This paper discusses the grey accumulation of original data and the grey derivative's white value, and proposes an unbiased directgrey model.
本文在深入讨论了灰色系统背景值以及灰色序列生成等问题，提出了无偏直接灰色模型。
2
The model has the advantages of directgrey model and unbiased grey model; it can express the changing characteristics of raw sequence, and is unbiased.
该模型同时具备直接灰色模型和无偏灰色模型的优点，能够直接描述原始数列的变化特性并且没有偏差。
3
If data have accurate index law, direct data grey model should build to do with them.