Institution: | 1. College of Mathematics and Information Sciences, Hebei Normal University, Shijiazhuang, Hebei 050016, PR China;2. Information College, Zhejiang Ocean University, Zhoushan, Zhejiang 316000, PR China;3. Department of Basic Sciences, Shijiazhuang Institute of Railway Technology, Shijiazhuang, Hebei 050041, PR China |