Variational Autoencoders with Jointly Optimized Latent Dependency Structure
Authors: Jiawei He, Yu Gong, Joseph Marino, Greg Mori, Andreas Lehrmann
Keywords: deep generative models, structure learning
TL;DR: We propose a method for learning latent dependency structure in variational autoencoders.
Abstract: We propose a method for learning the dependency structure between latent variables in deep latent variable models.  Our general modeling and inference framework combines the complementary strengths of deep generative models and probabilistic graphical models. In particular, we express the latent variable space of a variational autoencoder (VAE) in terms of a Bayesian network with a learned, flexible dependency structure.  The network parameters, variational parameters as well as the latent topology are optimized simultaneously with a single objective.  Inference is formulated via a sampling procedure that produces expectations over latent variable structures and incorporates top-down and bottom-up reasoning over latent variable values.  We validate our framework in extensive experiments on MNIST, Omniglot, and CIFAR-10. Comparisons to state-of-the-art structured variational autoencoder baselines show improvements in terms of the expressiveness of the learned model.