中文摘要：

在面向服务的应用中，服务集成商通过选择已有服务并对这些服务进行组合，为其消费者提供增值（value—added）服务．然而，现有的组合服务选择模型中，各可选服务被认为是相互独立的，可选服务的服务质量独立于其他服务．而在实际的面向服务应用中，可选服务的服务质量往往依赖于其他可选服务，现有组合服务选择方法无法应对这种普遍存在的场景．文中提出了一个支持服务关联关系的QoS描述模型，用于刻画可选服务的服务质量对其他可选服务的依赖关系，并给出该QoS描述的自动生成方法．在此基础上，提出了支持服务关联的组合服务选择方法，包括基于整数规划求解最优解的组合服务选择方法和基于启发求解次优解的组合服务选择方法．通过实例分析，体现了文中方法具有良好的适用性．对比实验结果表明，文中基于整数规划方法获取的组合服务QoS明显优于同类方法；并且，文中基于启发式方法能够高效地获取较优组合服务QoS．

英文摘要：

In service oriented application, value-added service is composed of some component services which are selected from the candidate services. However, in current service selection model, the QoS of a candidate service is independent from other candidate services. Therefore, current service selection approaches cantt deal with the situation in which the QoS of a candidate service has a correlation with other candidate services. This paper presents a systematic approach to construct the service-correlation aware QoS description to characterize the QoS dependence of an individual service on the other related services. Based on this model, it also proposes service correlation aware selection approaches for above situation, including integer programming based selection approach for optimal solution and heuristic based selection approach for sub-optimal solution. A case study is conducted and demonstrates the applicability of the proposed approach. Experiment results indicate that, based on the service correlation aware QoS description model, the QoS of composite service through integer programming based selection approach reach an obviously high level, and a sub-optimal QoS of composite service can be gained efficiently through the heuristic based selection approach.