光谱学与光谱分析
光譜學與光譜分析
광보학여광보분석
SPECTROSCOPY AND SPECTRAL ANALYSIS
2014年
6期
1624-1628
,共5页
赵肖宇%方一鸣%关勇%王志刚%佟亮%谭峰
趙肖宇%方一鳴%關勇%王誌剛%佟亮%譚峰
조초우%방일명%관용%왕지강%동량%담봉
总体平均经验模态分解%残余量%相关性%基线校正%自适应性
總體平均經驗模態分解%殘餘量%相關性%基線校正%自適應性
총체평균경험모태분해%잔여량%상관성%기선교정%자괄응성
Ensemble empirical mode decomposition%Residual%Correlation%Baseline correction%Adaptive
基线校正是光谱分析的重要环节,现有算法通常需要设定关键参数,不具备自适应性。根据总体平均经验模态分解(ensemble empirical mode decomposition,EEMD)残余量特点,提出用残余量拟合光谱基线。通过残余量与信号相关性、残余量自相关和互相关性(称为残余相关准则)判断残余量是否是基线组成部分,以此为基础提出一种自适应的EEMD残余相关基线校正算法。对叠加曲线背景和线性背景的模拟光谱数据进行实验,结果显示在已知基线数学假设情况下,EEMD残余相关法逊于多项式拟合,同非线性拟合相差不多,优于小波分解。在没有光谱背景知识情况下,对真实拉曼光谱数据进行试验。经过上述方法预处理过的玉米叶片光谱采用3层BP神经网络建立与叶绿素之间预测模型,经过残余相关基线校正的模型具有最大校正相关系数和预测相关系数,最小交叉验证标准差和相对分析误差。各种基线校正方法中,残余相关基线校正对特征峰峰位、峰强和峰宽影响最小。实验表明,该算法可用于拉曼谱图基线校正,无需分析样品成分的先验知识,无需选择合适的拟合函数、拟合数据点、拟合阶次以及基函数和分解层数,也无需基线信号分布的数学假设,自适应性很强。
基線校正是光譜分析的重要環節,現有算法通常需要設定關鍵參數,不具備自適應性。根據總體平均經驗模態分解(ensemble empirical mode decomposition,EEMD)殘餘量特點,提齣用殘餘量擬閤光譜基線。通過殘餘量與信號相關性、殘餘量自相關和互相關性(稱為殘餘相關準則)判斷殘餘量是否是基線組成部分,以此為基礎提齣一種自適應的EEMD殘餘相關基線校正算法。對疊加麯線揹景和線性揹景的模擬光譜數據進行實驗,結果顯示在已知基線數學假設情況下,EEMD殘餘相關法遜于多項式擬閤,同非線性擬閤相差不多,優于小波分解。在沒有光譜揹景知識情況下,對真實拉曼光譜數據進行試驗。經過上述方法預處理過的玉米葉片光譜採用3層BP神經網絡建立與葉綠素之間預測模型,經過殘餘相關基線校正的模型具有最大校正相關繫數和預測相關繫數,最小交扠驗證標準差和相對分析誤差。各種基線校正方法中,殘餘相關基線校正對特徵峰峰位、峰彊和峰寬影響最小。實驗錶明,該算法可用于拉曼譜圖基線校正,無需分析樣品成分的先驗知識,無需選擇閤適的擬閤函數、擬閤數據點、擬閤階次以及基函數和分解層數,也無需基線信號分佈的數學假設,自適應性很彊。
기선교정시광보분석적중요배절,현유산법통상수요설정관건삼수,불구비자괄응성。근거총체평균경험모태분해(ensemble empirical mode decomposition,EEMD)잔여량특점,제출용잔여량의합광보기선。통과잔여량여신호상관성、잔여량자상관화호상관성(칭위잔여상관준칙)판단잔여량시부시기선조성부분,이차위기출제출일충자괄응적EEMD잔여상관기선교정산법。대첩가곡선배경화선성배경적모의광보수거진행실험,결과현시재이지기선수학가설정황하,EEMD잔여상관법손우다항식의합,동비선성의합상차불다,우우소파분해。재몰유광보배경지식정황하,대진실랍만광보수거진행시험。경과상술방법예처리과적옥미협편광보채용3층BP신경망락건립여협록소지간예측모형,경과잔여상관기선교정적모형구유최대교정상관계수화예측상관계수,최소교차험증표준차화상대분석오차。각충기선교정방법중,잔여상관기선교정대특정봉봉위、봉강화봉관영향최소。실험표명,해산법가용우랍만보도기선교정,무수분석양품성분적선험지식,무수선택합괄적의합함수、의합수거점、의합계차이급기함수화분해층수,야무수기선신호분포적수학가설,자괄응성흔강。
Baseline correction is an important part of spectral analysis;the existing algorithms usually need to set the key param-eters and does not have adaptability.The spectral baseline is fitted by the residue according to the feature of ensemble empirical mode decomposition (EEMD for short).The correlation between residual and original signal,the self-correlation and the cross-correlation of residual form the residual related rule.The residual related rule is proposed to judge whether the residual is a com-ponent of baseline,based on which adaptive EEMD residual related base line algorithm is proposed.With experiment on the sim-ulated spectrum data of superimposing curve background and the linear background,the results showed that in the case of known baseline mathematical assumption:EEMD residual related method is not so good for polynomial fitting,it is almost no difference from linear fitting,but is better than the wavelet decomposition.In the absence of spectral background knowledge,the real Ra-man spectrum data are tested.The model is established between Raman spectra treated by the procedure above and chlorophyll, and the model corrected by EEMD residual related baseline method has the biggest correlation coefficient and prediction coeffi-cient,but the smallest root mean square error of cross validation and relative prediction deviation.The effect of EEMD residual related baseline method effects on the peak position,peak intensity and peak width is the smallest in all kinds of baseline correc-tion methods.EEMD residual method has the best baseline correction effect.Experiments show that this algorithm can be used for Raman spectra baseline correction,without prior knowledge of the sample composition analysis,and there is no need to select appropriate fitting function,fitting data points,fitting order as well as basis function and decomposition levels,also there is no need of mathematical hypothesis of baseline signal distribution,so the adaptability is very strong.