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arXiv 1802.02468cs.AI
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有界树宽贝叶斯网络在完备和不完备数据集上的有效学习

Efficient Learning of Bounded-Treewidth Bayesian Networks from Complete and Incomplete Data Sets

IDSIA(瑞士人工智能研究所);Seoul National University(首尔国立大学)

Mauro Scanagatta, Giorgio Corani, Marco Zaffalon, Jaemin Yoo, U Kang

摘要:

学习树宽有界的贝叶斯网络对于降低推理的复杂性具有重要意义。我们提出了一种新的随时算法(K-MAX)的方法,该方法可以扩展到数千个变量。通过大量的实验,我们表明,它始终产生更高的评分结构比它的竞争对手在完整的数据集。然后,我们考虑从不完整的数据集的结构学习的问题。这可以通过结构EM来解决,然而这在计算上要求很高。因此,我们在结构EM的最大化步骤中采用了新的k-MAX算法,获得了期望的充分统计量的有效计算。我们测试所得到的结构EM方法的任务,填补缺失的数据,比较它对国家的最先进的方法的基础上随机森林。我们的方法实现了与竞争对手相同的插补精度,但时间只有竞争对手的十分之一。此外,我们表明,它有最坏情况下的复杂性线性的输入大小,它是很容易并行化。

英文摘要:

Learning a Bayesian networks with bounded treewidth is important for reducing the complexity of the inferences. We present a novel anytime algorithm (k-MAX) method for this task, which scales up to thousands of variables. Through extensive experiments we show that it consistently yields higher-scoring structures than its competitors on complete data sets. We then consider the problem of structure learning from incomplete data sets. This can be addressed by structural EM, which however is computationally very demanding. We thus adopt the novel k-MAX algorithm in the maximization step of structural EM, obtaining an efficient computation of the expected sufficient statistics. We test the resulting structural EM method on the task of imputing missing data, comparing it against the state-of-the-art approach based on random forests. Our approach achieves the same imputation accuracy of the competitors, but in about one tenth of the time. Furthermore we show that it has worst-case complexity linear in the input size, and that it is easily parallelizable.

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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