【作者】 杨文军；

【导师】 王克宏； 李涓子；

【作者基本信息】 清华大学 ， 计算机科学与技术， 2005， 博士

【摘要】 随着IT和Web应用的快速发展,Web服务组装技术逐渐成为企业信息集成的主流技术。但是目前Web服务组装技术仍然存在以下问题:如何控制业务流程中业务操作的粒度,使每个业务操作都能绑定在Web服务实例上;如何利用Web服务通用属性以及与应用领域相关的属性综合评价Web服务质量;如何处理在消息匹配时前一个服务的输出与后一个服务的输入存在消息异构的情况等等。本文针对上述问题展开研究。为解决现有业务流程模型缺乏组装粒度控制的问题,本文提出了基于层次化分析方法的业务流程层次化模型,自上而下分解业务需求,生成不同功能粒度的业务活动。业务活动包括业务需求描述和业务执行描述,同时还包含动态刻画业务逻辑的子流程。服务组装人员可以选择不同功能粒度的业务活动组成业务流程。层次化模型可以有效控制服务组装的粒度,并且可以通过检索业务活动实现子流程级别的复用。为充分衡量Web服务质量,本文提出了领域自适应的Web服务选取方法,采用本体语言来描述服务选取中的概念及其关系,通过领域专家定制不同应用领域的服务评价因子,并利用机器学习方法从历史数据自动学习评价因子的权重分布,结合领域专家给出的先验知识,提出交互的权重优化算法。与相关研究相比,该方法能够模拟用户选取Web服务的标准,提高Web服务选取准确率。本文提出并分析了在服务组装的消息匹配操作中可能出现的消息异构问题,把这个问题转化为异构消息的转换问题,采用元数据自动映射方法实现消息转换,并把消息转换操作包装为Web服务,无缝集成到现有Web服务组装系统中。异构消息匹配问题的提出与解决,扩大了Web服务选取范围,提高了Web服务组装的成功率。上述方法和算法在原型系统WSCS中得到了验证。更多还原

【Abstract】 With the rapid development of IT technology and Web application, web service composition is becoming the main technology for enterprise information integration. However, there still exist several problems which hobble web service composition. Some of them are how to design the activities in the business process with the exact granularity so that they can be bound to concrete web service, how to comprehensively evaluate web service quality by using not only the general attributes but also domain specific attributes so as to select the most available web services, and how to deal with the problem that the type of the output messages of the preceding service is subtly heterogeneous with the type of the input messages of the subsequent service. This dissertation analyzes and studies these problems in web service composition. The main contributions of this dissertation are as follows.In order to control service granularity in the composition, a new business process model called Hierarchical Web Service Composition Model is proposed based on hierarchical analyzing method. This model provides the mechanism to decompose business requirements in top-down mode to generate hierarchical business activities with different functional clarities. Business activity contains both business requirement description and business execution description, also contains sub-process for dynamically describing the business logic. Business process can be generated by selecting business activities in different level. In this way, hierarchical Web Service Composition Model provides the ability to control the composition granularity effectively and reuses sub-process with business activity as a unit.In order to select web service with high quality, a domain-adaptive web service selection method is presented. This method uses ontologies to describe更多还原