1. State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, P. R. China
2. Department of Mechanical Engineering, Iowa State University, 271 ASC II, 1915 Scholl Road, Ames, IA 50011, USA
3. School of Mechanical and Automotive Engineering, Shanghai University of Engineering Science, Shanghai 201620, P. R. China