Abstract: To estimate null value in the database is a main task of data-processing, first it gets the cloud models which present the raw nonempty value in the database, then recoves the value with the cloud to replace the null value. The method considers the original data’s distribution sufficiently and can simulate the humans’ behavior, so it can estimate the null value more precisely.

Key words: Null value, Cloud model, Expected value, Entropy, Hyper entropy

摘要： 数据库中空值的估计是数据处理的一项重要内容，数值型数据的云模型空值估计方法是将数据库中之数据先作云的数字化处理，然后利用云模型产生空值替代值，这种估计空值的新方法尊重原始数据的分布特征，具有人类自然行为的特征，比其它的方法具有更高的平均估计准确率。

关键词: 空值, 云模型, 期望值, 熵, 超熵

CLC Number: 

• TP393