Modèle à Blocs Stochastiques corrigé en degrés pour des graphes dynamiques
Abstract
Stochastic Block Models (SBM) provide a statistical tool for modeling and clustering network
data. In this paper, we propose an extension of this model for discrete-time dynamic
networks that takes into account the variability in node degrees, allowing us to model a broader
class of networks. We develop a probabilistic model that generates temporal graphs with a dynamic
cluster structure and time-dependent degree corrections for each node. Thanks to these
degree corrections, the nodes can have variable degrees, allowing for more complex cluster
structures and for model interactions that decrease or increase over time. The proposed model
is compared to an existing model without degree correction and its advantages in terms of
global performances are highlighted. We propose an inference procedure based on Variational
EM that provides the means to estimate time-dependent parameters while reducing the risk of
local label-switchings.