Variational Graph Recurrent Neural Networks
This work addresses the challenge of representation learning for dynamic graphs, which is an incremental advancement in graph neural networks for applications like social network analysis.
The paper tackled the problem of modeling dynamic graphs by developing a hierarchical variational model that introduces latent variables to capture topology and node attribute changes, resulting in significant performance improvements in dynamic link prediction over existing methods.
Representation learning over graph structured data has been mostly studied in static graph settings while efforts for modeling dynamic graphs are still scant. In this paper, we develop a novel hierarchical variational model that introduces additional latent random variables to jointly model the hidden states of a graph recurrent neural network (GRNN) to capture both topology and node attribute changes in dynamic graphs. We argue that the use of high-level latent random variables in this variational GRNN (VGRNN) can better capture potential variability observed in dynamic graphs as well as the uncertainty of node latent representation. With semi-implicit variational inference developed for this new VGRNN architecture (SI-VGRNN), we show that flexible non-Gaussian latent representations can further help dynamic graph analytic tasks. Our experiments with multiple real-world dynamic graph datasets demonstrate that SI-VGRNN and VGRNN consistently outperform the existing baseline and state-of-the-art methods by a significant margin in dynamic link prediction.