1. Department of Electrical Engineering, Universidad de Concepción, Concepción 4070386, Chile
2. Department of Electrical and Electronic Engineering, Universidad del Bío-Bío, Concepción 4051381, Chile
3. Department of Electrical Engineering, Universidad de Talca, Curicó 3340000, Chile
4. Department of Engineering Science, Universidad de los Lagos Concepción, Avenida Alberto Hertha Fuchslocher 1305, Osorno 5290000, Chile
5. Department of Electrical and Electronic Engineering, University of Nottingham, Nottingham NG7 2RD, UK