presented. Applications of the principles in biological signal processing are discussed in a manner that brings out the key ideas involved. Current and potential future directions in adaptive biological signal processing are also discussed. PMID:2180633</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26518411','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26518411"><span id="translatedtitle">Robust depth <span class="hlt">filter</span> sizing for centrate clarification.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lutz, Herb; Chefer, Kate; Felo, Michael; Cacace, Benjamin; Hove, Sarah; Wang, Bin; Blanchard, Mark; Oulundsen, George; Piper, Rob; Zhao, Xiaoyang</p> <p>2015-11-01</p> <p>Cellulosic depth <span class="hlt">filters</span> embedded with diatomaceous earth are widely used to remove colloidal cell debris from centrate as a secondary clarification <span class="hlt">step</span> during the harvest of mammalian cell culture fluid. The high cost associated with process failure in a GMP (Good Manufacturing Practice) environment highlights the need for a robust process scale depth <span class="hlt">filter</span> sizing that allows for (1) stochastic batch-to-batch variations from <span class="hlt">filter</span> media, bioreactor feed and operation, and (2) systematic scaling differences in average performance between <span class="hlt">filter</span> sizes and formats. Matched-lot depth <span class="hlt">filter</span> media tested at the same conditions with consecutive batches of the same molecule were used to assess the sources and magnitudes of process variability. Depth <span class="hlt">filter</span> sizing safety factors of 1.2-1.6 allow a filtration process to compensate for random batch-to-batch process variations. Matched-lot depth <span class="hlt">filter</span> media in four different devices tested simultaneously at the same conditions was used with a common feed to assess scaling effects. All <span class="hlt">filter</span> devices showed <11% capacity difference and the Pod format devices showed no statistically different capacity differences. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:1542-1550, 2015. PMID:26518411</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/803674','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/803674"><span id="translatedtitle">HEPA <span class="hlt">Filter</span> Vulnerability Assessment</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>GUSTAVSON, R.D.</p> <p>2000-05-11</p> <p>This assessment of High Efficiency Particulate Air (HEPA) <span class="hlt">filter</span> vulnerability was requested by the USDOE Office of River Protection (ORP) to satisfy a DOE-HQ directive to evaluate the effect of <span class="hlt">filter</span> degradation on the facility authorization basis assumptions. Within the scope of this assessment are ventilation system HEPA <span class="hlt">filters</span> that are classified as Safety-Class (SC) or Safety-Significant (SS) components that perform an accident mitigation function. The objective of the assessment is to verify whether HEPA <span class="hlt">filters</span> that perform a safety function during an accident are likely to perform as intended to limit release of hazardous or radioactive materials, considering factors that could degrade the <span class="hlt">filters</span>. <span class="hlt">Filter</span> degradation factors considered include aging, wetting of <span class="hlt">filters</span>, exposure to high temperature, exposure to corrosive or reactive chemicals, and exposure to radiation. Screening and evaluation criteria were developed by a site-wide group of HVAC engineers and HEPA <span class="hlt">filter</span> experts from published empirical data. For River Protection Project (RPP) <span class="hlt">filters</span>, the only degradation factor that exceeded the screening threshold was for <span class="hlt">filter</span> aging. Subsequent evaluation of the effect of <span class="hlt">filter</span> aging on the <span class="hlt">filter</span> strength was conducted, and the results were compared with required performance to meet the conditions assumed in the RPP Authorization Basis (AB). It was found that the reduction in <span class="hlt">filter</span> strength due to aging does not affect the <span class="hlt">filter</span> performance requirements as specified in the AB. A portion of the HEPA <span class="hlt">filter</span> vulnerability assessment is being conducted by the ORP and is not part of the scope of this study. The ORP is conducting an assessment of the existing policies and programs relating to maintenance, testing, and change-out of HEPA <span class="hlt">filters</span> used for SC/SS service. This document presents the results of a HEPA <span class="hlt">filter</span> vulnerability assessment conducted for the River protection project as requested by the DOE Office of River Protection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6887066','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6887066"><span id="translatedtitle">Cordierite silicon nitride <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sawyer, J.; Buchan, B. ); Duiven, R.; Berger, M. ); Cleveland, J.; Ferri, J. )</p> <p>1992-02-01</p> <p>The objective of this project was to develop a silicon nitride based crossflow <span class="hlt">filter</span>. This report summarizes the findings and results of the project. The project was phased with Phase I consisting of <span class="hlt">filter</span> material development and crossflow <span class="hlt">filter</span> design. Phase II involved <span class="hlt">filter</span> manufacturing, <span class="hlt">filter</span> testing under simulated conditions and reporting the results. In Phase I, Cordierite Silicon Nitride (CSN) was developed and tested for permeability and strength. Target values for each of these parameters were established early in the program. The values were met by the material development effort in Phase I. The crossflow <span class="hlt">filter</span> design effort proceeded by developing a macroscopic design based on required surface area and estimated stresses. Then the thermal and pressure stresses were estimated using finite element analysis. In Phase II of this program, the <span class="hlt">filter</span> manufacturing technique was developed, and the manufactured <span class="hlt">filters</span> were tested. The technique developed involved press-bonding extruded tiles to form a <span class="hlt">filter</span>, producing a monolithic <span class="hlt">filter</span> after sintering. <span class="hlt">Filters</span> manufactured using this technique were tested at Acurex and at the Westinghouse Science and Technology Center. The <span class="hlt">filters</span> did not delaminate during testing and operated and high collection efficiency and good cleanability. Further development in areas of sintering and <span class="hlt">filter</span> design is recommended.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/835852','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/835852"><span id="translatedtitle">Novel Backup <span class="hlt">Filter</span> Device for Candle <span class="hlt">Filters</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bishop, B.; Goldsmith, R.; Dunham, G.; Henderson, A.</p> <p>2002-09-18</p> <p>The currently preferred means of particulate removal from process or combustion gas generated by advanced coal-based power production processes is filtration with candle <span class="hlt">filters</span>. However, candle <span class="hlt">filters</span> have not shown the requisite reliability to be commercially viable for hot gas clean up for either integrated gasifier combined cycle (IGCC) or pressurized fluid bed combustion (PFBC) processes. Even a single candle failure can lead to unacceptable ash breakthrough, which can result in (a) damage to highly sensitive and expensive downstream equipment, (b) unacceptably low system on-stream factor, and (c) unplanned outages. The U.S. Department of Energy (DOE) has recognized the need to have fail-safe devices installed within or downstream from candle <span class="hlt">filters</span>. In addition to CeraMem, DOE has contracted with Siemens-Westinghouse, the Energy & Environmental Research Center (EERC) at the University of North Dakota, and the Southern Research Institute (SRI) to develop novel fail-safe devices. Siemens-Westinghouse is evaluating honeycomb-based <span class="hlt">filter</span> devices on the clean-side of the candle <span class="hlt">filter</span> that can operate up to 870 C. The EERC is developing a highly porous ceramic disk with a sticky yet temperature-stable coating that will trap dust in the event of <span class="hlt">filter</span> failure. SRI is developing the Full-Flow Mechanical Safeguard Device that provides a positive seal for the candle <span class="hlt">filter</span>. Operation of the SRI device is triggered by the higher-than-normal gas flow from a broken candle. The CeraMem approach is similar to that of Siemens-Westinghouse and involves the development of honeycomb-based <span class="hlt">filters</span> that operate on the clean-side of a candle <span class="hlt">filter</span>. The overall objective of this project is to fabricate and test silicon carbide-based honeycomb failsafe <span class="hlt">filters</span> for protection of downstream equipment in advanced coal conversion processes. The fail-safe <span class="hlt">filter</span>, installed directly downstream of a candle <span class="hlt">filter</span>, should have the capability for stopping essentially all particulate bypassing a broken or leaking candle while having a low enough pressure drop to allow the candle to be backpulse-regenerated. Forward-flow pressure drop should increase by no more than 20% because of incorporation of the fail-safe <span class="hlt">filter</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986STIN...8722869K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986STIN...8722869K"><span id="translatedtitle">HEPA <span class="hlt">filter</span> monitoring program</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kirchner, K. N.; Johnson, C. M.; Aiken, W. F.; Lucerna, J. J.; Barnett, R. L.; Jensen, R. T.</p> <p>1986-07-01</p> <p>The testing and replacement of HEPA <span class="hlt">filters</span>, widely used in the nuclear industry to purify process air, are costly and labor-intensive. Current methods of testing <span class="hlt">filter</span> performance, such as differential pressure measurement and scanning air monitoring, allow determination of overall <span class="hlt">filter</span> performance but preclude detection of incipient <span class="hlt">filter</span> failure such as small holes in the <span class="hlt">filters</span>. Using current technology, a continual in-situ monitoring system was designed which provides three major improvements over current methods of <span class="hlt">filter</span> testing and replacement. The improvements include: cost savings by reducing the number of intact <span class="hlt">filters</span> which are currently being replaced unnecessarily; more accurate and quantitative measurement of <span class="hlt">filter</span> performance; and reduced personnel exposure to a radioactive environment by automatically performing most testing operations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1177887','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1177887"><span id="translatedtitle">MST <span class="hlt">Filterability</span> Tests</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Poirier, M. R.; Burket, P. R.; Duignan, M. R.</p> <p>2015-03-12</p> <p>The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). The low <span class="hlt">filter</span> flux through the ARP has limited the rate at which radioactive liquid waste can be treated. Recent <span class="hlt">filter</span> flux has averaged approximately 5 gallons per minute (gpm). Salt Batch 6 has had a lower processing rate and required frequent <span class="hlt">filter</span> cleaning. Savannah River Remediation (SRR) has a desire to understand the causes of the low <span class="hlt">filter</span> flux and to increase ARP/MCU throughput. In addition, at the time the testing started, SRR was assessing the impact of replacing the 0.1 micron <span class="hlt">filter</span> with a 0.5 micron <span class="hlt">filter</span>. This report describes testing of MST <span class="hlt">filterability</span> to investigate the impact of <span class="hlt">filter</span> pore size and MST particle size on <span class="hlt">filter</span> flux and testing of <span class="hlt">filter</span> enhancers to attempt to increase <span class="hlt">filter</span> flux. The authors constructed a laboratory-scale crossflow <span class="hlt">filter</span> apparatus with two crossflow <span class="hlt">filters</span> operating in parallel. One <span class="hlt">filter</span> was a 0.1 micron Mott sintered SS <span class="hlt">filter</span> and the other was a 0.5 micron Mott sintered SS <span class="hlt">filter</span>. The authors also constructed a dead-end filtration apparatus to conduct screening tests with potential <span class="hlt">filter</span> aids and body feeds, referred to as <span class="hlt">filter</span> enhancers. The original baseline for ARP was 5.6 M sodium salt solution with a free hydroxide concentration of approximately 1.7 M.3 ARP has been operating with a sodium concentration of approximately 6.4 M and a free hydroxide concentration of approximately 2.5 M. SRNL conducted tests varying the concentration of sodium and free hydroxide to determine whether those changes had a significant effect on <span class="hlt">filter</span> flux. The feed slurries for the MST <span class="hlt">filterability</span> tests were composed of simple salts (NaOH, NaNO<sub>2</sub>, and NaNO<sub>3</sub>) and MST (0.2 – 4.8 g/L). The feed slurry for the <span class="hlt">filter</span> enhancer tests contained simulated salt batch 6 supernate, MST, and <span class="hlt">filter</span> enhancers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730011529','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730011529"><span id="translatedtitle">Survey of digital <span class="hlt">filtering</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nagle, H. T., Jr.</p> <p>1972-01-01</p> <p>A three part survey is made of the state-of-the-art in digital <span class="hlt">filtering</span>. Part one presents background material including sampled data transformations and the discrete Fourier transform. Part two, digital <span class="hlt">filter</span> theory, gives an in-depth coverage of <span class="hlt">filter</span> categories, transfer function synthesis, quantization and other nonlinear errors, <span class="hlt">filter</span> structures and computer aided design. Part three presents hardware mechanization techniques. Implementations by general purpose, mini-, and special-purpose computers are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983vswc.rept.....D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983vswc.rept.....D"><span id="translatedtitle">An active <span class="hlt">filter</span> primer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Delagrange, A. D.</p> <p>1983-02-01</p> <p>In the past few years active <span class="hlt">filters</span> have become very popular. This report explains why, and explains what active <span class="hlt">filters</span> can (and can't) do. It gives the basics of active <span class="hlt">filter</span> design, both theory and practice. It can be used as a handbook to build working active <span class="hlt">filters</span> of the most common types. This report is an update of the original issued in 1979.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/doepatents/biblio/985719','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/doepatents/biblio/985719"><span id="translatedtitle"><span class="hlt">Filter</span> service system</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Sellers, Cheryl L. (Peoria, IL); Nordyke, Daniel S. (Arlington Heights, IL); Crandell, Richard A. (Morton, IL); Tomlins, Gregory (Peoria, IL); Fei, Dong (Peoria, IL); Panov, Alexander (Dunlap, IL); Lane, William H. (Chillicothe, IL); Habeger, Craig F. (Chillicothe, IL)</p> <p>2008-12-09</p> <p>According to an exemplary embodiment of the present disclosure, a system for removing matter from a <span class="hlt">filtering</span> device includes a gas pressurization assembly. An element of the assembly is removably attachable to a first orifice of the <span class="hlt">filtering</span> device. The system also includes a vacuum source fluidly connected to a second orifice of the <span class="hlt">filtering</span> device.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060009010','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060009010"><span id="translatedtitle">Practical Active Capacitor <span class="hlt">Filter</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shuler, Robert L., Jr. (Inventor)</p> <p>2005-01-01</p> <p>A method and apparatus is described that <span class="hlt">filters</span> an electrical signal. The <span class="hlt">filtering</span> uses a capacitor multiplier circuit where the capacitor multiplier circuit uses at least one amplifier circuit and at least one capacitor. A <span class="hlt">filtered</span> electrical signal results from a direct connection from an output of the at least one amplifier circuit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/875123','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/875123"><span id="translatedtitle">HEPA <span class="hlt">filter</span> encapsulation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Gates-Anderson, Dianne D.; Kidd, Scott D.; Bowers, John S.; Attebery, Ronald W.</p> <p>2003-01-01</p> <p>A low viscosity resin is delivered into a spent HEPA <span class="hlt">filter</span> or other waste. The resin is introduced into the <span class="hlt">filter</span> or other waste using a vacuum to assist in the mass transfer of the resin through the <span class="hlt">filter</span> media or other waste.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6008992','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/6008992"><span id="translatedtitle"><span class="hlt">Stepping</span> motor controller</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Bourret, S.C.; Swansen, J.E.</p> <p>1982-07-02</p> <p>A <span class="hlt">stepping</span> motor is microprocessor controlled by digital circuitry which monitors the output of a shaft encoder adjustably secured to the <span class="hlt">stepping</span> motor and generates a subsequent <span class="hlt">stepping</span> pulse only after the preceding <span class="hlt">step</span> has occurred and a fixed delay has expired. The fixed delay is variable on a real-time basis to provide for smooth and controlled deceleration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/865125','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/865125"><span id="translatedtitle"><span class="hlt">Stepping</span> motor controller</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Bourret, Steven C.; Swansen, James E.</p> <p>1984-01-01</p> <p>A <span class="hlt">stepping</span> motor is microprocessingly controlled by digital circuitry which monitors the output of a shaft encoder adjustably secured to the <span class="hlt">stepping</span> motor and generates a subsequent <span class="hlt">stepping</span> pulse only after the preceding <span class="hlt">step</span> has occurred and a fixed delay has expired. The fixed delay is variable on a real-time basis to provide for smooth and controlled deceleration.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=kinetic+AND+polymerization&id=EJ256943','ERIC'); return false;" href="http://eric.ed.gov/?q=kinetic+AND+polymerization&id=EJ256943"><span id="translatedtitle"><span class="hlt">Step</span>-Growth Polymerization.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Stille, J. K.</p> <p>1981-01-01</p> <p>Following a comparison of chain-growth and <span class="hlt">step</span>-growth polymerization, focuses on the latter process by describing requirements for high molecular weight, <span class="hlt">step</span>-growth polymerization kinetics, synthesis and molecular weight distribution of some linear <span class="hlt">step</span>-growth polymers, and three-dimensional network <span class="hlt">step</span>-growth polymers. (JN)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6321168','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6321168"><span id="translatedtitle">Reduction of turbidity by a coal-aluminium <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Collins, A.G.; Johnson, R.L.</p> <p>1985-06-01</p> <p>Coal-aluminium granular <span class="hlt">filters</span> successfully reduce turbidity in low-alkalinity raw waters to less than 1.0 ntu, without a coagulation <span class="hlt">step</span> or external coagulant aids. Data from experiments conducted with control and pilot-plant <span class="hlt">filters</span> show the viability of the process and indicate the turbidity and retention mechanisms. Operational characteristics of the process are similar to those of a conventional <span class="hlt">filter</span>. The costs of the coal-aluminium process compare favourably with those of traditional treatment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730014357','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730014357"><span id="translatedtitle">Regenerative particulate <span class="hlt">filter</span> development</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Descamp, V. A.; Boex, M. W.; Hussey, M. W.; Larson, T. P.</p> <p>1972-01-01</p> <p>Development, design, and fabrication of a prototype <span class="hlt">filter</span> regeneration unit for regenerating clean fluid particle <span class="hlt">filter</span> elements by using a backflush/jet impingement technique are reported. Development tests were also conducted on a vortex particle separator designed for use in zero gravity environment. A maintainable <span class="hlt">filter</span> was designed, fabricated and tested that allows <span class="hlt">filter</span> element replacement without any leakage or spillage of system fluid. Also described are spacecraft fluid system design and <span class="hlt">filter</span> maintenance techniques with respect to inflight maintenance for the space shuttle and space station.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950010874','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950010874"><span id="translatedtitle">Low-complexity wavelet <span class="hlt">filter</span> design for image compression</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Majani, E.</p> <p>1994-01-01</p> <p>Image compression algorithms based on the wavelet transform are an increasingly attractive and flexible alternative to other algorithms based on block orthogonal transforms. While the design of orthogonal wavelet <span class="hlt">filters</span> has been studied in significant depth, the design of nonorthogonal wavelet <span class="hlt">filters</span>, such as linear-phase (LP) <span class="hlt">filters</span>, has not yet reached that point. Of particular interest are wavelet transforms with low complexity at the encoder. In this article, we present known and new parameterizations of the two families of LP perfect reconstruction (PR) <span class="hlt">filters</span>. The first family is that of all PR LP <span class="hlt">filters</span> with finite impulse response (FIR), with equal complexity at the encoder and decoder. The second family is one of LP PR <span class="hlt">filters</span>, which are FIR at the encoder and infinite impulse response (IIR) at the decoder, i.e., with controllable encoder complexity. These parameterizations are used to <span class="hlt">optimize</span> the subband/wavelet transform coding gain, as defined for nonorthogonal wavelet transforms. <span class="hlt">Optimal</span> LP wavelet <span class="hlt">filters</span> are given for low levels of encoder complexity, as well as their corresponding integer approximations, to allow for applications limited to using integer arithmetic. These <span class="hlt">optimal</span> LP <span class="hlt">filters</span> yield larger coding gains than orthogonal <span class="hlt">filters</span> with an equivalent complexity. The parameterizations described in this article can be used for the <span class="hlt">optimization</span> of any other appropriate objective function.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110014886','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110014886"><span id="translatedtitle">Software Would Largely Automate Design of Kalman <span class="hlt">Filter</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chuang, Jason C. H.; Negast, William J.</p> <p>2005-01-01</p> <p>Embedded Navigation <span class="hlt">Filter</span> Automatic Designer (ENFAD) is a computer program being developed to automate the most difficult tasks in designing embedded software to implement a Kalman <span class="hlt">filter</span> in a navigation system. The most difficult tasks are selection of error states of the <span class="hlt">filter</span> and tuning of <span class="hlt">filter</span> parameters, which are timeconsuming trial-and-error tasks that require expertise and rarely yield optimum results. An optimum selection of error states and <span class="hlt">filter</span> parameters depends on navigation-sensor and vehicle characteristics, and on <span class="hlt">filter</span> processing time. ENFAD would include a simulation module that would incorporate all possible error states with respect to a given set of vehicle and sensor characteristics. The first of two iterative <span class="hlt">optimization</span> loops would vary the selection of error states until the best <span class="hlt">filter</span> performance was achieved in Monte Carlo simulations. For a fixed selection of error states, the second loop would vary the <span class="hlt">filter</span> parameter values until an <span class="hlt">optimal</span> performance value was obtained. Design constraints would be satisfied in the <span class="hlt">optimization</span> loops. Users would supply vehicle and sensor test data that would be used to refine digital models in ENFAD. <span class="hlt">Filter</span> processing time and <span class="hlt">filter</span> accuracy would be computed by ENFAD.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8783E..18W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8783E..18W"><span id="translatedtitle">Gabor <span class="hlt">filter</span> based fingerprint image enhancement</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Jin-Xiang</p> <p>2013-03-01</p> <p>Fingerprint recognition technology has become the most reliable biometric technology due to its uniqueness and invariance, which has been most convenient and most reliable technique for personal authentication. The development of Automated Fingerprint Identification System is an urgent need for modern information security. Meanwhile, fingerprint preprocessing algorithm of fingerprint recognition technology has played an important part in Automatic Fingerprint Identification System. This article introduces the general <span class="hlt">steps</span> in the fingerprint recognition technology, namely the image input, preprocessing, feature recognition, and fingerprint image enhancement. As the key to fingerprint identification technology, fingerprint image enhancement affects the accuracy of the system. It focuses on the characteristics of the fingerprint image, Gabor <span class="hlt">filters</span> algorithm for fingerprint image enhancement, the theoretical basis of Gabor <span class="hlt">filters</span>, and demonstration of the <span class="hlt">filter</span>. The enhancement algorithm for fingerprint image is in the windows XP platform with matlab.65 as a development tool for the demonstration. The result shows that the Gabor <span class="hlt">filter</span> is effective in fingerprint image enhancement technology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MeScT..27b5001Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MeScT..27b5001Z"><span id="translatedtitle">An adaptive demodulation approach for bearing fault detection based on adaptive wavelet <span class="hlt">filtering</span> and spectral subtraction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Yan; Tang, Baoping; Liu, Ziran; Chen, Rengxiang</p> <p>2016-02-01</p> <p>Fault diagnosis of rolling element bearings is important for improving mechanical system reliability and performance. Vibration signals contain a wealth of complex information useful for state monitoring and fault diagnosis. However, any fault-related impulses in the original signal are often severely tainted by various noises and the interfering vibrations caused by other machine elements. Narrow-band amplitude demodulation has been an effective technique to detect bearing faults by identifying bearing fault characteristic frequencies. To achieve this, the key <span class="hlt">step</span> is to remove the corrupting noise and interference, and to enhance the weak signatures of the bearing fault. In this paper, a new method based on adaptive wavelet <span class="hlt">filtering</span> and spectral subtraction is proposed for fault diagnosis in bearings. First, to eliminate the frequency associated with interfering vibrations, the vibration signal is bandpass <span class="hlt">filtered</span> with a Morlet wavelet <span class="hlt">filter</span> whose parameters (i.e. center frequency and bandwidth) are selected in separate <span class="hlt">steps</span>. An alternative and efficient method of determining the center frequency is proposed that utilizes the statistical information contained in the production functions (PFs). The bandwidth parameter is <span class="hlt">optimized</span> using a local ‘greedy’ scheme along with Shannon wavelet entropy criterion. Then, to further reduce the residual in-band noise in the <span class="hlt">filtered</span> signal, a spectral subtraction procedure is elaborated after wavelet <span class="hlt">filtering</span>. Instead of resorting to a reference signal as in the majority of papers in the literature, the new method estimates the power spectral density of the in-band noise from the associated PF. The effectiveness of the proposed method is validated using simulated data, test rig data, and vibration data recorded from the transmission system of a helicopter. The experimental results and comparisons with other methods indicate that the proposed method is an effective approach to detecting the fault-related impulses hidden in vibration signals and performs well for bearing fault diagnosis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SPIE.8285E..6PS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SPIE.8285E..6PS"><span id="translatedtitle">B-spline design of digital FIR <span class="hlt">filter</span> using evolutionary computation techniques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Swain, Manorama; Panda, Rutuparna</p> <p>2011-10-01</p> <p>In the forth coming era, digital <span class="hlt">filters</span> are becoming a true replacement for the analog <span class="hlt">filter</span> designs. Here in this paper we examine a design method for FIR <span class="hlt">filter</span> using global search <span class="hlt">optimization</span> techniques known as Evolutionary computation via genetic algorithm and bacterial foraging, where the <span class="hlt">filter</span> design considered as an <span class="hlt">optimization</span> problem. In this paper, an effort is made to design the maximally flat <span class="hlt">filters</span> using generalized B-spline window. The key to our success is the fact that the bandwidth of the filer response can be modified by changing tuning parameters incorporated well within the B-spline function. This is an <span class="hlt">optimization</span> problem. Direct approach has been deployed to design B-spline window based FIR digital <span class="hlt">filters</span>. Four parameters (order, width, length and tuning parameter) have been <span class="hlt">optimized</span> by using GA and EBFS. It is observed that the desired response can be obtained with lower order FIR <span class="hlt">filters</span> with <span class="hlt">optimal</span> width and tuning parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120010617','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120010617"><span id="translatedtitle">Compact planar microwave blocking <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>U-Yen, Kongpop (Inventor); Wollack, Edward J. (Inventor)</p> <p>2012-01-01</p> <p>A compact planar microwave blocking <span class="hlt">filter</span> includes a dielectric substrate and a plurality of <span class="hlt">filter</span> unit elements disposed on the substrate. The <span class="hlt">filter</span> unit elements are interconnected in a symmetrical series cascade with <span class="hlt">filter</span> unit elements being organized in the series based on physical size. In the <span class="hlt">filter</span>, a first <span class="hlt">filter</span> unit element of the plurality of <span class="hlt">filter</span> unit elements includes a low impedance open-ended line configured to reduce the shunt capacitance of the <span class="hlt">filter</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910018548','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910018548"><span id="translatedtitle">A superior edge preserving <span class="hlt">filter</span> with a systematic analysis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Holladay, Kenneth W.; Rickman, Doug</p> <p>1991-01-01</p> <p>A new, adaptive, edge preserving <span class="hlt">filter</span> for use in image processing is presented. It had superior performance when compared to other <span class="hlt">filters</span>. Termed the contiguous K-average, it aggregates pixels by examining all pixels contiguous to an existing cluster and adding the pixel closest to the mean of the existing cluster. The process is iterated until K pixels were accumulated. Rather than simply compare the visual results of processing with this operator to other <span class="hlt">filters</span>, some approaches were developed which allow quantitative evaluation of how well and <span class="hlt">filter</span> performs. Particular attention is given to the standard deviation of noise within a feature and the stability of imagery under iterative processing. Demonstrations illustrate the performance of several <span class="hlt">filters</span> to discriminate against noise and retain edges, the effect of <span class="hlt">filtering</span> as a preprocessing <span class="hlt">step</span>, and the utility of the contiguous K-average <span class="hlt">filter</span> when used with remote sensing data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/869376','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/869376"><span id="translatedtitle"><span class="hlt">Stepped</span> frequency ground penetrating radar</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Vadnais, Kenneth G.; Bashforth, Michael B.; Lewallen, Tricia S.; Nammath, Sharyn R.</p> <p>1994-01-01</p> <p>A <span class="hlt">stepped</span> frequency ground penetrating radar system is described comprising an RF signal generating section capable of producing <span class="hlt">stepped</span> frequency signals in spaced and equal increments of time and frequency over a preselected bandwidth which serves as a common RF signal source for both a transmit portion and a receive portion of the system. In the transmit portion of the system the signal is processed into in-phase and quadrature signals which are then amplified and then transmitted toward a target. The reflected signals from the target are then received by a receive antenna and mixed with a reference signal from the common RF signal source in a mixer whose output is then fed through a low pass <span class="hlt">filter</span>. The DC output, after amplification and demodulation, is digitized and converted into a frequency domain signal by a Fast Fourier Transform. A plot of the frequency domain signals from all of the <span class="hlt">stepped</span> frequencies broadcast toward and received from the target yields information concerning the range (distance) and cross section (size) of the target.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120007101','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120007101"><span id="translatedtitle">Application of an <span class="hlt">Optimal</span> Tuner Selection Approach for On-Board Self-Tuning Engine Models</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Simon, Donald L.; Armstrong, Jeffrey B.; Garg, Sanjay</p> <p>2012-01-01</p> <p>An enhanced design methodology for minimizing the error in on-line Kalman <span class="hlt">filter</span>-based aircraft engine performance estimation applications is presented in this paper. It specific-ally addresses the under-determined estimation problem, in which there are more unknown parameters than available sensor measurements. This work builds upon an existing technique for systematically selecting a model tuning parameter vector of appropriate dimension to enable estimation by a Kalman <span class="hlt">filter</span>, while minimizing the estimation error in the parameters of interest. While the existing technique was <span class="hlt">optimized</span> for open-loop engine operation at a fixed design point, in this paper an alternative formulation is presented that enables the technique to be <span class="hlt">optimized</span> for an engine operating under closed-loop control throughout the flight envelope. The theoretical Kalman <span class="hlt">filter</span> mean squared estimation error at a steady-state closed-loop operating point is derived, and the tuner selection approach applied to minimize this error is discussed. A technique for constructing a globally <span class="hlt">optimal</span> tuning parameter vector, which enables full-envelope application of the technology, is also presented, along with design <span class="hlt">steps</span> for adjusting the dynamic response of the Kalman <span class="hlt">filter</span> state estimates. Results from the application of the technique to linear and nonlinear aircraft engine simulations are presented and compared to the conventional approach of tuner selection. The new methodology is shown to yield a significant improvement in on-line Kalman <span class="hlt">filter</span> estimation accuracy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9138E..0OR','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9138E..0OR"><span id="translatedtitle">Precise dispersion equations of absorbing <span class="hlt">filter</span> glasses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reichel, S.; Biertümpfel, Ralf</p> <p>2014-05-01</p> <p>The refractive indices versus wavelength of optical transparent glasses are measured at a few wavelengths only. In order to calculate the refractive index at any wavelength, a so-called Sellmeier series is used as an approximation of the wavelength dependent refractive index. Such a Sellmeier representation assumes an absorbing free (= loss less) material. In optical transparent glasses this assumption is valid since the absorption of such transparent glasses is very low. However, optical <span class="hlt">filter</span> glasses have often a rather high absorbance in certain regions of the spectrum. The exact description of the wavelength dependent function of the refractive index is essential for an <span class="hlt">optimized</span> design for sophisticated optical applications. Digital cameras use an IR cut <span class="hlt">filter</span> to ensure good color rendition and image quality. In order to reduce ghost images by reflections and to be nearly angle independent absorbing <span class="hlt">filter</span> glass is used, e.g. blue glass BG60 from SCHOTT. Nowadays digital cameras improve their performance and so the IR cut <span class="hlt">filter</span> needs to be improved and thus the accurate knowledge of the refractive index (dispersion) of the used glasses must be known. But absorbing <span class="hlt">filter</span> glass is not loss less as needed for a Sellmeier representation. In addition it is very difficult to measure it in the absorption region of the <span class="hlt">filter</span> glass. We have focused a lot of effort on measuring the refractive index at specific wavelength for absorbing <span class="hlt">filter</span> glass - even in the absorption region. It will be described how to do such a measurement. In addition we estimate the use of a Sellmeier representation for <span class="hlt">filter</span> glasses. It turns out that in most cases a Sellmeier representation can be used even for absorbing <span class="hlt">filter</span> glasses. Finally Sellmeier coefficients for the approximation of the refractive index will be given for different <span class="hlt">filter</span> glasses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730011769','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730011769"><span id="translatedtitle">Optical <span class="hlt">filtering</span> for star trackers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, R. E.</p> <p>1973-01-01</p> <p>The <span class="hlt">optimization</span> of optical <span class="hlt">filtering</span> was investigated for tracking faint stars, down to the fifth magnitude. The effective wavelength and bandwidth for tracking pre-selected guide stars are discussed along with the results of an all-electronic tracker with a star tracking photomultiplier, which was tested with a simulated second magnitude star. Tables which give the sum of zodiacal light and galactic background light over the entire sky for intervals of five degrees in declination, and twenty minutes in right ascension are included.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/20726883','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/20726883"><span id="translatedtitle">2-<span class="hlt">Step</span> IMAT and 2-<span class="hlt">Step</span> IMRT in three dimensions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bratengeier, Klaus</p> <p>2005-12-15</p> <p>In two dimensions, 2-<span class="hlt">Step</span> Intensity Modulated Arc Therapy (2-<span class="hlt">Step</span> IMAT) and 2-<span class="hlt">Step</span> Intensity Modulated Radiation Therapy (IMRT) were shown to be powerful methods for the <span class="hlt">optimization</span> of plans with organs at risk (OAR) (partially) surrounded by a target volume (PTV). In three dimensions, some additional boundary conditions have to be considered to establish 2-<span class="hlt">Step</span> IMAT as an <span class="hlt">optimization</span> method. A further aim was to create rules for ad hoc adaptations of an IMRT plan to a daily changing PTV-OAR constellation. As a test model, a cylindrically symmetric PTV-OAR combination was used. The centrally placed OAR can adapt arbitrary diameters with different gap widths toward the PTV. Along the rotation axis the OAR diameter can vary, the OAR can even vanish at some axis positions, leaving a circular PTV. The width and weight of the second segment were the free parameters to <span class="hlt">optimize</span>. The objective function f to minimize was the root of the integral of the squared difference of the dose in the target volume and a reference dose. For the problem, two local minima exist. Therefore, as a secondary criteria, the magnitude of hot and cold spots were taken into account. As a result, the solution with a larger segment width was recommended. From plane to plane for varying radii of PTV and OAR and for different gaps between them, different sets of weights and widths were <span class="hlt">optimal</span>. Because only one weight for one segment shall be used for all planes (respectively leaf pairs), a strategy for complex three-dimensional (3-D) cases was established to choose a global weight. In a second <span class="hlt">step</span>, a suitable segment width was chosen, minimizing f for this global weight. The concept was demonstrated in a planning study for a cylindrically symmetric example with a large range of different radii of an OAR along the patient axis. The method is discussed for some classes of tumor/organ at risk combinations. Noncylindrically symmetric cases were treated exemplarily. The product of width and weight of the additional segment as well as the integral across the segment profile was demonstrated to be an important value. This product was up to a factor of 3 larger than in the 2-D case. Even in three dimensions, the <span class="hlt">optimized</span> 2-<span class="hlt">Step</span> IMAT increased the homogeneity of the dose distribution in the PTV profoundly. Rules for adaptation to varying target-OAR combinations were deduced. It can be concluded that 2-<span class="hlt">Step</span> IMAT and 2-<span class="hlt">Step</span> IMRT are also applicable in three dimensions. In the majority of cases, weights between 0.5 and 2 will occur for the additional segment. The width-weight product of the second segment is always smaller than the normalized radius of the OAR. The width-weight product of the additional segment is strictly connected to the relevant diameter of the organ at risk and the target volume. The derived formulas can be helpful to adapt an IMRT plan to altering target shapes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JARS....9.5990S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JARS....9.5990S"><span id="translatedtitle">Impact of atmospheric correction and image <span class="hlt">filtering</span> on hyperspectral classification of tree species using support vector machine</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shahriari Nia, Morteza; Wang, Daisy Zhe; Bohlman, Stephanie Ann; Gader, Paul; Graves, Sarah J.; Petrovic, Milenko</p> <p>2015-01-01</p> <p>Hyperspectral images can be used to identify savannah tree species at the landscape scale, which is a key <span class="hlt">step</span> in measuring biomass and carbon, and tracking changes in species distributions, including invasive species, in these ecosystems. Before automated species mapping can be performed, image processing and atmospheric correction is often performed, which can potentially affect the performance of classification algorithms. We determine how three processing and correction techniques (atmospheric correction, Gaussian <span class="hlt">filters</span>, and shade/green vegetation <span class="hlt">filters</span>) affect the prediction accuracy of classification of tree species at pixel level from airborne visible/infrared imaging spectrometer imagery of longleaf pine savanna in Central Florida, United States. Species classification using fast line-of-sight atmospheric analysis of spectral hypercubes (FLAASH) atmospheric correction outperformed ATCOR in the majority of cases. Green vegetation (normalized difference vegetation index) and shade (near-infrared) <span class="hlt">filters</span> did not increase classification accuracy when applied to large and continuous patches of specific species. Finally, applying a Gaussian <span class="hlt">filter</span> reduces interband noise and increases species classification accuracy. Using the <span class="hlt">optimal</span> preprocessing <span class="hlt">steps</span>, our classification accuracy of six species classes is about 75%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6307355','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6307355"><span id="translatedtitle"><span class="hlt">Filtering</span> separators having <span class="hlt">filter</span> cleaning apparatus</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Margraf, A.</p> <p>1984-08-28</p> <p>This invention relates to <span class="hlt">filtering</span> separators of the kind having a housing which is subdivided by a partition, provided with parallel rows of holes or slots, into a dust-laden gas space for receiving <span class="hlt">filter</span> elements positioned in parallel rows and being impinged upon by dust-laden gas from the outside towards the inside, and a clean gas space. In addition, the housing is provided with a chamber for cleansing the <span class="hlt">filter</span> element surfaces of a row by counterflow action while covering at the same time the partition holes or slots leading to the adjacent rows of <span class="hlt">filter</span> elements. The chamber is arranged for the supply of compressed air to at least one injector arranged to feed compressed air and secondary air to the row of <span class="hlt">filter</span> elements to be cleansed. The chamber is also reciprocatingly displaceable along the partition in periodic and intermittent manner. According to the invention, a surface of the chamber facing towards the partition covers at least two of the rows of holes or slots of the partition, and the chamber is closed upon itself with respect to the clean gas space, and is connected to a compressed air reservoir via a distributor pipe and a control valve. At least one of the rows of holes or slots of the partition and the respective row of <span class="hlt">filter</span> elements in flow communication therewith are in flow communication with the discharge side of at least one injector acted upon with compressed air. At least one other row of the rows of holes or slots of the partition and the respective row of <span class="hlt">filter</span> elements is in flow communication with the suction side of the injector.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=recovery&pg=7&id=EJ866872','ERIC'); return false;" href="http://eric.ed.gov/?q=recovery&pg=7&id=EJ866872"><span id="translatedtitle"><span class="hlt">Step</span> by <span class="hlt">Step</span>: Avoiding Spiritual Bypass in 12-<span class="hlt">Step</span> Work</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Cashwell, Craig S.; Clarke, Philip B.; Graves, Elizabeth G.</p> <p>2009-01-01</p> <p>With spirituality as a cornerstone, 12-<span class="hlt">step</span> groups serve a vital role in the recovery community. It is important for counselors to be mindful, however, of the potential for clients to be in spiritual bypass, which likely will undermine the recovery process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19965002','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19965002"><span id="translatedtitle">Mammogram enhancement using alpha weighted quadratic <span class="hlt">filter</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhou, Yicong; Panetta, Karen; Agaian, Sos</p> <p>2009-01-01</p> <p>Mammograms are widely used to detect breast cancer in women. The quality of the image may suffer from poor resolution or low contrast due to the limitations of the X-ray hardware systems. Image enhancement is a powerful tool to improve the visual quality of mammograms. This paper introduces a new powerful nonlinear <span class="hlt">filter</span> called the alpha weighted quadratic <span class="hlt">filter</span> for mammogram enhancement. The user has the flexibility to design the <span class="hlt">filter</span> by selecting all of the parameters manually or using an existing quantitative measure to select the <span class="hlt">optimal</span> enhancement parameters. Computer simulations show that excellent enhancement results can be obtained with no apriori knowledge of the mammogram contents. The <span class="hlt">filter</span> can also be used for automatic segmentation. PMID:19965002</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970002920','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970002920"><span id="translatedtitle">Canonical Signed Digit Study. Part 2; FIR Digital <span class="hlt">Filter</span> Simulation Results</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kim, Heechul</p> <p>1996-01-01</p> <p>Finite Impulse Response digital <span class="hlt">filter</span> using Canonical Signed-Digit (CSD) number representation for the coefficients has been studied and its computer simulation results are presented here. Minimum Mean Square Error (MMSE) criterion is employed to <span class="hlt">optimize</span> <span class="hlt">filter</span> coefficients into the corresponding CSD numbers. To further improve coefficients <span class="hlt">optimization</span> process, an extra non-zero bit is added for any <span class="hlt">filter</span> coefficients exceeding 1/2. This technique improves frequency response of <span class="hlt">filter</span> without increasing <span class="hlt">filter</span> complexity almost at all. The simulation results show outstanding performance in bit-error-rate (BER) curve for all CSD implemented digital <span class="hlt">filters</span> included in this presentation material.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998JASS...15..175K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998JASS...15..175K"><span id="translatedtitle">Efficient Speckle Noise <span class="hlt">Filtering</span> of SAR Images</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Byoungsoo; Choi, Kyu-Hong; Won, Joong-Sun</p> <p>1998-06-01</p> <p>Any classification process using SAR images presupposes the reduction of multiplicative speckle noise, since the variations caused by speckle make it extremely difficult to distinguish between neighboring classes within the feature space. Therefore, several adaptive <span class="hlt">filter</span> algorithms have been developed in order to distinguish between them. These algorithms aim at the preservation of edges and single scattering peaks, and smoothe homogeneous areas as much as possible. This task is rendered more difficult by the multiplicative nature of the speckle noise; the signal variation depends on the signal itself. In this paper, LEE (Lee 1980) and R-LEE (Lee 1981) <span class="hlt">filters</span> using local statistics, local mean and variance, are applied to RADARSAT SAR images. Also, a new method of speckle <span class="hlt">filtering</span>, EPOS (Edge Preserving <span class="hlt">Optimized</span> Speckle) (Hagg & Sties 1994) <span class="hlt">filter</span> based on the statistical properties of speckle noise is described and applied. And then, the results of <span class="hlt">filtering</span> SAR images with LEE, R-LEE and EPOS <span class="hlt">filters</span> are compared with mean and median <span class="hlt">filters</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110015119','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110015119"><span id="translatedtitle">Generic Kalman <span class="hlt">Filter</span> Software</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lisano, Michael E., II; Crues, Edwin Z.</p> <p>2005-01-01</p> <p>The Generic Kalman <span class="hlt">Filter</span> (GKF) software provides a standard basis for the development of application-specific Kalman-<span class="hlt">filter</span> programs. Historically, Kalman <span class="hlt">filters</span> have been implemented by customized programs that must be written, coded, and debugged anew for each unique application, then tested and tuned with simulated or actual measurement data. Total development times for typical Kalman-<span class="hlt">filter</span> application programs have ranged from months to weeks. The GKF software can simplify the development process and reduce the development time by eliminating the need to re-create the fundamental implementation of the Kalman <span class="hlt">filter</span> for each new application. The GKF software is written in the ANSI C programming language. It contains a generic Kalman-<span class="hlt">filter</span>-development directory that, in turn, contains a code for a generic Kalman <span class="hlt">filter</span> function; more specifically, it contains a generically designed and generically coded implementation of linear, linearized, and extended Kalman <span class="hlt">filtering</span> algorithms, including algorithms for state- and covariance-update and -propagation functions. The mathematical theory that underlies the algorithms is well known and has been reported extensively in the open technical literature. Also contained in the directory are a header file that defines generic Kalman-<span class="hlt">filter</span> data structures and prototype functions and template versions of application-specific subfunction and calling navigation/estimation routine code and headers. Once the user has provided a calling routine and the required application-specific subfunctions, the application-specific Kalman-<span class="hlt">filter</span> software can be compiled and executed immediately. During execution, the generic Kalman-<span class="hlt">filter</span> function is called from a higher-level navigation or estimation routine that preprocesses measurement data and post-processes output data. The generic Kalman-<span class="hlt">filter</span> function uses the aforementioned data structures and five implementation- specific subfunctions, which have been developed by the user on the basis of the aforementioned templates. The GKF software can be used to develop many different types of unfactorized Kalman <span class="hlt">filters</span>. A developer can choose to implement either a linearized or an extended Kalman <span class="hlt">filter</span> algorithm, without having to modify the GKF software. Control dynamics can be taken into account or neglected in the <span class="hlt">filter</span>-dynamics model. <span class="hlt">Filter</span> programs developed by use of the GKF software can be made to propagate equations of motion for linear or nonlinear dynamical systems that are deterministic or stochastic. In addition, <span class="hlt">filter</span> programs can be made to operate in user-selectable "covariance analysis" and "propagation-only" modes that are useful in design and development stages.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150022091','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150022091"><span id="translatedtitle">Concentric Split Flow <span class="hlt">Filter</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stapleton, Thomas J. (Inventor)</p> <p>2015-01-01</p> <p>A concentric split flow <span class="hlt">filter</span> may be configured to remove odor and/or bacteria from pumped air used to collect urine and fecal waste products. For instance, <span class="hlt">filter</span> may be designed to effectively fill the volume that was previously considered wasted surrounding the transport tube of a waste management system. The concentric split flow <span class="hlt">filter</span> may be configured to split the air flow, with substantially half of the air flow to be treated traveling through a first bed of <span class="hlt">filter</span> media and substantially the other half of the air flow to be treated traveling through the second bed of <span class="hlt">filter</span> media. This split flow design reduces the air velocity by 50%. In this way, the pressure drop of <span class="hlt">filter</span> may be reduced by as much as a factor of 4 as compare to the conventional design.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995ApOpt..34.8230J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995ApOpt..34.8230J"><span id="translatedtitle">Optically tunable optical <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>James, Robert T. B.; Wah, Christopher; Iizuka, Keigo; Shimotahira, Hiroshi</p> <p>1995-12-01</p> <p>We experimentally demonstrate an optically tunable optical <span class="hlt">filter</span> that uses photorefractive barium titanate. With our <span class="hlt">filter</span> we implement a spectrum analyzer at 632.8 nm with a resolution of 1.2 nm. We simulate a wavelength-division multiplexing system by separating two semiconductor laser diodes, at 1560 nm and 1578 nm, with the same <span class="hlt">filter</span>. The <span class="hlt">filter</span> has a bandwidth of 6.9 nm. We also use the same <span class="hlt">filter</span> to take 2.5-nm-wide slices out of a 20-nm-wide superluminescent diode centered at 840 nm. As a result, we experimentally demonstrate a phenomenal tuning range from 632.8 to 1578 nm with a single <span class="hlt">filtering</span> device.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6308620','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/6308620"><span id="translatedtitle">Contactor/<span class="hlt">filter</span> improvements</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Stelman, D.</p> <p>1988-06-30</p> <p>A contactor/<span class="hlt">filter</span> arrangement for removing particulate contaminants from a gaseous stream is described. The <span class="hlt">filter</span> includes a housing having a substantially vertically oriented granular material retention member with upstream and downstream faces, a substantially vertically oriented microporous gas <span class="hlt">filter</span> element, wherein the retention member and the <span class="hlt">filter</span> element are spaced apart to provide a zone for the passage of granular material therethrough. A gaseous stream containing particulate contaminants passes through the gas inlet means as well as through the upstream face of the granular material retention member, passing through the retention member, the body of granular material, the microporous gas <span class="hlt">filter</span> element, exiting out of the gas outlet means. A cover screen isolates the <span class="hlt">filter</span> element from contact with the moving granular bed. In one embodiment, the granular material is comprised of porous alumina impregnated with CuO, with the cover screen cleaned by the action of the moving granular material as well as by backflow pressure pulses. 6 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010IEITF..91.1347S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010IEITF..91.1347S"><span id="translatedtitle">Robust Frequency Domain Acoustic Echo Cancellation <span class="hlt">Filter</span> Employing Normalized Residual Echo Enhancement</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shimauchi, Suehiro; Haneda, Yoichi; Kataoka, Akitoshi</p> <p></p> <p>We propose a new robust frequency domain acoustic echo cancellation <span class="hlt">filter</span> that employs a normalized residual echo enhancement. By interpreting the conventional robust <span class="hlt">step</span>-size control approaches as a statistical-model-based residual echo enhancement problem, the <span class="hlt">optimal</span> <span class="hlt">step</span>-size introduced in the most of conventional approaches is regarded as <span class="hlt">optimal</span> only on the assumption that both the residual echo and the outlier in the error output signal are described by Gaussian distributions. However, the Gaussian-Gaussian mixture assumption does not always hold well, especially when both the residual echo and the outlier are speech signals (known as a double-talk situation). The proposed <span class="hlt">filtering</span> scheme is based on the Gaussian-Laplacian mixture assumption for the signals normalized by the reference input signal amplitude. By comparing the performances of the proposed and conventional approaches through the simulations, we show that the Gaussian-Laplacian mixture assumption for the normalized signals can provide a better control scheme for the acoustic echo cancellation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IAUGA..2257439M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IAUGA..2257439M"><span id="translatedtitle">The J-PAS <span class="hlt">filter</span> system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marin-Franch, Antonio; Taylor, Keith; Cenarro, Javier; Cristobal-Hornillos, David; Moles, Mariano</p> <p>2015-08-01</p> <p>J-PAS (Javalambre-PAU Astrophysical Survey) is a Spanish-Brazilian collaboration to conduct a narrow-band photometric survey of 8500 square degrees of northern sky using an innovative <span class="hlt">filter</span> system of 59 <span class="hlt">filters</span>, 56 relatively narrow-band (FWHM=14.5 nm) <span class="hlt">filters</span> continuously populating the spectrum between 350 to 1000nm in 10nm <span class="hlt">steps</span>, plus 3 broad-band <span class="hlt">filters</span>. This <span class="hlt">filter</span> system will be able to produce photometric redshifts with a precision of 0.003(1 + z) for Luminous Red Galaxies, allowing J-PAS to measure the radial scale of the Baryonic Acoustic Oscillations. The J-PAS survey will be carried out using JPCam, a 14-CCD mosaic camera using the new e2v 9k-by-9k, 10μm pixel, CCDs mounted on the JST/T250, a dedicated 2.55m wide-field telescope at the Observatorio Astrofísico de Javalambre (OAJ) near Teruel, Spain. The <span class="hlt">filters</span> will operate in a fast (f/3.6) converging beam. The requirements for average transmissions greater than 85% in the passband, <10-5 blocking from 250 to 1050nm, steep bandpass edges and high image quality impose significant challenges for the production of the J-PAS <span class="hlt">filters</span> that have demanded the development of new design solutions. This talk presents the J-PAS <span class="hlt">filter</span> system and describes the most challenging requirements and adopted design strategies. Measurements and tests of the first manufactured <span class="hlt">filters</span> are also presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120016267','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120016267"><span id="translatedtitle">Hybrid <span class="hlt">Filter</span> Membrane</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Laicer, Castro; Rasimick, Brian; Green, Zachary</p> <p>2012-01-01</p> <p>Cabin environmental control is an important issue for a successful Moon mission. Due to the unique environment of the Moon, lunar dust control is one of the main problems that significantly diminishes the air quality inside spacecraft cabins. Therefore, this innovation was motivated by NASA s need to minimize the negative health impact that air-suspended lunar dust particles have on astronauts in spacecraft cabins. It is based on fabrication of a hybrid <span class="hlt">filter</span> comprising nanofiber nonwoven layers coated on porous polymer membranes with uniform cylindrical pores. This design results in a high-efficiency gas particulate <span class="hlt">filter</span> with low pressure drop and the ability to be easily regenerated to restore filtration performance. A hybrid <span class="hlt">filter</span> was developed consisting of a porous membrane with uniform, micron-sized, cylindrical pore channels coated with a thin nanofiber layer. Compared to conventional <span class="hlt">filter</span> media such as a high-efficiency particulate air (HEPA) <span class="hlt">filter</span>, this <span class="hlt">filter</span> is designed to provide high particle efficiency, low pressure drop, and the ability to be regenerated. These membranes have well-defined micron-sized pores and can be used independently as air <span class="hlt">filters</span> with discreet particle size cut-off, or coated with nanofiber layers for filtration of ultrafine nanoscale particles. The <span class="hlt">filter</span> consists of a thin design intended to facilitate <span class="hlt">filter</span> regeneration by localized air pulsing. The two main features of this invention are the concept of combining a micro-engineered straight-pore membrane with nanofibers. The micro-engineered straight pore membrane can be prepared with extremely high precision. Because the resulting membrane pores are straight and not tortuous like those found in conventional <span class="hlt">filters</span>, the pressure drop across the <span class="hlt">filter</span> is significantly reduced. The nanofiber layer is applied as a very thin coating to enhance filtration efficiency for fine nanoscale particles. Additionally, the thin nanofiber coating is designed to promote capture of dust particles on the <span class="hlt">filter</span> surface and to facilitate dust removal with pulse or back airflow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/862498','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/862498"><span id="translatedtitle"><span class="hlt">Filter</span> vapor trap</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Guon, Jerold</p> <p>1976-04-13</p> <p>A sintered <span class="hlt">filter</span> trap is adapted for insertion in a gas stream of sodium vapor to condense and deposit sodium thereon. The <span class="hlt">filter</span> is heated and operated above the melting temperature of sodium, resulting in a more efficient means to remove sodium particulates from the effluent inert gas emanating from the surface of a liquid sodium pool. Preferably the <span class="hlt">filter</span> leaves are precoated with a natrophobic coating such as tetracosane.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/15000188','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/15000188"><span id="translatedtitle">Real time inverse <span class="hlt">filter</span> focusing through iterative time reversal.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Montaldo, Gabriel; Tanter, Mickaël; Fink, Mathias</p> <p>2004-02-01</p> <p>In order to achieve an <span class="hlt">optimal</span> focusing through heterogeneous media we need to build the inverse <span class="hlt">filter</span> of the propagation operator. Time reversal is an easy and robust way to achieve such an inverse <span class="hlt">filter</span> in nondissipative media. However, as soon as losses appear in the medium, time reversal is not equivalent to the inverse <span class="hlt">filter</span> anymore. Consequently, it does not produce the <span class="hlt">optimal</span> focusing and beam degradations may appear. In such cases, we showed in previous works that the <span class="hlt">optimal</span> focusing can be recovered by using the so-called spatiotemporal inverse <span class="hlt">filter</span> technique. This process requires the presence of a complete set of receivers inside the medium. It allows one to reach the <span class="hlt">optimal</span> focusing even in extreme situations such as ultrasonic focusing through human skull or audible sound focusing in strongly reverberant rooms. But, this technique is time consuming and implied fastidious numerical calculations. In this paper we propose a new way to process this inverse <span class="hlt">filter</span> focusing technique in real time and without any calculation. The new process is based on iterative time reversal process. Contrary to the classical inverse <span class="hlt">filter</span> technique, this iteration does not require any computation and achieves the inverse <span class="hlt">filter</span> in an experimental way using wave propagation instead of computational power. The convergence from time reversal to inverse <span class="hlt">filter</span> during the iterative process is theoretically explained. Finally, the feasibility of this iterative technique is experimentally demonstrated for ultrasound applications. PMID:15000188</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090039414','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090039414"><span id="translatedtitle">Nanofiber <span class="hlt">Filters</span> Eliminate Contaminants</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2009-01-01</p> <p>With support from Phase I and II SBIR funding from Johnson Space Center, Argonide Corporation of Sanford, Florida tested and developed its proprietary nanofiber water <span class="hlt">filter</span> media. Capable of removing more than 99.99 percent of dangerous particles like bacteria, viruses, and parasites, the media was incorporated into the company's commercial NanoCeram water <span class="hlt">filter</span>, an inductee into the Space Foundation's Space Technology Hall of Fame. In addition to its drinking water <span class="hlt">filters</span>, Argonide now produces large-scale nanofiber <span class="hlt">filters</span> used as part of the reverse osmosis process for industrial water purification.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/63450','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/63450"><span id="translatedtitle">Linear phase compressive <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>McEwan, T.E.</p> <p>1995-06-06</p> <p>A phase linear <span class="hlt">filter</span> for soliton suppression is in the form of a laddered series of stages of non-commensurate low pass <span class="hlt">filters</span> with each low pass <span class="hlt">filter</span> having a series coupled inductance (L) and a reverse biased, voltage dependent varactor diode, to ground which acts as a variable capacitance (C). L and C values are set to levels which correspond to a linear or conventional phase linear <span class="hlt">filter</span>. Inductance is mapped directly from that of an equivalent nonlinear transmission line and capacitance is mapped from the linear case using a large signal equivalent of a nonlinear transmission line. 2 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/869921','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/869921"><span id="translatedtitle">Linear phase compressive <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>McEwan, Thomas E.</p> <p>1995-01-01</p> <p>A phase linear <span class="hlt">filter</span> for soliton suppression is in the form of a laddered series of stages of non-commensurate low pass <span class="hlt">filters</span> with each low pass <span class="hlt">filter</span> having a series coupled inductance (L) and a reverse biased, voltage dependent varactor diode, to ground which acts as a variable capacitance (C). L and C values are set to levels which correspond to a linear or conventional phase linear <span class="hlt">filter</span>. Inductance is mapped directly from that of an equivalent nonlinear transmission line and capacitance is mapped from the linear case using a large signal equivalent of a nonlinear transmission line.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920007072','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920007072"><span id="translatedtitle">Birefringent <span class="hlt">filter</span> design</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bair, Clayton H. (Inventor)</p> <p>1991-01-01</p> <p>A birefringent <span class="hlt">filter</span> is provided for tuning the wavelength of a broad band emission laser. The <span class="hlt">filter</span> comprises thin plates of a birefringent material having thicknesses which are non-unity, integral multiples of the difference between the thicknesses of the two thinnest plates. The resulting wavelength selectivity is substantially equivalent to the wavelength selectivity of a conventional <span class="hlt">filter</span> which has a thinnest plate having a thickness equal to this thickness difference. The present invention obtains an acceptable tuning of the wavelength while avoiding a decrease in optical quality associated with conventional <span class="hlt">filters</span> wherein the respective plate thicknesses are integral multiples of the thinnest plate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001OptEn..40.2414C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001OptEn..40.2414C"><span id="translatedtitle">Independent task Fourier <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Caulfield, H. John</p> <p>2001-11-01</p> <p>Since the early 1960s, a major part of optical computing systems has been Fourier pattern recognition, which takes advantage of high speed <span class="hlt">filter</span> changes to enable powerful nonlinear discrimination in `real time.' Because <span class="hlt">filter</span> has a task quite independent of the tasks of the other <span class="hlt">filters</span>, they can be applied and evaluated in parallel or, in a simple approach I describe, in sequence very rapidly. Thus I use the name ITFF (independent task Fourier <span class="hlt">filter</span>). These <span class="hlt">filters</span> can also break very complex discrimination tasks into easily handled parts, so the wonderful space invariance properties of Fourier <span class="hlt">filtering</span> need not be sacrificed to achieve high discrimination and good generalizability even for ultracomplex discrimination problems. The training procedure proceeds sequentially, as the task for a given <span class="hlt">filter</span> is defined a posteriori by declaring it to be the discrimination of particular members of set A from all members of set B with sufficient margin. That is, we set the threshold to achieve the desired margin and note the A members discriminated by that threshold. Discriminating those A members from all members of B becomes the task of that <span class="hlt">filter</span>. Those A members are then removed from the set A, so no other <span class="hlt">filter</span> will be asked to perform that already accomplished task.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=muscular+AND+system&pg=5&id=EJ502347','ERIC'); return false;" href="http://eric.ed.gov/?q=muscular+AND+system&pg=5&id=EJ502347"><span id="translatedtitle">A <span class="hlt">Step</span> Circuit Program.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Herman, Susan</p> <p>1995-01-01</p> <p>Aerobics instructors can use <span class="hlt">step</span> aerobics to motivate students. One creative method is to add the <span class="hlt">step</span> to the circuit workout. By incorporating the <span class="hlt">step</span>, aerobic instructors can accommodate various fitness levels. The article explains necessary equipment and procedures, describing sample stations for cardiorespiratory fitness, muscular strength,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20010072443','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20010072443"><span id="translatedtitle">Design-<span class="hlt">Filter</span> Selection for H2 Control of Microgravity Isolation Systems: A Single-Degree-of-Freedom Case Study</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hampton, R. David; Whorton, Mark S.</p> <p>2000-01-01</p> <p>Many microgravity space-science experiments require active vibration isolation, to attain suitably low levels of background acceleration for useful experimental results. The design of state-space controllers by <span class="hlt">optimal</span> control methods requires judicious choices of frequency-weighting design <span class="hlt">filters</span>. Kinematic coupling among states greatly clouds designer intuition in the choices of these <span class="hlt">filters</span>, and the masking effects of the state observations cloud the process further. Recent research into the practical application of H2 synthesis methods to such problems, indicates that certain <span class="hlt">steps</span> can lead to state frequency-weighting design-<span class="hlt">filter</span> choices with substantially improved promise of usefulness, even in the face of these difficulties. In choosing these <span class="hlt">filters</span> on the states, one considers their relationships to corresponding design <span class="hlt">filters</span> on appropriate pseudo-sensitivity- and pseudo-complementary-sensitivity functions. This paper investigates the application of these considerations to a single-degree-of-freedom microgravity vibration-isolation test case. Significant observations that were noted during the design process are presented. along with explanations based on the existent theory for such problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMOS21A1615W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMOS21A1615W"><span id="translatedtitle">The importance of time-<span class="hlt">stepping</span> errors in ocean models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Williams, P. D.</p> <p>2011-12-01</p> <p>Many ocean models use leapfrog time <span class="hlt">stepping</span>. The Robert-Asselin (RA) <span class="hlt">filter</span> is usually applied after each leapfrog <span class="hlt">step</span>, to control the computational mode. However, it will be shown in this presentation that the RA <span class="hlt">filter</span> generates very large amounts of numerical diapycnal mixing. In some ocean models, the numerical diapycnal mixing from the RA <span class="hlt">filter</span> is as large as the physical diapycnal mixing. This lowers our confidence in the fidelity of the simulations. In addition to the above problem, the RA <span class="hlt">filter</span> also damps the physical solution and degrades the numerical accuracy. These two concomitant problems occur because the RA <span class="hlt">filter</span> does not conserve the mean state, averaged over the three time slices on which it operates. The presenter has recently proposed a simple modification to the RA <span class="hlt">filter</span>, which does conserve the three-time-level mean state. The modified <span class="hlt">filter</span> has become known as the Robert-Asselin-Williams (RAW) <span class="hlt">filter</span>. When used in conjunction with the leapfrog scheme, the RAW <span class="hlt">filter</span> eliminates the numerical damping of the physical solution and increases the amplitude accuracy by two orders, yielding third-order accuracy. The phase accuracy is unaffected and remains second-order. The RAW <span class="hlt">filter</span> can easily be incorporated into existing models of the ocean, typically via the insertion of just a single line of code. Better simulations are obtained, at almost no additional computational expense. Results will be shown from recent implementations of the RAW <span class="hlt">filter</span> in various ocean models. For example, in the UK Met Office Hadley Centre ocean model, sea-surface temperature and sea-ice biases in the North Atlantic Ocean are found to be reduced. These improvements are encouraging for the use of the RAW <span class="hlt">filter</span> in other ocean models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060000017','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060000017"><span id="translatedtitle">Kalman <span class="hlt">Filter</span> Constraint Tuning for Turbofan Engine Health Estimation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Simon, Dan; Simon, Donald L.</p> <p>2005-01-01</p> <p>Kalman <span class="hlt">filters</span> are often used to estimate the state variables of a dynamic system. However, in the application of Kalman <span class="hlt">filters</span> some known signal information is often either ignored or dealt with heuristically. For instance, state variable constraints are often neglected because they do not fit easily into the structure of the Kalman <span class="hlt">filter</span>. Recently published work has shown a new method for incorporating state variable inequality constraints in the Kalman <span class="hlt">filter</span>, which has been shown to generally improve the <span class="hlt">filter</span> s estimation accuracy. However, the incorporation of inequality constraints poses some risk to the estimation accuracy as the Kalman <span class="hlt">filter</span> is theoretically <span class="hlt">optimal</span>. This paper proposes a way to tune the <span class="hlt">filter</span> constraints so that the state estimates follow the unconstrained (theoretically <span class="hlt">optimal</span>) <span class="hlt">filter</span> when the confidence in the unconstrained <span class="hlt">filter</span> is high. When confidence in the unconstrained <span class="hlt">filter</span> is not so high, then we use our heuristic knowledge to constrain the state estimates. The confidence measure is based on the agreement of measurement residuals with their theoretical values. The algorithm is demonstrated on a linearized simulation of a turbofan engine to estimate engine health.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EJASP2015...35S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EJASP2015...35S"><span id="translatedtitle">Performance analysis of ?- ?- ?tracking <span class="hlt">filters</span> using position and velocity measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saho, Kenshi; Masugi, Masao</p> <p>2015-12-01</p> <p>This paper examines the performance of two position-velocity-measured (PVM) ?- ?- ? tracking <span class="hlt">filters</span>. The first estimates the target acceleration using the measured velocity, and the second, which is proposed for the first time in this paper, estimates acceleration using the measured position. To quantify the performance of these PVM ?- ?- ? <span class="hlt">filters</span>, we analytically derive steady-state errors that assume that the target is moving with constant acceleration or jerk. With these performance indices, the <span class="hlt">optimal</span> gains of the PVM ?- ?- ? <span class="hlt">filters</span> are determined using a minimum-variance <span class="hlt">filter</span> criterion. The performance of each <span class="hlt">filter</span> under these <span class="hlt">optimal</span> gains is then analyzed and compared. Numerical analyses clarify the performance of the PVM ?- ?- ? <span class="hlt">filters</span> and verify that their accuracy is better than that of the general position-only-measured ?- ?- ? <span class="hlt">filter</span>, even when the variance in velocity measurement noise is comparatively large. We identify the conditions under which the proposed PVM ?- ?- ? <span class="hlt">filter</span> outperforms the general ?- ?- ? <span class="hlt">filter</span> for different ratios of noise variance in the velocity and position measurements. Finally, numerical simulations verify the effectiveness of the PVM ?- ?- ? <span class="hlt">filters</span> for a realistic maneuvering target.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ChJME.tmp...53D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ChJME.tmp...53D"><span id="translatedtitle">Frequency weighting <span class="hlt">filter</span> design for automotive ride comfort evaluation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Du, Feng</p> <p>2016-04-01</p> <p>Few study gives guidance to design weighting <span class="hlt">filters</span> according to the frequency weighting factors, and the additional evaluation method of automotive ride comfort is not made good use of in some countries. Based on the regularities of the weighting factors, a method is proposed and the vertical and horizontal weighting <span class="hlt">filters</span> are developed. The whole frequency range is divided several times into two parts with respective regularity. For each division, a parallel <span class="hlt">filter</span> constituted by a low- and a high-pass <span class="hlt">filter</span> with the same cutoff frequency and the quality factor is utilized to achieve section factors. The cascading of these parallel <span class="hlt">filters</span> obtains entire factors. These <span class="hlt">filters</span> own a high order. But, low order <span class="hlt">filters</span> are preferred in some applications. The bilinear transformation method and the least P-norm <span class="hlt">optimal</span> infinite impulse response(IIR) <span class="hlt">filter</span> design method are employed to develop low order <span class="hlt">filters</span> to approximate the weightings in the standard. In addition, with the window method, the linear phase finite impulse response(FIR) <span class="hlt">filter</span> is designed to keep the signal from distorting and to obtain the staircase weighting. For the same case, the traditional method produces 0.330 7 m • s-2 weighted root mean square(r.m.s.) acceleration and the <span class="hlt">filtering</span> method gives 0.311 9 m • s-2 r.m.s. The fourth order <span class="hlt">filter</span> for approximation of vertical weighting obtains 0.313 9 m • s-2 r.m.s. Crest factors of the acceleration signal weighted by the weighting <span class="hlt">filter</span> and the fourth order <span class="hlt">filter</span> are 3.002 7 and 3.011 1, respectively. This paper proposes several methods to design frequency weighting <span class="hlt">filters</span> for automotive ride comfort evaluation, and these developed weighting <span class="hlt">filters</span> are effective.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/335459','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/335459"><span id="translatedtitle"><span class="hlt">Filter</span> holder and gasket assembly for candle or tube <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Lippert, T.E.; Alvin, M.A.; Bruck, G.J.; Smeltzer, E.E.</p> <p>1999-03-02</p> <p>A <span class="hlt">filter</span> holder and gasket assembly are disclosed for holding a candle <span class="hlt">filter</span> element within a hot gas cleanup system pressure vessel. The <span class="hlt">filter</span> holder and gasket assembly includes a <span class="hlt">filter</span> housing, an annular spacer ring securely attached within the <span class="hlt">filter</span> housing, a gasket sock, a top gasket, a middle gasket and a cast nut. 9 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/872165','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/872165"><span id="translatedtitle"><span class="hlt">Filter</span> holder and gasket assembly for candle or tube <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Lippert, Thomas Edwin; Alvin, Mary Anne; Bruck, Gerald Joseph; Smeltzer, Eugene E.</p> <p>1999-03-02</p> <p>A <span class="hlt">filter</span> holder and gasket assembly for holding a candle <span class="hlt">filter</span> element within a hot gas cleanup system pressure vessel. The <span class="hlt">filter</span> holder and gasket assembly includes a <span class="hlt">filter</span> housing, an annular spacer ring securely attached within the <span class="hlt">filter</span> housing, a gasket sock, a top gasket, a middle gasket and a cast nut.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26734037','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26734037"><span id="translatedtitle">Depth <span class="hlt">Filters</span> Containing Diatomite Achieve More Efficient Particle Retention than <span class="hlt">Filters</span> Solely Containing Cellulose Fibers.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Buyel, Johannes F; Gruchow, Hannah M; Fischer, Rainer</p> <p>2015-01-01</p> <p>The clarification of biological feed stocks during the production of biopharmaceutical proteins is challenging when large quantities of particles must be removed, e.g., when processing crude plant extracts. Single-use depth <span class="hlt">filters</span> are often preferred for clarification because they are simple to integrate and have a good safety profile. However, the combination of <span class="hlt">filter</span> layers must be <span class="hlt">optimized</span> in terms of nominal retention ratings to account for the unique particle size distribution in each feed stock. We have recently shown that predictive models can facilitate <span class="hlt">filter</span> screening and the selection of appropriate <span class="hlt">filter</span> layers. Here we expand our previous study by testing several <span class="hlt">filters</span> with different retention ratings. The <span class="hlt">filters</span> typically contain diatomite to facilitate the removal of fine particles. However, diatomite can interfere with the recovery of large biopharmaceutical molecules such as virus-like particles and aggregated proteins. Therefore, we also tested filtration devices composed solely of cellulose fibers and cohesive resin. The capacities of both <span class="hlt">filter</span> types varied from 10 to 50 L m(-2) when challenged with tobacco leaf extracts, but the filtrate turbidity was ~500-fold lower (~3.5 NTU) when diatomite <span class="hlt">filters</span> were used. We also tested pre-coat filtration with dispersed diatomite, which achieved capacities of up to 120 L m(-2) with turbidities of ~100 NTU using bulk plant extracts, and in contrast to the other depth <span class="hlt">filters</span> did not require an upstream bag <span class="hlt">filter</span>. Single pre-coat filtration devices can thus replace combinations of bag and depth <span class="hlt">filters</span> to simplify the processing of plant extracts, potentially saving on time, labor and consumables. The protein concentrations of TSP, DsRed and antibody 2G12 were not affected by pre-coat filtration, indicating its general applicability during the manufacture of plant-derived biopharmaceutical proteins. PMID:26734037</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4685141','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4685141"><span id="translatedtitle">Depth <span class="hlt">Filters</span> Containing Diatomite Achieve More Efficient Particle Retention than <span class="hlt">Filters</span> Solely Containing Cellulose Fibers</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Buyel, Johannes F.; Gruchow, Hannah M.; Fischer, Rainer</p> <p>2015-01-01</p> <p>The clarification of biological feed stocks during the production of biopharmaceutical proteins is challenging when large quantities of particles must be removed, e.g., when processing crude plant extracts. Single-use depth <span class="hlt">filters</span> are often preferred for clarification because they are simple to integrate and have a good safety profile. However, the combination of <span class="hlt">filter</span> layers must be <span class="hlt">optimized</span> in terms of nominal retention ratings to account for the unique particle size distribution in each feed stock. We have recently shown that predictive models can facilitate <span class="hlt">filter</span> screening and the selection of appropriate <span class="hlt">filter</span> layers. Here we expand our previous study by testing several <span class="hlt">filters</span> with different retention ratings. The <span class="hlt">filters</span> typically contain diatomite to facilitate the removal of fine particles. However, diatomite can interfere with the recovery of large biopharmaceutical molecules such as virus-like particles and aggregated proteins. Therefore, we also tested filtration devices composed solely of cellulose fibers and cohesive resin. The capacities of both <span class="hlt">filter</span> types varied from 10 to 50 L m−2 when challenged with tobacco leaf extracts, but the filtrate turbidity was ~500-fold lower (~3.5 NTU) when diatomite <span class="hlt">filters</span> were used. We also tested pre–coat filtration with dispersed diatomite, which achieved capacities of up to 120 L m−2 with turbidities of ~100 NTU using bulk plant extracts, and in contrast to the other depth <span class="hlt">filters</span> did not require an upstream bag <span class="hlt">filter</span>. Single pre-coat filtration devices can thus replace combinations of bag and depth <span class="hlt">filters</span> to simplify the processing of plant extracts, potentially saving on time, labor and consumables. The protein concentrations of TSP, DsRed and antibody 2G12 were not affected by pre-coat filtration, indicating its general applicability during the manufacture of plant-derived biopharmaceutical proteins. PMID:26734037</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10186289','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10186289"><span id="translatedtitle">Durability of ceramic <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Alvin, M.A.; Tressler, R.E.; Lippert, T.E.; Diaz, E.S.; Smeltzer, E.E.</p> <p>1994-10-01</p> <p>The objectives of this program are to identify the potential long-term thermal/chemical effects that advanced coal-based power generating systems have on the stability of porous ceramic <span class="hlt">filter</span> materials, as well as to assess the influence of these effects on <span class="hlt">filter</span> operating performance and life.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4308957','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4308957"><span id="translatedtitle">Aircraft Recirculation <span class="hlt">Filter</span> for Air-Quality and Incident Assessment</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Eckels, Steven J.; Jones, Byron; Mann, Garrett; Mohan, Krishnan R.; Weisel, Clifford P.</p> <p>2015-01-01</p> <p>The current research examines the possibility of using recirculation <span class="hlt">filters</span> from aircraft to document the nature of air-quality incidents on aircraft. These <span class="hlt">filters</span> are highly effective at collecting solid and liquid particulates. Identification of engine oil contaminants arriving through the bleed air system on the <span class="hlt">filter</span> was chosen as the initial focus. A two-<span class="hlt">step</span> study was undertaken. First, a compressor/bleed air simulator was developed to simulate an engine oil leak, and samples were analyzed with gas chromatograph-mass spectrometry. These samples provided a concrete link between tricresyl phosphates and a homologous series of synthetic pentaerythritol esters from oil and contaminants found on the sample paper. The second <span class="hlt">step</span> was to test 184 used aircraft <span class="hlt">filters</span> with the same gas chromatograph-mass spectrometry system; of that total, 107 were standard <span class="hlt">filters</span>, and 77 were nonstandard. Four of the standard <span class="hlt">filters</span> had both markers for oil, with the homologous series synthetic pentaerythritol esters being the less common marker. It was also found that 90% of the <span class="hlt">filters</span> had some detectable level of tricresyl phosphates. Of the 77 nonstandard <span class="hlt">filters</span>, 30 had both markers for oil, a significantly higher percent than the standard <span class="hlt">filters</span>. PMID:25641977</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.6090W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.6090W"><span id="translatedtitle">A method for improving time-<span class="hlt">stepping</span> numerics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Williams, P. D.</p> <p>2012-04-01</p> <p>In contemporary numerical simulations of the atmosphere, evidence suggests that time-<span class="hlt">stepping</span> errors may be a significant component of total model error, on both weather and climate time-scales. This presentation will review the available evidence, and will then suggest a simple but effective method for substantially improving the time-<span class="hlt">stepping</span> numerics at no extra computational expense. The most common time-<span class="hlt">stepping</span> method is the leapfrog scheme combined with the Robert-Asselin (RA) <span class="hlt">filter</span>. This method is used in the following atmospheric models (and many more): ECHAM, MAECHAM, MM5, CAM, MESO-NH, HIRLAM, KMCM, LIMA, SPEEDY, IGCM, PUMA, COSMO, FSU-GSM, FSU-NRSM, NCEP-GFS, NCEP-RSM, NSEAM, NOGAPS, RAMS, and CCSR/NIES-AGCM. Although the RA <span class="hlt">filter</span> controls the time-splitting instability in these models, it also introduces non-physical damping and reduces the accuracy. This presentation proposes a simple modification to the RA <span class="hlt">filter</span>. The modification has become known as the RAW <span class="hlt">filter</span> (Williams 2011). When used in conjunction with the leapfrog scheme, the RAW <span class="hlt">filter</span> eliminates the non-physical damping and increases the amplitude accuracy by two orders, yielding third-order accuracy. (The phase accuracy remains second-order.) The RAW <span class="hlt">filter</span> can easily be incorporated into existing models, typically via the insertion of just a single line of code. Better simulations are obtained at no extra computational expense. Results will be shown from recent implementations of the RAW <span class="hlt">filter</span> in various atmospheric models, including SPEEDY and COSMO. For example, in SPEEDY, the skill of weather forecasts is found to be significantly improved. In particular, in tropical surface pressure predictions, five-day forecasts made using the RAW <span class="hlt">filter</span> have approximately the same skill as four-day forecasts made using the RA <span class="hlt">filter</span> (Amezcua, Kalnay & Williams 2011). These improvements are encouraging for the use of the RAW <span class="hlt">filter</span> in other models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/430756','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/430756"><span id="translatedtitle">An average-reward reinforcement learning algorithm for computing bias-<span class="hlt">optimal</span> policies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mahadevan, S.</p> <p>1996-12-31</p> <p>Average-reward reinforcement learning (ARL) is an undiscounted <span class="hlt">optimality</span> framework that is generally applicable to a broad range of control tasks. ARL computes gain-<span class="hlt">optimal</span> control policies that maximize the expected payoff per <span class="hlt">step</span>. However, gain-<span class="hlt">optimality</span> has some intrinsic limitations as an <span class="hlt">optimality</span> criterion, since for example, it cannot distinguish between different policies that all reach an absorbing goal state, but incur varying costs. A more selective criterion is bias <span class="hlt">optimality</span>, which can <span class="hlt">filter</span> gain-<span class="hlt">optimal</span> policies to select those that reach absorbing goals with the minimum cost. While several ARL algorithms for computing gain-<span class="hlt">optimal</span> policies have been proposed, none of these algorithms can guarantee bias <span class="hlt">optimality</span>, since this requires solving at least two nested <span class="hlt">optimality</span> equations. In this paper, we describe a novel model-based ARL algorithm for computing bias-<span class="hlt">optimal</span> policies. We test the proposed algorithm using an admission control queuing system, and show that it is able to utilize the queue much more efficiently than a gain-<span class="hlt">optimal</span> method by learning bias-<span class="hlt">optimal</span> policies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990navy.reptR....E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990navy.reptR....E"><span id="translatedtitle">Tracking harmonic notch <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Emo, Frederick L.</p> <p>1990-07-01</p> <p>Disclosed in this patent is an electronic <span class="hlt">filter</span> for automatically tracking and removing harmonically related interfering electrical signals such as power line interference harmonics without attenuating other signals of interest even though the signals are frequency stable and/or near the interference signal frequencies. The <span class="hlt">filter</span> comprises a very narrow band electronic commutated capacitor-bank comb-notch <span class="hlt">filter</span> driven by a counter/decoder circuit which is in turn driven by a phase locked loop. The <span class="hlt">filter</span> also comprises two narrow band analog <span class="hlt">filters</span> tuned to the two lowest harmonics of the interfering signal and drives the comb-notch at unit multiples of the fundamental of the interference frequency. This action is continuous such that center frequencies of the notches are automatically adjusted to compensate for small variations in the interference frequency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1001798','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1001798"><span id="translatedtitle">Sub-micron <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Tepper, Frederick; Kaledin, Leonid</p> <p>2009-10-13</p> <p>Aluminum hydroxide fibers approximately 2 nanometers in diameter and with surface areas ranging from 200 to 650 m.sup.2/g have been found to be highly electropositive. When dispersed in water they are able to attach to and retain electronegative particles. When combined into a composite <span class="hlt">filter</span> with other fibers or particles they can <span class="hlt">filter</span> bacteria and nano size particulates such as viruses and colloidal particles at high flux through the <span class="hlt">filter</span>. Such <span class="hlt">filters</span> can be used for purification and sterilization of water, biological, medical and pharmaceutical fluids, and as a collector/concentrator for detection and assay of microbes and viruses. The alumina fibers are also capable of <span class="hlt">filtering</span> sub-micron inorganic and metallic particles to produce ultra pure water. The fibers are suitable as a substrate for growth of cells. Macromolecules such as proteins may be separated from each other based on their electronegative charges.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6557815','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/6557815"><span id="translatedtitle">Sintered composite <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Bergman, W.</p> <p>1986-05-02</p> <p>A particulate <span class="hlt">filter</span> medium formed of a sintered composite of 0.5 micron diameter quartz fibers and 2 micron diameter stainless steel fibers is described. Preferred composition is about 40 vol.% quartz and about 60 vol.% stainless steel fibers. The media is sintered at about 1100/sup 0/C to bond the stainless steel fibers into a cage network which holds the quartz fibers. High <span class="hlt">filter</span> efficiency and low flow resistance are provided by the smaller quartz fibers. High strength is provided by the stainless steel fibers. The resulting media has a high efficiency and low pressure drop similar to the standard HEPA media, with tensile strength at least four times greater, and a maximum operating temperature of about 550/sup 0/C. The invention also includes methods to form the composite media and a HEPA <span class="hlt">filter</span> utilizing the composite media. The <span class="hlt">filter</span> media can be used to <span class="hlt">filter</span> particles in both liquids and gases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040089138&hterms=px&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dpx','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040089138&hterms=px&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dpx"><span id="translatedtitle">Implicit Kalman <span class="hlt">filtering</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Skliar, M.; Ramirez, W. F.</p> <p>1997-01-01</p> <p>For an implicitly defined discrete system, a new algorithm for Kalman <span class="hlt">filtering</span> is developed and an efficient numerical implementation scheme is proposed. Unlike the traditional explicit approach, the implicit <span class="hlt">filter</span> can be readily applied to ill-conditioned systems and allows for generalization to descriptor systems. The implementation of the implicit <span class="hlt">filter</span> depends on the solution of the congruence matrix equation (A1)(Px)(AT1) = Py. We develop a general iterative method for the solution of this equation, and prove necessary and sufficient conditions for convergence. It is shown that when the system matrices of an implicit system are sparse, the implicit Kalman <span class="hlt">filter</span> requires significantly less computer time and storage to implement as compared to the traditional explicit Kalman <span class="hlt">filter</span>. Simulation results are presented to illustrate and substantiate the theoretical developments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920043940&hterms=Sef&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DSef','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920043940&hterms=Sef&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DSef"><span id="translatedtitle">Multidimensional synthetic estimation <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Monroe, Stanley E., Jr.; Juday, Richard D.</p> <p>1990-01-01</p> <p>The synthetic estimation <span class="hlt">filter</span> (SEF) crafts an affine variation into its response to a changing parameter (e.g. scale or rotation). Sets of such <span class="hlt">filters</span> are used in an estimation correlator to reduce the number of <span class="hlt">filters</span> required for a given tracking accuracy. By overspecifying the system (one more SEF than parameters to be tracked), the ratio of correlation responses between <span class="hlt">filters</span> forms a robust estimator into the spanned domain of the parameters. Previous results dealt with a laboratory correlator which could track a single parameter. This paper explores the SEF and the estimator's extension to more dimensions. A 2D example is given in which a reduction of <span class="hlt">filters</span> from 25 to 3 is demonstrated to span a 4-degree square portion of pose space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MeScT..27c5601M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MeScT..27c5601M"><span id="translatedtitle"><span class="hlt">Step</span>-wise transient method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Malinarič, Svetozár</p> <p>2016-03-01</p> <p>The <span class="hlt">step</span>-wise transient (SWT) method is an experimental technique for measuring the thermal diffusivity and conductivity of solid materials. A theoretical model, design of the experimental apparatus and sources of error are presented. Methods of experiment <span class="hlt">optimization</span> and evaluation are illustrated by charts. The experiment is verified for polymethylmethacrylate (PMMA), yielding the thermal diffusivity 0.112 mm2 s-1 and thermal conductivity 0.197 W.m-1 K-1 with the coefficient of variation around 0.7% for various values of input heat power and specimen thicknesses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989ion..meet..273C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989ion..meet..273C"><span id="translatedtitle">Dynamic interaction of separate INS/GPS Kalman <span class="hlt">filters</span> (<span class="hlt">Filter</span>-driving - <span class="hlt">Filter</span> dynamics)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cunningham, Joseph R.; Lewantowicz, Zdzislaw H.</p> <p></p> <p>This paper examines the basic behavior of the inertial navigation system (INS) errors under high-dynamic conditions, such as combat maneuvering of a fighter aircraft. Examination of the INS linearized error dynamics eigenvalue migrations during various dynamic maneuvers reveals significantly stronger instability than the classical vertical channel instability. The Global Positioning System (GPS) offers high accuracy navigation performance benefits with global coverage, but is has limitations during the dynamic maneuvering of fighter aircraft. The <span class="hlt">optimal</span> integration of the GPS with an INS promises synergistic system performance benefits not realizable with either system individually. A candidate maneuver is selected for which a covariance analysis is performed to demonstrate the performance characteristics of an <span class="hlt">optimally</span> integrated INS/GPS system. Significant insight into the potential instability of a particular INS/GPS integration scheme is presented. The characteristic and unstable behavior of the INS error dynamics eigenfunctions provides the basis for the '<span class="hlt">filter-driving-filter</span>' performance analysis. Several phenomena were observed which should aid future efforts attempting to characterize the performance of various INS/GPS integration methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19940002777&hterms=math+models&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dmath%2Bmodels','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19940002777&hterms=math+models&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dmath%2Bmodels"><span id="translatedtitle">BIREFRINGENT <span class="hlt">FILTER</span> MODEL</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cross, P. L.</p> <p>1994-01-01</p> <p>Birefringent <span class="hlt">filters</span> are often used as line-narrowing components in solid state lasers. The Birefringent <span class="hlt">Filter</span> Model program generates a stand-alone model of a birefringent <span class="hlt">filter</span> for use in designing and analyzing a birefringent <span class="hlt">filter</span>. It was originally developed to aid in the design of solid state lasers to be used on aircraft or spacecraft to perform remote sensing of the atmosphere. The model is general enough to allow the user to address problems such as temperature stability requirements, manufacturing tolerances, and alignment tolerances. The input parameters for the program are divided into 7 groups: 1) general parameters which refer to all elements of the <span class="hlt">filter</span>; 2) wavelength related parameters; 3) <span class="hlt">filter</span>, coating and orientation parameters; 4) input ray parameters; 5) output device specifications; 6) component related parameters; and 7) transmission profile parameters. The program can analyze a birefringent <span class="hlt">filter</span> with up to 12 different components, and can calculate the transmission and summary parameters for multiple passes as well as a single pass through the <span class="hlt">filter</span>. The Jones matrix, which is calculated from the input parameters of Groups 1 through 4, is used to calculate the transmission. Output files containing the calculated transmission or the calculated Jones' matrix as a function of wavelength can be created. These output files can then be used as inputs for user written programs. For example, to plot the transmission or to calculate the eigen-transmittances and the corresponding eigen-polarizations for the Jones' matrix, write the appropriate data to a file. The Birefringent <span class="hlt">Filter</span> Model is written in Microsoft FORTRAN 2.0. The program format is interactive. It was developed on an IBM PC XT equipped with an 8087 math coprocessor, and has a central memory requirement of approximately 154K. Since Microsoft FORTRAN 2.0 does not support complex arithmetic, matrix routines for addition, subtraction, and multiplication of complex, double precision variables are included. The Birefringent <span class="hlt">Filter</span> Model was written in 1987.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999SPIE.3809..320C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999SPIE.3809..320C"><span id="translatedtitle">Federated <span class="hlt">filter</span> for multiplatform track fusion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carlson, Neal A.</p> <p>1999-10-01</p> <p>The federated <span class="hlt">filter</span> is a near globally <span class="hlt">optimal</span> distributed estimation method based on rigorous information-sharing principles. It is applied here to multi-perform target tracking systems where platform-level target tracks are fused across platforms into global tracks. Global track accuracy is enhanced by the geometric diversity of measurements from different platforms, in addition to the greater number of measurements. On each platform, the federated <span class="hlt">filter</span> employs dual platform-level <span class="hlt">filters</span> (PFs) for each track. The primary PFs are locally <span class="hlt">optimal</span>, and contain all the information gathered from the platform track sensors. The secondary PFs are identical except that they contain only the incremental track information gained since the last fusion cycle. On each platform, global track solutions are near globally <span class="hlt">optimal</span> because they receive only new tracklet information from the onboard and off-board PFs, and don to re-use old platform-level information. Logistically, platforms can operate autonomously with no need for synchronized operations or master/slave designations; the architecture is completely symmetric. Platforms can enter or leave the group with no changes in other global trackers. Communications bandwidth is minimal because global tracks need not be shared. The paper describes the theoretical basis of the federated fusing <span class="hlt">filter</span>, the related data association functions, and preliminary simulation results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/871359','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/871359"><span id="translatedtitle">Method of producing monolithic ceramic cross-flow <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Larsen, David A.; Bacchi, David P.; Connors, Timothy F.; Collins, III, Edwin L.</p> <p>1998-01-01</p> <p>Ceramic <span class="hlt">filter</span> of various configuration have been used to <span class="hlt">filter</span> particulates from hot gases exhausted from coal-fired systems. Prior ceramic cross-flow <span class="hlt">filters</span> have been favored over other types, but those previously horn have been assemblies of parts somehow fastened together and consequently subject often to distortion or delamination on exposure hot gas in normal use. The present new monolithic, seamless, cross-flow ceramic <span class="hlt">filters</span>, being of one-piece construction, are not prone to such failure. Further, these new products are made by novel casting process which involves the key <span class="hlt">steps</span> of demolding the ceramic <span class="hlt">filter</span> green body so that none of the fragile inner walls of the <span class="hlt">filter</span> is cracked or broken.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/570478','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/570478"><span id="translatedtitle">Method of producing monolithic ceramic cross-flow <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Larsen, D.A.; Bacchi, D.P.; Connors, T.F.; Collins, E.L. III</p> <p>1998-02-10</p> <p>Ceramic <span class="hlt">filter</span> of various configuration have been used to <span class="hlt">filter</span> particulates from hot gases exhausted from coal-fired systems. Prior ceramic cross-flow <span class="hlt">filters</span> have been favored over other types, but those previously have been assemblies of parts somehow fastened together and consequently subject often to distortion or delamination on exposure hot gas in normal use. The present new monolithic, seamless, cross-flow ceramic <span class="hlt">filters</span>, being of one-piece construction, are not prone to such failure. Further, these new products are made by a novel casting process which involves the key <span class="hlt">steps</span> of demolding the ceramic <span class="hlt">filter</span> green body so that none of the fragile inner walls of the <span class="hlt">filter</span> is cracked or broken. 2 figs.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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