1. Department of Informatics Engineering, Faculty of Sciences and Technology, University of Coimbra/CISUC, University of Coimbra, Coimbra, Portugal
2. Department of Informatics Engineering, Faculty of Engineering, University of Porto, Porto, Portugal
3. LIACC – Artificial Intelligence and Computer Science Laboratory, University of Porto, Porto, Portugal
4. LIAAD – Laboratory of Artificial Intelligence and Decision Support, University of Porto, Porto, Portugal
5. School of Engineering, University of Minho, Guimarães, Portugal