Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains viii, 58 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 55-58).

Two brain segmentation approaches based on Hidden Markov Models are proposed. The first approach aims to segment normal brain 3D multi-channel MR images into three tissues WM, GM, and CSF. Linear Discriminant Analysis, LDA, is applied to separate voxels belonging to different tissues as well as to reduce their features vector size. The second approach aims to detect MS lesions in Brain 3D multi-channel MR images and to label WM, GM, and CSF tissues. Preprocessing is applied in both approaches to reduce the noise level and to address sudden intensity and global intensity correction. The proposed techniques are tested using 3D images from Montereal BrainWeb data set. In the first approach, the results were numerically assessed and compared to results reported using techniques based on single channel data and applied to the same data sets. The results obtained using the multi channel HMM-based algorithm were better than the results reported for single channel data in terms of an objective measure of overlap, Dice coefficient, compared to other methods. In the second approach, the segmentation accuracy is measured using Dice coefficient and total lesions load percentage

This thesis presents a method to investigate the extent to which articulatory based acoustic features can be exploited to reduce ambiguity in automatic speech recognition search. The method proposed is based on a lattice re-scoring paradigm implemented to integrate articulatory based features into automatic speech recognition systems. Time delay neural networks are trained as feature detectors to generate feature streams over which hidden Markov models (HMMs) are defined. These articulatory based HMMs are combined with HMMs defined over spectral energy based Mel frequency cepstrum coefficient (MFCC) acoustic features through a sequential lattice re-scoring procedure. The optimum phone strings are found by maximizing the log-linear combination of acoustic and language models likelihoods during recognition. The associated log-linear weights are estimated using a discriminative model combination approach. All the experiments are performed using the DARPA TIMIT speech database and the results are presented in terms of phone accuracies.

Thesis (Ph. D.)--University of Wyoming, 2005. / Title from PDF title page (viewed on March 10, 2008). Includes bibliographical references (p. 107-111).

Thesis (M.Eng.(Mechanical Engineering))--University of Pretoria, 2004. / Summaries in Afrikaans and English. Includes bibliographical references (leaves 80-82).

Thesis (M.S. in Operations Research)--Naval Postgraduate School, June 2010. / Thesis Advisor(s): Kress, Moshe ; Szechtman, Roberto ; Second Reader: Atkinson, Michael. "June 2010." Description based on title screen as viewed on July 14, 2010. Author(s) subject terms: Lebanese Hizbullah; Lebanese Diaspora; Lebanon; Markov Decision Process; Dynamic Bayesian Network; Hidden Markov Models; Decision Analysis; Decision Theory; Decision Tree; State Tree; Influence Diagram; GeNIe; Stakeholder; State Space; Rational Actor; Action; Interest; Distribution; Forecast. Includes bibliographical references (p. 65). Also available in print.

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Wireless has proved to be one of the most important and fastest growing fields of communications especially during last few decades. To achieve reliable communication, we model a wireless system to analyze its performance and to find ways to improve the reliability of a particular system. Extensive research is being done to accurately model wireless systems, and to achieve better performance. Simulation techniques have been in use for many years to support the design and evaluation of electronic communication systems. Over the past few decades, Computer Aided Design (CAD) techniques (including both computerized analytical techniques and simulation) have matured, and are now usually applied at some point in the system design/development process. The aim of this thesis is to find efficient algorithms that can model third generation wireless channels in a discrete sense. For modeling these channels, mathematical tools known as hidden Markov models are used. These models have proved themselves to be very efficient in many areas of electrical engineering including speech recognition, pattern recognition, artificial intelligence, wavelets and queuing theory. Wideband Code Division Multiple Access (W-CDMA) wireless communication parameters including channels fading statistics, Bit Error Rate (BER) performance and interval distribution of errors are modeled using different Markov models, and their results are tested and validated. Four algorithms for modeling error sources are implemented, and their results are discussed. Both hidden Markov models and semi-hidden Markov models are used in this thesis, and their results are validated for the W-CDMA environment. The state duration distributions for these channels are also approximated using Phase-Type (PH) distribution. / Master of Science