We adopt a way of attribute selection based on word entropy, use vectors which are represented by word frequency, and deduce its corresponding Bayesian formula.

我们采用了基于词熵的特征项提取方法，并且使用特征项单词出现频率来表示向量，推导出相应的贝叶斯计算公式。

On the base of the general theory of thin-walled members, we deduce a new critical moment formula of steel beam under transverse loads which pass the shear center and parallel to the main axis.

就国内现有的薄壁钢梁弯扭失稳理论进行了分析，从薄壁杆件的一般理论出发，推导出荷载过截面弯心并与主轴平行的受弯钢梁的临界弯矩公式。

Deduce the air permeability calculating formula base on the regression analysis method. Provide a strong basis for the selection of PET, aluminum PET and PVDC film in food packaging.

最后利用回归分析法推导出pet、镀铝PET及PVDC薄膜的透气率计算公式，为塑料包装材料在果品包装方面的选用提供有力依据。