1. Digital Manufacturing and Design Centre, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore e-mail:
2. The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332;
3. Digital Manufacturing and Design Centre, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore e-mails: ;
4. Systems Integration Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899 e-mail: