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arXiv 2602.16709cs.LGmath.STstat.MEstat.TH

嵌入知识的潜在投影用于鲁棒表征学习

Knowledge-Embedded Latent Projection for Robust Representation Learning

Department of Statistics and Data Science, Carnegie Mellon University(卡内基梅隆大学统计学与数据科学系);Department of Statistics, Columbia University(哥伦比亚大学统计学系);Department of Neurology, University of Pittsburgh(匹兹堡大学神经病学系);Department of Biostatistics, Harvard University(哈佛大学生物统计学系)

Weijing Tang, Ming Yuan, Zongqi Xia, Tianxi Cai

AI总结:

本文提出嵌入知识的潜在投影模型,通过语义信息正则化表征学习,解决高维不平衡数据下的鲁棒表示问题。

摘要:

潜在空间模型被广泛用于分析高维离散数据矩阵,例如电子健康记录(EHRs)中的患者-特征矩阵,通过低维嵌入捕捉复杂的依赖结构。然而,在不平衡情况下,估计变得具有挑战性,其中一个矩阵维度远大于另一个。在EHR应用中,队列大小通常受到疾病发病率或数据可用性的限制,而特征空间由于医学编码系统的广度仍然非常大。受外部语义嵌入日益可用的启发,例如预训练的临床概念嵌入,我们提出了一种嵌入知识的潜在投影模型,利用语义侧信息来正则化表征学习。具体而言,我们通过在再生核希尔伯特空间中的映射将列嵌入建模为语义嵌入的平滑函数。我们开发了一种计算效率高的两步估计过程,结合通过核主成分分析进行的语义引导子空间构建与可扩展的投影梯度下降。我们建立了估计误差界限,这些界限刻画了统计误差和由核投影引起的近似误差之间的权衡。此外,我们为非凸优化过程提供了局部收敛保证。广泛的模拟研究和真实世界EHR应用证明了所提方法的有效性。

英文摘要:

Latent space models are widely used for analyzing high-dimensional discrete data matrices, such as patient-feature matrices in electronic health records (EHRs), by capturing complex dependence structures through low-dimensional embeddings. However, estimation becomes challenging in the imbalanced regime, where one matrix dimension is much larger than the other. In EHR applications, cohort sizes are often limited by disease prevalence or data availability, whereas the feature space remains extremely large due to the breadth of medical coding system. Motivated by the increasing availability of external semantic embeddings, such as pre-trained embeddings of clinical concepts in EHRs, we propose a knowledge-embedded latent projection model that leverages semantic side information to regularize representation learning. Specifically, we model column embeddings as smooth functions of semantic embeddings via a mapping in a reproducing kernel Hilbert space. We develop a computationally efficient two-step estimation procedure that combines semantically guided subspace construction via kernel principal component analysis with scalable projected gradient descent. We establish estimation error bounds that characterize the trade-off between statistical error and approximation error induced by the kernel projection. Furthermore, we provide local convergence guarantees for our non-convex optimization procedure. Extensive simulation studies and a real-world EHR application demonstrate the effectiveness of the proposed method.

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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