1. College of Electronic and Information Engineering, Shandong University of Science and Technology, Qingdao 266590, China
2. School of Computer Engineering, Weifang University, Weifang 261061, China
3. Qingdao Intelligence Ocean Technology Co., Ltd., Qingdao 266590, China
4. Shandong Branch of China Mobile Communication Group Co., Ltd., Binzhou 256600, China
5. College of Transportation, Shandong University of Science and Technology, Qingdao 266590, China