1. Control and Industrial Processes DepartmentFederal Institute of ParanáAssis ChateaubriandParanáBrazil
2. Telecommunications Engineering and Control DepartmentEPUSP ‐ University of São PauloSão PauloBrazil
3. Electrical Engineering DepartmentState University of LondrinaRod. Celso Garcia Cid ‐ PR445, CEP86057‐970LondrinaPRBrazil