1. Department of Mechanical and Industrial Engineering, University of Massachusetts Amherst, Amherst, MA 01003 e-mail:
2. National Institute of Standards and Technology, Engineering Laboratory, Gaithersburg, MA 20899 e-mail:
3. Department of Computer Science, University of Massachusetts Amherst, Amherst, MA 01003 e-mail:
4. Department of Mechanical and Aerospace Engineering, University at Buffalo—SUNY, Buffalo, NY 14150 e-mail: