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Analysis And Design Of MinimaxOptimal Interpolators
 IEEE Trans. Signal Proc
, 1998
"... We consider a class of interpolation algorithms, including the leastsquares optimal Yen interpolator, and we derive a closedform expression for the interpolation error for interpolators of this type. The error depends on the eigenvalue distribution of a matrix which is specified for each set of sa ..."
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Cited by 17 (3 self)
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We consider a class of interpolation algorithms, including the leastsquares optimal Yen interpolator, and we derive a closedform expression for the interpolation error for interpolators of this type. The error depends on the eigenvalue distribution of a matrix which is specified for each set of sampling points. The error expression can be used to prove that the Yen interpolator is optimal. The implementation of the Yen algorithm suffers from numerical illconditioning, forcing the use of a regularized, approximate solution. We suggest a new, approximate solution, consisting of a sinckernel interpolator with specially chosen weighting coefficients. The newly designed sinckernel interpolator is compared with the usual sinc interpolator using Jacobian (area) weighting, through numerical simulations. We show that the sinc interpolator with Jacobian weighting works well only when the sampling is nearly uniform. The newly designed sinckernel interpolator is shown to perform better than ...
Prediction Accuracy for Air Traffic Management Decision Support
 Tools,” Paper 110, 3 rd USA / EUROCONTROL Air Traffic Management R&D Seminar
, 2000
"... Air traffic automation depends on accurate trajectory predictions. Flight tests show that wind errors are a large source of error. Windfield accuracy is sufficient on average, but large errors occasionally exist that cause significant errors in trajectoryprediction. A year long study was conducted ..."
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Cited by 8 (2 self)
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Air traffic automation depends on accurate trajectory predictions. Flight tests show that wind errors are a large source of error. Windfield accuracy is sufficient on average, but large errors occasionally exist that cause significant errors in trajectoryprediction. A year long study was conducted to better understand the windprediction errors, to establish metrics for quantifying large errors, and to validate two approaches to improve wind prediction accuracy. Three methods are discussed for quantifying large errors: percentage of point errors that exceed 10 m/s, probability distribution of point errors, and the number of hourly time periods with a high number of large errors. The baseline windprediction system evaluated for this study is the Rapid Update Cycle (RUC). Two approaches to improving the original RUC wind predictions are examined. The first approach is to enhance RUC in terms of increased model resolution, enhancement of the model physics, and increased observational input data. The second method is to augment the RUC output, in nearreal time, through an optimalinterpolation scheme that incorporates the latest aircraft reports received since the last RUC update. Both approaches are shown to greatly reduce the occurrence of large wind errors.
OnLine Parameter Estimation For InfiniteDimensional Dynamical Systems
, 1997
"... The online or adaptive identification of parameters in abstract linear and nonlinear infinitedimensional dynamical systems is considered. An estimator in the form of an infinitedimensional linear evolution system having the state and parameter estimates as its states is defined. Convergence of th ..."
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Cited by 5 (0 self)
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The online or adaptive identification of parameters in abstract linear and nonlinear infinitedimensional dynamical systems is considered. An estimator in the form of an infinitedimensional linear evolution system having the state and parameter estimates as its states is defined. Convergence of the state estimator is established via a Lyapunov estimate. The finitedimensional notion of a plant being sufficiently rich or persistently excited is extended to infinite dimensions. Convergence of the parameter estimates is established under the additional assumption that the plant is persistently excited. A finitedimensional approximation theory is developed, and convergence results are established. Numerical results for examples involving the estimation of both constant and functional parameters in onedimensional linear and nonlinear heat or diffusion equations and the estimation of sti#ness and damping parameters in a onedimensional wave equation with KelvinVoigt viscoelastic damping ...
Synonyms Facial Motion Estimation Definition
"... In many face recognition systems, the input is a video sequence consisting of one or more faces. It is necessary to track each face over this video sequence so as to extract the information that will be processed by the recognition system. Tracking is also necessary for 3D modelbased recognition sy ..."
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In many face recognition systems, the input is a video sequence consisting of one or more faces. It is necessary to track each face over this video sequence so as to extract the information that will be processed by the recognition system. Tracking is also necessary for 3D modelbased recognition systems where the 3D model is estimated from the input video. Face tracking can be divided along different lines depending upon the method used, e.g., head tracking, feature tracking, imagebased tracking, modelbased tracking. The output of the face tracker can be the 2D position of the face in each image of the video (2D tracking), the 3D pose of the face (3D tracking), or the location of features on the face. Some trackers are able to output other parameters related to lighting or expression. The major challenges encountered by face tracking systems are robustness to pose changes, lighting variations, and facial deformations due to changes of expression, occlusions of the face to be tracked and clutter in the scene that makes it difficult to distinguish the face from the other objects. Main Body Text
CON Advisory System (CTAS), a set of Air Traffic Management (ATM) Decision Support Tools
"... The National Aeronautics and Space Administration (NASA) is developing the Center–TRA ..."
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The National Aeronautics and Space Administration (NASA) is developing the Center–TRA
2.7 THE USE OF THE GAUSS–MARKOV THEOREM IN WINDS ANALYSIS * �
"... tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use ” under Section 107 of the U.S. Copyright Act or that satisfies the conditions specified in Se ..."
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tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use ” under Section 107 of the U.S. Copyright Act or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108, as revised by P.L. 94553) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form on servers, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. Additional details are provided in the AMS CopyrightPolicy, available on the AMS Web site located at
CON Advisory System (CTAS), a set of Air Traffic Management (ATM) Decision Support Tools
"... The National Aeronautics and Space Administration (NASA) is developing the Center–TRA ..."
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The National Aeronautics and Space Administration (NASA) is developing the Center–TRA
Research Article Simulation of a owing snow avalanche using molecular dynamics
"... Abstract: This paper presents an approach for the modeling and simulation of a
owing snow avalanche, which is formed of dry and liqueed snow that slides down a slope, using molecular dynamics and the discrete element method. A particle system is utilized as a base method for the simulation and marc ..."
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Abstract: This paper presents an approach for the modeling and simulation of a
owing snow avalanche, which is formed of dry and liqueed snow that slides down a slope, using molecular dynamics and the discrete element method. A particle system is utilized as a base method for the simulation and marching cubes with realtime shaders are employed for rendering. A uniform gridbased neighbor search algorithm is used for collision detection for interparticle and particleterrain interactions. A massspring model of the collision resolution is employed to mimic the compressibility of the snow and particle attraction forces are put into use between the particles and terrain surface. In order to achieve greater performance, general purpose GPU language and multithreaded programming are utilized for collision detection and resolution. The results are displayed with dierent combinations of rendering methods for the realistic representation of the owing avalanche.
Analysis and Design of
"... Abstract — We consider a class of interpolation algorithms, including the leastsquares optimal Yen interpolator, and we derive a closedform expression for the interpolation error for interpolators of this type. The error depends on the eigenvalue distribution of a matrix that is specified for each ..."
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Abstract — We consider a class of interpolation algorithms, including the leastsquares optimal Yen interpolator, and we derive a closedform expression for the interpolation error for interpolators of this type. The error depends on the eigenvalue distribution of a matrix that is specified for each set of sampling points. The error expression can be used to prove that the Yen interpolator is optimal. The implementation of the Yen algorithm suffers from numerical ill conditioning, forcing the use of a regularized, approximate solution. We suggest a new, approximate solution consisting of a sinckernel interpolator with specially chosen weighting coefficients. The newly designed sinckernel interpolator is compared with the usual sinc interpolator using Jacobian (area) weighting through numerical simulations. We show that the sinc interpolator with Jacobian weighting works well only when the sampling is nearly uniform. The newly designed sinckernel interpolator is shown to perform better than the sinc interpolator with Jacobian weighting. I.