1. Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, USA;
2. The Art Institute of Chicago, Chicago, Illinois 60603, USA;
3. Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA;
4. TRACES Laboratory, Université de Toulouse, CNRS UMR 5608, F-31058 Toulouse CEDEX 9, France;
5. Center for Scientific Studies in the Arts, Northwestern University, Evanston, Illinois 60208, USA;