[Ye, Junmin;Zhan, Zemei;Zhang, Zhenfang] Cent China Normal Univ, Dept Comp Sci, Wuhan 430079, Peoples R China.^[Zhan, Zemei] Yangtze Univ, Coll Comp Sci, Jingzhou 434023, Peoples R China.^[Ye, Junmin;Dong, Wei;Qi, Zhichang] Natl Univ Def Technol, Sch Comp, Changsha 410073, Hunan, Peoples R China.