1. Departamento de Estadistica, Informatica y Matematicas, Universidad Publica de Navarra, Campus de Arrosadia, Pamplona, Spain
2. School of Computer Science and Electronic Engineering, University of Essex, Colchester, United Kingdom
3. Dept. of Computer Science and Artificial Intelligence and with Andalusian Research Institute “Data Science and Computational Intelligence” (DaSCI), University of Granada, Granada, Spain