Mon travail de thèse est consacré à l’étude de quelques aspects de la physique quantique des systèmes quantiques à N corps en interaction. Il est orienté vers l’étude des chaînes de spins quantiques. Je me suis intéressé à plusieurs questions relatives aux chaînes de spins quantiques, du point de vue numérique et analytique à la fois. J'aborde en particulier les questions relatives à la structure des fonctions d'onde, la forme de la densité d'états et les propriétés spectrales des Hamiltoniens de chaînes de spins. Dans un premier temps, je présenterais très rapidement les techniques numériques de base pour le calcul des vecteurs et valeurs propres des Hamiltonien de chaînes de spins. Les densités d’états des modèles quantiques constituent des quantités importantes et très simples qui permettent de caractériser les propriétés spectrales des systèmes avec un grand nombre de degrés de liberté. Alors que dans la limite thermodynamique, les densités d'états de la plupart des modèles intégrables sont bien décrites par une loi gaussienne, dans certaines limites de couplage de la chaîne de spins au champ magnétique et pour un nombre de spins N fini sur la chaîne, on observe l’apparition de pics dans la densité d’états. Je montrerais que la connaissance des deux premiers moments du Hamiltonien dans le sous-espace dégénéré associé à chaque pics donne une bonne approximation de la densité d’états. Dans un deuxième temps je m'intéresserais aux propriétés spectrales des Hamiltoniens de chaînes de spins quantiques. L’un des principal résultats sur la statistique spectrale des systèmes quantiques concerne le comportement universel des fluctuations des mesures telles que l’espacement entre valeurs propres consécutives. Ces fluctuations sont bien décrites par la théorie des matrices aléatoires mais la comparaison avec les prédictions de cette théorie nécessite généralement une opération sur le spectre du Hamiltonien appelée unfolding. Dans les problèmes quantiques de N corps, la taille de l’espace de Hilbert croît généralement exponentiellement avec le nombre de particules, entraînant un manque de données pour pouvoir faire une statistique. Ces limitations ont amené l’introduction d’une nouvelle mesure se passant de la procédure d’unfolding basée sur le rapport d’espacements successifs plutôt que les espacements. En suivant l’idée du “surmise” de Wigner pour le calcul de la distribution de l’espacement, je montre comment calculer une approximation de la distribution du rapport d’espacements dans les trois ensembles gaussiens invariants en faisant le calcul pour des matrices 3x3. Les résultats obtenus pour les différents ensembles de matrices aléatoires se sont révélés être en excellent accord avec les résultats numériques. Enfin je m’intéresserais à la structure des fonctions d’ondes fondamentales des modèles de chaînes de spins quantiques. Les fonctions d’onde constituent, avec le spectre en énergie, les objets fondamentaux des systèmes quantiques : leur structure est assez compliquée et n’est pas très bien comprise pour la plupart des systèmes à N corps. En raison de la croissance exponentielle de la taille de l’espace de Hilbert avec le nombre de particules, l’étude des vecteurs propres est une tâche très difficile, non seulement du point de vue analytique mais aussi du point de vue numérique. Je démontrerais en particulier que l’état fondamental de tous les modèles que nous avons étudiés est multifractal avec en général une dimension fractale non triviale. / My thesis is devoted to the study of some aspects of many body quantum interacting systems. In particular we focus on quantum spin chains. I have studied several aspects of quantum spin chains, from both numerical and analytical perspectives. I addressed especially questions related to the structure of eigenfunctions, the level densities and the spectral properties of spin chain Hamiltonians. In this thesis, I first present the basic numerical techniques used for the computation of eigenvalues and eigenvectors of spin chain Hamiltonians. Level densities of quantum models are important and simple quantities that allow to characterize spectral properties of systems with large number of degrees of freedom. It is well known that the level densities of most integrable models tend to the Gaussian in the thermodynamic limit. However, it appears that in certain limits of coupling of the spin chain to the magnetic field and for finite number of spins on the chain, one observes peaks in the level density. I will show that the knowledge of the first two moments of the Hamiltonian in the degenerate subspace associated with each peak give a good approximation to the level density. Next, I study the statistical properties of the eigenvalues of spin chain Hamiltonians. One of the main achievements in the study of the spectral statistics of quantum complex systems concerns the universal behaviour of the fluctuation of measure such as the distribution of spacing between two consecutive eigenvalues. These fluctuations are very well described by the theory of random matrices but the comparison with the theoretical prediction generally requires a transformation of the spectrum of the Hamiltonian called the unfolding procedure. For many-body quantum systems, the size of the Hilbert space generally grows exponentially with the number of particles leading to a lack of data to make a proper statistical study. These constraints have led to the introduction of a new measure free of the unfolding procedure and based on the ratio of consecutive level spacings rather than the spacings themselves. This measure is independant of the local level density. By following the Wigner surmise for the computation of the level spacing distribution, I obtained approximation for the distribution of the ratio of consecutive level spacings by analyzing random 3x3 matrices for the three canonical ensembles. The prediction are compared with numerical results showing excellent agreement. Finally, I investigate eigenfunction statistics of some canonical spin-chain Hamiltonians. Eigenfunctions together with the energy spectrum are the fundamental objects of quantum systems: their structure is quite complicated and not well understood. Due to the exponential growth of the size of the Hilbert space, the study of eigenfunctions is a very difficult task from both analytical and numerical points of view. I demonstrate that the groundstate eigenfunctions of all canonical models of spin chain are multifractal, by computing numerically the Rényi entropy and extrapolating it to obtain the multifractal dimensions.

L'une des difficultés d'une langue peu dotée est l'inexistence des services liés aux technologies du traitement de l'écrit et de l'oral. Dans cette thèse, nous avons affronté la problématique de l'étude acoustique de la parole isolée et de la parole continue en Fongbe dans le cadre de la reconnaissance automatique de la parole. La complexité tonale de l'oral et la récente convention de l'écriture du Fongbe nous ont conduit à étudier le Fongbe sur toute la chaîne de la reconnaissance automatique de la parole. En plus des ressources linguistiques collectées (vocabulaires, grands corpus de texte, grands corpus de parole, dictionnaires de prononciation) pour permettre la construction des algorithmes, nous avons proposé une recette complète d'algorithmes (incluant des algorithmes de classification et de reconnaissance de phonèmes isolés et de segmentation de la parole continue en syllabe), basés sur une étude acoustique des différents sons, pour le traitement automatique du Fongbe. Dans ce manuscrit, nous avons aussi présenté une méthodologie de développement de modèles accoustiques et de modèles du langage pour faciliter la reconnaissance automatique de la parole en Fongbe. Dans cette étude, il a été proposé et évalué une modélisation acoustique à base de graphèmes (vu que le Fongbe ne dispose pas encore de dictionnaire phonétique) et aussi l'impact de la prononciation tonale sur la performance d'un système RAP en Fongbe. Enfin, les ressources écrites et orales collectées pour le Fongbe ainsi que les résultats expérimentaux obtenus pour chaque aspect de la chaîne de RAP en Fongbe valident le potentiel des méthodes et algorithmes que nous avons proposés. / One of the difficulties of an unresourced language is the lack of technology services in the speech and text processing. In this thesis, we faced the problematic of an acoustical study of the isolated and continous speech in Fongbe as part of the speech recognition. Tonal complexity of the oral and the recent agreement of writing the Fongbe led us to study the Fongbe throughout the chain of an automatic speech recognition. In addition to the collected linguistic resources (vocabularies, large text and speech corpus, pronunciation dictionaries) for building the algorithms, we proposed a complete recipe of algorithms (including algorithms of classification and recognition of isolated phonemes and segmentation of continuous speech into syllable), based on an acoustic study of the different sounds, for Fongbe automatic processing. In this manuscript, we also presented a methodology for developing acoustic models and language models to facilitate speech recognition in Fongbe. In this study, it was proposed and evaluated an acoustic modeling based on grapheme (since the Fongbe don't have phonetic dictionary) and also the impact of tonal pronunciation on the performance of a Fongbe ASR system. Finally, the written and oral resources collected for Fongbe and experimental results obtained for each aspect of an ASR chain in Fongbe validate the potential of the methods and algorithms that we proposed.

In this thesis, we study statistical inference for entropy, divergence, and related functionals of one or two probability distributions. Asymptotic properties of particular nonparametric estimators of such functionals are investigated. We consider estimation from both independent and dependent observations. The thesis consists of an introductory survey of the subject and some related theory and four papers (A-D). In Paper A, we consider a general class of entropy-type functionals which includes, for example, integer order Rényi entropy and certain Bregman divergences. We propose U-statistic estimators of these functionals based on the coincident or epsilon-close vector observations in the corresponding independent and identically distributed samples. We prove some asymptotic properties of the estimators such as consistency and asymptotic normality. Applications of the obtained results related to entropy maximizing distributions, stochastic databases, and image matching are discussed. In Paper B, we provide some important generalizations of the results for continuous distributions in Paper A. The consistency of the estimators is obtained under weaker density assumptions. Moreover, we introduce a class of functionals of quadratic order, including both entropy and divergence, and prove normal limit results for the corresponding estimators which are valid even for densities of low smoothness. The asymptotic properties of a divergence-based two-sample test are also derived. In Paper C, we consider estimation of the quadratic Rényi entropy and some related functionals for the marginal distribution of a stationary m-dependent sequence. We investigate asymptotic properties of the U-statistic estimators for these functionals introduced in Papers A and B when they are based on a sample from such a sequence. We prove consistency, asymptotic normality, and Poisson convergence under mild assumptions for the stationary m-dependent sequence. Applications of the results to time-series databases and entropy-based testing for dependent samples are discussed. In Paper D, we further develop the approach for estimation of quadratic functionals with m-dependent observations introduced in Paper C. We consider quadratic functionals for one or two distributions. The consistency and rate of convergence of the corresponding U-statistic estimators are obtained under weak conditions on the stationary m-dependent sequences. Additionally, we propose estimators based on incomplete U-statistics and show their consistency properties under more general assumptions.

Modelos e teorias científicas surgem da necessidade do homem entender melhor o funcionamento do mundo em que vive. Constantemente, novos modelos e técnicas são criados com esse objetivo. Uma dessas teorias recentemente desenvolvida é a da Criticalidade Auto-Organizada. No Capítulo 2 desta tese, apresentamos uma breve introdução a Criticalidade Auto-Organizada. Tendo a criticalidade auto-organizada como pano de fundo, no Capítulo 3, estudamos a dinâmica Bak-Sneppen (e diversas variantes) e a comparamos com alguns algoritmos de otimização. Apresentamos no Capítulo 4, uma revisão histórica e conceitual das redes complexas. Revisamos alguns importantes modelos tais como: Erdös-Rényi, Watts-Strogatz, de configuração e Barabási-Albert. No Capítulo 5, estudamos o modelo Barabási-Albert não-linear. Para este modelo, obtivemos uma expressão analítica para a distribuição de conectividades P(k), válida para amplo espectro do espaço de parâmetros. Propusemos também uma forma analítica para o coeficiente de agrupamento, que foi corroborada por nossas simulações numéricas. Verificamos que a rede Barabási-Albert não-linear pode ser assortativa ou desassortativa e que, somente no caso da rede Barabási-Albert linear, ela é não assortativa. No Capítulo 6, utilizando dados coletados do CD-ROM da revista Placar, construímos uma rede bastante peculiar -- a rede do futebol brasileiro. Primeiramente analisamos a rede bipartida formada por jogadores e clubes. Verificamos que a probabilidade de que um jogador tenha participado de M partidas decai exponencialmente com M, ao passo que a probabilidade de que um jogador tenha marcado G gols segue uma lei de potência. A partir da rede bipartida, construímos a rede unipartida de jogadores, que batizamos de rede de jogadores do futebol brasileiro. Nessa rede, determinamos várias grandezas: o comprimento médio do menor caminho e os coeficientes de agrupamento e de assortatividade. A rede de jogadores de futebol brasileiro nos permitiu analisar a evolução temporal dessas grandezas, uma oportunidade rara em se tratando de redes reais. / Models and scientific theories arise from the necessity of the human being to better understand how the world works. Driven by this purpose new models and techniques have been created. For instance, one of these theories recently developed is the Self-Organized Criticality, which is shortly introduced in the Chapter 2 of this thesis. In the framework of the Self-Organized Criticality theory, we investigate the standard Bak-Sneppen dynamics as well some variants of it and compare them with optimization algorithms (Chapter 3). We present a historical and conceptual review of complex networks in the Chapter 4. Some important models like: Erdös-Rényi, Watts-Strogatz, configuration model and Barabási-Albert are revised. In the Chapter 5, we analyze the nonlinear Barabási-Albert model. For this model, we got an analytical expression for the connectivity distribution P(k), which is valid for a wide range of the space parameters. We also proposed an exact analytical expression for the clustering coefficient which corroborates very well with our numerical simulations. The nonlinear Barabási-Albert network can be assortative or disassortative and only in the particular case of the linear Barabási-Albert model, the network is no assortative. In the Chapter 6, we used collected data from a CD-ROM released by the magazine Placar and constructed a very peculiar network -- the Brazilian soccer network. First, we analyzed the bipartite network formed by players and clubs. We find out that the probability of a footballer has played M matches decays exponentially with M, whereas the probability of a footballer to score G gols follows a power-law. From the bipartite network, we built the unipartite Brazilian soccer players network. For this network, we determined several important quantities: the average shortest path length, the clustering coefficient and the assortative coefficient. We were also able to analise the time evolution of these quantities -- which represents a very rare opportunity in the study of real networks.

Ce mémoire présente différentes contributions dans les domaines du traitement et la théorie de l'information (plus particulièrement l'étude et l'exploitation de mesures d'information) et de la radiotechnique (statistique). On présente quelques techniques fondées sur le principe du maximum d'entropie, comprenant le maximum d'entropie sur la moyenne et une extension itérative. On décrit ensuite comment on peut interpréter la technique des superstatistiques de Beck et Cohen comme une conséquence d'un maximum d'entropie avec contraintes aléatoires, et on explicite un cas particulier qui mène aux K-distributions. Pour appliquer pratiquement des résultats impliquant des mesures d'entropie, on propose et on caractérise un estimateur de l'entropie de Shannon, et on décrit quelques applications possibles. On décrit également, à partir d'une inégalité de convolution, comment on peut une utiliser une forme alternative, l'entropie de Rényi, pour des problèmes de déconvolution. On s'intéresse ensuite de manière un peu plus précise aux entropies de Rényi-Tsallis, aux distributions à maximum d'entropie de Rényi-Tsallis que l'on peut en déduire, et à leurs justifications et applications. On montre notamment que les entropies de Rényi-Tsallis peuvent être déduites à partir d'une approche classique de maximum d'entropie, en prenant en compte une contrainte figurant un système dont l'équilibre est déplacé. D'un autre côté, on relie les distributions de Rényi-Tsallis à la distribution des excès en théorie des extrêmes, ce qui fournit une justification potentielle à la relative ubiquité de ces distributions. Comme conséquence des problèmes de maximum d'entropie de Rényi-Tsallis, on peut définir des fonctionnelles entropiques, que l'on étudie et dont on donne quelques propriétés et caractérisations. On s'intéresse également à l'information de Fisher, et on décrit quelques contributions. Plus spécifiquement, nous avons étudié l'extension au cas multivarié, et aux transformations non inversibles, de l'inégalité sur l'information de Fisher. On a considéré également l'utilisation conjointe de l'information de Fisher et l'entropie de Shannon pour l'analyse de signaux, en définissant un plan d'information de Fisher-Shannon. Pour des distributions à support borné, typiquement définies sur R+ ou sur un intervalle, on caractérise les distributions à minimum d'information de Fisher sous contrainte de variance, et on étudie la fonctionnelle d'information de Fisher associée. En ce qui concerne l'aspect radiotechnique, on s'intéresse à des problèmes d'architecture des émetteurs-récepteurs numériques, et au développement d'algorithmes de correction, calibration ou contrôle. Les contraintes posées pour la réalisation des émetteurs radio amènent à sélectionner des solutions de type polaire, où le signal est décomposé en un module (l'enveloppe) et une phase (le cosinus de la phase). On propose ici notamment une évolution de l'architecture EER (Envelope Elimination and Restoration), permettant de fournir à un amplificateur de puissance un signal à enveloppe constante, la restauration de l'enveloppe étant opérée par filtrage passe-bande en sortie de l'émetteur. Au niveau composants, d'autres contributions concernent les boucles à verrouillage de phase entièrement numérique pour lesquelles on propose un modèle comportemental complet du système, ainsi que des algorithmes rapides permettant d'alléger l'implantation. Toujours au niveau composants, on s'intéresse aussi à la réalisation et la stabilisation d'une horloge de référence très haute fréquence, reposant sur l'utilisation d'un BAW, pour laquelle il est important d'établir un modèle direct fiable, d'estimer ses paramètre et de maîtriser la variabilité statistique. Dans les architectures polaires, on étudie et on illustre les conséquences néfastes d'une désynchronisation entre l'enveloppe et la phase sur les différents indicateurs de performance. On propose et on caractérise plusieurs algorithmes, reposant sur des techniques de gradient stochastique, permettant de compenser ces décalages temporels, tout en prenant en charge d'éventuelles distorsions supplémentaires en gain et phase.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-08-08T19:36:59Z No. of bitstreams: 1 ELIZABETE CARDOSO MACHADO - DISSERTAÇÃO PPGMAT 2013..pdf: 1253783 bytes, checksum: 102940a8c9aabedecfa013e695047eb1 (MD5) / Made available in DSpace on 2018-08-08T19:36:59Z (GMT). No. of bitstreams: 1 ELIZABETE CARDOSO MACHADO - DISSERTAÇÃO PPGMAT 2013..pdf: 1253783 bytes, checksum: 102940a8c9aabedecfa013e695047eb1 (MD5) Previous issue date: 2013-09 / Capes / Neste trabalho fizemos um estudo sobre a classe de distribuições generalizadas exponencializadas, a distribuição Fréchet generalizada e a distribuição Weibull inversa log-generalizada. Obtemos algumas propriedades da distribuição Fréchet generalizada. Uma nova distribuição é proposta: a distribuição log-Fréchet generalizada. Esta distribuição é uma estensão da distribuição Fréchet. Outra proposta deste trabalho é introduzir um modelo de regressão log-Fréchet generalizada com censura Tipo I baseado na distribuição log-Fréchet generalizada. / In this work, we did a research study about the exponentiated generalized class of distributions, the generalized Fréchet distribution and the log-generalized inverse Weibull distribution. We obtain some properties of generalized Fréchet distribution. Furthermore, a new distribution is proposed: the generalized log-Fréchet distribution. This new distribution is an extension of Fréchet distribution. Another propose of this work is to introduce a generalized log-Frechét regression model with Type-I censoringbased on the generalized log-Frechét distribution.

Modelos e teorias científicas surgem da necessidade do homem entender melhor o funcionamento do mundo em que vive. Constantemente, novos modelos e técnicas são criados com esse objetivo. Uma dessas teorias recentemente desenvolvida é a da Criticalidade Auto-Organizada. No Capítulo 2 desta tese, apresentamos uma breve introdução a Criticalidade Auto-Organizada. Tendo a criticalidade auto-organizada como pano de fundo, no Capítulo 3, estudamos a dinâmica Bak-Sneppen (e diversas variantes) e a comparamos com alguns algoritmos de otimização. Apresentamos no Capítulo 4, uma revisão histórica e conceitual das redes complexas. Revisamos alguns importantes modelos tais como: Erdös-Rényi, Watts-Strogatz, de configuração e Barabási-Albert. No Capítulo 5, estudamos o modelo Barabási-Albert não-linear. Para este modelo, obtivemos uma expressão analítica para a distribuição de conectividades P(k), válida para amplo espectro do espaço de parâmetros. Propusemos também uma forma analítica para o coeficiente de agrupamento, que foi corroborada por nossas simulações numéricas. Verificamos que a rede Barabási-Albert não-linear pode ser assortativa ou desassortativa e que, somente no caso da rede Barabási-Albert linear, ela é não assortativa. No Capítulo 6, utilizando dados coletados do CD-ROM da revista Placar, construímos uma rede bastante peculiar -- a rede do futebol brasileiro. Primeiramente analisamos a rede bipartida formada por jogadores e clubes. Verificamos que a probabilidade de que um jogador tenha participado de M partidas decai exponencialmente com M, ao passo que a probabilidade de que um jogador tenha marcado G gols segue uma lei de potência. A partir da rede bipartida, construímos a rede unipartida de jogadores, que batizamos de rede de jogadores do futebol brasileiro. Nessa rede, determinamos várias grandezas: o comprimento médio do menor caminho e os coeficientes de agrupamento e de assortatividade. A rede de jogadores de futebol brasileiro nos permitiu analisar a evolução temporal dessas grandezas, uma oportunidade rara em se tratando de redes reais. / Models and scientific theories arise from the necessity of the human being to better understand how the world works. Driven by this purpose new models and techniques have been created. For instance, one of these theories recently developed is the Self-Organized Criticality, which is shortly introduced in the Chapter 2 of this thesis. In the framework of the Self-Organized Criticality theory, we investigate the standard Bak-Sneppen dynamics as well some variants of it and compare them with optimization algorithms (Chapter 3). We present a historical and conceptual review of complex networks in the Chapter 4. Some important models like: Erdös-Rényi, Watts-Strogatz, configuration model and Barabási-Albert are revised. In the Chapter 5, we analyze the nonlinear Barabási-Albert model. For this model, we got an analytical expression for the connectivity distribution P(k), which is valid for a wide range of the space parameters. We also proposed an exact analytical expression for the clustering coefficient which corroborates very well with our numerical simulations. The nonlinear Barabási-Albert network can be assortative or disassortative and only in the particular case of the linear Barabási-Albert model, the network is no assortative. In the Chapter 6, we used collected data from a CD-ROM released by the magazine Placar and constructed a very peculiar network -- the Brazilian soccer network. First, we analyzed the bipartite network formed by players and clubs. We find out that the probability of a footballer has played M matches decays exponentially with M, whereas the probability of a footballer to score G gols follows a power-law. From the bipartite network, we built the unipartite Brazilian soccer players network. For this network, we determined several important quantities: the average shortest path length, the clustering coefficient and the assortative coefficient. We were also able to analise the time evolution of these quantities -- which represents a very rare opportunity in the study of real networks.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-08-13T16:22:35Z No. of bitstreams: 1 WASHINGTON CÉSAR DE ALMEIDA COSTA - TESE PPGEE 2012..pdf: 6463355 bytes, checksum: 40d8703ef8a6dd3ef05acde3025cf628 (MD5) / Made available in DSpace on 2018-08-13T16:22:35Z (GMT). No. of bitstreams: 1 WASHINGTON CÉSAR DE ALMEIDA COSTA - TESE PPGEE 2012..pdf: 6463355 bytes, checksum: 40d8703ef8a6dd3ef05acde3025cf628 (MD5) Previous issue date: 2012-11-09 / Patologias na laringe podem afetar a qualidade vocal, prejudicando a comunicação humana. As técnicas objetivas tradicionais para o diagnóstico dessas patologias fazem uso de exames considerados invasivos, causando certo desconforto ao paciente. Análise acústica, utilizando técnicas de processamento digital de sinais de voz, pode ser utilizada para o desenvolvimento de ferramentas não invasivas de auxílio ao diagnóstico de patologias laríngeas. A precisão do diagnóstico, contudo, depende da escolha das características e parâmetros da fala que melhor representem a desordem vocal provocada por uma determinada patologia. Este trabalho trata da caracterização e da classificação de sinais de vozes saudáveis e vozes afetadas por diferentes patologias laríngeas (edema, paralisia e nódulos nas pregas vocais), por meio da análise dinâmica não linear (e teoria do caos), como também por meio da análise de quantificação de recorrência. No processo de caracterização é investigado, por meio de testes estatísticos, o potencial de cada característica em discriminar os tipos de sinais de voz considerados. Para a classificação é empregada a técnica de análise discriminante com as funções linear ou quadrática, com validação cruzada, sendo considerado um intervalo de confiança de 95% para as médias das taxas de acuraria do classificador. A partir da combinação de características dos conjuntos das medidas de análise não linear (MNL) e das medidas de quantificação de recorrência (MQR), as médias da taxa de acurácia obtidas variaram nos intervalos de confiança: [95,44%; 100%) para a classificação entre vozes saudáveis e patológicas; [94,75%; 100%] entre vozes saudáveis e afetadas por edema, e entre saudáveis e nódulos. Para a classificação entre saudável e paralisia, obteve-se uma acurácia de 100% . Também são avaliados os efeitos do uso de vetores híbridos formados por características MNL, MQR e coeficientes extraídos da análise preditiva linear (LPC). Neste caso. as taxas de acurácia variaram nos intervalos de confiança: [95,02%; 97,62%] na discriminação entre vozes afetadas por paralisia e edema; [98,29%; 99,93%] para paralisia versus nódulos e [97,98%; 99,84%] para edema versus nódulos. Os resultados encontrados indicam que o método utilizado é promissor, podendo ser empregado no desenvolvimento de uma ferramenta computacional para apoio ao diagnóstico de patologias laríngeas. / Laryngeal pathologies may affect the voice quality, harniing human communication. The traditional objective techniques for diagnosing these pathologies make use of exams, considered invasive, causing discomfort to the patient. Acoustic analysis, using digital speech signal processing techniques. can be used for the development of non-invasive tools in order to aid laryngeal diseases diagnosis. The accuracy of diagnosis, however. depends on the choice of parameters and the speech characteristics diat better represent the voice disorder caused by a given pathology. This work deals with the characterization and classification of healthy voice signals and voices affecied by different laryngeal diseases (edema, paralysis and vocal fold nodules), by means of nonlinear dynamic analysis (and chãos theory) as well as recurrence quantification analysis. In the characterization process, the potential of each feature is investigated to discriminate the types of voice signals considered, by means of statistical tests. For the classification, the technique of discriminam analysis is employed with linear or quadratic functions, with cross-validation. A 95% confidence levei was considered for the average of accuracy rates of the classifier performance. From the feature combination of the set of nonlinear analysis measures (MNL) and the quantification recurrence measures (MQR). the average of accuracy rates varied in the following confidence intervals: [95.44%; 100%] for healthy and pathologícal classification: [94.75%; 100%] between healdiy and edema voices, and also between healthy and nodules. The accuracy rate was 100% between healthy and paralysis. We also evaluated the effects of using hybrid vectors formed by MNL, MQR and linear predictive coding (LPC) coefficients. In this case, the accuracy rates ranged in the confidence intervals: [95.02%; 97.62%] in the paralysis versus edema voices discrimination; [98.29%; 99.93%] for paralysis versus nodules and [97.98%; 99.84%] for edema versus nodules. Obtained results indicate that the used method is promising and it can even be used to develop a computational tool to support diagnosis of laryngeal diseases.