Charles E. Wilson is a Professor with the Department of Mechanical Engineering, New Jersey Institute of Technology. He received the B.S. and M.S. degrees in mechanical engineering from the Newark College of Engineering, the M.S. in engineering mechanics from New York University, and the Ph.D. degree in mechanical engineering from Brooklyn Polytechnic Institute. He is a licensed professional engineer, and has been awarded fellowships by the National Aeronautics and Space Administration, Department of Energy and National Science Foundation. Dr. Wilson has published papers in a number of journals and transactions. Textbooks he has authored and co-authored are widely used in the United States and Canada. English language versions are also published in Britain, Taiwan, India, and the Philippines, and translations are published in Korea and Mexico. Dr. Wilson served as a U.S. Air Force electronics and armament officer, and as an engineer and consultant for a number of companies. He is often called on to investigate functional and design problems in vehicles, machinery, and consumer products. He has investigated and given expert testimony on auto, truck, bus, and ambulance accidents, and accidents involving elevators, hydraulic presses, welds, playground equipment, garden equipment, and truck-mounted machinery. J. Peter Sadler is a Professor with the Department of Mechanical Engineering, University of Kentucky. He has previously held faculty positions at the State University of New York at Buffalo and the University of North Dakota. He received the B.S.M.E, M.S.M.E., and Ph.D. degrees from Rensselaer Polytechnic Institute. Dr. Sadler is a registered professional engineer and a member of many technical societies. He served as Editor for dynamics for the Journal of Mechanism and Machine Theory and Associate Editor of the Journal of Applied Mechanics and Robotics. Dr. Sadler holds a U.S. patent related to predicting optimum machining coditions. His industrial projects and research include kinematics and dynamics, robotics, computer aided design, engineering optimization, and "lean" manufacturing. The SI Adapters Yeo Song Huat and Chen I-Ming are Associate Professors at the School of Mechanical and Aerospace Engineering, Nanyang Technological University.