1. College of Computer Science, Sichuan University, Chengdu, China
2. School of Computer Science and Informatics, De Montfort University, Leicester, U.K.
3. Law School, Sichuan University, Chengdu, China
4. School of Mechanical Electronic and Information Engineering, China University of Mining and Technology (Beijing), Beijing, China
5. Department of Computer and Information Sciences, Northumbria University, Newcastle upon Tyne, U.K.