1. Engineering and Public Policy, Carnegie Mellon University, 5000 Forbes Avenue, 129 Baker Hall, Pittsburgh, PA 15213 e-mail:
2. Mechanical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Scaife Hall, Pittsburgh, PA 15213 e-mail:
3. Mechanical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Scaife Hall 301, Pittsburgh, PA 15213 e-mail:
4. Engineering and Public Policy, Carnegie Mellon University, 5000 Forbes Avenue, 131 Baker Hall, Pittsburgh, PA 15213 e-mail: