1. State Key Laboratory of Mechanical System and Vibration, Department of Industrial Engineering and Management, School of Mechanical Engineering, Shanghai Jiao Tong University, No. 800 Dongchuan Road, Shanghai 200240, China e-mail:
2. State Key Laboratory of Mechanical System and Vibration, Department of Industrial Engineering and Management, School of Mechanical Engineering, Shanghai Jiao Tong University, No. 800 Dongchuan Road, Shanghai 200240, China;
3. Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109-2136 e-mail: