\chapter*{Acknowledgment}

Firstly, I would like to express my sincere gratitude to my advisor Prof. Pierre Boulet for all kind of supports during my PhD.
I never forget his supports specially during the last step of my PhD that I was very busy due to teaching duties.
Pierre was really punctual and during three years of different meetings and discussions, 
he was always available on time and as a record he never canceled any meeting. 
I learned a lot form you Pierre, specially the way of writing, communicating and presenting. 
you were an ideal supervisor for me.

Secondly, I am grateful of my co-supervisor Dr Philippe Devienne. 
As I did not knew any French at the beginning of my study, it was not that easy  
to settle down and with Philippe supports the life was more comfortable and enjoyable for
me and my family here in Lille. I have never forgotten our joyful time in concert and playing violin with
ELV music group, your delicious foods and cakes, visiting London, Vienna, Kermanshah and Tehran all nice moments we spended with Philippe.
With Philippe support we started a scientific collaboration with Razy University at my hometown city Kermanshah.
We got the Gundishapour grants for two years collaboration between Lille 1 and Razy Universities 
In addition to signing a MoU for long term collaboration between two universities all thanks to Philippe efforts.

I would like to acknowledge and thanks to my thesis committee: Prof. Hélène Paugam-Moisy, Prof. Michel Paindavoine, Prof. Said Hamdioui 
and the president of the jury, Prof. Virginie Hoel for their insightful comments and encouragement, and reviewing my thesis.

My sincere thanks also goes to CRIStAL lab and Émeraude team colleagues, prof. Giuseppe Lipari, Dr Richard Olejnik,
Dr Clément Ballabriga and specially to Dr Julien Forget.
I will never forget Forget supports specially for the first time teaching at Polytech Lille. 
I appreciate my Émeraude team friends Antoine Bertout, Khalil Ibrahim Hamzaoui, Houssam Zahaf, Pierre Falez and Yassine sidlakhdar
for nice discussions, coffee drinking and playing football together. I would like to thanks to our colleague Dr Fabien Alibart in IEMN lab for his technical consultancy
during my research particularly during developing new synapse. I gratefully acknowledge my previous friends and colleagues in 
TUDelft in The Neterlands, my lovely and kind friends Faisal Nadeem, Arash Ostadzadeh, Mahmood Ahmadi that shared with me valuable knowledge and information.
Thanks again to Prof. Said Hamdioui that we started working on memristor together in CE group at TUDelft.

Special thanks go to my Iranian friends in Lille Farzan, Hamid, Hamidreza, Ehsan, Babak, and Sina thanks for bing there for me.
Eric and Leopoled, my lovely officemates and friends, I never forget your kindnesses in our calm office in M3 building. 
I am grateful of my Iranian friends and colleagues at Razi University, Prof. Mohsen Hayati Dr Mahmood Ahmadi, Dr Arash Ahmadi and one of my best friend
Mazdak Fatahi
that we started working on neural network research for his Master thesis. We have done many skype meetings that both of us
learned a lot during those scientific discussions. Actually the last chapter of my thesis is related to his master thesis topic.
I appreciate my father in law Prof. Mohammad Mehdi Khodaei
for his guidance during my research as well as supporting us for starting collaboration between Razi and Lille 1 universities.
I really  Dr Mahmood Ahmadi,
and Mazdak Fatahi for their supports and being kindly present specially during the time our French professors and colleagues visited 
Kermanshah and Razi university. Without Mahmood helps and supports this collaboration was not feasible.

I am very grateful of my close family in Iran, my kind father, my lovely mother and two supportive brothers Mehdi and Mahziar
and my little nephews Abolfazl and Ali who always prayed for me and encouraged me 
continuously not only during my PhD but also in whole my life.  

Last, but not the least, I would like to express my appreciation to my better-half Hanieh, actually Dr Hanieh Khodaei.
She was a kind wife, the best friend that we shared whole the beautiful, sad and even stressful moments of our PhD together.
Thanks for all those understanding and supports. The best gift during my PhD was from my Almighty, Hana was my best 
gift, thanks God. Sorry Hana that I consisted part of the time that I should have played with you to 
my thesis and research. \\\\
Be yari Parvardegar Yekta\\
Mahyar Shahsavari,\\
December 2016













