Poster
A New Distribution on the Simplex with Auto-Encoding Applications
Andrew Stirn · Tony Jebara · David Knowles
Keywords: [ Probabilistic Methods ] [ Variational Inference ] [ Generative Models ] [ Algorithms -> Semi-Supervised Learning; Deep Learning -> Deep Autoencoders; Deep Learning ]
We construct a new distribution for the simplex using the Kumaraswamy distribution and an ordered stick-breaking process. We explore and develop the theoretical properties of this new distribution and prove that it exhibits symmetry (exchangeability) under the same conditions as the well-known Dirichlet. Like the Dirichlet, the new distribution is adept at capturing sparsity but, unlike the Dirichlet, has an exact and closed form reparameterization--making it well suited for deep variational Bayesian modeling. We demonstrate the distribution's utility in a variety of semi-supervised auto-encoding tasks. In all cases, the resulting models achieve competitive performance commensurate with their simplicity, use of explicit probability models, and abstinence from adversarial training.