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arXiv 2104.09162math.NAcs.NA
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振荡高对比度随机椭圆问题BDDC算法的自适应粗空间学习

Learning adaptive coarse spaces of BDDC algorithms for stochastic elliptic problems with oscillatory and high contrast coefficients

Eric Chung, Hyea Hyun Kim, Ming Fai Lam, Lina Zhao

摘要:

本文研究了一类随机椭圆问题的自适应粗空间平衡区域分解算法。在粗空间的建设的关键成分是当地的谱问题,这取决于偏微分方程的系数的解决方案。这对随机系数提出了重大挑战,因为对于系数的每个实现,解决局部谱问题在计算上是昂贵的。为了解决这个计算负担,我们提出了一种机器学习方法。我们的方法是基于使用深度神经网络(DNN)来近似随机系数和粗糙空间之间的关系。对于DNN的输入,我们应用Karhunen-Loève展开,并在展开中使用前几个主导项。DNN的输出是产生的粗空间,然后使用标准自适应BDDC算法应用。我们将给出一些数值结果与振荡和高对比度系数显示所提出的计划的效率和鲁棒性。

英文摘要:

In this paper, we consider the balancing domain decomposition by constraints (BDDC) algorithm with adaptive coarse spaces for a class of stochastic elliptic problems. The key ingredient in the construction of the coarse space is the solutions of local spectral problems, which depend on the coefficient of the PDE. This poses a significant challenge for stochastic coefficients as it is computationally expensive to solve the local spectral problems for every realisation of the coefficient. To tackle this computational burden, we propose a machine learning approach. Our method is based on the use of a deep neural network (DNN) to approximate the relation between the stochastic coefficients and the coarse spaces. For the input of the DNN, we apply the Karhunen-Loève expansion and use the first few dominant terms in the expansion. The output of the DNN is the resulting coarse space, which is then applied with the standard adaptive BDDC algorithm. We will present some numerical results with oscillatory and high contrast coefficients to show the efficiency and robustness of the proposed scheme.

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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