https://hal-mines-paristech.archives-ouvertes.fr/hal-00647370 Contributor : Médard ThiryConnect in order to contact the contributor Submitted on : Thursday, December 1, 2011 - 9:39:34 PM Last modification on : Thursday, November 18, 2021 - 3:46:47 AM Long-term archiving on: : Friday, March 2, 2012 - 2:55:59 AM