Maximum Conditional Likelihood via Bound Maximization and the CEM Algorithm

Part of Advances in Neural Information Processing Systems 11 (NIPS 1998)

Authors

Tony Jebara, Alex Pentland

Abstract

We present the CEM (Conditional Expectation Maximi::ation) al(cid:173) gorithm as an extension of the EM (Expectation M aximi::ation) algorithm to conditional density estimation under missing data. A bounding and maximization process is given to specifically optimize conditional likelihood instead of the usual joint likelihood. We ap(cid:173) ply the method to conditioned mixture models and use bounding techniques to derive the model's update rules . Monotonic conver(cid:173) gence, computational efficiency and regression results superior to EM are demonstrated.