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Sample records for optimized particle filter

  1. 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.

  2. Design of reflective color filters with high angular tolerance by particle swarm optimization method.

    PubMed

    Yang, Chenying; Hong, Liang; Shen, Weidong; Zhang, Yueguang; Liu, Xu; Zhen, Hongyu

    2013-04-22

    We propose three color filters (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 optimization (PSO) method is employed to design these filters 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 optimization procedure. Three primary color filters 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.

  3. Optimizing Parameters of Process-Based Terrestrial Ecosystem Model with Particle Filter

    NASA Astrophysics Data System (ADS)

    Ito, A.

    2014-12-01

    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 filter (or Sequential Monte Carlo filer) to optimize parameters of a process-based terrestrial ecosystem model (VISIT). The Particle filter 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 filter 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 steps were used to optimize 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 filter is an effective method of data-assimilation for process-based models, enhancing collaboration between field and model researchers.

  4. An Optimal Observing System Study for the Kuroshio Extension using Particle Filters

    NASA Astrophysics Data System (ADS)

    Kramer, Werner; van Leeuwen, Peter Jan; Pierieni, Stefano; Dijkstra, Henk

    2010-05-01

    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 filters 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 filter 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 filter, different sets of observations, e.g. with different geometrical configurations, locations and/or time resolutions, can be analyzed a posteriori. The particle filter 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

  5. Optimization of integrated polarization filters.

    PubMed

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

    2014-10-01

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

  6. Towards robust particle filters for high-dimensional systems

    NASA Astrophysics Data System (ADS)

    van Leeuwen, Peter Jan

    2015-04-01

    In recent years particle filters 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 Filters. Unfortunately it is unclear what approximations are made when these hybrids are used. The proper way to derive particle filters for high-dimensional systems is exploring the freedom in the proposal density. It is well known that using an Ensemble Kalman Filter as proposal density (the so-called Weighted Ensemble Kalman Filter) 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 filter. Still this filter is degenerate when the number of independent observations is large. The Equivalent-Weights Particle Filter is a filter 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 filters for high-dimensional systems. Using ideas from large-deviation theory and optimal transportation particle filters will be generated that are robust and work well in these systems. It will be shown that all successful filters can be derived from one general framework. Also, the performance of the filters will be tested on simple but high-dimensional systems, and, if time permits, on a high-dimensional highly nonlinear barotropic vorticity equation model.

  7. Particle Swarm Optimization

    NASA Technical Reports Server (NTRS)

    Venter, Gerhard; Sobieszczanski-Sobieski Jaroslaw

    2002-01-01

    The purpose of this paper is to show how the search algorithm known as particle swarm optimization performs. Here, particle swarm optimization is applied to structural design problems, but the method has a much wider range of possible applications. The paper's new contributions are improvements to the particle swarm optimization algorithm and conclusions and recommendations as to the utility of the algorithm, Results of numerical experiments for both continuous and discrete applications are presented in the paper. The results indicate that the particle swarm optimization algorithm does locate the constrained minimum design in continuous applications with very good precision, albeit at a much higher computational cost than that of a typical gradient based optimizer. However, the true potential of particle swarm optimization is primarily in applications with discrete and/or discontinuous functions and variables. Additionally, particle swarm optimization has the potential of efficient computation with very large numbers of concurrently operating processors.

  8. Gaussian particle flow implementation of PHD filter

    NASA Astrophysics Data System (ADS)

    Zhao, Lingling; Wang, Junjie; Li, Yunpeng; Coates, Mark J.

    2016-05-01

    Particle filter and Gaussian mixture implementations of random finite set filters have been proposed to tackle the issue of jointly estimating the number of targets and their states. The Gaussian mixture PHD (GM-PHD) filter has a closed-form expression for the PHD for linear and Gaussian target models, and extensions using the extended Kalman filter or unscented Kalman Filter have been developed to allow the GM-PHD filter to accommodate mildly nonlinear dynamics. Errors resulting from linearization or model mismatch are unavoidable. A particle filter implementation of the PHD filter (PF-PHD) is more suitable for nonlinear and non-Gaussian target models. The particle filter implementations are much more computationally expensive and performance can suffer when the proposal distribution is not a good match to the posterior. In this paper, we propose a novel implementation of the PHD filter named the Gaussian particle flow PHD filter (GPF-PHD). It employs a bank of particle flow filters to approximate the PHD; these play the same role as the Gaussian components in the GM-PHD filter but are better suited to non-linear dynamics and measurement equations. Using the particle flow filter allows the GPF-PHD filter to migrate particles to the dense regions of the posterior, which leads to higher efficiency than the PF-PHD. We explore the performance of the new algorithm through numerical simulations.

  9. State estimation in large-scale open channel networks using sequential Monte Carlo methods: Optimal sampling importance resampling and implicit particle filters

    NASA Astrophysics Data System (ADS)

    Rafiee, Mohammad; Barrau, Axel; Bayen, Alexandre M.

    2013-06-01

    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 optimal sampling importance resampling filter to perform state estimation in a case in which measurements are available at every time step. Considering a case in which measurements become available intermittently, a random-map implementation of the implicit particle filter 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 step, we apply the implicit particle filter 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.

  10. Westinghouse Advanced Particle Filter System

    SciTech Connect

    Lippert, T.E.; Bruck, G.J.; Sanjana, Z.N.; Newby, R.A.; Bachovchin, D.M.

    1996-12-31

    Integrated Gasification Combined Cycles (IGCC) and Pressurized Fluidized Bed Combustion (PFBC) are being developed and demonstrated for commercial, power generation application. Hot gas particulate filters are key components for the successful implementation of IGCC and PFBC in power generation gas turbine cycles. The objective of this work is to develop and qualify through analysis and testing a practical hot gas ceramic barrier filter system that meets the performance and operational requirements of PFBC and IGCC systems. This paper reports on the development and status of testing of the Westinghouse Advanced Hot Gas Particle Filter (W-APF) including: W-APF integrated operation with the American Electric Power, 70 MW PFBC clean coal facility--approximately 6000 test hours completed; approximately 2500 hours of testing at the Hans Ahlstrom 10 MW PCFB facility located in Karhula, Finland; over 700 hours of operation at the Foster Wheeler 2 MW 2nd generation PFBC facility located in Livingston, New Jersey; status of Westinghouse HGF supply for the DOE Southern Company Services Power System Development Facility (PSDF) located in Wilsonville, Alabama; the status of the Westinghouse development and testing of HGF`s for Biomass Power Generation; and the status of the design and supply of the HGF unit for the 95 MW Pinon Pine IGCC Clean Coal Demonstration.

  11. Particle Swarm Optimization Toolbox

    NASA Technical Reports Server (NTRS)

    Grant, Michael J.

    2010-01-01

    The Particle Swarm Optimization Toolbox is a library of evolutionary optimization tools developed in the MATLAB environment. The algorithms contained in the library include a genetic algorithm (GA), a single-objective particle swarm optimizer (SOPSO), and a multi-objective particle swarm optimizer (MOPSO). Development focused on both the SOPSO and MOPSO. A GA was included mainly for comparison purposes, and the particle swarm optimizers appeared to perform better for a wide variety of optimization problems. All algorithms are capable of performing unconstrained and constrained optimization. The particle swarm optimizers are capable of performing single and multi-objective optimization. The SOPSO and MOPSO algorithms are based on swarming theory and bird-flocking patterns to search the trade space for the optimal solution or optimal trade in competing objectives. The MOPSO generates Pareto fronts for objectives that are in competition. A GA, based on Darwin evolutionary theory, is also included in the library. The GA consists of individuals that form a population in the design space. The population mates to form offspring at new locations in the design space. These offspring contain traits from both of the parents. The algorithm is based on this combination of traits from parents to hopefully provide an improved solution than either of the original parents. As the algorithm progresses, individuals that hold these optimal traits will emerge as the optimal solutions. Due to the generic design of all optimization algorithms, each algorithm interfaces with a user-supplied objective function. This function serves as a "black-box" to the optimizers in which the only purpose of this function is to evaluate solutions provided by the optimizers. Hence, the user-supplied function can be numerical simulations, analytical functions, etc., since the specific detail of this function is of no concern to the optimizer. These algorithms were originally developed to support entry

  12. System and Apparatus for Filtering Particles

    NASA Technical Reports Server (NTRS)

    Agui, Juan H. (Inventor); Vijayakumar, Rajagopal (Inventor)

    2015-01-01

    A modular pre-filtration apparatus may be beneficial to extend the life of a filter. The apparatus may include an impactor that can collect a first set of particles in the air, and a scroll filter that can collect a second set of particles in the air. A filter may follow the pre-filtration apparatus, thus causing the life of the filter to be increased.

  13. Angle only tracking with particle flow filters

    NASA Astrophysics Data System (ADS)

    Daum, Fred; Huang, Jim

    2011-09-01

    We show the results of numerical experiments for tracking ballistic missiles using only angle measurements. We compare the performance of an extended Kalman filter with a new nonlinear filter using particle flow to compute Bayes' rule. For certain difficult geometries, the particle flow filter is an order of magnitude more accurate than the EKF. Angle only tracking is of interest in several different sensors; for example, passive optics and radars in which range and Doppler data are spoiled by jamming.

  14. 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

  15. Depth Filters Containing Diatomite Achieve More Efficient Particle Retention than Filters Solely Containing Cellulose Fibers

    PubMed Central

    Buyel, Johannes F.; Gruchow, Hannah M.; Fischer, Rainer

    2015-01-01

    The clarification of biological feed stocks during the production of biopharmaceutical proteins is challenging when large quantities of particles must be removed, e.g., when processing crude plant extracts. Single-use depth filters are often preferred for clarification because they are simple to integrate and have a good safety profile. However, the combination of filter layers must be optimized in terms of nominal retention ratings to account for the unique particle size distribution in each feed stock. We have recently shown that predictive models can facilitate filter screening and the selection of appropriate filter layers. Here we expand our previous study by testing several filters with different retention ratings. The filters typically contain diatomite to facilitate the removal of fine particles. However, diatomite can interfere with the recovery of large biopharmaceutical molecules such as virus-like particles and aggregated proteins. Therefore, we also tested filtration devices composed solely of cellulose fibers and cohesive resin. The capacities of both filter types varied from 10 to 50 L m−2 when challenged with tobacco leaf extracts, but the filtrate turbidity was ~500-fold lower (~3.5 NTU) when diatomite filters were used. We also tested pre–coat filtration with dispersed diatomite, which achieved capacities of up to 120 L m−2 with turbidities of ~100 NTU using bulk plant extracts, and in contrast to the other depth filters did not require an upstream bag filter. Single pre-coat filtration devices can thus replace combinations of bag and depth filters to simplify the processing of plant extracts, potentially saving on time, labor and consumables. The protein concentrations of TSP, DsRed and antibody 2G12 were not affected by pre-coat filtration, indicating its general applicability during the manufacture of plant-derived biopharmaceutical proteins. PMID:26734037

  16. Particle filtering for passive fathometer tracking.

    PubMed

    Michalopoulou, Zoi-Heleni; Yardim, Caglar; Gerstoft, Peter

    2012-01-01

    Seabed interface depths and fathometer amplitudes are tracked for an unknown and changing number of sub-bottom reflectors. This is achieved by incorporating conventional and adaptive fathometer processors into sequential Monte Carlo methods for a moving vertical line array. Sediment layering information and time-varying fathometer response amplitudes are tracked by using a multiple model particle filter with an uncertain number of reflectors. Results are compared to a classical particle filter where the number of reflectors is considered to be known. Reflector tracking is demonstrated for both conventional and adaptive processing applied to the drifting array data from the Boundary 2003 experiment. The layering information is successfully tracked by the multiple model particle filter even for noisy fathometer outputs.

  17. Quantitative filter forensics for indoor particle sampling.

    PubMed

    Haaland, D; Siegel, J A

    2017-03-01

    Filter forensics is a promising indoor air investigation technique involving the analysis of dust which has collected on filters in central forced-air heating, ventilation, and air conditioning (HVAC) or portable systems to determine the presence of indoor particle-bound contaminants. In this study, we summarize past filter forensics research to explore what it reveals about the sampling technique and the indoor environment. There are 60 investigations in the literature that have used this sampling technique for a variety of biotic and abiotic contaminants. Many studies identified differences between contaminant concentrations in different buildings using this technique. Based on this literature review, we identified a lack of quantification as a gap in the past literature. Accordingly, we propose an approach to quantitatively link contaminants extracted from HVAC filter dust to time-averaged integrated air concentrations. This quantitative filter forensics approach has great potential to measure indoor air concentrations of a wide variety of particle-bound contaminants. Future studies directly comparing quantitative filter forensics to alternative sampling techniques are required to fully assess this approach, but analysis of past research suggests the enormous possibility of this approach.

  18. 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.

  19. Analyzing Meteoroid Flights Using Particle Filters

    NASA Astrophysics Data System (ADS)

    Sansom, E. K.; Rutten, M. G.; Bland, P. A.

    2017-02-01

    Fireball observations from camera networks provide position and time information along the trajectory of a meteoroid that is transiting our atmosphere. The complete dynamical state of the meteoroid at each measured time can be estimated using Bayesian filtering techniques. A particle filter is a novel approach to modeling the uncertainty in meteoroid trajectories and incorporates errors in initial parameters, the dynamical model used, and observed position measurements. Unlike other stochastic approaches, a particle filter does not require predefined values for initial conditions or unobservable trajectory parameters. The Bunburra Rockhole fireball, observed by the Australian Desert Fireball Network (DFN) in 2007, is used to determine the effectiveness of a particle filter for use in fireball trajectory modeling. The final mass is determined to be 2.16+/- 1.33 {kg} with a final velocity of 6030+/- 216 {{m}} {{{s}}}-1, similar to previously calculated values. The full automatability of this approach will allow an unbiased evaluation of all events observed by the DFN and lead to a better understanding of the dynamical state and size frequency distribution of asteroid and cometary debris in the inner solar system.

  20. Ultrasonic tracking of shear waves using a particle filter

    PubMed Central

    Ingle, Atul N.; Ma, Chi; Varghese, Tomy

    2015-01-01

    Purpose: This paper discusses an application of particle filtering for estimating shear wave velocity in tissue using ultrasound elastography data. Shear wave velocity estimates are of significant clinical value as they help differentiate stiffer areas from softer areas which is an indicator of potential pathology. Methods: Radio-frequency ultrasound echo signals are used for tracking axial displacements and obtaining the time-to-peak displacement at different lateral locations. These time-to-peak data are usually very noisy and cannot be used directly for computing velocity. In this paper, the denoising problem is tackled using a hidden Markov model with the hidden states being the unknown (noiseless) time-to-peak values. A particle filter is then used for smoothing out the time-to-peak curve to obtain a fit that is optimal in a minimum mean squared error sense. Results: Simulation results from synthetic data and finite element modeling suggest that the particle filter provides lower mean squared reconstruction error with smaller variance as compared to standard filtering methods, while preserving sharp boundary detail. Results from phantom experiments show that the shear wave velocity estimates in the stiff regions of the phantoms were within 20% of those obtained from a commercial ultrasound scanner and agree with estimates obtained using a standard method using least-squares fit. Estimates of area obtained from the particle filtered shear wave velocity maps were within 10% of those obtained from B-mode ultrasound images. Conclusions: The particle filtering approach can be used for producing visually appealing SWV reconstructions by effectively delineating various areas of the phantom with good image quality properties comparable to existing techniques. PMID:26520761

  1. 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.

  2. 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.

  3. 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.

  4. Point Set Registration via Particle Filtering and Stochastic Dynamics

    PubMed Central

    Sandhu, Romeil; Dambreville, Samuel; Tannenbaum, Allen

    2013-01-01

    In this paper, we propose a particle filtering approach for the problem of registering two point sets that differ by a rigid body transformation. Typically, registration algorithms compute the transformation parameters by maximizing a metric given an estimate of the correspondence between points across the two sets of interest. This can be viewed as a posterior estimation problem, in which the corresponding distribution can naturally be estimated using a particle filter. In this work, we treat motion as a local variation in pose parameters obtained by running a few iterations of a certain local optimizer. Employing this idea, we introduce stochastic motion dynamics to widen the narrow band of convergence often found in local optimizer approaches for registration. Thus, the novelty of our method is threefold: First, we employ a particle filtering scheme to drive the point set registration process. Second, we present a local optimizer that is motivated by the correlation measure. Third, we increase the robustness of the registration performance by introducing a dynamic model of uncertainty for the transformation parameters. In contrast with other techniques, our approach requires no annealing schedule, which results in a reduction in computational complexity (with respect to particle size) as well as maintains the temporal coherency of the state (no loss of information). Also unlike some alternative approaches for point set registration, we make no geometric assumptions on the two data sets. Experimental results are provided that demonstrate the robustness of the algorithm to initialization, noise, missing structures, and/or differing point densities in each set, on several challenging 2D and 3D registration scenarios. PMID:20558877

  5. 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.

  6. 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

  7. Incremental Particle Swarm Optimization

    NASA Astrophysics Data System (ADS)

    Xu, Xiaohua; Pan, Zhoujin; Xi, Yanqiu; Chen, Ling

    By simulating the population size of the human evolution, a PSO algorithm with increment of particle size (IPPSO) was proposed. Without changing the PSO operations, IPPSO can obtain better solutions with less time cost by modifying the structure of traditional PSO. Experimental results show that IPPSO using logistic model is more efficient and requires less computation time than using linear function in solving more complex program problems.

  8. Groupwise surface correspondence using particle filtering

    NASA Astrophysics Data System (ADS)

    Li, Guangxu; Kim, Hyoungseop; Tan, Joo Kooi; Ishikawa, Seiji

    2015-03-01

    To obtain an effective interpretation of organic shape using statistical shape models (SSMs), the correspondence of the landmarks through all the training samples is the most challenging part in model building. In this study, a coarse-tofine groupwise correspondence method for 3-D polygonal surfaces is proposed. We manipulate a reference model in advance. Then all the training samples are mapped to a unified spherical parameter space. According to the positions of landmarks of the reference model, the candidate regions for correspondence are chosen. Finally we refine the perceptually correct correspondences between landmarks using particle filter algorithm, where the likelihood of local surface features are introduced as the criterion. The proposed method was performed on the correspondence of 9 cases of left lung training samples. Experimental results show the proposed method is flexible and under-constrained.

  9. State estimation and prediction using clustered particle filters

    PubMed Central

    Lee, Yoonsang; Majda, Andrew J.

    2016-01-01

    Particle filtering is an essential tool to improve uncertain model predictions by incorporating noisy observational data from complex systems including non-Gaussian features. A class of particle filters, clustered particle filters, is introduced for high-dimensional nonlinear systems, which uses relatively few particles compared with the standard particle filter. The clustered particle filter captures non-Gaussian features of the true signal, which are typical in complex nonlinear dynamical systems such as geophysical systems. The method is also robust in the difficult regime of high-quality sparse and infrequent observations. The key features of the clustered particle filtering are coarse-grained localization through the clustering of the state variables and particle adjustment to stabilize the method; each observation affects only neighbor state variables through clustering and particles are adjusted to prevent particle collapse due to high-quality observations. The clustered particle filter is tested for the 40-dimensional Lorenz 96 model with several dynamical regimes including strongly non-Gaussian statistics. The clustered particle filter shows robust skill in both achieving accurate filter results and capturing non-Gaussian statistics of the true signal. It is further extended to multiscale data assimilation, which provides the large-scale estimation by combining a cheap reduced-order forecast model and mixed observations of the large- and small-scale variables. This approach enables the use of a larger number of particles due to the computational savings in the forecast model. The multiscale clustered particle filter is tested for one-dimensional dispersive wave turbulence using a forecast model with model errors. PMID:27930332

  10. Comparative evaluation of ensemble Kalman filter, particle filter and variational techniques for river discharge forecast

    NASA Astrophysics Data System (ADS)

    Hirpa, F. A.; Gebremichael, M.; LEE, H.; Hopson, T. M.

    2012-12-01

    Hydrologic data assimilation techniques provide a means to improve river discharge forecasts through updating hydrologic model states and correcting the atmospheric forcing data via optimally combining model outputs with observations. The performance of the assimilation procedure, however, depends on the data assimilation techniques used and the amount of uncertainty in the data sets. To investigate the effects of these, we comparatively evaluate three data assimilation techniques, including ensemble Kalman filter (EnKF), particle filter (PF) and variational (VAR) technique, which assimilate discharge and synthetic soil moisture data at various uncertainty levels into the Sacramento Soil Moisture accounting (SAC-SMA) model used by the National Weather Service (NWS) for river forecasting in The United States. The study basin is Greens Bayou watershed with area of 178 km2 in eastern Texas. In the presentation, we summarize the results of the comparisons, and discuss the challenges of applying each technique for hydrologic applications.

  11. A backtracking algorithm that deals with particle filter degeneracy

    NASA Astrophysics Data System (ADS)

    Baarsma, Rein; Schmitz, Oliver; Karssenberg, Derek

    2016-04-01

    Particle filters are an excellent way to deal with stochastic models incorporating Bayesian data assimilation. While they are computationally demanding, the particle filter has no problem with nonlinearity and it accepts non-Gaussian observational data. In the geoscientific field it is this computational demand that creates a problem, since dynamic grid-based models are often already quite computationally demanding. As such it is of the utmost importance to keep the amount of samples in the filter as small as possible. Small sample populations often lead to filter degeneracy however, especially in models with high stochastic forcing. Filter degeneracy renders the sample population useless, as the population is no longer statistically informative. We have created an algorithm in an existing data assimilation framework that reacts to and deals with filter degeneracy based on Spiller et al. [2008]. During the Bayesian updating step of the standard particle filter, the algorithm tests the sample population for filter degeneracy. If filter degeneracy has occurred, the algorithm resets to the last time the filter did work correctly and recalculates the failed timespan of the filter with an increased sample population. The sample population is then reduced to its original size and the particle filter continues as normal. This algorithm was created in the PCRaster Python framework, an open source tool that enables spatio-temporal forward modelling in Python [Karssenberg et al., 2010] . The framework already contains several data assimilation algorithms, including a standard particle filter and a Kalman filter. The backtracking particle filter algorithm has been added to the framework, which will make it easy to implement in other research. The performance of the backtracking particle filter is tested against a standard particle filter using two models. The first is a simple nonlinear point model, and the second is a more complex geophysical model. The main testing

  12. A Parallel Particle Swarm Optimizer

    DTIC Science & Technology

    2003-01-01

    by a computationally demanding biomechanical system identification problem, we introduce a parallel implementation of a stochastic population based...concurrent computation. The parallelization of the Particle Swarm Optimization (PSO) algorithm is detailed and its performance and characteristics demonstrated for the biomechanical system identification problem as example.

  13. 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

  14. Blended particle filters for large-dimensional chaotic dynamical systems.

    PubMed

    Majda, Andrew J; Qi, Di; Sapsis, Themistoklis P

    2014-05-27

    A major challenge in contemporary data science is the development of statistically accurate particle filters to capture non-Gaussian features in large-dimensional chaotic dynamical systems. Blended particle filters that capture non-Gaussian features in an adaptively evolving low-dimensional subspace through particles interacting with evolving Gaussian statistics on the remaining portion of phase space are introduced here. These blended particle filters are constructed in this paper through a mathematical formalism involving conditional Gaussian mixtures combined with statistically nonlinear forecast models compatible with this structure developed recently with high skill for uncertainty quantification. Stringent test cases for filtering involving the 40-dimensional Lorenz 96 model with a 5-dimensional adaptive subspace for nonlinear blended filtering in various turbulent regimes with at least nine positive Lyapunov exponents are used here. These cases demonstrate the high skill of the blended particle filter algorithms in capturing both highly non-Gaussian dynamical features as well as crucial nonlinear statistics for accurate filtering in extreme filtering regimes with sparse infrequent high-quality observations. The formalism developed here is also useful for multiscale filtering of turbulent systems and a simple application is sketched below.

  15. Motion-compensated speckle tracking via particle filtering

    NASA Astrophysics Data System (ADS)

    Liu, Lixin; Yagi, Shin-ichi; Bian, Hongyu

    2015-07-01

    Recently, an improved motion compensation method that uses the sum of absolute differences (SAD) has been applied to frame persistence utilized in conventional ultrasonic imaging because of its high accuracy and relative simplicity in implementation. However, high time consumption is still a significant drawback of this space-domain method. To seek for a more accelerated motion compensation method and verify if it is possible to eliminate conventional traversal correlation, motion-compensated speckle tracking between two temporally adjacent B-mode frames based on particle filtering is discussed. The optimal initial density of particles, the least number of iterations, and the optimal transition radius of the second iteration are analyzed from simulation results for the sake of evaluating the proposed method quantitatively. The speckle tracking results obtained using the optimized parameters indicate that the proposed method is capable of tracking the micromotion of speckle throughout the region of interest (ROI) that is superposed with global motion. The computational cost of the proposed method is reduced by 25% compared with that of the previous algorithm and further improvement is necessary.

  16. Modular particle filtering FPGA hardware architecture for brain machine interfaces.

    PubMed

    Mountney, John; Obeid, Iyad; Silage, Dennis

    2011-01-01

    As the computational complexities of neural decoding algorithms for brain machine interfaces (BMI) increase, their implementation through sequential processors becomes prohibitive for real-time applications. This work presents the field programmable gate array (FPGA) as an alternative to sequential processors for BMIs. The reprogrammable hardware architecture of the FPGA provides a near optimal platform for performing parallel computations in real-time. The scalability and reconfigurability of the FPGA accommodates diverse sets of neural ensembles and a variety of decoding algorithms. Throughput is significantly increased by decomposing computations into independent parallel hardware modules on the FPGA. This increase in throughput is demonstrated through a parallel hardware implementation of the auxiliary particle filtering signal processing algorithm.

  17. Symmetric Phase-Only Filtering in Particle-Image Velocimetry

    NASA Technical Reports Server (NTRS)

    Wemet, Mark P.

    2008-01-01

    and second- image subregions are normalized by the square roots of their respective magnitudes. This scheme yields optimal performance because the amounts of normalization applied to the spatial-frequency contents of the input and filter scenes are just enough to enhance their high-spatial-frequency contents while reducing their spurious low-spatial-frequency content. As a result, in SPOF PIV processing, particle-displacement correlation peaks can readily be detected above spurious background peaks, without need for masking or background subtraction.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Application of the implicit particle filter to a model of nearshore circulation

    NASA Astrophysics Data System (ADS)

    Miller, R. N.; Ehret, L. L.

    2014-04-01

    The implicit particle filter 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 filter 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 step of the numerical model, the implicit particle filter is equivalent to the optimal importance filter, i.e., at each step 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.

  3. Genetic particle filter application to land surface temperature downscaling

    NASA Astrophysics Data System (ADS)

    Mechri, Rihab; Ottlé, Catherine; Pannekoucke, Olivier; Kallel, Abdelaziz

    2014-03-01

    Thermal infrared data are widely used for surface flux estimation giving the possibility to assess water and energy budgets through land surface temperature (LST). Many applications require both high spatial resolution (HSR) and high temporal resolution (HTR), which are not presently available from space. It is therefore necessary to develop methodologies to use the coarse spatial/high temporal resolutions LST remote-sensing products for a better monitoring of fluxes at appropriate scales. For that purpose, a data assimilation method was developed to downscale LST based on particle filtering. The basic tenet of our approach is to constrain LST dynamics simulated at both HSR and HTR, through the optimization of aggregated temperatures at the coarse observation scale. Thus, a genetic particle filter (GPF) data assimilation scheme was implemented and applied to a land surface model which simulates prior subpixel temperatures. First, the GPF downscaling scheme was tested on pseudoobservations generated in the framework of the study area landscape (Crau-Camargue, France) and climate for the year 2006. The GPF performances were evaluated against observation errors and temporal sampling. Results show that GPF outperforms prior model estimations. Finally, the GPF method was applied on Spinning Enhanced Visible and InfraRed Imager time series and evaluated against HSR data provided by an Advanced Spaceborne Thermal Emission and Reflection Radiometer image acquired on 26 July 2006. The temperatures of seven land cover classes present in the study area were estimated with root-mean-square errors less than 2.4 K which is a very promising result for downscaling LST satellite products.

  4. COMPUTATIONS ON THE PERFORMANCE OF PARTICLE FILTERS AND ELECTRONIC AIR CLEANERS

    EPA Science Inventory

    The paper discusses computations on the performance of particle filters and electronic air cleaners (EACs). The collection efficiency of particle filters and ACs is calculable if certain factors can be assumed or calibrated. For fibrous particulate filters, measurement of colle...

  5. 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.

  6. Effect of particle-fiber friction coefficient on ultrafine aerosol particles clogging in nanofiber based filter

    NASA Astrophysics Data System (ADS)

    Sambaer, Wannes; Zatloukal, Martin; Kimmer, Dusan

    2013-04-01

    Realistic SEM image based 3D filter model considering transition/free molecular flow regime, Brownian diffusion, aerodynamic slip, particle-fiber and particle-particle interactions together with a novel Euclidian distance map based methodology for the pressure drop calculation has been utilized for a polyurethane nanofiber based filter prepared via electrospinning process in order to more deeply understand the effect of particle-fiber friction coefficient on filter clogging and basic filter characteristics. Based on the performed theoretical analysis, it has been revealed that the increase in the fiber-particle friction coefficient causes, firstly, more weaker particle penetration in the filter, creation of dense top layers and generation of higher pressure drop (surface filtration) in comparison with lower particle-fiber friction coefficient filter for which deeper particle penetration takes place (depth filtration), secondly, higher filtration efficiency, thirdly, higher quality factor and finally, higher quality factor sensitivity to the increased collected particle mass. Moreover, it has been revealed that even if the particle-fiber friction coefficient is different, the cake morphology is very similar.

  7. Analysis of video-based microscopic particle trajectories using Kalman filtering.

    PubMed

    Wu, Pei-Hsun; Agarwal, Ashutosh; Hess, Henry; Khargonekar, Pramod P; Tseng, Yiider

    2010-06-16

    The fidelity of the trajectories obtained from video-based particle tracking determines the success of a variety of biophysical techniques, including in situ single cell particle tracking and in vitro motility assays. However, the image acquisition process is complicated by system noise, which causes positioning error in the trajectories derived from image analysis. Here, we explore the possibility of reducing the positioning error by the application of a Kalman filter, a powerful algorithm to estimate the state of a linear dynamic system from noisy measurements. We show that the optimal Kalman filter parameters can be determined in an appropriate experimental setting, and that the Kalman filter can markedly reduce the positioning error while retaining the intrinsic fluctuations of the dynamic process. We believe the Kalman filter can potentially serve as a powerful tool to infer a trajectory of ultra-high fidelity from noisy images, revealing the details of dynamic cellular processes.

  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. Effects of particle size and velocity on burial depth of airborne particles in glass fiber filters

    SciTech Connect

    Higby, D.P.

    1984-11-01

    Air sampling for particulate radioactive material involves collecting airborne particles on a filter and then determining the amount of radioactivity collected per unit volume of air drawn through the filter. The amount of radioactivity collected is frequently determined by directly measuring the radiation emitted from the particles collected on the filter. Counting losses caused by the particle becoming buried in the filter matrix may cause concentrations of airborne particulate radioactive materials to be underestimated by as much as 50%. Furthermore, the dose calculation for inhaled radionuclides will also be affected. The present study was designed to evaluate the extent to which particle size and sampling velocity influence burial depth in glass-fiber filters. Aerosols of high-fired /sup 239/PuO/sub 2/ were collected at various sampling velocities on glass-fiber filters. The fraction of alpha counts lost due to burial was determined as the ratio of activity detected by direct alpha count to the quantity determined by photon spectrometry. The results show that burial of airborne particles collected on glass-fiber filters appears to be a weak function of sampling velocity and particle size. Counting losses ranged from 0 to 25%. A correction that assumes losses of 10 to 15% would ensure that the concentration of airborne alpha-emitting radionuclides would not be underestimated when glass-fiber filters are used. 32 references, 21 figures, 11 tables.

  12. 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.

  13. 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.

  14. 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.

  15. Sequential bearings-only-tracking initiation with particle filtering method.

    PubMed

    Liu, Bin; Hao, Chengpeng

    2013-01-01

    The tracking initiation problem is examined in the context of autonomous bearings-only-tracking (BOT) of a single appearing/disappearing target in the presence of clutter measurements. In general, this problem suffers from a combinatorial explosion in the number of potential tracks resulted from the uncertainty in the linkage between the target and the measurement (a.k.a the data association problem). In addition, the nonlinear measurements lead to a non-Gaussian posterior probability density function (pdf) in the optimal Bayesian sequential estimation framework. The consequence of this nonlinear/non-Gaussian context is the absence of a closed-form solution. This paper models the linkage uncertainty and the nonlinear/non-Gaussian estimation problem jointly with solid Bayesian formalism. A particle filtering (PF) algorithm is derived for estimating the model's parameters in a sequential manner. Numerical results show that the proposed solution provides a significant benefit over the most commonly used methods, IPDA and IMMPDA. The posterior Cramér-Rao bounds are also involved for performance evaluation.

  16. Sequential Bearings-Only-Tracking Initiation with Particle Filtering Method

    PubMed Central

    Hao, Chengpeng

    2013-01-01

    The tracking initiation problem is examined in the context of autonomous bearings-only-tracking (BOT) of a single appearing/disappearing target in the presence of clutter measurements. In general, this problem suffers from a combinatorial explosion in the number of potential tracks resulted from the uncertainty in the linkage between the target and the measurement (a.k.a the data association problem). In addition, the nonlinear measurements lead to a non-Gaussian posterior probability density function (pdf) in the optimal Bayesian sequential estimation framework. The consequence of this nonlinear/non-Gaussian context is the absence of a closed-form solution. This paper models the linkage uncertainty and the nonlinear/non-Gaussian estimation problem jointly with solid Bayesian formalism. A particle filtering (PF) algorithm is derived for estimating the model's parameters in a sequential manner. Numerical results show that the proposed solution provides a significant benefit over the most commonly used methods, IPDA and IMMPDA. The posterior Cramér-Rao bounds are also involved for performance evaluation. PMID:24453865

  17. A local particle filter for high-dimensional geophysical systems

    NASA Astrophysics Data System (ADS)

    Penny, Stephen G.; Miyoshi, Takemasa

    2016-11-01

    A local particle filter (LPF) is introduced that outperforms traditional ensemble Kalman filters in highly nonlinear/non-Gaussian scenarios, both in accuracy and computational cost. The standard sampling importance resampling (SIR) particle filter is augmented with an observation-space localization approach, for which an independent analysis is computed locally at each grid point. The deterministic resampling approach of Kitagawa is adapted for application locally and combined with interpolation of the analysis weights to smooth the transition between neighboring points. Gaussian noise is applied with magnitude equal to the local analysis spread to prevent particle degeneracy while maintaining the estimate of the growing dynamical instabilities. The approach is validated against the local ensemble transform Kalman filter (LETKF) using the 40-variable Lorenz-96 (L96) model. The results show that (1) the accuracy of LPF surpasses LETKF as the forecast length increases (thus increasing the degree of nonlinearity), (2) the cost of LPF is significantly lower than LETKF as the ensemble size increases, and (3) LPF prevents filter divergence experienced by LETKF in cases with non-Gaussian observation error distributions.

  18. Nonlinear Statistical Signal Processing: A Particle Filtering Approach

    SciTech Connect

    Candy, J

    2007-09-19

    A introduction to particle filtering is discussed starting with an overview of Bayesian inference from batch to sequential processors. Once the evolving Bayesian paradigm is established, simulation-based methods using sampling theory and Monte Carlo realizations are discussed. Here the usual limitations of nonlinear approximations and non-gaussian processes prevalent in classical nonlinear processing algorithms (e.g. Kalman filters) are no longer a restriction to perform Bayesian inference. It is shown how the underlying hidden or state variables are easily assimilated into this Bayesian construct. Importance sampling methods are then discussed and shown how they can be extended to sequential solutions implemented using Markovian state-space models as a natural evolution. With this in mind, the idea of a particle filter, which is a discrete representation of a probability distribution, is developed and shown how it can be implemented using sequential importance sampling/resampling methods. Finally, an application is briefly discussed comparing the performance of the particle filter designs with classical nonlinear filter implementations.

  19. Localization using omnivision-based manifold particle filters

    NASA Astrophysics Data System (ADS)

    Wong, Adelia; Yousefhussien, Mohammed; Ptucha, Raymond

    2015-01-01

    Developing precise and low-cost spatial localization algorithms is an essential component for autonomous navigation systems. Data collection must be of sufficient detail to distinguish unique locations, yet coarse enough to enable real-time processing. Active proximity sensors such as sonar and rangefinders have been used for interior localization, but sonar sensors are generally coarse and rangefinders are generally expensive. Passive sensors such as video cameras are low cost and feature-rich, but suffer from high dimensions and excessive bandwidth. This paper presents a novel approach to indoor localization using a low cost video camera and spherical mirror. Omnidirectional captured images undergo normalization and unwarping to a canonical representation more suitable for processing. Training images along with indoor maps are fed into a semi-supervised linear extension of graph embedding manifold learning algorithm to learn a low dimensional surface which represents the interior of a building. The manifold surface descriptor is used as a semantic signature for particle filter localization. Test frames are conditioned, mapped to a low dimensional surface, and then localized via an adaptive particle filter algorithm. These particles are temporally filtered for the final localization estimate. The proposed method, termed omnivision-based manifold particle filters, reduces convergence lag and increases overall efficiency.

  20. Model Adaptation for Prognostics in a Particle Filtering Framework

    NASA Technical Reports Server (NTRS)

    Saha, Bhaskar; Goebel, Kai Frank

    2011-01-01

    One of the key motivating factors for using particle filters for prognostics is the ability to include model parameters as part of the state vector to be estimated. This performs model adaptation in conjunction with state tracking, and thus, produces a tuned model that can used for long term predictions. This feature of particle filters works in most part due to the fact that they are not subject to the "curse of dimensionality", i.e. the exponential growth of computational complexity with state dimension. However, in practice, this property holds for "well-designed" particle filters only as dimensionality increases. This paper explores the notion of wellness of design in the context of predicting remaining useful life for individual discharge cycles of Li-ion batteries. Prognostic metrics are used to analyze the tradeoff between different model designs and prediction performance. Results demonstrate how sensitivity analysis may be used to arrive at a well-designed prognostic model that can take advantage of the model adaptation properties of a particle filter.

  1. 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.

  2. Object tracking by co-trained classifiers and particle filters

    NASA Astrophysics Data System (ADS)

    Tang, Liang; Li, Shanqing; Liu, Keyan; Wang, Lei

    2010-01-01

    This paper presents an online object tracking method, in which co-training and particle filters algorithms cooperate and complement each other for robust and effective tracking. Under framework of particle filters, the semi-supervised cotraining algorithm is adopted to construct, on-line update, and mutually boost two complementary object classifiers, which consequently improves discriminant ability of particles and its adaptability to appearance variants caused by illumination changing, pose verying, camera shaking, and occlusion. Meanwhile, to make sampling procedure more efficient, knowledge from coarse confidence maps and spatial-temporal constraints are introduced by importance sampling. It improves not only the accuracy and efficiency of sampling procedure, but also provides more reliable training samples for co-training. Experimental results verify the effectiveness and robustness of our method.

  3. Distributed Particle Filter for Target Tracking: With Reduced Sensor Communications

    PubMed Central

    Ghirmai, Tadesse

    2016-01-01

    For efficient and accurate estimation of the location of objects, a network of sensors can be used to detect and track targets in a distributed manner. In nonlinear and/or non-Gaussian dynamic models, distributed particle filtering methods are commonly applied to develop target tracking algorithms. An important consideration in developing a distributed particle filtering algorithm in wireless sensor networks is reducing the size of data exchanged among the sensors because of power and bandwidth constraints. In this paper, we propose a distributed particle filtering algorithm with the objective of reducing the overhead data that is communicated among the sensors. In our algorithm, the sensors exchange information to collaboratively compute the global likelihood function that encompasses the contribution of the measurements towards building the global posterior density of the unknown location parameters. Each sensor, using its own measurement, computes its local likelihood function and approximates it using a Gaussian function. The sensors then propagate only the mean and the covariance of their approximated likelihood functions to other sensors, reducing the communication overhead. The global likelihood function is computed collaboratively from the parameters of the local likelihood functions using an average consensus filter or a forward-backward propagation information exchange strategy. PMID:27618057

  4. Utilizing Time Redundancy for Particle Filter-Based Transfer Alignment

    NASA Astrophysics Data System (ADS)

    Chattaraj, Suvendu; Mukherjee, Abhik

    2016-07-01

    Signal detection in the presence of high noise is a challenge in natural sciences. From understanding signals emanating out of deep space probes to signals in protein interactions for systems biology, domain specific innovations are needed. The present work is in the domain of transfer alignment (TA), which deals with estimation of the misalignment of deliverable daughter munitions with respect to that of the delivering mother platform. In this domain, the design of noise filtering scheme has to consider a time varying and nonlinear system dynamics at play. The accuracy of conventional particle filter formulation suffers due to deviations from modeled system dynamics. An evolutionary particle filter can overcome this problem by evolving multiple system models through few support points per particle. However, this variant has even higher time complexity for real-time execution. As a result, measurement update gets deferred and the estimation accuracy is compromised. By running these filter algorithms on multiple processors, the execution time can be reduced, to allow frequent measurement updates. Such scheme ensures better system identification so that performance improves in case of simultaneous ejection of multiple daughters and also results in better convergence of TA algorithms for single daughter.

  5. Multiswarm Particle Swarm Optimization with Transfer of the Best Particle

    PubMed Central

    Wei, Xiao-peng; Zhang, Jian-xia; Zhou, Dong-sheng; Zhang, Qiang

    2015-01-01

    We propose an improved algorithm, for a multiswarm particle swarm optimization with transfer of the best particle called BMPSO. In the proposed algorithm, we introduce parasitism into the standard particle swarm algorithm (PSO) in order to balance exploration and exploitation, as well as enhancing the capacity for global search to solve nonlinear optimization problems. First, the best particle guides other particles to prevent them from being trapped by local optima. We provide a detailed description of BMPSO. We also present a diversity analysis of the proposed BMPSO, which is explained based on the Sphere function. Finally, we tested the performance of the proposed algorithm with six standard test functions and an engineering problem. Compared with some other algorithms, the results showed that the proposed BMPSO performed better when applied to the test functions and the engineering problem. Furthermore, the proposed BMPSO can be applied to other nonlinear optimization problems. PMID:26345200

  6. Ensemble Kalman Filter vs Particle Filter in a Physically Based Coupled Model of Surface-Subsurface Flow (Invited)

    NASA Astrophysics Data System (ADS)

    Putti, M.; Camporese, M.; Pasetto, D.

    2010-12-01

    Data assimilation (DA) has recently received growing interest by the hydrological modeling community due to its capability to merge observations into model prediction. Among the many DA methods available, the Ensemble Kalman Filter (EnKF) and the Particle Filter (PF) are suitable alternatives for applications to detailed physically-based hydrological models. For each assimilation period, both methods use a Monte Carlo approach to approximate the state probability distribution (in terms of mean and covariance matrix) by a finite number of independent model trajectories, also called particles or realizations. The two approaches differ in the way the filtering distribution is evaluated. EnKF implements the classical Kalman filter, optimal only for linear dynamics and Gaussian error statistics. Particle filters, instead, use directly the recursive formula of the sequential Bayesian framework and approximate the posterior probability distributions by means of appropriate weights associated to each realization. We use the Sequential Importance Resampling (SIR) technique, which retains only the most probable particles, in practice the trajectories closest in a statistical sense to the observations, and duplicates them when needed. In contrast to EnKF, particle filters make no assumptions on the form of the prior distribution of the model state, and convergence to the true state is ensured for large enough ensemble size. In this study EnKF and PF have been implemented in a physically based catchment simulator that couples a three-dimensional finite element Richards equation solver with a finite difference diffusion wave approximation based on a digital elevation data for surface water dynamics. We report on the retrieval performance of the two schemes using a three-dimensional tilted v-catchment synthetic test case in which multi-source observations are assimilated (pressure head, soil moisture, and streamflow data). The comparison between the results of the two approaches

  7. 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.

  8. A Parameterized Design Framework for Hardware Implementation of Particle Filters

    DTIC Science & Technology

    2008-03-01

    explore differ- ent design options for implementing two different particle filtering applications on field-programmable gate arrays ( FPGAs ), and we present...associated results on trade-offs between area ( FPGA resource requirements) and execution speed. Index Terms — Field programmable gate arrays, Parallel...programmable gate arrays ( FPGAs ) is proposed to enable comprehensive design space exploration of the whole system with attention to the interaction

  9. Chi-squared smoothed adaptive particle-filtering based prognosis

    NASA Astrophysics Data System (ADS)

    Ley, Christopher P.; Orchard, Marcos E.

    2017-01-01

    This paper presents a novel form of selecting the likelihood function of the standard sequential importance sampling/re-sampling particle filter (SIR-PF) with a combination of sliding window smoothing and chi-square statistic weighting, so as to: (a) increase the rate of convergence of a flexible state model with artificial evolution for online parameter learning (b) improve the performance of a particle-filter based prognosis algorithm. This is applied and tested with real data from oil total base number (TBN) measurements from three haul trucks. The oil data has high measurement uncertainty and an unknown phenomenological state model. Performance of the proposed algorithm is benchmarked against the standard form of SIR-PF estimation which utilises the Normal (Gaussian) likelihood function. Both implementations utilise the same particle filter based prognosis algorithm so as to provide a common comparison. A sensitivity analysis is also performed to further explore the effects of the combination of sliding window smoothing and chi-square statistic weighting to the SIR-PF.

  10. 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.

  11. Ensemble Data Assimilation for Streamflow Forecasting: Experiments with Ensemble Kalman Filter and Particle Filter

    NASA Astrophysics Data System (ADS)

    Hirpa, F. A.; Gebremichael, M.; Hopson, T. M.; Wojick, R.

    2011-12-01

    We present results of data assimilation of ground discharge observation and remotely sensed soil moisture observations into Sacramento Soil Moisture Accounting (SACSMA) model in a small watershed (1593 km2) in Minnesota, the Unites States. Specifically, we perform assimilation experiments with Ensemble Kalman Filter (EnKF) and Particle Filter (PF) in order to improve streamflow forecast accuracy at six hourly time step. The EnKF updates the soil moisture states in the SACSMA from the relative errors of the model and observations, while the PF adjust the weights of the state ensemble members based on the likelihood of the forecast. Results of the improvements of each filter over the reference model (without data assimilation) will be presented. Finally, the EnKF and PF are coupled together to further improve the streamflow forecast accuracy.

  12. 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

  13. 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.

  14. Models of filter-based particle light absorption measurements

    NASA Astrophysics Data System (ADS)

    Hamasha, Khadeejeh M.

    Light absorption by aerosol is very important in the visible, near UN, and near I.R region of the electromagnetic spectrum. Aerosol particles in the atmosphere have a great influence on the flux of solar energy, and also impact health in a negative sense when they are breathed into lungs. Aerosol absorption measurements are usually performed by filter-based methods that are derived from the change in light transmission through a filter where particles have been deposited. These methods suffer from interference between light-absorbing and light-scattering aerosol components. The Aethalometer is the most commonly used filter-based instrument for aerosol light absorption measurement. This dissertation describes new understanding of aerosol light absorption obtained by the filter method. The theory uses a multiple scattering model for the combination of filter and particle optics. The theory is evaluated using Aethalometer data from laboratory and ambient measurements in comparison with photoacoustic measurements of aerosol light absorption. Two models were developed to calculate aerosol light absorption coefficients from the Aethalometer data, and were compared to the in-situ aerosol light absorption coefficients. The first is an approximate model and the second is a "full" model. In the approximate model two extreme cases of aerosol optics were used to develop a model-based calibration scheme for the 7-wavelength Aethalometer. These cases include those of very strong scattering aerosols (Ammonium sulfate sample) and very absorbing aerosols (kerosene soot sample). The exponential behavior of light absorption in the strong multiple scattering limit is shown to be the square root of the total absorption optical depth rather than linear with optical depth as is commonly assumed with Beer's law. 2-stream radiative transfer theory was used to develop the full model to calculate the aerosol light absorption coefficients from the Aethalometer data. This comprehensive model

  15. 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.

  16. 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.

  17. Particle swarm optimization for complex nonlinear optimization problems

    NASA Astrophysics Data System (ADS)

    Alexandridis, Alex; Famelis, Ioannis Th.; Tsitouras, Charalambos

    2016-06-01

    This work presents the application of a technique belonging to evolutionary computation, namely particle swarm optimization (PSO), to complex nonlinear optimization problems. To be more specific, a PSO optimizer is setup and applied to the derivation of Runge-Kutta pairs for the numerical solution of initial value problems. The effect of critical PSO operational parameters on the performance of the proposed scheme is thoroughly investigated.

  18. Selectively-informed particle swarm optimization

    PubMed Central

    Gao, Yang; Du, Wenbo; Yan, Gang

    2015-01-01

    Particle swarm optimization (PSO) is a nature-inspired algorithm that has shown outstanding performance in solving many realistic problems. In the original PSO and most of its variants all particles are treated equally, overlooking the impact of structural heterogeneity on individual behavior. Here we employ complex networks to represent the population structure of swarms and propose a selectively-informed PSO (SIPSO), in which the particles choose different learning strategies based on their connections: a densely-connected hub particle gets full information from all of its neighbors while a non-hub particle with few connections can only follow a single yet best-performed neighbor. Extensive numerical experiments on widely-used benchmark functions show that our SIPSO algorithm remarkably outperforms the PSO and its existing variants in success rate, solution quality, and convergence speed. We also explore the evolution process from a microscopic point of view, leading to the discovery of different roles that the particles play in optimization. The hub particles guide the optimization process towards correct directions while the non-hub particles maintain the necessary population diversity, resulting in the optimum overall performance of SIPSO. These findings deepen our understanding of swarm intelligence and may shed light on the underlying mechanism of information exchange in natural swarm and flocking behaviors. PMID:25787315

  19. 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> </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/2016MS%26E..143a2018L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MS%26E..143a2018L"><span>Auxiliary <span class="hlt">particle</span> <span class="hlt">filter</span>-model predictive control of the vacuum arc remelting process</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lopez, F.; Beaman, J.; Williamson, R.</p> <p>2016-07-01</p> <p>Solidification control is required for the suppression of segregation defects in vacuum arc remelting of superalloys. In recent years, process controllers for the VAR process have been proposed based on linear models, which are known to be inaccurate in highly-dynamic conditions, e.g. start-up, hot-top and melt rate perturbations. A novel controller is proposed using auxiliary <span class="hlt">particle</span> <span class="hlt">filter</span>-model predictive control based on a nonlinear stochastic model. The auxiliary <span class="hlt">particle</span> <span class="hlt">filter</span> approximates the probability of the state, which is fed to a model predictive controller that returns an <span class="hlt">optimal</span> control signal. For simplicity, the estimation and control problems are solved using Sequential Monte Carlo (SMC) methods. The validity of this approach is verified for a 430 mm (17 in) diameter Alloy 718 electrode melted into a 510 mm (20 in) diameter ingot. Simulation shows a more accurate and smoother performance than the one obtained with an earlier version of the controller.</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('http://adsabs.harvard.edu/abs/2015EGUGA..1711125M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1711125M"><span>Improving the LPJ-GUESS modelled carbon balance with a <span class="hlt">particle</span> <span class="hlt">filter</span> data assimilation technique</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McRobert, Andrew; Scholze, Marko; Kemp, Sarah; Smith, Ben</p> <p>2015-04-01</p> <p>The recent increases in anthropogenic carbon dioxide (CO_2) emissions have disrupted the equilibrium in the global carbon cycle pools with the ocean and terrestrial pools increasing their respective storages to accommodate roughly half of the anthropogenic increase. Dynamic global vegetation models (DGVM) have been developed to quantify the modern carbon cycle changes. In this study, a <span class="hlt">particle</span> <span class="hlt">filter</span> data assimilation technique has been used to calibrate the process parameters in the DGVM LPJ-GUESS (Lund-Potsdam-Jena General Ecosystem Simulator). LPJ-GUESS simulates individual plant function types (pft) as a competitive balance within high resolution forest patches. Thirty process parameters have been <span class="hlt">optimized</span> twice, using both a sequential and iterative method of <span class="hlt">particle</span> <span class="hlt">filter</span>. The iterative method runs the model for the full time period of thirteen years and then evaluates the cost function from the mismatch of observations and model results before adjusting the parameters and repeating the full time period. The sequential method runs the model and <span class="hlt">particle</span> <span class="hlt">filter</span> for each year of the time series in order, adjusting the parameters between each year, then loops back to beginning of the series to repeat. For each <span class="hlt">particle</span>, the model output of NEP (Net Ecosystem Productivity) is compared to eddy flux measurements from ICOS flux towers to minimize the cost function. A high-resolution regional carbon balance has been simulated for central Sweden using a network of several ICOS flux towers.</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/2014SPIE.9248E..0JB','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9248E..0JB"><span>Independent motion detection with a rival penalized adaptive <span class="hlt">particle</span> <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>Becker, Stefan; Hübner, Wolfgang; Arens, Michael</p> <p>2014-10-01</p> <p>Aggregation of pixel based motion detection into regions of interest, which include views of single moving objects in a scene is an essential pre-processing step in many vision systems. Motion events of this type provide significant information about the object type or build the basis for action recognition. Further, motion is an essential saliency measure, which is able to effectively support high level image analysis. When applied to static cameras, background subtraction methods achieve good results. On the other hand, motion aggregation on freely moving cameras is still a widely unsolved problem. The image flow, measured on a freely moving camera is the result from two major motion types. First the ego-motion of the camera and second object motion, that is independent from the camera motion. When capturing a scene with a camera these two motion types are adverse blended together. In this paper, we propose an approach to detect multiple moving objects from a mobile monocular camera system in an outdoor environment. The overall processing pipeline consists of a fast ego-motion compensation algorithm in the preprocessing stage. Real-time performance is achieved by using a sparse optical flow algorithm as an initial processing stage and a densely applied probabilistic <span class="hlt">filter</span> in the post-processing stage. Thereby, we follow the idea proposed by Jung and Sukhatme. Normalized intensity differences originating from a sequence of ego-motion compensated difference images represent the probability of moving objects. Noise and registration artefacts are <span class="hlt">filtered</span> out, using a Bayesian formulation. The resulting a posteriori distribution is located on image regions, showing strong amplitudes in the difference image which are in accordance with the motion prediction. In order to effectively estimate the a posteriori distribution, a <span class="hlt">particle</span> <span class="hlt">filter</span> is used. In addition to the fast ego-motion compensation, the main contribution of this paper is the design of the probabilistic</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 <span class="hlt">Particle</span> 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('https://www.ncbi.nlm.nih.gov/pubmed/18681501','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18681501"><span><span class="hlt">Particle</span> <span class="hlt">filtering</span> for dispersion curve tracking in ocean acoustics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zorych, Ivan; Michalopoulou, Zoi-Heleni</p> <p>2008-08-01</p> <p>A <span class="hlt">particle</span> <span class="hlt">filtering</span> method is developed for dispersion curve extraction from spectrograms of broadband acoustic signals propagating in underwater media. The goal is to obtain accurate representation of modal dispersion which can be employed for source localization and geoacoustic inversion. Results are presented from the application of the method to synthetic data, demonstrating the potential of the approach for accurate estimation of waveguide dispersion characteristics. The method outperforms simple time-frequency analysis providing estimates that are very close to numerically calculated dispersion curves. The method also provides uncertainty information on modal arrival time estimates, typically unavailable when traditional methods are used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/7301185','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/7301185"><span><span class="hlt">Particle</span> <span class="hlt">filter</span> based on thermophoretic deposition from natural convection flow</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sasse, A.G.B.M.; Nazaroff, W.W. ); Gadgil, A.J. )</p> <p>1994-04-01</p> <p>We present an analysis of <span class="hlt">particle</span> migration in a natural convection flow between parallel plates and within the annulus of concentric tubes. The flow channel is vertically oriented with one surface maintained at a higher temperature than the other. <span class="hlt">Particle</span> migration is dominated by advection in the vertical direction and thermophoresis in the horizontal direction. From scale analysis it is demonstrated that <span class="hlt">particles</span> are completely removed from air flowing through the channel if its length exceeds L[sub c] = (b[sup 4]g/24K[nu][sup 2]), where b is the width of the channel, g is the acceleration of gravity, K is a thermophoretic coefficient of order 0.5, and [nu] is the kinematic viscosity of air. Precise predictions of <span class="hlt">particle</span> removal efficiency as a function of system parameters are obtained by numerical solution of the governing equations. Based on the model results, it appears feasible to develop a practical <span class="hlt">filter</span> for removing smoke <span class="hlt">particles</span> from a smoldering cigarette in an ashtray by using natural convection in combination with thermophoresis. 22 refs., 8 figs., 1 tab.</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 <span class="hlt">particle</span> picking, extracting structural features and segmentation of tomograms.</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 step 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), <span class="hlt">Particle</span> 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('https://www.ncbi.nlm.nih.gov/pubmed/27333615','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27333615"><span>ECG Denoising Using Marginalized <span class="hlt">Particle</span> Extended Kalman <span class="hlt">Filter</span> with an Automatic <span class="hlt">Particle</span> Weighting Strategy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hesar, Hamed; Mohebbi, Maryam</p> <p>2016-06-20</p> <p>In this paper a model-based Bayesian <span class="hlt">filtering</span> framework called the "marginalized <span class="hlt">particle</span>-extended Kalman <span class="hlt">filter</span> (MP-EKF) algorithm" is proposed for electrocardiogram (ECG) denoising. This algorithm does not have the extended Kalman <span class="hlt">filter</span> (EKF) shortcoming in handling non-Gaussian nonstationary situations because of its nonlinear framework. In addition, it has less computational complexity compared with <span class="hlt">particle</span> <span class="hlt">filter</span>. This <span class="hlt">filter</span> improves ECG denoising performance by implementing marginalized <span class="hlt">particle</span> <span class="hlt">filter</span> framework while reducing its computational complexity using EKF framework. An automatic <span class="hlt">particle</span> weighting strategy is also proposed here that controls the reliance of our framework to the acquired measurements. We evaluated the proposed <span class="hlt">filter</span> on several normal ECGs selected from MIT-BIH normal sinus rhythm database. To do so, artificial white Gaussian and colored noises as well as nonstationary real muscle artifact (MA) noise over a range of low SNRs from 10 to -5 dB were added to these normal ECG segments. The benchmark methods were the EKF and extended Kalman smoother (EKS) algorithms which are the first model-based Bayesian algorithms introduced in the field of ECG denoising. From SNR viewpoint, the experiments showed that in the presence of Gaussian white noise, the proposed framework outperforms the EKF and EKS algorithms in lower input SNRs where the measurements and state model are not reliable. Owing to its nonlinear framework and <span class="hlt">particle</span> weighting strategy, the proposed algorithm attained better results at all input SNRs in non-Gaussian non-stationary situations (such as presence of pink noise, brown noise, and real muscle artifacts). In addition, the impact of the proposed <span class="hlt">filtering</span> method on the distortion of diagnostic features of the ECG was investigated and compared with EKF/EKS methods using an ECG diagnostic distortion measure called the "Multi-Scale Entropy Based Weighted Distortion Measure" or MSEWPRD. The results revealed that our</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('http://adsabs.harvard.edu/abs/2006AtmEn..40.4797Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AtmEn..40.4797Y"><span>Loss of fine <span class="hlt">particle</span> ammonium from denuded nylon <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>Yu, Xiao-Ying; Lee, Taehyoung; Ayres, Benjamin; Kreidenweis, Sonia M.; Malm, William; Collett, Jeffrey L.</p> <p></p> <p>Ammonium is an important constituent of fine particulate mass in the atmosphere, but can be difficult to quantify due to possible sampling artifacts. Losses of semivolatile species such as NH 4NO 3 can be particularly problematic. In order to evaluate ammonium losses from aerosol <span class="hlt">particles</span> collected on <span class="hlt">filters</span>, a series of field experiments was conducted using denuded nylon and Teflon <span class="hlt">filters</span> at Bondville, IL (February 2003), San Gorgonio, CA (April 2003 and July 2004), Grand Canyon NP, AZ (May, 2003), Brigantine, NJ (November 2003), and Great Smoky Mountains National Park (NP), TN (July-August 2004). Samples were collected over 24 h periods. Losses from denuded nylon <span class="hlt">filters</span> ranged from 10% (monthly average) in Bondville, IL to 28% in San Gorgonio, CA in summer. Losses on individual sample days ranged from 1% to 65%. Losses tended to increase with increasing diurnal temperature and relative humidity changes and with the fraction of ambient total N(-III) (particulate NH 4++gaseous NH 3) present as gaseous NH 3. The amount of ammonium lost at most sites could be explained by the amount of NH 4NO 3 present in the sampled aerosol. Ammonium losses at Great Smoky Mountains NP, however, significantly exceeded the amount of NH 4NO 3 collected. Ammoniated organic salts are suggested as additional important contributors to observed ammonium loss at this location.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/909252','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/909252"><span>Loss of Fine <span class="hlt">Particle</span> Ammonium from Denuded Nylon <span class="hlt">Filters</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yu, Xiao-Ying; Lee, Taehyoung; Ayres, Benjamin; Kreidenweis, Sonia M.; Malm, William C.; Collett, Jeffrey L.</p> <p>2006-08-01</p> <p>Ammonium is an important constituent of fine particulate mass in the atmosphere, but can be difficult to quantify due to possible sampling artifacts. Losses of semivolatile species such as NH4NO3 can be particularly problematic. In order to evaluate ammonium losses from aerosol <span class="hlt">particles</span> collected on <span class="hlt">filters</span>, a series of field experiments was conducted using denuded nylon and Teflon <span class="hlt">filters</span> at Bondville, Illinois (February 2003), San Gorgonio, California (April 2003 and July 2004), Grand Canyon National Park, Arizona (May, 2003), Brigantine, New Jersey (November 2003), and Great Smoky Mountains National Park (NP), Tennessee (July–August 2004). Samples were collected over 24-hr periods. Losses from denuded nylon <span class="hlt">filters</span> ranged from 10% (monthly average) in Bondville, Illinois to 28% in San Gorgonio, California in summer. Losses on individual sample days ranged from 1% to 65%. Losses tended to increase with increasing diurnal temperature and relative humidity changes and with the fraction of ambient total N(--III) (particulate NH4+ plus gaseous NH3) present as gaseous NH3. The amount of ammonium lost at most sites could be explained by the amount of NH4NO3 present in the sampled aerosol. Ammonium losses at Great Smoky Mountains NP, however, significantly exceeded the amount of NH4NO3 collected. Ammoniated organic salts are suggested as additional important contributors to observed ammonium loss at this location.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19884080','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19884080"><span>Speech enhancement based on nonlinear models using <span class="hlt">particle</span> <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>Mustière, Frédéric; Bolić, Miodrag; Bouchard, Martin</p> <p>2009-12-01</p> <p>Motivated by the reportedly strong performance of <span class="hlt">particle</span> <span class="hlt">filters</span> (PFs) for noise reduction on essentially linear speech production models, and the mounting evidence that the introduction of nonlinearities can lead to a refined speech model, this paper presents a study of PF solutions to the problem of speech enhancement in the context of nonlinear, neural-type speech models. Several variations of a global model are presented (single/multiple neurons; bias/no bias), and corresponding PF solutions are derived. Different importance functions are given when beneficial, Rao-Blackwellization is proposed when possible, and dual/nondual versions of each algorithms are presented. The method shown can handle both white and colored noise. Using a variety of speech and noise signals and different objective quality measures, the performance of these algorithms are evaluated against other PF solutions running on linear models, as well as some traditional enhancement algorithms. A certain hierarchy in performance is established between each algorithm in the paper. Depending on the experimental conditions, the best-performing algorithms are a classical Rao-Blackwellized <span class="hlt">particle</span> <span class="hlt">filter</span> (RBPF) running on a linear model, and a proposed PF employing a nondual, nonlinear model with multiple neurons and no biases. With consistence, the neural-network-based PF outperforms RBPF at low signal-to-noise ratio (SNR).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EJASP2012...17A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EJASP2012...17A"><span>Proposed hardware architectures of <span class="hlt">particle</span> <span class="hlt">filter</span> for object tracking</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abd El-Halym, Howida A.; Mahmoud, Imbaby Ismail; Habib, SED</p> <p>2012-12-01</p> <p>In this article, efficient hardware architectures for <span class="hlt">particle</span> <span class="hlt">filter</span> (PF) are presented. We propose three different architectures for Sequential Importance Resampling <span class="hlt">Filter</span> (SIRF) implementation. The first architecture is a two-step sequential PF machine, where <span class="hlt">particle</span> sampling, weight, and output calculations are carried out in parallel during the first step followed by sequential resampling in the second step. For the weight computation step, a piecewise linear function is used instead of the classical exponential function. This decreases the complexity of the architecture without degrading the results. The second architecture speeds up the resampling step via a parallel, rather than a serial, architecture. This second architecture targets a balance between hardware resources and the speed of operation. The third architecture implements the SIRF as a distributed PF composed of several processing elements and central unit. All the proposed architectures are captured using VHDL synthesized using Xilinx environment, and verified using the ModelSim simulator. Synthesis results confirmed the resource reduction and speed up advantages of our architectures.</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://adsabs.harvard.edu/abs/2011SPIE.8193E..2IS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SPIE.8193E..2IS"><span>The new approach for infrared target tracking based on the <span class="hlt">particle</span> <span class="hlt">filter</span> algorithm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Hang; Han, Hong-xia</p> <p>2011-08-01</p> <p>Target tracking on the complex background in the infrared image sequence is hot research field. It provides the important basis in some fields such as video monitoring, precision, and video compression human-computer interaction. As a typical algorithms in the target tracking framework based on <span class="hlt">filtering</span> and data connection, the <span class="hlt">particle</span> <span class="hlt">filter</span> with non-parameter estimation characteristic have ability to deal with nonlinear and non-Gaussian problems so it were widely used. There are various forms of density in the <span class="hlt">particle</span> <span class="hlt">filter</span> algorithm to make it valid when target occlusion occurred or recover tracking back from failure in track procedure, but in order to capture the change of the state space, it need a certain amount of <span class="hlt">particles</span> to ensure samples is enough, and this number will increase in accompany with dimension and increase exponentially, this led to the increased amount of calculation is presented. In this paper <span class="hlt">particle</span> <span class="hlt">filter</span> algorithm and the Mean shift will be combined. Aiming at deficiencies of the classic mean shift Tracking algorithm easily trapped into local minima and Unable to get global <span class="hlt">optimal</span> under the complex background. From these two perspectives that "adaptive multiple information fusion" and "with <span class="hlt">particle</span> <span class="hlt">filter</span> framework combining", we expand the classic Mean Shift tracking framework .Based on the previous perspective, we proposed an improved Mean Shift infrared target tracking algorithm based on multiple information fusion. In the analysis of the infrared characteristics of target basis, Algorithm firstly extracted target gray and edge character and Proposed to guide the above two characteristics by the moving of the target information thus we can get new sports guide grayscale characteristics and motion guide border feature. Then proposes a new adaptive fusion mechanism, used these two new information adaptive to integrate into the Mean Shift tracking framework. Finally we designed a kind of automatic target model updating strategy</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002SPIE.4728..240L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002SPIE.4728..240L"><span>Comparison of EKF, pseudomeasurement, and <span class="hlt">particle</span> <span class="hlt">filters</span> for a bearing-only target tracking problem</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lin, Xiangdong; Kirubarajan, Thiagalingam; Bar-Shalom, Yaakov; Maskell, Simon</p> <p>2002-08-01</p> <p>In this paper we consider a nonlinear bearing-only target tracking problem using three different methods and compare their performances. The study is motivated by a ground surveillance problem where a target is tracked from an airborne sensor at an approximately known altitude using depression angle observations. Two nonlinear suboptimal estimators, namely, the extended Kalman <span class="hlt">Filter</span> (EKF) and the pseudomeasurement tracking <span class="hlt">filter</span> are applied in a 2-D bearing-only tracking scenario. The EKF is based on the linearization of the nonlinearities in the dynamic and/or the measurement equations. The pseudomeasurement tracking <span class="hlt">filter</span> manipulates the original nonlinear measurement algebraically to obtain the linear-like structures measurement. Finally, the <span class="hlt">particle</span> <span class="hlt">filter</span>, which is a Monte Carlo integration based <span class="hlt">optimal</span> nonlinear <span class="hlt">filter</span> and has been presented in the literature as a better alternative to linearization via EKF, is used on the same problem. The performances of these three different techniques in terms of accuracy and computational load are presented in this paper. The results demonstrate the limitations of these algorithms on this deceptively simple tracking problem.</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('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://adsabs.harvard.edu/abs/2011SPIE.8050E..0XD','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SPIE.8050E..0XD"><span>Hollywood log-homotopy: movies of <span class="hlt">particle</span> flow for nonlinear <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>Daum, Fred; Huang, Jim</p> <p>2011-06-01</p> <p>In this paper we show five movies of <span class="hlt">particle</span> flow to provide insight and intuition about this new algorithm. The <span class="hlt">particles</span> flow solves the well known and important problem of <span class="hlt">particle</span> degeneracy. Bayes' rule is implemented by <span class="hlt">particle</span> flow rather than as a pointwise multiplication. This theory is roughly seven orders of magnitude faster than standard <span class="hlt">particle</span> <span class="hlt">filters</span>, and it often beats the extended Kalman <span class="hlt">filter</span> by two orders of magnitude in accuracy for difficult nonlinear problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AMT....10.1043D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AMT....10.1043D"><span>The <span class="hlt">filter</span>-loading effect by ambient aerosols in <span class="hlt">filter</span> absorption photometers depends on the coating of the sampled <span class="hlt">particles</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Drinovec, Luka; Gregorič, Asta; Zotter, Peter; Wolf, Robert; Bruns, Emily Anne; Prévôt, André S. H.; Petit, Jean-Eudes; Favez, Olivier; Sciare, Jean; Arnold, Ian J.; Chakrabarty, Rajan K.; Moosmüller, Hans; Filep, Agnes; Močnik, Griša</p> <p>2017-03-01</p> <p>Black carbon is a primary aerosol tracer for high-temperature combustion emissions and can be used to characterize the time evolution of its sources. It is correlated with a decrease in public health and contributes to atmospheric warming. Black carbon measurements are usually conducted with absorption <span class="hlt">filter</span> photometers, which are prone to several artifacts, including the <span class="hlt">filter</span>-loading effect - a saturation of the instrumental response due to the accumulation of the sample in the <span class="hlt">filter</span> matrix. In this paper, we investigate the hypothesis that this <span class="hlt">filter</span>-loading effect depends on the optical properties of <span class="hlt">particles</span> present in the <span class="hlt">filter</span> matrix, especially on the black carbon <span class="hlt">particle</span> coating. We conducted field campaigns in contrasting environments to determine the influence of source characteristics, <span class="hlt">particle</span> age and coating on the magnitude of the <span class="hlt">filter</span>-loading effect. High-time-resolution measurements of the <span class="hlt">filter</span>-loading parameter in <span class="hlt">filter</span> absorption photometers show daily and seasonal variations of the effect. The variation is most pronounced in the near-infrared region, where the black carbon mass concentration is determined. During winter, the <span class="hlt">filter</span>-loading parameter value increases with the absorption Ångström exponent. It is suggested that this effect is related to the size of the black carbon <span class="hlt">particle</span> core as the wood burning (with higher values of the absorption Ångström exponent) produces soot <span class="hlt">particles</span> with larger diameters. A reduction of the <span class="hlt">filter</span>-loading effect is correlated with the availability of the coating material. As the coating of ambient aerosols is reduced or removed, the <span class="hlt">filter</span>-loading parameter increases. Coatings composed of ammonium sulfate and secondary organics seem to be responsible for the variation of the loading effect. The potential source contribution function analysis shows that high values of the <span class="hlt">filter</span>-loading parameter in the infrared are indicative of local pollution, whereas low values of the <span class="hlt">filter</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24344695','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24344695"><span>Multi-strategy coevolving aging <span class="hlt">particle</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>Iacca, Giovanni; Caraffini, Fabio; Neri, Ferrante</p> <p>2014-02-01</p> <p>We propose Multi-Strategy Coevolving Aging <span class="hlt">Particles</span> (MS-CAP), a novel population-based algorithm for black-box <span class="hlt">optimization</span>. In a memetic fashion, MS-CAP combines two components with complementary algorithm logics. In the first stage, each <span class="hlt">particle</span> is perturbed independently along each dimension with a progressively shrinking (decaying) radius, and attracted towards the current best solution with an increasing force. In the second phase, the <span class="hlt">particles</span> are mutated and recombined according to a multi-strategy approach in the fashion of the ensemble of mutation strategies in Differential Evolution. The proposed algorithm is tested, at different dimensionalities, on two complete black-box <span class="hlt">optimization</span> benchmarks proposed at the Congress on Evolutionary Computation 2010 and 2013. To demonstrate the applicability of the approach, we also test MS-CAP to train a Feedforward Neural Network modeling the kinematics of an 8-link robot manipulator. The numerical results show that MS-CAP, for the setting considered in this study, tends to outperform the state-of-the-art <span class="hlt">optimization</span> algorithms on a large set of problems, thus resulting in a robust and versatile <span class="hlt">optimizer</span>.</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> <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('https://www.ncbi.nlm.nih.gov/pubmed/26352625','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26352625"><span>A MultiScale <span class="hlt">Particle</span> <span class="hlt">Filter</span> Framework for Contour Detection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Widynski, Nicolas; Mignotte, Max</p> <p>2014-10-01</p> <p>We investigate the contour detection task in complex natural images. We propose a novel contour detection algorithm which jointly tracks at two scales small pieces of edges called edgelets. This multiscale edgelet structure naturally embeds semi-local information and is the basic element of the proposed recursive Bayesian modeling. Prior and transition distributions are learned offline using a shape database. Likelihood functions are learned online, thus are adaptive to an image, and integrate color and gradient information via local, textural, oriented, and profile gradient-based features. The underlying model is estimated using a sequential Monte Carlo approach, and the final soft contour detection map is retrieved from the approximated trajectory distribution. We also propose to extend the model to the interactive cut-out task. Experiments conducted on the Berkeley Segmentation data sets show that the proposed MultiScale <span class="hlt">Particle</span> <span class="hlt">Filter</span> Contour Detector method performs well compared to competing state-of-the-art methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20649203','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20649203"><span>Geoacoustic and source tracking using <span class="hlt">particle</span> <span class="hlt">filtering</span>: experimental results.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yardim, Caglar; Gerstoft, Peter; Hodgkiss, William S</p> <p>2010-07-01</p> <p>A <span class="hlt">particle</span> <span class="hlt">filtering</span> (PF) approach is presented for performing sequential geoacoustic inversion of a complex ocean acoustic environment using a moving acoustic source. This approach treats both the environmental parameters [e.g., water column sound speed profile (SSP), water depth, sediment and bottom parameters] at the source location and the source parameters (e.g., source depth, range and speed) as unknown random variables that evolve as the source moves. This allows real-time updating of the environment and accurate tracking of the moving source. As a sequential Monte Carlo technique that operates on nonlinear systems with non-Gaussian probability densities, the PF is an ideal algorithm to perform tracking of environmental and source parameters, and their uncertainties via the evolving posterior probability densities. The approach is demonstrated on both simulated data in a shallow water environment with a sloping bottom and experimental data collected during the SWellEx-96 experiment.</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/2001SPIE.4512..193V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001SPIE.4512..193V"><span>Emergent system identification using <span class="hlt">particle</span> swarm <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>Voss, Mark S.; Feng, Xin</p> <p>2001-10-01</p> <p>Complex Adaptive Structures can be viewed as a combination of Complex Adaptive Systems and fully integrated autonomous Smart Structures. Traditionally when designing a structure, one combines rules of thumb with theoretical results to develop an acceptable solution. This methodology will have to be extended for Complex Adaptive Structures, since they, by definition, will participate in their own design. In this paper we introduce a new methodology for Emergent System Identification that is concerned with combining the methodologies of self-organizing functional networks (GMDH - Alexy G. Ivakhnenko), <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO - James Kennedy and Russell C. Eberhart) and Genetic Programming (GP - John Koza). This paper will concentrate on the utilization of <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> in this effort and discuss how <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> relates to our ultimate goal of emergent self-organizing functional networks that can be used to identify overlapping internal structural models. The ability for Complex Adaptive Structures to identify emerging internal models will be a key component for their success.</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://www.ncbi.nlm.nih.gov/pubmed/22225500','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22225500"><span>Artefact-reduced kinematics measurement using a geometric finger model with mixture-prior <span class="hlt">particle</span> <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>Chang, Cheung-Wen; Kuo, Li-Chieh; Jou, I-Ming; Su, Fong-Chin; Sun, Yung-Nien</p> <p>2013-01-01</p> <p>It is challenging to measure the finger's kinematics of underlying bones in vivo. This paper presents a new method of finger kinematics measurement, using a geometric finger model and several markers deliberately stuck on skin surface. Using a multiple-view camera system, the <span class="hlt">optimal</span> motion parameters of finger model were estimated using the proposed mixture-prior <span class="hlt">particle</span> <span class="hlt">filtering</span>. This prior, consisting of model and marker information, avoids generating improper <span class="hlt">particles</span> for achieving near real-time performance. This method was validated using a planar fluoroscopy system that worked simultaneously with photographic system. Ten male subjects with asymptomatic hands were investigated in experiments. The results showed that the kinematic parameters could be estimated more accurately by the proposed method than by using only markers. There was 20-40% reduction in skin artefacts achieved for finger flexion/extension. Thus, this profile system can be developed as a tool of reliable kinematics measurement with good applicability for hand rehabilitation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006ChOpL...4..569Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006ChOpL...4..569Z"><span>Joint tracking algorithm using <span class="hlt">particle</span> <span class="hlt">filter</span> and mean shift with target model updating</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Bo; Tian, Weifeng; Jin, Zhihua</p> <p>2006-10-01</p> <p>Roughly, visual tracking algorithms can be divided into two main classes: deterministic tracking and stochastic tracking. Mean shift and <span class="hlt">particle</span> <span class="hlt">filter</span> are their typical representatives, respectively. Recently, a hybrid tracker, seamlessly integrating the respective advantages of mean shift and <span class="hlt">particle</span> <span class="hlt">filter</span> (MSPF) has achieved impressive success in robust tracking. The pivot of MSPF is to sample fewer <span class="hlt">particles</span> using <span class="hlt">particle</span> <span class="hlt">filter</span> and then those <span class="hlt">particles</span> are shifted to their respective local maximum of target searching space by mean shift. MSPF not only can greatly reduce the number of <span class="hlt">particles</span> that <span class="hlt">particle</span> <span class="hlt">filter</span> required, but can remedy the deficiency of mean shift. Unfortunately, due to its inherent principle, MSPF is restricted to those applications with little changes of the target model. To make MSPF more flexible and robust, an adaptive target model is extended to MSPF in this paper. Experimental results show that MSPF with target model updating can robustly track the target through the whole sequences regardless of the change of target model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26858747','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26858747"><span><span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> with Double Learning Patterns.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shen, Yuanxia; Wei, Linna; Zeng, Chuanhua; Chen, Jian</p> <p>2016-01-01</p> <p><span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO) is an effective tool in solving <span class="hlt">optimization</span> problems. However, PSO usually suffers from the premature convergence due to the quick losing of the swarm diversity. In this paper, we first analyze the motion behavior of the swarm based on the probability characteristic of learning parameters. Then a PSO with double learning patterns (PSO-DLP) is developed, which employs the master swarm and the slave swarm with different learning patterns to achieve a trade-off between the convergence speed and the swarm diversity. The <span class="hlt">particles</span> in the master swarm and the slave swarm are encouraged to explore search for keeping the swarm diversity and to learn from the global best <span class="hlt">particle</span> for refining a promising solution, respectively. When the evolutionary states of two swarms interact, an interaction mechanism is enabled. This mechanism can help the slave swarm in jumping out of the local optima and improve the convergence precision of the master swarm. The proposed PSO-DLP is evaluated on 20 benchmark functions, including rotated multimodal and complex shifted problems. The simulation results and statistical analysis show that PSO-DLP obtains a promising performance and outperforms eight PSO variants.</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('http://adsabs.harvard.edu/abs/2014ExFl...55.1809R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ExFl...55.1809R"><span><span class="hlt">Optimization</span> of astigmatic <span class="hlt">particle</span> tracking velocimeters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rossi, Massimiliano; Kähler, Christian J.</p> <p>2014-09-01</p> <p>Astigmatic <span class="hlt">particle</span> tracking velocimetry (APTV) has been developed in the last years to measure the three-dimensional displacement of tracer <span class="hlt">particles</span> using a single-camera view. The measurement principle relies on an astigmatic optical system that provides aberrated <span class="hlt">particle</span> images with a characteristic elliptical shape univocally related to the corresponding <span class="hlt">particle</span> depth position. Because of the precision of this method, this concept is well established for measuring and controlling the distance between a CD/DVD and the reading head. The optical arrangement of an APTV system essentially consists of a primary stigmatic optics (e.g., a microscope, or a camera objective) and an astigmatic optics, typically a cylindrical lens placed in front of the camera sensor. This paper focuses on the uncertainty of APTV in the depth direction. First, an approximated analytical model is derived and experimentally validated. From the model, a set of three non-dimensional parameters that are the most significant in the <span class="hlt">optimization</span> of the APTV performance are identified. Finally, the effect of different parameter settings and calibration approaches are studied systematically using numerical Monte Carlo simulations. The results allow for the derivation of general criteria to minimize the overall error in APTV measurements and provide the basis for reliable uncertainty estimation for a wide range of applications.</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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4849747','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4849747"><span>Lagrange Interpolation Learning <span class="hlt">Particle</span> Swarm <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></p> <p>2016-01-01</p> <p>In recent years, comprehensive learning <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (CLPSO) has attracted the attention of many scholars for using in solving multimodal problems, as it is excellent in preserving the particles’ diversity and thus preventing premature convergence. However, CLPSO exhibits low solution accuracy. Aiming to address this issue, we proposed a novel algorithm called LILPSO. First, this algorithm introduced a Lagrange interpolation method to perform a local search for the global best point (gbest). Second, to gain a better exemplar, one gbest, another two particle’s historical best points (pbest) are chosen to perform Lagrange interpolation, then to gain a new exemplar, which replaces the CLPSO’s comparison method. The numerical experiments conducted on various functions demonstrate the superiority of this algorithm, and the two methods are proven to be efficient for accelerating the convergence without leading the <span class="hlt">particle</span> to premature convergence. PMID:27123982</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/2017AIPC.1806h0002Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AIPC.1806h0002Y"><span><span class="hlt">Particle</span> <span class="hlt">filtering</span> based structural assessment with acoustic emission sensing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yan, Wuzhao; Abdelrahman, Marwa; Zhang, Bin; Ziehl, Paul</p> <p>2017-02-01</p> <p>Nuclear structures are designed to withstand severe loading events under various stresses. Over time, aging of structural systems constructed with concrete and steel will occur. This deterioration may reduce service life of nuclear facilities and/or lead to unnecessary or untimely repairs. Therefore, online monitoring of structures in nuclear power plants and waste storage has drawn significant attention in recent years. Of many existing non-destructive evaluation and structural monitoring approaches, acoustic emission is promising for assessment of structural damage because it is non-intrusive and is sensitive to corrosion and crack growth in reinforced concrete elements. To provide a rapid, actionable, and graphical means for interpretation Intensity Analysis plots have been developed. This approach provides a means for classification of damage. Since the acoustic emission measurement is only an indirect indicator of structural damage, potentially corrupted by non-genuine data, it is more suitable to estimate the states of corrosion and cracking in a Bayesian estimation framework. In this paper, we will utilize the accelerated corrosion data from a specimen at the University of South Carolina to develop a <span class="hlt">particle</span> <span class="hlt">filtering</span>-based diagnosis and prognosis algorithm. Promising features of the proposed algorithm are described in terms of corrosion state estimation and prediction of degradation over time to a predefined threshold.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23590456','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23590456"><span>Ultrafine <span class="hlt">particle</span> removal by residential heating, ventilating, and air-conditioning <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>Stephens, B; Siegel, J A</p> <p>2013-12-01</p> <p>This work uses an in situ <span class="hlt">filter</span> test method to measure the size-resolved removal efficiency of indoor-generated ultrafine <span class="hlt">particles</span> (approximately 7-100 nm) for six new commercially available <span class="hlt">filters</span> installed in a recirculating heating, ventilating, and air-conditioning (HVAC) system in an unoccupied test house. The fibrous HVAC <span class="hlt">filters</span> were previously rated by the manufacturers according to ASHRAE Standard 52.2 and ranged from shallow (2.5 cm) fiberglass panel <span class="hlt">filters</span> (MERV 4) to deep-bed (12.7 cm) electrostatically charged synthetic media <span class="hlt">filters</span> (MERV 16). Measured removal efficiency ranged from 0 to 10% for most ultrafine <span class="hlt">particles</span> (UFP) sizes with the lowest rated <span class="hlt">filters</span> (MERV 4 and 6) to 60-80% for most UFP sizes with the highest rated <span class="hlt">filter</span> (MERV 16). The deeper bed <span class="hlt">filters</span> generally achieved higher removal efficiencies than the panel <span class="hlt">filters</span>, while maintaining a low pressure drop and higher airflow rate in the operating HVAC system. Assuming constant efficiency, a modeling effort using these measured values for new <span class="hlt">filters</span> and other inputs from real buildings shows that MERV 13-16 <span class="hlt">filters</span> could reduce the indoor proportion of outdoor UFPs (in the absence of indoor sources) by as much as a factor of 2-3 in a typical single-family residence relative to the lowest efficiency <span class="hlt">filters</span>, depending in part on <span class="hlt">particle</span> size.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25333110','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25333110"><span><span class="hlt">Optimally</span> stabilized PET image denoising using trilateral <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>Mansoor, Awais; Bagci, Ulas; Mollura, Daniel J</p> <p>2014-01-01</p> <p>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 <span class="hlt">filter</span> 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 <span class="hlt">filtering</span> method into trilateral <span class="hlt">filtering</span> through multiscaling and <span class="hlt">optimal</span> 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.</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('http://adsabs.harvard.edu/abs/2002SPIE.4792..193B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002SPIE.4792..193B"><span>Continuous and Discrete Space <span class="hlt">Particle</span> <span class="hlt">Filters</span> for Predictions in Acoustic Positioning</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bauer, Will; Kim, Surrey; Kouritzin, Michael A.</p> <p>2002-12-01</p> <p>Predicting the future state of a random dynamic signal based on corrupted, distorted, and partial observations is vital for proper real-time control of a system that includes time delay. Motivated by problems from Acoustic Positioning Research Inc., we consider the continual automated illumination of an object moving within a bounded domain, which requires object location prediction due to inherent mechanical and physical time lags associated with robotic lighting. Quality computational predictions demand high fidelity models for the coupled moving object signal and observation equipment pair. In our current problem, the signal represents the vector position, orientation, and velocity of a stage performer. Acoustic observations are formed by timing ultrasonic waves traveling from four perimeter speakers to a microphone attached to the performer. The goal is to schedule lighting movements that are coordinated with the performer by anticipating his/her future position based upon these observations using <span class="hlt">filtering</span> theory. <span class="hlt">Particle</span> system based methods have experienced rapid development and have become an essential technique of contemporary <span class="hlt">filtering</span> strategies. Hitherto, researchers have largely focused on continuous state <span class="hlt">particle</span> <span class="hlt">filters</span>, ranging from traditional weighted <span class="hlt">particle</span> <span class="hlt">filters</span> to adaptive refining <span class="hlt">particle</span> <span class="hlt">filters</span>, readily able to perform path-space estimation and prediction. Herein, we compare the performance of a state-of-the-art refining <span class="hlt">particle</span> <span class="hlt">filter</span> to that of a novel discrete-space <span class="hlt">particle</span> <span class="hlt">filter</span> on the acoustic positioning problem. By discrete space <span class="hlt">particle</span> <span class="hlt">filter</span> we mean a Markov chain that counts <span class="hlt">particles</span> in discretized cells of the signal state space in order to form an approximated unnormalized distribution of the signal state. For both <span class="hlt">filters</span> mentioned above, we will examine issues like the mean time to localize a signal, the fidelity of <span class="hlt">filter</span> estimates at various signal to noise ratios, computational costs, and the effect of signal</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/952810','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/952810"><span>Using triaxial magnetic fields to create <span class="hlt">optimal</span> <span class="hlt">particle</span> composites.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Martin, James Ellis</p> <p>2004-05-01</p> <p>The properties of a <span class="hlt">particle</span> composite can be controlled by organizing the <span class="hlt">particles</span> into assemblies. The properties of the composite will depend on the structure of the <span class="hlt">particle</span> assemblies, and for any give property there is some <span class="hlt">optimal</span> structure. Through simulation and experiment we show that the application of heterodyned triaxial magnetic or electric fields generates structures that <span class="hlt">optimize</span> the magnetic and dielectric properties of <span class="hlt">particle</span> composites. We suggest that <span class="hlt">optimizing</span> these properties <span class="hlt">optimizes</span> other properties, such as transport properties, and we give as one example of this <span class="hlt">optimization</span> the magnetostriction of magnetic <span class="hlt">particle</span> composites formed in a silicone elastomer.</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/2012IJE....99..239Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012IJE....99..239Z"><span>Distributed multi-sensor <span class="hlt">particle</span> <span class="hlt">filter</span> for bearings-only tracking</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Jungen; Ji, Hongbing</p> <p>2012-02-01</p> <p>In this article, the classical bearings-only tracking (BOT) problem for a single target is addressed, which belongs to the general class of non-linear <span class="hlt">filtering</span> problems. Due to the fact that the radial distance observability of the target is poor, the algorithm-based sequential Monte-Carlo (<span class="hlt">particle</span> <span class="hlt">filtering</span>, PF) methods generally show instability and <span class="hlt">filter</span> divergence. A new stable distributed multi-sensor PF method is proposed for BOT. The sensors process their measurements at their sites using a hierarchical PF approach, which transforms the BOT problem from Cartesian coordinate to the logarithmic polar coordinate and separates the observable components from the unobservable components of the target. In the fusion centre, the target state can be estimated by utilising the multi-sensor <span class="hlt">optimal</span> information fusion rule. Furthermore, the computation of a theoretical Cramer-Rao lower bound is given for the multi-sensor BOT problem. Simulation results illustrate that the proposed tracking method can provide better performances than the traditional PF method.</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/2011JEPT...84.1267K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JEPT...84.1267K"><span>Evaporation of suspensions to form an incompressible cake and to fill <span class="hlt">filter</span> pores with solid <span class="hlt">particles</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khuzhayorov, B. Kh.</p> <p>2011-11-01</p> <p>Equations of filtration of suspensions to form an incompressible cake of <span class="hlt">particles</span> on the surface of the <span class="hlt">filter</span> with simultaneous passage of a certain share of the <span class="hlt">particles</span> from the cake to the <span class="hlt">filter</span>'s pore space and next to the region of a <span class="hlt">filtered</span> liquid are derived from the principles of the mechanics of multiphase media. The influence of the travel of the <span class="hlt">particles</span> in the region of the cake and the <span class="hlt">filter</span> on the dynamics of growth of the cake bed is investigated. An analysis of the derived dynamic filtration equations shows that allowance for the factors of travel and accumulation of <span class="hlt">particles</span> in the cake and the <span class="hlt">filter</span> causes their total filtration resistance, in particular the resistance in the inertial component of the filtration law, to decrease.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21308091','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21308091"><span><span class="hlt">Particle</span> <span class="hlt">filtering</span> with path sampling and an application to a bimodal ocean current model</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Weare, Jonathan</p> <p>2009-07-01</p> <p>This paper introduces a recursive <span class="hlt">particle</span> <span class="hlt">filtering</span> algorithm designed to <span class="hlt">filter</span> high dimensional systems with complicated non-linear and non-Gaussian effects. The method incorporates a parallel marginalization (PMMC) step in conjunction with the hybrid Monte Carlo (HMC) scheme to improve samples generated by standard <span class="hlt">particle</span> <span class="hlt">filters</span>. Parallel marginalization is an efficient Markov chain Monte Carlo (MCMC) strategy that uses lower dimensional approximate marginal distributions of the target distribution to accelerate equilibration. As a validation the algorithm is tested on a 2516 dimensional, bimodal, stochastic model motivated by the Kuroshio current that runs along the Japanese coast. The results of this test indicate that the method is an attractive alternative for problems that require the generality of a <span class="hlt">particle</span> <span class="hlt">filter</span> but have been inaccessible due to the limitations of standard <span class="hlt">particle</span> <span class="hlt">filtering</span> strategies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22225057','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22225057"><span>ASME AG-1 Section FC Qualified HEPA <span class="hlt">Filters</span>; a <span class="hlt">Particle</span> Loading Comparison - 13435</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Stillo, Andrew; Ricketts, Craig I.</p> <p>2013-07-01</p> <p>High Efficiency Particulate Air (HEPA) <span class="hlt">Filters</span> used to protect personnel, the public and the environment from airborne radioactive materials are designed, manufactured and qualified in accordance with ASME AG-1 Code section FC (HEPA <span class="hlt">Filters</span>) [1]. The qualification process requires that <span class="hlt">filters</span> manufactured in accordance with this ASME AG-1 code section must meet several performance requirements. These requirements include performance specifications for resistance to airflow, aerosol penetration, resistance to rough handling, resistance to pressure (includes high humidity and water droplet exposure), resistance to heated air, spot flame resistance and a visual/dimensional inspection. None of these requirements evaluate the <span class="hlt">particle</span> loading capacity of a HEPA <span class="hlt">filter</span> design. Concerns, over the <span class="hlt">particle</span> loading capacity, of the different designs included within the ASME AG-1 section FC code[1], have been voiced in the recent past. Additionally, the ability of a <span class="hlt">filter</span> to maintain its integrity, if subjected to severe operating conditions such as elevated relative humidity, fog conditions or elevated temperature, after loading in use over long service intervals is also a major concern. Although currently qualified HEPA <span class="hlt">filter</span> media are likely to have similar loading characteristics when evaluated independently, <span class="hlt">filter</span> pleat geometry can have a significant impact on the in-situ <span class="hlt">particle</span> loading capacity of <span class="hlt">filter</span> packs. Aerosol <span class="hlt">particle</span> characteristics, such as size and composition, may also have a significant impact on <span class="hlt">filter</span> loading capacity. Test results comparing <span class="hlt">filter</span> loading capacities for three different aerosol <span class="hlt">particles</span> and three different <span class="hlt">filter</span> pack configurations are reviewed. The information presented represents an empirical performance comparison among the <span class="hlt">filter</span> designs tested. The results may serve as a basis for further discussion toward the possible development of a <span class="hlt">particle</span> loading test to be included in the qualification requirements of ASME AG-1</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPRS..105....1J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPRS..105....1J"><span><span class="hlt">Particle</span> <span class="hlt">filtering</span> methods for georeferencing panoramic image sequence in complex urban scenes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ji, Shunping; Shi, Yun; Shan, Jie; Shao, Xiaowei; Shi, Zhongchao; Yuan, Xiuxiao; Yang, Peng; Wu, Wenbin; Tang, Huajun; Shibasaki, Ryosuke</p> <p>2015-07-01</p> <p>Georeferencing image sequences is critical for mobile mapping systems. Traditional methods such as bundle adjustment need adequate and well-distributed ground control points (GCP) when accurate GPS data are not available in complex urban scenes. For applications of large areas, automatic extraction of GCPs by matching vehicle-born image sequences with geo-referenced ortho-images will be a better choice than intensive GCP collection with field surveying. However, such image matching generated GCP's are highly noisy, especially in complex urban street environments due to shadows, occlusions and moving objects in the ortho images. This study presents a probabilistic solution that integrates matching and localization under one framework. First, a probabilistic and global localization model is formulated based on the Bayes' rules and Markov chain. Unlike many conventional methods, our model can accommodate non-Gaussian observation. In the next step, a <span class="hlt">particle</span> <span class="hlt">filtering</span> method is applied to determine this model under highly noisy GCP's. Owing to the multiple hypotheses tracking represented by diverse <span class="hlt">particles</span>, the method can balance the strength of geometric and radiometric constraints, i.e., drifted motion models and noisy GCP's, and guarantee an approximately <span class="hlt">optimal</span> trajectory. Carried out tests are with thousands of mobile panoramic images and aerial ortho-images. Comparing with the conventional extended Kalman <span class="hlt">filtering</span> and a global registration method, the proposed approach can succeed even under more than 80% gross errors in GCP's and reach a good accuracy equivalent to the traditional bundle adjustment with dense and precise control.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011HESSD...8.3383N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011HESSD...8.3383N"><span>Applying sequential Monte Carlo methods into a distributed hydrologic model: lagged <span class="hlt">particle</span> <span class="hlt">filtering</span> approach with regularization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Noh, S. J.; Tachikawa, Y.; Shiiba, M.; Kim, S.</p> <p>2011-04-01</p> <p>Applications of data assimilation techniques have been widely used to improve hydrologic prediction. Among various data assimilation techniques, sequential Monte Carlo (SMC) methods, known as "<span class="hlt">particle</span> <span class="hlt">filters</span>", provide the capability to handle non-linear and non-Gaussian state-space models. In this paper, we propose an improved <span class="hlt">particle</span> <span class="hlt">filtering</span> approach to consider different response time of internal state variables in a hydrologic model. The proposed method adopts a lagged <span class="hlt">filtering</span> approach to aggregate model response until uncertainty of each hydrologic process is propagated. The regularization with an additional move step based on Markov chain Monte Carlo (MCMC) is also implemented to preserve sample diversity under the lagged <span class="hlt">filtering</span> approach. A distributed hydrologic model, WEP is implemented for the sequential data assimilation through the updating of state variables. <span class="hlt">Particle</span> <span class="hlt">filtering</span> is parallelized and implemented in the multi-core computing environment via open message passing interface (MPI). We compare performance results of <span class="hlt">particle</span> <span class="hlt">filters</span> in terms of model efficiency, predictive QQ plots and <span class="hlt">particle</span> diversity. The improvement of model efficiency and the preservation of <span class="hlt">particle</span> diversity are found in the lagged regularized <span class="hlt">particle</span> <span class="hlt">filter</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21682358','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21682358"><span>A <span class="hlt">particle</span> <span class="hlt">filtering</span> approach for spatial arrival time tracking in ocean acoustics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jain, Rashi; Michalopoulou, Zoi-Heleni</p> <p>2011-06-01</p> <p>The focus of this work is on arrival time and amplitude estimation from acoustic signals recorded at spatially separated hydrophones in the ocean. A <span class="hlt">particle</span> <span class="hlt">filtering</span> approach is developed that treats arrival times as "targets" and tracks their "location" across receivers, also modeling arrival time gradient. The method is evaluated via Monte Carlo simulations and is compared to a maximum likelihood estimator, which does not relate arrivals at neighboring receivers. The comparison demonstrates a significant advantage in using the <span class="hlt">particle</span> <span class="hlt">filter</span>. It is also shown that posterior probability density functions of times and amplitudes become readily available with <span class="hlt">particle</span> <span class="hlt">filtering</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/95647','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/95647"><span>A novel permanently magnetised high gradient magnetic <span class="hlt">filter</span> using assisted capture for fine <span class="hlt">particles</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Watson, J.H.P.</p> <p>1995-02-01</p> <p>This paper describes the structure and properties of a novel permanently magnetised magnetic <span class="hlt">filter</span> for fine friable radioactive material. Previously a <span class="hlt">filter</span> was described and tested. This <span class="hlt">filter</span> was designed so that the holes in the <span class="hlt">filter</span> are left open as capture proceeds which means the pressure drop builds up only slowly. This <span class="hlt">filter</span> is not suitable for friable composite <span class="hlt">particles</span> which can be broken by mechanical forces. The structure of magnetic part of the second <span class="hlt">filter</span> has been changed so as to strongly capture <span class="hlt">particles</span> composed of fine <span class="hlt">particles</span> weakly bound together which tend to break when captured. This uses a principle of assisted-capture in which coarse <span class="hlt">particles</span> aid the capture of the fine fragments. The technique has the unfortunate consequence that the pressure drop across the <span class="hlt">filter</span> rises faster as capture capture proceeds than the <span class="hlt">filter</span> described previously. These <span class="hlt">filters</span> have the following characteristics: (1) No external magnet is required. (2) No external power is required. (3) Small is size and portable. (4) Easily interchangeable. (5) Can be cleaned without demagnetising.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/823418','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/823418"><span><span class="hlt">PARTICLE</span> TRANSPORTATION AND DEPOSITION IN HOT GAS <span class="hlt">FILTER</span> VESSELS - A COMPUTATIONAL AND EXPERIMENTAL MODELING APPROACH</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Goodarz Ahmadi</p> <p>2002-07-01</p> <p>In this project, a computational modeling approach for analyzing flow and ash transport and deposition in <span class="hlt">filter</span> vessels was developed. An Eulerian-Lagrangian formulation for studying hot-gas filtration process was established. The approach uses an Eulerian analysis of gas flows in the <span class="hlt">filter</span> vessel, and makes use of the Lagrangian trajectory analysis for the <span class="hlt">particle</span> transport and deposition. Particular attention was given to the Siemens-Westinghouse <span class="hlt">filter</span> vessel at Power System Development Facility in Wilsonville in Alabama. Details of hot-gas flow in this tangential flow <span class="hlt">filter</span> vessel are evaluated. The simulation results show that the rapidly rotation flow in the spacing between the shroud and the vessel refractory acts as cyclone that leads to the removal of a large fraction of the larger <span class="hlt">particles</span> from the gas stream. Several alternate designs for the <span class="hlt">filter</span> vessel are considered. These include a vessel with a short shroud, a <span class="hlt">filter</span> vessel with no shroud and a vessel with a deflector plate. The hot-gas flow and <span class="hlt">particle</span> transport and deposition in various vessels are evaluated. The deposition patterns in various vessels are compared. It is shown that certain <span class="hlt">filter</span> vessel designs allow for the large <span class="hlt">particles</span> to remain suspended in the gas stream and to deposit on the <span class="hlt">filters</span>. The presence of the larger <span class="hlt">particles</span> in the <span class="hlt">filter</span> cake leads to lower mechanical strength thus allowing for the back-pulse process to more easily remove the <span class="hlt">filter</span> cake. A laboratory-scale <span class="hlt">filter</span> vessel for testing the cold flow condition was designed and fabricated. A laser-based flow visualization technique is used and the gas flow condition in the laboratory-scale vessel was experimental studied. A computer model for the experimental vessel was also developed and the gas flow and <span class="hlt">particle</span> transport patterns are evaluated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JPhCS.484a2047P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JPhCS.484a2047P"><span>Cosmological parameter estimation using <span class="hlt">Particle</span> Swarm <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>Prasad, J.; Souradeep, T.</p> <p>2014-03-01</p> <p>Constraining parameters of a theoretical model from observational data is an important exercise in cosmology. There are many theoretically motivated models, which demand greater number of cosmological parameters than the standard model of cosmology uses, and make the problem of parameter estimation challenging. It is a common practice to employ Bayesian formalism for parameter estimation for which, in general, likelihood surface is probed. For the standard cosmological model with six parameters, likelihood surface is quite smooth and does not have local maxima, and sampling based methods like Markov Chain Monte Carlo (MCMC) method are quite successful. However, when there are a large number of parameters or the likelihood surface is not smooth, other methods may be more effective. In this paper, we have demonstrated application of another method inspired from artificial intelligence, called <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO) for estimating cosmological parameters from Cosmic Microwave Background (CMB) data taken from the WMAP satellite.</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://hdl.handle.net/2060/20130012659','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130012659"><span>Surface Navigation Using <span class="hlt">Optimized</span> Waypoints and <span class="hlt">Particle</span> Swarm <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>Birge, Brian</p> <p>2013-01-01</p> <p>The design priority for manned space exploration missions is almost always placed on human safety. Proposed manned surface exploration tasks (lunar, asteroid sample returns, Mars) have the possibility of astronauts traveling several kilometers away from a home base. Deviations from preplanned paths are expected while exploring. In a time-critical emergency situation, there is a need to develop an <span class="hlt">optimal</span> home base return path. The return path may or may not be similar to the outbound path, and what defines <span class="hlt">optimal</span> may change with, and even within, each mission. A novel path planning algorithm and prototype program was developed using biologically inspired <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) that generates an <span class="hlt">optimal</span> path of traversal while avoiding obstacles. Applications include emergency path planning on lunar, Martian, and/or asteroid surfaces, generating multiple scenarios for outbound missions, Earth-based search and rescue, as well as human manual traversal and/or path integration into robotic control systems. The strategy allows for a changing environment, and can be re-tasked at will and run in real-time situations. Given a random extraterrestrial planetary or small body surface position, the goal was to find the fastest (or shortest) path to an arbitrary position such as a safe zone or geographic objective, subject to possibly varying constraints. The problem requires a workable solution 100% of the time, though it does not require the absolute theoretical optimum. Obstacles should be avoided, but if they cannot be, then the algorithm needs to be smart enough to recognize this and deal with it. With some modifications, it works with non-stationary error topologies as well.</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 <span class="hlt">particle</span> 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> <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('http://adsabs.harvard.edu/abs/2016amos.confE..41M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016amos.confE..41M"><span>Homotopy <span class="hlt">Particle</span> <span class="hlt">Filter</span> for Ground-Based Tracking of Satellites at GEO</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moshtagh, N.; Chan, J.; Chan, M.</p> <p>2016-09-01</p> <p>Ground telescopes enable low-cost tracking and characterization of meter-class space objects. Since a telescope may be tasked to observe multiple fields of the sky, the time between observations for each object may vary from several seconds to tens of minutes. Long propagation times with nonlinear dynamics are challenging for traditional <span class="hlt">filtering</span> methods such as the Extended Kalman <span class="hlt">Filter</span> (EKF). Sampling-based <span class="hlt">filters</span> based on the <span class="hlt">Particle</span> <span class="hlt">Filter</span> (PF) are promising for this type of problem but typically require maintaining a large number of samples. In this work, we evaluate the Homotopy <span class="hlt">Particle</span> <span class="hlt">Filter</span> (HPF) which promises effective performance with orders of magnitude fewer <span class="hlt">particles</span>. The performance of the HPF is evaluated against GEO satellite observations collected by a ground telescope at Lockheed Martin's Space Object Tracking (SPOT) facility.</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://hdl.handle.net/2060/20080004151','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080004151"><span>Array of micro-machined mass energy micro-<span class="hlt">filters</span> for charged <span class="hlt">particles</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stalder, Roland E. (Inventor); Van Zandt, Thomas R. (Inventor); Hecht, Michael H. (Inventor); Grunthaner, Frank J. (Inventor)</p> <p>1996-01-01</p> <p>An energy <span class="hlt">filter</span> for charged <span class="hlt">particles</span> includes a stack of micro-machined wafers including plural apertures passing through the stack of wafers, focusing electrodes bounding charged <span class="hlt">particle</span> paths through the apertures, an entrance orifice to each of the plural apertures and an exit orifice from each of the plural apertures and apparatus for biasing the focusing electrodes with an electrostatic potential corresponding to an energy pass band of the <span class="hlt">filter</span>.</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=4813895','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4813895"><span>Research on a Lamb Wave and <span class="hlt">Particle</span> <span class="hlt">Filter</span>-Based On-Line Crack Propagation Prognosis 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>Chen, Jian; Yuan, Shenfang; Qiu, Lei; Cai, Jian; Yang, Weibo</p> <p>2016-01-01</p> <p>Prognostics and health management techniques have drawn widespread attention due to their ability to facilitate maintenance activities based on need. On-line prognosis of fatigue crack propagation can offer information for <span class="hlt">optimizing</span> operation and maintenance strategies in real-time. This paper proposes a Lamb wave-<span class="hlt">particle</span> <span class="hlt">filter</span> (LW-PF)-based method for on-line prognosis of fatigue crack propagation which takes advantages of the possibility of on-line monitoring to evaluate the actual crack length and uses a <span class="hlt">particle</span> <span class="hlt">filter</span> to deal with the crack evolution and monitoring uncertainties. The piezoelectric transducers (PZTs)-based active Lamb wave method is adopted for on-line crack monitoring. The state space model relating to crack propagation is established by the data-driven and finite element methods. Fatigue experiments performed on hole-edge crack specimens have validated the advantages of the proposed method. PMID:26950130</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26950130','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26950130"><span>Research on a Lamb Wave and <span class="hlt">Particle</span> <span class="hlt">Filter</span>-Based On-Line Crack Propagation Prognosis Method.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Jian; Yuan, Shenfang; Qiu, Lei; Cai, Jian; Yang, Weibo</p> <p>2016-03-03</p> <p>Prognostics and health management techniques have drawn widespread attention due to their ability to facilitate maintenance activities based on need. On-line prognosis of fatigue crack propagation can offer information for <span class="hlt">optimizing</span> operation and maintenance strategies in real-time. This paper proposes a Lamb wave-<span class="hlt">particle</span> <span class="hlt">filter</span> (LW-PF)-based method for on-line prognosis of fatigue crack propagation which takes advantages of the possibility of on-line monitoring to evaluate the actual crack length and uses a <span class="hlt">particle</span> <span class="hlt">filter</span> to deal with the crack evolution and monitoring uncertainties. The piezoelectric transducers (PZTs)-based active Lamb wave method is adopted for on-line crack monitoring. The state space model relating to crack propagation is established by the data-driven and finite element methods. Fatigue experiments performed on hole-edge crack specimens have validated the advantages of the proposed method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNG24A..07M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNG24A..07M"><span>Toward the Application of the Implicit <span class="hlt">Particle</span> <span class="hlt">Filter</span> to Real Data in a Shallow Water Model of the Nearshore Ocean</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.</p> <p>2015-12-01</p> <p>Following the success of the implicit <span class="hlt">particle</span> <span class="hlt">filter</span> in twin experiments with a shallow water model of the nearshore environment, the planned next step is application to the intensive Sandy Duck data set, gathered at Duck, NC. Adaptation of the present system to the Sandy Duck data set will require construction and evaluation of error models for both the model and the data, as well as significant modification of the system to allow for the properties of the data set. Successful implementation of the <span class="hlt">particle</span> <span class="hlt">filter</span> promises to shed light on the details of the capabilities and limitations of shallow water models of the nearshore ocean relative to more detailed models. Since the shallow water model admits distinct dynamical regimes, reliable parameter estimation will be important. Previous work by other groups give cause for <span class="hlt">optimism</span>. In this talk I will describe my progress toward implementation of the new system, including problems solved, pitfalls remaining and preliminary results</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://omicsonline.org/assessing-consumption-of-bioactive-micro-particles-by-filter-feeding-asian-carp-2155-9546.1000126.php?aid=5288','USGSPUBS'); return false;" href="http://omicsonline.org/assessing-consumption-of-bioactive-micro-particles-by-filter-feeding-asian-carp-2155-9546.1000126.php?aid=5288"><span>Assessing consumption of bioactive micro-<span class="hlt">particles</span> by <span class="hlt">filter</span>-feeding Asian carp</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Jensen, Nathan R.; Amberg, Jon J.; Luoma, James A.; Walleser, Liza R.; Gaikowski, Mark P.</p> <p>2012-01-01</p> <p>Silver carp Hypophthalmichthys molitrix (SVC) and bighead carp H. nobilis (BHC) have impacted waters in the US since their escape. Current chemical controls for aquatic nuisance species are non-selective. Development of a bioactive micro-<span class="hlt">particle</span> that exploits <span class="hlt">filter</span>-feeding habits of SVC or BHC could result in a new control tool. It is not fully understood if SVC or BHC will consume bioactive micro-<span class="hlt">particles</span>. Two discrete trials were performed to: 1) evaluate if SVC and BHC consume the candidate micro-<span class="hlt">particle</span> formulation; 2) determine what size they consume; 3) establish methods to evaluate consumption of <span class="hlt">filter</span>-feeders for future experiments. Both SVC and BHC were exposed to small (50-100 μm) and large (150-200 μm) micro-<span class="hlt">particles</span> in two 24-h trials. <span class="hlt">Particles</span> in water were counted electronically and manually (microscopy). <span class="hlt">Particles</span> on gill rakers were counted manually and intestinal tracts inspected for the presence of micro-<span class="hlt">particles</span>. In Trial 1, both manual and electronic count data confirmed reductions of both size <span class="hlt">particles</span>; SVC appeared to remove more small <span class="hlt">particles</span> than large; more BHC consumed <span class="hlt">particles</span>; SVC had fewer overall <span class="hlt">particles</span> in their gill rakers than BHC. In Trial 2, electronic counts confirmed reductions of both size <span class="hlt">particles</span>; both SVC and BHC consumed <span class="hlt">particles</span>, yet more SVC consumed micro-<span class="hlt">particles</span> compared to BHC. Of the fish that ate micro-<span class="hlt">particles</span>, SVC consumed more than BHC. It is recommended to use multiple metrics to assess consumption of candidate micro-<span class="hlt">particles</span> by <span class="hlt">filter</span>-feeders when attempting to distinguish differential <span class="hlt">particle</span> consumption. This study has implications for developing micro-<span class="hlt">particles</span> for species-specific delivery of bioactive controls to help fisheries, provides some methods for further experiments with bioactive micro-<span class="hlt">particles</span>, and may also have applications in aquaculture.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20599512','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20599512"><span>An adaptive non-local means <span class="hlt">filter</span> for denoising live-cell images and improving <span class="hlt">particle</span> detection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Lei; Parton, Richard; Ball, Graeme; Qiu, Zhen; Greenaway, Alan H; Davis, Ilan; Lu, Weiping</p> <p>2010-12-01</p> <p>Fluorescence imaging of dynamical processes in live cells often results in a low signal-to-noise ratio. We present a novel feature-preserving non-local means approach to denoise such images to improve feature recovery and <span class="hlt">particle</span> detection. The commonly used non-local means <span class="hlt">filter</span> is not <span class="hlt">optimal</span> for noisy biological images containing small features of interest because image noise prevents accurate determination of the correct coefficients for averaging, leading to over-smoothing and other artifacts. Our adaptive method addresses this problem by constructing a <span class="hlt">particle</span> feature probability image, which is based on Haar-like feature extraction. The <span class="hlt">particle</span> probability image is then used to improve the estimation of the correct coefficients for averaging. We show that this <span class="hlt">filter</span> achieves higher peak signal-to-noise ratio in denoised images and has a greater capability in identifying weak <span class="hlt">particles</span> when applied to synthetic data. We have applied this approach to live-cell images resulting in enhanced detection of end-binding-protein 1 foci on dynamically extending microtubules in photo-sensitive Drosophila tissues. We show that our feature-preserving non-local means <span class="hlt">filter</span> can reduce the threshold of imaging conditions required to obtain meaningful data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10191024','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10191024"><span>Ceramem <span class="hlt">filters</span> for removal of <span class="hlt">particles</span> from hot gas streams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bishop, B.A.; Goldsmith, R.L.</p> <p>1994-11-01</p> <p>The need for hot gas cleanup in the power, advanced coal conversion, process and incineration industries is well documented and extensive development is being undertaken to develop and demonstrate suitable filtration technologies. In general, process conditions include (a) oxidizing or reducing atmospheres, (b) temperatures to 1800{degree}F, (c) pressures to 300 psi, and (d) potentially corrosive components in the gas stream. The most developed technologies entail the use of candle or tube <span class="hlt">filters</span>, which suffer from fragility, lack of oxidation/corrosion resistance, and high cost. The ceramic membrane <span class="hlt">filter</span> described below offers the potential to eliminate these limitations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19007929','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19007929"><span><span class="hlt">Particle</span> and Kalman <span class="hlt">filtering</span> for state estimation and control of DC motors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rigatos, Gerasimos G</p> <p>2009-01-01</p> <p>State estimation is a major problem in industrial systems. To this end, Gaussian and nonparametric <span class="hlt">filters</span> have been developed. In this paper the Kalman <span class="hlt">Filter</span>, which assumes Gaussian measurement noise, is compared to the <span class="hlt">Particle</span> <span class="hlt">Filter</span>, which does not make any assumption on the measurement noise distribution. As a case study the estimation of the state vector of a DC motor is used. The reconstructed state vector is used in a feedback control loop to generate the control input of the DC motor. In simulation tests it was observed that for a large number of <span class="hlt">particles</span> the <span class="hlt">Particle</span> <span class="hlt">Filter</span> could succeed in accurately estimating the motor's state vector, but at the same time it required higher computational effort.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010LNCS.6466..163R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010LNCS.6466..163R"><span>Expedite <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> Algorithm (EPSO) for <span class="hlt">Optimization</span> of MSA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rathi, Amit; Vijay, Ritu</p> <p></p> <p>This paper presents a new designing method of Rectangular patch Microstrip Antenna using an Artificial searches Algorithm with some constraints. It requires two stages for designing. In first stage, bandwidth of MSA is modeled using bench Mark function. In second stage, output of first stage give to modified Artificial search Algorithm which is <span class="hlt">Particle</span> Swarm Algorithm (PSO) as input and get output in the form of five parameter- dimensions width, frequency range, dielectric loss tangent, length over a ground plane with a substrate thickness and electrical thickness. In PSO Cognition, factor and Social learning Factor give very important effect on balancing the local search and global search in PSO. Basing the modification of cognition factor and social learning factor, this paper presents the strategy that at the starting process cognition-learning factor has more effect then social learning factor. Gradually social learning factor has more impact after learning cognition factor for find out global best. The aim is to find out under above circumstances these modifications in PSO can give better result for <span class="hlt">optimization</span> of microstrip Antenna (MSA).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=115033&keyword=photometry&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=90644748&CFTOKEN=75299341','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=115033&keyword=photometry&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=90644748&CFTOKEN=75299341"><span>NASAL <span class="hlt">FILTERING</span> OF FINE <span class="hlt">PARTICLES</span> IN CHILDREN VS. ADULTS</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Nasal efficiency for removing fine <span class="hlt">particles</span> may be affected by developmental changes in nasal structure associated with age. In healthy Caucasian children (age 6-13, n=17) and adults (age 18-28, n=11) we measured the fractional deposition (DF) of fine <span class="hlt">particles</span> (1 and 2um MMAD)...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/2391172','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/2391172"><span>[<span class="hlt">Particle</span> load in intensive therapy. Possible solutions using a multi-lumen catheter and Intrapur <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>Schröder, F</p> <p>1990-06-01</p> <p>Patients at intensive care units need very many drugs applicated via a central venous katheter. <span class="hlt">Particles</span> caused by incompatibility reactions or coming from disposible materials possibly can provoke severe complications such as embolism, anaphylactoid reactions or ARDS. The combined use of multilumen katheters and Intrapur <span class="hlt">filters</span> brings a significant reduction of these <span class="hlt">particles</span>, as shown by an infusion regime.</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 <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO)- and a Boolean <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (BPSO)-based algorithm is proposed to provide suitable Gabor <span class="hlt">filters</span> for each involved test dataset without predefinition or manual modulation. Several comparative experiments on JLUBR-IRIS, CASIA-I, and CASIA-V4-Interval iris datasets are conducted, and the results show that our work can generate improved local Gabor features by using <span class="hlt">optimized</span> Gabor <span class="hlt">filters</span> for each dataset. In addition, our SVR fusion strategy may make full use of their discriminative ability to improve accuracy and reliability. Other comparative experiments show that our approach may outperform other popular iris systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10322E..2AM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10322E..2AM"><span>Research on <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> algorithm based on <span class="hlt">optimal</span> movement probability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ma, Jianhong; Zhang, Han; He, Baofeng</p> <p>2017-01-01</p> <p>The <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> algorithm to improve the control precision, and has great application value training neural network and fuzzy system control fields etc.The traditional <span class="hlt">particle</span> swarm algorithm is used for the training of feed forward neural networks,the search efficiency is low, and easy to fall into local convergence.An improved <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> algorithm is proposed based on error back propagation gradient descent. <span class="hlt">Particle</span> swarm <span class="hlt">optimization</span> for Solving Least Squares Problems to meme group, the <span class="hlt">particles</span> in the fitness ranking, <span class="hlt">optimization</span> problem of the overall consideration, the error back propagation gradient descent training BP neural network, <span class="hlt">particle</span> to update the velocity and position according to their individual <span class="hlt">optimal</span> and global <span class="hlt">optimization</span>, make the <span class="hlt">particles</span> more to the social <span class="hlt">optimal</span> learning and less to its <span class="hlt">optimal</span> learning, it can avoid the <span class="hlt">particles</span> fall into local optimum, by using gradient information can accelerate the PSO local search ability, improve the multi beam <span class="hlt">particle</span> swarm depth zero less trajectory information search efficiency, the realization of improved <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> algorithm. Simulation results show that the algorithm in the initial stage of rapid convergence to the global <span class="hlt">optimal</span> solution can be near to the global <span class="hlt">optimal</span> solution and keep close to the trend, the algorithm has faster convergence speed and search performance in the same running time, it can improve the convergence speed of the algorithm, especially the later search efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JOM....65b.272S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JOM....65b.272S"><span><span class="hlt">Optimization</span> of Al Matrix Reinforced with B4C <span class="hlt">Particles</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shabani, Mohsen Ostad; Mazahery, Ali</p> <p>2013-02-01</p> <p>In the current study, abrasive wear resistance and mechanical properties of A356 composite reinforced with B4C particulates were investigated. A center <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> algorithm (CenterPSO) is proposed to predict the <span class="hlt">optimal</span> process conditions in fabrication of aluminum matrix composites. Unlike other ordinary <span class="hlt">particles</span>, the center <span class="hlt">particle</span> has no explicit velocity and is set to the center of the swarm at every iteration. Other aspects of the center <span class="hlt">particle</span> are the same as that of the ordinary <span class="hlt">particle</span>, such as fitness evaluation and competition for the best <span class="hlt">particle</span> of the swarm. Because the center of the swarm is a promising position, the center <span class="hlt">particle</span> generally gets good fitness value. More importantly, due to frequent appearance as the best <span class="hlt">particle</span> of swarm, it often attracts other <span class="hlt">particles</span> and guides the search direction of the whole swarm.</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('https://www.ncbi.nlm.nih.gov/pubmed/27023034','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27023034"><span><span class="hlt">Particle</span> Density Using Deposition <span class="hlt">Filters</span> at the Full Scale RDD Experiments.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Berg, Rodney; Gilhuly, Colleen; Korpach, Ed; Ungar, Kurt</p> <p>2016-05-01</p> <p>During the Full-Scale Radiological Dispersal Device (FSRDD) Field Trials carried out in Suffield, Alberta, Canada, several suites of detection equipment and software models were used to measure and characterize the ground deposition. The FSRDD Field Trials were designed to disperse radioactive lanthanum of known activity to better understand such an event. This paper focuses on one means of measuring both concentration and the <span class="hlt">particle</span> size distribution of the deposition using electrostatic <span class="hlt">filters</span> placed around the trial site to collect deposited <span class="hlt">particles</span> for analysis. The measurements made from ground deposition <span class="hlt">filters</span> provided a basis to guide modeling and validate results by giving insight on how <span class="hlt">particles</span> are distributed by a plume.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SPIE.7497E..2QW','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SPIE.7497E..2QW"><span><span class="hlt">Particle</span> <span class="hlt">filtering</span> for tracking of GLUT4 vesicles in TIRF microscpy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Xiangping; Liu, Xiaofang; Xu, Wenglong; Yan, Dandan; Chen, Yongli</p> <p>2009-10-01</p> <p>GLUT4 is responsible for insulin-stimulated glucose uptake into fat cells and description of the dynamic behavior of it can give insight in some working mechanisms and structures of these cells. Quantitative analysis of the dynamical process requires tracking of hundreds of GLUT4 vesicles characterized as bright spots in noisy image sequences. In this paper, a 3D tracking algorithm built in Bayesian probabilistic framework is put forward, combined with the unique features of the TIRF microscopy. A brightness-correction procedure is firstly applied to ensure that the intensity of a vesicle is constant along time and is only affected by spatial factors. Then, tracking is formalized as a state estimation problem and a developed <span class="hlt">particle</span> <span class="hlt">filter</span> integrated by a sub-<span class="hlt">optimizer</span> that steers the <span class="hlt">particles</span> towards a region with high likelihood is used. Once each tracked vesicle is located in image plane, the depth information of a granule can be indirectly inferred according to the exponential relationship between its intensity and its vertical position. The experimental results indicate that the vesicles are tracked well under different motion styles. More, the algorithm provides the depth information of the tracked vesicle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26703615','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26703615"><span>Damage Detection in Flexible Plates through Reduced-Order Modeling and Hybrid <span class="hlt">Particle</span>-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>Capellari, Giovanni; Azam, Saeed Eftekhar; Mariani, Stefano</p> <p>2015-12-22</p> <p>Health monitoring of lightweight structures, like thin flexible plates, is of interest in several engineering fields. In this paper, a recursive Bayesian procedure is proposed to monitor the health of such structures through data collected by a network of <span class="hlt">optimally</span> placed inertial sensors. As a main drawback of standard monitoring procedures is linked to the computational costs, two remedies are jointly considered: first, an order-reduction of the numerical model used to track the structural dynamics, enforced with proper orthogonal decomposition; and, second, an improved <span class="hlt">particle</span> <span class="hlt">filter</span>, which features an extended Kalman updating of each evolving <span class="hlt">particle</span> before the resampling stage. The former remedy can reduce the number of effective degrees-of-freedom of the structural model to a few only (depending on the excitation), whereas the latter one allows to track the evolution of damage and to locate it thanks to an intricate formulation. To assess the effectiveness of the proposed procedure, the case of a plate subject to bending is investigated; it is shown that, when the procedure is appropriately fed by measurements, damage is efficiently and accurately estimated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4732035','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4732035"><span>Damage Detection in Flexible Plates through Reduced-Order Modeling and Hybrid <span class="hlt">Particle</span>-Kalman <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>Capellari, Giovanni; Eftekhar Azam, Saeed; Mariani, Stefano</p> <p>2015-01-01</p> <p>Health monitoring of lightweight structures, like thin flexible plates, is of interest in several engineering fields. In this paper, a recursive Bayesian procedure is proposed to monitor the health of such structures through data collected by a network of <span class="hlt">optimally</span> placed inertial sensors. As a main drawback of standard monitoring procedures is linked to the computational costs, two remedies are jointly considered: first, an order-reduction of the numerical model used to track the structural dynamics, enforced with proper orthogonal decomposition; and, second, an improved <span class="hlt">particle</span> <span class="hlt">filter</span>, which features an extended Kalman updating of each evolving <span class="hlt">particle</span> before the resampling stage. The former remedy can reduce the number of effective degrees-of-freedom of the structural model to a few only (depending on the excitation), whereas the latter one allows to track the evolution of damage and to locate it thanks to an intricate formulation. To assess the effectiveness of the proposed procedure, the case of a plate subject to bending is investigated; it is shown that, when the procedure is appropriately fed by measurements, damage is efficiently and accurately estimated. PMID:26703615</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/2006AdRS....4...65W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AdRS....4...65W"><span>Optimierung von FSS-Bandpassfiltern mit Hilfe der Schwarmintelligenz (<span class="hlt">Particle</span> Swarm <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>Wu, G.; Hansen, V.; Kreysa, E.; Gemünd, H.-P.</p> <p>2006-09-01</p> <p>In diesem Beitrag wird ein neues Verfahren zur Optimierung von Bandpassfiltern aus mehrlagigen frequenzselektiven Schirmen (FSS), die in ein Dielektrikum eingebettet sind, vorgestellt. Das Ziel ist es, die Parameter der gesamten Struktur so zu optimieren, dass ihre Transmissionseigenschaften hohe Filteranforderungen erfüllen. Als Optimierungsverfahren wird die <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO) eingesetzt. PSO ist eine neue stochastische Optimierungsmethode, die in verschieden Gebieten, besonders aber bei der Optimierung nicht linearer Probleme mit mehreren Zielfunktionen erfolgreich eingesetzt wird. In dieser Arbeit wird die PSO in die Spektralbereichsanalyse zur Berechnung komplexer FSS-Strukturen integriert. Die numerische Berechnung basiert auf einer Integralgleichungsformulierung mit Hilfe der spektralen Greenschen Funktion für geschichtete Strukturen. This paper presents a novel procedure for the <span class="hlt">optimization</span> of band-pass <span class="hlt">filters</span> consisting of frequency selective surfaces (FSS) embedded in a dielectric. The aim is to <span class="hlt">optimize</span> the parameters of the complete structure so that the transmission characteristics of the <span class="hlt">filters</span> fulfill the demanding requirements. The <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO) is used as the <span class="hlt">optimization</span> procedure. PSO is a new stochastic <span class="hlt">optimization</span> method that is successfully applied in different areas for the <span class="hlt">optimization</span> of non-linear problems with several object-functions. In this work, PSO is integrated into the spectral domain analysis for the calculation of the complex FSS structures. The numerical computation is based on the formulation of an integral equation with the help of the spectral Green's function for layered media.</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/2016SPIE.9870E..0JY','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9870E..0JY"><span>Segmentation and outline detection in underwater video images using <span class="hlt">particle</span> <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>Yoerger, Edward J.; Charalampidis, Dimitrios; Ioup, George E.; Ioup, Juliette W.</p> <p>2016-05-01</p> <p>Recently we have been concerned with locating and tracking images of fish in underwater videos. While edge detection and region growing have assisted in obtaining some advances in this effort, a more extensive, non-linear approach appears necessary for improved results. In particular, the use of <span class="hlt">particle</span> <span class="hlt">filtering</span> applied to contour detection in natural images has met with some success. Following recent ideas in the literature, we are proposing to use a recursive Bayesian model which employs a sequential Monte Carlo approach, also known as the <span class="hlt">particle</span> <span class="hlt">filter</span>. This approach uses the corroboration between two scales of an image to produce various local features which characterize the different probability densities required by the <span class="hlt">particle</span> <span class="hlt">filter</span>. Since our data consist of video images of fish recorded by a stationary camera, we are capable of augmenting this process by means of background subtraction. Moreover, we are proposing a method that does not require the pre-computation of the distributions required by the <span class="hlt">particle</span> <span class="hlt">filter</span>. The above capabilities are applied to our dataset for the purpose of using contour detection with the aim of eventual segmentation of the fish images and fish classification. Although our dataset consists of fish images, the proposed techniques can be employed in applications involving different kinds of non-stationary underwater objects. We present results and examples of this analysis and discuss the <span class="hlt">particle</span> <span class="hlt">filter</span> application to our dataset.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23846470','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23846470"><span>A Gaussian process guided <span class="hlt">particle</span> <span class="hlt">filter</span> for tracking 3D human pose in video.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sedai, Suman; Bennamoun, Mohammed; Huynh, Du Q</p> <p>2013-11-01</p> <p>In this paper, we propose a hybrid method that combines Gaussian process learning, a <span class="hlt">particle</span> <span class="hlt">filter</span>, and annealing to track the 3D pose of a human subject in video sequences. Our approach, which we refer to as annealed Gaussian process guided <span class="hlt">particle</span> <span class="hlt">filter</span>, comprises two steps. In the training step, we use a supervised learning method to train a Gaussian process regressor that takes the silhouette descriptor as an input and produces multiple output poses modeled by a mixture of Gaussian distributions. In the tracking step, the output pose distributions from the Gaussian process regression are combined with the annealed <span class="hlt">particle</span> <span class="hlt">filter</span> to track the 3D pose in each frame of the video sequence. Our experiments show that the proposed method does not require initialization and does not lose tracking of the pose. We compare our approach with a standard annealed <span class="hlt">particle</span> <span class="hlt">filter</span> using the HumanEva-I dataset and with other state of the art approaches using the HumanEva-II dataset. The evaluation results show that our approach can successfully track the 3D human pose over long video sequences and give more accurate pose tracking results than the annealed <span class="hlt">particle</span> <span class="hlt">filter</span>.</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/27706087','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27706087"><span>Characterization of Airborne <span class="hlt">Particles</span> Collected from Car Engine Air <span class="hlt">Filters</span> Using SEM and EDX Techniques.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Heredia Rivera, Birmania; Gerardo Rodriguez, Martín</p> <p>2016-10-01</p> <p>Particulate matter accumulated on car engine air-<span class="hlt">filters</span> (CAFs) was examined in order to investigate the potential use of these devices as efficient samplers for collecting street level air that people are exposed to. The morphology, microstructure, and chemical composition of a variety of <span class="hlt">particles</span> were studied using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). The particulate matter accumulated by the CAFs was studied in two categories; the first was of removed <span class="hlt">particles</span> by friction, and the second consisted of <span class="hlt">particles</span> retained on the <span class="hlt">filters</span>. Larger <span class="hlt">particles</span> with a diameter of 74-10 µm were observed in the first category. In the second one, the detected <span class="hlt">particles</span> had a diameter between 16 and 0.7 µm. These <span class="hlt">particles</span> exhibited different morphologies and composition, indicating mostly a soil origin. The elemental composition revealed the presence of three groups: mineral (clay and asphalt), metallic (mainly Fe), and biological <span class="hlt">particles</span> (vegetal and animal debris). The palynological analysis showed the presence of pollen grains associated with urban plants. These results suggest that CAFs capture a mixture of atmospheric <span class="hlt">particles</span>, which can be analyzed in order to monitor urban air. Thus, the continuous availability of large numbers of <span class="hlt">filters</span> and the retroactivity associated to the car routes suggest that these CAFs are very useful for studying the high traffic zones within a city.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5086724','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5086724"><span>Characterization of Airborne <span class="hlt">Particles</span> Collected from Car Engine Air <span class="hlt">Filters</span> Using SEM and EDX Techniques</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Heredia Rivera, Birmania; Gerardo Rodriguez, Martín</p> <p>2016-01-01</p> <p>Particulate matter accumulated on car engine air-<span class="hlt">filters</span> (CAFs) was examined in order to investigate the potential use of these devices as efficient samplers for collecting street level air that people are exposed to. The morphology, microstructure, and chemical composition of a variety of <span class="hlt">particles</span> were studied using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX). The particulate matter accumulated by the CAFs was studied in two categories; the first was of removed <span class="hlt">particles</span> by friction, and the second consisted of <span class="hlt">particles</span> retained on the <span class="hlt">filters</span>. Larger <span class="hlt">particles</span> with a diameter of 74–10 µm were observed in the first category. In the second one, the detected <span class="hlt">particles</span> had a diameter between 16 and 0.7 µm. These <span class="hlt">particles</span> exhibited different morphologies and composition, indicating mostly a soil origin. The elemental composition revealed the presence of three groups: mineral (clay and asphalt), metallic (mainly Fe), and biological <span class="hlt">particles</span> (vegetal and animal debris). The palynological analysis showed the presence of pollen grains associated with urban plants. These results suggest that CAFs capture a mixture of atmospheric <span class="hlt">particles</span>, which can be analyzed in order to monitor urban air. Thus, the continuous availability of large numbers of <span class="hlt">filters</span> and the retroactivity associated to the car routes suggest that these CAFs are very useful for studying the high traffic zones within a city. PMID:27706087</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18477653','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18477653"><span><span class="hlt">Filter</span> performance of n99 and n95 facepiece respirators against viruses and ultrafine <span class="hlt">particles</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Eninger, Robert M; Honda, Takeshi; Adhikari, Atin; Heinonen-Tanski, Helvi; Reponen, Tiina; Grinshpun, Sergey A</p> <p>2008-07-01</p> <p>The performance of three <span class="hlt">filtering</span> facepiece respirators (two models of N99 and one N95) challenged with an inert aerosol (NaCl) and three virus aerosols (enterobacteriophages MS2 and T4 and Bacillus subtilis phage)-all with significant ultrafine components-was examined using a manikin-based protocol with respirators sealed on manikins. Three inhalation flow rates, 30, 85, and 150 l min(-1), were tested. The <span class="hlt">filter</span> penetration and the quality factor were determined. Between-respirator and within-respirator comparisons of penetration values were performed. At the most penetrating <span class="hlt">particle</span> size (MPPS), >3% of MS2 virions penetrated through <span class="hlt">filters</span> of both N99 models at an inhalation flow rate of 85 l min(-1). Inhalation airflow had a significant effect upon <span class="hlt">particle</span> penetration through the tested respirator <span class="hlt">filters</span>. The <span class="hlt">filter</span> quality factor was found suitable for making relative performance comparisons. The MPPS for challenge aerosols was <0.1 mum in electrical mobility diameter for all tested respirators. Mean <span class="hlt">particle</span> penetration (by count) was significantly increased when the size fraction of <0.1 mum was included as compared to <span class="hlt">particles</span> >0.1 mum. The filtration performance of the N95 respirator approached that of the two models of N99 over the range of <span class="hlt">particle</span> sizes tested ( approximately 0.02 to 0.5 mum). <span class="hlt">Filter</span> penetration of the tested biological aerosols did not exceed that of inert NaCl aerosol. The results suggest that inert NaCl aerosols may generally be appropriate for modeling <span class="hlt">filter</span> penetration of similarly sized virions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JQSRT.113..607P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JQSRT.113..607P"><span>Absorption coefficient measurements of <span class="hlt">particle</span>-laden <span class="hlt">filters</span> using laser heating: Validation with nigrosin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Presser, Cary</p> <p>2012-05-01</p> <p>A laser-heating technique, referred as the laser-driven thermal reactor, was used in conjunction with laser transmissivity measurements to determine the absorption coefficient of <span class="hlt">particle</span>-laden substrates (e.g., quartz-fiber <span class="hlt">filters</span>). The novelty of this approach is that it analyzes a wide variety of specific samples (not just <span class="hlt">filtered</span> samples) and overcomes measurement issues (e.g., absorption enhancement) associated with other <span class="hlt">filter</span>-based <span class="hlt">particle</span> absorption techniques. The absorption coefficient was determined for nigrosin-laden, quartz-fiber <span class="hlt">filters</span> and the effect of the <span class="hlt">filter</span> on the absorption measurements was estimated when compared to the isolated nigrosin results. The isolated nigrosin absorption coefficient compared favorably with Lorenz-Mie calculations for an idealized polydispersion of spherical <span class="hlt">particles</span> (based on a measured nigronsin/de-ionized water suspension size distribution) dispersed throughout a volume equivalent to that of the nigrosin-laden <span class="hlt">filter</span>. To validate the approach, the absorption coefficient of a nigrosin/de-ionized water suspension was in good agreement with results obtained from an ultraviolet/visible spectrometer. In addition, the estimated imaginary part of the refractive index from the Lorenz-Mie calculations compared well with literature values and was used to estimate the absorption coefficient of optically opaque packed nigrosin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/932608','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/932608"><span>Distributed Adaptive <span class="hlt">Particle</span> Swarm <span class="hlt">Optimizer</span> in Dynamic Environment</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cui, Xiaohui; Potok, Thomas E</p> <p>2007-01-01</p> <p>In the real world, we have to frequently deal with searching and tracking an <span class="hlt">optimal</span> solution in a dynamical and noisy environment. This demands that the algorithm not only find the <span class="hlt">optimal</span> solution but also track the trajectory of the changing solution. <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO) is a population-based stochastic <span class="hlt">optimization</span> technique, which can find an <span class="hlt">optimal</span>, or near <span class="hlt">optimal</span>, solution to a numerical and qualitative problem. In PSO algorithm, the problem solution emerges from the interactions between many simple individual agents called <span class="hlt">particles</span>, which make PSO an inherently distributed algorithm. However, the traditional PSO algorithm lacks the ability to track the <span class="hlt">optimal</span> solution in a dynamic and noisy environment. In this paper, we present a distributed adaptive PSO (DAPSO) algorithm that can be used for tracking a non-stationary <span class="hlt">optimal</span> solution in a dynamically changing and noisy environment.</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('https://www.ncbi.nlm.nih.gov/pubmed/25105154','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25105154"><span><span class="hlt">Particle</span> <span class="hlt">filtering</span> for obstacle tracking in UAS sense and avoid applications.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tirri, Anna Elena; Fasano, Giancarmine; Accardo, Domenico; Moccia, Antonio</p> <p>2014-01-01</p> <p>Obstacle detection and tracking is a key function for UAS sense and avoid applications. In fact, obstacles in the flight path must be detected and tracked in an accurate and timely manner in order to execute a collision avoidance maneuver in case of collision threat. The most important parameter for the assessment of a collision risk is the Distance at Closest Point of Approach, that is, the predicted minimum distance between own aircraft and intruder for assigned current position and speed. Since assessed methodologies can cause some loss of accuracy due to nonlinearities, advanced <span class="hlt">filtering</span> methodologies, such as <span class="hlt">particle</span> <span class="hlt">filters</span>, can provide more accurate estimates of the target state in case of nonlinear problems, thus improving system performance in terms of collision risk estimation. The paper focuses on algorithm development and performance evaluation for an obstacle tracking system based on a <span class="hlt">particle</span> <span class="hlt">filter</span>. The <span class="hlt">particle</span> <span class="hlt">filter</span> algorithm was tested in off-line simulations based on data gathered during flight tests. In particular, radar-based tracking was considered in order to evaluate the impact of <span class="hlt">particle</span> <span class="hlt">filtering</span> in a single sensor framework. The analysis shows some accuracy improvements in the estimation of Distance at Closest Point of Approach, thus reducing the delay in collision detection.</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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4102095','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4102095"><span><span class="hlt">Particle</span> <span class="hlt">Filtering</span> for Obstacle Tracking in UAS Sense and Avoid 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>Moccia, Antonio</p> <p>2014-01-01</p> <p>Obstacle detection and tracking is a key function for UAS sense and avoid applications. In fact, obstacles in the flight path must be detected and tracked in an accurate and timely manner in order to execute a collision avoidance maneuver in case of collision threat. The most important parameter for the assessment of a collision risk is the Distance at Closest Point of Approach, that is, the predicted minimum distance between own aircraft and intruder for assigned current position and speed. Since assessed methodologies can cause some loss of accuracy due to nonlinearities, advanced <span class="hlt">filtering</span> methodologies, such as <span class="hlt">particle</span> <span class="hlt">filters</span>, can provide more accurate estimates of the target state in case of nonlinear problems, thus improving system performance in terms of collision risk estimation. The paper focuses on algorithm development and performance evaluation for an obstacle tracking system based on a <span class="hlt">particle</span> <span class="hlt">filter</span>. The <span class="hlt">particle</span> <span class="hlt">filter</span> algorithm was tested in off-line simulations based on data gathered during flight tests. In particular, radar-based tracking was considered in order to evaluate the impact of <span class="hlt">particle</span> <span class="hlt">filtering</span> in a single sensor framework. The analysis shows some accuracy improvements in the estimation of Distance at Closest Point of Approach, thus reducing the delay in collision detection. PMID:25105154</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22752097','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22752097"><span>Evaluation of <span class="hlt">filter</span> media for <span class="hlt">particle</span> number, surface area and mass penetrations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Lin; Zuo, Zhili; Japuntich, Daniel A; Pui, David Y H</p> <p>2012-07-01</p> <p>The National Institute for Occupational Safety and Health (NIOSH) developed a standard for respirator certification under 42 CFR Part 84, using a TSI 8130 automated <span class="hlt">filter</span> tester with photometers. A recent study showed that photometric detection methods may not be sensitive for measuring engineered nanoparticles. Present NIOSH standards for penetration measurement are mass-based; however, the threshold limit value/permissible exposure limit for an engineered nanoparticle worker exposure is not yet clear. There is lack of standardized <span class="hlt">filter</span> test development for engineered nanoparticles, and development of a simple nanoparticle <span class="hlt">filter</span> test is indicated. To better understand the <span class="hlt">filter</span> performance against engineered nanoparticles and correlations among different tests, initial penetration levels of one fiberglass and two electret <span class="hlt">filter</span> media were measured using a series of polydisperse and monodisperse aerosol test methods at two different laboratories (University of Minnesota <span class="hlt">Particle</span> Technology Laboratory and 3M Company). Monodisperse aerosol penetrations were measured by a TSI 8160 using NaCl <span class="hlt">particles</span> from 20 to 300 nm. <span class="hlt">Particle</span> penetration curves and overall penetrations were measured by scanning mobility <span class="hlt">particle</span> sizer (SMPS), condensation <span class="hlt">particle</span> counter (CPC), nanoparticle surface area monitor (NSAM), and TSI 8130 at two face velocities and three layer thicknesses. Results showed that reproducible, comparable filtration data were achieved between two laboratories, with proper control of test conditions and calibration procedures. For <span class="hlt">particle</span> penetration curves, the experimental results of monodisperse testing agreed well with polydisperse SMPS measurements. The most penetrating <span class="hlt">particle</span> sizes (MPPSs) of electret and fiberglass <span class="hlt">filter</span> media were ~50 and 160 nm, respectively. For overall penetrations, the CPC and NSAM results of polydisperse aerosols were close to the penetration at the corresponding median <span class="hlt">particle</span> sizes. For each <span class="hlt">filter</span> type, power</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NJPh...19b3025W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NJPh...19b3025W"><span>On <span class="hlt">optimal</span> currents of indistinguishable <span class="hlt">particles</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Walschaers, Mattia; Buchleitner, Andreas; Fannes, Mark</p> <p>2017-02-01</p> <p>We establish a mathematically rigorous, general and quantitative framework to describe currents of non- (or weakly) interacting, indistinguishable <span class="hlt">particles</span> driven far from equilibrium. We derive tight upper and lower bounds for the achievable fermionic and bosonic steady state current, respectively, which can serve as benchmarks for special cases of interacting many-<span class="hlt">particle</span> dynamics. For fermionic currents, we identify a symmetry-induced enhancement mechanism in parameter regimes where the coupling between system and reservoirs is weak. This mechanism is broadly applicable provided the inter-<span class="hlt">particle</span> interaction strength is small as compared to typical exchange interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EJASP2015...33R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EJASP2015...33R"><span>Kalman <span class="hlt">filter</span> with a linear state model for PDR+WLAN positioning and its application to assisting a <span class="hlt">particle</span> <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>Raitoharju, Matti; Nurminen, Henri; Piché, Robert</p> <p>2015-12-01</p> <p>Indoor positioning based on wireless local area network (WLAN) signals is often enhanced using pedestrian dead reckoning (PDR) based on an inertial measurement unit. The state evolution model in PDR is usually nonlinear. We present a new linear state evolution model for PDR. In simulated-data and real-data tests of tightly coupled WLAN-PDR positioning, the positioning accuracy with this linear model is better than with the traditional models when the initial heading is not known, which is a common situation. The proposed method is computationally light and is also suitable for smoothing. Furthermore, we present modifications to WLAN positioning based on Gaussian coverage areas and show how a Kalman <span class="hlt">filter</span> using the proposed model can be used for integrity monitoring and (re)initialization of a <span class="hlt">particle</span> <span class="hlt">filter</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4335141','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4335141"><span>Chaotic <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> with Mutation for Classification</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Assarzadeh, Zahra; Naghsh-Nilchi, Ahmad Reza</p> <p>2015-01-01</p> <p>In this paper, a chaotic <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> with mutation-based classifier <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> is proposed to classify patterns of different classes in the feature space. The introduced mutation operators and chaotic sequences allows us to overcome the problem of early convergence into a local minima associated with <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> algorithms. That is, the mutation operator sharpens the convergence and it tunes the best possible solution. Furthermore, to remove the irrelevant data and reduce the dimensionality of medical datasets, a feature selection approach using binary version of the proposed <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> is introduced. In order to demonstrate the effectiveness of our proposed classifier, mutation-based classifier <span class="hlt">particle</span> swarm <span class="hlt">optimization</span>, it is checked out with three sets of data classifications namely, Wisconsin diagnostic breast cancer, Wisconsin breast cancer and heart-statlog, with different feature vector dimensions. The proposed algorithm is compared with different classifier algorithms including k-nearest neighbor, as a conventional classifier, <span class="hlt">particle</span> swarm-classifier, genetic algorithm, and Imperialist competitive algorithm-classifier, as more sophisticated ones. The performance of each classifier was evaluated by calculating the accuracy, sensitivity, specificity and Matthews's correlation coefficient. The experimental results show that the mutation-based classifier <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> unequivocally performs better than all the compared algorithms. PMID:25709937</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25709937','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25709937"><span>Chaotic <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> with mutation for classification.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Assarzadeh, Zahra; Naghsh-Nilchi, Ahmad Reza</p> <p>2015-01-01</p> <p>In this paper, a chaotic <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> with mutation-based classifier <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> is proposed to classify patterns of different classes in the feature space. The introduced mutation operators and chaotic sequences allows us to overcome the problem of early convergence into a local minima associated with <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> algorithms. That is, the mutation operator sharpens the convergence and it tunes the best possible solution. Furthermore, to remove the irrelevant data and reduce the dimensionality of medical datasets, a feature selection approach using binary version of the proposed <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> is introduced. In order to demonstrate the effectiveness of our proposed classifier, mutation-based classifier <span class="hlt">particle</span> swarm <span class="hlt">optimization</span>, it is checked out with three sets of data classifications namely, Wisconsin diagnostic breast cancer, Wisconsin breast cancer and heart-statlog, with different feature vector dimensions. The proposed algorithm is compared with different classifier algorithms including k-nearest neighbor, as a conventional classifier, <span class="hlt">particle</span> swarm-classifier, genetic algorithm, and Imperialist competitive algorithm-classifier, as more sophisticated ones. The performance of each classifier was evaluated by calculating the accuracy, sensitivity, specificity and Matthews's correlation coefficient. The experimental results show that the mutation-based classifier <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> unequivocally performs better than all the compared algorithms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/827943','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/827943"><span><span class="hlt">Optimized</span> Loading for <span class="hlt">Particle</span>-in-cell Gyrokinetic Simulations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>J.L.V. Lewandowski</p> <p>2004-05-13</p> <p>The problem of <span class="hlt">particle</span> loading in <span class="hlt">particle</span>-in-cell gyrokinetic simulations is addressed using a quadratic <span class="hlt">optimization</span> algorithm. <span class="hlt">Optimized</span> loading in configuration space dramatically reduces the short wavelength modes in the electrostatic potential that are partly responsible for the non-conservation of total energy; further, the long wavelength modes are resolved with good accuracy. As a result, the conservation of energy for the <span class="hlt">optimized</span> loading is much better that the conservation of energy for the random loading. The method is valid for any geometry and can be coupled to <span class="hlt">optimization</span> algorithms in velocity space.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19926110','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19926110"><span>Removal of virus to protozoan sized <span class="hlt">particles</span> in point-of-use ceramic water <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>Bielefeldt, Angela R; Kowalski, Kate; Schilling, Cherylynn; Schreier, Simon; Kohler, Amanda; Scott Summers, R</p> <p>2010-03-01</p> <p>The <span class="hlt">particle</span> removal performance of point-of-use ceramic water <span class="hlt">filters</span> (CWFs) was characterized in the size range of 0.02-100 microm using carboxylate-coated polystyrene fluorescent microspheres, natural <span class="hlt">particles</span> and clay. <span class="hlt">Particles</span> were spiked into dechlorinated tap water, and three successive water batches treated in each of six different CWFs. <span class="hlt">Particle</span> removal generally increased with increasing size. The removal of virus-sized 0.02 and 0.1 microm spheres were highly variable between the six <span class="hlt">filters</span>, ranging from 63 to 99.6%. For the 0.5 microm spheres removal was less variable and in the range of 95.1-99.6%, while for the 1, 2, 4.5, and 10 microm spheres removal was >99.6%. Recoating four of the CWFs with colloidal silver solution improved removal of the 0.02 microm spheres, but had no significant effects on the other <span class="hlt">particle</span> sizes. Log removals of 1.8-3.2 were found for natural turbidity and spiked kaolin clay <span class="hlt">particles</span>; however, <span class="hlt">particles</span> as large as 95 microm were detected in <span class="hlt">filtered</span> water.</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/837305','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/837305"><span>Removal of <span class="hlt">Particles</span> and Acid Gases (SO2 or HCl) with a Ceramic <span class="hlt">Filter</span> by Addition of Dry Sorbents</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hemmer, G.; Kasper, G.; Wang, J.; Schaub, G.</p> <p>2002-09-20</p> <p>The present investigation intends to add to the fundamental process design know-how for dry flue gas cleaning, especially with respect to process flexibility, in cases where variations in the type of fuel and thus in concentration of contaminants in the flue gas require <span class="hlt">optimization</span> of operating conditions. In particular, temperature effects of the physical and chemical processes occurring simultaneously in the gas-<span class="hlt">particle</span> dispersion and in the <span class="hlt">filter</span> cake/<span class="hlt">filter</span> medium are investigated in order to improve the predictive capabilities for identifying optimum operating conditions. Sodium bicarbonate (NaHCO{sub 3}) and calcium hydroxide (Ca(OH){sub 2}) are known as efficient sorbents for neutralizing acid flue gas components such as HCl, HF, and SO{sub 2}. According to their physical properties (e.g. porosity, pore size) and chemical behavior (e.g. thermal decomposition, reactivity for gas-solid reactions), optimum conditions for their application vary widely. The results presented concentrate on the development of quantitative data for filtration stability and overall removal efficiency as affected by operating temperature. Experiments were performed in a small pilot unit with a ceramic <span class="hlt">filter</span> disk of the type Dia-Schumalith 10-20 (Fig. 1, described in more detail in Hemmer 2002 and Hemmer et al. 1999), using model flue gases containing SO{sub 2} and HCl, flyash from wood bark combustion, and NaHCO{sub 3} as well as Ca(OH){sub 2} as sorbent material (<span class="hlt">particle</span> size d{sub 50}/d{sub 84} : 35/192 {micro}m, and 3.5/16, respectively). The pilot unit consists of an entrained flow reactor (gas duct) representing the raw gas volume of a <span class="hlt">filter</span> house and the <span class="hlt">filter</span> disk with a <span class="hlt">filter</span> cake, operating continuously, simulating <span class="hlt">filter</span> cake build-up and cleaning of the <span class="hlt">filter</span> medium by jet pulse. Temperatures varied from 200 to 600 C, sorbent stoichiometric ratios from zero to 2, inlet concentrations were on the order of 500 to 700 mg/m{sup 3}, water vapor contents ranged from</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhCS.801a2003H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhCS.801a2003H"><span>Distributed Multi Robot Simultaneous Localization and Mapping with Consensus <span class="hlt">Particle</span> <span class="hlt">Filtering</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hidayat, F.; Trilaksono, B. R.; Hindersah, H.</p> <p>2017-01-01</p> <p>These paper present distributed computations of join probabilities SLAM with consensus <span class="hlt">particle</span> <span class="hlt">filtering</span> algorithm. We consider groups of robot observe an unknown environment and build the global maps. In this paper, every local map is a global map. Global maps build by using its own information and the information obtained from the other robots. We use <span class="hlt">particles</span> likelihood as transfer parameters. The information can be transferred to other robot if reach global agreement on <span class="hlt">particles</span> weight. The global agreement can be obtained by using the Consensus <span class="hlt">Particle</span> <span class="hlt">Filtering</span> algorithm, computation is done locally on each robot. After reaching an agreement, then the global map can be built and information of the global map is owned on each robot.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12230184','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12230184"><span><span class="hlt">Particle</span> size distribution in effluent of trickling <span class="hlt">filters</span> and in humus tanks.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schubert, W; Günthert, F W</p> <p>2001-11-01</p> <p><span class="hlt">Particles</span> and aggregates from trickling <span class="hlt">filters</span> must be eliminated from wastewater. Usually this happens through sedimentation in humus tanks. Investigations to characterize these solids by way of <span class="hlt">particle</span> size measurements, image analysis and <span class="hlt">particle</span> charge measurements (zeta potential) are made within the scope of Research Center for Science and Technology "Fundamentals of Aerobic biological wastewater treatment" (SFB 411). The <span class="hlt">particle</span> size measuring results given within this report were obtained at the Ingolstadt wastewater treatment plant, Germany, which served as an example. They have been confirmed by similar results from other facilities. <span class="hlt">Particles</span> flushed out from trickling <span class="hlt">filters</span> will be partially destroyed on their way to the humus tank. A large amount of small <span class="hlt">particles</span> is to be found there. On average 90% of the <span class="hlt">particles</span> are smaller than 30 microm. <span class="hlt">Particle</span> size plays a decisive role in the sedimentation behaviour of solids. Small <span class="hlt">particles</span> need sedimentation times that cannot be provided in settling tanks. As a result they cause turbidity in the final effluent. Therefore quality of sewage discharge suffers, and there are hardly advantages of the fixed film reactor treatment compared to the activated sludge process regarding sedimentation behaviour.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EJASP2009..105L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EJASP2009..105L"><span>Epileptic Seizure Prediction by a System of <span class="hlt">Particle</span> <span class="hlt">Filter</span> Associated with a Neural Network</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Derong; Pang, Zhongyu; Wang, Zhuo</p> <p>2009-12-01</p> <p>None of the current epileptic seizure prediction methods can widely be accepted, due to their poor consistency in performance. In this work, we have developed a novel approach to analyze intracranial EEG data. The energy of the frequency band of 4-12 Hz is obtained by wavelet transform. A dynamic model is introduced to describe the process and a hidden variable is included. The hidden variable can be considered as indicator of seizure activities. The method of <span class="hlt">particle</span> <span class="hlt">filter</span> associated with a neural network is used to calculate the hidden variable. Six patients' intracranial EEG data are used to test our algorithm including 39 hours of ictal EEG with 22 seizures and 70 hours of normal EEG recordings. The minimum least square error algorithm is applied to determine <span class="hlt">optimal</span> parameters in the model adaptively. The results show that our algorithm can successfully predict 15 out of 16 seizures and the average prediction time is 38.5 minutes before seizure onset. The sensitivity is about 93.75% and the specificity (false prediction rate) is approximately 0.09 FP/h. A random predictor is used to calculate the sensitivity under significance level of 5%. Compared to the random predictor, our method achieved much better performance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27249002','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27249002"><span>Adaptive <span class="hlt">Particle</span> <span class="hlt">Filter</span> for Nonparametric Estimation with Measurement Uncertainty in Wireless 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>Li, Xiaofan; Zhao, Yubin; Zhang, Sha; Fan, Xiaopeng</p> <p>2016-05-30</p> <p><span class="hlt">Particle</span> <span class="hlt">filters</span> (PFs) are widely used for nonlinear signal processing in wireless sensor networks (WSNs). However, the measurement uncertainty makes the WSN observations unreliable to the actual case and also degrades the estimation accuracy of the PFs. In addition to the algorithm design, few works focus on improving the likelihood calculation method, since it can be pre-assumed by a given distribution model. In this paper, we propose a novel PF method, which is based on a new likelihood fusion method for WSNs and can further improve the estimation performance. We firstly use a dynamic Gaussian model to describe the nonparametric features of the measurement uncertainty. Then, we propose a likelihood adaptation method that employs the prior information and a belief factor to reduce the measurement noise. The <span class="hlt">optimal</span> belief factor is attained by deriving the minimum Kullback-Leibler divergence. The likelihood adaptation method can be integrated into any PFs, and we use our method to develop three versions of adaptive PFs for a target tracking system using wireless sensor network. The simulation and experimental results demonstrate that our likelihood adaptation method has greatly improved the estimation performance of PFs in a high noise environment. In addition, the adaptive PFs are highly adaptable to the environment without imposing computational complexity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JNR....17..407S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JNR....17..407S"><span>Antibacterial performance of nano polypropylene <span class="hlt">filter</span> media containing nano-TiO2 and clay <span class="hlt">particles</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shafiee, Sara; Zarrebini, Mohammad; Naghashzargar, Elham; Semnani, Dariush</p> <p>2015-10-01</p> <p>Disinfection and elimination of pathogenic microorganisms from liquid can be achieved by filtration process using antibacterial <span class="hlt">filter</span> media. The advent of nanotechnology has facilitated the introduction of membranes consisting of nano-fiber in filtration operations. The melt electro-spun fibers due to their extremely small diameters are used in the production of this particular filtration medium. In this work, antibacterial polypropylene <span class="hlt">filter</span> medium containing clay <span class="hlt">particles</span> and nano-TiO2 were made using melt electro-spun technology. Antibacterial performance of polypropylene nano-<span class="hlt">filters</span> was evaluated using E. coli bacteria. Additionally, filtration efficiency of the samples in terms fiber diameter, <span class="hlt">filter</span> porosity, and fiber distribution using image processing technique was determined. Air permeability and dust aerosol tests were conducted to establish the suitability of the samples as a <span class="hlt">filter</span> medium. It was concluded that as far as antibacterial property is concerned, nano-fibers <span class="hlt">filter</span> media containing clay <span class="hlt">particles</span> are preferential to similar media containing TiO2 nanoparticles.</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> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22306056','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22306056"><span>Boundary <span class="hlt">filters</span> for vector <span class="hlt">particles</span> passing parity breaking domains</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kolevatov, S. S.; Andrianov, A. A.</p> <p>2014-07-23</p> <p>The electrodynamics supplemented with a Lorenz and CPT invariance violating Chern-Simons (CS) action (Carrol-Field-Jackiw electrodynamics) is studied when the parity-odd medium is bounded by a hyperplane separating it from the vacuum. The solutions in both half-spaces are carefully discussed and for space-like boundary stitched on the boundary with help of the Bogolubov transformations. The presence of two different Fock vacua is shown. The passage of photons and massive vector mesons through a boundary between the CS medium and the vacuum of conventional Maxwell electrodynamics is investigated. Effects of reflection from a boundary (up to the total one) are revealed when vector <span class="hlt">particles</span> escape to vacuum and income from vacuum passing the boundary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JSV...306..111S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JSV...306..111S"><span>Use of <span class="hlt">particle</span> <span class="hlt">filters</span> in an active control algorithm for noisy nonlinear structural dynamical systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sajeeb, R.; Manohar, C. S.; Roy, D.</p> <p>2007-09-01</p> <p>The problem of active control of nonlinear structural dynamical systems, in the presence of both process and measurement noises, is considered. The focus of the study is on the use of <span class="hlt">particle</span> <span class="hlt">filters</span> for state estimation in feedback control algorithms for nonlinear structures, when a limited number of noisy output measurements are available. The control design is done using the state-dependent Riccati equation (SDRE) method. The stochastic differential equations (SDEs) governing the dynamical systems are discretized using explicit forms of Ito-Taylor expansions. The Bayesian bootstrap <span class="hlt">filter</span> and that based on sequential important sampling (SIS) are employed for state estimation. The simulation results show the feasibility of using <span class="hlt">particle</span> <span class="hlt">filters</span> and SDRE techniques in control of nonlinear structural dynamical systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA609311','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA609311"><span>Computer Vision Tracking Using <span class="hlt">Particle</span> <span class="hlt">Filters</span> for 3D Position Estimation</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>2014-03-27</p> <p>5 2.2 Photogrammetry ...focus on <span class="hlt">particle</span> <span class="hlt">filters</span>. 2.2 Photogrammetry Photogrammetry is the process of determining 3-D coordinates through images. The mathematical underpinnings...of photogrammetry are rooted in the 1480s with Leonardo da Vinci’s study of perspectives [8, p. 1]. However, digital photogrammetry did not emerge</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('https://www.ncbi.nlm.nih.gov/pubmed/17764353','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17764353"><span>High-efficiency particulate air <span class="hlt">filter</span> test stand and aerosol generator for <span class="hlt">particle</span> loading studies.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Arunkumar, R; Hogancamp, Kristina U; Parsons, Michael S; Rogers, Donna M; Norton, Olin P; Nagel, Brian A; Alderman, Steven L; Waggoner, Charles A</p> <p>2007-08-01</p> <p>This manuscript describes the design, characterization, and operational range of a test stand and high-output aerosol generator developed to evaluate the performance of 30 x 30 x 29 cm(3) nuclear grade high-efficiency particulate air (HEPA) <span class="hlt">filters</span> under variable, highly controlled conditions. The test stand system is operable at volumetric flow rates ranging from 1.5 to 12 standard m(3)/min. Relative humidity levels are controllable from 5%-90% and the temperature of the aerosol stream is variable from ambient to 150 degrees C. Test aerosols are produced through spray drying source material solutions that are introduced into a heated stainless steel evaporation chamber through an air-atomizing nozzle. Regulation of the <span class="hlt">particle</span> size distribution of the aerosol challenge is achieved by varying source solution concentrations and through the use of a postgeneration cyclone. The aerosol generation system is unique in that it facilitates the testing of standard HEPA <span class="hlt">filters</span> at and beyond rated media velocities by consistently providing, into a nominal flow of 7 standard m(3)/min, high mass concentrations (approximately 25 mg/m(3)) of dry aerosol streams having count mean diameters centered near the most penetrating <span class="hlt">particle</span> size for HEPA <span class="hlt">filters</span> (120-160 nm). Aerosol streams that have been generated and characterized include those derived from various concentrations of KCl, NaCl, and sucrose solutions. Additionally, a water insoluble aerosol stream in which the solid component is predominantly iron (III) has been produced. Multiple ports are available on the test stand for making simultaneous aerosol measurements upstream and downstream of the test <span class="hlt">filter</span>. Types of <span class="hlt">filter</span> performance related studies that can be performed using this test stand system include <span class="hlt">filter</span> lifetime studies, <span class="hlt">filtering</span> efficiency testing, media velocity testing, evaluations under high mass loading and high humidity conditions, and determination of the downstream <span class="hlt">particle</span> size distributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PASP..125..838P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PASP..125..838P"><span>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/25815446','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25815446"><span>Integration of GPS precise point positioning and MEMS-based INS using unscented <span class="hlt">particle</span> <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>Abd Rabbou, Mahmoud; El-Rabbany, Ahmed</p> <p>2015-03-25</p> <p>Integration of Global Positioning System (GPS) and Inertial Navigation System (INS) integrated system involves nonlinear motion state and measurement models. However, the extended Kalman <span class="hlt">filter</span> (EKF) is commonly used as the estimation <span class="hlt">filter</span>, which might lead to solution divergence. This is usually encountered during GPS outages, when low-cost micro-electro-mechanical sensors (MEMS) inertial sensors are used. To enhance the navigation system performance, alternatives to the standard EKF should be considered. <span class="hlt">Particle</span> <span class="hlt">filtering</span> (PF) is commonly considered as a nonlinear estimation technique to accommodate severe MEMS inertial sensor biases and noise behavior. However, the computation burden of PF limits its use. In this study, an improved version of PF, the unscented <span class="hlt">particle</span> <span class="hlt">filter</span> (UPF), is utilized, which combines the unscented Kalman <span class="hlt">filter</span> (UKF) and PF for the integration of GPS precise point positioning and MEMS-based inertial systems. The proposed <span class="hlt">filter</span> is examined and compared with traditional estimation <span class="hlt">filters</span>, namely EKF, UKF and PF. Tightly coupled mechanization is adopted, which is developed in the raw GPS and INS measurement domain. Un-differenced ionosphere-free linear combinations of pseudorange and carrier-phase measurements are used for PPP. The performance of the UPF is analyzed using a real test scenario in downtown Kingston, Ontario. It is shown that the use of UPF reduces the number of samples needed to produce an accurate solution, in comparison with the traditional PF, which in turn reduces the processing time. In addition, UPF enhances the positioning accuracy by up to 15% during GPS outages, in comparison with EKF. However, all <span class="hlt">filters</span> produce comparable results when the GPS measurement updates are available.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4431276','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4431276"><span>Integration of GPS Precise Point Positioning and MEMS-Based INS Using Unscented <span class="hlt">Particle</span> <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>Abd Rabbou, Mahmoud; El-Rabbany, Ahmed</p> <p>2015-01-01</p> <p>Integration of Global Positioning System (GPS) and Inertial Navigation System (INS) integrated system involves nonlinear motion state and measurement models. However, the extended Kalman <span class="hlt">filter</span> (EKF) is commonly used as the estimation <span class="hlt">filter</span>, which might lead to solution divergence. This is usually encountered during GPS outages, when low-cost micro-electro-mechanical sensors (MEMS) inertial sensors are used. To enhance the navigation system performance, alternatives to the standard EKF should be considered. <span class="hlt">Particle</span> <span class="hlt">filtering</span> (PF) is commonly considered as a nonlinear estimation technique to accommodate severe MEMS inertial sensor biases and noise behavior. However, the computation burden of PF limits its use. In this study, an improved version of PF, the unscented <span class="hlt">particle</span> <span class="hlt">filter</span> (UPF), is utilized, which combines the unscented Kalman <span class="hlt">filter</span> (UKF) and PF for the integration of GPS precise point positioning and MEMS-based inertial systems. The proposed <span class="hlt">filter</span> is examined and compared with traditional estimation <span class="hlt">filters</span>, namely EKF, UKF and PF. Tightly coupled mechanization is adopted, which is developed in the raw GPS and INS measurement domain. Un-differenced ionosphere-free linear combinations of pseudorange and carrier-phase measurements are used for PPP. The performance of the UPF is analyzed using a real test scenario in downtown Kingston, Ontario. It is shown that the use of UPF reduces the number of samples needed to produce an accurate solution, in comparison with the traditional PF, which in turn reduces the processing time. In addition, UPF enhances the positioning accuracy by up to 15% during GPS outages, in comparison with EKF. However, all <span class="hlt">filters</span> produce comparable results when the GPS measurement updates are available. PMID:25815446</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.1486Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.1486Z"><span>Joint State and Parameter Estimation for Two Land Surface Models Using the Ensemble Kalman <span class="hlt">Filter</span> and <span class="hlt">Particle</span> <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>Zhang, Hongjuan; Hendricks-Franssen, Harrie-Jan; Han, Xujun; Vrugt, Jasper A.; Vereecken, Harry</p> <p>2016-04-01</p> <p>Land surface models (LSMs) resolve the water and energy balance with different parameters and state variables. Many of the parameters of these models cannot be measured directly in the field, and require calibration against flux and soil moisture data. Two LSMs are used in our work: Variable Infiltration Capacity Hydrologic Model (VIC) and the Community Land Model (CLM). Temporal variations in soil moisture content at 5, 20 and 50 cm depth in the Rollesbroich experimental watershed in Germany are simulated in both LSMs. Data assimilation (DA) provides a good way to jointly estimate soil moisture content and soil properties of the resolved soil domain. Four DA methods combined with the two LSMs are used in our work: the Ensemble Kalman <span class="hlt">Filter</span> (EnKF) using state augmentation or dual estimation, the Residual Resampling <span class="hlt">Particle</span> <span class="hlt">Filter</span> (RRPF) and Markov chain Monte Carlo <span class="hlt">Particle</span> <span class="hlt">Filter</span> (MCMCPF). These four DA methods are tuned and calibrated for a five month period, and subsequently evaluated for another five month period. Performances of the two LSMs and the four DA methods are compared. Our results show that all DA methods improve the estimation of soil moisture content of the VIC and CLM models, especially if the soil hydraulic properties (VIC), the maximum baseflow velocity (VIC) and/or soil texture (CLM) are jointly estimated with soil moisture content. The augmentation and dual estimation methods performed slightly better than RRPF and MCMCPF in the evaluation period. The differences in simulated soil moisture content between CLM and VIC were larger than variations among the DA methods. The CLM performed better than the VIC model. The strong underestimation of soil moisture content in the third layer of the VIC model is likely related to an inadequate parameterization of groundwater drainage.</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('https://www.osti.gov/scitech/biblio/22304120','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22304120"><span><span class="hlt">Optimization</span> of magnetic switches for single <span class="hlt">particle</span> and cell transport</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Abedini-Nassab, Roozbeh; Yellen, Benjamin B.; Murdoch, David M.; Kim, CheolGi</p> <p>2014-06-28</p> <p>The ability to manipulate an ensemble of single <span class="hlt">particles</span> and cells is a key aim of lab-on-a-chip research; however, the control mechanisms must be <span class="hlt">optimized</span> for minimal power consumption to enable future large-scale implementation. Recently, we demonstrated a matter transport platform, which uses overlaid patterns of magnetic films and metallic current lines to control magnetic <span class="hlt">particles</span> and magnetic-nanoparticle-labeled cells; however, we have made no prior attempts to <span class="hlt">optimize</span> the device geometry and power consumption. Here, we provide an <span class="hlt">optimization</span> analysis of <span class="hlt">particle</span>-switching devices based on stochastic variation in the <span class="hlt">particle</span>'s size and magnetic content. These results are immediately applicable to the design of robust, multiplexed platforms capable of transporting, sorting, and storing single cells in large arrays with low power and high efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EnOp...47..129W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EnOp...47..129W"><span>Self-regulating and self-evolving <span class="hlt">particle</span> swarm <span class="hlt">optimizer</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, Hui-Min; Qiao, Zhao-Wei; Xia, Chang-Liang; Li, Liang-Yu</p> <p>2015-01-01</p> <p>In this article, a novel self-regulating and self-evolving <span class="hlt">particle</span> swarm <span class="hlt">optimizer</span> (SSPSO) is proposed. Learning from the idea of direction reversal, self-regulating behaviour is a modified position update rule for <span class="hlt">particles</span>, according to which the algorithm improves the best position to accelerate convergence in situations where the traditional update rule does not work. Borrowing the idea of mutation from evolutionary computation, self-evolving behaviour acts on the current best <span class="hlt">particle</span> in the swarm to prevent the algorithm from prematurely converging. The performance of SSPSO and four other improved <span class="hlt">particle</span> swarm <span class="hlt">optimizers</span> is numerically evaluated by unimodal, multimodal and rotated multimodal benchmark functions. The effectiveness of SSPSO in solving real-world problems is shown by the magnetic <span class="hlt">optimization</span> of a Halbach-based permanent magnet machine. The results show that SSPSO has good convergence performance and high reliability, and is well matched to actual problems.</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/2014EGUGA..1615059E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1615059E"><span>Station Based Polynomial Modeling of the local ionospheric Vertical Total Electron Content (VTEC) using <span class="hlt">Particle</span> <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>Erdogan, Eren; Onur Karslioglu, Mahmut; Durmaz, Murat; Aghakarimi, Armin</p> <p>2014-05-01</p> <p>In this study, <span class="hlt">particle</span> <span class="hlt">filter</span> (PF) which is mainly based on the Monte Carlo simulation technique has been carried out for polynomial modeling of the local ionospheric conditions above the selected ground based stations. Less sensitivity to the errors caused by linearization of models and the effect of unknown or unmodeled components in the system model is one of the advantages of the <span class="hlt">particle</span> <span class="hlt">filter</span> as compared to the Kalman <span class="hlt">filter</span> which is commonly used as a recursive <span class="hlt">filtering</span> method in VTEC modeling. Besides, probability distribution of the system models is not necessarily required to be Gaussian. In this work third order polynomial function has been incorporated into the <span class="hlt">particle</span> <span class="hlt">filter</span> implementation to represent the local VTEC distribution. Coefficients of the polynomial model presenting the ionospheric parameters and the receiver inter frequency biases are the unknowns forming the state vector which has been estimated epoch-wise for each ground station. To consider the time varying characteristics of the regional VTEC distribution, dynamics of the state vector parameters changing permanently have been modeled using the first order Gauss-Markov process. In the processing of the <span class="hlt">particle</span> <span class="hlt">filtering</span>, multi-variety probability distribution of the state vector through the time has been approximated by means of randomly selected samples and their associated weights. A known drawback of the <span class="hlt">particle</span> <span class="hlt">filtering</span> is that the increasing number of the state vector parameters results in an inefficient <span class="hlt">filter</span> performance and requires more samples to represent the probability distribution of the state vector. Considering the total number of unknown parameters for all ground stations, estimation of these parameters which were inserted into a single state vector has caused the <span class="hlt">particle</span> <span class="hlt">filter</span> to produce inefficient results. To solve this problem, the PF implementation has been carried out separately for each ground station at current time epochs. After estimation of unknown</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 <span class="hlt">particles</span> generated by a constant output atomizer were used as challenge aerosols to minimize <span class="hlt">particle</span> loading effects. A scanning mobility <span class="hlt">particle</span> 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 <span class="hlt">particle</span> 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 <span class="hlt">particle</span> diameter of 122 nm. From the aspect of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.A42C..08M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.A42C..08M"><span>Implicit <span class="hlt">particle</span> <span class="hlt">filtering</span> for equations with partial noise and application to geomagnetic 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>Morzfeld, M.; Atkins, E.; Chorin, A. J.</p> <p>2011-12-01</p> <p>The task in data assimilation is to identify the state of a system from an uncertain model supplemented by a stream of incomplete and noisy data. The model is typically given in form of a discretization of an Ito stochastic differential equation (SDE), x(n+1) = R(x(n))+ G W(n), where x is an m-dimensional vector and n=0,1,2,.... The m-dimensional vector function R and the m x m matrix G depend on the SDE as well as on the discretization scheme, and W is an m-dimensional vector whose elements are independent standard normal variates. The data are y(n) = h(x(n))+QV(n) where h is a k-dimensional vector function, Q is a k x k matrix and V is a vector whose components are independent standard normal variates. One can use statistics of the conditional probability density (pdf) of the state given the observations, p(n+1)=p(x(n+1)|y(1), ... , y(n+1)), to identify the state x(n+1). <span class="hlt">Particle</span> <span class="hlt">filters</span> approximate p(n+1) by sequential Monte Carlo and rely on the recursive formulation of the target pdf, p(n+1)∝p(x(n+1)|x(n)) p(y(n+1)|x(n+1)). The pdf p(x(n+1)|x(n)) can be read off of the model equations to be a Gaussian with mean R(x(n)) and covariance matrix Σ = GG^T, where the T denotes a transposed; the pdf p(y(n+1)|x(n+1)) is a Gaussian with mean h(x(n+1)) and covariance QQ^T. In a sampling-importance-resampling (SIR) <span class="hlt">filter</span> one samples new values for the <span class="hlt">particles</span> from a prior pdf and then one weighs these samples with weights determined by the observations, to yield an approximation to p(n+1). Such weighting schemes often yield small weights for many of the <span class="hlt">particles</span>. Implicit <span class="hlt">particle</span> <span class="hlt">filtering</span> overcomes this problem by using the observations to generate the <span class="hlt">particles</span>, thus focusing attention on regions of large probability. A suitable algebraic equation that depends on the model and the observations is constructed for each <span class="hlt">particle</span>, and its solution yields high probability samples of p(n+1). In the current formulation of the implicit <span class="hlt">particle</span> <span class="hlt">filter</span>, the state</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20850737','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20850737"><span>An improved <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> algorithm for reliability problems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, Peifeng; Gao, Liqun; Zou, Dexuan; Li, Steven</p> <p>2011-01-01</p> <p>An improved <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (IPSO) algorithm is proposed to solve reliability problems in this paper. The IPSO designs two position updating strategies: In the early iterations, each <span class="hlt">particle</span> flies and searches according to its own best experience with a large probability; in the late iterations, each <span class="hlt">particle</span> flies and searches according to the fling experience of the most successful <span class="hlt">particle</span> with a large probability. In addition, the IPSO introduces a mutation operator after position updating, which can not only prevent the IPSO from trapping into the local optimum, but also enhances its space developing ability. Experimental results show that the proposed algorithm has stronger convergence and stability than the other four <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> algorithms on solving reliability problems, and that the solutions obtained by the IPSO are better than the previously reported best-known solutions in the recent literature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999JPhD...32.1097A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999JPhD...32.1097A"><span><span class="hlt">Particle</span> capture in axial magnetic <span class="hlt">filters</span> with power law flow model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abbasov, T.; Herdem, S.; Köksal, M.</p> <p>1999-05-01</p> <p>A theory of capture of magnetic <span class="hlt">particle</span> carried by laminar flow of viscous non-Newtonian (power law) fluid in axially ordered <span class="hlt">filters</span> is presented. The velocity profile of the fluid flow is determined by the Kuwabara-Happel cell model. For the trajectory of the <span class="hlt">particle</span>, the capture area and the <span class="hlt">filter</span> performance simple analytical expressions are obtained. These expressions are valid for <span class="hlt">particle</span> capture processes from both Newtonian and non-Newtonian fluids. For this reason the obtained theoretical results make it possible to widen the application of high-gradient magnetic filtration (HGMF) to other industrial areas. For Newtonian fluids the theoretical results are shown to be in good agreement with the experimental ones reported in the literature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23095291','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23095291"><span><span class="hlt">Filtering</span> capacity of Daphnia magna on sludge <span class="hlt">particles</span> in treated wastewater.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pau, Conxi; Serra, Teresa; Colomer, Jordi; Casamitjana, Xavier; Sala, Lluís; Kampf, Ruud</p> <p>2013-01-01</p> <p>A great challenge in water reuse is the reduction of suspended <span class="hlt">particle</span> concentration in wastewater. In particular the reduction of the presence of small <span class="hlt">particles</span> in suspension which cause a cloudy appearance in the water and, which also make disinfection difficult. The present study evaluates the <span class="hlt">filtering</span> capacity of a population of Cladodera (Daphnia magna) in secondary effluents from a wastewater plant. The study was performed in both a mesocosm and the laboratory, in an effort to compare the grazing on sludge <span class="hlt">particles</span> by Daphnia versus the settling rate of those sludge <span class="hlt">particles</span>. The <span class="hlt">particle</span> volume concentration of small <span class="hlt">particles</span> (with a diameter below 30 μm) was used to evaluate the efficiency of the proposed biotreatment system for small <span class="hlt">particles</span>. Both laboratory and mesocosm results showed that the suspended <span class="hlt">particle</span> volume concentration decreased with time due to the Daphnia filtration, with the highest reduction in experiments carried out with the highest Daphnia concentration. In the mesocosm experiments, the Daphnia diameter was also found to play an important role, with an allometric relationship between the <span class="hlt">filtering</span> rate of Daphnia and the Daphnia nondimensional diameter. In laboratory experiments, the effect of D. magna in the suspended concentration of small <span class="hlt">particles</span> was in the range of 10.1-29.4%, according to the range of Daphnia concentration of 10-50 ind/l. For laboratory experiments, sedimentation was responsible for 62.2% of the suspended <span class="hlt">particle</span> concentration reduction. For the mesocosm experiments, the reduction in the <span class="hlt">particle</span> concentration attributed to the Daphnia filtration ranged between 2.5 and 39%, corresponding to Daphnia concentrations of between 5 and 100 ind/l (i.e. biovolumes of 8-60 ind/l).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18726819','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18726819"><span>Evaluation of the effect of media velocity on <span class="hlt">filter</span> efficiency and most penetrating <span class="hlt">particle</span> size of nuclear grade high-efficiency particulate air <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>Alderman, Steven L; Parsons, Michael S; Hogancamp, Kristina U; Waggoner, Charles A</p> <p>2008-11-01</p> <p>High-efficiency particulate air (HEPA) <span class="hlt">filters</span> are widely used to control particulate matter emissions from processes that involve management or treatment of radioactive materials. Section FC of the American Society of Mechanical Engineers AG-1 Code on Nuclear Air and Gas Treatment currently restricts media velocity to a maximum of 2.5 cm/sec in any application where this standard is invoked. There is some desire to eliminate or increase this media velocity limit. A concern is that increasing media velocity will result in higher emissions of ultrafine <span class="hlt">particles</span>; thus, it is unlikely that higher media velocities will be allowed without data to demonstrate the effect of media velocity on removal of ultrafine <span class="hlt">particles</span>. In this study, the performance of nuclear grade HEPA <span class="hlt">filters</span>, with respect to <span class="hlt">filter</span> efficiency and most penetrating <span class="hlt">particle</span> size, was evaluated as a function of media velocity. Deep-pleat nuclear grade HEPA <span class="hlt">filters</span> (31 cm x 31 cm x 29 cm) were evaluated at media velocities ranging from 2.0 to 4.5 cm/sec using a potassium chloride aerosol challenge having a <span class="hlt">particle</span> size distribution centered near the HEPA <span class="hlt">filter</span> most penetrating <span class="hlt">particle</span> size. <span class="hlt">Filters</span> were challenged under two distinct mass loading rate regimes through the use of or exclusion of a 3 microm aerodynamic diameter cut point cyclone. <span class="hlt">Filter</span> efficiency and most penetrating <span class="hlt">particle</span> size measurements were made throughout the duration of <span class="hlt">filter</span> testing. <span class="hlt">Filter</span> efficiency measured at the onset of aerosol challenge was noted to decrease with increasing media velocity, with values ranging from 99.999 to 99.977%. The <span class="hlt">filter</span> most penetrating <span class="hlt">particle</span> size recorded at the onset of testing was noted to decrease slightly as media velocity was increased and was typically in the range of 110-130 nm. Although additional testing is needed, these findings indicate that <span class="hlt">filters</span> operating at media velocities up to 4.5 cm/sec will meet or exceed current <span class="hlt">filter</span> efficiency requirements. Additionally</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16351153','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16351153"><span>Continuous collection of soluble atmospheric <span class="hlt">particles</span> with a wetted hydrophilic <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>Takeuchi, Masaki; Ullah, S M Rahmat; Dasgupta, Purnendu K; Collins, Donald R; Williams, Allen</p> <p>2005-12-15</p> <p>Approximately one-third of the area (14-mm diameter of a 25-mm diameter) of a 5-microm uniform pore size polycarbonate <span class="hlt">filter</span> is continuously wetted by a 0.25 mL/min water mist. The water forms a continuous thin film on the <span class="hlt">filter</span> and percolates through it. The flowing water substantially reduces the effective pore size of the <span class="hlt">filter</span>. At the operational air sampling flow rate of 1.5 standard liters per minute, such a <span class="hlt">particle</span> collector (PC) efficiently captures <span class="hlt">particles</span> down to very small size. As determined by fluorescein-tagged NaCl aerosol generated by a vibrating orifice aerosol generator, the capture efficiency was 97.7+% for <span class="hlt">particle</span> aerodynamic diameters ranging from 0.28 to 3.88 microm. Further, 55.3 and 80.3% of 25- and 100-nm (NH4)2SO4 <span class="hlt">particles</span> generated by size classification with a differential mobility analyzer were respectively collected by the device. The PC is integrally coupled with a liquid collection reservoir. The liquid effluent from the wetted <span class="hlt">filter</span> collector, bearing the soluble components of the aerosol, can be continuously collected or periodically withdrawn. The latter strategy permits the use of a robust syringe pump for the purpose. Coupled with a PM2.5 cyclone inlet and a membrane-based parallel plate denuder at the front end and an ion chromatograph at the back end, the PC readily operated for at least 4-week periods without <span class="hlt">filter</span> replacement or any other maintenance.</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('https://www.ncbi.nlm.nih.gov/pubmed/23961391','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23961391"><span>Gravity inversion of a fault by <span class="hlt">Particle</span> swarm <span class="hlt">optimization</span> (PSO).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Toushmalani, Reza</p> <p>2013-01-01</p> <p><span class="hlt">Particle</span> swarm <span class="hlt">optimization</span> is a heuristic global <span class="hlt">optimization</span> method and also an <span class="hlt">optimization</span> algorithm, which is based on swarm intelligence. It comes from the research on the bird and fish flock movement behavior. In this paper we introduce and use this method in gravity inverse problem. We discuss the solution for the inverse problem of determining the shape of a fault whose gravity anomaly is known. Application of the proposed algorithm to this problem has proven its capability to deal with difficult <span class="hlt">optimization</span> problems. The technique proved to work efficiently when tested to a number of models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22862434','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22862434"><span>Variation in penetration of submicrometric <span class="hlt">particles</span> through electrostatic <span class="hlt">filtering</span> facepieces during exposure to paraffin oil aerosol.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Plebani, Carmela; Listrani, Stefano; Tranfo, Giovanna; Tombolini, Francesca</p> <p>2012-01-01</p> <p>Several studies show the increase of penetration through electrostatic <span class="hlt">filters</span> during exposure to an aerosol flow, because of <span class="hlt">particle</span> deposition on <span class="hlt">filter</span> fibers. We studied the effect of increasing loads of paraffin oil aerosol on the penetration of selected <span class="hlt">particle</span> sizes through an electrostatic <span class="hlt">filtering</span> facepiece. FFP2 facepieces were exposed for 8 hr to a flow rate of 95.0 ± 0.5 L/min of polydisperse paraffin aerosol at 20.0 ± 0.5 mg/m(3). The penetration of bis(2-ethylhexyl)sebacate (DEHS) monodisperse neutralized aerosols, with selected <span class="hlt">particle</span> size in the 0.03-0.40 μm range, was measured immediately prior to the start of the paraffin aerosol loading and at 1, 4, and 8 hr after the start of paraffin aerosol loading. Penetration through isopropanol-treated facepieces not oil paraffin loaded was also measured to evaluate facepiece behavior when electrostatic capture mechanisms are practically absent. During exposure to paraffin aerosol, DEHS penetration gradually increased for all aerosol sizes, and the most penetrating <span class="hlt">particle</span> size (0.05 μm at the beginning of exposure) shifted slightly to larger diameters. After the isopropanol treatment, the higher penetration value was 0.30 μm. In addition to an increased penetration during paraffin loading at a given <span class="hlt">particle</span> size, the relative degree of increase was greater as the <span class="hlt">particle</span> size increased. Penetration value measured after 8 hr for 0.03-μm <span class="hlt">particles</span> was on average 1.6 times the initial value, whereas it was about 8 times for 0.40-μm <span class="hlt">particles</span>. This behavior, as well evidenced in the measurements of isopropanol-treated facepieces, can be attributed to the increasing action in <span class="hlt">particle</span> capture of the electrostatic forces (Coulomb and polarization), which depend strictly on the diameter and electrical charge of neutralized aerosol <span class="hlt">particles</span>. With reference to electrostatic <span class="hlt">filtering</span> facepieces as personal protective equipment, results suggest the importance of complying with the manufacturer</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://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5101411','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5101411"><span>Tracking Algorithm of Multiple Pedestrians Based on <span class="hlt">Particle</span> <span class="hlt">Filters</span> in Video Sequences</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Liu, Yun; Wang, Chuanxu; Zhang, Shujun; Cui, Xuehong</p> <p>2016-01-01</p> <p>Pedestrian tracking is a critical problem in the field of computer vision. <span class="hlt">Particle</span> <span class="hlt">filters</span> have been proven to be very useful in pedestrian tracking for nonlinear and non-Gaussian estimation problems. However, pedestrian tracking in complex environment is still facing many problems due to changes of pedestrian postures and scale, moving background, mutual occlusion, and presence of pedestrian. To surmount these difficulties, this paper presents tracking algorithm of multiple pedestrians based on <span class="hlt">particle</span> <span class="hlt">filters</span> in video sequences. The algorithm acquires confidence value of the object and the background through extracting a priori knowledge thus to achieve multipedestrian detection; it adopts color and texture features into <span class="hlt">particle</span> <span class="hlt">filter</span> to get better observation results and then automatically adjusts weight value of each feature according to current tracking environment. During the process of tracking, the algorithm processes severe occlusion condition to prevent drift and loss phenomena caused by object occlusion and associates detection results with <span class="hlt">particle</span> state to propose discriminated method for object disappearance and emergence thus to achieve robust tracking of multiple pedestrians. Experimental verification and analysis in video sequences demonstrate that proposed algorithm improves the tracking performance and has better tracking results. PMID:27847514</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27847514','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27847514"><span>Tracking Algorithm of Multiple Pedestrians Based on <span class="hlt">Particle</span> <span class="hlt">Filters</span> in Video Sequences.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Hui; Liu, Yun; Wang, Chuanxu; Zhang, Shujun; Cui, Xuehong</p> <p>2016-01-01</p> <p>Pedestrian tracking is a critical problem in the field of computer vision. <span class="hlt">Particle</span> <span class="hlt">filters</span> have been proven to be very useful in pedestrian tracking for nonlinear and non-Gaussian estimation problems. However, pedestrian tracking in complex environment is still facing many problems due to changes of pedestrian postures and scale, moving background, mutual occlusion, and presence of pedestrian. To surmount these difficulties, this paper presents tracking algorithm of multiple pedestrians based on <span class="hlt">particle</span> <span class="hlt">filters</span> in video sequences. The algorithm acquires confidence value of the object and the background through extracting a priori knowledge thus to achieve multipedestrian detection; it adopts color and texture features into <span class="hlt">particle</span> <span class="hlt">filter</span> to get better observation results and then automatically adjusts weight value of each feature according to current tracking environment. During the process of tracking, the algorithm processes severe occlusion condition to prevent drift and loss phenomena caused by object occlusion and associates detection results with <span class="hlt">particle</span> state to propose discriminated method for object disappearance and emergence thus to achieve robust tracking of multiple pedestrians. Experimental verification and analysis in video sequences demonstrate that proposed algorithm improves the tracking performance and has better tracking results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MeScT..28d5205L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MeScT..28d5205L"><span>Full-waveform LiDAR echo decomposition based on wavelet decomposition and <span class="hlt">particle</span> swarm <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>Li, Duan; Xu, Lijun; Li, Xiaolu</p> <p>2017-04-01</p> <p>To measure the distances and properties of the objects within a laser footprint, a decomposition method for full-waveform light detection and ranging (LiDAR) echoes is proposed. In this method, firstly, wavelet decomposition is used to <span class="hlt">filter</span> the noise and estimate the noise level in a full-waveform echo. Secondly, peak and inflection points of the <span class="hlt">filtered</span> full-waveform echo are used to detect the echo components in the <span class="hlt">filtered</span> full-waveform echo. Lastly, <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) is used to remove the noise-caused echo components and <span class="hlt">optimize</span> the parameters of the most probable echo components. Simulation results show that the wavelet-decomposition-based <span class="hlt">filter</span> is of the best improvement of SNR and decomposition success rates than Wiener and Gaussian smoothing <span class="hlt">filters</span>. In addition, the noise level estimated using wavelet-decomposition-based <span class="hlt">filter</span> is more accurate than those estimated using other two commonly used methods. Experiments were carried out to evaluate the proposed method that was compared with our previous method (called GS-LM for short). In experiments, a lab-build full-waveform LiDAR system was utilized to provide eight types of full-waveform echoes scattered from three objects at different distances. Experimental results show that the proposed method has higher success rates for decomposition of full-waveform echoes and more accurate parameters estimation for echo components than those of GS-LM. The proposed method based on wavelet decomposition and PSO is valid to decompose the more complicated full-waveform echoes for estimating the multi-level distances of the objects and measuring the properties of the objects in a laser footprint.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JIEIB..97..525B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JIEIB..97..525B"><span>Improved <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> for Global <span class="hlt">Optimization</span> of Unimodal and Multimodal Functions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Basu, Mousumi</p> <p>2016-12-01</p> <p><span class="hlt">Particle</span> swarm <span class="hlt">optimization</span> (PSO) performs well for small dimensional and less complicated problems but fails to locate global minima for complex multi-minima functions. This paper proposes an improved <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (IPSO) which introduces Gaussian random variables in velocity term. This improves search efficiency and guarantees a high probability of obtaining the global optimum without significantly impairing the speed of convergence and the simplicity of the structure of <span class="hlt">particle</span> swarm <span class="hlt">optimization</span>. The algorithm is experimentally validated on 17 benchmark functions and the results demonstrate good performance of the IPSO in solving unimodal and multimodal problems. Its high performance is verified by comparing with two popular PSO variants.</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/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 <span class="hlt">particle</span> 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 <span class="hlt">particle</span> 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('http://adsabs.harvard.edu/abs/2012EGUGA..14.3008P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.3008P"><span>Joint global <span class="hlt">optimization</span> of tomographic data based on <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> and decision theory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paasche, H.; Tronicke, J.</p> <p>2012-04-01</p> <p>In many near surface geophysical applications multiple tomographic data sets are routinely acquired to explore subsurface structures and parameters. Linking the model generation process of multi-method geophysical data sets can significantly reduce ambiguities in geophysical data analysis and model interpretation. Most geophysical inversion approaches rely on local search <span class="hlt">optimization</span> methods used to find an <span class="hlt">optimal</span> model in the vicinity of a user-given starting model. The final solution may critically depend on the initial model. Alternatively, global <span class="hlt">optimization</span> (GO) methods have been used to invert geophysical data. They explore the solution space in more detail and determine the <span class="hlt">optimal</span> model independently from the starting model. Additionally, they can be used to find sets of <span class="hlt">optimal</span> models allowing a further analysis of model parameter uncertainties. Here we employ <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) to realize the global <span class="hlt">optimization</span> of tomographic data. PSO is an emergent methods based on swarm intelligence characterized by fast and robust convergence towards <span class="hlt">optimal</span> solutions. The fundamental principle of PSO is inspired by nature, since the algorithm mimics the behavior of a flock of birds searching food in a search space. In PSO, a number of <span class="hlt">particles</span> cruise a multi-dimensional solution space striving to find <span class="hlt">optimal</span> model solutions explaining the acquired data. The <span class="hlt">particles</span> communicate their positions and success and direct their movement according to the position of the currently most successful <span class="hlt">particle</span> of the swarm. The success of a <span class="hlt">particle</span>, i.e. the quality of the currently found model by a <span class="hlt">particle</span>, must be uniquely quantifiable to identify the swarm leader. When jointly inverting disparate data sets, the <span class="hlt">optimization</span> solution has to satisfy multiple <span class="hlt">optimization</span> objectives, at least one for each data set. Unique determination of the most successful <span class="hlt">particle</span> currently leading the swarm is not possible. Instead, only statements about the Pareto</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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4187218','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4187218"><span>Combining Video, Audio and Lexical Indicators of Affect in Spontaneous Conversation via <span class="hlt">Particle</span> <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>Savran, Arman; Cao, Houwei; Shah, Miraj; Nenkova, Ani; Verma, Ragini</p> <p>2013-01-01</p> <p>We present experiments on fusing facial video, audio and lexical indicators for affect estimation during dyadic conversations. We use temporal statistics of texture descriptors extracted from facial video, a combination of various acoustic features, and lexical features to create regression based affect estimators for each modality. The single modality regressors are then combined using <span class="hlt">particle</span> <span class="hlt">filtering</span>, by treating these independent regression outputs as measurements of the affect states in a Bayesian <span class="hlt">filtering</span> framework, where previous observations provide prediction about the current state by means of learned affect dynamics. Tested on the Audio-visual Emotion Recognition Challenge dataset, our single modality estimators achieve substantially higher scores than the official baseline method for every dimension of affect. Our <span class="hlt">filtering</span>-based multi-modality fusion achieves correlation performance of 0.344 (baseline: 0.136) and 0.280 (baseline: 0.096) for the fully continuous and word level sub challenges, respectively. PMID:25300451</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhFl...28k5106I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhFl...28k5106I"><span>Lagrangian <span class="hlt">filtered</span> density function for LES-based stochastic modelling of turbulent <span class="hlt">particle</span>-laden flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Innocenti, Alessio; Marchioli, Cristian; Chibbaro, Sergio</p> <p>2016-11-01</p> <p>The Eulerian-Lagrangian approach based on Large-Eddy Simulation (LES) is one of the most promising and viable numerical tools to study <span class="hlt">particle</span>-laden turbulent flows, when the computational cost of Direct Numerical Simulation (DNS) becomes too expensive. The applicability of this approach is however limited if the effects of the Sub-Grid Scales (SGSs) of the flow on <span class="hlt">particle</span> dynamics are neglected. In this paper, we propose to take these effects into account by means of a Lagrangian stochastic SGS model for the equations of <span class="hlt">particle</span> motion. The model extends to <span class="hlt">particle</span>-laden flows the velocity-<span class="hlt">filtered</span> density function method originally developed for reactive flows. The underlying <span class="hlt">filtered</span> density function is simulated through a Lagrangian Monte Carlo procedure that solves a set of Stochastic Differential Equations (SDEs) along individual <span class="hlt">particle</span> trajectories. The resulting model is tested for the reference case of turbulent channel flow, using a hybrid algorithm in which the fluid velocity field is provided by LES and then used to advance the SDEs in time. The model consistency is assessed in the limit of <span class="hlt">particles</span> with zero inertia, when "duplicate fields" are available from both the Eulerian LES and the Lagrangian tracking. Tests with inertial <span class="hlt">particles</span> were performed to examine the capability of the model to capture the <span class="hlt">particle</span> preferential concentration and near-wall segregation. Upon comparison with DNS-based statistics, our results show improved accuracy and considerably reduced errors with respect to the case in which no SGS model is used in the equations of <span class="hlt">particle</span> motion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25240099','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25240099"><span>Retention of radioactive <span class="hlt">particles</span> and associated effects in the <span class="hlt">filter</span>-feeding marine mollusc Mytilus edulis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jaeschke, B C; Lind, O C; Bradshaw, C; Salbu, B</p> <p>2015-01-01</p> <p>Radioactive <span class="hlt">particles</span> are aggregates of radioactive atoms that may contain significant activity concentrations. They have been released into the environment from nuclear weapons tests, and from accidents and effluents associated with the nuclear fuel cycle. Aquatic <span class="hlt">filter</span>-feeders can capture and potentially retain radioactive <span class="hlt">particles</span>, which could then provide concentrated doses to nearby tissues. This study experimentally investigated the retention and effects of radioactive <span class="hlt">particles</span> in the blue mussel, Mytilus edulis. Spent fuel <span class="hlt">particles</span> originating from the Dounreay nuclear establishment, and collected in the field, comprised a U and Al alloy containing fission products such as (137)Cs and (90)Sr/(90)Y. <span class="hlt">Particles</span> were introduced into mussels in suspension with plankton-food or through implantation in the extrapallial cavity. Of the <span class="hlt">particles</span> introduced with food, 37% were retained for 70 h, and were found on the siphon or gills, with the notable exception of one <span class="hlt">particle</span> that was ingested and found in the stomach. <span class="hlt">Particles</span> not retained seemed to have been actively rejected and expelled by the mussels. The largest and most radioactive <span class="hlt">particle</span> (estimated dose rate 3.18 ± 0.06 Gyh(-1)) induced a significant increase in Comet tail-DNA %. In one case this <span class="hlt">particle</span> caused a large white mark (suggesting necrosis) in the mantle tissue with a simultaneous increase in micronucleus frequency observed in the haemolymph collected from the muscle, implying that non-targeted effects of radiation were induced by radiation from the retained <span class="hlt">particle</span>. White marks found in the tissue were attributed to ionising radiation and physical irritation. The results indicate that current methods used for risk assessment, based upon the absorbed dose equivalent limit and estimating the "no-effect dose" are inadequate for radioactive <span class="hlt">particle</span> exposures. Knowledge is lacking about the ecological implications of radioactive <span class="hlt">particles</span> released into the environment, for example potential</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.H31A0824K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.H31A0824K"><span>Real-Time Flood Forecasting System Using Channel Flow Routing Model with Updating by <span class="hlt">Particle</span> <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>Kudo, R.; Chikamori, H.; Nagai, A.</p> <p>2008-12-01</p> <p>A real-time flood forecasting system using channel flow routing model was developed for runoff forecasting at water gauged and ungaged points along river channels. The system is based on a flood runoff model composed of upstream part models, tributary part models and downstream part models. The upstream part models and tributary part models are lumped rainfall-runoff models, and the downstream part models consist of a lumped rainfall-runoff model for hillslopes adjacent to a river channel and a kinematic flow routing model for a river channel. The flow forecast of this model is updated by <span class="hlt">Particle</span> <span class="hlt">filtering</span> of the downstream part model as well as by the extended Kalman <span class="hlt">filtering</span> of the upstream part model and the tributary part models. The <span class="hlt">Particle</span> <span class="hlt">filtering</span> is a simple and powerful updating algorithm for non-linear and non-gaussian system, so that it can be easily applied to the downstream part model without complicated linearization. The presented flood runoff model has an advantage in simlecity of updating procedure to the grid-based distributed models, which is because of less number of state variables. This system was applied to the Gono-kawa River Basin in Japan, and flood forecasting accuracy of the system with both <span class="hlt">Particle</span> <span class="hlt">filtering</span> and extended Kalman <span class="hlt">filtering</span> and that of the system with only extended Kalman <span class="hlt">filtering</span> were compared. In this study, water gauging stations in the objective basin were divided into two types of stations, that is, reference stations and verification stations. Reference stations ware regarded as ordinary water gauging stations and observed data at these stations are used for calibration and updating of the model. Verification stations ware considered as ungaged or arbitrary points and observed data at these stations are used not for calibration nor updating but for only evaluation of forecasting accuracy. The result confirms that <span class="hlt">Particle</span> <span class="hlt">filtering</span> of the downstream part model improves forecasting accuracy of runoff at</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ExA....42..343A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ExA....42..343A"><span>Adaptive <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> for <span class="hlt">optimal</span> orbital elements of binary stars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Attia, Abdel-Fattah</p> <p>2016-12-01</p> <p>The paper presents an adaptive <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (APSO) as an alternative method to determine the <span class="hlt">optimal</span> orbital elements of the star η Bootis of MK type G0 IV. The proposed algorithm transforms the problem of finding periodic orbits into the problem of detecting global minimizers as a function, to get a best fit of Keplerian and Phase curves. The experimental results demonstrate that the proposed approach of APSO generally more accurate than the standard <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) and other published <span class="hlt">optimization</span> algorithms, in terms of solution accuracy, convergence speed and algorithm reliability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27505357','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27505357"><span>Inversion method based on stochastic <span class="hlt">optimization</span> for <span class="hlt">particle</span> sizing.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sánchez-Escobar, Juan Jaime; Barbosa-Santillán, Liliana Ibeth; Vargas-Ubera, Javier; Aguilar-Valdés, Félix</p> <p>2016-08-01</p> <p>A stochastic inverse method is presented based on a hybrid evolutionary <span class="hlt">optimization</span> algorithm (HEOA) to retrieve a monomodal <span class="hlt">particle</span>-size distribution (PSD) from the angular distribution of scattered light. By solving an <span class="hlt">optimization</span> problem, the HEOA (with the Fraunhofer approximation) retrieves the PSD from an intensity pattern generated by Mie theory. The analyzed light-scattering pattern can be attributed to unimodal normal, gamma, or lognormal distribution of spherical <span class="hlt">particles</span> covering the interval of modal size parameters 46≤α≤150. The HEOA ensures convergence to the near-<span class="hlt">optimal</span> solution during the <span class="hlt">optimization</span> of a real-valued objective function by combining the advantages of a multimember evolution strategy and locally weighted linear regression. The numerical results show that our HEOA can be satisfactorily applied to solve the inverse light-scattering problem.</p> </li> <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 <span class="hlt">particle</span> <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 <span class="hlt">particle</span> <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/21905841','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21905841"><span>Quantum-behaved <span class="hlt">particle</span> swarm <span class="hlt">optimization</span>: analysis of individual <span class="hlt">particle</span> behavior and parameter selection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sun, Jun; Fang, Wei; Wu, Xiaojun; Palade, Vasile; Xu, Wenbo</p> <p>2012-01-01</p> <p>Quantum-behaved <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (QPSO), motivated by concepts from quantum mechanics and <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO), is a probabilistic <span class="hlt">optimization</span> algorithm belonging to the bare-bones PSO family. Although it has been shown to perform well in finding the <span class="hlt">optimal</span> solutions for many <span class="hlt">optimization</span> problems, there has so far been little analysis on how it works in detail. This paper presents a comprehensive analysis of the QPSO algorithm. In the theoretical analysis, we analyze the behavior of a single <span class="hlt">particle</span> in QPSO in terms of probability measure. Since the <span class="hlt">particle</span>'s behavior is influenced by the contraction-expansion (CE) coefficient, which is the most important parameter of the algorithm, the goal of the theoretical analysis is to find out the upper bound of the CE coefficient, within which the value of the CE coefficient selected can guarantee the convergence or boundedness of the <span class="hlt">particle</span>'s position. In the experimental analysis, the theoretical results are first validated by stochastic simulations for the <span class="hlt">particle</span>'s behavior. Then, based on the derived upper bound of the CE coefficient, we perform empirical studies on a suite of well-known benchmark functions to show how to control and select the value of the CE coefficient, in order to obtain generally good algorithmic performance in real world applications. Finally, a further performance comparison between QPSO and other variants of PSO on the benchmarks is made to show the efficiency of the QPSO algorithm with the proposed parameter control and selection methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24607536','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24607536"><span><span class="hlt">Optimization</span> of detector positioning in the radioactive <span class="hlt">particle</span> tracking technique.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dubé, Olivier; Dubé, David; Chaouki, Jamal; Bertrand, François</p> <p>2014-07-01</p> <p>The radioactive <span class="hlt">particle</span> tracking (RPT) technique is a non-intrusive experimental velocimetry and tomography technique extensively applied to the study of hydrodynamics in a great variety of systems. In this technique, arrays of scintillation detector are used to track the motion of a single radioactive tracer <span class="hlt">particle</span> emitting isotropic γ-rays. This work describes and applies an <span class="hlt">optimization</span> strategy developed to find an <span class="hlt">optimal</span> set of positions for the scintillation detectors used in the RPT technique. This strategy employs the overall resolution of the detectors as the objective function and a mesh adaptive direct search (MADS) algorithm to solve the <span class="hlt">optimization</span> problem. More precisely, NOMAD, a C++ implementation of the MADS algorithm is used. First, the <span class="hlt">optimization</span> strategy is validated using simple cases with known <span class="hlt">optimal</span> detector configurations. Next, it is applied to a three-dimensional axisymmetric system (i.e. a vertical cylinder, which could represent a fluidized bed, bubble column, riser or else). The results obtained using the <span class="hlt">optimization</span> strategy are in agreement with what was previously recommended by Roy et al. (2002) for a similar system. Finally, the <span class="hlt">optimization</span> strategy is used for a system consisting of a partially filled cylindrical tumbler. The application of insights gained by the <span class="hlt">optimization</span> strategy is shown to lead to a significant reduction in the error made when reconstructing the position of a tracer <span class="hlt">particle</span>. The results of this work show that the <span class="hlt">optimization</span> strategy developed is sensitive to both the type of objective function used and the experimental conditions. The limitations and drawbacks of the <span class="hlt">optimization</span> strategy are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020002861','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020002861"><span><span class="hlt">Particle</span> <span class="hlt">Filters</span> for Real-Time Fault Detection in Planetary Rovers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dearden, Richard; Clancy, Dan; Koga, Dennis (Technical Monitor)</p> <p>2001-01-01</p> <p>Planetary rovers provide a considerable challenge for robotic systems in that they must operate for long periods autonomously, or with relatively little intervention. To achieve this, they need to have on-board fault detection and diagnosis capabilities in order to determine the actual state of the vehicle, and decide what actions are safe to perform. Traditional model-based diagnosis techniques are not suitable for rovers due to the tight coupling between the vehicle's performance and its environment. Hybrid diagnosis using <span class="hlt">particle</span> <span class="hlt">filters</span> is presented as an alternative, and its strengths and weakeners are examined. We also present some extensions to <span class="hlt">particle</span> <span class="hlt">filters</span> that are designed to make them more suitable for use in diagnosis problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24248280','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24248280"><span>Unscented <span class="hlt">particle</span> <span class="hlt">filtering</span> for estimation of shipboard deformation based on inertial measurement units.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Bo; Xiao, Xuan; Xia, Yuanqing; Fu, Mengyin</p> <p>2013-11-15</p> <p>Shipboard is not an absolute rigid body. Many factors could cause deformations which lead to large errors of mounted devices, especially for the navigation systems. Such errors should be estimated and compensated effectively, or they will severely reduce the navigation accuracy of the ship. In order to estimate the deformation, an unscented <span class="hlt">particle</span> <span class="hlt">filter</span> method for estimation of shipboard deformation based on an inertial measurement unit is presented. In this method, a nonlinear shipboard deformation model is built. Simulations demonstrated the accuracy reduction due to deformation. Then an attitude plus angular rate match mode is proposed as a frame to estimate the shipboard deformation using inertial measurement units. In this frame, for the nonlinearity of the system model, an unscented <span class="hlt">particle</span> <span class="hlt">filter</span> method is proposed to estimate and compensate the deformation angles. Simulations show that the proposed method gives accurate and rapid deformation estimations, which can increase navigation accuracy after compensation of deformation.</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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3871098','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3871098"><span>Unscented <span class="hlt">Particle</span> <span class="hlt">Filtering</span> for Estimation of Shipboard Deformation Based on Inertial Measurement Units</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, Bo; Xiao, Xuan; Xia, Yuanqing; Fu, Mengyin</p> <p>2013-01-01</p> <p>Shipboard is not an absolute rigid body. Many factors could cause deformations which lead to large errors of mounted devices, especially for the navigation systems. Such errors should be estimated and compensated effectively, or they will severely reduce the navigation accuracy of the ship. In order to estimate the deformation, an unscented <span class="hlt">particle</span> <span class="hlt">filter</span> method for estimation of shipboard deformation based on an inertial measurement unit is presented. In this method, a nonlinear shipboard deformation model is built. Simulations demonstrated the accuracy reduction due to deformation. Then an attitude plus angular rate match mode is proposed as a frame to estimate the shipboard deformation using inertial measurement units. In this frame, for the nonlinearity of the system model, an unscented <span class="hlt">particle</span> <span class="hlt">filter</span> method is proposed to estimate and compensate the deformation angles. Simulations show that the proposed method gives accurate and rapid deformation estimations, which can increase navigation accuracy after compensation of deformation. PMID:24248280</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3324861','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3324861"><span><span class="hlt">Particle</span> <span class="hlt">Filtering</span> with Region-based Matching for Tracking of Partially Occluded and Scaled Targets*</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nakhmani, Arie; Tannenbaum, Allen</p> <p>2012-01-01</p> <p>Visual tracking of arbitrary targets in clutter is important for a wide range of military and civilian applications. We propose a general framework for the tracking of scaled and partially occluded targets, which do not necessarily have prominent features. The algorithm proposed in the present paper utilizes a modified normalized cross-correlation as the likelihood for a <span class="hlt">particle</span> <span class="hlt">filter</span>. The algorithm divides the template, selected by the user in the first video frame, into numerous patches. The matching process of these patches by <span class="hlt">particle</span> <span class="hlt">filtering</span> allows one to handle the target’s occlusions and scaling. Experimental results with fixed rectangular templates show that the method is reliable for videos with nonstationary, noisy, and cluttered background, and provides accurate trajectories in cases of target translation, scaling, and occlusion. PMID:22506088</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040087092','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040087092"><span>Combining <span class="hlt">Particle</span> <span class="hlt">Filters</span> and Consistency-Based Approaches for Monitoring and Diagnosis of Stochastic Hybrid Systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Narasimhan, Sriram; Dearden, Richard; Benazera, Emmanuel</p> <p>2004-01-01</p> <p>Fault detection and isolation are critical tasks to ensure correct operation of systems. When we consider stochastic hybrid systems, diagnosis algorithms need to track both the discrete mode and the continuous state of the system in the presence of noise. Deterministic techniques like Livingstone cannot deal with the stochasticity in the system and models. Conversely Bayesian belief update techniques such as <span class="hlt">particle</span> <span class="hlt">filters</span> may require many computational resources to get a good approximation of the true belief state. In this paper we propose a fault detection and isolation architecture for stochastic hybrid systems that combines look-ahead Rao-Blackwellized <span class="hlt">Particle</span> <span class="hlt">Filters</span> (RBPF) with the Livingstone 3 (L3) diagnosis engine. In this approach RBPF is used to track the nominal behavior, a novel n-step prediction scheme is used for fault detection and L3 is used to generate a set of candidates that are consistent with the discrepant observations which then continue to be tracked by the RBPF scheme.</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('http://hdl.handle.net/2060/20080048261','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080048261"><span>Ares-I Bending <span class="hlt">Filter</span> Design using a Constrained <span class="hlt">Optimization</span> Approach</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hall, Charles; Jang, Jiann-Woei; Hall, Robert; Bedrossian, Nazareth</p> <p>2008-01-01</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 is required to ensure adequate stable response to guidance commands while minimizing trajectory deviations. 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 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 <span class="hlt">filters</span> 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 <span class="hlt">optimization</span> problem. Imposing these constrains minimizes performance degradation caused by the addition of the bending <span class="hlt">filters</span>. The first stage bending <span class="hlt">filter</span> 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 <span class="hlt">filter</span> design gain stabilizes all the flex bending modes. The bending <span class="hlt">filter</span> 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.</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('http://hdl.handle.net/2060/20120016941','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120016941"><span>Statistical Orbit Determination using the <span class="hlt">Particle</span> <span class="hlt">Filter</span> for Incorporating Non-Gaussian Uncertainties</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mashiku, Alinda; Garrison, James L.; Carpenter, J. Russell</p> <p>2012-01-01</p> <p>The tracking of space objects requires frequent and accurate monitoring for collision avoidance. As even collision events with very low probability are important, accurate prediction of collisions require the representation of the full probability density function (PDF) of the random orbit state. Through representing the full PDF of the orbit state for orbit maintenance and collision avoidance, we can take advantage of the statistical information present in the heavy tailed distributions, more accurately representing the orbit states with low probability. The classical methods of orbit determination (i.e. Kalman <span class="hlt">Filter</span> and its derivatives) provide state estimates based on only the second moments of the state and measurement errors that are captured by assuming a Gaussian distribution. Although the measurement errors can be accurately assumed to have a Gaussian distribution, errors with a non-Gaussian distribution could arise during propagation between observations. Moreover, unmodeled dynamics in the orbit model could introduce non-Gaussian errors into the process noise. A <span class="hlt">Particle</span> <span class="hlt">Filter</span> (PF) is proposed as a nonlinear <span class="hlt">filtering</span> technique that is capable of propagating and estimating a more complete representation of the state distribution as an accurate approximation of a full PDF. The PF uses Monte Carlo runs to generate <span class="hlt">particles</span> that approximate the full PDF representation. The PF is applied in the estimation and propagation of a highly eccentric orbit and the results are compared to the Extended Kalman <span class="hlt">Filter</span> and Splitting Gaussian Mixture algorithms to demonstrate its proficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22003741','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22003741"><span>Segmentation of nerve bundles and ganglia in spine MRI using <span class="hlt">particle</span> <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>Dalca, Adrian; Danagoulian, Giovanna; Kikinis, Ron; Schmidt, Ehud; Golland, Polina</p> <p>2011-01-01</p> <p>Automatic segmentation of spinal nerve bundles that originate within the dural sac and exit the spinal canal is important for diagnosis and surgical planning. The variability in intensity, contrast, shape and direction of nerves seen in high resolution myelographic MR images makes segmentation a challenging task. In this paper, we present an automatic tracking method for nerve segmentation based on <span class="hlt">particle</span> <span class="hlt">filters</span>. We develop a novel approach to <span class="hlt">particle</span> representation and dynamics, based on Bézier splines. Moreover, we introduce a robust image likelihood model that enables delineation of nerve bundles and ganglia from the surrounding anatomical structures. We demonstrate accurate and fast nerve tracking and compare it to expert manual segmentation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/86929','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/86929"><span>Advanced <span class="hlt">particle</span> <span class="hlt">filter</span>. Technical progress report No. 19, January 1995--March 1995</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p></p> <p>1995-08-01</p> <p>Tidd advanced <span class="hlt">particle</span> filtration (APF) test runs 25 through 34 were completed during the first quarter of 1995. All Tidd testing was completed with the conclusion of APF test run 34 on 3/30/95. The Westinghouse activities supporting the APF operation during this quarter included processing of test data and participating in one APF borescope inspection. Data is included on the <span class="hlt">filter</span> operation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AIPC.1375..320S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AIPC.1375..320S"><span>3D Air Filtration Modeling for Nanofiber Based <span class="hlt">Filters</span> in the Ultrafine <span class="hlt">Particle</span> Size Range</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sambaer, Wannes; Zatloukal, Martin; Kimmer, Dusan</p> <p>2011-07-01</p> <p>In this work, novel 3D filtration model for nanofiber based <span class="hlt">filters</span> has been proposed and tested. For the model validation purposes, filtration efficiency characteristics of two different polyurethane nanofiber based structures (prepared by the electrospinning process) were determined experimentally in the ultrafine <span class="hlt">particle</span> size range (20-400 nm). It has been found that the proposed model is able to reasonably predict the measured filtration efficiency curves for both tested samples.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20608503','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20608503"><span><span class="hlt">Particle</span> properties in granular activated carbon <span class="hlt">filter</span> during drinking water treatment.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Tao; Chen, Wei; Wang, Leilei</p> <p>2010-01-01</p> <p>The elemental composition and bacteria attached in <span class="hlt">particles</span> were investigated during granular activated carbon (GAC) filtration. The experimental results showed that trapped influent <span class="hlt">particles</span> could form new, larger <span class="hlt">particles</span> on GAC surface. The sloughing of individuals off GAC surface caused an increase in effluent <span class="hlt">particles</span> in the size range from 5 to 25 tm. The selectivity for element removal in GAC <span class="hlt">filters</span> caused an increasing proportion of metallic elements in the effluent <span class="hlt">particles</span>. The distribution of molar ratio indicated a complicated composition for large <span class="hlt">particles</span>, involving organic and inorganic substances. The organic proportion accounted for 40% of total carbon attached to the <span class="hlt">particles</span>. Compared with dissolved carbon, there was potential for the formation of trihalomethanes by organic carbon attached to <span class="hlt">particles</span>, especially for those with size larger than 10 im. The pure carbon energy spectrum was found only in the GAC effluent and the size distribution of carbon fines was mainly above 10 microm. The larger carbon fines provided more space for bacterial colonization and stronger protection for attached bacteria against disinfection. The residual attached bacteria after chorine disinfection was increased to 10(2)-l0(3) CFU/mL within 24 hours at 25 degrees C.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/835884','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/835884"><span>A HIGH TEMPERATURE TEST FACILITY FOR STUDYING ASH <span class="hlt">PARTICLE</span> CHARACTERISTICS OF CANDLE <span class="hlt">FILTER</span> DURING SURFACE REGENERATION</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kang, B.S-J.; Johnson, E.K.; Rincon, J.</p> <p>2002-09-19</p> <p>Hot gas particulate filtration is a basic component in advanced power generation systems such as Integrated Gasification Combined Cycle (IGCC) and Pressurized Fluidized Bed Combustion (PFBC). These systems require effective particulate removal to protect the downstream gas turbine and also to meet environmental emission requirements. The ceramic barrier <span class="hlt">filter</span> is one of the options for hot gas filtration. Hot gases flow through ceramic candle <span class="hlt">filters</span> leaving ash deposited on the outer surface of the <span class="hlt">filter</span>. A process known as surface regeneration removes the deposited ash periodically by using a high pressure back pulse cleaning jet. After this cleaning process has been done there may be some residual ash on the <span class="hlt">filter</span> surface. This residual ash may grow and this may lead to mechanical failure of the <span class="hlt">filter</span>. A High Temperature Test Facility (HTTF) was built to investigate the ash characteristics during surface regeneration at high temperatures. The system is capable of conducting surface regeneration tests of a single candle <span class="hlt">filter</span> at temperatures up to 1500 F. Details of the HTTF apparatus as well as some preliminary test results are presented in this paper. In order to obtain sequential digital images of ash <span class="hlt">particle</span> distribution during the surface regeneration process, a high resolution, high speed image acquisition system was integrated into the HTTF system. The regeneration pressure and the transient pressure difference between the inside of the candle <span class="hlt">filter</span> and the chamber during regeneration were measured using a high speed PC data acquisition system. The control variables for the high temperature regeneration tests were (1) face velocity, (2) pressure of the back pulse, and (3) cyclic ash built-up time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4208186','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4208186"><span>Robust Dead Reckoning System for Mobile Robots Based on <span class="hlt">Particle</span> <span class="hlt">Filter</span> and Raw Range Scan</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Duan, Zhuohua; Cai, Zixing; Min, Huaqing</p> <p>2014-01-01</p> <p>Robust dead reckoning is a complicated problem for wheeled mobile robots (WMRs), where the robots are faulty, such as the sticking of sensors or the slippage of wheels, for the discrete fault models and the continuous states have to be estimated simultaneously to reach a reliable fault diagnosis and accurate dead reckoning. <span class="hlt">Particle</span> <span class="hlt">filters</span> are one of the most promising approaches to handle hybrid system estimation problems, and they have also been widely used in many WMRs applications, such as pose tracking, SLAM, video tracking, fault identification, etc. In this paper, the readings of a laser range finder, which may be also interfered with by noises, are used to reach accurate dead reckoning. The main contribution is that a systematic method to implement fault diagnosis and dead reckoning in a <span class="hlt">particle</span> <span class="hlt">filter</span> framework concurrently is proposed. Firstly, the perception model of a laser range finder is given, where the raw scan may be faulty. Secondly, the kinematics of the normal model and different fault models for WMRs are given. Thirdly, the <span class="hlt">particle</span> <span class="hlt">filter</span> for fault diagnosis and dead reckoning is discussed. At last, experiments and analyses are reported to show the accuracy and efficiency of the presented method. PMID:25192318</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AIPC..914..192X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AIPC..914..192X"><span>Electrostatic Introduction Theory Based Spatial <span class="hlt">Filtering</span> Method for Solid <span class="hlt">Particle</span> Velocity Measurement</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Chuanlong; Tang, Guanghua; Zhou, Bin; Yang, Daoye; Zhang, Jianyong; Wang, Shimin</p> <p>2007-06-01</p> <p>Electrostatic induction theory based spatial <span class="hlt">filtering</span> method for <span class="hlt">particle</span> velocity measurement has the advantages of the simplicity of measurement system and of the convenience of data processing. In this paper, the relationship between solid <span class="hlt">particle</span> velocity and the power spectrum of the output signal of the electrostatic senor was derived theoretically. And the effects of the length of the electrode, the thickness of the dielectric pipe and its length on the spatial <span class="hlt">filtering</span> characteristics of the electrostatic sensor were investigated numerically using finite element method. Additionally, as for the roughness and the difficult determination of the peak frequency fmax of the power spectrum characteristics curve of the output signal, a wavelet analysis based <span class="hlt">filtering</span> method was adopted to smooth the curve, which can determine peak frequency fmax accurately. Finally, the velocity measurement method was applied in a dense phase pneumatic conveying system under high pressure, and the experimental results show that the system repeatability is within ±4% over the gas superficial velocity range of 8.63-18.62 m/s for <span class="hlt">particle</span> concentration range 0.067-0.130 m3/m3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22624307','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22624307"><span>Fitting complex population models by combining <span class="hlt">particle</span> <span class="hlt">filters</span> with Markov chain Monte Carlo.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Knape, Jonas; de Valpine, Perry</p> <p>2012-02-01</p> <p>We show how a recent framework combining Markov chain Monte Carlo (MCMC) with <span class="hlt">particle</span> <span class="hlt">filters</span> (PFMCMC) may be used to estimate population state-space models. With the purpose of utilizing the strengths of each method, PFMCMC explores hidden states by <span class="hlt">particle</span> <span class="hlt">filters</span>, while process and observation parameters are estimated using an MCMC algorithm. PFMCMC is exemplified by analyzing time series data on a red kangaroo (Macropus rufus) population in New South Wales, Australia, using MCMC over model parameters based on an adaptive Metropolis-Hastings algorithm. We fit three population models to these data; a density-dependent logistic diffusion model with environmental variance, an unregulated stochastic exponential growth model, and a random-walk model. Bayes factors and posterior model probabilities show that there is little support for density dependence and that the random-walk model is the most parsimonious model. The <span class="hlt">particle</span> <span class="hlt">filter</span> Metropolis-Hastings algorithm is a brute-force method that may be used to fit a range of complex population models. Implementation is straightforward and less involved than standard MCMC for many models, and marginal densities for model selection can be obtained with little additional effort. The cost is mainly computational, resulting in long running times that may be improved by parallelizing the algorithm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24606255','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24606255"><span>Sound speed estimation and source localization with linearization and <span class="hlt">particle</span> <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>Lin, Tao; Michalopoulou, Zoi-Heleni</p> <p>2014-03-01</p> <p>A method is developed for the estimation of source location and sound speed in the water column relying on linearization. The Jacobian matrix, necessary for the proposed linearization approach, includes derivatives with respect to empirical orthogonal function coefficients instead of sound speed directly. First, the inversion technique is tested on synthetic arrival times, using Gaussian distributions for the errors in the considered arrival times. The approach is efficient, requiring a few iterations, and produces accurate results. Probability densities of the estimates are calculated for different levels of noise in the arrival times. Subsequently, <span class="hlt">particle</span> <span class="hlt">filtering</span> is employed for the estimation of arrival times from signals recorded during the Shallow Water 06 experiment. It has been shown in the past that <span class="hlt">particle</span> <span class="hlt">filtering</span> can be employed for the successful estimation of multipath arrival times from short-range data and, consequently, in geometry, bathymetry, and sound speed inversion. Here probability density functions of arrival times computed via <span class="hlt">particle</span> <span class="hlt">filtering</span> are propagated backward through the proposed inversion process. Inversion estimates are consistent with values reported in the literature for the same quantities. Last it is shown that results are consistent with estimates resulting from fast simulated annealing applied to the same data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22067435','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22067435"><span>A self-learning <span class="hlt">particle</span> swarm <span class="hlt">optimizer</span> for global <span class="hlt">optimization</span> problems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Changhe; Yang, Shengxiang; Nguyen, Trung Thanh</p> <p>2012-06-01</p> <p><span class="hlt">Particle</span> swarm <span class="hlt">optimization</span> (PSO) has been shown as an effective tool for solving global <span class="hlt">optimization</span> problems. So far, most PSO algorithms use a single learning pattern for all <span class="hlt">particles</span>, which means that all <span class="hlt">particles</span> in a swarm use the same strategy. This monotonic learning pattern may cause the lack of intelligence for a particular <span class="hlt">particle</span>, which makes it unable to deal with different complex situations. This paper presents a novel algorithm, called self-learning <span class="hlt">particle</span> swarm <span class="hlt">optimizer</span> (SLPSO), for global <span class="hlt">optimization</span> problems. In SLPSO, each <span class="hlt">particle</span> has a set of four strategies to cope with different situations in the search space. The cooperation of the four strategies is implemented by an adaptive learning framework at the individual level, which can enable a <span class="hlt">particle</span> to choose the <span class="hlt">optimal</span> strategy according to its own local fitness landscape. The experimental study on a set of 45 test functions and two real-world problems show that SLPSO has a superior performance in comparison with several other peer algorithms.</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/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> </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/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://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 step 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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2683099','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2683099"><span><span class="hlt">Filter</span> feeders and plankton increase <span class="hlt">particle</span> encounter rates through flow regime control</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Humphries, Stuart</p> <p>2009-01-01</p> <p>Collisions between <span class="hlt">particles</span> or between <span class="hlt">particles</span> and other objects are fundamental to many processes that we take for granted. They drive the functioning of aquatic ecosystems, the onset of rain and snow precipitation, and the manufacture of pharmaceuticals, powders and crystals. Here, I show that the traditional assumption that viscosity dominates these situations leads to consistent and large-scale underestimation of encounter rates between <span class="hlt">particles</span> and of deposition rates on surfaces. Numerical simulations reveal that the encounter rate is Reynolds number dependent and that encounter efficiencies are consistent with the sparse experimental data. This extension of aerosol theory has great implications for understanding of selection pressure on the physiology and ecology of organisms, for example <span class="hlt">filter</span> feeders able to gather food at rates up to 5 times higher than expected. I provide evidence that <span class="hlt">filter</span> feeders have been strongly selected to take advantage of this flow regime and show that both the predicted peak concentration and the steady-state concentrations of plankton during blooms are ≈33% of that predicted by the current models of <span class="hlt">particle</span> encounter. Many ecological and industrial processes may be operating at substantially greater rates than currently assumed. PMID:19416879</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120008933','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120008933"><span>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('https://www.ncbi.nlm.nih.gov/pubmed/27294931','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27294931"><span>A Novel Multi-Sensor Environmental Perception Method Using Low-Rank Representation and a <span class="hlt">Particle</span> <span class="hlt">Filter</span> for Vehicle Reversing Safety.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Zutao; Li, Yanjun; Wang, Fubing; Meng, Guanjun; Salman, Waleed; Saleem, Layth; Zhang, Xiaoliang; Wang, Chunbai; Hu, Guangdi; Liu, Yugang</p> <p>2016-06-09</p> <p>Environmental perception and information processing are two key steps of active safety for vehicle reversing. Single-sensor environmental perception cannot meet the need for vehicle reversing safety due to its low reliability. In this paper, we present a novel multi-sensor environmental perception method using low-rank representation and a <span class="hlt">particle</span> <span class="hlt">filter</span> for vehicle reversing safety. The proposed system consists of four main steps, namely multi-sensor environmental perception, information fusion, target recognition and tracking using low-rank representation and a <span class="hlt">particle</span> <span class="hlt">filter</span>, and vehicle reversing speed control modules. First of all, the multi-sensor environmental perception module, based on a binocular-camera system and ultrasonic range finders, obtains the distance data for obstacles behind the vehicle when the vehicle is reversing. Secondly, the information fusion algorithm using an adaptive Kalman <span class="hlt">filter</span> is used to process the data obtained with the multi-sensor environmental perception module, which greatly improves the robustness of the sensors. Then the framework of a <span class="hlt">particle</span> <span class="hlt">filter</span> and low-rank representation is used to track the main obstacles. The low-rank representation is used to <span class="hlt">optimize</span> an objective <span class="hlt">particle</span> template that has the smallest L-1 norm. Finally, the electronic throttle opening and automatic braking is under control of the proposed vehicle reversing control strategy prior to any potential collisions, making the reversing control safer and more reliable. The final system simulation and practical testing results demonstrate the validity of the proposed multi-sensor environmental perception method using low-rank representation and a <span class="hlt">particle</span> <span class="hlt">filter</span> for vehicle reversing safety.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4934274','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4934274"><span>A Novel Multi-Sensor Environmental Perception Method Using Low-Rank Representation and a <span class="hlt">Particle</span> <span class="hlt">Filter</span> for Vehicle Reversing Safety</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, Zutao; Li, Yanjun; Wang, Fubing; Meng, Guanjun; Salman, Waleed; Saleem, Layth; Zhang, Xiaoliang; Wang, Chunbai; Hu, Guangdi; Liu, Yugang</p> <p>2016-01-01</p> <p>Environmental perception and information processing are two key steps of active safety for vehicle reversing. Single-sensor environmental perception cannot meet the need for vehicle reversing safety due to its low reliability. In this paper, we present a novel multi-sensor environmental perception method using low-rank representation and a <span class="hlt">particle</span> <span class="hlt">filter</span> for vehicle reversing safety. The proposed system consists of four main steps, namely multi-sensor environmental perception, information fusion, target recognition and tracking using low-rank representation and a <span class="hlt">particle</span> <span class="hlt">filter</span>, and vehicle reversing speed control modules. First of all, the multi-sensor environmental perception module, based on a binocular-camera system and ultrasonic range finders, obtains the distance data for obstacles behind the vehicle when the vehicle is reversing. Secondly, the information fusion algorithm using an adaptive Kalman <span class="hlt">filter</span> is used to process the data obtained with the multi-sensor environmental perception module, which greatly improves the robustness of the sensors. Then the framework of a <span class="hlt">particle</span> <span class="hlt">filter</span> and low-rank representation is used to track the main obstacles. The low-rank representation is used to <span class="hlt">optimize</span> an objective <span class="hlt">particle</span> template that has the smallest L-1 norm. Finally, the electronic throttle opening and automatic braking is under control of the proposed vehicle reversing control strategy prior to any potential collisions, making the reversing control safer and more reliable. The final system simulation and practical testing results demonstrate the validity of the proposed multi-sensor environmental perception method using low-rank representation and a <span class="hlt">particle</span> <span class="hlt">filter</span> for vehicle reversing safety. PMID:27294931</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008MeScT..19k5403C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008MeScT..19k5403C"><span><span class="hlt">Optimization</span> and evaluation of fluorescent tracers for flare removal in gas-phase <span class="hlt">particle</span> image velocimetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chennaoui, M.; Angarita-Jaimes, D.; Ormsby, M. P.; Angarita-Jaimes, N.; McGhee, E.; Towers, C. E.; Jones, A. C.; Towers, D. P.</p> <p>2008-11-01</p> <p>We report the development of <span class="hlt">optimized</span> fluorescent dye-doped tracer <span class="hlt">particles</span> for gas-phase <span class="hlt">particle</span> image velocimetry (PIV) and their use to eliminate 'flare' from the images obtained. In such applications, micron-sized tracer <span class="hlt">particles</span> are normally required to accurately follow the flow. However, as the tracer size is reduced the amount of light incident on the <span class="hlt">particle</span> diminishes and consequently the intensity of emitted light (fluorescence). Hence, there is a requirement to identify dyes with high quantum yield that can be dissolved in conventional tracer media at high concentrations. We describe the selection and characterization of a highly fluorescent blue-emitting dye, Bis-MSB, using a novel method, employing stabilized micro-emulsions, to emulate the fluorescence properties of tracer <span class="hlt">particles</span>. We present the results of PIV experiments, using 1 µm tracer <span class="hlt">particles</span> of o-xylene doped with Bis-MSB, in which elastically scattered 'flare' has been successfully removed from the images using an appropriate optical <span class="hlt">filter</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.A23K..05K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.A23K..05K"><span>Effects of <span class="hlt">Particle</span> <span class="hlt">Filters</span> and Accelerated Engine Replacement on Heavy-Duty Diesel Vehicle Emissions of Black Carbon, Nitrogen Oxides, and Ultrafine <span class="hlt">Particles</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kirchstetter, T.; Preble, C.; Dallmann, T. R.; DeMartini, S. J.; Tang, N. W.; Kreisberg, N. M.; Hering, S. V.; Harley, R. A.</p> <p>2013-12-01</p> <p>Diesel <span class="hlt">particle</span> <span class="hlt">filters</span> have become widely used in the United States since the introduction in 2007 of a more stringent exhaust particulate matter emission standard for new heavy-duty diesel vehicle engines. California has instituted additional regulations requiring retrofit or replacement of older in-use engines to accelerate emission reductions and air quality improvements. This presentation summarizes pollutant emission changes measured over several field campaigns at the Port of Oakland in the San Francisco Bay Area associated with diesel particulate <span class="hlt">filter</span> use and accelerated modernization of the heavy-duty truck fleet. Pollutants in the exhaust plumes of hundreds of heavy-duty trucks en route to the Port were measured in 2009, 2010, 2011, and 2013. Ultrafine <span class="hlt">particle</span> number, black carbon (BC), nitrogen oxides (NOx), and nitrogen dioxide (NO2) concentrations were measured at a frequency ≤ 1 Hz and normalized to measured carbon dioxide concentrations to quantify fuel-based emission factors (grams of pollutant emitted per kilogram of diesel consumed). The size distribution of <span class="hlt">particles</span> in truck exhaust plumes was also measured at 1 Hz. In the two most recent campaigns, emissions were linked on a truck-by-truck basis to installed emission control equipment via the matching of transcribed license plates to a Port truck database. Accelerated replacement of older engines with newer engines and retrofit of trucks with diesel <span class="hlt">particle</span> <span class="hlt">filters</span> reduced fleet-average emissions of BC and NOx. Preliminary results from the two most recent field campaigns indicate that trucks without diesel <span class="hlt">particle</span> <span class="hlt">filters</span> emit 4 times more BC than <span class="hlt">filter</span>-equipped trucks. Diesel <span class="hlt">particle</span> <span class="hlt">filters</span> increase emissions of NO2, however, and <span class="hlt">filter</span>-equipped trucks have NO2/NOx ratios that are 4 to 7 times greater than trucks without <span class="hlt">filters</span>. Preliminary findings related to <span class="hlt">particle</span> size distribution indicate that (a) most trucks emitted <span class="hlt">particles</span> characterized by a single mode of approximately</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/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/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 step 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.ncbi.nlm.nih.gov/pubmed/24342270','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24342270"><span>Cascaded Kalman and <span class="hlt">particle</span> <span class="hlt">filters</span> for photogrammetry based gyroscope drift and robot attitude estimation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sadaghzadeh N, Nargess; Poshtan, Javad; Wagner, Achim; Nordheimer, Eugen; Badreddin, Essameddin</p> <p>2014-03-01</p> <p>Based on a cascaded Kalman-<span class="hlt">Particle</span> <span class="hlt">Filtering</span>, gyroscope drift and robot attitude estimation method is proposed in this paper. Due to noisy and erroneous measurements of MEMS gyroscope, it is combined with Photogrammetry based vision navigation scenario. Quaternions kinematics and robot angular velocity dynamics with augmented drift dynamics of gyroscope are employed as system state space model. Nonlinear attitude kinematics, drift and robot angular movement dynamics each in 3 dimensions result in a nonlinear high dimensional system. To reduce the complexity, we propose a decomposition of system to cascaded subsystems and then design separate cascaded observers. This design leads to an easier tuning and more precise debugging from the perspective of programming and such a setting is well suited for a cooperative modular system with noticeably reduced computation time. Kalman <span class="hlt">Filtering</span> (KF) is employed for the linear and Gaussian subsystem consisting of angular velocity and drift dynamics together with gyroscope measurement. The estimated angular velocity is utilized as input of the second <span class="hlt">Particle</span> <span class="hlt">Filtering</span> (PF) based observer in two scenarios of stochastic and deterministic inputs. Simulation results are provided to show the efficiency of the proposed method. Moreover, the experimental results based on data from a 3D MEMS IMU and a 3D camera system are used to demonstrate the efficiency of the method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015FlDyR..47e1404C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015FlDyR..47e1404C"><span>A <span class="hlt">particle</span> <span class="hlt">filter</span> to reconstruct a free-surface flow from a depth camera</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Combés, Benoit; Heitz, Dominique; Guibert, Anthony; Mémin, Etienne</p> <p>2015-10-01</p> <p>We investigate the combined use of a kinect depth sensor and of a stochastic data assimilation (DA) method to recover free-surface flows. More specifically, we use a weighted ensemble Kalman <span class="hlt">filter</span> method to reconstruct the complete state of free-surface flows from a sequence of depth images only. This <span class="hlt">particle</span> <span class="hlt">filter</span> accounts for model and observations errors. This DA scheme is enhanced with the use of two observations instead of one classically. We evaluate the developed approach on two numerical test cases: a collapse of a water column as a toy-example and a flow in an suddenly expanding flume as a more realistic flow. The robustness of the method to depth data errors and also to initial and inflow conditions is considered. We illustrate the interest of using two observations instead of one observation into the correction step, especially for unknown inflow boundary conditions. Then, the performance of the Kinect sensor in capturing the temporal sequences of depth observations is investigated. Finally, the efficiency of the algorithm is qualified for a wave in a real rectangular flat bottomed tank. It is shown that for basic initial conditions, the <span class="hlt">particle</span> <span class="hlt">filter</span> rapidly and remarkably reconstructs the velocity and height of the free surface flow based on noisy measurements of the elevation alone.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DPPC12065B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DPPC12065B"><span><span class="hlt">Optimizing</span> Stellarators for Energetic <span class="hlt">Particle</span> Confinement using BEAMS3D</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bolgert, Peter; Drevlak, Michael; Lazerson, Sam; Gates, David; White, Roscoe</p> <p>2015-11-01</p> <p>Energetic <span class="hlt">particle</span> (EP) loss has been called the ``Achilles heel of stellarators,'' (Helander, Rep. Prog. Phys. 77 087001 (2014)) and there is a great need for magnetic configurations with improved EP confinement. In this study we utilize a newly developed capability of the stellarator <span class="hlt">optimization</span> code STELLOPT: the ability to <span class="hlt">optimize</span> EP confinement via an interface with guiding center code BEAMS3D (McMillan et al., Plasma Phys. Control. Fusion 56, 095019 (2014)). Using this new tool, <span class="hlt">optimizations</span> of the W7-X experiment and ARIES-CS reactor are performed where the EP loss fraction is one of many target functions to be minimized. In W7-X, we simulate the experimental NBI system using realistic beam geometry and beam deposition physics. The goal is to find configurations with improved neutral beam deposition and energetic <span class="hlt">particle</span> confinement. These calculations are compared to previous studies of W7-X NBI deposition. In ARIES-CS, we launch 3.5 MeV alpha <span class="hlt">particles</span> from a near-axis flux surface using a uniform grid in toroidal and poloidal angle. As these <span class="hlt">particles</span> are born from D-T reactions, we consider an isotropic distribution in velocity space. This research is supported by DoE Contract Number DE-AC02-09CH11466.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23145590','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23145590"><span><span class="hlt">Particle</span> <span class="hlt">filtering</span> for arrival time tracking in space and source localization.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Michalopoulou, Zoi-Heleni; Jain, Rashi</p> <p>2012-11-01</p> <p>Locating and tracking a source in an ocean environment and estimating environmental parameters of a sound propagation medium are critical tasks in ocean acoustics. Many approaches for both are based on full field calculations which are computationally intensive and sensitive to assumptions on the structure of the environment. Alternative methods that use only select features of the acoustic field for localization and environmental parameter estimation have been proposed. The focus of this paper is the development of a method that extracts arrival times and amplitudes of distinct paths from measured acoustic time-series using sequential Bayesian <span class="hlt">filtering</span>, namely, <span class="hlt">particle</span> <span class="hlt">filtering</span>. These quantities, along with complete posterior probability density functions, also extracted by <span class="hlt">filtering</span>, are employed in source localization and bathymetry estimation. Aspects of the <span class="hlt">filtering</span> methodology are presented and studied in terms of their impact on the uncertainty in the arrival time estimates. Using the posterior probability densities of arrival times, source localization and water depth estimation are performed for the Haro Strait Primer experiment; the results are compared to those of conventional methods. The comparison demonstrates a significant advantage in the proposed approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20804146','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20804146"><span>Analysis of the bromate-sulfite-ferrocyanide pH oscillator using the <span class="hlt">particle</span> <span class="hlt">filter</span>: toward the automated modeling of complex chemical systems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sato, Naoya; Hasegawa, Hiroshi H; Kimura, Rika; Mori, Yoshihito; Okazaki, Noriaki</p> <p>2010-09-23</p> <p>This study was aimed at identifying a quantitatively accurate reaction model of the bromate-sulfilte-ferrocyanide (BSF) pH oscillator by using the simulation-based model estimation algorithm known as the <span class="hlt">particle</span> <span class="hlt">filter</span>. The Rbai-Kaminaga-Hanazaki (RKH) model proposed for the BSF system was extended by adding the protonation equilibrium of SO42-, for which the <span class="hlt">particle</span> <span class="hlt">filter</span> analysis was carried out to <span class="hlt">optimize</span> the rate constants involved with reference to the measured pH oscillation data. The extended RKH model with the <span class="hlt">optimized</span> rate constants almost completely reproduced the measured pH oscillations and the state diagram, showing the validity of the present analysis. Chemical oscillators such as the BSF system show drastic switching of the dominant reaction path, which strongly disturbs the convergence of the rate constants if the objective function is defined in a conventional manner to reflect only a single time step datum. In this study, the objective function was defined as the residual sum of squares with respect to pH taken over an interval longer than one oscillatory period, so that all of the relevant reaction steps can contribute to the objective function. This is the first report which exemplifies the effectiveness of the <span class="hlt">particle</span> <span class="hlt">filter</span> in the analysis of real complex chemical systems.</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.osti.gov/scitech/biblio/1337650','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1337650"><span>Absorption/transmission measurements of PSAP <span class="hlt">particle</span>-laden <span class="hlt">filters</span> from the Biomass Burning Observation Project (BBOP) field campaign</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Presser, Cary; Nazarian, Ashot; Conny, Joseph M.; Chand, Duli; Sedlacek, Arthur; Hubbe, John M.</p> <p>2016-12-02</p> <p>Absorptivity measurements with a laser-heating approach, referred to as the laser-driven thermal reactor (LDTR), were carried out in the infrared and applied at ambient (laboratory) nonreacting conditions to <span class="hlt">particle</span>-laden <span class="hlt">filters</span> from a three-wavelength (visible) <span class="hlt">particle</span>/soot absorption photometer (PSAP). Here, the <span class="hlt">particles</span> were obtained during the Biomass Burning Observation Project (BBOP) field campaign. The focus of this study was to determine the <span class="hlt">particle</span> absorption coefficient from field-campaign <span class="hlt">filter</span> samples using the LDTR approach, and compare results with other commercially available instrumentation (in this case with the PSAP, which has been compared with numerous other optical techniques).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RAA....17...30J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RAA....17...30J"><span><span class="hlt">Particle</span> swarm <span class="hlt">optimization</span> based space debris surveillance network scheduling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, Hai; Liu, Jing; Cheng, Hao-Wen; Zhang, Yao</p> <p>2017-02-01</p> <p>The increasing number of space debris has created an orbital debris environment that poses increasing impact risks to existing space systems and human space flights. For the safety of in-orbit spacecrafts, we should <span class="hlt">optimally</span> schedule surveillance tasks for the existing facilities to allocate resources in a manner that most significantly improves the ability to predict and detect events involving affected spacecrafts. This paper analyzes two criteria that mainly affect the performance of a scheduling scheme and introduces an artificial intelligence algorithm into the scheduling of tasks of the space debris surveillance network. A new scheduling algorithm based on the <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> algorithm is proposed, which can be implemented in two different ways: individual <span class="hlt">optimization</span> and joint <span class="hlt">optimization</span>. Numerical experiments with multiple facilities and objects are conducted based on the proposed algorithm, and simulation results have demonstrated the effectiveness of the proposed algorithm.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AMT.....5.2859Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AMT.....5.2859Z"><span>Using <span class="hlt">particle</span> <span class="hlt">filter</span> to track horizontal variations of atmospheric duct structure from radar sea clutter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, X. F.; Huang, S. X.; Wang, D. X.</p> <p>2012-11-01</p> <p>This paper addresses the problem of estimating range-varying parameters of the height-dependent refractivity over the sea surface from radar sea clutter. In the forward simulation, the split-step Fourier parabolic equation (PE) is used to compute the radar clutter power in the complex refractive environments. Making use of the inherent Markovian structure of the split-step Fourier PE solution, the refractivity from clutter (RFC) problem is formulated within a nonlinear recursive Bayesian state estimation framework. <span class="hlt">Particle</span> <span class="hlt">filter</span> (PF), which is a technique for implementing a recursive Bayesian <span class="hlt">filter</span> by Monte Carlo simulations, is used to track range-varying characteristics of the refractivity profiles. Basic ideas of employing PF to solve RFC problem are introduced. Both simulation and real data results are presented to confirm the feasibility of PF-RFC performances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AMTD....5.6059Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AMTD....5.6059Z"><span>Using <span class="hlt">particle</span> <span class="hlt">filter</span> to track horizontal variations of atmospheric duct structure from radar sea clutter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, X. F.; Huang, S. X.</p> <p>2012-08-01</p> <p>This paper addresses the problem of estimating range-varying parameters of the height-dependent refractivity over the sea surface from radar sea clutter. In the forward simulation, the split-step Fourier parabolic equation (PE) is used to compute the radar clutter power in the complex refractive environments. Making use of the inherent Markovian structure of the split-step Fourier PE solution, the refractivity from clutter (RFC) problem is formulated within a nonlinear recursive Bayesian state estimation framework. <span class="hlt">Particle</span> <span class="hlt">filter</span> (PF) that is a technique for implementing a recursive Bayesian <span class="hlt">filter</span> by Monte Carlo simulations is used to track range-varying characteristics of the refractivity profiles. Basic ideas of employing PF to solve RFC problem are introduced. Both simulation and real data results are presented to check up the feasibility of PF-RFC performances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23818832','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23818832"><span><span class="hlt">Optimal</span> control for a parallel hybrid hydraulic excavator using <span class="hlt">particle</span> swarm <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>Wang, Dong-yun; Guan, Chen</p> <p>2013-01-01</p> <p><span class="hlt">Optimal</span> control using <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) is put forward in a parallel hybrid hydraulic excavator (PHHE). A power-train mathematical model of PHHE is illustrated along with the analysis of components' parameters. Then, the <span class="hlt">optimal</span> control problem is addressed, and PSO algorithm is introduced to deal with this nonlinear <span class="hlt">optimal</span> problem which contains lots of inequality/equality constraints. Then, the comparisons between the <span class="hlt">optimal</span> control and rule-based one are made, and the results show that hybrids with the <span class="hlt">optimal</span> control would increase fuel economy. Although PSO algorithm is off-line <span class="hlt">optimization</span>, still it would bring performance benchmark for PHHE and also help have a deep insight into hybrid excavators.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......124J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......124J"><span>Multivariable <span class="hlt">optimization</span> of liquid rocket engines using <span class="hlt">particle</span> swarm algorithms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jones, Daniel Ray</p> <p></p> <p>Liquid rocket engines are highly reliable, controllable, and efficient compared to other conventional forms of rocket propulsion. As such, they have seen wide use in the space industry and have become the standard propulsion system for launch vehicles, orbit insertion, and orbital maneuvering. Though these systems are well understood, historical <span class="hlt">optimization</span> techniques are often inadequate due to the highly non-linear nature of the engine performance problem. In this thesis, a <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO) variant was applied to maximize the specific impulse of a finite-area combustion chamber (FAC) equilibrium flow rocket performance model by controlling the engine's oxidizer-to-fuel ratio and de Laval nozzle expansion and contraction ratios. In addition to the PSO-controlled parameters, engine performance was calculated based on propellant chemistry, combustion chamber pressure, and ambient pressure, which are provided as inputs to the program. The performance code was validated by comparison with NASA's Chemical Equilibrium with Applications (CEA) and the commercially available Rocket Propulsion Analysis (RPA) tool. Similarly, the PSO algorithm was validated by comparison with brute-force <span class="hlt">optimization</span>, which calculates all possible solutions and subsequently determines which is the optimum. <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> was shown to be an effective <span class="hlt">optimizer</span> capable of quick and reliable convergence for complex functions of multiple non-linear variables.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15380432','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15380432"><span><span class="hlt">Particle</span> capture processes and evaporation on a microscopic scale in wet <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>Mullins, Benjamin J; Braddock, Roger D; Agranovski, Igor E</p> <p>2004-11-01</p> <p>This paper details results of an experimental study of the capture of solid and liquid aerosols on fibrous <span class="hlt">filters</span> wetted with water. A microscopic cell containing a single fibre (made from a variety of materials) was observed via a microscope, with a high speed CCD camera used to dynamically image the interactions between liquid droplets, zeolite and PSL <span class="hlt">particles</span> and fibres. Variable quantities of liquid irrigation were used, and the possibility for subsequent fibre regeneration after clogging or drying was also studied. It was found that drainage of the wetting liquid (water) from the fibres occurred, even at very low irrigation rates when the droplet consisted almost completely of captured <span class="hlt">particles</span>. It was also found that the fibre was rapidly loaded with captured <span class="hlt">particles</span> when the irrigation was not supplied. However, almost complete regeneration (removal of the collected cake) by the liquid droplets occurred shortly after recommencement of the water supply. The study also examined the capture of oily liquid aerosols on fibres wetted with water. A predominance of the barrel shaped droplet on the fibre was observed, with oil droplets displacing water droplets (if the oil and fibre combination created a barrel shaped droplet), creating various compound droplets of oil and water not previously reported in literature. This preferential droplet shape implies that whatever the initial substance wetting a <span class="hlt">filter</span>, a substance with a greater preferential adherence to the fibre will displace the former one.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120017458','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120017458"><span>Representation of Probability Density Functions from Orbit Determination using the <span class="hlt">Particle</span> <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>Mashiku, Alinda K.; Garrison, James; Carpenter, J. Russell</p> <p>2012-01-01</p> <p>Statistical orbit determination enables us to obtain estimates of the state and the statistical information of its region of uncertainty. In order to obtain an accurate representation of the probability density function (PDF) that incorporates higher order statistical information, we propose the use of nonlinear estimation methods such as the <span class="hlt">Particle</span> <span class="hlt">Filter</span>. The <span class="hlt">Particle</span> <span class="hlt">Filter</span> (PF) is capable of providing a PDF representation of the state estimates whose accuracy is dependent on the number of <span class="hlt">particles</span> or samples used. For this method to be applicable to real case scenarios, we need a way of accurately representing the PDF in a compressed manner with little information loss. Hence we propose using the Independent Component Analysis (ICA) as a non-Gaussian dimensional reduction method that is capable of maintaining higher order statistical information obtained using the PF. Methods such as the Principal Component Analysis (PCA) are based on utilizing up to second order statistics, hence will not suffice in maintaining maximum information content. Both the PCA and the ICA are applied to two scenarios that involve a highly eccentric orbit with a lower apriori uncertainty covariance and a less eccentric orbit with a higher a priori uncertainty covariance, to illustrate the capability of the ICA in relation to the PCA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1813669P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1813669P"><span>A localized <span class="hlt">particle</span> <span class="hlt">filter</span> for data assimilation in high-dimensional geophysical models.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Poterjoy, Jonathan; Anderon, Jeffrey</p> <p>2016-04-01</p> <p>This talk introduces an ensemble data assimilation approach based on the <span class="hlt">particle</span> <span class="hlt">filter</span> (PF) that has potential for nonlinear/non-Gaussian applications in geoscience. PFs make no assumptions regarding prior and posterior error distributions, allowing them to perform well for most applications provided with a sufficiently large number of <span class="hlt">particles</span>. The proposed method is similar to the PF in that ensemble realizations of the model state are weighted based on the likelihood of observations to approximate posterior probabilities of the system state. The new approach, denoted the local PF, reduces the influence of distant observations on the weight calculations via a localization function. Unlike standard PFs, the local PF provides accurate results using ensemble sizes small enough to be affordable for large models. Comparisons of the local PF and ensemble Kalman <span class="hlt">filters</span> using a simplified atmospheric general circulation model (with 25 <span class="hlt">particles</span>) demonstrate that the new method is a viable data assimilation technique for large geophysical systems. The local PF also shows substantial benefits over the EnKF when observation networks consist of measurements that relate nonlinearly to the model state - analogous to remotely sensed data used frequently in atmospheric analyses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22231171','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22231171"><span>Alignment of 3-D optical coherence tomography scans to correct eye movement using a <span class="hlt">particle</span> <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>Xu, Juan; Ishikawa, Hiroshi; Wollstein, Gadi; Kagemann, Larry; Schuman, Joel S</p> <p>2012-07-01</p> <p>Eye movement artifacts occurring during 3-D optical coherence tomography (OCT) scanning is a well-recognized problem that may adversely affect image analysis and interpretation. A <span class="hlt">particle</span> <span class="hlt">filtering</span> algorithm is presented in this paper to correct motion in a 3-D dataset by considering eye movement as a target tracking problem in a dynamic system. The proposed <span class="hlt">particle</span> <span class="hlt">filtering</span> algorithm is an independent 3-D alignment approach, which does not rely on any reference image. 3-D OCT data is considered as a dynamic system, while the location of each A-scan is represented by the state space. A <span class="hlt">particle</span> set is used to approximate the probability density of the state in the dynamic system. The state of the system is updated frame by frame to detect A-scan movement. The proposed method was applied on both simulated data for objective evaluation and experimental data for subjective evaluation. The sensitivity and specificity of the x-movement detection were 98.85% and 99.43%, respectively, in the simulated data. For the experimental data (74 3-D OCT images), all the images were improved after z-alignment, while 81.1% images were improved after x-alignment. The proposed algorithm is an efficient way to align 3-D OCT volume data and correct the eye movement without using references.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4634417','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4634417"><span>Modified <span class="hlt">Particle</span> <span class="hlt">Filtering</span> Algorithm for Single Acoustic Vector Sensor DOA Tracking</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, Xinbo; Sun, Haixin; Jiang, Liangxu; Shi, Yaowu; Wu, Yue</p> <p>2015-01-01</p> <p>The conventional direction of arrival (DOA) estimation algorithm with static sources assumption usually estimates the source angles of two adjacent moments independently and the correlation of the moments is not considered. In this article, we focus on the DOA estimation of moving sources and a modified <span class="hlt">particle</span> <span class="hlt">filtering</span> (MPF) algorithm is proposed with state space model of single acoustic vector sensor. Although the <span class="hlt">particle</span> <span class="hlt">filtering</span> (PF) algorithm has been introduced for acoustic vector sensor applications, it is not suitable for the case that one dimension angle of source is estimated with large deviation, the two dimension angles (pitch angle and azimuth angle) cannot be simultaneously employed to update the state through resampling processing of PF algorithm. To solve the problems mentioned above, the MPF algorithm is proposed in which the state estimation of previous moment is introduced to the <span class="hlt">particle</span> sampling of present moment to improve the importance function. Moreover, the independent relationship of pitch angle and azimuth angle is considered and the two dimension angles are sampled and evaluated, respectively. Then, the MUSIC spectrum function is used as the “likehood” function of the MPF algorithm, and the modified PF-MUSIC (MPF-MUSIC) algorithm is proposed to improve the root mean square error (RMSE) and the probability of convergence. The theoretical analysis and the simulation results validate the effectiveness and feasibility of the two proposed algorithms. PMID:26501280</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SPIE.6764E..0UC','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SPIE.6764E..0UC"><span>Dynamic omni-directional vision localization using a beacon tracker based on <span class="hlt">particle</span> <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>Cao, Zuoliang; Liu, Shiyu</p> <p>2007-09-01</p> <p>Omni-directional vision navigation for AGVs appears definite significant since its advantage of panoramic sight with a single compact visual scene. This unique guidance technique involves target recognition, vision tracking, object positioning, path programming. An algorithm for omni-vision based global localization which utilizes two overhead features as beacon pattern is proposed in this paper. An approach for geometric restoration of omni-vision images has to be considered since an inherent distortion exists. The mapping between image coordinates and physical space parameters of the targets can be obtained by means of the imaging principle on the fisheye lens. The localization of the robot can be achieved by geometric computation. Dynamic localization employs a beacon tracker to follow the landmarks in real time during the arbitrary movement of the vehicle. The coordinate transformation is devised for path programming based on time sequence images analysis. The beacon recognition and tracking are a key procedure for an omni-vision guided mobile unit. The conventional image processing such as shape decomposition, description, matching and other usually employed technique are not directly applicable in omni-vision. <span class="hlt">Particle</span> <span class="hlt">filter</span> (PF) has been shown to be successful for several nonlinear estimation problems. A beacon tracker based on <span class="hlt">Particle</span> <span class="hlt">Filter</span> which offers a probabilistic framework for dynamic state estimation in visual tracking has been developed. We independently use two <span class="hlt">Particle</span> <span class="hlt">Filters</span> to track double landmarks but a composite algorithm on multiple objects tracking conducts for vehicle localization. We have implemented the tracking and localization system and demonstrated the relevant of the algorithm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4723399','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4723399"><span>Enhancement of microfluidic <span class="hlt">particle</span> separation using cross-flow <span class="hlt">filters</span> with hydrodynamic focusing</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chiu, Yun-Yen; Huang, Chen-Kang</p> <p>2016-01-01</p> <p>A microfluidic chip is proposed to separate microparticles using cross-flow filtration enhanced with hydrodynamic focusing. By exploiting a buffer flow from the side, the microparticles in the sample flow are pushed on one side of the microchannels, lining up to pass through the <span class="hlt">filters</span>. Meanwhile a larger pressure gradient in the <span class="hlt">filters</span> is obtained to enhance separation efficiency. Compared with the traditional cross-flow filtration, our proposed mechanism has the buffer flow to create a moving virtual boundary for the sample flow to actively push all the <span class="hlt">particles</span> to reach the <span class="hlt">filters</span> for separation. It further allows higher flow rates. The device only requires soft lithograph fabrication to create microchannels and a novel pressurized bonding technique to make high-aspect-ratio filtration structures. A mixture of polystyrene microparticles with 2.7 μm and 10.6 μm diameters are successfully separated. 96.2 ± 2.8% of the large <span class="hlt">particle</span> are recovered with a purity of 97.9 ± 0.5%, while 97.5 ± 0.4% of the small <span class="hlt">particle</span> are depleted with a purity of 99.2 ± 0.4% at a sample throughput of 10 μl/min. The experiment is also conducted to show the feasibility of this mechanism to separate biological cells with the sample solutions of spiked PC3 cells in whole blood. By virtue of its high separation efficiency, our device offers a label-free separation technique and potential integration with other components, thereby serving as a promising tool for continuous cell filtration and analysis applications. PMID:26858812</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26858812','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26858812"><span>Enhancement of microfluidic <span class="hlt">particle</span> separation using cross-flow <span class="hlt">filters</span> with hydrodynamic focusing.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chiu, Yun-Yen; Huang, Chen-Kang; Lu, Yen-Wen</p> <p>2016-01-01</p> <p>A microfluidic chip is proposed to separate microparticles using cross-flow filtration enhanced with hydrodynamic focusing. By exploiting a buffer flow from the side, the microparticles in the sample flow are pushed on one side of the microchannels, lining up to pass through the <span class="hlt">filters</span>. Meanwhile a larger pressure gradient in the <span class="hlt">filters</span> is obtained to enhance separation efficiency. Compared with the traditional cross-flow filtration, our proposed mechanism has the buffer flow to create a moving virtual boundary for the sample flow to actively push all the <span class="hlt">particles</span> to reach the <span class="hlt">filters</span> for separation. It further allows higher flow rates. The device only requires soft lithograph fabrication to create microchannels and a novel pressurized bonding technique to make high-aspect-ratio filtration structures. A mixture of polystyrene microparticles with 2.7 μm and 10.6 μm diameters are successfully separated. 96.2 ± 2.8% of the large <span class="hlt">particle</span> are recovered with a purity of 97.9 ± 0.5%, while 97.5 ± 0.4% of the small <span class="hlt">particle</span> are depleted with a purity of 99.2 ± 0.4% at a sample throughput of 10 μl/min. The experiment is also conducted to show the feasibility of this mechanism to separate biological cells with the sample solutions of spiked PC3 cells in whole blood. By virtue of its high separation efficiency, our device offers a label-free separation technique and potential integration with other components, thereby serving as a promising tool for continuous cell filtration and analysis applications.</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.osti.gov/scitech/biblio/21396177','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21396177"><span>Multiobjective <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> for the <span class="hlt">optimal</span> design of photovoltaic grid-connected systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kornelakis, Aris</p> <p>2010-12-15</p> <p><span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO) is a highly efficient evolutionary <span class="hlt">optimization</span> algorithm. In this paper a multiobjective <span class="hlt">optimization</span> algorithm based on PSO applied to the <span class="hlt">optimal</span> design of photovoltaic grid-connected systems (PVGCSs) is presented. The proposed methodology intends to suggest the <span class="hlt">optimal</span> number of system devices and the <span class="hlt">optimal</span> PV module installation details, such that the economic and environmental benefits achieved during the system's operational lifetime period are both maximized. The objective function describing the economic benefit of the proposed <span class="hlt">optimization</span> process is the lifetime system's total net profit which is calculated according to the method of the Net Present Value (NPV). The second objective function, which corresponds to the environmental benefit, equals to the pollutant gas emissions avoided due to the use of the PVGCS. The <span class="hlt">optimization</span>'s decision variables are the <span class="hlt">optimal</span> number of the PV modules, the PV modules <span class="hlt">optimal</span> tilt angle, the <span class="hlt">optimal</span> placement of the PV modules within the available installation area and the <span class="hlt">optimal</span> distribution of the PV modules among the DC/AC converters. (author)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA625084','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA625084"><span>Earth Observing Satellite Orbit Design Via <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</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>2014-08-01</p> <p>Earth Observing Satellite Orbit Design Via <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> Sharon Vtipil ∗ and John G. Warner ∗ US Naval Research Laboratory, Washington...DC, 20375, United States Designing the orbit of an Earth observing satellite is generally tedious work. Typically, a large number of numerical...orbit parameters. This methodology only pertains to a single satellite in a circular orbit. I. Introduction Designing the orbit of an Earth observing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17891226','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17891226"><span>Parallel global <span class="hlt">optimization</span> with the <span class="hlt">particle</span> swarm algorithm.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schutte, J F; Reinbolt, J A; Fregly, B J; Haftka, R T; George, A D</p> <p>2004-12-07</p> <p>Present day engineering <span class="hlt">optimization</span> problems often impose large computational demands, resulting in long solution times even on a modern high-end processor. To obtain enhanced computational throughput and global search capability, we detail the coarse-grained parallelization of an increasingly popular global search method, the <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) algorithm. Parallel PSO performance was evaluated using two categories of <span class="hlt">optimization</span> problems possessing multiple local minima-large-scale analytical test problems with computationally cheap function evaluations and medium-scale biomechanical system identification problems with computationally expensive function evaluations. For load-balanced analytical test problems formulated using 128 design variables, speedup was close to ideal and parallel efficiency above 95% for up to 32 nodes on a Beowulf cluster. In contrast, for load-imbalanced biomechanical system identification problems with 12 design variables, speedup plateaued and parallel efficiency decreased almost linearly with increasing number of nodes. The primary factor affecting parallel performance was the synchronization requirement of the parallel algorithm, which dictated that each iteration must wait for completion of the slowest fitness evaluation. When the analytical problems were solved using a fixed number of swarm iterations, a single population of 128 <span class="hlt">particles</span> produced a better convergence rate than did multiple independent runs performed using sub-populations (8 runs with 16 <span class="hlt">particles</span>, 4 runs with 32 <span class="hlt">particles</span>, or 2 runs with 64 <span class="hlt">particles</span>). These results suggest that (1) parallel PSO exhibits excellent parallel performance under load-balanced conditions, (2) an asynchronous implementation would be valuable for real-life problems subject to load imbalance, and (3) larger population sizes should be considered when multiple processors are available.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28372799','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28372799"><span>Fault prediction for nonlinear stochastic system with incipient faults based on <span class="hlt">particle</span> <span class="hlt">filter</span> and nonlinear regression.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ding, Bo; Fang, Huajing</p> <p>2017-03-31</p> <p>This paper is concerned with the fault prediction for the nonlinear stochastic system with incipient faults. Based on the <span class="hlt">particle</span> <span class="hlt">filter</span> and the reasonable assumption about the incipient faults, the modified fault estimation algorithm is proposed, and the system state is estimated simultaneously. According to the modified fault estimation, an intuitive fault detection strategy is introduced. Once each of the incipient fault is detected, the parameters of which are identified by a nonlinear regression method. Then, based on the estimated parameters, the future fault signal can be predicted. Finally, the effectiveness of the proposed method is verified by the simulations of the Three-tank system.</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> </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('https://www.ncbi.nlm.nih.gov/pubmed/19435332','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19435332"><span><span class="hlt">Optimization</span> of encoded hydrogel <span class="hlt">particles</span> for nucleic acid quantification.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pregibon, Daniel C; Doyle, Patrick S</p> <p>2009-06-15</p> <p>The accurate quantification of nucleic acids is of utmost importance for clinical diagnostics, drug discovery, and basic science research. These applications require the concurrent measurement of multiple targets while demanding high-throughput analysis, high sensitivity, specificity between closely related targets, and a wide dynamic range. In attempt to create a technology that can simultaneously meet these demands, we recently developed a method of multiplexed analysis using encoded hydrogel <span class="hlt">particles</span>. Here, we demonstrate tuning of hydrogel porosity with semi-interpenetrating networks of poly(ethylene glycol), develop a quantitative model to understand hybridization kinetics, and use the findings from these studies to enhance <span class="hlt">particle</span> design for nucleic acid detection. With an <span class="hlt">optimized</span> <span class="hlt">particle</span> design and efficient fluorescent labeling scheme, we demonstrate subattomole sensitivity and single-nucleotide specificity for small RNA targets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhRvE..89b2726V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhRvE..89b2726V"><span><span class="hlt">Optimal</span> estimation of diffusion coefficients from single-<span class="hlt">particle</span> trajectories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vestergaard, Christian L.; Blainey, Paul C.; Flyvbjerg, Henrik</p> <p>2014-02-01</p> <p>How does one <span class="hlt">optimally</span> determine the diffusion coefficient of a diffusing <span class="hlt">particle</span> from a single-time-lapse recorded trajectory of the <span class="hlt">particle</span>? We answer this question with an explicit, unbiased, and practically <span class="hlt">optimal</span> covariance-based estimator (CVE). This estimator is regression-free and is far superior to commonly used methods based on measured mean squared displacements. In experimentally relevant parameter ranges, it also outperforms the analytically intractable and computationally more demanding maximum likelihood estimator (MLE). For the case of diffusion on a flexible and fluctuating substrate, the CVE is biased by substrate motion. However, given some long time series and a substrate under some tension, an extended MLE can separate <span class="hlt">particle</span> diffusion on the substrate from substrate motion in the laboratory frame. This provides benchmarks that allow removal of bias caused by substrate fluctuations in CVE. The resulting unbiased CVE is <span class="hlt">optimal</span> also for short time series on a fluctuating substrate. We have applied our estimators to human 8-oxoguanine DNA glycolase proteins diffusing on flow-stretched DNA, a fluctuating substrate, and found that diffusion coefficients are severely overestimated if substrate fluctuations are not accounted for.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26221132','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26221132"><span>Designing Artificial Neural Networks Using <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> Algorithms.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Garro, Beatriz A; Vázquez, Roberto A</p> <p>2015-01-01</p> <p>Artificial Neural Network (ANN) design is a complex task because its performance depends on the architecture, the selected transfer function, and the learning algorithm used to train the set of synaptic weights. In this paper we present a methodology that automatically designs an ANN using <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> algorithms such as Basic <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO), Second Generation of <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (SGPSO), and a New Model of PSO called NMPSO. The aim of these algorithms is to evolve, at the same time, the three principal components of an ANN: the set of synaptic weights, the connections or architecture, and the transfer functions for each neuron. Eight different fitness functions were proposed to evaluate the fitness of each solution and find the best design. These functions are based on the mean square error (MSE) and the classification error (CER) and implement a strategy to avoid overtraining and to reduce the number of connections in the ANN. In addition, the ANN designed with the proposed methodology is compared with those designed manually using the well-known Back-Propagation and Levenberg-Marquardt Learning Algorithms. Finally, the accuracy of the method is tested with different nonlinear pattern classification problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25353527','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25353527"><span><span class="hlt">Optimal</span> estimation of diffusion coefficients from single-<span class="hlt">particle</span> trajectories.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vestergaard, Christian L; Blainey, Paul C; Flyvbjerg, Henrik</p> <p>2014-02-01</p> <p>How does one <span class="hlt">optimally</span> determine the diffusion coefficient of a diffusing <span class="hlt">particle</span> from a single-time-lapse recorded trajectory of the <span class="hlt">particle</span>? We answer this question with an explicit, unbiased, and practically <span class="hlt">optimal</span> covariance-based estimator (CVE). This estimator is regression-free and is far superior to commonly used methods based on measured mean squared displacements. In experimentally relevant parameter ranges, it also outperforms the analytically intractable and computationally more demanding maximum likelihood estimator (MLE). For the case of diffusion on a flexible and fluctuating substrate, the CVE is biased by substrate motion. However, given some long time series and a substrate under some tension, an extended MLE can separate <span class="hlt">particle</span> diffusion on the substrate from substrate motion in the laboratory frame. This provides benchmarks that allow removal of bias caused by substrate fluctuations in CVE. The resulting unbiased CVE is <span class="hlt">optimal</span> also for short time series on a fluctuating substrate. We have applied our estimators to human 8-oxoguanine DNA glycolase proteins diffusing on flow-stretched DNA, a fluctuating substrate, and found that diffusion coefficients are severely overestimated if substrate fluctuations are not accounted for.</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 step 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 step 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.ncbi.nlm.nih.gov/pubmed/26064085','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26064085"><span>An Improved Quantum-Behaved <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> Algorithm with Elitist Breeding 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>Yang, Zhen-Lun; Wu, Angus; Min, Hua-Qing</p> <p>2015-01-01</p> <p>An improved quantum-behaved <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> with elitist breeding (EB-QPSO) for unconstrained <span class="hlt">optimization</span> is presented and empirically studied in this paper. In EB-QPSO, the novel elitist breeding strategy acts on the elitists of the swarm to escape from the likely local optima and guide the swarm to perform more efficient search. During the iterative <span class="hlt">optimization</span> process of EB-QPSO, when criteria met, the personal best of each <span class="hlt">particle</span> and the global best of the swarm are used to generate new diverse individuals through the transposon operators. The new generated individuals with better fitness are selected to be the new personal best <span class="hlt">particles</span> and global best <span class="hlt">particle</span> to guide the swarm for further solution exploration. A comprehensive simulation study is conducted on a set of twelve benchmark functions. Compared with five state-of-the-art quantum-behaved <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> algorithms, the proposed EB-QPSO performs more competitively in all of the benchmark functions in terms of better global search capability and faster convergence rate.</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/2008AIPC.1052..116O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AIPC.1052..116O"><span><span class="hlt">Optimal</span> Pid Tuning for Power System Stabilizers Using Adaptive <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> Technique</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oonsivilai, Anant; Marungsri, Boonruang</p> <p>2008-10-01</p> <p>An application of the intelligent search technique to find <span class="hlt">optimal</span> parameters of power system stabilizer (PSS) considering proportional-integral-derivative controller (PID) for a single-machine infinite-bus system is presented. Also, an efficient intelligent search technique, adaptive <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (APSO), is engaged to express usefulness of the intelligent search techniques in tuning of the PID—PSS parameters. Improve damping frequency of system is <span class="hlt">optimized</span> by minimizing an objective function with adaptive <span class="hlt">particle</span> swarm <span class="hlt">optimization</span>. At the same operating point, the PID—PSS parameters are also tuned by the Ziegler-Nichols method. The performance of proposed controller compared to the conventional Ziegler-Nichols PID tuning controller. The results reveal superior effectiveness of the proposed APSO based PID controller.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AcAau.113..149H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AcAau.113..149H"><span><span class="hlt">Optimal</span> satellite formation reconfiguration using co-evolutionary <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> in deep space</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Haibin; Zhuang, Yufei</p> <p>2015-08-01</p> <p>This paper proposes a method that plans energy-<span class="hlt">optimal</span> trajectories for multi-satellite formation reconfiguration in deep space environment. A novel co-evolutionary <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> algorithm is stated to solve the nonlinear programming problem, so that the computational complexity of calculating the gradient information could be avoided. One swarm represents one satellite, and through communication with other swarms during the evolution, collisions between satellites can be avoided. In addition, a dynamic depth first search algorithm is proposed to solve the redundant search problem of a co-evolutionary <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> method, with which the computation time can be shorten a lot. In order to make the actual trajectories <span class="hlt">optimal</span> and collision-free with disturbance, a re-planning strategy is deduced for formation reconfiguration maneuver.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3232745','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3232745"><span>Segmentation of Nerve Bundles and Ganglia in Spine MRI Using <span class="hlt">Particle</span> <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>Dalca, Adrian; Danagoulian, Giovanna; Kikinis, Ron; Schmidt, Ehud; Golland, Polina</p> <p>2011-01-01</p> <p>Automatic segmentation of spinal nerve bundles that originate within the dural sac and exit the spinal canal is important for diagnosis and surgical planning. The variability in intensity, contrast, shape and direction of nerves seen in high resolution myelographic MR images makes segmentation a challenging task. In this paper, we present an automatic tracking method for nerve segmentation based on <span class="hlt">particle</span> <span class="hlt">filters</span>. We develop a novel approach to <span class="hlt">particle</span> representation and dynamics, based on Bézier splines. Moreover, we introduce a robust image likelihood model that enables delineation of nerve bundles and ganglia from the surrounding anatomical structures. We demonstrate accurate and fast nerve tracking and compare it to expert manual segmentation. PMID:22003741</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4475762','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4475762"><span>Nanodosimetry-Based Plan <span class="hlt">Optimization</span> for <span class="hlt">Particle</span> Therapy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Casiraghi, Margherita; Schulte, Reinhard W.</p> <p>2015-01-01</p> <p>Treatment planning for <span class="hlt">particle</span> therapy is currently an active field of research due uncertainty in how to modify physical dose in order to create a uniform biological dose response in the target. A novel treatment plan <span class="hlt">optimization</span> strategy based on measurable nanodosimetric quantities rather than biophysical models is proposed in this work. Simplified proton and carbon treatment plans were simulated in a water phantom to investigate the <span class="hlt">optimization</span> feasibility. Track structures of the mixed radiation field produced at different depths in the target volume were simulated with Geant4-DNA and nanodosimetric descriptors were calculated. The fluences of the treatment field pencil beams were <span class="hlt">optimized</span> in order to create a mixed field with equal nanodosimetric descriptors at each of the multiple positions in spread-out <span class="hlt">particle</span> Bragg peaks. For both proton and carbon ion plans, a uniform spatial distribution of nanodosimetric descriptors could be obtained by <span class="hlt">optimizing</span> opposing-field but not single-field plans. The results obtained indicate that uniform nanodosimetrically weighted plans, which may also be radiobiologically uniform, can be obtained with this approach. Future investigations need to demonstrate that this approach is also feasible for more complicated beam arrangements and that it leads to biologically uniform response in tumor cells and tissues. PMID:26167202</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=81405&keyword=effects+AND+information+AND+technology+AND+relationships&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=90814980&CFTOKEN=28328886','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=81405&keyword=effects+AND+information+AND+technology+AND+relationships&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=90814980&CFTOKEN=28328886"><span>EFFECT OF VENTILATION SYSTEMS AND AIR <span class="hlt">FILTERS</span> ON DECAY RATES OF <span class="hlt">PARTICLES</span> PRODUCED BY INDOOR SOURCES IN AN OCCUPIED TOWNHOUSE</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Several studies have shown the importance of <span class="hlt">particle</span> losses in real homes due to deposition and filtration; however, none have quantitatively shown the impact of using a central forced air fan and in-duct <span class="hlt">filter</span> on <span class="hlt">particle</span> loss rates. In an attempt to provide such data, we me...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26176879','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26176879"><span>Biofuel-Promoted Polychlorinated Dibenzodioxin/furan Formation in an Iron-Catalyzed Diesel <span class="hlt">Particle</span> <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>Heeb, Norbert V; Rey, Maria Dolores; Zennegg, Markus; Haag, Regula; Wichser, Adrian; Schmid, Peter; Seiler, Cornelia; Honegger, Peter; Zeyer, Kerstin; Mohn, Joachim; Bürki, Samuel; Zimmerli, Yan; Czerwinski, Jan; Mayer, Andreas</p> <p>2015-08-04</p> <p>Iron-catalyzed diesel <span class="hlt">particle</span> <span class="hlt">filters</span> (DPFs) are widely used for <span class="hlt">particle</span> abatement. Active catalyst <span class="hlt">particles</span>, so-called fuel-borne catalysts (FBCs), are formed in situ, in the engine, when combusting precursors, which were premixed with the fuel. The obtained iron oxide <span class="hlt">particles</span> catalyze soot oxidation in <span class="hlt">filters</span>. Iron-catalyzed DPFs are considered as safe with respect to their potential to form polychlorinated dibenzodioxins/furans (PCDD/Fs). We reported that a bimetallic potassium/iron FBC supported an intense PCDD/F formation in a DPF. Here, we discuss the impact of fatty acid methyl ester (FAME) biofuel on PCDD/F emissions. The iron-catalyzed DPF indeed supported a PCDD/F formation with biofuel but remained inactive with petroleum-derived diesel fuel. PCDD/F emissions (I-TEQ) increased 23-fold when comparing biofuel and diesel data. Emissions of 2,3,7,8-TCDD, the most toxic congener [toxicity equivalence factor (TEF) = 1.0], increased 90-fold, and those of 2,3,7,8-TCDF (TEF = 0.1) increased 170-fold. Congener patterns also changed, indicating a preferential formation of tetra- and penta-chlorodibenzofurans. Thus, an inactive iron-catalyzed DPF becomes active, supporting a PCDD/F formation, when operated with biofuel containing impurities of potassium. Alkali metals are inherent constituents of biofuels. According to the current European Union (EU) legislation, levels of 5 μg/g are accepted. We conclude that risks for a secondary PCDD/F formation in iron-catalyzed DPFs increase when combusting potassium-containing biofuels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3773454','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3773454"><span>Discrete <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> with Scout <span class="hlt">Particles</span> for Library Materials Acquisition</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lin, Bertrand M. T.</p> <p>2013-01-01</p> <p>Materials acquisition is one of the critical challenges faced by academic libraries. This paper presents an integer programming model of the studied problem by considering how to select materials in order to maximize the average preference and the budget execution rate under some practical restrictions including departmental budget, limitation of the number of materials in each category and each language. To tackle the constrained problem, we propose a discrete <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (DPSO) with scout <span class="hlt">particles</span>, where each <span class="hlt">particle</span>, represented as a binary matrix, corresponds to a candidate solution to the problem. An initialization algorithm and a penalty function are designed to cope with the constraints, and the scout <span class="hlt">particles</span> are employed to enhance the exploration within the solution space. To demonstrate the effectiveness and efficiency of the proposed DPSO, a series of computational experiments are designed and conducted. The results are statistically analyzed, and it is evinced that the proposed DPSO is an effective approach for the studied problem. PMID:24072983</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24072983','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24072983"><span>Discrete <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> with scout <span class="hlt">particles</span> for library materials acquisition.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, Yi-Ling; Ho, Tsu-Feng; Shyu, Shyong Jian; Lin, Bertrand M T</p> <p>2013-01-01</p> <p>Materials acquisition is one of the critical challenges faced by academic libraries. This paper presents an integer programming model of the studied problem by considering how to select materials in order to maximize the average preference and the budget execution rate under some practical restrictions including departmental budget, limitation of the number of materials in each category and each language. To tackle the constrained problem, we propose a discrete <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (DPSO) with scout <span class="hlt">particles</span>, where each <span class="hlt">particle</span>, represented as a binary matrix, corresponds to a candidate solution to the problem. An initialization algorithm and a penalty function are designed to cope with the constraints, and the scout <span class="hlt">particles</span> are employed to enhance the exploration within the solution space. To demonstrate the effectiveness and efficiency of the proposed DPSO, a series of computational experiments are designed and conducted. The results are statistically analyzed, and it is evinced that the proposed DPSO is an effective approach for the studied problem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22915477','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22915477"><span><span class="hlt">Particle</span> image velocimetry (PIV) study of rotating cylindrical <span class="hlt">filters</span> for animal cell perfusion processes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Figueredo-Cardero, Alvio; Chico, Ernesto; Castilho, Leda; de Andrade Medronho, Ricardo</p> <p>2012-01-01</p> <p>In the present work, the main fluid flow features inside a rotating cylindrical filtration (RCF) system used as external cell retention device for animal cell perfusion processes were investigated using <span class="hlt">particle</span> image velocimetry (PIV). The motivation behind this work was to provide experimental fluid dynamic data for such turbulent flow using a high-permeability <span class="hlt">filter</span>, given the lack of information about this system in the literature. The results shown herein gave evidence that, at the boundary between the <span class="hlt">filter</span> mesh and the fluid, a slip velocity condition in the tangential direction does exist, which had not been reported in the literature so far. In the RCF system tested, this accounted for a fluid velocity 10% lower than that of the <span class="hlt">filter</span> tip, which could be important for the cake formation kinetics during filtration. Evidence confirming the existence of Taylor vortices under conditions of turbulent flow and high permeability, typical of animal cell perfusion RCF systems, was obtained. Second-order turbulence statistics were successfully calculated. The radial behavior of the second-order turbulent moments revealed that turbulence in this system is highly anisotropic, which is relevant for performing numerical simulations of this system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26357418','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26357418"><span><span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> With Interswarm Interactive Learning Strategy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qin, Quande; Cheng, Shi; Zhang, Qingyu; Li, Li; Shi, Yuhui</p> <p>2016-10-01</p> <p>The learning strategy in the canonical <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) algorithm is often blamed for being the primary reason for loss of diversity. Population diversity maintenance is crucial for preventing <span class="hlt">particles</span> from being stuck into local optima. In this paper, we present an improved PSO algorithm with an interswarm interactive learning strategy (IILPSO) by overcoming the drawbacks of the canonical PSO algorithm's learning strategy. IILPSO is inspired by the phenomenon in human society that the interactive learning behavior takes place among different groups. <span class="hlt">Particles</span> in IILPSO are divided into two swarms. The interswarm interactive learning (IIL) behavior is triggered when the best <span class="hlt">particle</span>'s fitness value of both the swarms does not improve for a certain number of iterations. According to the best <span class="hlt">particle</span>'s fitness value of each swarm, the softmax method and roulette method are used to determine the roles of the two swarms as the learning swarm and the learned swarm. In addition, the velocity mutation operator and global best vibration strategy are used to improve the algorithm's global search capability. The IIL strategy is applied to PSO with global star and local ring structures, which are termed as IILPSO-G and IILPSO-L algorithm, respectively. Numerical experiments are conducted to compare the proposed algorithms with eight popular PSO variants. From the experimental results, IILPSO demonstrates the good performance in terms of solution accuracy, convergence speed, and reliability. Finally, the variations of the population diversity in the entire search process provide an explanation why IILPSO performs effectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5111067','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5111067"><span><span class="hlt">Optimal</span> 2D-SIM reconstruction by two <span class="hlt">filtering</span> steps with Richardson-Lucy deconvolution</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Perez, Victor; Chang, Bo-Jui; Stelzer, Ernst Hans Karl</p> <p>2016-01-01</p> <p>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 <span class="hlt">filter</span>. 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 <span class="hlt">optimal</span> results by two straightforward <span class="hlt">filtering</span> 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 <span class="hlt">filtering</span> steps improve images of test specimens, microtubules, yeast and mammalian cells. PMID:27849043</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NatSR...637149P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NatSR...637149P"><span><span class="hlt">Optimal</span> 2D-SIM reconstruction by two <span class="hlt">filtering</span> steps with Richardson-Lucy deconvolution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Perez, Victor; Chang, Bo-Jui; Stelzer, Ernst Hans Karl</p> <p>2016-11-01</p> <p>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 <span class="hlt">filter</span>. 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 <span class="hlt">optimal</span> results by two straightforward <span class="hlt">filtering</span> 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 <span class="hlt">filtering</span> steps improve images of test specimens, microtubules, yeast and mammalian cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GMD.....9.3919X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GMD.....9.3919X"><span>A method for retrieving clouds with satellite infrared radiances using the <span class="hlt">particle</span> <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>Xu, Dongmei; Auligné, Thomas; Descombes, Gaël; Snyder, Chris</p> <p>2016-11-01</p> <p>Ensemble-based techniques have been widely utilized in estimating uncertainties in various problems of interest in geophysical applications. A new cloud retrieval method is proposed based on the <span class="hlt">particle</span> <span class="hlt">filter</span> (PF) by using ensembles of cloud information in the framework of Gridpoint Statistical Interpolation (GSI) system. The PF cloud retrieval method is compared with the Multivariate Minimum Residual (MMR) method that was previously established and verified. Cloud retrieval experiments involving a variety of cloudy types are conducted with the PF and MMR methods with measurements of infrared radiances on multi-sensors onboard both geostationary and polar satellites, respectively. It is found that the retrieved cloud masks with both methods are consistent with other independent cloud products. MMR is prone to producing ambiguous small-fraction clouds, while PF detects clearer cloud signals, yielding closer heights of cloud top and cloud base to other references. More collections of small-fraction <span class="hlt">particles</span> are able to effectively estimate the semi-transparent high clouds. It is found that radiances with high spectral resolutions contribute to quantitative cloud top and cloud base retrievals. In addition, a different way of resolving the <span class="hlt">filtering</span> problem over each model grid is tested to better aggregate the weights with all available sensors considered, which is proven to be less constrained by the ordering of sensors. Compared to the MMR method, the PF method is overall more computationally efficient, and the cost of the model grid-based PF method scales more directly with the number of computing nodes.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014E%26ES...17a2126B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014E%26ES...17a2126B"><span>Assimilation of microwave brightness temperatures for soil moisture estimation using <span class="hlt">particle</span> <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>Bi, H. Y.; Ma, J. W.; Qin, S. X.; Zeng, J. Y.</p> <p>2014-03-01</p> <p>Soil moisture plays a significant role in global water cycles. Both model simulations and remote sensing observations have their limitations when estimating soil moisture on a large spatial scale. Data assimilation (DA) is a promising tool which can combine model dynamics and remote sensing observations to obtain more precise ground soil moisture distribution. Among various DA methods, the <span class="hlt">particle</span> <span class="hlt">filter</span> (PF) can be applied to non-linear and non-Gaussian systems, thus holding great potential for DA. In this study, a data assimilation scheme based on the residual resampling <span class="hlt">particle</span> <span class="hlt">filter</span> (RR-PF) was developed to assimilate microwave brightness temperatures into the macro-scale semi-distributed Variance Infiltration Capacity (VIC) Model to estimate surface soil moisture. A radiative transfer model (RTM) was used to link brightness temperatures with surface soil moisture. Finally, the data assimilation scheme was validated by experimental data obtained at Arizona during the Soil Moisture Experiment 2004 (SMEX04). The results show that the estimation accuracy of soil moisture can be improved significantly by RR-PF through assimilating microwave brightness temperatures into VIC model. Both the overall trends and specific values of the assimilation results are more consistent with ground observations compared with model simulation results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H41A0773Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H41A0773Y"><span>Improving Hydrologic Data Assimilation by a Multivariate <span class="hlt">Particle</span> <span class="hlt">Filter</span>-Markov Chain Monte Carlo</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yan, H.; DeChant, C. M.; Moradkhani, H.</p> <p>2014-12-01</p> <p>Data assimilation (DA) is a popular method for merging information from multiple sources (i.e. models and remotely sensing), leading to improved hydrologic prediction. With the increasing availability of satellite observations (such as soil moisture) in recent years, DA is emerging in operational forecast systems. Although these techniques have seen widespread application, developmental research has continued to further refine their effectiveness. This presentation will examine potential improvements to the <span class="hlt">Particle</span> <span class="hlt">Filter</span> (PF) through the inclusion of multivariate correlation structures. Applications of the PF typically rely on univariate DA schemes (such as assimilating the outlet observed discharge), and multivariate schemes generally ignore the spatial correlation of the observations. In this study, a multivariate DA scheme is proposed by introducing geostatistics into the newly developed <span class="hlt">particle</span> <span class="hlt">filter</span> with Markov chain Monte Carlo (PF-MCMC) method. This new method is assessed by a case study over one of the basin with natural hydrologic process in Model Parameter Estimation Experiment (MOPEX), located in Arizona. The multivariate PF-MCMC method is used to assimilate the Advanced Scatterometer (ASCAT) grid (12.5 km) soil moisture retrievals and the observed streamflow in five gages (four inlet and one outlet gages) into the Sacramento Soil Moisture Accounting (SAC-SMA) model for the same scale (12.5 km), leading to greater skill in hydrologic predictions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ITEIS.131..227I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ITEIS.131..227I"><span>A Robust Indoor Autonomous Positioning System Using <span class="hlt">Particle</span> <span class="hlt">Filter</span> Based on ISM Band Wireless Communications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ikeda, Takeshi; Kawamoto, Mitsuru; Sashima, Akio; Suzuki, Keiji; Kurumatani, Koichi</p> <p></p> <p>In the field of the ubiquitous computing, positioning systems which can provide users' location information have paid attention as an important technical element which can be applied to various services, for example, indoor navigation services, evacuation services, market research services, guidance services, and so on. A lot of researchers have proposed various outdoor and indoor positioning systems. In this paper, we deal with indoor positioning systems. Many conventional indoor positioning systems use expensive infrastructures, because the propagated times of radio waves are used to measure users' positions with high accuracy. In this paper, we propose an indoor autonomous positioning system using radio signal strengths (RSSs) based on ISM band communications. In order to estimate users' positions, the proposed system utilizes a <span class="hlt">particle</span> <span class="hlt">filter</span> that is one of the Monte Carlo methods. Because the RSS information is used in the proposed system, the equipments configuring the system are not expensive compared with the conventional indoor positioning systems and it can be installed easily. Moreover, because the <span class="hlt">particle</span> <span class="hlt">filter</span> is used to estimate user's position, even if the RSS fluctuates due to, for example, multi-paths, the system can carry out position estimation robustly. We install the proposed system in one floor of a building and carry out some experiments in order to verify the validity of the proposed system. As a result, we confirmed that the average of the estimation errors of the proposed system was about 1.8 m, where the result is enough accuracy for achieving the services mentioned above.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3683548','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3683548"><span>Deform PF-MT: <span class="hlt">Particle</span> <span class="hlt">Filter</span> With Mode Tracker for Tracking Nonaffine Contour Deformations</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Vaswani, Namrata; Rathi, Yogesh; Yezzi, Anthony; Tannenbaum, Allen</p> <p>2013-01-01</p> <p>We propose algorithms for tracking the boundary contour of a deforming object from an image sequence, when the nonaffine (local) deformation over consecutive frames is large and there is overlapping clutter, occlusions, low contrast, or outlier imagery. When the object is arbitrarily deforming, each, or at least most, contour points can move independently. Contour deformation then forms an infinite (in practice, very large), dimensional space. Direct application of <span class="hlt">particle</span> <span class="hlt">filters</span> (PF) for large dimensional problems is impractically expensive. However, in most real problems, at any given time, most of the contour deformation occurs in a small number of dimensions (“effective basis space”) while the residual deformation in the rest of the state space (“residual space”) is small. This property enables us to apply the <span class="hlt">particle</span> <span class="hlt">filtering</span> with mode tracking (PF-MT) idea that was proposed for such large dimensional problems in recent work. Since most contour deformation is low spatial frequency, we propose to use the space of deformation at a subsampled set of locations as the effective basis space. The resulting algorithm is called deform PF-MT. It requires significant modifications compared to the original PF-MT because the space of contours is a non-Euclidean infinite dimensional space. PMID:19933014</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19610293','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19610293"><span>Heuristic <span class="hlt">optimization</span> of the scanning path of <span class="hlt">particle</span> therapy beams.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pardo, J; Donetti, M; Bourhaleb, F; Ansarinejad, A; Attili, A; Cirio, R; Garella, M A; Giordanengo, S; Givehchi, N; La Rosa, A; Marchetto, F; Monaco, V; Pecka, A; Peroni, C; Russo, G; Sacchi, R</p> <p>2009-06-01</p> <p>Quasidiscrete scanning is a delivery strategy for proton and ion beam therapy in which the beam is turned off when a slice is finished and a new energy must be set but not during the scanning between consecutive spots. Different scanning paths lead to different dose distributions due to the contribution of the unintended transit dose between spots. In this work an algorithm to <span class="hlt">optimize</span> the scanning path for quasidiscrete scanned beams is presented. The classical simulated annealing algorithm is used. It is a heuristic algorithm frequently used in combinatorial <span class="hlt">optimization</span> problems, which allows us to obtain nearly <span class="hlt">optimal</span> solutions in acceptable running times. A study focused on the best choice of operational parameters on which the algorithm performance depends is presented. The convergence properties of the algorithm have been further improved by using the next-neighbor algorithm to generate the starting paths. Scanning paths for two clinical treatments have been <span class="hlt">optimized</span>. The <span class="hlt">optimized</span> paths are found to be shorter than the back-and-forth, top-to-bottom (zigzag) paths generally provided by the treatment planning systems. The gamma method has been applied to quantify the improvement achieved on the dose distribution. Results show a reduction of the transit dose when the <span class="hlt">optimized</span> paths are used. The benefit is clear especially when the fluence per spot is low, as in the case of repainting. The minimization of the transit dose can potentially allow the use of higher beam intensities, thus decreasing the treatment time. The algorithm implemented for this work can <span class="hlt">optimize</span> efficiently the scanning path of quasidiscrete scanned <span class="hlt">particle</span> beams. <span class="hlt">Optimized</span> scanning paths decrease the transit dose and lead to better dose distributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4730493','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4730493"><span>Experimental Study on Ultrafine <span class="hlt">Particle</span> Removal Performance of Portable Air Cleaners with Different <span class="hlt">Filters</span> in an Office Room</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ma, Huan; Shen, Henggen; Shui, Tiantian; Li, Qing; Zhou, Liuke</p> <p>2016-01-01</p> <p>Size- and time-dependent aerodynamic behaviors of indoor <span class="hlt">particles</span>, including PM1.0, were evaluated in a school office in order to test the performance of air-cleaning devices using different <span class="hlt">filters</span>. In-situ real-time measurements were taken using an optical <span class="hlt">particle</span> counter. The filtration characteristics of <span class="hlt">filter</span> media, including single-pass efficiency, volume and effectiveness, were evaluated and analyzed. The electret <span class="hlt">filter</span> (EE) medium shows better initial removal efficiency than the high efficiency (HE) medium in the 0.3–3.5 μm <span class="hlt">particle</span> size range, while under the same face velocity, the filtration resistance of the HE medium is several times higher than that of the EE medium. During service life testing, the efficiency of the EE medium decreased to 60% with a total purifying air flow of 25 × 104 m3/m2. The resistance curve rose slightly before the efficiency reached the bottom, and then increased almost exponentially. The single-pass efficiency of portable air cleaner (PAC) with the pre-<span class="hlt">filter</span> (PR) or the active carbon granule <span class="hlt">filter</span> (CF) was relatively poor. While PAC with the pre-<span class="hlt">filter</span> and the high efficiency <span class="hlt">filter</span> (PR&HE) showed maximum single-pass efficiency for PM1.0 (88.6%), PAC with the HE was the most effective at removing PM1.0. The enhancement of PR with HE and electret <span class="hlt">filters</span> augmented the single-pass efficiency, but lessened the airflow rate and effectiveness. Combined with PR, the decay constant of large-sized <span class="hlt">particles</span> could be greater than for PACs without PR. Without regard to the lifetime, the electret <span class="hlt">filters</span> performed better with respect to resource saving and purification improvement. A most penetrating <span class="hlt">particle</span> size range (MPPS: 0.4–0.65 μm) exists in both HE and electret <span class="hlt">filters</span>; the MPPS tends to become larger after HE and electret <span class="hlt">filters</span> are combined with PR. These results serve to provide a better understanding of the indoor <span class="hlt">particle</span> removal performance of PACs when combined with different kinds of <span class="hlt">filters</span> in school</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AcAau..94..852P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AcAau..94..852P"><span><span class="hlt">Particle</span> swarm <span class="hlt">optimization</span> of ascent trajectories of multistage launch vehicles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pontani, Mauro</p> <p>2014-02-01</p> <p>Multistage launch vehicles are commonly employed to place spacecraft and satellites in their operational orbits. If the rocket characteristics are specified, the <span class="hlt">optimization</span> of its ascending trajectory consists of determining the <span class="hlt">optimal</span> control law that leads to maximizing the final mass at orbit injection. The numerical solution of a similar problem is not trivial and has been pursued with different methods, for decades. This paper is concerned with an original approach based on the joint use of swarming theory and the necessary conditions for <span class="hlt">optimality</span>. The <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> technique represents a heuristic population-based <span class="hlt">optimization</span> method inspired by the natural motion of bird flocks. Each individual (or <span class="hlt">particle</span>) that composes the swarm corresponds to a solution of the problem and is associated with a position and a velocity vector. The formula for velocity updating is the core of the method and is composed of three terms with stochastic weights. As a result, the population migrates toward different regions of the search space taking advantage of the mechanism of information sharing that affects the overall swarm dynamics. At the end of the process the best <span class="hlt">particle</span> is selected and corresponds to the <span class="hlt">optimal</span> solution to the problem of interest. In this work the three-dimensional trajectory of the multistage rocket is assumed to be composed of four arcs: (i) first stage propulsion, (ii) second stage propulsion, (iii) coast arc (after release of the second stage), and (iv) third stage propulsion. The Euler-Lagrange equations and the Pontryagin minimum principle, in conjunction with the Weierstrass-Erdmann corner conditions, are employed to express the thrust angles as functions of the adjoint variables conjugate to the dynamics equations. The use of these analytical conditions coming from the calculus of variations leads to obtaining the overall rocket dynamics as a function of seven parameters only, namely the unknown values of the initial state</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19473938','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19473938"><span>Wavelet-based SAR image despeckling and information extraction, using <span class="hlt">particle</span> <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>Gleich, Dusan; Datcu, Mihai</p> <p>2009-10-01</p> <p>This paper proposes a new-wavelet-based synthetic aperture radar (SAR) image despeckling algorithm using the sequential Monte Carlo method. A model-based Bayesian approach is proposed. This paper presents two methods for SAR image despeckling. The first method, called WGGPF, models a prior with Generalized Gaussian (GG) probability density function (pdf) and the second method, called WGMPF, models prior with a Generalized Gaussian Markov random field (GGMRF). The likelihood pdf is modeled using a Gaussian pdf. The GGMRF model is used because it enables texture parameter estimation. The prior is modeled using GG pdf, when texture parameters are not needed. A <span class="hlt">particle</span> <span class="hlt">filter</span> is used for drawing <span class="hlt">particles</span> from the prior for different shape parameters of GG pdf. When the GGMRF prior is used, the <span class="hlt">particles</span> are drawn from prior in order to estimate noise-free wavelet coefficients and for those coefficients the texture parameter is changed in order to obtain the best textural parameters. The texture parameters are changed for a predefined set of shape parameters of GGMRF. The <span class="hlt">particles</span> with the highest weights represents the final noise-free estimate with corresponding textural parameters. The despeckling algorithms are compared with the state-of-the-art methods using synthetic and real SAR data. The experimental results show that the proposed despeckling algorithms efficiently remove noise and proposed methods are comparable with the state-of-the-art methods regarding objective measurements. The proposed WGMPF preserves textures of the real, high-resolution SAR images well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23470039','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23470039"><span><span class="hlt">Filterable</span> redox cycling activity: a comparison between diesel exhaust <span class="hlt">particles</span> and secondary organic aerosol constituents.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McWhinney, Robert D; Badali, Kaitlin; Liggio, John; Li, Shao-Meng; Abbatt, Jonathan P D</p> <p>2013-04-02</p> <p>The redox activity of diesel exhaust <span class="hlt">particles</span> (DEP) collected from a light-duty diesel passenger car engine was examined using the dithiothreitol (DTT) assay. DEP was highly redox-active, causing DTT to decay at a rate of 23-61 pmol min(-1) μg(-1) of <span class="hlt">particle</span> used in the assay, which was an order of magnitude higher than ambient coarse and fine particulate matter (PM) collected from downtown Toronto. Only 2-11% of the redox activity was in the water-soluble portion, while the remainder occurred at the black carbon surface. This is in contrast to redox-active secondary organic aerosol constituents, in which upward of 90% of the activity occurs in the water-soluble fraction. The redox activity of DEP is not extractable by moderately polar (methanol) and nonpolar (dichloromethane) organic solvents, and is hypothesized to arise from redox-active moieties contiguous with the black carbon portion of the <span class="hlt">particles</span>. These measurements illustrate that "<span class="hlt">Filterable</span> Redox Cycling Activity" may therefore be useful to distinguish black carbon-based oxidative capacity from water-soluble organic-based activity. The difference in chemical environment leading to redox activity highlights the need to further examine the relationship between activity in the DTT assay and toxicology measurements across <span class="hlt">particles</span> of different origins and composition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SPIE.7497E..0LX','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SPIE.7497E..0LX"><span><span class="hlt">Optimal</span> control of switched linear systems based on Migrant <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> algorithm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xie, Fuqiang; Wang, Yongji; Zheng, Zongzhun; Li, Chuanfeng</p> <p>2009-10-01</p> <p>The <span class="hlt">optimal</span> control problem for switched linear systems with internally forced switching has more constraints than with externally forced switching. Heavy computations and slow convergence in solving this problem is a major obstacle. In this paper we describe a new approach for solving this problem, which is called Migrant <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (Migrant PSO). Imitating the behavior of a flock of migrant birds, the Migrant PSO applies naturally to both continuous and discrete spaces, in which definitive <span class="hlt">optimization</span> algorithm and stochastic search method are combined. The efficacy of the proposed algorithm is illustrated via a numerical example.</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://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1757777','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1757777"><span>Bronchoalveolar inflammation after exposure to diesel exhaust: comparison between unfiltered and <span class="hlt">particle</span> trap <span class="hlt">filtered</span> exhaust</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rudell, B.; Blomberg, A.; Helleday, R.; Ledin, M. C.; Lundback, B.; Stjernberg, N.; Horstedt, P.; Sandstrom, T.</p> <p>1999-01-01</p> <p>OBJECTIVES: Air pollution particulates have been identified as having adverse effects on respiratory health. The present study was undertaken to further clarify the effects of diesel exhaust on bronchoalveolar cells and soluble components in normal healthy subjects. The study was also designed to evaluate whether a ceramic <span class="hlt">particle</span> trap at the end of the tail pipe, from an idling engine, would reduce indices of airway inflammation. METHODS: The study comprised three exposures in all 10 healthy never smoking subjects; air, diluted diesel exhaust, and diluted diesel exhaust <span class="hlt">filtered</span> with a ceramic <span class="hlt">particle</span> trap. The exposures were given for 1 hour in randomised order about 3 weeks apart. The diesel exhaust exposure apperatus has previously been carefully developed and evaluated. Bronchoalveolar lavage was performed 24 hours after exposures and the lavage fluids from the bronchial and bronchoalveolar region were analysed for cells and soluble components. RESULTS: The <span class="hlt">particle</span> trap reduced the mean steady state number of <span class="hlt">particles</span> by 50%, but the concentrations of the other measured compounds were almost unchanged. It was found that diesel exhaust caused an increase in neutrophils in airway lavage, together with an adverse influence on the phagocytosis by alveolar macrophages in vitro. Furthermore, the diesel exhaust was found to be able to induce a migration of alveolar macrophages into the airspaces, together with reduction in CD3+CD25+ cells. (CD = cluster of differentiation) The use of the specific ceramic <span class="hlt">particle</span> trap at the end of the tail pipe was not sufficient to completely abolish these effects when interacting with the exhaust from an idling vehicle. CONCLUSIONS: The current study showed that exposure to diesel exhaust may induce neutrophil and alveolar macrophage recruitment into the airways and suppress alveolar macrophage function. The <span class="hlt">particle</span> trap did not cause significant reduction of effects induced by diesel exhaust compared with unfiltered diesel</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003SPIE.5100...73T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003SPIE.5100...73T"><span><span class="hlt">Particle</span> swarm <span class="hlt">optimization</span> for the clustering of wireless sensors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tillett, Jason C.; Rao, Raghuveer M.; Sahin, Ferat; Rao, T. M.</p> <p>2003-07-01</p> <p>Clustering is necessary for data aggregation, hierarchical routing, <span class="hlt">optimizing</span> sleep patterns, election of extremal sensors, <span class="hlt">optimizing</span> coverage and resource allocation, reuse of frequency bands and codes, and conserving energy. <span class="hlt">Optimal</span> clustering is typically an NP-hard problem. Solutions to NP-hard problems involve searches through vast spaces of possible solutions. Evolutionary algorithms have been applied successfully to a variety of NP-hard problems. We explore one such approach, <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO), an evolutionary programming technique where a 'swarm' of test solutions, analogous to a natural swarm of bees, ants or termites, is allowed to interact and cooperate to find the best solution to the given problem. We use the PSO approach to cluster sensors in a sensor network. The energy efficiency of our clustering in a data-aggregation type sensor network deployment is tested using a modified LEACH-C code. The PSO technique with a recursive bisection algorithm is tested against random search and simulated annealing; the PSO technique is shown to be robust. We further investigate developing a distributed version of the PSO algorithm for clustering <span class="hlt">optimally</span> a wireless sensor network.</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('http://adsabs.harvard.edu/abs/2005NIMPB.231..384R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005NIMPB.231..384R"><span><span class="hlt">Optimization</span> of <span class="hlt">particle</span> fluence in micromachining of CR-39</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rajta, I.; Baradács, E.; Bettiol, A. A.; Csige, I.; Tőkési, K.; Budai, L.; Kiss, Á. Z.</p> <p>2005-04-01</p> <p>Polyallyl diglycol carbonate (CR-39 etched track detector) material was irradiated with various doses of 2 MeV protons and alpha-<span class="hlt">particles</span> in order to <span class="hlt">optimize</span> the fluence for P-beam writing of CR-39. Irradiation were performed at the Institute of Nuclear Research, Debrecen, Hungary and at the National University of Singapore. Post irradiation work has been carried out in Debrecen. The fluence in the irradiated area was sufficiently high that the latent tracks overlapped and the region could be removed collectively by short etching times of the order of less than 1 min. Theoretical calculations based on analytical and Monte Carlo simulations were done in order to calculate the probability of multiple latent track overlap. <span class="hlt">Optimal</span> <span class="hlt">particle</span> fluence was found by minimising the fluence and etching time at which collective removal of latent tracks could be observed. Short etching time is required to obtain high resolution microstructures, while low <span class="hlt">particle</span> fluence is desirable for economical reasons, and also because high fluences increase the risk of unwanted damage (e.g. melting).</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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4942599','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4942599"><span><span class="hlt">Optimizing</span> the Shunting Schedule of Electric Multiple Units Depot Using an Enhanced <span class="hlt">Particle</span> Swarm <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>Jin, Junchen</p> <p>2016-01-01</p> <p>The shunting schedule of electric multiple units depot (SSED) is one of the essential plans for high-speed train maintenance activities. This paper presents a 0-1 programming model to address the problem of determining an <span class="hlt">optimal</span> SSED through automatic computing. The objective of the model is to minimize the number of shunting movements and the constraints include track occupation conflicts, shunting routes conflicts, time durations of maintenance processes, and shunting running time. An enhanced <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (EPSO) algorithm is proposed to solve the <span class="hlt">optimization</span> problem. Finally, an empirical study from Shanghai South EMU Depot is carried out to illustrate the model and EPSO algorithm. The <span class="hlt">optimization</span> results indicate that the proposed method is valid for the SSED problem and that the EPSO algorithm outperforms the traditional PSO algorithm on the aspect of <span class="hlt">optimality</span>. PMID:27436998</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27436998','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27436998"><span><span class="hlt">Optimizing</span> the Shunting Schedule of Electric Multiple Units Depot Using an Enhanced <span class="hlt">Particle</span> Swarm <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>Wang, Jiaxi; Lin, Boliang; Jin, Junchen</p> <p>2016-01-01</p> <p>The shunting schedule of electric multiple units depot (SSED) is one of the essential plans for high-speed train maintenance activities. This paper presents a 0-1 programming model to address the problem of determining an <span class="hlt">optimal</span> SSED through automatic computing. The objective of the model is to minimize the number of shunting movements and the constraints include track occupation conflicts, shunting routes conflicts, time durations of maintenance processes, and shunting running time. An enhanced <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (EPSO) algorithm is proposed to solve the <span class="hlt">optimization</span> problem. Finally, an empirical study from Shanghai South EMU Depot is carried out to illustrate the model and EPSO algorithm. The <span class="hlt">optimization</span> results indicate that the proposed method is valid for the SSED problem and that the EPSO algorithm outperforms the traditional PSO algorithm on the aspect of <span class="hlt">optimality</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_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://hdl.handle.net/2060/20050182658','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050182658"><span>A Parallel <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> Algorithm Accelerated by Asynchronous Evaluations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Venter, Gerhard; Sobieszczanski-Sobieski, Jaroslaw</p> <p>2005-01-01</p> <p>A parallel <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO) algorithm is presented. <span class="hlt">Particle</span> swarm <span class="hlt">optimization</span> is a fairly recent addition to the family of non-gradient based, probabilistic search algorithms that is based on a simplified social model and is closely tied to swarming theory. Although PSO algorithms present several attractive properties to the designer, they are plagued by high computational cost as measured by elapsed time. One approach to reduce the elapsed time is to make use of coarse-grained parallelization to evaluate the design points. Previous parallel PSO algorithms were mostly implemented in a synchronous manner, where all design points within a design iteration are evaluated before the next iteration is started. This approach leads to poor parallel speedup in cases where a heterogeneous parallel environment is used and/or where the analysis time depends on the design point being analyzed. This paper introduces an asynchronous parallel PSO algorithm that greatly improves the parallel e ciency. The asynchronous algorithm is benchmarked on a cluster assembled of Apple Macintosh G5 desktop computers, using the multi-disciplinary <span class="hlt">optimization</span> of a typical transport aircraft wing as an example.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28089602','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28089602"><span><span class="hlt">Particle</span> swarm <span class="hlt">optimizer</span> for weighting factor selection in intensity-modulated radiation therapy <span class="hlt">optimization</span> algorithms.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Jie; Zhang, Pengcheng; Zhang, Liyuan; Shu, Huazhong; Li, Baosheng; Gui, Zhiguo</p> <p>2017-01-01</p> <p>In inverse treatment planning of intensity-modulated radiation therapy (IMRT), the objective function is typically the sum of the weighted sub-scores, where the weights indicate the importance of the sub-scores. To obtain a high-quality treatment plan, the planner manually adjusts the objective weights using a trial-and-error procedure until an acceptable plan is reached. In this work, a new <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) method which can adjust the weighting factors automatically was investigated to overcome the requirement of manual adjustment, thereby reducing the workload of the human planner and contributing to the development of a fully automated planning process. The proposed <span class="hlt">optimization</span> method consists of three steps. (i) First, a swarm of weighting factors (i.e., <span class="hlt">particles</span>) is initialized randomly in the search space, where each <span class="hlt">particle</span> corresponds to a global objective function. (ii) Then, a plan <span class="hlt">optimization</span> solver is employed to obtain the <span class="hlt">optimal</span> solution for each <span class="hlt">particle</span>, and the values of the evaluation functions used to determine the <span class="hlt">particle</span>'s location and the population global location for the PSO are calculated based on these results. (iii) Next, the weighting factors are updated based on the <span class="hlt">particle</span>'s location and the population global location. Step (ii) is performed alternately with step (iii) until the termination condition is reached. In this method, the evaluation function is a combination of several key points on the dose volume histograms. Furthermore, a perturbation strategy - the crossover and mutation operator hybrid approach - is employed to enhance the population diversity, and two arguments are applied to the evaluation function to improve the flexibility of the algorithm. In this study, the proposed method was used to develop IMRT treatment plans involving five unequally spaced 6MV photon beams for 10 prostate cancer cases. The proposed <span class="hlt">optimization</span> algorithm yielded high-quality plans for all of the cases, without human</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 steps, 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/20064026','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20064026"><span>Strength Pareto <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> and hybrid EA-PSO for multi-objective <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>Elhossini, Ahmed; Areibi, Shawki; Dony, Robert</p> <p>2010-01-01</p> <p>This paper proposes an efficient <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) technique that can handle multi-objective <span class="hlt">optimization</span> problems. It is based on the strength Pareto approach originally used in evolutionary algorithms (EA). The proposed modified <span class="hlt">particle</span> swarm algorithm is used to build three hybrid EA-PSO algorithms to solve different multi-objective <span class="hlt">optimization</span> problems. This algorithm and its hybrid forms are tested using seven benchmarks from the literature and the results are compared to the strength Pareto evolutionary algorithm (SPEA2) and a competitive multi-objective PSO using several metrics. The proposed algorithm shows a slower convergence, compared to the other algorithms, but requires less CPU time. Combining PSO and evolutionary algorithms leads to superior hybrid algorithms that outperform SPEA2, the competitive multi-objective PSO (MO-PSO), and the proposed strength Pareto PSO based on different metrics.</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('http://adsabs.harvard.edu/abs/2017CosRe..55...79P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017CosRe..55...79P"><span><span class="hlt">Optimization</span> of measurements of the Earth's radiation belt <span class="hlt">particle</span> fluxes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Panasyuk, M. I.; Podzolko, M. V.; Kovtyukh, A. S.; Brilkov, I. A.; Vlasova, N. A.; Kalegaev, V. V.; Osedlo, V. I.; Tulupov, V. I.; Yashin, I. V.</p> <p>2017-03-01</p> <p>The Earth's radiation belts discovered at the end of the 1950s have great scientific and practical interest. Their main characteristics in magnetically quiet periods are well known. However, the dynamics of the Earth's radiation belts during magnetic storms and substorms, particularly the dynamics of relativistic electrons of the outer belt, when Earth's radiation belt <span class="hlt">particle</span> fluxes undergo significant time variations, is studied insufficiently. At present, principally new experiments have been performed and planned with the intention to better study the dynamics of the Earth's radiation belts and to operationally control the space-energy distributions of the Earth's radiation belt <span class="hlt">particle</span> fluxes. In this paper, for spacecraft designed to measure the fluxes of electrons and protons of the Earth's radiation belts at altitudes of 0.5-10000 km, the <span class="hlt">optimal</span> versions for detector orientation and orbital parameters have been considered and selected.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JAP...105i4502Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JAP...105i4502Y"><span>Parameter extraction of solar cells using <span class="hlt">particle</span> swarm <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>Ye, Meiying; Wang, Xiaodong; Xu, Yousheng</p> <p>2009-05-01</p> <p>In this article, <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) was applied to extract the solar cell parameters from illuminated current-voltage characteristics. The performance of the PSO was compared with the genetic algorithms (GAs) for the single and double diode models. Based on synthetic and experimental current-voltage data, it has been confirmed that the proposed method can obtain higher parameter precision with better computational efficiency than the GA method. Compared with conventional gradient-based methods, even without a good initial guess, the PSO method can obtain the parameters of solar cells as close as possible to the practical parameters only based on a broad range specified for each of the parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhPro..33..983T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhPro..33..983T"><span>PMSM Driver Based on Hybrid <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> and CMAC</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tu, Ji; Cao, Shaozhong</p> <p></p> <p>A novel hybrid <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) and cerebellar model articulation controller (CMAC) is introduced to the permanent magnet synchronous motor (PMSM) driver. PSO can simulate the random learning among the individuals of population and CMAC can simulate the self-learning of an individual. To validate the ability and superiority of the novel algorithm, experiments and comparisons have been done in MATLAB/SIMULINK. Analysis among PSO, hybrid PSO-CMAC and CMAC feed-forward control is also given. The results prove that the electric torque ripple and torque disturbance of the PMSM driver can be reduced by using the hybrid PSO-CMAC algorithm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010LNCS.6466..506Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010LNCS.6466..506Z"><span><span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> with Watts-Strogatz Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, Zhuanghua</p> <p></p> <p><span class="hlt">Particle</span> swarm <span class="hlt">optimization</span> (PSO) is a popular swarm intelligent methodology by simulating the animal social behaviors. Recent study shows that this type of social behaviors is a complex system, however, for most variants of PSO, all individuals lie in a fixed topology, and conflict this natural phenomenon. Therefore, in this paper, a new variant of PSO combined with Watts-Strogatz small-world topology model, called WSPSO, is proposed. In WSPSO, the topology is changed according to Watts-Strogatz rules within the whole evolutionary process. Simulation results show the proposed algorithm is effective and efficient.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009LNCS.5854..281F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009LNCS.5854..281F"><span>Constraint Web Service Composition Based on Discrete <span class="hlt">Particle</span> Swarm <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>Fang, Xianwen; Fan, Xiaoqin; Yin, Zhixiang</p> <p></p> <p>Web service composition provides an open, standards-based approach for connecting web services together to create higher-level business processes. The Standards are designed to reduce the complexity required to compose web services, hence reducing time and costs, and increase overall efficiency in businesses. This paper present independent global constrains web service composition <span class="hlt">optimization</span> methods based on Discrete <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (DPSO) and associate Petri net (APN). Combining with the properties of APN, an efficient DPSO algorithm is presented which is used to search a legal firing sequence in the APN model. Using legal firing sequences of the Petri net makes the service composition locating space based on DPSO shrink greatly. Finally, for comparing our methods with the approximating methods, the simulation experiment is given out. Theoretical analysis and experimental results indicate that this method owns both lower computation cost and higher success ratio of service composition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5021892','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5021892"><span>R2-Based Multi/Many-Objective <span class="hlt">Particle</span> Swarm <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>Toscano, Gregorio; Barron-Zambrano, Jose Hugo; Tello-Leal, Edgar</p> <p>2016-01-01</p> <p>We propose to couple the R2 performance measure and <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> in order to handle multi/many-objective problems. Our proposal shows that through a well-designed interaction process we could maintain the metaheuristic almost inalterable and through the R2 performance measure we did not use neither an external archive nor Pareto dominance to guide the search. The proposed approach is validated using several test problems and performance measures commonly adopted in the specialized literature. Results indicate that the proposed algorithm produces results that are competitive with respect to those obtained by four well-known MOEAs. Additionally, we validate our proposal in many-objective <span class="hlt">optimization</span> problems. In these problems, our approach showed its main strength, since it could outperform another well-known indicator-based MOEA. PMID:27656200</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMGC23C0943Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMGC23C0943Y"><span>Climatological sensitivity analysis of crop yield to changes in temperature and precipitation using <span class="hlt">particle</span> <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>Yokozawa, M.; Sakurai, G.; Iizumi, T.</p> <p>2010-12-01</p> <p>The climatological sensitivities of crop yields to changes in mean temperature and precipitation during a period of the growing season were statistically examined. The sensitivity is defined as the change of yield in response to the change of climatic condition in the growth period from sowing to harvesting. The objective crops are maize and soybean, which are being cultivated in United States, Brazil and China as the world major production countries. We collected the yield data of maize and soybean on county level of United States from USDA during a period of 1980-2006, on Município level of Brazil during a period of 1990-2006 and on Xiàn level of China during a period of 1980-2005. While the data on only four provinces in China are used (Heilongjiang, Henan, Liaoning, and Shandong), total production of the four provinces reaches about 40% (maize) and 51% (soybean) to the country total (USDA 1997). We used JRA-25 reanalysis climate data distributed from the Japanese Meteorological Agency during a period of 1980 through 2006 with a resolution of 1.125° in latitude and longitude. To coincide in resolution, the crop yield data were reallocated into the same grids as climate. To eliminate economical and technical effects on yield, we detrended the time series data of yield and climate. We applied a local regression model to conduct the detrend (cubic weighting and M estimator of Tukey's bi-weight function). The time series data on the deviation from the trend were examined with the changes in temperature and precipitation for each grid using the <span class="hlt">particle</span> <span class="hlt">filter</span>. The <span class="hlt">particle</span> <span class="hlt">filter</span> used here is based on self-organizing state-space model. As a result, in the northern hemisphere, positive sensitivity, i.e. increase in temperature shifts the crop yield positively, is generally found especially in higher latitude, while negative sensitivity is found in the lower latitude. The neutral sensitivity is found in the regions where the mean temperature during growing season</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMNS41A..02F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMNS41A..02F"><span>What is <span class="hlt">Particle</span> Swarm <span class="hlt">optimization</span>? Application to hydrogeophysics (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fernández Martïnez, J.; García Gonzalo, E.; Mukerji, T.</p> <p>2009-12-01</p> <p>Inverse problems are generally ill-posed. This yields lack of uniqueness and/or numerical instabilities. These features cause local <span class="hlt">optimization</span> methods without prior information to provide unpredictable results, not being able to discriminate among the multiple models consistent with the end criteria. Stochastic approaches to inverse problems consist in shifting attention to the probability of existence of certain interesting subsurface structures instead of "looking for a unique model". Some well-known stochastic methods include genetic algorithms and simulated annealing. A more recent method, <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span>, is a global <span class="hlt">optimization</span> technique that has been successfully applied to solve inverse problems in many engineering fields, although its use in geosciences is still limited. Like all stochastic methods, PSO requires reasonably fast forward modeling. The basic idea behind PSO is that each model searches the model space according to its misfit history and the misfit of the other models of the swarm. PSO algorithm can be physically interpreted as a damped spring-mass system. This physical analogy was used to define a whole family of PSO <span class="hlt">optimizers</span> and to establish criteria, based on the stability of <span class="hlt">particle</span> swarm trajectories, to tune the PSO parameters: inertia, local and global accelerations. In this contribution we show application to different low-cost hydrogeophysical inverse problems: 1) a salt water intrusion problem using Vertical Electrical Soundings, 2) the inversion of Spontaneous Potential data for groundwater modeling, 3) the identification of Cole-Cole parameters for Induced Polarization data. We show that with this stochastic approach we are able to answer questions related to risk analysis, such as what is the depth of the salt intrusion with a certain probability, or giving probabilistic bounds for the water table depth. Moreover, these measures of uncertainty are obtained with small computational cost and time, allowing us a very</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JNEng..14a6014P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JNEng..14a6014P"><span><span class="hlt">Particle</span> swarm <span class="hlt">optimization</span> for programming deep brain stimulation arrays</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peña, Edgar; Zhang, Simeng; Deyo, Steve; Xiao, YiZi; Johnson, Matthew D.</p> <p>2017-02-01</p> <p>Objective. Deep brain stimulation (DBS) therapy relies on both precise neurosurgical targeting and systematic <span class="hlt">optimization</span> of stimulation settings to achieve beneficial clinical outcomes. One recent advance to improve targeting is the development of DBS arrays (DBSAs) with electrodes segmented both along and around the DBS lead. However, increasing the number of independent electrodes creates the logistical challenge of <span class="hlt">optimizing</span> stimulation parameters efficiently. Approach. Solving such complex problems with multiple solutions and objectives is well known to occur in biology, in which complex collective behaviors emerge out of swarms of individual organisms engaged in learning through social interactions. Here, we developed a <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) algorithm to program DBSAs using a swarm of individual <span class="hlt">particles</span> representing electrode configurations and stimulation amplitudes. Using a finite element model of motor thalamic DBS, we demonstrate how the PSO algorithm can efficiently <span class="hlt">optimize</span> a multi-objective function that maximizes predictions of axonal activation in regions of interest (ROI, cerebellar-receiving area of motor thalamus), minimizes predictions of axonal activation in regions of avoidance (ROA, somatosensory thalamus), and minimizes power consumption. Main results. The algorithm solved the multi-objective problem by producing a Pareto front. ROI and ROA activation predictions were consistent across swarms (<1% median discrepancy in axon activation). The algorithm was able to accommodate for (1) lead displacement (1 mm) with relatively small ROI (⩽9.2%) and ROA (⩽1%) activation changes, irrespective of shift direction; (2) reduction in maximum per-electrode current (by 50% and 80%) with ROI activation decreasing by 5.6% and 16%, respectively; and (3) disabling electrodes (n  =  3 and 12) with ROI activation reduction by 1.8% and 14%, respectively. Additionally, comparison between PSO predictions and multi-compartment axon</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSA11A1913T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSA11A1913T"><span>Investigation on the internal acceleration process of the outer radiation belt using the <span class="hlt">particle</span> <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>Toyama, H.; Miyoshi, Y.; Ueno, G.; Koshiishi, H.; Matsumoto, H.; Shiokawa, K.</p> <p>2013-12-01</p> <p>It is known that high energy electrons in the radiation belts often cause satellite anomalies and malfunctions. Thus, a forecast of the time variation of the energetic electrons is necessary to protect satellites in the radiation belts. Time variations of the radiation belt electrons have been modeled with the Fokker-Plank equation. Performance of the forecast using the Fokker-Planck equation depends on the parameters used in the model, so that improvement of the parameters is important for the space weather forecast. We performed data assimilation using the <span class="hlt">particle</span> <span class="hlt">filter</span> by a code which was developed by Miyoshi et al.[2006]. We prepare 1000 <span class="hlt">particles</span> used for the calculation. In this study, phase space density, the diffusion coefficient, and wave amplitude, and the source amplitude of the internal acceleration compose the state vector. The observation vector consists of the differential flux measured by the Tsubasa satellite. We also apply the <span class="hlt">particle</span> smoother to estimate the smoothed distribution. While there were several discrepancies between the simulation without the data assimilation and the observations, the data assimilation improves the simulation result, and captures the typical flux variations of the outer belt during magnetic storms. We also discuss the internal acceleration process on the basis of the source amplitude estimated through the data assimilation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21567510','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21567510"><span>GRAVITATIONAL LENS MODELING WITH GENETIC ALGORITHMS AND <span class="hlt">PARTICLE</span> SWARM <span class="hlt">OPTIMIZERS</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rogers, Adam; Fiege, Jason D.</p> <p>2011-02-01</p> <p>Strong gravitational lensing of an extended object is described by a mapping from source to image coordinates that is nonlinear and cannot generally be inverted analytically. Determining the structure of the source intensity distribution also requires a description of the blurring effect due to a point-spread function. This initial study uses an iterative gravitational lens modeling scheme based on the semilinear method to determine the linear parameters (source intensity profile) of a strongly lensed system. Our 'matrix-free' approach avoids construction of the lens and blurring operators while retaining the least-squares formulation of the problem. The parameters of an analytical lens model are found through nonlinear <span class="hlt">optimization</span> by an advanced genetic algorithm (GA) and <span class="hlt">particle</span> swarm <span class="hlt">optimizer</span> (PSO). These global <span class="hlt">optimization</span> routines are designed to explore the parameter space thoroughly, mapping model degeneracies in detail. We develop a novel method that determines the L-curve for each solution automatically, which represents the trade-off between the image {chi}{sup 2} and regularization effects, and allows an estimate of the <span class="hlt">optimally</span> regularized solution for each lens parameter set. In the final step of the <span class="hlt">optimization</span> procedure, the lens model with the lowest {chi}{sup 2} is used while the global <span class="hlt">optimizer</span> solves for the source intensity distribution directly. This allows us to accurately determine the number of degrees of freedom in the problem to facilitate comparison between lens models and enforce positivity on the source profile. In practice, we find that the GA conducts a more thorough search of the parameter space than the PSO.</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/2013JEI....22d1123C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JEI....22d1123C"><span>Panorama parking assistant system with improved <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> method</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheng, Ruzhong; Zhao, Yong; Li, Zhichao; Jiang, Weigang; Wang, Xin'an; Xu, Yong</p> <p>2013-10-01</p> <p>A panorama parking assistant system (PPAS) for the automotive aftermarket together with a practical improved <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> method (IPSO) are proposed in this paper. In the PPAS system, four fisheye cameras are installed in the vehicle with different views, and four channels of video frames captured by the cameras are processed as a 360-deg top-view image around the vehicle. Besides the embedded design of PPAS, the key problem for image distortion correction and mosaicking is the efficiency of parameter <span class="hlt">optimization</span> in the process of camera calibration. In order to address this problem, an IPSO method is proposed. Compared with other parameter <span class="hlt">optimization</span> methods, the proposed method allows a certain range of dynamic change for the intrinsic and extrinsic parameters, and can exploit only one reference image to complete all of the <span class="hlt">optimization</span>; therefore, the efficiency of the whole camera calibration is increased. The PPAS is commercially available, and the IPSO method is a highly practical way to increase the efficiency of the installation and the calibration of PPAS in automobile 4S shops.</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('https://www.ncbi.nlm.nih.gov/pubmed/21301027','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21301027"><span>A Framework for 3D Model-Based Visual Tracking Using a GPU-Accelerated <span class="hlt">Particle</span> <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>Brown, J A; Capson, D W</p> <p>2012-01-01</p> <p>A novel framework for acceleration of <span class="hlt">particle</span> <span class="hlt">filtering</span> approaches to 3D model-based, markerless visual tracking in monocular video is described. Specifically, we present a methodology for partitioning and mapping the computationally expensive weight-update stage of a <span class="hlt">particle</span> <span class="hlt">filter</span> to a graphics processing unit (GPU) to achieve <span class="hlt">particle</span>- and pixel-level parallelism. Nvidia CUDA and Direct3D are employed to harness the massively parallel computational power of modern GPUs for simulation (3D model rendering) and evaluation (segmentation, feature extraction, and weight calculation) of hundreds of <span class="hlt">particles</span> at high speeds. The proposed framework addresses the computational intensity that is intrinsic to all <span class="hlt">particle</span> <span class="hlt">filter</span> approaches, including those that have been modified to minimize the number of <span class="hlt">particles</span> required for a particular task. Performance and tracking quality results for rigid object and articulated hand tracking experiments demonstrate markerless, model-based visual tracking on consumer-grade graphics hardware with pixel-level accuracy up to 95 percent at 60+ frames per second. The framework accelerates <span class="hlt">particle</span> evaluation up to 49 times over a comparable CPU-only implementation, providing an increased <span class="hlt">particle</span> count while maintaining real-time frame rates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27700022','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27700022"><span>Highly Integrated Polysulfone/polyacrylonitrile/polyamide-6 Air <span class="hlt">Filter</span> for Multi-level Physical Sieving Airborne <span class="hlt">Particles</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Shichao; Tang, Ning; Cao, Leitao; Yin, Xia; Yu, Jianyong; Ding, Bin</p> <p>2016-10-04</p> <p>Rational structural design involving controlled pore size, high porosity, and <span class="hlt">particle</span>-targeted function is critical to the realization of highly efficient air <span class="hlt">filters</span>, and the <span class="hlt">filter</span> with absolute <span class="hlt">particle</span>-screen ability has significant technological implications for applications including individual protection, industrial security, and environmental governance; however, it remains an ongoing challenge. In this study, we first report a facile and scalable strategy to fabricate the highly integrated polysulfone/polyacrylonitrile/polyamide-6 (PSU/PAN/PA-6) air <span class="hlt">filter</span> for multi-level physical sieving airborne <span class="hlt">particles</span> via sequential electrospinning. Our strategy causes the PSU microfiber (diameter of ~1 μm) layer, PAN nanofiber (diameter of ~200 nm) layer, and PA-6 nanonets (diameter of ~20 nm) layer to orderly assemble into the integrated <span class="hlt">filter</span> with gradually varied pore structures and high porosity; thus enables the <span class="hlt">filter</span> to work efficiently by employing different layers to cut off penetration of <span class="hlt">particles</span> with certain size that exceeds the designed threshold level. By virtue of its elaborate gradient structure, robust hydrophobicity (WCA of ~130o), and superior mechanical property (5.6 MPa), our PSU/PAN/PA-6 <span class="hlt">filter</span> even can filtrate the 300 nm <span class="hlt">particles</span> with a high removal efficiency of 99.992% and a low pressure drop of 118 Pa in the way of physical sieving manner, which completely gets rid of the negative impact from high airflow speed, electret failure, and high humidity. It is expected that our highly integrated <span class="hlt">filter</span> has wider applications for filtration and separation, and design of 3D functional structure in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMNG43A1572S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMNG43A1572S"><span>Numerical experiments with an implicit <span class="hlt">particle</span> <span class="hlt">filter</span> for the shallow water equations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Souopgui, I.; Chorin, A. J.; Hussaini, M.</p> <p>2012-12-01</p> <p> of the state space. In our numerical experiments, we varied the availability of the data (in both space and time) as well as the variance of the observation noise. We found that the implicit <span class="hlt">particle</span> <span class="hlt">filter</span> is reliable and efficient in all scenarios we considered. The implicit sampling method could improve the accuracy of the traditional variational approach. Moreover, we obtain quantitative measures of the uncertainty of the state estimate ``for free,'' while no information about the uncertainty is easily available using the traditional 4D-Var method only.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE10157E..28T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE10157E..28T"><span>Toeplitz block circulant matrix <span class="hlt">optimized</span> with <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> for compressive imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tao, Huifeng; Yin, Songfeng; Tang, Cong</p> <p>2016-10-01</p> <p>Compressive imaging is an imaging way based on the compressive sensing theory, which could achieve to capture the high resolution image through a small set of measurements. As the core of the compressive imaging, the design of the measurement matrix is sufficient to ensure that the image can be recovered from the measurements. Due to the fast computing capacity and the characteristic of easy hardware implementation, The Toeplitz block circulant matrix is proposed to realize the encoded samples. The measurement matrix is usually <span class="hlt">optimized</span> for improving the image reconstruction quality. However, the existing <span class="hlt">optimization</span> methods can destroy the matrix structure easily when applied to the Toeplitz block circulant matrix <span class="hlt">optimization</span> process, and the deterministic iterative processes of them are inflexible, because of requiring the task <span class="hlt">optimized</span> to need to satisfy some certain mathematical property. To overcome this problem, a novel method of <span class="hlt">optimizing</span> the Toeplitz block circulant matrix based on the <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> intelligent algorithm is proposed in this paper. The objective function is established by the way of approaching the target matrix that is the Gram matrix truncated by the Welch threshold. The <span class="hlt">optimized</span> object is the vector composed by the free entries instead of the Gram matrix. The experimental results indicate that the Toeplitz block circulant measurement matrix can be <span class="hlt">optimized</span> while preserving the matrix structure by our method, and result in the reconstruction quality improvement.</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('http://www.osti.gov/scitech/servlets/purl/790968','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/790968"><span><span class="hlt">OPTIMIZATION</span> OF COAL <span class="hlt">PARTICLE</span> FLOW PATTERNS IN LOW NOX BURNERS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jost O.L. Wendt; Gregory E. Ogden; Jennifer Sinclair; Caner Yurteri</p> <p>2001-08-20</p> <p>The proposed research is directed at evaluating the effect of flame aerodynamics on NO{sub x} emissions from coal fired burners in a systematic manner. This fundamental research includes both experimental and modeling efforts being performed at the University of Arizona in collaboration with Purdue University. The objective of this effort is to develop rational design tools for <span class="hlt">optimizing</span> low NO{sub x} burners to the kinetic emissions limit (below 0.2 lb./MMBTU). Experimental studies include both cold and hot flow evaluations of the following parameters: flame holder geometry, secondary air swirl, primary and secondary inlet air velocity, coal concentration in the primary air and coal <span class="hlt">particle</span> size distribution. Hot flow experiments will also evaluate the effect of wall temperature on burner performance. Cold flow studies will be conducted with surrogate <span class="hlt">particles</span> as well as pulverized coal. The cold flow furnace will be similar in size and geometry to the hot-flow furnace but will be designed to use a laser Doppler velocimeter/phase Doppler <span class="hlt">particle</span> size analyzer. The results of these studies will be used to predict <span class="hlt">particle</span> trajectories in the hot-flow furnace as well as to estimate the effect of flame holder geometry on furnace flow field. The hot-flow experiments will be conducted in a novel near-flame down-flow pulverized coal furnace. The furnace will be equipped with externally heated walls. Both reactors will be sized to minimize wall effects on <span class="hlt">particle</span> flow fields. The cold-flow results will be compared with Fluent computation fluid dynamics model predictions and correlated with the hot-flow results with the overall goal of providing insight for novel low NO{sub x} burner geometry's.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4481977','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4481977"><span>Mobile Robot Positioning with 433-MHz Wireless Motes with Varying Transmission Powers and a <span class="hlt">Particle</span> <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>Canedo-Rodriguez, Adrian; Rodriguez, Jose Manuel; Alvarez-Santos, Victor; Iglesias, Roberto; Regueiro, Carlos V.</p> <p>2015-01-01</p> <p>In wireless positioning systems, the transmitter's power is usually fixed. In this paper, we explore the use of varying transmission powers to increase the performance of a wireless localization system. To this extent, we have designed a robot positioning system based on wireless motes. Our motes use an inexpensive, low-power sub-1-GHz system-on-chip (CC1110) working in the 433-MHz ISM band. Our localization algorithm is based on a <span class="hlt">particle</span> <span class="hlt">filter</span> and infers the robot position by: (1) comparing the power received with the expected one; and (2) integrating the robot displacement. We demonstrate that the use of transmitters that vary their transmission power over time improves the performance of the wireless positioning system significantly, with respect to a system that uses fixed power transmitters. This opens the door for applications where the robot can localize itself actively by requesting the transmitters to change their power in real time. PMID:25942641</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016HMT...tmp..180M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016HMT...tmp..180M"><span>A numerical investigation of the diesel <span class="hlt">particle</span> <span class="hlt">filter</span> regeneration process under temperature pulse conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meng, Zhongwei; Zhang, Jing; Chen, Chao; Yan, Yan</p> <p>2016-10-01</p> <p>A one-dimensional transient diesel <span class="hlt">particle</span> <span class="hlt">filter</span> (DPF) model is applied to study DPF regeneration performance. Numerical simulations are performed to predict the effects of various factors influencing regeneration performance under temperature pulse conditions, and the regeneration performances of three typical DPFs are compared and analyzed. Numerical results indicate that the thermal conductivity characteristics of DPF configurations can greatly affect soot oxidation, which in turn influences the regeneration process. The transition points of the regeneration flow rate indicate a balance between its promotion of the regeneration process and retardation owing to cooling effects. The sensitive ranges of soot loading, oxygen concentration, and inlet temperature are observed to provide a reference for controlling DPF regeneration. The multi-step exhaust condition is employed to control DPF regeneration. It was found that a transient increase in the flow rate is more effective at reducing the peak temperature and peak temperature gradient than a transient decrease of oxygen concentration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015OptRv..22..294J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015OptRv..22..294J"><span>Indoor anti-occlusion visible light positioning systems based on <span class="hlt">particle</span> <span class="hlt">filtering</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, Meng; Huang, Zhitong; Li, Jianfeng; Zhang, Ruqi; Ji, Yuefeng</p> <p>2015-04-01</p> <p>As one of the most popular categories of mobile services, a rapid growth of indoor location-based services has been witnessed over the past decades. Indoor positioning methods based on Wi-Fi, radio-frequency identification or Bluetooth are widely commercialized; however, they have disadvantages such as low accuracy or high cost. An emerging method using visible light is under research recently. The existed visible light positioning (VLP) schemes using carrier allocation, time allocation and multiple receivers all have limitations. This paper presents a novel mechanism using <span class="hlt">particle</span> <span class="hlt">filtering</span> in VLP system. By this method no additional devices are needed and the occlusion problem in visible light would be alleviated which will effectively enhance the flexibility for indoor positioning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Nanos...715175D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Nanos...715175D"><span>A challenge for theranostics: is the <span class="hlt">optimal</span> <span class="hlt">particle</span> for therapy also <span class="hlt">optimal</span> for diagnostics?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dreifuss, Tamar; Betzer, Oshra; Shilo, Malka; Popovtzer, Aron; Motiei, Menachem; Popovtzer, Rachela</p> <p>2015-09-01</p> <p>Theranostics is defined as the combination of therapeutic and diagnostic capabilities in the same agent. Nanotechnology is emerging as an efficient platform for theranostics, since nanoparticle-based contrast agents are powerful tools for enhancing in vivo imaging, while therapeutic nanoparticles may overcome several limitations of conventional drug delivery systems. Theranostic nanoparticles have drawn particular interest in cancer treatment, as they offer significant advantages over both common imaging contrast agents and chemotherapeutic drugs. However, the development of platforms for theranostic applications raises critical questions; is the <span class="hlt">optimal</span> <span class="hlt">particle</span> for therapy also the <span class="hlt">optimal</span> <span class="hlt">particle</span> for diagnostics? Are the specific characteristics needed to <span class="hlt">optimize</span> diagnostic imaging parallel to those required for treatment applications? This issue is examined in the present study, by investigating the effect of the gold nanoparticle (GNP) size on tumor uptake and tumor imaging. A series of anti-epidermal growth factor receptor conjugated GNPs of different sizes (diameter range: 20-120 nm) was synthesized, and then their uptake by human squamous cell carcinoma head and neck cancer cells, in vitro and in vivo, as well as their tumor visualization capabilities were evaluated using CT. The results showed that the size of the nanoparticle plays an instrumental role in determining its potential activity in vivo. Interestingly, we found that although the highest tumor uptake was obtained with 20 nm C225-GNPs, the highest contrast enhancement in the tumor was obtained with 50 nm C225-GNPs, thus leading to the conclusion that the <span class="hlt">optimal</span> <span class="hlt">particle</span> size for drug delivery is not necessarily <span class="hlt">optimal</span> for imaging. These findings stress the importance of the investigation and design of <span class="hlt">optimal</span> nanoparticles for theranostic applications.Theranostics is defined as the combination of therapeutic and diagnostic capabilities in the same agent. Nanotechnology is emerging as an</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26999130','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26999130"><span><span class="hlt">Particle</span> <span class="hlt">Filter</span> with Novel Nonlinear Error Model for Miniature Gyroscope-Based Measurement While Drilling Navigation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Tao; Yuan, Gannan; Li, Wang</p> <p>2016-03-15</p> <p>The derivation of a conventional error model for the miniature gyroscope-based measurement while drilling (MGWD) system is based on the assumption that the errors of attitude are small enough so that the direction cosine matrix (DCM) can be approximated or simplified by the errors of small-angle attitude. However, the simplification of the DCM would introduce errors to the navigation solutions of the MGWD system if the initial alignment cannot provide precise attitude, especially for the low-cost microelectromechanical system (MEMS) sensors operated in harsh multilateral horizontal downhole drilling environments. This paper proposes a novel nonlinear error model (NNEM) by the introduction of the error of DCM, and the NNEM can reduce the propagated errors under large-angle attitude error conditions. The zero velocity and zero position are the reference points and the innovations in the states estimation of <span class="hlt">particle</span> <span class="hlt">filter</span> (PF) and Kalman <span class="hlt">filter</span> (KF). The experimental results illustrate that the performance of PF is better than KF and the PF with NNEM can effectively restrain the errors of system states, especially for the azimuth, velocity, and height in the quasi-stationary condition.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4813946','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4813946"><span><span class="hlt">Particle</span> <span class="hlt">Filter</span> with Novel Nonlinear Error Model for Miniature Gyroscope-Based Measurement While Drilling Navigation</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, Tao; Yuan, Gannan; Li, Wang</p> <p>2016-01-01</p> <p>The derivation of a conventional error model for the miniature gyroscope-based measurement while drilling (MGWD) system is based on the assumption that the errors of attitude are small enough so that the direction cosine matrix (DCM) can be approximated or simplified by the errors of small-angle attitude. However, the simplification of the DCM would introduce errors to the navigation solutions of the MGWD system if the initial alignment cannot provide precise attitude, especially for the low-cost microelectromechanical system (MEMS) sensors operated in harsh multilateral horizontal downhole drilling environments. This paper proposes a novel nonlinear error model (NNEM) by the introduction of the error of DCM, and the NNEM can reduce the propagated errors under large-angle attitude error conditions. The zero velocity and zero position are the reference points and the innovations in the states estimation of <span class="hlt">particle</span> <span class="hlt">filter</span> (PF) and Kalman <span class="hlt">filter</span> (KF). The experimental results illustrate that the performance of PF is better than KF and the PF with NNEM can effectively restrain the errors of system states, especially for the azimuth, velocity, and height in the quasi-stationary condition. PMID:26999130</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016InPhT..78...58L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016InPhT..78...58L"><span><span class="hlt">Particle</span> <span class="hlt">filter</span>-based relative rolling estimation algorithm for non-cooperative infrared spacecraft</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Zhengzhou; Ge, Fengzeng; Chen, Wenhao; Shao, Wanxing; Liu, Bing; Cheng, Bei</p> <p>2016-09-01</p> <p>The issue of feature point mismatching among infrared image sequence would bring big challenge to estimating the relative motion of non-cooperative spacecraft for it couldn't provide the prior knowledge about its geometric structure and motion pattern. The paper introduces <span class="hlt">particle</span> <span class="hlt">filter</span> to precisely match the feature points within a desired region predicted by a kinetic equation, and presents a least square estimation-based algorithm to measure the relative rolling motion of non-cooperative spacecraft. The state transition equation and the measurement update equation of non-cooperative spacecraft are represented by establishing its kinetic equations, and then the relative pose measurement is converted to the maximum posteriori probability estimation via assuming the uncertainties about geometric structure and motion pattern as random and time-varying variables. These uncertainties would be interpreted and even solved through continuously measuring the image feature points of the rotating non-cooperative infrared spacecraft. Subsequently, the feature point is matched within a predicted region among sequence infrared image using <span class="hlt">particle</span> <span class="hlt">filter</span> algorithm to overcome the position estimation noise caused by the uncertainties of geometric structure and motion pattern. Finally, the position parameters including rotation motion are estimated by means of solving the minimum error of feature point mismatching using least square estimate theory. Both simulated and real infrared image sequences are induced in the experiment to evaluate the performance of the relative rolling estimation, and the experimental data show that the rolling motion estimated by the proposed algorithm is more robust to the feature extraction noise and various rotation speed. Meanwhile, the relative rolling estimation error would increase dramatically with distance and rotation speed increasing.</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 step.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16060353','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16060353"><span>Evaluation of a <span class="hlt">particle</span> swarm algorithm for biomechanical <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>Schutte, Jaco F; Koh, Byung-Il; Reinbolt, Jeffrey A; Haftka, Raphael T; George, Alan D; Fregly, Benjamin J</p> <p>2005-06-01</p> <p><span class="hlt">Optimization</span> is frequently employed in biomechanics research to solve system identification problems, predict human movement, or estimate muscle or other internal forces that cannot be measured directly. Unfortunately, biomechanical <span class="hlt">optimization</span> problems often possess multiple local minima, making it difficult to find the best solution. Furthermore, convergence in gradient-based algorithms can be affected by scaling to account for design variables with different length scales or units. In this study we evaluate a recently-developed version of the <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) algorithm to address these problems. The algorithm's global search capabilities were investigated using a suite of difficult analytical test problems, while its scale-independent nature was proven mathematically and verified using a biomechanical test problem. For comparison, all test problems were also solved with three off-the-shelf <span class="hlt">optimization</span> algorithms--a global genetic algorithm (GA) and multistart gradient-based sequential quadratic programming (SQP) and quasi-Newton (BFGS) algorithms. For the analytical test problems, only the PSO algorithm was successful on the majority of the problems. When compared to previously published results for the same problems, PSO was more robust than a global simulated annealing algorithm but less robust than a different, more complex genetic algorithm. For the biomechanical test problem, only the PSO algorithm was insensitive to design variable scaling, with the GA algorithm being mildly sensitive and the SQP and BFGS algorithms being highly sensitive. The proposed PSO algorithm provides a new off-the-shelf global <span class="hlt">optimization</span> option for difficult biomechanical problems, especially those utilizing design variables with different length scales or units.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012MSSP...28..597C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012MSSP...28..597C"><span>Machine remaining useful life prediction: An integrated adaptive neuro-fuzzy and high-order <span class="hlt">particle</span> <span class="hlt">filtering</span> approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Chaochao; Vachtsevanos, George; Orchard, Marcos E.</p> <p>2012-04-01</p> <p>Machine prognosis can be considered as the generation of long-term predictions that describe the evolution in time of a fault indicator, with the purpose of estimating the remaining useful life (RUL) of a failing component/subsystem so that timely maintenance can be performed to avoid catastrophic failures. This paper proposes an integrated RUL prediction method using adaptive neuro-fuzzy inference systems (ANFIS) and high-order <span class="hlt">particle</span> <span class="hlt">filtering</span>, which forecasts the time evolution of the fault indicator and estimates the probability density function (pdf) of RUL. The ANFIS is trained and integrated in a high-order <span class="hlt">particle</span> <span class="hlt">filter</span> as a model describing the fault progression. The high-order <span class="hlt">particle</span> <span class="hlt">filter</span> is used to estimate the current state and carry out p-step-ahead predictions via a set of <span class="hlt">particles</span>. These predictions are used to estimate the RUL pdf. The performance of the proposed method is evaluated via the real-world data from a seeded fault test for a UH-60 helicopter planetary gear plate. The results demonstrate that it outperforms both the conventional ANFIS predictor and the <span class="hlt">particle-filter</span>-based predictor where the fault growth model is a first-order model that is trained via the ANFIS.</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('http://adsabs.harvard.edu/abs/2010LNCS.6466..639S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010LNCS.6466..639S"><span>Security Constrained <span class="hlt">Optimal</span> Power Flow with FACTS Devices Using Modified <span class="hlt">Particle</span> Swarm <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>Somasundaram, P.; Muthuselvan, N. B.</p> <p></p> <p>This paper presents new computationally efficient improved <span class="hlt">Particle</span> Swarm algorithms for solving Security Constrained <span class="hlt">Optimal</span> Power Flow (SCOPF) in power systems with the inclusion of FACTS devices. The proposed algorithms are developed based on the combined application of Gaussian and Cauchy Probability distribution functions incorporated in <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO). The power flow algorithm with the presence of Static Var Compensator (SVC) Thyristor Controlled Series Capacitor (TCSC) and Unified Power Flow Controller (UPFC), has been formulated and solved. The proposed algorithms are tested on standard IEEE 30-bus system. The analysis using PSO and modified PSO reveals that the proposed algorithms are relatively simple, efficient, reliable and suitable for real-time applications. And these algorithms can provide accurate solution with fast convergence and have the potential to be applied to other power engineering problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AIPC.1315.1419K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AIPC.1315.1419K"><span>Application of <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> in Computer Aided Setup Planning</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kafashi, Sajad; Shakeri, Mohsen; Abedini, Vahid</p> <p>2011-01-01</p> <p>New researches are trying to integrate computer aided design (CAD) and computer aided manufacturing (CAM) environments. The role of process planning is to convert the design specification into manufacturing instructions. Setup planning has a basic role in computer aided process planning (CAPP) and significantly affects the overall cost and quality of machined part. This research focuses on the development for automatic generation of setups and finding the best setup plan in feasible condition. In order to computerize the setup planning process, three major steps are performed in the proposed system: a) Extraction of machining data of the part. b) Analyzing and generation of all possible setups c) <span class="hlt">Optimization</span> to reach the best setup plan based on cost functions. Considering workshop resources such as machine tool, cutter and fixture, all feasible setups could be generated. Then the problem is adopted with technological constraints such as TAD (tool approach direction), tolerance relationship and feature precedence relationship to have a completely real and practical approach. The <span class="hlt">optimal</span> setup plan is the result of applying the PSO (<span class="hlt">particle</span> swarm <span class="hlt">optimization</span>) algorithm into the system using cost functions. A real sample part is illustrated to demonstrate the performance and productivity of the system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AtmEn..44..909T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AtmEn..44..909T"><span>Diesel passenger car PM emissions: From Euro 1 to Euro 4 with <span class="hlt">particle</span> <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>Tzamkiozis, Theodoros; Ntziachristos, Leonidas; Samaras, Zissis</p> <p>2010-03-01</p> <p>This paper examines the impact of the emission control and fuel technology development on the emissions of gaseous and, in particular, PM pollutants from diesel passenger cars. Three cars in five configurations in total were measured, and covered the range from Euro 1 to Euro 4 standards. The emission control ranged from no aftertreatment in the Euro 1 case, an oxidation catalyst in Euro 2, two oxidation catalysts and exhaust gas recirculation in Euro 3 and Euro 4, while a catalyzed diesel <span class="hlt">particle</span> <span class="hlt">filter</span> (DPF) fitted in the Euro 4 car led to a Euro 4 + DPF configuration. Both certification test and real-world driving cycles were employed. The results showed that CO and HC emissions were much lower than the emission standard over the hot-start real-world cycles. However, vehicle technologies from Euro 2 to Euro 4 exceeded the NOx and PM emission levels over at least one real-world cycle. The NOx emission level reached up to 3.6 times the certification level in case of the Euro 4 car. PM were up to 40% and 60% higher than certification level for the Euro 2 and Euro 3 cars, while the Euro 4 car emitted close or slightly below the certification level over the real-world driving cycles. PM mass reductions from Euro 1 to Euro 4 were associated with a relevant decrease in the total <span class="hlt">particle</span> number, in particular over the certification test. This was not followed by a respective reduction in the solid <span class="hlt">particle</span> number which remained rather constant between the four technologies at 0.86 × 10 14 km -1 (coefficient of variation 9%). As a result, the ratio of solid vs. total <span class="hlt">particle</span> number ranged from ˜50% in Euro 1-100% in Euro 4. A significant reduction of more than three orders of magnitude in solid <span class="hlt">particle</span> number is achieved with the introduction of the DPF. However, the potential for nucleation mode formation at high speed from the DPF car is an issue that needs to be considered in the over all assessment of its environmental benefit. Finally, comparison of 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_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://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('http://adsabs.harvard.edu/abs/2016EnOp...48.1679W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EnOp...48.1679W"><span>Parallel <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> on a graphics processing unit with application to trajectory <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>Wu, Q.; Xiong, F.; Wang, F.; Xiong, Y.</p> <p>2016-10-01</p> <p>In order to reduce the computational time, a fully parallel implementation of the <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) algorithm on a graphics processing unit (GPU) is presented. Instead of being executed on the central processing unit (CPU) sequentially, PSO is executed in parallel via the GPU on the compute unified device architecture (CUDA) platform. The processes of fitness evaluation, updating of velocity and position of all <span class="hlt">particles</span> are all parallelized and introduced in detail. Comparative studies on the <span class="hlt">optimization</span> of four benchmark functions and a trajectory <span class="hlt">optimization</span> problem are conducted by running PSO on the GPU (GPU-PSO) and CPU (CPU-PSO). The impact of design dimension, number of <span class="hlt">particles</span> and size of the thread-block in the GPU and their interactions on the computational time is investigated. The results show that the computational time of the developed GPU-PSO is much shorter than that of CPU-PSO, with comparable accuracy, which demonstrates the remarkable speed-up capability of GPU-PSO.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8301E..0WR','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8301E..0WR"><span>Object tracking with adaptive HOG detector and adaptive Rao-Blackwellised <span class="hlt">particle</span> <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>Rosa, Stefano; Paleari, Marco; Ariano, Paolo; Bona, Basilio</p> <p>2012-01-01</p> <p>Scenarios for a manned mission to the Moon or Mars call for astronaut teams to be accompanied by semiautonomous robots. A prerequisite for human-robot interaction is the capability of successfully tracking humans and objects in the environment. In this paper we present a system for real-time visual object tracking in 2D images for mobile robotic systems. The proposed algorithm is able to specialize to individual objects and to adapt to substantial changes in illumination and object appearance during tracking. The algorithm is composed by two main blocks: a detector based on Histogram of Oriented Gradient (HOG) descriptors and linear Support Vector Machines (SVM), and a tracker which is implemented by an adaptive Rao-Blackwellised <span class="hlt">particle</span> <span class="hlt">filter</span> (RBPF). The SVM is re-trained online on new samples taken from previous predicted positions. We use the effective sample size to decide when the classifier needs to be re-trained. Position hypotheses for the tracked object are the result of a clustering procedure applied on the set of <span class="hlt">particles</span>. The algorithm has been tested on challenging video sequences presenting strong changes in object appearance, illumination, and occlusion. Experimental tests show that the presented method is able to achieve near real-time performances with a precision of about 7 pixels on standard video sequences of dimensions 320 × 240.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPS...331..208T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPS...331..208T"><span>State-of-charge estimation in lithium-ion batteries: A <span class="hlt">particle</span> <span class="hlt">filter</span> approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tulsyan, Aditya; Tsai, Yiting; Gopaluni, R. Bhushan; Braatz, Richard D.</p> <p>2016-11-01</p> <p>The dynamics of lithium-ion batteries are complex and are often approximated by models consisting of partial differential equations (PDEs) relating the internal ionic concentrations and potentials. The Pseudo two-dimensional model (P2D) is one model that performs sufficiently accurately under various operating conditions and battery chemistries. Despite its widespread use for prediction, this model is too complex for standard estimation and control applications. This article presents an original algorithm for state-of-charge estimation using the P2D model. Partial differential equations are discretized using implicit stable algorithms and reformulated into a nonlinear state-space model. This discrete, high-dimensional model (consisting of tens to hundreds of states) contains implicit, nonlinear algebraic equations. The uncertainty in the model is characterized by additive Gaussian noise. By exploiting the special structure of the pseudo two-dimensional model, a novel <span class="hlt">particle</span> <span class="hlt">filter</span> algorithm that sweeps in time and spatial coordinates independently is developed. This algorithm circumvents the degeneracy problems associated with high-dimensional state estimation and avoids the repetitive solution of implicit equations by defining a 'tether' <span class="hlt">particle</span>. The approach is illustrated through extensive simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013OptEn..52k3105K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013OptEn..52k3105K"><span>Human tracking in thermal images using adaptive <span class="hlt">particle</span> <span class="hlt">filters</span> with online random forest learning</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ko, Byoung Chul; Kwak, Joon-Young; Nam, Jae-Yeal</p> <p>2013-11-01</p> <p>This paper presents a fast and robust human tracking method to use in a moving long-wave infrared thermal camera under poor illumination with the existence of shadows and cluttered backgrounds. To improve the human tracking performance while minimizing the computation time, this study proposes an online learning of classifiers based on <span class="hlt">particle</span> <span class="hlt">filters</span> and combination of a local intensity distribution (LID) with oriented center-symmetric local binary patterns (OCS-LBP). Specifically, we design a real-time random forest (RF), which is the ensemble of decision trees for confidence estimation, and confidences of the RF are converted into a likelihood function of the target state. First, the target model is selected by the user and <span class="hlt">particles</span> are sampled. Then, RFs are generated using the positive and negative examples with LID and OCS-LBP features by online learning. The learned RF classifiers are used to detect the most likely target position in the subsequent frame in the next stage. Then, the RFs are learned again by means of fast retraining with the tracked object and background appearance in the new frame. The proposed algorithm is successfully applied to various thermal videos as tests and its tracking performance is better than those of other methods.</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('http://www.dtic.mil/docs/citations/ADA631314','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA631314"><span>Challenge of N95 and P100 <span class="hlt">Filtering</span> Facepiece Respirators with <span class="hlt">Particles</span> Containing Viable H1N1</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>2016-06-13</p> <p>Zhao B, Zhang Z, and Li X. 2005. Numerical study of the transport of droplets or <span class="hlt">particles</span> generated by respiratory system indoors. Bldg. Environment... respiratory U U U SAR 35 Joseph D. Wander 850 283 6240 Reset Challenge of N95 and P100 <span class="hlt">Filtering</span> Facepiece Respirators with <span class="hlt">Particles</span> Containing...transmission include the use of respiratory protection devices in some situations. Furthermore, in the past decade, respirators have become commonplace</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1340849','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1340849"><span><span class="hlt">Filtered</span> sub-grid constitutive models for fluidized gas-<span class="hlt">particle</span> flows constructed from 3-D simulations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sarkar, Avik; Milioli, Fernando E.; Ozarkar, Shailesh; Li, Tingwen; Sun, Xin; Sundaresan, Sankaran</p> <p>2016-10-01</p> <p>The accuracy of fluidized-bed CFD predictions using the two-fluid model can be improved significantly, even when using coarse grids, by replacing the microscopic kinetic-theory-based closures with coarse-grained constitutive models. These coarse-grained constitutive relationships, called <span class="hlt">filtered</span> models, account for the unresolved gas-<span class="hlt">particle</span> structures (clusters and bubbles) via sub-grid corrections. Following the previous 2-D approaches of Igci et al. [AIChE J., 54(6), 1431-1448, 2008] and Milioli et al. [AIChE J., 59(9), 3265-3275, 2013], new <span class="hlt">filtered</span> models are constructed from highly-resolved 3-D simulations of gas-<span class="hlt">particle</span> flows. Although qualitatively similar to the older 2-D models, the new 3-D relationships exhibit noticeable quantitative and functional differences. In particular, the <span class="hlt">filtered</span> stresses are strongly dependent on the gas-<span class="hlt">particle</span> slip velocity. Closures for the <span class="hlt">filtered</span> inter-phase drag, gas- and solids-phase pressures and viscosities are reported. A new model for solids stress anisotropy is also presented. These new <span class="hlt">filtered</span> 3-D constitutive relationships are better suited to practical coarse-grid 3-D simulations of large, commercial-scale devices.</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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5305220','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5305220"><span>Multiswarm comprehensive learning <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> for solving multiobjective <span class="hlt">optimization</span> problems</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yu, Xiang; Zhang, Xueqing</p> <p>2017-01-01</p> <p>Comprehensive learning <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (CLPSO) is a powerful state-of-the-art single-objective metaheuristic. Extending from CLPSO, this paper proposes multiswarm CLPSO (MSCLPSO) for multiobjective <span class="hlt">optimization</span>. MSCLPSO involves multiple swarms, with each swarm associated with a separate original objective. Each particle’s personal best position is determined just according to the corresponding single objective. Elitists are stored externally. MSCLPSO differs from existing multiobjective <span class="hlt">particle</span> swarm <span class="hlt">optimizers</span> in three aspects. First, each swarm focuses on <span class="hlt">optimizing</span> the associated objective using CLPSO, without learning from the elitists or any other swarm. Second, mutation is applied to the elitists and the mutation strategy appropriately exploits the personal best positions and elitists. Third, a modified differential evolution (DE) strategy is applied to some extreme and least crowded elitists. The DE strategy updates an elitist based on the differences of the elitists. The personal best positions carry useful information about the Pareto set, and the mutation and DE strategies help MSCLPSO discover the true Pareto front. Experiments conducted on various benchmark problems demonstrate that MSCLPSO can find nondominated solutions distributed reasonably over the true Pareto front in a single run. PMID:28192508</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AtmEn..37.5295H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AtmEn..37.5295H"><span>Effect of ventilation systems and air <span class="hlt">filters</span> on decay rates of <span class="hlt">particles</span> produced by indoor sources in an occupied townhouse</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Howard-Reed, Cynthia; Wallace, Lance A.; Emmerich, Steven J.</p> <p></p> <p>Several studies have shown the importance of <span class="hlt">particle</span> losses in real homes due to deposition and filtration; however, none have quantitatively shown the impact of using a central forced air fan and in-duct <span class="hlt">filter</span> on <span class="hlt">particle</span> loss rates. In an attempt to provide such data, we measured the deposition of <span class="hlt">particles</span> ranging from 0.3 to 10 μm in an occupied townhouse and also in an unoccupied test house. Experiments were run with three different sources (cooking with a gas stove, citronella candle, pouring kitty litter), with the central heating and air conditioning (HAC) fan on or off, and with two different types of in-duct <span class="hlt">filters</span> (electrostatic precipitator and ordinary furnace <span class="hlt">filter</span>). <span class="hlt">Particle</span> size, HAC fan operation, and the electrostatic precipitator had significant effects on <span class="hlt">particle</span> loss rates. The standard furnace <span class="hlt">filter</span> had no effect. Surprisingly, the type of source (combustion vs. mechanical generation) and the type of furnishings (fully furnished including carpet vs. largely unfurnished including mostly bare floor) also had no measurable effect on the deposition rates of <span class="hlt">particles</span> of comparable size. With the HAC fan off, average deposition rates varied from 0.3 h -1 for the smallest <span class="hlt">particle</span> range (0.3-0.5 μm) to 5.2 h -1 for <span class="hlt">particles</span> greater than 10 μm. Operation of the central HAC fan approximately doubled these rates for <span class="hlt">particles</span> <5 μm, and increased rates by 2 h -1 for the larger <span class="hlt">particles</span>. An in-duct electrostatic precipitator increased the loss rates compared to the fan-off condition by factors of 5-10 for <span class="hlt">particles</span> <2.5 μm, and by a factor of 3 for 2.5-5.0 μm <span class="hlt">particles</span>. In practical terms, use of the central fan alone could reduce indoor <span class="hlt">particle</span> concentrations by 25-50%, and use of an in-duct ESP could reduce <span class="hlt">particle</span> concentrations by 55-85% compared to fan-off conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012TRACE..23..145M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012TRACE..23..145M"><span>The <span class="hlt">Optimization</span> of a Cogeneration System for Commercial Buildings by the <span class="hlt">Particle</span> Swarm <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>Miyazaki, Takahiko; Akisawa, Atsushi; Kashiwagi, Takao</p> <p></p> <p>The cogeneration system provides electricity as well as heating and cooling, which consequently leads to a complexity of the design and operation of the system. It requires, therefore, the <span class="hlt">optimization</span> of parameters such as the number of machines and the capacity of equipment. Generally, the problem can be expressed as a mixed integer nonlinear programming problem, and a lot of efforts would be required to solve it. In this paper, we present a different approach to the <span class="hlt">optimization</span> of cogeneration systems, which facilitates to find a quasi-optimum solution. The <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> combined with a simulation of the system is applied to the minimization of the primary energy consumption and of the system cost. The results present the optimum system constitutions for medium- and large-sized buildings. The result of the system cost minimization under a constraint of the energy saving rate is also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AIPC.1168..240S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AIPC.1168..240S"><span><span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> Approach in a Consignment Inventory System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sharifyazdi, Mehdi; Jafari, Azizollah; Molamohamadi, Zohreh; Rezaeiahari, Mandana; Arshizadeh, Rahman</p> <p>2009-09-01</p> <p>Consignment Inventory (CI) is a kind of inventory which is in the possession of the customer, but is still owned by the supplier. This creates a condition of shared risk whereby the supplier risks the capital investment associated with the inventory while the customer risks dedicating retail space to the product. This paper considers both the vendor's and the retailers' costs in an integrated model. The vendor here is a warehouse which stores one type of product and supplies it at the same wholesale price to multiple retailers who then sell the product in independent markets at retail prices. Our main aim is to design a CI system which generates minimum costs for the two parties. Here a <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO) algorithm is developed to calculate the proper values. Finally a sensitivity analysis is performed to examine the effects of each parameter on decision variables. Also PSO performance is compared with genetic algorithm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4979957','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4979957"><span>A Triangle Mesh Standardization Method Based on <span class="hlt">Particle</span> Swarm <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>Duan, Liming; Bai, Yang; Wang, Haoyu; Shao, Hui; Zhong, Siyang</p> <p>2016-01-01</p> <p>To enhance the triangle quality of a reconstructed triangle mesh, a novel triangle mesh standardization method based on <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) is proposed. First, each vertex of the mesh and its first order vertices are fitted to a cubic curve surface by using least square method. Additionally, based on the condition that the local fitted surface is the searching region of PSO and the best average quality of the local triangles is the goal, the vertex position of the mesh is regulated. Finally, the threshold of the normal angle between the original vertex and regulated vertex is used to determine whether the vertex needs to be adjusted to preserve the detailed features of the mesh. Compared with existing methods, experimental results show that the proposed method can effectively improve the triangle quality of the mesh while preserving the geometric features and details of the original mesh. PMID:27509129</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28287980','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28287980"><span>Constructing DNA Barcode Sets based on <span class="hlt">Particle</span> Swarm <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>Waang, Bin; Zheng, Xuedong; Zhou, Shihua; Zhou, Changjun; Wei, Xiaopeng; Zhang, Qiang; Wei, Ziqi</p> <p>2017-03-07</p> <p>Following the completion of the human genome project, a large amount of high-throughput bio-data was generated. To analyze these data, massively parallel sequencing, namely next-generation sequencing, was rapidly developed. DNA barcodes are used to identify the ownership between sequences and samples when they are attached at the beginning or end of sequencing reads. Constructing DNA barcode sets provides the candidate DNA barcodes for this application. To increase the accuracy of DNA barcode sets, a <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) algorithm has been modified and used to construct the DNA barcode sets in this paper. Compared with the extant results, some lower bounds of DNA barcode sets are improved. The results show that the proposed algorithm is effective in constructing DNA barcode sets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24738856','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24738856"><span>Order-2 Stability Analysis of <span class="hlt">Particle</span> Swarm <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>Liu, Qunfeng</p> <p>2015-01-01</p> <p>Several stability analyses and stable regions of <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO) have been proposed before. The assumption of stagnation and different definitions of stability are adopted in these analyses. In this paper, the order-2 stability of PSO is analyzed based on a weak stagnation assumption. A new definition of stability is proposed and an order-2 stable region is obtained. Several existing stable analyses for canonical PSO are compared, especially their definitions of stability and the corresponding stable regions. It is shown that the classical stagnation assumption is too strict and not necessary. Moreover, among all these definitions of stability, it is shown that our definition requires the weakest conditions, and additional conditions bring no benefit. Finally, numerical experiments are reported to show that the obtained stable region is meaningful. A new parameter combination of PSO is also shown to be good, even better than some known best parameter combinations.</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> </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('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/2012EGUGA..14.4386T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.4386T"><span>MODIS SCA assimilation with the <span class="hlt">particle</span> <span class="hlt">filter</span> for improving discharge simulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thirel, G.; Salamon, P.; Burek, P.; Kalas, M.</p> <p>2012-04-01</p> <p>LISFLOOD is a distributed, semi-physical rainfall-runoff model designed for the simulation of hydrological processes in medium to large scale river basins. This model is used at the European Commission Joint Research Centre for studying floods, global hydrological changes and droughts. LISFLOOD is the basis of the European Flood Alert System (EFAS), which is a real-time probabilistic flood prediction system with a lead-time of up to 10 days. The aim of this study is to evaluate the feasibility of assimilation of satellite snow data into LISFLOOD. Furthermore, the impact of the assimilation on the snow simulation as well as on discharge will be assessed. For this purpose, MODIS Snow Cover Area (SCA) has been used here. Since cloud coverage limits the availability of MODIS data, we implemented methods for improving the data set, such as - combination of the data from the two MODIS satellites - merging data from previous days - extrapolate data from neighboring pixels - extrapolate data from pixels with similar altitudes. The data provided by the MODIS satellites is SCA, i.e. presence or not of snow, whereas the LISFLOOD model simulates Snow Water Equivalent (SWE). For the conversion from SWE to SCA we employed a snow depletion curve. The assimilation method used is the <span class="hlt">particle</span> <span class="hlt">filter</span>. This method is based on multiple perturbed simulations of the model, which at each assimilation time step are either kept or removed based on the similarity between the modeled SCA and the observed SCA (i.e., MODIS data). One major advantage of the <span class="hlt">particle</span> <span class="hlt">filter</span> as applied here is, that model states are not modified directly and hence the model conserves the mass balance throughout the assimilation. Tests have been performed on synthetic data (normal LISFLOOD SCA used as observations) on a small basin (1-dimensional problem) and on a larger basin (7-dimensional problem), both located in the Czech Morava River basin. These experiments showed the positive performance of the</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://www.ncbi.nlm.nih.gov/pubmed/21767869','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21767869"><span>Fabrication of a multi-walled carbon nanotube-deposited glass fiber air <span class="hlt">filter</span> for the enhancement of nano and submicron aerosol <span class="hlt">particle</span> filtration and additional antibacterial efficacy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Park, Jae Hong; Yoon, Ki Young; Na, Hyungjoo; Kim, Yang Seon; Hwang, Jungho; Kim, Jongbaeg; Yoon, Young Hun</p> <p>2011-09-01</p> <p>We grew multi-walled carbon nanotubes (MWCNTs) on a glass fiber air <span class="hlt">filter</span> using thermal chemical vapor deposition (CVD) after the <span class="hlt">filter</span> was catalytically activated with a spark discharge. After the CNT deposition, filtration and antibacterial tests were performed with the <span class="hlt">filters</span>. Potassium chloride (KCl) <span class="hlt">particles</span> (<1 μm) were used as the test aerosol <span class="hlt">particles</span>, and their number concentration was measured using a scanning mobility <span class="hlt">particle</span> sizer. Antibacterial tests were performed using the colony counting method, and Escherichia coli (E. coli) was used as the test bacteria. The results showed that the CNT deposition increased the filtration efficiency of nano and submicron-sized <span class="hlt">particles</span>, but did not increase the pressure drop across the <span class="hlt">filter</span>. When a pristine glass fiber <span class="hlt">filter</span> that had no CNTs was used, the <span class="hlt">particle</span> filtration efficiencies at <span class="hlt">particle</span> sizes under 30 nm and near 500 nm were 48.5% and 46.8%, respectively. However, the efficiencies increased to 64.3% and 60.2%, respectively, when the CNT-deposited <span class="hlt">filter</span> was used. The reduction in the number of viable cells was determined by counting the colony forming units (CFU) of each test <span class="hlt">filter</span> after contact with the cells. The pristine glass fiber <span class="hlt">filter</span> was used as a control, and 83.7% of the E. coli were inactivated on the CNT-deposited <span class="hlt">filter</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MSSP...75..301J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MSSP...75..301J"><span><span class="hlt">Particle</span> <span class="hlt">filter</span> based hybrid prognostics for health monitoring of uncertain systems in bond graph framework</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jha, Mayank Shekhar; Dauphin-Tanguy, G.; Ould-Bouamama, B.</p> <p>2016-06-01</p> <p>The paper's main objective is to address the problem of health monitoring of system parameters in Bond Graph (BG) modeling framework, by exploiting its structural and causal properties. The system in feedback control loop is considered uncertain globally. Parametric uncertainty is modeled in interval form. The system parameter is undergoing degradation (prognostic candidate) and its degradation model is assumed to be known a priori. The detection of degradation commencement is done in a passive manner which involves interval valued robust adaptive thresholds over the nominal part of the uncertain BG-derived interval valued analytical redundancy relations (I-ARRs). The latter forms an efficient diagnostic module. The prognostics problem is cast as joint state-parameter estimation problem, a hybrid prognostic approach, wherein the fault model is constructed by considering the statistical degradation model of the system parameter (prognostic candidate). The observation equation is constructed from nominal part of the I-ARR. Using <span class="hlt">particle</span> <span class="hlt">filter</span> (PF) algorithms; the estimation of state of health (state of prognostic candidate) and associated hidden time-varying degradation progression parameters is achieved in probabilistic terms. A simplified variance adaptation scheme is proposed. Associated uncertainties which arise out of noisy measurements, parametric degradation process, environmental conditions etc. are effectively managed by PF. This allows the production of effective predictions of the remaining useful life of the prognostic candidate with suitable confidence bounds. The effectiveness of the novel methodology is demonstrated through simulations and experiments on a mechatronic system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeCar..63..219Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeCar..63..219Z"><span>Usefulness of Nonlinear Interpolation and <span class="hlt">Particle</span> <span class="hlt">Filter</span> in Zigbee Indoor Positioning</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Xiang; Wu, Helei; Uradziński, Marcin</p> <p>2014-12-01</p> <p>The key to fingerprint positioning algorithm is establishing effective fingerprint information database based on different reference nodes of received signal strength indicator (RSSI). Traditional method is to set the location area calibration multiple information sampling points, and collection of a large number sample data what is very time consuming. With Zigbee sensor networks as platform, considering the influence of positioning signal interference, we proposed an improved algorithm of getting virtual database based on polynomial interpolation, while the pre-estimated result was disposed by <span class="hlt">particle</span> <span class="hlt">filter</span>. Experimental result shows that this method can generate a quick, simple fine-grained localization information database, and improve the positioning accuracy at the same time. Kluczem do algorytmu pozycjonowania wykorzystującego metodę fi ngerprinting jest ustanowienie skutecznej bazy danych na podstawie informacji z radiowych nadajników referencyjnych przy wykorzystaniu wskaźnika mocy odbieranego sygnału (RSSI). Tradycyjna metoda oparta jest na przeprowadzeniu kalibracji obszaru lokalizacji na podstawie wielu punktów pomiarowych i otrzymaniu dużej liczby próbek, co jest bardzo czasochłonne.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.A11M0233T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.A11M0233T"><span>Air quality benefits of universal <span class="hlt">particle</span> <span class="hlt">filter</span> and NOx controls on diesel trucks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tao, L.; Mcdonald, B. C.; Harley, R.</p> <p>2015-12-01</p> <p>Heavy-duty diesel trucks are a major source of black carbon/particulate matter and nitrogen oxide emissions on urban and regional scales. These emissions are relevant to both air quality and climate change. Since 2010 in the US, new engines are required to be equipped with emission control systems that greatly reduce both PM and NOx emissions, by ~98% relative to 1988 levels. To reduce emissions from the legacy fleet of older trucks that still remain on the road, regulations have been adopted in Califonia to accelerate the replacement of older trucks and thereby reduce associated emissions of PM and NOx. Use of diesel <span class="hlt">particle</span> <span class="hlt">filters</span> will be widespread by 2016, and universal use of catalytic converters for NOx control is required by 2023. We assess the air quality consequences of this clean-up effort in Southern California, using the Community Multiscale Air Quality model (CMAQ), and comparing three scenarios: historical (2005), present day (2016), and future year (2023). Emissions from the motor vehicle sector are mapped at high spatial resolution based on traffic count and fuel sales data. NOx emissions from diesel engines in 2023 are expected to decrease by ~80% compared to 2005, while the fraction of NOx emitted as NO2 is expected to increase from 5 to 18%. Air quality model simulations will be analyzed to quantify changes in NO2, black carbon, particulate matter, and ozone, both basin-wide and near hot spots such as ports and major highways.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AdWR...94..364Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AdWR...94..364Y"><span>Combined assimilation of streamflow and satellite soil moisture with the <span class="hlt">particle</span> <span class="hlt">filter</span> and geostatistical modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yan, Hongxiang; Moradkhani, Hamid</p> <p>2016-08-01</p> <p>Assimilation of satellite soil moisture and streamflow data into a distributed hydrologic model has received increasing attention over the past few years. This study provides a detailed analysis of the joint and separate assimilation of streamflow and Advanced Scatterometer (ASCAT) surface soil moisture into a distributed Sacramento Soil Moisture Accounting (SAC-SMA) model, with the use of recently developed <span class="hlt">particle</span> <span class="hlt">filter</span>-Markov chain Monte Carlo (PF-MCMC) method. Performance is assessed over the Salt River Watershed in Arizona, which is one of the watersheds without anthropogenic effects in Model Parameter Estimation Experiment (MOPEX). A total of five data assimilation (DA) scenarios are designed and the effects of the locations of streamflow gauges and the ASCAT soil moisture on the predictions of soil moisture and streamflow are assessed. In addition, a geostatistical model is introduced to overcome the significantly biased satellite soil moisture and also discontinuity issue. The results indicate that: (1) solely assimilating outlet streamflow can lead to biased soil moisture estimation; (2) when the study area can only be partially covered by the satellite data, the geostatistical approach can estimate the soil moisture for those uncovered grid cells; (3) joint assimilation of streamflow and soil moisture from geostatistical modeling can further improve the surface soil moisture prediction. This study recommends that the geostatistical model is a helpful tool to aid the remote sensing technique and the hydrologic DA study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JNEng..12d6018S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JNEng..12d6018S"><span>Incorporating advanced language models into the P300 speller using <span class="hlt">particle</span> <span class="hlt">filtering</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Speier, W.; Arnold, C. W.; Deshpande, A.; Knall, J.; Pouratian, N.</p> <p>2015-08-01</p> <p>Objective. The P300 speller is a common brain-computer interface (BCI) application designed to communicate language by detecting event related potentials in a subject’s electroencephalogram signal. Information about the structure of natural language can be valuable for BCI communication, but attempts to use this information have thus far been limited to rudimentary n-gram models. While more sophisticated language models are prevalent in natural language processing literature, current BCI analysis methods based on dynamic programming cannot handle their complexity. Approach. Sampling methods can overcome this complexity by estimating the posterior distribution without searching the entire state space of the model. In this study, we implement sequential importance resampling, a commonly used <span class="hlt">particle</span> <span class="hlt">filtering</span> (PF) algorithm, to integrate a probabilistic automaton language model. Main result. This method was first evaluated offline on a dataset of 15 healthy subjects, which showed significant increases in speed and accuracy when compared to standard classification methods as well as a recently published approach using a hidden Markov model (HMM). An online pilot study verified these results as the average speed and accuracy achieved using the PF method was significantly higher than that using the HMM method. Significance. These findings strongly support the integration of domain-specific knowledge into BCI classification to improve system performance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4509796','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4509796"><span>Incorporating advanced language models into the P300 speller using <span class="hlt">particle</span> <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>Speier, W; Arnold, CW; Deshpande, A; Knall, J</p> <p>2015-01-01</p> <p>Objective The P300 speller is a common brain–computer interface (BCI) application designed to communicate language by detecting event related potentials in a subject’s electroencephalogram (EEG) signal. Information about the structure of natural language can be valuable for BCI communication, but attempts to use this information have thus far been limited to rudimentary n-gram models. While more sophisticated language models are prevalent in natural language processing literature, current BCI analysis methods based on dynamic programming cannot handle their complexity. Approach Sampling methods can overcome this complexity by estimating the posterior distribution without searching the entire state space of the model. In this study, we implement sequential importance resampling, a commonly used <span class="hlt">particle</span> <span class="hlt">filtering</span> (PF) algorithm, to integrate a probabilistic automaton language model. Main Result This method was first evaluated offline on a dataset of 15 healthy subjects, which showed significant increases in speed and accuracy when compared to standard classification methods as well as a recently published approach using a hidden Markov model (HMM). An online pilot study verified these results as the average speed and accuracy achieved using the PF method was significantly higher than that using the HMM method. Significance These findings strongly support the integration of domain-specific knowledge into BCI classification to improve system performance. PMID:26061188</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3775392','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3775392"><span><span class="hlt">Particle</span> <span class="hlt">Filters</span> and Occlusion Handling for Rigid 2D-3D Pose Tracking</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lee, Jehoon; Sandhu, Romeil; Tannenbaum, Allen</p> <p>2013-01-01</p> <p>In this paper, we address the problem of 2D-3D pose estimation. Specifically, we propose an approach to jointly track a rigid object in a 2D image sequence and to estimate its pose (position and orientation) in 3D space. We revisit a joint 2D segmentation/3D pose estimation technique, and then extend the framework by incorporating a <span class="hlt">particle</span> <span class="hlt">filter</span> to robustly track the object in a challenging environment, and by developing an occlusion detection and handling scheme to continuously track the object in the presence of occlusions. In particular, we focus on partial occlusions that prevent the tracker from extracting an exact region properties of the object, which plays a pivotal role for region-based tracking methods in maintaining the track. To this end, a dynamical choice of how to invoke the objective functional is performed online based on the degree of dependencies between predictions and measurements of the system in accordance with the degree of occlusion and the variation of the object’s pose. This scheme provides the robustness to deal with occlusions of an obstacle with different statistical properties from that of the object of interest. Experimental results demonstrate the practical applicability and robustness of the proposed method in several challenging scenarios. PMID:24058277</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20227980','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20227980"><span>Microtubule dynamics analysis using kymographs and variable-rate <span class="hlt">particle</span> <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>Smal, Ihor; Grigoriev, Ilya; Akhmanova, Anna; Niessen, Wiro J; Meijering, Erik</p> <p>2010-07-01</p> <p>Studying intracellular dynamics is of fundamental importance for understanding healthy life at the molecular level and for developing drugs to target disease processes. One of the key technologies to enable this research is the automated tracking and motion analysis of these objects in microscopy image sequences. To make better use of the spatiotemporal information than common frame-by-frame tracking methods, two alternative approaches have recently been proposed, based upon either Bayesian estimation or space-time segmentation. In this paper, we propose to combine the power of both approaches, and develop a new probabilistic method to segment the traces of the moving objects in kymograph representations of the image data. It is based on variable-rate <span class="hlt">particle</span> <span class="hlt">filtering</span> and uses multiscale trend analysis of the extracted traces to estimate the relevant kinematic parameters. Experiments on realistic synthetically generated images as well as on real biological image data demonstrate the improved potential of the new method for the analysis of microtubule dynamics in vitro.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9804E..0EB','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9804E..0EB"><span><span class="hlt">Particle</span> swarm <span class="hlt">optimization</span> for <span class="hlt">optimal</span> sensor placement in ultrasonic SHM systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blanloeuil, Philippe; Nurhazli, Nur A. E.; Veidt, Martin</p> <p>2016-04-01</p> <p>A <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO) algorithm is used to improve sensors placement in an ultrasonic Structural Health Monitoring (SHM) system where the detection is performed through the beam-forming imaging algorithm. The imaging algorithm reconstructs the defect image and estimates its location based on analytically generated signals, considering circular through hole damage in an aluminum plate as the tested structure. Then, the PSO algorithm changes the position of sensors to improve the accuracy of the detection. Thus, the two algorithms are working together iteratively to <span class="hlt">optimize</span> the system configuration, taking into account a complete modeling of the SHM system. It is shown that this approach can provide good sensors placements for detection of multiple defects in the target area, and for different numbers of sensors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JIEIB..95..231K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JIEIB..95..231K"><span>Reliability <span class="hlt">Optimization</span> of Radial Distribution Systems Employing Differential Evolution and Bare Bones <span class="hlt">Particle</span> Swarm <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>Kela, K. B.; Arya, L. D.</p> <p>2014-09-01</p> <p>This paper describes a methodology for determination of optimum failure rate and repair time for each section of a radial distribution system. An objective function in terms of reliability indices and their target values is selected. These indices depend mainly on failure rate and repair time of a section present in a distribution network. A cost is associated with the modification of failure rate and repair time. Hence the objective function is <span class="hlt">optimized</span> subject to failure rate and repair time of each section of the distribution network considering the total budget allocated to achieve the task. The problem has been solved using differential evolution and bare bones <span class="hlt">particle</span> swarm <span class="hlt">optimization</span>. The algorithm has been implemented on a sample radial distribution system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/862917','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/862917"><span><span class="hlt">Filtering</span> coal-derived oil through a <span class="hlt">filter</span> media precoated with <span class="hlt">particles</span> partially solubilized by said oil</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Rodgers, Billy R.; Edwards, Michael S.</p> <p>1977-01-01</p> <p>Solids such as char, ash, and refractory organic compounds are removed from coal-derived liquids from coal liquefaction processes by the pressure precoat filtration method using <span class="hlt">particles</span> of 85-350 mesh material selected from the group of bituminous coal, anthracite coal, lignite, and devolatilized coals as precoat materials and as body feed to the unfiltered coal-derived liquid.</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/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://www.osti.gov/scitech/servlets/purl/10172571','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10172571"><span>Study of the effect of humidity, <span class="hlt">particle</span> hygroscopicity and size on the mass loading capacity of HEPA <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gupta, A.</p> <p>1992-09-01</p> <p>The effect of humidity, <span class="hlt">particle</span> hygroscopicity and size on the mass loading capacity of glass fiber HEPA <span class="hlt">filters</span> has been studied. At humidifies above the deliquescent point, the pressure drop across the HEPA <span class="hlt">filter</span> increased non-linearly with the areal loading density (mass collected/filtration area) of NaCl aerosol, thus significantly reducing the mass loading capacity of the <span class="hlt">filter</span> compared to dry hygroscopic or non-hygroscopic <span class="hlt">particle</span> mass loadings. The specific cake resistance, K{sub 2}, has been computed for different test conditions and used as a measure of the mass loading capacity. K. was found to decrease with increasing humidity for the non-hygroscopic aluminum oxide <span class="hlt">particles</span> and the hygroscopic NaCl <span class="hlt">particles</span> (at humidities below the deliquescent point). It is postulated that an increase in humidity leads to the formation of a more open particulate cake which lowers the pressure drop for a given mass loading. A formula for predicting K{sub 2} for lognormally distributed aerosols (parameters obtained from impactor data) is derived. The resistance factor, R, calculated using this formula was compared to the theoretical R calculated using the Rudnick-Happel expression. For the non-hygroscopic aluminum oxide the agreement was good but for the hygroscopic sodium chloride, due to large variation in the cake porosity estimates, the agreement was poor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5685673','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5685673"><span>Effect of humidity and <span class="hlt">particle</span> hygroscopicity on the mass loading capacity of high efficiency particulate air (HEPA) <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gupta, A.; Biswas, P. ); Monson, P.R. ); Novick, V.J. )</p> <p>1993-07-01</p> <p>The effect of humidity, <span class="hlt">particle</span> hygroscopicity, and size on the mass loading capacity of glass fiber high efficiency particulate air <span class="hlt">filters</span> was studied. Above the deliquescent point, the pressure drop across the <span class="hlt">filter</span> increased nonlinearly with areal loading density (mass collected/filtration area) of a NaCl aerosol, thus significantly reducing the mass loading capacity of the <span class="hlt">filter</span> compared to dry hygroscopic or nonhygroscopic <span class="hlt">particle</span> mass loadings. The specific cake resistance K[sub 2] was computed for different test conditions and used as a measure of the mass loading capacity. K[sub 2] was found to decrease with increasing humidity for nonhygroscopic aluminum oxide <span class="hlt">particles</span> and for hygroscopic NaCl <span class="hlt">particles</span> (at humidities below the deliquescent point). It is postulated that an increase in humidity leads to the formation of a more open particulate cake which lowers the pressure drop for a given mass loading. A formula for predicting K[sub 2] for lognormally distributed aerosols (parameters obtained from impactor data) was derived. The resistance factor, R, calculated using this formula was compared to the theoretical R calculated using the Rudnick-Happel expression. For the nonhygroscopic aluminum oxide, the agreement was good but for the hygroscopic sodium chloride, due to large variation in the cake porosity estimates, the agreement was poor. 17 refs., 6 figs., 3 tabs.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/7270999','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/7270999"><span>Study of the effect of humidity, <span class="hlt">particle</span> hygroscopicity and size on the mass loading capacity of HEPA <span class="hlt">filters</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gupta, A.</p> <p>1992-01-01</p> <p>The effect of humidity, <span class="hlt">particle</span> hygroscopicity and size on the mass loading capacity of glass fiber HEPA <span class="hlt">filters</span> has been studied. At humidifies above the deliquescent point, the pressure drop across the HEPA <span class="hlt">filter</span> increased non-linearly with the areal loading density (mass collected/filtration area) of NaCl aerosol, thus significantly reducing the mass loading capacity of the <span class="hlt">filter</span> compared to dry hygroscopic or non-hygroscopic <span class="hlt">particle</span> mass loadings. The specific cake resistance, K{sub 2}, has been computed for different test conditions and used as a measure of the mass loading capacity. K. was found to decrease with increasing humidity for the non-hygroscopic aluminum oxide <span class="hlt">particles</span> and the hygroscopic NaCl <span class="hlt">particles</span> (at humidities below the deliquescent point). It is postulated that an increase in humidity leads to the formation of a more open particulate cake which lowers the pressure drop for a given mass loading. A formula for predicting K{sub 2} for lognormally distributed aerosols (parameters obtained from impactor data) is derived. The resistance factor, R, calculated using this formula was compared to the theoretical R calculated using the Rudnick-Happel expression. For the non-hygroscopic aluminum oxide the agreement was good but for the hygroscopic sodium chloride, due to large variation in the cake porosity estimates, the agreement was poor.</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('http://adsabs.harvard.edu/abs/2016EGUGA..1812984K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812984K"><span>Developments in non-linear Kalman Ensemble and <span class="hlt">Particle</span> <span class="hlt">Filtering</span> techniques for hydrological 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>Khaki, Mehdi; Forootan, Ehsan; Kuhn, Michael; Awange, Joseph; Pattiaratchi, Charitha</p> <p>2016-04-01</p> <p>Quantifying large-scale (basin/global) water storage changes is essential to understand the Earth's hydrological water cycle. Hydrological models have usually been used to simulate variations in storage compartments resulting from changes in water fluxes (i.e., precipitation, evapotranspiration and runoff) considering physical or conceptual frameworks. Models however represent limited skills in accurately simulating the storage compartments that could be the result of e.g., the uncertainty of forcing parameters, model structure, etc. In this regards, data assimilation provides a great chance to combine observational data with a prior forecast state to improve both the accuracy of model parameters and to improve the estimation of model states at the same time. Various methods exist that can be used to perform data assimilation into hydrological models. The one more frequently used <span class="hlt">particle</span>-based algorithms suitable for non-linear systems high-dimensional systems is the Ensemble Kalman <span class="hlt">Filtering</span> (EnKF). Despite efficiency and simplicity (especially in EnKF), this method indicate some drawbacks. To implement EnKF, one should use the sample covariance of observations and model state variables to update a priori estimates of the state variables. The sample covariance can be suboptimal as a result of small ensemble size, model errors, model nonlinearity, and other factors. Small ensemble can also lead to the development of correlations between state components that are at a significant distance from one another where there is no physical relation. To investigate the under-sampling issue raise by EnKF, covariance inflation technique in conjunction with localization was implemented. In this study, a comparison between latest methods used in the data assimilation framework, to overcome the mentioned problem, is performed. For this, in addition to implementing EnKF, we introduce and apply the Local Ensemble Kalman <span class="hlt">Filter</span> (LEnKF) utilizing covariance localization to remove</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/790986','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/790986"><span><span class="hlt">OPTIMIZATION</span> OF COAL <span class="hlt">PARTICLE</span> FLOW PATTERNS IN LOW NOX BURNERS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jost O.L. Wendt; Gregory E. Ogden; Jennifer Sinclair; Stephanus Budilarto</p> <p>2001-09-04</p> <p>It is well understood that the stability of axial diffusion flames is dependent on the mixing behavior of the fuel and combustion air streams. Combustion aerodynamic texts typically describe flame stability and transitions from laminar diffusion flames to fully developed turbulent flames as a function of increasing jet velocity. Turbulent diffusion flame stability is greatly influenced by recirculation eddies that transport hot combustion gases back to the burner nozzle. This recirculation enhances mixing and heats the incoming gas streams. Models describing these recirculation eddies utilize conservation of momentum and mass assumptions. Increasing the mass flow rate of either fuel or combustion air increases both the jet velocity and momentum for a fixed burner configuration. Thus, differentiating between gas velocity and momentum is important when evaluating flame stability under various operating conditions. The research efforts described herein are part of an ongoing project directed at evaluating the effect of flame aerodynamics on NO{sub x} emissions from coal fired burners in a systematic manner. This research includes both experimental and modeling efforts being performed at the University of Arizona in collaboration with Purdue University. The objective of this effort is to develop rational design tools for <span class="hlt">optimizing</span> low NO{sub x} burners. Experimental studies include both cold-and hot-flow evaluations of the following parameters: primary and secondary inlet air velocity, coal concentration in the primary air, coal <span class="hlt">particle</span> size distribution and flame holder geometry. Hot-flow experiments will also evaluate the effect of wall temperature on burner performance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27560945','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27560945"><span>A Novel Flexible Inertia Weight <span class="hlt">Particle</span> Swarm <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>Amoshahy, Mohammad Javad; Shamsi, Mousa; Sedaaghi, Mohammad Hossein</p> <p>2016-01-01</p> <p><span class="hlt">Particle</span> swarm <span class="hlt">optimization</span> (PSO) is an evolutionary computing method based on intelligent collective behavior of some animals. It is easy to implement and there are few parameters to adjust. The performance of PSO algorithm depends greatly on the appropriate parameter selection strategies for fine tuning its parameters. Inertia weight (IW) is one of PSO's parameters used to bring about a balance between the exploration and exploitation characteristics of PSO. This paper proposes a new nonlinear strategy for selecting inertia weight which is named Flexible Exponential Inertia Weight (FEIW) strategy because according to each problem we can construct an increasing or decreasing inertia weight strategy with suitable parameters selection. The efficacy and efficiency of PSO algorithm with FEIW strategy (FEPSO) is validated on a suite of benchmark problems with different dimensions. Also FEIW is compared with best time-varying, adaptive, constant and random inertia weights. Experimental results and statistical analysis prove that FEIW improves the search performance in terms of solution quality as well as convergence rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4999183','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4999183"><span>A Novel Flexible Inertia Weight <span class="hlt">Particle</span> Swarm <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>Shamsi, Mousa; Sedaaghi, Mohammad Hossein</p> <p>2016-01-01</p> <p><span class="hlt">Particle</span> swarm <span class="hlt">optimization</span> (PSO) is an evolutionary computing method based on intelligent collective behavior of some animals. It is easy to implement and there are few parameters to adjust. The performance of PSO algorithm depends greatly on the appropriate parameter selection strategies for fine tuning its parameters. Inertia weight (IW) is one of PSO’s parameters used to bring about a balance between the exploration and exploitation characteristics of PSO. This paper proposes a new nonlinear strategy for selecting inertia weight which is named Flexible Exponential Inertia Weight (FEIW) strategy because according to each problem we can construct an increasing or decreasing inertia weight strategy with suitable parameters selection. The efficacy and efficiency of PSO algorithm with FEIW strategy (FEPSO) is validated on a suite of benchmark problems with different dimensions. Also FEIW is compared with best time-varying, adaptive, constant and random inertia weights. Experimental results and statistical analysis prove that FEIW improves the search performance in terms of solution quality as well as convergence rate. PMID:27560945</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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4650781','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4650781"><span>Spatial mapping of the biologic effectiveness of scanned <span class="hlt">particle</span> beams: towards biologically <span class="hlt">optimized</span> <span class="hlt">particle</span> therapy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Guan, Fada; Bronk, Lawrence; Titt, Uwe; Lin, Steven H.; Mirkovic, Dragan; Kerr, Matthew D.; Zhu, X. Ronald; Dinh, Jeffrey; Sobieski, Mary; Stephan, Clifford; Peeler, Christopher R.; Taleei, Reza; Mohan, Radhe; Grosshans, David R.</p> <p>2015-01-01</p> <p>The physical properties of <span class="hlt">particles</span> used in radiation therapy, such as protons, have been well characterized, and their dose distributions are superior to photon-based treatments. However, proton therapy may also have inherent biologic advantages that have not been capitalized on. Unlike photon beams, the linear energy transfer (LET) and hence biologic effectiveness of <span class="hlt">particle</span> beams varies along the beam path. Selective placement of areas of high effectiveness could enhance tumor cell kill and simultaneously spare normal tissues. However, previous methods for mapping spatial variations in biologic effectiveness are time-consuming and often yield inconsistent results with large uncertainties. Thus the data needed to accurately model relative biological effectiveness to guide novel treatment planning approaches are limited. We used Monte Carlo modeling and high-content automated clonogenic survival assays to spatially map the biologic effectiveness of scanned proton beams with high accuracy and throughput while minimizing biological uncertainties. We found that the relationship between cell kill, dose, and LET, is complex and non-unique. Measured biologic effects were substantially greater than in most previous reports, and non-linear surviving fraction response was observed even for the highest LET values. Extension of this approach could generate data needed to <span class="hlt">optimize</span> proton therapy plans incorporating variable RBE. PMID:25984967</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/989127','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/989127"><span>An Analysis of Field-Aged Diesel Particulate <span class="hlt">Filter</span> Performance: <span class="hlt">Particle</span> Emissions Before, During and After Regeneration</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Barone, Teresa L; Storey, John Morse; Domingo, Norberto</p> <p>2010-01-01</p> <p>A field-aged, passive diesel particulate <span class="hlt">filter</span> (DPF) employed in a school bus retrofit program was evaluated for emissions of <span class="hlt">particle</span> mass and number concentration before, during and after regeneration. For the <span class="hlt">particle</span> mass measurements, <span class="hlt">filter</span> samples were collected for gravimetric analysis with a partial flow sampling system, which sampled proportionally to the exhaust flow. Total number concentration and number-size distributions were measured by a condensation <span class="hlt">particle</span> counter and scanning mobility <span class="hlt">particle</span> sizer, respectively. The results of the evaluation show that the number concentration emissions decreased as the DPF became loaded with soot. However after soot removal by regeneration, the number concentration emissions were approximately 20 times greater, which suggests the importance of the soot layer in helping to trap <span class="hlt">particles</span>. Contrary to the number concentration results, <span class="hlt">particle</span> mass emissions decreased from 6 1 mg/hp-hr before regeneration to 3 2 mg/hp-hr after regeneration. This indicates that nanoparticles with diameter less than 50 nm may have been emitted after regeneration since these <span class="hlt">particles</span> contribute little to the total mass. Overall, average <span class="hlt">particle</span> emission reductions of 95% by mass and 10,000-fold by number concentration after four years of use provided evidence of the durability of a field-aged DPF. In contrast to previous reports for new DPFs in which elevated number concentrations occurred during the first 200 seconds of a transient cycle, the number concentration emissions were elevated during the second half of the heavy-duty federal test procedure when high speed was sustained. This information is relevant for the analysis of mechanisms by which <span class="hlt">particles</span> are emitted from field-aged DPFs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20842937','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20842937"><span>An analysis of field-aged diesel particulate <span class="hlt">filter</span> performance: <span class="hlt">particle</span> emissions before, during, and after regeneration.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barone, Teresa L; Storey, John M E; Domingo, Norberto</p> <p>2010-08-01</p> <p>A field-aged, passive diesel particulate <span class="hlt">filter</span> (DPF) used in a school bus retrofit program was evaluated for emissions of <span class="hlt">particle</span> mass and number concentration before, during, and after regeneration. For the <span class="hlt">particle</span> mass measurements, <span class="hlt">filter</span> samples were collected for gravimetric analysis with a partial flow sampling system, which sampled proportionally to the exhaust flow. A condensation <span class="hlt">particle</span> counter and scanning mobility <span class="hlt">particle</span> sizer measured total number concentration and number-size distributions, respectively. The results of the evaluation show that the number concentration emissions decreased as the DPF became loaded with soot. However, after soot removal by regeneration, the number concentration emissions were approximately 20 times greater, which suggests the importance of the soot layer in helping to trap <span class="hlt">particles</span>. Contrary to the number concentration results, <span class="hlt">particle</span> mass emissions decreased from 6 +/- 1 mg/hp-hr before regeneration to 3 +/- 2 mg/hp-hr after regeneration. This indicates that nanoparticles with diameters less than 50 nm may have been emitted after regeneration because these <span class="hlt">particles</span> contribute little to the total mass. Overall, average <span class="hlt">particle</span> emission reductions of 95% by mass and 10,000-fold by number concentration after 4 yr of use provided evidence of the durability of a field-aged DPF. In contrast to previous reports for new DPFs in which elevated number concentrations occurred during the first 200 sec of a transient cycle, the number concentration emissions were elevated during the second half of the heavy-duty Federal Test Procedure (FTP) when high speed was sustained. This information is relevant for the analysis of mechanisms by which <span class="hlt">particles</span> are emitted from field-aged DPFs.</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.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4175470','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4175470"><span>Biologically Induced Deposition of Fine Suspended <span class="hlt">Particles</span> by <span class="hlt">Filter</span>-Feeding Bivalves in Land-Based Industrial Marine Aquaculture Wastewater</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhou, Yi; Zhang, Shaojun; Liu, Ying; Yang, Hongsheng</p> <p>2014-01-01</p> <p>Industrial aquaculture wastewater contains large quantities of suspended <span class="hlt">particles</span> that can be easily broken down physically. Introduction of macro-bio-<span class="hlt">filters</span>, such as bivalve <span class="hlt">filter</span> feeders, may offer the potential for treatment of fine suspended matter in industrial aquaculture wastewater. In this study, we employed two kinds of bivalve <span class="hlt">filter</span> feeders, the Pacific oyster Crassostrea gigas and the blue mussel Mytilus galloprovincialis, to deposit suspended solids from marine fish aquaculture wastewater in flow-through systems. Results showed that the biodeposition rate of suspended <span class="hlt">particles</span> by C. gigas (shell height: 8.67±0.99 cm) and M. galloprovincialis (shell height: 4.43±0.98 cm) was 77.84±7.77 and 6.37±0.67 mg ind−1•d−1, respectively. The total solid suspension (TSS) deposition rates of oyster and mussel treatments were 3.73±0.27 and 2.76±0.20 times higher than that of the control treatment without bivalves, respectively. The TSS deposition rates of bivalve treatments were significantly higher than the natural sedimentation rate of the control treatment (P<0.001). Furthermore, organic matter and C, N in the sediments of bivalve treatments were significantly lower than those in the sediments of the control (P<0.05). It was suggested that the <span class="hlt">filter</span> feeders C. gigas and M. galloprovincialis had considerable potential to <span class="hlt">filter</span> and accelerate the deposition of suspended <span class="hlt">particles</span> from industrial aquaculture wastewater, and simultaneously yield value-added biological products. PMID:25250730</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25250730','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25250730"><span>Biologically induced deposition of fine suspended <span class="hlt">particles</span> by <span class="hlt">filter</span>-feeding bivalves in land-based industrial marine aquaculture wastewater.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhou, Yi; Zhang, Shaojun; Liu, Ying; Yang, Hongsheng</p> <p>2014-01-01</p> <p>Industrial aquaculture wastewater contains large quantities of suspended <span class="hlt">particles</span> that can be easily broken down physically. Introduction of macro-bio-<span class="hlt">filters</span>, such as bivalve <span class="hlt">filter</span> feeders, may offer the potential for treatment of fine suspended matter in industrial aquaculture wastewater. In this study, we employed two kinds of bivalve <span class="hlt">filter</span> feeders, the Pacific oyster Crassostrea gigas and the blue mussel Mytilus galloprovincialis, to deposit suspended solids from marine fish aquaculture wastewater in flow-through systems. Results showed that the biodeposition rate of suspended <span class="hlt">particles</span> by C. gigas (shell height: 8.67 ± 0.99 cm) and M. galloprovincialis (shell height: 4.43 ± 0.98 cm) was 77.84 ± 7.77 and 6.37 ± 0.67 mg ind(-1) • d(-1), respectively. The total solid suspension (TSS) deposition rates of oyster and mussel treatments were 3.73 ± 0.27 and 2.76 ± 0.20 times higher than that of the control treatment without bivalves, respectively. The TSS deposition rates of bivalve treatments were significantly higher than the natural sedimentation rate of the control treatment (P < 0.001). Furthermore, organic matter and C, N in the sediments of bivalve treatments were significantly lower than those in the sediments of the control (P < 0.05). It was suggested that the <span class="hlt">filter</span> feeders C. gigas and M. galloprovincialis had considerable potential to <span class="hlt">filter</span> and accelerate the deposition of suspended <span class="hlt">particles</span> from industrial aquaculture wastewater, and simultaneously yield value-added biological products.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJSyS..47.3812D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJSyS..47.3812D"><span>Multi-faults detection and estimation for nonlinear stochastic system based on <span class="hlt">particle</span> <span class="hlt">filter</span> and hypothesis test</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ding, Bo; Fang, Huajing</p> <p>2016-12-01</p> <p>This paper is concerned with the fault detection and estimation for nonlinear stochastic system with additive multi-faults. The states of system are estimated by the improved <span class="hlt">particle</span> <span class="hlt">filter</span> which composed of basic <span class="hlt">particle</span> <span class="hlt">filter</span> and preliminary fault estimation. Since the preliminary fault estimation contains noise, the faults are detected by the method of hypothesis testing, while the amplitude of each fault is estimated by the average of the sample of preliminary fault estimation. Meanwhile, the relationship of the sample size, the significance level of two types of error, the amplitude of fault and the variance of the error of preliminary fault estimation are also given. The effectiveness of the proposed method is verified by the simulation of three-vessel water tank system.</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('https://www.osti.gov/scitech/biblio/22382184','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22382184"><span>An iterative <span class="hlt">particle</span> <span class="hlt">filter</span> approach for coupled hydro-geophysical inversion of a controlled infiltration experiment</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Manoli, Gabriele; Rossi, Matteo; Pasetto, Damiano; Deiana, Rita; Ferraris, Stefano; Cassiani, Giorgio; Putti, Mario</p> <p>2015-02-15</p> <p>The modeling of unsaturated groundwater flow is affected by a high degree of uncertainty related to both measurement and model errors. Geophysical methods such as Electrical Resistivity Tomography (ERT) can provide useful indirect information on the hydrological processes occurring in the vadose zone. In this paper, we propose and test an iterated <span class="hlt">particle</span> <span class="hlt">filter</span> method to solve the coupled hydrogeophysical inverse problem. We focus on an infiltration test monitored by time-lapse ERT and modeled using Richards equation. The goal is to identify hydrological model parameters from ERT electrical potential measurements. Traditional uncoupled inversion relies on the solution of two sequential inverse problems, the first one applied to the ERT measurements, the second one to Richards equation. This approach does not ensure an accurate quantitative description of the physical state, typically violating mass balance. To avoid one of these two inversions and incorporate in the process more physical simulation constraints, we cast the problem within the framework of a SIR (Sequential Importance Resampling) data assimilation approach that uses a Richards equation solver to model the hydrological dynamics and a forward ERT simulator combined with Archie's law to serve as measurement model. ERT observations are then used to update the state of the system as well as to estimate the model parameters and their posterior distribution. The limitations of the traditional sequential Bayesian approach are investigated and an innovative iterative approach is proposed to estimate the model parameters with high accuracy. The numerical properties of the developed algorithm are verified on both homogeneous and heterogeneous synthetic test cases based on a real-world field experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JHyd..399..410M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JHyd..399..410M"><span>Hydraulic parameter estimation by remotely-sensed top soil moisture observations with the <span class="hlt">particle</span> <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>Montzka, Carsten; Moradkhani, Hamid; Weihermüller, Lutz; Franssen, Harrie-Jan Hendricks; Canty, Morton; Vereecken, Harry</p> <p>2011-03-01</p> <p>SummaryIn a synthetic study we explore the potential of using surface soil moisture measurements obtained from different satellite platforms to retrieve soil moisture profiles and soil hydraulic properties using a sequential data assimilation procedure and a 1D mechanistic soil water model. Four different homogeneous soil types were investigated including loamy sand, loam, silt, and clayey soils. The forcing data including precipitation and potential evapotranspiration were taken from the meteorological station of Aachen (Germany). With the aid of the forward model run, a synthetic data set was designed and observations were generated. The virtual top soil moisture observations were then assimilated to update the states and hydraulic parameters of the model by means of a <span class="hlt">particle</span> <span class="hlt">filtering</span> data assimilation method. Our analyses include the effect of assimilation strategy, measurement frequency, accuracy in surface soil moisture measurements, and soils differing in textural and hydraulic properties. With this approach we were able to assess the value of periodic spaceborne observations of top soil moisture for soil moisture profile estimation and identify the adequate conditions (e.g. temporal resolution and measurement accuracy) for remotely sensed soil moisture data assimilation. Updating of both hydraulic parameters and state variables allowed better predictions of top soil moisture contents as compared with updating of states only. An important conclusion is that the assimilation of remotely-sensed top soil moisture for soil hydraulic parameter estimation generates a bias depending on the soil type. Results indicate that the ability of a data assimilation system to correct the soil moisture state and estimate hydraulic parameters is driven by the non linearity between soil moisture and pressure head.</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://adsabs.harvard.edu/abs/2015JCoPh.283...37M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JCoPh.283...37M"><span>An iterative <span class="hlt">particle</span> <span class="hlt">filter</span> approach for coupled hydro-geophysical inversion of a controlled infiltration experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Manoli, Gabriele; Rossi, Matteo; Pasetto, Damiano; Deiana, Rita; Ferraris, Stefano; Cassiani, Giorgio; Putti, Mario</p> <p>2015-02-01</p> <p>The modeling of unsaturated groundwater flow is affected by a high degree of uncertainty related to both measurement and model errors. Geophysical methods such as Electrical Resistivity Tomography (ERT) can provide useful indirect information on the hydrological processes occurring in the vadose zone. In this paper, we propose and test an iterated <span class="hlt">particle</span> <span class="hlt">filter</span> method to solve the coupled hydrogeophysical inverse problem. We focus on an infiltration test monitored by time-lapse ERT and modeled using Richards equation. The goal is to identify hydrological model parameters from ERT electrical potential measurements. Traditional uncoupled inversion relies on the solution of two sequential inverse problems, the first one applied to the ERT measurements, the second one to Richards equation. This approach does not ensure an accurate quantitative description of the physical state, typically violating mass balance. To avoid one of these two inversions and incorporate in the process more physical simulation constraints, we cast the problem within the framework of a SIR (Sequential Importance Resampling) data assimilation approach that uses a Richards equation solver to model the hydrological dynamics and a forward ERT simulator combined with Archie's law to serve as measurement model. ERT observations are then used to update the state of the system as well as to estimate the model parameters and their posterior distribution. The limitations of the traditional sequential Bayesian approach are investigated and an innovative iterative approach is proposed to estimate the model parameters with high accuracy. The numerical properties of the developed algorithm are verified on both homogeneous and heterogeneous synthetic test cases based on a real-world field experiment.</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://ntrs.nasa.gov/search.jsp?R=19720014625&hterms=pigment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dpigment','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720014625&hterms=pigment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dpigment"><span>The determination and <span class="hlt">optimization</span> of (rutile) pigment <span class="hlt">particle</span> size distributions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richards, L. W.</p> <p>1972-01-01</p> <p>A light scattering <span class="hlt">particle</span> size test which can be used with materials having a broad <span class="hlt">particle</span> size distribution is described. This test is useful for pigments. The relation between the <span class="hlt">particle</span> size distribution of a rutile pigment and its optical performance in a gray tint test at low pigment concentration is calculated and compared with experimental data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27333616','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27333616"><span>A Novel Consensus-Based <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span>-Assisted Trust-Tech Methodology for Large-Scale Global <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>Zhang, Yong-Feng; Chiang, Hsiao-Dong</p> <p>2016-06-20</p> <p>A novel three-stage methodology, termed the "consensus-based <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> (PSO)-assisted Trust-Tech methodology," to find global <span class="hlt">optimal</span> solutions for nonlinear <span class="hlt">optimization</span> problems is presented. It is composed of Trust-Tech methods, consensus-based PSO, and local <span class="hlt">optimization</span> methods that are integrated to compute a set of high-quality local <span class="hlt">optimal</span> solutions that can contain the global <span class="hlt">optimal</span> solution. The proposed methodology compares very favorably with several recently developed PSO algorithms based on a set of small-dimension benchmark <span class="hlt">optimization</span> problems and 20 large-dimension test functions from the CEC 2010 competition. The analytical basis for the proposed methodology is also provided. Experimental results demonstrate that the proposed methodology can rapidly obtain high-quality <span class="hlt">optimal</span> solutions that can contain the global <span class="hlt">optimal</span> solution. The scalability of the proposed methodology is promising.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27873181','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27873181"><span>Inhalable Ipratropium Bromide <span class="hlt">Particle</span> Engineering with Multicriteria <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>Vinjamuri, Bhavani Prasad; Haware, Rahul V; Stagner, William C</p> <p>2016-11-21</p> <p>Spray-dried ipratropium bromide (IPB) microspheres for oral inhalation were engineered using Quality by Design. The interrogation of material properties, process parameters, and critical product quality attributes interplay enabled rational product design. A 2(7-3) screening design exhibited the Maillard reaction between L-leucine (LL) and lactose at studied outlet temperatures (OT) >130°C. A response surface custom design was used in conjunction with multicriteria <span class="hlt">optimization</span> to determine the operating design space to achieve inhalable microparticles. Statistically significant predictive models were developed for volume median diameter (p = 0.0001, adjusted R (2)  = 0.9938), span (p = 0.0278, adjusted R (2)  = 0.7912), yield (p = 0.0020, adjusted R (2)  = 0.9320), and OT (p = 0.0082, adjusted R (2)  = 0.8768). An independent verification batch confirmed the model's predictive capability. The prediction and actual values were in good agreement. <span class="hlt">Particle</span> size and span were 3.32 ± 0.09 μm and 1.71 ± 0.18, which were 4.7 and 5.3% higher than the predicted values. The process yield was 50.3%, compared to the predicted value of 65.3%. The OT was 100°C versus the predicted value of 105°C. The label strength of IPB microparticles was 99.0 to 105.9% w/w suggesting that enrichment occurred during the spray-drying process. The present study can be utilized to initiate the design of the first commercial IPB dry powder inhaler.</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('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5375773','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5375773"><span>Parameter Selection and Performance Comparison of <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> in Sensor Networks Localization</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cui, Huanqing; Shu, Minglei; Song, Min; Wang, Yinglong</p> <p>2017-01-01</p> <p>Localization is a key technology in wireless sensor networks. Faced with the challenges of the sensors’ memory, computational constraints, and limited energy, <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> has been widely applied in the localization of wireless sensor networks, demonstrating better performance than other <span class="hlt">optimization</span> methods. In <span class="hlt">particle</span> swarm <span class="hlt">optimization</span>-based localization algorithms, the variants and parameters should be chosen elaborately to achieve the best performance. However, there is a lack of guidance on how to choose these variants and parameters. Further, there is no comprehensive performance comparison among <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> algorithms. The main contribution of this paper is three-fold. First, it surveys the popular <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> variants and <span class="hlt">particle</span> swarm <span class="hlt">optimization</span>-based localization algorithms for wireless sensor networks. Secondly, it presents parameter selection of nine <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> variants and six types of swarm topologies by extensive simulations. Thirdly, it comprehensively compares the performance of these algorithms. The results show that the <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> with constriction coefficient using ring topology outperforms other variants and swarm topologies, and it performs better than the second-order cone programming algorithm. PMID:28257060</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3669212','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3669212"><span>Design <span class="hlt">Optimization</span> of Pin Fin Geometry Using <span class="hlt">Particle</span> Swarm <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>Hamadneh, Nawaf; Khan, Waqar A.; Sathasivam, Saratha; Ong, Hong Choon</p> <p>2013-01-01</p> <p><span class="hlt">Particle</span> swarm <span class="hlt">optimization</span> (PSO) is employed to investigate the overall performance of a pin fin.The following study will examine the effect of governing parameters on overall thermal/fluid performance associated with different fin geometries, including, rectangular plate fins as well as square, circular, and elliptical pin fins. The idea of entropy generation minimization, EGM is employed to combine the effects of thermal resistance and pressure drop within the heat sink. A general dimensionless expression for the entropy generation rate is obtained by considering a control volume around the pin fin including base plate and applying the conservations equations for mass and energy with the entropy balance. Selected fin geometries are examined for the heat transfer, fluid friction, and the minimum entropy generation rate corresponding to different parameters including axis ratio, aspect ratio, and Reynolds number. The results clearly indicate that the preferred fin profile is very dependent on these parameters. PMID:23741525</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010LNCS.6466..440S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010LNCS.6466..440S"><span>A <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> Algorithm for <span class="hlt">Optimal</span> Operating Parameters of VMI Systems in a Two-Echelon Supply Chain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sue-Ann, Goh; Ponnambalam, S. G.</p> <p></p> <p>This paper focuses on the operational issues of a Two-echelon Single-Vendor-Multiple-Buyers Supply chain (TSVMBSC) under vendor managed inventory (VMI) mode of operation. To determine the <span class="hlt">optimal</span> sales quantity for each buyer in TSVMBC, a mathematical model is formulated. Based on the <span class="hlt">optimal</span> sales quantity can be obtained and the <span class="hlt">optimal</span> sales price that will determine the <span class="hlt">optimal</span> channel profit and contract price between the vendor and buyer. All this parameters depends upon the understanding of the revenue sharing between the vendor and buyers. A <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO) is proposed for this problem. Solutions obtained from PSO is compared with the best known results reported in literature.</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 <span class="hlt">particles</span> 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 <span class="hlt">particle</span> <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 <span class="hlt">particle</span> <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('http://adsabs.harvard.edu/abs/2016APS..DPPY10035K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..DPPY10035K"><span><span class="hlt">Particle</span> Pusher for the Investigation of Wave-<span class="hlt">Particle</span> Interactions in the Magnetic Centrifugal Mass <span class="hlt">Filter</span> (MCMF)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kulp-McDowall, Taylor; Ochs, Ian; Fisch, Nathaniel</p> <p>2016-10-01</p> <p>A <span class="hlt">particle</span> pusher was constructed in MATLAB using a fourth order Runge-Kutta algorithm to investigate the wave-<span class="hlt">particle</span> interactions within theoretical models of the MCMF. The model simplified to a radial electric field and a magnetic field focused in the z direction. Studies on an average velocity calculation were conducted in order to test the program's behavior in the large radius limit. The results verified that the <span class="hlt">particle</span> pusher was behaving correctly. Waves were then simulated on the rotating <span class="hlt">particles</span> with a periodic divergenceless perturbation in the Bz component of the magnetic field. Preliminary runs indicate an agreement of the <span class="hlt">particle</span>'s motion with analytical predictions-ie. cyclic contractions of the doubly rotating <span class="hlt">particle</span>'s gyroradius.The next stage of the project involves the implementation of <span class="hlt">particle</span> collisions and turbulence within the <span class="hlt">particle</span> pusher in order to increase its accuracy and applicability. This will allow for a further investigation of the alpha channeling electrode replacement thesis first proposed by Abraham Fetterman in 2011. Made possible by Grants from the Princeton Environmental Institute (PEI) and the Program for Plasma Science and Technology (PPST).</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> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19520569','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19520569"><span>The performance of biological anaerobic <span class="hlt">filters</span> packed with sludge-fly ash ceramic <span class="hlt">particles</span> (SFCP) and commercial ceramic <span class="hlt">particles</span> (CCP) during the restart period: effect of the C/N ratios and <span class="hlt">filter</span> media.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yue, Qinyan; Han, Shuxin; Yue, Min; Gao, Baoyu; Li, Qian; Yu, Hui; Zhao, Yaqin; Qi, Yuanfeng</p> <p>2009-11-01</p> <p>Two lab-scale upflow biological anaerobic <span class="hlt">filters</span> (BAF) packed with sludge-fly ash ceramic <span class="hlt">particles</span> (SFCP) and commercial ceramic <span class="hlt">particles</span> (CCP) were employed to investigate effects of the C/N ratios and <span class="hlt">filter</span> media on the BAF performance during the restart period. The results indicated that BAF could be restarted normally after one-month cease. The C/N ratio of 4.0 was the thresholds of nitrate removal and nitrite accumulation. TN removal and phosphate uptake reached the maximum value at the same C/N ratio of 5.5. Ammonia formation was also found and excreted a negative influence on TN removal, especially when higher C/N ratios were applied. Nutrients were mainly degraded within the height of 25 cm from the bottom. In addition, SFCP, as novel <span class="hlt">filter</span> media manufactured by wastes-dewatered sludge and fly ash, represented a better potential in inhibiting nitrite accumulation, TN removal and phosphate uptake due to their special characteristics in comparison with CCP.</p> </li> <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('http://adsabs.harvard.edu/abs/2011SPIE.7965E..2IL','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SPIE.7965E..2IL"><span>The impact of <span class="hlt">filtering</span> direct-feedthrough on the x-space theory of magnetic <span class="hlt">particle</span> imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, Kuan; Goodwill, Patrick; Zheng, Bo; Conolly, Steven</p> <p>2011-03-01</p> <p>Magnetic <span class="hlt">particle</span> imaging (MPI) is a new medical imaging modality that maps the instantaneous response of superparamagnetic <span class="hlt">particles</span> under an applied magnetic field. In MPI, the excitation and detection of the nanoparticles occur simultaneously. Therefore, when a sinusoidal excitation field is applied to the system, the received signal spectrum contains both harmonics from the <span class="hlt">particles</span> and a direct feedthrough signal from the source at the fundamental drive frequency. Removal of the induced feedthrough signal from the received signal requires significant <span class="hlt">filtering</span>, which also removes part of the signal spectrum. In this paper, we present a method to investigate the impact of temporally <span class="hlt">filtering</span> out individual lower order harmonics on the reconstructed x-space image. Analytic and simulation results show that the loss of <span class="hlt">particle</span> signal at low frequency leads to a recoverable loss of low spatial frequency information in the x-space image. Initial experiments validate the findings and demonstrate the feasibility of the recovery of the lost signal. This builds on earlier work that discusses the ideal one-dimensional MPI system and harmonic decomposition of the MPI signal.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26027708','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26027708"><span><span class="hlt">Optimal</span> multi-floor plant layout based on the mathematical programming and <span class="hlt">particle</span> swarm <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>Lee, Chang Jun</p> <p>2015-01-01</p> <p>In the fields of researches associated with plant layout <span class="hlt">optimization</span>, the main goal is to minimize the costs of pipelines and pumping between connecting equipment under various constraints. However, what is the lacking of considerations in previous researches is to transform various heuristics or safety regulations into mathematical equations. For example, proper safety distances between equipments have to be complied for preventing dangerous accidents on a complex plant. Moreover, most researches have handled single-floor plant. However, many multi-floor plants have been constructed for the last decade. Therefore, the proper algorithm handling various regulations and multi-floor plant should be developed. In this study, the Mixed Integer Non-Linear Programming (MINLP) problem including safety distances, maintenance spaces, etc. is suggested based on mathematical equations. The objective function is a summation of pipeline and pumping costs. Also, various safety and maintenance issues are transformed into inequality or equality constraints. However, it is really hard to solve this problem due to complex nonlinear constraints. Thus, it is impossible to use conventional MINLP solvers using derivatives of equations. In this study, the <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO) technique is employed. The ethylene oxide plant is illustrated to verify the efficacy of this study.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5025108','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5025108"><span>Automated Sperm Head Detection Using Intersecting Cortical Model Optimised by <span class="hlt">Particle</span> Swarm <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>Tan, Weng Chun; Mat Isa, Nor Ashidi</p> <p>2016-01-01</p> <p>In human sperm motility analysis, sperm segmentation plays an important role to determine the location of multiple sperms. To ensure an improved segmentation result, the Laplacian of Gaussian <span class="hlt">filter</span> is implemented as a kernel in a pre-processing step before applying the image segmentation process to automatically segment and detect human spermatozoa. This study proposes an intersecting cortical model (ICM), which was derived from several visual cortex models, to segment the sperm head region. However, the proposed method suffered from parameter selection; thus, the ICM network is optimised using <span class="hlt">particle</span> swarm <span class="hlt">optimization</span> where feature mutual information is introduced as the new fitness function. The final results showed that the proposed method is more accurate and robust than four state-of-the-art segmentation methods. The proposed method resulted in rates of 98.14%, 98.82%, 86.46% and 99.81% in accuracy, sensitivity, specificity and precision, respectively, after testing with 1200 sperms. The proposed algorithm is expected to be implemented in analysing sperm motility because of the robustness and capability of this algorithm. PMID:27632581</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SPIE.8006E..1ZP','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SPIE.8006E..1ZP"><span>Combining heterogeneous features for face detection using multiscale feature selection with binary <span class="hlt">particle</span> swarm <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>Pan, Hong; Xia, Si-Yu; Jin, Li-Zuo; Xia, Liang-Zheng</p> <p>2011-12-01</p> <p>We propose a fast multiscale face detector that boosts a set of SVM-based hierarchy classifiers constructed with two heterogeneous features, i.e. Multi-block Local Binary Patterns (MB-LBP) and Speeded Up Robust Features (SURF), at different image resolutions. In this hierarchical architecture, simple and fast classifiers using efficient MB-LBP descriptors remove large parts of the background in low and intermediate scale layers, thus only a small percentage of background patches look similar to faces and require a more accurate but slower classifier that uses distinctive SURF descriptor to avoid false classifications in the finest scale. By propagating only those patterns that are not classified as background, we can quickly decrease the amount of data need to be processed. To lessen the training burden of the hierarchy classifier, in each scale layer, a feature selection scheme using Binary <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (BPSO) searches the entire feature space and <span class="hlt">filters</span> out the minimum number of discriminative features that give the highest classification rate on a validation set, then these selected distinctive features are fed into the SVM classifier. We compared detection performance of the proposed face detector with other state-of-the-art methods on the CMU+MIT face dataset. Our detector achieves the best overall detection performance. The training time of our algorithm is 60 times faster than the standard Adaboost algorithm. It takes about 70 ms for our face detector to process a 320×240 image, which is comparable to Viola and Jones' detector.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016MS%26E..114a2055I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016MS%26E..114a2055I"><span>Performance evaluation of different types of <span class="hlt">particle</span> representation procedures of <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> in Job-shop Scheduling Problems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Izah Anuar, Nurul; Saptari, Adi</p> <p>2016-02-01</p> <p>This paper addresses the types of <span class="hlt">particle</span> representation (encoding) procedures in a population-based stochastic <span class="hlt">optimization</span> technique in solving scheduling problems known in the job-shop manufacturing environment. It intends to evaluate and compare the performance of different <span class="hlt">particle</span> representation procedures in <span class="hlt">Particle</span> Swarm <span class="hlt">Optimization</span> (PSO) in the case of solving Job-shop Scheduling Problems (JSP). <span class="hlt">Particle</span> representation procedures refer to the mapping between the <span class="hlt">particle</span> position in PSO and the scheduling solution in JSP. It is an important step to be carried out so that each <span class="hlt">particle</span> in PSO can represent a schedule in JSP. Three procedures such as Operation and <span class="hlt">Particle</span> Position Sequence (OPPS), random keys representation and random-key encoding scheme are used in this study. These procedures have been tested on FT06 and FT10 benchmark problems available in the OR-Library, where the objective function is to minimize the makespan by the use of MATLAB software. Based on the experimental results, it is discovered that OPPS gives the best performance in solving both benchmark problems. The contribution of this paper is the fact that it demonstrates to the practitioners involved in complex scheduling problems that different <span class="hlt">particle</span> representation procedures can have significant effects on the performance of PSO in solving JSP.</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> </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('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.osti.gov/scitech/biblio/387286','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/387286"><span>A comparison of biologically active <span class="hlt">filters</span> for the removal of ozone by-products, turbidity, and <span class="hlt">particles</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Coffey, B.M.; Krasner, S.W.; Sclimenti, M.J.; Hacker, P.A.; Gramith, J.T.</p> <p>1996-11-01</p> <p>Biofiltration tests were performed at the Metropolitan Water District of Southern California`s 5.5-mgd (21,000 m{sup 3}d) demonstration plant using two 400 ft{sup 2} (37 m{sup 2}) anthracite/sand <span class="hlt">filters</span> and a 6 ft{sup 2} (0.56 m{sup 2}) granular activated carbon (GAC)/sand <span class="hlt">filter</span> operated in parallel. The empty-bed contact time (EBCT) within the GAC and anthracite ranged from 2.1-3.1 min. The <span class="hlt">filters</span> were evaluated based on (1) conventional filtration performance (turbidity, <span class="hlt">particle</span> removal, and headloss); (2) removal of biodegradable ozone by-products (assimilable organic carbon [AOC], aldehydes, and aldoketoacids) after startup; (3) removal of biodegradable ozone by-products at steady state; and (4) resistance to short-term process upsets such as intermittent chlorination or <span class="hlt">filter</span> out-of-service time. Approximately 80 percent formaldehyde removal was achieved by the anthracite/sand <span class="hlt">filter</span> operated at a 2.1-min EBCT (6 gpm/ft{sup 2} [15 m/h]) within 8 days of ozone operation. The GAC/sand <span class="hlt">filter</span> operated at the same rate achieved 80 percent removal within 1 day, possibly as an additive effect of adsorption and biological removal. In-depth aldehyde monitoring at four depths (0.5-min EBCT intervals) provided additional insight into the removal kinetics. During periods of warmer water temperature, from 20 to 48 percent of the AOC was removed in the flocculation/sedimentation basins by 40-75 percent. This percentage removal typically resulted in AOC concentrations within 40 {mu}g C/L of the raw, unozonated water levels.</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('http://www.dtic.mil/docs/citations/ADA562462','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA562462"><span>Decentralized Riemannian <span class="hlt">Particle</span> <span class="hlt">Filtering</span> with Applications to Multi-Agent Localization</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>2012-06-14</p> <p>USA, December 10-12 1997. 172 52. Brown, Robert G. and Patrick Y.C. Hwang. Introduction To Random Signals and Applied Kalman <span class="hlt">Filtering</span>. John Wiley...London, 1994. 234. Randal Beard, Jonathan Lawton Wynn Stirling , Jacob Gunther. “Nonlinear Projec- tion <span class="hlt">Filter</span> based on Galerkin Approximation”. AIAA...Sensor Networks and Information Processing, 161 – 166. 2004. 242. Roberts , S. Reece S. “Robust, Low-Bandwidth, Multi-Vehicle Mapping”. in Pro</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.A53A0203R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.A53A0203R"><span>Estimation of ice activation parameters within a <span class="hlt">particle</span> tracking Lagrangian cloud model using the ensemble Kalman <span class="hlt">filter</span> to match ISCDAC golden case observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reisner, J. M.; Dubey, M. K.</p> <p>2010-12-01</p> <p>To both quantify and reduce uncertainty in ice activation parameterizations for stratus clouds occurring in the temperature range between -5 to -10 C ensemble simulations of an ISDAC golden case have been conducted. To formulate the ensemble, three parameters found within an ice activation model have been sampled using a Latin hypercube technique over a parameter range that induces large variability in both number and mass of ice. The ice activation model is contained within a Lagrangian cloud model that simulates <span class="hlt">particle</span> number as a function of radius for cloud ice, snow, graupel, cloud, and rain <span class="hlt">particles</span>. A unique aspect of this model is that it produces very low levels of numerical diffusion that enable the model to accurately resolve the sharp cloud edges associated with the ISDAC stratus deck. Another important aspect of the model is that near the cloud edges the number of <span class="hlt">particles</span> can be significantly increased to reduce sampling errors and accurately resolve physical processes such as collision-coalescence that occur in this region. Thus, given these relatively low numerical errors, as compared to traditional bin models, the sensitivity of a stratus deck to changes in parameters found within the activation model can be examined without fear of numerical contamination. Likewise, once the ensemble has been completed, ISDAC observations can be incorporated into a Kalman <span class="hlt">filter</span> to <span class="hlt">optimally</span> estimate the ice activation parameters and reduce overall model uncertainty. Hence, this work will highlight the ability of an ensemble Kalman <span class="hlt">filter</span> system coupled to a highly accurate numerical model to estimate important parameters found within microphysical parameterizations containing high uncertainty.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=131206&keyword=carbon+AND+fiber&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=90573628&CFTOKEN=56678294','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=131206&keyword=carbon+AND+fiber&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=90573628&CFTOKEN=56678294"><span>MODELING REFLECTANCE AND TRANSMITTANCE OF QUARTZ-FIBER <span class="hlt">FILTER</span> SAMPLES CONTAINING ELEMENTAL CARBON <span class="hlt">PARTICLES</span>: IMPLICATIONS FOR THERMAL/OPTICAL ANALYSIS. (R831086)</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p><p>A radiative transfer scheme that considers absorption, scattering, and distribution of light-absorbing elemental carbon (EC) <span class="hlt">particles</span> collected on a quartz-fiber <span class="hlt">filter</span> was developed to explain simultaneous <span class="hlt">filter</span> reflectance and transmittance observations prior to and during...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9387E..0OG','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9387E..0OG"><span>Three dimensional indoor positioning based on visible light with Gaussian mixture sigma-point <span class="hlt">particle</span> <span class="hlt">filter</span> technique</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gu, Wenjun; Zhang, Weizhi; Wang, Jin; Amini Kashani, M. R.; Kavehrad, Mohsen</p> <p>2015-01-01</p> <p>Over the past decade, location based services (LBS) have found their wide applications in indoor environments, such as large shopping malls, hospitals, warehouses, airports, etc. Current technologies provide wide choices of available solutions, which include Radio-frequency identification (RFID), Ultra wideband (UWB), wireless local area network (WLAN) and Bluetooth. With the rapid development of light-emitting-diodes (LED) technology, visible light communications (VLC) also bring a practical approach to LBS. As visible light has a better immunity against multipath effect than radio waves, higher positioning accuracy is achieved. LEDs are utilized both for illumination and positioning purpose to realize relatively lower infrastructure cost. In this paper, an indoor positioning system using VLC is proposed, with LEDs as transmitters and photo diodes as receivers. The algorithm for estimation is based on received-signalstrength (RSS) information collected from photo diodes and trilateration technique. By appropriately making use of the characteristics of receiver movements and the property of trilateration, estimation on three-dimensional (3-D) coordinates is attained. <span class="hlt">Filtering</span> technique is applied to enable tracking capability of the algorithm, and a higher accuracy is reached compare to raw estimates. Gaussian mixture Sigma-point <span class="hlt">particle</span> <span class="hlt">filter</span> (GM-SPPF) is proposed for this 3-D system, which introduces the notion of Gaussian Mixture Model (GMM). The number of <span class="hlt">particles</span> in the <span class="hlt">filter</span> is reduced by approximating the probability distribution with Gaussian components.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24527647','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24527647"><span>Preliminary study on filamentous <span class="hlt">particle</span> distribution in septic tank effluent and their impact on <span class="hlt">filter</span> cake development.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Spychała, Marcin; Nieć, Jakub; Pawlak, Maciej</p> <p>2013-01-01</p> <p>In this paper, the preliminary study on the impact of filamentous <span class="hlt">particles</span> (FP) in the septic tank effluent (STE) on <span class="hlt">filter</span> cake (FC) development was presented. The number, length and diameter (30 p./cm3, 451 and 121 microm, respectively, on average) of FPs were measured using microscope image analysis of STE samples condensed using a vacuum evaporation set. Results of this study showed, that 0.73% of volatile suspended solids (VSSs) mass from the STE occurs in the form of FPs. No correlation between FP total mass and VSS was found. An experiment with a layer of FPs simulated by ground toilet paper was conducted and showed the impact of this layer (4.89 mg/cm2) on wastewater hydraulic conductivity--for an FC with FPs (FC-FP), hydraulic conductivity was seven times lower than for the FC without the FP layer, and on outflow quality (lower concentration of organic matter expressed as chemical oxygen demand (COD) in effluent from the FC-FP <span class="hlt">filter</span> than in the effluent from the FC <span class="hlt">filter</span>: 618 and 732 gO2/m3, respectively). Despite a relatively small amount of FPs in STE solids (as volume fraction), they play an important role in FC development due to their relatively high length and low degradability. Probably relatively small pores of the FC containing FPs (FC-FP) caused a small <span class="hlt">particle</span> blocking and a decrease in permeability.</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. Re