arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1502.07252stat.CO
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计算机代码校准的自适应数值设计

Adaptive numerical designs for the calibration of computer codes

Guillaume Damblin, Pierre Barbillon, Merlin Keller, Alberto Pasanisi, Eric Parent

摘要:

使用计算机代码对物理系统进行良好的预测需要仔细指定输入。这些输入中的一些称为控制变量,必须再现物理条件,而其他输入称为参数,是特定于计算机代码的,并且通常是不确定的。统计校准的目标在于借助统计模型估计这些参数,该模型将代码输出与现场测量相关联。在贝叶斯设置中,这些参数的后验分布通常使用MCMC方法进行采样。然而,当代码运行非常耗时时,它们是不切实际的。一种解决方法是用高斯过程模拟器代替计算机代码,然后根据它采样一个便宜的后验后验分布,这样做的话,校准会受到误差的影响,而误差很大程度上取决于用于拟合模拟器的实验的数值设计。我们的目的是通过建立一个适当的序列设计,通过预期改善标准,以减少这种错误。在几个方面的数值说明评估这种顺序策略的效率。

英文摘要:

Making good predictions of a physical system using a computer code requires the inputs to be carefully specified. Some of these inputs called control variables have to reproduce physical conditions whereas other inputs, called parameters, are specific to the computer code and most often uncertain. The goal of statistical calibration consists in estimating these parameters with the help of a statistical model which links the code outputs with the field measurements. In a Bayesian setting, the posterior distribution of these parameters is normally sampled using MCMC methods. However, they are impractical when the code runs are high time-consuming. A way to circumvent this issue consists of replacing the computer code with a Gaussian process emulator, then sampling a cheap-to-evaluate posterior distribution based on it. Doing so, calibration is subject to an error which strongly depends on the numerical design of experiments used to fit the emulator. We aim at reducing this error by building a proper sequential design by means of the Expected Improvement criterion. Numerical illustrations in several dimensions assess the efficiency of such sequential strategies.

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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