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arXiv 1302.6792cs.AI
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贝叶斯信度网络学习算法的性质

Properties of Bayesian Belief Network Learning Algorithms

Utrecht University(乌得勒支大学)

Remco R. Bouckaert

摘要:

贝叶斯信念网络学习算法有三个基本组成部分:网络结构和数据库的测量,选择要考虑的网络结构的搜索启发式,以及从数据库估计概率表的方法。本文对这三个主题都有贡献。库珀和Herskovits和最小描述长度(MDL)措施的贝叶斯措施的行为进行了比较,就其性质的限制大小和有限大小的数据库。结果表明,MDL措施比贝叶斯措施时,要学习的分布具有更理想的属性。研究表明,选择具有某些极小性属性的信念网络是NP难的。这个结果证明了使用搜索算法而不是精确算法来选择要考虑的网络结构是合理的。在某些情况下,一个信念网络的集合可以用一个信念网络来表示,这导致了一种新的概率表估计,称为平滑。我们认为,平滑可以有效地实现将其纳入搜索启发式。实验结果表明,平滑的信念网络的学习概率是有帮助的。

英文摘要:

Bayesian belief network learning algorithms have three basic components: a measure of a network structure and a database, a search heuristic that chooses network structures to be considered, and a method of estimating the probability tables from the database. This paper contributes to all these three topics. The behavior of the Bayesian measure of Cooper and Herskovits and a minimum description length (MDL) measure are compared with respect to their properties for both limiting size and finite size databases. It is shown that the MDL measure has more desirable properties than the Bayesian measure when a distribution is to be learned. It is shown that selecting belief networks with certain minimallity properties is NP-hard. This result justifies the use of search heuristics instead of exact algorithms for choosing network structures to be considered. In some cases, a collection of belief networks can be represented by a single belief network which leads to a new kind of probability table estimation called smoothing. We argue that smoothing can be efficiently implemented by incorporating it in the search heuristic. Experimental results suggest that for learning probabilities of belief networks smoothing is helpful.

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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