论文标题
迈向灵活的稀疏感建模:使用广义双曲线先验
Towards Flexible Sparsity-Aware Modeling: Automatic Tensor Rank Learning Using The Generalized Hyperbolic Prior
论文作者
论文摘要
长期以来,张量的多核分解(CPD)的张量排名学习一直被视为一个必不可少但具有挑战性的问题。特别是,由于张量等级控制了CPD模型的复杂性,因此其不准确的学习会导致过度适合噪声或对信号源的不合格,甚至破坏了模型参数的可解释性。但是,已知张量级的最佳确定是一项非确定性的多项式硬度(NP-HARD)任务。在概率CPD建模的背景下,引入了高斯 - 伽马之前的贝叶斯推断,而不是通过试用和错误实验详尽地搜索最佳张量排名,而是在概率CPD建模的背景下引入了贝叶斯的推断,并被证明是自动张量级级别确定的有效策略。这引发了对具有自动张量排名学习的其他结构化张量CPD的繁荣研究。在硬币的另一侧,这些研究作品还表明,高斯 - 伽马模型对于高级别张量和/或低信噪比(SNR)的表现不佳。为了克服这些缺点,在本文中,我们在概率CPD模型之前引入了更先进的广义双曲线(GH),该模型不仅包括高斯 - 伽马模型作为一种特殊情况,而且更灵活地适应不同水平的稀疏度。基于这个新颖的概率模型,在变异推理的框架下开发了一种算法,其中每个更新均以封闭形式获得。使用合成数据和现实世界数据集的广泛数值结果表明,即使在低SNR案例中,甚至在学习低张量和高张量排列方面,提出的方法的性能显着提高。
Tensor rank learning for canonical polyadic decomposition (CPD) has long been deemed as an essential yet challenging problem. In particular, since the tensor rank controls the complexity of the CPD model, its inaccurate learning would cause overfitting to noise or underfitting to the signal sources, and even destroy the interpretability of model parameters. However, the optimal determination of a tensor rank is known to be a non-deterministic polynomial-time hard (NP-hard) task. Rather than exhaustively searching for the best tensor rank via trial-and-error experiments, Bayesian inference under the Gaussian-gamma prior was introduced in the context of probabilistic CPD modeling, and it was shown to be an effective strategy for automatic tensor rank determination. This triggered flourishing research on other structured tensor CPDs with automatic tensor rank learning. On the other side of the coin, these research works also reveal that the Gaussian-gamma model does not perform well for high-rank tensors and/or low signal-to-noise ratios (SNRs). To overcome these drawbacks, in this paper, we introduce a more advanced generalized hyperbolic (GH) prior to the probabilistic CPD model, which not only includes the Gaussian-gamma model as a special case, but also is more flexible to adapt to different levels of sparsity. Based on this novel probabilistic model, an algorithm is developed under the framework of variational inference, where each update is obtained in a closed-form. Extensive numerical results, using synthetic data and real-world datasets, demonstrate the significantly improved performance of the proposed method in learning both low as well as high tensor ranks even for low SNR cases.