1. Federal Technological University of Paraná - UTFPR/CP, Departament of Computer, Cornélio Procópio, PR, Brazil
2. Blekinge Institute of Technology and University of Oulu, Depart. of Software Engineering, Karlskrona, Sweden
3. Fluminense Federal University, Graduate Programm in Computing, Niterói, RJ, Brazil
4. Department of Comp. and Applied Mathematics, National Institute for Space Research, INPE, São José dos Campos, SP, Brazil