We investigated correlation of the slope of the initial part of P-wave envelope, hypocenter depth and plate boundaries by B-Δ method, which is used to determine epicentral distances in the Japan Meteorological Agency...We investigated correlation of the slope of the initial part of P-wave envelope, hypocenter depth and plate boundaries by B-Δ method, which is used to determine epicentral distances in the Japan Meteorological Agency and Japan Railway Company earthquake early warning(EEW) systems. The Tohoku region was chosen as the study region. 19,899 strong motion data for 265 events with magnitudes in the range from 5.0 to 7.6 from KiK-net(Kiban Kyoshin network) had been collected. The coefficient c to investigate is obtained from the linear relation between log B and log Δ. Compared to the hypocenter depth, the coefficients c of events is more likely to decide by the spatial correlation of the plate boundaries. The differences are likely to be due to earthquake characteristics, since deeper events in the subducting slabs the structural effects are likely to be larger than or comparable to those for shallow crust events.展开更多
The multisplitting algorithm for solving large systems of ordinary differential equations on parallel computers was introduced by Jeltsch and Pohl in [1]. On fixed time intervals conver gence results could be derived ...The multisplitting algorithm for solving large systems of ordinary differential equations on parallel computers was introduced by Jeltsch and Pohl in [1]. On fixed time intervals conver gence results could be derived if the subsystems are solving exactly.Firstly,in theis paper,we deal with an extension of the waveform relaxation algorithm by us ing multisplittin AOR method based on an overlapping block decomposition. We restricted our selves to equidistant timepoints and dealed with the case that an implicit integration method was used to solve the subsystems numerically in parallel. Then we have proved convergence of multi splitting AOR waveform relaxation algorithm on a fixed window containing a finite number of timepoints.展开更多
The present paper contributes in studying the phase velocities of P- and S-waves in a half space subjected to a compressive initial stress and gravity field. The density and acceleration due to gravity vary quadratica...The present paper contributes in studying the phase velocities of P- and S-waves in a half space subjected to a compressive initial stress and gravity field. The density and acceleration due to gravity vary quadratically along the depth. The dispersion equation is derived in a closed form. It is shown that the phase velocities depend not only on the initial stress, gravity, and direction of propagation but also on the inhomogeneity parameter associated with the density and acceleration due to gravity. Various particular cases are obtained, and the results match with the classical results. Numerical investigations on the phase velocities of P- and S-waves against the wave number are made for various sets of values of the material parameters, and the results are illustrated graphically. The graphical user interface model is developed to generalize the effect.展开更多
Full waveform inversion is mainly used to obtain high resolution velocity models of subsurface. The size of full waveform inversion will lead to a gigantic computation cost. Under the available computer resource and t...Full waveform inversion is mainly used to obtain high resolution velocity models of subsurface. The size of full waveform inversion will lead to a gigantic computation cost. Under the available computer resource and the limitation of full waveform inversion,the authors propose L-BFGS algorithm as the optimization method to solve this problem. In order to demonstrate the flexibility of the method,three different numerical experiments have been done to analyze the properties of full waveform inversion based on L-BFGS.展开更多
地震随机反演方法由于井间数据缺失,反演结果的横向连续性较差。且反演效率低、反演结果随机性强。为此,我们提出基于地震波形约束的地质统计学反演方法。用地震数据的相关系数来衡量地震波形的相似程度,代替传统的变差函数进行序贯高...地震随机反演方法由于井间数据缺失,反演结果的横向连续性较差。且反演效率低、反演结果随机性强。为此,我们提出基于地震波形约束的地质统计学反演方法。用地震数据的相关系数来衡量地震波形的相似程度,代替传统的变差函数进行序贯高斯模拟。在贝叶斯框架下,结合地震数据的约束,利用马尔科夫链-蒙特卡洛(Markov Chain Monte Carlo,MCMC)算法对模拟结果进行随机扰动和全局寻优,获得优化的参数反演结果。模型测试结果表明,基于地震波形约束的初始模型较为精确地刻画了地下储层的空间结构。对其进行迭代优化可以加快马尔科夫链的收敛速度,有效提高反演结果的精度。本文将提出的地质统计学反演方法用于某油田实际地震数据,在随机模拟过程和目标函数的约束中,充分挖掘了地震波形蕴含的地质信息,并为实现多数据联合约束地震反演提供了理论依据。展开更多
对主动模拟肺平台进行了调查研究,发现现有的主动模拟肺平台存在算法复杂、价格昂贵等缺点。针对以上不足,设计了一款可用于呼吸机综合测试的主动模拟肺平台。该平台通过在运动控制器上设置呼吸频率、潮气量等呼吸参数,计算相关参数并...对主动模拟肺平台进行了调查研究,发现现有的主动模拟肺平台存在算法复杂、价格昂贵等缺点。针对以上不足,设计了一款可用于呼吸机综合测试的主动模拟肺平台。该平台通过在运动控制器上设置呼吸频率、潮气量等呼吸参数,计算相关参数并向直线电机驱动器发送相应的脉冲指令,由直线电机带动麻醉机风箱气囊活塞做往复运动,以模拟人体正常生理及疾病状态时的各种呼吸。经过Certifier FA Plus气流分析仪的测试,主动模拟肺平台可以用于模拟人体的各种呼吸状况。该平台具有良好的可扩展性,可用于临床医学和呼吸机的综合测试。展开更多
基金supported by the Director Foundation of the Institute of Seismology,China Earthquake Administration,China(IS200756046)
文摘We investigated correlation of the slope of the initial part of P-wave envelope, hypocenter depth and plate boundaries by B-Δ method, which is used to determine epicentral distances in the Japan Meteorological Agency and Japan Railway Company earthquake early warning(EEW) systems. The Tohoku region was chosen as the study region. 19,899 strong motion data for 265 events with magnitudes in the range from 5.0 to 7.6 from KiK-net(Kiban Kyoshin network) had been collected. The coefficient c to investigate is obtained from the linear relation between log B and log Δ. Compared to the hypocenter depth, the coefficients c of events is more likely to decide by the spatial correlation of the plate boundaries. The differences are likely to be due to earthquake characteristics, since deeper events in the subducting slabs the structural effects are likely to be larger than or comparable to those for shallow crust events.
文摘The multisplitting algorithm for solving large systems of ordinary differential equations on parallel computers was introduced by Jeltsch and Pohl in [1]. On fixed time intervals conver gence results could be derived if the subsystems are solving exactly.Firstly,in theis paper,we deal with an extension of the waveform relaxation algorithm by us ing multisplittin AOR method based on an overlapping block decomposition. We restricted our selves to equidistant timepoints and dealed with the case that an implicit integration method was used to solve the subsystems numerically in parallel. Then we have proved convergence of multi splitting AOR waveform relaxation algorithm on a fixed window containing a finite number of timepoints.
基金supported by the Research Fellow of Indian School of Mines in Dhanbad (No. 2010DR0016)
文摘The present paper contributes in studying the phase velocities of P- and S-waves in a half space subjected to a compressive initial stress and gravity field. The density and acceleration due to gravity vary quadratically along the depth. The dispersion equation is derived in a closed form. It is shown that the phase velocities depend not only on the initial stress, gravity, and direction of propagation but also on the inhomogeneity parameter associated with the density and acceleration due to gravity. Various particular cases are obtained, and the results match with the classical results. Numerical investigations on the phase velocities of P- and S-waves against the wave number are made for various sets of values of the material parameters, and the results are illustrated graphically. The graphical user interface model is developed to generalize the effect.
文摘Full waveform inversion is mainly used to obtain high resolution velocity models of subsurface. The size of full waveform inversion will lead to a gigantic computation cost. Under the available computer resource and the limitation of full waveform inversion,the authors propose L-BFGS algorithm as the optimization method to solve this problem. In order to demonstrate the flexibility of the method,three different numerical experiments have been done to analyze the properties of full waveform inversion based on L-BFGS.
基金funded by the project‘Study on tomographic velocity inversion method based on P-wave and S-Wave constraints’(33550000-21-FW0399-0009)of State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development and Sinopec Key Laboratory of Seismic Elastic Wave Technology.
基金supported by the National Natural Science Foundation of China[Grant Nos.42174146,42074136,42174144]Innovation Fund Project for Graduate Students of China University of Petroleum(East China)[Grant No.23CX04015A].
文摘地震随机反演方法由于井间数据缺失,反演结果的横向连续性较差。且反演效率低、反演结果随机性强。为此,我们提出基于地震波形约束的地质统计学反演方法。用地震数据的相关系数来衡量地震波形的相似程度,代替传统的变差函数进行序贯高斯模拟。在贝叶斯框架下,结合地震数据的约束,利用马尔科夫链-蒙特卡洛(Markov Chain Monte Carlo,MCMC)算法对模拟结果进行随机扰动和全局寻优,获得优化的参数反演结果。模型测试结果表明,基于地震波形约束的初始模型较为精确地刻画了地下储层的空间结构。对其进行迭代优化可以加快马尔科夫链的收敛速度,有效提高反演结果的精度。本文将提出的地质统计学反演方法用于某油田实际地震数据,在随机模拟过程和目标函数的约束中,充分挖掘了地震波形蕴含的地质信息,并为实现多数据联合约束地震反演提供了理论依据。
文摘对主动模拟肺平台进行了调查研究,发现现有的主动模拟肺平台存在算法复杂、价格昂贵等缺点。针对以上不足,设计了一款可用于呼吸机综合测试的主动模拟肺平台。该平台通过在运动控制器上设置呼吸频率、潮气量等呼吸参数,计算相关参数并向直线电机驱动器发送相应的脉冲指令,由直线电机带动麻醉机风箱气囊活塞做往复运动,以模拟人体正常生理及疾病状态时的各种呼吸。经过Certifier FA Plus气流分析仪的测试,主动模拟肺平台可以用于模拟人体的各种呼吸状况。该平台具有良好的可扩展性,可用于临床医学和呼吸机的综合测试。
