Besides my supervisors, I would like to express my gratitude to Prof.~Dr.~Ye-Qiong~Song and Assoc~Prof.~Dr.~Hamida~Seba (HDR) for accepting to review my dissertation and for their insightful and appreciated comments. I would like to thank also Prof.~Dr.~Sylvain~Contassot-Vivier for accepting to participate in my dissertation committee.
-I would like to gratefully acknowledge the University of Babylon, Iraq for financial support; Campus France and University of Franche-Comté for the received support.
+I would like to gratefully acknowledge the University of Babylon, Iraq for financial support as well as I would also like to express my thanks to Campus France and University of Franche-Comté for the received support.
My appreciation and thanks go to the members of the team AND ({\it Algorithmique Numérique Distribuée}) for the warm and friendly atmosphere in which they allowed me to work. So thank you to Jacques Bahi, Pierre-Cyrille Héam, Huu Quan Do, Bassam Alkindy, Abdallah Makhoul, Huda Al-Nayyef, Jean-Claude Charr, Jean-François Couchot, Ahmed Mostefaoui, Ahmed Fanfakh, Yousra Ahmed Fadil, Stéphane Domas, Pierre Saenger, Zeinab Fawaz, Arnaud Giersch, Christophe Guyeux, Mourad Hakem, David Laiymani, Gilles Perrot, Christian Salim, Bashar Al-Nuaimi, Santiago Costarelli, Carol Habib, Hassan Moustafa Harb, and Ke Du. I would like to express my thanks and my best wishes to Ingrid Couturier for all the received assistance during my study. I would also like to express my thanks to Dr.~Lilia~Ziane Khodja, PostDoc at $LTAS-A\&M$, Liege, Belgium. I would like to thank Béatrice Domenge and Maxim Moureaux from the {\it Reprographie service} for all received assistance during my study. I would also like to thank Patricia Py, Computer Science Department secretary. I dare not risk missing to mention anyone’s name, so I will simply say 'thank you ALL for being there for me'.
