[Dai, Yinglong] Cent S Univ, Sch Informat Sci & Engn, Changsha 410083, Hunan, Peoples R China.^[Wang, Guojun;Xie, Dongqing;Chen, Shuhong] Guangzhou Univ, Sch Comp Sci & Educ Software, Guangzhou 510006, Guangdong, Peoples R China.^[Chen, Sihong] Hunan Univ Chinese Med, Hosp 1, Prevent Treatment Ctr, Changsha 410007, Hunan, Peoples R China.