% ringraziamenti

This thesis summarizes my university journey, which gives me the possibility to improve my background knowledge and also to seek goals accordingly to my personal interests.

First and foremost, I would like to acknowledge my thesis' supervisors. I thank the Professor Basile and Professor Lioy who believed in me and gave me the possibility to work on research matters, and I thank the Professor Valenza for his incessant help during the thesis work and for his advice, not only regarding technical issues, but also concerning his experience.

The most important acknowledge goes to my parents that undoubtedly always supported me during these five years, with their sacrifices they allowed me to study and to make easier any problems I faced. They have always been there if I needed help and they always listened to me talking about things they do not understand and giving reasonable meanings to my words.

Then I want to acknowledge all my friends, no one excluded, who closer, who further, but anyone gives his contribution to my achievements, unfortunately I cannot mention them one by one.
I want to thank my room mates Dario e Federico. Our friendship became stronger during the first years of university. 

As well Alessandro, Riccardo and Andrea who make these years easy and funny, with them I shared a lot of nice moments of my university life, including my thesis work on which Andrea gave his contribution.

This work means the end of this unique five-year path which is an experience I would suggest to anyone.
Hopefully what I achieved will open new possibilities to improve myself,\break because I learned that \textit{the moment you give up your dreams, you are lost}.