基于概率方法的QoS感知Web服务组合  

QoS-Aware Web Service Composition Based on Probabilistic Approach

作　　者：陶春华[1] 冯志勇[1] 

机构地区：[1]天津大学计算机科学与技术学院,天津300072

出　　处：《天津大学学报》2010年第10期860-865,共6页Journal of Tianjin University(Science and Technology)

基　　金：国家高技术研究发展计划(863计划)资助项目(2007AA01Z130)

摘　　要：针对Web服务的服务质量(QoS)的随机本质,提出了一个基于概率QoS感知的Web服务组合方法,实现传统方法难以描述的QoS需求.在概率QoS模型的基础上,定义QoS目标以及组合方案与QoS目标之间的距离函数.通过将服务组合问题转化为组合优化问题,应用Rollout算法作为求解问题的计算框架,对一个具体问题设计了相应的启发函数.以跨国旅游方案提供商作为具体案例演示基于概率方法的QoS感知服务组合.该方法很好地解决了概率QoS模型难以应用到动态服务组合中的问题.理论分析和实验数据表明该方法可以很好地满足用户对于组合服务的QoS需求.The quality of service （QoS） of Web service has a nature of stochastic. A probabilistic approach for QoS- aware Web service composition was proposed to meet the QoS requirements that were difficult to process in traditional methods. The definition of QoS target, based on probabilistic QoS model, was proposed, and further defined a distance function measuring the composite service＇s QoS. The service composite problem was modeled as a combinatorial optimal problem. Rollout algorithm was employed as a framework solving the problem and a specific heuristic function was derived from experiments. A case study on an abroad travel consultation service was investigated. The problem of applying probabilistic QoS model to dynamic Web service composition was well solved. Theoretical analysis and experiment results show that QoS requirements are well satisfied via this method.

关 键 词：WEB服务组合 服务质量 概率方法 ROLLOUT算法 

分 类 号：TP301[自动化与计算机技术—计算机系统结构]