基于DEC_POMDP的Web服务组合优化算法  

Web Service Composition Optimization Algorithm Based on DEC_POMDP

作　　者：赵莉[1] 李蜀瑜[1] 

机构地区：[1]陕西师范大学计算机科学学院,陕西西安710062

出　　处：《计算机技术与发展》2014年第3期74-78,共5页Computer Technology and Development

基　　金：国家自然科学基金资助项目(41271387);中央高校基本科研业务费项目(GK201002011);西安市科技局项目(SF1228-3)

摘　　要：面向服务计算(SOC)和面向服务架构(SOA)技术共同推动了Web服务及其组合技术的发展。网络环境的动态变化及其对Web服务质量(QoS)的影响,给服务成功组合带来挑战,为服务组合效果满足用户需求带来难题。为了得到经济、省时且成功率高的服务组合策略,综合考虑网络环境的动态变化、服务质量的可变性、用户需求的多样性,采用分散的部分可观测马尔可夫决策(DEC_POMDP)模型描述多个服务Agent的自组织服务组合系统,在基本Q学习算法基础上做出改进,求解模型得到组合策略。实验结果表明求解的策略较大地提高了组合服务的成本、时间消耗,且组合成功率较高。采用的DEC_POMDP模型有效地将Web服务组合动态过程描述出来,并自适应地更新了QoS值,采用Q学习算法及时使用了最新的QoS值。Service-Oriented Computing （ SOC） and Service-Oriented Architecture （ SOA） promoted Web service and its composition of technology development. Changes in the network environment and its impact on Quality of Service （ QoS） ,brought challenge to the suc-cessful combination and problems to the service composition effect to meet customer needs. In order to get economic,time-saving and high success-rate service composition strategy,considering the changes in the network environment,variability of QoS and the diversity of user needs,use DEC_POMDP model to describe the service Agent combination of self-organizing systems,making an improvement based on Q learning algorithm to solve composition of the model. Experimental results show that solving strategy largely improves the services composition cost,time-consuming and the composition success rate is higher. The DEC_POMDP model describes the dynamic process of Web service composition and adaptively updates the QoS values,the use of Q-learning algorithm makes it in a timely manner using the latest QoS values.

关 键 词：服务质量 自组织 服务组合 Q学习 

分 类 号：TP301.6[自动化与计算机技术—计算机系统结构]