Lizhen Lin - Colloquium Speaker

Huisking Foundation, Inc. Assistant Professor, Department of Applied and Computational Mathematics and Statistics, University of Notre Dame
Thursday, May 9, 2019 - 11:00am
Colloquium Title: 
Hierarchical stochastic block model for community detection in multiplex networks
Reception at 10:30 a.m. in 241 SH / Talk at 11:00 a.m. in 61 SH

Lizhen Lin


Multiplex networks have become increasingly more prevalent in many fields, and have emerged as a powerful tool for modeling the complexity of real networks. There is a critical need for developing inference models for multiplex networks that can take into account potential dependencies across different layers, particularly when the aim is community detection. We add to a limited literature by proposing a novel and efficient Bayesian model for community detection in multiplex networks. A key feature of our approach is the ability to model varying communities at different network layers. Moreover, our model has an appealing feature of being able to automatically pick up the necessary number of communities at each layer (as validated by real data examples). Borrowing ideas from hierarchical Bayesian modeling, we use a hierarchical Dirichlet prior to model community labels across layers, allowing dependency in their structure. Given the community labels, a stochastic block model (SBM) is assumed for each layer. We develop an efficient slice sampler for sampling the posterior distribution of the community labels as well as the link probabilities between communities. An extensive empirical validation is performed on simulated and real data, demonstrating the superior performance of the model over single-layer alternatives, as well as the ability to uncover interesting structures in real networks. This is a joint work with Marina Paez and Arash Amini.