1. Univ. Trás-os-Montes and Alto Douro,Department of Engineering,Vila Real,Portugal
2. Univ. Trás-os-Montes and Alto Douro LIAAD-INESCTEC UTAD Pole,Department of Mathematics,Vila Real,Portugal
3. EDS- Energy Drawing Systems,Bragança,5300-358
4. Univ. Trás-os-Montes and Alto Douro CPES-INESCTEC UTAD Pole,Department of Engineering,Vila Real,Portugal