| 摘要: |
| 为了解决动态服务组合过程中功能执行时序与工作流的关系问题，提出了一种基于时变Petri网技术的Web服务组合模型.引入Petri网有向网结构来描述组合过程中输入/输出功能及时间因素影响，以Petri网的有向弧结构表示服务组合过程中服务功能时间参数输入/输出表达式，利用时变函数表示服务的时间消耗，进而将服务组合转化为时变Petri网的流程正确性检验和时间开销优化问题，使建立的服务组合模型在组合成功率和用户满意度间达到良好的动态平衡.提出了一种基于回溯方法的服务组合流程检验和QoS计算方法，用于时变Petri网系统下服务组合策略的构建和验证.为了说明该方法的有效性，以一个实际电厂信息调度平台系统提供的Web服务为研究对象，通过两组仿真实验，分别说明该方法具有良好的组合成功率及使用相同候选服务集构建组合策略的有效性.实验数据和结果分析表明，该建模方法能够达到特定用户对服务功能的使用需求. |
| 关键词: Web服务 时变Petri网 QoS量化 回溯网络节点 服务组合 |
| DOI：10.13328/j.cnki.jos.005514 |
| 分类号:TP311 |
| 基金项目:国家重点基础研究发展计划（973）（2013CB430403）；国家自然科学基金（61374154，61272375） |
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| Test Method to Quality of Service Composition Based on Time-varying Petri Net |
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HAN Min, SUN Guo-Qing, ZHENG Dan-Chen, ZHOU Hui-Wei
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Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian 116023, China
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| Abstract: |
| In order to solve the problems of system interface and optimal service matching, this study puts forward a kind of Web service composition system which is based on the time-varying Petri net. It brings in the probability of service call to change the invalid trouble in distributed network. It uses the structure of Petri net to achieve sound dynamic balance in the composition success rate and user satisfaction. For demonstrating the correctness and validity of the system, this paper presents a kind of global fish algorithm based on backward theory to get the optimal combination of QoS. And it defines the evaluation index of system performance. By comparing different efficiency of combinations, it proves the feasibility of the composite method and can meet the needs of specific users of the service function. |
| Key words: Web service time-varying Petri net QoS quantization backtracking net node services composition |
