Web Services Evaluation Model Based on Variant Time Utility

To solve the problems of the KNN (k-nearest neighbor) method in the quantification of time utility, the width of evaluation windows and the control of feedback, a web services evaluation model with variant time utility (WSEM-VTU) was proposed. In WSEM-VTU, the system dynamics is used to investigate the complex quantification method of the time utility to achieve the variant time utility. From the results of the quantification method, the width of the evaluation windows is adaptively calculated. In terms of the statistics of feedbacks, a feedback control strategy is involved. By means of experiments, WSEM-VTU was compared with the current evaluation models, WSEM-E and WSEM-KNN. The experimental results show that the average error of WSEM-VTU is 0.877, being lower 1.020 and 0.135 than the errors of WSEM-E and WSEM-KNN respectively. With the feedback control strategy, malicious ratings are reduced by an average of 67%.