PREDICTION OF ANNUAL PRODUCTION-RATES OF CRUDE STEEL IN VARIOUS COUNTRIES BY A MODIFIED LOGISTIC FUNCTION

Annual production rates of crude steel of various countries in future are estimated by the following procedure: First, real production rates are corrected by a regular procedure. Then equations of relationship between the corrected production rate and the year are expressed by re gression of a logistic equation. Estimated production in various count ries can be obtained by subtracting the difference of the corrected an d the real productions from the regressed amount. For examples of resu lts, the maximum production rate of Japan in future can be estimated a s 120Mt/y. It is also suggested that annual production rate under depr ession in near future can be estimated.