1. Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, 842 W. Taylor Street, Chicago, IL, 60607-7022
2. Gear R&D Department, Research and Development Operations, Yamaha Motor Co. Ltd., 2500 Shingai, Iwata, Shizuoka 438-8501, Japan
3. Department of Mechanical Engineering, Polytechnic University of Cartagena, Campus Universitario Muralla del Mar, C∕Doctor Fleming, s∕n, 30202 Cartagena, Spain