1. INEGI, Faculty of Engineering, University of Porto, Porto, Portugal
2. PPGM, State University of Feira de Santana, Feira de Santana, Brazil
3. Department of Technology, State University of Feira de Santana, Feira de Santana, Brazil
4. INESC-TEC, Faculty of Engineering, University of Porto, Porto, Portugal
5. Computer Science Department, Federal University of Bahia, Salvador, Brazil