[1] China Southern Power Grid, Informat Dept, Guangzhou, Peoples R China
[2] Shanghai Jiao Tong Univ, Dept Comp Sci & Engn, Shanghai, Peoples R China
[3] Chinese Acad Sci, State Key Lab Comp Sci, Inst Software, Beijing, Peoples R China
[4] Educ Univ Hong Kong, Dept Math & Informat Technol, Hong Kong, Peoples R China
[5] COMSATS Inst Informat Technol, Dept Comp Sci, Wah Cantt, Pakistan
[6] Shanghai Jiao Tong Univ, Dept Elect Engn & Automat, Shanghai, Peoples R China