https://hal.archives-ouvertes.fr/hal-01462818 Contributor : Pierre PetitConnect in order to contact the contributor Submitted on : Wednesday, February 15, 2017 - 2:10:58 PM Last modification on : Friday, April 16, 2021 - 1:52:03 PM Long-term archiving on: : Tuesday, May 16, 2017 - 2:55:03 PM