1. Postgraduate Program in Electrical and Computer Engineering (PPgEEC), LACI/DEE, Federal University of Rio Grande do Norte, 59078-970 Natal, RN, Brazil
2. The Computer Science Institute at the Federal University of Alagoas (UFAL), 57072-900 Maceió, AL, Brazil
3. Department of Electrical Engineering (DEE), Federal University of Rio Grande do Norte, 59078-970 Natal, RN, Brazil