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Sample records for optimized filtering step

  1. Optimal 2D-SIM reconstruction by two filtering steps with Richardson-Lucy deconvolution

    PubMed Central

    Perez, Victor; Chang, Bo-Jui; Stelzer, Ernst Hans Karl

    2016-01-01

    Structured illumination microscopy relies on reconstruction algorithms to yield super-resolution images. Artifacts can arise in the reconstruction and affect the image quality. Current reconstruction methods involve a parametrized apodization function and a Wiener filter. Empirically tuning the parameters in these functions can minimize artifacts, but such an approach is subjective and produces volatile results. We present a robust and objective method that yields optimal results by two straightforward filtering steps with Richardson-Lucy-based deconvolutions. We provide a resource to identify artifacts in 2D-SIM images by analyzing two main reasons for artifacts, out-of-focus background and a fluctuating reconstruction spectrum. We show how the filtering steps improve images of test specimens, microtubules, yeast and mammalian cells. PMID:27849043

  2. Optimal 2D-SIM reconstruction by two filtering steps with Richardson-Lucy deconvolution

    NASA Astrophysics Data System (ADS)

    Perez, Victor; Chang, Bo-Jui; Stelzer, Ernst Hans Karl

    2016-11-01

    Structured illumination microscopy relies on reconstruction algorithms to yield super-resolution images. Artifacts can arise in the reconstruction and affect the image quality. Current reconstruction methods involve a parametrized apodization function and a Wiener filter. Empirically tuning the parameters in these functions can minimize artifacts, but such an approach is subjective and produces volatile results. We present a robust and objective method that yields optimal results by two straightforward filtering steps with Richardson-Lucy-based deconvolutions. We provide a resource to identify artifacts in 2D-SIM images by analyzing two main reasons for artifacts, out-of-focus background and a fluctuating reconstruction spectrum. We show how the filtering steps improve images of test specimens, microtubules, yeast and mammalian cells.

  3. 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.

  4. 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.

  5. 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

  6. Adaptive Mallow's optimization for weighted median filters

    NASA Astrophysics Data System (ADS)

    Rachuri, Raghu; Rao, Sathyanarayana S.

    2002-05-01

    This work extends the idea of spectral optimization for the design of Weighted Median filters and employ adaptive filtering that updates the coefficients of the FIR filter from which the weights of the median filters are derived. Mallows' theory of non-linear smoothers [1] has proven to be of great theoretical significance providing simple design guidelines for non-linear smoothers. It allows us to find a set of positive weights for a WM filter whose sample selection probabilities (SSP's) are as close as possible to a SSP set predetermined by Mallow's. Sample selection probabilities have been used as a basis for designing stack smoothers as they give a measure of the filter's detail preserving ability and give non-negative filter weights. We will extend this idea to design weighted median filters admitting negative weights. The new method first finds the linear FIR filter coefficients adaptively, which are then used to determine the weights of the median filter. WM filters can be designed to have band-pass, high-pass as well as low-pass frequency characteristics. Unlike the linear filters, however, the weighted median filters are robust in the presence of impulsive noise, as shown by the simulation results.

  7. 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

  8. Optimal multiobjective design of digital filters using spiral optimization technique.

    PubMed

    Ouadi, Abderrahmane; Bentarzi, Hamid; Recioui, Abdelmadjid

    2013-01-01

    The multiobjective design of digital filters using spiral optimization technique is considered in this paper. This new optimization tool is a metaheuristic technique inspired by the dynamics of spirals. It is characterized by its robustness, immunity to local optima trapping, relative fast convergence and ease of implementation. The objectives of filter design include matching some desired frequency response while having minimum linear phase; hence, reducing the time response. The results demonstrate that the proposed problem solving approach blended with the use of the spiral optimization technique produced filters which fulfill the desired characteristics and are of practical use.

  9. Optimal Multiobjective Design of Digital Filters Using Taguchi Optimization Technique

    NASA Astrophysics Data System (ADS)

    Ouadi, Abderrahmane; Bentarzi, Hamid; Recioui, Abdelmadjid

    2014-01-01

    The multiobjective design of digital filters using the powerful Taguchi optimization technique is considered in this paper. This relatively new optimization tool has been recently introduced to the field of engineering and is based on orthogonal arrays. It is characterized by its robustness, immunity to local optima trapping, relative fast convergence and ease of implementation. The objectives of filter design include matching some desired frequency response while having minimum linear phase; hence, reducing the time response. The results demonstrate that the proposed problem solving approach blended with the use of the Taguchi optimization technique produced filters that fulfill the desired characteristics and are of practical use.

  10. 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.

  11. Fractional-step Tow-Thomas biquad filters

    NASA Astrophysics Data System (ADS)

    Freeborn, Todd J.; Maundy, Brent; Elwakil, Ahmed

    In this paper we propose the use of fractional capacitors in the Tow-Thomas biquad to realize both fractional lowpass and asymmetric bandpass filters of order 0<α1+α2≤2, where α1 and α2 are the orders of the fractional capacitors and 0<α1,2≤1. We show how these filters can be designed using an integer-order transfer function approximation of the fractional capacitors. MATLAB and PSPICE simulations of first order fractional-step low and bandpass filters of order 1.1, 1.5, and 1.9 are given as examples. Experimental results of fractional low pass filters of order 1.5 implemented with silicon-fabricated fractional capacitors verify the operation of the fractional Tow-Thomas biquad.

  12. 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.

  13. 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

  14. Optimization Integrator for Large Time Steps.

    PubMed

    Gast, Theodore F; Schroeder, Craig; Stomakhin, Alexey; Jiang, Chenfanfu; Teran, Joseph M

    2015-10-01

    Practical time steps in today's state-of-the-art simulators typically rely on Newton's method to solve large systems of nonlinear equations. In practice, this works well for small time steps but is unreliable at large time steps at or near the frame rate, particularly for difficult or stiff simulations. We show that recasting backward Euler as a minimization problem allows Newton's method to be stabilized by standard optimization techniques with some novel improvements of our own. The resulting solver is capable of solving even the toughest simulations at the [Formula: see text] frame rate and beyond. We show how simple collisions can be incorporated directly into the solver through constrained minimization without sacrificing efficiency. We also present novel penalty collision formulations for self collisions and collisions against scripted bodies designed for the unique demands of this solver. Finally, we show that these techniques improve the behavior of Material Point Method (MPM) simulations by recasting it as an optimization problem.

  15. 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.

  16. 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

  17. 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

  18. Optimizing step gauge measurements and uncertainties estimation

    NASA Astrophysics Data System (ADS)

    Hennebelle, F.; Coorevits, T.; Vincent, R.

    2017-02-01

    According to the standard ISO 10360-2 (2001 Geometrical product specifications (GPS)—acceptance and reverification tests for coordinate measuring machines (CMM)—part 2: CMMs used for measuring size (ISO 10360-2:2001)), we verify the coordinate measuring machine (CMM) performance against the manufacturer specification. There are many types of gauges used for the calibration and verification of CMMs. The step gauges with parallel faces (KOBA, MITUTOYO) are well known gauges to perform this test. Often with these gauges, only the unidirectional measurements are considered which avoids having to deal with a residual error that affects the tip radius compensation. However the ISO 10360-2 standard imposes the use of a bidirectional measurement. Thus, the bidirectional measures must be corrected by the residual constant offset probe. In this paper, we optimize the step gauge measurement and a method is given to mathematically avoid the problem of the constant offset of the tip radius. This method involves measuring the step gauge once and to measure it a second time with a shift of one slot in order to obtain a new set of equations. Uncertainties are also presented.

  19. Iris recognition using Gabor filters optimized by the particle swarm algorithm

    NASA Astrophysics Data System (ADS)

    Tsai, Chung-Chih; Taur, Jin-Shiuh; Tao, Chin-Wang

    2009-04-01

    An efficient feature extraction algorithm based on optimized Gabor filters and a relative variation analysis approach is proposed for iris recognition. The Gabor filters are optimized by using the particle swarm algorithm to adjust the parameters. Moreover, a sequential scheme is developed to determine the number of filters in the optimal Gabor filter bank. In the preprocessing step, the lower part of the iris image is unwrapped and normalized to a rectangular block that is then decomposed by the optimal Gabor filters. After that, a simple encoding method is adopted to generate a compact iris code. Experimental results show that with a smaller iris code size, the proposed method can produce comparable performance to that of the existing iris recognition systems.

  20. An Adaptive Fourier Filter for Relaxing Time Stepping Constraints for Explicit Solvers

    SciTech Connect

    Gelb, Anne; Archibald, Richard K

    2015-01-01

    Filtering is necessary to stabilize piecewise smooth solutions. The resulting diffusion stabilizes the method, but may fail to resolve the solution near discontinuities. Moreover, high order filtering still requires cost prohibitive time stepping. This paper introduces an adaptive filter that controls spurious modes of the solution, but is not unnecessarily diffusive. Consequently we are able to stabilize the solution with larger time steps, but also take advantage of the accuracy of a high order filter.

  1. 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.

  2. 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.

  3. Optimal filters for detecting cosmic bubble collisions

    NASA Astrophysics Data System (ADS)

    McEwen, J. D.; Feeney, S. M.; Johnson, M. C.; Peiris, H. V.

    2012-05-01

    A number of well-motivated extensions of the ΛCDM concordance cosmological model postulate the existence of a population of sources embedded in the cosmic microwave background. One such example is the signature of cosmic bubble collisions which arise in models of eternal inflation. The most unambiguous way to test these scenarios is to evaluate the full posterior probability distribution of the global parameters defining the theory; however, a direct evaluation is computationally impractical on large datasets, such as those obtained by the Wilkinson Microwave Anisotropy Probe (WMAP) and Planck. A method to approximate the full posterior has been developed recently, which requires as an input a set of candidate sources which are most likely to give the largest contribution to the likelihood. In this article, we present an improved algorithm for detecting candidate sources using optimal filters, and apply it to detect candidate bubble collision signatures in WMAP 7-year observations. We show both theoretically and through simulations that this algorithm provides an enhancement in sensitivity over previous methods by a factor of approximately two. Moreover, no other filter-based approach can provide a superior enhancement of these signatures. Applying our algorithm to WMAP 7-year observations, we detect eight new candidate bubble collision signatures for follow-up analysis.

  4. Optimization of photon correlations by frequency filtering

    NASA Astrophysics Data System (ADS)

    González-Tudela, Alejandro; del Valle, Elena; Laussy, Fabrice P.

    2015-04-01

    Photon correlations are a cornerstone of quantum optics. Recent works [E. del Valle, New J. Phys. 15, 025019 (2013), 10.1088/1367-2630/15/2/025019; A. Gonzalez-Tudela et al., New J. Phys. 15, 033036 (2013), 10.1088/1367-2630/15/3/033036; C. Sanchez Muñoz et al., Phys. Rev. A 90, 052111 (2014), 10.1103/PhysRevA.90.052111] have shown that by keeping track of the frequency of the photons, rich landscapes of correlations are revealed. Stronger correlations are usually found where the system emission is weak. Here, we characterize both the strength and signal of such correlations, through the introduction of the "frequency-resolved Mandel parameter." We study a plethora of nonlinear quantum systems, showing how one can substantially optimize correlations by combining parameters such as pumping, filtering windows and time delay.

  5. Application of the Two-Step Filter to Process Ranging Measurements for Relative Navigation in an Elliptical Orbit

    NASA Technical Reports Server (NTRS)

    Garrison, James L.; Axelrad, Penina

    1997-01-01

    This estimator breaks a nonlinear estimation problem into a set of over determined 'first step' states which are linear in the observations and 'second step' states which are ultimately the states of interest. Linear estimation methods are applied to filter the observations and produce the optimal first step state estimate. The 'second step' states are obtained through iterative nonlinear parameter estimation considering the first step states as observations. It has been shown that this process exactly minimizes the least squares cost function for static problems and provides a better solution than the iterated extended Kalman filter (EKF) for dynamic problems. The two step filter is applied in this paper to process range and range rate measurements between the two spacecraft. Details of the application of the two step estimator to this problem will be given, highlighting the use of a test for ill-conditioned covariance estimates that can result from the first order covariance propagation. A comparison will be made between the performance of the two step filter and the IEKF.

  6. Optimally stabilized PET image denoising using trilateral filtering.

    PubMed

    Mansoor, Awais; Bagci, Ulas; Mollura, Daniel J

    2014-01-01

    Low-resolution and signal-dependent noise distribution in positron emission tomography (PET) images makes denoising process an inevitable step prior to qualitative and quantitative image analysis tasks. Conventional PET denoising methods either over-smooth small-sized structures due to resolution limitation or make incorrect assumptions about the noise characteristics. Therefore, clinically important quantitative information may be corrupted. To address these challenges, we introduced a novel approach to remove signal-dependent noise in the PET images where the noise distribution was considered as Poisson-Gaussian mixed. Meanwhile, the generalized Anscombe's transformation (GAT) was used to stabilize varying nature of the PET noise. Other than noise stabilization, it is also desirable for the noise removal filter to preserve the boundaries of the structures while smoothing the noisy regions. Indeed, it is important to avoid significant loss of quantitative information such as standard uptake value (SUV)-based metrics as well as metabolic lesion volume. To satisfy all these properties, we extended bilateral filtering method into trilateral filtering through multiscaling and optimal Gaussianization process. The proposed method was tested on more than 50 PET-CT images from various patients having different cancers and achieved the superior performance compared to the widely used denoising techniques in the literature.

  7. Probabilistic-based approach to optimal filtering

    PubMed

    Hannachi

    2000-04-01

    The signal-to-noise ratio maximizing approach in optimal filtering provides a robust tool to detect signals in the presence of colored noise. The method fails, however, when the data present a regimelike behavior. An approach is developed in this manuscript to recover local (in phase space) behavior in an intermittent regimelike behaving system. The method is first formulated in its general form within a Gaussian framework, given an estimate of the noise covariance, and demands that the signal corresponds to minimizing the noise probability distribution for any given value, i.e., on isosurfaces, of the data probability distribution. The extension to the non-Gaussian case is provided through the use of finite mixture models for data that show regimelike behavior. The method yields the correct signal when applied in a simplified manner to synthetic time series with and without regimes, compared to the signal-to-noise ratio approach, and helps identify the right frequency of the oscillation spells in the classical and variants of the Lorenz system.

  8. Optimized multichannel decomposition for texture segmentation using Gabor filter bank

    NASA Astrophysics Data System (ADS)

    Nezamoddini-Kachouie, Nezamoddin; Alirezaie, Javad

    2004-05-01

    Texture segmentation and analysis is an important aspect of pattern recognition and digital image processing. Previous approaches to texture analysis and segmentation perform multi-channel filtering by applying a set of filters to the image. In this paper we describe a texture segmentation algorithm based on multi-channel filtering that is optimized using diagonal high frequency residual. Gabor band pass filters with different radial spatial frequencies and different orientations have optimum resolution in time and frequency domain. The image is decomposed by a set of Gabor filters into a number of filtered images; each one contains variation of intensity on a sub-band frequency and orientation. The features extracted by Gabor filters have been applied for image segmentation and analysis. There are some important considerations about filter parameters and filter bank coverage in frequency domain. This filter bank does not completely cover the corners of the frequency domain along the diagonals. In our method we optimize the spatial implementation for the Gabor filter bank considering the diagonal high frequency residual. Segmentation is accomplished by a feedforward backpropagation multi-layer perceptron that is trained by optimized extracted features. After MLP is trained the input image is segmented and each pixel is assigned to the proper class.

  9. A Low Cost Structurally Optimized Design for Diverse Filter Types

    PubMed Central

    Kazmi, Majida; Aziz, Arshad; Akhtar, Pervez; Ikram, Nassar

    2016-01-01

    A wide range of image processing applications deploys two dimensional (2D)-filters for performing diversified tasks such as image enhancement, edge detection, noise suppression, multi scale decomposition and compression etc. All of these tasks require multiple type of 2D-filters simultaneously to acquire the desired results. The resource hungry conventional approach is not a viable option for implementing these computationally intensive 2D-filters especially in a resource constraint environment. Thus it calls for optimized solutions. Mostly the optimization of these filters are based on exploiting structural properties. A common shortcoming of all previously reported optimized approaches is their restricted applicability only for a specific filter type. These narrow scoped solutions completely disregard the versatility attribute of advanced image processing applications and in turn offset their effectiveness while implementing a complete application. This paper presents an efficient framework which exploits the structural properties of 2D-filters for effectually reducing its computational cost along with an added advantage of versatility for supporting diverse filter types. A composite symmetric filter structure is introduced which exploits the identities of quadrant and circular T-symmetries in two distinct filter regions simultaneously. These T-symmetries effectually reduce the number of filter coefficients and consequently its multipliers count. The proposed framework at the same time empowers this composite filter structure with additional capabilities of realizing all of its Ψ-symmetry based subtypes and also its special asymmetric filters case. The two-fold optimized framework thus reduces filter computational cost up to 75% as compared to the conventional approach as well as its versatility attribute not only supports diverse filter types but also offers further cost reduction via resource sharing for sequential implementation of diversified image

  10. 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.

  11. 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.

  12. Optimal filter bandwidth for pulse oximetry.

    PubMed

    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.

  13. 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.

  14. 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.

  15. Optimizing internal structure of membrane filters

    NASA Astrophysics Data System (ADS)

    Cummings, Linda; Sanaei, Pejman

    2016-11-01

    Membrane filters are in widespread use, and manufacturers have considerable interest in improving their performance, in terms of particle retention properties, and total throughput over the filter lifetime. In this regard, it has long been known that membrane properties should not be uniform over the membrane depth; rather, membrane permeability should decrease in the direction of flow. While much research effort has been focused on investigating favorable membrane permeability gradients, this work has been largely empirical in nature. We present a simple, first-principles model for flow through and fouling of a membrane filter, accounting for permeability gradients via variable pore size. Our model accounts for two fouling modes: sieving; and particle adsorption within pores. For filtration driven by a fixed pressure drop, flux through the membrane eventually goes to zero, as fouling occurs and pores close. We address issues of filter performance as the internal pore structure is varied, by comparing the total throughput obtained with equal-resistance membranes. Within certain classes of pore profiles we are able to find the optimum pore profile that maximizes total throughput over the filter lifetime, while maintaining acceptable particle removal from the feed. Partial support from NSF DMS 1261596 is gratefully acknowledged.

  16. 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.

  17. Design of optimal correlation filters for hybrid vision systems

    NASA Technical Reports Server (NTRS)

    Rajan, Periasamy K.

    1990-01-01

    Research is underway at the NASA Johnson Space Center on the development of vision systems that recognize objects and estimate their position by processing their images. This is a crucial task in many space applications such as autonomous landing on Mars sites, satellite inspection and repair, and docking of space shuttle and space station. Currently available algorithms and hardware are too slow to be suitable for these tasks. Electronic digital hardware exhibits superior performance in computing and control; however, they take too much time to carry out important signal processing operations such as Fourier transformation of image data and calculation of correlation between two images. Fortunately, because of the inherent parallelism, optical devices can carry out these operations very fast, although they are not quite suitable for computation and control type operations. Hence, investigations are currently being conducted on the development of hybrid vision systems that utilize both optical techniques and digital processing jointly to carry out the object recognition tasks in real time. Algorithms for the design of optimal filters for use in hybrid vision systems were developed. Specifically, an algorithm was developed for the design of real-valued frequency plane correlation filters. Furthermore, research was also conducted on designing correlation filters optimal in the sense of providing maximum signal-to-nose ratio when noise is present in the detectors in the correlation plane. Algorithms were developed for the design of different types of optimal filters: complex filters, real-value filters, phase-only filters, ternary-valued filters, coupled filters. This report presents some of these algorithms in detail along with their derivations.

  18. 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

  19. 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.

  20. Study on a stepped eco-filter for treating greywater from single farm household

    NASA Astrophysics Data System (ADS)

    Chen, Jianjun; Liao, Zaiyi; Lu, Shaoyong; Hu, Guangcai; Liu, Yaoxin; Tang, Cilai

    2017-02-01

    A stepped eco-filter based greywater treating facility was built on-site in a typical farm house of China. This study was aimed to investigate the hydraulic loading rate (HLR) for the optimal removal efficiency and to analyze the processing performance throughout an entire year. The results showed that, the average value of TP from the influent was much lower while the linear alkylbenzene sulfonate was a little higher compared with other related studies. The removal rates of the indexes were all showed a distinct decline and dropped to a low level while the HLR was raised from 0.2 m3/(m2 day) to 0.4 m3/(m2 day). Therefore, the optimal HLR of the process ought to be in the range of 0.2-0.4 m3/(m2 day). The average system removal rates in summer were all higher than that in winter, but the facility still performed well in winter. Clogging has never occurred in the facility during the operation over an entire year. Together with the good performance, advantaged of lower cost and easier maintenance, this process has shown good applicability for greywater treatment in rural area.

  1. 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.

  2. Single-channel noise reduction using optimal rectangular filtering matrices.

    PubMed

    Long, Tao; Chen, Jingdong; Benesty, Jacob; Zhang, Zhenxi

    2013-02-01

    This paper studies the problem of single-channel noise reduction in the time domain and presents a block-based approach where a vector of the desired speech signal is recovered by filtering a frame of the noisy signal with a rectangular filtering matrix. With this formulation, the noise reduction problem becomes one of estimating an optimal filtering matrix. To achieve such estimation, a method is introduced to decompose a frame of the clean speech signal into two orthogonal components: One correlated and the other uncorrelated with the current desired speech vector to be estimated. Different optimization cost functions are then formulated from which non-causal optimal filtering matrices are derived. The relationships among these optimal filtering matrices are discussed. In comparison with the classical sample-based technique that uses only forward prediction, the block-based method presented in this paper exploits both the forward and backward prediction as well as the temporal interpolation and, therefore, can improve the noise reduction performance by fully taking advantage of the speech property of self correlation. There is also a side advantage of this block-based method as compared to the sample-based technique, i.e., it is computationally more efficient and, as a result, more suitable for practical implementation.

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

    PubMed

    Chang, Guoqing; Li, Chih-Hao; Phillips, David F; Szentgyorgyi, Andrew; Walsworth, Ronald L; Kärtner, 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.

  4. 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/2007JPS...168..391K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JPS...168..391K"><span>Fuel cell cathode air <span class="hlt">filters</span>: Methodologies for design and <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>Kennedy, Daniel M.; Cahela, Donald R.; Zhu, Wenhua H.; Westrom, Kenneth C.; Nelms, R. Mark; Tatarchuk, Bruce J.</p> <p></p> <p>Proton exchange membrane (PEM) fuel cells experience performance degradation, such as reduction in efficiency and life, as a result of poisoning of platinum catalysts by airborne contaminants. Research on these contaminant effects suggests that the best possible solution to allowing fuel cells to operate in contaminated environments is by filtration of the harmful contaminants from the cathode air. A cathode air <span class="hlt">filter</span> design methodology was created that connects properties of cathode air stream, <span class="hlt">filter</span> design options, and <span class="hlt">filter</span> footprint, to a set of adsorptive <span class="hlt">filter</span> parameters that must be <span class="hlt">optimized</span> to efficiently operate the fuel cell. <span class="hlt">Filter</span> <span class="hlt">optimization</span> requires a study of the trade off between two causal factors of power loss: first, a reduction in power production due to poisoning of the platinum catalyst by chemical contaminants and second, an increase in power requirements to operate the air compressor with a larger pressure drop from additional contaminant filtration. The design methodology was successfully applied to a 1.2 kW fuel cell using a programmable algorithm and predictions were made about the relationships between inlet concentration, breakthrough time, <span class="hlt">filter</span> design, pressure drop, and compressor power requirements.</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>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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4190536','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4190536"><span>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('https://ntrs.nasa.gov/search.jsp?R=19880040084&hterms=Single+Variable&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DSingle%2BVariable','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880040084&hterms=Single+Variable&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DSingle%2BVariable"><span>Single <span class="hlt">step</span> <span class="hlt">optimization</span> of manipulator maneuvers with variable structure control</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chen, N.; Dwyer, T. A. W., III</p> <p>1987-01-01</p> <p>One <span class="hlt">step</span> ahead <span class="hlt">optimization</span> has been recently proposed for spacecraft attitude maneuvers as well as for robot manipulator maneuvers. Such a technique yields a discrete time control algorithm implementable as a sequence of state-dependent, quadratic programming problems for acceleration <span class="hlt">optimization</span>. Its sensitivity to model accuracy, for the required inversion of the system dynamics, is shown in this paper to be alleviated by a fast variable structure control correction, acting between the sampling intervals of the slow one <span class="hlt">step</span> ahead discrete time acceleration command generation algorithm. The slow and fast looping concept chosen follows that recently proposed for <span class="hlt">optimal</span> aiming strategies with variable structure control. Accelerations required by the VSC correction are reserved during the slow one <span class="hlt">step</span> ahead command generation so that the ability to overshoot the sliding surface is guaranteed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JTePh..59..749O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JTePh..59..749O"><span><span class="hlt">Optimal</span> <span class="hlt">filtering</span> in multipulse sequences for nuclear quadrupole resonance detection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Osokin, D. Ya.; Khusnutdinov, R. R.; Mozzhukhin, G. V.; Rameev, B. Z.</p> <p>2014-05-01</p> <p>The application of the multipulse sequences in nuclear quadrupole resonance (NQR) detection of explosive and narcotic substances has been studied. Various approaches to increase the signal to noise ratio (SNR) of signal detection are considered. We discussed two modifications of the phase-alternated multiple-pulse sequence (PAMS): the 180° pulse sequence with a preparatory pulse and the 90° pulse sequence. The advantages of <span class="hlt">optimal</span> <span class="hlt">filtering</span> to detect NQR in the case of the coherent steady-state precession have been analyzed. It has been shown that this technique is effective in <span class="hlt">filtering</span> high-frequency and low-frequency noise and increasing the reliability of NQR detection. Our analysis also shows the PAMS with 180° pulses is more effective than PSL sequence from point of view of the application of <span class="hlt">optimal</span> <span class="hlt">filtering</span> procedure to the steady-state NQR signal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010LNCS.6466..370R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010LNCS.6466..370R"><span>Swarm Intelligence for <span class="hlt">Optimizing</span> Hybridized Smoothing <span class="hlt">Filter</span> in Image Edge Enhancement</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rao, B. Tirumala; Dehuri, S.; Dileep, M.; Vindhya, A.</p> <p></p> <p>In this modern era, image transmission and processing plays a major role. It would be impossible to retrieve information from satellite and medical images without the help of image processing techniques. Edge enhancement is an image processing <span class="hlt">step</span> that enhances the edge contrast of an image or video in an attempt to improve its acutance. Edges are the representations of the discontinuities of image intensity functions. For processing these discontinuities in an image, a good edge enhancement technique is essential. The proposed work uses a new idea for edge enhancement using hybridized smoothening <span class="hlt">filters</span> and we introduce a promising technique of obtaining best hybrid <span class="hlt">filter</span> using swarm algorithms (Artificial Bee Colony (ABC), Particle Swarm <span class="hlt">Optimization</span> (PSO) and Ant Colony <span class="hlt">Optimization</span> (ACO)) to search for an <span class="hlt">optimal</span> sequence of <span class="hlt">filters</span> from among a set of rather simple, representative image processing <span class="hlt">filters</span>. This paper deals with the analysis of the swarm intelligence techniques through the combination of hybrid <span class="hlt">filters</span> generated by these algorithms for image edge enhancement.</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>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('https://www.ncbi.nlm.nih.gov/pubmed/15285252','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15285252"><span>Degeneracy, frequency response and <span class="hlt">filtering</span> in IMRT <span class="hlt">optimization</span>.</span></a></p> <p><a target="_blank" href="https://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>2004-07-07</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('https://www.ncbi.nlm.nih.gov/pubmed/26849867','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26849867"><span>Fourier Spectral <span class="hlt">Filter</span> Array for <span class="hlt">Optimal</span> Multispectral Imaging.</span></a></p> <p><a target="_blank" href="https://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.</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>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</p> </li> <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><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://hdl.handle.net/2060/19960023550','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960023550"><span><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> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25933101','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25933101"><span>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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1636674','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1636674"><span><span class="hlt">Optimal</span> Noise <span class="hlt">Filtering</span> in the Chemotactic Response of Escherichia coli</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Andrews, Burton W; Yi, Tau-Mu; Iglesias, Pablo A</p> <p>2006-01-01</p> <p>Information-carrying signals in the real world are often obscured by noise. A challenge for any system is to <span class="hlt">filter</span> the signal from the corrupting noise. This task is particularly acute for the signal transduction network that mediates bacterial chemotaxis, because the signals are subtle, the noise arising from stochastic fluctuations is substantial, and the system is effectively acting as a differentiator which amplifies noise. Here, we investigated the <span class="hlt">filtering</span> properties of this biological system. Through simulation, we first show that the cutoff frequency has a dramatic effect on the chemotactic efficiency of the cell. Then, using a mathematical model to describe the signal, noise, and system, we formulated and solved an <span class="hlt">optimal</span> <span class="hlt">filtering</span> problem to determine the cutoff frequency that bests separates the low-frequency signal from the high-frequency noise. There was good agreement between the theory, simulations, and published experimental data. Finally, we propose that an elegant implementation of the <span class="hlt">optimal</span> <span class="hlt">filter</span> in combination with a differentiator can be achieved via an integral control system. This paper furnishes a simple quantitative framework for interpreting many of the key notions about bacterial chemotaxis, and, more generally, it highlights the constraints on biological systems imposed by noise. PMID:17112312</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050180325','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050180325"><span>"The Design of a Compact, Wide Spurious-Suppression Bandwidth Bandpass <span class="hlt">Filter</span> Using <span class="hlt">Stepped</span> Impedance Resonators"</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; Wollack, Edward J.; Doiron, Terence; Papapolymerou, John; Laskar, Joy</p> <p>2005-01-01</p> <p>We propose an analytical design for a microstrip broadband spurious-suppression <span class="hlt">filter</span>. The proposed design uses every section of the transmission lines as both a coupling and a spurious suppression element, which creates a very compact, planar <span class="hlt">filter</span>. While a traditional <span class="hlt">filter</span> length is greater than the multiple of the quarter wavelength at the center passband frequency (lambda(sub g)/4), the proposed <span class="hlt">filter</span> length is less than (order n(Ssup th) + l)center dot lambda(sub g)/8. The <span class="hlt">filter</span> s spurious response and physical dimension are controlled by the <span class="hlt">step</span> impedance ratio (R) between two transmission line sections as a lambda(sub g)/4 resonator. The experimental result shows that, with R of 0.2, the out-of-band attenuation is greater than 40 dB; and the first spurious mode is shifted to more than 5 times the fundamental frequency. Moreover, it is the most compact planar <span class="hlt">filter</span> design to date. The results also indicate a low in-band insertion loss.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Nanop...6..110W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Nanop...6..110W"><span>Stochastic simulation and robust design <span class="hlt">optimization</span> of integrated photonic <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>Weng, Tsui-Wei; Melati, Daniele; Melloni, Andrea; Daniel, Luca</p> <p>2017-01-01</p> <p>Manufacturing variations are becoming an unavoidable issue in modern fabrication processes; therefore, it is crucial to be able to include stochastic uncertainties in the design phase. In this paper, integrated photonic coupled ring resonator <span class="hlt">filters</span> are considered as an example of significant interest. The sparsity structure in photonic circuits is exploited to construct a sparse combined generalized polynomial chaos model, which is then used to analyze related statistics and perform robust design <span class="hlt">optimization</span>. Simulation results show that the <span class="hlt">optimized</span> circuits are more robust to fabrication process variations and achieve a reduction of 11%-35% in the mean square errors of the 3 dB bandwidth compared to unoptimized nominal designs.</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://adsabs.harvard.edu/abs/2016Nanop...6..110W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Nanop...6..110W"><span>Stochastic simulation and robust design <span class="hlt">optimization</span> of integrated photonic <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>Weng, Tsui-Wei; Melati, Daniele; Melloni, Andrea; Daniel, Luca</p> <p>2016-07-01</p> <p>Manufacturing variations are becoming an unavoidable issue in modern fabrication processes; therefore, it is crucial to be able to include stochastic uncertainties in the design phase. In this paper, integrated photonic coupled ring resonator <span class="hlt">filters</span> are considered as an example of significant interest. The sparsity structure in photonic circuits is exploited to construct a sparse combined generalized polynomial chaos model, which is then used to analyze related statistics and perform robust design <span class="hlt">optimization</span>. Simulation results show that the <span class="hlt">optimized</span> circuits are more robust to fabrication process variations and achieve a reduction of 11%-35% in the mean square errors of the 3 dB bandwidth compared to unoptimized nominal designs.</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>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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3195949','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3195949"><span>A Peptide <span class="hlt">Filtering</span> Relation Quantifies MHC Class I Peptide <span class="hlt">Optimization</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>Goldstein, Leonard D.; Howarth, Mark; Cardelli, Luca; Emmott, Stephen; Elliott, Tim; Werner, Joern M.</p> <p>2011-01-01</p> <p>Major Histocompatibility Complex (MHC) class I molecules enable cytotoxic T lymphocytes to destroy virus-infected or cancerous cells, thereby preventing disease progression. MHC class I molecules provide a snapshot of the contents of a cell by binding to protein fragments arising from intracellular protein turnover and presenting these fragments at the cell surface. Competing fragments (peptides) are selected for cell-surface presentation on the basis of their ability to form a stable complex with MHC class I, by a process known as peptide <span class="hlt">optimization</span>. A better understanding of the <span class="hlt">optimization</span> process is important for our understanding of immunodominance, the predominance of some T lymphocyte specificities over others, which can determine the efficacy of an immune response, the danger of immune evasion, and the success of vaccination strategies. In this paper we present a dynamical systems model of peptide <span class="hlt">optimization</span> by MHC class I. We incorporate the chaperone molecule tapasin, which has been shown to enhance peptide <span class="hlt">optimization</span> to different extents for different MHC class I alleles. Using a combination of published and novel experimental data to parameterize the model, we arrive at a relation of peptide <span class="hlt">filtering</span>, which quantifies peptide <span class="hlt">optimization</span> as a function of peptide supply and peptide unbinding rates. From this relation, we find that tapasin enhances peptide unbinding to improve peptide <span class="hlt">optimization</span> without significantly delaying the transit of MHC to the cell surface, and differences in peptide <span class="hlt">optimization</span> across MHC class I alleles can be explained by allele-specific differences in peptide binding. Importantly, our <span class="hlt">filtering</span> relation may be used to dynamically predict the cell surface abundance of any number of competing peptides by MHC class I alleles, providing a quantitative basis to investigate viral infection or disease at the cellular level. We exemplify this by simulating <span class="hlt">optimization</span> of the distribution of peptides derived from Human</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>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://www.osti.gov/scitech/servlets/purl/147746','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/147746"><span>A bench scale study of a one-<span class="hlt">step</span> dissolution process for treating contaminated fiberglass <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Policke, T.A.; Ritter, J.A.</p> <p>1995-12-01</p> <p>High efficiency mist eliminators (HEME) and high efficiency particulate air <span class="hlt">filters</span> (HEPA) made of High fiberglass will be used at the Savannah River Site (SRS) to remove particulate matter from offgases generated during melter feed preparation and vitrification of high-level radioactive waste (HLW) at the Defense Waste Processing Facility (DWPF). These <span class="hlt">filters</span> will be contaminated with high-level, radioactive species and also with various high-boiling organic compounds. For this reason, a process was developed at the Savannah River Technology Center (SRTC) that will dissolve the spent <span class="hlt">filters</span> so that the residues may be recycled to the HLW tanks for eventual vitrification. This process involves boiling the <span class="hlt">filters</span> sequentially in NaOH, HN0{sub 3} and NaOH, while contained in a stainless steal wire mesh frame assembly. The objective of this communication is to present some of the original preliminary work done by Ritter on the simple one-<span class="hlt">step</span> dissolution process. The results from six bench-scale experiments are reported for the dissolution of an organically-fouled sample of HEME obtained from the Integrated DWPF Melter (IDMS) offgas filtration system. The preliminary effects of <span class="hlt">filter</span> packing density, air sparging versus rotating basket agitation, fouling, and adding Triton X-405 as a dispersing agent are reported.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ITSP...65..467D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ITSP...65..467D"><span>Consensus+Innovations Distributed Kalman <span class="hlt">Filter</span> With <span class="hlt">Optimized</span> Gains</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Das, Subhro; Moura, Jose M. F.</p> <p>2017-01-01</p> <p>In this paper, we address the distributed <span class="hlt">filtering</span> and prediction of time-varying random fields represented by linear time-invariant (LTI) dynamical systems. The field is observed by a sparsely connected network of agents/sensors collaborating among themselves. We develop a Kalman <span class="hlt">filter</span> type consensus+innovations distributed linear estimator of the dynamic field termed as Consensus+Innovations Kalman <span class="hlt">Filter</span>. We analyze the convergence properties of this distributed estimator. We prove that the mean-squared error of the estimator asymptotically converges if the degree of instability of the field dynamics is within a pre-specified threshold defined as tracking capacity of the estimator. The tracking capacity is a function of the local observation models and the agent communication network. We design the <span class="hlt">optimal</span> consensus and innovation gain matrices yielding distributed estimates with minimized mean-squared error. Through numerical evaluations, we show that, the distributed estimator with <span class="hlt">optimal</span> gains converges faster and with approximately 3dB better mean-squared error performance than previous distributed estimators.</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>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('https://ntrs.nasa.gov/search.jsp?R=19910068705&hterms=polarizer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dpolarizer','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910068705&hterms=polarizer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dpolarizer"><span>Design of <span class="hlt">optimal</span> binary phase and amplitude <span class="hlt">filters</span> for maximization of correlation peak sharpness</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>1991-01-01</p> <p>Current binary-phase <span class="hlt">filters</span> used for optical correlation are usually assumed to have uniform amplitude transmission. Here, a new type of <span class="hlt">filter</span> is studied, the binary-phase-and-amplitude <span class="hlt">filter</span>. If binary phase values of 0 and pi are assumed, the amplitude transmittance values of this type of <span class="hlt">filter</span> can be <span class="hlt">optimized</span> to maximize the peak sharpness. For a polarization-encoded binary-phase <span class="hlt">filter</span> this can be translated into <span class="hlt">optimization</span> of the rotation angle of the output polarizer following the <span class="hlt">filter</span>-spatial-light modulator. An analytic expression is presented for the optimum polarizer angle and thus for the optimum binary-phase-and-amplitude <span class="hlt">filter</span> design.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25227070','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25227070"><span><span class="hlt">Optimal</span> subband Kalman <span class="hlt">filter</span> for normal and oesophageal speech enhancement.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ishaq, Rizwan; García Zapirain, Begoña</p> <p>2014-01-01</p> <p>This paper presents the single channel speech enhancement system using subband Kalman <span class="hlt">filtering</span> by estimating <span class="hlt">optimal</span> Autoregressive (AR) coefficients and variance for speech and noise, using Weighted Linear Prediction (WLP) and Noise Weighting Function (NWF). The system is applied for normal and Oesophageal speech signals. The method is evaluated by Perceptual Evaluation of Speech Quality (PESQ) score and Signal to Noise Ratio (SNR) improvement for normal speech and Harmonic to Noise Ratio (HNR) for Oesophageal Speech (OES). Compared with previous systems, the normal speech indicates 30% increase in PESQ score, 4 dB SNR improvement and OES shows 3 dB HNR improvement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720013470','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720013470"><span><span class="hlt">Optimal</span> <span class="hlt">filter</span> design subject to output delobe constraints</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fortmann, T. E.; Athans, M.</p> <p>1972-01-01</p> <p>The design of <span class="hlt">filters</span> for detection and estimation in radar and communications systems is considered, with inequality constraints on the maximum output sidelobe levels. A constrained <span class="hlt">optimization</span> problem in Hilbert space is formulated, incorporating the sidelobe constraints via a partial ordering of continuous functions. Generalized versions (in Hilbert space) of the Kuhn-Tucker and Duality Theorems allow the reduction of this problem to an unconstrained one in the dual space of regular Borel measures. A convergent algorithm is presented for computational solution of the dual problem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25968205','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25968205"><span><span class="hlt">Optimal</span> design of one-dimensional photonic crystal <span class="hlt">filters</span> using minimax <span class="hlt">optimization</span> approach.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hassan, Abdel-Karim S O; Mohamed, Ahmed S A; Maghrabi, Mahmoud M T; Rafat, Nadia H</p> <p>2015-02-20</p> <p>In this paper, we introduce a simulation-driven <span class="hlt">optimization</span> approach for achieving the <span class="hlt">optimal</span> design of electromagnetic wave (EMW) <span class="hlt">filters</span> consisting of one-dimensional (1D) multilayer photonic crystal (PC) structures. The PC layers' thicknesses and/or material types are considered as designable parameters. The <span class="hlt">optimal</span> design problem is formulated as a minimax <span class="hlt">optimization</span> problem that is entirely solved by making use of readily available software tools. The proposed approach allows for the consideration of problems of higher dimension than usually treated before. In addition, it can proceed starting from bad initial design points. The validity, flexibility, and efficiency of the proposed approach is demonstrated by applying it to obtain the <span class="hlt">optimal</span> design of two practical examples. The first is (SiC/Ag/SiO(2))(N) wide bandpass optical <span class="hlt">filter</span> operating in the visible range. Contrarily, the second example is (Ag/SiO(2))(N) EMW low pass spectral <span class="hlt">filter</span>, working in the infrared range, which is used for enhancing the efficiency of thermophotovoltaic systems. The approach shows a good ability to converge to the <span class="hlt">optimal</span> solution, for different design specifications, regardless of the starting design point. This ensures that the approach is robust and general enough to be applied for obtaining the <span class="hlt">optimal</span> design of all 1D photonic crystals promising applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26731782','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26731782"><span>Evolutionary Dynamic Multiobjective <span class="hlt">Optimization</span> Via Kalman <span class="hlt">Filter</span> Prediction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Muruganantham, Arrchana; Tan, Kay Chen; Vadakkepat, Prahlad</p> <p>2016-12-01</p> <p>Evolutionary algorithms are effective in solving static multiobjective <span class="hlt">optimization</span> problems resulting in the emergence of a number of state-of-the-art multiobjective evolutionary algorithms (MOEAs). Nevertheless, the interest in applying them to solve dynamic multiobjective <span class="hlt">optimization</span> problems has only been tepid. Benchmark problems, appropriate performance metrics, as well as efficient algorithms are required to further the research in this field. One or more objectives may change with time in dynamic <span class="hlt">optimization</span> problems. The <span class="hlt">optimization</span> algorithm must be able to track the moving optima efficiently. A prediction model can learn the patterns from past experience and predict future changes. In this paper, a new dynamic MOEA using Kalman <span class="hlt">filter</span> (KF) predictions in decision space is proposed to solve the aforementioned problems. The predictions help to guide the search toward the changed optima, thereby accelerating convergence. A scoring scheme is devised to hybridize the KF prediction with a random reinitialization method. Experimental results and performance comparisons with other state-of-the-art algorithms demonstrate that the proposed algorithm is capable of significantly improving the dynamic <span class="hlt">optimization</span> performance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999SPIE.3766..386G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999SPIE.3766..386G"><span>Polyimide x-ray <span class="hlt">filter</span> substrates <span class="hlt">optimized</span> for cryogenic temperatures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grove, David A.</p> <p>1999-09-01</p> <p>New generation x-ray instruments for spacecraft such as ASTRO-E and CONSTELLATION-X have very specialized requirements, notably operation at cryogenic temperatures. Luxel Corporation, under a NASA Phase I SBIR contract, undertook the demonstration of feasibility of producing polyimide films suitable for use as x-ray <span class="hlt">filter</span> substrates specifically <span class="hlt">optimized</span> for cryogenic applications. 5000 angstrom thick polyimide films were processed using different cure cycles, and burst pressure analyses were performed at 293, 77, and 4 Kelvin. Test data showed that polyimide films are inherently stronger at cryogenic temperatures than at room temperature. Through cure modification, film strength was increased an additional 9 percent at 4K over that of the standard cure clearly showing the feasibility of film <span class="hlt">optimization</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23796954','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23796954"><span><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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17076408','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17076408"><span>An <span class="hlt">optimal</span> nonorthogonal separation of the anisotropic Gaussian convolution <span class="hlt">filter</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lampert, Christoph H; Wirjadi, Oliver</p> <p>2006-11-01</p> <p>We give an analytical and geometrical treatment of what it means to separate a Gaussian kernel along arbitrary axes in R(n), and we present a separation scheme that allows us to efficiently implement anisotropic Gaussian convolution <span class="hlt">filters</span> for data of arbitrary dimensionality. Based on our previous analysis we show that this scheme is <span class="hlt">optimal</span> with regard to the number of memory accesses and interpolation operations needed. The proposed method relies on nonorthogonal convolution axes and works completely in image space. Thus, it avoids the need for a fast Fourier transform (FFT)-subroutine. Depending on the accuracy and speed requirements, different interpolation schemes and methods to implement the one-dimensional Gaussian (finite impulse response and infinite impulse response) can be integrated. Special emphasis is put on analyzing the performance and accuracy of the new method. In particular, we show that without any special <span class="hlt">optimization</span> of the source code, it can perform anisotropic Gaussian <span class="hlt">filtering</span> faster than methods relying on the FFT.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001PhDT........61Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001PhDT........61Y"><span>Aircraft flight data processing and parameter identification with iterative extended Kalman <span class="hlt">filter</span>/smoother and two-<span class="hlt">step</span> estimator</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Qiuli</p> <p>2001-12-01</p> <p>Aircraft flight test data are processed by <span class="hlt">optimal</span> estimation programs to estimate the aircraft state trajectory (3 DOF) and to identify the unknown parameters, including constant biases and scale factor of the measurement instrumentation system. The methods applied in processing aircraft flight test data are the iterative extended Kalman <span class="hlt">filter</span>/smoother and fixed-point smoother (IEKFSFPS) method and the two-<span class="hlt">step</span> estimator (TSE) method. The models of an aircraft flight dynamic system and measurement instrumentation system are established. The principles of IEKFSFPS and TSE methods are derived and summarized, and their algorithms are programmed with MATLAB codes. Several numerical experiments of flight data processing and parameter identification are carried out by using IEKFSFPS and TSE algorithm programs. Comparison and discussion of the simulation results with the two methods are made. The TSE+IEKFSFPS combination method is presented and proven to be effective and practical. Figures and tables of the results are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28287973','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28287973"><span><span class="hlt">Optimized</span> Color <span class="hlt">Filter</span> Arrays for Sparse Representation Based Demosaicking.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Jia; Bai, Chenyan; Lin, Zhouchen; Yu, Jian</p> <p>2017-03-08</p> <p>Demosaicking is the problem of reconstructing a color image from the raw image captured by a digital color camera that covers its only imaging sensor with a color <span class="hlt">filter</span> array (CFA). Sparse representation based demosaicking has been shown to produce superior reconstruction quality. However, almost all existing algorithms in this category use the CFAs which are not specifically <span class="hlt">optimized</span> for the algorithms. In this paper, we consider <span class="hlt">optimally</span> designing CFAs for sparse representation based demosaicking, where the dictionary is well-chosen. The fact that CFAs correspond to the projection matrices used in compressed sensing inspires us to <span class="hlt">optimize</span> CFAs via minimizing the mutual coherence. This is more challenging than that for traditional projection matrices because CFAs have physical realizability constraints. However, most of the existing methods for minimizing the mutual coherence require that the projection matrices should be unconstrained, making them inapplicable for designing CFAs. We consider directly minimizing the mutual coherence with the CFA's physical realizability constraints as a generalized fractional programming problem, which needs to find sufficiently accurate solutions to a sequence of nonconvex nonsmooth minimization problems. We adapt the redistributed proximal bundle method to address this issue. Experiments on benchmark images testify to the superiority of the proposed method. In particular, we show that a simple sparse representation based demosaicking algorithm with our specifically <span class="hlt">optimized</span> CFA can outperform LSSC [1]. To the best of our knowledge, it is the first sparse representation based demosaicking algorithm that beats LSSC in terms of CPSNR.</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>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('https://www.ncbi.nlm.nih.gov/pubmed/25007608','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25007608"><span>[Characteristic wavelength variable <span class="hlt">optimization</span> of near-infrared spectroscopy based on Kalman <span class="hlt">filtering</span>].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Li-Qi; Ge, Hui-Fang; Li, Gui-Bin; Yu, Dian-Yu; Hu, Li-Zhi; Jiang, Lian-Zhou</p> <p>2014-04-01</p> <p>Combining classical Kalman <span class="hlt">filter</span> with NIR analysis technology, a new method of characteristic wavelength variable selection, namely Kalman <span class="hlt">filtering</span> method, is presented. The principle of Kalman <span class="hlt">filter</span> for selecting <span class="hlt">optimal</span> wavelength variable was analyzed. The wavelength selection algorithm was designed and applied to NIR detection of soybean oil acid value. First, the PLS (partial leastsquares) models were established by using different absorption bands of oil. The 4 472-5 000 cm(-1) characteristic band of oil acid value, including 132 wavelengths, was selected preliminarily. Then the Kalman <span class="hlt">filter</span> was used to select characteristic wavelengths further. The PLS calibration model was established using selected 22 characteristic wavelength variables, the determination coefficient R2 of prediction set and RMSEP (root mean squared error of prediction) are 0.970 8 and 0.125 4 respectively, equivalent to that of 132 wavelengths, however, the number of wavelength variables was reduced to 16.67%. This algorithm is deterministic iteration, without complex parameters setting and randomicity of variable selection, and its physical significance was well defined. The modeling using a few selected characteristic wavelength variables which affected modeling effect heavily, instead of total spectrum, can make the complexity of model decreased, meanwhile the robustness of model improved. The research offered important reference for developing special oil near infrared spectroscopy analysis instruments on next <span class="hlt">step</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23940576','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23940576"><span>Effects of rate-limiting <span class="hlt">steps</span> in transcription initiation on genetic <span class="hlt">filter</span> motifs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Häkkinen, Antti; Tran, Huy; Yli-Harja, Olli; Ribeiro, Andre S</p> <p>2013-01-01</p> <p>The behavior of genetic motifs is determined not only by the gene-gene interactions, but also by the expression patterns of the constituent genes. Live single-molecule measurements have provided evidence that transcription initiation is a sequential process, whose kinetics plays a key role in the dynamics of mRNA and protein numbers. The extent to which it affects the behavior of cellular motifs is unknown. Here, we examine how the kinetics of transcription initiation affects the behavior of motifs performing <span class="hlt">filtering</span> in amplitude and frequency domain. We find that the performance of each <span class="hlt">filter</span> is degraded as transcript levels are lowered. This effect can be reduced by having a transcription process with more <span class="hlt">steps</span>. In addition, we show that the kinetics of the stepwise transcription initiation process affects features such as <span class="hlt">filter</span> cutoffs. These results constitute an assessment of the range of behaviors of genetic motifs as a function of the kinetics of transcription initiation, and thus will aid in tuning of synthetic motifs to attain specific characteristics without affecting their protein products.</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://adsabs.harvard.edu/abs/2011AGUFM.G33B0985D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.G33B0985D"><span><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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25571430','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25571430"><span>A cascaded two-<span class="hlt">step</span> Kalman <span class="hlt">filter</span> for estimation of human body segment orientation using MEMS-IMU.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zihajehzadeh, S; Loh, D; Lee, M; Hoskinson, R; Park, E J</p> <p>2014-01-01</p> <p>Orientation of human body segments is an important quantity in many biomechanical analyses. To get robust and drift-free 3-D orientation, raw data from miniature body worn MEMS-based inertial measurement units (IMU) should be blended in a Kalman <span class="hlt">filter</span>. Aiming at less computational cost, this work presents a novel cascaded two-<span class="hlt">step</span> Kalman <span class="hlt">filter</span> orientation estimation algorithm. Tilt angles are estimated in the first <span class="hlt">step</span> of the proposed cascaded Kalman <span class="hlt">filter</span>. The estimated tilt angles are passed to the second <span class="hlt">step</span> of the <span class="hlt">filter</span> for yaw angle calculation. The orientation results are benchmarked against the ones from a highly accurate tactical grade IMU. Experimental results reveal that the proposed algorithm provides robust orientation estimation in both kinematically and magnetically disturbed conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25983690','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25983690"><span>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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</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.</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>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/2014AGUFM.B13C0189I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.B13C0189I"><span><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/2015EJASP2015...83Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EJASP2015...83Z"><span>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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5137138','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5137138"><span>DNA intercalation <span class="hlt">optimized</span> by two-<span class="hlt">step</span> molecular lock mechanism</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Almaqwashi, Ali A.; Andersson, Johanna; Lincoln, Per; Rouzina, Ioulia; Westerlund, Fredrik; Williams, Mark C.</p> <p>2016-01-01</p> <p>The diverse properties of DNA intercalators, varying in affinity and kinetics over several orders of magnitude, provide a wide range of applications for DNA-ligand assemblies. Unconventional intercalation mechanisms may exhibit high affinity and slow kinetics, properties desired for potential therapeutics. We used single-molecule force spectroscopy to probe the free energy landscape for an unconventional intercalator that binds DNA through a novel two-<span class="hlt">step</span> mechanism in which the intermediate and final states bind DNA through the same mono-intercalating moiety. During this process, DNA undergoes significant structural rearrangements, first lengthening before relaxing to a shorter DNA-ligand complex in the intermediate state to form a molecular lock. To reach the final bound state, the molecular length must increase again as the ligand threads between disrupted DNA base pairs. This unusual binding mechanism results in an unprecedented <span class="hlt">optimized</span> combination of high DNA binding affinity and slow kinetics, suggesting a new paradigm for rational design of DNA intercalators. PMID:27917863</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SPIE.6790E..3VZ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SPIE.6790E..3VZ"><span><span class="hlt">Optimizing</span> spatial <span class="hlt">filters</span> with kernel methods for BCI applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Jiacai; Tang, Jianjun; Yao, Li</p> <p>2007-11-01</p> <p>Brain Computer Interface (BCI) is a communication or control system in which the user's messages or commands do not depend on the brain's normal output channels. The key <span class="hlt">step</span> of BCI technology is to find a reliable method to detect the particular brain signals, such as the alpha, beta and mu components in EEG/ECOG trials, and then translate it into usable control signals. In this paper, our objective is to introduce a novel approach that is able to extract the discriminative pattern from the non-stationary EEG signals based on the common spatial patterns(CSP) analysis combined with kernel methods. The basic idea of our Kernel CSP method is performing a nonlinear form of CSP by the use of kernel methods that can efficiently compute the common and distinct components in high dimensional feature spaces related to input space by some nonlinear map. The algorithm described here is tested off-line with dataset I from the BCI Competition 2005. Our experiments show that the spatial <span class="hlt">filters</span> employed with kernel CSP can effectively extract discriminatory information from single-trial EGOG recorded during imagined movements. The high recognition of linear discriminative rates and computational simplicity of "Kernel Trick" make it a promising method for BCI systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1266690','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1266690"><span>Pattern recognition with composite correlation <span class="hlt">filters</span> designed with multi-object combinatorial <span class="hlt">optimization</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Awwal, Abdul; Diaz-Ramirez, Victor H.; Cuevas, Andres; Kober, Vitaly; Trujillo, Leonardo</p> <p>2014-10-23</p> <p>Composite correlation <span class="hlt">filters</span> are used for solving a wide variety of pattern recognition problems. These <span class="hlt">filters</span> are given by a combination of several training templates chosen by a designer in an ad hoc manner. In this work, we present a new approach for the design of composite <span class="hlt">filters</span> based on multi-objective combinatorial <span class="hlt">optimization</span>. Given a vast search space of training templates, an iterative algorithm is used to synthesize a <span class="hlt">filter</span> with an <span class="hlt">optimized</span> performance in terms of several competing criteria. Furthermore, by employing a suggested binary-search procedure a <span class="hlt">filter</span> bank with a minimum number of <span class="hlt">filters</span> can be constructed, for a prespecified trade-off of performance metrics. Computer simulation results obtained with the proposed method in recognizing geometrically distorted versions of a target in cluttered and noisy scenes are discussed and compared in terms of recognition performance and complexity with existing state-of-the-art <span class="hlt">filters</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1266690-pattern-recognition-composite-correlation-filters-designed-multi-object-combinatorial-optimization','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1266690-pattern-recognition-composite-correlation-filters-designed-multi-object-combinatorial-optimization"><span>Pattern recognition with composite correlation <span class="hlt">filters</span> designed with multi-object combinatorial <span class="hlt">optimization</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Awwal, Abdul; Diaz-Ramirez, Victor H.; Cuevas, Andres; ...</p> <p>2014-10-23</p> <p>Composite correlation <span class="hlt">filters</span> are used for solving a wide variety of pattern recognition problems. These <span class="hlt">filters</span> are given by a combination of several training templates chosen by a designer in an ad hoc manner. In this work, we present a new approach for the design of composite <span class="hlt">filters</span> based on multi-objective combinatorial <span class="hlt">optimization</span>. Given a vast search space of training templates, an iterative algorithm is used to synthesize a <span class="hlt">filter</span> with an <span class="hlt">optimized</span> performance in terms of several competing criteria. Furthermore, by employing a suggested binary-search procedure a <span class="hlt">filter</span> bank with a minimum number of <span class="hlt">filters</span> can be constructed, formore » a prespecified trade-off of performance metrics. Computer simulation results obtained with the proposed method in recognizing geometrically distorted versions of a target in cluttered and noisy scenes are discussed and compared in terms of recognition performance and complexity with existing state-of-the-art <span class="hlt">filters</span>.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18255473','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18255473"><span><span class="hlt">Optimal</span> tradeoff circular harmonic function correlation <span class="hlt">filter</span> methods providing controlled in-plane rotation response.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vijaya Kumar, B K; Mahalanobis, A; Takessian, A</p> <p>2000-01-01</p> <p>Correlation methods are becoming increasingly attractive tools for image recognition and location. This renewed interest in correlation methods is spurred by the availability of high-speed image processors and the emergence of correlation <span class="hlt">filter</span> designs that can <span class="hlt">optimize</span> relevant figures of merit. In this paper, a new correlation <span class="hlt">filter</span> design method is presented that allows one to <span class="hlt">optimally</span> tradeoff among potentially conflicting correlation output performance criteria while achieving desired correlation peak value behavior in response to in-plane rotation of input images. Such controlled in-plane rotation response is useful in image analysis and pattern recognition applications where the sensor follows a pre-arranged trajectory while imaging an object. Since this new correlation <span class="hlt">filter</span> design is based on circular harmonic function (CHF) theory, we refer to the resulting <span class="hlt">filters</span> as <span class="hlt">optimal</span> tradeoff circular harmonic function (OTCHF) <span class="hlt">filters</span>. Underlying theory, OTCHF <span class="hlt">filter</span> design method, and illustrative numerical results are presented.</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>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://adsabs.harvard.edu/abs/1995ApOpt..34..346F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995ApOpt..34..346F"><span>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('https://ntrs.nasa.gov/search.jsp?R=20060028978&hterms=kalman+filter&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dkalman%2Bfilter','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060028978&hterms=kalman+filter&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dkalman%2Bfilter"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/25569031','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25569031"><span>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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27161757','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27161757"><span>Closed-loop <span class="hlt">step</span> response for tuning PID-fractional-order-<span class="hlt">filter</span> controllers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Amoura, Karima; Mansouri, Rachid; Bettayeb, Maâmar; Al-Saggaf, Ubaid M</p> <p>2016-09-01</p> <p>Analytical methods are usually applied for tuning fractional controllers. The present paper proposes an empirical method for tuning a new type of fractional controller known as PID-Fractional-Order-<span class="hlt">Filter</span> (FOF-PID). Indeed, the setpoint overshoot method, initially introduced by Shamsuzzoha and Skogestad, has been adapted for tuning FOF-PID controller. Based on simulations for a range of first order with time delay processes, correlations have been derived to obtain PID-FOF controller parameters similar to those obtained by the Internal Model Control (IMC) tuning rule. The setpoint overshoot method requires only one closed-loop <span class="hlt">step</span> response experiment using a proportional controller (P-controller). To highlight the potential of this method, simulation results have been compared with those obtained with the IMC method as well as other pertinent techniques. Various case studies have also been considered. The comparison has revealed that the proposed tuning method performs as good as the IMC. Moreover, it might offer a number of advantages over the IMC tuning rule. For instance, the parameters of the fractional controller are directly obtained from the setpoint closed-loop response data without the need of any model of the plant to be controlled.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28385666','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28385666"><span><span class="hlt">Optimal</span> point process <span class="hlt">filtering</span> and estimation of the coalescent process.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Parag, Kris V; Pybus, Oliver G</p> <p>2017-04-03</p> <p>The coalescent process is a widely used approach for inferring the demographic history of a population, from samples of its genetic diversity. Several parametric and non-parametric coalescent inference methods, involving Markov chain Monte Carlo, Gaussian processes, and other algorithms, already exist. However, these techniques are not always easy to adapt and apply, thus creating a need for alternative methodologies. We introduce the Bayesian Snyder <span class="hlt">filter</span> as an easily implementable and flexible minimum mean square error estimator for parametric demographic functions on fixed genealogies. By reinterpreting the coalescent as a self-exciting Markov process, we show that the Snyder <span class="hlt">filter</span> can be applied to both isochronously and heterochronously sampled datasets. We analytically solve the <span class="hlt">filter</span> equations for the constant population size Kingman coalescent, derive expressions for its mean squared estimation error, and estimate its robustness to prior distribution specification. For populations with deterministically time-varying size we numerically solve the Snyder equations, and test this solution on common demographic models. We find that the Snyder <span class="hlt">filter</span> accurately recovers the true demographic history for these models. We also apply the <span class="hlt">filter</span> to a well-studied, dataset of hepatitis C virus sequences and show that the <span class="hlt">filter</span> compares well to a popular phylodynamic inference method. The Snyder <span class="hlt">filter</span> is an exact (given discretised priors, it does not approximate the posterior) and direct Bayesian estimation method that has the potential to become a useful alternative tool for coalescent inference.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AIPC.1806n0002L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1806n0002L"><span>A robust approach to <span class="hlt">optimal</span> matched <span class="hlt">filter</span> design in ultrasonic non-destructive evaluation (NDE)</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>2017-02-01</p> <p>The matched <span class="hlt">filter</span> was demonstrated to be a powerful yet efficient technique to enhance defect detection and imaging in ultrasonic non-destructive evaluation (NDE) of coarse grain materials, provided that the <span class="hlt">filter</span> was properly designed and <span class="hlt">optimized</span>. In the literature, in order to accurately approximate the defect echoes, the design utilized the real excitation signals, which made it time consuming and less straightforward to implement in practice. In this paper, we present a more robust and flexible approach to <span class="hlt">optimal</span> matched <span class="hlt">filter</span> design using the simulated excitation signals, and the control parameters are chosen and <span class="hlt">optimized</span> based on the real scenario of array transducer, transmitter-receiver system response, and the test sample, as a result, the <span class="hlt">filter</span> response is <span class="hlt">optimized</span> and depends on the material characteristics. Experiments on industrial samples are conducted and the results confirm the great benefits of the method.</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>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://www.osti.gov/scitech/servlets/purl/610743','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/610743"><span><span class="hlt">Optimized</span> <span class="hlt">filtering</span> of regional and teleseismic seismograms: results of maximizing SNR measurements from the wavelet transform and <span class="hlt">filter</span> banks</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Leach, R.R.; Schultz, C.; Dowla, F.</p> <p>1997-07-15</p> <p>Development of a worldwide network to monitor seismic activity requires deployment of seismic sensors in areas which have not been well studied or may have from available recordings. Development and testing of detection and discrimination algorithms requires a robust representative set of calibrated seismic events for a given region. Utilizing events with poor signal-to-noise (SNR) can add significant numbers to usable data sets, but these events must first be adequately <span class="hlt">filtered</span>. Source and path effects can make this a difficult task as <span class="hlt">filtering</span> demands are highly varied as a function of distance, event magnitude, bearing, depth etc. For a given region, conventional methods of <span class="hlt">filter</span> selection can be quite subjective and may require intensive analysis of many events. In addition, <span class="hlt">filter</span> parameters are often overly generalized or contain complicated switching. We have developed a method to provide an <span class="hlt">optimized</span> <span class="hlt">filter</span> for any regional or teleseismically recorded event. Recorded seismic signals contain arrival energy which is localized in frequency and time. Localized temporal signals whose frequency content is different from the frequency content of the pre-arrival record are identified using rms power measurements. The method is based on the decomposition of a time series into a set of time series signals or scales. Each scale represents a time-frequency band with a constant Q. SNR is calculated for a pre-event noise window and for a window estimated to contain the arrival. Scales with high SNR are used to indicate the band pass limits for the <span class="hlt">optimized</span> <span class="hlt">filter</span>.The results offer a significant improvement in SNR particularly for low SNR events. Our method provides a straightforward, <span class="hlt">optimized</span> <span class="hlt">filter</span> which can be immediately applied to unknown regions as knowledge of the geophysical characteristics is not required. The <span class="hlt">filtered</span> signals can be used to map the seismic frequency response of a region and may provide improvements in travel-time picking, bearing estimation</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://adsabs.harvard.edu/abs/2013PASP..125..838P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PASP..125..838P"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/20136212','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20136212"><span>Automatic parameter <span class="hlt">optimization</span> in epsilon-<span class="hlt">filter</span> for acoustical signal processing utilizing correlation coefficient.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Abe, Tomomi; Hashimoto, Shuji; Matsumoto, Mitsuharu</p> <p>2010-02-01</p> <p>epsilon-<span class="hlt">filter</span> can reduce most kinds of noise from a single-channel noisy signal while preserving signals that vary drastically such as speech signals. It can reduce not only stationary noise but also nonstationary noise. However, it has some parameters whose values are set empirically. So far, there have been few studies to evaluate the appropriateness of the parameter settings for epsilon-<span class="hlt">filter</span>. This paper employs the correlation coefficient of the <span class="hlt">filter</span> output and the difference between the <span class="hlt">filter</span> input and output as the evaluation function of the parameter setting. This paper also describes the algorithm to set the <span class="hlt">optimal</span> parameter value of epsilon-<span class="hlt">filter</span> automatically. To evaluate the adequateness of the obtained parameter, the mean absolute error is calculated. The experimental results show that the adequate parameter in epsilon-<span class="hlt">filter</span> can be obtained automatically by using the proposed method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE10150E..0HM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE10150E..0HM"><span><span class="hlt">Optimization</span> of optical <span class="hlt">filter</span> using triple coupler ring resonators structure based on polyimide substrate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mahmudin, D.; Estu, T. T.; Fathnan, A. A.; Maulana, Y. Y.; Daud, P.; Sugandhi, G.; Wijayanto, Y. N.</p> <p>2016-11-01</p> <p>Optical <span class="hlt">filter</span> is very important components in WDM network. MRR is a basic structure to design the optical <span class="hlt">filter</span> because of easy to design for improving its performance. This paper discusses an innovative structure of the MRR, which is Triple Coupler Ring Resonators (TCRR) for optical <span class="hlt">filter</span> applications. Values of width between bus and ring and values of radius of the ring in the structure TCRR were analyzed and <span class="hlt">optimized</span> for several variations for obtaining coupling coefficient values. Therefore, wide Free Spectral Range (FSR) and high crosstalk suppression bandwidth can be obtained. As results, at the <span class="hlt">optimized</span> width of gap of 100 nm and the <span class="hlt">optimized</span> radiation of 8 μm, FSR of 2.85 THz and crosstalk suppression bandwidth of 60 GHz were achieved. Based on the results, this structure can be used for <span class="hlt">filtering</span> optical signals in optical fiber communication.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhCS.734c2117H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhCS.734c2117H"><span>Finite element based <span class="hlt">optimization</span> study on hydroformed <span class="hlt">stepped</span> tube</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Harisankar, K. R.; Omar, A.; Narasimhan, K.</p> <p>2016-08-01</p> <p>Tube hydroforming process is an advanced manufacturing process in which tube is placed in between the dies and deformed with the help of hydraulic pressure. A sound tube hydroformed part depends upon die conditions, material properties and process conditions. In this work, a finite element study, along with response surface methodology (RSM) for designing the simulation, has been used to construct models with loading path, friction, anisotropic index, strain hardening exponent and tube thickness. The responses studied are the die corner radius filling and strain non-uniformity index (SNI) chosen in each <span class="hlt">step</span> of the tube with maximum 30% thinning as stopping criteria. The factors effect and their interactions on each response were determined and analysed.</p> </li> <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>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://hdl.handle.net/2060/19860001918','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860001918"><span>A simple, first <span class="hlt">step</span> to the <span class="hlt">optimization</span> of regenerator geometry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Radebaugh, R.; Louie, B.</p> <p>1985-01-01</p> <p>This paper presents a simplified set of equations for calculating and <span class="hlt">optimizing</span> regenerator geometries. A number of competing parameters must be accounted for in the design of a regenerator. To obtain high values of effectiveness, there is need for a large surface area for heat transfer and high heat capacity. The void volume should be small to maintain the pressure ratio in the entire system. Moreover, the pressure drop should be small compared to the absolute pressure. With the assumptions made here, the calculations can be done with a hand calculator. The equations show that the optimum regenerator length, hydraulic radius, and porosity are independent of mass flow rate and the gas cross sectional area is proportional to the mass flow rate. It is shown that using gas gaps between parallel plates produces a significantly better regenerator than is possible with packed spheres or screens, particularly at temperatures below approximately 50%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993SPIE.1902...30D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993SPIE.1902...30D"><span><span class="hlt">Optimal</span> morphological hit-or-miss <span class="hlt">filtering</span> of gray-level images</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dougherty, Edward R.</p> <p>1993-05-01</p> <p>The binary hit-or-miss transform is applied to <span class="hlt">filter</span> digital gray-scale signals. This is accomplished by applying a union of hit-or-miss transforms to an observed signal's umbra and then taking the surface of the <span class="hlt">filtered</span> umbra as the estimate of the ideal signal. The hit-or-miss union is constructed to provide the <span class="hlt">optimal</span> mean-absolute-error <span class="hlt">filter</span> for both the ideal signal and its umbra. The method is developed in detail for thinning hit-or-miss <span class="hlt">filters</span> and applies at once to the dual thickening <span class="hlt">filters</span>. It requires the output of the umbra <span class="hlt">filter</span> to be an umbra, which in general is not true. A key aspect of the paper is the complete characterization of umbra-preserving union-of-hit-or-miss thinning and thickening <span class="hlt">filters</span>. Taken together, the mean-absolute-error theory and the umbra-preservation characterization provide a full characterization of binary hit-or-miss <span class="hlt">filtering</span> as applied to digital gray-scale signals. The theory is at once applicable to hit-or-miss <span class="hlt">filtering</span> of digital gray-scale signals via the three- dimensional binary hit-or-miss transform.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25227085','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25227085"><span>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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AAS...22531109E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AAS...22531109E"><span><span class="hlt">Optimizing</span> the Choice of <span class="hlt">Filter</span> Sets for Space Based Imaging Instruments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Elliott, Rachel E.; Farrah, Duncan; Petty, Sara M.; Harris, Kathryn Amy</p> <p>2015-01-01</p> <p>We investigate the challenge of selecting a limited number of <span class="hlt">filters</span> for space based imaging instruments such that they are able to address multiple heterogeneous science goals. The number of available <span class="hlt">filter</span> slots for a mission is bounded by factors such as instrument size and cost. We explore methods used to extract the <span class="hlt">optimal</span> group of <span class="hlt">filters</span> such that they complement each other most effectively. We focus on three approaches; maximizing the separation of objects in two-dimensional color planes, SED fitting to select those <span class="hlt">filter</span> sets that give the finest resolution in fitted physical parameters, and maximizing the orthogonality of physical parameter vectors in N-dimensional color-color space. These techniques are applied to a test-case, a UV/optical imager with space for five <span class="hlt">filters</span>, with the goal of measuring the properties of local stars through to distant galaxies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28245584','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28245584"><span><span class="hlt">Optimal</span> Divergence-Free Hatch <span class="hlt">Filter</span> for GNSS Single-Frequency Measurement.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Park, Byungwoon; Lim, Cheolsoon; Yun, Youngsun; Kim, Euiho; Kee, Changdon</p> <p>2017-02-24</p> <p>The Hatch <span class="hlt">filter</span> is a code-smoothing technique that uses the variation of the carrier phase. It can effectively reduce the noise of a pseudo-range with a very simple <span class="hlt">filter</span> construction, but it occasionally causes an ionosphere-induced error for low-lying satellites. Herein, we propose an <span class="hlt">optimal</span> single-frequency (SF) divergence-free Hatch <span class="hlt">filter</span> that uses a satellite-based augmentation system (SBAS) message to reduce the ionospheric divergence and applies the <span class="hlt">optimal</span> smoothing constant for its smoothing window width. According to the data-processing results, the overall performance of the proposed <span class="hlt">filter</span> is comparable to that of the dual frequency (DF) divergence-free Hatch <span class="hlt">filter</span>. Moreover, it can reduce the horizontal error of 57 cm to 37 cm and improve the vertical accuracy of the conventional Hatch <span class="hlt">filter</span> by 25%. Considering that SF receivers dominate the global navigation satellite system (GNSS) market and that most of these receivers include the SBAS function, the <span class="hlt">filter</span> suggested in this paper is of great value in that it can make the differential GPS (DGPS) performance of the low-cost SF receivers comparable to that of DF receivers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5375734','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5375734"><span><span class="hlt">Optimal</span> Divergence-Free Hatch <span class="hlt">Filter</span> for GNSS Single-Frequency Measurement</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Park, Byungwoon; Lim, Cheolsoon; Yun, Youngsun; Kim, Euiho; Kee, Changdon</p> <p>2017-01-01</p> <p>The Hatch <span class="hlt">filter</span> is a code-smoothing technique that uses the variation of the carrier phase. It can effectively reduce the noise of a pseudo-range with a very simple <span class="hlt">filter</span> construction, but it occasionally causes an ionosphere-induced error for low-lying satellites. Herein, we propose an <span class="hlt">optimal</span> single-frequency (SF) divergence-free Hatch <span class="hlt">filter</span> that uses a satellite-based augmentation system (SBAS) message to reduce the ionospheric divergence and applies the <span class="hlt">optimal</span> smoothing constant for its smoothing window width. According to the data-processing results, the overall performance of the proposed <span class="hlt">filter</span> is comparable to that of the dual frequency (DF) divergence-free Hatch <span class="hlt">filter</span>. Moreover, it can reduce the horizontal error of 57 cm to 37 cm and improve the vertical accuracy of the conventional Hatch <span class="hlt">filter</span> by 25%. Considering that SF receivers dominate the global navigation satellite system (GNSS) market and that most of these receivers include the SBAS function, the <span class="hlt">filter</span> suggested in this paper is of great value in that it can make the differential GPS (DGPS) performance of the low-cost SF receivers comparable to that of DF receivers. PMID:28245584</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4020995','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4020995"><span>NAAG Detection in the Human Brain at 7T by TE <span class="hlt">Optimization</span> and Improved Wiener <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>An, Li; Li, Shizhe; Wood, Emily T; Reich, Daniel S; Shen, Jun</p> <p>2014-01-01</p> <p>Purpose We report enhanced signal detection for measuring N-acetyl-aspartyl-glutamate (NAAG) in the human brain at 7T by TE-<span class="hlt">optimized</span> point-resolved spectroscopy (PRESS) and improved Wiener <span class="hlt">filtering</span>. Methods Using a highly efficient in-house developed numerical simulation program, a PRESS sequence with (TE1, TE2) = (26, 72) ms was found to maximize the NAAG signals relative to the overlapping Glu signals. A new Wiener <span class="hlt">filtering</span> water reference deconvolution method was developed to reduce broadening and distortions of metabolite peaks caused by B0 inhomogeneity and eddy currents. Results Monte Carlo simulation results demonstrated that the new Wiener <span class="hlt">filtering</span> method offered higher spectral resolution, reduced spectral artifacts, and higher accuracy in NAAG quantification compared to the original Wiener <span class="hlt">filtering</span> method. In vivo spectra and point spread functions of signal distortion confirmed that the new Wiener <span class="hlt">filtering</span> method lead to improved spectral resolution and reduced spectral artifacts. Conclusions TE-<span class="hlt">optimized</span> PRESS in combination with a new Wiener <span class="hlt">filtering</span> method made it possible to fully utilize both the NAAG singlet signal at 2.05 ppm and the NAAG multiplet signal at 2.18 ppm in the quantification of NAAG. A more accurate characterization of lineshape distortion for Wiener <span class="hlt">filtering</span> needs B0 field maps and segmented anatomical images to exclude contribution from cerebral spinal fluid. PMID:24243344</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27918015','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27918015"><span>Highly efficient polymer solar cells by <span class="hlt">step-by-step</span> <span class="hlt">optimizing</span> donor molecular packing and acceptor redistribution.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sun, Qianqian; Zhang, Fujun; An, Qiaoshi; Zhang, Miao; Wang, Jian; Zhang, Jian</p> <p>2016-12-21</p> <p>The dynamic drying process of the active layer should play a vitally important role in determining the performance of polymer solar cells (PSCs). Donor molecular packing and acceptor redistribution can be <span class="hlt">optimized</span> by two successive post-treatments on the active layer. The blend films were freshly prepared by spin-coating method and then immediately transferred to a covered glass Petri dish to allow self-assembly of the donor molecules. The films were then treated with methanol or PFN-methanol solution to adjust the acceptor redistribution. In this study, power conversion efficiencies (PCEs) of PSCs with PffBT4T-2OD:PC71BM as the active layer were improved from 6.74% to 8.75% by employing 80 min for self-assembly and 20 s of methanol soaking. The PCE was improved even further to 9.72% by inserting a PFN interfacial layer. The performance improvement was mainly attributed to the <span class="hlt">optimized</span> PffBT4T-2OD molecular packing during the self-assembly process, ideal vertical phase separation driven by methanol soaking and efficient charge collection by insertion of a PFN interfacial layer. The molecular packing and vertical phase separation were characterized by grazing incidence X-ray diffraction (GIXD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS), respectively. The experimental results solidly supported the effectiveness of the <span class="hlt">step-by-step</span> <span class="hlt">optimization</span> strategy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26391486','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26391486"><span><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="https://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.</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><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://adsabs.harvard.edu/abs/2017EPJST.226..391M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EPJST.226..391M"><span>On salesmen and tourists: Two-<span class="hlt">step</span> <span class="hlt">optimization</span> in deterministic foragers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maya, Miguel; Miramontes, Octavio; Boyer, Denis</p> <p>2017-02-01</p> <p>We explore a two-<span class="hlt">step</span> <span class="hlt">optimization</span> problem in random environments, the so-called restaurant-coffee shop problem, where a walker aims at visiting the nearest and better restaurant in an area and then move to the nearest and better coffee-shop. This is an extension of the Tourist Problem, a one-<span class="hlt">step</span> <span class="hlt">optimization</span> dynamics that can be viewed as a deterministic walk in a random medium. A certain amount of heterogeneity in the values of the resources to be visited causes the emergence of power-laws distributions for the <span class="hlt">steps</span> performed by the walker, similarly to a Lévy flight. The fluctuations of the <span class="hlt">step</span> lengths tend to decrease as a consequence of multiple-<span class="hlt">step</span> planning, thus reducing the foraging uncertainty. We find that the first and second <span class="hlt">steps</span> of each planned movement play very different roles in heterogeneous environments. The two-<span class="hlt">step</span> process improves only slightly the foraging efficiency compared to the one-<span class="hlt">step</span> <span class="hlt">optimization</span>, at a much higher computational cost. We discuss the implications of these findings for animal and human mobility, in particular in relation to the computational effort that informed agents should deploy to solve search problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JMSA...15..452V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JMSA...15..452V"><span><span class="hlt">Optimal</span> <span class="hlt">filtering</span> correction for marine dynamical positioning control system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Veremey, Evgeny; Sotnikova, Margarita</p> <p>2016-12-01</p> <p>The paper focuses on the problem of control law <span class="hlt">optimization</span> for marine vessels working in a dynamical positioning (DP) regime. The approach proposed here is based on the use of a special unified multipurpose control law structure constructed on the basis of nonlinear asymptotic observers, that allows the decoupling of a synthesis into simpler particular <span class="hlt">optimization</span> problems. The primary reason for the observers is to restore deficient information concerning the unmeasured velocities of the vessel. Using a number of separate items in addition to the observers, it is possible to achieve desirable dynamical features of the closed loop connection. The most important feature is the so-called dynamical corrector, and this paper is therefore devoted to solving its <span class="hlt">optimal</span> synthesis in marine vessels controlled by DP systems under the action of sea wave disturbances. The problem involves the need for minimal intensity of the control action determined by high frequency sea wave components. A specialized approach for designing the dynamical corrector is proposed and the applicability and effectiveness of the approach are illustrated using a practical example of underwater DP system synthesis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28086106','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28086106"><span>Inverse design of high-Q wave <span class="hlt">filters</span> in two-dimensional phononic crystals by topology <span class="hlt">optimization</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dong, Hao-Wen; Wang, Yue-Sheng; Zhang, Chuanzeng</p> <p>2017-04-01</p> <p>Topology <span class="hlt">optimization</span> of a waveguide-cavity structure in phononic crystals for designing narrow band <span class="hlt">filters</span> under the given operating frequencies is presented in this paper. We show that it is possible to obtain an ultra-high-Q <span class="hlt">filter</span> by only <span class="hlt">optimizing</span> the cavity topology without introducing any other coupling medium. The <span class="hlt">optimized</span> cavity with highly symmetric resonance can be utilized as the multi-channel <span class="hlt">filter</span>, raising <span class="hlt">filter</span> and T-splitter. In addition, most <span class="hlt">optimized</span> high-Q <span class="hlt">filters</span> have the Fano resonances near the resonant frequencies. Furthermore, our <span class="hlt">filter</span> <span class="hlt">optimization</span> based on the waveguide and cavity, and our simple illustration of a computational approach to wave control in phononic crystals can be extended and applied to design other acoustic devices or even opto-mechanical devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA618193','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA618193"><span><span class="hlt">Optimal</span> Numerical Schemes for Time Accurate Compressible Large Eddy Simulations: Comparison of Artificial Dissipation and <span class="hlt">Filtering</span> Schemes</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2014-11-01</p> <p>content (ie: low- pass response) 1) compare damping character of Artificial Dissipation and <span class="hlt">Filtering</span> 2) formulate <span class="hlt">filter</span> as an equivalent...Artificial Dissipation scheme - consequence of <span class="hlt">filter</span> damping for stiff problems 3) insight on achieving “ideal” low- pass response for general...require very high order for low- pass response –  overly dissipative for small time-<span class="hlt">steps</span> •  Implicit <span class="hlt">filters</span> can be efficiently designed for low- pass</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20599508','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20599508"><span>An <span class="hlt">optimized</span> locally adaptive non-local means denoising <span class="hlt">filter</span> for cryo-electron microscopy data.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wei, Dai-Yu; Yin, Chang-Cheng</p> <p>2010-12-01</p> <p>Cryo-electron microscopy (cryo-EM) now plays an important role in structural analysis of macromolecular complexes, organelles and cells. However, the cryo-EM images obtained close to focus and under low dose conditions have a very high level of noise and a very low contrast, which hinders high-resolution structural analysis. Here, an <span class="hlt">optimized</span> locally adaptive non-local (LANL) means <span class="hlt">filter</span>, which can preserve signal details and simultaneously significantly suppress noise for cryo-EM data, is presented. This <span class="hlt">filter</span> takes advantage of a wide range of pixels to estimate the denoised pixel values instead of the traditional <span class="hlt">filter</span> that only uses pixels in the local neighborhood. The <span class="hlt">filter</span> performed well on simulated data and showed promising results on raw cryo-EM images and tomograms. The predominant advantage of this <span class="hlt">optimized</span> LANL-means <span class="hlt">filter</span> is the structural signal and the background are clearly distinguishable. This locally adaptive non-local means <span class="hlt">filter</span> may become a useful tool in the analysis of cryo-EM data, such as automatic particle picking, extracting structural features and segmentation of tomograms.</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://hdl.handle.net/2060/20120008933','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120008933"><span>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://adsabs.harvard.edu/abs/2010EGUGA..12.5797B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.5797B"><span>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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20643606','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20643606"><span><span class="hlt">Optimal</span> design of FIR triplet halfband <span class="hlt">filter</span> bank and application in image coding.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kha, H H; Tuan, H D; Nguyen, T Q</p> <p>2011-02-01</p> <p>This correspondence proposes an efficient semidefinite programming (SDP) method for the design of a class of linear phase finite impulse response triplet halfband <span class="hlt">filter</span> banks whose <span class="hlt">filters</span> have <span class="hlt">optimal</span> frequency selectivity for a prescribed regularity order. The design problem is formulated as the minimization of the least square error subject to peak error constraints and regularity constraints. By using the linear matrix inequality characterization of the trigonometric semi-infinite constraints, it can then be exactly cast as a SDP problem with a small number of variables and, hence, can be solved efficiently. Several design examples of the triplet halfband <span class="hlt">filter</span> bank are provided for illustration and comparison with previous works. Finally, the image coding performance of the <span class="hlt">filter</span> bank is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.5745..283T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.5745..283T"><span>Image quality and dose <span class="hlt">optimization</span> using novel x-ray source <span class="hlt">filters</span> tailored to patient size</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Toth, Thomas L.; Cesmeli, Erdogan; Ikhlef, Aziz; Horiuchi, Tetsuya</p> <p>2005-04-01</p> <p>The expanding set of CT clinical applications demands increased attention to obtaining the maximum image quality at the lowest possible dose. Pre-patient beam shaping <span class="hlt">filters</span> provide an effective means to improve dose utilization. In this paper we develop and apply characterization methods that lead to a set of <span class="hlt">filters</span> appropriately matched to the patient. We developed computer models to estimate image noise and a patient size adjusted CTDI dose. The noise model is based on polychromatic X-ray calculations. The dose model is empirically derived by fitting CTDI style dose measurements for a demographically representative set of phantom sizes and shapes with various beam shaping <span class="hlt">filters</span>. The models were validated and used to determine the optimum IQ vs dose for a range of patient sizes. The models clearly show that an optimum beam shaping <span class="hlt">filter</span> exists as a function of object diameter. Based on noise and dose alone, overall dose efficiency advantages of 50% were obtained by matching the <span class="hlt">filter</span> shape to the size of the object. A set of patient matching <span class="hlt">filters</span> are used in the GE LightSpeed VCT and Pro32 to provide a practical solution for optimum image quality at the lowest possible dose over the range of patient sizes and clinical applications. Moreover, these <span class="hlt">filters</span> mark the beginning of personalized medicine where CT scanner image quality and radiation dose utilization is truly individualized and <span class="hlt">optimized</span> to the patient being scanned.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ESASP.740E.286K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ESASP.740E.286K"><span>Kalman <span class="hlt">Filtered</span> Daily GRACE Gravity Field Solutions in Near Real-Time- First <span class="hlt">Steps</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kvas, Andreas; Mayer-Gurr, Torsten</p> <p>2016-08-01</p> <p>As part of the EGSIEM (European Gravity Service for Improved Emergency Management) project, a technology demonstrator for a near real-time (NRT) gravity field service will be established. In preparation of the operational phase, several aspects of the daily gravity field processing chain at Graz University of Technology have been inspected in order to improve the gravity field solutions and move towards NRT. The effect of these adaptions is investigated by comparison with post-processing and forward-only <span class="hlt">filtered</span> solutions and evaluated using in-situ data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23609642','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23609642"><span>Design of reflective color <span class="hlt">filters</span> with high angular tolerance by particle swarm <span class="hlt">optimization</span> method.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Chenying; Hong, Liang; Shen, Weidong; Zhang, Yueguang; Liu, Xu; Zhen, Hongyu</p> <p>2013-04-22</p> <p>We propose three color <span class="hlt">filters</span> (red, green, blue) based on a two-dimensional (2D) grating, which maintain the same perceived specular colors for a broad range of incident angles with the average polarization. Particle swarm <span class="hlt">optimization</span> (PSO) method is employed to design these <span class="hlt">filters</span> for the first time to our knowledge. Two merit functions involving the reflectance curves and color difference in CIEDE2000 formula are respectively constructed to adjust the structural parameters during the <span class="hlt">optimization</span> procedure. Three primary color <span class="hlt">filters</span> located at 637nm, 530nm and 446nm with high saturation are obtained with the peak reflectance of 89%, 83%, 66%. The reflectance curves at different incident angles are coincident and the color difference is less than 8 for the incident angle up to 45°. The electric field distribution of the structure is finally studied to analyze the optical property.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AcMSn..32..649Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AcMSn..32..649Y"><span>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>2016-08-01</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('https://www.ncbi.nlm.nih.gov/pubmed/23844390','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23844390"><span>Efficient and accurate <span class="hlt">optimal</span> linear phase FIR <span class="hlt">filter</span> design using opposition-based harmony search algorithm.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Saha, S K; Dutta, R; Choudhury, R; Kar, R; Mandal, D; Ghoshal, S P</p> <p>2013-01-01</p> <p>In this paper, opposition-based harmony search has been applied for the <span class="hlt">optimal</span> design of linear phase FIR <span class="hlt">filters</span>. RGA, PSO, and DE have also been adopted for the sake of comparison. The original harmony search algorithm is chosen as the parent one, and opposition-based approach is applied. During the initialization, randomly generated population of solutions is chosen, opposite solutions are also considered, and the fitter one is selected as a priori guess. In harmony memory, each such solution passes through memory consideration rule, pitch adjustment rule, and then opposition-based reinitialization generation jumping, which gives the optimum result corresponding to the least error fitness in multidimensional search space of FIR <span class="hlt">filter</span> design. Incorporation of different control parameters in the basic HS algorithm results in the balancing of exploration and exploitation of search space. Low pass, high pass, band pass, and band stop FIR <span class="hlt">filters</span> are designed with the proposed OHS and other aforementioned algorithms individually for comparative <span class="hlt">optimization</span> performance. A comparison of simulation results reveals the <span class="hlt">optimization</span> efficacy of the OHS over the other <span class="hlt">optimization</span> techniques for the solution of the multimodal, nondifferentiable, nonlinear, and constrained FIR <span class="hlt">filter</span> design problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26486362','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26486362"><span>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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016OptLE..85...29R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OptLE..85...29R"><span>Two-<span class="hlt">step</span> fringe pattern analysis with a Gabor <span class="hlt">filter</span> bank</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rivera, Mariano; Dalmau, Oscar; Gonzalez, Adonai; Hernandez-Lopez, Francisco</p> <p>2016-10-01</p> <p>We propose a two-shot fringe analysis method for Fringe Patterns (FPs) with random phase-shift and changes in illumination components. These conditions reduce the acquisition time and simplify the experimental setup. Our method builds upon a Gabor <span class="hlt">Filter</span> (GF) bank that eliminates noise and estimates the phase from the FPs. The GF bank allows us to obtain two phase maps with a sign ambiguity between them. Due to the fact that the random sign map is common to both computed phases, we can correct the sign ambiguity. We estimate a local phase-shift from the absolute wrapped residual between the estimated phases. Next, we robustly compute the global phase-shift. In order to unwrap the phase, we propose a robust procedure that interpolates unreliable phase regions obtained after applying the GF bank. We present numerical experiments that demonstrate the performance of our method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24388927','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24388927"><span>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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004SPIE.5377.1323E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004SPIE.5377.1323E"><span>Implementation of pattern-specific illumination pupil <span class="hlt">optimization</span> on <span class="hlt">Step</span> & Scan systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Engelen, Andre; Socha, Robert J.; Hendrickx, Eric; Scheepers, Wieger; Nowak, Frank; Van Dam, Marco; Liebchen, Armin; Faas, Denis A.</p> <p>2004-05-01</p> <p><span class="hlt">Step</span>&Scan systems are pushed towards low k1 applications. Contrast enhancement techniques are crucial for successful implementation of these applications in a production environment. A NA - sigma - illumination mode <span class="hlt">optimizer</span> and a contrast-based <span class="hlt">optimization</span> algorithm are implemented in LithoCruiser in order to <span class="hlt">optimize</span> illumination setting and illumination pupil for a specific repetitive pattern. Calculated illumination pupils have been realized using Diffractive Optical Elements (DOE), which are supported by ASML's AERIAL II illuminator. The qualification of the illumination pupil is done using inline metrology on the ASML <span class="hlt">Step</span> & Scan system. This paper describes the process of pattern specific illumination <span class="hlt">optimization</span> for a given mask. Multiple examples will be used to demonstrate the advantage of using non-standard illumination pupils.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940031131','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940031131"><span>Comparison of Kalman <span class="hlt">filter</span> and <span class="hlt">optimal</span> smoother estimates of spacecraft attitude</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sedlak, J.</p> <p>1994-01-01</p> <p>Given a valid system model and adequate observability, a Kalman <span class="hlt">filter</span> will converge toward the true system state with error statistics given by the estimated error covariance matrix. The errors generally do not continue to decrease. Rather, a balance is reached between the gain of information from new measurements and the loss of information during propagation. The errors can be further reduced, however, by a second pass through the data with an <span class="hlt">optimal</span> smoother. This algorithm obtains the <span class="hlt">optimally</span> weighted average of forward and backward propagating Kalman <span class="hlt">filters</span>. It roughly halves the error covariance by including future as well as past measurements in each estimate. This paper investigates whether such benefits actually accrue in the application of an <span class="hlt">optimal</span> smoother to spacecraft attitude determination. Tests are performed both with actual spacecraft data from the Extreme Ultraviolet Explorer (EUVE) and with simulated data for which the true state vector and noise statistics are exactly known.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26569247','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26569247"><span><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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hu, Shaoxing; Xu, Shike; Wang, Duhu; Zhang, Aiwu</p> <p>2015-11-11</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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4701286','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4701286"><span><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.osti.gov/scitech/servlets/purl/1010409','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1010409"><span>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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003nlgd.conf..172H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003nlgd.conf..172H"><span>Data Reduction in the Gravity Probe B Experiment: <span class="hlt">Optimal</span> Estimation and <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>Heifetz, M. I.; Keiser, G. M.; Silbergleit, A. S.</p> <p>2003-05-01</p> <p>Data analysis is one of the most essential components of the Gravity Probe B (GP-B) experiment. We discuss three main problems that need to be resolve in the data reduction: 1)direct observation of the GP-B gyroscope's precession angle; 2)precise estimation of the gyroscope's geodetic and frame-draggig average drift rates; 3)gyroscope-telescope matching: elimination of the reference direction pointing error. We formulate these problems from the point of view of the modern control theory and describe our approach to the GP-B data analysis as the "bank" of <span class="hlt">filters</span> that estimate the model-dependent system state vectors and calculate corresponding covariance matrices. For the problems 1), 2), and 3) estimation recursive algorithms are obtained based on the two-<span class="hlt">step</span> nonlinear <span class="hlt">filtering</span> approach and these <span class="hlt">filters</span> will be used in the GP-B data reduction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150009149&hterms=PASSIVE+FILTER&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DPASSIVE%2BFILTER','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150009149&hterms=PASSIVE+FILTER&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DPASSIVE%2BFILTER"><span><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://adsabs.harvard.edu/abs/2016EnOp...48..519R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EnOp...48..519R"><span>Multi-<span class="hlt">step</span> <span class="hlt">optimization</span> strategy for fuel-<span class="hlt">optimal</span> orbital transfer of low-thrust spacecraft</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rasotto, M.; Armellin, R.; Di Lizia, P.</p> <p>2016-03-01</p> <p>An effective method for the design of fuel-<span class="hlt">optimal</span> transfers in two- and three-body dynamics is presented. The <span class="hlt">optimal</span> control problem is formulated using calculus of variation and primer vector theory. This leads to a multi-point boundary value problem (MPBVP), characterized by complex inner constraints and a discontinuous thrust profile. The first issue is addressed by embedding the MPBVP in a parametric <span class="hlt">optimization</span> problem, thus allowing a simplification of the set of transversality constraints. The second problem is solved by representing the discontinuous control function by a smooth function depending on a continuation parameter. The resulting trajectory <span class="hlt">optimization</span> method can deal with different intermediate conditions, and no a priori knowledge of the control structure is required. Test cases in both the two- and three-body dynamics show the capability of the method in solving complex trajectory design problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26517548','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26517548"><span>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="https://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.</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://adsabs.harvard.edu/abs/2014AIPC.1602..601C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AIPC.1602..601C"><span>Global <span class="hlt">optimization</span> using homotopy with 2-<span class="hlt">step</span> predictor-corrector method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chang, Kerk Lee; Ahmad, Rohanin Bt.</p> <p>2014-06-01</p> <p>In this research, we suggest a new method for solving global <span class="hlt">optimization</span> problem by improving Homotopy <span class="hlt">Optimization</span> with Perturbations and Ensembles (HOPE) method. Our new method, named as Homotopy 2-<span class="hlt">Step</span> Predictor-corrector Method (HSPM) is based on the intermediate Value Theorem (IVT) coupled with modified Predictor-Corrector Halley method (PCH) for solving global <span class="hlt">optimization</span> problem. HSPM does not require a good initial guess since it contains the element of homotopy, which is a globally convergent method. This paper discusses the time complexity of the new algorithm, which makes it more efficient than HOPE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26724066','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26724066"><span>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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22482666','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22482666"><span>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/2009MSSP...23..652C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009MSSP...23..652C"><span><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('https://ntrs.nasa.gov/search.jsp?R=20050123787&hterms=Richard+Muller&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DRichard%2BA.%2BMuller','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20050123787&hterms=Richard+Muller&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DRichard%2BA.%2BMuller"><span>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</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>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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22285081','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22285081"><span>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('https://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="https://ntrs.nasa.gov/search.jsp?R=19950028531&hterms=discrimination&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddiscrimination"><span><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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5316463','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5316463"><span>Retinal Image Denoising via Bilateral <span class="hlt">Filter</span> with a Spatial Kernel of <span class="hlt">Optimally</span> Oriented Line Spread Function</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>He, Yunlong; Zhao, Yanna; Ren, Yanju; Gee, James</p> <p>2017-01-01</p> <p><span class="hlt">Filtering</span> belongs to the most fundamental operations of retinal image processing and for which the value of the <span class="hlt">filtered</span> image at a given location is a function of the values in a local window centered at this location. However, preserving thin retinal vessels during the <span class="hlt">filtering</span> process is challenging due to vessels' small area and weak contrast compared to background, caused by the limited resolution of imaging and less blood flow in the vessel. In this paper, we present a novel retinal image denoising approach which is able to preserve the details of retinal vessels while effectively eliminating image noise. Specifically, our approach is carried out by determining an <span class="hlt">optimal</span> spatial kernel for the bilateral <span class="hlt">filter</span>, which is represented by a line spread function with an orientation and scale adjusted adaptively to the local vessel structure. Moreover, this approach can also be served as a preprocessing tool for improving the accuracy of the vessel detection technique. Experimental results show the superiority of our approach over state-of-the-art image denoising techniques such as the bilateral <span class="hlt">filter</span>. PMID:28261320</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>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/2010EGUGA..12.5485W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.5485W"><span>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</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><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('https://www.ncbi.nlm.nih.gov/pubmed/25950644','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25950644"><span><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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</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('https://www.ncbi.nlm.nih.gov/pubmed/27247483','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27247483"><span>Creation of an iOS and Android Mobile Application for Inferior Vena Cava (IVC) <span class="hlt">Filters</span>: A Powerful Tool to <span class="hlt">Optimize</span> Care of Patients with IVC <span class="hlt">Filters</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Deso, Steven E; Idakoji, Ibrahim A; Muelly, Michael C; Kuo, William T</p> <p>2016-06-01</p> <p>Owing to a myriad of inferior vena cava (IVC) <span class="hlt">filter</span> types and their potential complications, rapid and correct identification may be challenging when encountered on routine imaging. The authors aimed to develop an interactive mobile application that allows recognition of all IVC <span class="hlt">filters</span> and related complications, to <span class="hlt">optimize</span> the care of patients with indwelling IVC <span class="hlt">filters</span>. The FDA Premarket Notification Database was queried from 1980 to 2014 to identify all IVC <span class="hlt">filter</span> types in the United States. An electronic search was then performed on MEDLINE and the FDA MAUDE database to identify all reported complications associated with each device. High-resolution photos were taken of each <span class="hlt">filter</span> type and corresponding computed tomographic and fluoroscopic images were obtained from an institutional review board-approved IVC <span class="hlt">filter</span> registry. A wireframe and storyboard were created, and software was developed using HTML5/CSS compliant code. The software was deployed using PhoneGap (Adobe, San Jose, CA), and the prototype was tested and refined. Twenty-three IVC <span class="hlt">filter</span> types were identified for inclusion. Safety data from FDA MAUDE and 72 relevant peer-reviewed studies were acquired, and complication rates for each <span class="hlt">filter</span> type were highlighted in the application. Digital photos, fluoroscopic images, and CT DICOM files were seamlessly incorporated. All data were succinctly organized electronically, and the software was successfully deployed into Android (Google, Mountain View, CA) and iOS (Apple, Cupertino, CA) platforms. A powerful electronic mobile application was successfully created to allow rapid identification of all IVC <span class="hlt">filter</span> types and related complications. This application may be used to <span class="hlt">optimize</span> the care of patients with IVC <span class="hlt">filters</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25386617','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25386617"><span>Miniaturized bandpass <span class="hlt">filter</span> using a meandered <span class="hlt">stepped</span>-impedance resonator with a meandered-line stub-load on a GaAs substrate.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chuluunbaatar, Z; Wang, C; Kim, N Y</p> <p>2014-01-01</p> <p>This paper reports a compact bandpass <span class="hlt">filter</span> with improved skirt selectivity using integrated passive device fabrication technology on a GaAs substrate. The structure of the <span class="hlt">filter</span> consists of electromagnetically coupled meandered-line symmetric <span class="hlt">stepped</span>-impedance resonators. The strength of the coupling between the resonators is enhanced by using a meandered-line stub-load inside the resonators to improve the selectivity and miniaturize the size of the <span class="hlt">filter</span>. In addition, the center frequency of the <span class="hlt">filter</span> can be flexibly controlled by varying degrees of the capacitive coupling between resonator and stub-load. To verify the proposed concept, a protocol bandpass <span class="hlt">filter</span> with center frequency of 6.53 GHz was designed, fabricated, and measured, with a return loss and insertion loss of 39.1 dB and 1.63 dB.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20392564','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20392564"><span><span class="hlt">Optimization</span> of EFTEM image acquisition by using elastically <span class="hlt">filtered</span> images for drift correction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Heil, Tobias; Kohl, Helmut</p> <p>2010-06-01</p> <p>Because of its high spatial resolution, energy-<span class="hlt">filtering</span> transmission electron microscopy (EFTEM) has become widely used for the analysis of the chemical composition of nanostructures. To obtain the best spatial resolution, the precise correction of instrumental influences and the <span class="hlt">optimization</span> of the data acquisition procedure are very important. In this publication, we discuss a modified image acquisition procedure that <span class="hlt">optimizes</span> the acquisition process of the EFTEM images, especially for long exposure times and measurements that are affected by large spatial drift. To alleviate the blurring of the image caused by the spatial drift, we propose to take several EFTEM images with a shorter exposure time (sub-images) and merge these sub-images afterwards. To correct for the drift between these sub-images, elastically <span class="hlt">filtered</span> images are acquired between two subsequent sub-images. These elastically <span class="hlt">filtered</span> images are highly suitable for spatial drift correction based on the cross-correlation method. The use of the drift information between two elastically <span class="hlt">filtered</span> images permits to merge the drift-corrected sub-images automatically and with high accuracy, resulting in sharper edges and an improved signal intensity in the final EFTEM image. Artefacts that are caused by prominent noise-peaks in the dark reference image have been suppressed by calculating the dark reference image from three images. Furthermore, using the information given by the elastically <span class="hlt">filtered</span> images, it is possible to drift-correct a set of EFTEM images already during the acquisition. This simplifies the post-processing for elemental mapping and offers the possibility for active drift correction using the image shift function of the microscope, leading to an increased field of view.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B33B0474H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B33B0474H"><span><span class="hlt">Optimization</span> of ecosystem model parameters with different temporal variabilities using tower flux data and an ensemble 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>He, L.; Chen, J. M.; Liu, J.; Mo, G.; Zhen, T.; Chen, B.; Wang, R.; Arain, M.</p> <p>2013-12-01</p> <p>Terrestrial ecosystem models have been widely used to simulate carbon, water and energy fluxes and climate-ecosystem interactions. In these models, some vegetation and soil parameters are determined based on limited studies from literatures without consideration of their seasonal variations. Data assimilation (DA) provides an effective way to <span class="hlt">optimize</span> these parameters at different time scales . In this study, an ensemble Kalman <span class="hlt">filter</span> (EnKF) is developed and applied to <span class="hlt">optimize</span> two key parameters of an ecosystem model, namely the Boreal Ecosystem Productivity Simulator (BEPS): (1) the maximum photosynthetic carboxylation rate (Vcmax) at 25 °C, and (2) the soil water stress factor (fw) for stomatal conductance formulation. These parameters are <span class="hlt">optimized</span> through assimilating observations of gross primary productivity (GPP) and latent heat (LE) fluxes measured in a 74 year-old pine forest, which is part of the Turkey Point Flux Station's age-sequence sites. Vcmax is related to leaf nitrogen concentration and varies slowly over the season and from year to year. In contrast, fw varies rapidly in response to soil moisture dynamics in the root-zone. Earlier studies suggested that DA of vegetation parameters at daily time <span class="hlt">steps</span> leads to Vcmax values that are unrealistic. To overcome the problem, we developed a three-<span class="hlt">step</span> scheme to <span class="hlt">optimize</span> Vcmax and fw. First, the EnKF is applied daily to obtain precursor estimates of Vcmax and fw. Then Vcmax is <span class="hlt">optimized</span> at different time scales assuming fw is unchanged from first <span class="hlt">step</span>. The best temporal period or window size is then determined by analyzing the magnitude of the minimized cost-function, and the coefficient of determination (R2) and Root-mean-square deviation (RMSE) of GPP and LE between simulation and observation. Finally, the daily fw value is <span class="hlt">optimized</span> for rain free days corresponding to the Vcmax curve from the best window size. The <span class="hlt">optimized</span> fw is then used to model its relationship with soil moisture. We found that</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>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('https://www.ncbi.nlm.nih.gov/pubmed/2065151','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/2065151"><span><span class="hlt">Optimization</span> of an adaptive nonlinear <span class="hlt">filter</span> for the analysis of nystagmus.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Engelken, E J; Stevens, K W; Enderle, J D</p> <p>1991-01-01</p> <p>An adaptive nonlinear digital <span class="hlt">filter</span> has been designed for the analysis of an eye-movement signal called nystagmus. Nystagmus is a bi-phasic signal consisting of a sequence of tracking eye movements called "slow-phase" interspersed with brief, high-velocity refixation movements called "fast-phase." The objective of the analysis is to separate the nystagmus signal into its fast- and slow-phase components. Specifically, the goal is to produce an evenly sampled estimate of slow-phase velocity (SPV) and an estimate of the peak fast-phase velocity. Classically this has been done using pattern recognition methods that exploit the fact that the fast-phase is a relatively short duration, high-velocity movement compared to the slow-phase. Unfortunately, these velocity and duration differences do not reliably separate the slow- and fast-phases under all conditions, especially when the signal is noisy. We have designed and built an adaptive nonlinear digital <span class="hlt">filter</span> that easily outperforms the more complex pattern recognition algorithms. This new <span class="hlt">filter</span>, called an Adaptive Asymmetrically Trimmed-Mean (AATM) <span class="hlt">filter</span>, works under the assumption that, on the average, the eyes spend more time in slow-phase than in fast-phase. Thus, in any given data segment, most of the data samples are slow-phase samples. By analyzing the amplitude distribution of the data samples in the segment we can determine which of these samples are slow-phase. We used computer generated nystagmus signals contaminated with 3 levels of noise to evaluate the <span class="hlt">filter</span>. The <span class="hlt">filter</span> parameters were then <span class="hlt">optimized</span> using Monte Carlo procedures producing an extremely robust analysis method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25034647','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25034647"><span>Design of two-channel <span class="hlt">filter</span> bank using nature inspired <span class="hlt">optimization</span> based fractional derivative constraints.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kuldeep, B; Singh, V K; Kumar, A; Singh, G K</p> <p>2015-01-01</p> <p>In this article, a novel approach for 2-channel linear phase quadrature mirror <span class="hlt">filter</span> (QMF) bank design based on a hybrid of gradient based <span class="hlt">optimization</span> and <span class="hlt">optimization</span> of fractional derivative constraints is introduced. For the purpose of this work, recently proposed nature inspired <span class="hlt">optimization</span> techniques such as cuckoo search (CS), modified cuckoo search (MCS) and wind driven <span class="hlt">optimization</span> (WDO) are explored for the design of QMF bank. 2-Channel QMF is also designed with particle swarm <span class="hlt">optimization</span> (PSO) and artificial bee colony (ABC) nature inspired <span class="hlt">optimization</span> techniques. The design problem is formulated in frequency domain as sum of L2 norm of error in passband, stopband and transition band at quadrature frequency. The contribution of this work is the novel hybrid combination of gradient based <span class="hlt">optimization</span> (Lagrange multiplier method) and nature inspired <span class="hlt">optimization</span> (CS, MCS, WDO, PSO and ABC) and its usage for <span class="hlt">optimizing</span> the design problem. Performance of the proposed method is evaluated by passband error (ϕp), stopband error (ϕs), transition band error (ϕt), peak reconstruction error (PRE), stopband attenuation (As) and computational time. The design examples illustrate the ingenuity of the proposed method. Results are also compared with the other existing algorithms, and it was found that the proposed method gives best result in terms of peak reconstruction error and transition band error while it is comparable in terms of passband and stopband error. Results show that the proposed method is successful for both lower and higher order 2-channel QMF bank design. A comparative study of various nature inspired <span class="hlt">optimization</span> techniques is also presented, and the study singles out CS as a best QMF <span class="hlt">optimization</span> technique.</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://adsabs.harvard.edu/abs/2015ChPhC..39a8101L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ChPhC..39a8101L"><span><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('https://www.osti.gov/scitech/biblio/21120896','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21120896"><span>Combining segment generation with direct <span class="hlt">step</span>-and-shoot <span class="hlt">optimization</span> in intensity-modulated radiation therapy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Carlsson, Fredrik</p> <p>2008-09-15</p> <p>A method for generating a sequence of intensity-modulated radiation therapy <span class="hlt">step</span>-and-shoot plans with increasing number of segments is presented. The objectives are to generate high-quality plans with few, large and regular segments, and to make the planning process more intuitive. The proposed method combines segment generation with direct <span class="hlt">step</span>-and-shoot <span class="hlt">optimization</span>, where leaf positions and segment weights are <span class="hlt">optimized</span> simultaneously. The segment generation is based on a column generation approach. The method is evaluated on a test suite consisting of five head-and-neck cases and five prostate cases, planned for delivery with an Elekta SLi accelerator. The adjustment of segment shapes by direct <span class="hlt">step</span>-and-shoot <span class="hlt">optimization</span> improves the plan quality compared to using fixed segment shapes. The improvement in plan quality when adding segments is larger for plans with few segments. Eventually, adding more segments contributes very little to the plan quality, but increases the plan complexity. Thus, the method provides a tool for controlling the number of segments and, indirectly, the delivery time. This can support the planner in finding a sound trade-off between plan quality and treatment complexity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MMTB...46..473T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MMTB...46..473T"><span><span class="hlt">Optimization</span> of a Permanent <span class="hlt">Step</span> Mold Design for Mg Alloy Castings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Timelli, Giulio; Capuzzi, Stefano; Bonollo, Franco</p> <p>2015-02-01</p> <p>The design of a permanent <span class="hlt">Step</span> mold for the evaluation of the mechanical properties of light alloys has been reviewed. An <span class="hlt">optimized</span> <span class="hlt">Step</span> die with a different runner and gating systems is proposed to minimize the amount of casting defects. Numerical simulations have been performed to study the filling and solidification behavior of an AM60B alloy to predict the turbulence of the melt and the microshrinkage formation. The results reveal how a correct design of the trap in the runners prevents the backwave of molten metal, which could eventually reverse out and enter the die cavity. The tapered runner in the <span class="hlt">optimized</span> die configuration gently leads the molten metal to the ingate, avoiding turbulence and producing a balanced die cavity filling. The connection between the runner system and the die cavity by means of a fan ingate produces a laminar filling in contrast with a finger-type ingate. Solidification defects such as shrinkage-induced microporosity, numerically predicted through a dimensionless version of the Niyama criterion, are considerably reduced in the <span class="hlt">optimized</span> permanent <span class="hlt">Step</span> mold.</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>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('https://www.osti.gov/scitech/biblio/22413389','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22413389"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/23388811','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23388811"><span><span class="hlt">Optimal</span> synthesis of double-phase computer generated holograms using a phase-only spatial light modulator with grating <span class="hlt">filter</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Song, Hoon; Sung, Geeyoung; Choi, Sujin; Won, Kanghee; Lee, Hong-Seok; Kim, Hwi</p> <p>2012-12-31</p> <p>We propose an optical system for synthesizing double-phase complex computer-generated holograms using a phase-only spatial light modulator and a phase grating <span class="hlt">filter</span>. Two separated areas of the phase-only spatial light modulator are optically superposed by 4-f configuration with an <span class="hlt">optimally</span> designed grating <span class="hlt">filter</span> to synthesize arbitrary complex optical field distributions. The tolerances related to misalignment factors are analyzed, and the <span class="hlt">optimal</span> synthesis method of double-phase computer-generated holograms is described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26736755','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26736755"><span>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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Yubo; Mohanarangam, Krithikaa; Mallipeddi, Rammohan; Veluvolu, K C</p> <p>2015-01-01</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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EnOp...42...45N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EnOp...42...45N"><span>IFQP: A hybrid <span class="hlt">optimization</span> method for <span class="hlt">filter</span> management in fluid power systems under uncertainty</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nie, S. L.; Li, Y. P.; Xiong, Z. B.; Huang, G. H.; Hu, B.</p> <p>2010-01-01</p> <p>An interval-fuzzy quadratic programming (IFQP) method is developed for the assessment of <span class="hlt">filter</span> allocation and replacement strategies in fluid power systems (FPS) under uncertainty. It can directly handle uncertainties expressed as interval values and/or fuzzy sets that exist in the left-hand and right-hand sides of constraints, as well as in the objective function. Multiple control variables are used to tackle independent uncertainties in the model's right-hand sides and thus <span class="hlt">optimize</span> the overall satisfaction of the system performance. The IFQP method is applied to a case of planning <span class="hlt">filter</span> allocation and replacement strategies under uncertainty for an FPS with a single circuit. A piecewise linearization approach is firstly employed to convert the nonlinear FPS problem into a linear one. The generated decision alternatives can help decision makers to identify desired policies for contamination control under various total costs, satisfaction degrees, and system-failure risks under different contaminant-ingression/generation rates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MSSP...85..146L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MSSP...85..146L"><span>Diagonal slice spectrum assisted <span class="hlt">optimal</span> scale morphological <span class="hlt">filter</span> for rolling element bearing fault diagnosis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Yifan; Liang, Xihui; Zuo, Ming J.</p> <p>2017-02-01</p> <p>This paper presents a novel signal processing scheme, diagonal slice spectrum assisted <span class="hlt">optimal</span> scale morphological <span class="hlt">filter</span> (DSS-OSMF), for rolling element fault diagnosis. In this scheme, the concept of quadratic frequency coupling (QFC) is firstly defined and the ability of diagonal slice spectrum (DSS) in detection QFC is derived. The DSS-OSMF possesses the merits of depressing noise and detecting QFC. It can remove fault independent frequency components and give a clear representation of fault symptoms. A simulated vibration signal and experimental vibration signals collected from a bearing test rig are employed to evaluate the effectiveness of the proposed method. Results show that the proposed method has a superior performance in extracting fault features of defective rolling element bearing. In addition, comparisons are performed between a multi-scale morphological <span class="hlt">filter</span> (MMF) and a DSS-OSMF. DSS-OSMF outperforms MMF in detection of an outer race fault and a rolling element fault of a rolling element bearing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21096003','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21096003"><span>Common spatial pattern patches - an <span class="hlt">optimized</span> <span class="hlt">filter</span> ensemble for adaptive brain-computer interfaces.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sannelli, Claudia; Vidaurre, Carmen; Muller, Klaus-Robert; Blankertz, Benjamin</p> <p>2010-01-01</p> <p>Laplacian <span class="hlt">filters</span> are commonly used in Brain Computer Interfacing (BCI). When only data from few channels are available, or when, like at the beginning of an experiment, no previous data from the same user is available complex features cannot be used. In this case band power features calculated from Laplacian <span class="hlt">filtered</span> channels represents an easy, robust and general feature to control a BCI, since its calculation does not involve any class information. For the same reason, the performance obtained with Laplacian features is poor in comparison to subject-specific <span class="hlt">optimized</span> spatial <span class="hlt">filters</span>, such as Common Spatial Patterns (CSP) analysis, which, on the other hand, can be used just in a later phase of the experiment, since they require a considerable amount of training data in order to enroll a stable and good performance. This drawback is particularly evident in case of poor performing BCI users, whose data is highly non-stationary and contains little class relevant information. Therefore, Laplacian <span class="hlt">filtering</span> is preferred to CSP, e.g., in the initial period of co-adaptive calibration, a novel BCI paradigm designed to alleviate the problem of BCI illiteracy. In fact, in the co-adaptive calibration design the experiment starts with a subject-independent classifier and simple features are needed in order to obtain a fast adaptation of the classifier to the newly acquired user's data. Here, the use of an ensemble of local CSP patches (CSPP) is proposed, which can be considered as a compromise between Laplacians and CSP: CSPP needs less data and channels than CSP, while being superior to Laplacian <span class="hlt">filtering</span>. This property is shown to be particularly useful for the co-adaptive calibration design and is demonstrated on off-line data from a previous co-adaptive BCI study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10817828','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10817828"><span><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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16696461','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16696461"><span>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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cao, Daliang; Earl, Matthew A; Luan, Shuang; Shepard, David M</p> <p>2006-04-01</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 Pinnacle3 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/2016JEE....67..358H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JEE....67..358H"><span>A Multi-Objective <span class="hlt">Optimization</span> for Performance Improvement of the Z-Source Active Power <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>Hosseini, Seyed Mohsen; Beromi, Yousef Alinejad</p> <p>2016-09-01</p> <p>The high power dissipation is one of the most important problems of the z-source inverter (ZSI). By using an appropriate <span class="hlt">optimization</span> scheme, the losses can be significantly reduced without any negative impact on the other characteristics of the inverter. In this paper, a multi-objective <span class="hlt">optimization</span> is implemented in order to reduce the ZSI total losses as well as to improve the z-source active power <span class="hlt">filter</span> (APF) performance. The <span class="hlt">optimization</span> is focused on the four important objectives including power losses of the Z-source APF, the initial cost of the system components, the voltage and current ripples, and the boost factor of the z-source network. For these purposes, the multi-objective genetic algorithm (MOGA) is employed. The numerical and simulation results are presented to evaluate the <span class="hlt">optimization</span> performance. The results show that a good balance can be achieved between the switching power losses, the voltage-current ripple levels, the component costs and the boost factor using the <span class="hlt">optimized</span> parameters.</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>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('https://www.ncbi.nlm.nih.gov/pubmed/17522318','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17522318"><span><span class="hlt">Optimal</span> sensorimotor integration in recurrent cortical networks: a neural implementation of Kalman <span class="hlt">filters</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Denève, Sophie; Duhamel, Jean-René; Pouget, Alexandre</p> <p>2007-05-23</p> <p>Several behavioral experiments suggest that the nervous system uses an internal model of the dynamics of the body to implement a close approximation to a Kalman <span class="hlt">filter</span>. This <span class="hlt">filter</span> can be used to perform a variety of tasks nearly <span class="hlt">optimally</span>, such as predicting the sensory consequence of motor action, integrating sensory and body posture signals, and computing motor commands. We propose that the neural implementation of this Kalman <span class="hlt">filter</span> involves recurrent basis function networks with attractor dynamics, a kind of architecture that can be readily mapped onto cortical circuits. In such networks, the tuning curves to variables such as arm velocity are remarkably noninvariant in the sense that the amplitude and width of the tuning curves of a given neuron can vary greatly depending on other variables such as the position of the arm or the reliability of the sensory feedback. This property could explain some puzzling properties of tuning curves in the motor and premotor cortex, and it leads to several new predictions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006SPIE.6272E..1TP','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006SPIE.6272E..1TP"><span>First laboratory demonstration of closed-loop Kalman based <span class="hlt">optimal</span> control for vibration <span class="hlt">filtering</span> and simplified MCAO</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Petit, C.; Conan, J.-M.; Kulcsár, C.; Raynaud, H.-F.; Fusco, T.; Montri, J.; Rabaud, D.</p> <p>2006-06-01</p> <p>Classic Adaptive Optics (AO) is now successfully implemented on a growing number of ground-based imaging systems. Nevertheless some limitations are still to cope with. First, the AO standard control laws are unable to easily handle vibrations. In the particular case of eXtreme AO (XAO), which requires a highly efficient AO, these vibrations can thus be much penalizing. We have previously shown that a Kalman based control law can provide both an efficient correction of the turbulence and a strong vibration <span class="hlt">filtering</span>. Second, anisoplanatism effects lead to a small corrected field of view. Multi-Conjugate AO (MCAO) is a promising concept that should increase significantly this field of view. We have shown numerically that MCAO correction can be highly improved by <span class="hlt">optimal</span> control based on a Kalman <span class="hlt">filter</span>. This article presents the first laboratory demonstration of these two concepts. We use a classic AO bench available at Onera with a deformable mirror (DM) in the pupil and a Shack-Hartmann Wave Front Sensor (WFS) pointing at an on-axis guide-star. The turbulence is produced by a rotating phase screen in altitude. First, this AO configuration is used to validate the ability of our control approach to <span class="hlt">filter</span> out system vibrations and improve the overall performance of the AO closed-loop, compared to classic controllers. The consequences on the RTC design of an XAO system is discussed. Then, we <span class="hlt">optimize</span> the correction for an off-axis star although the WFS still points at the on-axis star. This Off-Axis AO (OAAO) can be seen as a first <span class="hlt">step</span> towards MCAO or Multi-Object AO in a simplified configuration. It proves the ability of our control law to estimate the turbulence in altitude and correct in the direction of interest. We describe the off-axis correction tests performed in a dynamic mode (closed-loop) using our Kalman based control. We present the evolution of the off-axis correction according to the angular separation between the stars. A highly significant</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26575920','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26575920"><span>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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Suleimanov, Yury V; Green, William H</p> <p>2015-09-08</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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995SPIE.2491..248H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995SPIE.2491..248H"><span><span class="hlt">Optimized</span> perfect reconstruction quadrature mirror <span class="hlt">filter</span> (PR-QMF) based codes for multi-user communications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hetling, Kenneth J.; Saulnier, Gary J.; Das, Pankaj K.</p> <p>1995-04-01</p> <p>In communications systems, the message signal is sometimes spread over a large bandwidth in order to realize performance gains in the presence of narrowband interference, multipath propagation, and multiuser interference. The extent to which performance is improved is highly dependent upon the spreading code implemented. Traditionally, the spreading codes have consisted of pseudo-noise (PN) sequences whose chip values are limited to bipolar values. Recently, however, alternatives to the PN sequences have been studied including wavelet based and PR-QMF based spreading codes. The spreading codes implemented are the basis functions of a particular wavelet transform or PR-QMF bank. Since the choice of available basis functions is much larger than that of PN sequences, it is hoped that better performance can be achieved by choosing a basis tailored to the system requirements mentioned above. In this paper, a design method is presented to construct a PR-QMF bank which will generate spreading codes <span class="hlt">optimized</span> for operating in a multiuser interference environment. Objective functions are developed for the design criteria and a multivariable constrained <span class="hlt">optimization</span> problem is employed to generate the coefficients used in the <span class="hlt">filter</span> bank. Once the <span class="hlt">filter</span> bank is complete, the spreading codes are extracted and implemented in the spread spectrum system. System bit error rate (BER) curves are generated from computer simulation for analysis. Curves are generated for both the single user and the CDMA environment and performance is compared to that attained using gold codes.</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>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('https://ntrs.nasa.gov/search.jsp?R=20050180257&hterms=impedance&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dimpedance','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20050180257&hterms=impedance&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dimpedance"><span>Ultra-Compact Broadband High-Spurious Suppression Bandpass <span class="hlt">Filter</span> Using Double Split-end <span class="hlt">Stepped</span> Impedance Resonators</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; Wollack, Ed; Papapolymerou, John; Laskar, Joy</p> <p>2005-01-01</p> <p>We propose an ultra compact single-layer spurious suppression band pass <span class="hlt">filter</span> design which has the following benefit: 1) Effective coupling area can be increased with no fabrication limitation and no effect on the spurious response; 2) Two fundamental poles are introduced to suppress spurs; 3) <span class="hlt">Filter</span> can be designed with up to 30% bandwidth; 4) The <span class="hlt">Filter</span> length is reduced by at least 100% when compared to the conventional <span class="hlt">filter</span>; 5) Spurious modes are suppressed up to at the seven times the fundamental frequency; and 6) It uses only one layer of metallization which minimize the fabrication cost.</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('https://www.ncbi.nlm.nih.gov/pubmed/26748662','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26748662"><span>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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25271026','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25271026"><span><span class="hlt">Optimization</span> of a preparative multimodal ion exchange <span class="hlt">step</span> for purification of a potential malaria vaccine.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Paul, Jessica; Jensen, Sonja; Dukart, Arthur; Cornelissen, Gesine</p> <p>2014-10-31</p> <p>In 2000 the implementation of quality by design (QbD) was introduced by the Food and Drug Administration (FDA) and described in the ICH Q8, Q9 and Q10 guidelines. Since that time, systematic <span class="hlt">optimization</span> strategies for purification of biopharmaceuticals have gained a more important role in industrial process development. In this investigation, the <span class="hlt">optimization</span> strategy was carried out by adopting design of experiments (DoE) in small scale experiments. A combination method comprising a desalting and a multimodal ion exchange <span class="hlt">step</span> was used for the experimental runs via the chromatographic system ÄKTA™ avant. The multimodal resin Capto™ adhere was investigated as an alternative to conventional ion exchange and hydrophobic interaction resins for the intermediate purification of the potential malaria vaccine D1M1. The ligands, used in multimodal chromatography, interact with the target molecule in different ways. The multimodal functionality includes the binding of proteins in spite of the ionic strength of the loading material. The target protein binds at specific salt conditions and can be eluted by a <span class="hlt">step</span> gradient decreasing the pH value and reducing the ionic strength. It is possible to achieve a maximized purity and recovery of the product because degradation products and other contaminants do not bind at specific salt concentrations at which the product still binds to the ligands.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19586794','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19586794"><span><span class="hlt">Optimal</span> real-time Q-ball imaging using regularized Kalman <span class="hlt">filtering</span> with incremental orientation sets.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Deriche, Rachid; Calder, Jeff; Descoteaux, Maxime</p> <p>2009-08-01</p> <p>Diffusion MRI has become an established research tool for the investigation of tissue structure and orientation. Since its inception, Diffusion MRI has expanded considerably to include a number of variations such as diffusion tensor imaging (DTI), diffusion spectrum imaging (DSI) and Q-ball imaging (QBI). The acquisition and analysis of such data is very challenging due to its complexity. Recently, an exciting new Kalman <span class="hlt">filtering</span> framework has been proposed for DTI and QBI reconstructions in real-time during the repetition time (TR) of the acquisition sequence. In this article, we first revisit and thoroughly analyze this approach and show it is actually sub-<span class="hlt">optimal</span> and not recursively minimizing the intended criterion due to the Laplace-Beltrami regularization term. Then, we propose a new approach that implements the QBI reconstruction algorithm in real-time using a fast and robust Laplace-Beltrami regularization without sacrificing the <span class="hlt">optimality</span> of the Kalman <span class="hlt">filter</span>. We demonstrate that our method solves the correct minimization problem at each iteration and recursively provides the <span class="hlt">optimal</span> QBI solution. We validate with real QBI data that our proposed real-time method is equivalent in terms of QBI estimation accuracy to the standard offline processing techniques and outperforms the existing solution. Last, we propose a fast algorithm to recursively compute gradient orientation sets whose partial subsets are almost uniform and show that it can also be applied to the problem of efficiently ordering an existing point-set of any size. This work enables a clinician to start an acquisition with just the minimum number of gradient directions and an initial estimate of the orientation distribution functions (ODF) and then the next gradient directions and ODF estimates can be recursively and <span class="hlt">optimally</span> determined, allowing the acquisition to be stopped as soon as desired or at any iteration with the <span class="hlt">optimal</span> ODF estimates. This opens new and interesting opportunities for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013WRR....49.3194R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013WRR....49.3194R"><span>State estimation in large-scale open channel networks using sequential Monte Carlo methods: <span class="hlt">Optimal</span> sampling importance resampling and implicit particle <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>Rafiee, Mohammad; Barrau, Axel; Bayen, Alexandre M.</p> <p>2013-06-01</p> <p>This article investigates the performance of Monte Carlo-based estimation methods for estimation of flow state in large-scale open channel networks. After constructing a state space model of the flow based on the Saint-Venant equations, we implement the <span class="hlt">optimal</span> sampling importance resampling <span class="hlt">filter</span> to perform state estimation in a case in which measurements are available at every time <span class="hlt">step</span>. Considering a case in which measurements become available intermittently, a random-map implementation of the implicit particle <span class="hlt">filter</span> is applied to estimate the state trajectory in the interval between the measurements. Finally, some heuristics are proposed, which are shown to improve the estimation results and lower the computational cost. In the first heuristics, considering the case in which measurements are available at every time <span class="hlt">step</span>, we apply the implicit particle <span class="hlt">filter</span> over time intervals of a desired size while incorporating all the available measurements over the corresponding time interval. As a second heuristic method, we introduce a maximum a posteriori (MAP) method, which does not require sampling. It will be seen, through implementation, that the MAP method provides more accurate results in the case of our application while having a smaller computational cost. All estimation methods are tested on a network of 19 tidally forced subchannels and 1 reservoir, Clifton Court Forebay, in Sacramento-San Joaquin Delta in California, and numerical results are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AIPC.1655c0010U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AIPC.1655c0010U"><span>Rod-<span class="hlt">filter</span>-field <span class="hlt">optimization</span> of the J-PARC RF-driven H- 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>Ueno, A.; Ohkoshi, K.; Ikegami, K.; Takagi, A.; Yamazaki, S.; Oguri, H.</p> <p>2015-04-01</p> <p>In order to satisfy the Japan Proton Accelerator Research Complex (J-PARC) second-stage requirements of an H- 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- 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- 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- 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 (TPE) 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 TPE around 60°C.</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><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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9889E..1DG','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9889E..1DG"><span><span class="hlt">Optimized</span> design of high-order series coupler Yb3+/Er3+ codoped phosphate glass microring resonator <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>Galatus, Ramona; Valles, Juan</p> <p>2016-04-01</p> <p>The <span class="hlt">optimized</span> geometry based on high-order active microring resonators (MRR) geometry is proposed. The solution possesses both the <span class="hlt">filtering</span> and amplifying functions for the signal at around 1534nm (pump 976 nm). The cross-grid resonator with laterally, series-coupled triple-microrings, having 15.35μm radius, in a co-propagation topology between signal and pump, is the structure under analysis (commonly termed an add-drop <span class="hlt">filter</span>).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22047775','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22047775"><span>An <span class="hlt">optimized</span> Kalman <span class="hlt">filter</span> for the estimate of trunk orientation from inertial sensors data during treadmill walking.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mazzà, Claudia; Donati, Marco; McCamley, John; Picerno, Pietro; Cappozzo, Aurelio</p> <p>2012-01-01</p> <p>The aim of this study was the fine tuning of a Kalman <span class="hlt">filter</span> with the intent to provide <span class="hlt">optimal</span> estimates of lower trunk orientation in the frontal and sagittal planes during treadmill walking at different speeds using measured linear acceleration and angular velocity components represented in a local system of reference. Data were simultaneously collected using both an inertial measurement unit (IMU) and a stereophotogrammetric system from three healthy subjects walking on a treadmill at natural, slow and fast speeds. These data were used to estimate the parameters of the Kalman <span class="hlt">filter</span> that minimized the difference between the trunk orientations provided by the <span class="hlt">filter</span> and those obtained through stereophotogrammetry. The <span class="hlt">optimized</span> parameters were then used to process the data collected from a further 15 healthy subjects of both genders and different anthropometry performing the same walking tasks with the aim of determining the robustness of the <span class="hlt">filter</span> set up. The <span class="hlt">filter</span> proved to be very robust. The root mean square values of the differences between the angles estimated through the IMU and through stereophotogrammetry were lower than 1.0° and the correlation coefficients between the corresponding curves were greater than 0.91. The proposed <span class="hlt">filter</span> design can be used to reliably estimate trunk lateral and frontal bending during walking from inertial sensor data. Further studies are needed to determine the <span class="hlt">filter</span> parameters that are most suitable for other motor tasks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JKPS...69.1157C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JKPS...69.1157C"><span>Design and <span class="hlt">optimization</span> of an analog <span class="hlt">filter</span> with a CdTe detector for X-ray fluorescence applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Choi, Hyojeong; Kim, Hui Su; Kim, Young Soo; Ha, Jang Ho; Chai, Jong-Seo</p> <p>2016-10-01</p> <p>An analog pre-<span class="hlt">filter</span> circuit for digital pulse processing is designed and <span class="hlt">optimized</span> for X-ray fluorescence (XRF) applications to replace traditional analog shaping amplifiers. To <span class="hlt">optimize</span> the pre-<span class="hlt">filter</span> performance, we characterized noise electrons as a function of the input pulse rise time and decay time of the output pulse by using the full width at half maximum. In addition, gamma-ray energy measurements at room temperature showed that the commercially available CdTe Schottky-type radiation detector with our newly designed and <span class="hlt">optimized</span> pre-<span class="hlt">filter</span> circuit exhibited full widths at half maxima of 4.97 (Ba-133, at 53 keV) and 5.56 keV (Am-241, at 59.5 keV), respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27455532','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27455532"><span>Weighted <span class="hlt">Optimization</span>-Based Distributed Kalman <span class="hlt">Filter</span> for Nonlinear Target Tracking in Collaborative Sensor Networks.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Jie; Li, Jiahong; Yang, Shuanghua; Deng, Fang</p> <p>2016-07-21</p> <p>The identification of the nonlinearity and coupling is crucial in nonlinear target tracking problem in collaborative sensor networks. According to the adaptive Kalman <span class="hlt">filtering</span> (KF) method, the nonlinearity and coupling can be regarded as the model noise covariance, and estimated by minimizing the innovation or residual errors of the states. However, the method requires large time window of data to achieve reliable covariance measurement, making it impractical for nonlinear systems which are rapidly changing. To deal with the problem, a weighted <span class="hlt">optimization</span>-based distributed KF algorithm (WODKF) is proposed in this paper. The algorithm enlarges the data size of each sensor by the received measurements and state estimates from its connected sensors instead of the time window. A new cost function is set as the weighted sum of the bias and oscillation of the state to estimate the "best" estimate of the model noise covariance. The bias and oscillation of the state of each sensor are estimated by polynomial fitting a time window of state estimates and measurements of the sensor and its neighbors weighted by the measurement noise covariance. The best estimate of the model noise covariance is computed by minimizing the weighted cost function using the exhaustive method. The sensor selection method is in addition to the algorithm to decrease the computation load of the <span class="hlt">filter</span> and increase the scalability of the sensor network. The existence, suboptimality and stability analysis of the algorithm are given. The local probability data association method is used in the proposed algorithm for the multitarget tracking case. The algorithm is demonstrated in simulations on tracking examples for a random signal, one nonlinear target, and four nonlinear targets. Results show the feasibility and superiority of WODKF against other <span class="hlt">filtering</span> algorithms for a large class of systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26278994','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26278994"><span><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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JKPS...60.1161O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JKPS...60.1161O"><span>Application of digital tomosynthesis (DTS) of <span class="hlt">optimal</span> deblurring <span class="hlt">filters</span> for dental X-ray imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oh, J. E.; Cho, H. S.; Kim, D. S.; Choi, S. I.; Je, U. K.</p> <p>2012-04-01</p> <p>Digital tomosynthesis (DTS) is a limited-angle tomographic technique that provides some of the tomographic benefits of computed tomography (CT) but at reduced dose and cost. Thus, the potential for application of DTS to dental X-ray imaging seems promising. As a continuation of our dental radiography R&D, we developed an effective DTS reconstruction algorithm and implemented it in conjunction with a commercial dental CT system for potential use in dental implant placement. The reconstruction algorithm employed a backprojection <span class="hlt">filtering</span> (BPF) method based upon <span class="hlt">optimal</span> deblurring <span class="hlt">filters</span> to suppress effectively both the blur artifacts originating from the out-focus planes and the high-frequency noise. To verify the usefulness of the reconstruction algorithm, we performed systematic simulation works and evaluated the image characteristics. We also performed experimental works in which DTS images of enhanced anatomical resolution were successfully obtained by using the algorithm and were promising to our ongoing applications to dental X-ray imaging. In this paper, our approach to the development of the DTS reconstruction algorithm and the results are described in detail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PMB....54..285B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PMB....54..285B"><span>A pseudo-dynamic sub-<span class="hlt">optimal</span> <span class="hlt">filter</span> for elastography under static loading and measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Banerjee, B.; Roy, D.; Vasu, R. M.</p> <p>2009-01-01</p> <p>We propose a pseudo-dynamic form of a sub-<span class="hlt">optimal</span> Kalman <span class="hlt">filter</span> for elastography of plane-strain models of soft tissues under strictly static deformations and partial measurements. Since the tissue material is nearly incompressible and is thus prone to volumetric locking via standard displacement-based finite element formulations, we use a Cosserat point approach for deriving the static equilibrium equations. A pseudo-dynamical form of the equilibrium equations, with added noise and appropriate augmentation by the discretized shear modulus as additional states, is then adopted as the process equation such that its steady-state solution approaches the static response of the plane-strain model. A fictitious noise of small intensity is also added to the measurement equation and, following linearization of the process equation, a Kalman <span class="hlt">filter</span> is applied to reconstruct the shear modulus profile. We present several numerical experiments, some of which also bring forth the relative advantages of the proposed approach over a deterministic reconstruction based on a quasi-Newton search.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AIPC.1738U0031F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AIPC.1738U0031F"><span>New efficient <span class="hlt">optimizing</span> techniques for Kalman <span class="hlt">filters</span> and numerical weather prediction models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Famelis, Ioannis; Galanis, George; Liakatas, Aristotelis</p> <p>2016-06-01</p> <p>The need for accurate local environmental predictions and simulations beyond the classical meteorological forecasts are increasing the last years due to the great number of applications that are directly or not affected: renewable energy resource assessment, natural hazards early warning systems, global warming and questions on the climate change can be listed among them. Within this framework the utilization of numerical weather and wave prediction systems in conjunction with advanced statistical techniques that support the elimination of the model bias and the reduction of the error variability may successfully address the above issues. In the present work, new <span class="hlt">optimization</span> methods are studied and tested in selected areas of Greece where the use of renewable energy sources is of critical. The added value of the proposed work is due to the solid mathematical background adopted making use of Information Geometry and Statistical techniques, new versions of Kalman <span class="hlt">filters</span> and state of the art numerical analysis tools.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24319367','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24319367"><span>A compact symmetric microstrip <span class="hlt">filter</span> based on a rectangular meandered-line <span class="hlt">stepped</span> impedance resonator with a triple-band bandstop response.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dhakal, Rajendra; Kim, Nam-Young</p> <p>2013-01-01</p> <p>This paper presents a symmetric-type microstrip triple-band bandstop <span class="hlt">filter</span> incorporating a tri-section meandered-line <span class="hlt">stepped</span> impedance resonator (SIR). The length of each section of the meandered line is 0.16, 0.15, and 0.83 times the guided wavelength (λ g ), so that the <span class="hlt">filter</span> features three stop bands at 2.59 GHz, 6.88 GHz, and 10.67 GHz, respectively. Two symmetric SIRs are employed with a microstrip transmission line to obtain wide bandwidths of 1.12, 1.34, and 0.89 GHz at the corresponding stop bands. Furthermore, an equivalent circuit model of the proposed <span class="hlt">filter</span> is developed, and the model matches the electromagnetic simulations well. The return losses of the fabricated <span class="hlt">filter</span> are measured to be -29.90 dB, -28.29 dB, and -26.66 dB while the insertion losses are 0.40 dB, 0.90 dB, and 1.10 dB at the respective stop bands. A drastic reduction in the size of the <span class="hlt">filter</span> was achieved by using a simplified architecture based on a meandered-line SIR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.4640K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.4640K"><span>An <span class="hlt">Optimal</span> Observing System Study for the Kuroshio Extension using Particle <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>Kramer, Werner; van Leeuwen, Peter Jan; Pierieni, Stefano; Dijkstra, Henk</p> <p>2010-05-01</p> <p>The Kuroshio Extension - the eastward-flowing free jet formed when the warm waters of the Kuroshio separate from the Japanese coast - reveals bimodal behavior. It changes from an elongated, energetic meandering jet into a weaker, unstable jet with a reduced zonal penetration. Many of its characteristics, e.g. the decadal period and the more stable character of the elongated state, are also observed in a reduced-gravity ocean model of the northern Pacific basin with a schematic Japanese coastline driven by a constant double-gyre wind field. The success of this idealized model suggests that intrinsic nonlinear mechanisms play a major role in determining the meander pattern of the mean flow. The low complexity of the model makes it ideal to perform an observing system study. Here, we take a new approach by using particle <span class="hlt">filters</span> to assimilate observations into the model. An ensemble of model states is integrated over time from an initial distribution. The first approach is to pick one run as the synthetic truth. Observations are produced from this synthetic truth with an additional observation error. The particle <span class="hlt">filter</span> technique adjusts the weight of each ensemble run - each particle - according to the observation value and the error distribution. From the ensemble and its weight distribution the expectation and probability distribution of the state vector can be computed. As the ensemble itself is not altered by the <span class="hlt">filter</span>, different sets of observations, e.g. with different geometrical configurations, locations and/or time resolutions, can be analyzed a posteriori. The particle <span class="hlt">filter</span> analyses allows us to identify which observations have a large impact on reconstructing the true state of Kuroshio Extension. More precisely, which observations contribute to a (local) reduction in the entropy of the ensemble. In a way each observation is then linked to an area of influence, which permits for determining the flow of information. We will present results where</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24556175','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24556175"><span>ARTcrystal process for industrial nanocrystal production--<span class="hlt">optimization</span> of the ART MICCRA pre-milling <span class="hlt">step</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Scholz, Patrik; Arntjen, Anja; Müller, Rainer H; Keck, Cornelia M</p> <p>2014-04-25</p> <p>The ARTcrystal process is a new approach for the production of drug nanocrystals. It is a combination of a special pre-treatment <span class="hlt">step</span> with subsequent high pressure homogenization (HPH) at low pressures. In the pre-treatment <span class="hlt">step</span> the particle size is already reduced to the nanometer range by use of the newly developed ART MICCRA rotor-stator system. In this study, the running parameters for the ART MICCRA system are systematically studied, i.e. temperature, stirring speed, flow rate, foaming effects, size of starting material, valve position from 0° to 45°. The antioxidant rutin was used as model drug. Applying <span class="hlt">optimized</span> parameters, the pre-milling yielded already a nanosuspension with a photon correlation spectroscopy (PCS) diameter of about 650 nm. On lab scale production time was 5 min for 1L nanosuspension (5% rutin content), i.e. the capacity of the setup is also suitable for medium industrial scale production. Compared to other nanocrystal production methods (bead milling, HPH, etc.), similar sizes are achievable, but the process is more cost-effective, faster in time and easily scale-able, thus being an interesting novel process for nanocrystal production on lab and industrial scale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.H13I..05K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.H13I..05K"><span>A Reduced Extended Kalman <span class="hlt">Filter</span> Method For Data Assimilation And 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>Kao, C. J.</p> <p>2007-12-01</p> <p>This work is an extension of our two recent papers [Kao et al., 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, and Kao et al., 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>, J. Comp. Phys., 214 (2006), 725-737 ] about the applications of the extended Kalman <span class="hlt">filter</span> (EKF) to data assimilation in predictive codes. We have shown through the above two studies that the EKF method successfully estimates the evolving model state variables as well as model parameters of a shock-wave system by merging single-point pressure data into an Euler-equations computer code. We here intend to introduce a reduced EKF for the same purposes in terms of data assimilation and parameter <span class="hlt">optimization</span>, but with a much smaller computational cost so that the applications of EKF to multi-dimensional realistic problems can be made possible. One of the distinctive features of EKF is that, as the system evolves forward in time, the EKF algorithm tracks the time-dependent error-covariance matrix of the model's state variables and parameters based on a consistent tangent-linear approximation of the model dynamics. When data becomes available at one instant in time, the update of the model state variables and parameters is achieved through a functional form of the linear merger of the model prediction and the data, subjective to the minimization of the trace of the error-covariance matrix of the model state variables and parameters. It, however, has been a concern that the calculation for the time evolution of the error-covariance matrix in applying EKF is computationally demanding and prohibitively expensive for real multi-dimensional problems. Several simplified approaches of EKF have been proposed to reduce the computational burden. This current study was actually motivated by Dee's work [Dee, P. D., 1991: Simplification of the</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>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://hdl.handle.net/2060/20040006352','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040006352"><span>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_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/2012OptCo.285.3042F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012OptCo.285.3042F"><span><span class="hlt">Optimizing</span> the optical field distribution of near-field SIL optical storage system using five-zone binary phase <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>Fang, Chaolong; Zhang, Yaoju; Zhu, Haiyong</p> <p>2012-06-01</p> <p>Five-zone binary phase <span class="hlt">filters</span> (FBPFs) are proposed for decreasing the spot size and/or increasing the focal depth of the near-field optical storage system with a hemisphere solid immersion lens (SIL). The design of <span class="hlt">filters</span> is based on the vector diffraction theory and the MATLAB <span class="hlt">optimizing</span> toolbox. Three FBPFs with rotationally symmetrical pupil function have been designed, where the one FBPF is for increasing the focal depth as big as possible, the second FBPF is for improving the resolution as high as possible, and the third FBPF integrate the increase of focal depth with the improvement of resolution. Numerical results show that compared with the three-zone amplitude <span class="hlt">filter</span>, the designed five-zone binary phase-only <span class="hlt">filters</span> have more prominent performances in improving the focal depth and the resolution of the near-field SIL optical storage system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18594682','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18594682"><span>Demonstration of differential phase-shift keying demodulation at 10 Gbit/s <span class="hlt">optimal</span> fiber Bragg grating <span class="hlt">filters</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gatti, Davide; Galzerano, Gianluca; Laporta, Paolo; Longhi, Stefano; Janner, Davide; Guglierame, Andrea; Belmonte, Michele</p> <p>2008-07-01</p> <p><span class="hlt">Optimal</span> demodulation of differential phase-shift keying signals at 10 Gbit/s is experimentally demonstrated using a specially designed structured fiber Bragg grating composed by Fabry-Perot coupled cavities. Bit-error-rate measurements show that, as compared with a conventional Gaussian-shaped <span class="hlt">filter</span>, our demodulator gives approximately 2.8 dB performance improvement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16189969','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16189969"><span>SVD-based <span class="hlt">optimal</span> <span class="hlt">filtering</span> for noise reduction in dual microphone hearing aids: a real time implementation and perceptual evaluation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Maj, Jean-Baptiste; Royackers, Liesbeth; Moonen, Marc; Wouters, Jan</p> <p>2005-09-01</p> <p>In this paper, the first real-time implementation and perceptual evaluation of a singular value decomposition (SVD)-based <span class="hlt">optimal</span> <span class="hlt">filtering</span> technique for noise reduction in a dual microphone behind-the-ear (BTE) hearing aid is presented. This evaluation was carried out for a speech weighted noise and multitalker babble, for single and multiple jammer sound source scenarios. Two basic microphone configurations in the hearing aid were used. The SVD-based <span class="hlt">optimal</span> <span class="hlt">filtering</span> technique was compared against an adaptive beamformer, which is known to give significant improvements in speech intelligibility in noisy environment. The <span class="hlt">optimal</span> <span class="hlt">filtering</span> technique works without assumptions about a speaker position, unlike the two-stage adaptive beamformer. However this strategy needs a robust voice activity detector (VAD). A method to improve the performance of the VAD was presented and evaluated physically. By connecting the VAD to the output of the noise reduction algorithms, a good discrimination between the speech-and-noise periods and the noise-only periods of the signals was obtained. The perceptual experiments demonstrated that the SVD-based <span class="hlt">optimal</span> <span class="hlt">filtering</span> technique could perform as well as the adaptive beamformer in a single noise source scenario, i.e., the ideal scenario for the latter technique, and could outperform the adaptive beamformer in multiple noise source scenarios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/4020513','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/4020513"><span>Uncertainty relation for resolution in space, spatial frequency, and orientation <span class="hlt">optimized</span> by two-dimensional visual cortical <span class="hlt">filters</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Daugman, J G</p> <p>1985-07-01</p> <p>Two-dimensional spatial linear <span class="hlt">filters</span> are constrained by general uncertainty relations that limit their attainable information resolution for orientation, spatial frequency, and two-dimensional (2D) spatial position. The theoretical lower limit for the joint entropy, or uncertainty, of these variables is achieved by an <span class="hlt">optimal</span> 2D <span class="hlt">filter</span> family whose spatial weighting functions are generated by exponentiated bivariate second-order polynomials with complex coefficients, the elliptic generalization of the one-dimensional elementary functions proposed in Gabor's famous theory of communication [J. Inst. Electr. Eng. 93, 429 (1946)]. The set includes <span class="hlt">filters</span> with various orientation bandwidths, spatial-frequency bandwidths, and spatial dimensions, favoring the extraction of various kinds of information from an image. Each such <span class="hlt">filter</span> occupies an irreducible quantal volume (corresponding to an independent datum) in a four-dimensional information hyperspace whose axes are interpretable as 2D visual space, orientation, and spatial frequency, and thus such a <span class="hlt">filter</span> set could subserve an <span class="hlt">optimally</span> efficient sampling of these variables. Evidence is presented that the 2D receptive-field profiles of simple cells in mammalian visual cortex are well described by members of this <span class="hlt">optimal</span> 2D <span class="hlt">filter</span> family, and thus such visual neurons could be said to <span class="hlt">optimize</span> the general uncertainty relations for joint 2D-spatial-2D-spectral information resolution. The variety of their receptive-field dimensions and orientation and spatial-frequency bandwidths, and the correlations among these, reveal several underlying constraints, particularly in width/length aspect ratio and principal axis organization, suggesting a polar division of labor in occupying the quantal volumes of information hyperspace.(ABSTRACT TRUNCATED AT 250 WORDS)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22413537','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22413537"><span><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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23834855','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23834855"><span>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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18954974','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18954974"><span><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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998OptEn..37.2376N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998OptEn..37.2376N"><span>Model-based multirate Kalman <span class="hlt">filtering</span> approach for <span class="hlt">optimal</span> two-dimensional signal reconstruction from noisy subband systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ni, Jiang Q.; Ho, Ka L.; Tse, Kai W.</p> <p>1998-08-01</p> <p>Conventional synthesis <span class="hlt">filters</span> in subband systems lose their <span class="hlt">optimality</span> when additive noise (due, for example, to signal quantization) disturbs the subband components. The multichannel representation of subband signals is combined with the statistical model of input signal to derive the multirate state-space model for the <span class="hlt">filter</span> bank system with additive subband noises. Thus the signal reconstruction problem in subband systems can be formulated as the process of <span class="hlt">optimal</span> state estimation in the equivalent multirate state-space model. Incorporated with the vector dynamic model, a 2D multirate state-space model suitable for 2D Kalman <span class="hlt">filtering</span> is developed. The performance of the proposed 2D multirate Kalman <span class="hlt">filter</span> can be further improved through adaptive segmentation of the object plane. The object plane is partitioned into disjoint regions based on their spatial activity, and different vector dynamical models are used to characterize the nonstationary object- plane distributions. Finally, computer simulations with the proposed 2D multirate Kalman <span class="hlt">filter</span> give favorable results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3188653','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3188653"><span>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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27247479','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27247479"><span>A Dedicated Inferior Vena Cava <span class="hlt">Filter</span> Service Line: How to <span class="hlt">Optimize</span> Your Practice.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Karp, Jennifer K; Desai, Kush R; Salem, Riad; Ryu, Robert K; Lewandowski, Robert J</p> <p>2016-06-01</p> <p>Despite the increased placement of retrievable inferior vena cava <span class="hlt">filters</span> (rIVCFs), efforts to remove these devices are not commensurate. The majority of rIVCFs are left in place beyond their indicated usage, and often are retained permanently. With a growing understanding of the clinical issues associated with these devices, the United States Food and Drug Administration (FDA) has prompted clinicians to remove rIVCF when they are no longer indicated. However, major obstacles exist to <span class="hlt">filter</span> retrieval, chief among them being poor clinical follow-up. The establishment of a dedicated IVC <span class="hlt">filter</span> service line, or clinic, has been shown to improve <span class="hlt">filter</span> retrieval rates. Usage of particular devices, specifically permanent versus retrievable <span class="hlt">filters</span>, is enhanced by prospective physician consultation. In this article, the rationale behind a dedicated IVC <span class="hlt">filter</span> service line is presented as well as described the structure and activities of the authors' IVC <span class="hlt">filter</span> clinic; supporting data will also be provided when appropriate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4662124','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4662124"><span><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/2016ExFl...57..185A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ExFl...57..185A"><span>Analysis of the <span class="hlt">filtering</span> effect of the stochastic estimation and accuracy improvement by sensor location <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>Arnault, A.; Dandois, J.; Monnier, J.-C.; Delva, J.; Foucaut, J.-M.</p> <p>2016-12-01</p> <p>The reconstruction of the flow behind a backward-facing <span class="hlt">step</span> at a Reynolds number of 60,000 using linear stochastic estimation (LSE) and modified LSE (with or without multi-time-delay) is investigated. In particular, the turbulent spatial integral length scales estimated for several sensor configurations are studied. The estimation of the proper orthogonal decomposition (POD) modes is also performed in order to show the limitations of the SE for complex flows, for which taking into account only a few POD modes may not be enough to represent the flow dynamics. The importance of the sensor locations on the estimation is also emphasized, and the opportunity to use a sensor location <span class="hlt">optimization</span> algorithm is investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18350999','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18350999"><span>Numerical simulation of an industrial microwave assisted <span class="hlt">filter</span> dryer: criticality assessment and <span class="hlt">optimization</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Leonelli, Cristina; Veronesi, Paolo; Grisoni, Fabio</p> <p>2007-01-01</p> <p>Industrial-scale <span class="hlt">filter</span> dryers, equipped with one or more microwave input ports, have been modelled with the aim of detecting existing criticalities, proposing possible solutions and <span class="hlt">optimizing</span> the overall system efficiency and treatment homogeneity. Three different loading conditions have been simulated, namely the empty applicator, the applicator partially loaded by both a high-loss and low loss load whose dielectric properties correspond to the one measured on real products. Modeling results allowed for the implementation of improvements to the original design such as the insertion of a wave guide transition and a properly designed pressure window, modification of the microwave inlet's position and orientation, alteration of the nozzles' geometry and distribution, and changing of the cleaning metallic torus dimensions and position. Experimental testing on representative loads, as well as in production sites, allowed for the confirmation of the validity of the implemented improvements, thus showing how numerical simulation can assist the designer in removing critical features and improving equipment performances when moving from conventional heating to hybrid microwave-assisted processing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20080047455&hterms=decomposition&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddecomposition','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20080047455&hterms=decomposition&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddecomposition"><span>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('https://ntrs.nasa.gov/search.jsp?R=20100042588&hterms=decomposition&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddecomposition','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100042588&hterms=decomposition&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Ddecomposition"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/18689747','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18689747"><span>Selection of plants for <span class="hlt">optimization</span> of vegetative <span class="hlt">filter</span> strips treating runoff from turfgrass.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Smith, Katy E; Putnam, Raymond A; Phaneuf, Clifford; Lanza, Guy R; Dhankher, Om P; Clark, John M</p> <p>2008-01-01</p> <p>Runoff from turf environments, such as golf courses, is of increasing concern due to the associated chemical contamination of lakes, reservoirs, rivers, and ground water. Pesticide runoff due to fungicides, herbicides, and insecticides used to maintain golf courses in acceptable playing condition is a particular concern. One possible approach to mitigate such contamination is through the implementation of effective vegetative <span class="hlt">filter</span> strips (VFS) on golf courses and other recreational turf environments. The objective of the current study was to screen ten aesthetically acceptable plant species for their ability to remove four commonly-used and degradable pesticides: chlorpyrifos (CP), chlorothalonil (CT), pendimethalin (PE), and propiconazole (PR) from soil in a greenhouse setting, thus providing invaluable information as to the species composition that would be most efficacious for use in VFS surrounding turf environments. Our results revealed that blue flag iris (Iris versicolor) (76% CP, 94% CT, 48% PE, and 33% PR were lost from soil after 3 mo of plant growth), eastern gama grass (Tripsacum dactyloides) (47% CP, 95% CT, 17% PE, and 22% PR were lost from soil after 3 mo of plant growth), and big blue stem (Andropogon gerardii) (52% CP, 91% CT, 19% PE, and 30% PR were lost from soil after 3 mo of plant growth) were excellent candidates for the <span class="hlt">optimization</span> of VFS as buffer zones abutting turf environments. Blue flag iris was most effective at removing selected pesticides from soil and had the highest aesthetic value of the plants tested.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014MNRAS.443.2311L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014MNRAS.443.2311L"><span>Matched <span class="hlt">filter</span> <span class="hlt">optimization</span> of kSZ measurements with a reconstructed cosmological flow field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Ming; Angulo, R. E.; White, S. D. M.; Jasche, J.</p> <p>2014-09-01</p> <p>We develop and test a new statistical method to measure the kinematic Sunyaev-Zel'dovich (kSZ) effect. A sample of independently detected clusters is combined with the cosmic flow field predicted from a galaxy redshift survey in order to derive a matched <span class="hlt">filter</span> that <span class="hlt">optimally</span> weights the kSZ signal for the sample as a whole given the noise involved in the problem. We apply this formalism to realistic mock microwave skies based on cosmological N-body simulations, and demonstrate its robustness and performance. In particular, we carefully assess the various sources of uncertainty, cosmic microwave background primary fluctuations, instrumental noise, uncertainties in the determination of the velocity field, and effects introduced by miscentring of clusters and by uncertainties of the mass-observable relation (normalization and scatter). We show that available data (Planck maps and the MaxBCG catalogue) should deliver a 7.7σ detection of the kSZ. A similar cluster catalogue with broader sky coverage should increase the detection significance to ˜13σ. We point out that such measurements could be binned in order to study the properties of the cosmic gas and velocity fields, or combined into a single measurement to constrain cosmological parameters or deviations of the law of gravity from General Relativity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22453408','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22453408"><span><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="https://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.</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>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://adsabs.harvard.edu/abs/2014EJASP2014...95H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EJASP2014...95H"><span>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> </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('https://ntrs.nasa.gov/search.jsp?R=19720057234&hterms=Optimal+design&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DOptimal%2Bdesign','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720057234&hterms=Optimal+design&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DOptimal%2Bdesign"><span>Time-domain technique for <span class="hlt">optimal</span> design of digital-<span class="hlt">filter</span> equalizers.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlage, D. W.; Houts, R. C.</p> <p>1972-01-01</p> <p>A technique is presented for the design of frequency-sampling and transversal digital <span class="hlt">filters</span> from specified unit-impulse responses. The multiplier coefficients for the digital <span class="hlt">filter</span> are specified by the use of a linear-programming algorithm. Examples include the design of digital <span class="hlt">filters</span> to generate intersymbol-free pulses for data transmission over ideal bandlimited channels and to equalize data transmission channels that have known unit-impulse responses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27873977','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27873977"><span>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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Luo, Yingting; Zhu, Yunmin; Luo, Dandan; Zhou, Jie; Song, Enbin; Wang, Donghua</p> <p>2008-12-08</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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3791008','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3791008"><span>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. PMID:27873977</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>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://pubs.er.usgs.gov/publication/70025457','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70025457"><span>Moment-tensor solutions estimated using <span class="hlt">optimal</span> <span class="hlt">filter</span> theory: Global seismicity, 2001</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.; Bufe, C.G.; Zirbes, M.D.</p> <p>2003-01-01</p> <p>This paper is the 12th in a series published yearly containing moment-tensor solutions computed at the US Geological Survey using an algorithm based on the theory of <span class="hlt">optimal</span> <span class="hlt">filter</span> design (Sipkin, 1982 and Sipkin, 1986b). An inversion has been attempted for all earthquakes with a magnitude, mb or MS, of 5.5 or greater. Previous listings include solutions for earthquakes that occurred from 1981 to 2000 (Sipkin, 1986b; Sipkin and Needham, 1989, Sipkin and Needham, 1991, Sipkin and Needham, 1992, Sipkin and Needham, 1993, Sipkin and Needham, 1994a and Sipkin and Needham, 1994b; Sipkin and Zirbes, 1996 and Sipkin and Zirbes, 1997; Sipkin et al., 1998, Sipkin et al., 1999, Sipkin et al., 2000a, Sipkin et al., 2000b and Sipkin et al., 2002).The entire USGS moment-tensor catalog can be obtained via anonymous FTP at ftp://ghtftp.cr.usgs.gov. After logging on, change directory to “momten”. This directory contains two compressed ASCII files that contain the finalized solutions, “mt.lis.Z” and “fmech.lis.Z”. “mt.lis.Z” contains the elements of the moment tensors along with detailed event information; “fmech.lis.Z” contains the decompositions into the principal axes and best double-couples. The fast moment-tensor solutions for more recent events that have not yet been finalized and added to the catalog, are gathered by month in the files “jan01.lis.Z”, etc. “fmech.doc.Z” describes the various fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2956227','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2956227"><span>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://adsabs.harvard.edu/abs/2003SPIE.5094...18V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003SPIE.5094...18V"><span><span class="hlt">Optimal</span>-tradeoff circular harmonic function <span class="hlt">filters</span> for 3D target recognition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vijaya Kumar, Bhagavatula V. K.; Xie, Chunyan; Mahalanobis, Abhijit</p> <p>2003-09-01</p> <p>3D target recognition is of significant interest because representing the object in 3D space couuld essentially provide a solution to pose variation and self-occlusion problems that are big challenges in 2D pattern recognition. Correlation filers have been used in a variety of 2D pattern matching applications and many correlation <span class="hlt">filter</span> designs have been developed to handle problems such as rotations. Correlation <span class="hlt">filters</span> also offer other benefits such as shift-invariance, graceful degradation and closed-form solutions. The 3D extension of correlation <span class="hlt">filter</span> is a natural extension to handle 3D pattern recognition problem. In this paper, we propose a 3D correlation <span class="hlt">filter</span> design method based on cylindrical circular harmonic function (CCHF) and use LADAR imagery to illustrate the good performance of CCHF <span class="hlt">filters</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21032835','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21032835"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/22254562','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22254562"><span>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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhDT........94N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhDT........94N"><span>Nature-inspired <span class="hlt">optimization</span> of quasicrystalline arrays and all-dielectric optical <span class="hlt">filters</span> and metamaterials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Namin, Frank Farhad A.</p> <p></p> <p> (photonic resonance) and the plasmonic response of the spheres (plasmonic resonance). In particular the couplings between the photonic and plasmonic modes are studied. In periodic arrays this coupling leads to the formation of a so called photonic-plasmonic hybrid mode. The formation of hybrid modes is studied in quasicrystalline arrays. Quasicrystalline structures in essence possess several periodicities which in some cases can lead to the formation of multiple hybrid modes with wider bandwidths. It is also demonstrated that the performance of these arrays can be further enhanced by employing a perturbation method. The second property considered is local field enhancements in quasicrystalline arrays of gold nanospheres. It will be shown that despite a considerably smaller filling factor quasicrystalline arrays generate larger local field enhancements which can be even further enhanced by <span class="hlt">optimally</span> placing perturbing spheres within the prototiles that comprise the aperiodic arrays. The second thrust of research in this dissertation focuses on designing all-dielectric <span class="hlt">filters</span> and metamaterial coatings for the optical range. In higher frequencies metals tend to have a high loss and thus they are not suitable for many applications. Hence dielectrics are used for applications in optical frequencies. In particular we focus on designing two types of structures. First a near-perfect optical mirror is designed. The design is based on <span class="hlt">optimizing</span> a subwavelength periodic dielectric grating to obtain appropriate effective parameters that will satisfy the desired perfect mirror condition. Second, a broadband anti-reflective all-dielectric grating with wide field of view is designed. The second design is based on a new computationally efficient genetic algorithm (GA) <span class="hlt">optimization</span> method which shapes the sidewalls of the grating based on <span class="hlt">optimizing</span> the roots of polynomial functions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H41E0877U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H41E0877U"><span><span class="hlt">Optimal</span> Scaling of <span class="hlt">Filtered</span> GRACE dS/dt Anomalies over Sacramento and San Joaquin River Basins, California</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ukasha, M.; Ramirez, J. A.</p> <p>2014-12-01</p> <p>Signals from Gravity Recovery and Climate Experiments (GRACE) twin satellites mission mapping the time invariant earth's gravity field are degraded due to measurement and leakage errors. Dampening of these errors using different <span class="hlt">filters</span> results in a modification of the true geophysical signals. Therefore, use of a scale factor is suggested to recover the modified signals. For basin averaged dS/dt anomalies computed from data available at University of Colorado GRACE data analysis website - http://geoid.colorado.edu/grace/, <span class="hlt">optimal</span> time invariant and time variant scale factors for Sacramento and San Joaquin river basins, California, are derived using observed precipitation (P), runoff (Q) and evapotranspiration (ET). Using the derived <span class="hlt">optimal</span> scaling factor for GRACE data <span class="hlt">filtered</span> using a 300 km- wide gaussian <span class="hlt">filter</span> resulted in scaled GRACE dS/dt anomalies that match better with observed dS/dt anomalies (P-ET-Q) as compared to the GRACE dS/dt anomalies computed from scaled GRACE product at University of Colorado GRACE data analysis website. This paper will present the procedure, the <span class="hlt">optimal</span> values, and the statistical analysis of the results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26681183','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26681183"><span><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="https://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.</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><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('https://www.ncbi.nlm.nih.gov/pubmed/16306648','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16306648"><span><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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Comani, S; Mantini, D; Alleva, G; Di Luzio, S; Romani, G L</p> <p>2005-12-07</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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4530527','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4530527"><span><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://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</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>2015-01-01</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 1,048 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. PMID:26273124</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><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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3447875','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3447875"><span>Identifying the Preferred Subset of Enzymatic Profiles in Nonlinear Kinetic Metabolic Models via Multiobjective Global <span class="hlt">Optimization</span> and Pareto <span class="hlt">Filters</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>Pozo, Carlos; Guillén-Gosálbez, Gonzalo; Sorribas, Albert; Jiménez, Laureano</p> <p>2012-01-01</p> <p><span class="hlt">Optimization</span> models in metabolic engineering and systems biology focus typically on <span class="hlt">optimizing</span> a unique criterion, usually the synthesis rate of a metabolite of interest or the rate of growth. Connectivity and non-linear regulatory effects, however, make it necessary to consider multiple objectives in order to identify useful strategies that balance out different metabolic issues. This is a fundamental aspect, as <span class="hlt">optimization</span> of maximum yield in a given condition may involve unrealistic values in other key processes. Due to the difficulties associated with detailed non-linear models, analysis using stoichiometric descriptions and linear <span class="hlt">optimization</span> methods have become rather popular in systems biology. However, despite being useful, these approaches fail in capturing the intrinsic nonlinear nature of the underlying metabolic systems and the regulatory signals involved. Targeting more complex biological systems requires the application of global <span class="hlt">optimization</span> methods to non-linear representations. In this work we address the multi-objective global <span class="hlt">optimization</span> of metabolic networks that are described by a special class of models based on the power-law formalism: the generalized mass action (GMA) representation. Our goal is to develop global <span class="hlt">optimization</span> methods capable of efficiently dealing with several biological criteria simultaneously. In order to overcome the numerical difficulties of dealing with multiple criteria in the <span class="hlt">optimization</span>, we propose a heuristic approach based on the epsilon constraint method that reduces the computational burden of generating a set of Pareto <span class="hlt">optimal</span> alternatives, each achieving a unique combination of objectives values. To facilitate the post-<span class="hlt">optimal</span> analysis of these solutions and narrow down their number prior to being tested in the laboratory, we explore the use of Pareto <span class="hlt">filters</span> that identify the preferred subset of enzymatic profiles. We demonstrate the usefulness of our approach by means of a case study that <span class="hlt">optimizes</span> the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19746797','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19746797"><span>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="https://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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4818102','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4818102"><span>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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27035820','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27035820"><span>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="https://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</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('https://www.ncbi.nlm.nih.gov/pubmed/22384176','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22384176"><span><span class="hlt">Optimal</span> use of conservation and accessibility <span class="hlt">filters</span> in microRNA target prediction.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Marín, Ray M; Vaníček, Jiří</p> <p>2012-01-01</p> <p>It is generally accepted that <span class="hlt">filtering</span> microRNA (miRNA) target predictions by conservation or by accessibility can reduce the false discovery rate. However, these two strategies are usually not exploited in a combined and flexible manner. Here, we introduce PACCMIT, a flexible method that <span class="hlt">filters</span> miRNA binding sites by their conservation, accessibility, or both. The improvement in performance obtained with each of these three <span class="hlt">filters</span> is demonstrated on the prediction of targets for both i) highly and ii) weakly conserved miRNAs, i.e., in two scenarios in which the miRNA-target interactions are subjected to different evolutionary pressures. We show that in the first scenario conservation is a better <span class="hlt">filter</span> than accessibility (as both sensitivity and precision are higher among the top predictions) and that the combined <span class="hlt">filter</span> improves performance of PACCMIT even further. In the second scenario, on the other hand, the accessibility <span class="hlt">filter</span> performs better than both the conservation and combined <span class="hlt">filters</span>, suggesting that the site conservation is not equally effective in rejecting false positive predictions for all miRNAs. Regarding the quality of the ranking criterion proposed by Robins and Press and used in PACCMIT, it is shown that top ranking interactions correspond to more downregulated proteins than do the lower ranking interactions. Comparison with several other target prediction algorithms shows that the ranking of predictions provided by PACCMIT is at least as good as the ranking generated by other conservation-based methods and considerably better than the energy-based ranking used in other accessibility-based methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17424948','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17424948"><span>Two <span class="hlt">step</span> derivatization for the analyses of organic, amino acids and glycines on <span class="hlt">filter</span> paper plasma by GC-MS/SIM.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yoon, Hye-Ran</p> <p>2007-03-01</p> <p>A rapid dried-<span class="hlt">filter</span> paper plasma-spot analytical method was developed to quantify organic acids, amino acids, and glycines simultaneously in a two-<span class="hlt">step</span> derivatization procedure with good sensitivity and specificity. The new method involves a two-<span class="hlt">step</span> trimethylsilyl (TMS) - trifluoroacyl (TFA) derivatization procedure using GC-MS/ selective ion monitoring (GC-MS/SIM). The dried-<span class="hlt">filter</span> paper plasma was fortified with an internal standard (tropate) as well as a standard mixture of distilled water and methanol. Methyl orange was added to the residue as an indicator. N-methyl-N-(trimethylsilyl-trifluoroacetamide) and N-methyl-bis-trifluoroacetamide were then added and heated to 60 degrees C for 10 and 15 min to produce the TMS and TFA derivatives, respectively. Using this method, the silylation of carboxylic functional groups was carried out, which was followed by the trifluoroacyl derivatization of the amino functional group. The derivatives were analyzed by GC-MS/SIM. A calibration cure showed a linear relationship for the target compounds between concentrations of 10-500 ng/mL. The limit of detection and quantification on a plasma spot were 10-90 ng/mL (S/N=9) and 80-500 ng/ mL, respectively. The correlation coefficient ranged from 0.938 and 0.999. When applied to the samples from positive patients, the method clearly differentiated normal subjects from the patients with various metabolic disorders such as PKU, MSUD, OTC and a Propionic Aciduria. The new developed method might be useful for making a rapid, sensitive and simultaneous diagnosis of inherited organic and amino acid disorders. In addition, this method is expected to be an alternative method for screening newborns for metabolic disorders in laboratories where expensive MS/MS is unavailable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22325161','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22325161"><span>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://adsabs.harvard.edu/abs/2017JaJAP..56b2202S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JaJAP..56b2202S"><span>Antireflective surface with a <span class="hlt">step</span> in the taper: Numerical <span class="hlt">optimization</span> and large-area fabrication</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shinotsuka, Kei; Hongo, Koki; Dai, Kotaro; Hirama, Satoru; Hatta, Yoshihisa</p> <p>2017-02-01</p> <p>In this study, we developed a practical method to improve the optical performance of subwavelength antireflective two-dimensional (2D) gratings. A numerical simulation of both convex and concave paraboloids suggested that surface reflectivity drastically decreases when a <span class="hlt">step</span> is introduced in the taper. The optimum height and depth of a <span class="hlt">step</span> provided average reflectances of 0.098% for convex protrusions and 0.040% for concave protrusions in the visible range. Furthermore, a <span class="hlt">stepped</span> paraboloid was experimentally fabricated by dry etching of a Si substrate with SiO2 particle monolayer mask. A cyclo-olefin polymer (COP) reverse replica (concave) imprinted by the Si mold exhibited a measured reflectance of 0.077% on average in the visible range. It was also demonstrated that the antireflective structure was fabricated on the whole surface of a 6 in. Si wafer, which is a sufficient size for industrial utilization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5339417','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5339417"><span>Modeling and <span class="hlt">optimization</span> of the <span class="hlt">step</span> coverage of tungsten LPCVD in trenches and contact holes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hasper, A.; Holleman, J.; Middelhock, J. ); Kleijn, C.R.; Hoogendoorn, C.J. )</p> <p>1991-06-01</p> <p>In this paper a model is presented to calculate the <span class="hlt">step</span> coverage of blanket tungsten low pressure chemical vapor deposition (W-LPCVD) from tungsten hexafluoride (WF{sub 6}). The model can calculate tungsten growth in trenches and circular contact holes, in the case of the WF{sub 6} reduction by H{sub 2}, SiH{sub 4}, or both. The <span class="hlt">step</span> coverage model predictions have been verified experimentally by scanning electron microscopy (SEM). The authors found that the predictions of the <span class="hlt">step</span> coverage model for the H{sub 2} reduction of WF{sub 6} are very accurate, if the partial pressures of the reactants at the inlet of the trench or contact hole are known. To get these reactant inlet partial pressures, the authors used a reactor model which calculates the surface partial pressures of all the reactants. These calculated surface partial pressures are used as input for the authors' <span class="hlt">step</span> coverage model. In this study the authors showed that thermodiffusion plays a very important role in the actual surface partial pressure. In the case where SiH{sub 4} was present in the gas mixture trends are predicted very well but the absolute values predicted by the <span class="hlt">step</span> coverage model are too high. The partial pressure of HF, which is a by-product of the H{sub 2} reduction reaction, may be very high inside trenches or contact holes, especially just before closing of the trench or contact hole. The authors found no influence of the calculated HF partial pressure on the <span class="hlt">step</span> coverage.</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>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://hdl.handle.net/2060/20120000816','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120000816"><span><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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010LNCS.6466..727P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010LNCS.6466..727P"><span>Particle Swarm <span class="hlt">Optimization</span> and Varying Chemotactic <span class="hlt">Step</span>-Size Bacterial Foraging <span class="hlt">Optimization</span> Algorithms Based Dynamic Economic Dispatch with Non-smooth Fuel Cost Functions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Praveena, P.; Vaisakh, K.; Rama Mohana Rao, S.</p> <p></p> <p>The Dynamic economic dispatch (DED) problem is an <span class="hlt">optimization</span> problem with an objective to determine the <span class="hlt">optimal</span> combination of power outputs for all generating units over a certain period of time in order to minimize the total fuel cost while satisfying dynamic operational constraints and load demand in each interval. Recently social foraging behavior of Escherichia coli bacteria has been explored to develop a novel algorithm for distributed <span class="hlt">optimization</span> and control. The Bacterial Foraging <span class="hlt">Optimization</span> Algorithm (BFOA) is currently gaining popularity in the community of researchers, for its effectiveness in solving certain difficult real-world <span class="hlt">optimization</span> problems. This article comes up with a hybrid approach involving Particle Swarm <span class="hlt">Optimization</span> (PSO) and BFO algorithms with varying chemo tactic <span class="hlt">step</span> size for solving the DED problem of generating units considering valve-point effects. The proposed hybrid algorithm has been extensively compared with those methods reported in the literature. The new method is shown to be statistically significantly better on two test systems consisting of five and ten generating units.</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><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('https://www.ncbi.nlm.nih.gov/pubmed/26932018','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26932018"><span><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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</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('https://www.osti.gov/scitech/biblio/22482956','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22482956"><span><span class="hlt">Optimization</span> of plasma parameters with magnetic <span class="hlt">filter</span> field and pressure to maximize H{sup −} ion density in a negative hydrogen ion source</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cho, Won-Hwi; Dang, Jeong-Jeung; Kim, June Young; Hwang, Y. S.; Chung, Kyoung-Jae</p> <p>2016-02-15</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{sup −} populations for various <span class="hlt">filter</span> field strengths and pressures. Enhanced H{sup −} 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{sup −} 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('https://www.ncbi.nlm.nih.gov/pubmed/12708547','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12708547"><span>Simulation results for on-line <span class="hlt">optimization</span> of a batch bioreactor using nonlinear <span class="hlt">filtering</span> and <span class="hlt">optimal</span> control.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dondo, Rodolfo; Marqués, Dardo</p> <p>2003-04-01</p> <p>The computation of <span class="hlt">optimal</span> control profiles for batch bioreactors is based on the use of simple and empirical dynamic models. Since these models present some level of uncertainty, the difference between the model dynamics and the reactor dynamics can have significant effects in the reliability of the calculated profile. To develop near <span class="hlt">optimal</span> control trajectories considering this drawback, we propose to calculate successive control profiles on a moving time horizon using a mathematical model in which the kinetic parameters are estimated by an observer. The desired objective is to generate a near <span class="hlt">optimal</span> control trajectory adapted to the "running" fermentation. This idea results in a nonlinear estimator plus an <span class="hlt">optimizer</span> arrangement that so far has not been applied to batch fermentors. Numerical simulations are performed on xanthan-gum batch fermentations and reasonably good results are obtained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26737966','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26737966"><span>A comparison of ERP spatial <span class="hlt">filtering</span> methods for <span class="hlt">optimal</span> mental workload estimation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Roy, Raphaelle N; Bonnet, Stephane; Charbonnier, Sylvie; Jallon, Pierre; Campagne, Aurelie</p> <p>2015-01-01</p> <p>Mental workload estimation is of crucial interest for user adaptive interfaces and neuroergonomics. Its estimation can be performed using event-related potentials (ERPs) extracted from electroencephalographic recordings (EEG). Several ERP spatial <span class="hlt">filtering</span> methods have been designed to enhance relevant EEG activity for active brain-computer interfaces. However, to our knowledge, they have not yet been used and compared for mental state monitoring purposes. This paper presents a thorough comparison of three ERP spatial <span class="hlt">filtering</span> methods: principal component analysis (PCA), canonical correlation analysis (CCA) and the xDAWN algorithm. Those methods are compared in their performance to allow for an accurate classification of mental workload when applied in an otherwise similar processing chain. The data of 20 healthy participants that performed a memory task for 10 minutes each was used for classification. Two levels of mental workload were considered depending on the number of digits participants had to memorize (2/6). The highest performances were obtained using the CCA <span class="hlt">filtering</span> and the xDAWN algorithm respectively with 98% and 97% of correct classification. Their performances were significantly higher than that obtained using the PCA <span class="hlt">filtering</span> (88%).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=286120','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=286120"><span><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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9982E..0GD','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9982E..0GD"><span><span class="hlt">Optimal</span> speckle noise reduction <span class="hlt">filter</span> for range gated laser illuminated imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dayton, David; Gonglewski, John; Lasche, James; Hassall, Arthur</p> <p>2016-09-01</p> <p>Laser illuminated imaging has a number of applications in the areas of night time air-to-ground target surveillance, ID, and pointing and tracking. Using a laser illuminator, the illumination intensity and thus the signal to noise ratio can be controlled. With the advent of high performance range gated cameras in the short-wave infra-red band, higher spatial resolution can be achieved over passive thermal night imaging cameras in the mid-wave infra-red due to the shorter wave-length. If a coherent illuminator is used the resulting imagery often suffers from speckle noise due to the scattering off of a rough target surface, which gives it a grainy "salt and pepper" appearance. The probability density function for the intensity of focal plane speckle is well understood to follow a negative exponential distribution. This can be exploited to develop a Bayesian speckle noise <span class="hlt">filter</span>. The <span class="hlt">filter</span> has the advantage over simple frame averaging approaches in that it preserves target features and motion while reducing speckle noise without smearing or blurring the images. The resulting <span class="hlt">filtered</span> images have the appearance of passive imagery and so are more amenable to sensor fusion with simultaneous mid-wave infra-red thermal images for enhanced target ID. The noise <span class="hlt">filter</span> improvement is demonstrated using examples from real world laser imaging tests on tactical targets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/971914','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/971914"><span><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('https://www.ncbi.nlm.nih.gov/pubmed/28003954','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28003954"><span>Improved tomographic reconstruction of large-scale real-world data by <span class="hlt">filter</span> <span class="hlt">optimization</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pelt, Daniël M; De Andrade, Vincent</p> <p>2017-01-01</p> <p>In advanced tomographic experiments, large detector sizes and large numbers of acquired datasets can make it difficult to process the data in a reasonable time. At the same time, the acquired projections are often limited in some way, for example having a low number of projections or a low signal-to-noise ratio. Direct analytical reconstruction methods are able to produce reconstructions in very little time, even for large-scale data, but the quality of these reconstructions can be insufficient for further analysis in cases with limited data. Iterative reconstruction methods typically produce more accurate reconstructions, but take significantly more time to compute, which limits their usefulness in practice. In this paper, we present the application of the SIRT-FBP method to large-scale real-world tomographic data. The SIRT-FBP method is able to accurately approximate the simultaneous iterative reconstruction technique (SIRT) method by the computationally efficient <span class="hlt">filtered</span> backprojection (FBP) method, using precomputed experiment-specific <span class="hlt">filters</span>. We specifically focus on the many implementation details that are important for application on large-scale real-world data, and give solutions to common problems that occur with experimental data. We show that SIRT-FBP <span class="hlt">filters</span> can be computed in reasonable time, even for large problem sizes, and that precomputed <span class="hlt">filters</span> can be reused for future experiments. Reconstruction results are given for three different experiments, and are compared with results of popular existing methods. The results show that the SIRT-FBP method is able to accurately approximate iterative reconstructions of experimental data. Furthermore, they show that, in practice, the SIRT-FBP method can produce more accurate reconstructions than standard direct analytical reconstructions with popular <span class="hlt">filters</span>, without increasing the required computation time.</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><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('https://www.ncbi.nlm.nih.gov/pubmed/28189580','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28189580"><span>Automated Design of Synthetic Cell Classifier Circuits Using a Two-<span class="hlt">Step</span> <span class="hlt">Optimization</span> Strategy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mohammadi, Pejman; Beerenwinkel, Niko; Benenson, Yaakov</p> <p>2017-02-22</p> <p>Cell classifiers are genetic logic circuits that transduce endogenous molecular inputs into cell-type-specific responses. Designing classifiers that achieve <span class="hlt">optimal</span> differential response between specific cell types is a hard computational problem because it involves selection of endogenous inputs and <span class="hlt">optimization</span> of both biochemical parameters and a logic function. To address this problem, we first derive an <span class="hlt">optimal</span> set of biochemical parameters with the largest expected differential response over a diverse set of logic circuits, and second, we use these parameters in an evolutionary algorithm to select circuit inputs and <span class="hlt">optimize</span> the logic function. Using this approach, we design experimentally feasible microRNA-based circuits capable of perfect discrimination for several real-world cell-classification tasks. We also find that under realistic cell-to-cell variation, circuit performance is comparable to standard cross-validation performance estimates. Our approach facilitates the generation of candidate circuits for experimental testing in therapeutic settings that require precise cell targeting, such as cancer therapy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26362231','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26362231"><span>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="https://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.</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('https://www.ncbi.nlm.nih.gov/pubmed/25285187','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25285187"><span>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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23639906','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23639906"><span>A comparison of reanalysis techniques: applying <span class="hlt">optimal</span> interpolation and Ensemble Kalman <span class="hlt">Filtering</span> to improve air quality monitoring at mesoscale.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Candiani, Gabriele; Carnevale, Claudio; Finzi, Giovanna; Pisoni, Enrico; Volta, Marialuisa</p> <p>2013-08-01</p> <p>To fulfill the requirements of the 2008/50 Directive, which allows member states and regional authorities to use a combination of measurement and modeling to monitor air pollution concentration, a key approach to be properly developed and tested is the data assimilation one. In this paper, with a focus on regional domains, a comparison between <span class="hlt">optimal</span> interpolation and Ensemble Kalman <span class="hlt">Filter</span> is shown, to stress pros and drawbacks of the two techniques. These approaches can be used to implement a more accurate monitoring of the long-term pollution trends on a geographical domain, through an <span class="hlt">optimal</span> combination of all the available sources of data. The two approaches are formalized and applied for a regional domain located in Northern Italy, where the PM10 level which is often higher than EU standard limits is measured.</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>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://adsabs.harvard.edu/abs/2017InPhT..81..276M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017InPhT..81..276M"><span>Engineering <span class="hlt">steps</span> for <span class="hlt">optimizing</span> high temperature LWIR HgCdTe photodiodes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Madejczyk, Pawel; Gawron, Waldemar; Martyniuk, Piotr; Keblowski, Artur; Pusz, Wioletta; Pawluczyk, Jaroslaw; Kopytko, Malgorzata; Rutkowski, Jaroslaw; Rogalski, Antoni; Piotrowski, Jozef</p> <p>2017-03-01</p> <p>The authors report on energy gap engineering solutions to improve the high-temperature performance of long-wave infrared (LWIR) HgCdTe photodiodes. Metalorganic chemical vapour deposition (MOCVD) technology with a wide range of composition and donor/acceptor doping and without ex-situ post grown annealing seems to be an excellent tool for HgCdTe heterostructure epitaxial growth. The heterojunction HgCdTe photovoltaic device based on epitaxial graded gap structures integrated with Auger-suppression is a magnificent solution for high operating temperature (HOT) infrared detectors. The thickness, composition and doping of HgCdTe heterostructure were <span class="hlt">optimized</span> with respect to photoelectrical parameters like dark current, the responsivity and the response time. In this paper we focus on graded interface abruptness in the progressive <span class="hlt">optimization</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004NIMPB.213..172O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004NIMPB.213..172O"><span>MCNP <span class="hlt">optimization</span> of <span class="hlt">filtered</span> neutron beams for calibration of the SIMPLE detector</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oliveira, C.; Giuliani, F.; Girard, T. A.; Marques, J. G.; Salgado, J.; Collar, J. I.; Morlat, T.; Limagne, D.; Waysand, G.</p> <p>2004-01-01</p> <p>We report an MCNP study of <span class="hlt">filtered</span> monochromatic neutron beams of energies 25, 54 and 149 keV for response studies of a superheated droplet detector for the SIMPLE experiment. The results identify the importance of the detector temperature stabilizing water bath and the aqueous gel of the detector on the beam quality, in general agreement with recent measurements made on the thermal port of the Portuguese research reactor.</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><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/2007SPIE.6629E..03L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SPIE.6629E..03L"><span>Dynamic optical tomographic imager with <span class="hlt">optimized</span> digital lock-in <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>Lasker, Joseph M.; Masciotti, James M.; Li, Yang; Fong, Chris; Hielscher, Andreas H.</p> <p>2007-07-01</p> <p>We describe a new dynamic optical tomography system that is, unlike currently available analog instrumentation, based on digital data-acquisition and <span class="hlt">filtering</span> techniques. At the heart of this continuous wave instrument is a digital signal processor (DSP) that collects, collates, processes, and <span class="hlt">filters</span> the digitized data set. A digital lock-in <span class="hlt">filter</span> that has been designed for this particular application maximizes measurement fidelity. The synchronously-timed processes are controlled by a complex programmable logic device (CPLD) that is also used in conjunction with the DSP to orchestrate data flow. Real-time data rates as high as 140Hz can be achieved. The operation of the system is implemented through a graphical user interface designed with LabVIEW software, Performance analysis shows very low system noise (~600fW RMS noise equivalent power), excellent signal precision (<0.04% - 0.2%) and long-term system stability (<1% over 40 min). A large dynamic range (~195dB) accommodates a wide scope of measurement geometries and tissue types. First experiments on tissue phantoms show that dynamic behavior is accurately captured and spatial location can be correctly tracked using this system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SPIE.8192E..4NL','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SPIE.8192E..4NL"><span>System <span class="hlt">optimization</span> of a field-widened Michelson interferometric spectral <span class="hlt">filter</span> for high spectral resolution lidar</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Dong; Miller, Ian; Hostetler, Chris; Cook, Anthony; Hair, Johnathan</p> <p>2011-06-01</p> <p>High spectral resolution lidars (HSRLs) have recently shown great value in aerosol measurements form aircraft and are being called for in future space-based aerosol remote sensing applications. A quasi-monolithic field-widened, off-axis Michelson interferometer had been developed as the spectral discrimination <span class="hlt">filter</span> for an HSRL currently under development at NASA Langley Research Center (LaRC). The Michelson <span class="hlt">filter</span> consists of a cubic beam splitter, a solid arm and an air arm. The input light is injected at 1.5° off-axis to provide two output channels: standard Michelson output and the reflected complementary signal. Piezo packs connect the air arm mirror to the main part of the <span class="hlt">filter</span> that allows it to be tuned within a small range. In this paper, analyses of the throughput wavephase, locking error, AR coating, and tilt angle of the interferometer are described. The transmission ratio for monochromatic light at the transmitted wavelength is used as a figure of merit for assessing each of these parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010CG.....36.1005G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010CG.....36.1005G"><span>An <span class="hlt">optimized</span> solution of multi-criteria evaluation analysis of landslide susceptibility using fuzzy sets and 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>Gorsevski, Pece V.; Jankowski, Piotr</p> <p>2010-08-01</p> <p>The Kalman recursive algorithm has been very widely used for integrating navigation sensor data to achieve <span class="hlt">optimal</span> system performances. This paper explores the use of the Kalman <span class="hlt">filter</span> to extend the aggregation of spatial multi-criteria evaluation (MCE) and to find <span class="hlt">optimal</span> solutions with respect to a decision strategy space where a possible decision rule falls. The approach was tested in a case study in the Clearwater National Forest in central Idaho, using existing landslide datasets from roaded and roadless areas and terrain attributes. In this approach, fuzzy membership functions were used to standardize terrain attributes and develop criteria, while the aggregation of the criteria was achieved by the use of a Kalman <span class="hlt">filter</span>. The approach presented here offers advantages over the classical MCE theory because the final solution includes both the aggregated solution and the areas of uncertainty expressed in terms of standard deviation. A comparison of this methodology with similar approaches suggested that this approach is promising for predicting landslide susceptibility and further application as a spatial decision support system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4034478','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4034478"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/24895663','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24895663"><span>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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20003887','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20003887"><span>Single-<span class="hlt">step</span> syngas-to-dimethyl ether processes for <span class="hlt">optimal</span> productivity, minimal emissions, and natural gas-derived syngas</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Peng, X.D.; Wang, A.W.; Toseland, B.A.; Tijm, P.J.A.</p> <p>1999-11-01</p> <p>Process schemes for single-<span class="hlt">step</span> syngas-to-dimethyl ether (DME) were developed in two stages: (1) the performance of the syngas-to-DME reactor was <span class="hlt">optimized</span> with respect to the feed gas composition and (2) the <span class="hlt">optimal</span> reactor feed gas system was integrated with synthesis gas generators. It was shown that the reactor performance is very sensitive to the H{sub 2}:CO ratio in the feed gas. The <span class="hlt">optimal</span> DME productivity and best material utilization were obtained with a feed gas containing 50% hydrogen and 50% carbon monoxide. In the second phase the syngas generation units considered were CO{sub 2}-methane reformer, steam-methane reformer, methane partial oxidation, and coal gasifier. The integration adjusts the H{sub 2}:CO ratio in natural gas-derived syngas to fit the <span class="hlt">optimal</span> DME reactor operation and minimizes CO{sub 2} emissions and material loss. The technical feasibility of these schemes was demonstrated by simulations using realistic reactor models, kinetics, and thermodynamics under commercially relevant conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22391418','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22391418"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/23296038','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23296038"><span>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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</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('https://www.osti.gov/scitech/biblio/1248732','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1248732"><span><span class="hlt">Optimizing</span> multi-<span class="hlt">step</span> B-side charge separation in photosynthetic reaction centers from Rhodobacter capsulatus</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Faries, Kaitlyn M.; Kressel, Lucas L.; Dylla, Nicholas P.; Wander, Marc J.; Hanson, Deborah K.; Holten, Dewey; Laible, Philip D.; Kirmaier, Christine</p> <p>2016-02-01</p> <p>Using high-throughput methods for mutagenesis, protein isolation and charge-separation functionality, we have assayed 40 Rhodobacter capsulatus reaction center (RC) mutants for their P+ QB- yield (P is a dimer of bacteriochlorophylls and Q is a ubiquinone) as produced using the normally inactive B-side cofactors BB and HB (where B is a bacteriochlorophyll and H is a bacteriopheophytin). Two sets of mutants explore all possible residues at M131 (M polypeptide, native residue Val near HB) in tandem with either a fixed His or a fixed Asn at L181 (L polypeptide, native residue Phe near BB). A third set of mutants explores all possible residues at L181 with a fixed Glu at M131 that can form a hydrogen bond to HB. For each set of mutants, the results of a rapid millisecond screening assay that probes the yield of P+ QB- are compared among that set and to the other mutants reported here or previously. For a subset of eight mutants, the rate constants and yields of the individual B-side electron transfer processes are determined via transient absorption measurements spanning 100 fs to 50 μs. The resulting ranking of mutants for their yield of P+ QB- from ultrafast experiments is in good agreement with that obtained from the millisecond screening assay, further validating the efficient, high-throughput screen for B-side transmembrane charge separation. Results from mutants that individually show progress toward <span class="hlt">optimization</span> of P+ HB- → P+ QB- electron transfer or initial P* → P+ HB- conversion highlight unmet challenges of <span class="hlt">optimizing</span> both processes simultaneously.</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>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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EJASP2002...70M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EJASP2002...70M"><span>SVD-Based <span class="hlt">Optimal</span> <span class="hlt">Filtering</span> Technique for Noise Reduction in Hearing Aids Using Two Microphones</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maj, Jean-Baptiste; Moonen, Marc; Wouters, Jan</p> <p>2002-12-01</p> <p>We introduce a new SVD-based (Singular value decomposition) strategy for noise reduction in hearing aids. This technique is evaluated for noise reduction in a behind-the-ear (BTE) hearing aid where two omnidirectional microphones are mounted in an endfire configuration. The behaviour of the SVD-based technique is compared to a two-stage adaptive beamformer for hearing aids developed by Vanden Berghe and Wouters (1998). The evaluation and comparison is done with a performance metric based on the speech intelligibility index (SII). The speech and noise signals are recorded in reverberant conditions with a signal-to-noise ratio of [InlineEquation not available: see fulltext.] and the spectrum of the noise signals is similar to the spectrum of the speech signal. The SVD-based technique works without initialization nor assumptions about a look direction, unlike the two-stage adaptive beamformer. Still, for different noise scenarios, the SVD-based technique performs as well as the two-stage adaptive beamformer, for a similar <span class="hlt">filter</span> length and adaptation time for the <span class="hlt">filter</span> coefficients. In a diffuse noise scenario, the SVD-based technique performs better than the two-stage adaptive beamformer and hence provides a more flexible and robust solution under speaker position variations and reverberant conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9743E..18T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9743E..18T"><span>Design <span class="hlt">optimization</span> for two-<span class="hlt">step</span> photon absorption in quantum dot solar cells by using infrared photocurrent spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tamaki, R.; Shoji, Y.; Okada, Y.</p> <p>2016-03-01</p> <p>Multi-stacked quantum dot solar cell (QDSC) is a promising candidate for intermediate band solar cell, which can exceed thermodynamic efficiency limit of single-junction solar cells. In recent years, lots of effort has been made to evaluate and understand the photo-carrier response of two-<span class="hlt">step</span> photon absorption in QDSCs. One crucial issue is to suppress thermal excitation of photo-carriers out of QDs, which obscures the QD filling under quasi-equilibrium at operation conditions. We have investigated infrared photocurrent spectra of the QD states to conduction band (CB) transition by using Fourier transform infrared (FTIR) spectroscopy. Multi-stacked In(Ga)As QDSCs with different barrier materials, such as GaAs, GaNAs, GaAsSb, and AlGaAs, were investigated. The IR absorption edge of the QD to CB transition was evaluated at low temperature by analyzing the low energy tail of the FTIR spectra. The threshold temperature of the two-<span class="hlt">step</span> photon absorption in In(Ga)As QDSCs was determined by observing temperature dependence of the IR photo-response. A universal linear relationship between the threshold temperature and the IR absorption edge was obtained in In(Ga)As QDSCs with varied barrier materials. The threshold temperature of 295 K was predicted for the absorption edge at 0.459 eV by extrapolating the linear relationship. It reveals strategy for cell <span class="hlt">optimization</span> to achieve efficient two-<span class="hlt">step</span> photon absorption at ambient conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25794715','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25794715"><span><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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22548480','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22548480"><span>SU-E-T-435: Flattening <span class="hlt">Filter</span> Free Beams for Head and Neck IMRT and VMAT <span class="hlt">Optimization</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ghahremani, S; Chavez, R; Li, Y; Crownover, R; Baacke, D; Papanikolaou, N; Stathakis, S</p> <p>2015-06-15</p> <p>Purpose: To investigate if there is benefits of using flattening <span class="hlt">filter</span> free (FFF) versus flattening <span class="hlt">filter</span> (FF) beams during plan <span class="hlt">optimization</span> for head and neck targets. Methods: Five head and neck cancer patients previously treated were selected for this study. Each plan was <span class="hlt">optimized</span> for volumetric modulated arc therapy (VMAT) using 2 full arcs. Target volumes and the organs at risk (OAR) were outlined by the same physician. The prescription doses for each patient and the dose limits for each OAR were specified by the physician. For each patient four plans were created by varying the photon beam energy (6MV vs 10MV) and the use of FF or FFF. For each patient the prescription dose and OAR dose limits remained unchanged. Furthermore, the number of <span class="hlt">optimization</span> iterations remained the same for each plan without user interference. The plans were compared using dose volume histograms, conformity and homogeneity indices. Results: Our results showed that the plans <span class="hlt">optimized</span> with FF beams produced more homogeneous dose distributions in the PTV than the ones with FFF beams (0.92 vs. 0.86 and 0.92 vs.85 for 6MVFF, 6MVFFF, 10MVFF and 10MVFFF respectively). The conformity was better for FFF beams than for FF beams (1.26 vs. 1.20 and 1.27 vs. 1.21 for 6MVFF, 6MVFFF, 10MVFF and 10MVFFF respectively). The overall minimum, maximum and means doses were reduced for the FFF plans by approximately 4% to 6%. All FFF plans allowed more sparing of organs at risk by 7% to 9% on average. Only one 10MVFFF plan had a 1% higher dose than the respective 10MVFF for the spinal cord. Conclusion: The 6MVFFF and 10MVFFF beams illustrated the improvement of normal tissue sparing while achieving similar target dose distribution compared to 6MVFF and 10MVFF beams. Further investigation is required to determine the magnitude of improvement. case specific, fluence-based <span class="hlt">optimization</span> improved both PTV and OAR dosimetry in 80% of cases.</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('https://ntrs.nasa.gov/search.jsp?R=19820013596&hterms=noise-like&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dnoise-like','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820013596&hterms=noise-like&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dnoise-like"><span><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('https://www.ncbi.nlm.nih.gov/pubmed/18565647','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18565647"><span>Permeability <span class="hlt">optimization</span> and performance evaluation of hot aerosol <span class="hlt">filters</span> made using foam incorporated alumina suspension.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Innocentini, Murilo D M; Rodrigues, Vanessa P; Romano, Roberto C O; Pileggi, Rafael G; Silva, Gracinda M C; Coury, José R</p> <p>2009-02-15</p> <p>Porous ceramic samples were prepared from aqueous foam incorporated alumina suspension for application as hot aerosol <span class="hlt">filtering</span> membrane. The procedure for establishment of membrane features required to maintain a desired flow condition was theoretically described and experimental work was designed to prepare ceramic membranes to meet the predicted criteria. Two best membranes, thus prepared, were selected for permeability tests up to 700 degrees C and their total and fractional collection efficiencies were experimentally evaluated. Reasonably good performance was achieved at room temperature, while at 700 degrees C, increased permeability was obtained with significant reduction in collection efficiency, which was explained by a combination of thermal expansion of the structure and changes in the gas properties.</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><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://adsabs.harvard.edu/abs/2010AIPC.1285..450J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AIPC.1285..450J"><span>Reduction of Common-Mode Conducted Noise Emissions in PWM Inverter-fed AC Motor Drive Systems using <span class="hlt">Optimized</span> Passive EMI <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>Jettanasen, C.; Ngaopitakkul, A.</p> <p>2010-10-01</p> <p>Conducted electromagnetic interference (EMI) generated by PWM inverter-fed induction motor drive systems, which are currently widely used in many industrial and/or avionic applications, causes severe parasitic current problems, especially at high frequencies (HF). These restrict power electronic drive's evolution. In order to reduce or minimize these EMI problems, several techniques can be applied. In this paper, insertion of an <span class="hlt">optimized</span> passive EMI <span class="hlt">filter</span> is proposed. This <span class="hlt">filter</span> is <span class="hlt">optimized</span> by taking into account real impedances of each part of a considered AC motor drive system contrarily to commercial EMI <span class="hlt">filters</span> designed by considering internal impedance of disturbance source and load, equal to 50Ω. Employing the latter EMI <span class="hlt">filter</span> would make EMI minimization less effective. The proposed EMI <span class="hlt">filter</span> <span class="hlt">optimization</span> is mainly dedicated to minimize common mode (CM) currents due to its most dominant effects in this kind of system. The efficiency of the proposed <span class="hlt">optimization</span> method using two-port network approach is deduced by comparing the minimized CM current spectra to an applied normative level (ex. DO-160D in aeronautics).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26273732','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26273732"><span>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="https://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>2016-01-01</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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23367417','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23367417"><span>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="https://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.</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>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('https://www.osti.gov/scitech/biblio/22046993','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22046993"><span>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>Fetterman, Abraham J.; Fisch, Nathaniel J.</p> <p>2011-10-15</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://hdl.handle.net/2060/19750005841','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750005841"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/26974772','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26974772"><span>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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5324642','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5324642"><span><span class="hlt">Optimal</span> experimental design for <span class="hlt">filter</span> exchange imaging: Apparent exchange rate measurements in the healthy brain and in intracranial tumors</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Szczepankiewicz, Filip; van Westen, Danielle; Englund, Elisabet; C Sundgren, Pia; Lätt, Jimmy; Ståhlberg, Freddy; Nilsson, Markus</p> <p>2016-01-01</p> <p>Purpose <span class="hlt">Filter</span> exchange imaging (FEXI) is sensitive to the rate of diffusional water exchange, which depends, eg, on the cell membrane permeability. The aim was to <span class="hlt">optimize</span> and analyze the ability of FEXI to infer differences in the apparent exchange rate (AXR) in the brain between two populations. Methods A FEXI protocol was <span class="hlt">optimized</span> for minimal measurement variance in the AXR. The AXR variance was investigated by test‐retest acquisitions in six brain regions in 18 healthy volunteers. Preoperative FEXI data and postoperative microphotos were obtained in six meningiomas and five astrocytomas. Results Protocol <span class="hlt">optimization</span> reduced the coefficient of variation of AXR by approximately 40%. Test‐retest AXR values were heterogeneous across normal brain regions, from 0.3 ± 0.2 s−1 in the corpus callosum to 1.8 ± 0.3 s−1 in the frontal white matter. According to analysis of statistical power, in all brain regions except one, group differences of 0.3–0.5 s−1 in the AXR can be inferred using 5 to 10 subjects per group. An AXR difference of this magnitude was observed between meningiomas (0.6 ± 0.1 s−1) and astrocytomas (1.0 ± 0.3 s−1). Conclusions With the <span class="hlt">optimized</span> protocol, FEXI has the ability to infer relevant differences in the AXR between two populations for small group sizes. Magn Reson Med 77:1104–1114, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made. PMID:26968557</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003PhDT.......169G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003PhDT.......169G"><span>Measurement and <span class="hlt">optimization</span> of fiber mechanical properties for use in a novel HTS 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>Guo, Libing</p> <p>2003-10-01</p> <p>This dissertation is a study of the thermal physical properties of a single fiber to be used as a key part of an HTS tunable <span class="hlt">filter</span>. Eight classes of candidate fibers were narrowed down to carbon and borosilicate fibers for more study. Novel measurement methods were used in this project that overcame the shortcomings of literature methods, which can only measure the properties at room temperature. The experimental apparatus was designed and built, and measurements were made of Young's modulus, tensile strength, ultimate strain, torsional modulus and thermal linear expansion of both types of fibers at both room temperature and 95K. The errors of the measurement, including random variations in fiber diameter, were analyzed statistically to determine error bounds. The measurement results were used to determine the mechanical performance of each of the fibers when applied to suspending the toractor system. Based on the working conditions of both carbon fiber and borosilicate fiber, the borosilicate fiber was chosen for this purpose. The performance margin of the fiber suspending system was estimated by using a statistical model. A new model was proposed to demonstrate the relationship of the cross-section structure of Polyacrylonitrile (PAN)-based carbon fiber and its mechanical properties. The theoretical predictions on the properties of PAN-based carbon fiber based on this model agree very well with the experimental data. The Young's modulus and tensile strength of PAN-based carbon fiber with known diameter can be calculated by a simple equation without taking time to do an experimental measurement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22753308','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22753308"><span>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="https://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.</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>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://adsabs.harvard.edu/abs/2015MSSP...52..465T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MSSP...52..465T"><span>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://hdl.handle.net/2060/20140009131','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140009131"><span>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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5346028','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5346028"><span>Analytical and Clinical Validity Study of First<span class="hlt">Step</span>Dx PLUS: A Chromosomal Microarray <span class="hlt">Optimized</span> for Patients with Neurodevelopmental Conditions</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hensel, Charles; Vanzo, Rena; Martin, Megan; Dixon, Sean; Lambert, Christophe; Levy, Brynn; Nelson, Lesa; Peiffer, Andy; Ho, Karen S.; Rushton, Patricia; Serrano, Moises; South, Sarah; Ward, Kenneth; Wassman, Edward</p> <p>2017-01-01</p> <p>Introduction: Chromosomal microarray analysis (CMA) is recognized as the first-tier test in the genetic evaluation of children with developmental delays, intellectual disabilities, congenital anomalies and autism spectrum disorders of unknown etiology. Array Design: To <span class="hlt">optimize</span> detection of clinically relevant copy number variants associated with these conditions, we designed a whole-genome microarray, First<span class="hlt">Step</span>Dx PLUS (FSDX). A set of 88,435 custom probes was added to the Affymetrix CytoScanHD platform targeting genomic regions strongly associated with these conditions. This combination of 2,784,985 total probes results in the highest probe coverage and clinical yield for these disorders. Results and Discussion: Clinical testing of this patient population is validated on DNA from either non-invasive buccal swabs or traditional blood samples. In this report we provide data demonstrating the analytic and clinical validity of FSDX and provide an overview of results from the first 7,570 consecutive patients tested clinically. We further demonstrate that buccal sampling is an effective method of obtaining DNA samples, which may provide improved results compared to traditional blood sampling for patients with neurodevelopmental disorders who exhibit somatic mosaicism. PMID:28357155</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4161121','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4161121"><span><span class="hlt">Optimism</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>Carver, Charles S.; Scheier, Michael F.; Segerstrom, Suzanne C.</p> <p>2010-01-01</p> <p><span class="hlt">Optimism</span> is an individual difference variable that reflects the extent to which people hold generalized favorable expectancies for their future. Higher levels of <span class="hlt">optimism</span> have been related prospectively to better subjective well-being in times of adversity or difficulty (i.e., controlling for previous well-being). Consistent with such findings, <span class="hlt">optimism</span> has been linked to higher levels of engagement coping and lower levels of avoidance, or disengagement, coping. There is evidence that <span class="hlt">optimism</span> is associated with taking proactive <span class="hlt">steps</span> to protect one's health, whereas pessimism is associated with health-damaging behaviors. Consistent with such findings, <span class="hlt">optimism</span> is also related to indicators of better physical health. The energetic, task-focused approach that optimists take to goals also relates to benefits in the socioeconomic world. Some evidence suggests that <span class="hlt">optimism</span> relates to more persistence in educational efforts and to higher later income. Optimists also appear to fare better than pessimists in relationships. Although there are instances in which <span class="hlt">optimism</span> fails to convey an advantage, and instances in which it may convey a disadvantage, those instances are relatively rare. In sum, the behavioral patterns of optimists appear to provide models of living for others to learn from. PMID:20170998</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>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('https://www.ncbi.nlm.nih.gov/pubmed/18326869','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18326869"><span><span class="hlt">Filter</span> quality of pleated <span class="hlt">filter</span> cartridges.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Chun-Wan; Huang, Sheng-Hsiu; Chiang, Che-Ming; Hsiao, Ta-Chih; Chen, Chih-Chieh</p> <p>2008-04-01</p> <p>The performance of dust cartridge <span class="hlt">filters</span> commonly used in dust masks and in room ventilation depends both on the collection efficiency of the <span class="hlt">filter</span> material and the pressure drop across the <span class="hlt">filter</span>. Currently, the <span class="hlt">optimization</span> of <span class="hlt">filter</span> design is based only on minimizing the pressure drop at a set velocity chosen by the manufacturer. The collection efficiency, an equally important factor, is rarely considered in the <span class="hlt">optimization</span> process. In this work, a <span class="hlt">filter</span> quality factor, which combines the collection efficiency and the pressure drop, is used as the <span class="hlt">optimization</span> criterion for <span class="hlt">filter</span> evaluation. Most respirator manufacturers pleat the <span class="hlt">filter</span> to various extents to increase the filtration area in the limit space within the dust cartridge. Six sizes of <span class="hlt">filter</span> holders were fabricated to hold just one pleat of <span class="hlt">filter</span>, simulating six different pleat counts, ranging from 0.5 to 3.33 pleats cm(-1). The possible electrostatic charges on the <span class="hlt">filter</span> were removed by dipping in isopropyl alcohol, and the air velocity is fixed at 100 cm s(-1). Liquid dicotylphthalate particles generated by a constant output atomizer were used as challenge aerosols to minimize particle loading effects. A scanning mobility particle sizer was used to measure the challenge aerosol number concentrations and size distributions upstream and downstream of the pleated <span class="hlt">filter</span>. The pressure drop across the <span class="hlt">filter</span> was monitored by using a calibrated pressure transducer. The results showed that the performance of pleated <span class="hlt">filters</span> depend not only on the size of the particle but also on the pleat count of the pleated <span class="hlt">filter</span>. Based on <span class="hlt">filter</span> quality factor, the <span class="hlt">optimal</span> pleat count (OPC) is always higher than that based on pressure drop by about 0.3-0.5 pleats cm(-1). For example, the OPC is 2.15 pleats cm(-1) from the standpoint of pressure drop, but for the highest <span class="hlt">filter</span> quality factor, the pleated <span class="hlt">filter</span> needed to have a pleat count of 2.65 pleats cm(-1) at particle diameter of 122 nm. From the aspect of</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://hdl.handle.net/2060/19720021544','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720021544"><span>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://www.osti.gov/scitech/servlets/purl/1175646','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1175646"><span><span class="hlt">Filter</span> and method of fabricating</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Janney, Mark A.</p> <p>2006-02-14</p> <p>A method of making a <span class="hlt">filter</span> includes the <span class="hlt">steps</span> of: providing a substrate having a porous surface; applying to the porous surface a coating of dry powder comprising particles to form a <span class="hlt">filter</span> preform; and heating the <span class="hlt">filter</span> preform to bind the substrate and the particles together to form a <span class="hlt">filter</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110012130','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110012130"><span>GPU Accelerated Vector Median <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>Aras, Rifat; Shen, Yuzhong</p> <p>2011-01-01</p> <p>Noise reduction is an important <span class="hlt">step</span> for most image processing tasks. For three channel color images, a widely used technique is vector median <span class="hlt">filter</span> in which color values of pixels are treated as 3-component vectors. Vector median <span class="hlt">filters</span> are computationally expensive; for a window size of n x n, each of the n(sup 2) vectors has to be compared with other n(sup 2) - 1 vectors in distances. General purpose computation on graphics processing units (GPUs) is the paradigm of utilizing high-performance many-core GPU architectures for computation tasks that are normally handled by CPUs. In this work. NVIDIA's Compute Unified Device Architecture (CUDA) paradigm is used to accelerate vector median <span class="hlt">filtering</span>. which has to the best of our knowledge never been done before. The performance of GPU accelerated vector median <span class="hlt">filter</span> is compared to that of the CPU and MPI-based versions for different image and window sizes, Initial findings of the study showed 100x improvement of performance of vector median <span class="hlt">filter</span> implementation on GPUs over CPU implementations and further speed-up is expected after more extensive <span class="hlt">optimizations</span> of the GPU algorithm .</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15646356','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15646356"><span>[A new impulse noise <span class="hlt">filter</span> based on pulse coupled neural network].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ma, Yide; Shi, Fei; Li, Lian; An, Lizhe</p> <p>2004-12-01</p> <p>This paper presents a new impulse noise <span class="hlt">filter</span> based on pulse coupled neural networks according to the apparent difference of gray value between noised pixels and the pixels around them. Comparing with the state-of-the-art denoised PCNN <span class="hlt">filter</span>, the <span class="hlt">step</span> by <span class="hlt">step</span> modifying algorithm based on PCNN also, the new PCNN <span class="hlt">filter</span> suggested in this paper costs less computation and less execution time. At the same time this new PCNN <span class="hlt">filter</span> has been compared with other nonlinear <span class="hlt">filters</span>, such as median <span class="hlt">filter</span>, the stack <span class="hlt">filter</span> based on omnidirectional structural elements constrains, the Omnidirectional morphology Open-Closing maximum <span class="hlt">filter</span> (OOCmax) and the Omnidirectional morphology Close-Opening minimum (OCOmin) <span class="hlt">filter</span>. The results of simulation shows that this algorithm is superior to standard median <span class="hlt">filter</span>, the state-of-the-art PCNN <span class="hlt">filter</span>, the maximal, minimal morphological <span class="hlt">filter</span> with omnidirectional structuring elements, and the <span class="hlt">optimal</span> stack <span class="hlt">filter</span> based on omnidirectional structural elements constrains in the aspect of the impulse noise removal. What is more important is that this algorithm can keep the details of images more effectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24443896','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24443896"><span>Ultralong, small-diameter TiOTiO₂ nanotubes achieved by an <span class="hlt">optimized</span> two-<span class="hlt">step</span> anodization for efficient dye-sensitized solar cells.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Xiaoyan; Sun, Lidong; Zhang, Sam; Wang, Xiu</p> <p>2014-02-12</p> <p>An <span class="hlt">optimized</span> two-<span class="hlt">step</span> anodization is developed to fabricate ultralong, small-diameter TiO2 nanotubes, that is, with tube length of up to 31 μm and pore diameter of about 35 nm in this work. This overcomes the length limitation of small diameter tubes that usually presents in conventional one-<span class="hlt">step</span> anodization. The small tubes with lengths of 23 μm yield a conversion efficiency of 5.02% in dye-sensitized solar cells under nonoptimized conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JEMat..46..535W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JEMat..46..535W"><span>The Effects of Negative Differential Resistance, Bipolar Spin-<span class="hlt">Filtering</span>, and Spin-Rectifying on <span class="hlt">Step</span>-Like Zigzag Graphene Nanoribbons Heterojunctions with Single or Double Edge-Saturated Hydrogen</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Lihua; Zhao, Jianguo; Ding, Bingjun; Guo, Yong</p> <p>2017-01-01</p> <p>In this study, we investigated the spin-resolved transport aspects of <span class="hlt">step</span>-like zigzag graphene ribbons (ZGNRs) with single or double edge-saturated hydrogen using a method that combined the density functional theory with the nonequilibrium Green's function method under the local spin density approximation. We found that, when the ZGNR-based heterojunctions were in a parallel or antiparallel layout, negative differential resistance, the maximum bipolar spin-<span class="hlt">filtering</span>, and spin-rectifying effects occurred synchronously except for the case of spin-down electrons in the parallel magnetic layouts. Interestingly, these spin-resolved transport properties were almost unaffected by altering the widths of the two component ribbons. Therefore, <span class="hlt">step</span>-like ZGNR heterojunctions are promising for use in designing high-performance multifunctional spintronic devices.</p> </li> <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>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('https://www.ncbi.nlm.nih.gov/pubmed/26803003','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26803003"><span><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="https://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.</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>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('https://www.osti.gov/scitech/biblio/22105751','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22105751"><span>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('https://www.osti.gov/scitech/biblio/22253223','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22253223"><span>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; 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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JChPh.139x4106O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JChPh.139x4106O"><span>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://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Omelyan, Igor; Kovalenko, Andriy</p> <p>2013-12-01</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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24110283','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24110283"><span>An <span class="hlt">optimized</span> and low-cost FPGA-based DNA sequence alignment--a <span class="hlt">step</span> towards personal genomics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shah, Hurmat Ali; Hasan, Laiq; Ahmad, Nasir</p> <p>2013-01-01</p> <p>DNA sequence alignment is a cardinal process in computational biology but also is much expensive computationally when performing through traditional computational platforms like CPU. Of many off the shelf platforms explored for speeding up the computation process, FPGA stands as the best candidate due to its performance per dollar spent and performance per watt. These two advantages make FPGA as the most appropriate choice for realizing the aim of personal genomics. The previous implementation of DNA sequence alignment did not take into consideration the price of the device on which <span class="hlt">optimization</span> was performed. This paper presents <span class="hlt">optimization</span> over previous FPGA implementation that increases the overall speed-up achieved as well as the price incurred by the platform that was <span class="hlt">optimized</span>. The <span class="hlt">optimizations</span> are (1) The array of processing elements is made to run on change in input value and not on clock, so eliminating the need for tight clock synchronization, (2) the implementation is unrestrained by the size of the sequences to be aligned, (3) the waiting time required for the sequences to load to FPGA is reduced to the minimum possible and (4) an efficient method is devised to store the output matrix that make possible to save the diagonal elements to be used in next pass, in parallel with the computation of output matrix. Implemented on Spartan3 FPGA, this implementation achieved 20 times performance improvement in terms of CUPS over GPP implementation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28069162','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28069162"><span>A constrained extended Kalman <span class="hlt">filter</span> for the <span class="hlt">optimal</span> estimate of kinematics and kinetics of a sagittal symmetric exercise.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bonnet, V; Dumas, R; Cappozzo, A; Joukov, V; Daune, G; Kulić, D; Fraisse, P; Andary, S; Venture, G</p> <p>2016-12-29</p> <p>This paper presents a method for real-time estimation of the kinematics and kinetics of a human body performing a sagittal symmetric motor task, which would minimize the impact of the stereophotogrammetric soft tissue artefacts (STA). The method is based on a bi-dimensional mechanical model of the locomotor apparatus the state variables of which (joint angles, velocities and accelerations, and the segments lengths and inertial parameters) are estimated by a constrained extended Kalman <span class="hlt">filter</span> (CEKF) that fuses input information made of both stereophotogrammetric and dynamometric measurement data. <span class="hlt">Filter</span> gains are made to saturate in order to obtain plausible state variables and the measurement covariance matrix of the <span class="hlt">filter</span> accounts for the expected STA maximal amplitudes. We hypothesised that the ensemble of constraints and input redundant information would allow the method to attenuate the STA propagation to the end results. The method was evaluated in ten human subjects performing a squat exercise. The CEKF estimated and measured skin marker trajectories exhibited a RMS difference lower than 4mm, thus in the range of STAs. The RMS differences between the measured ground reaction force and moment and those estimated using the proposed method (9N and 10Nm) were much lower than obtained using a classical inverse dynamics approach (22N and 30Nm). From the latter results it may be inferred that the presented method allows for a significant improvement of the accuracy with which kinematic variables and relevant time derivatives, model parameters and, therefore, intersegmental moments are estimated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22339801','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22339801"><span>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 4–5 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 91–102), sigmoid D2cc was reduced on average by 37% (range 16–73), bladder by 28% (range 20–47) and rectum by 27% (range 15–45). Similar reductions were obtained on plans with “good” coverage, with an average D90 of 93% (range 90–99). 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 4–5 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('https://www.ncbi.nlm.nih.gov/pubmed/21290603','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21290603"><span>Orthogonal array design for the <span class="hlt">optimization</span> of ionic liquid-based dispersive liquid-liquid microextraction of benzophenone-type UV <span class="hlt">filters</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ye, Lei; Liu, Juanjuan; Yang, Xin; Peng, Yan; Xu, Li</p> <p>2011-03-01</p> <p>In the present study, dispersive liquid-liquid microextraction (DLLME) using an ionic liquid (IL) as the extractant was successfully developed to extract four benzophenone-type UV <span class="hlt">filters</span> from the different water matrices. Orthogonal array experimental design (OAD), based on five factors and four levels (L(16)(4(5))), was employed to <span class="hlt">optimize</span> IL-dispersive liquid-liquid microextraction procedure. The five factors included pH of sample solution, the volume of IL and methanol addition, extraction time and the amount of salt added. The <span class="hlt">optimal</span> extraction condition was as follows. Sample solution was at a pH of 2.63 in the presence of 60 mg/mL sodium chloride; 30 μL IL and 15 μL methanol were used as extractant and disperser solvent, respectively; extraction was achieved by vortexing for 4 min. Using high-performance liquid chromatography-UV analysis, the limits of detection of the target analytes ranged between 1.9 and 6.4 ng/mL. The linear ranges were between 10 or 20 ng/mL and 1000 ng/mL. This procedure afforded a convenient, fast and cost-saving operation with high extraction efficiency for the model analytes. Spiked waters from two rivers and one lake were examined by the developed method. For the swimming pool water, the standard addition method was employed to determine the actual concentrations of the UV <span class="hlt">filters</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000ApOpt..39..913S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000ApOpt..39..913S"><span>Wide-angle narrow-bandpass optical detection system <span class="hlt">optimally</span> designed to have a large signal-to-noise ratio</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schweitzer, Naftali; Arieli, Yoel</p> <p>2000-02-01</p> <p>A method for achieving <span class="hlt">optimal</span> design of a wide-angle narrow-bandpass optical detection system composed of a spherical interference <span class="hlt">filter</span> and a circular photodetector is introduced. It was found that there is an <span class="hlt">optimal</span> photodetector diameter that maximizes the signal-to-noise ratio (SNR) for a given <span class="hlt">filter</span> configuration. We show how to <span class="hlt">optimize</span> optical detection systems based on spherical interference <span class="hlt">filters</span> for all the important parameters simultaneously. The SNR values of these systems are compared with the SNR values of spherical-<span class="hlt">step-filter</span>-based detection systems. When large silicon photodetectors are used, the two systems have equal SNR values so that the more economical <span class="hlt">step-filter</span> systems are preferable. The results given here in the near-infrared region can be used for the <span class="hlt">optimization</span> of any configuration of a detection system based on a spherical interference <span class="hlt">filter</span> and a silicon photodetector working at the same wavelength range, without further calculations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920057751&hterms=sartori&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsartori','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920057751&hterms=sartori&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsartori"><span>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://eric.ed.gov/?q=network+AND+security+AND+threats&pg=2&id=EJ711631','ERIC'); return false;" href="http://eric.ed.gov/?q=network+AND+security+AND+threats&pg=2&id=EJ711631"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/18785761','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18785761"><span>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="https://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</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('https://www.ncbi.nlm.nih.gov/pubmed/26381742','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26381742"><span>A Conjugate Gradient Algorithm with Function Value Information and N-<span class="hlt">Step</span> Quadratic Convergence for Unconstrained <span class="hlt">Optimization</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Xiangrong; Zhao, Xupei; Duan, Xiabin; Wang, Xiaoliang</p> <p>2015-01-01</p> <p>It is generally acknowledged that the conjugate gradient (CG) method achieves global convergence--with at most a linear convergence rate--because CG formulas are generated by linear approximations of the objective functions. The quadratically convergent results are very limited. We introduce a new PRP method in which the restart strategy is also used. Moreover, the method we developed includes not only n-<span class="hlt">step</span> quadratic convergence but also both the function value information and gradient value information. In this paper, we will show that the new PRP method (with either the Armijo line search or the Wolfe line search) is both linearly and quadratically convergent. The numerical experiments demonstrate that the new PRP algorithm is competitive with the normal CG method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4575111','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4575111"><span>A Conjugate Gradient Algorithm with Function Value Information and N-<span class="hlt">Step</span> Quadratic Convergence for Unconstrained <span class="hlt">Optimization</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>Li, Xiangrong; Zhao, Xupei; Duan, Xiabin; Wang, Xiaoliang</p> <p>2015-01-01</p> <p>It is generally acknowledged that the conjugate gradient (CG) method achieves global convergence—with at most a linear convergence rate—because CG formulas are generated by linear approximations of the objective functions. The quadratically convergent results are very limited. We introduce a new PRP method in which the restart strategy is also used. Moreover, the method we developed includes not only n-<span class="hlt">step</span> quadratic convergence but also both the function value information and gradient value information. In this paper, we will show that the new PRP method (with either the Armijo line search or the Wolfe line search) is both linearly and quadratically convergent. The numerical experiments demonstrate that the new PRP algorithm is competitive with the normal CG method. PMID:26381742</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27939321','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27939321"><span>Transfer of a three <span class="hlt">step</span> mAb chromatography process from batch to continuous: <span class="hlt">Optimizing</span> productivity to minimize consumable requirements.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gjoka, Xhorxhi; Gantier, Rene; Schofield, Mark</p> <p>2017-01-20</p> <p>The goal of this study was to adapt a batch mAb purification chromatography platform for continuous operation. The experiments and rationale used to convert from batch to continuous operation are described. Experimental data was used to design chromatography methods for continuous operation that would exceed the threshold for critical quality attributes and minimize the consumables required as compared to batch mode of operation. Four unit operations comprising of Protein A capture, viral inactivation, flow-through anion exchange (AEX), and mixed-mode cation exchange chromatography (MMCEX) were integrated across two Cadence BioSMB PD multi-column chromatography systems in order to process a 25L volume of harvested cell culture fluid (HCCF) in less than 12h. Transfer from batch to continuous resulted in an increase in productivity of the Protein A <span class="hlt">step</span> from 13 to 50g/L/h and of the MMCEX <span class="hlt">step</span> from 10 to 60g/L/h with no impact on the purification process performance in term of contaminant removal (4.5 log reduction of host cell proteins, 50% reduction in soluble product aggregates) and overall chromatography process yield of recovery (75%). The increase in productivity, combined with continuous operation, reduced the resin volume required for Protein A and MMCEX chromatography by more than 95% compared to batch. The volume of AEX membrane required for flow through operation was reduced by 74%. Moreover, the continuous process required 44% less buffer than an equivalent batch process. This significant reduction in consumables enables cost-effective, disposable, single-use manufacturing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26357282','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26357282"><span>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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22858472','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22858472"><span>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="https://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.</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>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('https://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="https://ntrs.nasa.gov/search.jsp?R=19870024403&hterms=water+filter&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dwater%2Bfilter"><span>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://adsabs.harvard.edu/abs/2011JCrGr.315...74B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JCrGr.315...74B"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/27851793','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27851793"><span>Two-<span class="hlt">Step</span> Production of Phenylpyruvic Acid from L-Phenylalanine by Growing and Resting Cells of Engineered Escherichia coli: Process <span class="hlt">Optimization</span> and Kinetics Modeling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hou, Ying; Hossain, Gazi Sakir; Li, Jianghua; Shin, Hyun-Dong; Liu, Long; Du, Guocheng; Chen, Jian</p> <p>2016-01-01</p> <p>Phenylpyruvic acid (PPA) is widely used in the pharmaceutical, food, and chemical industries. Here, a two-<span class="hlt">step</span> bioconversion process, involving growing and resting cells, was established to produce PPA from l-phenylalanine using the engineered Escherichia coli constructed previously. First, the biotransformation conditions for growing cells were <span class="hlt">optimized</span> (l-phenylalanine concentration 20.0 g·L-1, temperature 35°C) and a two-stage temperature control strategy (keep 20°C for 12 h and increase the temperature to 35°C until the end of biotransformation) was performed. The biotransformation conditions for resting cells were then <span class="hlt">optimized</span> in 3-L bioreactor and the <span class="hlt">optimized</span> conditions were as follows: agitation speed 500 rpm, aeration rate 1.5 vvm, and l-phenylalanine concentration 30 g·L-1. The total maximal production (mass conversion rate) reached 29.8 ± 2.1 g·L-1 (99.3%) and 75.1 ± 2.5 g·L-1 (93.9%) in the flask and 3-L bioreactor, respectively. Finally, a kinetic model was established, and it was revealed that the substrate and product inhibition were the main limiting factors for resting cell biotransformation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5112894','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5112894"><span>Two-<span class="hlt">Step</span> Production of Phenylpyruvic Acid from L-Phenylalanine by Growing and Resting Cells of Engineered Escherichia coli: Process <span class="hlt">Optimization</span> and Kinetics Modeling</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hou, Ying; Hossain, Gazi Sakir; Li, Jianghua; Shin, Hyun-dong; Liu, Long; Du, Guocheng; Chen, Jian</p> <p>2016-01-01</p> <p>Phenylpyruvic acid (PPA) is widely used in the pharmaceutical, food, and chemical industries. Here, a two-<span class="hlt">step</span> bioconversion process, involving growing and resting cells, was established to produce PPA from l-phenylalanine using the engineered Escherichia coli constructed previously. First, the biotransformation conditions for growing cells were <span class="hlt">optimized</span> (l-phenylalanine concentration 20.0 g·L−1, temperature 35°C) and a two-stage temperature control strategy (keep 20°C for 12 h and increase the temperature to 35°C until the end of biotransformation) was performed. The biotransformation conditions for resting cells were then <span class="hlt">optimized</span> in 3-L bioreactor and the <span class="hlt">optimized</span> conditions were as follows: agitation speed 500 rpm, aeration rate 1.5 vvm, and l-phenylalanine concentration 30 g·L−1. The total maximal production (mass conversion rate) reached 29.8 ± 2.1 g·L−1 (99.3%) and 75.1 ± 2.5 g·L−1 (93.9%) in the flask and 3-L bioreactor, respectively. Finally, a kinetic model was established, and it was revealed that the substrate and product inhibition were the main limiting factors for resting cell biotransformation. PMID:27851793</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22105810','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22105810"><span><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('https://www.ncbi.nlm.nih.gov/pubmed/25071964','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25071964"><span>Modelling of diffraction grating based optical <span class="hlt">filters</span> for fluorescence detection of biomolecules.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kovačič, M; Krč, J; Lipovšek, B; Topič, M</p> <p>2014-07-01</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 λ exc = 480 nm and λ em = 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>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25145201','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25145201"><span><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="https://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.</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>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>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://adsabs.harvard.edu/abs/2017SPIE10322E..49F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10322E..49F"><span>Analysis on strength and stiffness of double-deck plates <span class="hlt">filter</span> system of mechanical water treatment plant</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Feng, De-zhen; Yu, Qi-qi</p> <p>2017-01-01</p> <p>Domestic water treatment is a very important technology field. Now, mechanical water treatment technology is getting wide use in production. In the process of life water treatment, <span class="hlt">filter</span> process is a very important <span class="hlt">step</span>. In this paper, the strength and deformation of double-deck plates <span class="hlt">filter</span> system which includes upper <span class="hlt">filter</span> plate, lower <span class="hlt">filter</span> plate and reinforced ribs were analyzed with ANSYS and useful results were got. Through the analysis on strength and deformation, the paper found the advantages and disadvantages of production and design of <span class="hlt">filter</span> systems. After analyzing and comparing the stresses and deformations of several different design schemes, the paper provided the <span class="hlt">optimized</span> design plan of <span class="hlt">filter</span> system which can satisfy the strength need and decrease the creep deformation of plastic <span class="hlt">filter</span> plates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26706748','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26706748"><span><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="https://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.</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>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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4664066','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4664066"><span>Definitive screening design <span class="hlt">optimization</span> of mass spectrometry parameters for sensitive comparison of <span class="hlt">filter</span> and SPE purified, INLIGHT plasma N-glycans</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hecht, Elizabeth S.; McCord, James P.; Muddiman, David C.</p> <p>2015-01-01</p> <p>High-throughput, quantitative processing of N-linked glycans would facilitate large-scale studies correlating the glycome with disease and open the field to basic and applied researchers. We sought to meet these goals by coupling <span class="hlt">Filter</span>-Aided-N-Glycan Separation (FANGS) to the individuality normalization when labeling with glycan hydrazide tags (INLIGHT™) for analysis of plasma. A quantitative comparison of this method was conducted against solid phase extraction (SPE), a ubiquitous and trusted method for glycan purification. We demonstrate that FANGS-INLIGHT purification was not significantly different from SPE in terms of glycan abundances, variability, functional classes, or molecular weight distributions. Furthermore, to increase the depth of glycome coverage, we executed a definitive screening design of experiments (DOE) to <span class="hlt">optimize</span> the MS parameters for glycan analyses. We <span class="hlt">optimized</span> MS parameters across five N-glycan responses using a standard glycan mixture, translated these to plasma and achieved up to a three-fold increase in ion abundances. PMID:26086806</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26091782','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26091782"><span><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="https://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.</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/2014APS..DFDD24004C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DFDD24004C"><span>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('https://www.osti.gov/scitech/biblio/22570208','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22570208"><span>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://www.osti.gov/scitech">SciTech Connect</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. -- Highlights: •Extension of Eyre's convex–concave splitting scheme to multiphase systems. •Efficient solution of spinodal decomposition in multi-component systems. •Efficient solution of least perimeter periodic space partitioning problem. •Developing a penalization strategy to avoid trivial solutions. •Presentation of MATLAB implementation of the introduced algorithm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25454824','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25454824"><span>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="https://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).</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>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> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA454279','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA454279"><span>Multiscale Systems, Kalman <span class="hlt">Filters</span>, and Riccati Equations</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2006-01-01</p> <p>Rauch -Tung-Striebel algorithm- consisting of a fine-to-coarse Kalman-<span class="hlt">filter</span>-like sweep followed by a coarse-to-fine smoothing <span class="hlt">step</span>- was developed. In...MODELS 5 wv(t) = w(t) - E[w(t)lx(t)] (2.9) E[w(t)ifT(t)] = I- B T(t)P -l(t)B(t) - (t) (2.10) In [1] we derive a generalization of the Rauch -Tung...particular, this framework leads to an extremely efficient and highly parallelizable scale-recursive <span class="hlt">optimal</span> estimation algorithm generalizing the Rauch</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ191125.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ191125.pdf"><span>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>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('https://www.ncbi.nlm.nih.gov/pubmed/16570864','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16570864"><span><span class="hlt">Filter</span> validation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Madsen, Russell E</p> <p>2006-01-01</p> <p>Validation of a sterilizing filtration process is critical since it is impossible with currently available technology to measure the sterility of each filled container; therefore, sterility assurance of the <span class="hlt">filtered</span> product must be achieved through validation of the filtration process. Validating a pharmaceutical sterile filtration process involves three things: determining the effect of the liquid on the <span class="hlt">filter</span>, determining the effect of the <span class="hlt">filter</span> on the liquid, and demonstrating that the <span class="hlt">filter</span> removes all microorganisms from the liquid under actual processing conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26342871','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26342871"><span>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="https://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>2015-10-02</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</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><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://hdl.handle.net/2060/20020087779','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020087779"><span>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://adsabs.harvard.edu/abs/2004EJASP2004..120B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004EJASP2004..120B"><span>Performance Analysis of Adaptive Volterra <span class="hlt">Filters</span> in the Finite-Alphabet Input Case</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Besbes, Hichem; Jaïdane, Mériem; Ezzine, Jelel</p> <p>2004-12-01</p> <p>This paper deals with the analysis of adaptive Volterra <span class="hlt">filters</span>, driven by the LMS algorithm, in the finite-alphabet inputs case. A tailored approach for the input context is presented and used to analyze the behavior of this nonlinear adaptive <span class="hlt">filter</span>. Complete and rigorous mean square analysis is provided without any constraining independence assumption. Exact transient and steady-state performances expressed in terms of critical <span class="hlt">step</span> size, rate of transient decrease, <span class="hlt">optimal</span> <span class="hlt">step</span> size, excess mean square error in stationary mode, and tracking nonstationarities are deduced.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998SPIE.3338.1127L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998SPIE.3338.1127L"><span>Theoretical framework for <span class="hlt">filtered</span> back projection in tomosynthesis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lauritsch, Guenter; Haerer, Wolfgang H.</p> <p>1998-06-01</p> <p>Tomosynthesis provides only incomplete 3D-data of the imaged object. Therefore it is important for reconstruction tasks to take all available information carefully into account. We are focusing on geometrical aspects of the scan process which can be incorporated into reconstruction algorithms by <span class="hlt">filtered</span> backprojection methods. Our goal is a systematic approach to <span class="hlt">filter</span> design. A unified theory of tomosynthesis is derived in the context of linear system theory, and a general four-<span class="hlt">step</span> <span class="hlt">filter</span> design concept is presented. Since the effects of <span class="hlt">filtering</span> are understandable in this context, a methodical formulation of <span class="hlt">filter</span> functions is possible in order to <span class="hlt">optimize</span> image quality regarding the specific requirements of any application. By variation of <span class="hlt">filter</span> parameters the slice thickness and the spatial resolution can easily be adjusted. The proposed general concept of <span class="hlt">filter</span> design is exemplarily discussed for circular scanning but is valid for any specific scan geometry. The inherent limitations of tomosynthesis are pointed out and strategies for reducing the effects of incomplete sampling are developed. Results of a dental application show a striking improvement in image quality.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4559244','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4559244"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/27018144','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27018144"><span>A new balancing three level three dimensional space vector modulation strategy for three level neutral point clamped four leg inverter based shunt active power <span class="hlt">filter</span> controlling by nonlinear back <span class="hlt">stepping</span> controllers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chebabhi, Ali; Fellah, Mohammed Karim; Kessal, Abdelhalim; Benkhoris, Mohamed F</p> <p>2016-07-01</p> <p>In this paper is proposed a new balancing three-level three dimensional space vector modulation (B3L-3DSVM) strategy which uses a redundant voltage vectors to realize precise control and high-performance for a three phase three-level four-leg neutral point clamped (NPC) inverter based Shunt Active Power <span class="hlt">Filter</span> (SAPF) for eliminate the source currents harmonics, reduce the magnitude of neutral wire current (eliminate the zero-sequence current produced by single-phase nonlinear loads), and to compensate the reactive power in the three-phase four-wire electrical networks. This strategy is proposed in order to gate switching pulses generation, dc bus voltage capacitors balancing (conserve equal voltage of the two dc bus capacitors), and to switching frequency reduced and fixed of inverter switches in same times. A Nonlinear Back <span class="hlt">Stepping</span> Controllers (NBSC) are used for regulated the dc bus voltage capacitors and the SAPF injected currents to robustness, stabilizing the system and to improve the response and to eliminate the overshoot and undershoot of traditional PI (Proportional-Integral). Conventional three-level three dimensional space vector modulation (C3L-3DSVM) and B3L-3DSVM are calculated and compared in terms of error between the two dc bus voltage capacitors, SAPF output voltages and THDv, THDi of source currents, magnitude of source neutral wire current, and the reactive power compensation under unbalanced single phase nonlinear loads. The success, robustness, and the effectiveness of the proposed control strategies are demonstrated through simulation using Sim Power Systems and S-Function of MATLAB/SIMULINK.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25564205','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25564205"><span><span class="hlt">Optimization</span> of three operating parameters for a two-<span class="hlt">step</span> fed sequencing batch reactor (SBR) system to remove nutrients from swine wastewater.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, Xiao; Zhu, Jun; Cheng, Jiehong; Zhu, Nanwen</p> <p>2015-03-01</p> <p>In this study, the effect of three operating parameters, i.e., the first/second volumetric feeding ratio (milliliters/milliliters), the first anaerobic/aerobic (an/oxic) time ratio (minute/minute), and the second an/oxic time ratio (minute/minute), on the performance of a two-<span class="hlt">step</span> fed sequencing batch reactor (SBR) system to treat swine wastewater for nutrients removal was examined. Central Composite Design, coupled with Response Surface Methodology, was employed to test these parameters at five levels in order to <span class="hlt">optimize</span> the SBR to achieve the best removal efficiencies for six response variables including total nitrogen (TN), ammonium nitrogen (NH4-N), total phosphorus (TP), dissolved phosphorus (DP), chemical oxygen demand (COD), and biochemical oxygen demand (BOD). The results showed that the three parameters investigated had significant impact on all the response variables (TN, NH4-N, TP, DP, COD, and BOD), although the highest removal efficiency for each individual responses was associated with different combination of the three parameters. The maximum TN, NH4-N, TP, DP, COD, and BOD removal efficiencies of 96.38%, 95.38%, 93.62%, 94.3%, 95.26%, and 92.84% were obtained at the <span class="hlt">optimal</span> first/second volumetric feeding ratio, first an/oxic time ratio, and second an/oxic time ratio of 3.23, 0.4, and 0.8 for TN; 2.64, 0.72, and 0.76 for NH4-N; 3.08, 1.16, and 1.07 for TP; 1.32, 0.81, and 1.0 for DP; 2.57, 0.96, and 1.12 for COD; and 1.62, 0.64, and 1.61 for BOD, respectively. Good linear relationships between the predicted and observed results for all the response variables were observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18450479','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18450479"><span>Variational <span class="hlt">filtering</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Friston, K J</p> <p>2008-07-01</p> <p>This note presents a simple Bayesian <span class="hlt">filtering</span> scheme, using variational calculus, for inference on the hidden states of dynamic systems. Variational <span class="hlt">filtering</span> is a stochastic scheme that propagates particles over a changing variational energy landscape, such that their sample density approximates the conditional density of hidden and states and inputs. The key innovation, on which variational <span class="hlt">filtering</span> rests, is a formulation in generalised coordinates of motion. This renders the scheme much simpler and more versatile than existing approaches, such as those based on particle <span class="hlt">filtering</span>. We demonstrate variational <span class="hlt">filtering</span> using simulated and real data from hemodynamic systems studied in neuroimaging and provide comparative evaluations using particle <span class="hlt">filtering</span> and the fixed-form homologue of variational <span class="hlt">filtering</span>, namely dynamic expectation maximisation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25499147','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25499147"><span>An <span class="hlt">optimal</span> glucose feeding strategy integrated with <span class="hlt">step</span>-wise regulation of the dissolved oxygen level improves N-acetylglucosamine production in recombinant Bacillus subtilis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhu, Yanqiu; Liu, Yanfeng; Li, Jianghua; Shin, Hyun-dong; Du, Guocheng; Liu, Long; Chen, Jian</p> <p>2015-02-01</p> <p>In our previous work, a recombinant Bacillus subtilis strain for the microbial production of N-acetylglucosamine (GlcNAc) was constructed through modular pathway engineering. In this study, to enhance GlcNAc production, glucose feeding approaches and dissolved oxygen (DO) control methods in fed-batch culture were systematically investigated. We first studied the effects of different glucose feeding strategies, including exponential fed-batch culture, pulse fed-batch culture, constant rate fed-batch culture, and glucose control (5 g/L, 10 g/L, 15 g/L) fed-batch culture, on cell growth and GlcNAc synthesis. We found that GlcNAc production in glucose control (5 g/L) fed-batch culture reached 26.58 g/L, which was 3.10 times that in batch culture. Next, the effect of DO level (20%, 30%, 40%, and 50%) on GlcNAc production was investigated, and a <span class="hlt">step</span>-wise DO control strategy (0-7 h, 30%; 7-15 h, 50%; 15-50 h, 40%; 50-72 h, 30%) was introduced. With the <span class="hlt">optimal</span> glucose and DO control strategy, GlcNAc production reached 35.77 g/L, which was 4.17 times the production in batch culture without DO control.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5244389','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5244389"><span>Viral Phylogenomics Using an Alignment-Free Method: A Three-<span class="hlt">Step</span> Approach to Determine <span class="hlt">Optimal</span> Length of k-mer</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, Qian; Jun, Se-Ran; Leuze, Michael; Ussery, David; Nookaew, Intawat</p> <p>2017-01-01</p> <p>The development of rapid, economical genome sequencing has shed new light on the classification of viruses. As of October 2016, the National Center for Biotechnology Information (NCBI) database contained >2 million viral genome sequences and a reference set of ~4000 viral genome sequences that cover a wide range of known viral families. Whole-genome sequences can be used to improve viral classification and provide insight into the viral “tree of life”. However, due to the lack of evolutionary conservation amongst diverse viruses, it is not feasible to build a viral tree of life using traditional phylogenetic methods based on conserved proteins. In this study, we used an alignment-free method that uses k-mers as genomic features for a large-scale comparison of complete viral genomes available in RefSeq. To determine the <span class="hlt">optimal</span> feature length, k (an essential <span class="hlt">step</span> in constructing a meaningful dendrogram), we designed a comprehensive strategy that combines three approaches: (1) cumulative relative entropy, (2) average number of common features among genomes, and (3) the Shannon diversity index. This strategy was used to determine k for all 3,905 complete viral genomes in RefSeq. The resulting dendrogram shows consistency with the viral taxonomy of the ICTV and the Baltimore classification of viruses. PMID:28102365</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25577357','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25577357"><span>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="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bernard, Lise; Cueff, Régis; Bourdeaux, Daniel; Breysse, Colette; Sautou, Valérie</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.</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/868447','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/868447"><span><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><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.dtic.mil/docs/citations/ADA225312','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA225312"><span><span class="hlt">Optimal</span> Phase-Only <span class="hlt">Filters</span></span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>1990-04-01</p> <p>HYDE III Directorate of Plans & Programs If your address has changed or if you wish to be removed from the RADC mailing list, or if the addressee is... changes in the reference image and thus their performance deteriorates significantly in the presence of image distortions. " The light throughput...This may suggest an enhancement to the new algorithm by adaptively changing N (eg. N- a slow function of d). Before moving to the next section, a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23125051','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23125051"><span><span class="hlt">Optimization</span> of a two-<span class="hlt">step</span> process comprising lipase catalysis and thermal cyclization improves the efficiency of synthesis of six-membered cyclic carbonate from trimethylolpropane and dimethylcarbonate.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bornadel, Amin; Hatti-Kaul, Rajni; Sörensen, Kent; Lundmark, Stefan; Pyo, Sang-Hyun</p> <p>2013-01-01</p> <p>Six-membered cyclic carbonates are potential monomers for phosgene and/or isocyanate free polycarbonates and polyurethanes via ring-opening polymerization. A two-<span class="hlt">step</span> process for their synthesis comprising lipase-catalyzed transesterification of a polyol, trimethylolpropane (TMP) with dimethylcarbonate (DMC) in a solvent-free system followed by thermal cyclization was <span class="hlt">optimized</span> to improve process efficiency and selectivity. Using full factorial designed experiments and partial least squares (PLS) modeling for the reaction catalyzed by Novozym®435 (N435; immobilized Candida antarctica lipase B), the optimum conditions for obtaining either high proportion of monocarbonated TMP and TMP-cyclic-carbonate (3 and 4), or dicarbonated TMP and monocarbonated TMP-cyclic-carbonate (5 and 6) were found. The PLS model predicted that the reactions using 15%-20% (w/w) N435 at DMC:TMP molar ratio of 10-30 can reach about 65% total yield of 3 and 4 within 10 h, and 65%-70% total yield of 5 and 6 within 32-37 h, respectively. High consistency between the predicted results and empirical data was shown with 66.1% yield of 3 and 4 at 7 h and 67.4% yield of 5 and 6 at 35 h, using 18% (w/w) biocatalyst and DMC:TMP molar ratio of 20. Thermal cyclization of the product from 7 h reaction, at 110°C in the presence of acetonitrile increased the overall yield of cyclic carbonate 4 from about 2% to more than 75% within 24 h. N435 was reused for five consecutive batches, 10 h each, to give 3+4 with a yield of about 65% in each run.</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>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('https://www.ncbi.nlm.nih.gov/pubmed/20354639','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20354639"><span>Ultraviolet <span class="hlt">filters</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shaath, Nadim A</p> <p>2010-04-01</p> <p>The chemistry, photostability and mechanism of action of ultraviolet <span class="hlt">filters</span> are reviewed. The worldwide regulatory status of the 55 approved ultraviolet <span class="hlt">filters</span> and their optical properties are documented. The photostabilty of butyl methoxydibenzoyl methane (avobenzone) is considered and methods to stabilize it in cosmetic formulations are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19424388','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19424388"><span>Neutral density <span class="hlt">filters</span> with Risley prisms: analysis and design.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Duma, Virgil-Florin; Nicolov, Mirela</p> <p>2009-05-10</p> <p>We achieve the analysis and design of optical attenuators with double-prism neutral density <span class="hlt">filters</span>. A comparative study is performed on three possible device configurations; only two are presented in the literature but without their design calculus. The characteristic parameters of this optical attenuator with Risley translating prisms for each of the three setups are defined and their analytical expressions are derived: adjustment scale (attenuation range) and interval, minimum transmission coefficient and sensitivity. The setups are compared to select the <span class="hlt">optimal</span> device, and, from this study, the best solution for double-prism neutral density <span class="hlt">filters</span>, both from a mechanical and an optical point of view, is determined with two identical, symmetrically movable, no mechanical contact prisms. The design calculus of this <span class="hlt">optimal</span> device is developed in essential <span class="hlt">steps</span>. The parameters of the prisms, particularly their angles, are studied to improve the design, and we demonstrate the maximum attenuation range that this type of attenuator can provide.</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>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://adsabs.harvard.edu/abs/2016OEJV..176...10Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OEJV..176...10Z"><span>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('https://www.osti.gov/scitech/biblio/22496304','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22496304"><span>SU-E-T-591: <span class="hlt">Optimizing</span> the Flattening <span class="hlt">Filter</span> Free Beam Selection in RapidArc-Based Stereotactic Body Radiotherapy for Stage I Lung Cancer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Huang, B-T; Lu, J-Y</p> <p>2015-06-15</p> <p>Purpose: To <span class="hlt">optimize</span> the flattening <span class="hlt">filter</span> free (FFF) beam energy selection in stereotactic body radiotherapy (SBRT) treatment for stage I lung cancer with different fraction schemes. Methods: Twelve patients suffering from stage I lung cancer were enrolled in this study. Plans were designed using 6XFFF and 10XFFF beams with the most widely used fraction schemes of 4*12 Gy, 3*18 Gy and 1*34 Gy, respectively. The plan quality was appraised in terms of planning target volume (PTV) coverage, conformity of the prescribed dose (CI100%), intermediate dose spillage (R50% and D2cm), organs at risk (OARs) sparing and beam-on time. Results: The 10XFFF beam predicted 1% higher maximum, mean dose to the PTV and 4–5% higher R50% compared with the 6XFFF beam in the three fraction schemes, whereas the CI100% and D2cm was similar. Most importantly, the 6XFFF beam exhibited 3–10% lower dose to all the OARs. However, the 10XFFF beam reduced the beam-on time by 31.9±7.2%, 38.7±2.8% and 43.6±4.0% compared with the 6XFFF beam in the 4*12 Gy, 3*18 Gy and 1*34 Gy schemes, respectively. Beam-on time was 2.2±0.2 vs 1.5±0.1, 3.3±0.9 vs 2.0±0.5 and 6.3±0.9 vs 3.5±0.4 minutes for the 6XFFF and 10XFFF one in the three fraction schemes. Conclusion: The 6XFFF beam obtains better OARs sparing in SBRT treatment for stage I lung cancer, but the 10XFFF one provides improved treatment efficiency. To balance the OARs sparing and intrafractional variation as a function of prolonged treatment time, the authors recommend to use the 6XFFF beam in the 4*12 Gy and 3*18 Gy schemes for better OARs sparing. However, for the 1*34 Gy scheme, the 10XFFF beam is recommended to achieve improved treatment efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.4597T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.4597T"><span>Hierarchical Bayes Ensemble Kalman <span class="hlt">Filter</span> for geophysical data assimilation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsyrulnikov, Michael; Rakitko, Alexander</p> <p>2016-04-01</p> <p>In the Ensemble Kalman <span class="hlt">Filter</span> (EnKF), the forecast error covariance matrix B is estimated from a sample (ensemble), which inevitably implies a degree of uncertainty. This uncertainty is especially large in high dimensions, where the affordable ensemble size is orders of magnitude less than the dimensionality of the system. Common remedies include ad-hoc devices like variance inflation and covariance localization. The goal of this study is to <span class="hlt">optimize</span> the account for the inherent uncertainty of the B matrix in EnKF. Following the idea by Myrseth and Omre (2010), we explicitly admit that the B matrix is unknown and random and estimate it along with the state (x) in an <span class="hlt">optimal</span> hierarchical Bayes analysis scheme. We separate forecast errors into predictability errors (i.e. forecast errors due to uncertainties in the initial data) and model errors (forecast errors due to imperfections in the forecast model) and include the two respective components P and Q of the B matrix into the extended control vector (x,P,Q). Similarly, we break the traditional forecast ensemble into the predictability-error related ensemble and model-error related ensemble. The reason for the separation of model errors from predictability errors is the fundamental difference between the two sources of error. Model error are external (i.e. do not depend on the <span class="hlt">filter</span>'s performance) whereas predictability errors are internal to a <span class="hlt">filter</span> (i.e. are determined by the <span class="hlt">filter</span>'s behavior). At the analysis <span class="hlt">step</span>, we specify Inverse Wishart based priors for the random matrices P and Q and conditionally Gaussian prior for the state x. Then, we update the prior distribution of (x,P,Q) using both observation and ensemble data, so that ensemble members are used as generalized observations and ordinary observations are allowed to influence the covariances. We show that for linear dynamics and linear observation operators, conditional Gaussianity of the state is preserved in the course of <span class="hlt">filtering</span>. At the forecast</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>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://www.osti.gov/scitech/servlets/purl/1107790','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1107790"><span>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> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840000095&hterms=Aquatic+Plants&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DAquatic%2BPlants','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840000095&hterms=Aquatic+Plants&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DAquatic%2BPlants"><span>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://adsabs.harvard.edu/abs/2015AGUFMED33D0959B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMED33D0959B"><span>Bioaerosol DNA Extraction Technique from Air <span class="hlt">Filters</span> Collected from Marine and Freshwater Locations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beckwith, M.; Crandall, S. G.; Barnes, A.; Paytan, A.</p> <p>2015-12-01</p> <p>Bioaerosols are composed of microorganisms suspended in air. Among these organisms include bacteria, fungi, virus, and protists. Microbes introduced into the atmosphere can drift, primarily by wind, into natural environments different from their point of origin. Although bioaerosols can impact atmospheric dynamics as well as the ecology and biogeochemistry of terrestrial systems, very little is known about the composition of bioaerosols collected from marine and freshwater environments. The first <span class="hlt">step</span> to determine composition of airborne microbes is to successfully extract environmental DNA from air <span class="hlt">filters</span>. We asked 1) can DNA be extracted from quartz (SiO2) air <span class="hlt">filters</span>? and 2) how can we <span class="hlt">optimize</span> the DNA yield for downstream metagenomic sequencing? Aerosol <span class="hlt">filters</span> were collected and archived on a weekly basis from aquatic sites (USA, Bermuda, Israel) over the course of 10 years. We successfully extracted DNA from a subsample of ~ 20 <span class="hlt">filters</span>. We modified a DNA extraction protocol (Qiagen) by adding a beadbeating <span class="hlt">step</span> to mechanically shear cell walls in order to <span class="hlt">optimize</span> our DNA product. We quantified our DNA yield using a spectrophotometer (Nanodrop 1000). Results indicate that DNA can indeed be extracted from quartz <span class="hlt">filters</span>. The additional beadbeating <span class="hlt">step</span> helped increase our yield - up to twice as much DNA product was obtained compared to when this <span class="hlt">step</span> was omitted. Moreover, bioaerosol DNA content does vary across time. For instance, the DNA extracted from <span class="hlt">filters</span> from Lake Tahoe, USA collected near the end of June decreased from 9.9 ng/μL in 2007 to 3.8 ng/μL in 2008. Further next-generation sequencing analysis of our extracted DNA will be performed to determine the composition of these microbes. We will also model the meteorological and chemical factors that are good predictors for microbial composition for our samples over time and space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5349295','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5349295"><span>Output‐Sensitive <span class="hlt">Filtering</span> of Streaming Volume Data</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Solteszova, Veronika; Birkeland, Åsmund; Stoppel, Sergej; Viola, Ivan; Bruckner, Stefan</p> <p>2016-01-01</p> <p>Abstract Real‐time volume data acquisition poses substantial challenges for the traditional visualization pipeline where data enhancement is typically seen as a pre‐processing <span class="hlt">step</span>. In the case of 4D ultrasound data, for instance, costly processing operations to reduce noise and to remove artefacts need to be executed for every frame. To enable the use of high‐quality <span class="hlt">filtering</span> operations in such scenarios, we propose an output‐sensitive approach to the visualization of streaming volume data. Our method evaluates the potential contribution of all voxels to the final image, allowing us to skip expensive processing operations that have little or no effect on the visualization. As <span class="hlt">filtering</span> operations modify the data values which may affect the visibility, our main contribution is a fast scheme to predict their maximum effect on the final image. Our approach prioritizes <span class="hlt">filtering</span> of voxels with high contribution to the final visualization based on a maximal permissible error per pixel. With zero permissible error, the <span class="hlt">optimized</span> <span class="hlt">filtering</span> will yield a result that is identical to <span class="hlt">filtering</span> of the entire volume. We provide a thorough technical evaluation of the approach and demonstrate it on several typical scenarios that require on‐the‐fly processing. PMID:28356607</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4934273','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4934273"><span>Networked Fusion <span class="hlt">Filtering</span> from Outputs with Stochastic Uncertainties and Correlated Random Transmission Delays</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Caballero-Águila, Raquel; Hermoso-Carazo, Aurora; Linares-Pérez, Josefa</p> <p>2016-01-01</p> <p>This paper is concerned with the distributed and centralized fusion <span class="hlt">filtering</span> problems in sensor networked systems with random one-<span class="hlt">step</span> delays in transmissions. The delays are described by Bernoulli variables correlated at consecutive sampling times, with different characteristics at each sensor. The measured outputs are subject to uncertainties modeled by random parameter matrices, thus providing a unified framework to describe a wide variety of network-induced phenomena; moreover, the additive noises are assumed to be one-<span class="hlt">step</span> autocorrelated and cross-correlated. Under these conditions, without requiring the knowledge of the signal evolution model, but using only the first and second order moments of the processes involved in the observation model, recursive algorithms for the <span class="hlt">optimal</span> linear distributed and centralized <span class="hlt">filters</span> under the least-squares criterion are derived by an innovation approach. Firstly, local estimators based on the measurements received from each sensor are obtained and, after that, the distributed fusion <span class="hlt">filter</span> is generated as the least-squares matrix-weighted linear combination of the local estimators. Also, a recursive algorithm for the <span class="hlt">optimal</span> linear centralized <span class="hlt">filter</span> is proposed. In order to compare the estimators performance, recursive formulas for the error covariance matrices are derived in all the algorithms. The effects of the delays in the <span class="hlt">filters</span> accuracy are analyzed in a numerical example which also illustrates how some usual network-induced uncertainties can be dealt with using the current observation model described by random matrices. PMID:27338387</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016OptEn..55g4102X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016OptEn..55g4102X"><span><span class="hlt">Filter</span> selection based on light source for multispectral imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Peng; Xu, Haisong</p> <p>2016-07-01</p> <p>In multispectral imaging, it is necessary to select a reduced number of <span class="hlt">filters</span> to balance the imaging efficiency and spectral reflectance recovery accuracy. Due to the combined effect of <span class="hlt">filters</span> and light source on reflectance recovery, the <span class="hlt">optimal</span> <span class="hlt">filters</span> are influenced by the employed light source in the multispectral imaging system. By casting the <span class="hlt">filter</span> selection as an <span class="hlt">optimization</span> issue, the selection of <span class="hlt">optimal</span> <span class="hlt">filters</span> corresponding to the employed light source proceeds with respect to a set of target samples utilizing one kind of genetic algorithms, regardless of the detailed spectral characteristics of the light source, <span class="hlt">filters</span>, and sensor. Under three light sources with distinct spectral power distributions, the proposed <span class="hlt">filter</span> selection method was evaluated on a <span class="hlt">filter</span>-wheel based multispectral device with a set of interference <span class="hlt">filters</span>. It was verified that the <span class="hlt">filters</span> derived by the proposed method achieve better spectral and colorimetric accuracy of reflectance recovery than the conventional one under different light sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/865082','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/865082"><span><span class="hlt">Filter</span> apparatus</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kuban, Daniel P.; Singletary, B. Huston; Evans, John H.</p> <p>1984-01-01</p> <p>A plurality of holding tubes are respectively mounted in apertures in a partition plate fixed in a housing receiving gas contaminated with particulate material. A <span class="hlt">filter</span> cartridge is removably held in each holding tube, and the cartridges and holding tubes are arranged so that gas passes through apertures therein and across the partition plate while particulate material is collected in the cartridges. Replacement <span class="hlt">filter</span> cartridges are respectively held in holding canisters mounted on a support plate which can be secured to the aforesaid housing, and screws mounted on said canisters are arranged to push replacement cartridges into the cartridge holding tubes and thereby eject used cartridges therefrom.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5283620','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/5283620"><span><span class="hlt">Filter</span> apparatus</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Kuban, D.P.; Singletary, B.H.; Evans, J.H.</p> <p></p> <p>A plurality of holding tubes are respectively mounted in apertures in a partition plate fixed in a housing receiving gas contaminated with particulate material. A <span class="hlt">filter</span> cartridge is removably held in each holding tube, and the cartridges and holding tubes are arranged so that gas passes through apertures therein and across the the partition plate while particulate material is collected in the cartridges. Replacement <span class="hlt">filter</span> cartridges are respectively held in holding canisters mounted on a support plate which can be secured to the aforesaid housing, and screws mounted on said canisters are arranged to push replacement cartridges into the cartridge holding tubes and thereby eject used cartridges therefrom.</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('https://ntrs.nasa.gov/search.jsp?R=19850021138&hterms=sigma+model&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsigma%2Bmodel','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850021138&hterms=sigma+model&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dsigma%2Bmodel"><span>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>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('https://www.ncbi.nlm.nih.gov/pubmed/21664782','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21664782"><span>Bilateral <span class="hlt">filtering</span> of magnetic resonance phase images.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McPhee, Kelly C; Denk, Christian; Al-Rekabi, Zeinab; Rauscher, Alexander</p> <p>2011-09-01</p> <p>High-pass <span class="hlt">filtering</span> is required for the removal of background field inhomogeneities in magnetic resonance phase images. This high-pass <span class="hlt">filtering</span> smooths across boundaries between areas with large differences in phase. The most prominent boundary is the surface of the brain where areas with large phase values inside the brain are located close to areas outside the brain where the phase is, on average, zero. Cortical areas, which are of great interest in brain MRI, are therefore often degraded by high-pass <span class="hlt">filtering</span>. Here, we propose the use of the bilateral <span class="hlt">filter</span> for the high-pass <span class="hlt">filtering</span> <span class="hlt">step</span>. The bilateral <span class="hlt">filter</span> is essentially a Gaussian <span class="hlt">filter</span> that stops smoothing at boundaries. We show that the bilateral <span class="hlt">filter</span> improves image quality at the brain's surface, without sacrificing contrast within the brain.</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>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('https://www.ncbi.nlm.nih.gov/pubmed/15286755','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15286755"><span>Carbon nanotube <span class="hlt">filters</span>.</span></a></p> <p><a target="_blank" href="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23567732','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23567732"><span>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="https://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.</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>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://hdl.handle.net/2060/19770011363','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770011363"><span>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://www.dtic.mil/docs/citations/ADA582272','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA582272"><span>A Multi-Resolution Approach to the Fokker-Planck-Kolmogorov Equation with Application to Stochastic Nonlinear <span class="hlt">Filtering</span> and <span class="hlt">Optimal</span> Design</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2012-12-14</p> <p>surprise since the I-POD uses different time -scales, as well as the adjoint information to get a higher fidelity ROM. 5. Application of I-POD to <span class="hlt">Filtering</span> of...Turbulent and Magnetohydrodynamic Flows . Boston, MA: Systems and Control: Foundations and Applications , Birkhauser, 2007. [31] H. T. Banks and K...been one of the most successful applications of control theoretic techniques in the industry [4]. The MPC techniques solve a sequence of finite horizon</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20452206','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20452206"><span><span class="hlt">Optimization</span> of medium for one-<span class="hlt">step</span> fermentation of inulin extract from Jerusalem artichoke tubers using Paenibacillus polymyxa ZJ-9 to produce R,R-2,3-butanediol.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gao, Jian; Xu, Hong; Li, Qiu-jie; Feng, Xiao-hai; Li, Sha</p> <p>2010-09-01</p> <p>The medium for one-<span class="hlt">step</span> fermentation of raw inulin extract from Jerusalem artichoke tubers by Paenibacillus polymyxa ZJ-9 to produce R,R-2,3-butanediol (R,R-2,3-BD) was developed. Inulin, K(2)HPO(4) and NH(4)Cl were found to be the key factors in the fermentation according to the results obtained from the Plackett-Burman experimental design. The <span class="hlt">optimal</span> concentration range of the three factors was examined by the steepest ascent path, and their <span class="hlt">optimal</span> concentration was further investigated according to the Box-Behnken design and determined to be 77.14 g/L, 3.09 g/L and 0.93 g/L, respectively. Under the <span class="hlt">optimal</span> conditions, the concentration of the obtained R,R-2,3-BD was 36.92 g/L, at more than 98% optical purity. Compared with other investigated carbon resources, fermentation of the raw inulin extract afforded the highest yield of R,R-2,3-BD. This process featured one-<span class="hlt">step</span> fermentation of inulin without further hydrolyzing, which greatly decreased the raw material cost and thus facilitated its practical application.</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>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('https://www.ncbi.nlm.nih.gov/pubmed/24517443','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24517443"><span>Holographic photopolymer linear variable <span class="hlt">filter</span> with enhanced blue reflection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moein, Tania; Ji, Dengxin; Zeng, Xie; Liu, Ke; Gan, Qiaoqiang; Cartwright, Alexander N</p> <p>2014-03-12</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>.</p> </li> <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>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://hdl.handle.net/2060/20030002766','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030002766"><span>Water <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></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>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('https://www.osti.gov/pages/biblio/1302921-multilevel-ensemble-kalman-filtering','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1302921-multilevel-ensemble-kalman-filtering"><span>Multilevel ensemble Kalman <span class="hlt">filtering</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Hoel, Hakon; Law, Kody J. H.; Tempone, Raul</p> <p>2016-06-14</p> <p>This study embeds a multilevel Monte Carlo sampling strategy into the Monte Carlo <span class="hlt">step</span> of the ensemble Kalman <span class="hlt">filter</span> (EnKF) in the setting of finite dimensional signal evolution and noisy discrete-time observations. The signal dynamics is assumed to be governed by a stochastic differential equation (SDE), and a hierarchy of time grids is introduced for multilevel numerical integration of that SDE. Finally, the resulting multilevel EnKF is proved to asymptotically outperform EnKF in terms of computational cost versus approximation accuracy. The theoretical results are illustrated numerically.</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><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/biblio/672502','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/672502"><span><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('https://www.ncbi.nlm.nih.gov/pubmed/22885040','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22885040"><span><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="https://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.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006Optik.117..453L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006Optik.117..453L"><span>Design and application of three-zone annular <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>Liu, Ximin; Liu, Liren; Liu, De'an; Bai, Lihua</p> <p>2006-10-01</p> <p>We design three-zone annular <span class="hlt">filters</span> to be applied to optical storage system. The designed <span class="hlt">filters</span> extend the depth of focus and realize transverse superresolution simultaneously, which will improve the performance of optical storage system greatly. And we propose two feasible schemes to improve imaging resolution of three-dimensional imaging system. One scheme depends on a complex <span class="hlt">filter</span> formed by cascading of a three-zone phase <span class="hlt">filter</span> and a three-zone amplitude <span class="hlt">filter</span>. The complex <span class="hlt">filter</span> converge the <span class="hlt">optimized</span> transverse superresolution and the <span class="hlt">optimized</span> axial superresolution of two different <span class="hlt">filters</span> onto a single <span class="hlt">filter</span>. It can improve the three-dimensional imaging performances greatly. Another scheme depends on a single three-zone complex <span class="hlt">filter</span>. We propose a three-zone complex <span class="hlt">filter</span> with phase shift 0.8[pi], which presents bigger design margin, better imaging quality and stronger three-dimensional superresolution capability.</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://adsabs.harvard.edu/abs/1995PhyC..251...27R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995PhyC..251...27R"><span>Microstructurally <span class="hlt">optimized</span> heat treatment for melt-processed, Ag clad Bi 2Sr 2CaCu 2O y tape <span class="hlt">step</span>-solidification melt processing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ray, Roger D.; Hellstrom, Eric E.</p> <p>1995-02-01</p> <p>We have studied the behavior of (Sr 1- xCa x)CuO 2 (1:1) and the development of Bi 2Sr 2CaCu 2O y (2212) alignment during melt processing of silver-clad 2212 tapes in air in the critical temperature region of 870-860°C. We found that remnant 1:1 grains can be reduced in size with extended annealing just below 865°C. The highest 2212 alignment was achieved by annealing just below the 2212 solidus temperature (870°C). An alignment mechanism based on grain growth of fortuitously aligned, plate-like 2212 grains within a mostly two-dimensional environment (opportunistic grain growth) was proposed to explain the high degree of alignment that can develop in melt-processed tape. Based on the microstructural data obtained from this study, a heat treatment that uses <span class="hlt">step</span>-wise cooling (<span class="hlt">step</span> solidification) was developed yielding a microstructure consisting of highly aligned 2212 and small 1:1 grains.</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>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.dtic.mil/docs/citations/AD0287800','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD0287800"><span>CRYSTAL <span class="hlt">FILTER</span> TEST SET</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p></p> <p>CRYSTAL <span class="hlt">FILTERS</span>, *HIGH FREQUENCY, *RADIOFREQUENCY <span class="hlt">FILTERS</span>, AMPLIFIERS, ELECTRIC POTENTIAL, FREQUENCY, IMPEDANCE MATCHING , INSTRUMENTATION, RADIOFREQUENCY, RADIOFREQUENCY AMPLIFIERS, TEST EQUIPMENT, TEST METHODS</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=site+AND+name&pg=3&id=EJ625144','ERIC'); return false;" href="http://eric.ed.gov/?q=site+AND+name&pg=3&id=EJ625144"><span><span class="hlt">Filtered</span> or Unfiltered?</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>Curry, Ann; Haycock, Ken</p> <p>2001-01-01</p> <p>Discusses results of a survey questionnaire of public and school libraries that investigated the use of Internet <span class="hlt">filtering</span> software. Considers <span class="hlt">filter</span> alternatives; reasons for <span class="hlt">filtering</span> or not <span class="hlt">filtering</span>; brand names; satisfaction with site blocking; satisfaction with the decision to install <span class="hlt">filter</span> software; and guidelines for considering <span class="hlt">filters</span>.…</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>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://www.osti.gov/scitech/servlets/purl/220576','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/220576"><span>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://www.dtic.mil/docs/citations/ADA626002','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA626002"><span><span class="hlt">Filtering</span> Drifter Trajectories Sampled at Submesoscale Resolution</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2015-05-11</p> <p>40, NO. 3, JULY 2015 497 <span class="hlt">Filtering</span> Drifter Trajectories Sampled at Submesoscale Resolution Max Yaremchuk and Emanuel F. Coelho Abstract—In this paper...accel- erations while keeping the difference between the <span class="hlt">filtered</span> and ob- served trajectories within the error bars of the positioning noise...Mexico in 2012. Index Terms—Computers and information processing/data pro- cessing,mathematics/ <span class="hlt">filtering</span> algorithms, <span class="hlt">optimization</span>, smoothing methods</p> </li> <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>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://adsabs.harvard.edu/abs/2015SPIE.9412E..1ML','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9412E..1ML"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/27332141','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27332141"><span>Single-<span class="hlt">step</span> quantitative susceptibility mapping with variational penalties.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chatnuntawech, Itthi; McDaniel, Patrick; Cauley, Stephen F; Gagoski, Borjan A; Langkammer, Christian; Martin, Adrian; Grant, P Ellen; Wald, Lawrence L; Setsompop, Kawin; Adalsteinsson, Elfar; Bilgic, Berkin</p> <p>2017-04-01</p> <p>Quantitative susceptibility mapping (QSM) estimates the underlying tissue magnetic susceptibility from the gradient echo (GRE) phase signal through background phase removal and dipole inversion <span class="hlt">steps</span>. Each of these <span class="hlt">steps</span> typically requires the solution of an ill-posed inverse problem and thus necessitates additional regularization. Recently developed single-<span class="hlt">step</span> QSM algorithms directly relate the unprocessed GRE phase to the unknown susceptibility distribution, thereby requiring the solution of a single inverse problem. In this work, we show that such a holistic approach provides susceptibility estimation with artifact mitigation and develop efficient algorithms that involve simple analytical solutions for all of the <span class="hlt">optimization</span> <span class="hlt">steps</span>. Our methods employ total variation (TV) and total generalized variation (TGV) to jointly perform the background removal and dipole inversion in a single <span class="hlt">step</span>. Using multiple spherical mean value (SMV) kernels of varying radii permits high-fidelity background removal whilst retaining the phase information in the cortex. Using numerical simulations, we demonstrate that the proposed single-<span class="hlt">step</span> methods reduce the reconstruction error by up to 66% relative to the multi-<span class="hlt">step</span> methods that involve SMV background <span class="hlt">filtering</span> with the same number of SMV kernels, followed by TV- or TGV-regularized dipole inversion. In vivo single-<span class="hlt">step</span> experiments demonstrate a dramatic reduction in dipole streaking artifacts and improved homogeneity of image contrast. These acquisitions employ the rapid three-dimensional echo planar imaging (3D EPI) and Wave-CAIPI (controlled aliasing in parallel imaging) trajectories for signal-to-noise ratio-efficient whole-brain imaging. Herein, we also demonstrate the multi-echo capability of the Wave-CAIPI sequence for the first time, and introduce an automated, phase-sensitive coil sensitivity estimation scheme based on a 4-s calibration acquisition. Copyright © 2016 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA124628','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA124628"><span>Advances in Techniques for Tracking and Terminal State Estimation of a Goal Seeking Vehicle (The Target RV) via an <span class="hlt">Optimal</span> BMD Intercept Vehicle <span class="hlt">Filter</span>.</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>1982-03-01</p> <p>subsequently. Figure I presents a smoothed plot of the absolute error values x1(k) - x1 (k) for a sam- pling interval of at-0.625. I The <span class="hlt">optimal</span> estimation...Seeking Vehicles," IEEE Transactions on Automatic Control, Volume AC-13, Number 1, pp. 74-77, February 1968. 7. Meditch , J.S., Stochastic <span class="hlt">Optimal</span>...Linear Estimation and Control, McGraw-Hill Book Company, 1969. 8. Meditch , J.S. and Hostetter, G.H., "Techniques for Initial Condi- tion Estimation in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26111580','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26111580"><span>From cutting edge to guideline: A first <span class="hlt">step</span> in harmonization of the zebrafish embryotoxicity test (ZET) by describing the most <span class="hlt">optimal</span> test conditions and morphology scoring system.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Beekhuijzen, Manon; de Koning, Coco; Flores-Guillén, Maria-Eugenia; de Vries-Buitenweg, Selinda; Tobor-Kaplon, Marysia; van de Waart, Beppy; Emmen, Harry</p> <p>2015-08-15</p> <p>In the last couple of years, the interest in the zebrafish embryotoxicity test (ZET) for use in developmental toxicity assessment has been growing exponentially. This is also evident from the recent proposal for updating the ICHS5 guideline. The methodology of the ZET used by the different groups varies greatly. To further evaluate its successfulness and to take the ZET to the next level, harmonization of procedures is crucial. In the present study, based on literature and empirical data, the most <span class="hlt">optimal</span> study design regarding temperature, test chamber, exposure period, presence of chorion, solvent use, exposure method, choice of concentrations, and teratogenic classification is proposed. Furthermore, our morphology scoring system is reported in detail as protocol to further enhance study design harmonization.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27739243','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27739243"><span><span class="hlt">Optimization</span> of an online heart-cutting multidimensional gas chromatography clean-up <span class="hlt">step</span> for isotopic ratio mass spectrometry and simultaneous quadrupole mass spectrometry measurements of endogenous anabolic steroid in urine.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Casilli, Alessandro; Piper, Thomas; de Oliveira, Fábio Azamor; Padilha, Monica Costa; Pereira, Henrique Marcelo; Thevis, Mario; de Aquino Neto, Francisco Radler</p> <p>2016-11-01</p> <p>Measuring carbon isotope ratios (CIRs) of urinary analytes represents a cornerstone of doping control analysis and has been particularly <span class="hlt">optimized</span> for the detection of the misuse of endogenous steroids. Isotope ratio mass spectrometry (IRMS) of appropriate quality, however, necessitates adequate purities of the investigated steroids, which requires extensive pre-analytical sample clean-up <span class="hlt">steps</span> due to both the natural presence of the target analytes and the high complexity of the matrix. In order to accelerate the sample preparation and increase the automation of the process, the use of multidimensional gas chromatography (MDGC) prior to IRMS experiments, was investigated. A well-established instrumental configuration based on two independent GC ovens and one heart-cutting device was <span class="hlt">optimized</span>. The first dimension (1D) separation was obtained by a non-polar column which assured high efficiency and good loading capacity, while the second dimension (2D), based on a mid-polar stationary phase, provided good selectivity. A flame ionization detector monitored the 1D, and the 2D was simultaneously recorded by isotope ratio and quadrupole mass spectrometry. The assembled MDGC set-up was applied for measuring testosterone, 5α- and 5β-androstanediol, androsterone, and etiocholanolone as target compounds and pregnanediol as endogenous reference compound. The urine sample were pretreated by conventional sample preparation <span class="hlt">steps</span> comprising solid-phase extraction, hydrolysis, and liquid-liquid extraction. The extract obtained was acetylated and different aliquots were injected into the MDGC system. Two high performance liquid chromatography <span class="hlt">steps</span>, conventionally adopted prior to CIR measurements, were replaced by the MDGC approach. The obtained values were consistent with the conventional ones. Copyright © 2016 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21064241','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21064241"><span>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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4285650','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4285650"><span>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('https://www.osti.gov/scitech/biblio/22390800','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22390800"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/16783431','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16783431"><span><span class="hlt">Filter</span> for biomedical imaging and image processing.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mondal, Partha P; Rajan, K; Ahmad, Imteyaz</p> <p>2006-07-01</p> <p>Image <span class="hlt">filtering</span> techniques have numerous potential applications in biomedical imaging and image processing. The design of <span class="hlt">filters</span> largely depends on the a priori, knowledge about the type of noise corrupting the image. This makes the standard <span class="hlt">filters</span> application specific. Widely used <span class="hlt">filters</span> such as average, Gaussian, and Wiener reduce noisy artifacts by smoothing. However, this operation normally results in smoothing of the edges as well. On the other hand, sharpening <span class="hlt">filters</span> enhance the high-frequency details, making the image nonsmooth. An integrated general approach to design a finite impulse response <span class="hlt">filter</span> based on Hebbian learning is proposed for <span class="hlt">optimal</span> image <span class="hlt">filtering</span>. This algorithm exploits the interpixel correlation by updating the <span class="hlt">filter</span> coefficients using Hebbian learning. The algorithm is made iterative for achieving efficient learning from the neighborhood pixels. This algorithm performs <span class="hlt">optimal</span> smoothing of the noisy image by preserving high-frequency as well as low-frequency features. Evaluation results show that the proposed finite impulse response <span class="hlt">filter</span> is robust under various noise distributions such as Gaussian noise, salt-and-pepper noise, and speckle noise. Furthermore, the proposed approach does not require any a priori knowledge about the type of noise. The number of unknown parameters is few, and most of these parameters are adaptively obtained from the processed image. The proposed <span class="hlt">filter</span> is successfully applied for image reconstruction in a positron emission tomography imaging modality. The images reconstructed by the proposed algorithm are found to be superior in quality compared with those reconstructed by existing PET image reconstruction methodologies.</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>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://hdl.handle.net/2060/20080005023','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080005023"><span>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://adsabs.harvard.edu/abs/1989PhDT........62S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989PhDT........62S"><span>Discrete-time <span class="hlt">filtering</span> of linear continuous-time processes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shats, Samuel</p> <p>1989-06-01</p> <p>Continuous-time measurements are prefiltered before sampling, to remove additive white noise. The discrete-time <span class="hlt">optimal</span> <span class="hlt">filter</span> comprises a digital algorithm which is applied to the prefiltered, sampled measurements; the algorithm is based on the discrete-time equivalent model of the overall system. For the case of an integrate-and-dump analog prefilter, a discrete-time equivalent model was developed and the corresponding <span class="hlt">optimal</span> <span class="hlt">filter</span> was found for the general case, where the continuous-time measurement and process noise signals are correlated. A commonly used approximate discrete-time model was analyzed by defining and evaluating the true-error-covariance matrix of the estimate, and comparing it with the supposed error covariance matrix. It was shown that there is a class of unstable processes for which the former error covariance matrix attains unbounded norm, in spite of the continuing bounded nature of the other error covariance matrix. The main part of the thesis concerns the problem of finding an <span class="hlt">optimal</span> prefilter. The <span class="hlt">steps</span> of obtaining the <span class="hlt">optimal</span> prefilter comprise: deriving a discrete-time equivalent-model of the overall system; finding the equation which is satisfied by the error covariance matrix; deriving the expressions which are satisfied by the first coefficients of the Maclaurin expansions of the error covariance matrix in the small parameter T; and obtaining the <span class="hlt">optimal</span> prefilter by matrix <span class="hlt">optimization</span>. The results obtained indicate that the <span class="hlt">optimal</span> prefilter may be implemented through systems of different orders; the minimum order required is discussed, which is of great practical importance as the simplest possible prefilter. In discussion of the problem of discrete-time quadratic regulation of linear continuous time processes, the case of practical interest, where a zero-order hold is part of the digital-to-analog converter, is considered. It is shown that the duality between the regulation and <span class="hlt">filtering</span> problems is not conserved after</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('https://www.osti.gov/scitech/biblio/22409672','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22409672"><span>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://hdl.handle.net/2060/20040110662','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040110662"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/21807983','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21807983"><span>Pharmacokinetic/pharmacodynamic (PK/PD) indices of antibiotics predicted by a semimechanistic PKPD model: a <span class="hlt">step</span> toward model-based dose <span class="hlt">optimization</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nielsen, Elisabet I; Cars, Otto; Friberg, Lena E</p> <p>2011-10-01</p> <p>A pharmacokinetic-pharmacodynamic (PKPD) model that characterizes the full time course of in vitro time-kill curve experiments of antibacterial drugs was here evaluated in its capacity to predict the previously determined PK/PD indices. Six drugs (benzylpenicillin, cefuroxime, erythromycin, gentamicin, moxifloxacin, and vancomycin), representing a broad selection of mechanisms of action and PK and PD characteristics, were investigated. For each drug, a dose fractionation study was simulated, using a wide range of total daily doses given as intermittent doses (dosing intervals of 4, 8, 12, or 24 h) or as a constant drug exposure. The time course of the drug concentration (PK model) as well as the bacterial response to drug exposure (in vitro PKPD model) was predicted. Nonlinear least-squares regression analyses determined the PK/PD index (the maximal unbound drug concentration [fC(max)]/MIC, the area under the unbound drug concentration-time curve [fAUC]/MIC, or the percentage of a 24-h time period that the unbound drug concentration exceeds the MIC [fT(>MIC)]) that was most predictive of the effect. The in silico predictions based on the in vitro PKPD model identified the previously determined PK/PD indices, with fT(>MIC) being the best predictor of the effect for β-lactams and fAUC/MIC being the best predictor for the four remaining evaluated drugs. The selection and magnitude of the PK/PD index were, however, shown to be sensitive to differences in PK in subpopulations, uncertainty in MICs, and investigated dosing intervals. In comparison with the use of the PK/PD indices, a model-based approach, where the full time course of effect can be predicted, has a lower sensitivity to study design and allows for PK differences in subpopulations to be considered directly. This study supports the use of PKPD models built from in vitro time-kill curves in the development of <span class="hlt">optimal</span> dosing regimens for antibacterial drugs.</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>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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26198051','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26198051"><span>Improving dimensional measurement from noisy atomic force microscopy images by non-local means <span class="hlt">filtering</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Yuhang</p> <p>2016-01-01</p> <p>Quantitative evaluation of dimensional parameters from noisy atomic force microscopy (AFM) images was investigated. Non-local means (NLM) denoising was adopted to reduce noise and maintain fine image structures. Major tuning parameters in NLM <span class="hlt">filtering</span>, such as the patch size and the window size, were <span class="hlt">optimized</span> on simulated surface structures. The ability of dimensional evaluation from noisy data was demonstrated to be improved by almost 15 times. Finally, NLM <span class="hlt">filtering</span> with <span class="hlt">optimal</span> settings was applied on experimental AFM images, which were scanned on a patterned few-layer graphene specimen. Evaluations of the <span class="hlt">step</span> height and the pattern size were verified to be much more accurate and robust. Such a data processing method can enhance the AFM dimensional measurements, particularly when the noise-level is reached.</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>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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993PhDT.......150K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993PhDT.......150K"><span>Triple-Quantum <span class="hlt">Filtered</span> NMR Imaging of Sodium -23 in the Human Brain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Keltner, John Robinson</p> <p></p> <p>In the past multiple-quantum <span class="hlt">filtered</span> imaging of biexponential relaxation sodium-23 nuclei in the human brain has been limited by low signal to noise ratios; this thesis demonstrates that such imaging is feasible when using a modified gradient-selected triple-quantum <span class="hlt">filter</span> at a repetition time which maximizes the signal to noise ratio. Nuclear magnetic resonance imaging of biexponential relaxation sodium-23 (^{23}Na) nuclei in the human brain may be useful for detecting ischemia, cancer, and pathophysiology related to manic-depression. Multiple -quantum <span class="hlt">filters</span> may be used to selectively image biexponential relaxation ^{23}Na signals since these <span class="hlt">filters</span> suppress single-exponential relaxation ^{23}Na signals. In this thesis, the typical repetition times (200 -300 ms) used for in vivo multiple-quantum <span class="hlt">filtered</span> ^{23}Na experiments are shown to be approximately 5 times greater than the <span class="hlt">optimal</span> repetition time which maximizes multiple-quantum <span class="hlt">filtered</span> SNR. Calculations and experimental verification show that the gradient-selected triple-quantum (GS3Q) <span class="hlt">filtered</span> SNR for ^ {23}Na in a 4% agarose gel increases by a factor of two as the repetition time decreases from 300 ms to 55 ms. It is observed that a simple reduction of repetition time also increases spurious single-quantum signals from GS3Q <span class="hlt">filtered</span> experiments. Irreducible superoperator calculations have been used to design a modified GS3Q <span class="hlt">filter</span> which more effectively suppresses the spurious single-quantum signals. The modified GS3Q <span class="hlt">filter</span> includes a preparatory crusher gradient and two-<span class="hlt">step</span>-phase cycling. Using the modified GS3Q <span class="hlt">filter</span> and a repetition time of 70 ms, a three dimensional triple-quantum <span class="hlt">filtered</span> image of a phantom modelling ^{23} Na in the brain was obtained. The phantom consisted of two 4 cm diameter spheres inside of a 8.5 cm x 7 cm ellipsoid. The two spheres contained 0.012 and 0.024 M ^{23}Na in 4% agarose gel. Surrounding the spheres and inside the ellipsoid was 0.03 M aqueous ^{23}Na. The image</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD0462155','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD0462155"><span>NOVEL MICROWAVE <span class="hlt">FILTER</span> DESIGN TECHNIQUES.</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p></p> <p>ELECTROMAGNETIC WAVE <span class="hlt">FILTERS</span>, MICROWAVE FREQUENCY, PHASE SHIFT CIRCUITS, BANDPASS <span class="hlt">FILTERS</span>, TUNED CIRCUITS, NETWORKS, IMPEDANCE MATCHING , LOW PASS <span class="hlt">FILTERS</span>, MULTIPLEXING, MICROWAVE EQUIPMENT, WAVEGUIDE <span class="hlt">FILTERS</span>, WAVEGUIDE COUPLERS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/10140625','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/10140625"><span>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('https://www.osti.gov/scitech/biblio/22325165','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22325165"><span>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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19212073','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19212073"><span>[Evaluation of an adaptive <span class="hlt">filter</span> for CT under low-CNR condition: comparison with linear <span class="hlt">filter</span>].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mori, Issei; Uchida, Miho; Sato, Ami; Sato, Shingo; Tamura, Hajime; Takai, Yoshihiro; Ishibashi, Tadashi; Saito, Haruo; Hosokai, Yoshiyuki; Ogura, Takahide; Chida, Koichi; Machida, Yoshio</p> <p>2009-01-20</p> <p>The use of an adaptive <span class="hlt">filter</span> for CT images is becoming a common procedure and is said to reduce image noise while preserving sharpness and helping to reduce the required X-ray dose. Although many reports support this view, the validity of such evaluations is arguable. When the linearity of a system is in question, physical performance indexes should be measured under conditions similar to those of clinical use. Evaluations of diagnosis using clinical images may be fallible because the non-<span class="hlt">filtered</span> image used as the reference might not have been <span class="hlt">optimally</span> reconstructed. We have chosen simple, but commonly used, adaptive <span class="hlt">filters</span> for our evaluation. As a reference for comparing performance, we designed linear <span class="hlt">filters</span> that best approximate the noise characteristics of the adaptive <span class="hlt">filters</span>. MTF is measured through observation of the edge-spread function. Clinical abdominal images are used to compare the performance of adaptive <span class="hlt">filters</span> and linear <span class="hlt">filters</span>. We conclude that the performance of the type of adaptive <span class="hlt">filter</span> we have chosen is virtually the same as that of the linear <span class="hlt">filter</span>, as long as the image quality of soft tissues is our interest. Both the noise SD and MTF are virtually the same if the contrast of the object is not substantially higher than 150 HU. Images of soft tissues obtained with the use of adaptive <span class="hlt">filters</span> are also virtually the same as those obtained by linear <span class="hlt">filters</span>. The edge-preservation characteristic of this adaptive <span class="hlt">filter</span> is not observable for soft tissues.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhCS.738a2130M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhCS.738a2130M"><span>Design of order statistics <span class="hlt">filters</span> using feedforward neural networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maslennikova, Yu. S.; Bochkarev, V. V.</p> <p>2016-08-01</p> <p>In recent years significant progress have been made in the development of nonlinear data processing techniques. Such techniques are widely used in digital data <span class="hlt">filtering</span> and image enhancement. Many of the most effective nonlinear <span class="hlt">filters</span> based on order statistics. The widely used median <span class="hlt">filter</span> is the best known order statistic <span class="hlt">filter</span>. Generalized form of these <span class="hlt">filters</span> could be presented based on Lloyd's statistics. <span class="hlt">Filters</span> based on order statistics have excellent robustness properties in the presence of impulsive noise. In this paper, we present special approach for synthesis of order statistics <span class="hlt">filters</span> using artificial neural networks. <span class="hlt">Optimal</span> Lloyd's statistics are used for selecting of initial weights for the neural network. Adaptive properties of neural networks provide opportunities to <span class="hlt">optimize</span> order statistics <span class="hlt">filters</span> for data with asymmetric distribution function. Different examples demonstrate the properties and performance of presented approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PCE....36.1135V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PCE....36.1135V"><span>The use of <span class="hlt">filter</span> media to determine <span class="hlt">filter</span> cleanliness</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Van Staden, S. J.; Haarhoff, J.</p> <p></p> <p>It is general believed that a sand <span class="hlt">filter</span> starts its life with new, perfectly clean media, which becomes gradually clogged with each filtration cycle, eventually getting to a point where either head loss or filtrate quality starts to deteriorate. At this point the backwash cycle is initiated and, through the combined action of air and water, returns the media to its original perfectly clean state. Reality, however, dictates otherwise. Many treatment plants visited a decade or more after commissioning are found to have unacceptably dirty <span class="hlt">filter</span> sand and backwash systems incapable of returning the <span class="hlt">filter</span> media to a desired state of cleanliness. In some cases, these problems are common ones encountered in filtration plants but many reasons for media deterioration remain elusive, falling outside of these common problems. The South African conditions of highly eutrophic surface waters at high temperatures, however, exacerbate the problems with dirty <span class="hlt">filter</span> media. Such conditions often lead to the formation of biofilm in the <span class="hlt">filter</span> media, which is shown to inhibit the effective backwashing of sand and carbon <span class="hlt">filters</span>. A systematic investigation into <span class="hlt">filter</span> media cleanliness was therefore started in 2002, ending in 2005, at the University of Johannesburg (the then Rand Afrikaans University). This involved media from eight South African Water Treatment Plants, varying between sand and sand-anthracite combinations and raw water types from eutrophic through turbid to low-turbidity waters. Five states of cleanliness and four fractions of specific deposit were identified relating to in situ washing, column washing, cylinder inversion and acid-immersion techniques. These were measured and the results compared to acceptable limits for specific deposit, as determined in previous studies, though expressed in kg/m 3. These values were used to determine the state of the <span class="hlt">filters</span>. In order to gain greater insight into the composition of the specific deposits stripped from the media, a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910031204&hterms=bistatic+sar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbistatic%2Bsar','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910031204&hterms=bistatic+sar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbistatic%2Bsar"><span>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> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19834210','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19834210"><span>Isosurface extraction and view-dependent <span class="hlt">filtering</span> from time-varying fields using Persistent Time-Octree (PTOT).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Cong; Chiang, Yi-Jen</p> <p>2009-01-01</p> <p>We develop a new algorithm for isosurface extraction and view-dependent <span class="hlt">filtering</span> from large time-varying fields, by using a novel Persistent Time-Octree (PTOT) indexing structure. Previously, the Persistent Octree (POT) was proposed to perform isosurface extraction and view-dependent <span class="hlt">filtering</span>, which combines the advantages of the interval tree (for <span class="hlt">optimal</span> searches of active cells) and of the Branch-On-Need Octree (BONO, forview-dependent <span class="hlt">filtering</span>), but it only works for steady-state(i.e., single time <span class="hlt">step</span>) data. For time-varying fields, a 4D version of POT, 4D-POT, was proposed for 4D isocontour slicing, where slicing on the time domain gives all active cells in the queried timestep and isovalue. However, such slicing is not output sensitive and thus the searching is sub-<span class="hlt">optimal</span>. Moreover, it was not known how to support view-dependent <span class="hlt">filtering</span> in addition to time-domain slicing.In this paper, we develop a novel Persistent Time-Octree (PTOT) indexing structure, which has the advantages of POT and performs 4D isocontour slicing on the time domain with an output-sensitive and <span class="hlt">optimal</span> searching. In addition, when we query the same isovalue q over m consecutive time <span class="hlt">steps</span>, there is no additional searching overhead (except for reporting the additionalactive cells) compared to querying just the first time <span class="hlt">step</span>. Such searching performance for finding active cells is asymptotically <span class="hlt">optimal</span>, with asymptotically <span class="hlt">optimal</span> space and preprocessing time as well. Moreover, our PTOT supports view-dependent <span class="hlt">filtering</span> in addition to time-domain slicing. We propose a simple and effective out-of-core scheme, where we integrate our PTOT with implicit occluders, batched occlusion queries and batched CUDA computing tasks, so that we can greatly reduce the I/O cost as well as increase the amount of data being concurrently computed in GPU.This results in an efficient algorithm for isosurface extraction with view-dependent <span class="hlt">filtering</span> utilizing a state-of-the-art programmable GPUfor time</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.6041..517A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.6041..517A"><span>Design of suboptimal adaptive <span class="hlt">filter</span> for stochastic systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ahn, Jun Il; Shin, Vladimir</p> <p>2005-12-01</p> <p>In this paper, the problem of estimating the system state in for linear discrete-time systems with uncertainties is considered. In [1], [2], we have proposed the fusion formula (FF) for an arbitrary number of correlated and uncorrelated estimates. The FF is applied to detection and <span class="hlt">filtering</span> problem. The new suboptimal adaptive <span class="hlt">filter</span> with parallel structure is herein proposed. In consequence of parallel structure of the proposed <span class="hlt">filter</span>, parallel computers can be used for their design. A lower computational complexity and lower memory demand are achieved with the proposed <span class="hlt">filter</span> than in the <span class="hlt">optimal</span> adaptive Lainiotis-Kalman <span class="hlt">filter</span>. Example demonstrates the accuracy of the new <span class="hlt">filter</span>.</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>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/servlets/purl/867499','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/867499"><span>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://adsabs.harvard.edu/abs/2014JGRC..119.2363M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRC..119.2363M"><span>Application of the implicit particle <span class="hlt">filter</span> to a model of nearshore circulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miller, R. N.; Ehret, L. L.</p> <p>2014-04-01</p> <p>The implicit particle <span class="hlt">filter</span> is applied to a stochastically forced shallow water model of nearshore flow, and found to produce reliable state estimates with tens of particles. The state vector of this model consists of a height anomaly and two horizontal velocity components at each point on a 128 × 98 regular rectangular grid, making for a state dimension O(104). The particle <span class="hlt">filter</span> was applied to the model with two parameter choices representing two distinct dynamical regimes, and performed well in both. Demands on computing resources were manageable. Simulations with as many as a hundred particles ran overnight on a modestly configured workstation. In this case of observations defined by a linear function of the state vector, taken every time <span class="hlt">step</span> of the numerical model, the implicit particle <span class="hlt">filter</span> is equivalent to the <span class="hlt">optimal</span> importance <span class="hlt">filter</span>, i.e., at each <span class="hlt">step</span> any given particle is drawn from the density of the system conditioned jointly upon observations and the state of that particle at the previous time. Even in this ideal case, the sample occasionally collapses to a single particle, and resampling is necessary. In those cases, the sample rapidly reinflates, and the analysis never loses track. In both dynamical regimes, the ensembles of particles deviated significantly from normality.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22340201','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22340201"><span>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> </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://www.osti.gov/scitech/servlets/purl/1295680','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1295680"><span>The Sloan Digital Sky Survey Stripe 82 Imaging Data: Depth-<span class="hlt">Optimized</span> Co-adds Over 300 deg$^2$ 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; 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>2014-06-25</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(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(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://www.osti.gov/scitech/biblio/5210680','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/5210680"><span>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>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://www.osti.gov/scitech/servlets/purl/866054','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/866054"><span>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/servlets/purl/10171262','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10171262"><span>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/biblio/5381258','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/5381258"><span>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://hdl.handle.net/2060/20000052704','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000052704"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/23533612','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23533612"><span><span class="hlt">Step</span> detection in single-molecule real time trajectories embedded in correlated noise.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Arunajadai, Srikesh G; Cheng, Wei</p> <p>2013-01-01</p> <p>Single-molecule real time trajectories are embedded in high noise. To extract kinetic or dynamic information of the molecules from these trajectories often requires idealization of the data in <span class="hlt">steps</span> and dwells. One major premise behind the existing single-molecule data analysis algorithms is the gaussian 'white' noise, which displays no correlation in time and whose amplitude is independent on data sampling frequency. This so-called 'white' noise is widely assumed but its validity has not been critically evaluated. We show that correlated noise exists in single-molecule real time trajectories collected from optical tweezers. The assumption of white noise during analysis of these data can lead to serious over- or underestimation of the number of <span class="hlt">steps</span> depending on the algorithms employed. We present a statistical method that quantitatively evaluates the structure of the underlying noise, takes the noise structure into account, and identifies <span class="hlt">steps</span> and dwells in a single-molecule trajectory. Unlike existing data analysis algorithms, this method uses Generalized Least Squares (GLS) to detect <span class="hlt">steps</span> and dwells. Under the GLS framework, the <span class="hlt">optimal</span> number of <span class="hlt">steps</span> is chosen using model selection criteria such as Bayesian Information Criterion (BIC). Comparison with existing <span class="hlt">step</span> detection algorithms showed that this GLS method can detect <span class="hlt">step</span> locations with highest accuracy in the presence of correlated noise. Because this method is automated, and directly works with high bandwidth data without pre-<span class="hlt">filtering</span> or assumption of gaussian noise, it may be broadly useful for analysis of single-molecule real time trajectories.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1980ITAES..16..112Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1980ITAES..16..112Z"><span>Minimum peak range sidelobe <span class="hlt">filters</span> for binary phase-coded waveforms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zoraster, S.</p> <p>1980-01-01</p> <p>Linear programming techniques are utilized to determine the <span class="hlt">optimal</span> <span class="hlt">filter</span> weights for minimizing the peak range sidelobes of a binary phase-coded waveform. The resulting <span class="hlt">filter</span> is compared with the <span class="hlt">filter</span> obtained by use of the least square approximation to the ideal inverse <span class="hlt">filter</span>. For a test case using the 13-element Barker code the linear programming <span class="hlt">filter</span> is found to have peak sidelobes as much as 5 dB lower than the least squares <span class="hlt">filter</span> of the same length.</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>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('https://ntrs.nasa.gov/search.jsp?R=19850007945&hterms=theory+segmentation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dtheory%2Bsegmentation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850007945&hterms=theory+segmentation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dtheory%2Bsegmentation"><span>Texture classification using autoregressive <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>Lawton, W. M.; Lee, M.</p> <p>1984-01-01</p> <p>A general theory of image texture models is proposed and its applicability to the problem of scene segmentation using texture classification is discussed. An algorithm, based on half-plane autoregressive <span class="hlt">filtering</span>, which <span class="hlt">optimally</span> utilizes second order statistics to discriminate between texture classes represented by arbitrary wide sense stationary random fields is described. Empirical results of applying this algorithm to natural and sysnthesized scenes are presented and future research is outlined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24807028','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24807028"><span>Quantum neural network-based EEG <span class="hlt">filtering</span> for a brain-computer interface.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gandhi, Vaibhav; Prasad, Girijesh; Coyle, Damien; Behera, Laxmidhar; McGinnity, Thomas Martin</p> <p>2014-02-01</p> <p>A novel neural information processing architecture inspired by quantum mechanics and incorporating the well-known Schrodinger wave equation is proposed in this paper. The proposed architecture referred to as recurrent quantum neural network (RQNN) can characterize a nonstationary stochastic signal as time-varying wave packets. A robust unsupervised learning algorithm enables the RQNN to effectively capture the statistical behavior of the input signal and facilitates the estimation of signal embedded in noise with unknown characteristics. The results from a number of benchmark tests show that simple signals such as dc, staircase dc, and sinusoidal signals embedded within high noise can be accurately <span class="hlt">filtered</span> and particle swarm <span class="hlt">optimization</span> can be employed to select model parameters. The RQNN <span class="hlt">filtering</span> procedure is applied in a two-class motor imagery-based brain-computer interface where the objective was to <span class="hlt">filter</span> electroencephalogram (EEG) signals before feature extraction and classification to increase signal separability. A two-<span class="hlt">step</span> inner-outer fivefold cross-validation approach is utilized to select the algorithm parameters subject-specifically for nine subjects. It is shown that the subject-specific RQNN EEG <span class="hlt">filtering</span> significantly improves brain-computer interface performance compared to using only the raw EEG or Savitzky-Golay <span class="hlt">filtered</span> EEG across multiple sessions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20529733','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20529733"><span>Harmonic <span class="hlt">filters</span> for 3D multichannel data: rotation invariant detection of mitoses in colorectal cancer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schlachter, Matthias; Reisert, Marco; Herz, Corinna; Schlürmann, Fabienne; Lassmann, Silke; Werner, Martin; Burkhardt, Hans; Ronneberger, Olaf</p> <p>2010-08-01</p> <p>In this paper, we present a novel approach for a trainable rotation invariant detection of complex structures in 3D microscopic multichannel data using a nonlinear <span class="hlt">filter</span> approach. The basic idea of our approach is to compute local features in a window around each 3D position and map these features by means of a nonlinear mapping onto new local harmonic descriptors of the local window. These local harmonic descriptors are then combined in a linear way to form the output of the <span class="hlt">filter</span>. The <span class="hlt">optimal</span> combination of the computed local harmonic descriptors is determined in previous training <span class="hlt">step</span>, and allows the <span class="hlt">filter</span> to be adapted to an arbitrary structure depending on the problem at hand. Our approach is not limited to scalar-valued images and can also be used for vector-valued (multichannel) images such as gradient vector flow fields. We present realizations of a scalar-valued and a vector-valued multichannel <span class="hlt">filter</span>. Our proposed algorithm was quantitatively evaluated on colorectal cancer cell lines (cells grown under controlled conditions), on which we successfully detected complex 3D mitotic structures. For a qualitative evaluation we tested our algorithms on human 3D tissue samples of colorectal cancer. We compare our results with a steerable <span class="hlt">filter</span> approach as well as a morphology-based approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20457535','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20457535"><span>3D early embryogenesis image <span class="hlt">filtering</span> by nonlinear partial differential equations.</span></a></p> <p><a target="_blank" href="https://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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/922835','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/922835"><span>A <span class="hlt">Filtering</span> Method For Gravitationally Stratified Flows</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gatti-Bono, Caroline; Colella, Phillip</p> <p>2005-04-25</p> <p>Gravity waves arise in gravitationally stratified compressible flows at low Mach and Froude numbers. These waves can have a negligible influence on the overall dynamics of the fluid but, for numerical methods where the acoustic waves are treated implicitly, they impose a significant restriction on the time <span class="hlt">step</span>. A way to alleviate this restriction is to <span class="hlt">filter</span> out the modes corresponding to the fastest gravity waves so that a larger time <span class="hlt">step</span> can be used. This paper presents a <span class="hlt">filtering</span> strategy of the fully compressible equations based on normal mode analysis that is used throughout the simulation to compute the fast dynamics and that is able to damp only fast gravity modes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012RaPC...81..874C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012RaPC...81..874C"><span>Effects of electron beam irradiation of cellulose acetate cigarette <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>Czayka, M.; Fisch, M.</p> <p>2012-07-01</p> <p>A method to reduce the molecular weight of cellulose acetate used in cigarette <span class="hlt">filters</span> by using electron beam irradiation is demonstrated. Radiation levels easily obtained with commercially available electron accelerators result in a decrease in average molecular weight of about six-times with no embrittlement, or significant change in the elastic behavior of the <span class="hlt">filter</span>. Since a first <span class="hlt">step</span> in the biodegradation of cigarette <span class="hlt">filters</span> is reduction in the <span class="hlt">filter</span> material's molecular weight this invention has the potential to allow the production of significantly faster degrading <span class="hlt">filters</span>.</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>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('https://www.ncbi.nlm.nih.gov/pubmed/16161654','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16161654"><span>Porous silicon-based rugate <span class="hlt">filters</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lorenzo, Eduardo; Oton, Claudio J; Capuj, Néstor E; Ghulinyan, Mher; Navarro-Urrios, Daniel; Gaburro, Zeno; Pavesi, Lorenzo</p> <p>2005-09-10</p> <p>We report an experimental study of porous silicon-based rugate <span class="hlt">filters</span>. We performed <span class="hlt">filter</span> apodization, following a half-apodization approach, which successfully attenuated the sidelobes at both sides of the photonic stop band. We achieved successful reduction of interference ripples through the insertion of index-matching layers on the first and last interfaces. An apodized dielectric mirror and a rugate <span class="hlt">filter</span> are compared: Appreciable differences in the harmonic presence and stop-band performance were observed and are commented on. Bandwidth control when index contrast is modified is also demonstrated. Finally, the possibility of combining different rugate <span class="hlt">filter</span> designs to attain more complex responses is demonstrated by the achievement of a multi-stop-band <span class="hlt">filter</span>. Numerical calculations for design <span class="hlt">optimization</span> and comparison with experimental data are reported too.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1327974','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1327974"><span>Method of securing <span class="hlt">filter</span> elements</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Brown, Erik P.; Haslam, Jeffery L.; Mitchell, Mark A.</p> <p>2016-10-04</p> <p>A <span class="hlt">filter</span> securing system including a <span class="hlt">filter</span> unit body housing; at least one tubular <span class="hlt">filter</span> element positioned in the <span class="hlt">filter</span> unit body housing, the tubular <span class="hlt">filter</span> element having a closed top and an open bottom; a dimple in either the <span class="hlt">filter</span> unit body housing or the top of the tubular <span class="hlt">filter</span> element; and a socket in either the <span class="hlt">filter</span> unit body housing or the top of the tubular <span class="hlt">filter</span> element that receives the dimple in either the <span class="hlt">filter</span> unit body housing or the top of the tubular <span class="hlt">filter</span> element to secure the tubular <span class="hlt">filter</span> element to the <span class="hlt">filter</span> unit body housing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21064240','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21064240"><span>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_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://www.osti.gov/scitech/servlets/purl/872975','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/872975"><span>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; Straub, Douglas L.; Dennis, Richard A.</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('https://www.osti.gov/scitech/biblio/6077681','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6077681"><span>A semblance-guided median <span class="hlt">filter</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Reiter, E.C. ); Toksoz, M.N. ); Purdy, G.M. )</p> <p>1993-01-01</p> <p>A slowness selective median <span class="hlt">filter</span> based on information from a local set of traces is described and implemented. The <span class="hlt">filter</span> is constructed in two <span class="hlt">steps</span>, the first being an estimation of a preferred slowness and the second, the selection of a median or trimmed mean value to replace the original data point. A symmetric window of traces defining the <span class="hlt">filter</span> aperture is selected about each trace to be <span class="hlt">filtered</span> and the <span class="hlt">filter</span> applied repeatedly to each time point. The preferred slowness is determined by scanning a range of linear moveouts within the user-specified slowness passband. Semblance is computed for each trial slowness and the preferred slowness selected from the peak semblance value. Data points collected along this preferred slowness are then sorted from lowest to highest and in the case of a pure median <span class="hlt">filter</span>, the middle point(s) selected to replace the original data point. This approach may be sued as a velocity <span class="hlt">filter</span> to estimate coherent signal within a specified slowness passband and reject coherent energy outside this range. For applications of this type, other velocity estimators may be used in place of the authors semblance measure to provide improved velocity estimation and better <span class="hlt">filter</span> performance. The <span class="hlt">filter</span> aperture may also be extended to provide increased velocity estimation, but will result in additional lateral smearing of signal. The authors show that, in addition to a velocity <span class="hlt">filter</span>, their approach may be used to improve signal-to-noise ratios in noisy data. The median <span class="hlt">filter</span> tends to suppress the amplitude of random background noise and semblance weighting may be used to reduce the amplitude of background noise further while enhancing coherent signal.</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><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://www.osti.gov/scitech/biblio/458574','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/458574"><span><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://adsabs.harvard.edu/abs/2016EJASP2016...87P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EJASP2016...87P"><span>Generalized Hampel <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>Pearson, Ronald K.; Neuvo, Yrjö; Astola, Jaakko; Gabbouj, Moncef</p> <p>2016-12-01</p> <p>The standard median <span class="hlt">filter</span> based on a symmetric moving window has only one tuning parameter: the window width. Despite this limitation, this <span class="hlt">filter</span> has proven extremely useful and has motivated a number of extensions: weighted median <span class="hlt">filters</span>, recursive median <span class="hlt">filters</span>, and various cascade structures. The Hampel <span class="hlt">filter</span> is a member of the class of decsion <span class="hlt">filters</span> that replaces the central value in the data window with the median if it lies far enough from the median to be deemed an outlier. This <span class="hlt">filter</span> depends on both the window width and an additional tuning parameter t, reducing to the median <span class="hlt">filter</span> when t=0, so it may be regarded as another median <span class="hlt">filter</span> extension. This paper adopts this view, defining and exploring the class of generalized Hampel <span class="hlt">filters</span> obtained by applying the median <span class="hlt">filter</span> extensions listed above: weighted Hampel <span class="hlt">filters</span>, recursive Hampel <span class="hlt">filters</span>, and their cascades. An important concept introduced here is that of an implosion sequence, a signal for which generalized Hampel <span class="hlt">filter</span> performance is independent of the threshold parameter t. These sequences are important because the added flexibility of the generalized Hampel <span class="hlt">filters</span> offers no practical advantage for implosion sequences. Partial characterization results are presented for these sequences, as are useful relationships between root sequences for generalized Hampel <span class="hlt">filters</span> and their median-based counterparts. To illustrate the performance of this <span class="hlt">filter</span> class, two examples are considered: one is simulation-based, providing a basis for quantitative evaluation of signal recovery performance as a function of t, while the other is a sequence of monthly Italian industrial production index values that exhibits glaring outliers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994PhDT.......261S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994PhDT.......261S"><span>Analysis and Design of Time-Varying <span class="hlt">Filter</span> Banks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sodagar, Iraj</p> <p></p> <p>Analysis-synthesis <span class="hlt">filter</span> banks have been studied extensively and a wide range of theoretical problems have been subsequently addressed. However, almost all the research activity has been concentrated on time-invariant <span class="hlt">filter</span> banks whose components are fixed and do not change in time. The objective of this thesis is to develop analysis and design techniques for time-varying FIR analysis-synthesis <span class="hlt">filter</span> banks that are perfect reconstructing (PR). In such systems, the analysis and/or synthesis <span class="hlt">filters</span>, the down-up sampling rates, or even the number of bands can change in time. The underlying idea is that by adapting the basis functions of the <span class="hlt">filter</span> bank transform to the signal properties, one can represent the relevant information of the signal more efficiently. For analysis purposes, we derive the time-varying impulse response of the <span class="hlt">filter</span> bank in terms of the analysis and synthesis <span class="hlt">filter</span> coefficients. We are able to represent this impulse response in terms of the product of the analysis and synthesis matrix transforms. Our approach to the PR time-varying <span class="hlt">filter</span> bank design is to change the analysis -synthesis <span class="hlt">filter</span> bank among a set of time-invariant <span class="hlt">filter</span> banks. The analysis <span class="hlt">filter</span> banks are switched instantaneously. To eliminate the distortion during switching, a new time-varying synthesis section is designed for each transition. Three design techniques are developed for the time-varying <span class="hlt">filter</span> bank design. The first technique uses the least squares synthesis <span class="hlt">filters</span>. This method improves the reconstruction quality significantly, but does not usually achieve the perfect reconstruction. Using the second technique, one can design PR time-varying systems by redesigning the analysis <span class="hlt">filters</span>. The drawback is that this method requires numerical <span class="hlt">optimizations</span>. The third technique introduces a new structure for exactly reconstructing time-varying <span class="hlt">filter</span> banks. This structure consists of the conventional <span class="hlt">filter</span> bank followed by a time-varying post <span class="hlt">filter</span>. The post</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760000296&hterms=design+analog+filters&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddesign%2Banalog%2Bfilters','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760000296&hterms=design+analog+filters&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddesign%2Banalog%2Bfilters"><span>Counting digital <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>Zohar, S.</p> <p>1977-01-01</p> <p>Overall design of <span class="hlt">filter</span> combines radix converter with ADC in single functional unit that directly converts analog input to its negative binary representation. Four basic elements of <span class="hlt">filter</span> are fixed register, shift register, counter, and accumulator.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20978376','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20978376"><span>Bag <span class="hlt">filters</span> for TPP</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>L.V. Chekalov; Yu.I. Gromov; V.V. Chekalov</p> <p>2007-05-15</p> <p>Cleaning of TPP flue gases with bag <span class="hlt">filters</span> capable of pulsed regeneration is examined. A new <span class="hlt">filtering</span> element with a three-dimensional <span class="hlt">filtering</span> material formed from a needle-broached cloth in which the filtration area, as compared with a conventional smooth bag, is increased by more than two times, is proposed. The design of a new FRMI type of modular <span class="hlt">filter</span> is also proposed. A standard series of FRMI <span class="hlt">filters</span> with a filtration area ranging from 800 to 16,000 m{sup 2} is designed for an output more than 1 million m{sub 3}/h of with respect to cleaned gas. The new bag <span class="hlt">filter</span> permits dry collection of sulfur oxides from waste gases at TPP operating on high-sulfur coals. The design of the <span class="hlt">filter</span> makes it possible to replace <span class="hlt">filter</span> elements without taking the entire unit out of service.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770014977','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770014977"><span>Modeling error analysis of stationary linear discrete-time <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>Patel, R.; Toda, M.</p> <p>1977-01-01</p> <p>The performance of Kalman-type, linear, discrete-time <span class="hlt">filters</span> in the presence of modeling errors is considered. The discussion is limited to stationary performance, and bounds are obtained for the performance index, the mean-squared error of estimates for suboptimal and <span class="hlt">optimal</span> (Kalman) <span class="hlt">filters</span>. The computation of these bounds requires information on only the model matrices and the range of errors for these matrices. Consequently, a design can easily compare the performance of a suboptimal <span class="hlt">filter</span> with that of the <span class="hlt">optimal</span> <span class="hlt">filter</span>, when only the range of errors in the elements of the model matrices is available.</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>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://adsabs.harvard.edu/abs/2016JSV...383...76C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JSV...383...76C"><span>Acoustic bandpass <span class="hlt">filters</span> employing shaped resonators</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Červenka, M.; Bednařík, M.</p> <p>2016-11-01</p> <p>This work deals with acoustic bandpass <span class="hlt">filters</span> realized by shaped waveguide-elements inserted between two parts of an acoustic transmission line with generally different characteristic impedance. It is shown that the formation of a wide passband is connected with the eigenfrequency spectrum of the <span class="hlt">filter</span> element which acts as an acoustic resonator and that the required <span class="hlt">filter</span> shape substantially depends on whether the <span class="hlt">filter</span> characteristic impedance is higher or lower than the characteristic impedance of the waveguide. It is further shown that this class of <span class="hlt">filters</span> can be realized even without the need of different characteristic impedance. A heuristic technique is proposed to design <span class="hlt">filter</span> shapes with required transmission properties; it is employed for <span class="hlt">optimization</span> of low-frequency bandpass <span class="hlt">filters</span> as well as for design of bandpass <span class="hlt">filters</span> with wide passband surrounded by wide stopbands as it is typical for phononic crystals, however, in this case the arrangement is much simpler as it consists of only one simple-shaped homogeneous element.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA102478','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA102478"><span>Problems in <span class="hlt">Optimal</span> <span class="hlt">Filtering</span> and Stochastic Control.</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>1981-05-01</p> <p>Linear prograirni g and sequential decisions, Management Science, 6(1960) , 259-267. 23. R. Rishel, Dynamic program:i.ng and minirium principles for... nternat . J. Non-Linear Mech., 11 (1976), 41-47. 7. Parabolic boundary layerS, Indiana Univ. Math. J., 25 (1976), 809-819. 8. On a formula in diffusion...ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT . TASK Department of Mathematics AREA 6 WORK UNIT NUMBERS Purdue University PE61102F, 2304/A6</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810004926','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810004926"><span>Geomagnetic field modeling by <span class="hlt">optimal</span> recursive <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></p> <p>1980-01-01</p> <p>Data sets selected for mini-batches and the software modifications required for processing these sets are described. Initial analysis was performed on minibatch field model recovery. Studies are being performed to examine the convergence of the solutions and the maximum expansion order the data will support in the constant and secular terms.</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>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/1993SPIE.2028..260H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993SPIE.2028..260H"><span>Image texture classification with digital <span class="hlt">filter</span> banks and transforms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Husoy, John H.; Randen, Trygve; Gulsrud, Thor O.</p> <p>1993-10-01</p> <p>Several frequency domain or joint spatial/frequency domain techniques for image texture classification have been published. We formulate these techniques within a common signal processing framework based on digital <span class="hlt">filter</span> banks. The usefulness of computationally efficient IIR <span class="hlt">filter</span> banks as channel <span class="hlt">filters</span> in texture classifiers is demonstrated. Using estimates of local energy in the frequency channels we also propose a technique for selecting optimum <span class="hlt">filter</span> banks by maximizing a between class distance measure. This <span class="hlt">optimization</span> is particularly simple when using the IIR based <span class="hlt">filter</span> banks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ256943.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ256943.pdf"><span><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/servlets/purl/865125','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/865125"><span><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> <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><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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4024107','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4024107"><span>ON THE CONVERGENCE OF THE ENSEMBLE KALMAN <span class="hlt">FILTER</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>Mandel, Jan; Cobb, Loren; Beezley, Jonathan D.</p> <p>2013-01-01</p> <p>Convergence of the ensemble Kalman <span class="hlt">filter</span> in the limit for large ensembles to the Kalman <span class="hlt">filter</span> is proved. In each <span class="hlt">step</span> of the <span class="hlt">filter</span>, convergence of the ensemble sample covariance follows from a weak law of large numbers for exchangeable random variables, the continuous mapping theorem gives convergence in probability of the ensemble members, and Lp bounds on the ensemble then give Lp convergence. PMID:24843228</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19123628','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19123628"><span><span class="hlt">Filtering</span> by nonlinear systems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Campos Cantón, E; González Salas, J S; Urías, J</p> <p>2008-12-01</p> <p>Synchronization of nonlinear systems forced by external signals is formalized as the response of a nonlinear <span class="hlt">filter</span>. Sufficient conditions for a nonlinear system to behave as a <span class="hlt">filter</span> are given. Some examples of generalized chaos synchronization are shown to actually be special cases of nonlinear <span class="hlt">filtering</span>.</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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2930609','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2930609"><span>The Ribosome <span class="hlt">Filter</span> Redux</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mauro, Vincent P.; Edelman, Gerald M.</p> <p>2010-01-01</p> <p>The ribosome <span class="hlt">filter</span> hypothesis postulates that ribosomes are not simply translation machines but also function as regulatory elements that differentially affect or <span class="hlt">filter</span> the translation of particular mRNAs. On the basis of new information, we take the opportunity here to review the ribosome <span class="hlt">filter</span> hypothesis, suggest specific mechanisms of action, and discuss recent examples from the literature that support it. PMID:17890902</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>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/servlets/purl/985719','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/985719"><span><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.; Nordyke, Daniel S.; Crandell, Richard A.; Tomlins, Gregory; Fei, Dong; Panov, Alexander; Lane, William H.; Habeger, Craig F.</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://adsabs.harvard.edu/abs/2005SPIE.5779..460C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.5779..460C"><span>MINACE-<span class="hlt">filter</span>-based facial pose estimation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Casasent, David P.; Patnaik, Rohit</p> <p>2005-03-01</p> <p>A facial pose estimation system is presented that functions with illumination variations present. Pose estimation is a useful first stage in a face recognition system. A separate minimum noise and correlation energy (MINACE) <span class="hlt">filter</span> is synthesized for each pose. To select the MINACE parameter c for the <span class="hlt">filter</span> for a pose, a training set of illumination differences of several faces at that pose, and a validation set of other poses (illumination differences of several faces at a few other poses) is used in the automated <span class="hlt">filter</span>-synthesis <span class="hlt">step</span>. However, the <span class="hlt">filter</span> for each pose is a combination of faces at only that pose. The pose estimation system is evaluated using images from the CMU Pose, Illumination and Expression (PIE) database. The classification performance (PC) scores are presented for several pose estimation tests. The pose estimate will be used for a subsequent image transformation of a test face to a reference pose for face identification.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.7195V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.7195V"><span>Towards robust particle <span class="hlt">filters</span> for high-dimensional systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van Leeuwen, Peter Jan</p> <p>2015-04-01</p> <p>In recent years particle <span class="hlt">filters</span> have matured and several variants are now available that are not degenerate for high-dimensional systems. Often they are based on ad-hoc combinations with Ensemble Kalman <span class="hlt">Filters</span>. Unfortunately it is unclear what approximations are made when these hybrids are used. The proper way to derive particle <span class="hlt">filters</span> for high-dimensional systems is exploring the freedom in the proposal density. It is well known that using an Ensemble Kalman <span class="hlt">Filter</span> as proposal density (the so-called Weighted Ensemble Kalman <span class="hlt">Filter</span>) does not work for high-dimensional systems. However, much better results are obtained when weak-constraint 4Dvar is used as proposal, leading to the implicit particle <span class="hlt">filter</span>. Still this <span class="hlt">filter</span> is degenerate when the number of independent observations is large. The Equivalent-Weights Particle <span class="hlt">Filter</span> is a <span class="hlt">filter</span> that works well in systems of arbitrary dimensions, but it contains a few tuning parameters that have to be chosen well to avoid biases. In this paper we discuss ways to derive more robust particle <span class="hlt">filters</span> for high-dimensional systems. Using ideas from large-deviation theory and <span class="hlt">optimal</span> transportation particle <span class="hlt">filters</span> will be generated that are robust and work well in these systems. It will be shown that all successful <span class="hlt">filters</span> can be derived from one general framework. Also, the performance of the <span class="hlt">filters</span> will be tested on simple but high-dimensional systems, and, if time permits, on a high-dimensional highly nonlinear barotropic vorticity equation model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ITSP...65.1644H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ITSP...65.1644H"><span><span class="hlt">Filter</span> Design for Generalized Frequency-Division Multiplexing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Han, Seungyul; Sung, Youngchul; Lee, Yong H.</p> <p>2017-04-01</p> <p>In this paper, <span class="hlt">optimal</span> <span class="hlt">filter</span> design for generalized frequency-division multiplexing (GFDM) is considered under two design criteria: rate maximization and out-of-band (OOB) emission minimization. First, the problem of GFDM <span class="hlt">filter</span> <span class="hlt">optimization</span> for rate maximization is formulated by expressing the transmission rate of GFDM as a function of GFDM <span class="hlt">filter</span> coefficients. It is shown that Dirichlet <span class="hlt">filters</span> are rate-<span class="hlt">optimal</span> in additive white Gaussian noise (AWGN) channels with no carrier frequency offset (CFO) under linear zero-forcing (ZF) or minimum mean-square error (MMSE) receivers, but in general channels perturbed by CFO a properly designed nontrivial GFDM <span class="hlt">filter</span> can yield better performance than Dirichlet <span class="hlt">filters</span> by adjusting the subcarrier waveform to cope with the channel-induced CFO. Next, the problem of GFDM <span class="hlt">filter</span> design for OOB emission minimization is formulated by expressing the power spectral density (PSD) of the GFDM transmit signal as a function of GFDM <span class="hlt">filter</span> coefficients, and it is shown that the OOB emission can be reduced significantly by designing the GFDM <span class="hlt">filter</span> properly. Finally, joint design of GFDM <span class="hlt">filter</span> and window for the two design criteria is considered.</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>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://hdl.handle.net/2060/19950010874','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950010874"><span>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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=243916','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=243916"><span>Detection of Escherichia coli in Foods: Indole Staining Methods for Cellulosic and Polysulfone Membrane <span class="hlt">Filters</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>Sharpe, Anthony N.; Peterkin, Pearl I.; Rayman, M. Khalil</p> <p>1981-01-01</p> <p><span class="hlt">Optimized</span> procedures for staining Escherichia coli colonies on cellulosic and polysulfone membrane <span class="hlt">filters</span> are described. An explanation for the behavior of the Ehrlich reaction on membrane <span class="hlt">filters</span> is suggested. Images PMID:6166249</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>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://adsabs.harvard.edu/abs/2017AIPC.1798b0157S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1798b0157S"><span>A unified 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>Stubberud, Allen R.</p> <p>2017-01-01</p> <p>When considering problems of linear sequential estimation, two versions of the Kalman <span class="hlt">filter</span>, the continuous-time version and the discrete-time version, are often used. (A hybrid <span class="hlt">filter</span> also exists.) In many applications in which the Kalman <span class="hlt">filter</span> is used, the system to which the <span class="hlt">filter</span> is applied is a linear continuous-time system, but the Kalman <span class="hlt">filter</span> is implemented on a digital computer, a discrete-time device. The two general approaches for developing a discrete-time <span class="hlt">filter</span> for implementation on a digital computer are: (1) approximate the continuous-time system by a discrete-time system (called discretization of the continuous-time system) and develop a <span class="hlt">filter</span> for the discrete-time approximation; and (2) develop a continuous-time <span class="hlt">filter</span> for the system and then discretize the continuous-time <span class="hlt">filter</span>. Generally, the two discrete-time <span class="hlt">filters</span> will be different, that is, it can be said that discretization and <span class="hlt">filter</span> generation are not, in general, commutative operations. As a result, any relationship between the discrete-time and continuous-time versions of the <span class="hlt">filter</span> for the same continuous-time system is often obfuscated. This is particularly true when an attempt is made to generate the continuous-time version of the Kalman <span class="hlt">filter</span> through a simple limiting process (the sample period going to zero) applied to the discrete-time version. The correct result is, generally, not obtained. In a 1961 research report, Kalman showed that the continuous-time Kalman <span class="hlt">filter</span> can be obtained from the discrete-time Kalman <span class="hlt">filter</span> by taking limits as the sample period goes to zero if the white noise process for the continuous-time version is appropriately defined. Using this basic concept, a discrete-time Kalman <span class="hlt">filter</span> can be developed for a continuous-time system as follows: (1) discretize the continuous-time system using Kalman's technique; and (2) develop a discrete-time Kalman <span class="hlt">filter</span> for that discrete-time system. Kalman's results show that the discrete-time <span class="hlt">filter</span> generated in</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><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://adsabs.harvard.edu/abs/2016MeScT..27b5001Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MeScT..27b5001Z"><span>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</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGE....13..412R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGE....13..412R"><span>VSP wave separation by adaptive masking <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>Rao, Ying; Wang, Yanghua</p> <p>2016-06-01</p> <p>In vertical seismic profiling (VSP) data processing, the first <span class="hlt">step</span> might be to separate the down-going wavefield from the up-going wavefield. When using a masking <span class="hlt">filter</span> for VSP wave separation, there are difficulties associated with two termination ends of the up-going waves. A critical challenge is how the masking <span class="hlt">filter</span> can restore the energy tails, the edge effect associated with these terminations uniquely exist in VSP data. An effective strategy is to implement masking <span class="hlt">filters</span> in both τ-p and f-k domain sequentially. Meanwhile it uses a median <span class="hlt">filter</span>, producing a clean but smooth version of the down-going wavefield, used as a reference data set for designing the masking <span class="hlt">filter</span>. The masking <span class="hlt">filter</span> is implemented adaptively and iteratively, gradually restoring the energy tails cut-out by any surgical mute. While the τ-p and the f-k domain masking <span class="hlt">filters</span> target different depth ranges of VSP, this combination strategy can accurately perform in wave separation from field VSP data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22095302','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22095302"><span>Truncation correction for oblique <span class="hlt">filtering</span> lines</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hoppe, Stefan; Hornegger, Joachim; Lauritsch, Guenter; Dennerlein, Frank; Noo, Frederic</p> <p>2008-12-15</p> <p>State-of-the-art <span class="hlt">filtered</span> backprojection (FBP) algorithms often define the <span class="hlt">filtering</span> operation to be performed along oblique <span class="hlt">filtering</span> lines in the detector. A limited scan field of view leads to the truncation of those <span class="hlt">filtering</span> lines, which causes artifacts in the final reconstructed volume. In contrast to the case where <span class="hlt">filtering</span> is performed solely along the detector rows, no methods are available for the case of oblique <span class="hlt">filtering</span> lines. In this work, the authors present two novel truncation correction methods which effectively handle data truncation in this case. Method 1 (basic approach) handles data truncation in two successive preprocessing <span class="hlt">steps</span> by applying a hybrid data extrapolation method, which is a combination of a water cylinder extrapolation and a Gaussian extrapolation. It is independent of any specific reconstruction algorithm. Method 2 (kink approach) uses similar concepts for data extrapolation as the basic approach but needs to be integrated into the reconstruction algorithm. Experiments are presented from simulated data of the FORBILD head phantom, acquired along a partial-circle-plus-arc trajectory. The theoretically exact M-line algorithm is used for reconstruction. Although the discussion is focused on theoretically exact algorithms, the proposed truncation correction methods can be applied to any FBP algorithm that exposes oblique <span class="hlt">filtering</span> lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19175146','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19175146"><span>Truncation correction for oblique <span class="hlt">filtering</span> lines.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hoppe, Stefan; Hornegger, Joachim; Lauritsch, Günter; Dennerlein, Frank; Noo, Frédéric</p> <p>2008-12-01</p> <p>State-of-the-art <span class="hlt">filtered</span> backprojection (FBP) algorithms often define the <span class="hlt">filtering</span> operation to be performed along oblique <span class="hlt">filtering</span> lines in the detector. A limited scan field of view leads to the truncation of those <span class="hlt">filtering</span> lines, which causes artifacts in the final reconstructed volume. In contrast to the case where <span class="hlt">filtering</span> is performed solely along the detector rows, no methods are available for the case of oblique <span class="hlt">filtering</span> lines. In this work, the authors present two novel truncation correction methods which effectively handle data truncation in this case. Method 1 (basic approach) handles data truncation in two successive preprocessing <span class="hlt">steps</span> by applying a hybrid data extrapolation method, which is a combination of a water cylinder extrapolation and a Gaussian extrapolation. It is independent of any specific reconstruction algorithm. Method 2 (kink approach) uses similar concepts for data extrapolation as the basic approach but needs to be integrated into the reconstruction algorithm. Experiments are presented from simulated data of the FORBILD head phantom, acquired along a partial-circle-plus-arc trajectory. The theoretically exact M-line algorithm is used for reconstruction. Although the discussion is focused on theoretically exact algorithms, the proposed truncation correction methods can be applied to any FBP algorithm that exposes oblique <span class="hlt">filtering</span> lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22225991','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22225991"><span>Use of astronomy <span class="hlt">filters</span> in fluorescence microscopy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Piper, Jörg</p> <p>2012-02-01</p> <p>Monochrome astronomy <span class="hlt">filters</span> are well suited for use as excitation or suppression <span class="hlt">filters</span> in fluorescence microscopy. Because of their particular optical design, such <span class="hlt">filters</span> can be combined with standard halogen light sources for excitation in many fluorescent probes. In this "low energy excitation," photobleaching (fading) or other irritations of native specimens are avoided. Photomicrographs can be taken from living motile fluorescent specimens also with a flash so that fluorescence images can be created free from indistinctness caused by movement. Special <span class="hlt">filter</span> cubes or dichroic mirrors are not needed for our method. By use of suitable astronomy <span class="hlt">filters</span>, fluorescence microscopy can be carried out with standard laboratory microscopes equipped with condensers for bright-field (BF) and dark-field (DF) illumination in transmitted light. In BF excitation, the background brightness can be modulated in tiny <span class="hlt">steps</span> up to dark or black. Moreover, standard industry microscopes fitted with a vertical illuminator for examinations of opaque probes in DF or BF illumination based on incident light (wafer inspections, for instance) can also be used for excitation in epi-illumination when adequate astronomy <span class="hlt">filters</span> are inserted as excitatory and suppression <span class="hlt">filters</span> in the illuminating and imaging light path. In all variants, transmission bands can be modulated by transmission shift.</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>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/450754','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/450754"><span>Ceramic fiber <span class="hlt">filter</span> technology</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>1996-06-01</p> <p>Fibrous <span class="hlt">filters</span> have been used for centuries to protect individuals from dust, disease, smoke, and other gases or particulates. In the 1970s and 1980s ceramic <span class="hlt">filters</span> were developed for filtration of hot exhaust gases from diesel engines. Tubular, or candle, <span class="hlt">filters</span> have been made to remove particles from gases in pressurized fluidized-bed combustion and gasification-combined-cycle power plants. Very efficient filtration is necessary in power plants to protect the turbine blades. The limited lifespan of ceramic candle <span class="hlt">filters</span> has been a major obstacle in their development. The present work is focused on forming fibrous ceramic <span class="hlt">filters</span> using a papermaking technique. These <span class="hlt">filters</span> are highly porous and therefore very lightweight. The papermaking process consists of <span class="hlt">filtering</span> a slurry of ceramic fibers through a steel screen to form paper. Papermaking and the selection of materials will be discussed, as well as preliminary results describing the geometry of papers and relative strengths.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995SPIE.2565..124K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995SPIE.2565..124K"><span>Fast algorithm for calculating optical binary amplitude <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>Knopp, Jerome; Matalgah, Mustafa M.</p> <p>1995-08-01</p> <p>A new geometric viewpoint is presented for <span class="hlt">optimizing</span> a binary amplitude <span class="hlt">filter</span> based on finding an ordered set of phasors, the uncoiled phasor set (UPS), from the <span class="hlt">filter</span> object's discrete Fourier transform that determines a convex polygon. The maximum distance across the polygon determines the value of the correlation peak and the set of frequencies that the <span class="hlt">optimal</span> <span class="hlt">filter</span> should pass. Algorithms are presented for finding the UPS and the maximum distance across the polygon that are competititve with <span class="hlt">optimization</span> approaches that use the binning (Farn and Goodman). The new viewpoint provides a simple way to establish a bound on binning error.</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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