1. School of Mechanical Engineering, Shenyang University of Technology, Shenyang 110870, China
2. Shenyang Research Institute, China Coal Technology & Engineering Group, Fushun 113122, China
3. Nippon Institute of Technology, Saitama 345-8501, Japan
4. School of Information Science and Engineering, Shenyang University of Technology, Shenyang 110870, China