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Well-Conditioned Recursive Least-Squared Estimation Algorithms

IFAC Proceedings Volumes 1992年第14期25卷 453-458页

作者： K.V. Lever Electronics Research Laboratory Defence Science and Technology Organisation P.O. Box 1500 Salisbury South Australia 5108 Australia Signal Processing Research Institute University of South Australia Levels Campus South Australia 5095 Australia

This paper explains the inadequacies due to ill-conditioning of classical recursive least squares signal estimation algorithms based on Taylor series expansions, then shows how the algorithms may be restructured using orthogonal expansions, at little cost in extra complexity, to provide well-conditioned versions suitable for implementation in a variety of digital signal processing applications. Several open questions are posed, mainly connected with the incorporation of signal windowing to provide smoothing filters.

关键词： Least-squares estimation recursive algorithms well-conditioning

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IMAGE SEQUENCE CODING BY SPLIT AND MERGE

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IEEE TRANSACTIONS ON COMMUNICATIONS 1991年第12期39卷 1845-1855页

作者： WILLEMIN, P REED, TR KUNT, M Signal and Image Processing Laboratory Swiss Federal Institute of Technology Lausanne Switzerland Department of Electrical Engineering and Computer Science University of California Davis CA USA

This paper describes a method for reducing the information contained in an image sequence, while retaining the information necessary for the interpretation of the sequence by a human observer. The method consists of first locating the redundant information, reducing the degree of redundancy, and coding the result. The sequence is treated as a single 3-D data volume, the voxels of which are grouped into several regions, obtained by a 3-D split and merge algorithm. To find these regions, we first obtain an initial region space by splitting the image sequence until the gray-level variation over each region can be approximated by a 3-D polynomial, to a specified accuracy. This results in a set of parallelepipedic regions of various sizes. To represent the gray-level variation over these regions, the coefficients of the approximating polynomial are used as features. The most similar regions are then merged, using a region adjacency graph. The information is coded by representing the borders of the regions using a pyramidal structure in the x, y, t space. The coefficients of the approximating polynomials are coded in a straightforward manner. For 256 x 256 pixel, 25 frames/s image sequences, compressions allowing transmission rates near 64 kbit/s are obtained.

关键词： Image sequences Image coding Pixel Bandwidth Layout Polynomials Image segmentation Humans Helium ISDN

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A new, efficient structure for the short-time Fourier transform, with an application in code-division sonar imaging

A new, efficient structure for the short-time Fourier transf...

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International Conference on Acoustics, Speech, and signal processing (ICASSP)

作者： M. Covell J. Richardson Acoustics & Radar Technology Laboratory SRI International Inc. Menlo Park CA USA Digital Signal Processing Group Massachusetts Institute of Technology Cambridge MA USA

Although most applications which use the short-time Fourier transform (STFT) temporally downsample the output, some applications exploit a dense temporal sampling of the STFT. One example, coded-division multiple-beam sonar, is discussed. Given a need for the densely sampled STFT, the complexity of the computation can be reduced from O(N log N) for the general short-time FFT structure to O(N) using the Goertzel algorithm. The authors introduce the pruned short-time FFT, a novel computational structure for efficiently computing the STFT with dense temporal sampling. The pruned FFT achieves the same computational savings as the Goertzel algorithm, but is unconditionally stable.< >

关键词： Fourier transforms Frequency shift keying Sampling methods Sonar applications signal resolution Azimuth Acoustic imaging Acoustic applications radar applications radar imaging

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Convergence behavior and convergence rates of stack filters

Convergence behavior and convergence rates of stack filters

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IEEE International Symposium on Circuits and Systems (ISCAS)

作者： M. Gabbouj P.-T. Yu E.J. Coyle Signal Processing Laboratory Tampere University of Technology Tampere Finland Institute of Computer Science and Information Engineering National Chung Cheng University Chiayi Taiwan School of Electrical Engineering Purdue University West Lafayette IN USA

The convergence behavior of type-0 through type-3 stack filters is investigated. It is shown that stack filters of type-0 through type-2 all possess the convergence property; that is, they filter any input signal to a root after consecutive passes of the filter under any appending strategy. A counterexample is given to show that not all type-3 stack filters have this convergence property. The rate of convergence for convergent stack filters is also shown. It is shown that stack filters of type-0 will take at most a single pass to filter any input signal to a root. The rate of convergence of type-1 and type-2 stack filters is shown to be linear in the length of the input signal.< >

关键词： Convergence Filters Boolean functions signal processing Laboratories Computer science Shape Filtering theory Design methodology signal design

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FULL-WAVE SOLUTION OF DIELECTRIC LOADED WAVE-GUIDES AND SHIELDED MICROSTRIPS UTILIZING FINITE-DIFFERENCE AND THE CONJUGATE-GRADIENT METHOD

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INTERNATIONAL JOURNAL OF MICROWAVE AND MILLIMETER-WAVE COMPUTER-AIDED ENGINEERING 1991年第4期1卷 346-357页

作者： NARAYANAN, V MANELA, M LADE, RK SARKAR, TK Department of Electrical and Computer Engineering Syracuse University Syracuse New York 13244-1240 Viswanathan Narayanan was born in Bangalore India on December 14 1965. He received the BE degree in Electronics and Communications from B.M.S. College of Engineering Bangalore in 1988. He joined the Department of Electrical Engineering at Syracuse University for his graduate studies in 1989 where he is currently a research assistant. His research interests are in microwave measurements numerical electromagnetics and signal processing. Biographies and photos are not available for M. Manela and R. K. Lade. Tapan K. Sarkar (Sf69-M'76-SM'X1) was born in Calcutta. India on August 2 1948. He received the BTech degree from the Indian Institute of Technology Kharagpur India in 1969 the MScE degree from the University of New Brunswick Fredericton Canada in 1971. and the MS and PhD degrees from Syracuse University. Syracuse NY in 1975. From 1975-1976 he was with the TACO Division of the General Instruments Corporation. He was with the Rochester Institute of Technology (Rochester NY) from 1976-1985. He was a Research Fellow at the Gordon Mckay Laboratory Harvard University Cambridge MA from 1977 to 1978. He is now a Professor in the Department of Electrical and Computer Engineering Syracuse University. His current research interests deal with numerical solutions of operator equations arising in electromagnetics and signal processing with application to system design. He obtained one of the “ best solution” awards in May 1977 at the Rome Air Development Center (RADC) Spectral Estimation Workshop. He has authored or coauthored more than 154 journal articles and conference papers and has written chapters in eight books. Dr. Sarkar is a registered professional engineer in the state of New York. He received the Best Paper Award of the IEEE Transactions on Electromagnetic Compatibility in 1979. He was an Associate Editor for feature articles of the lEEE Antennas arid Propagation Sociefy Newsletter and was

Dynamic analysis of waveguide structures containing dielectric and metal strips is presented. The analysis utilizes a finite difference frequency domain procedure to reduce the problem to a symmetric matrix eigenvalue problem. Since the matrix is also sparse, the eigenvalue problem can be solved quickly and efficiently using the conjugate gradient method resulting in considerable savings in computer storage and time. Comparison is made with the analytical solution for the loaded dielectric waveguide case. For the microstrip case, we get both waveguide modes and quasi-TEM modes. The quasi-TEM modes in the limit of zero frequency are checked with the static analysis which also uses finite difference. Some of the quasi-TEM modes are spurious. This article describes their origin and discusses how to eliminate them. Numerical results are presented to illustrate the principles.

关键词： Waveguides

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Visual Informatics: Bridging Research and Practice 1

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丛书名： Lecture Notes in Computer science

1000年

作者： Halimah Badioze Zaman Peter Robinson Maria Petrou Patrick Olivier Heiko Schröder Timothy K. Shih

ISBN: (数字)9783642050367

ISBN: (纸本)9783642050350

Visual informatics is a field of interest not just among the information technology and computer science community, but also other related fields such as engineering, me- cal and health informatics and education starting in the early 1990s. Recently, the field is gaining more attention from researchers and industry. It has become a mul- disciplinary and trans-disciplinary field related to research areas such as computer vision, visualization, information visualization, real-time image processing, medical image processing, image information retrieval, virtual reality, augmented reality, - pressive visual mathematics, 3D graphics, multimedia-fusion, visual data mining, visual ontology, as well as services and visual culture. Various efforts has been - vested in different research, but operationally, many of these systems are not pro- nent in the mass market and thus knowledge and research on these phenomena within the mentioned areas need to be shared and disseminated. It is for this reason that the Visual Informatics Research Group from Universiti - bangsaan Malaysia (UKM) decided to spearhead this initiative to bring together experts in this very diversified but important research area so that more concerted efforts can be undertaken not just within the visual informatics community in Malaysia but from other parts of the world, namely, Asia, Europe, Oceania, and USA. This first International Visual Informatics Conference (IVIC 2009) was conducted collaboratively, by the visual informatics research community from the various public and private institutions of higher learning in Malaysia, and hosted by UKM.

关键词： Image processing and Computer Vision Pattern Recognition Computer Graphics Artificial Intelligence Algorithm Analysis and Problem Complexity User Interfaces and Human Computer Interaction

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LINES—A discussion of some of the factors affecting the choice of a transmission line type for a specific application in Navy electronics

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Journal of the American Society for Naval Engineers 1949年第2期61卷 333-345页

作者： Harrison, Charles W. U.S.N Lieut. Comdr. Charles W. Harrison Jr. U.S.N. attended the U. S. Naval Academy Preparatory School the U. S. Coast Guard Academy and the University of Virginia where in 1939 he received the S. B. degree in engineering and in 1940 the degree of electrical engineer. In 1942 he was graduated with the S. M. degree in communication engineering from Cruft Laboratory Harvard University and that summer completed the Navy course in radar engineering at the Massachusetts Institute of Technology. From the fall of 1942 to the spring of 1944 he was engaged in lecturing to officers of the Armed Forces assigned to the radar schools at Harvard and Princeton Universities. His experience includes amateur naval and broadcast-station operation in addition to some four years of research work in the Bureau of Ships Navy Department and the U. S. Naval Research Laboratory. He is the author of several papers dealing with various phases of electronics. In 1945 Lieut Comdr. Harrison was naval liaison officer at the Evans Signal Laboratory Belmar New Jersey. In early 1946 he matriculated at Harvard to continue work on the degree of Doctor of Science in Engineering. Later in that year he reported for duty at the Philadelphia Naval Shipyard where he served as Acting Electronics Officer for approximately a year. Other assignments included duty as Electronics Planning Officer and Assistant for Shore Electronics. Lieut. Comdr. Harrison is presently attached to the Electronics Design Division Bureau of Ships. He is a member of the Harvard Chapter of Sigma Xi the American Physical Society the Institute of Radio Engineers and the Audio Engineering Society. He is registered as an electrical and radio engineer in Virginia.

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A COMPARISON OF 3 NON-LINEAR FILTERS

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AUTOMATICA 1969年第4期5卷 487-+页

作者： WISHNER, RP TABACZYNSKI, JA ATHANS, M Radar Signal Processing Group M.I.T. Lincoln Laboratory Lexington Massachusetts 02173 USA Department of Electrical Engineering Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA

This paper examines three distinct methods for the recursive estimation of the state variables of a continuous time non-linear plant on the basis of measuring the time discrete outputs of the plant in the presence of noise. The three suboptimal estimation algorithms are the Extended Kalman filter, a second-order non-linear filter, and a single stage iteration filter. The three filters are derived from the same theoretical basis in order to facilitate their comparison. Simulation results are used to compare the performance of the filters in the cases of linear plant dynamics and a non-linear output, non-linear plant dynamics and a linear output, and non-linear plant dynamics and non-linear output. We are able to conclude that the single stage iteration filter has superior mean squared error performance under all conditions, followed by the second-order filter. The second-order filter appears to be more of an unbiased estimator than the other filters. The results also show that both the single stage iteration filter and second order filter have more capability in treating non-linearities in the plant dynamics than in treating output non-linearities. Cet article examine trois méthodes distinctes d'évaluation repétitive des variables d'état d'une installation non-linéaire, en temps continu, sur la base de la mesure, en temps discret, des sorties de l'installation en présence du bruit. Les trois algorithmes suboptimaux d'évaluation sont constitués par le filtre étendu de Kalman, un filtre non-linéaire du second ordre et un filtre répétitif à un seuel étage. Les trois filtres sont déduits de la même base theorique, de manière à faciliter leur comparaison. Des résultats de simulation sont utilisées pour comparer les performances des filtres dans les cas d'une dynamique linéaire de l'installation avec une sortie non-linéaire, d'une dynamique non-linéaire de l'installation avec une sortie linéaire et d'une dynamique non-linéaire d'installation avec une sortie non-linéaire. N

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QUALITATIVE ANALYSIS OF LOOP ANTENNA BEHA VIOR IN LINEARLY AND ELLIPTICALLY POLARIZED ELECTRIC FIELDS

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Journal of the American Society for Naval Engineers 1957年第2期69卷 369-374页

作者： HARRISON, CHARLES W. COMMANDER CHARLES W. HARRISON JR. USN attended the U. S. Naval Academy Preparatory School the U. S. Coast Guard Academy and the University of Virginia where in 1939 he received the S.B. degree in Engineering and in 1940 the degree of Electrical Engineer. In 1942 he was graduated with the S.M. degree in Communication Engineering from Cruft Laboratory Harvard University and that summer completed the Navy Course in Radar Engineering at Massachusetts Institute of Technology. Subsequently for several years he was engaged in lecturing to officers of the Armed Forces assigned to the radar schools at Harvard and Princeton Universities. He has had four tours of duty in the Electronics Design and Development Division Bureau of Ships two at the U.S. Naval Research Laboratory one at the Signal Corps Engineering Laboratories (Evans Signal Laboratory) and one at the Philadelphia Naval Shipyard. His experience includes amateur naval and broadcasting operation. In 1951 Commander Harrison was selected for training in Advanced Science at Harvard University under sponsorship of the Office of Naval Research. This program led to the M. Eng. degree in 1952 and Ph.D. degree in Applied Physics in 1954. Commander Harrison is presently Electronics Officer on the Staff of Commander Operational Development Force. He is a member of several societies and associations including the Harvard Chapter of the Society of Sigma Xi.

Summary: The measurement of the magnetic field associated with a linearly or elliptically polarized electric field, using a small loop, or magnetic probe, is discussed. It is shown that in general a loop will not measure the magnetic field faithfully because the sensing element responds to the antenna modes as well as the transmission line mode excited in the loop structure by the incident electromagnetic field. A special shielded loop with two gaps was invented to eliminate or reduce the effect of the antenna modes. It is anticipated that this device will be found useful in the field of direction finding. © 1957 by the American Society of Naval Engineers, Inc.

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