Using Unsupervised Learning Methods to Extract Structure in Value Functions. 
 David Foster    Peter Dayan 
 
 Machine Learning, in press. 
 Abstract 
  Solving in an efficient manner many different optimal control tasks
  within the same underlying environment requires decomposing the
  environment into its computationally elemental fragments. We suggest
  how to find fragmentations using unsupervised, mixture model,
  learning methods on data derived from optimal value functions for
  multiple tasks, and show that these fragmentations are in accord
  with observable structure in the environments. Further, we present
  evidence that such fragments can be of use in a practical
  reinforcement learning context, by facilitating online,
  actor-critic learning of multiple goals MDPs.
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