Web服务组合规范WS-CDL的类型化形式化模型

为了形式化地推理和验证web服务编排规范WS-CDL所描述的web服务组合,提出了一个WS-CDL规范的类型化形式化模型——typed abstract WS-CDL.在typed abstract WS-CDL中,定义了类型和会话的语法、类型判定规则和操作语义;web服务间的协作由会话来描述;利用会话的操作语义能对web服务编排的执行进行推理;利用类型判定规则能检查web服务间交换信息类型一致性并捕获由于类型不一致导致的运行时错误.特别地提出了类型假设集的外延和类型假设集相容性的概念,并定义了类型假设集的合并算法以消除类型假设冲突.在该模型基础上,还定义了从choreography到orchestration的类型化映射规则,通过这组规则,可以从一个给定的web服务choreography得到orchestration桩代码及其类型假设集,因而web服务组合能在choreography和orchestration层被验证.提出的模型被证明具有类型安全性,并且通过一个案例分析说明了所提出的模型是有助于对web服务组合进行推理和验证的.     

一种适应性web服务匹配方法

为提高服务匹配对请求多样性和服务能力描述差异性的适应能力,提出了一种基于时态逻辑模型检验的适应性服务匹配方法——ASMA.该方法基于一个抽象服务模型ASM-TL,ASM-TL包含了影响服务匹配的服务内部约束和调用约束等重要因素,以及一个描述服务行为属性的虚拟过程模型.ASMA将服务请求统一描述为一种时态约束条件,基于ASM-TL将服务转换为一种时态模型,并引入模型检验的思想进行服务匹配.因此,ASMA可提高服务匹配的准确度,并很好地适应服务请求的多样性和服务能力描述的差异性.该方法已应用到生物信息领域的问题求解环境(PSE)中.应用表明,该方法对动态环境具有良好的适应能力.     

Function oriented service composition modeling

Formal models for service composition have been proposed with the variation of the requirements of service developers. Some famous models have provided checking and verification techniques and tools for the behavior of service composition. These models generally focus much on the message flow of web services and neglecting the data contained in the exchanged messages among services, which restrict the application range of these models and also the web service techniques. As new kind of services with different protocols and communication methods have appeared, it is needed to model service composition from a new view which is adapted to the new development in service area. In this paper we offer a function oriented model of service composition which treats the composite service as a software system and specify the function of services which can be directly used to the realization by service providers.     

Function oriented service composition modeling

Formal models for service composition have been proposed with the variation of the requirements of service developers.Some famous models have provided checking and verification techniques and tools for the behavior of service composition.These models generally focus much on the message flow of web services and neglecting the data contained in the exchanged messages among services,which restrict the application range of these models and also the web service techniques.As new kind of services with different p...     

使用NWA对组合web服务进行可达性分析

为了提高组合web服务的设计和实现质量,使用形式化方法对其进行建模并对其关键性质进行验证.使用web服务接口控制流自动机（WCFA）对web服务进行建模,主要描述其控制流及与其他web服务的交互关系.组合web服务由一组交互的WCFA组成.使用嵌套字自动机（NWA）对组合web服务的整体行为进行建模.将一组WCFA转换为嵌套字自动机（NWA）的算法是深度优先搜索算法的变种,算法中使用路径相关的可达性分析计算NWA的每个节点的状态公式和调用栈.安全性相关性质、调用栈相关性质及服务调用的前置和后置条件都可以用断言来描述,然后使用一个自动的可满足性（SAT）求解工具对这些断言进行验证.     

一个基于有色Petri网的Web服务合成模型

In this paper, a model based colored Petri net (CPN) to provide semantic support for web service composition is proposed, and the reliability and maintainability of composite services are improved. The composite constructs in the model are sequence, concurrent, choice, loop and replace. The web service is formally defined by a CPN. A closed composing algebra is defined to obtain a framework which enables declarative composition of web services. Availability, confidentiality, and integrity of composite service are analyzed within the framework of the model based CPN.     

A web product data management system based on Simple Object Access Protocol

1. Introduction Product data management (PDM) is a technology helping workgroup, department, division, or enterprise manage product data and development process throughout the product life cycle, from inception, through development and production to dispatch and beyond. As an integration tool connecting many different areas, PDM manages product data throughout the enterprise, ensuring that right information is available to the right person at the right time and in the right form. Web-based …     

Smart home architecture based on event-driven DPWS～+

With the advances of electronic information technology and computer network, especially the embedded technology, smart home is no more just a vision but being practical. The interoperability of heterogeneous devices and flexibility of devices’ usage are two key problems that challenge the implementation of smart home. To deal with these two issues, this paper proposes an event-driven service oriented architecture using device profile for web services (DPWS). DPWS inherits the advantages of the traditional web services in achieving interoperability without dependence on platform, while improving service discovery and security as well as being optimized for deploying on resource constrained devices. By providing a visual interface for describing a service workflow (SW), the user can easily customize the actions of devices by services composition. Devices automatically cooperate without user’s intervention to complete required business logic. This is achieved by fully exploiting the eventing capabilities on DPWS enabled home devices. Finally, a home theater scenario is given to illustrate the event driven mechanism for the SW in the proposed smart home framework.     

基于模拟退火算法的QoS约束web服务组合

针对web服务组合中选择服务需感知服务的QoS属性问题,采用向量表示法描述原子服务及组合服务的QoS属性和用户提出的多项全局约束,把寻求满足多项非功能属性约束的最优服务组合问题转化为在有向图中搜索最优多约束路径问题,采用有向图对组合服务建模.设计了多QoS属性约束的服务组合模拟退火算法,进行组合服务QoS属性的归一化处理和二次寻优.实验结果表明该方法可求得满足各项QoS约束的可行解,模拟过程显示该算法以多项式时间复杂度选出近似最优解.     

基于决策树算法的Web服务分类的研究

Web服务(Web Services)是计算机网络技术研究热点之一,主要用来研究应用程序在Internet上实现互操作,拓展应用程序的功能。近年来,电子商务迅速崛起,Web服务数量不断增加,很多Web服务提供的功能是相似的,用户难以找到最适合自身需求的Web服务。使用决策树ID3算法,分析影响Web服务功能的质量参数,将其作为属性特征,得到Web服务的分类,帮助用户更好地选择合适的Web服务。     

基于Petri网的经济预警服务组合模型研究

针对当前经济预警领域单一模型预测效果不理想,以及模型组合、管理和重用困难等问题,提出了采用面向服务的体系结构构建宏观经济预警平台,将单一预警模型发布为Web服务,并利用Petri网组合预警服务模型的方法,讨论了系统构建方法和服务组合的建模过程,验证了基于Petri网的组合服务模型能够保证组合服务的可达性、安全性、正确性和可终止性。     

基于XML与Web服务的图书馆资源整合与集成模式探讨

通过分析XML与Web服务技术,设计了一种基于XML和Web服务技术的数字图书馆资源整合和集成模型体系:以XML为标准的数据交换格式,以Web服务为分布式计算机制.通过该模型解决了新形势下分布、异构和自主的数字图书馆资源给读者检索和利用带来的困难.     

基于XML与Web服务的图书馆资源整合与集成模式的探讨

通过分析XML与Web服务技术,设计了一种基于XML和Web服务技术的数字图书馆资源整合和集成模型体系:以XML为标准的数据交换格式,以Web服务为分布式计算机制.通过该模型解决了新形势下分布、异构和自主的数字图书馆资源给读者检索和利用带来的困难.     

利用Topic-Group构建Web服务

针对传统Web服务机制的注册集中、标注语义缺乏和自动处理困难的问题,提出了一种基于主题组(Topic-Group)的Web服务机制;以基于超节点的peer-to-peer作为网络架构,OWL-S/UDDI作为服务注册平台,用语义Web服务技术对传统的Web服务机制进行了改进。研究表明,模型提高了Web服务的注册、发现和匹配的自动化处理能力。     

基于语义P2P的Web服务模型

Web服务是一种新的网络计算模式,怎样发布、查找、集成Web服务以使其发挥出巨大作用是重要的研究课题。P2P系统具有很好的实用性、动态性和可扩展性。本文利用P2P技术提出一种基于UDDI的分布式Web服务注册中心模型,同时利用领域本体对注册中心进行语义分组,并在该模型上实现了Web服务的查找和发布算法。     

User-preferences based service selection model in large-scale services with various QoS properties

With the rapid growth of service scale, there are many services with the same functional properties but different non-functional properties on the Internet. There have been some global optimizing service selection algorithms for service selection. However, most of those approaches cannot fully reflect users’ preferences or are not fully suitable for large-scale services selection. In this paper, an ant colony optimization (ACO) algorithm for the model of global optimizing service selection with various quality of srevice (QoS) properties is employed, and a user-preference based large-scale service selection algorithm is proposed. This algorithm aims at optimizing user-preferred QoS properties and selecting services that meet all user-defined QoS thresholds. Experiment results prove that this algorithm is very efficient in this regard.     

基于服务质量的Web服务可用性评价方法

为提高Web服务的可用性,设计一种基于可用度的Web服务可用性测试模型,提出了一种Web服务可用性的评价方法,对服务质量指标进行量化评估,为服务请求者选择最优服务提供参考依据。实验表明,该方法具有很好的灵活性和实用性。     

一种可扩展的单点登录系统

为解决传统单点登录系统的可扩展性和身份联合问题,将系统划分为不同的安全域,每个安全域具有域内的安全验证服务器,并且不同的安全域之间具有信任关系以支持身份联合.安全服务器负责域内用户的验证和授权,同时为不同域之间的用户提供身份联合.系统使用SAML断言作为安全令牌以完成验证、授权和身份联合过程.单点登录过程的设计基于web服务安全框架和多安全域,并且授权总是在服务提供者所在的域内实施,因此无论对于域内还是域外用户,系统提供了一种简单、可扩展、标准并且安全的访问web服务的方法.