Application of PCA-SVM and ANN Techniques for Plastic Identification by Raman Spectroscopy

Deep Learning for Chemometric Analysis of Plastic Spectral Data from Infrared and Raman Databases

“…PCA was used in earlier chemometrics work to identify the potential on distinguishing plastics by IR spectra (De Biasio et al, 2010) and LIBS spectra (Grégoire et al, 2011). It also continues to be used as a pre-processing technique prior to machine learning model training (Musu et al, 2019;Yan et al, 2021;Yang et al, 2020;Zhu et al, 2019) Supervised machine learning techniques include PLS, kNN and SVM are also popular chemometric techniques. For PLS, latent variables are constructed that best explain the relationship between the spectral data and the output label.…”

“…The kNN algorithm classifies data based on the majority class of its surrounding neighbors (Costa et al, 2017;Yang et al, 2020). SVM algorithm works based on the construction of a hyperplane that serves as a decision boundary between different classes (Musu et al, 2019;Yang et al, 2020;Yu et al, 2014;Zhu et al, 2019). These machine learning techniques have been found to give good results with IR spectra (Bonifazi et al, 2014;Calvini et al, 2018;Karaca et al, 2013;Rani et al, 2019;Said et al, 2020;S Serranti et al, 2020;Silvia Serranti et al, 2012Ulrici et al, 2013;Wu et al, 2020;Yang et al, 2020;Zhu et al, 2019), Raman spectra (Allen et al, 1999;L.…”

“…These machine learning techniques have been found to give good results with IR spectra (Bonifazi et al, 2014;Calvini et al, 2018;Karaca et al, 2013;Rani et al, 2019;Said et al, 2020;S Serranti et al, 2020;Silvia Serranti et al, 2012Ulrici et al, 2013;Wu et al, 2020;Yang et al, 2020;Zhu et al, 2019), Raman spectra (Allen et al, 1999;L. Chen et al, 2017;Musu et al, 2019;Silva & Wiebeck, 2019) and LIBS spectra (Costa et al, 2017;Vahid Dastjerdi et al, 2018;Yan et al, 2021;Yu et al, 2014).…”

“…The use of artificial neural networks for chemometric analysis of plastic has also been studied with IR spectra (Feldhoff et al, 1997;Wienke et al, 1995;Yang et al, 2020), Raman spectra (Musu et al, 2019;Roh et al, 2017) and LIBS spectra (Boueri et al, 2011;, 2020Roh et al, 2018). These works generally used basic three-layered neural network architecture, containing only one hidden layer.…”

“…However, recent advances have seen the development of high-speed MIR, Raman and LIBS spectrometers that can be applied in industrial sorting lines as well. For instance, an array of specialized Raman spectrometers was used to identify plastic on a conveyor belt moving at 100 m/s (Musu et al, 2019). Commercial MIR hyperspectral cameras and LIBS sorting sensor have also recently entered the market (Ocean Insight, n.d.;Specim, 2020).…”