https://hal-univ-pau.archives-ouvertes.fr/tel-02437272 Contributor : Philippe RooseConnect in order to contact the contributor Submitted on : Monday, January 13, 2020 - 4:42:16 PM Last modification on : Tuesday, February 15, 2022 - 3:41:28 AM Long-term archiving on: : Tuesday, April 14, 2020 - 4:43:26 PM