银河分布计算环境

分布式客户／服务器计算环境是90年代分布处理的主流计算环境．应用需求的发展使分布式客户／服务器计算环境面临许多新的技术问题，包括应用级系统集成问题、智能服务问题和支持协同工作问题等等．本文以银河分布式客户／服务器计算机系统YHCS为背景，讨论YHCS分布计算环境的构成及主要设计技术．该环境以系统集成技术为重点，在解决上述3个技术问题方面取得了重要进展．     

基于Web Service的分布式协同CAD系统框架

采用XML定义了基于Web Service分布式协同CAD系统框架中服务器端和客户端之间特征操作和协同设计的通信协议．该系统以特征为基本协同设计单元，服务器端和客户端之间采用增量式特征信息交互，降低网络流量，增强了系统的响应能力．由于系统基于Web Service构造，因此可以支持跨异构平台协同设计，原型系统的应用表明，该系统可以较好地支持分布式条件下的协同设计。     

基于客户／服务器模型的程序设计

客户／服务器模型已经成为网络环境下的程序设计的实际标准模式，本文在简单介绍提出这种模型的背景之后，着重论述了它的基本工作原理，并以算形式讨论了客户程序和服务器程序的基本设计方法，最后，对这种思想的应用前景作了展望。     

An efficient user authentication and key exchange protocol for mobile client–server environment

Considering the low-power computing capability of mobile devices, the security scheme design is a nontrivial challenge. The identity (ID)-based public-key system with bilinear pairings defined on elliptic curves offers a flexible approach to achieve simplifying the certificate management. In the past, many user authentication schemes with bilinear pairings have been proposed. In 2009, Goriparthi et al. also proposed a new user authentication scheme for mobile client–server environment. However, these schemes do not provide mutual authentication and key exchange between the client and the server that are necessary for mobile wireless networks. In this paper, we present a new user authentication and key exchange protocol using bilinear pairings for mobile client–server environment. As compared with the recently proposed pairing-based user authentication schemes, our protocol provides both mutual authentication and key exchange. Performance analysis is made to show that our presented protocol is well suited for mobile client–server environment. Security analysis is given to demonstrate that our proposed protocol is provably secure against previous attacks.     

Multi-User Collaborative Assembly Planning over the Internet

1 Introduction Assembly planning is an important issue of product design for assembly, and many achievements have been obtained. Techniques such as geometric reasoning [1,2], genetic algorithms (GA) [3], virtual assembly [4,5] and so on are employed to assembly planning of relatively simple products successfully. But for the more complex cases, there is a combinational complexity problem when the geometric reasoning method is used. The fitness function in GA cannot take into account various…     

Developing distributed applications for integrated product and process design

A heterogeneous computing environment characterizes today's manufacturing situation. This is a stumbling block for the efficient implementation of manufacturing concepts such as integrated product and process design (IPPD). A computing environment for IPPD would require the seamless integration of the various product and process design software systems. The exchange of information between these systems should be efficient, compatible and synchronous. This article presents an approach for developing distributed manufacturing applications that are compatible and synchronized and thus, able to support IPPD. The approach involves the use of a common manufacturing application ‘middleware’, which is distributed between a central geometric modelling server and application clients. The portability of the middleware is ensured through the use of Java for code portability and XML for data portability. The compatible product model problem is solved through the use of common data structures developed using reusable application client classes. Efficient transfer of product data is proposed using compressed model information embedded in a product data XML schema. Synchronization of design changes among all applications is achieved through the creation of relationships on an Application Relationship Manager.     

Multi-User Collaborative Assembly Planning over the Internet

Due to the increasing complexity of products and for the distributed product development, more closely collaborative work among designers is required. A collaborative assembly planning approach is proposed to support assembly planning in a networked environment. The working procedure is depicted and the key techniques including collaborative-planning-oriented assembly decomposition modeling, assembly assignment modeling, and sub-plans merging are addressed. By incorporating visual models at client side with assembly application models at server side, a web-based supporting environment for collaborative assembly planning has been developed using VRML and Java-EAI techniques. A case study is given to illustrate the feasibility and validity of the idea.     

分布式协作模型及应用研究

With the development of the Web technology,the application environment has acquired many new characters such as dynamic, openness,distribution and information uncertainty.The processing mode of application systems is more complicated than ever.For example,it requires application systems to have more community processing ability,interactive ability,distributed processing ability and collaborative ability.Accordingly the research and development of the computer application system transited from client/server information processing system into distributed collaborative processing system based on Web.Especially in the environment where the information and resources are highly distributed,the accomplishment of complicated tasks is dependent more on the resources coordination,information sharing and coordinator collaboration.The collaboration is one aspect of the group behavior and its goal is to provide a optimal method to utilize the resource through the information interaction and to solve the task which couldn't be accomplished by each coordinator alone and get the more total benefits than the sum of each benefit.The collaboration problem is the important one for distributed tasks processing.This paper surveys,the research and application status of distributed collaborative models and several representative architectures of distributed collaborative processing are proposed.However,the existing problems and the future researching direction are presented.     

基于Agent的分布计算环境

为适应分布计算向分散对等的协同计算方向发展，我们开展了基于ａｇｅｎｔ的分布计算环境的研究开发，试图在分布式多ａｇｅｎｔ协同工作系统的开发与当前的分布计算环境之间架起一座桥梁。本文讨论了ａｇｅｎｔ的独立性、自主性和交互性的特点，描述了以事件处理为核心的ａｇｅｎｔ基本模型；研究了基于ａｇｅｎｔ的分布计算环境的构造技术；分析了一种基于ａｇｅｎｔ模型的客户／服务器计算环境ＣＳＥ／ＭＡ的设计与实现，及其超越     

基于机群操作系统的并行调试器

并行调试工具的设计，是并行计算环境工具研究开发中的一个突出难点。介绍了一个在曙光3000上实现的并行调试器DCDB3．0。该调试器是未来曙光4000机群操作系统的一部分，是曙光3000上的第1个可运行版本，采用典型的客户／服务器模式。客户端的用户界面可将冗繁的调试信息与操作可视化。客户端可以远离提供服务的大型机，其远程通信依赖的是机群操作系统中的DRPC和任务管理，前者提供远程方法调用，后者使得客户端能够在服务器上启动相应的任务。DCDB3．0的服务器端负责处理调试任务和同客户端进行信息交互。DCDB3．0的功能具有可扩放性，使得可以在此平台上研究一些高级并行调试技术的实现。改进了已有的方式，实现了重放技术，并计划进一步添加其他高级并行调试技术。     

一个通用的数据操作构件集

该文在分析企业信息系统数据操作模块的共性的基础上,介绍了863/CIMS国产数据库客户端开发工具Open-Tools的数据操作构件集的实现机制。该构件集封装了数据操作和数据显示功能,并提供属性、事件以及调用接口支持用户逻辑的实现;它支持客户/服务器体系结构和Web应用,能够有效地提高企业信息系统的开发效率和质量。     

On developing an inventory management system in the client/server environment

It is reported that client/server technology can make it easier for users to access information, to use and to develop applications, and to manage a distributed computing environment. This paper describes the implementation of client/server technology to an inventory management system. Methodology developed and barriers faced in this study are useful for practitioners in building client/server applications.     

分布式网络自动抓包管理系统的设计与实现

讨论了网络抓包原理及WinPcap体系结构,探索了不同于传统客户端被动抓包的方法,对自动抓包进行了研究,提出了由客户端在特定事件触发机制下自动抓包然后推送至服务端的设计思想.在此基础上进行设计与开发实践,给出了一套应用于分布式网络管理环境,包含服务端与客户端的网络自动抓包管理系统的架构及详细设计,并给出了程序实现细节.设计并实现的系统在真实环境中得到成功应用,为网络管理提供了有效的支持.     

基于Delphi7的智能仪表OPC DA服务器设计

为了有效解决分布式异构系统的集成问题,采用了OPC客户/服务器体系结构的解决方案。通过对OPC技术和规范的深入研究,以Delphi7作为开发平台,Huafu OPC ToolK it作为开发工具,研发了宇电AI808智能仪表OPC数据访问服务器的设计方法。最后,注册并测试了服务器的性能,同时与工控组态软件MCGS实现了信息交互和集成。所述方法具有一定的可行性和有效性。     

Web Services环境下基于私有UDDI的分布式系统研究

针对异构系统间交互性差的问题,研究了如何采用Axis构建一个基于Web Services的分布式信息系统,实现了分布式环境中基于XML的SOAP通信,通过WSDL文件实现服务器端和客户端的信息交互,将具体应用封装为服务的形式并配置私有UDDI服务器,实现服务的动态注册、发现,最终实现分布式环境下的资源共享与协同工作.     

Distributed computing for multidisciplinary design optimization using Java

The programming language Java (recently referred to as the computer language of the Web) offers substantial possibilities for the type of complex engineering problems typically encountered in multidisciplinary design optimization (MDO) problems. In order to demonstrate the potential uses of Java for MDO problems, this paper presents the development of the Web Interface for complex engineering design (WICkED) software, which simulates the convergence of a decomposed complex system in a distributed computing environment and computes the sensitivity derivatives of the system with respect to the independent input variables using the GSE method or the finite difference method. In this application, one computer is designated as the server and sends out required inputs to a number of client subsystems over the Internet. A number of client computers can connect to the server and then receive the inputs necessary to calculate the solution to their model. As the code necessary to solve the model already exists at the client, only the inputs have to be sent over the network. When the client has solved the calculation, it returns the results to the server which processes the result to produce new inputs.WICkED is written entirely in the Java programming language which allows server and clients to exist on completely different computer types and in heterogeneous, distributed networks. A number of parametric studies on the behaviour of complex systems in a distributed environment are performed and the results are reported in this paper. This research serves to identify potential problems as well as advantages in using Java for MDO applications.     

分布式并行服务器透明性及任务调度研究

针对当前多服务器系统透明性和任务调度研究中存在的问题，提出一种分布式并行服务器的网络服务透明性实现机制和相应的任务调度算法。该透明性机制修改服务器结点的ARP地址解析协议以及客户端到服务器端的连接和数据请求处理，使得整个服务器系统对外界表现为惟一的VIP地址和VMAC地址；相应的任务调度算法则根据负载和阈值设置将服务器结点分成两个链：有效服务器结点链和过载服务器结点链，然后由量值循环法对有效服务器结点链进行任务调度，在修改Linux内核网卡驱动程序和部分底层网络协议的基础上进行了实现，测试结果表明其具有良好的响应特性和较强的服务能力。     

基于LDAPv3的目录服务系统中推荐的设计与实现

推荐机制是分布式目录服务系统中一个十分重要功能,它的构成和使用都充体现了分布式目录服务的特征。本文简要介绍了ＬＤＡＰｖ３对协议中服务器端笔客户端对推荐的使用及处理,提出了基于ＬＤＡＰｖ３的目录服务系统中推荐机制的设计与实现方案,在实际系统实现中取得了较好的分布式操作效果。     

WWW文档协同写作系统中通信中间件的设计与实现

ＷＷＷＤＯＣ是一个基于ＴＣＰ／ＩＰ协议的分布式协同写作系统,ＤＯＣＯＭ作为通信中间件将客户和服务器有机地联系起来。本文分析了ＤＯＣＯＭ的设计任务和目标,介绍ＤＯＣＯＭ的对象模型、通信接口和公用服务。