1. Departament d’Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, Tarragona, Spain;
2. IN3 – Computer Science Department, Open University of Catalonia, Castelldefels, Spain;
3. Department of Mathematics, Technical University of Catalonia, Barcelona, Spain;
4. Euncet Business School, Terrassa, Spain;
5. School of Science, Engineering and Information Technology, Federation University Australia, Ballarat, VIC, Australia