1. Instituto Ibermática de Innovación. Sistemas Inteligentes de Control y Gestión Parque Tecnológico de Álava, Leonardo Da Vinci, Miñano, Spain
2. Department of Systems Engineering and Automatic Control, University College of Engineering of Vitoria, Basque Country University (UPV/EHU), Vitoria, Spain; Computational Intelligence Group (UPV/EHU)
3. Departamento de Educación del Gobierno Vasco, Vitoria, Spain
4. Department of Computer Science and Artificial Intelligence, Faculty of Informatics, Basque Country Univesrsity (UPV/EHU), San Sebastian, Spain; Computational Intelligence Group (UPV/EHU)