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arXiv 1910.04086stat.MLcs.LGmath.STstat.APstat.MEstat.TH
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使用RKHS嵌入的有限集上的核及其在贝叶斯(组合)优化中的应用

Kernels over Sets of Finite Sets using RKHS Embeddings, with Application to Bayesian (Combinatorial) Optimization

Mahidol University(玛希隆大学);Idiap Research Institute(Idiap研究所);University of Bern(伯尔尼大学);Centre of Excellence in Mathematics(数学卓越中心)

Poompol Buathong, David Ginsbourger, Tipaluck Krityakierne

摘要:

我们专注于集值输入的核方法及其在贝叶斯集优化,特别是组合优化中的应用。我们研究了两类依赖于再生核希尔伯特空间嵌入的集合核,即最近在贝叶斯集合优化中考虑的“双和”(DS)核,以及在这里引入的一类称为“深嵌入”(DE)核,其基本上包括在希尔伯特空间上应用径向核,该径向核是由另一个核(如DS核)引起的正则距离。我们建立特别是,虽然DS内核通常遭受缺乏严格的正定性,巨大的子类DE内核建立在DS内核拥有这个属性,从而使组合优化,而不需要引入抖动参数。关于考虑内核的理论结果的证明补充了一些关于超参数拟合的实用性。我们还证明了我们的方法在预测和优化任务的适用性,依靠玩具的例子和两个测试案例,分别从机械工程和水文地质。实验结果突出了所考虑的方法的适用性和比较的优点,同时在预测和序列设计与设置输入打开新的视角。

英文摘要:

We focus on kernel methods for set-valued inputs and their application to Bayesian set optimization, notably combinatorial optimization. We investigate two classes of set kernels that both rely on Reproducing Kernel Hilbert Space embeddings, namely the ``Double Sum'' (DS) kernels recently considered in Bayesian set optimization, and a class introduced here called ``Deep Embedding'' (DE) kernels that essentially consists in applying a radial kernel on Hilbert space on top of the canonical distance induced by another kernel such as a DS kernel. We establish in particular that while DS kernels typically suffer from a lack of strict positive definiteness, vast subclasses of DE kernels built upon DS kernels do possess this property, enabling in turn combinatorial optimization without requiring to introduce a jitter parameter. Proofs of theoretical results about considered kernels are complemented by a few practicalities regarding hyperparameter fitting. We furthermore demonstrate the applicability of our approach in prediction and optimization tasks, relying both on toy examples and on two test cases from mechanical engineering and hydrogeology, respectively. Experimental results highlight the applicability and compared merits of the considered approaches while opening new perspectives in prediction and sequential design with set inputs.

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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