[Chung, Tong Lee;Xu, Bin] Tsinghua Univ, Dept Comp Sci & Technol, Beijing, Peoples R China.^[Chung, Tong Lee;Xu, Bin] Beijing Natl Res Ctr Informat Sci & Technol BNRis, Beijing, Peoples R China.^[Liu, Yongbin;Ouyang, Chunping] Univ South China, Coll Comp, Hengyang, Peoples R China.