Search results for "partial least square"
showing 10 items of 152 documents
Direct determination of polymerised triacylglycerides in deep-frying vegetable oil by near infrared spectroscopy using Partial Least Squares regressi…
2012
Abstract A green method for the determination of polymerised triacylglyceride (PTG) in deep-frying vegetable oils of different botanic origin has been developed employing near infrared (NIR) spectroscopy and Partial Least Squares (PLS) regression. Four different types of oil were heated during several hours, with and without the addition of foodstuff. NIR transmission spectra were obtained directly from sample aliquots stored in glass vials, thus avoiding the consumption of solvents and minimising waste generation. Variables employed for building the PLS models were selected applying interval PLS (iPLS) as well as Uninformative Variable Elimination-PLS (UVE-PLS). A global PLS model using sp…
Individual Performance in Turbulent Environments: The Role of Organizational Learning Capability and Employee Flexibility
2015
Organizational learning capability (OLC) and employee flexibility help firms navigate the challenges faced by organizations operating in turbulent environments. OLC includes dimensions such as experimentation, risk taking, openness, dialogue, and participative decision making. Employee flexibility is considered a crucial tool for strategic human resource management in tackling environmental turbulence. Accordingly, we pose the following research question: how, and to what extent, is individual performance enhanced by OLC and employee flexibility in turbulent environments? The major impact that environmental turbulence has on change and flexibility requirements suggests that employee flexibi…
Evaluating Assessment. Validation with PLS-SEM of ATAE Scale for the Analysis of Assessment Tasks
2020
One of the essential functions of university teachers lies in the decision-making process regarding the various components included in assessment process design, where the quality of assessment tasks is a key aspect. This study presents both validation of an instrument for students to evaluate the assessment tasks and the model that upholds the relationships between constructs that characterise the assessment tasks. Working from a review of the literature, a theoretical model has been devised featuring the characteristics of the assessment tasks and the relationships between them. The Analysis of the Assessment and Learning Tasks questionnaire (ATAE) has been designed to check them, based o…
Linking market orientation, innovation and performance: an empirical study on small industrial enterprises in Spain
2016
Many studies uphold market orientation as a key factor in creating and sustaining a firm’s competitive advantage. The present research model explores this topic further by including within the model the links between organizations’ innovation outcomes and business performance. In particular, the model empirically tests the mediating role of innovation outcomes in the relationship between market orientation and business performance. The present study uses a sample of 145 firms belonging to the Spanish automotive components manufacturing sector, which is essentially composed of small and medium sized enterprises (SMEs). In order to test and validate our research model and hypotheses, this stu…
Biopartitioning micellar chromatography to predict skin permeability
2003
Dermal absorption of chemicals is an area of increasing interest to the pharmaceutical and cosmetic industries, as well as in dermal exposure and risk assessment processes. In this paper the capability of biopartitioning micellar chromatography (BMC) as an in vitro technique to describe compound percutaneous absorption is evaluated. A multivariate study (principal component analysis, partial least squares) is performed in order to evaluate the importance of some physicochemical variables on the skin permeability constant values. From these results, a quantitative retention-activity relationship model for predicting the skin permeability constants that uses the BMC retention data and melting…
Transition paths between phases IV, III and II of ammonium nitrate predicted from X-ray powder diffractometer and differential scanning calorimeter d…
1994
Abstract Ammonium nitrate solid phase transition paths between phases IV, III and II were explained and predicted on the basis of X-ray powder diffraction (XRD) and differential scanning calorimetry (DSC) data by applying partial least-squares regression (PLS) and principal component analysis (PCA). The samples were clustered according to their different transition paths with the PLS and PCA models, and the transition paths were predicted with PLS component clusters. The best PLS clusters were formed by a few first components. Prediction of the transition path with the PLS clusters made a semiquantitative prediction of the transition energy possible. In PCA, principal components 6 and 11, w…
A modified least squares FE-method for ideal fluid flow problems
1982
A modified least squares FE-method suitable e.g. for calculating the ideal fluid flow is presented. It turns out to be essentially more efficient than the conventional least squares method. peerReviewed
Smartphone determination of fat in cured meat products
2017
Abstract A method has been developed to determine the fat content in different cold meat products by image processing using the camera of a mobile phone. Salchichon , chorizo , salami and cured ham pictures were taken with a Meizu M2 Mini mobile phone camera under fixed lighting conditions of the light emitting diode flash of the mobile phone. Images were treated with Matlab to obtain the mean pixels of average red, green and blue camera values colours (RGB) of the pixels and different data pretreatments were taken into account to correlate colour parameters with fat content values determined in a series of commercially available samples by the Soxhlet method. RGB values were used as input …
Quantification of phenolic acids by partial least squares Fourier-transform infrared (PLS-FTIR) in extracts of medicinal plants.
2020
Introduction Phenolic compounds are ubiquitous compounds found in all plants as their secondary metabolites. Phenols are becoming increasingly important particularly because of their beneficial effects on health. Objective To provide a faithful calibration model for the simultaneous determination and quantification of phenolic acids, as salicylic, vanillic, p-hydroxybenzoic acids, eugenol and thymol in different extracts of medicinal plants, a comparative study was made between two methods of infrared measurements based on attenuated total reflectance (ATR) and transmission. Methods Characteristic absorbance peak heights of mid-infrared spectra of individual phenolic acids were measured for…
Characterization of pre-treatments on wood chips prior to delignification by near infrared spectroscopy
2017
A near infrared (NIR) spectroscopy-based method for predicting yields and lignin contents of differently pre-treated silver/white birch (Betula pendula/B. pubescens) and Scots pine (Pinus sylvestris) chips was developed. The approach was to create multivariate calibration models from the NIR data by the partial least squares (PLS) method. Both parameters are important factors when adjusting adequate conditions for pre-treatments either with hot-water (HW) as such and slightly acidified HW (collectively referred to as autohydrolysis) or dilute alkaline aqueous solutions prior to alkaline pulping. Pre-treatment conditions were varied with respect to temperature (130 °C and 150 °C) and treatme…