【摘要】 Web服务描述语言是基于模式优先(schema-first)的,Web服务发现方法需要花费较高的前期构建成本,目前的研究没有涉及如何在pay-as-you-go模式下发现Web服务这一问题.提出了一个基于数据空间技术的服务发现框架,支持pay-as-you-go模式下基于关键词匹配和基于相似度的Web服务发现.首先给出一个schema-later数据模型用于描述Web服务及其关系,并讨论了该模型的延迟计算和查询方法,该方法不必事先物化模型就可以提供查询服务;然后给出一个基于相似度的Web服务发现算法及其正确性证明,该算法将相似度看作是极松散结构模型的虚拟边(关系),在计算相似度之前,通过延迟计算得到需要进行比较的服务节点集及其信息,以便在pay-as-you-go模式下计算相似度;最后通过实验表明该方法是可行和有效的.更多还原

【Abstract】 With the increasing growth in popularity of Web services, extensive efforts have been brought forth to assist in Web service discovery. Web services are usually described by WSDL and advertised in UDDI registries. UDDI provides limited keyword-based search which is not powerful enough. To address this problem, information retrieval techniques are exploited to assess the similarity between two services descriptions. However, Web services description languages are schema-first, and the systems require hard up-front investment before offering powerful functionalities for Web service discovery, that is, the current research does not study how to discover Web services in a pay-as-you-go fashion. In this paper, a framework based on dataspace techniques is proposed to discover Web services in a pay-as-you-go fashion. A loosely structured data model is presented to describe Web services and the relationships among them, and then the ways to lazily compute and query this model are discussed. Furthermore, similarity is defined as intensional edges in the data model, the service information used to measure the degree of similarity can be obtained lazily, and thus the similarity can be computed in a pay-as-you-go fashion. An algorithm to support similarity-based service discovery is also presented along with a proof of its correctness. Finally, the validity of the framework is proved by the experiment.更多还原