1. School of Data and Computer Science, Shandong Women’s University, Jinan 250300, China
2. Institute of Financial Engineering, Shandong University of Science and Technology, Qingdao 266590, China
3. Office of Academic Research, Shandong Women’s University, Jinan 250300, China
4. College of Computer Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China