1. Computer Science Faculty, University of the Basque Country, UPV/EHU, Spain and Irisbond Crowdbonding SL, Spain
2. Computer Science Faculty, University of the Basque Country, UPV/EHU, Spain
3. Irisbond Crowdbonding SL, Spain
4. Fundación Vicomtech, Basque Research and Technology Alliance (BRTA), Spain
5. Electrical, Electronics and Communications Eng. Dept., Public University of Navarre, Spain