School of Information Science and Engineering, Central South University, Changsha, Peoples Republic of China.|School of Information Science and Engineering, Central South University, Changsha, Peoples Republic of China.|School of Computing, Clemson University, Clemson, SC, USA.|Division of Biomedical Engineering, University of Saskatchewan, Saskatchewan, Canada.|School of Information Science and Engineering, Central South University, Changsha, Peoples Republic of China.|Department of Computer Science, Georgia State University, Atlanta, GA, USA.|Department of Computer Science, Old Dominion University, Norfolk, VA, USA.|School of Information Science and Engineering, Central South University, Changsha, Peoples Republic of China.