1 University of California at Berkely, Electrical Engineering and Computer Sciences, Berkeley CA 94720-170
2 CNRS and Institut de Mathématiques de Jussieu, 4 place Jussieu, Université Pierre et Marie Curie, case 247, 75252 Paris,
3 Ifsttar, COSYS-GRETTIA, 14-20 boulevard Newton, Cité Descartes Champs sur Marne, 77447 Marne la Vallée Cedex 2
4 Joseph and Loretta Lopez Chair Professor of Mathematics, Department of Mathematical Sciences and Program Director, Center for Computational and Integrative Biology, Rutgers University - Camden, 311 N 5th Street, Camden, NJ 08102
5 Civil and Environmental Engineering, University of California, 1 Shields Avenue, 2001 Engineering III, Davis California 95616