1. Ph.D. Candidate, School of Mechanical Engineering, Tongji Univ., Shanghai, China.
2. Ph.D. Candidate, School of Mechanics and Civil Engineering, China Univ. of Mining and Technology, Xuzhou, China (corresponding author).
3. Professor, School of Mechanics and Civil Engineering, China Univ. of Mining and Technology, Xuzhou, China.
4. Professor, School of Economics and Management, Tongji Univ., Shanghai, China.