Affiliation: | 1. Department of Mathematics, Bohai University, Jinzhou, 121000, PR China;2. College of Science, Beijing University of Civil Engineering and Architecture, Beijing, 100044, PR China;3. College of Computer and Communication Engineering, Chinese University of Petroleum, Qingdao, Shandong 266580, PR China;4. School of Computer Science and Technology, Tianjin University, Tianjin 300072, PR China |