1. Laboratory of Instrumentation, Biomedical Engineering and Radiation Physics (LIBPhys-UNL), Department of Physics, NOVA School of Science and Technology, NOVA University of Lisbon, 2829-516 Caparica, Portugal
2. Institute of Physics of Sao Carlos, University of Sao Paulo, São Carlos 13566-590, Brazil
3. LASI—Associated Laboratory of Intelligent Systems, CTS—Centre for Technology and Systems, UNINOVA, Department of Electrotechnical and Computer Engineering, NOVA School of Science and Technology, NOVA University of Lisbon, 2829-516 Caparica, Portugal