https://cel.archives-ouvertes.fr/cel-00675138 Contributor : Rémi FlamaryConnect in order to contact the contributor Submitted on : Wednesday, February 29, 2012 - 10:43:32 AM Last modification on : Wednesday, March 2, 2022 - 10:10:08 AM Long-term archiving on: : Friday, November 23, 2012 - 3:15:58 PM