需求驱动的自适应Web服务组合研究

发布时间：2018-11-08 15:03

【摘要】：功能单一、结构简单的Web服务无法满足日渐复杂的业务需求,因此对Web服务组合研究的必要性日渐凸显。然而在服务组合的过程中,又面临着运行时环境的变化以及用户需求信息的变化而引发的诸多问题。为了使Web服务组合能够适应外部环境及用户需求的动态变化,自适应机制被引入到Web服务组合中。根据制定的自适应策略,通过感知外部环境及用户需求的变化,自适应的服务组合系统能够自主地调整自身行为以应对感知到的外部环境及用户需求的变化。同时,随着服务组合规模的扩大以及系统需求的日益复杂和不断增长,系统开发迎来了新的挑战,因此,需求工程概念也被引入到服务组合研究领域。将需求建模技术与自适应Web服务组合技术相结合,研究需求驱动的自适应Web服务组合具有重要的现实意义。针对当前Web服务组合的研究现状,在研究学习相关理论知识的基础上,结合需求建模技术,给出了一个需求驱动的自适应Web服务组合框架,并对其执行原理和流程进行了相应介绍。首先构建用户的需求模型,采用I*框架及其扩充语义相结合的方式对用户的功能需求和非功能需求进行建模；然后将建立的需求模型转换为抽象Web服务组合模型,并将抽象Web服务组合模型映射为用CCML语言描述的具体Web服务组合模型。设计并实现了框架的主要功能模块,主要包括执行引擎、发现引擎、监控器和规划器等,并对框架中的自适应机制进行了详细描述。最后给出了一个外出旅游的Web服务组合实例,通过模拟该实例的执行过程验证了本文给出的需求驱动的自适应Web服务组合框架的可行性和有效性。
[Abstract]:The single function and simple structure of Web services can not meet the increasingly complex business requirements, so the necessity of research on Web services composition becomes more and more important. However, in the process of service composition, there are many problems caused by the change of runtime environment and the change of user demand information. In order to adapt Web service composition to the dynamic changes of external environment and user needs, adaptive mechanism is introduced into Web service composition. According to the developed adaptive strategy, the adaptive service composition system can adjust its own behavior to cope with the change of perceived external environment and user needs by sensing the changes of external environment and user needs. At the same time, with the expansion of service composition scale and the increasing complexity and growth of system requirements, system development is facing new challenges. Therefore, the concept of requirement engineering has been introduced into the field of service composition research. It is of great practical significance to combine the requirement modeling technology with the adaptive Web service composition technology to study the requirement driven adaptive Web service composition. According to the current research situation of Web services composition, based on the study of relevant theoretical knowledge and requirements modeling technology, this paper presents a demand-driven adaptive Web service composition framework. The principle and flow of its execution are also introduced. Firstly, the user's requirement model is constructed, and the functional and non-functional requirements of the user are modeled by the combination of the I * framework and the extended semantics. Then the requirements model is transformed into an abstract Web service composition model, and the abstract Web service composition model is mapped to a concrete Web service composition model described in CCML language. The main function modules of the framework are designed and implemented, including execution engine, discovery engine, monitor and planner, etc. The adaptive mechanism in the framework is described in detail. Finally, an example of traveling Web service composition is given, and the feasibility and effectiveness of the proposed framework are verified by simulating the execution process of the example.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP393.09

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