Professor.  Computer Sci. & Eng., Sogang Univ., Seoul, Korea.

RESEARCH FIELD

      ∈ {Markov Decision Process} ∪/∩ {Stochastic Game} ∪/∩ {Stochastic Optimization}
      ∪/∩ {Computational Intelligence}  ∪/∩ {Learning Theory}


      ACM Library Index Terms

PUBLICATION

  1. [Book] H. S. Chang, J. Hu, M. Fu, & S. I. Marcus, "Simulation-based Algorithms for Markov Decision Processes,"
    Springer, 2nd Edition, ISBN: 978-1-4471-5021-3, 2013. (978-1-84628-689-6, 2007).
  2. R. L. Givan, E. K. P. Chong, and H. S. Chang, "Scheduling Multiclass Packet Streams to Minimize Weighted Loss,"
    Queueing Systems, Vol. 41, No.3, 2002, pp. 241-270.
  3. H. S. Chang, P. Fard, S. I. Marcus, and M. Shayman, "Multi-time Scale Markov Decision Processes,"
    IEEE Trans. on Automatic Control, Vol. 48, No. 6, 2003, pp. 976-987.
  4. H. S. Chang and S. I. Marcus, "Approximate Receding Horizon Approach for Markov Decision Processes: Average Reward Case,"
    J. of Mathematical Analysis and Applications, Vol. 286, No. 2, 2003, pp. 636-651.
  5. H. S. Chang, "Localization and A Distributed Local Optimal Solution Algorithm for a Class of Multi-agent Markov Decision Processes,"
    Int. J. of Control, Automation, and Systems, Vol. 1, No. 3, 2003, pp. 358-367.
  6. H. S. Chang and S. I. Marcus, "Two-Person Zero-Sum Markov Games: Receding Horizon Approach,"
    IEEE Trans. on Automatic Control, Vol. 48, No. 11, 2003, pp. 1951-1961.
  7. H. S. Chang, R. L. Givan, and E. K. P. Chong, "Parallel Rollout for Online Solution of Partially Observable Markov Decision Processes,"
    Discrete Event Dynamic Systems, Vol. 14, No. 3, 2004, pp. 309-341.
  8. H. S. Chang, "On Ordinal Comparison of Policies in Markov Reward Processes,"
    J. of Optimization Theory and Applications, Vol. 122, No. 1, 2004, pp. 207-217.
  9. H. S. Chang, "Multi-policy Iteration with a Distributed Voting,"
    Mathematical Methods of Operations Research, Vol. 60, No. 2, 2004.11, pp. 299-310.
  10. H. S. Chang, "A Model for Multi-time Scaled Sequential Decision Making Processes with Adversary,"
    Mathematical and Computer Modeling of Dynamical Systems, Vol. 10, No. 3-4, 2004.12, pp. 287-302.
  11. H. S. Chang, M. Fu, J. Hu, and S. I. Marcus, "An Adaptive Sampling Algorithm for Solving Markov Decision Processes,"
    Operations Research, Vol. 53, No. 1, 2005.1, pp. 126-139.
  12. H. S. Chang, "Multi-policy Improvement in Stochastic Optimization with Forward Recursive Function Criteria,"
    J. of Mathematical Analysis and Applications, Vol. 305, No. 1, 2005.5, pp. 130-139.
  13. H. S. Chang, "On the Probability of Correct Selection by Distributed Voting in Stochastic Optimization,"
    J. of Optimization Theory and Applications, Vol. 125, No. 1, 2005.4, pp. 231-240.
  14. H. S. Chang, "Error Bounds for Finite Step Approximations for Solving Infinite Horizon Controlled Markov Set-Chains,"
    IEEE Trans. on Automatic Control, Vol. 50, No. 9, 2005.9, pp. 1413-1418.
  15. H. S. Chang, H-G. Lee, M. Fu, and S. I. Marcus, "Evolutionary Policy Iteration for Solving Markov Decision Processes,"
    IEEE Trans. on Automatic Control, Vol. 50, No. 11, 2005.11, pp. 1804-1808.
  16. H. S. Chang, "Converging Marriage in Honey-Bees Optimization and Application to Stochastic Dynamic Programming,"
    J. of Global Optimization, Vol. 35, No. 3, 2006.7, pp. 423-441.
  17. H. S. Chang, "On Convergence Rate of the Shannon Entropy Rate of Ergodic Markov Chains via Sample-path Simulation,"
    Statistics & Probability Letters, Vol. 76, No. 12, 2006.7, pp. 1261-1264.
  18. H. S. Chang, "Perfect Information Two-Person Zero-Sum Markov Games with Imprecise Transition Probabilities,"
    Mathematical Methods of Operations Research, Vol. 64, No. 2, 2006.10, pp. 335-351.
  19. H. S. Chang, "A Policy Improvement Method in Constrained Stochastic Dynamic Programming,"
    IEEE Trans. on Automatic Control, Vol. 51, No. 9, 2006.9, pp. 1523-1526.
  20. H. S. Chang, M. Fu, J. Hu, and S. I. Marcus, "A Survey of Some Simulation-Based Algorithms for Markov Decision Processes,"
    Communications in Information and Systems, Vol. 7, No. 1, 2007.7, pp. 59-92.
  21. H. S. Chang, "A Policy Improvement Method for Constrained Average Markov Decision Processes,"
    Operations Research Letters, Vol. 35, No. 4, 2007.7, pp. 434-438.
  22. H. S. Chang, M. Fu, J. Hu, and S. I. Marcus, "An Asymptotically Efficient Simulation-Based Algorithm for Finite Horizon Stochastic Dynamic Programming,"
    IEEE Trans. on Automatic Control, Vol. 52, No.1, 2007.1, pp. 89-94.
  23. H. S. Chang and E. K. P. Chong, "Solving Controlled Markov Set-Chains with Discounting via Multi-policy Improvement,"
    IEEE Trans. on Automatic Control, Vol. 52, No.3, 2007.3, pp. 564-569.
  24. H. S. Chang, M. Fu, J. Hu, and S. I. Marcus, "Recursive Learning Automata Approach to Markov Decision Processes,"
    IEEE Trans. on Automatic Control, Vol. 52, No.7, 2007.7, pp. 1349-1355.
  25. H. S. Chang, "Finite Step Approximation Error Bounds for Solving Average Reward Controlled Markov Set-Chains,"
    IEEE Trans. on Automatic Control, Vol. 53, No.1, 2008.2, pp. 350-355.
  26. H. S. Chang, "Converging Co-Evolutionary Algorithm for Two-Person Zero-Sum Discounted Markov Games with Perfect Information,"
    IEEE Trans. on Automatic Control, Vol. 53, No.2, 2008.3, pp. 596-601.
  27. H. S. Chang, "Decentralized Learning in Finite Markov Chains: Revisited,"
    IEEE Trans. on Automatic Control, Vol. 54, No.7, 2009.7, pp. 1648-1653.
  28. H. S. Chang, J. Hu, M. Fu, and S. I. Marcus, "Adaptive Adversarial Multi-Armed Bandit Approach to Two-Person Zero-Sum Markov Games,"
    IEEE Trans. on Automatic Control, Vol. 55, No. 2, 2010.2, pp. 463-468.
  29. J. Hu, H. S. Chang, M. Fu, and S. I. Marcus, "Dynamic Sample Budget Allocation in Model-Based Optimization,"
    J. of Global Optimization, Vol. 50, No. 4, 2011.8, pp. 575-596.
  30. J. Hu, P. Hu, and H. S. Chang, "A Stochastic Approximation Framework for a Class of Randomized Optimization Algorithms,"
    IEEE Trans. on Automatic Control, Vol. 57, No. 1, 2012.1, pp. 165-178.
  31. H. S. Chang, "A Policy Iteration Heuristic for Constrained Discounted Controlled Markov Chains,"
    Optimization Letters, Vol. 6, No. 7, 2012.10, pp. 1573-1577.
  32. J. Hu and H. S. Chang, "Approximate Stochastic Annealing for Online Control of Infinite Horizon Markov Decision Processes,"
    Automatica, Vol. 48, No. 9, 2012.9, pp. 2182-2188.
  33. H. S. Chang and J. Hu, "On the Probability of Correct Selection in Ordinal Comparison over Dynamic Networks,"
    J. of Optimization Theory and Applications, Vol. 155, No. 2, 2012.11, pp. 594-604.
  34. H. S. Chang, "On Functional Equations for Kth Best Policies in Markov Decision Processes,"
    Automatica, Vol. 49, No. 1, 2013.1, pp. 297-300.
  35. H. S. Chang, "Policy Set Iteration for Markov Decision Processes,"
    Automatica, Vol. 49, No. 12, 2013.12, pp. 3687-3689.
  36. H. S. Chang, "A Necessary Condition for Nash Equilibrium in Two-Person Zero-Sum Constrained Stochastic Games,"
    Game Theory, Vol. 2013, Article ID 290427, 5 pages, 2013.12.
  37. H. S. Chang, "On Modification of Population-based Search Algorithms for Convergence in Stochastic Combinatorial Optimization,"
    Optimization, Vol. 64, No. 7, 2015.7, pp. 1647-1655.
  38. H. S. Chang, "An Exact Iterative Search Algorithm for Constrained Markov Decision Processes,"
    Automatica, Vol. 50, No. 5, 2014.5, pp. 1531-1534.
  39. H. S. Chang, "Value Set Iteration for Markov Decision Processes,"
    Automatica, Vol. 50, No. 7, 2014.7, pp. 1940-1943. Corrigendum
  40. H. S. Chang, "Sleeping Experts and Bandits Approach to Constrained Markov Decision Processes,"
    Automatica, Vol. 63, No. 1, 2016.1, pp. 182-186.
  41. H. S. Chang and S. Choe, "Combining Multiple Strategies for Multi-armed Bandit Problems and Asymptotic Optimality,"
    Journal of Control Science and Engineering, Vol. 2015, Article ID 264953, 7 pages, 2015.3.
  42. H. S. Chang, "Random Search for Constrained Markov Decision Processes with Multi-policy Improvement,"
    Automatica, Vol. 58, No. 8, 2015.8, pp. 127-130.
  43. H. S. Chang, "Value Set Iteration for Two-Person Zero-Sum Markov Games,"
    Automatica, Vol. 76, No. 2, 2017.2, pp. 61-64.
  44. H. S. Chang, "An Asymptotically Optimal Strategy for Constrained Multi-armed Bandit Problems,"
    Mathematical Methods of Operations Research, Vol. 91, No. 3, 2020.6, pp. 545-557.
  45. H. S. Chang, "An Index-based Deterministic Convergent Optimal Algorithm for Constrained Multi-armed Bandit Problems,"
    Automatica, Vol. 129, 109673, 2021.7.
  46. H. S. Chang, "On Supervised On-Line Rolling-Horizon Control for Infinite-Horizon Discounted Markov Decision Processes,"
    IEEE Trans. on Automatic Control, Vol. 69, No. 2, 2024.2, pp. 1060-1065.

MISC.