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Frequency-domain elastic full-waveform multiscale inversion method based on dual-level parallelism 被引量:2
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作者 李媛媛 李振春 +1 位作者 张凯 张旋 《Applied Geophysics》 SCIE CSCD 2015年第4期545-554,628,共11页
The complexity of an elastic wavefield increases the nonlinearity of inversion, To some extent, multiscale inversion decreases the nonlinearity of inversion and prevents it from falling into local extremes. A multisca... The complexity of an elastic wavefield increases the nonlinearity of inversion, To some extent, multiscale inversion decreases the nonlinearity of inversion and prevents it from falling into local extremes. A multiscale strategy based on the simultaneous use of frequency groups and layer stripping method based on damped wave field improves the stability of inversion. A dual-level parallel algorithm is then used to decrease the computational cost and improve practicability. The seismic wave modeling of a single frequency and inversion in a frequency group are computed in parallel by multiple nodes based on multifrontal massively parallel sparse direct solver and MPI. Numerical tests using an overthrust model show that the proposed inversion algorithm can effectively improve the stability and accuracy of inversion by selecting the appropriate inversion frequency and damping factor in low- frequency seismic data. 展开更多
关键词 frequency-domain inversion multiscale frequency groups layer stripping dual-level parallelism
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Frequency-domain auto-adapting full waveform inversion with blended source and frequency-group encoding 被引量:2
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作者 韩淼 韩立国 +1 位作者 刘春成 陈宝书 《Applied Geophysics》 SCIE CSCD 2013年第1期41-52,118,共13页
As a high quality seismic imaging method, full waveform inversion (FWI) can accurately reconstruct the physical parameter model for the subsurface medium. However, application of the FWI in seismic data processing i... As a high quality seismic imaging method, full waveform inversion (FWI) can accurately reconstruct the physical parameter model for the subsurface medium. However, application of the FWI in seismic data processing is computationally expensive, especially for the three-dimension complex medium inversion. Introducing blended source technology into the frequency-domain FWI can greatly reduce the computational burden and improve the efficiency of the inversion. However, this method has two issues: first, crosstalk noise is caused by interference between the sources involved in the encoding, resulting in an inversion result with some artifacts; second, it is more sensitive to ambient noise compared to conventional FWI, therefore noisy data results in a poor inversion. This paper introduces a frequency-group encoding method to suppress crosstalk noise, and presents a frequency- domain auto-adapting FWI based on source-encoding technology. The conventional FWI method and source-encoding based FWI method are combined using an auto-adapting mechanism. This improvement can both guarantee the quality of the inversion result and maximize the inversion efficiency. 展开更多
关键词 Full waveform inversion frequency-domain Blended source Frequency-group encod!ng Au!o adapt!rig I
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Three-dimensional frequency-domain full waveform inversion based on the nearly-analytic discrete method 被引量:4
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作者 DeYao Zhang WenYong Pan +3 位作者 DingHui Yang LingYun Qiu XingPeng Dong WeiJuan Meng 《Earth and Planetary Physics》 CSCD 2021年第2期149-157,共9页
The nearly analytic discrete(NAD)method is a kind of finite difference method with advantages of high accuracy and stability.Previous studies have investigated the NAD method for simulating wave propagation in the tim... The nearly analytic discrete(NAD)method is a kind of finite difference method with advantages of high accuracy and stability.Previous studies have investigated the NAD method for simulating wave propagation in the time-domain.This study applies the NAD method to solving three-dimensional(3D)acoustic wave equations in the frequency-domain.This forward modeling approach is then used as the“engine”for implementing 3D frequency-domain full waveform inversion(FWI).In the numerical modeling experiments,synthetic examples are first given to show the superiority of the NAD method in forward modeling compared with traditional finite difference methods.Synthetic 3D frequency-domain FWI experiments are then carried out to examine the effectiveness of the proposed methods.The inversion results show that the NAD method is more suitable than traditional methods,in terms of computational cost and stability,for 3D frequency-domain FWI,and represents an effective approach for inversion of subsurface model structures. 展开更多
关键词 THREE-DIMENSION frequency-domain NAD method forward modeling full waveform inversion
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A Numerical Method on Inverse Determination of Heat Transfer Coefficient Based on Thermographic Temperature Measurement 被引量:6
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作者 范春利 孙丰瑞 杨立 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第6期901-908,共8页
The heat transfer coefficient in a multidimensional heat conduction problem is obtained from the solution of the inverse heat conduction problem based on the thermographic temperature measurement. The modified one-dim... The heat transfer coefficient in a multidimensional heat conduction problem is obtained from the solution of the inverse heat conduction problem based on the thermographic temperature measurement. The modified one-dimensional correction method (MODCM), along with the finite volume method, is employed for both two- and three-dimensional inverse problems. A series of numerical experiments are conducted in order to verify the effectiveness of the method. In addition, the effect of the temperature measurement error, the ending criterion of the iteration, etc. on the result of the inverse problem is investigated. It is proved that the method is a simple, stable and accurate one that can solve successfully the inverse heat conduction problem. 展开更多
关键词 inverse heat conduction problem heat transfer coefficient finite volume method modified one-dimensional correction method measurement error
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A DISCRETE ALGORITHM FOR COMPLEX FREQUENCY-DOMAIN CONVOLUTIONS
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作者 蔡坤宝 杨瑞芳 俞集辉 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2000年第5期537-542,共6页
A discrete algorithm suitable for the computation of complex frequency-domain convolution on computers was derived. The Durbin's numerical inversion of Laplace transforms can be used to figure out the time-domain ... A discrete algorithm suitable for the computation of complex frequency-domain convolution on computers was derived. The Durbin's numerical inversion of Laplace transforms can be used to figure out the time-domain digital solution of the result of complex frequency-domain convolutions. Compared with the digital solutions and corresponding analytical solutions, it is shown that the digital solutions have high precision. 展开更多
关键词 complex frequency-domain CONVOLUTION Laplace transforms numerical inversion
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Estimation of vertical diffusion coefficient based on a onedimensional temperature diffusion equation with an inverse method
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作者 LIANG Hui ZHAO Wei +1 位作者 DAI Dejun ZHANG Jun 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第5期28-36,共9页
Diapycnal mixing is important in oceanic circulation. An inverse method in which a semi-explicit scheme is applied to discretize the one-dimensional temperature diffusion equation is established to estimate the vertic... Diapycnal mixing is important in oceanic circulation. An inverse method in which a semi-explicit scheme is applied to discretize the one-dimensional temperature diffusion equation is established to estimate the vertical temperature diffusion coefficient based on the observed temperature profiles. The sensitivity of the inverse model in the idealized and actual conditions is tested in detail. It can be found that this inverse model has high feasibility under multiple situations ensuring the stability of the inverse model, and can be considered as an efficient way to estimate the temperature diffusion coefficient in the weak current regions of the ocean. Here, the hydrographic profiles from Argo floats are used to estimate the temporal and spatial distribution of the vertical mixing in the north central Pacific based on this inverse method. It is further found that the vertical mixing in the upper ocean displays a distinct seasonal variation with the amplitude decreasing with depth, and the vertical mixing over rough topography is stronger than that over smooth topography It is suggested that the high-resolution profiles from Argo floats and a more reasonable design of the inverse scheme will serve to understand mixing processes. 展开更多
关键词 inverse method temperature diffusivity one-dimensional vertical diffusion equation
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Inverse Piston Problem for the System of One-Dimensional Isentropic Flow 被引量:5
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作者 Tatsien LI 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2007年第3期265-282,共18页
In this paper, the authors consider the inverse piston problem for the system of one-dimensional isentropic flow and obtain that, under suitable conditions, the piston velocity can be uniquely determined by the initia... In this paper, the authors consider the inverse piston problem for the system of one-dimensional isentropic flow and obtain that, under suitable conditions, the piston velocity can be uniquely determined by the initial state of the gas on the right side of the piston and the position of the forward shock. 展开更多
关键词 inverse piston problem System of one-dimensional isentropic flow Shock
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Application of Frequency-Domain Waveform Inversion Method in Marmousi Shots Data
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作者 WANG Meng ZHANG Dong +2 位作者 YAO Di QIN Qianqing XU Lin 《Wuhan University Journal of Natural Sciences》 CAS 2012年第4期326-330,共5页
Frequency-domain waveform seismic tomography includes modeling of wave propagation and full waveform inversion of correcting the initial velocity model. In the forward modeling, we use direct solution based on sparse ... Frequency-domain waveform seismic tomography includes modeling of wave propagation and full waveform inversion of correcting the initial velocity model. In the forward modeling, we use direct solution based on sparse matrix factorization, combined with nine-point finite-difference for the linear system of equations. In the waveform inversion, we use preconditioned gradient method where the preconditioner is provided by the diagonal of the approximate Hessian matrix. We successfully applied waveform inversion method from low to high frequency in two sets of Marmousi data. One is the data set generated by frequencydomain finite-difference modeling, and the other is the original Marmousi shots data set. The former result is very close to the true velocity model. In the original shots data set inversion, we replace the prior source with estimated source; the result is also acceptable, and consistent with the true model. 展开更多
关键词 preconditioned gradient method frequency-domain waveform inversion Marmousi shots data
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INVERSE SCATTERING PROBLEM FOR ONE-DIMENSIONAL SCHRDINGER OPERATORS RELATED TO THE GENERAL STARK EFFECT
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作者 林源渠 钱敏 张青 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 1989年第2期116-136,共21页
This paper disccusses the inverse scattering problem for one-dimensional Schrodinger operatorsrelated to the general Stark effect. We provide a ganeral framework which can be applied both to theStark-effect operator a... This paper disccusses the inverse scattering problem for one-dimensional Schrodinger operatorsrelated to the general Stark effect. We provide a ganeral framework which can be applied both to theStark-effect operator and the ordinary Schrodinger operator. 展开更多
关键词 DINGER OPERATORS RELATED TO THE GENERAL STARK EFFECT inversE SCATTERING PROBLEM FOR one-dimensional SCHR
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