1. Applied Physics Laboratory, Air and Missile Defense Department, The Johns Hopkins University, Laurel, MD 20723-6099 e-mail:
2. University Distinguished Professor Department of Mechanical Engineering, Michigan State University, East Lansing, MI 48824-1226 e-mail:
3. Department of Mechanical Engineering, University of California, Berkeley, Berkeley, CA 94720 e-mail:
4. Professor and Vice President for Academic Affairs Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 e-mail:
5. L.S. Randolph Professor and Department Head Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 e-mail: