“…By contrast, developing a soft sensor based on DDMs only requires obtaining the historical operational data without considering the complex mechanism or process knowledge, and this has been successfully applied to many spheres, which has attracted more and more attention from academia and industry. Classical data-driven modeling methods include principle component analysis (PCA) [ 11 , 12 , 13 , 14 , 15 , 16 ], support vector machine (SVM) [ 17 , 18 , 19 , 20 ], partial least squares (PLS) [ 21 , 22 ], Gaussian process regression (GPR) [ 23 , 24 ], Bayesian prediction [ 25 , 26 ], slow feature analysis (SFA) [ 27 , 28 , 29 , 30 ], extreme learning machine (ELM) [ 31 ] and their improved models, artificial neural networks (ANNs) [ 32 ] and two or more hybrid models [ 33 , 34 , 35 ], among others. The advantage of PCA is that it is convenient for simplifying the model and is generally used for the correlation analysis between the same matrix vectors.…”