论文标题
一类随机模型的有效认识不确定性定量算法:后处理和域分解框架
An efficient epistemic uncertainty quantification algorithm for a class of stochastic models: A post-processing and domain decomposition framework
论文作者
论文摘要
部分微分方程(PDE)对于理论上描述了许多基于空间配置中某些输入字段的物理过程的基础。通常,了解物理过程需要PDE的计算建模。计算模型中的不确定性由于缺乏对输入字段或配置的精确知识而表现出来。输出物理过程中的不确定性定量(UQ)通常是通过使用适当的协方差函数控制的随机字段对不确定性进行建模的。这导致解决PDE计算模型的高维随机对应物。这样的UQ-PDE模型需要大量的PDE模拟与高维概率空间中的样品结合使用,并且概率分布与协方差函数相关。那些具有明确了解协方差函数知识的UQ计算模型称为Aleatoric UQ(AUQ)模型。缺乏这种明确的知识会导致认知UQ(EUQ)模型,通常需要解决大量AUQ模型。在本文中,使用替代物,后处理和域分解框架和粗糙的随机解决方案适应,我们开发了一种离线/在线算法,以有效地模拟一类EUQ-PDE模型。
Partial differential equations (PDEs) are fundamental for theoretically describing numerous physical processes that are based on some input fields in spatial configurations. Understanding the physical process, in general, requires computational modeling of the PDE. Uncertainty in the computational model manifests through lack of precise knowledge of the input field or configuration. Uncertainty quantification (UQ) in the output physical process is typically carried out by modeling the uncertainty using a random field, governed by an appropriate covariance function. This leads to solving high-dimensional stochastic counterparts of the PDE computational models. Such UQ-PDE models require a large number of simulations of the PDE in conjunction with samples in the high-dimensional probability space, with probability distribution associated with the covariance function. Those UQ computational models having explicit knowledge of the covariance function are known as aleatoric UQ (AUQ) models. The lack of such explicit knowledge leads to epistemic UQ (EUQ) models, which typically require solution of a large number of AUQ models. In this article, using a surrogate, post-processing, and domain decomposition framework with coarse stochastic solution adaptation, we develop an offline/online algorithm for efficiently simulating a class of EUQ-PDE models.