本文選題：參數(shù)化模型　切入點：外推性　出處：《光譜學與光譜分析》2017年10期

【摘要】：太赫茲(Terahertz,THz)波通常是指位于微波和近紅外之間的電磁波。由于很多化學和生物分子的振動和轉(zhuǎn)動模式正好都位于THz波段,因此可以利用物質(zhì)的這些"指紋譜"特性開展定性和定量分析研究。目前用于THz光譜的定量分析主要有主成分回歸(PCR)以及偏最小二乘回歸(PLSR)等方法,這些算法在建模時往往需要大量的樣本進行監(jiān)督學習,模型精度對訓練樣本依賴性較高,同時模型的外推性不易保證,在樣本量不足或者外推性要求較高的場合,這些算法的使用會受到一定限制。針對這些問題,該研究提出一種利用光譜的參數(shù)化模型——間接硬建模方法(IHM),進行混合物太赫茲光譜解析和量化分析技術(shù)方案的研究。首先使用S-G平滑濾波方法濾除光譜中的噪聲影響;同時考慮到太赫茲光譜特性,消除了人工基線對光譜解析產(chǎn)生的影響;隨后,開展了IHM建模與分析研究,重點討論了在兩個訓練樣本數(shù)目情況下模型預(yù)測準確度的問題;為了驗證該算法的可行性,制備了利福平、乳糖一水合物、微晶纖維素以及硬脂酸鎂的四元混合物進行實驗與建模分析;使用回歸相關(guān)系數(shù)R和均方根誤差RMSE對定量模型進行評價。將IHM方法和PLSR方法進行了比較,理論分析和實驗結(jié)果表明,相對于傳統(tǒng)方法,IHM方法建模所需的訓練樣本數(shù)量可減少至2個,與此同時量化分析準確度獲得了提高,同時外推性也有所提升。
[Abstract]:Terahertzt THz wave is usually the electromagnetic wave between microwave and near infrared.Since the vibration and rotation modes of many chemical and biological molecules are located in the THz band, the qualitative and quantitative studies can be carried out by using these "fingerprint spectrum" characteristics of matter.At present, the quantitative analysis of THz spectrum mainly includes principal component regression (PCA) and partial least squares regression (PLSR). These algorithms often require a large number of samples to monitor and learn when modeling, and the model accuracy is highly dependent on training samples.At the same time, the extrapolation of the model is not easy to guarantee, and the use of these algorithms will be limited in the case of insufficient sample size or high extrapolation requirements.To solve these problems, an indirect hard modeling method based on the parameterized model of spectrum is proposed to study the technical scheme of terahertz spectral analysis and quantitative analysis of mixtures.First, S-G smoothing filtering method is used to filter the noise in the spectrum. Considering the terahertz spectrum characteristics, the influence of artificial baseline on spectral analysis is eliminated. Then, IHM modeling and analysis are carried out.In order to verify the feasibility of the algorithm, rifampicin and lactose hydrate were prepared.The quaternary mixture of microcrystalline cellulose and magnesium stearate was tested and analyzed, and the regression correlation coefficient R and root mean square error (RMSE) were used to evaluate the quantitative model.Compared with the IHM method and the PLSR method, the theoretical analysis and experimental results show that compared with the traditional method, the number of training samples needed for modeling can be reduced to 2, and the accuracy of quantitative analysis is improved.At the same time, extrapolation is also improved.
【作者單位】： 浙江大學控制科學與工程學院 工業(yè)控制技術(shù)國家重點實驗室;
【基金】：國家自然科學基金項目(61473255,61307127) 國家教育部博士點專項基金項目(20110101110063) 浙江省自然科學基金項目(Q14F050010)資助
【分類號】：O433.4

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