Conventional gradient-based full waveform inversion (FWI) is a local optimization, which is highly dependent on the initial model and prone to trapping in local minima. Globally optimal FWI that can overcome this limi...Conventional gradient-based full waveform inversion (FWI) is a local optimization, which is highly dependent on the initial model and prone to trapping in local minima. Globally optimal FWI that can overcome this limitation is particularly attractive, but is currently limited by the huge amount of calculation. In this paper, we propose a globally optimal FWI framework based on GPU parallel computing, which greatly improves the efficiency, and is expected to make globally optimal FWI more widely used. In this framework, we simplify and recombine the model parameters, and optimize the model iteratively. Each iteration contains hundreds of individuals, each individual is independent of the other, and each individual contains forward modeling and cost function calculation. The framework is suitable for a variety of globally optimal algorithms, and we test the framework with particle swarm optimization algorithm for example. Both the synthetic and field examples achieve good results, indicating the effectiveness of the framework. .展开更多
By using the concept of multigraphs, the difference graphs of a class of alternating block Crank-Nicolson methods are defined and described, which extends the results on difference graphs of parallel computing for the...By using the concept of multigraphs, the difference graphs of a class of alternating block Crank-Nicolson methods are defined and described, which extends the results on difference graphs of parallel computing for the finite difference method.展开更多
研究并实现了介质电与磁本构参数均为各向异性时的三维ANI-FDTD(anisotropic medium finite-dif-ference time-domain)方法及其并行计算。分析表明,电磁场分量节点的FDTD迭代计算均涉及到其邻近28个其他场分量节点值。在此基础上,分析...研究并实现了介质电与磁本构参数均为各向异性时的三维ANI-FDTD(anisotropic medium finite-dif-ference time-domain)方法及其并行计算。分析表明,电磁场分量节点的FDTD迭代计算均涉及到其邻近28个其他场分量节点值。在此基础上,分析了实行区域分割后ANI-FDTD并行计算中的数据通信规律。通过采用相邻子域重叠半个网格的区域划分方式,传递分界面两边相关节点的场值,实现了计算机局域网内各节点机的协同并行计算。数值计算结果表明了该方法和程序的正确性。展开更多
摘要Conventional gradient-based full waveform inversion (FWI) is a local optimization, which is highly dependent on the initial model and prone to trapping in local minima. Globally optimal FWI that can overcome this limitation is particularly attractive, but is currently limited by the huge amount of calculation. In this paper, we propose a globally optimal FWI framework based on GPU parallel computing, which greatly improves the efficiency, and is expected to make globally optimal FWI more widely used. In this framework, we simplify and recombine the model parameters, and optimize the model iteratively. Each iteration contains hundreds of individuals, each individual is independent of the other, and each individual contains forward modeling and cost function calculation. The framework is suitable for a variety of globally optimal algorithms, and we test the framework with particle swarm optimization algorithm for example. Both the synthetic and field examples achieve good results, indicating the effectiveness of the framework. .
摘要By using the concept of multigraphs, the difference graphs of a class of alternating block Crank-Nicolson methods are defined and described, which extends the results on difference graphs of parallel computing for the finite difference method.
摘要研究并实现了介质电与磁本构参数均为各向异性时的三维ANI-FDTD(anisotropic medium finite-dif-ference time-domain)方法及其并行计算。分析表明,电磁场分量节点的FDTD迭代计算均涉及到其邻近28个其他场分量节点值。在此基础上,分析了实行区域分割后ANI-FDTD并行计算中的数据通信规律。通过采用相邻子域重叠半个网格的区域划分方式,传递分界面两边相关节点的场值,实现了计算机局域网内各节点机的协同并行计算。数值计算结果表明了该方法和程序的正确性。