1. Department of Information Engineering, Guangxi Transport Vocational and Technical College, Nanning, Guangxi 530028, China
2. Department of Information Technology, Guangxi Police College, Nanning, Guangxi 530028, China
3. Department of Computer Engineering, PaiChai University, 35345 Daejeon, Republic of Korea
4. Nanning Tobacco Monopoly Administration, Nanning, Guangxi 530022, China