Affiliation: | Authors Cabrera, Zapata, de Buckle and Sandoval are with the Insti-tuto de lnvestigaciones Tecnológicas, Avenida 30 N°-52A-77, Bogotá, D.E. Colombia.;Authors Ben-Gera andShomerare with the Institute for Technology &Storage, P.O.B. 6, Bet-Dagan (20-500), Israel. |