O crescimento acelerado da internet proporcionou uma quantidade grande de informações acessíveis aos usuários. Ainda que tal quantidade possua algumas vantagens, os usuários que possuem pouca ou nenhuma experiência para escolher uma alternativa dentre as várias apresentadas terão dificuldades em encontrar informações (ou itens, considerando o escopo deste trabalho) úteis e que atendam às suas necessidades. Devido a esse contexto, os sistemas de recomendação foram desenvolvidos para auxiliar os usuários a encontrar itens relevantes e personalizados. Tais sistemas são divididos em diversas arquiteturas. Como exemplo estão as arquiteturas baseadas em: conteúdo, filtro colaborativo e conhecimento. Para este trabalho, a primeira arquitetura foi explorada. A arquitetura baseada em conteúdo recomenda itens ao usuário com base na similaridade desses aos itens que o usuário mostrou interesse no passado. Por consequência, essa arquitetura possui a limitação de, geralmente, realizar recomendações com baixa serendipidade, uma vez que os itens recomendados tendem a ser semelhantes àqueles observados pelo o usuário e, portanto, não apresentam novidade ou surpresa. Diante desta limitação, o aspecto de serendipidade tem destaque nas discussões apresentadas neste trabalho. Assim, o objetivo deste trabalho é minimizar o problema da baixa serendipidade das recomendações por meio da utilização da análise de similaridades parciais implementada usando ensemble de agrupamentos. Para alcançar este objetivo, estratégias de recomendação baseadas em conteúdo implementadas usando agrupamento e ensemble de agrupamento foram propostas e avaliadas neste trabalho. A avaliação contou com análises qualitativas sobre as recomendações produzidas e com um estudo com usuários. Nesse estudo, quatro estratégias de recomendação de notícias foram avaliadas, incluindo as duas propostas neste trabalhos, uma estratégia baseada em recomendação aleatória, e uma estratégia baseada em coagrupamento. As avaliações consideraram aspectos de relevância, surpresa e serendipidade de recomendações. Esse último aspecto é descrito como itens que apresentam tanto surpresa quanto relevância ao usuário. Os resultados de ambas análises mostraram a viabilidade da utilização de agrupamento como base de recomendação, uma vez que o ensemble de agrupamentos obteve resultados satisfatórios em todos os aspectos, principalmente em surpresa, enquanto a estratégia baseada em agrupamento simples obteve os melhores resultados em relevância e serendipidade / The accelerated growth of the internet has provided a large amount of information accessible to users. Although this amount of information has some advantages, users who have little or no experience in choosing one of several alternatives will find it difficulty to find useful information (or items, considering the scope of this work) that meets their needs. Due to this context, recommender systems have been developed to help users find relevant and personalized items. Such systems are divided into several architectures as content-based, collaborative filtering and knowledge-based. The first architecture was explored in this work. The content-based architecture recommends items to the user based on their similarity to items that the user has shown interest in the past. Consequently, this architecture has the limitation of generally making recommendations with low serendipity, since the recommended items tend to be similar to those observed by the user and, therefore, do not present novelty or surprise. Given this limitation, the aspect of serendipity is highlighted in the discussions presented in this work. Thus, the objective of this work is to minimize the problem of the low serendipity of the recommendations through the use of the partial similarity analysis implemented using cluster ensemble. To achieve this goal, content-based recommendation strategies implemented using clustering and cluster ensemble were proposed and evaluated. The evaluation involved qualitative analysis of the recommendations and a study with users. In such a study, four news recommendation strategies were evaluated including the two strategies proposed in this work, a strategy based on random recommendation, and a strategy based on co-clustering. The evaluations considered aspects of relevance, surprise and serendipity of recommendations. This last aspect is described as items that present both surprise and relevance to the user. The results of both analyzes showed the feasibility of using clustering as the basis of recommendation, since cluster ensemble had satisfactory results in all aspects, mainly in surprise, whereas the simple clustering-based strategy obtained the best results in relevance and serendipity

Interface Cérebro-Computador é um meio que permite a comunicação do cérebro com dispositivos externos e tem como principal público-alvo as pessoas com problemas motores, incapazes de se comunicarem e/ou se locomoverem. Uma das principais aplicações são os soletradores baseados no P300 que fornecem um meio de indivíduos se comunicarem através de um teclado virtual. Devolver a capacidade de comunicação para uma pessoa é de extrema importância para a qualidade de vida das pessoas. Esse tipo de aplicação possui diversos desafios, um deles é a necessidade da BCI ser treinada especificamente para cada indivíduo. Esse treinamento pode levar horas e até mesmo dias. Uma das formas de diminuir esse tempo é utilizar um dos conjuntos de canais pré-definidos que são sugeridos na literatura, porém esses conjuntos não garantem um funcionamento adequado da BCI, o que pode frustar os indivíduos não desejar mais utilizar uma BCI. Para solucionar esse problema, é proposto no presente trabalho a seleção de canais a partir de um conjunto de canais para agilizar o processo de treinamento e atingir um ótimo desempenho com a BCI. / Brain-Computer Interface is a means that allows the communication of the brain with external devices and has as main target audience the people with motor problems, unable to communicate and/or move around. One of the main applications is the P300-based spellers that provide a means for individuals to communicate through a virtual keyboard. Recovering the ability to communicate to a person is of extreme importance to the quality of peoples lives. This type of application has several challenges, one of which is the need for BCI to be trained specifically for each individual. This training can take hours and even days. One of the ways to decrease this time is to use one of the predefined set of channels that are suggested in the literature, but these sets do not guarantee an adequate functioning of BCI, which can frustrate individuals no longer want to use a BCI. To solve this problem, it is proposed in the present work the selection of channels from a set of channels to accelerate the training process and achieve optimal performance with BCI.

Martin Streda is a one-act monodrama for baritone and an ensemble of eight instrumentalists. The libretto was written by the composer. The drama concerns Martin Streda, a Czech political prisoner in a solitary confinement cell of a communist concentration camp on the eve of his death. The opera has a duration of approximately 30 minutes and is divided into four main parts. The analytical essay describes the development and operation of Mar-sys, a collection of twenty pitch aggregates derived from intervalic cells, rhythmic cells drawn from the Morse code alphabet, and other pitch organization systems.

Les ensembles à vent existent dans toute l’Europe. Ils sont un trait de culture partagé. La miseà jour d’une sub-culture fanfaristique s’effectue à partir des comparaisons, migrations,circulations, étudiées à travers les ensembles à vent et par emboîtement d’échelles. A partird’exemples représentatifs, pris à hauteur d’Hommes, l’existence d’un modèle européen de lafanfare, dans son fonctionnement, son image, son rôle… est mis au jour. Pluriels, les ensemblesà vent ne sont pas des copies parfaites, mais de nombreux points communs permettent demodéliser cette pratique socioculturelle.Même si pour beaucoup au second XXe siècle, le mouvement orphéonique relève du passé,notre étude des ensembles à vent débute dans les années 1940 avec la Seconde Guerre Mondialepuis la Libération, et s’achève dans les années 1980 marquées par un tournant social, politiqueet culturel. Plus que sur le déclin, la fanfare est, au cours de la période, en mutation. Inventé auXIXe siècle, l’ensemble à vent répond à une triple définition. Il s’agit tout d’abord d’unensemble d’instruments à vent (cuivres et bois) et de percussions joués par des musiciensamateurs. La fanfare est également un orchestre de plein air. Enfin, c’est une musique qui «marche », qui défile pour animer la cité.La nature même de cette pratique musicale collective, effectuée par des musiciens nonprofessionnels, inclut une dimension sociale capitale. Autour de cette pratique récréative, seforme un groupe avec ses sociabilités, qui le cimentent. Les ensembles à vent répondent aussià une demande sociale multiple et notamment un rôle d’éducation populaire.L’ensemble à vent apparaît comme un modèle transnational qui possède une réelle identité.Inclassable, il n’appartient ni à la culture populaire, ni à la culture savante. La catégorisationentre une culture dominée et une culture dominante doit être remise en cause au profit d’uneautonomisation des normes de valeurs et de l’abolition des hiérarchies. Le fonctionnement, toutcomme les appropriations qu’il subit et qu’il réalise, plaident en faveur d’une autonomisationdes ensembles à vent. Ils sont une pratique et un genre autonome et reconnaissable dans toutel’Europe. / Wind ensembles exist all over Europe. They are a shared cultural feature. The exposure of aband sub-culture is established from comparisons, migrations, circulations, through windensembles, and interlocking at various levels. Drawing from representative examples, on aperspective centered on Man, the existence of a European standard for brass-bands, in itsoperation, image, role is brought forward. In their varied nature, wind ensembles are not perfectduplicates, but many common features make a modelling of such a sociocultural practicepossible.Even though, for many, in the second half of the twentieth century, brass-band culture was athing of the past, our study of wind ensembles begins in the 1940s with the Second World War,then the Liberation, and ends in the 1980s with its social, political and cultural turning point.Rather than being declining, brass bands were, over the period, evolving sharply. Invented inthe nineteenth century, the wind ensemble meets three different definitions. It is first anensemble of wind instruments (brass and woodwind) and percussions played by amateurmusicians. Brass-bands is also an outdoor orchestra. Finally, it is a “marching” music, one thatparades to animate the city.The very nature of this collective music-making, carried out by non-professional musiciansincludes a major social dimension. Around this recreational activity, a group gathers, and iscemented by its sociabilities. Wind ensembles also respond to a multiple social demand, inparticular a role in popular education.The wind ensemble appears as a transnational model with a full identity. Unclassifiable, itbelongs neither to popular culture, nor to high brow culture. The categorization betweendominated and dominant culture should be called into question. Empowering standards as wellas abolishing hierarchies must be promoted instead. Its functioning as well as the ownerships itis subjected to and it achieves, advocates for an empowerment of wind ensembles. They are anautonomous and recognizable practice throughout Europe.

La logique Here-and-there (HT) est une logique monotone à trois valeurs, intermédiaire entre les logiques intuitionniste et classique. La logique de l'équilibre est un formalisme non-monotone dont la sémantique est donnée par un critère de minimalisation sur les modèles de la logique HT. Ce formalisme est fortement lié à la programmation orientée ensemble réponse (ASP), un paradigme relativement nouveau de programmation déclarative. La logique de l'équilibre constitue la base logique de l'ASP: elle reproduit la sémantique par ensemble réponse des programmes logiques et étend la syntaxe de l'ASP à des théories propositionnelles plus générales, i.e., des ensembles finis de formules propositionnelles. Cette thèse traite aussi bien des logiques modales sous-jacentes à la logique de l'équilibre que de ses extensions modales. Ceci nous permet de produire un cadre complet pour l'ASP et d'examiner de nouveau la base logique de l'ASP. A cet égard, nous présentons d'abord une logique modale monotone appelée MEM et capable de caractériser aussi bien l'existence d'un modèle de la logique de l'équilibre que la relation de conséquence dans ces modèles. La logique MEM reproduit donc la propriété de minimalisation qui est essentielle dans la définition des modèles de la logique de l'équilibre. Nous définissons ensuite une extension dynamique de la logique de l'équilibre. Pour ce faire, nous étendons le langage de la logique HT par deux ensembles de programmes atomiques qui permettent de mettre à jour, si possible, les valeurs de vérité des variables propositionnelles. Ces programmes atomiques sont ensuite combinés au moyen des connecteurs habituels de la logique dynamique. Le formalisme résultant est appelé logique Here-and-there dynamique (D-HT) et permet la mise-à-jour des modèles de la logique de l'équilibre. Par ailleurs, nous établissons un lien entre la logique D-HT et la logique dynamique des affectations propositionnelles (DL-PA): les affectations propositionnelles mettent à vrai ou à faux les valeurs de vérité des variables propositionnelles et transforment le modèle courant comme en logique dynamique propositionnelle. En conséquence, DL-PA constitue également une logique modale sous-jacente à la logique de l'équilibre. Au début des années 1990, Gelfond avait défini les spécifications épistémiques (E-S) comme une extension de la programmation logique disjonctive par des notions épistémiques. L'idée de base des E-S est de raisonner correctement à propos d'une information incomplète au moyen de la notion de vue-monde dans des situations où la notion précédente d'ensemble réponse n'est pas assez précise pour traiter le raisonnement de sens commun et où il y a une multitude d'ensembles réponses. Nous ajoutons ici des opérateurs épistémiques au langage original de la logique HT et nous définissons une version épistémique de la logique de l'équilibre. Cette version épistémique constitue une nouvelle sémantique non seulement pour les spécifications épistémiques de Gelfond, mais aussi plus généralement pour les programmes logiques épistémiques étendus. Enfin, nous comparons notre approche avec les sémantiques existantes et nous proposons une équivalence forte pour les théories de l'E-HT. Ceci nous conduit naturellement des E-S aux ASP épistémiques et peut être considéré comme point de départ pour les nouvelles extensions du cadre ASP. / Here-and-there (HT) logic is a three-valued monotonic logic which is intermediate between classical logic and intuitionistic logic. Equilibrium logic is a nonmonotonic formalism whose semantics is given through a minimisation criterion over HT models. It is closely aligned with answer set programming (ASP), which is a relatively new paradigm for declarative programming. To spell it out, equilibrium logic provides a logical foundation for ASP: it captures the answer set semantics of logic programs and extends the syntax of answer set programs to more general propositional theories, i.e., finite sets of propositional formulas. This dissertation addresses modal logics underlying equilibrium logic as well as its modal extensions. It allows us to provide a comprehensive framework for ASP and to reexamine its logical foundations. In this respect, we first introduce a monotonic modal logic called MEM that is powerful enough to characterise the existence of an equilibrium model as well as the consequence relation in equilibrium models. The logic MEM thus captures the minimisation attitude that is central in the definition of equilibrium models. Then we introduce a dynamic extension of equilibrium logic. We first extend the language of HT logic by two kinds of atomic programs, allowing to update the truth value of a propositional variable here or there, if possible. These atomic programs are then combined by the usual dynamic logic connectives. The resulting formalism is called dynamic here-and-there logic (D-HT), and it allows for atomic change of equilibrium models. Moreover, we relate D-HT to dynamic logic of propositional assignments (DL-PA): propositional assignments set the truth values of propositional variables to either true or false and update the current model in the style of dynamic epistemic logics. Eventually, DL-PA constitutes an alternative monotonic modal logic underlying equilibrium logic. In the beginning of the 90s, Gelfond has introduced epistemic specifications (E-S) as an extension of disjunctive logic programming by epistemic notions. The underlying idea of E-S is to correctly reason about incomplete information, especially in situations when there are multiple answer sets. Related to this aim, he has proposed the world view semantics because the previous answer set semantics was not powerful enough to deal with commonsense reasoning. We here add epistemic operators to the original language of HT logic and define an epistemic version of equilibrium logic. This provides a new semantics not only for Gelfond's epistemic specifications, but also for more general nested epistemic logic programs. Finally, we compare our approach with the already existing semantics, and also provide a strong equivalence result for EHT theories. This paves the way from E-S to epistemic ASP, and can be regarded as a nice starting point for further frameworks of extensions of ASP.

Ces dernières années se caractérisent par la prolifération des systèmes de vidéo-surveillance et par l’automatisation des traitements que ceux-ci intègrent. Parallèlement, le problème du suivi d’objets est devenu en quelques années un problème récurrent dans de nombreux domaines et notamment en vidéo-surveillance. Dans le cadre de cette thèse, nous proposons une nouvelle méthode de suivi d’objet, basée sur la méthode Ensemble Tracking et intégrant deux améliorations majeures. La première repose sur une séparation de l’espace hétérogène des caractéristiques en un ensemble de sous-espaces homogènes appelés modules et sur l’application, sur chacun d’eux, d’un algorithme basé Ensemble Tracking. La seconde adresse, quant à elle, l’apport d’une solution à la nouvelle problématique de suivi induite par cette séparation des espaces, à savoir la construction d’un filtre particulaire spécifique exploitant une pondération des différents modules utilisés afin d’estimer à la fois, pour chaque image de la séquence, la position et les dimensions de l’objet suivi, ainsi que la combinaison linéaire des différentes décisions modulaires conduisant à l’observation la plus discriminante. Les différents résultats que nous présentons illustrent le bon fonctionnement global et individuel de l’ensemble des propriétés spécifiques de la méthode et permettent de comparer son efficacité à celle de plusieurs algorithmes de suivi de référence. De plus, l’ensemble des travaux a fait l’objet d’un développement industriel sur les consoles de traitement de la société partenaire. En conclusion de ces travaux, nous présentons les perspectives que laissent entrevoir ces développements originaux, notamment en exploitant les possibilités offertes par la modularité de l’algorithme ou encore en rendant dynamique le choix des modules utilisés en fonction de l’efficacité de chacun dans une situation donnée. / Recent years have been characterized by the overgrowth of video-surveillance systems and by automation of treatments they integrate. At the same time, object tracking has become, within years, a recurring problem in many domains and particularly in video-surveillance. In this dissertation, we propose a new object tracking method, based on the Ensemble Tracking method and integrating two main improvements. The first one lies on the separation of the heterogeneous feature space into a set of homogenous sub-spaces called modules and on the application, on each of them, of an Ensemble Tracking-based algorithm. The second one deals with the new tracking problem induced by this separation by building a specific particle filter. This filter weights each used module in order to estimate, for each frame in the sequence, both position and dimensions of the tracked object and the linear combination of modular decisions leading to the most discriminative observation. The results we present illustrate the global and individual efficiency of all the specific properties of our method and allow comparing this efficiency with the one of several reference tracking algorithms. Furthermore, all this work has led to an industrial development on the treatment systems of the partner company. In conclusion of this work, we present the prospects generated by these original developments, more particularly using the possibilities offered by the algorith mmodularity or making the modules choice dynamic according to their efficiency in a given situation.

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Submitted by (ana.araujo@ufrpe.br) on 2016-07-05T16:55:56Z No. of bitstreams: 1 Evert Elvis Batista Almeida.pdf: 8214568 bytes, checksum: 34db767d9a38f53b7b60aaf92ca37a20 (MD5) / Made available in DSpace on 2016-07-05T16:55:56Z (GMT). No. of bitstreams: 1 Evert Elvis Batista Almeida.pdf: 8214568 bytes, checksum: 34db767d9a38f53b7b60aaf92ca37a20 (MD5) Previous issue date: 2009-02-26 / We applied a non-supervisioned data clustering technique based on a map of the problem into an inhomogeneous granular magnet problem. The physical behavior of the magnet is studied through the usual Monte Carlo method. Each data item is described by a set of numerical attributes, interpreted as points in a multiple-dimensional Euclidian space. The mapping consists in associating a Potts spin to each data point. The physical system is described by a disordered Potts Hamiltonian with several states with an exponentially decaying interaction among spins. The magnet reaches a superparamagnetic state at high temperatures in which the spins in certain grains are strongly correlated whereas the grains are loosely linked. In this way, each grain corresponds to a group or cluster. We implemented the method in a microcanonical ensemble where the conserved total energy is the control parameter. The temperature is calculated during the simulation and, besides thermodynamic stable states, it is possible to sample unstable and metastable state as well. We work with three artificial multiple-dimensional data set and a four-dimensional real data set. We obtained good results in all cases and discuss some issues concerning the microcanonical implementation of the superparamagnetic data clustering. / Aplicamos um método não supervisionado de agrupamento de dados para identificar padrões em vários conjuntos dados. A técnica baseia-se em um mapeamento do problema em um sistema magnético granular heterogêneo, cujo comportamento é investigado através de métodos Monte Carlo comumente empregado no campo da física estatística. Cada objeto é descrito por um conjunto de atributos de valores numéricos, interpretados como um ponto em um espaço euclidiano de dimensão apropriada. O mapeamento consiste em associar a cada item do conjunto, um ponto no espaço, um spin de Potts. O sistema físico é descrito por um hamiltoniano de Potts de muitos estados, no qual a interação entre os spins decai exponencialmente com a distância entre eles. Itens semelhantes, próximos, interagem fortemente enquanto que aqueles mais distantes entre si interagem apenas fracamente. O magneto atinge um estado superparamagnético para temperaturas suficientemente altas, no qual os spins de alguns grãos permanecem fortemente correlacionados, porém, os grãos estão fracamente ligados entre si. Cada grão corresponde a um grupo. Implementamos o método no ensemble microcanônico, no qual a energia total é conservada e constitui o parâmetro de controle. Nesse caso, a temperatura é calculada ao longo do processo e podemos acessar estados termodinamicamente estáveis, metaestáveis, bem como, instáveis. Trabalhamos com três conjuntos artificiais de dados, em duas e três dimensões, e um conjunto de dados reais com quatro dimensões. O desempenho do método foi satisfatório em todos os casos investigados.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-06-07T17:28:53Z No. of bitstreams: 1 karenbragaenes.pdf: 607859 bytes, checksum: f7907cc35c012dd829a223c7d46a7e6b (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-06-24T13:13:01Z (GMT) No. of bitstreams: 1 karenbragaenes.pdf: 607859 bytes, checksum: f7907cc35c012dd829a223c7d46a7e6b (MD5) / Made available in DSpace on 2017-06-24T13:13:01Z (GMT). No. of bitstreams: 1 karenbragaenes.pdf: 607859 bytes, checksum: f7907cc35c012dd829a223c7d46a7e6b (MD5) Previous issue date: 2016-01-08 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Recentemente, abordagens baseadas em ensemble de classificadores têm sido bastante exploradas por serem uma alternativa eficaz para a construção de classificadores mais acurados. A melhoria da capacidade de generalização de um ensemble está diretamente relacionada à acurácia individual e à diversidade de seus componentes. Este trabalho apresenta duas contribuições principais: um método ensemble gerado pela combinação de Perceptrons balanceados e um método para geração de uma hipótese equivalente ao voto majoritário de um ensemble. Para o método ensemble, os componentes são selecionados por medidas de diversidade, que inclui a introdução de uma medida de dissimilaridade, e avaliados segundo a média e o voto majoritário das soluções. No caso de voto majoritário, o teste de novas amostras deve ser realizado perante todas as hipóteses geradas. O método para geração da hipótese equivalente é utilizado para reduzir o custo desse teste. Essa hipótese é obtida a partir de uma estratégia iterativa de redução do espaço de versões. Um estudo experimental foi conduzido para avaliação dos métodos propostos. Os resultados mostram que os métodos propostos são capazes de superar, na maior parte dos casos, outros algoritmos testados como o SVM e o AdaBoost. Ao avaliar o método de redução do espaço de versões, os resultados obtidos mostram a equivalência da hipótese gerada com a votação de um ensemble de Perceptrons balanceados. / Recently, ensemble learning theory has received much attention in the machine learning community, since it has been demonstrated as a great alternative to generate more accurate predictors with higher generalization abilities. The improvement of generalization performance of an ensemble is directly related to the diversity and accuracy of the individual classifiers. In this work, we present two main contribuitions: we propose an ensemble method by combining Balanced Perceptrons and we also propose a method for generating a hypothesis equivalent to the majority voting of an ensemble. Considering the ensemble method, we select the components by using some diversity strategies, which include a dissimilarity measure. We also apply two strategies in view of combining the individual classifiers decisions: majority unweighted vote and the average of all components. Considering the majority vote strategy, the set of unseen samples must be evaluate towards the generated hypotheses. The method for generating a hypothesis equivalent to the majority voting of an ensemble is applied in order to reduce the costs of the test phase. The hypothesis is obtained by successive reductions of the version space. We conduct a experimental study to evaluate the proposed methods. Reported results show that our methods outperforms, on most cases, other classifiers such as SVM and AdaBoost. From the results of the reduction of the version space, we observe that the genareted hypothesis is, in fact, equivalent to the majority voting of an ensemble.