Jonas Hruska, Luís Pádua, Telmo Adão, University of Trás-os-Montes e Alto Douro, Portugal; Emanuel Peres, University of Trás-os-Montes e Alto Douro and INESC-TEC, Portugal; José Martinho, University of Trás-os-Montes e Alto Douro, Portugal; Joaquim J. Sousa, University of Trás-os-Montes e Alto Douro and INESC-TEC, Portugal