1. Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System, Institute of Design Science and Basic Components. School of Mechanical Engineering, Xi’an Jiaotong University, Xi'an 710049, P.R.China
2. School of Marine Science and Technology, Northwestern Polytechnical University, Xi’an, Shaanxi 710072, P.R.China
3. Key Laboratory of Biomedical Information of Ministry of Education, School of Life Science and Technology, Xi’an Jiaotong University, Xi'an 710049, P.R.China