1. Carnegie Mellon University, Pittsburgh, PA 15213; Manufacturing Systems Integration Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-8263
2. LE2i Laboratory, University of Burgundy, B.P. 47870, 21078 Dijon, France; Manufacturing Systems Integration Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-8263
3. Manufacturing Systems Integration Division, National Institute of Standards and Technology, Gaithersburg, MD 20899-8263