Program;
in;
Applied;
Informaties;
(PPGIA),;
University;
of;
Fortaleza;
(UNIFOR),;
Fortaleza,;
Ceara;
60181-225,;
Brazil;
Science;
Laboratory,;
Unified;
Center;
ofTeresina;
(CEUT),;
Teresina,;
Piaui,;
Brazil;
University;
of;
Piaui;
(UESPI),;
Teresina,;
Piaui;
64000-000,;
Brazil;