Les réseaux complexes sont des ensembles constitués d’un grand nombre d’entités interconnectées par des liens. Ils sont modélisés par des graphes dans lesquels les noeuds représentent les entités et les arêtes entre les noeuds représentent les liens entre ces entités. Ces graphes se caractérisent par un très grand nombre de sommets et une très faible densité de liens. Les réseaux sociaux sont des exemples de réseaux complexes où les entités sont des individus et les liens sont les relations (d’amitié, d’échange de messages) entre ces individus.L’analyse des réseaux complexes est généralement basée sur l’exploration locale du graphe sous-jacent : après avoir traité un nœud u, les prochains noeuds auxquels l’application fait référence appartiennent au voisinage de u. Étant donné que le graphe sous-jacent est habituellement non structuré, les séquences d’accès aux données en mémoire tendent à avoir une faible localité lorsque qu’on utilise par exemple le stockage de Yale qui est l’un des meilleurs connus. En plus, dans les applications basées sur l’analyse des réseaux le nombre de calculs requis pour chaque noeud peut être très variable, ce qui, dans les mises en œuvre parallèles (multithreadées), se traduit par un déséquilibre de charges entre les threads.Le travail réalisé dans cette thèse était lié au développement d’applications d’analyse des réseaux sociaux, qui soient à la fois faciles à écrire et efficaces. A cet effet, deux pistes ont été explorées: a)L’exploitation de la structure en communautés pour définir des techniques de stockage qui réduisent les défauts de cache lors de l’analyse des réseaux sociaux; b)La prise en compte de l’hétérogénéité des degrés des noeuds pour optimiser la mise en oeuvre parallèle.La première contribution de cette thèse met en évidence l'exploitation de la structure en communautés des réseaux complexes pour la conception des algorithmes de numérotation des graphes (NumBaCo, CN-order) permettant la réduction des défauts de cache des applications tournant dans ces graphes.Les résultats expérimentaux en mode séquentiel sur plusieurs architectures (comme Numa4) ont montré que les défauts de cache et ensuite le temps d'exécution étaient effectivement réduits; et que CN-order se sert bien des avantages des autres heuristiques de numérotation (Gorder, Rabbit, NumBaCo) pour produire les meilleurs résultats.La deuxième contribution de cette thèse a considéré le cas des applications multi-threadées. Dans ce cas, la réduction des défauts de cache n'est pas suffisante pour assurer la diminution du temps d'exécution; l'équilibre des charges entre les threads doit être assuré pour éviter que certains threads prennent du retard et ralentissent ainsi toute l'application. Dans ce sens, nous nous sommes servis de la propriéte de l'hétérogénéité des dégrés des noeuds pour développer l'heuristique Deg-scheduling. Les résultats expérimentaux avec plusieurs threads sur l'architecture Numa4 montrent que Deg-scheduling combiné aux heuristiques de numérotation permet d'obtenir de meilleur résultats.La dernière contribution de cette thèse porte sur l'intégration des deux catégories d'heuristiques développées dans les DSLs parallèles d'analyse des graphes. Par exemple, avec le DSL Green-Marl, les performances sont améliorées à la fois grâce aux heuristiques de numérotation et grâce aux heuristiques d’ordonnancement (temps réduit de 35% grâce aux heuristiques). Mais avec le DSL Galois, les performances sont améliorées uniquement grâce aux heuristiques de numérotation (réduction de 48%). / A complex network is a set of entities in a relationship, modeled by a graph where nodes represent entities and edges between nodes represent relationships. Graph algorithms have inherent characteristics, including data-driven computations and poor locality. These characteristics expose graph algorithms to several challenges, because most well studied (parallel) abstractions and implementation are not suitable for them. The main question in this thesis is how to develop graph analysis applications that are both --easy to write (implementation challenge), -- and efficient (performance challenge)? We answer this question with parallelism (parallel DSLs) and also with knowledge that we have on complex networks (complex networks properties such as community structure and heterogeneity of node degree).The first contribution of this thesis shows the exploitation of community structure in order to design community-aware graph ordering for cache misses reduction. We proposed NumBaCo and compared it with Gorder and Rabbit (which appeared in the literature at the same period NumBaCo was proposed). This comparison allowed to design Cn-order, another heuristic that combines advantages of the three algorithms (Gorder, Rabbit and NumBaCo) to solve the problem of complex-network ordering for cache misses reduction. Experimental results with one thread on Core2, Numa4 and Numa24 (with Pagerank and livejournal for example) showed that Cn-order uses well the advantages of the other orders and outperforms them.The second contribution of this thesis considered the case of multiple threads applications. In that case, cache misses reduction was not sufficient to ensure execution time reduction; one should also take into account load balancing among threads. In that way, heterogeneity of node degree was used in order to design Deg-scheduling, a heuristic to solve degree-aware scheduling problem. Deg-scheduling was combined to Cn-order, NumBaCo, Rabbit, and Gorder to form respectively Comm-deg-scheduling, Numb-deg-scheduling, Rab-deg-scheduling and Gor-deg-scheduling. Experimental results with many threads on Numa4 showed that Degree-aware scheduling heuristics (Comm-deg-scheduling, Numb-deg-scheduling, Rab-deg-scheduling and Gor-deg-scheduling) outperform their homologous graph ordering heuristics (Cn-order, NumBaCo, Rabbit, and Gorder) when they are compared two by two.The last contribution was the integration of graph ordering heuristics and degree-aware scheduling heuristics in graph DSLs and particularly Galois and Green-Marl DSLs. We showed that with Green-Marl, performances are increased by both graph ordering heuristics and degree-aware scheduling heuristics (time was reduced by 35% due to heuristics). But with Galois, performances are increased only with graph ordering heuristics (time was reduced by 48% due to heuristics).In perspective, instead of using complex networks properties to design heuristics, one can imagine to use machine learning. Another perspective concerns the theoretical aspect of this thesis. We showed that graph ordering for cache misses reduction and degree-aware scheduling for load balancing problems are NP-complete. We provided heuristics to solve them. But we didn't show how far these heuristics are to the optimal solutions. It is good to know it in the future.

Word-of-mouth (WOM) communication is a well studied phenomenon in the literature and content propagation in Online Social Networks (OSNs) is one of the forms of WOM mechanism that have been prevalent in recent years specially with the widespread surge of online communities and online social networks. The basic piece of information in most OSNs is a post (e.g., a tweet in Twitter or a post in Facebook). A post can contain different types of content such as text, photo, video, etc, or a mixture of two or more them. There are also various ways to enrich the text by mentioning other users, using hashtags, and adding URLs to external contents. The goal of this study is to investigate what factors contribute into the propagation of messages in Google+. To answer to this question a multidimensional study will be conducted. On one hand this question could be viewed as a natural language processing problem where topic or sentiment of posts cause message dissemination. On the other hand the propagation can be effect of graph properties i.e., popularity of message originators (node degree) or activities of communities. Other aspects of this problem are time, external contents, and external events. All of these factors are studied carefully to find the most highly correlated attribute(s) in the propagation of posts.

Orientador: Eduardo Strachman / Banca: Claudio Cesar de Paiva / Banca: Paulo Furquim de Azevedo / Resumo: Na presente dissertação buscamos estudar de maneira profunda uma característica comum a regimes democráticos proposta pela Escola da Escolha Pública. Determinados ramos desta Escola de Pensamento afirmam que os políticos trocam votos entre si buscando apoio futuro para seus projetos. Utilizando a metodologia de Análise de Redes Sociais, buscamos primeiramente mapear a atuação e os contatos dos Senadores da República Federativa do Brasil dentro das comissões fixas desta casa de leis no período compreendido pela 52ª Legislatura. Após este mapeamento procuramos criar meios de análise para responder a questão proposta pelos ramos da escola citada, ou seja, desejamos responder a questão teórica da existência ou não do logrolling no Senado Brasileiro. Anteriormente a análise empírica e resposta aos problemas propostos, apresentaremos a devida introdução teórica compreendida por uma revisão de literatura sobre os temas pertinentes, sejam eles puramente teóricos a respeito da troca de apoio, sejam eles analíticos a respeito do sistema político brasileiro / Abstract: In this dissertation we aimed to study in a profound way one common feature of democratic regimes proposed by the School of Public Choice. Certain branches of this school of thought claim that politicians swap votes between them seeking support for their future projects. Using the method of social networks analysis, we first map the activities and contacts of the Senators of the Federative Republic of Brazil within the fixed committees of this house of laws in the period by the 52nd Legislature. After this analysis we seek to create means to answer the question proposed by the branches of the school mentioned above, ie, we wish to answer the following question: can we see logrolling in the Brazilian Senate? Previously the empirical analysis and response to problems posed, we present the necessary theoretical introduction understood by reviewing the literature on relevant subjects, whether they are purely theoretical with respect to the exchange of support, or analytical about the brazilian political system / Mestre

abstract: This study examined the enactment of a high school district's college-going mission. Treating mission enactment as a case of policy implementation, this study used the lens of complexity theory to understand how system actors and contexts influenced variation and adaptation. Data collection methods included observations, interviews, focus groups, and surveys of various system actors including district staff, principals, counselors, teachers, and students. This study used a mixed methods analytic inductive technique and Social Network Analysis to describe the mission's implementation. Findings reflect that the mission was a vaguely defined value statement; school staff reacted to the mission with limited buy-in and confusion about what it really meant in practice. The mission lacked clear boundaries of what constituted related programs or policies. Consequently, in this site-based district, schools unevenly implemented related programs and policies. School staff wanted more guidance from district staff and clear expectations for mission-related actions. To help meet this need, the district was moving to a more centralized, hierarchical approach. Though they were providing information about the mission, district staff were not providing specific, responsive support to organize school staff's efforts around implementation. District staff were trying to find an approach that both supported schools towards a common vision and provided flexibility for school-level adaptations. Yet, the district had not yet fully formed its position as a facilitator of implementation. Further, as the district lacked a cohesive measurement system, the effectiveness of this initiative was unknown. This study sought to present policy implementation as varied phenomenon, influenced by system actors and conditions. Findings suggest that while policy cannot determine actions, district staff could help create conditions that would support implementation. / Dissertation/Thesis / Ph.D. Educational Leadership and Policy Studies 2011

This thesis seeks to extend the application of Social Network Analysis (SNA) to temporal graphs, in particular providing new insights for the understanding of covert networks. The analyses undertaken reveal informative features and properties of individuals' affiliations under covertness that also illustrate how both individuals and events influence the network structure. The review of the literature on covert networks provided in the initial two chapters suggests the presence of some ambiguities concerning how authors define structural properties and dynamics of covert networks. Authors sometimes disagree and use their findings to explain opposite views about covert networks. The controversy in the field is used as a starting point in order to justify the methodological application of SNA to understand how individuals involved in criminal and illegal activities interact with each other. I attempt to use a deductive approach, without preconceived notions about covert network characteristics. In particular, I avoid considering covert networks as organisations in themselves or as cohesive groups. I focus on individuals and their linkages constructed from their common participation in illicit events such as secret meetings, bombing attacks and criminal operations. In order to tackle these processes I developed innovative methods for investigating criminals' behaviours over time and their willingness to exchange tacit information. The strategy implies the formulation of a network model in order to represent and incorporate in a graph three types of information: individuals, events, and the temporal dimension of events. The inclusion of the temporal dimension offers the possibility of adopting a more comprehensive theoretical framework for considering individuals and event affiliations. This thesis expands the analysis of bipartite covert networks by adopting several avenues to explore in this perspective. Chapter 3 proposes a different way to represent two-mode networks starting from the use of line-graphs, namely the bi-dynamic line-graph data representation (BDLG), through which it is possible to represent the temporal evolution of individual's trajectories. The following chapter 4 presents some reflections about the idea of cohesion and cohesive subgroups specific to the case of two-mode networks. Based on the affiliation matrices, the analysis of local clustering through bi-cliques offers an attempt to analyse the mechanism of selecting accomplices while taking into account time. Chapter 5 is concerned with the concept of centrality of individuals involved in flows of knowledge exchanges. The theoretical and analytical framework helps in elaborating how individuals share their acquired hands-on experiences with others by attending joint task activities over time. Chapter 6 provides an application of the approaches introduced in the preceding chapters to the specific case of the Noordin Top terrorist network. Here, the knowledge of experience flow centrality measure opens up a new way to quantify the transmission of information and investigate the formation of the criminal capital. Finally, the last Chapter 7 presents some future research extensions by illustrating the versatility of the proposed approaches in order to provide new insights for the understanding of criminals' behaviours.

Personality, that is intra-individual consistency and inter-individual variation in behaviour, is widespread throughout the animal kingdom. This challenges traditional evolutionary assumptions that selection should favour behavioural flexibility, and that variation in behavioural strategies reflects stochastic variation around a single optimal behavioural strategy. Adaptive models to explain personality within the framework of evolutionary and behavioural ecology exist, and are typically empirically explored by identifying proximate associations to, and the functional consequences of, personality expression. To date, such studies have typically quantified a narrow range of personality traits within a species, and focused on captive populations or species with relatively limited behavioural or social repertoires. In this thesis, personality is studied in wild Barbary macaques (Macaca sylvanus). Quantification of personality structure in the species was conducted using a multi-method approach, and subsequently, it was examined whether physiological stress response (a proximate association) was related to personality expression, and whether personality expression affected social (functional) outcomes for individuals. Seven personality constructs were identified in Barbary macaques. Three personality constructs were related to physiological stress responses (Excitability, Tactility and Exploration), with the relationship between stress and personality expression dependent on sex, and in some cases rank or age. Two personality constructs (Excitability and Exploration) were associated with measures of social integration. Subjects generally socially assorted themselves according to personality, tending to be in proximity to individuals with a similar personality to themselves. This study contributes methodologically by demonstrating the plausibility of multi-method approaches to measuring personality in wild primates, and empirically, by generating evidence supporting adaptive models for the evolution of personality, namely that intra-individual consistency in behaviour may be mediated by physiology and that inter-individual variation in behaviour has functional benefits in the formation of social relationships and social structures.

Research in the relationship between second language (L2) production and study abroad has largely focused on establishing a connection between exchange studies and the success rate of second language acquisition. This Bachelor's thesis investigates L2 production by studying L2 English speakers' attitudes regarding the target language culture in relation to their production of a regionally typical phoneme by formulating the research question “How does cultural identification with the target language environment influence L2 phonetic production in the L1 language community?” in hopes of contributing to sociophonetic studies. This is done by conducting a qualitative study based on the phonetic production of rhoticity and the experiences of nine Swedish former exchange students to the United States. The study draws on existing research that highlights the saliency of rhoticity, as well as provides insight into the importance of identity in language use and into the relevance of motivation and the establishing of social networks for L2 gains during study abroad. To provide a framework for understanding these issues, the Social Network Strength Scale is applied. The results and data analysis suggest that, opposite to expectation, there is no clear relationship between cultural identification and L2 phonetic production for speakers who are no longer immersed into the L2 environment. However, the results establish a possible connection between maintaining a dense social network with native speaker members of the L2 community, as well as of having an awareness and capacity to understand the L2 culture, and a higher percentage of phonetic production of sounds typical for the L2 environment.

Com o aumento dos usuários acessando a internet no Brasil, cresce a quantidade de conteúdo produzido por brasileiros. Assim se torna importante classificar os melhores autores para que se tenha mais confiança nos textos lidos. Nesse sentido, esta dissertação faz um estudo sobre a descoberta de autoridades em tópicos na blogosfera brasileira. O escopo de estudo e análise é a plataforma de publicação de blogs, Blogspot, sobre os blogueiros que se identificam como brasileiros. Para tanto, foram coletados nove milhões de postagens do ano de 2012 e considerados os comentários como fonte de relacionamento entre os blogueiros para gerar uma rede social. Essa rede foi usada para experimentos do algoritmo de identificação de autoridades em tópicos. O algoritmo utilizado como base é o Topic PageRank, separando os diversos tópicos da blogosfera pelas tags que os usuários definem em suas postagens e posteriormente construindo a lista das autoridades em tais tópicos. Experimentos realizados demonstram que o método proposto resulta em melhor ranqueamento que o algoritmo original do PageRank. Cabe salientar que foi feita uma caracterização dos dados coletados por um questionário aplicado a quatro mil autores. / With the intesification of users accessing the Internet in Brazil, the amount of content produced by Brazilians increases. Thus, it becomes important to classify the best authors to have more confidence in the texts read. In this sense, this work presents a study on subject of topic authorities discovery in the Brazilian blogosphere. The scope of the study is the Blogspot platform, focusing on bloggers who identify themselves as Brazilians. To this end, we collected nine millions posts in the year of 2012 and considered the comments as a source of relationship between bloggers to generate a social network. This network was used for performing experiments considering the proposed approach to identify topic authorities. The algorithm used is based on the Topic PageRank, which can separate the different blogosphere’s topics by tags that users use on their posts, and then building the list of authorities on such topics. The experiments conducted show that the proposed approach results in better ranking than the original PageRank algorithm. We also characterize the collected database with a survey of over four thousand authors.

218f. / Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2013-04-30T16:34:36Z No. of bitstreams: 1 Tese_ Alessandra de Assis.pdf: 1034096 bytes, checksum: a9887a8bda2b5eb53877b7a5a760e8aa (MD5) / Approved for entry into archive by Valdinéia Ferreira(neiabf@ufba.br) on 2013-05-02T15:59:45Z (GMT) No. of bitstreams: 1 Tese_ Alessandra de Assis.pdf: 1034096 bytes, checksum: a9887a8bda2b5eb53877b7a5a760e8aa (MD5) / Made available in DSpace on 2013-05-02T15:59:45Z (GMT). No. of bitstreams: 1 Tese_ Alessandra de Assis.pdf: 1034096 bytes, checksum: a9887a8bda2b5eb53877b7a5a760e8aa (MD5) Previous issue date: 2007 / A educação brasileira tem passado por transformações, em especial a partir da exigência de formação em nível superior de professores da Educação Básica, estabelecida pela Lei de Diretrizes e Bases da Educação Nacional, LDB n. 9.394, aprovada em 1996. Neste texto são apresentados resultados da investigação sobre as condições de interação e produção de informação e conhecimento, proporcionadas pela utilização de diferentes Tecnologias da Informação e Comunicação (TIC) em cursos de formação em nível superior de professores da Educação Básica, ofertados por universidades públicas brasileiras, focalizando o que tais condições potencializam ou limitam em termos de organização dos professores em redes de colaboração. Considerando os princípios da pesquisa qualitativa em educação, foram analisados documentos produzidos por instâncias nacionais e estaduais, bem como as ações desenvolvidas na Universidade Federal da Bahia, através da parceria entre o Município de Irecê e a Faculdade de Educação que concebeu e executou o Programa de Formação Continuada de Professores. O uso das tecnologias está articulado à formulação de um projeto político para a formação de professores da Educação Básica, considerando o conjunto de mudanças que podem ser observadas nos processos sociais na contemporaneidade, nos quais novos modos de agir, ser e pensar estão em construção. O estudo aponta que enfrentar o desafio de expansão do ensino superior sem descaracterizar os pilares da formação universitária do professor é uma ação que pode ser fortalecida quando a Universidade desencadeia um processo de intervenção social ampliada, alterando as condições de acesso e produção de informação entre esses sujeitos, ao mesmo tempo em que são reunidas sinergias para uma prática educativa integrada às ações culturais, sociais, políticas e econômicas, segundo uma dinâmica de relações sociais horizontais e descentralizadas, garantindo a construção de percursos singulares de formação, fortalecendo a dinâmica de ensinar e aprender e o trabalho docente em rede. / Salvador

Submitted by Maria Creuza Silva (mariakreuza@yahoo.com.br) on 2013-05-31T13:20:09Z No. of bitstreams: 1 Tese Sandra Brignol. 2013.pdf: 4356092 bytes, checksum: 8471a9d9b8dbdafaeb02e20e0c99bfa4 (MD5) / Approved for entry into archive by Maria Creuza Silva(mariakreuza@yahoo.com.br) on 2013-05-31T13:20:19Z (GMT) No. of bitstreams: 1 Tese Sandra Brignol. 2013.pdf: 4356092 bytes, checksum: 8471a9d9b8dbdafaeb02e20e0c99bfa4 (MD5) / Made available in DSpace on 2013-05-31T13:20:19Z (GMT). No. of bitstreams: 1 Tese Sandra Brignol. 2013.pdf: 4356092 bytes, checksum: 8471a9d9b8dbdafaeb02e20e0c99bfa4 (MD5) Previous issue date: 2013 / A epidemia da infecção por HIV na população dos homens que fazem sexo com homens (HSH) continua a crescer em várias regiões do mundo, em parte devido à existência de homofobia e desrespeito aos direitos Humanos. Diante destas evidências e ausência de dados sobre a epidemia do HIV em Salvador, nós estimamos a prevalência do HIV, descrevemos e identificamos os fatores de vulnerabilidade associados a esta infecção. Analisamos e classificamos as redes sociais dos participantes, redes de parceiros sexuais e potenciais contatos sexuais via rede de afiliação formada indiretamente via frequência a locais para busca de parceiros sexuais. Este estudo de corte transversal faz parte da pesquisa multicêntrica “Comportamento, atitudes, práticas e prevalência de HIV e sífilis entre homens que fazem sexo com homens (HSH) em 10 cidades brasileiras”, em que analisamos os dados dos 383 HSH que participaram da pesquisa em Salvador. Utilizou-se a metodologia de recrutamento indicada para populações de difícil acesso ou escondidas, a Respondet Driven Sampling (RDS), para a seleção dos participantes. Utilizou-se a Regressão Logística Exata devido à baixa frequência da infecção por HIV e pequeno tamanho da amostra para estimar a associação do HIV e fatores de vulnerabilidade. E sob a perspectiva da Teoria das Redes Sociais Complexas, analisou-se as redes sociais de interesse dos HSH. A prevalência do HIV foi de 6,3%(IC95%=4%-9%), e a análise descritiva mostrou que os HSH estão em situação de vulnerabilidade com proporções expressivas de indivíduos com baixa escolaridade(33%), de classe social mais baixas(75%), desempregados(37%) e com experiências com algum tipo de discriminação (57%). A sífilis na vida teve uma prevalência de 9,7% (IC95%= 7%-13%). 20% dos HSH tiveram mais de oito parceiros sexuais, sexo anal desprotegido com ultimo parceiro casual e fixo foi similar (41%). Não fizeram o teste para sífilis na vida 79%, não tiveram acesso ao gel lubrificante 88% dos HSH. Os fatores que se associaram à infecção pelo HIV foram: não realizar teste de sífilis alguma vez na vida (OR=3,07; IC95%=1,29-7,31), ter mais de oito parceiros sexuais (OR=3,34;IC95%=1,38-8,07), início da vida sexual antes do 15 anos de idade (OR=2,36; IC95%=0,95-5,85) e não contou para alguém que sente atração por homens (OR=2,69; IC95%=0,95-7,58). A rede de relações pessoais dos HSH apresenta características de uma rede livre escala e mundo pequeno, onde os HSH estão muito próximos, alguns deles com alto grau de conexão ocupando áreas centrais e estratégicas na rede. Concluímos que há uma situação de vulnerabilidade social, individual e programática dos HSH que participaram da pesquisa em Salvador e alta prevalência do HIV. Confirmamos a importância da realização do teste de sífilis na vida. Há uma perda de oportunidade para testagem para HIV, pois verificamos uma alta proporção de testes da sífilis que contrastou com uma baixa testagem para HIV. Não contar para alguém que sente atração por homem poder ser reflexo de um alto grau de estigma social. Além disso, encontramos uma alta porcentagem de HSH com experiência com discriminação. As ações de prevenção devem focar os HSH mais conectados nas redes pessoais de relacionamento. / Salvador