摘要
为提高土壤养分近红外光谱预测模型的鲁棒性和预测精度,提出一种基于改进遗传算法的近红外区间光谱特征波长变量选择方法.利用土壤速效磷近红外光谱全光谱波长变量纯度梯度的正负变化次数将全光谱划分为多个波长间隔,以偏最小二乘回归模型(PLS-R)输出的变量投影重要性系数(VVIP)大于1作为提取准则,提取对土壤养分预测目标量解释性较强的波长间隔,并合并成一个区间光谱.建立区间光谱特征波长变量(FWV)PLS-R模型,利用改进遗传算法选择PLS-R的均方根误差为最小对应的FWV为最优FWV.试验结果表明:该方法在区间光谱选择最优FWV,能提高回归模型的鲁棒性和预测精度,简化模型结构;改进遗传算法采用一种改进的实数编码差分变异算子,扩大了全局最优解搜索空间,提高了收敛速度.
To improve the robustness and prediction accuracy of the soil nutrient near-infrared spectroscopy prediction model,a near infrared interval spectrum selection method was proposed based on the improved genetic algorithm.According to the positive and negative change times in the NIRS full spectrum wavelength variables purity gradients of the soil available phosphorus,the full spectrum was divided into multiple wavelength intervals.Using the variable projection importance coefficients(VVIP)from partial least squares regression model(PLS-R)output greater than one as extraction criteria,the wavelength intervals with stronger interpretability for predicting soil nutrient target amount were extracted,and the wavelength intervals were combined into an interval spectrum.PLS-R was modeled with the interval spectrum feature wavelength variable(FWV),and an improved genetic algorithm was used to select the optimal FWV corresponding to PLS-R root mean square error minimum.The experimental results show that the proposed method for selecting optimal FWV can improve the robustness and prediction accuracy of regression model with simplified model structure.The improved real coded differential mutation operator can improve the genetic algorithm to expand the search space of global optimal solution and increase the convergence rate.
作者
刘鑫
冒智康
张小鸣
李绍稳
金秀
LIU Xin;MAO Zhikang;ZHANG Xiaoming;LI Shaowen;JIN Xiu(School of Information Science and Engineering, Changzhou University, Changzhou, Jiangsu 213164, China;School of Information and Computer, Anhui Agricultural University, Hefei, Anhui 230036, China)
出处
《江苏大学学报（自然科学版）》
EI
CAS
北大核心
2020年第3期321-327,共7页
Journal of Jiangsu University：Natural Science Edition
基金
农业部农业物联网技术集成与应用重点实验室开放基金资助项目(2016KL07)。
关键词
近红外光谱
区间光谱
特征波长变量
变量投影重要性系数
偏最小二乘回归模型
near infrared spectroscopy
interval spectrum
feature wavelength variable
variableimportance projection coefficient
partial least squares regression model
