1. Engineering Systems Doctoral Program, Faculty of Engineering, Universidad de Talca, Curicó, Chile
2. Department of Electrical Engineering, Faculty of Engineering, Universidad de Talca, Curicó, Chile
3. Department of Electrical Engineering, Universidad de Oviedo, Gijón, Spain
4. Ingeniería Eléctrica, Electrónica, de Computadores y Sistemas, Universidad de Oviedo, Gijón, Spain