1. ENIT-LAMSIN, University of Tunis El Manar , Tunis, Tunisia.
2. ESPRIT , Ariana, Tunisia.
3. IPEST, University of Carthage , LaMarsa, Tunisia.
4. INRIA Paris Rocquencourt , Le Chesnay Cedex, France.
5. ENIT-LMHE, University of Tunis El Manar , Tunis, Tunisia.