Total nitrogen has been determined by using a model developed between the conventional chemical measurements and diffuse reflectance spectra in the near-infrared region. Samples (244) from different types of soils with total nitrogen contents ranging from 0.20 to 13.60% (m/m) were modeled by partial least-squares regression (PLS), multi-layer perceptron feed-forward networks (MLP) and radial ba...

Changes in colors of an array of optical sensors that responds in full pH range were recorded using a CCD camera. The data of the camera were transferred to the computer through a capture card. Simple software was written to read the specific color of each sensor. In order to associate sensor array responses with pH values, a number of different mathematics and chemometrics methods were investi...

The direct determination in drinking water of perylene, chrysene, pyrene, benzo[a]pyrene, and benzo[k]fluoranthene, by front-face synchronous fluorimetry on a commercial SPE disk, has been evaluated. Sorbent treatment, influence of humic substances, and pH effect are discussed. In pure water the detection limits were estimated to be in the range 0.03-0.01 microg L(-1). A working pH in the range...

Absorption spectra of polycrystalline L-, D-, and DL-tartaric acid have been measured by terahertz time domain spectroscopy (THz-TDS). Different absorption bands are observed for DL-tartaric acid and its enantiomers (L- and D-tartaric acid). This result shows that the THz-TDS can be used for distinguishing between DL-tartaric acid and enantiomers (L- and D-tartaric acid). Moreover, partial leas...

A quantitative method to evaluate social risk using structural equation model (SEM) is developed. Evaluation of social risk is the essential step in early warning of social risk. On the basic of the society stability, a scientific and applicable index system of social risk is put forward, which includes 6 first-level indexes and 40 second-level indexes. Based on these indexes and relationships ...

BACKGROUND Given the serious threats posed to terrestrial ecosystems by industrial contamination, environmental monitoring is a standard procedure used for assessing the current status of an environment or trends in environmental parameters. Measurement of metal concentrations at different trophic levels followed by their statistical analysis using exploratory multivariate methods can provide m...

Even though a practical in vitro semen assay for determining bull fertility would be of great benefit to reproductive programs [6], it is unlikely that the evaluation of a single sperm characteristic may reflect the real sperm fertilization capacity of a semen sample. Hence, finding a set of sperm characteristics considered important for predicting conception rate would be a useful method of mo...

Genomic selection involves computing a prediction equation from the estimated effects of a large number of DNA markers based on a limited number of genotyped animals with phenotypes. The number of observations is much smaller than the number of independent variables, and the challenge is to find methods that perform well in this context. Partial least squares regression (PLS) and sparse PLS wer...

This research focuses on the development and empirical validation of a model of software piracy behavior in Vietnam on the basis of institution isomorphism theory, deterrence theory, and expected utility theory. A survey of 145 respondents and PLS (Partial Least Square) were utilized for analysis. The test of this study reveals that mimetic pressure is the greatest significant factor to influen...

Pharmacological and physicochemical classification of the furan and thiophene amide derivatives by multiple regression analysis and partial least square (PLS) based on semi-empirical ab initio molecular modeling studies and high-performance liquid chromatography (HPLC) retention data is proposed. Structural parameters obtained from the PCM (Polarizable Continuum Model) method and the literature...