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arXiv 2206.07751cs.LGcs.AIstat.ML
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非线性ICA的可识别性:稀疏性及其超越

On the Identifiability of Nonlinear ICA: Sparsity and Beyond

Carnegie Mellon University(卡内基梅隆大学);Mohamed bin Zayed University of Artificial Intelligence(穆罕默德·本·扎耶德人工智能大学)

Yujia Zheng, Ignavier Ng, Kun Zhang

AI总结:

本文针对无辅助变量的非线性ICA可识别性问题,提出仅依赖混合过程的结构稀疏性假设,证明隐源可被识别至置换与逐分量变换,并通过实验验证了该理论。

摘要:

非线性独立成分分析(ICA)旨在从其可观测的非线性混合中恢复潜在的独立隐源。如何使非线性ICA模型在特定平凡不确定性意义下可识别,是无监督学习中一个长期存在的问题。近期突破将源的标准独立性假设重新表述为在给定某些辅助变量(例如类别标签和/或域/时间索引)条件下的条件独立性,作为弱监督或归纳偏置。然而,具有无条件先验的非线性ICA无法受益于这些进展。我们探索另一条路径,仅考虑混合过程的假设,例如结构稀疏性。我们证明,在此类约束的特定实例化下,独立的潜在隐源可以从其非线性混合中被识别出来,至多相差一个置换和一个逐分量变换,从而在没有辅助变量的情况下实现非线性ICA的非平凡可识别性。我们提供了估计方法,并通过实验验证了理论结果。在图像数据上的结果表明,我们的条件可能在许多实际数据生成过程中成立。

英文摘要:

Nonlinear independent component analysis (ICA) aims to recover the underlying independent latent sources from their observable nonlinear mixtures. How to make the nonlinear ICA model identifiable up to certain trivial indeterminacies is a long-standing problem in unsupervised learning. Recent breakthroughs reformulate the standard independence assumption of sources as conditional independence given some auxiliary variables (e.g., class labels and/or domain/time indexes) as weak supervision or inductive bias. However, nonlinear ICA with unconditional priors cannot benefit from such developments. We explore an alternative path and consider only assumptions on the mixing process, such as Structural Sparsity. We show that under specific instantiations of such constraints, the independent latent sources can be identified from their nonlinear mixtures up to a permutation and a component-wise transformation, thus achieving nontrivial identifiability of nonlinear ICA without auxiliary variables. We provide estimation methods and validate the theoretical results experimentally. The results on image data suggest that our conditions may hold in a number of practical data generating processes.

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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