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马尔可夫决策过程中的一个参数策略搜索方法的统一视角

A Unifying Perspective of Parametric Policy Search Methods for Markov Decision Processes
课程网址: http://videolectures.net/nips2012_furmston_processes/  
主讲教师: Thomas Furmston
开课单位: 伦敦大学学院
开课时间: 2013-01-16
课程语种: 英语
中文简介:
参数策略搜索算法是马尔可夫决策过程优化的一种选择方法,期望最大化和自然梯度上升被认为是该领域的最新技术。本文通过证明这两种算法在参数空间中的步进方向与近似牛顿法的搜索方向密切相关,给出了这两种算法的统一观点。这种分析自然而然地将牛顿近似法作为马尔可夫决策过程的一种基于梯度的替代方法加以考虑。我们可以证明,该算法有许多理想的性质,在牛顿方法的幼稚应用中没有,这使得它成为一个可行的替代方案,要么期望最大化,要么自然梯度上升。实验结果表明,该算法具有良好的收敛性和鲁棒性,与期望最大化和自然梯度上升相比,具有很强的鲁棒性。
课程简介: Parametric policy search algorithms are one of the methods of choice for the optimisation of Markov Decision Processes, with Expectation Maximisation and natural gradient ascent being considered the current state of the art in the field. In this article we provide a unifying perspective of these two algorithms by showing that their step-directions in the parameter space are closely related to the search direction of an approximate Newton method. This analysis leads naturally to the consideration of this approximate Newton method as an alternative gradient-based method for Markov Decision Processes. We are able show that the algorithm has numerous desirable properties, absent in the naive application of Newton's method, that make it a viable alternative to either Expectation Maximisation or natural gradient ascent. Empirical results suggest that the algorithm has excellent convergence and robustness properties, performing strongly in comparison to both Expectation Maximisation and natural gradient ascent.
关 键 词: 参数策略搜索算法; 马尔可夫决策; 牛顿法; 收敛性; 鲁棒性
课程来源: 视频讲座网
最后编审: 2020-10-22:chenxin
阅读次数: 55