| Affiliation: | (1) Present address: Centre d'Enseignement et de Recherche en Mathématique, Informatique et Calcul Scientifique (CERMICS), Ecole Nationale des Ponts et Chaussées (ENPC), La Courtine, 93167 Noisy-le-Grand Cedex, France;(2) Present address: Department of Mechanical Engineering, University of Calgary, 2500 University Drive N.W., T2N 1N4 Calgary, Alberta, Canada;(3) Present address: Instituto de Matemáticas y Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid, Spain |
