云制造环境下基于可信评价的云服务选择

针对云制造环境下因存在大量功能相同或相似的制造云服务而导致用户很难获得合适云服务的问题，提出了一种基于可信评价的制造云服务选择方法。对问题进行了抽象，将可靠性、可用性、时效性、价格和诚信度纳入可信特征集，并考虑评价时间、评价者的诚信度对可信值的影响，采用加权平均的方法计算制造云服务的整体可信度；在此基础上，综合考虑制造云服务的功能、任务负载、当前状态和物理距离等因素，通过匹配功能、任务负载和价格，并结合可信评价值来指导云服务的选择。仿真结果表明，所提方法能够有效地识别云制造环境下的制造云服务实体，可提高交易活动的成功率，满足用户的功能需求和非功能需求。

Cloud service selection based on trust evaluation for cloud manufacturing environment

For cloud manufacturing environment, many manufacturing cloud services have the same or similar function, so it is difficult to get the most suitable cloud services. This study designed a selection method of the manufacturing cloud services based on trust evaluation. How to select cloud services was described by abstraction; the reliability, usability, timeliness, price and honesty were used as the trust characteristics together; and the evaluation time and effect of estimators' honesty on the service's credibility were also taken into account; and then the overall credibility was calculated from all above data by weighted average method. Furthermore, with all factors such as the cloud services' function, workload, current state and physical distance considered in package, the method was built to guide the cloud service selection by matching the services' function, workload and price and combining the trust evaluation. The results of simulation experiments show that the service selection method is able to recognize entities of manufacturing cloud services, and it improves the rate of the cloud service trades and meets users' functional and non-functional requests better.