[Hu Wenbin;Liu Ya;Su Wen;Ding Mao;Pan Ziyao] Wuhan Univ, Comp Sch, Wuhan 430079, Peoples R China.^[Hu Wenbin] Nanjing Univ, State Key Lab Novel Software Technol, Nanjing, Peoples R China.^[Hu Zhengbing] Huanzhong Normal Univ, Dept Informat Technol, Huazhong, Peoples R China.