1. Beijing Key Laboratory on Integration and Analysis of Large-scale Stream Data, School of Information Science and Technology, North China University of Technology, Beijing, P. R. China
2. School of Management Engineering, Shandong Jianzhu University, Jinan, Shandong, P. R. China
3. Department of Computer Science and Technology, College of Information Science and Engineering, China University of Petroleum (Beijing), Beijing, P. R. China