Optimal Transport for Measures with Noisy Tree Metric

التفاصيل البيبلوغرافية
العنوان: Optimal Transport for Measures with Noisy Tree Metric
المؤلفون: Le, Tam, Nguyen, Truyen, Fukumizu, Kenji
سنة النشر: 2023
المجموعة: Computer Science
Statistics
مصطلحات موضوعية: Statistics - Machine Learning, Computer Science - Machine Learning
الوصف: We study optimal transport (OT) problem for probability measures supported on a tree metric space. It is known that such OT problem (i.e., tree-Wasserstein (TW)) admits a closed-form expression, but depends fundamentally on the underlying tree structure over supports of input measures. In practice, the given tree structure may be, however, perturbed due to noisy or adversarial measurements. To mitigate this issue, we follow the max-min robust OT approach which considers the maximal possible distances between two input measures over an uncertainty set of tree metrics. In general, this approach is hard to compute, even for measures supported in one-dimensional space, due to its non-convexity and non-smoothness which hinders its practical applications, especially for large-scale settings. In this work, we propose novel uncertainty sets of tree metrics from the lens of edge deletion/addition which covers a diversity of tree structures in an elegant framework. Consequently, by building upon the proposed uncertainty sets, and leveraging the tree structure over supports, we show that the robust OT also admits a closed-form expression for a fast computation as its counterpart standard OT (i.e., TW). Furthermore, we demonstrate that the robust OT satisfies the metric property and is negative definite. We then exploit its negative definiteness to propose positive definite kernels and test them in several simulations on various real-world datasets on document classification and topological data analysis.
Comment: To appear in AISTATS 2024
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2310.13653
رقم الأكسشن: edsarx.2310.13653
قاعدة البيانات: arXiv