Décomposition et visualisation de graphes : applications aux données biologiques

The amount of information stored in databases is constantly increasing making necessary to develop systems for analysis and visualization. In this thesis, we are interested in relational data and in particular, in biological data. This thesis focuses on three main axes : firstly, the decomposition of graph into clusters of "similar" elements in order to detect the community structures ; the second aspect is to highlight these structures in a visualization system; and thirdly, we are interested in the usability of one of these visualization systems through an experimental evaluation. The work presented in this thesis was applied on real data from two fields of biology : the metabolic networks and the gene-protein interaction networks.