1. State Key Laboratory of Mechanical Transmissions, Chongqing University, Chongqing 400044, China e-mail:
2. Office of The Provost, University of Texas Arlington, Box 19118, 701 South Nedderman Drive Davis Hall, Suite 321, Arlington, TX 76019 e-mail:
3. Sino-European Institute of Aviation Engineering, Civil Aviation University of China, Tianjin 300300, China e-mail: