1. Methods to be considered for multivariate calibration Many methods for multivariate calibration have been proposed. It turns out that many of the methods perform similarly. To avoid confusion due to use of many different methods, it is suggested that only the following should be considered: Multiple linear regression (MLR) Principal component regression (PCR) Partial least squares (PLS) Neur...

The composite-factor estimation dichotomy has been the epicenter of a long and ongoing debate among proponents and detractors of the use of the partial least squares (PLS) approach for structural equation modeling (SEM). In this brief research note we discuss the implementation of a new method to conduct factor-based PLS-SEM analyses, which could be a solid step in the resolution of this debate...

A simple and rapid method for the determination of Ba isotope abundances in water samples by inductively coupled plasma-optical emission spectrometry (ICP-OES) coupled with least-squares support vector machine regression (LS-SVM) is reported. By evaluation of emission lines of barium, it was found that the emission line at 493.408 nm provides the best results for the determination of Ba abundan...

Histone deacetylase 2 is a promising target for drug intervention and its inhibitors are useful in treating cancer. QSAR (2D and 3D) studies were performed on a series of N-(2-Aminophenyl)-Benzamide derivatives using Cerius2 software (accelrys). QSAR study performed on 25 analogues of which 21 were used in the training set and the rest 4 considered for the test set. 2DQSAR study performed using...

In the present work, an artificial neural network (ANN) model was used to study the quantitative structure retention relationship (QSRR) of retention index (RI) of some volatile compounds in natural cocoa and conched chocolate powder. Molecular structural descriptors are selected using genetic algorithm to construct the nonlinear QSRR models, kernel partial least squares PLS (KPLS) and Levenber...

The terahertz (THz) spectra of rapeseed leaves with different water content (WC) were investigated. The transmission and absorption spectra in the range of 0.3-2 THz were measured by using THz time-domain spectroscopy. The mean transmittance and absorption coefficients were applied to analyze the change regulation of WC. In addition, the Savitzky-Golay method was performed to preprocess the spe...

Panax ginseng C.A. Meyer is a herb used for medicinal purposes, and its discrimination according to cultivation age has been an important and practical issue. This study employed Fourier-transform infrared (FT-IR) spectroscopy with multivariate statistical analysis to obtain a prediction model for discriminating cultivation ages (5 and 6 years) and three different parts (rhizome, tap root, and ...

The purpose of the paper is to propose a new method for classification. Our MSPLS method was deduced from the classic Partial Least Squares (PLS) algorithm. In this method we applied the Maximum Separation Criterion. On the basis of the approach we are able to find such weight vectors that the dispersion between the classes is maximal and the dispersion within the classes is minimal. In order t...

A vital extension to partial least squares (PLS) path modeling is introduced: consistency. While maintaining all the strengths of PLS, the consistent version provides two key improvements. Path coefficients, parameters of simultaneous equations, construct correlations, and indicator loadings are estimated consistently. The global goodness-of-fit of the structural model can also now be assessed,...

Evaluation of the physico-chemical properties that affected the experimental data was performed for 45 newly synthesized compounds, derivatives of 2,4-dioksotetrahydro-1,3-thiazole. In order to quantify molecular structure various molecular descriptors were calculated for each of the 45 compounds. Evaluation of physico-chemical properties was done by the partial least-squares (PLS) regression. ...