1. Center for Research and Development in Mathematics and Applications (CIDMA); Department of Mathematics University of Aveiro; 3810-193 Aveiro Portugal
2. School of Business Studies; Viana do Castelo Polytechnic Institute; Avenida Miguel Dantas 4930-678 Valença Portugal
3. Algoritmi R&D Center, Department of Production and Systems; University of Minho, Campus de Gualtar; 4710-057 Braga Portugal