in ordet to investigate economic efficiency of five cultural systems in sugar beet crop, including high input, medium input  low input , high  and medium inputs without 3 times irrigation after emergence, an experiment was conducted over  two years  (2002-2003) in agricultural and natural resources research center of khorasan. these systems were analysed by marginal analysis and  linear program...

In this paper we consider production economic and cost related yield rate in a JIT (Just in Time) system. Based on the traditional EPQ (Economic Production Quantity) model, we establish the relation between cost and yield rate. The geometric programming approach is applied in our model to solve this optimizing posynomials problem. A numerical example is carried out to verify the proposed model....

For more than forty years, economists have routinely rejected the postulate that economic theory should be realistic. Ever since Milton Friedman sketchily outlined a positive methodology for economics, most students of our science have come to endorse Friedman’s view and have claimed that the only quality standard of economic reasoning was its predictive power. Good theories yield fairly correc...