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Numerical Simulation of Underwater Explosion Loads

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Transactions of Tianjin university 2008年第B10期14卷 519-522页

作者：辛春亮徐更光刘科种 State Key laboratory of Explosion Science and technology Beijing Institute of Technology

Numerical simulation of TNT underwater explosion was carried out with AUTODYN soft-ware. Influences of artificial viscosity and mesh density on simulation results were discussed. Deto-nation waves in explosive and shock wave in water during early time of explosion are high frequency waves. Fine meshes (less than 1 mm) in explosive and water nearby, and small linear viscosity co-efficients and quadratic viscosity coefficients (0.02 and 0.1 respectively, 1/10 of default values) are needed in numerical simulation model. According to these rules, numerical computing pressure profiles can match well with those calculated by Zamyshlyayev empirical formula. Otherwise peak pressure would be smeared off and upstream relative errors would be cumulated downstream to make downstream peak pressure lower.

关键词： TNT underwater explosion AUTODYN software artificial viscosity mesh density

Fast Fourier-Galerkin methods for first-kind logarithmic-kernel integral equations on open arcs

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Science china Mathematics 2010年第1期53卷 1-22页

作者： WANG Bo1,WANG Rui2 & XU YueSheng3,4,1Academy of Mathematics and Systems Science,Chinese Academy of Sciences,beijing 100190,china 2School of Information Science and Engineering,Graduate university of the Chinese Academy of Sciences,beijing 100190,china 3Department of Mathematics,Syracuse university,Syracuse,NY 13244,USA 4Department of Scientific computing and Computer Applications,Sun Yat-sen university,Guangzhou 510275,china Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing China School of Information Science and Engineering Graduate University of the Chinese Academy of Sciences Beijing China Department of Mathematics Syracuse University Syracuse USA Department of Scientific computing and Computer Applications Sun Yat-sen University Guangzhou China

We propose a fully discrete fast Fourier-Galerkin method for solving an integral equation of the first kind with a logarithmic kernel on a smooth open arc,which is a reformulation of the Dirichlet problem of the Laplace equation in the *** optimal convergence order and quasi-linear complexity order of the proposed method are established.A precondition is *** this method with an efficient numerical integration algorithm for computing the single-layer potential defined on an open arc,we obtain the solution of the Dirichlet problem on a smooth open arc in the *** examples are presented to confirm the theoretical estimates and to demonstrate the efficiency and accuracy of the proposed method.

关键词： Dirichlet problem open arc singular boundary integral equations Fourier-Galerkin methods logarithmic potentials

SWHC-Strict Weak Hybrid Coherence Model for Pthread

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Journal of Systems Engineering and Electronics 1995年第3期6卷 70-75页

作者： Rong Li Dingxing Wang & Meiming Shen(Department of Computer Science & technologyTsing Hua university, beijing 100084, china) Department of Computer Science & technology Tsing Hua university Beijing 100084 China

DSM(SVM) is a memory model which was proposed at the 1980s'. DSM solved the problem thatscalability was contradict with easy programming and merge their merits. The efficiency of DSM is still aproblem. The proposed solutions include prefetching and adopting new coherence model, but neither ofthem is a perfect solution. Prefetch will be less efficient when there are too many false sharing. The weak, relaxed coherence model is quite different from sequential coherence which was assumed by mostprogrammers intuitively, so programming and debugging becomes very difficult. We have proposed StrictWeak Hybrid Coherence (SWHC) model which can eliminate false sharing and provide more temporal andspatial locality, we also provide a scheme to keep sequential coherent. But SWHC model is complicate, asimplified model for Pthread share memory parallel computing model is proposed in the paper.

关键词： Parallel processing DSM Strict Weak Hybrid Coherence

The Constrained Solutions of Two Matrix Equations

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Acta Mathematica Sinica,English Series 2002年第4期18卷 671-678页

作者： An Ping LIAO Zhong Zhi BAI Department of Mathematics. Hunan university. Changshu, 410082. P. R. china Department of Mathematics and Information Science, Changsha university, Changsha 410003. P. R. china Academy of Mathematics and System. Sciences. Chinese Academy of Sciences. beijing 100080. P. R. china State Key laboratory of Scientific/Engineering computing. Chinese Academy of Sciences. Institute of Computational Mathematics and Scientific/Engineering computing. Academy of Mathematics and System Sciences. Chinese Academy of Sciences. P. O. Box 2719. beijing 100080. P. R. china Department of Mathematics Hunan University Changsha P. R. China Department of Mathematics and Information Sciences Changsha University Changsha P. R. China Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing P. R. China State Key laboratory of Scientific/Engineering computing Chinese Academy of Sciences Institue of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing P. R. China

We study the symmetric positive semidefinite solution of the matrix equation AX_1A^T + BX_2B^T=C. where A is a given real m×n matrix. B is a given real m×p matrix, and C is a given real m×m matrix, with m, n, p positive integers: and the bisymmetric positive semidefinite solution of the matrix equation D^T XD=C, where D is a given real n×m matrix. C is a given real m×m matrix, with m. n positive integers. By making use of the generalized singular value decomposition, we derive general analytic formulae, and present necessary and sufficient conditions for guaranteeing the existence of these solutions.

关键词： Matrix equation Symmetric positive semidefinite matrix Bisymmetric positive semidefinite matrix

New method for computing unstable equilibrium points of power systems with induction motors

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Science china(Technological Sciences) 2010年第4期53卷 881-885页

作者： CHEN Lei,XU Fei & MIN Yong State Key Lab of Power Systems,Department of Electrical Engineering,Tsinghua university,beijing 100084,china State Key Lab of Power Systems Department of Electrical Engineering Tsinghua University Beijing China

The computation of the unstable equilibrium point(UEP) is a key step involved in stability region estimation of nonlinear dynamic systems.A new continuation-based method to compute the UEPs of a power system with induction motors is *** mechanical torques of motors are changed to form a parameterized equation *** the solution curve of the equation set is traced by the continuation method from the stable equilibrium point to a *** direction of mechanical torque change is varied to get multiple *** obtained UEPs are mostly *** fast assessment of induction motor stability is studied by approximating the stable manifolds of the *** method is tested in several systems and satisfactory results are obtained.

关键词： power system stability transient voltage stability unstable equilibrium point(UEP) stability boundary induction motor

NUMERICAL APPLICATION OF THE RECURSION METHOD TO THE ELECTRONIC STRUCTURE OF C60

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原子与分子物理学报 1997年第3期 25-29页

作者： Lu Jing Zhang LiyuanDepartment of Physics, Peking university, beijing 100871, P.R.china

采用Ｒｅｃｕｒｓｉｏｎ方法计算了Ｃ６０分子的能态密度，所得的能隙、能级的简并度及顺序与ＬＤＡ方法或者解析方法得到的结果吻合。

关键词： C60 电子结构

A draft sequence of the rice (Oryza sativa ssp. indica) genome

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Chinese Science Bulletin 2001年第23期46卷 1937-1942页

作者： YU Jun, HU Songnian, WANG Jun,LI Songgang WONG Ka-Shu Gane, LIU Bin,DENG Yajun, DAI Li, ZHOU Yan,ZHANG Xiuqing, CAO Mengliang, LIU Jing,SUN Jiandong , TANG Jiabin, CHEN Yanjiong,HUANG Xiaobing, LIN Wei, YE Chen, TONG Wei,CONG Lijuan, GENG Jianing, HAN Yujun, LI Lin,LI Wei, HU Guangqiang, HUANG Xiangang,LI Wenjie, LI Jian, LIU Zhanwei, LI Long,LIU Jianping, Ql Qiuhui, LIU Jinsong, LI Li,WANG Xuegang, LU Hong, WU Tingling,ZHU Miao, Nl Peixiang, HAN Hua, DONG Wei,REN Xiaoyu, FENG Xiaoli, GUI Peng,LI Xianran, WANG Hao, XU Xin, ZHAI Wenxue,XU Zhao, ZHANG Jinsong, HE Sijie,ZHANG Jianguo, XU Jichen, ZHANG Kunlin,ZHENG Xianwu, DONG Jianhai, ZENG Wanyong,TAO Lin, CHEN Xuewei, HE Jun, LIU Daofeng,TIAN Wei, TIAN Chaoguang, XIA Hongai,LI Gang, GAO Hui, LI Ping, CHEN Wei ,WANG Xudong, ZHANG Yong, HU Jianfei,WANG Jing, LIU Song, YANG Jian,ZHANG Guangyu, XIONG Yuqing, LI Zhijie,MAO Long, ZHOU Chengshu, ZHU Zhen,CHEN Runsheng, HAO Bailin,ZHENG Weimou, CHEN Shouyi, QUO Wei,LI Guojie, LIU Siqi, HUANG Guyang,TAO Ming, WANG Jian, ZHU Lihuang,YUAN Longping& YANG Huanmingbeijing Genomics Institute/Center of Genomics & Bioinformatics, Chinese Academy of Sciences, beijing 101300, china Hangzhou Genomics Institute/Institute of Bioinformatics of Zhejiang university/Key laboratory of Bioinformatics of Zhejiang Province, Hangzhou 310007, china Institute of Genetics, Chinese Academy of Sciences, beijing 100101, china National Hybrid Rice R & D Center, Changsha 410125, china laboratory of Bioinformatics, Institute of Biophysics, Chinese Academy of Sciences, beijing 100101, china College of Life Sciences, Peking university, beijing 100871, china Institute of Theoretical Physics, Chinese Academy of Sciences, beijing 1Q0080, china Digital china Ltd., beijing 100080, china Institute of computing technology, Chinese Academy of Sciences, beijing 100080, china Medical College, Xi’an Jiaotong university, Xi’an 710061, chinaThese authors contributed equally to this work.Corresponding author.Corresponden beijing Genomics Institute/Center of Genomics & Bioinformatics Chinese Academy of Sciences Beijing China Hangzhou Genomics Institute/Institute of Bioinformatics of Zhejiang university/Key laboratory of Bioinformatics of Zhejiang Province Hangzhou China College of Life Sciences Peking University Beijing China Medical College Xi’an Jiaotong University Xi’an China Institute of Genetics Chinese Academy of Sciences Beijing China laboratory of Bioinformatics Institute of Biophysics Chinese Academy of Sciences Beijing China National Hybrid Rice R & D Center Changsha China Institute of Theoretical Physics Chinese Academy of Sciences Beijing China Digital china Ltd. Beijing China Institute of computing technology Chinese Academy of Sciences Beijing China

The sequence of the rice genome holds fundamental information for its biology, including physiology, genetics, development, and evolution, as well as information on many beneficial phenotypes of economic significance. Using a "whole genome shotgun" approach, we have pro-duced a draft rice genome sequence of Oryza sativa ssp. in-dica, the major crop rice subspecies in china and many other regions of Asia. The draft genome sequence is constructed from over 4.3 million successful sequencing traces with an accumulative total length of 2214.9 Mb. The initial assembly of the non-redundant sequences reached 409.76 Mb in length, based on 3.30 million successful sequencing traces with a total length of 1797.4 Mb from an indica variant cultivar 93-11, giving an estimated coverage of 95.29% of the rice genome with an average base accuracy of higher than 99%. The coverage of the draft sequence, the randomness of the sequence distribution, and the consistency of BIG-ASSEM-BLER, a custom-designed software package

关键词： rice genome draft sequences.

Dynamic Game Model of E-commerce——based on the perspective of information asymmetry

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Dynamic Game Model of E-commerce——based on the perspective...

MULTILEVEL CORRECTION FOR COLLOCATION SOLUTIONS OF VOLTERRA NONL INEARINTEGRO-DIFFERENTIAL EQUATIONS

2011 IEEE 2nd International Conference on computing, Control and Industrial Engineering(CCIE 2011)

作者： Hanpo Hou School of Business beijing technology and Business university beijing, china Jing Wen School of Business beijing technology and Business university beijing, china

Based on the perspective of information asymmetry, this paper uses game theory to construct a model, focusing on phenomena of concealing and cheating which are common in E-commerce between buyers and sellers in the process of transaction. Under the premise of setting participants, utility function and external environment, we take each equilibrium solution from signaling game and game of complete information to form a comparative analysis. As a result, we find out that lower level of information asymmetry do improve overall effectiveness level of the industry, and generate a positive impact on the efficiency of transaction;last but not least, governmental control plays a crucial regulatory function.

关键词： information asymmetry E-commerce game

来源： cnki会议评论

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Systems Science and Mathematical Sciences 2000年第2期13卷 170-180页

作者： HU Qiya (Institute of Computational Mathematics and Scientific/Engineering computing, Chinese Academy of Sciences, beijing 100080 Institute for computing Mathematics and Applied Mathematics, Xiangtan university, Hunan 411105, china) PENG Long (School of 中科院计算数学与科学工程计算所北京 100080 北京外国语大学国际商学院北京 100081

In this paper we give a complete analysis of the convergence acceleration method for collocation solutions of Volterra nonlinear integro-differential equations with smooth kernels. It will be shown that when continuous piecewise polynomials of degree m are used and collocation is based on the Lobatto points, the first derivative of this collocation approximation admits, at the knots, an error expansion in even powers of the step-size h, beginning with a term in h2m. On the basis of this expansion we show that when a correction procedure is applied to this collocation approximation for k times, the global accurary of the corresponding corrected approximation will be increased to O(h2m(k+1)).

关键词： Nonlinear integro-differential equation collocation solution error expansion multilevel correction.