Duan Hong-wei, Zhu Rong-guang, Xu Wei-dong, Qiu Yuan-yuan, Yao Xue-dong, Xu Cheng-jian
Guang Pu Xue Yu Guang Pu Fen Xi. 2017 Mar;37(3):847-52.
In the process of spectral modeling, spectral extraction of characteristic bands with different variable screening algorithms is an important step for improving the model effects. Total viable count of cooling mutton under vacuum packing condition was chosen as the research index in this paper, while the influence of 2 variable screening algorithms on its hyperspectral PLS model effects was compared. Mutton muscle spectra of Regions of interest (ROIs) were extracted and preprocessed. Subsequently, Genetic Algorithm (GA) and Competitive Adaptive Reweighted Sampling (CARS) were applied to extract characteristic bands from preprocessed spectra at full band range of 473~1 000 nm. Model effects of GA-PLS, CARS-PLS and W-PLS with corresponding bands selection were contrasted and analyzed. The results indicated that both model effects of GA-PLS, CARS-PLS were better than that of W-PLS, and CARS-PLS model effect was optimal. As for the CARS-PLS model, the determination coefficient (R2c) and root mean square error (RMSEC) of calibration set was 0.96 and 0.29, and the determination coefficient (R2cv) and root mean square error (RMSECV) of leave-one-out cross validation was 0.92 and 0.46, respectively. Meanwhile, the determination coefficient (R2p), root mean square error of prediction (RMSEP) and the ratio of standard deviation to standard error of prediction (RPD) of prediction set was 0.92 and 0.47 and 3.58, respectively. Therefore, hyperspectral imaging (HSI) technology combined with CARS-PLS can achieve quick, non-destructive and accurate detection of mutton total viable count.
在光谱建模过程中,采用不同变量筛选算法对特征波段进行光谱提取是提高模型效果的重要步骤。本文选取真空包装冷却羊肉的总活菌数作为研究指标,比较了两种变量筛选算法对其高光谱偏最小二乘(PLS)模型效果的影响。提取并预处理了感兴趣区域(ROIs)的羊肉肌肉光谱。随后,应用遗传算法(GA)和竞争性自适应重加权采样(CARS)从473~1000nm全波段范围的预处理光谱中提取特征波段。对比分析了GA-PLS、CARS-PLS和全波段PLS(W-PLS)在相应波段选择下的模型效果。结果表明,GA-PLS和CARS-PLS的模型效果均优于W-PLS,且CARS-PLS模型效果最佳。对于CARS-PLS模型,校正集的决定系数(R2c)和均方根误差(RMSEC)分别为0.96和0.29,留一法交叉验证的决定系数(R2cv)和均方根误差(RMSECV)分别为0.92和0.46。同时,预测集的决定系数(R2p)、预测均方根误差(RMSEP)和预测标准差与标准误差之比(RPD)分别为0.92、0.47和3.58。因此,高光谱成像(HSI)技术结合CARS-PLS能够实现对羊肉总活菌数的快速、无损和准确检测。