【摘要】 由于Internet环境的开放性和动态性,导致Web服务质量稳定性较差,进而严重影响服务组合的准确度.为此,提出一种基于QoS随机性和信任评价的全局动态服务组合方法.首先,剔除导致客观QoS不稳定的异常值,并估计其真实值;然后,分析服务提供商和用户的信任度,聚合计算主观QoS评价值;最后,结合主、客观QoS约束条件,构建全局动态服务组合优化模型,求解最优组合服务.基于真实和仿真数据的实验结果表明,所提出的方法能够显著提高服务组合的稳定性和准确度.更多还原

【Abstract】 In an open and dynamic Internet environment, the randomness of Web services with unreliable quality leads to low accuracy of optimization in service composition. Therefore, a global dynamic service composition approach is proposed based on randomness of QoS data and trust evaluation. Firstly, the uncertain outliers which lead to unstable objective QoS are removed, and the true values of objective QoS are estimated. Then, the credibility of the evaluation data from the providers and customers are analyzed to obtain the subjective QoS evaluation of current service. Finally, with the objective and subjective QoS data, the global dynamic service composition model is constructed and the optimal result is calculated.Experiment results with real and simulated data show that the proposed approach significantly improves the stability and accuracy of service composition.更多还原