arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2008.03707math.OCcs.AIcs.LG
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均值和方差组合的风险敏感马氏决策过程

Risk-Sensitive Markov Decision Processes with Combined Metrics of Mean and Variance

Business School, Sun Yat-Sen University(中山大学商学院)

Li Xia

摘要:

研究了同时考虑报酬均值和方差的具有长期平均度量的无限阶段离散时间马尔可夫决策过程的最优化问题。这样的绩效指标很重要,因为均值表示平均回报,方差表示风险或公平性。然而,方差度量耦合在所有阶段的奖励,传统的动态规划是不适用的时间一致性原则失效。我们研究这个问题从一个新的角度称为灵敏度为基础的优化理论。推导了一个性能差异公式,该公式可以量化任意两种策略下MDP的均值-方差组合度量的差异。差分公式可以用来产生新的政策,严格改进的均值-方差性能。给出了最优策略的一个必要条件和确定性策略的最优性。我们进一步发展了一种策略迭代形式的迭代算法,证明了该算法在混合和随机策略空间中均收敛于局部最优。特别地,当策略中的平均报酬为常数时,保证算法收敛到全局最优值。最后,我们应用我们的方法来研究在储能系统中的风力发电的波动减少,这表明我们的最优化方法的潜在适用性。

英文摘要:

This paper investigates the optimization problem of an infinite stage discrete time Markov decision process (MDP) with a long-run average metric considering both mean and variance of rewards together. Such performance metric is important since the mean indicates average returns and the variance indicates risk or fairness. However, the variance metric couples the rewards at all stages, the traditional dynamic programming is inapplicable as the principle of time consistency fails. We study this problem from a new perspective called the sensitivity-based optimization theory. A performance difference formula is derived and it can quantify the difference of the mean-variance combined metrics of MDPs under any two different policies. The difference formula can be utilized to generate new policies with strictly improved mean-variance performance. A necessary condition of the optimal policy and the optimality of deterministic policies are derived. We further develop an iterative algorithm with a form of policy iteration, which is proved to converge to local optima both in the mixed and randomized policy space. Specially, when the mean reward is constant in policies, the algorithm is guaranteed to converge to the global optimum. Finally, we apply our approach to study the fluctuation reduction of wind power in an energy storage system, which demonstrates the potential applicability of our optimization method.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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