论文标题

与嘈杂或关系的学习贝叶斯网络的得分和搜索方法

A Score-and-Search Approach to Learning Bayesian Networks with Noisy-OR Relations

论文作者

Sharma, Charupriya, Liao, Zhenyu A., Cussens, James, van Beek, Peter

论文摘要

贝叶斯网络是一个概率图形模型,由有向的无环图(DAG)组成,其中每个节点都是一个随机变量,并且连接到每个节点是条件概率分布(CPD)。可以使用众所周知的分数和搜索方法从数据中学到贝叶斯网络,在这种方法中,关键考虑是如何以基础DAG的形式同时学习全局结构和CPD中的本地结构。文献中已经确定了几种有用的局部结构形式,但到目前为止,得分和搜索方法仅扩展了以特定于上下文独立性的形式处理本地结构。在本文中,我们展示了如何将分数和搜索方法扩展到嘈杂或关系的重要案例。我们提供有效的梯度下降算法,以使用广泛使用的BIC分数来评分候选噪声,并提供修剪规则,使搜索能够成功扩展到中等大小的网络。我们的经验结果为我们学习结合嘈杂或关系的贝叶斯网络的方法提供了证据。

A Bayesian network is a probabilistic graphical model that consists of a directed acyclic graph (DAG), where each node is a random variable and attached to each node is a conditional probability distribution (CPD). A Bayesian network can be learned from data using the well-known score-and-search approach, and within this approach a key consideration is how to simultaneously learn the global structure in the form of the underlying DAG and the local structure in the CPDs. Several useful forms of local structure have been identified in the literature but thus far the score-and-search approach has only been extended to handle local structure in form of context-specific independence. In this paper, we show how to extend the score-and-search approach to the important and widely useful case of noisy-OR relations. We provide an effective gradient descent algorithm to score a candidate noisy-OR using the widely used BIC score and we provide pruning rules that allow the search to successfully scale to medium sized networks. Our empirical results provide evidence for the success of our approach to learning Bayesian networks that incorporate noisy-OR relations.

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