通过张量展开揭示离散隐变量图模型的结构,实现可解释性建模。
Unfolding Tensors to Identify the Graph in Discrete Latent Bipartite Graphical Models
- 用张量展开法构造性证明图结构可识别
- 仅需每个隐变量连两个纯观测变量即可识别
- 适用于医疗诊断与生成模型,适合可解释性研究
本文利用张量展开技术,证明了离散二分图模型的新型可识别性结果。这类模型在观测层与隐层之间具有二分图结构,涵盖医学诊断中的Noisy-Or贝叶斯网络和机器学习中的受限玻尔兹曼机,也是深度生成模型的基础组件。我们的可识别性证明具有三个优点:第一,证明过程是构造性的,通过将模型的总体张量展开为矩阵并分析其秩性质,可直接推导出隐变量数量与二分图结构;第二,允许变量间存在多种非线性依赖关系,不依赖连续变量模型所需的线性假设;第三,可识别条件具有明确可解释性,仅要求每个隐变量至少连接两个“纯”观测变量。该结果不仅推动代数统计发展,也对科学建模与可解释机器学习具有实际意义。
原文摘要 · Abstract (English)
We use a tensor unfolding technique to prove a new identifiability result for discrete bipartite graphical models, which have a bipartite graph between an observed and a latent layer. This model family includes popular models such as Noisy-Or Bayesian networks for medical diagnosis and Restricted Boltzmann Machines in machine learning. These models are also building blocks for deep generative models. Our result on identifying the graph structure enjoys the following nice properties. First, our identifiability proof is constructive, in which we innovatively unfold the population tensor under the model into matrices and inspect the rank properties of the resulting matrices to uncover the graph. This proof itself gives a population-level structure learning algorithm that outputs both the number of latent variables and the bipartite graph. Second, we allow various forms of nonlinear dependence among the variables, unlike many continuous latent variable graphical models that rely on linearity to show identifiability. Third, our identifiability condition is interpretable, only requiring each latent variable to connect to at least two "pure" observed variables in the bipartite graph. The new result not only brings novel advances in algebraic statistics, but also has useful implications for these models' trustworthy applications in scientific disciplines and interpretable machine learning.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。