Community Structure Characterization

This entry discusses the problem of describing some communities identified in a complex network of interest, in a way allowing to interpret them. We suppose the community structure has already been detected through one of the many methods proposed in the literature. The question is then to know how to extract valuable information from this first result, in order to allow human interpretation. This requires subsequent processing, which we describe in the rest of this entry

Social Interactions vs Revisions, What is important for Promotion in Wikipedia?

In epistemic community, people are said to be selected on their knowledge contribution to the project (articles, codes, etc.) However, the socialization process is an important factor for inclusion, sustainability as a contributor, and promotion. Finally, what does matter to be promoted? being a good contributor? being a good animator? knowing the boss? We explore this question looking at the process of election for administrator in the English Wikipedia community. We modeled the candidates according to their revisions and/or social attributes. These attributes are used to construct a predictive model of promotion success, based on the candidates's past behavior, computed thanks to a random forest algorithm. Our model combining knowledge contribution variables and social networking variables successfully explain 78% of the results which is better than the former models. It also helps to refine the criterion for election. If the number of knowledge contributions is the most important element, social interactions come close second to explain the election. But being connected with the future peers (the admins) can make the difference between success and failure, making this epistemic community a very social community too

Étude des corrélations d'orientation moléculaire par diffusion rayleigh dépolarisée dans les liquides purs et les solutions

L'étude de la Diffusion Rayleigh Dépolarisée (DRD) de solutions binaires permet de tracer des diagrammes isothermes d'intensité diffusée dépolarisée. L'interprétation de ces diagrammes à l'aide de modèles microscopiques simples met facilement en évidence l'existence de corrélations d'orientation moléculaire. C'est ainsi que nous avons pu montrer que les molécules de benzène tendent à se placer perpendiculairement les unes aux autres et celles d'alcanes normaux parallèlement. Ces corrélations binaires sont les plus importantes; toutes ces interactions orientées disparaissent quand la solution est diluée, la distance entre molécules étant alors trop grande