1. College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao 266590, China
2. College of Information Science and Engineering, Shandong Normal University, Jinan 250358, China
3. State Key Laboratory of Mining Disaster Prevention and Control Cofounded By Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, 266590 Qingdao, China