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

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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.

Architecture and key technologies of grid geographic information system

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Science china(Technological Sciences) 2008年第S1期51卷 102-113页

作者： FANG Yu,HUANG Zhou,CHEN Bin,WU Lun & YIN DaFei Institute of Remote Sensing and Geographic Information System,Peking university,beijing 100871,china Institute of Remote Sensing and Geographic Information System Peking University Beijing 100871 China

The highly efficient and stable collaborative computation platform for geospatial information can be constructed on the basis of Grid computing technology,com-bined with Peer-to-Peer (P2P) computing technology and geospatial database technology. This paper proposed the architecture and key technologies of the Grid GIS (Geographic Information System) incorporated with P2P structure,and corre-spondingly a Grid GIS prototype named Nebula was designed and then imple-mented. Nebula is a suite of middleware for geospatial Grid computing,which could be deployed onto various service nodes in network. Based on Grid protocols and infrastructure,Nebula provides invocation interfaces to users in form of Grid services. By using P2P message based communication mechanism,complex geospatial computation tasks could be accomplished by Nebula in a collaborative way. This paper introduced Nebula's architecture and key modules,and according to experimental data,we discussed the Grid GIS's advantages,application scenar-ios and future directions.

关键词： Grid GIS distributed geospatial computing Peer-to-Peer computing

TOPOLOGICAL FORMULAS FOR SUBNETWORK EXTRACTION THEOREMS AND MULTITERMINAL FEEDBACK NETWORKS

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Journal of Electronics(china) 1990年第3期7卷 248-257页

作者：黄汝激 university of Science and technology Beijing

The concepts of modified graphs of a composite graph with respect to two vertex-pairs and a hyperedge-decomposition are introduced,*** applying them and thedirected hypergraph theory,the topological formulas for the parameter-extraction theorem andsubnetwork-extraction theorems are derived,and then the topological formulas for multiterminalfeedback networks are *** these formulas the parameters of the feedback subnetworkare separated from that of the fundamental subnetwork,so that it is convenient to find out theeffect of the feedback ***,since one network is decomposed into two smallersubnetworks,the computing time complexity and space complexity can be reduced.

关键词： Network theory Graph theory Directed hypergraph Hyperedge decomposition Modified graph

基于LCCA的既有居住建筑节能改造成本效益分析

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土木工程学报 2011年第10期44卷 118-123页

作者：刘玉明北京交通大学北京100044

为了对既有居住建筑节能改造的成本效益问题进行分析,首先运用全寿命周期成本理论分析既有居住建筑节能改造的增量成本与增量效益构成;再运用建筑能耗基本公式推导节能改造增量经济效益测算模型,并通过数学推导证明热源热网节能改造的... 详细信息

为了对既有居住建筑节能改造的成本效益问题进行分析,首先运用全寿命周期成本理论分析既有居住建筑节能改造的增量成本与增量效益构成;再运用建筑能耗基本公式推导节能改造增量经济效益测算模型,并通过数学推导证明热源热网节能改造的经济效益要远好于建筑围护结构节能改造的经济效益;最后,运用增量经济效益测算模型和项目经济评价理论对实际案例的成本效益进行分析,计算结果表明:仅进行建筑围护结构节能改造存在投资额大、收益率低的特点,而仅进行热源热网节能改造本身投资收益水平较好。由此可见,建筑围护结构节能改造本身无法吸引社会资金投资,需要政府给予更多的经济激励才能吸引社会资金;而热源热网节能改造在政府适当的经济激励下能够通过市场进行改造资金筹措。

关键词：成本效益分析全寿命周期成本既有居住建筑节能改造

A REVOCATION SCHEME FOR THE CLOUD computing ENVIRONMENT

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A REVOCATION SCHEME FOR THE CLOUD COMPUTING ENVIRONMENT

Research on Education Data Resource integration Based OGSA-DAI

2011 IEEE International Conference on Cloud computing and Intelligence Systems(CCIS2011)

作者： Xiaobiao Li,Qiaoyan Wen State Key laboratory of Networking and Switching technology,beijing university of Posts and Telecommunications,beijing,china

In order to meet the authentication requirement of the revoking frequently and dynamic network environment,a revocation scheme for the cloud computing environment is *** entering,leaving,revoking and authentication of entities are implemented based on the public key cryptography and the secure dynamic one-way accumulator,and the cross-domain property is also *** results show that the proposed scheme is provable secure to realize the identity authentication,session key agreement and key update with entity secrecy and perfect forward secrecy *** the cloud computing environment,compared with the existing schemes,this solution has a higher level of security,better performance and more comprehensive problem solving for revocation.

关键词： cloud computing revocation authentication cross-domain

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International Journal of Systems and Control

International Journal of Systems and Control 2008年第1期 7-11页

作者： LI Wenzheng , HU Xiaoxia School of Computer, beijing technology and Business university, beijing 100037, china

The paper analyzed the problem emerged in current education Data resource sharing and network, which show a model which integrates Education Data Resource Based on OGSA-DAI.

关键词： Grid computing OGSA (Open Grid Services Architecture) OGSA-DAI(Data Access and Integration)

Finite Symmetry Transformation Groups and Some Exact Solutions to(2+1)-Dimensional Cubic Nonlinear Schrdinger Equantion

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Communications in Theoretical Physics 2009年第5期51卷 773-776页

作者： LI Biao~(1,3,+) LI Yu-Qi~(1,3) CHEN Yong~(1,2)1 Nonlinear Science Center,Ningbo university,Ningbo 315211,china2 Institute of Theoretical computing,East china Normal university,Shanghai 200062,china3 Key laboratory of Mathematics Mechanization,Chinese Academy of Sciences,beijing 100080,china Nonlinear Science Center Ningbo University Ningbo 315211 China Institute of Theoretical computing East China Normal University Shanghai 200062 China Key laboratory of Mathematics Mechanization Chinese Academy of Sciences Beijing 100080 China

Making use of the direct method proposed by Lou et al. and symbolic computation, finite symmetry trans-formation groups for a (2+1)-dimensional cubic nonlinear Schrdinger (NLS) equation and its corresponding cylindricalNLS equations are presented. Nine related linear independent infinitesimal generators can be obtained from the finitesymmetry transformation groups by restricting the arbitrary constants in infinitesimal forms. Some exact solutions arederived from a simple travelling wave solution.

关键词： symmetry groups cubic NLS equation exact solution

A Fast Pseudorandom Number Generator with BLAKE Hash Function

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Wuhan university Journal of Natural Sciences 2010年第5期15卷 393-397页

作者： WANG Houzhen1,2,ZHANG Huanguo1,2 1.Key laboratory of Aerospace Information Security and trusted computing of Ministry of Education,Wuhan university,Wuhan 430072,Hubei,china 2.School of Computer,Wuhan university,Wuhan 430072,Hubei,china Key laboratory of Aerospace Information Security and trusted computing of Ministry of Education Wuhan University Wuhan Hubei China School of Computer Wuhan University Wuhan Hubei China

This paper presents a fast pseudorandom generation algorithm,which is based on the BLAKE hash function and can pass the random test of the NIST（National Institute of Standards and technology） Statistical Test *** theoretical analysis and experimental imitation,our new algorithm is proven to be more secure and efficient than ***,we introduce and discuss the BLAKE in *** security shows that can be utilized to generate pseudorandom bit sequences,which the experimental results show the BLAKE hash function has excellent ***,we believe the BLAKE is one of the most potential candidate algorithms of SHA-3 program.

关键词： cryptography pseudorandom number generator hash function National Institute of Standards and technology Statistical Test Suite

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Alternating Graph

The Journal of china Universities of Posts and Telecommunications 1994年第1期1卷 11-15页

作者： Yang Yixian (Department of Information Engineering, beijing university of Posts and Telecommunications, beijing 100088, P. R. china)

in this paper, we present a new unidirectional graph, the 'alternating graph. Like the known (unidirectional) n-cube and (unidirectional) n-star, the alternating graph is shown to possess rich structure and symmetry p... 详细信息

关键词： Directed Graph Interconnection Network Distributed computing n-Star n-cube Alternating graph