Efficient Reinforcement Learning with Implicit Action Space

Abstract Reinforcement Learning (RL) based methods have seen their paramount successes in solving serial decision-making and control problems in recent years. In our recent work, DAIS researchers have successfully employed RL-based techniques for solving control and management tasks in Software Defined Coalition (SDC) networks. For conventional RL formulations, Markov Decision Process (MDP) and state-action-value function are the basis for the problem modeling and policy evaluation. However, several challenging issues still remain. Among most cited issues, the enormity of state/action space is an important factor that causes inefficiency in accurately approximating the state-action-value function. We observe that although actions directly define the agents’ behaviors, for many problems the next state after a state transition matters more than the action taken, in determining the return of such a state transition. In this regard, we propose a new learning paradigm, State Action Separable Reinforcement Learning (sasRL), wherein the action space is decoupled from the value function learning process for higher efficiency. Then, a light-weight transition model is learned to assist the agent to determine the action that triggers the associated state transition. In addition, our convergence analysis reveals that under certain conditions, the convergence time of sasRL is O(T 1/k ), where T is the convergence time for updating the value function in the MDP-based formulation and k is a weighting factor. Experiments show that sasRL outperforms state-of-the-art MDP-based RL algorithms.
  • Ziyao Zhang (Imperial)
  • Liang Ma (IBM US)
  • Kin K. Leung (Imperial)
  • Konstantinos Poularakis (Yale)
  • Mudhakar Srivatsa (Yale)
  • Franck Le (Yale)
Date Sep-2020
Venue 4th Annual Fall Meeting of the DAIS ITA, 2020