用广义射线和有限差分计算近场理论地震图的混合方法

本文提出一种结合广义射线和有限差分理论而形成的混合方法（以下简称混合方法）．在介质均匀区（包括平行介质分层区）应用广义射线理论，在介质不均匀区应用有限差分理论．在这种结合过程中，把均匀区广义射线的结果作为不均匀区有限差分区波场连续的输入．对于均匀介质模型，混合方法理论地震图和广义射线理论地震图、广义反射透射系数矩阵及离散波数法地震图的对比，取得了满意的结果，在数值上证明了该方法的正确性．计算了１９９０年８月５日Ｈａｋｏｎｅ地震前震在日本Ａｓｈｉｇａｒａ山谷盲测点的响应，理论地震图和实际资料的比较同样取得好的结果．这种方法可用于地震勘探、工程地震、强地面运动的研究．     

油气勘探地震资料处理GPU/CPU协同并行计算

随着图形处理器（Graphic Processing Unit: GPU）在通用计算领域的日趋成熟,使GPU/CPU协同并行计算应用到油气勘探地震资料处理中,对诸多大规模计算的关键性环节有重大提升.本文阐明协同并行计算机的思路、架构及编程环境, 着重分析其计算效率得以大幅度提升的关键所在.文中以地震资料处理中的叠前时间偏移和Gazdag深度偏移为切入点,展示样机测试结果的图像显示.显而易见,生产实践中,时常面临对诸多算法进行算法精度和计算速度之间的折中选择.本文阐明GPU/CPU样机协同计算具有高并行度,进而可在算法精度与计算速度的优化配置协调上获得广阔空间.笔者认为,本文的台式协同并行机研制思路及架构,或可作为地球物理配置高性能计算机全新选择的一项依据.     

A Parallel Implementation of the Lattice Solid Model for the Simulation of Rock Mechanics and Earthquake Dynamics

— The Lattice Solid Model has been used successfully as a virtual laboratory to simulate fracturing of rocks, the dynamics of faults, earthquakes and gouge processes. However, results from those simulations show that in order to make the next step towards more realistic experiments it will be necessary to use models containing a significantly larger number of particles than current models. Thus, those simulations will require a greatly increased amount of computational resources. Whereas the computing power provided by single processors can be expected to increase according to “Moore’s law,” i.e., to double every 18–24 months, parallel computers can provide significantly larger computing power today. In order to make this computing power available for the simulation of the microphysics of earthquakes, a parallel version of the Lattice Solid Model has been implemented. Benchmarks using large models with several millions of particles have shown that the parallel implementation of the Lattice Solid Model can achieve a high parallel-efficiency of about 80% for large numbers of processors on different computer architectures.     

中国地震网格试验系统中资源管理与作业调度研究-资源管理和作业动态分配模型ProRMJS的建立me

通过分析与研究建立资源管理和作业动态分配ProRMJS模型,解决了中国地震灾害仿真网格试验系统（CEDAGrid）中网格科学计算平台在初期建设中存在的一些资源管理方面的问题. 针对网格科学计算平台默认各个计算节点均能提供计算服务的问题,ProRMJS通过ldquo;计算池rdquo;这一虚拟组织为调度器分发作业提供支撑;而调度器则根据计算池中各个节点的计算能力和状态,动态分配任务,这样就保证了计算平台的稳定性. 针对默认各个计算节点均能完成任务的问题, ProRMJS通过监控各个节点所负担作业的运行进度和设定作业时间阈值来管理作业运行. 对于各个节点计算能力大小的区别, ProRMJS通过对各个节点计算性能的权值量化,实行按ldquo;需rdquo;分配作业. 对各个节点计算性能的权值量化, ProRMJS是通过综合考虑各个因素对机器计算能力大小的影响后通过加权计算的方式完成的,从而提高了整个计算平台的工作效率. 最后通过实现地震应力触发科学计算实例验证了方案的有效性,为网格技术在地震领域内的进一步应用作了有意义的探索.      

A Review of High-Performance Computational Strategies for Modeling and Imaging of Electromagnetic Induction Data

Many geoscientific applications exploit electrostatic and electromagnetic fields to interrogate and map subsurface electrical resistivity—an important geophysical attribute for characterizing mineral, energy, and water resources. In complex three-dimensional geologies, where many of these resources remain to be found, resistivity mapping requires large-scale modeling and imaging capabilities, as well as the ability to treat significant data volumes, which can easily overwhelm single-core and modest multicore computing hardware. To treat such problems requires large-scale parallel computational resources, necessary for reducing the time to solution to a time frame acceptable to the exploration process. The recognition that significant parallel computing processes must be brought to bear on these problems gives rise to choices that must be made in parallel computing hardware and software. In this review, some of these choices are presented, along with the resulting trade-offs. We also discuss future trends in high-performance computing and the anticipated impact on electromagnetic (EM) geophysics. Topics discussed in this review article include a survey of parallel computing platforms, graphics processing units to multicore CPUs with a fast interconnect, along with effective parallel solvers and associated solver libraries effective for inductive EM modeling and imaging.     

Computing Crustal Strain Using Repeated GPS Survey

A method for computing crustal horizontal velocities and strain-rates using repeated GPS survey and other crustal deformation measurement was presented in detail. Based on the data taken from the Crustal Deformation Monitoring-Networks with GPS in the whole country and North China, we derived the average horizontal velocities of the points of the networks and simulated the horizontal velocity and strain-rate fields in the corresponding areas. From these results, we can conclude: (1) GPS can effectively detect current crustal motion and deformation, and (2) the method presented in the paper is valid, and through its use, calculated results can provide more information about current crustal motion and deformation than direct observation data.     

基于Abaqus软件的并行计算集群平台构建与优化方法

根据有限元显式算法和隐式算法的特点,研究了岩土工程动力分析并行计算集群系统的硬件要求、集群系统的构建方法,构建了基于EM64T硬件构架、双路Intel Xeon处理器、Linux操作系统和64位Abaqus软件的32CPU并行计算集群平台,测试了存储子系统对集群性能的影响,比较了两种千兆以太网络作为、集群子网络的性能优化方法。以地下结构的地震反应分析为例,测试了优化前后该集群系统的计算速度,发现两种以太网络性能优化方法都可以有效提高集群计算速度。列举了该集群系统在深水桥梁基础流固耦合动力分析、地下结构地震反应分析和快速轨道交通环境振动分析中的应用,显示了该集群在显式算法、隐式算法及小规模、大规模数值计算问题中的并行计算效率,证明所构建的Abaqus数值模拟并行计算集群平台能够满足计算规模、计算精度和时效性的要求。     

Resource management and job scheduling of China earthquake grid experiment system： Construction of resource management and job dynamic scheduling model ProRMJS

Grid technique is taken as the third generation internet technology and resource management is the core of it. Aiming at the problems of resource management of CEDAGrid （China Earthquake Disaster Alleviation and Simulation Grid） in its preliminary construction, this paper presents a resource management and job scheduling model： ProRMJS to solve these problems. For platform supposed agreeably each computing node can provide computation service, ProRMJS uses ＂computation pool＂ to support scheduler, and then the scheduler allocates jobs dynamically according to computing capability and status of each node to ensure the stability of the platform. At the same time, ProRMJS monitors the status of job on each node and sets a time threshold to manage the job scheduling. By estimating the computing capability of each node, ProRMJS allocates jobs on demand to solve the problem of supposing each node can finish the job acquiescently. When calculating the computing capability of each node, ProRMJS allows for the various factors that affect the computing capability and then the efficiency of the platform is improved. Finally the validity of the model is verified by an example.     

利用位场及其高阶导数的功率谱计算岩层的深度与厚度

本文导出了利用重力与磁异常及其高阶导数的功率谱计算密度体和磁性体上顶与下底埋深的近似公式,还提供了利用垂向或水平导数谱计算深度的方法。理论模型的试验结果表明,由近似公式计算的精度可以满足实际需要。本文最后根据一条重力剖面资料,计算了密度层上、下界面。     

Solving the structural inverse gravity problem by the modified gradient methods

New methods for solving the three-dimensional inverse gravity problem in the class of contact surfaces are described. Based on the approach previously suggested by the authors, new algorithms are developed. Application of these algorithms significantly reduces the number of the iterations and computing time compared to the previous ones. The algorithms have been numerically implemented on the multicore processor. The example of solving the structural inverse gravity problem for a model of four-layer medium (with the use of gravity field measurements) is constructed.     

Neues mathematisches Verfahren zur Charakterisierung unbekannter organischer Vielstoffgemische durch die Adsorptionsanalyse

The adsorption analysis, a process-technology-oriented analytical method, characterizes complex organic multicomponent mixtures with respect to their different adsorbability by a sorbent such as activated carbon. The analytical method is based on the determination of adsorption isotherms and their mathematical interpretation. So far, this interpretation has required the use of a large computer or a time-consuming computing program, in general. With the BASIC computing program “MAVIAS 10”, on the basis of the IAS theory a mathematical approach has been found which provides sufficient accuracy, demands low expenditure of time and makes the use of a small computer possible.     

Response spectra for torsion,rocking and rigid foundations

Simple procedures are proposed for computing response spectra for torsional and rocking input ground motions assuming horizontally travelling waves of constant shape. It is shown that harmonic relationships exist between the rotational spectra and the corresponding translational spectra, and that SV rather than PSV is the correct basis for deriving the angular displacement, velocity and acceleration response spectra. An approximation enabling the use of the standard tripartite logarithmic response spectra is discussed. Simple expressions for ‘accidental’ eccentricity and rocking input effects are presented. Also proposed are multipliers to spectral ordinates to account for the filtering effects of rigid base mats resting on Winkler type foundations. For wave transit times shorter than half the natural period of the structure, these multipliers can be approximated by the frequency dependent averaging coefficients given in the literature, which are dependent, however, on the response, rather than the input, frequency.     

Simultaneous inversion of velocity distribution and interface positions

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三维地形频率域人工源电磁场的边界元模拟方法

提出了一种用边界元法计算频率域人工源三维地形电磁场的数值模拟方法.首先用矢量积分理论和电磁场边界条件,将上半空间（空气）和下半空间（地下介质）两个区域电磁场边值问题变为仅对地形界面的两个矢量面积分方程.然后将对地形界面的积分剖分为一系列的三角单元积分.在三角单元积分中,假设单元中电磁场为无限大气空间电磁场与地形影响的叠加,并假设地形影响为常项,这样既保证了计算精度又使得计算方法简便.通过分解和计算,每一个矢量面积分方程分解为对应三个坐标方向的三个常量线性方程,这些线性方程组成了对角占优的线性方程组,可用SSOR方法求解.文中给出了垂直磁偶源的垂直磁场地形影响的例子.     

关于地壳厚度计算方法的修正

利用前苏联学者（１９５８．）计算地壳厚度公式计算了兰州－天水－武都地区的布格重力异常．发现其结果与人工地震爆破得出的结果相差很大。造成差值大的原因可能是地壳界面边界效应的作用。为使计算结果尽量接近实际地壳厚度。所以要从计算地壳厚度公式中减去每一测点的效应值，依此法推算出任意点的地壳厚度。     

层状介质中内源引起的地震波理论地震图的部分分离变量——有限差分计算方法

文献〔1〕给出了震源在地表时计算理论地震图的部分分离变量——有限差分方法。本文继〔1〕讨论了震源在介质内部时,特别是震源在介质分界面上时理论地震图的计算方法。含贝塞尔函数的数值积分是用FiLon方法完成的,它具有精度高,运算速度快的特点。作为例子,本文最后给出了利用所述计算方法得到的不同内源在含两个高速夹层地壳模型中的理论地震图。     

Nonlinear performance of classical damping

The performance of a classical damping matrix, constructed either from the use of initial structural properties or current structural properties, in the step-by-step solution of a nonlinear multiple degree of freedom (MDOF) system is analytically evaluated. The analytical results are confirmed by numerical examples. Consequently, some conclusions are drawn from these analytical results that might be considered as rough guidelines for practical applications. It is found that a classical damping matrix constructed from initial structural properties is adequate for practical applications, since it has approximately the same damping effect as obtained by current structural properties and is more efficient in terms of computing.     

波动方程三维吸收边界分解与拟合深度偏移方法

在偏移问题中引入吸收边界条件，既可以消除由人工边界激发的虚假反射，从而提高剖面质量。又可以减少计算工作量．本文讨论了三维吸收边界条件方程，提出了求解具有吸收边界条件的三维波动方程偏移定解问题的分解与拟合方法。理论分析与合成记录及野外实际地震资料处理结果表明，本文方法为一有效的三维吸收边界深度偏移方法。     

Non‐ergodicity and PEER's framework formula

A framework formula for performance‐based earthquake engineering, advocated and used by researchers at the Pacific Earthquake Engineering Research (PEER) Center, is closely examined. The formula was originally intended for computing the mean annual rate of a performance measure exceeding a specified threshold. However, it has also been used for computing the probability that a performance measure will exceed a specified threshold during a given period of time. It is shown that the use of the formula to compute such probabilities could lead to errors when non‐ergodic variables (aleatory or epistemic) are present. Assuming a Poisson model for the occurrence of earthquakes in time, an exact expression is derived for the probability distribution of the maximum of a performance measure over a given period of time, properly accounting for non‐ergodic uncertainties. This result is used to assess the approximation involved in the PEER formula for computing probabilities. It is found that the PEER approximation of the probability has a negligible error for probabilities less than about 0.01. For larger probabilities, the error depends on the magnitude of non‐ergodic uncertainties and the duration of time considered and can be as much as 20% for probabilities around 0.05 and 30% for probabilities around 0.10. The error is always on the conservative side. Copyright © 2005 John Wiley & Sons, Ltd.     

日本兵库县南部大震灾对太原市防震减灾工作的启示

对日本阪神地区和太原市的活动断层、地震活动、城市工程地质环境、建筑物的抗震设防、老旧城区、生命线工程、次生灾害、震灾预测、防震意识等９个方面进行了对比分析，从中得到有益的启示，提出太原市在防震减灾中应引以为鉴的几项工作。