Overlapping Community Detection in Static and Dynamic Networks

Abstract

Studying behavior of systems through networks is important because it allows to understand them and make decisions based on this knowledge. Community detection is one of the tools used in this sense, for detection of groups in graphs. This can be done not only considering connections between nodes, but also including their attributes. Also, objects can be part of different groups with varying degrees, so overlapping fuzzy assignment is relevant in this context. Furthermore, most networks change overtime, so including this aspect also enhance the benefits of using community detection. Hence, in this doctoral thesis we propose to design models for overlapping community detection for static and dynamic networks with node attributes. Firstly, an approach based on a nonnegative matrix factorization generative model that automatically detects the number of communities in the network, is designed. Secondly, tensor factorization is used in order to overcome some of the challenges faced in the first model.