【摘要】 分析了GM(1,N)(N≥2)的建模原理,找出了其模型误差产生的部分原因,证明了在相关因素序列变化幅度很小(可视为灰常量)的条件下,GM(1,N)(N≥2)具有白指数律的充要条件与GM(1,1)模型的完全相同.并在此基础上提出了GM(1,2)模型的一个改进,从而避免了GM(1,2)模型因|a|较大而产生的误差,提高了模型的精度.更多还原

【Abstract】 This paper analyzes the building mechanism of GM(1 ,N)(N≥2),discovers some causes of error for GM( 1,N)(N≥2) .proves the sufficient and necessary condition of GM( 1 ,N) (N≥2) with white exponential law as same as GM (1,1) when the relative factor series change slightly (that is, they may be regarded as a constant). On the basis it proposes an improvement of GM(1,2) ,hence,avoids the error while |a|is a bigger number and improves the precision of the GM( 1,2) model.更多还原