Biased regression is an alternative to ordinary least squares (OLS) regression, especially when explanatory variables are highly correlated. In this paper, we examine the geometrical structure of the shrinkage factors of biased estimators. We show that, in most cases, shrinkage factors cannot belong to [0, 1] in all directions. We also compare the shrinkage factors of ridge regression (RR), pri...

A nondestructive method was developed for assessing total viable count (TVC) in pork during refrigerated storage by using hyperspectral imaging technique in this study. The hyperspectral images in the visible/near-infrared (VIS/NIR) region of 400–1100 nm were acquired for fifty pork samples, and their VIS/NIR diffuse reflectance spectra were extracted from the images. The reference values of TV...

We present a new regression method derived from standard PLSR which has a geometric point of view and consists of two projections. In the first, scores are obtained after an oblique projection of the spectra onto the loadings. In the second, the vector of response values is projected orthogonally onto the scores. A metric is introduced for the oblique projection and a new algorithm for calculat...

With 298 heterogeneous soil samples from Yixing (Jiangsu Province), Zhongxiang and Honghu (Hubei Province), this study aimed to combine a successive projections algorithm (SPA) with a support vector machine regression (SVMR) model (SPA-SVMR model) to improve the estimation accuracy of soil organic carbon (SOC) contents using the laboratory-based visible and near-infrared (VIS/NIR, 350−2500 nm) ...

Larix gmelinii is the major tree species in Northeast China. The wood properties of different are quite and under strong genetic controls, so it can be better improved through oriented breeding. In order to detect longitudinal compressive strength (LCS), modulus rupture (MOR) elasticity (MOE) real-time, fast non-destructively, a prediction model mechanical with high precision stability construc...

Variable selection is an important tool in QSAR. In this article, we employ three known techniques: sliced inverse regression (SIR), principal components regression (PCR) and partial least squares regression (PLSR) for models to predict the boiling points of 530 saturated hydrocarbons. With 122 topological indices as input variables our results show that these three methods have good performanc...

the use of chlorophyll fluorescence (chlf) technique was evaluated on nondestructive measurement of sugar content during fruit development. multivariate models, principal component analysis (pca), and partial least-squares regression (plsr), were developed for the classification and prediction of fructose, glucose, and sucrose in fig fruits. the results of this study showed a significant correl...