This thesis owes its existence to Patrick Bonnel. From the first day when I had expressed my will to undergo a PhD thesis, Patrick has always been of great support and help to me and to this work. His invaluable scientific supervision, commitment, and kindness have made of this 40-month PhD a valuable experience, rich of scientific learning and discoveries. I am also grateful to Louafi Bouzouina for being of advice to me. In his company, I have learnt a great deal on the academic macrocosm. This PhD would not have seen the day without the goodwill and the support of ForCity. A special thanks to Frédéric Derkx, Hakim Ouaras, and François Pacull for their engagement with this thesis. Without the backing and the arrangements made by Frédéric, this PhD would not be as it is today. The help of François Pacull and the supervision of Hakim Ouaras have been gratefully appreciated.