[1] Univ Nacl Rio Cuarto, Fac Ingn, GEA, Rio Cuarto, Argentina
[2] Nacl Invest Cient & Tecn CONICET, RA-1033 Buenos Aires, DF, Argentina
[3] Univ Nacl Sur, Dept Ingn Elect & Comp, Inst Invest Ingn Elect Alfredo Desages, RA-8000 Bahia Blanca, Buenos Aires, Argentina