基于烟叶近红外光谱主成分数据的投影方法研究及其在复烤配方中的应用

Study on the Projection Method Based on Principal Component of Tobacco Near-Infrared Spectrum and Application in Redrying Model

对近红外技术在烟草中的应用作了简要的概述,报道了两种基于近红外光谱主成分的投影矢量求解方法,分别简称为PPF_PCA和PPF_Eig,并对两种方法在复烤配方中的应用与评价做了比较研究。对9类烟叶工业分级样品光谱进行一维投影分析的结果表明:PPF_PCA方法得到的一维投影值的类间差异性和类内差异性均大于PPF_Eig方法,其中各类间投影均值的平均绝对偏差前者约为后者的1.26倍。同时应用第一维投影值所占贡献率的情况对此结果进行了解释,PPF_PCA方法一维投影值所占贡献率为93%,PPF_Eig方法一维投影值所占贡献率为77%,前者约为后者的1.21倍,因此,PPF_PCA方法得到的一维投影值中包含更多类间和类内的差异性信息。应用烟叶各类工业分级样品的一维投影图能客观的评价各类样品之间的相似性及各类内样品之间的差异性,可方便的作为烟叶复烤配方的参考依据,同时在其他农产品(如中药等)配方中也具有较好的应用前景。

The present paper briefly describes the application of near-infrared spectroscopy technology in tobacco. Two methods for solving projection vector based on the principal component of near-infrared spectrum are reported. They are named as projection of basing on principal component and Fisher criterion by principal component analysis method （PPF_PCA for short） and projection of basing on principal component and Fisher criterion by solving eigenvalue （PPF_Eig for short）,and they are studied and compared in the application and evaluation of the redrying model. The result of the first-dimensional projection on 9 kinds of tobacco leaf grading samples shows that,the diversity of the first-dimensional projection values of inter-class and intra-class by the PPF_PCA method is both larger than that by the PPF_Eig method,and the mean absolute deviation of the mean projection values of inter-class by the PPF_PCA method is about 1.26 times that of the PPF_Eig method. At the same time,this result is interpreted by using the contribution rate of the first-dimensional projection values. That is,the contribution rate of first-dimensional projection values by the PPF_PCA method is 93%,while the contribution rate of first-dimensional projection values by the PPF_Eig method is 77%. The former is about 1.21 times the later. Therefore,the first-dimensional projection values by PPF_PCA method include more information of diversity of both inter-class and intra-class. The similarity of samples inter-class and the diversity of samples intra-class can be evaluated more objectively from first-dimensional projection figure（on 9 kinds of tobacco leaf grading samples,33 kinds of tobacco leaf grading samples and 6 redrying blending models）,so it is more convenient to be used as a reference for the redrying model of tobacco,and it has a good application prospect in other formulation design of agricultural products （traditional Chinese medicine etc.）