Key Laboratory of Hilly and Mountain Areas of Chongqing, College of Engineering and Technology, Southwest University, Chongqing, China.
J Sci Food Agric. 2019 Aug 30;99(11):4898-4903. doi: 10.1002/jsfa.9717. Epub 2019 May 13.
The thick rind of Fukumoto navel orange is a great barrier to light penetration, which makes it difficult to evaluate the internal quality of Fukumoto navel orange accurately by visible-near-infrared (Vis-NIR) transmittance spectroscopy. The information carried by the transmission spectrum is limited. Thus, the application of genetic algorithm (GA) for variable selection may not reach the expected results, and selected variables may contain redundancy. In this paper, we present the use of discrete wavelet transforms for optimizing a GA-partial least squares (PLS) model based on Vis-NIR transmission spectra of Fukumoto navel orange. Haar, Db, Sym, Coif and Bior wavelets were used to compress the spectral data selected by GA. Then a PLS model was established based on the variables compressed by each wavelet function.
The use of Db4, Sym4, Coif2 and Bior3.5 succeeded in further simplification of the GA-PLS model by reducing the number of variables by 40-44% without decreasing the prediction accuracy. The application of Bior3.5 not only could reduce the number of variables in the GA-PLS model by 40%, but also increase the value of correlation coefficient of prediction by 1% and decrease the value of root mean square error of prediction by 3%.
The results indicated that the combination of GA and discrete wavelet transforms for variable selection in the internal quality assessment of Fukumoto navel orange by Vis-NIR transmittance spectroscopy was feasible. © 2019 Society of Chemical Industry.
福冈脐橙果皮较厚，对光的穿透有很大的阻碍，这使得利用可见-近红外（Vis-NIR）透射光谱法很难准确评估福冈脐橙的内部品质。透射光谱所携带的信息有限。因此，遗传算法（GA）的变量选择可能无法达到预期的结果，并且选择的变量可能包含冗余。在本文中，我们提出了一种利用离散小波变换优化基于福冈脐橙可见-近红外透射光谱的 GA-偏最小二乘（PLS）模型的方法。使用 Haar、Db、Sym、Coif 和 Bior 小波对 GA 选择的光谱数据进行压缩。然后，基于每个小波函数压缩的变量建立 PLS 模型。
使用 Db4、Sym4、Coif2 和 Bior3.5 成功地进一步简化了 GA-PLS 模型，将变量数减少了 40-44%，而预测精度没有降低。Bior3.5 的应用不仅可以将 GA-PLS 模型中的变量数减少 40%，还可以将预测相关系数提高 1%，将预测均方根误差降低 3%。
结果表明，GA 与离散小波变换相结合，用于 Vis-NIR 透射光谱法对福冈脐橙内部品质的变量选择是可行的。© 2019 英国化学学会。
