https://hal-univ-poitiers.archives-ouvertes.fr/cel-02053923 Contributor : Abderrazak HALLOUMIConnect in order to contact the contributor Submitted on : Friday, March 1, 2019 - 3:52:53 PM Last modification on : Wednesday, October 20, 2021 - 3:22:18 AM Long-term archiving on: : Thursday, May 30, 2019 - 4:02:17 PM