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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
341

Maximum likelihood estimation of nonlinear factor analysis model using MCECM algorithm.

January 2005 (has links)
by Long Mei. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 73-77). / Abstracts in English and Chinese. / Acknowledgements --- p.iv / Abstract --- p.v / Table of Contents --- p.vii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Nonlinear Factor Analysis Model --- p.1 / Chapter 1.2 --- Main Objectives --- p.2 / Chapter 1.2.1 --- Investigation of the performance of the ML approach with MCECM algorithm in NFA model --- p.2 / Chapter 1.2.2 --- Investigation of the Robustness of the ML approach with MCECM algorithm --- p.3 / Chapter 1.3 --- Structure of the Thesis --- p.3 / Chapter 2 --- Theoretical Background of the MCECM Algorithm --- p.5 / Chapter 2.1 --- Introduction of the EM algorithm --- p.5 / Chapter 2.2 --- Monte Carlo integration --- p.7 / Chapter 2.3 --- Markov Chains --- p.7 / Chapter 2.4 --- The Metropolis-Hastings algorithm --- p.8 / Chapter 3 --- Maximum Likelihood Estimation of a Nonlinear Factor Analysis Model --- p.10 / Chapter 3.1 --- MCECM Algorithm --- p.10 / Chapter 3.1.1 --- Motivation of Using MCECM algorithm --- p.11 / Chapter 3.1.2 --- Introduction of the Realization of the MCECM algorithm --- p.12 / Chapter 3.1.3 --- Implementation of the E-step via the MH Algorithm --- p.13 / Chapter 3.1.4 --- Maximization Step --- p.15 / Chapter 3.2 --- Monitoring Convergence of MCECM --- p.17 / Chapter 3.2.1 --- Bridge Sampling Method --- p.17 / Chapter 3.2.2 --- Average Batch Mean Method --- p.18 / Chapter 4 --- Simulation Studies --- p.20 / Chapter 4.1 --- The First Simulation Study with the Normal Distribution --- p.20 / Chapter 4.1.1 --- Model Specification --- p.20 / Chapter 4.1.2 --- The Selection of System Parameters --- p.22 / Chapter 4.1.3 --- Monitoring the Convergence --- p.22 / Chapter 4.1.4 --- Simulation Results for the ML Estimates --- p.25 / Chapter 4.2 --- The Second Simulation Study with the Normal Distribution --- p.34 / Chapter 4.2.1 --- Model Specification --- p.34 / Chapter 4.2.2 --- Monitoring the Convergence --- p.35 / Chapter 4.2.3 --- Simulation Results for the ML Estimates --- p.38 / Chapter 4.3 --- The Third Simulation Study on Robustness --- p.47 / Chapter 4.3.1 --- Model Specification --- p.47 / Chapter 4.3.2 --- Monitoring the Convergence --- p.48 / Chapter 4.3.3 --- Simulation Results for the ML Estimates --- p.51 / Chapter 4.4 --- The Fourth Simulation Study on Robustness --- p.59 / Chapter 4.4.1 --- Model Specification --- p.59 / Chapter 4.4.2 --- Monitoring the Convergence --- p.59 / Chapter 4.4.3 --- Simulation Results for the ML Estimates --- p.62 / Chapter 5 --- Conclusion --- p.71 / Bibliography --- p.73
342

Estimation of the scale matrix and their eigenvalues in the Wishart and the multivariate F distribution.

January 1996 (has links)
by Wai-Yin Chan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 42-45). / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Main Problems --- p.1 / Chapter 1.2 --- Class of Regularized Estimator --- p.4 / Chapter 1.3 --- Preliminaries --- p.6 / Chapter 1.4 --- Related Works --- p.9 / Chapter 1.5 --- Brief Summary --- p.10 / Chapter Chapter 2 --- Estimation of the Covariance Matrix and its Eigenvalues in a Wishart Distribution / Chapter 2.1 --- Significance of The Problem --- p.12 / Chapter 2.2 --- Review of the Previous Work --- p.13 / Chapter 2.3 --- Properties of the Wishart Distribution --- p.18 / Chapter 2.4 --- Main Results --- p.20 / Chapter 2.5 --- Simulation Study --- p.23 / Chapter Chapter 3 --- Estimation of the Scale Matrix and its Eigenvalues in a Multivariate F Distribution / Chapter 3.1 --- Formulation and significance of the Problem --- p.26 / Chapter 3.2 --- Review of the Previous Works --- p.28 / Chapter 3.3 --- Properties of Multivariate F Distribution --- p.30 / Chapter 3.4 --- Main Results --- p.33 / Chapter 3.5 --- Simulation Study --- p.38 / Chapter Chapter 4 --- Further research --- p.40 / Reference --- p.42 / Appendix --- p.46
343

Control and estimation for large-scale systems having spatial symmetry

Wall, Joseph Edward January 1978 (has links)
Thesis. 1978. Ph.D.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Vita. / Includes bibliographical references. / by Joseph Edward Wall, Jr. / Ph.D.
344

Semianalytical satellite theory and sequential estimation

Taylor, Stephen Paul January 1982 (has links)
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Stephen Paul Taylor. / M.S.
345

Contribuições da teoria da estimação para modulações digitais que utilizam sinais caóticos. / Contributions of the estimation theory to digital modulations that use chaotic signals.

Marcio Eisencraft 17 April 2006 (has links)
Neste trabalho investiga-se o emprego de técnicas de estimação em sistemas de modulação digital que utilizam sinais caóticos. Inicialmente, aspectos básicos das teorias de sistemas não-lineares e de modulações digitais são revisitados seguidos de técnicas recentemente propostas de modulações digitais caóticas com receptores por correlação coerente, não-coerente e diferencial: o CSK (Chaos Shift Keying), o DCSK (Differential Chaos Shift Keying) e algumas de suas variantes, em especial o FM-DCSK (Frequency Modulated DCSK). Nessa descrição, utiliza-se a notação de equivalente passa-baixas de tempo discreto para facilitar a comparação com modulações digitais convencionais. Deduz-se o limite de Cramér-Rao para a estimação da condição inicial de órbitas caóticas em função de propriedades estatísticas do mapa que as gerou e descrevem-se dois estimadores para elas: o MLE (Maximum Likelihood Estimator) que se aplica a mapas com densidade invariante uniforme e o algoritmo de Viterbi para o qual se apresenta uma generalização a fim de aplicá-lo a uma classe maior de mapas. Por apresentar ganho de estimação maior na faixa de relação sinal-ruído de interesse, este último é utilizado em propostas de sistemas de modulação digital que utilizam estimação de órbitas para detectar o símbolo enviado: o ML-CSK (Maximum Likelihood CSK) modificado para poder usar mapas com densidade invariante não-uniforme, empregando um ou dois mapas e o ML-DCSK (Maximum Likelihood DCSK). Por simulação, avaliou-se o desempenho em termos de taxa de erro desses sistemas sob ruído branco aditivo gaussiano. / In this work, we investigate the use of estimation techniques to digital modulation systems that use chaotic signals. Initially, basic aspects of nonlinear systems and digital modulation theory are reviewed followed by currently proposed techniques of chaotic digital modulation with coherent, noncoherent and differential correlation receivers: CSK (Chaos Shift Keying), DCSK (Differential Chaos Shift Keying) and some of its variants in special FM-DCSK (Frequency Modulated DCSK). These systems are described using a discrete-time lowpass equivalent model to facilitate comparison with conventional digital modulation systems. We derive Cramér-Rao lower bounds for the estimation of the initial condition of chaotic orbits as a function of the statistical properties of the chaos generating map and describe two chaotic orbits estimators: the MLE (Maximum Likelihood Estimator) that applies only to maps with uniform invariant density and the Viterbi algorithm for which a generalization is presented that allows its application to a broader class of maps. Because of the larger estimation gains attained in the signal-to-noise ratio range of interest, the latter is used in proposed digital modulation systems that use orbit estimation to detect the transmitted symbol: ML-CSK (Maximum Likelihood CSK) modified to allow maps with nonuniform invariant density using one map or two maps and ML-DCSK (Maximum Likelihood DCSK). The performance of these systems in terms of symbol error rate is accessed via simulation under additive white gaussian noise perturbations.
346

Hypothesis, estimation, and validation of dynamic social models : energy demand modeling.

Peterson, David Walter January 1975 (has links)
Thesis. 1975. Ph.D.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / Vita. / Bibliography: leaves 121-125. / Ph.D.
347

Median-unbiased estimation in linear autoregressive time series models

Chen, Donghui, 1970- January 2001 (has links)
Abstract not available
348

Robust state estimation and model validation techniques in computer vision

Al-Takrouri, Saleh Othman Saleh, Electrical Engineering & Telecommunications, Faculty of Engineering, UNSW January 2008 (has links)
The main objective of this thesis is to apply ideas and techniques from modern control theory, especially from robust state estimation and model validation, to various important problems in computer vision. Robust model validation is used in texture recognition where new approaches for classifying texture samples and segmenting textured images are developed. Also, a new model validation approach to motion primitive recognition is demonstrated by considering the motion segmentation problem for a mobile wheeled robot. A new approach to image inpainting based on robust state estimation is proposed where the implementation presented here concerns with recovering corrupted frames in video sequences. Another application addressed in this thesis based on robust state estimation is video-based tracking. A new tracking system is proposed to follow connected regions in video frames representing the objects in consideration. The system accommodates tracking multiple objects and is designed to be robust towards occlusions. To demonstrate the performance of the proposed solutions, examples are provided where the developed methods are applied to various gray-scale images, colored images, gray-scale videos and colored videos. In addition, a new algorithm is introduced for motion estimation via inverse polynomial interpolation. Motion estimation plays a primary role within the video-based tracking system proposed in this thesis. The proposed motion estimation algorithm is also applied to medical image sequences. Motion estimation results presented in this thesis include pairs of images from a echocardiography video and a robot-assisted surgery video.
349

Volatility estimation and price prediction using a hidden Markov model with empirical study

Yin, Pei, January 2007 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on December 18, 2007) Vita. Includes bibliographical references.
350

The estimation of the cylindrical wave reflection coefficient

January 1982 (has links)
by Andrew Loris Kurkjian. / Originally published as thesis (Dept. of Electrical Engineering and Computer Science, Ph.D., 1982). / Bibliography: p. 186-189. / Supported in part by the Advanced Research Projects Agency monitored by ONR under Contract N00014-81-K-0742 NR-049-506 Supported in part by the National Science Foundation under Grant ECS80-07102

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