Search results for "Least Squares"
showing 10 items of 268 documents
Continuous 3-year outdoor operation of a flat-panel membrane photobioreactor to treat effluent from an anaerobic membrane bioreactor
2020
[EN] A membrane photobioreactor (MPBR) plant was operated continuously for 3 years to evaluate the separate effects of different factors, including: biomass and hydraulic retention times (BRT, HRT), light path (Lp), nitrification rate (NOxR), nutrient loading rates (NLR, PLR) and others. The overall effect of all these parameters which influence MPBR performance had not previously been assessed. The multivariate projection approach chosen for this study provided a good description of the collected data and facilitated their visualisation and interpretation. Forty variables used to control and assess MPBR performance were evaluated during three years of continuous outdoor operation by means …
Online Estimation of the Mechanical Parameters of an Induction Machine Using Speed Loop characteristics and Recursive Least Square Technique
2022
This paper presents a novel approach for estimation of mechanical parameters, inertia and friction coefficient of an Induction Machine (IM) using speed loop characteristics and Recursive Least Square (RLS) estimator. Using the 5th order dynamic equation for Induction Machine and the forgetting factor based RLS algorithm the technique herein proposed employs the speed of the machine and the torque as the inputs for the estimator. Results obtained compares the estimated parameters with the actual parameters under multiple step varying and exponentially varying scenarios. Upon analyzing the results, the validity and the effectiveness of the proposed identification technique is confirmed
Efeitos das práticas verdes na lealdade: proposta de um modelo para o segmento hoteleiro colombiano
2021
Resumen El propósito de este estudio fue analizar la incidencia de las prácticas verdes como impulsoras para generar confianza, satisfacción y lealtad en los huéspedes. Para ello, a partir de una muestra de 302 huéspedes de hoteles en Bogotá, Colombia, se estimó un modelo de ecuaciones estructurales a través de la regresión de mínimos cuadrados parciales. Los resultados obtenidos evidencian que las prácticas sostenibles contribuyen al aumento de la confianza y la satisfacción de los huéspedes, y que estas, a su vez, influyen positivamente en su lealtad hacia el hotel. Además, dichos resultados ponen de manifiesto que una comprensión más profunda del perfil de los turistas medioambientalment…
Fast and direct analysis of oxidation levels of oil-in-water emulsions using ATR-FTIR.
2019
International audience; Oxidation of omega-3 fatty acids is a major limitation on its enrichment in food and beverages. An efficient and simple method to monitor lipid oxidation in complex systems is essential to limit lipid oxidation during formulation and processing. Fish oil-in-water emulsions (20% v/v) were exposed to iron or free radical initiated oxidation. Conjugated dienes (CDs) were rapidly measured using a previously developed fat extraction method. Fourier transform infrared (FTIR) spectroscopy has been used to directly record chemical changes occurring during oxidation. Variations were noticed in different spectral regions despite the presence of broad water bands near 3400 and …
Algorithms for rational discrete least squares approximation
1975
In this paper an algorithm for the computation of a locally optimal polefree solution to the discrete rational least squares problem under a mild regularity condition is presented. It is based on an adaptation of projection methods [8], [12], [13], [14], [18], [19] to the modified Gaus-Newton method [4], [10]. A special device makes possible the direct handling of the infinitely many linear constraints present in this problem.
Photoluminescence study of terbium-exchanged ultrastable Y zeolites: Number of species, photoluminescence decays and decay-associated spectra
2008
Terbium-exchanged ultrastable Y (USY) zeolites were investigated by using time-resolved photoluminescence spectroscopy techniques and methods. To determine the distribution of terbium species in USY zeolites together with their photoluminescence properties, several analysis methods for the time-resolved luminescence spectra were used such as the area normalization of time-resolved photoluminescence spectra, singular value decomposition, global nonlinear least squares, and the maximum entropy. Except for a questionable long lifetime, small contribution of a terbium species with lifetime of 1.9¿2.1 ms, all the experimental and analysis results converged to a two terbium species distribution w…
Maximum Likelihood Estimation and non-linear least squares fitting with Levenberg-Marquardt Algorithm implementation in FPGA devices for high resolut…
2012
This work compares two possible solutions to achieve a higher resolution in a hodoscope based on Plastic Scintillating Fibers (PSF) by obtaining the point of maximum incidence of the radioactive beam. The two fitting algorithms proposed have been tested and implemented in Field Programmable Gate Array (FPGA) devices. On one hand, a probabilistic model based on the Maximum Likelihood Estimation (MLE) and on the other hand, non-linear least-squares fit with the Levenberg-Marquardt Algorithm (LMA).
Consumer confidence: Causality links with subjective and objective information sources
2020
Abstract This study analyses the relationship of causality between consumer confidence and the economic information ecosystem from subjective (i.e., business sentiment) and objective sources (financial information from listed companies and the stock index). Our sample covers Spain from June 2011 to December 2018. Our results show that consumer confidence and economic information can exert a causality influence on each other. The results show Granger causality from IBEX35 and total assets in the financial sector and leverage of the companies in the energy sector to the consumer confidence index (CCI), in the first lag: from operating income in the telecommunications sector to the CCI in the …
Perceived Value in Tourism: A PLSPM Approach
2015
This paper examines the concept of perceived value in rural tourism referred to the specific context of Sicilian holiday farms. Herein main dimensions composing the rural tourist perceived value (RTPV) are discussed. Using Partial Least Squares Path Modelling (PLSPM) –a statistical technique especially suitable for exploratory purposes with small samples – a theoretical structural model of the multidimensional structure of RTPV is tested and the causal relationships among RTPV and its dimensions (Functional, Convenience, Emotional and Educational) and among RTPV and tourists’ satisfaction and loyalty are explored. Results from a field survey on 350 tourists give a contribution in terms of i…
Quantification and classification of high-resolution magic angle spinning data for brain tumor diagnosis.
2007
The goal of this work is to propose a complete protocol (preprocessing, processing and classification) for classifying brain tumors with proton high-resolution magic-angle spinning ((1)H HR-MAS) data. The different steps of the procedure are detailed and discussed. Feature extraction techniques such as peak integration, including also the automated quantitation method AQSES, were combined with linear (LDA) and non-linear (least-squares support vector machine or LS-SVM) classifiers. Classification accuracy was assessed using a stratified random sampling scheme. The results suggest that LS-SVM performs better than LDA while AQSES performs better than the standard peak integration feature extr…