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arXiv 2303.09196math.OC
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有序风险最小化:从更少数据中学习更多

Ordered Risk Minimization: Learning More from Less Data

Peter Coppens, Panagiotis Patrinos

AI总结:

本文提出“有序风险最小化”框架,利用离散分布置换不变模糊集的最坏期望作为代理成本,为期望风险提供任意样本量下可紧密确定的高置信度上界,并支持基于 $ϕ$-散度的模糊集校准,相比经验风险最小化泛化更好且对调参更不敏感。

摘要:

我们将离散分布的置换不变模糊集的最坏期望,作为数据驱动期望风险最小化的代理成本。针对此框架,我们提出“有序风险最小化”一词,以强调次序统计的结果如何启发该代理成本。具体而言,我们展示了此类成本如何作为期望风险的逐点高置信度上界。对于任意样本量,均可紧密确定其置信水平。反之,我们还说明了如何校准模糊集的大小,使得高置信度上界具有用户指定的置信度。值得注意的是,该校准过程支持基于 $ϕ$-散度的模糊集。数值实验表明,与经验风险最小化方法相比,所得方案泛化能力更好,且对调参敏感度更低。

英文摘要:

We consider the worst-case expectation of a permutation invariant ambiguity set of discrete distributions as a proxy-cost for data-driven expected risk minimization. For this framework, we coin the term ordered risk minimization to highlight how results from order statistics inspired the proxy-cost. Specifically, we show how such costs serve as point-wise high-confidence upper bounds of the expected risk. The confidence level can be determined tightly for any sample size. Conversely we also illustrate how to calibrate the size of the ambiguity set such that the high-confidence upper bound has some user specified confidence. This calibration procedure notably supports $ϕ$-divergence based ambiguity sets. Numerical experiments then illustrate how the resulting scheme both generalizes better and is less sensitive to tuning parameters compared to the empirical risk minimization approach.

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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