[1] Hong Kong Baptist Univ, Dept Comp Sci, Hong Kong, Hong Kong, Peoples R China
[2] Xidian Univ, Sch Comp Sci & Technol, Xian 710071, Peoples R China
[3] Guangdong Univ Technol, Sch Appl Math, Guangzhou 510520, Guangdong, Peoples R China
[4] RMIT Univ, Sch Comp Sci & Informat Technol, Melbourne, Vic, Australia