Add to ORKGiii Gratefully to my family, my mentor and friends ACKNOWLEDGEMENTS I would like to express my gratitude to all those who gave me the possibility to com-plete this thesis. I want to thank my supervisor Prof. Dr. M. Torres-Torriti from the Pon-tificia Universidad Católica de Chile whose assistance, encouragement and advice helped me in all the time of research for and writing of this thesis. I gratefully thank my father Luis Jiménez, my mother Monica Pinto and my brother Camilo Jiménez for giving me the support and strength to complete this work. Finally i gratefully acknowledge my friends that helped on the validation tests of my work, whom without their help this investigation would not have been possible