This thesis has been completed in a joint/double Doctoral Degree program between TAU and UJI as a part of the A-WEAR project for which I gratefully acknowledge the funding we have received from the European Union's Horizon 2020 Research and Innovation programme under the Marie Skłodowska Curie grant agreement No. 813278, A-WEAR. Without this support, this work would have never been possible.Furthermore, I would like to express my deepest gratitude to everyone, who has helped me to get to this point, supported me, and made me grow, both professionally and personally.First and foremost, I would like to express my sincere gratitude to my thesis supervisors. Thank you, Prof. Jari Nurmi, for letting me learn from the best, for your unlimited support, and encouragement throughout my ventures as a doctoral student. Thank you, Prof. Elena Simona Lohan, for the academic guidance, for teaching me how to grow as a researcher, as well as for all the care and encouragement you gave me throughout the years. Thank you, Dr. Carlos Granell Canut, xv for everything you did for me, your leadership, and your support. I would also like to extend my gratitude to Dr. Joaquín Torres-Sospedra (Ximo) for acting as my unofficial supervisor, for always supporting me in realizing my ideas, giving me invaluable feedback on my work, and helping me to see the paths ahead. Your guidance is highly appreciated. Furthermore, I would like to acknowledge and thank Dr. Jukka Talvitie for his support, fruitful discussions, and for letting me know about the existence of the A-WEAR project. Without you, I would have never been here. I would like to extend my thanks to Prof. Mikko Valkama, who provided me with motivation and guidance, and to my friend Asst. Prof. Bo Tan for continuous support, encouragement, and inspiration.I would like to extend my recognition to my thesis pre-examiners Prof. Fernando Javier Álvarez Franco and Dr. Christos Laoudias, as well as to my opponents Dr.Tobias Feigl, and Dr. Christos Laoudias, for investing time, energy, and effort into evaluating my thesis and offering me invaluable feedback. I am honored that scientists of such magnitude read my work.I would like to thank my colleagues and co-authors, with whom I had the pleasure to collaborate and learn from over the years. I would like to extend my thanks to all the staff of A-WEAR, TUNI, and UJI, who enabled me to successfully progress through my doctoral studies. I thank all other ESRs for creating a friendly and productive environment across the universities and for always supporting each other.Especially, I would like to thank Darwin for the fruitful collaboration that grew into a friendship. I would also like to extend my gratitude to Alex who has helped me, guided me, and always spoken his mind. To Olga and Nadia, for mutual support and for the memorable time spent together, to my friend Tomáš, as well as to Salwa, Asad, Pável, Viktoriia, and many others.Furthermore, I would like to acknowledge my colleagues and friends, with whom I have spent countless good moments he...