Orientador: Marilda do Couto Cavalcanti / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Estudos da Linguagem / Made available in DSpace on 2018-08-20T10:12:34Z (GMT). No. of bitstreams: 1 Kumada_KateMamhyOliveira_M.pdf: 1615016 bytes, checksum: cde5defde82fe88614d25abe159ceff0 (MD5) Previous issue date: 2012 / Resumo: Durante muito tempo os surdos tiveram o direito de se comunicar pela língua de sinais negado, pois esta não era vista pela sociedade como linguisticamente legítima. Recentemente a língua brasileira de sinais (LIBRAS) obteve o reconhecimento do seu estatuto linguístico (BRASIL, 2002) e, a partir de uma visão sócio-antropológica da surdez (SKLIAR, 1998), alguns estudos têm distanciado o surdo das concepções patologizadas baseadas na deficiência auditiva e inserido o mesmo em discussões sobre educação bilíngue em contextos de minorias e invisibilização (CAVALCANTI, 1999). No entanto, nessa educação bilíngue somente o português e a LIBRAS são aceitos pela escola, enquanto as outras línguas que permeiam esse contexto tendem a ser invisibilizadas (SILVA, 2008). Assim, o surdo que não atende às expectativas linguísticas da escola é, frequentemente, apontado como "sem língua". A partir desse panorama, a presente pesquisa qualitativa (DENZIN; LINCOLN, 2006) de cunho etnográfico (ERICKSON, 1984; 1989) está inserida no campo da Linguística Aplicada, mas baseou-se em perspectivas interdisciplinares/transdisciplinares (MOITA LOPES, 2008). O objetivo consistiu em investigar as representações sobre as línguas de sinais caseiras respondendo a seguinte pergunta de pesquisa: Quais as representações de familiares de crianças surdas e de profissionais e estagiários surdos e ouvintes participantes de um programa de apoio escolar bilíngue sobre as línguas de sinais caseiras? Para a geração (MASON, 1996) de registros (ERICKSON, 1989), o corpus da pesquisa proveio, de um lado, de reuniões de grupo focal (PETTENDORFER; MONTALVÃO, 2006; MOITA-LOPES, 2009) e conversas informais e, de outro lado, diário de campo e diário retrospectivo da pesquisadora. Os encontros de grupo focal (3 encontros com profissionais e 9 encontros com familiares) e as conversas informais foram realizados com participantes de um programa de apoio escolar bilíngue a surdos desenvolvido em um centro de estudos inserido dentro de uma universidade pública de uma cidade do interior localizada na região sudeste do país. Todos os encontros foram gravados em áudio e vídeo e registrados em diário de campo. A geração de registros, análise e discussão dos dados seguiu o processo de pesquisa tipicamente associado aos estudos etnográficos (cf. ERICKSON, 1984, 1989). A análise dos dados envolveu exaustivas (re)leituras do corpus que compõe a pesquisa (diário de campo e transcrições das gravações em áudio e vídeo das conversas informais e dos encontros de grupos focais) com intuito de reunir evidências confirmatórias e/ou desconfirmatórias (ERICKSON, 1989) que validassem asserções para a pergunta de pesquisa. A análise recorreu ainda aos estudos relacionados à Linguística Aplicada através da crítica ao semilinguismo de Martin-Jones e Romaine (1986) e Maher (2007a), além de buscar respaldo na remodelação do conceito de língua proposto por César e Cavalcanti (2007). Tal conceito é proposto através da adoção da metáfora do caleidoscópio onde inúmeras possibilidades podem ser tomadas como legítimas, sem sobreposições de uma língua sob a outra. Na análise, também fui guiada pelos Estudos Culturais para compreender conceitos como o de "representação" elaborado por autores como Silva (2000) e Woodward (2000), entre outros conceitos tais como o de "terceiro espaço" e "entre lugares" de Bhabha (2007). Em síntese, as asserções desenvolvidas indicaram que as representações dos profissionais e estagiários surdos e ouvintes e de familiares participantes recaem no não reconhecimento das mesmas enquanto língua, apesar da funcionalidade linguística apresentada dentro do contexto familiar a que se prestam. Além disso, o uso das línguas de sinais caseiras é visto como prejudicial ao aprendizado da LIBRAS e foi associado como um critério de exclusão das comunidades surdas. A discussão teórica sobre as asserções visou colaborar com a desconstrução de estereótipos (BHABHA, 2007) em torno do surdo perpetuado nos discursos como "sem-língua". Desse modo, espera-se que esta pesquisa traga contribuições para as discussões sobre a perspectiva do multilinguismo em contextos de minorias (CÉSAR; CAVALCANTI, 2007), neste caso, especificamente, a surdez, favorecendo uma educação inclusiva diferenciada que considere e valorize a diversidade linguística e cultural do surdo / Abstract: Deaf people have long had the right to communicate by sign language denied, because this was not seen by society as linguistically legitimate. Recently, Brazilian Sign Language (LIBRAS) obtained official recognition (BRASIL, 2002) and, from a socio-anthropological view (SKLIAR, 1998), some studies have challenged representations of the deaf based on pathologised concepts related to hearing deficit and have placed the language of the deaf in discussions about bilingual education in minority contexts and invisibility (CAVALCANTI, 1999). However, in bilingual education for deaf people only Portuguese and LIBRAS are accepted in school while other languages that permeate this context tend to be rendered invisible (SILVA, 2008). Thus, the deaf person who does not meet the expectations regarding use of the languages of the school is often described in school as having 'no language'. Given this background, the aim of this research was to investigate the representations about household sign languages. The study focused on a programme designed to support bilingual education in Portuguese and LIBRAS. The central research question for the study was: What are the representations of household sign languages among families of deaf children and among deaf and hearing professionals and trainees? This study was broadly located within the field of Applied Linguistics but drew on interdisciplinary and cross-disciplinary perspectives (MOITA LOPES, 2008). It was also qualitative and ethnographic in nature (ERICKSON, 1986; DENZIN; LINCOLN, 2006). For the generation of data (ERICKSON, 1989), the main research corpus came from focus group meetings (PETTENDORFER; MONTALVÃO, 2006; MOITA LOPES, 2009) and from informal conversations. It also came from field diary and the retrospective diary of the researcher. The focus group meetings (3 meetings with professionals and trainees and 9 meetings with family members) and the informal conversations were conducted with participants in the support programme for a bilingual school for the deaf, mentioned above, which was developed within a research centre housed in a public university in the southeast region of Brazil. All meetings were recorded on audio and video and notes were kept in a field diary. The generation, analysis and discussion of the data followed the research process typically associated with ethnographic studies (e.g. ERICKSON, 1984; 1989). The analysis of the data involved complete (re)readings of the corpus that was generated by the research (the field diary and the transcripts of audio and video recordings of informal conversations and meetings of focus groups) in order to gather evidence that confirmed or disconfirmed assertions related to the research question. The analysis resonated with studies within Applied Linguistics that have put forward a critique of notions such as 'semilingualism' (e.g. MARTIN-JONES; ROMAINE, 1986; MAHER, 2007a) and with the reshaping of the concept of language proposed by César and Cavalcanti (2007). This reshaping of the concept of language is proposed through the adoption of the metaphor of the kaleidoscope, where many possibilities are taken as legitimate without any one language being privileged over another. The analysis also drew on research in Cultural Studies, especially the concepts of 'representation' developed by authors such as Silva (2000) and Woodward (2000), among other concepts such as the 'Third Space' and the 'in-between' (BHABHA, 2007). In summary, the assertions drawn from my analysis of the corpus indicated that the representations of household sign languages among deaf and hearing professionals and trainees and among the family members participating in this study were not recognised as 'languages', despite the linguistic features that they displayed within the family context. Furthermore, the use of household sign languages is seen as detrimental to learning LIBRAS. In addition household sign language was associated as a criterion for exclusion of the deaf community. The theoretical discussion of the assertions aimed to collaborate with deconstruction of stereotypes (BHABHA, 2007) around the deaf as being 'no language'. Thus, it is expected that this research will make a contribution to discussions about the prospect of multilingualism in the context of minorities, in this case, specifically, deafness, and that it will promote inclusive education that values difference and the cultural and linguistic diversity among the deaf / Mestrado / Multiculturalismo, Plurilinguismo e Educação Bilingue / Mestre em Linguística Aplicada

Le Naturalisme a été peu étudié au Brésil, ainsi que les relations établies entre le Naturalisme brésilien et les modèles européens que l'ont influencé. Dans cette recherche, nous avons voulu éclairer les rapports tissés entre Emile Zola et Aluísio Azevedo, à travers l'analyse des représentations de la ville dans les romans Casa de Pensão et Pot-Bouille, en montrant les ressemblances et les divergences entre ces oeuvres. Cette recherche a donc décrit l'imaginaire urbain présent dans ces oeuvres par le moyen des catégories de Walter Benjamin qui se caractérise par l'opposition à la modernité et à la ville. Ces oeuvres s'appuient encore sur l'idée selon laquelle le topos urbain engendre la formation de certains types de subjectivité. Ainsi, les habitations collectives analysées - l'immeuble généralisé par les réformes urbaines d'Haussmann et la pension de famille carioca - produisent les manières d'être, d'agir et de penser spécifiques chez leurs habitants. Telle démarche anthropologique est au fond une sorte de pédagogie négative selon laquelle les écrivains démontrent un processus erroné d'éducation, en caractérisant ses mauvais résultats. En outre, Emile Zola et Aluísio Azevedo partent toujours d'un modèle éducatif correct qui est implicite ou explicite. Il faut encore ajouter que l'approche topologique et pédagogique, mise en oeuvre dans Pot-Bouille se transforme dans Casa de Pensão en une recherche de l'identité nationale qui se matérialise par l'analyse de plusieurs modèles de formation de subjectivité mis en fonction dans les habitations typiques du Rio de Janeiro du XIXème siècle - le "sobrado"portugais et la pension de famille. / Naturalism has been stereotyped and understudied in Brazil, and so have the relationships between Brazilian Naturalism and the European models that originated it. This thesis aims at shedding light on the relationships between Emile Zola and Aluisio Azevedo through the analysis of the representations of the city in the novels Casa de Pensão and Pot-Bouille. Parallelism and divergence between the two literary pieces will be presented. To this end, this study employs thematic criticism based on Walter Benjamin's categories in order to describe the urban imagery found in Azevedo's Casa de Pensão and Zola's Pot-Bouille, an imagery characterized by an opposition to modernity and the city. Also, both novels are inspired by the strong belief that the urban topos generates peculiar types of subjectivity. Hence, the collective habitations in focus – i.e., the immeuble disseminated by Baron Haussmann's urban reforms and the boardinghouses in Rio de Janeiro – would engender certain ways of being, acting and thinking in their dwellers. Such anthropological demarché translates as a sort of negative pedagogy, which displays an inappropriate educational process and points out its spurious results, thus implicitly or explicitly advancing an alternative educational model. It is here concluded that the pedagogical and topological approach implemented in Pot-Bouille appears in Casa de Pensão as a study of the national ailments, which is in turn demonstrated through the analysis of various models of subjectivity formation at specific loci of the city of Rio de Janeiro, namely the modest Portuguese two-storey houses and the typical boarding houses.

A novel framework based on cluster co-occurrence and graph theory for structure discovery is applied to audio to find new types of audio objects which enable the compression of an input signal. These new objects differ from those found in current object coding schemes as their shape is not restricted by any a priori psychoacoustic knowledge. The framework is novel from an application perspective, as it marks the first time that graph theory is applied to audio, and with regards to theoretical developments, as it involves new extensions to the areas of unsupervised learning algorithms and frequent subgraph mining methods. Tests are performed using a corpus of audio files spanning a wide range of sounds. Results show that the framework discovers new types of audio objects which yield average respective overall and relative compression gains of 15.90% and 23.53% while maintaining a very good average audio quality with imperceptible changes.

W. D. Munn proved that a finite dimensional representation of an inverse semigroup is equivalent to a ⋆-representation if and only if it is bounded. The first goal of this thesis will be to give new analytic proof that every finite dimensional representation of a compact inverse semigroup is equivalent to a ⋆-representation. The second goal is to parameterize all finite dimensional irreducible representations of a compact inverse semigroup in terms of maximal subgroups and order theoretic properties of the idempotent set. As a consequence, we obtain a new and simpler proof of the following theorem of Shneperman: a compact inverse semigroup has enough finite dimensional irreducible representations to separate points if and only if its idempotent set is totally disconnected. Our last theorem is the following: every norm continuous irreducible ∗-representation of a compact inverse semigroup on a Hilbert space is finite dimensional.

Throughout the first decade of the 2000s, LGBTQ+ visibility has steadily increased in North American popular culture, allowing for not only more LGBTQ+ characters/figures to surface, but also establishing more diverse and nuanced representations and storylines. Bisexuality, while being part of the increasingly popular phrase of inclusivity (LGBTQ+), however, is one sexuality that not only continues to be overlooked within popular culture but that also continues to be represented in limited ways. In this doctoral thesis I examine how bisexual women are represented within mainstream popular culture, in particular on American television, focusing on two, popular programs (The L Word and the Shot At Love series). These texts have been chosen for popularity and visibility in mainstream media and culture, as well as for how bisexual women are unprecedentedly made central to many of the storylines (The L Word) and the series as a whole (Shot At Love). This analysis provides not only a detailed historical account of bisexual visibility but also discusses bisexuality thematically, highlighting commonalities across bisexual representations as well as shared themes between and with other identities. By examining key examples of bisexuality in popular culture from the first decade of the twenty-first century, my research investigates how representations of bisexuality are often portrayed in conversation with hegemonic understandings of gender and sexuality, specifically highlighting the mainstream "gay rights" movement's narrative of "normality" and "just like you" politics. Finally, it is in recognizing how representations of bisexuality are framed by specific reoccurring themes/tropes, as well as how these themes/tropes work together within larger social, cultural, and political climates, that it becomes possible to challenge existing gender and sexuality norms and ideals and create a more nuanced and complex understanding of bisexuality.

The development of phonological representations remains a hot topic within both the developmental and neural network literature. Historically, theoretical accounts have fallen within one of two camps: the accessibility account which proposes that phonological representations are adult-like from infancy (Rozin & Gleitman, 1977; Liberman, Shankweiler & Liberman, 1989) and the emergent account which proposes that phonological representations become gradually restructured over development (Metsala & Walley, 1998; Ventura, Kolinsky, Fernandes, Querido & Morais, 2007; Ziegler & Goswami, 2005). Within this thesis we tested predictions made by the accessibility account and key variants of the emergent account using data from both behavioural (Chapters 2, 3 and 4) and neural network studies (Chapter 5). The novel measures used within Chapters 2 to 4 were devised to allow us to contrast implicit measures of phonological representation (PR) which probe the segmentedness of the representations themselves, with explicit PR measures which tap into children’s conscious awareness of phonological segments. Within Chapter 2 we present evidence that while explicit awareness of phonological structure is dependent on letter-sound knowledge, implicit sensitivity to the segments within words emerges independent of literacy. Within Chapter 3 a longitudinal study investigated the segmentedness of children’s phonological representations at the rime and phoneme level. These results demonstrate that implicit sensitivity to both rime and phoneme segments is driven by vocabulary growth and is not dependent on letter-sound knowledge. The results within Chapter 3 also suggest that, while awareness of rime segments emerges naturally through oral language experience, explicit awareness of individual phonemes is related to letter-sound knowledge. In Chapter 4 we explored the idea of global versus phonemic representation using a mispronunciation reconstruction task. We found that sensitivity to both global and phonemic similarity increased over time, but with global sensitivity reaching adult levels early on in development. In Chapter 5 a neural network was trained on the mappings between real acoustic input and articulatory output data allowing us to simulate the development of phonological representations computationally. The simulation data provide further evidence of a developmental increase in sensitivity to both global and phonemic similarity within a preliterate model. Taken together, the results provide strong evidence that as children’s vocabularies grow they become increasingly sensitive to both the global properties and segmental structure of words, independent of literacy experience. Children’s explicit awareness of phonemes, on the other hand, seems to emerge as a consequence of learning the correspondence between letters and sounds. Within the context of the wider literature, the current results are most consistent with the PRIMIR framework which predicts early detailed phonetic representations alongside gradually emerging phonemic categories (Werker & Curtin, 2005). This thesis underlines the importance of using implicit measures when trying to probe the representations themselves rather than children’s conscious awareness of them. The thesis also represents an important step towards modelling the emergence of segmental representation computationally using real speech data.

Dans le cadre de la préparation du Square Kilometre Array (SKA), le plus large radio interféromètre au monde, de nouveaux défis de traitement d'images sont à relever. En effet, les données fournies par SKA auront un débit énorme, nécessitant ainsi un traitement en temps réel. En outre, grâce à sa résolution et sa sensibilité sans précédent, les observations seront dotées d'une très forte dynamique sur des champs de vue très grands. De nouvelles méthodes de traitement d'images robustes, efficaces et automatisées sont alors exigées. L'objectif de la thèse consiste à développer une nouvelle méthode permettant la restauration du modèle de l'image du ciel à partir des observations. La méthode est conçue pour l'estimation des images de très forte dynamique avec une attention particulière à restaurer les émissions étendues et faibles en intensité, souvent noyées dans les lobes secondaires de la PSF et le bruit. L'approche proposée est basée sur les représentations parcimonieuses, nommée MORESANE. L'image du ciel est modélisée comme étant la superposition de sources, qui constitueront les atomes d'un dictionnaire de synthèse inconnu, ce dernier sera estimé par des a priori d'analyses. Les résultats obtenus sur des simulations réalistes montrent que MORESANE est plus performant que les outils standards et très compétitifs avec les méthodes récemment proposées dans la littérature. MORESANE est appliqué sur des simulations d'observations d'amas de galaxies avec SKA1 afin d'investiguer la détectabilité du milieu non thermique intra-amas. Nos résultats indiquent que cette émission, avec SKA, sera étudiée jusqu'à l'époque de la formation des amas de galaxies massifs. / Within the framework of the preparation for the Square Kilometre Array (SKA), that is the world largest radio telescope, new imaging challenges has to be conquered. The data acquired by SKA will have to be processed on real time because of their huge rate. In addition, thanks to its unprecedented resolution and sensitivity, SKA images will have very high dynamic range over wide fields of view. Hence, there is an urgent need for the design of new imaging techniques that are robust and efficient and fully automated. The goal of this thesis is to develop a new technique aiming to reconstruct a model image of the radio sky from the radio observations. The method have been designed to estimate images with high dynamic range with a particular attention to recover faint extended emission usually completely buried in the PSF sidelobes of the brighter sources and the noise. We propose a new approach, based on sparse representations, called MORESANE. The radio sky is assumed to be a summation of sources, considered as atoms of an unknown synthesis dictionary. These atoms are learned using analysis priors from the observed image. Results obtained on realistic simulations show that MORESANE is very promising in the restoration of radio images; it is outperforming the standard tools and very competitive with the newly proposed methods in the literature. MORESANE is also applied on simulations of observations using the SKA1 with the aim to investigate the detectability of the intracluster non thermal component. Our results indicate that these diffuse sources, characterized by very low surface brightness will be investigated up to the epoch of massive cluster formation with the SKA.

Orientador: Sérgio Antônio da Silva Leite / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Educação / Made available in DSpace on 2018-08-26T21:56:17Z (GMT). No. of bitstreams: 1 Lima_CinthiaVieiraBrum_M.pdf: 3165018 bytes, checksum: b2fae90581cef5aca5640a181a127ae9 (MD5) Previous issue date: 2014 / Resumo: Este estudo investiga as representações sociais de escola em produções de alunos do Ensino Fundamental de uma escola pública municipal em Campinas, SP. Está ancorado na Teoria das Representações Sociais (TRS), do franco-romeno Serge Moscovici, que parte dos estudos sobre Representações Coletivas de Durkheim para elaborar o conceito de representações sociais. Moscovici elege a TRS como o cerne da Psicologia Social. Está relacionada ao conhecimento do/elaborado pelo senso comum, com a finalidade de comunicação e orientação de comportamentos. Sendo a escola uma das instituições marcantes na vida do sujeito social, investigar as representações ali formadas sobre a própria instituição torna-se relevante. Inúmeros são os trabalhos que abordam as representações sociais sobre a escola ou elementos do universo escolar, formadas por educadores, no exercício da profissão, ou por estudantes universitários. Porém, os trabalhos que versam sobre as ideias, concepções, discursos e representações das crianças, "usuárias" diretas desta instituição aqui problematizada, são em menor quantidade, conforme se constata na literatura; neste cenário, dar voz aos alunos torna-se relevante. Foram então analisadas produções "livres" e direcionadas de alunos do 5º ano do Ensino Fundamental. A análise foi baseada nos pressupostos da pesquisa de cunho qualitativo, nos quais a análise é o processo de busca e de organização sistemática dos dados coletados, com o objetivo de aumentar a compreensão desses materiais e permitir apresentar aos outros o que foi encontrado. Assim, a partir da leitura cuidadosa das produções das crianças, foi feita a seleção daquelas que possuem conteúdos que contribuem para este estudo. Em seguida, buscou-se identificar possíveis núcleos e subnúcleos de significação referentes às representações sociais que os alunos têm de escola, os quais foram posteriormente discutidos à luz da base teórica assumida. Esperou-se, com este estudo, identificar e analisar as representações que os alunos têm de escola e, a partir daí, inferir as possíveis relações que essas representações têm com o modo de participação dos sujeitos nesse ambiente. Os resultados sugerem que os alunos representam positivamente a escola, como lugar privilegiado para a aquisição do conhecimento, espaço das relações, das brincadeiras e também como preparatória para a inserção no mercado de trabalho. Através de suas expectativas e sugestões, foi possível acessar seus desejos sobre a escola: é um lugar que deve ser limpo e organizado, harmonioso e preocupado em oferecer educação integral através de uma reorganização das práticas e espaços/tempos escolares. Ressalta-se a importância de se legitimar a voz dos alunos e engajá-los junto aos outros atores da comunidade escolar para participar das decisões escolares, a fim de forjar um sujeito autônomo e participativo / Abstract: This study investigates the school¿s social representations among children of a municipal public school in Campinas, by focusing on their school activities. It is based on the Theory of Social Representations of the Franco-Romanian, Serge Moscovici, who was inspired by the notion of Collectives Representations of Émile Durkheim. The Theory of Social Representations was elected by Moscovici as the core of the Social Psychology and it gives us an insight into how knowledge is understood by the common sense with the purposes of stablishing communication and guiding behaviours. Schools are strong influences at the lives of social subjects; therefore it is relevant to investigate what are the created representations of these institutions by those who are inside them. Most of the papers about social representations of schools and their elements have as their subjects professionals in education and university students. Children, however, have not received the same attention, and only a lower number of papers about pupil¿s representations of their schools have been written. In order to gather information about the views of these children, who are the direct "users" of the Elementary School here in study, an analysis of their schoolworks was done. The students were all on 5th grade, and some of their works were produced with the guidance of the educator and others without it. A framework of qualitative research was used in the analyses, thus the process of searching data and its posterior systematic organization, aim to increase the comprehension of the gathered material and to enable the presentation of the findings. After a careful reading of the children¿s productions, a selection of what would contribute to this study was made. Next step was to identify possible significant nucleus and sub-nucleus related to the pupils¿ social representations about the school. These were discussed under the chosen theoretical framework. The study expects to identify and analyse the social representations that the children have about the school and infer the possible relations between these representations and the way the subjects participate in school environment. The outcome of it suggests a positive representation of the school by its pupils, who view the school as a privileged place where they can acquire knowledge, build relationships, have fun and also be prepared for the labour market. Through their expectations and suggestions it was possible to know that they idealize school as a place that should be organized, clean and harmonious. They also demonstrated a wish to have a more extensive type of education, in its scope and content, by reorganizing school practices, space and timetables. It is noteworthy the importance of legitimizing pupil¿s voice and engaging them with the others at the school community for the decision making, in order to create autonomous and participative beings / Mestrado / Psicologia Educacional / Mestra em Educação

Orientadores: Adriano Adrega de Moura, Evgeny Mukhin / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação Científica / Made available in DSpace on 2018-08-26T22:56:39Z (GMT). No. of bitstreams: 1 Brito_MatheusBatagini_D.pdf: 1928614 bytes, checksum: bd194d09898859744dc51e0bcccd7fa1 (MD5) Previous issue date: 2015 / Resumo: Estudamos representações de dimensão finita para uma álgebra afim quantizada a partir de dois pontos de vista distintos. Na primeira parte deste trabalho estudamos o limite graduado de uma certa subclasse de representações irredutíveis. Seja V uma representação de dimensão finita para uma álgebra do tipo A e suponha que V é isomorfa ao produto tensorial de uma afinização minimal por partes cujo peso máximo é a soma de distintos pesos fundamentais por módulos de Kirillov--Reshetikhin cujos pesos máximos são o dobro de um peso fundamental. Provamos que V admite limite graduado L e que L é isomorfo a um módulo de Demazure de nível dois bem como ao produto de fusão dos limites graduados de cada um dos supramencionados fatores tensoriais de V. Provamos ainda que, se a álgebra for do tipo clássica (resp. G), o limite graduado das afinizações minimais (regulares) (resp. módulos de Kirillov--Reshetikhin) são isomorfos ao módulos CV para alguma R^+ partição descrita explicitamente. Na segunda parte provamos que um módulo para a álgebra afim quantizada do tipo B e posto n é manso se, e somente se, ele é fino. Em outras palavras, os geradores da subálgebra de Cartan afim são diagonalizáveis se, e somente se, os autoespaços generalizados associados têm dimensão um. Classificamos tais módulos e descrevemos seus respectivos q-caracteres. Em alguns casos, o q-caracter é descrito por super standard Young tableaux do tipo (2n|1) / Abstract: We study finite--dimensional representations for a quantum affine algebra from two different points of view. In the first part of this work we study the graded limit of a certain subclass of irreducible representations. Let V be a finite--dimensional representation for a quantum affine algebra of type A and assume that V is isomorphic to the tensor product of a minimal affinization by parts whose highest weight is a sum of distinct fundamental weights by Kirillov-Reshetkhin modules whose highest weights are twice a fundamental weight. We prove that V admits a graded limit L and that L is isomorphic to a level-two Demazure module as well as to the fusion product of the graded limits of each of the aforementioned tensor factors of V. We also prove that if the quantum affine algebra is of classical type (resp. type G), the graded limit of (regular) minimal affinizations (resp. Kirillov--Reshetkin modules) are isomorphic to CV-modules for some R^+ partition explicitly described. In the second part we show that a module for the quantum affine algebra of type B and rank n is tame if and only if it is thin. In other words, the Cartan currents are diagonalizable if and only if all joint generalized eigenspaces have dimension one. We classify all such modules and describe their q-characters. In some cases, the q-characters are described by super standard Young tableaux of type (2n|1) / Doutorado / Matematica / Doutor em Matemática

Le théorème de Mordell-Weil affirme que, pour toute variété abélienne définie sur un corps de nombres, le groupe des points K-rationnels est de type fini. Plus exactement, ce groupe peut être vu comme le produit d’un groupe libre et d’un sous-groupe fini de points de torsion définis sur K. Il est naturel de se demander si l’on peut obtenir une borne uniforme pour le cardinal du sous-groupe fini des points de torsion définis sur une extension finie de K, dépendant uniquement du degré de cette extension, lorsque la variété abélienne varie. Pour ce qui est des courbes elliptiques définies sur un corps de nombres, Merel a prouvé en 1994 que l’on peut obtenir une borne uniforme en utilisant des méthodes développées par Mazur, Kenku-Momose et Kamienny. Cependant, il est aussi naturel de se demander si l’on peut obtenir une borne de ce cardinal, qui dépend uniquement du degré de cette extension,lorsque l’extension varie et la variété abélienne est fixée. Concernant cette dernière question Hindry et Ratazzi ont énoncé plusieurs résultats concernant certaines classes de variétés abéliennes. L’objectif de cette thèse, sera de présenter des nouveaux résultats dans cette direction. On se concentrera sur la classe de variétés abéliennes de type III pleinement de type Lefschetz, c’est-à-dire, telles que leur groupe de Mumford-Tate soit le groupe des similitudes orthogonales qui commutent avec les endomorphismes et telles qu’elles vérifient la conjecture de Mumford-Tate. On démontre des nouveaux résultats concernant la conjecture de Mumford-Tate. En particulier, on fournit une liste de variétés abéliennes dont on sait prouver qu’elles sont pleinement de type Lefschetz. / Mordell-Weil’s theorem states that, for an abelian variety defined over a number field K the group of K-rational points is finitely generated. More precisely, it can be seen as a product of a free group by a finite subgroup of torsion points over K. One can wonder if we can get an uniform bound for the order of the subgroup of torsion points over a finite extension L over K, depending on the degree of this extension and the dimension of the abelian variety, when the abelian variety varies in a certain class. For elliptic curves defined over a number field K, Merel proved in 1994 that we can get a uniform bound using methods developed by Mazur, Kenku-Momose and Kamienny. A complementary question would be to ask if we can get a bound for the order of the subgroup of torsion points over a finite extension L over K, depending on the degree of this extension and the dimension of the abelian variety, when L varies over all the finite extensions of K and the abelian variety is fixed. This question had been already answered by Hindry and Ratazzi for certain classes of abelian variety.This thesis will focus on this last question and will extend the previous results. We are going to present some new results concerning the class of abelian variety of type III in Albert’s classification and “fully of Lefschetz type” (i.e. whose Mumford-Tate group is the group of symplectic or orthogonal similitudes commuting with endomorphisms and which satisfy the Mumford-Tate conjecture). We also show some new results in the direction of the Mumford-Tate conjecture. Moreover, we present a list of abelian varieties which, we know, are fully of Lefschetz type.