The Structure Method and Application of Background Value in Grey System GM(1,1) Model (Ⅱ)
GM(1,1)模型的背景值构造方法和应用(Ⅱ)

In this paper, a simple calculating formula of background value is reestablished. The formula can be used to established GM (1, 1) medel of equidistance series and non-equidistance series, and the application range of GM (1 , 1) model is extended. Meantime, the advantages that GM (1, 1 )medel can be established simply and easily are retaincd. Examples show that the new formula to calculate background value of non-equidistance series makes GM (1, 1) medel have a very high fitting and forecastingprecision.