https://hal-upec-upem.archives-ouvertes.fr/hal-00622392 Contributor : Michel CouprieConnect in order to contact the contributor Submitted on : Monday, September 12, 2011 - 2:11:44 PM Last modification on : Saturday, January 15, 2022 - 3:58:19 AM Long-term archiving on: : Tuesday, December 13, 2011 - 2:25:24 AM