一种分布式吴方法计算模型

吴方法是由我国科学家吴文俊院士开创的一个新兴研究领域.考虑到吴方法"分而治之"的思想非常适合分布式计算,将分布式计算技术引入到该方法的计算过程中,给出一种既可以在集群环境下,也可以在网格环境下实现的分布式吴方法计算框架.首先分析了吴方法分布式计算需求,并以特征列计算为例来说明吴方法分布式计算算法,然后讨论了符号计算基本数据类型:大整数和多项式的消息传递方法,最后简单给出了在网格环境下基于符号计算软件系统ELIMINO和网格中件间Globus Toolkits 3的分布式吴方法计算环境的设计、实现与实验结果.

分布式密码计算平台的架构设计及其实现

分析了常见的密码算法对于分布式计算平台的需求,定义了通用的任务表示格式,使用DCOM技术设计了一个针对密码计算的分布式通用平台及其外挂算法模块;并实现了两种常见的密码攻击算法,给出了测试结果.

地震反射系数成像方法研究

Reflectivity sequences extraction is a key part of impedance inversion in seismic exploration. Although many valid inversion methods exist, with crosswell seismic data, the frequency brand of seismic data can not be broadened to satisfy the practical need. It is an urgent problem to be solved. Pre-stack depth migration which developed in these years becomes more and more robust in the exploration. It is a powerful technology of imaging to the geological object with complex structure and its final result is reflectivity imaging. Based on the reflectivity imaging of crosswell seismic data and wave equation, this paper completed such works as follows: Completes the workflow of blind deconvolution, Cauchy criteria is used to regulate the inversion(sparse inversion). Also the precondition conjugate gradient(PCG) based on Krylov subspace is combined with to decrease the computation, improves the speed, and the transition matrix is not necessary anymore be positive and symmetric. This method is used to the high frequency recovery of crosswell seismic section and the result is satisfactory. Application of rotation transform and viterbi algorithm in the preprocess of equation prestack depth migration. In equation prestack depth migration, the grid of seismic dataset is required to be regular. Due to the influence of complex terrain and fold, the acquisition geometry sometimes becomes irregular. At the same time, to avoid the aliasing produced by the sparse sample along the on-line, interpolation should be done between tracks. In this paper, I use the rotation transform to make on-line run parallel with the coordinate, and also use the viterbi algorithm to complete the automatic picking of events, the result is satisfactory. 1. Imaging is a key part of pre-stack depth migration besides extrapolation. Imaging condition can influence the final result of reflectivity sequences imaging greatly however accurate the extrapolation operator is. The author does migration of Marmousi under different imaging conditions. And analyzes these methods according to the results. The results of computation show that imaging condition which stabilize source wave field and the least-squares estimation imaging condition in this paper are better than the conventional correlation imaging condition. The traditional pattern of "distributed computing and mass decision" is wisely adopted in the field of seismic data processing and becoming an obstacle of the promoting of the enterprise management level. Thus at the end of this paper, a systemic solution scheme, which employs the mode of "distributed computing - centralized storage - instant release", is brought forward, based on the combination of C/S and B/S release models. The architecture of the solution, the corresponding web technology and the client software are introduced. The application shows that the validity of this scheme.