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Submodular Variational Inference for Network Reconstruction
Proceedings of the 33rd Conference on Uncertainty in Artificial Intelligence, PMLR R15:770-779, 2017.
Abstract
In real-world and online social networks, in- dividuals receive and transmit information in real time. Cascading information transmis- sions (e.g. phone calls, text messages, social media posts) may be understood as a realiza- tion of a diffusion process operating on the net- work. The process only traverses and thereby reveals a limited portion of the edges. The network reconstruction/inference problem is to estimate the unrevealed connections. Most existing approaches derive a likelihood and attempt to find the network topology maxi- mizing the likelihood, yielding a highly in- tractable problem. In this paper, we focus on the network reconstruction problem for a broad class of real-world diffusion processes, exem- plified by a network diffusion scheme called respondent-driven sampling (RDS). We prove that under realistic and general models of net- work diffusion, the posterior distribution of an observed RDS realization is a Bayesian log- submodular model. We then propose VINE, a novel, accurate, and computationally efficient variational inference algorithm, for the net- work reconstruction problem under this model. Crucially, we do not assume any particular probabilistic model for the underlying net- work. VINE recovers any connected graph with high accuracy as shown by our experimental results on real-life networks.