1. Institute of Vibration Engineering, Northwestern Polytechnical University Xi'an, Shaanxi 710072 China
2. Department of Mechanical Engineering, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
3. School of Mechatronics Engineering, Foshan University, Foshan 528000, China
4. Centre for Efficiency and Performance Engineering, University of Huddersfield, Queensgate, HD1 3DH, UK