This thesis aims to develop an understanding about swelling and disintegration of multi-component polymeric structures such as pharmaceutical tablets. The thesis presents a model for the diffusion-driven water uptake, swelling deformation and subsequent disintegration of polymer matrix drug-delivery devices. Hygroscopic swelling occurs when a dry tablet enters a humid environment and absorbs water molecules. The modification of tablet structures changes the release profile of the drug in the desired manner. The previous research mostly focused on transport problems related to drug release. This study contributes an understanding of the mechanical behaviour of hydrophilic polymer release matrix materials which are treated as continuum. Modelling of the swelling problem involves concurrent large deformation of the polymer network and diffusion of the solvent through the network. A coupled diffusion-deformation model was created to study the relation between both physics. The coupled diffusion-deformation model was utilised to consider disintegration of polymer matrix through the inclusion of swelling agents. Two cases were presented to illustrate the application of the model: swelling-controlled and immediate-release drug delivery systems. This study used COMSOL Multiphysics®, a finite element commercial software to perform the analysis. Various physical modules: structural mechanics, chemical transport and mathematics were combined for solving coupled diffusion-deformation-damage boundary value problems. The numerical results were validated using existing experimental data from the literature. The model parameters were varied to investigate their sensitivity to the solution. Higher solvent concentration gradient in the matrix produced higher swelling strain, thus increased local stress. Disintegrability was measured by the time taken for the maximum principal stress to reach a given failure. Higher coefficient of water diffusion allows higher amount of water ingression into the matrix. Higher coefficient of hygroscopic swelling generates higher local swelling strain. This study facilitates in understanding the complex phenomena in the application of drug release formulation.

Recent experimental and theoretical studies have found evidence of coupled interactions between magnons and phonons. The aim of this study is to construct a model of coupled magnons and phonons, as well as analysing their frequency spectrum. The model is derived by quantizing spin and lattice degrees of freedom, and the frequency spectrum is derived by solving the equations of motion. We found that both the strength and the composition of the coupled interactions affect the frequencies of magnons and phonons, with emphasis on the magnons. Their frequencies are imaginary close to the center of the Brillouin zone, which opens questions for future research.

Li Xin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 81-86). / Abstracts in English and Chinese. / COHERENT OPTICAL CODE DIVISION MULTIPLE ACCESS BASED ON SUPERSTRUCTURE FIBER BRAGG GRATING ENCODERS AND DECODERS --- p.1 / ACKNOWLEDGEMENT --- p.2 / ABSTRACT --- p.III / 摘要 --- p.V / CONTENTS --- p.VI / LIST OF FIGURES --- p.1 / Chapter CHAPTER 1 --- INTRODUCTION --- p.3 / Chapter 1.1 --- Overview of OCDMA --- p.3 / Chapter 1.2 --- Classification of OCDMA Schemes --- p.6 / Chapter 1.3 --- Introduction of Coherent OCDMA Schemes --- p.9 / Chapter 1.4 --- Introduction of superstructure Fiber Bragg Gratings and Other Encoding and Decoding Components --- p.10 / Chapter 1.5 --- Outline of the Thesis --- p.13 / Chapter CHAPTER 2 --- COUPLED MODE THEORY AND SUPERSTRUCTURE FIBER BRAGG GRATING SIMULATION MODEL --- p.16 / Chapter 2.1 --- Fiber Bragg Grating Model Based on Coupled Mode Theory --- p.16 / Chapter 2.1.1 --- Introduction of FBG and the Coupled Mode Theory --- p.16 / Chapter 2.1.2 --- FBG Model Based on CMT --- p.18 / Chapter 2.1.3 --- FBG Model When there are Phase Discontinuities Between Different Parts --- p.20 / Chapter 2.2 --- Properties of Fiber Bragg Gratings --- p.22 / Chapter 2.3 --- Simulation Model of superstructure Fiber Bragg Gratings --- p.27 / Chapter 2.4 --- Summary --- p.31 / Chapter CHAPTER 3 --- COHERENT OCDMA CODING SCHEME BASED ON THE SUPERSTRUCTURE FIBER BRAGG GRATING ENCODER/DECODER --- p.33 / Chapter 3.1 --- Introduction and Theoretical Derivation of the Coding Scheme --- p.33 / Chapter 3.1.1 --- Introduction of the Coding Scheme --- p.33 / Chapter 3.1.2 --- Derivation of SSFBG Encoder --- p.34 / Chapter 3.1.3 --- Encoding for the SSFBG --- p.39 / Chapter 3.2 --- Introduction of the Simulation Model and the Research on It …… --- p.44 / Chapter 3.3 --- Summary --- p.47 / Chapter CHAPTER 4 --- RESEARCH ON THE SIMULATED COHERENT OCDMA SYSTEM IN IDEAL CASE --- p.48 / Chapter 4.1 --- Introduction of the ideal case and factors that affect the system performance --- p.48 / Chapter 4.2 --- Effects by Refractive Index Modulation of the SSFBG Encoder --- p.49 / Chapter 4.3 --- Effects by Code Type --- p.54 / Chapter 4.4 --- Effect by the Code Length --- p.57 / Chapter 4.5 --- Summary --- p.60 / Chapter CHAPTER 5 --- RESEARCH ON THE SIMULATED COHERENT OCDMA SYSTEM IN PRACTICAL ENVIRONMENT --- p.62 / Chapter 5.1 --- Introduction --- p.62 / Chapter 5.2 --- Comparison of System Performance in Synchronous and Asynchronous Cases --- p.63 / Chapter 5.3 --- Discussion on the System Performance When Users are In Different Power Levels --- p.65 / Chapter 5.4 --- Analysis of Channel Noise In the Coherent OCDMA System --- p.68 / Chapter 5.5 --- Summary --- p.70 / Chapter CHAPTER 6 --- CONCLUSIONS AND FUTURE WORK --- p.72 / Chapter 6.1 --- Conclusions --- p.72 / Chapter 6.2 --- Future Work --- p.75 / APPENDIX A PROOF OF SSFBG THEORETICAL MODEL APPROXIMATION --- p.77 / "APPENDIX B RANDOM SEQUENCE, M-SEQUENCE AND WALSH SEQUENCE" --- p.80 / REFERENCES --- p.81

In this thesis, we present a dynamical systems analysis of models of movement coordination, namely the Haken-Kelso-Bunz (HKB) model and the Jirsa-Kelso excitator (JKE). The dynamical properties of the models that can describe various phenomena in discrete and rhythmic movements have been explored in the models' parameter space. The dynamics of amplitude-phase approximation of the single HKB oscillator has been investigated. Furthermore, an approximated version of the scaled JKE system has been proposed and analysed. The canard phenomena in the JKE system has been analysed. A combination of slow-fast analysis, projection onto the Poincare sphere and blow-up method has been suggested to explain the dynamical mechanisms organising the canard cycles in JKE system, which have been shown to have different properties comparing to the classical canards known for the equivalent FitzHugh-Nagumo (FHN) model. Different approaches to de fining the maximal canard periodic solution have been presented and compared. The model of two HKB oscillators coupled by a neurologically motivated function, involving the effect of time-delay and weighted self- and mutual-feedback, has been analysed. The periodic regimes of the model have been shown to capture well the frequency-induced drop of oscillation amplitude and loss of anti-phase stability that have been experimentally observed in many rhythmic movements and by which the development of the HKB model has been inspired. The model has also been demonstrated to support a dynamic regime of stationary bistability with the absence of periodic regimes that can be used to describe discrete movement behaviours.

G蛋白偶聯雌激素受體（GPER，又名GPR30）乃最近於各種動物包括小鼠、大鼠、人類及斑馬魚中發現之新型跨膜雌激素受體。 GPER表達於脂肪組織及多種器官之中，其已被證明能與雌激素結合並介導各式快速反應及基因轉錄。針對GPER於成脂作用中角色之研究將達致對雌激素作用之更全面了解，且GPER亦有望成為治療肥胖症之一種新型標靶。 / 脂肪發育調控乃一複雜且精妙之排程，而雌激素已被證明能抑制脂肪形成，是故雌激素替代療法可舒減絶經後婦女之脂肪代謝問題。此項研究發現GPER於小鼠腹部脂肪組織及小鼠前脂肪細胞系3T3-L1中均有表達，且其信使RNA量於受誘導之3T3-L1成脂作用中錄得上調。 / 3T3-L1細胞分化作用會被名為G1之特異性GPER激動劑阻撓於克隆擴增階段（MCE），此即表明GPER有參與成脂調控之可能。通過油紅O染色發現，受G1處理之3T3-L1細胞於分化後所產生之油滴量實比其對照組為低，但此一效果能被特異性GPER小干擾RNA預處理抹除。另外，本研究以流式細胞儀及西方墨點法對細胞週期及細胞週期因子進行分析後，認為激活GPER能觸發對G1期細胞週期停滯之抑制。另一方面，受G1處理並分化中之3T3-L1細胞出現蛋白激酶B磷酸化效應，意味雌激素與GPER結合對成脂作用有雙向調節之可能性。 / 總而言之，本研究結果斷定GPER能介導雌激素對脂肪組織發育之影響，並為成脂作用之負調節因子，故此，一系列成果將有助肥胖症藥物之研發。 / A novel transmembrane estrogen receptor, G-protein coupled estrogen receptor (GPER, also known as GPR30), is recently identified in various animals including mouse, rat, human and zebrafish. GPER is expressed in many organs including fatty tissues, and has been demonstrated to mediate various rapid responses and transcriptional events upon estrogen binding. The study on the role of GPER in adipogenesis would lead to a more comprehensive understanding of estrogenic actions, with the view of identifying novel therapeutic targets for the treatment of obesity. / Regulation of adipose development is a complex and subtly orchestrated process. Estrogen has been shown to inhibit adipogenesis. Estrogen replacement therapy therefore affects fat metabolism in post-menopausal women. In this study, GPER is identified in mouse abdominal fatty tissues; and there is an up-regulation of GPER in the mouse preadipocyte cell line 3T3-L1 during induced adipogenesis. / Differentiation of 3T3-L1 cells is perturbed by the selective GPER agonist G1 at mitotic clonal expansion (MCE), indicating a possible involvement of GPER in the regulation of adipogenesis. By means of Oil-Red-O staining, the production of oil droplets in the G1-treated, differentiated 3T3-L1 cells is shown to be lower than the untreated control; and such effect is reversed by a specific siRNA knockdown of GPER. FACS analysis and Western blot analysis of cell cycle factors during MCE suggest that GPER activation triggers an inhibition of cell cycle arrest at the G1 stage. On the other hand, phosphorylation of Akt in G1-treated differentiating cells implies a possibility of bi-directional estrogenic regulation of adipogenesis via GPER. / To conclude, it is postulated that GPER mediates estrogenic actions in adipose tissues as a negative regulator of adipogenesis. These results provide insights into the development of therapeutic agents for the treatment of human obesity. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Yuen, Man Leuk. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 144-166). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Abstract (English version) --- p.I / Abstract (Chinese version) --- p.III / Acknowledgement --- p.V / Table of Contents --- p.VII / List of Abbreviations --- p.XI / List of Tables --- p.XII / List of Figures --- p.XIII / Chapter Chapter 1: --- Introduction --- p.1 / Chapter 1.1. --- Obesity and adipose tissue --- p.1 / Chapter 1.1.1. --- Obesity --- p.1 / Chapter 1.1.2. --- Fat deposition --- p.3 / Chapter 1.1.3. --- Origin and development of white adipose tissue --- p.5 / Chapter 1.2. --- Adipogenesis --- p.7 / Chapter 1.2.1. --- Origins of white adipocytes --- p.7 / Chapter 1.2.2. --- Signals for adipogenesis --- p.10 / Chapter 1.2.3. --- Regulation of gene expression during adipogenesis --- p.12 / Chapter 1.2.4. --- Common adipose cell lines --- p.16 / Chapter 1.2.5. --- Mechanism of in vitro adipogenesis --- p.21 / Chapter 1.2.5.1. --- Growth arrest --- p.23 / Chapter 1.2.5.2. --- Mitotic clonal expansion --- p.23 / Chapter 1.2.5.3. --- Early and terminal differentiation --- p.24 / Chapter 1.3. --- Estrogen and adipogenesis --- p.28 / Chapter 1.4. --- G-protein coupled estrogen receptor-1 --- p.33 / Chapter 1.4.1. --- General introduction of GPER --- p.33 / Chapter 1.4.2. --- Ligands of GPER --- p.36 / Chapter 1.4.3. --- Cellular signaling of GPER --- p.38 / Chapter 1.4.4. --- Metabolic actions of GPER: A brief introduction --- p.43 / Chapter 1.4.5. --- Metabolic actions of GPER on obesity and glucose metabolism --- p.48 / Chapter 1.4.6. --- Study objectives --- p.53 / Chapter Chapter 2: --- Expression profiles and cellular localization of Gper/GPER in mouse adipose, 3T3-L1 preadipocytes and 3T3-L1 mature adipocytes --- p.54 / Chapter 2.1. --- Introduction --- p.54 / Chapter 2.1.1. --- Expression and functional roles of GPER in adipose. --- p.55 / Chapter 2.1.2. --- Swiss mouse preadipocytes 3T3-L1 --- p.57 / Chapter 2.1.3. --- Study objectives --- p.57 / Chapter 2.2. --- Materials and Methods --- p.59 / Chapter 2.2.1. --- Reagents --- p.59 / Chapter 2.2.2. --- Animal tissues --- p.59 / Chapter 2.2.3. --- Cell culture --- p.60 / Chapter 2.2.4. --- Reverse transcription polymerase chain reaction (RT-PCR) --- p.62 / Chapter 2.2.5. --- Quantitative real-time RT-PCR (qRT-PCR) --- p.66 / Chapter 2.2.6. --- SDS-PAGE and Western blot analysis --- p.68 / Chapter 2.2.7. --- Immunofluorescence assay --- p.69 / Chapter 2.2.8. --- Statistical analysis --- p.70 / Chapter 2.3. --- Results --- p.71 / Chapter 2.3.1. --- Expression of Gper/GPER in mouse visceral adipose tissues --- p.72 / Chapter 2.3.2. --- Expression profiles of Gper/GPER in undifferentiated 3T3-L1 preadipocytes and differentiated 3T3-L1 adipocytes --- p.73 / Chapter 2.3.3. --- Cellular localization of GPER in undifferentiated 3T3-L1 preadipocytes and differentiated 3T3-L1 adipocytes --- p.75 / Chapter 2.4. --- Discussion --- p.76 / Chapter Chapter 3: --- Rapid cellular responses induced by GPER activation in 3T3-L1 preadipocytes --- p.78 / Chapter 3.1. --- Introduction --- p.78 / Chapter 3.1.1. --- Rapid cellular response of estrogen via GPER --- p.79 / Chapter 3.1.2. --- Study objectives --- p.81 / Chapter 3.2. --- Materials and Methods --- p.82 / Chapter 3.2.1. --- Reagents --- p.82 / Chapter 3.2.2. --- Cell culture --- p.82 / Chapter 3.2.3. --- SDS-PAGE and Western blot analysis --- p.83 / Chapter 3.2.4. --- Statistical analysis --- p.84 / Chapter 3.3. --- Results --- p.86 / Chapter 3.3.1. --- Phosphorylation of p44/42 MAPK after time-dependent activation of GPER by ICI182,780 and G1 --- p.87 / Chapter 3.3.2. --- Phosphorylation of p44/42 MAPK after dose-dependent activation of GPER by a combination of chemical agents --- p.88 / Chapter 3.4. --- Discussion --- p.89 / Chapter Chapter 4: --- GPER activation on cell viability of 3T3-L1 preadipocytes --- p.90 / Chapter 4.1. --- Introduction --- p.90 / Chapter 4.1.1. --- Cell proliferation mediated by GPER --- p.90 / Chapter 4.1.2. --- Study objectives --- p.92 / Chapter 4.2. --- Materials and Methods --- p.93 / Chapter 4.2.1. --- Reagents --- p.93 / Chapter 4.2.2. --- Cell culture --- p.93 / Chapter 4.2.3. --- MTT assay for cell viability --- p.94 / Chapter 4.2.4. --- Statistical analysis --- p.95 / Chapter 4.3. --- Results --- p.96 / Chapter 4.3.1. --- Cell viability of 3T3-L1 after dose-dependent activation of GPER by 17β-estradiol, ICI182,780 and G1 --- p.97 / Chapter 4.4. --- Discussion --- p.99 / Chapter Chapter 5: --- GPER-mediated estrogenic action on lipid accumulation in the mature 3T3-L1 adipocytes --- p.101 / Chapter 5.1. --- Introduction --- p.101 / Chapter 5.1.1. --- Induction of differentiation in Swiss mouse preadipocyte 3T3-L1 --- p.101 / Chapter 5.1.2. --- Study objectives --- p.102 / Chapter 5.2. --- Materials and Methods --- p.103 / Chapter 5.2.1. --- Reagents --- p.103 / Chapter 5.2.2. --- Cell culture --- p.103 / Chapter 5.2.3. --- Oil-Red-O staining and measurement of absorbance --- p.105 / Chapter 5.2.4. --- Knockdown of Gper/GPER by siRNA --- p.107 / Chapter 5.2.5. --- Reverse transcription polymerase chain reaction (RT-PCR) --- p.110 / Chapter 5.2.6. --- SDS-PAGE and Western blot analysis --- p.110 / Chapter 5.2.7. --- Statistical analysis --- p.110 / Chapter 5.3. --- Results --- p.112 / Chapter 5.3.1. --- GPER activation on 3T3-L1 differentiation --- p.114 / Chapter 5.3.2. --- Knockdown of Gper/GPER in Swiss mouse preadipocyte 3T3-L1 --- p.114 / Chapter 5.3.3. --- Phosphorylation of p44/42 MAPK in Gper/GPER-knockdown 3T3-L1 after time-dependent activation of GPER by G1 --- p.117 / Chapter 5.3.4. --- Action of drugs on differentiation of Gper/GPER-knockdown 3T3-L1 --- p.117 / Chapter 5.4. --- Discussion --- p.118 / Chapter Chapter 6: --- Role of GPER in regulating cell cycle progression during mitotic clonal expansion (MCE) stage in adipogenesis of 3T3-L1 --- p.120 / Chapter 6.1. --- Introduction --- p.120 / Chapter 6.1.1. --- Differentiation stages of Swiss mouse preadipocyte 3T3-L1 --- p.121 / Chapter 6.1.2. --- Apoptosis and cell cycle progression --- p.122 / Chapter 6.1.3. --- Study objectives --- p.126 / Chapter 6.2. --- Materials and Methods --- p.127 / Chapter 6.2.1. --- Reagents --- p.127 / Chapter 6.2.2. --- Cell culture --- p.127 / Chapter 6.2.3. --- Oil-Red-O staining and measurement of absorbance --- p.129 / Chapter 6.2.4. --- Trypan blue exclusion assay for cell viability determination --- p.129 / Chapter 6.2.5. --- SDS-PAGE and Western blot analysis --- p.131 / Chapter 6.2.6. --- Flow cytometry for analysis of cell cycle progression --- p.132 / Chapter 6.2.7. --- Statistical analysis --- p.133 / Chapter 6.3. --- Results --- p.134 / Chapter 6.3.1. --- Temporal effect of GPER activation on differentiation progress of Swiss mouse preadipocyte 3T3-L1 --- p.137 / Chapter 6.3.2. --- Effect of GPER activation on cell viability during adipogenesis --- p.139 / Chapter 6.3.3. --- Effect of GPER activation on apoptosis during adipogenesis --- p.139 / Chapter 6.3.4. --- Effect of GPER activation on cell cycle distribution during induced adipogenesis --- p.140 / Chapter 6.3.5. --- Effect of GPER activation on expression of cell cycle markers during induced adipogenesis --- p.142 / Chapter 6.3.6. --- Activation of PI3K/Akt pathway by GPER stimulation during induced adipogenesis --- p.143 / Chapter 6.4. --- Discussion --- p.144 / Chapter Chapter 7: --- Conclusions and Future Perspectives --- p.148 / References --- p.155

Ectopic and over-expression of G protein-coupled receptor (GPCR) have been reported to induce tumor formation. Mas protein is a member of GPCR family and was originally isolated from human epidermoid carcinoma. It was demonstrated that mas mRNA was abundantly expressed in human and rat brains by in situ hybridization and RNase protection assays. However, cellular mechanism that leads to such tumorigenic transformation is still an open question. / In order to identify the cellular mechanism of mas-induced tumor formation, a full-length mas cDNA was cloned into a mammalian expression vector pFRSV with dihydrofolate reductase gene as a selection marker. Detailed analyses of mas-transfected cell lines by Southern blot, Northern blot and tumorigenicity assay indicated that tumorigenicity of mas-transfected cells depended on the sites of chromosomal integration and the levels of mas expression. These results suggest that overexpression of mas is not sufficient to induce tumor formation. In line with the ability of mas-transfected cells Mc0M80 to form solid tumor in nude mice, MTT cell proliferation assay indicated that the mas-transfected cells Mc0M80 proliferated faster than vector-transfected cells. Moreover, mas-transfected cells Mc0M80 exhibited significantly increased anchorage-independent growth. Furthermore, mas-transfected cells Mc0M80 showed higher percentage cells in G2/M phase but lower in S-phase in comparison with vector-transfected cells. / Interestingly, Southern blot analysis of individual xenografted tumor tissue indicated that tumor was composed of cells not only derived from injected mas-transfected CHO cells but also cells from mouse tissues. The presence of mouse stromal cells in the tumor was confirmed by immunohistochemistry and in situ hybridization. Previously our laboratory had identified some up- and down-regulated genes in mas-transfected cells by fluorescent differential display (FluoroDD). Northern blot showed that these differential expressed genes were up- or down-regulated in mas-transfected cells and tumor samples, which might play an important role in cancerous growth. / Taken together, these results suggest that over-expression of GPCR mas up-regulated tumor-related genes, resulting in promoting excessive cell growth and tumorigenic transformation. In addition, when the tumor mass formed they secreted some growth factor(s) which altered the migration of mouse stromal cells into tumor mass. The interactions of transformed cells and stromal cells further aggravate the tumorigenicity process. / To complement our fluorescent differential display study and to compare changes of gene expression when transformed cells were exposed to the microenvironment in nude mice, protein expression profiles of mas over-expressing cells as well as tumor tissues were analyzed by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry. The 2D-PAGE analysis showed that a similar but distinct protein expression profiles in mas-transfected cells and in mas-induced tumor. Mass spectrometry analysis identified several cancerous growth-related proteins and they are involved in processes such as cell signaling, energy metabolism, transcription and translation and cytoskeleton organization. / Lin Wenzhen. / "December 2005." / Adviser: Cheung Wing Tai. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6381. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 222-240). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Bikkavilli Rama Kamesh. / "August 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (p. 212-223) / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1981. / Microfiche copy available in Archives and Barker. / Includes bibliographical references. / by Steven James Hollowell. / M.S.

As Redes Neurais Pulsadas são objeto de intensa pesquisa na atualidade. Neste trabalho é avaliado o potencial de aplicação deste paradigma neural, na tarefa de reconhecimento automático do locutor. Após uma revisão dos tópicos considerados importantes para o entendimento do reconhecimento automático do locutor e das redes neurais artificiais, é realizada a implementação e testes do modelo de neurônio com resposta por impulsos. A partir deste modelo é proposta uma nova arquitetura de rede com neurônios pulsados para a implementação de um sistema de reconhecimento automático do locutor. Para a realização dos testes foi utilizada a base de dados Speaker Recognition v1.0, do CSLU – Center for Spoken Language Understanding do Oregon Graduate Institute - E.U.A., contendo frases gravadas a partir de linhas telefônicas digitais. Para a etapa de classificação foi utilizada uma rede neural do tipo perceptron multicamada e os testes foram realizados no modo dependente e independente do texto. A viabilidade das Redes Neurais Pulsadas para o reconhecimento automático do locutor foi constatada, demonstrando que este paradigma neural é promissor para tratar as informações temporais do sinal de voz. / Pulsed Neural Networks have received a lot of attention from researchers. This work aims to verify the capability of this neural paradigm when applied to a speaker recognition task. After a description of the automatic speaker recognition and artificial neural networks fundamentals, a spike response model of neurons is tested. A novel neural network architecture based on this neuron model is proposed and used in a speaker recognition system. Text dependent and independent tests were performed using the Speaker Recognition v1.0 database from CSLU – Center for Spoken Language Understanding of Oregon Graduate Institute - U.S.A. A multilayer perceptron is used as a classifier. The Pulsed Neural Networks demonstrated its capability to deal with temporal information and the use of this neural paradigm in a speaker recognition task is promising.

L'étude porte sur les propriétés spectrales et spatiales de structures à réseaux résonants. Les réseaux résonants en cavité sont identifiés comme des structures permettant la réalisation de réflecteurs et de coupleurs efficaces sur de petites dimensions. Un modèle basé sur la théorie des modes couplés a été développé permettant la modélisation et la conception rapide de ce type de structures. La modélisation a contribué à la compréhension des propriétés spectrales et spatiales de réseaux résonants en cavité. Elle permet notamment de faire le lien entre les propriétés spectrales et spatiales des modes pouvant interagir efficacement avec les structures utilisées comme réflecteurs ou coupleurs. La conception de structures couplantes à fort facteur de qualité et aux profils spatiaux contrôlés sur des surfaces de l'ordre du cm a été étudiée. Deux axes de recherches sont présentés: des structures composées de plusieurs cavités et des structures possédant une seule grande cavité. Ce dernier axe permet une plus grande maîtrise des propriétés spatiales en intensité et en phase. Il est démontré que ces structures ont un fort potentiel en holographie. La conception de telles structures avec des matériaux de bas indice est également abordée, en particulier la conception et la réalisation de guides d'onde en polymères qui sont la base de ces structures. Les dimensionnements déterminés par la modélisation sont compatibles avec des matériaux présentant de faibles sauts d'indice. / The study is focused on the spectral and spatial properties of resonant grating structures. Resonant gratings in cavity are identified as structures allowing the fabrication of small-area and efficient reflectors and couplers. A model based on coupled mode theory has been developped, enabling fast modeling and design of this kind of structures. Thanks to this model we improved our understanding of the spectral and spatial properties of resonant gratings in cavity. In particular, we have established the relationship between the structure's geometry and the spectral and spatial properties of the modes which efficiently interact with the structures when used as reflectors or as couplers. The design of coupling structures with high-quality factor and controlled spatial profiles on cm-sized surfaces has been studied. Two axis of research are presented: structures composed of several cavities and structures composed by one large cavity. The later ones allow a better control of the spatial properties both in intensity and phase. We demonstrate that these structures have a high potential for holography. Design of such structures with low contrast index is also considered, particularly the design and fabrication of polymer-based waveguiding structures.