异种分布式对象技术互操作的分析与设计

现在以CORBA，DCOM和RMI为代表的三种分布式对象技术日益流行和不断发展，然而对于它们的互操作是否可行？主要就这三种技术在传统模式和基于Web的模式两种环境下对于它们的桥接和互操作进行一些研究和分析。     

异构分布式对象互操作模型研究

分布式对象技术,如EJB(EnterpriseJavaBeans)、CORBA(CommonObjectRequestBrokerArchitecture)、COM(CommonObjectModel),允许运行在一台机器上的对象被不同计算机上的客户端应用程序使用。该文在研究上述三种主流分布式对象标准及其两两互操作技术的基础上,提出了一种三种标准间互操作的模型及总体设计,并实现了桥中当已经得到某种标准的客户调用请求后对另外标准对象的调用。     

基于Web的分布式对象技术

随着Web应用的迅猛发展,复杂大型Web系统的设计需要更强大的软件设计技术来支撑。对此,文中探讨了基于Web的分布式对象技术,指出了分布式Web系统结构及其运作机制,深入分析了三大主流分布式对象和组件技术在Web系统开发中的应用,阐明了系统实现的方法。以此交流和推动分布式组件技术在Web中的应用,拓展Web软件设计的能力。     

一种基于SOAP的实现异种分布式组件互操作的方法

分析了现今流行的分布式组件技术,指出了在Internet环境下这些分布式组件技术在互操作性方面的不足,进而提出了一种基于SOAP的实现异种分布式组件互操作的方法,并且给出了在EJB Server上的具体实现方案。最后,讨论了该方法在今后的进一步的研究重点。     

基于Web的分布式对象技术

随着Web应用的迅猛发展,复杂大型Web系统的设计需要更强大的软件设计技术来支撑.对此,文中探讨了基于Web的分布式对象技术,指出了分布式Web系统结构及其运作机制,深入分析了三大主流分布式对象和组件技术在Web系统开发中的应用,阐明了系统实现的方法.以此交流和推动分布式组件技术在Web中的应用,拓展Web软件设计的能力.     

分布式对象技术在分布式GIS方面的应用

分布式GIS是目前GIS领域的研究热点，基于传统技术开发的GIS系统难以做到应用的高效性和平台无关性，更难以适应当前大型分布式系统的发展，文章首先分析了目前分布式对象技术的特点，进而结合分布对象技术，提出了商业化的分布式GIS开发模式以及分布式GIS与其它相关信息系统集成的设想。     

分布式对象技术分析及其发展研究

分布式对象技术是以面向对象为基础,支持分布式应用的软件技术。介绍了各种分布式对象技术及其原理,对几种主流分布式对象技术进行了分析比较。最后,对分布式对象的应用前景和发展方向进行了探讨。     

Web技术发展与分布式对象技术

本文论述了Ｗｅｂ技术的发展，指出了目前通用的ＨＴＴＰ／ＣＧＩ方式的缺陷，提出了Ｗｅｂ技术与分布式对象技术的结合是解决这些问题的良好方法。     

分布式UDDI互操作模型的研究

统一描述、发现与集成UDDI是Web服务中用来进行服务发布及查询操作的关键技术.目前的UDDI大多采用集中模式,随着服务数量的不断增加,其查找效率不断降低且对UDDI服务器的维护和管理也变得十分困难.此外,由于私有UDDI服务注册库的出现,且私有注册库之间缺乏互通机制,导致出现了新的服务孤岛.针对上述现状,本文提出了一种分布式UDDI互操作模型,将UDDI模型分为根UDDI、超域UDDI和普通UDDI三层架构,并对三层模型的维护和应用程序接口进行了较详细的讨论.仿真实验证明该模型可有效提高UDDI的查询效率并实现了UDDI注册库之间的信息互通.     

基于SOAP实现异种多Agent系统间互操作

为了解决应用在多Agent系统中的分布式组件技术在互操作性方面的不足,探讨了应用SOAP(simple object accessprotocol)技术实现多Agent系统间互操作的可行性,进而提出一种基于SOAP的实现多Agent系统间互操作方法,阐明了系统的工作原理,给出了具体应用实例,证明了其可行性,并总结了该方法的优点,讨论了进一步研究的重点。     

Large scale interoperability and distributed transaction processing

This article integrates an interoperability architecture, the OSCA^TM architecture, and a distributed transaction processing protocol, the X/Open^® Distributed Transaction Processing model, into a unified model of large scale interoperability and distributed transaction processing. Applications supporting different business operations are often deployed in heterogeneous environments in which applications are stand alone islands and operations are fragmented. But in order to have integrated operations, a loosely coupled system of autonomous applications is required often bound together via a distributed transaction processing protocol. This article describes a model for this configuration. It will propose that the span of control of a transaction manager defines the transaction environment for a single application. Any two applications need not conform to the same supplier's transaction environment nor reside in the same environment. Interoperability must be provided among applications, since any one application cannot assume that any other application is under the control of the same transaction manager. Requirements are imposed upon the interactions of applications to support interoperability. The interface between transaction managers must be compatible with these requirements. Other distributed architecture standards must define the requirements for release independence, resource independence, accessibility transparency, location transparency, contract interfaces, and secure environment.     

基于分布式对象的可视化分析

总结了分布式对象技术的基本概念和理论,并对航天器运动可视化分析这一具体问题的相关内容、方法和过程进行了讨论。提出了借助现有的技术和条件,应用分布式对象技术实现可视化分析系统的方案,验证了分布式对象技术在实现可视化分析系统及其多目标、多任务和多用户能力,并保障可靠性、可维护性、可扩展性、可伸缩性等计算机系统质量特性的可行性和优越性。     

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.     

A framework of auto-adapting distributed object for mobile computing

The low bandwidth hinders the development of mobile computing.Besides providing relatively higher bandwidth on communication layer,constructing adaptable upper application is important.In this paper,a framework of autoadapting distributed object is proposed,and evaluating methods of object performance are given as well.Bistributed objects can abjust their behaviors automatically in the framework and keep in relatively good performance to serve requests of remote applications.It is an efficient way to implement the performance transparency for mobile clients.     

NCL: A common language for achieving rule-based interoperability among heterogeneous systems

For achieving interoperability among heterogeneous computing systems, the Object Management Group (OMG) has adapted the Common Object Request Broker Architecture (CORBA) and the use of an Interface Definition Language (IDL) for specifying object properties and operations which encapsulate the data and programs of heterogeneous systems. This paper describes a common language which is an enhancement of IDL to include: 1) the semantic richness of EXPRESS, an information modeling language adapted by the ISO/STEP community for achieving product model and data exchange; and 2) the extensibility features and knowledge rule specification offered by the Object-oriented Semantic Association Model (OSAM^*). This common language, named the NIIIP Common Language (NCL), is a part of the R&D effort of a project entitled the National Industrial Information Infrastructure Protocols (NIIIP). The design of NCL is standards-based, incorporating the semantic features of the two standard languages, IDL and EXPRESS, and conforming to their syntaxes as much as possible. It is an extensible language which supports the addition of new class, constraint, and association types to the language and its underlying object model in order to satisfy the diverse modeling needs of virtual enterprises. The language also contains a high-level rule specification component. Rules in NCL can be used for defining and enforcing integrity and security constraints, government or enterprise policies and regulations, and other types of semantic constraints that are local or global to heterogeneous systems. In this paper, we shall show how such a modeling language and its supporting KBMS functions can be used to achieve rule-based interoperability in an active heterogeneous system as an enhancement to OMG's CORBA.This research is supported by the Advanced Research Project Agency under ARPA Order No. B761-00 and managed by the United States Air Force under contract F33615-94-2-4447. This is a part of the R&D effort of the NIIIP Consortium. The views and conclusions contained in this paper are those of the authors and should not be interpreted necessarily as representing the official policies, either expressed or implied, of all the NIIIP Consortium members, the Advanced Research Projects Agency, or the United States government.     

Web服务交互测试中SOAP消息的控制和分析

由于Web服务的平台异构性,Web服务的交互测试是一个重要的测试方面。阐述了一种通过截获和分析通讯消息进行Web服务交互测试的方法。在这种测试模型中,SOAP消息的控制和分析是关键。详细论述了SOAP消息的控制和分析在测试中的作用,并在结尾给出了系统的设计实现。     

Semantic interoperability in building design: Methods and tools

Semantic interoperability is a crucial element to make building information models understandable and model data sharable across multiple design disciplines and heterogeneous computer systems. This paper presents a new approach and its software implementation for the development of building design objects with semantics of interoperable information to support semantic interoperability in building designs. The novelty of the approach includes its incorporation of building design domain ontology, object-based CAD information modeling, and interoperability standard to make building information models and model data semantically interoperable. A set of methods are proposed to address the issues of object-based building information representation compliant with the Industrial Foundation Classes (IFC); extension of IFC models with the supplementary information; and semantic annotation of the interoperable and extensible information sets. The prototype implementation of these methods provides a set of Web-enabled software tools for effectively generating, managing, and reusing the semantically interoperable building objects in design applications of architectural CAD, structural analysis, and building code conformance checking.     

分布异构环境下数据库访问技术的研究

详细分析了当前分布异构数据库访问技术的研究现状和发展趋势,结合Web Services的优势构造了一个基于Web Services的分布异构数据库访问系统,并阐述了系统的实现过程。该系统能够有效地支持分布式数据查询,数据源透明并且支持跨平台检索。     

基于.Net的分布式Web Service模型的应用研究

Web不仅可以作为一个信息平台,而且可以作为一个服务平台。Web Service是建立可互操作的分布式应用程序的新平台。介绍了Web Service模型架构,讨论了基于．Net的分布式Web Service模型的应用设计,并展望了Web Service未来的发展。