一种面向QoS的Web服务动态评估模型

QoS-oriented Dynamic Evaluation Model for Web Service

为了降低Web服务评价指标数据中人为主观因素的不确定性?服务提供商服务质量(QoS)的不确定性和确保指标项权重准确性,提出一种Web服务动态评估模型,运用灰色系统理论(GST)中的灰色处理方法对人为主观评分数据进行模糊化处理.同时,Web服务的主客观因子权重分别采用层次分析法(AHP)和改进的熵值赋权法计算,将主客观的权重进行组合计算综合权重,该模型具有反馈机制,通过QoS监测中心修正服务提供商提供的QoS值,能够自适应服务的动态变化.最后,仿真实验验证了本文所提出的评估模型不仅能适应动态变化的环境,而且能够保证用户选择服务的实际质量,克服了评价中出现的个体差异、恶意评价,实验结果表明,所提出的服务评估模型与选择策略具有可行性和实用性.

In order to reduce the data evaluation of subjective factors and uncertainty in web services, the provider of web service with QoS uncertainty and ensure accuracy of the weight, a web service dynamic evaluation model was proposed. The gray processing meth- od of GSTI Grey System Theory} was used to solve user＇s subjective scoring fuzzy data. and then the subjective weight of web services were used to calculate by AHP, the objective weight of web services were calculated by an improved entropy weighting method, the model also had a feedback mechanism, the provider of web service with QoS was revised by the monitoring center of QoS. Finally, the simulation results showed that the model could not only adapt to the dynamic changes in the environment, but also to ensure the QoS of user select services, the model that endured the individual differences in the evaluation, and malicious evaluation, experimental re- suits showed that the service evaluation model and selection strategy were feasible and practical.