[Zeng, Shan] Wuhan Polytech Univ, Coll Math & Comp Sci, Wuhan, Hubei, Peoples R China.^[Bai, Jun] Wuhan Text Univ, Coll Math & Comp Sci, Wuhan, Hubei, Peoples R China.^[Huang, Rui] Huazhong Univ Sci & Technol, Sch Automat, Wuhan, Hubei, Peoples R China.