复合Web服务匹配方法的研究

发布时间：2018-09-05 08:45

【摘要】：随着Web服务应用的深入，网络Web服务数量的日益增多，提供相同或相似功能的服务也越来越多，如何准确高效地从数量庞大的Web服务群中发现并定位服务请求者最需要的服务成为制约Web服务应用发展的关键问题。现有的Web服务发现方法主要是基于语法级和语义级的。语法级的匹配方法存在结构异构和语义异构，对客户所感兴趣的服务不能准确描述，不支持细化、泛化、平级扩展等语义查询，导致查全率和查准率不高。语义级的匹配方法描述的是静态的Web服务，不包含任何有关服务执行过程的信息，缺乏考虑Web服务的非功能属性，导致查准率较低且所发现的服务不能较好地满足用户需求。由于上述两种方法没有考虑复合Web服务子服务的执行过程信息和QoS需求信息，导致不能准确的判断复合Web服务间的相似程度，降低了服务的查准率，且没有为复合Web服务的匹配提供一种有效的手段。因此，本文复合Web服务匹配方法的研究具有重要的学术意义和实用价值。针对上述问题，本文在扩展OWL-S的基础上，采用循环递进、逐步求精的本体建模方法建立过程本体并给出其形式化定义，增强了对QoS的语义描述能力。基于上述过程本体，，抽象出具有动态交互和过程控制功能的过程模型，最终提出一种复合Web服务匹配方法。该方法的基本思路是：首先利用UML模型对复合Web服务进行过程建模，一方面描述集成服务，另一方面从描述中构造相关复合Web服务的正确的执行模型，即平台无关模型；紧接着按照UML活动图到过程模型的映射关系，设计转换算法，将UML模型转换成基于本文建立的过程本体的过程模型；然后给出过程模型到过程图的转换规则，设计了转换算法，实现过程模型到过程图的转换；最后通过定义过程图间的相似度，设计一种高效的过程图的匹配算法来实现过程图相似度匹配，求出过程图的相似度值，通过这个值的大小来判断其对应的复合Web服务的匹配程度。根据上述理论基础，本文设计了一个复合Web服务匹配框架，该框架主要包括模型转换器、过程图转换器和过程图匹配器三个模块，在Eclipse开发环境下，采用Java编程语言，对它们进行编码实现。最后，通过实验对比及分析，验证了本文方法是可行的和有效的。
[Abstract]:With the deepening of the application of Web services, the number of network Web services is increasing, and the number of services providing the same or similar functions is also increasing. How to accurately and efficiently find and locate the services most needed by service requesters from a large number of Web services groups has become a key problem that restricts the development of Web services applications. The existing Web service discovery methods are mainly based on syntax and semantic level. Syntactic level matching methods have heterogeneous structure and semantic heterogeneity, which can not accurately describe the services of interest to customers, and do not support semantic queries such as refinement, generalization and level-level extension, which lead to low recall and precision. The semantic level matching method describes the static Web service, which does not contain any information about the service execution process, and lacks the non-functional attributes of the Web service, which leads to low precision and the discovery of the service can not meet the needs of the user. Because the above two methods do not consider the execution process information and the QoS requirement information of the composite Web service sub-service, the similarity degree between the composite Web services can not be judged accurately, and the precision rate of the service is reduced. Moreover, it does not provide an effective method for the matching of composite Web services. Therefore, the research of composite Web service matching method in this paper has important academic significance and practical value. In order to solve the above problems, based on the extension of OWL-S, this paper establishes the process ontology and gives its formal definition by using the ontology modeling method of loop progression and gradual refinement, which enhances the semantic description ability of QoS. Based on the above process ontology, a process model with dynamic interaction and process control is abstracted, and a composite Web service matching method is proposed. The basic ideas of this method are as follows: firstly, the process modeling of composite Web services is carried out by using UML model. On the one hand, the integrated services are described; on the other hand, the correct execution model of related composite Web services, i.e. platform-independent model, is constructed from the description. Then according to the mapping relationship between UML activity diagram and process model, the transformation algorithm is designed to transform the UML model into a process model based on the process ontology established in this paper. Then, the transformation rules from process model to process diagram are given, and the transformation algorithm is designed. Finally, by defining the similarity between the process diagrams, an efficient matching algorithm is designed to achieve the process diagram similarity matching, and the similarity value of the process diagram is obtained. The size of this value is used to determine the matching degree of the corresponding composite Web services. Based on the above theory, a composite Web service matching framework is designed in this paper. The framework consists of three modules: model converter, process diagram converter and process diagram matcher. In the Eclipse development environment, Java programming language is used. They are coded and implemented. Finally, the experimental results show that the method is feasible and effective.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP393.09

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