University of Aveiro, IEETA/DETI, Campus Universitxc3xa1rio de Santiago, Aveiro, Portugal. david.campos@ua.pt|University of Aveiro, IEETA/DETI, Campus Universitxc3xa1rio de Santiago, Aveiro, Portugal. david.campos@ua.pt|University of Aveiro, IEETA/DETI, Campus Universitxc3xa1rio de Santiago, Aveiro, Portugal. david.campos@ua.pt|University of Aveiro, IEETA/DETI, Campus Universitxc3xa1rio de Santiago, Aveiro, Portugal. david.campos@ua.pt|University of Aveiro, IEETA/DETI, Campus Universitxc3xa1rio de Santiago, Aveiro, Portugal. david.campos@ua.pt