School of Information Science and Engineering, Central South University, Changsha 410083, China.|School of Information Science and Engineering, Central South University, Changsha 410083, China.|Division of Biomedical Engineering, University of Saskatchewan, Saskatoon SKS7N5A9, Canada.|Department of Computer Science, Georgia State University, Atlanta, GA 30302, USA.|School of Information Science and Engineering, Central South University, Changsha 410083, China.