Unbiasedness and self-adaptability are two important properties of grey prediction model and the basis of studying the structure and performance of the model.The existing studies have mostly verified unbiased from the perspective of examples,without strict mathematical proof,and less analysis of the relationship between unbiased and adaptive.Firstly,using matrix theory,the unbiasedness of two kinds of common discrete grey prediction models is strictly proved in theory and verified by homogeneous index/nonhomogeneous index/linear function sequence.The results show that the two parameter discrete grey prediction model DGM(1,1)is unbiased only for the homogeneous exponential sequence,while the three parameter discrete grey prediction model TDGM(1,1)is unbiased for the exponential/non-homogeneous exponential/linear function sequence.Then,the adaptability of TDGM(1,1)to different feature sequences is analyzed from the perspective of model structure,and the internal relationship between self-adaptability and unbiased of model structure is verified.Finally,the TDGM(1,1)model is applied to forecast the world sales of new energy vehicles,and the predic-tion results are compared and analyzed.This study has positive significance for enriching and perfecting the grey prediction theory.
关键词
离散型灰色预测模型/模型无偏性/模型自适应性/世界新能源汽车销量预测
Key words
discrete grey prediction model/unbiasedness/self-adaptability/prediction of world sales of new energy vehicles
维普
万方数据