0


收敛的消息传递算法推理在一般图凸自由能量

Convergent Message-Passing Algorithms for Inference over General Graphs with Convex Free Energies
课程网址: http://videolectures.net/uai08_hazan_cmpa/  
主讲教师: Tamir Hazan
开课单位: 耶路撒冷希伯来大学
开课时间: 2008-07-30
课程语种: 英语
中文简介:
图形模型中的推理问题可以表示为自由能函数的约束优化。众所周知,当使用贝斯自由能时,信念传播(BP)算法的不动点对应于自由能的局部极小值。然而,在许多情况下,英国石油公司未能收敛。此外,对于具有循环的图形模型,贝斯自由能是非凸的,因此在推导一般图形自由能的局部极小值的有效算法时,引入了很大的困难。在本文中,我们介绍了两种有效的BP类算法,一种是顺序算法,另一种是并行算法,保证在任何图的能量类别上都收敛到全局最小值,称为“凸自由能”。此外,本文还提出了一种基于图结构的凸自由能参数设置的有效启发式方法。
课程简介: Inference problems in graphical models can be represented as a constrained optimization of a free energy function. It is known that when the Bethe free energy is used, the fixed points of the belief propagation (BP) algorithm correspond to the local minima of the free energy. However BP fails to converge in many cases of interest. Moreover, the Bethe free energy is non-convex for graphical models with cycles thus introducing great difficulty in deriving efficient algorithms for finding local minima of the free energy for general graphs. In this paper we introduce two efficient BP-like algorithms, one sequential and the other parallel, that are guaranteed to converge to the global minimum, for any graph, over the class of energies known as ”convex free energies”. In addition, we propose an efficient heuristic for setting the parameters of the convex free energy based on the structure of the graph.
关 键 词: 计算机科学; 机器学习; 图形模型; 人工智能
课程来源: 视频讲座网
最后编审: 2019-11-16:cwx
阅读次数: 42