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arXiv 1601.02557stat.CO
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贝叶斯子集模拟

Bayesian subset simulation

Julien Bect, Ling Li, Emmanuel Vazquez

摘要:

我们考虑的问题,估计故障概率$α$,定义为一个函数$f:\mathbb{X} \subseteq \mathbb{R}^{d} \to \mathbb{R}$在给定阈值以上的偏移集的体积,在给定的概率测度$\mathbb{X}$。在这篇文章中,我们结合流行的子集模拟算法(Au和贝克,Probab。Eng.Mech.2001)和我们用于估计故障概率的序贯贝叶斯方法(Bect,Ginsbourger,Li,Picheny和Vazquez,Stat. Comput. 2012年)。这使得当$f$的评估数量非常有限并且$α$非常小时,可以估计$α$。由此产生的算法被称为贝叶斯子集模拟(BSS)。一个关键的想法,在子集模拟算法中,是估计的概率的一个序列的偏移集的$f$以上的中间阈值,使用序贯蒙特卡罗(SMC)的方法。在$f$上使用高斯过程先验来定义SMC算法所针对的密度序列,并驱动$f$的评估点的选择以估计中间概率。提出了自适应程序来确定中间阈值和在算法的每个阶段要进行的评价的数量。数值实验表明,BSS实现了显着节省的功能评估的数量相对于其他蒙特卡罗方法。

英文摘要:

We consider the problem of estimating a probability of failure $α$, defined as the volume of the excursion set of a function $f:\mathbb{X} \subseteq \mathbb{R}^{d} \to \mathbb{R}$ above a given threshold, under a given probability measure on $\mathbb{X}$. In this article, we combine the popular subset simulation algorithm (Au and Beck, Probab. Eng. Mech. 2001) and our sequential Bayesian approach for the estimation of a probability of failure (Bect, Ginsbourger, Li, Picheny and Vazquez, Stat. Comput. 2012). This makes it possible to estimate $α$ when the number of evaluations of $f$ is very limited and $α$ is very small. The resulting algorithm is called Bayesian subset simulation (BSS). A key idea, as in the subset simulation algorithm, is to estimate the probabilities of a sequence of excursion sets of $f$ above intermediate thresholds, using a sequential Monte Carlo (SMC) approach. A Gaussian process prior on $f$ is used to define the sequence of densities targeted by the SMC algorithm, and drive the selection of evaluation points of $f$ to estimate the intermediate probabilities. Adaptive procedures are proposed to determine the intermediate thresholds and the number of evaluations to be carried out at each stage of the algorithm. Numerical experiments illustrate that BSS achieves significant savings in the number of function evaluations with respect to other Monte Carlo approaches.

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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