arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1909.01299math.NAcs.NA
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三维层状介质问题的快速finite-difference卷积

Fast finite-difference convolution for 3D problems in layered media

Vladimir Druskin, Mikhail Zaslavsky

摘要:

我们开发了三维Helmholtz和Maxwell方程的快速直接求解器。该算法基于可分矩阵循环约简的思想。对于大部分均匀网格(如地球物理勘探问题中的测量区域)和小部分非均匀网格(PML和粗化以近似无限区域中的问题),我们的方法的计算代价是$O(N_xN_ylog(N_xN_y)N_z)$。对于一般的非均匀网格,成本为$O(N^{3/2}_xN^{3/2}_yN_z)$。第一渐近符合基于FFT的方法的成本,它可以适用于均匀网格(在x和y)。我们的方法是显着更有效的算法相比,基于离散傅里叶变换的成本是$O(N^2_xN^2_yN_z)$。该算法也可以很容易地推广到弹性力学问题的求解。

英文摘要:

We developed fast direct solver for 3D Helmholtz and Maxwell equations in layered medium. The algorithm is based on the ideas of cyclic reduction for separable matrices. For the grids with major uniform part (within the survey domain in the problems of geophysical prospecting, for example) and small non-uniform part (PML and coarsening to approximate problems in infinite domain) the computational cost of our approach is $O(N_xN_ylog(N_xN_y)N_z)$. For general non-uniform grids the cost is $O(N^{3/2}_xN^{3/2}_yN_z)$. The first asymptotics coincide with the cost of FFT-based methods, which can be applied for uniform gridding (in x and y) only. Our approach is significantly more efficient compared to the algorithms based on discrete Fourier transform which cost is $O(N^2_xN^2_yN_z)$. The algorithm can be easily extended for solving the elasticity problems as well.

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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