A formal framework of multi-agent systems with requirement/service cooperative style

Adopting three kinds of speech acts:request,promise,and inform,this paper analyses the interaction among agents in a kind of multi-agent systems with requirements/services cooperation style(MASr-s).The paper gives the objective model the theoretic satisfaction conditions of three kinds of speech acts in MASr-s.The formal definition of MASr-s has been presented.To evaluate concrete implementation architecture and mechanism of the variant MASr-s.including client/server computing architecture and mechanism,a spectrum of MASr-s has been proposed,which captures direct request/passive service mechanism,direct request /active service mechanism,indirect request/active service mechanism,and peer to-peer request /service mechanism.The Spectrum shows a thread to improve traditional client/server computing.     

A distributed server architecture supporting dynamic resource provisioning for BPM-oriented workflow management systems

Workflow management systems have been widely used in many business process management (BPM) applications. There are also a lot of companies offering commercial software solutions for BPM. However, most of them adopt a simple client/server architecture with one single centralized workflow-management server only. As the number of incoming workflow requests increases, the single workflow-management server might become the performance bottleneck, leading to unacceptable response time. Development of parallel servers might be a possible solution. However, a parallel server architecture with a fixed-number of servers cannot efficiently utilize computing resources under time-varying system workloads. This paper presents a distributed workflow-management server architecture which adopts dynamic resource provisioning mechanisms to deal with the probable performance bottleneck. We implemented a prototype system of the proposed architecture based on a commercial workflow management system, Agentflow. A series of experiments were conducted on the prototype system for performance evaluation. The experimental results indicate that the proposed architecture can deliver scalable performance and effectively maintain stable request response time under a wide range of incoming workflow request workloads.     

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．     

A trusted decentralized access control framework for the client/server architecture

This paper proposes a trusted decentralized access control (TDAC) framework for the client/server architecture. As the fundamental principle, TDAC enforces access control policies at the client side and protects sensitive objects at the server side by leveraging trusted computing technologies. Compared with the previous work of Sandhu and Zhang (2005), TDAC uses fewer requirements for trusted components. To implement TDAC, we design a private trusted reference monitor that runs at the client side, evaluates an access control request, and signs a temporary access control credential for a client application trustworthily; we also design a master reference monitor that runs at the server side, evaluates the request from the client application only according to the temporary access control credential. As a typical application, TDAC can protect client's private context data in subject-context aware access control.     

基于CORBA消息服务的容错机制研究

CORBA逐渐成为面向对象分布式应用中间件的主要标准，但是CORBA当前没有为容错提供相应的机制，该文在比较各种容错方法的基础上，讨论了一种基于异步消息服务回调和查询模型的容错方法，该方法使服务对象的副本可以并行地处理客户请求，提高了容错的性能，该方法具有对服务对象透明，可以满足用户不同容错要求等特点，文中还给出了这种方法在为遗留应用增加容错能力时的应用实例。     

Energy-Efficient Redundant Execution of Processes in a Fault-Tolerant Cluster of Servers

This paper investigates into fault tolerance of cluster of servers and their energy efficiency to realize a reliable and energy aware server cluster system. A client issues a request to one server in a server cluster and the server sends a reply to the client in information systems. Once the server stops by fault, the client does not receive a reply of the request. Even if the request is performed on another server on detection of fault of the server, some QoS requirements like response time may not be satisfied. Hence, each request has to be redundantly performed on multiple servers to be tolerant of server faults. The redundant power consumption laxity-based (RPCLB) algorithm is discussed where multiple servers are selected to redundantly and energy-efficiently perform a request process in our previous studies. Since each application process is redundantly performed on more than one server, the larger amount of electric power is consumed. In this paper, we propose a novel and improved RPCLB (IRPCLB) algorithm to reduce the power consumption of servers, where once a process successfully terminates on one server, meaningless redundant processes are forced to terminate on the other servers. In the evaluation, we show the total power consumption of servers and total execution time of processes are reduced in homogeneous and heterogeneous types of clusters by the IRPCLB algorithm than the RPCLB and RR algorithms.     

基于三层架构的客户管理系统的研究与设计

该文通过分析构件技术在客户一服务架构系统中的作用,阐述了三层或多层架构相对传统二层客户一服务架构的优势：介绍了遵循J2EE规范的客服架构,并根据企业业务特点具体分析了支持构件思想的系统专用框架WSKBatch的工作原理．最后通过特定业务模块的具体示例来说明如何实现它与业务逻辑构件之间的交互。     

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.     

混合任务系统的服务质量保障调度算法

开放式系统中存在大量的客户/服务软件架构,其中大量的混合客户任务（实时任务,非实时任务）请求与作为服务端的任务进行处理交互。传统的非实时调度算法用于服务任务处理请求时不能保障客户任务的服务质量。通过改进GRUB算法（剩余带宽贪婪回收算法）,提出了一种优化的混合任务系统的服务质量保障调度算法,保证客户任务的实时性和系统吞吐率。仿真实验验证了该算法对客户任务的服务质量保障作用。     

A Framework for Community Information Systems

In this paper we present a generic framework architecture for Web-based community information systems (CIS). The framework has an open architecture based on COTS (commercial-off-the-shelf) software components and network technologies. We discuss how a component-based approach, a layered architecture model, and design patterns can be used to provide a common framework for CIS. The CIS framework architecture results in significant benefits that include reuse, a flexible user interface, powerful search mechanisms and an integrated and scalable architecture. XML and rule-based StyleSheet languages are used for storage, information search and graphical presentation at the server or client. The overall framework architecture, its individual components and the interaction among these components are outlined.     

A role-oriented service system architecture for enterprise process collaboration

Workflow management is a key technique for coordinating various business processes. Traditional workflow systems are often built with the client/server architecture, in which, a single workflow server takes the responsibility of the entire operation. This paper discusses a model-driven process enactment environment, which can support an enterprise businesses collaboration. Some key technologies regarding models and the system are discussed in the paper, including the mappings between activities in process models and the service function of applications, how to use XML in the process model, and other workflow engine techniques. A software architecture supporting role-oriented services within the process-driven enterprise enactment environment has been proposed and implemented. The proposed framework has been validated with a case study in the 4PL business system.     

基于中间件技术的数据批处理系统的设计与实现

该文通过分析中间件技术在客户一服务架构系统中的作用,阐述了三层或多层架构相对传统二层客户一服务架构的优势;介绍了遵循J2EE规范的客服架构,并根据企业业务特点具体分析了支持构件思想的系统专用中间件框架Sawara的工作原理,最后通过特定业务模块的实现来说明如何实现它与业务逻辑构件之间的交互。     

基于中间件技术的数据批处理系统的设计与实现

该文通过分析中间件技术在客户-服务架构系统中的作用,阐述了三层或多层架构相对传统二层客户-服务架构的优势;介绍了遵循J2EE规范的客服架构,并根据企业业务特点具体分析了支持构件思想的系统专用中间件框架Sawara的工作原理,最后通过特定业务模块的实现来说明如何实现它与业务逻辑构件之间的交互。     

基于信息空间模型的网络信息资源存储网格

随着知识管理第二阶段的到来,大多数企业中基于客户机/服务器或浏览器/服务器架构的知识管理系统的弊端日益突出。以指数级增长的网络信息资源及其访问量以及以同样速度递增的网络用户,极大地阻碍了人们有效地共享和管理各种网络资源。而现有的网络存储技术并不能有效地缓解存储压力。因此,论文提出了基于信息空间模型的网络信息资源存储网格方案来解决现有知识管理系统中存在的若干问题。在系统分析了导致现有知识管理系统存在相关弊端的根源并介绍了存储网络的相关研究后,详细介绍了信息空间模型,并在此基础上对各种网络信息资源进行了统一的、标准化的描述。然后给出了基于信息空间模型的网络信息资源存储网格的系统框架。在该环境下,统一组织和描述的各种网络信息资源分别存储在每一个分布式的网络终端,不仅有效解决了指数级增长的信息对存储容量的需求,而且能够有效消除“信息孤岛”现象,实现了负载均衡。而且,终端用户利用统一的语义映像能够实现对各种网络信息资源的共享与管理,极大地提高了资源的利用效率。基于信息空间模型的网格信息资源存储网格方案还极大地提高了系统的动态扩展性能。     

Service scheduling and rescheduling in an applications integration framework

Grid technologies are evolving towards a service oriented architecture (SOA) and the traditional client/server architecture of heterogeneous computing (HC) can be transformed into a grid service oriented architecture. In this architecture, when more than one service fulfills the user request, a service which can make scheduling decisions is essential. A scheduling service has been proposed in a framework which achieves the dynamic deployment and scheduling of scientific and engineering applications. The framework treats all components (resource service and scheduler service) as WSRF-compliant services which support the applications integration with underlying native platform facilities and facilitate the construction of the hierarchical scheduling system. In order to enhance the system performance, we replace the MWL scheduling algorithm with an MCT algorithm and integrate a rescheduling mechanism in the framework. The experiments show that the MCT algorithm can achieve a smaller makespan and the rescheduling mechanism ensures the task execution even if an application is removed from the Resource Service.     

综合集成研讨厅的软件体系结构

主要研究基于网络的分布式综合集成研讨厅的软件体系结构.采用了一种扩展请求器-中介器-供应器的嵌套式客户/Agent/服务器计算模式;并利用该模式给出了一个基于Java的智能信息Agent构建的宏观经济决策研讨厅框架和工作机制;综合了Agent移动性与消息传递机制、算法与交互能力、多种类型Agent和多种设计模式.与通常的C/S与B/S模型相比,该系统具有更大的灵活性、更快的响应性能、对网络性能的低需求等特性.     

基于WebService的WebGIS的设计与应用

基于WebGIS目前存在的一些不足,提出构建基于WebService的WebGIS系统,并说明这种系统的优势和特点。通过对正在开发的基于WebService的WebGIS系统的设计和一些已经完成的工作的介绍,来说明系统的可行性和先进性。     

STRATEGIC PLANNINGCREATING A CLIENT/SERVER STRATEGY

A go-slow approach to client/server computing is likely to be the strategy adopted by many firms after they have determined the business case for client/server computing, its fit with the organization, and its potential for facilitating organizational change     

信息系统中的客户机/服务器计算策略

文章介绍了Ｃｌｉｅｎｔ／Ｓｅｒｖｅｒ计算的概念及其在信息系统中的应用，并针对现有Ｃ／Ｓ结构的不足，结合一个银行系统的实践，从应用风格，计算模型等方面探讨了新一代Ｃ／Ｓ计算的基本思想与策略。     

债券监控模块设计与实现

根据债券业务要求,设计并实现了对债券交易平台的监控。提出了篝中管理债券客户服务器的思想,同时按客户类型和允许连接的最大客户端Client数进行了License的设计,并且实现了客户服务器的远程更新,用实际案例说明该设计思想的主要实现过程。