【作者】 周中成；

【导师】 须文波；

【作者基本信息】 江南大学 ， 计算机应用技术， 2005， 硕士

【摘要】 随着Web服务技术的不断普及,用户在将来很可能会面对大量的同类型Web服务可供选择,这些同类型Web服务的功能是相同的,但其性能参数如服务响应时间、服务费用、服务地域范围有可能不同,在这种情形下,要求用户手工寻找、选择Web服务不是不现实的就是效率低下的,比较好的解决方案是由程序根据用户自己的状态、要求及Web服务的参数实现自动寻找、选择Web服务并自动执行优选出来的Web服务。目前尚没有研究人员明确提出这个问题并给出相应的完整解决方案。本文给出了一个上述问题的基于OWL-S本体语言的实现方案,构建了在特定领域上的同类Web服务自动发现、选择及执行平台。在服务发现过程中,本平台没有采用常见的UDDI机制,而是采用了JADE的DF机制,大大减低了服务响应延迟,提高了系统效率。当然代价是平台不能太庞大,一般只在某个特定领域上予以实现。在服务选择过程中实现了基于地域本体的地域匹配功能,并为服务请求代理提供了一个初步的用户行为记忆功能。OWL-S所提供的语义支持,使本系统在自动选择、匹配过程中具备了初步的智能性,能够初步体现不同用户的差异化需求,达到了针对任何客户提供具有效率保障的最优服务的目标。而为使上述平台中的服务提供者能够在任何时间都能提供最优服务(这是通过动态组合Web服务来实现的),同时将动态组合Web服务的响应延迟限定在用户可接受的范围之内,本文提出了一个Web服务的高效动态组合实现方案。目前已经实现的Web服务动态组合平台一般都有执行效率比较低的问题,用户很可能无法忍受过于漫长的系统等待时间。因而,低下的系统执行效率很可能成为动态Web服务组合获得有效应用的重大障碍。通过组合Web服务替换过程的独立化、异步化、并行化,本文提出了一种可以有效提高动态组合Web服务的执行效率的实现方案,并给出了系统的实现平台原型。另外,为提高服务匹配的成功率,本文还提出了基于OWL共享本体的Web服务自动功能匹配。本文给出的两个平台联合起来可以在一定程度上实现在任何时间针对任何客户都提供高效的最优Web服务的目标。更多还原

【Abstract】 With rapid development and proliferation of Web services, users will often be faced with a lot of same type of Web services. These same types of Web services provide same function, but their other parameters (ie. service response time, service cost, and service area, etc) can be different. It’s unrealistic and ineffective to manually select and execute Web services. A good way to solve the problem is to automate the selection and execution of same type of Web services according to users’status (requirements) and parameters of Web services. Up to time, there are no researchers who bring up this problem and give a good solution. This paper gives a solution of this problem based on Web services ontology language—OWL-S, constructing a platform of automatic discovery, selection, and execution of Web services in a specific domain. In Web services discovery, this platform adopts DF mechanism of JADE rather than UDDI mechanism, which reduces the response time of services and lifts up the effiency of the system. But the platform can’t be too big; it’s usually realized on a specific domain. Area match function based on area ontology is realized in Web services selection. Service request agent gives a remembrance function of user bahavoiors. Through semantic support provided by OWL-S, the platform shows basic inteliggence in selection and matching of Web services. It also can adapt to user’s different need, and fulfill the requirement of providing best services to any customers with high efficiency.In order to provide best services any time (through dynamic composition of Web services), and the response time not exceeding the range that users can suffer. This paper gives a highly efficient dynamic composition of Web services. The platforms realized before usually have the shortcoming of low effiency. And users can’t suffer too long response period; the bad execution inefficiency can be a big obstacle of proliferation of dynamic composite Web services. Through distributed, independent, pallell replacement process of Web services composition, this paper gives an available methode to promote the effiency of dynamic Web services composition, and a prototype platform is presented. In order to promote the efficiency of services matching, an automic functional matching of Web services based on OWL shared ontology is alse presented.The combination of two platforms mentioned above can provide best services in specific domain any time for any costomers with high efficiency.更多还原