[Zhao, Hui-huang] Hengyang Normal Univ, Coll Comp Sci & Technol, Hengyang, Peoples R China.^[Zhao, Hui-huang;Zheng, Jin-Hua] Hunan Prov Key Lab Intelligent Informat Proc & Ap, Hengyang, Hunan, Peoples R China.^[Liu, Han] Cardiff Univ, Sch Comp Sci & Informat, Cardiff, S Glam, Wales.^[Fu, Bin] Univ Texas Rio Grande Valley, Dept Comp Sci, Edinburg, TX USA.