1. Key Lab of Intelligent Computing and Signal Processing of Ministry of Education, Anhui University, Hefei, Anhui, P.R. China
2. School of Computer Science and Technology, Anhui University, Hefei, Anhui, P.R. China
3. School of Management, Hefei University of Technology, Hefei, Anhui, P.R. China
4. Department of Computer Science, New Jersey Institute of Technology, Newark, NJ, USA