论文标题
离群值 - 有弹性的Web服务QoS预测
Outlier-Resilient Web Service QoS Prediction
论文作者
论文摘要
Web服务的扩散使用户很难在众多功能相同或相似的服务候选者中选择最合适的服务。服务质量(QOS)描述了Web服务的非功能特征,它已成为服务选择的关键区别。但是,用户无法调用所有Web服务,以获取由于较高的时间成本和巨大的资源开销,因此获得了相应的QoS值。因此,必须预测未知的QoS值。尽管已经提出了各种QoS预测方法,但其中很少有人考虑到异常值,这可能会极大地降低预测性能。为了克服这一限制,我们在本文中提出了一种异常弹性的QoS预测方法。我们的方法利用凯奇损失来衡量观察到的QoS值与预测值之间的差异。由于库奇损失的稳健性,我们的方法对异常值具有弹性。我们进一步扩展了我们通过考虑时间信息来提供时间感知QoS预测结果的方法。最后,我们对静态和动态数据集进行了广泛的实验。结果表明,我们的方法能够比最新的基线方法获得更好的性能。
The proliferation of Web services makes it difficult for users to select the most appropriate one among numerous functionally identical or similar service candidates. Quality-of-Service (QoS) describes the non-functional characteristics of Web services, and it has become the key differentiator for service selection. However, users cannot invoke all Web services to obtain the corresponding QoS values due to high time cost and huge resource overhead. Thus, it is essential to predict unknown QoS values. Although various QoS prediction methods have been proposed, few of them have taken outliers into consideration, which may dramatically degrade the prediction performance. To overcome this limitation, we propose an outlier-resilient QoS prediction method in this paper. Our method utilizes Cauchy loss to measure the discrepancy between the observed QoS values and the predicted ones. Owing to the robustness of Cauchy loss, our method is resilient to outliers. We further extend our method to provide time-aware QoS prediction results by taking the temporal information into consideration. Finally, we conduct extensive experiments on both static and dynamic datasets. The results demonstrate that our method is able to achieve better performance than state-of-the-art baseline methods.