可无限分类的Web服务发现匹配算法

Web服务的目的是为了将不同组织、公司甚至个人提供的服务进行无缝的连接,建立一种松耦合的Web应用,实现资源共享的最大化。而在众多候选服务集中快速、准确地发现和选择所需要的服务即服务匹配成为其中关键的问题。在服务匹配过程中,为了减少最终参与匹配的服务的数量,提高服务发现的效率,匹配算法对参与匹配的服务集进行了预处理。并且依据服务描述本身的特点,对服务匹配中基于语义的Web服务相似度计算方法进行了研究,提出了无限分类的思想。最后实现了匹配算法并对性能进行了对比。     

使用倒排索引优化面向组合的语义服务发现

提出为服务库中所有注册服务的输出建立倒排索引,以快速、准确、高效地发现目标服务.即为每个输出维护一个服务列表,用于记录在该服务库中所有能够产生该输出的服务.基于倒排索引机制,提出面向组合的服务发现算法.该方法利用倒排索引的优势,极大地减少了搜索空间,并通过挖掘服务组合提高服务发现的查全率.仿真实验表明,该方法能够在大规模服务库中快速、全面地响应用户请求.     

Semantic web service composition testbed

A huge amount of web services are deployed on the Web, nowadays. These services can be used to fulfill online requests. Requests are getting more and more complicated over time. So, there exists a lot of frequent request that cannot be fulfilled using just one web service. For using web services, composing individual services to create the added-value composite web service to fulfill the user request is necessary in most cases. Web services can be composed manually but it is a too tedious and time consuming task. The ability of automatic web service composition to create a new composite web service is one of the key enabling features for the future for the semantic web. There are some successful methods for automatic web service composition, but the lack of standard, open, and lightweight test environment makes the comparison and evaluation of these composition methods impossible. In this paper we propose an architecture for a light weight and scalable testbed to execute, test and evaluate automatic web service composition algorithms. The architecture provides mandatory components for implementing and evaluation of automatic web service composition algorithms. Also, this architecture provides some extension mechanisms to extend its default functionalities. We have also given reference implementations for web service matchmaking and composition. Also, some scenarios for testing and evaluating the testbed are given. We have found that the performance of the composition method will dramatically decrease as the number of web services increases.     

Web服务合成研究综述

Web服务的发展将Web应用从信息交互领域扩展到了服务交互领域。Web服务诸多的特性使得它非常适合于商务应用集成，因此工业界和学术界都希望能够通过合成多个Web服务从而获得增值的新服务。在服务合成的过程中，不仅需要语义清晰的服务描述语言和直观的建模方法，并且应该能够动态地发现构件服务，顺利地执行复合服务以及对其进行事务处理。此外对Web服务合成的分析评估也将有助于理解复合服务中每一项活动的行为，从而促使不断改进服务合成技术。     

基于WS-BPEL 的Web 服务组合技术

随着Web服务技术的不断发展,越来越多的Web服务已经发布在互联网上。然而独立的Web服务功能通常有限,不能满足用户或企业实际应用的需求。因此,Web服务的组合显得越来越重要。介绍了Web服务组合和WS-BPEL的相关知识,使用最新的业务流程执行语言WS-BPEL描述业务流程,在J2EE集成开发环境下设计并实现了基于业务流程思想的贷款审批应用实例,在Web服务执行引擎Active BPEL上进行部署,对Web服务进行了有效的组合。     

服务时间随机条件下服务组合质量分析

本文分析采用业务过程执行语言（BPEL2WS）描述的web服务组合的执行时间,给出在服务执行时间随机情况下,根据单个服务的执行时间概率分布密度和BPEL2WS模型的结构求解web服务组合执行时间的概率分布密度函数的算法。根据概率密度函数可以求得业务过程执行时间在任意时限内的概率,从而可以根据给定的概率条件优化组合服务,使得服务执行成本最低．最后通过一个应用实例验证了算法的有效性。     

面向动态工作流的Web服务组合

利用动态工作流模型,将Web服务的组合过程与工作流的过程模型有机结合起来,从而建立面向动态工作流的复合服务。在复合服务的执行过程中,通过引入服务评价函数,并根据工作流过程模型中所定义的各项任务之间的业务逻辑与业务规则,最终实现工作流任务的动态绑定与执行。     

基于功能语义的Web服务发现方法

随着Web服务技术的发展与应用,基于功能语义进行Web服务发现已经逐渐成为服务使用者最为迫切的需求.而现有的服务发现机制还不能很好地解决这一问题.所以提出了一种基于功能语义的Web服务发现方法.通过定义Web服务功能描述模型,规范服务提供者和使用者对Web服务功能的描述;同时构建了领域功能本体,提出语义标注的机制,从而让用户可以基于功能语义发现Web服务.并设计了基于功能语义的Web服务描述语言,构建了原型系统,为基于功能语义进行服务发现提供了一种有效可行的方法.     

基于Pi-演算的Web服务形式化描述模型*

当前对Web服务进行形式化描述的方法多是基于对某个具体Web服务组合规范的抽象,无法兼顾基于全局和局部的设计方法,并且无法描述Web服务组合的体系结构的动态性。本文在对现有的Web服务形式化描述方法进行回顾和总结的基础上,基于Pi-演算建立了Web服务形式化描述模型,将BPEL4WS规范和WS-CDL规范的重要行为在模型中做了映射。最后通过例子说明,基于局部和全局的设计方法在本文提出的模型中的映射是一致的。本文提出的描述模型直接用来进行Web服务组合的设计时,可以更好的描述动态的体系结构。     

基于语义的服务混合匹配方法研究

为了提高Web服务匹配的效率和灵活性,提出了一种基于语义的Web服务混合匹配方法。该方法首先扩展了服务的功能描述模型,并基于该扩展模型进行混合服务匹配。混合匹配方法联合使用了两种匹配策略：基于推理的匹配策略,通过本体概念的逻辑关系实现匹配;基于相似性计算的策略,通过本体概念间相似度计算进行服务的匹配。在服务匹配过程中,首先使用基于推理的匹配策略将服务分成4个匹配等级,然后,采用基于相似性计算的匹配策略对候选服务进行进一步地匹配。实验结果表明该方法是可行而有效的。     

Enhancing ebXML Registries to Make them OWL Aware

ebXML is a standard from OASIS and UN/CEFACT which specifies an infrastructure to facilitate electronic business. In this paper, we address how ebXML registry semantics support can be further enhanced to make it OWL aware. OWL constructs are represented through ebXML registry information model constructs, and stored procedures are defined in the ebXML registry for processing the OWL semantics. These predefined stored queries provide the necessary means to exploit the enhanced semantics stored in the registry. In this way, an application program does not have to be aware of the details of how this semantics support is achieved in ebXML registry, and does not have to contain additional code to process this semantics.We believe that this approach is quite powerful to associate semantics with registry objects: it becomes possible to retrieve knowledge through queries, the enhancements to the registry are generic and also the registry specification is kept intact. The capabilities provided move the semantics support beyond what is currently available in ebXML registries and it does so by using a standard ontology language.To be able to demonstrate the benefits of the enhancements, we also show how the resulting semantics can be made use of in Web service discovery and composition.Recommended by: Athman Bouguettaya and Boualem BenatallahThis work is supported in part by the European Commission, Project No: IST-1-002104-STP SATINE and the Scientific and Technical Research Council of Turkey (TÜBÍTAK), Project No: EEEAG 104E013 and is realized as a proposal to OASIS ebXML Semantic Content Management subcommittee which is working on possible semantic extensions to the registry.     

An aggregation composition compensation method based on paired net

With regard to the failure and cancellation of business logic of web services composition(WSC),this paper propose a novel web services transaction compensation mechanism based on paired net which can dynamically establish agile compensation-triggered process(CSCP-Nets),and satisfy prospective compensation requirements.The related execution semantics of five usual composition compensation patterns based on paired net are analyzed in the situations of successful execution,failure compensation and failure recovery.Paired net based application of trip reservation process(TRP) shows that it is feasible.     

Synthy: A system for end to end composition of web services

The demand for quickly delivering new applications is increasingly becoming a business imperative today. However, application development is often done in an ad hoc manner resulting in poor reuse of software assets and longer time-to-delivery. Web services have received much interest due to their potential in facilitating seamless business-to-business or enterprise application integration. A web service composition system can help automate the process, from specifying business process functionalities, to developing executable workflows that capture non-functional (e.g. Quality of Service (QoS)) requirements, to deploying them on a runtime infrastructure. Intuitively, web services can be viewed as software components and the process of web service composition similar to software synthesis. In addition, service composition needs to address the build-time and runtime issues of the integrated application, thereby making it a more challenging and practical problem than software synthesis. However, current solutions based on business web services (using WSDL, BPEL, SOAP, etc.) or semantic web services (using ontologies, goal-directed reasoning, etc.) are both piecemeal and insufficient. We formulate the web service composition problem and describe the first integrated system for composing web services end to end, i.e., from specification to deployment. The proposed solution is based on a novel two-staged composition approach that addresses the information modeling aspects of web services, provides support for contextual information while composing services, employs efficient decoupling of functional and non-functional requirements, and leads to improved scalability and failure handling. We also present Synthy, a prototype of the service composition system, and demonstrate its effectiveness with the help of an application scenario from the telecom domain.     

基于.NET的Web应用框架的设计与实现

分析了目前Web应用的不足,介绍了Web服务和持久层技术,提出了一种.NET平台下的Web应用框架.该框架将传统三层Web应用系统中的应用服务层进一步从逻辑上划分为三个层次：业务外观层、业务规则层和持久层.业务外观层采用Facade设计模式进行设计,以Web服务方式向Web表示层提供服务,并利用Tier Developer设计持久层,实现对象持久化.最后以供应链管理（SCM）系统中的采购单模块为例,给出了该框架的具体实现.     

Web服务复合技术在SOA系统中的研究与应用

随着以Web服务为基础的面向服务的体系结构的发展,如何复合分布的、自治的Web服务以构建新的企业业务应用的问题已成为软件工程领域一个新的热点问题。本文研究探讨了Web服务复合技术在面向服务体系的系统开发中的应用,并在此基础上提出一个基于Web服务复合技术的应用程序设计模式。     

Web服务复合技术在SOA系统中的研究与应用

随着以Web服务为基础的面向服务的体系结构的发展，如何复合分布的、自治的Web服务以构建新的企业业务应用的问题已成为软件工程领域一个新的热点问题。本文研究探讨了Web服务复合技术在面向服务体系的系统开发中的应用，并在此基础上提出一个基于Web服务复合技术的应用程序设计模式。     

基于模糊Petri网的服务发现框架研究

现有的主流服务发现方法不支持模糊逻辑推理，无法处理软计算语义，从而缺乏灵活性．为了弥补人类可理解的软计算逻辑和机器能够识别的硬逻辑的差异，提出了面向服务基于模糊Petri网的Multi-Agent服务发现框架．为支持这一框架。设计了一种模糊Petri网服务描述语言，其主要特点是变迁表示一个服务或者请求；变迁的输入库所表示服务执行前应满足的条件，变迁的输出库所表示只有在所需争件满足的情况下服务才能成功执行．变迁相关的CF值（certainty factor value）表示服务消费者对Agent所提供服务的置信度．其次，提出了支持软计算语义的松弛匹配机制，并且给出了模糊松弛匹配算法；借助于本体库（类库），通过计算命题的真实度，在不精确模糊信息情况下，可以实现服务和请求的模糊松弛匹配．     

用于科技基础条件平台的服务合成研究与应用

Web服务之间的交互是面向服务的体系结构（Service-Oriented Archimcmre,SOA,也称为面向服务架构）中的关键问题。单个Web服务提供的功能往往不能完全满足用户的实际需求．将多个Web服务进行合成实现功能更为强大的服务是SOA必须要解决的问题之一。分析了Web服务合成的研究现状,介绍了Web服务合成方式的分类和商业流程执行语言BPEL4WS,给出了“科技基础条件平台应用服务支撑系统”项目中SOA的设计方案．描述了Web服务合成的关键步骤。该研究成果成功地应用于科技基础条件平台应用服务集成之中,并已通过科技部的前期验收