Dans un contexte de densification des villes et de leurs réseaux de transport, les gens sont de plus en plus exposés au bruit. Ainsi, le résultat de l'étude d'impact vibro-acoustique joue un rôle primordial dans l'expansion du réseau ferroviaire. L'une des principales sources est le bruit de roulement : La rugosité de la surface de la roue et du rail produit un déplacement imposé sur ces derniers. Ce déplacement entraine une réponse vibratoire des roues et de la voie ferrée et leurs rayonnements acoustiques. Cette thèse propose une amélioration de la modélisation vibro-acoustique de la voie ferrée.Pour la réponse vibratoire, le coté infini de la voie et sa déformation dans les 3 dimensions rendent les modèles analytiques et les éléments finis non-optimales dans la gamme de fréquence de l’audible. La méthode élément fini semi-périodique (SAFEM) est utilisée dans cette thèse pour modéliser une voie à support continue. Elle est ensuite couplée au théorème de Floquet pour modéliser une voie à support périodique. Cependant, cette technique génère des problèmes numériques qui ont imposé un algorithme adapté. La méthode d'Arnoldi du second ordre (SOAR) est utilisée avant de résoudre l'équation SAFEM permet de résoudre ces problèmes ainsi qu’apporter la stabilité requise. Des comparaisons avec d’autres modèles et des données expérimentales permettent de valider la méthode.Pour le rayonnement acoustique, la simulation de grand domaine en haute fréquence rendent inadapté l'utilisation de techniques conventionnelles (FEM, BEM, ...). La méthode proposée ici : la théorie variationnelle du rayon complexe est particulièrement bien adaptée à ce cas. Les principales caractéristiques de l'approche VTCR sont l'utilisation d'une formulation faible du problème acoustique, qui permet de considérer automatiquement les conditions limites entre sous-domaines. Ensuite, l'utilisation d'une répartition intégrale des ondes planes dans toutes les directions permet de simuler le champ acoustique. Les inconnues du problème sont leurs amplitudes. Cette méthode qui a déjà montré son efficacité pour les domaines fermés a été étendue au domaine ouvert et couplée à la réponse vibratoire. Des comparaisons avec des solutions analytiques et des simulations FEM à basse fréquence permettent de valider la méthode. / In a context of urban and transport network densification, people are increasingly exposed to noise. Consequently, the result of vibro-acoustic impact assessment has a pivotal role in rail network expansion. One of the main sources is the rolling noise: Roughness on the wheel and rail surface produce an imposed displacement one the both. This last, generates vibrational response of wheels and the railway track and their acoustic radiation. This PhD thesis presents some improvements of the vibro-acoustic railway track modelling.Concerning vibrational response, the infinite dimension in the longitudinal direction of the track and its deformation in the 3 dimensions, make the analytical models and finite elements non-optimal. The Semi-analytical finite element method (SAFEM), used in this thesis, is particularly well adapted in this case. Firstly, it is used to model railway track on a continuous support. Then, it is coupled with Floquet theorem to model tracks with a periodic support. However, this technique suffers from numerical problems that imposed an adapted algorithm. The second-order Arnoldi method (SOAR) is used to tackle them. This reduction allows to eliminate critical values improving the robustness of the method. Comparison with existing techniques and experimental results validate this model.Concerning acoustic radiation, big domains simulations at high frequency are almost unfeasible when using conventional techniques (FEM, BEM,…). The method used in this thesis, the Variational theory of complex ray (VTCR) is particularly well adapted to these cases. The principal features of VTCR approach are the use of a weak formulation of the acoustic problem, which allows to consider automatically boundary conditions between sub-domains. Then, the use of an integral repartition of plane waves in all the direction allow to simulate the acoustic field. The unknowns of the problem are their amplitudes. This method well assessed for closed domain, has been extended to open domain and coupled to vibrational response of the rail. Comparison with analytic solution and FEM simulation at low frequency allow to validate the method.Coupling these both methods allowed to simulate complex real life vibro-acoustic scenarios. Result of different railway tracks are presented and validated

本研究選擇楊 (Iris Marion Young) 在1977年首次發表的文章〈像女孩那樣丟球—論女性身體經驗〉為主要藍本，對梅洛龐蒂《知覺現象學》的身體主體概念進行討論。楊在文章中採用梅洛龐蒂活生生身體做為核心，以《知覺現象學》中〈身體本身的空間性和運動機能〉此篇章做為對照架構，置入性別化的反思，重新編織由女性主體經驗出發的身體模態。 在2005年楊以此文為書名同時收錄多篇聚焦於女性身體經驗的現象學討論，從懷孕、乳房、月經、老年照護等女性身體的各個面向，經由性別觀點的探問辯證處理多位歐陸哲學家和現象學家的論述，透過理論思考和生命經驗交揉出女性身體主體的視野。在〈像女孩那樣丟球—論女性身體經驗〉中，楊選擇梅洛龐蒂《知覺現象學》對活生生身體與世界關係的描述架構，同時立基於西蒙波娃對女性存在的分析和觀察，分析陰性身體的特定風格，以及這種風格及活動方式，與其在世界中的交往有什麼樣的關係？又具有什麼樣的意義？梅洛龐蒂在《知覺現象學》裡說明主體如何通過身體在世界中展開存在活動，在這些活動的運作中，我們不是如同船長掌舵一樣，作為純粹的思維者操作客觀的身體，也不是一個刺激-反應的制約機體對世界做出規律和法則的回應，主體與世界的關係，就座落在我作為一個活生生的身體主體向世界開放，朝世界投射。但是，這個身體的分析架構是否為一個普遍性的論述？如果經驗世界中有一大部分的身體典型在特定的層次上展現的差異性，這種獨特風格是基於什麼樣的存在處境中出現的？梅洛龐蒂突破笛卡兒純粹思維者的傳統，修正胡賽爾在《觀念一》朝向超驗觀念論的追求路線，試圖以一個具體化、肉身化的樣貌來理解人的在世存有，然而是否必須面對我們活生生的身體中是帶著性別、文化的銘刻？因此本研究將以楊所提出的女性身體活動與空間經驗為基礎，對照梅洛龐蒂文本中描述的身體模態，重新思考梅洛龐蒂的身體論述，與性別向度之間的關連性。

O albinismo e uma alteracao genetica rara que compromete a producao de melanina. As alteracoes clinicas consistem na falta de pigmentacao da pele, cabelo e pelos. Apresenta alteracoes oftalmologicas importantes, que comprometem a acuidade visual de forma severa, na grande maioria dos casos. As alteracoes oftalmologicas sao, ametropias, nistagmo, rarefacao do epitelio pigmentado da iris e da retina, hipoplasia foveal e decussacao anomala do nervo optico. Este estudo foi dividido em tres diferentes partes com os seguintes objetivos principais: Parte 1: Analise comparativa entre o grau de transparencia da iris (GTI), o grau de transparencia da retina (GTR) e a espessura da regiao macular com a acuidade visual nos pacientes com albinismo. Parte 2: Teste de sensibilidade ao contraste espacial de luminancia e ofuscamento com lentes de contato filtrantes em ambientes claros e escuros. Parte 3: Avaliacao da visao de cores, utilizando\\se o teste de Pranchas de Ishihara e o Cambridge Color Test (CCT). Material\' e\' Métodos: Participaram do estudo 121 individuos albinos, com idade media de 31,18 (} 15,47) anos, o que totalizou 242 olhos. Os participantes foram divididos em diferentes grupos nas tres partes do estudo, alguns participaram de uma ou mais partes. Na primeira parte os participantes foram submetidos a consulta oftalmologica, classificacao do grau de transparencia da iris e da retina em uma nova classificacao baseada em quatro diferentes graus de transparencia, alem de avaliacao foveal pelo exame de Tomografia de Coerencia Optica (OCT). Na segunda parte, os participantes foram submetidos ao teste de contraste computadorizado, utilizando lentes de contato filtrante e transparentes, em ambientes claros e escuros. Nesta etapa foi avaliada a influencia da lente filtrante na sensibilidade de contraste visual dos individuos com albinismo. Na terceira parte, os participantes foram submetidos aos testes de Pranchas de Ishihara e de Cambridge Colour Test (CCT), para avaliacao da visao de cores nos pacientes albinos. Resultados: Os resultados foram os seguintes: Parte\'1: A correlacao entre AV logMAR e GTI foi positiva (+0,569) e significativa (p<0,001). A correlacao entre AV logMAR e GTR foi positiva (+0,531) e significativa (p<0,001). A correlacao entre AV logMAR e a espessura macular nao foi significativa (p=0,105). A correlacao entre GTI e GTR foi positiva (+ 0,627) e significativa (p<0,001). A correlacao entre espessura macular e GTI nao foi significativa (p=0,397). A correlacao entre espessura macular e GTR nao foi significativa (p=0,458). Parte 2: Houve melhora estatisticamente significante da sensibilidade ao contraste com as lentes filtrantes em relacao as lentes transparentes no ambiente de ofuscamento (claro), na frequencia de 0,3 cpg, 0,6 cpg e 1,0 cpg (ciclos por grau). Nao houve melhora significante nas frequencia 2,0 cpg e 4,0 cpg. Nao houve melhora estatisticamente significante da sensibilidade ao contraste de lentes filtrantes em relacao as lentes transparentes no ambiente escuro (penumbra) em nenhuma das frequencias espaciais estudadas. Parte\' 3: Todos os individuos com albinismo nao apresentaram nenhuma alteracao de visao de cores no teste de Pranchas de Ishihara. O CCT demonstrou piora no limiar de deteccao de cores significativa nos eixos protan (p=0,021) e deutan (p=0,017), mas nao houve diferenca no eixo tritan (p=0,212). Os testes estatisticos sugerem que uma amostra maior seja estudada para validacao dos resultados / Albinism is a rare genetic alteration that compromises the production of melanine in all body tissues. The clinical alterations are the lack of pigment in the skin and hair. It presents important ophthalmological changes that compromise the visual acuity, in most cases. The ophthalmological changes are: ametropia, nystagmus, iris pigmented epithelium rarefaction, retina pigmented epithelium rarefaction, foveal hipoplasia and abnormal optic nerve decussation. This study has been divided in three different parts and had the following main objectives: Part 1, comparative analysis of the iris transparency degree (ITD), the retina transparency degree (RTD) and macular thickness with the visual acuity in albino patients. Part 2: Spatial contrast sensitivity test of luminance and outshine wearing contact lenses with filters in light and dark environments. Part 3: color vision evaluation using the Ishihara Test and the Cambridge Color Test (CCT). For the study 121 individuals with albinism were included with an average of 31,18 years old } 15,47, a total of 242 eyes. The participants were divided in different groups in the three parts of the study, some participated in one or more parts. In the first part the participants have been through an ophthalmological exam, classification of the iris transparency degree (ITD) and the retinal transparency degree (RTD) by a new classification based in 4 different degrees of transparency. Foveal evaluation by the Optic Coherence Tomography exam (OCT) was made in the first part of this study. In the second part, the participants have been submitted to the computerized contrast test, using filtered and transparent contact lenses in light and dark environments. In this part the influence of the filtering lenses in the visual contrast sensitivity in the albinism patients has been evaluated. In the third part, the participants have been submitted to Ishihara Test and Cambridge Color Test in order to evaluate the color vision in albino patients. The results are as follows: Part\' 1: the correlation between visual acuity in Logarithm of the Minimum Angle of Resolution (logMAR) and ITD was positive (+0,569) and significant (p<0,001). The correlation between visual acuity in logMAR and RTD was positive (+0,531) and significant (p<0,001). The correlation between visual acuity in logMAR and the macular thickness was not significant (p=0,105). The correlation between ITD and RTD was positive (+ 0,627) and significant (p<0,001). The correlation between the macular thickness and the ITD was not significant (p=0,397). The correlation between the macular thickness and the RTD was not significant (p=0,458). Part\'2: There has been a statistically significant improvement of the contrast sensitivity wearing the filtering lenses in relation to the transparent ones in bright environment, in the frequencies of 0,3 cycles per degree (cpd), 0,6 cpd and 1,0 cpd. There has been no significant improvement in the frequencies 2,0 cpd and 4,0 cpd. There has been no statistically significant improvement in contrast sensitivity wearing the filtering lenses in relation to the transparent one in the dark environment (shadow) in any of the spatial frequencies studied. Part\' 3: all albinism patients did not present any color vision change in the Ishihara Test. The CCT has shown a worsening in the color detection threshold in the protan axis (p=0,021) and deutan axis (p=0,017), but there has been no difference in the tritan axis (p=0,212). The statistic tests show that a bigger sample is recommended to confirm part 3 results

Made available in DSpace on 2016-04-27T14:31:41Z (GMT). No. of bitstreams: 1 Dissertacao MARIA APARECIDA OUVINHAS GAVIOLI.pdf: 3764970 bytes, checksum: b68ea7bcc8b44581c9039488c90a6386 (MD5) Previous issue date: 2006-04-07 / The starting point of study is the question: How to evolve from integration to inclusion? How can regular and special schools overcome errors and assume new roles?" It was conceived at Municipal Special Education School Novo Arco-Íris , in Ibiúna, and was enriched by the experience of many teachers, students, parents, and principals, united by a desire for a better education for everyone. Therefore, this is a collective study, shared by many authors and people, whose lives fortunately have crossed with this project, which seeks to understand the proposed process of School Inclusion of the City of Ibiúna, including its theoretical and practical premises. This investigation involved qualitative fieldwork, originally of an exploratory nature, which evolved to an analysis of some selected schools. The analyses and interpretations used methodological approaches based on new educational paradigms and the concept of a single school, open to everyone. The recommendations of this research indicate that effective school inclusion requires more than the school s commitment, that is, more comprehensive public policies to ensure improved living conditions for the population. They also suggest some education issues that require urgent action, with prospects for change. / Este estudo parte da seguinte questão: Como evoluir da integração para a inclusão? Como poderão as escolas, regulares e especiais, romperem com equívocos e assumirem novos papéis? Foi germinado na Escola Municipal de Educação Especial Novo Arco-Íris , de Ibiúna, onde tudo começou. Ampliou-se e enriqueceu-se com a experiência de muitos docentes, alunos, pais e diretores, unidos pelo desejo de uma educação melhor para todos. Portanto, é um estudo coletivo, resultado de partilhas com muitos autores e pessoas, cujos trajetos de vida, felizmente se encontraram com o presente trabalho que procura compreender o processo da proposta de Inclusão Escolar do Município de Ibiúna, em seus pressupostos teóricos e práticos. Para esta investigação realizou-se uma pesquisa de campo de abordagem qualitativa, inicialmente de caráter exploratório evoluindo para a análise de algumas escolas selecionadas. As análises e as interpretações foram efetuadas à luz de abordagens metodológicas, tendo em vista novos paradigmas educacionais e a concepção de uma escola única, aberta para todos. As recomendações dessa pesquisa convergem no sentido de que, para uma efetiva inclusão escolar é necessário mais do que o compromisso da escola, ou seja, políticas públicas mais amplas que garantam a melhoria das condições de vida da população. Apontam ainda as questões a serem tratadas com urgência na educação, mostrando possibilidades de mudança.

La répartition spatiale des fonctions et des populations urbaines n’est pas due au hasard, elle peutmettre en évidence des inégalités qui interrogent nos sociétés démocratiques fondées avant tout sur leprincipe d’égalité. Celui-ci s’appuie sur les relations entre le « social » et le « spatial » qui consistentprincipalement à explorer les inégalités sociales dans les espaces urbains et ce qui est ressenti commeune injustice par les individus. Pour saisir ces dynamiques socio-spatiales, nous focalisons notrerecherche sur l’histoire urbaine de Besançon, Mulhouse et Strasbourg ainsi que sur les rapports entreles habitants et leur environnement résidentiel. À l’aide des grandes bases de données géo-localiséesde l’INSEE, nous étudions la distribution spatiale des ménages ainsi que son évolution sur une périodede près de vingt années (de 1990 à 2007). Par ailleurs, nous cherchons à observer les différents modesd’habiter des Bisontins, c’est-à-dire leurs stratégies résidentielles ainsi que leurs pratiques etreprésentations spatiales à l’aide d’enquêtes de terrain. Cette thèse s’appuie donc sur une doubleapproche : l’une macroscopique, historique et quantitative et l’autre microscopique et qualitative. Elleprésente finalement les structures socio-spatiales des zones d’étude et les trajectoires des quartiers(plus précisément des IRIS) afin de montrer les diverses tendances d’évolution (gentrification,paupérisation…) dans une optique comparative. Des facteurs d’évolution spécifiques apparaissentégalement en lien avec la localisation des villes d’étude ainsi qu’avec leurs fonctions urbaines etsociales, leur organisation interne et leur taille. Les enquêtes révèlent, pour leur part, plusieurs règlescomportementales qu’il s’agit de comparer compte tenu de la diversité sociale des quartiers. Cesinformations collectées à partir d’enquêtes sont plus subjectives, mais elles complètent les données desrecensements et leur donnent du sens. Au final, elles montrent que l’appartenance à un groupe sociospatialene détermine pas systématiquement les comportements résidentiels. / The spatial distribution of urban functions and populations is not random, this distribution canhighlight inequalities which call into question our democratic societies based on the principle ofequality. This principle is based on the relationship between the “social” and the “spatial” whichmainly consist in investigating social disparities in urban areas and what is perceived as an injustice byindividuals. To understand these socio-spatial dynamics, we focus our research on the urban history ofBesançon, Mulhouse and Strasbourg as well as the relations between the inhabitants and theirresidential environment. Using large geo-localized databases from INSEE, we study the spatialdistribution of households and its evolution over a period of nearly twenty years (1990-2007). Inaddition, we seek to observe the various ways of living of the residents of Besançon, that is to say theirresidential logics and their spatial practices and representations via field surveys. Thus, this thesis isbased on a double approach: the first one is macroscopic, historic and quantitative and the second oneis microscopic and qualitative. The study presents the socio-spatial structures of the studied cities andthe trajectories of districts (more exactly the IRIS: the smaller census area) in order to show thedifferent trends of evolution (gentrification, pauperisation...) in a comparative perspective. Specificfactors of evolution are also linked to the location of the studied cities as well as to their urban andsocial functions, their internal organisation and their size. The field surveys, for their part, revealseveral behavioural rules that we compare considering the social diversity of districts. Thisinformation collected from surveys is more subjective, but it completes the census data and gives themmeaning. Finally, we show that the membership of a socio-spatial group does not determinesystematically residential behaviours.

<p>This dissertation explains why behavioral genetic research can be better informed by using characteristics in the human iris as biomarkers for personality, and is divided into five parts. Part I gives an introduction to the classical twin method and an overview of the findings that have led most developmental researchers to recognize that the normal variation of personality depends on a complex interplay between genetic and environmental factors. Part II highlights empirical findings that during the last twenty years have gradually moved genetic and environmental theory and research to evolve toward one another, and also presents the theory of genetics and experience that currently is used to explain how the interplay between genes and the environment works. Part III explains why, from a developmental perspective, it is of interest to identify candidate genes for personality, and gives a brief overview of genes that have been associated with personality. Problems associated with genetic research on the molecular level and how these apply to personality are also highlighted. Part IV examines molecular research on the iris and the brain, which suggests that genes expressed in the iris could be associated with personality, and explains how the use of iris characteristics can increase power to test candidate genes for personality by taking advantage of the self-organizing properties of the nervous system. The empirical foundation for the questions posed in this dissertation and also the empirical results are presented here. Part V discusses the associations found between iris characteristics and personality, and exemplifies how iris characteristics can be used within the theoretical frameworks presented in parts I, II, III and IV. In other words, Part V explains how iris characteristics – in addition to identify as well as test candidate genes for personality – can be used to investigate how people’s experiences in themselves are influenced by genetic factors.</p>

Cette thèse propose un ensemble de méthodes visant à la description de la cinématique de la source sismique, et cela principalement à distance lointaine. Nous utilisons des données et des approches variées: d'une part nous combinons l'usage des ondes de volume et des ondes de surface et d'autre part nous considérons à la fois une modélisation déterministe de la propagation (à partir des modèles de Terre globaux) et une modélisation empirique (fournie par un véritable séisme, appelé "fonction de Green empirique"). Deux situations sont alors considérées : soit l'on s'intéresse à un séisme précis, que l'on étudie spécifiquement (1), soit l'on s'intéresse aux séismes de forte magnitude dans leur globalité, et l'on cherche les caractéristiques cinématiques qui peuvent être résolues de manière quasi-automatique (2). Dans les deux cas, nous portons un intérêt particulier à la vitesse de rupture, que nous laissons librement varier sur la faille. L'approche (1), est appliquée au séisme d'El Salvador (13/ 01/ 2001,Mw = 7,7) et révèle que l'ensemble des données utilisées (champ lointain , régional et proche) est compatible avec le scénario suivant: la rupture s'est produite sur un plan plongeant à 6°* vers la côte et s'est propagée à la fois vers la surface et le Nord-Ouest, à une vitesse de 3-3,5km/s. La surface de rupture est d'environ 50km x 25km , sur laquelle le glissement moyen atteint 3.5m. Ce mécanisme s'explique bien par une accommodation de la flexion du slab. L'approche (2) nous a conduit à proposer une nouvelle description de la faille sismique : dans un souci de simplification, nous décrivons la rupture comme un ensemble de zones de glissement ayant chacune un glissement et une vitesse de rupture propres. Dès lors que l'on se restreint à des périodes assez longues (typiquement plus longues que le quart du temps de rupture) , l'utilisation d 'une ou de deux de ces zones rend bien compte des grands traits de la rupture. La pertinence de cette approche est démontrée au travers des séismes d ' Izmit (Turquie, 1999) et de Jalisco (Mexique, 1995). Nous avons développé à cette occasion une nouvelle méthode d'analyse par fonction de Green empirique, fondée sur l'inclusion de contraintes physiques dans la déconvolution. Cette méthode est plus spécifiquement appliquée au séisme du Pérou du 23/06/ 2001 (Mw = 8, 4).

No description available.

This dissertation explains why behavioral genetic research can be better informed by using characteristics in the human iris as biomarkers for personality, and is divided into five parts. Part I gives an introduction to the classical twin method and an overview of the findings that have led most developmental researchers to recognize that the normal variation of personality depends on a complex interplay between genetic and environmental factors. Part II highlights empirical findings that during the last twenty years have gradually moved genetic and environmental theory and research to evolve toward one another, and also presents the theory of genetics and experience that currently is used to explain how the interplay between genes and the environment works. Part III explains why, from a developmental perspective, it is of interest to identify candidate genes for personality, and gives a brief overview of genes that have been associated with personality. Problems associated with genetic research on the molecular level and how these apply to personality are also highlighted. Part IV examines molecular research on the iris and the brain, which suggests that genes expressed in the iris could be associated with personality, and explains how the use of iris characteristics can increase power to test candidate genes for personality by taking advantage of the self-organizing properties of the nervous system. The empirical foundation for the questions posed in this dissertation and also the empirical results are presented here. Part V discusses the associations found between iris characteristics and personality, and exemplifies how iris characteristics can be used within the theoretical frameworks presented in parts I, II, III and IV. In other words, Part V explains how iris characteristics – in addition to identify as well as test candidate genes for personality – can be used to investigate how people’s experiences in themselves are influenced by genetic factors.

Made available in DSpace on 2016-03-15T19:37:30Z (GMT). No. of bitstreams: 1 Mauro Ulisses Schneider.pdf: 1455677 bytes, checksum: 6eba28391f8f6910fbf5457a57119bd3 (MD5) Previous issue date: 2010-08-23 / Fundo Mackenzie de Pesquisa / The use of biometric systems has been widely stimulated by both the government and private entities to replace or improve traditional security systems. Biometric systems are becoming increasingly indispensable to protecting life and property, mainly due to its robustness, reliability, difficult to counterfeit and fast authentication. In real world applications, the devices for image acquisition and the environment are not always controlled and may under certain circumstances produce noisy images or with large variations in tonality, texture, geometry, hindering segmentation and consequently the authentication of the an individual. To deal effectively with such problems, this dissertation investigates the possibility of using committee machines combined with digital image processing techniques for iris segmentation. The components employed in the composition of the committee machines are support vector clustering, k-means and self organizing maps. In order to evaluate the performance of the tools developed in this dissertation, the experimental results obtained are compared with related works reported in the literature. Experiments on publicity available UBIRIS database indicate that committee machine can be successfully applied to the iris segmentation. / A utilização de sistemas biométricos vem sendo amplamente; incentivados pelo governo e entidades privadas a fim de substituir ou melhorar os sistemas de segurança tradicionais. Os sistemas biométricos são cada vez mais indispensáveis para proteger vidas e bens, sendo robustos, confiáveis, de difícil falsificação e rápida autenticação. Em aplicações de mundo real, os dispositivos de aquisição de imagem e o ambiente nem sempre são controlados, podendo em certas circunstâncias produzir imagens ruidosas ou com grandes variações na tonalidade, textura, geometria, dificultando a sua segmentação e por conseqüência a autenticação do indivíduo. Para lidar eficazmente com tais problemas, nesta dissertação é estudado o emprego de comitês de máquinas em conjunto com técnicas de processamento de imagens digitais para a segmentação da íris. Os componentes estudados na composição do comitê de máquinas são agrupamento por vetores-suporte, k-means e mapas auto- organizáveis. Para a avaliação do desempenho das ferramentas desenvolvidas neste trabalho, os resultados obtidos são comparados com trabalhos relacionados na literatura. Foi utilizada a base de dados pública UBIRIS disponível na internet.