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Visibilité du capital social à travers les médias sociaux : Etudes de cas sur les dynamiques sociales de l'appropriation d'un outil d'Analyse de Réseaux Sociaux / Visibility of social capital through social media : Case studies on the social dynamics of the ownership of a Social Network Analysis ToolKaroui, Myriam 21 September 2012 (has links)
Ce travail de thèse vise à comprendre les dynamiques sociales qui viennent influencer le processus d’appropriation d’une technologie SNA au sein d’une organisation. Pour ce faire, nous avons mené une étude inter-cas menée au sein de deux collectivités territoriales françaises et une étude intra-cas chez BOUYGUES CONSTRUCTION en nous appuyant sur un cadre théorique mobilisant la théorie de l’acteur stratégique de Crozier et Friedberg et la théorie de la pratique de Bourdieu. Un des principaux résultats de cette thèse est que l’appropriation d’une technologie SNA passe principalement par une appropriation socio-politique en deux phases : une phase d’appropriation de la nouvelle dimension donnée au capital social et une phase d’appropriation de la technologie pour servir les intérêts des acteurs concernant le développement du capital social. Nous avons également identifié que l’introduction d’un outil SNA est assignée à différentes notions symboliques (symbole de la légitimité du contrôle et de la supervision, symbole du soutien du top-management des pratiques de travail transversales, le symbole de la rigidité des structures organisationnelles, le symbole de la gestion des ressources informelles comme une ressource spécifique, le symbole de l’exclusion…) qui viennent légitimer et asseoir les différentes stratégies des groupes d’acteurs. Enfin, nous avons constaté que certains symboles liés à l’introduction du SNA sont étroitement liés à la culture de l’organisation. Ces principaux résultats ont pu être confortés par l’étude intra-cas menée chez BOUYGUES CONSTRUCTION, présentée comme une étude d’un cas particulier pouvant complémenter l’investigation menée au sein des deux collectivités territoriales. / This thesis aims to understand the social dynamics that influences actors’ adoption of a SNA tool in an organization. We have conducted multiple-case studies of two French Administrations (Mayoral offices) and an additional single case referred to a French industry BOUYGUES CONSTRUCTION drawing on Crozier and Friedberg’s theory of strategic actor and Bourdieu’s theory of practice. The first principle result is that the adoption of a SNA technology is primarily a socio-political appropriation that occurs through two phases: in the first phase actors discover social capital as a new symbolic capital and in a second phase they use the technology to influence the development of the organizational social capital in order it can serve their own interests. We have also identified that the introduction of a SNAS tool is assigned to different symbolic notions (symbol of the legitimization for control and supervision, symbol of top-management support for the development of transversal work practices, symbol of the rigidity of organizational structure, symbol of the management of informal resource as specific resource, symbol of exclusion) useful to provide legitimacy to the actors’ strategies in organizations. Finally, we highlight that these symbolic notions appear connected to the organizational culture. These key findings have emerged from our multiple-case study and have been reinforced the additional single case studied in BOUYGUES CONSTRUCTION. This single case complements the investigation conducted in the two Mayoral offices.
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A Quantitative Theory of Social Cohesion / Une théorie quantitative de la cohésion socialeFriggeri, Adrien 28 August 2012 (has links)
La notion de communauté, transverse à l'analyse des réseaux sociaux, a attiré une attention grandissante à travers les sciences ces dix dernières années. Les nombreuses tentatives pour modéliser aussi bien l'incarnation sociologiquedu concept aussi bien que sa manifestation structurelle dans le réseau social n'ont jusqu'à présent que vaguement convergé. Aucun consensus formel n'a été atteint sur les aspects quantifiables de la communauté, et ceci malgré lesliens forts la reliant aux dimensions dynamique et topologique du réseau sous-jacent.Présentant une approche novatrice à l'évaluation des communautés, cette thèse introduit et se base sur la cohésion, une métrique qui capture la qualitéintrinsèque, en tant que communauté, d'un ensemble de sommets dans un réseau. Il a été montré au travers d'une experience à large échelle, dans laquelle les individus sondés ont pu noter l'aspect communautaires de groupes d'amis leur étant présentés, que la cohésion, définie en lien avec la notion de triades sociales, est fortement correlée à la perception subjective de la communauté. Reflétant la complexité des interactions sociales, il est démontré que leproblème de trouver des communautés maximalement cohésive est NP-dur. En utilisant une heuristique approximant les résultats de ce problème, un certain nombre d'applications de la cohésion à des données réelles sont mises en avant: de son application à la visualisation de réseaux complexes, à l'étude de l'évolution des groupes d'agrément du sénat états-unien, à la compréhesion des liens entre psychologie et structure du réseau social.L'utilisation de la cohésion apporte un éclairage non trivial dans l'étude de la structure des grands réseaux de terrain et dans la relation entre structure et sémantique. / Community, a notion transversal to all areas of Social Network Analysis, has drawn tremendous amount of attention across the sciences in the past decades. Numerous attempts to characterize both the sociological embodiment of the concept as well as its observable structural manifestation in the social network have to this date only converged in spirit. No formal consensus has been reached on the quantifiable aspects of community, despite it being deeply linked to topological and dynamic aspects of the underlying social network. Presenting a fresh approach to the evaluation of communities, this thesis introduces and builds upon the cohesion, a novel metric which captures the intrinsic quality, as a community, of a set of nodes in a network. The cohesion, defined in terms of social triads, was found to be highly correlated to the subjective perception of communitiness through the use of a large-scale online experiment in which users were able to compute and rate the quality of their social groups on Facebook. Adequately reflecting the complexity of social interactions, the problem of finding a maximally cohesive group inside a given social network is shown to be NP-hard. Using a heuristic approximation algorithm, applications of the cohesion to broadly different use cases are highlighted, ranging from its application to network visualization, to the study of the evolution of agreement groups in the United States Senate, to the understanding of the intertwinement between subjects' psychological traits and the cohesive structures in their social neighborhood. The use of the cohesion proves invaluable in that it offers non-trivial insights on the network structure and its relation to the associated semantic.
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Análise de redes metabólicas em Saccharomyces cerevisiae. / Metabolic network analysis of Saccharomyces cerevisiae.Andreas Karoly Gombert 17 May 2001 (has links)
Análise de Redes Metabólicas foi aplicada à cepa de Saccharomyces cerevisiae CEN.PK113-7D, e a alguns mutantes interrompidos em genes que codificam para proteínas regulatórias envolvidas no fenômeno de repressão por glicose. Todas as cepas foram cultivadas em aerobiose, em meio mínimo contendo [1-13C]glicose como substrato limitante. As células eram recolhidas em situação de crescimento balanceado e submetidas à hidrólise, seguida de derivação e posterior injeção da amostra resultante num cromatógrafo gasoso acoplado a um espectrômetro de massa, para análise da marcação em alguns fragmentos de metabólitos intracelulares. Estes dados serviram como base para a identificação da atividade de algumas vias metabólicas no metabolismo central de S. cerevisiae. Além disto, utilizando-os juntamente com um modelo estequiométrico, foi possível obter uma estimativa para os fluxos no metabolismo central na cepa referência e nos mutantes estudados. Num primeiro momento, a metodologia foi validada para cultivos contínuos e descontínuos. Calculou-se um desvio padrão para a medida da marcação em cada fragmento de metabólito detectado pela metodologia empregada. Na cepa referência, observou-se que o ciclo de Krebs opera de forma cíclica em células que respiram e de forma não cíclica em células que apresentam metabolismo respiratório-fermentativo. Verificou-se que uma maior parte da glicose consumida é desviada para a via das pentoses fosfato no primeiro caso, em relação ao segundo. Foram encontradas evidências para a biossíntese de glicina através da enzima treonina aldolase e para a atividade da enzima málica. A ausência das proteínas Mig1 e Mig2 não altera os padrões de crescimento, produção de etanol e de marcação em metabólitos intracelulares de S. cerevisiae. Já a ausência de Hxk2, Reg1 ou Grr1 provoca alívio na repressão por glicose, observado pelo aumento das atividades respiratórias. / Metabolic Network Analysis was applied to the reference strain CEN.PK113-7D of Saccharomyces cerevisiae, as well as to some mutants disrupted in genes which code for regulatory proteins involved in the glucose repression cascade. All strains were cultivated under aerobic conditions, using minimal medium with [1-13C]glucose as the limiting substrate. Cells were harvested under balanced growth conditions and submitted to hydrolysis, derivatization and injection of the sample into a gas chromatograph coupled to a mass spectrometer for analysis of the labeling pattern in some fragments of intracellular metabolites. These data were used for identifying the activity of some pathways in the central metabolism of S. cerevisiae. Furthermore, using the data together with a stoichiometric model, it was possible to estimate the fluxes in the central metabolism of the reference strain and in the mutant strains. First, the methodology was validated for batch and continuous cultivations. Standard deviations were calculated for the measurement of the fractional labeling in each of the detected fragments. In the reference strain, it was observed that the Krebs cycle operates in a cyclic manner in respiratory cells, whereas it operates in a non cyclic manner under respiro-fermentative metabolism. It was also seen that a greater part of the glucose consumed by the cells enters the pentose phosphate pathway in the former than in the later case. Evidence for the activity of the threonine aldolase and the malic enzyme catalyzed reactions was also found. The absence of the Mig1 and Mig2 proteins does not alter the growth, ethanol formation and labeling pattern of intracellular metabolites in S. cerevisiae. In contrast, the absence of Hxk2, Reg1, or Grr1 provoques a relief in glucose repression, which was observed by an increased respiratory activity.
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Identificação de autoridades em tópicos na blogosfera brasileira usando comentários como relacionamento / Topical authority identification in the brazilian blogosphere using comments as relationshipsSantos, Henrique Dias Pereira dos January 2013 (has links)
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.
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Abordagem baseada na análise de redes sociais para estimativa da reputação de fontes de informação em saúdeSilva, Leila Weitzel Coelho da January 2013 (has links)
Internet tem sido uma importante fonte para as pessoas que buscam informações de saúde. Isto é particularmente problemático na perspectiva da Web 2.0. A Web 2.0 é a segunda geração da World Wide Web, onde os usuários interagem e colaboram uns com os outros como criadores de conteúdo. A falta de qualidade das informações médicas na Web 2.0 tem suscitado preocupações com os impactos prejudiciais que podem acarretar. São muitos os aspectos relacionados à qualidade da informação que devem ser investigados, como por exemplo, existe alguma evidência de que o autor tem alguma autoridade no domínio da saúde? Há indícios de que os autores são tendenciosos? Como saber se a fonte de informação tem reputação, como separar as fontes de boa qualidade das outras? Esses questionamentos se tornam mais evidentes quando se faz buscas no Twitter. O usuário precisa por si só selecionar o conteúdo que acredita que tenha qualidade entre as centenas de resultados. Nesse contexto, o principal objetivo deste trabalho é propor e avaliar uma abordagem que permita estimar a reputação de fontes de informação no domínio da saúde. Acredita-se que discussões sobre reputação só fazem sentido quando possuem um propósito e estão inseridas em um contexto. Sendo assim, considera-se que reputação é um atributo que um usuário se apropria quando a informação que ele divulga é crível e digna de confiança. As contribuições desta tese incluem uma nova metodologia para estimar a reputação e uma estrutura topológica de rede baseada no grau de interação entre atores sociais. O estudo permitiu compreender como as métricas afetam o ordenamento da reputação. Escolher a métrica mais apropriada depende basicamente daquilo que se quer representar. No nosso caso, o Pagerank funcionou como um “contador de arcos” representando apenas uma medida de popularidade daquele nó. Verificou-se que popularidade (ou uma posição de destaque na rede) não necessariamente se traduz em reputação no domínio médico. Os resultados obtidos evidenciaram que a metodologia de ordenamento e a topologia da rede obtiveram sucesso em estimar a reputação. Além disso, foi verificado que o ambiente Twitter desempenha um papel importante na transmissão da informação e a “cultura” de encaminhar uma mensagem permitiu inferir processos de credibilidade e consequentemente a reputação. / The Internet is an important source for people who are seeking healthcare information. This is particularly problematic in era of Web 2.0. The Web 2.0 is a second generation of World Wide Web, where users interact and collaborate with each other as creators of content. Many concerns have arisen about the poor quality of health-care information on the Web 2.0, and the possibility that it leads to detrimental effects. There are many issues related to information quality that users continuously have to ask, for example, is there any evidence that the author has some authority in health domain? Are there clues that the authors are biased? How shall we know what our sources are worth, how shall we be able to separate the bad sources from the good ones? These questions become more obvious when searching for content in Twitter. The user then needs to manually pick out high quality content among potentially thousands of results. In this context, the main goal of this work is to propose an approach to infer the reputation of source information in the medical domain. We take into account that, discussion of reputation is usually not meaningful without a specific purpose and context. Thus, reputation is an attribute that a user comprises, and the information disseminated by him is credible and worthy of belief. Our contributions were to provide a new methodology to Rank Reputation and a new network topological structure based on weighted social interaction. The study gives us a clear understanding of how measures can affect the reputation rank. Choosing the most appropriate measure depends on what we want to represent. In our case, the PageRank operates look alike “edges counts” as the “popularity” measures. We noticed that popularity (or key position in a graph) does not necessarily refer to reputation in medical domain. The results shown that our rank methodology and the network topology have succeeded in achieving user reputation. Additionally, we verified that in Twitter community, trust plays an important role in spreading information; the culture of “retweeting” allowed us to infer trust and consequently reputation.
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Análise de redes sociais aplicada a projetos de software open source: um mapeamento sistemáticoCOSTA, Vitor de Barros 01 September 2014 (has links)
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Previous issue date: 2014-09-01 / A aplicação de Análise de Redes Sociais (SNA – Social Network Analysis) em times de projetos de software tem sido um tópico de pesquisa bastante explorado e usado na última década. A fim de entender as relações entre pessoas, grupos, organizações ou outros tipos de entidades sociais, por meio de grafos e métricas próprias, SNA aparece como uma alternativa para expandir a visão da dinâmica de projetos no campo das relações sociais. Visualizando um projeto representado por um grafo, as entidades sociais são representadas como nós e suas relações como arestas, e análises temporais e/ou atemporais sobre aspectos de projetos, como comunicação, formação de equipe, colaboração, entre outros, podem ser realizadas usando métricas próprias como por exemplo betweenness centrality e densidade. O tipo de projeto mais estudado por pesquisadores que usam Análise de Redes Sociais é o projeto de desenvolvimento de software open source (OSS – Open Source Software). Pela facilidade na obtenção dos dados, armazenados em repositórios online, esta categoria de projeto tem levantado a curiosidade da comunidade acadêmica a fim de investigar suas características. OSS se distingue dos projetos tradicionais (chamados de closed source) pois envolve a participação de vários integrantes de forma espontânea, geralmente de localidade distintas e que nunca tiveram um contato pessoal entre si. Tendo em vista a extensão, em quantidade, de pesquisas que combinam o uso de técnicas de SNA em projetos OSS, esta dissertação tem como objetivo, através de um mapeamento sistemático da literatura, mapear e categorizar estudos diretamente relacionados à análise de redes sociais em projetos de software open source. Por meio de estatística descritiva e análise qualitativa busca-se conhecer quais os principais benefícios e limitações encontrados na aplicação das métricas de análise de redes sociais nos projetos de software OSS, bem como os principais tópicos de pesquisa e fontes de dados utilizadas. O trabalho, em sua síntese, apresenta um diagnóstico da pesquisa atual sobre os temas abordados e colabora com a academia apontando tendências e trabalhos futuros. / The application of Social Network Analysis (SNA) in teams of software projects has been a well researched and used topic in the last decade. In order to understand the relation between people, groups, organizations and other social entities, by the use of its own graphs and metrics, SNA appears to be an alternative to expand the vision of the projects dynamics in the social relation field. Seeing a project represented in a graph, the social entities are represented as dots and its relations as edges, and the temporal and/or timeless analysis about the projects aspects, such as communication, team building, coworking and others, can be performed by the use of own metrics, e.g. betweenness centrality and density. The kind of project most studied by researchers that use Social Network Analysis is the open source (OSS – Open Source Software) software development. This project category has been raising the academic community curiosity to investigate its characteristics since it is easy to obtain the data, stored in online repositories. OSS distinguishes from traditional projects (called closed source) because involves the participation of many spontaneous member, usually from different location and that have never met. As there are many researches that combine the use of SNA techniques in OSS projects, this thesis has the purpose to map and categorize, through a systematic mapping of the literature, studies directly related to the analysis of social network in open source software projects. Using descriptive statistics and qualitative analysis, seeks the main benefits and limitations found on the application of social network analysis metrics in the OSS software projects, as well as the main research topics and the used data source. To sum up, this dissertation presents a diagnose of the research about the covered topics and collaborates with the academy pointing tendencies and future work.
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Tappning av datanätverk : Vad är det som gör att det går långsamt?Karlsson, Robert January 2016 (has links)
I ett datanätverk är det många som ska dela på de resurser som finns, av det kan användaren uppleva att nätverket går långsamt. Denna rapport gör en undersökning på Nya Slottet Bjärka Säby i Linköping varför deras nätverk upplevs långsamt. Genom att utföra en nätversktappning kunde en baseline skapas för att sedan ta ut information genom ett Perl skript. Resultatet visa inga direkta problematik på nätverket, men det noterades att IPv6 förekom på nätverket som är onödigt protokoll för detta nätverk. Det rekommendera alltså att avaktivera IPv6 så långt det är möjligt. Undersökningen varade under en vecka och har för lite information för att ge en riktigt förklaring för den upplevda hastigheten och det rekommenderas att göra flera tester, för att kunna hitta det eventuella felet. / In a computer network there are many users that need to share the same resources and by that the user may experience the network to be very slow. This report investigate the network in Nya Slottet Bjärka Säby i Linköping why it is slow. Be doing a network tapping and collecting whats on the network, with a written Perl script that graphed out collected data, showed that no direct problem could be pointed out. It was noted that IPv6 was present on the network, that for this network is unnecessary and it's recommend to turn it off where it's possible. The investigation was for a week and shows to little information to find the real problem for the network speed. It recommends that more testing is performed to find the problem.
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The domino effect : A network analysis of regime shifts drivers and causal pathwaysRocha, Juan Carlos January 2010 (has links)
The purpose of this paper is to perform an exploratory analysis of the causalinteractions among global change drivers of regime shifts. Causal loops diagrams were usedto collect a set of feedback mechanisms underlying abrupt change dynamics in 11 regimeshifts. In order to prioritize drivers and to map out possible causal pathways we used networkanalysis. Agricultural processes, global warming, biodiversity loss, demographic andeconomic drivers are the main causes of regime shifts. Based on the analysis of 400pathways, we intuitively suggest five types of cascading effects between regime shifts.Regime shifts dramatically affect the provision of ecosystem services and might underminethe achievement of the first Millennium Development Goal: reduction of hunger and poverty.
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Social Network Analysis Utilizing Big Data TechnologyMagnusson, Jonathan January 2012 (has links)
As of late there has been an immense increase of data within modern society. This is evident within the field of telecommunications. The amount of mobile data is growing fast. For a telecommunication operator, this provides means of getting more information of specific subscribers. The applications of this are many, such as segmentation for marketing purposes or detection of churners, people about to switching operator. Thus the analysis and information extraction is of great value. An approach of this analysis is that of social network analysis. Utilizing such methods yields ways of finding the importance of each individual subscriber in the network. This thesis aims at investigating the usefulness of social network analysis in telecommunication networks. As these networks can be very large the methods used to study them must scale linearly when the network size increases. Thus, an integral part of the study is to determine which social network analysis algorithms that have this scalability. Moreover, comparisons of software solutions are performed to find product suitable for these specific tasks. Another important part of using social network analysis is to be able to interpret the results. This can be cumbersome without expert knowledge. For that reason, a complete process flow for finding influential subscribers in a telecommunication network has been developed. The flow uses input easily available to the telecommunication operator. In addition to using social network analysis, machine learning is employed to uncover what behavior is associated with influence and pinpointing subscribers behaving accordingly.
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Innovative Planungskonzepte in der Flughafen-LogistikSchulze, Frank, Marquardt, Hans-Georg 18 April 2018 (has links) (PDF)
Die Gepäckförderanlagen von Luftfahrt-Drehkreuzen wie Peking oder Dubai gehören mit etwa 100 km Förderstrecke und 10.000 Transporteinheiten heute zu den größten automatisierten Logistiksystemen. Die Professur für Technische Logistik der TU Dresden ist an ihrer Planung und Simulation beteiligt und entwickelt Werkzeuge für den Systementwurf.
Der Beitrag stellt zuerst Gepäckförderanlagen und die Planungsaufgabe vor. Danach werden zwei innovative Konzepte für frühe Planungsstufen vorgestellt. Dabei wird das Anlagen-Layout in ein Knoten-Kanten-Modell überführt. So wird einerseits mit diskretisierten statistischen (Zeit-) Verteilungen das dynamische Anlagenverhalten schneller und ähnlich genau bewertet wie mit der Simulation. Andererseits werden statistische Maßzahlen aus der Theorie komplexer Netzwerke genutzt, um das Transportnetzwerk hinsichtlich Robustheit und Lastbalancierung zu optimieren. / Baggage handling systems of air hubs like Beijing or Dubai contain about 100 km of conveyor lines and 10,000 transport units. Thus they belong to today’s largest automated logistics systems. The Chair for Logistics Engineering at TU Dresden is involved in their planning and simulation and develops system design tools.
The paper first introduces into the field and the design targets. Than two innovative concepts for early planning stages are presented which derive a node-link-model from the system’s layout. Now, the system dynamic is evaluated by means of time-discrete statistic distributions more rapidly and as exactly as by simulations. Besides, statistic measures from complex network theory are used to optimise the transport with respect to robustness and load balancing.
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