Search results for "least square"
showing 10 items of 286 documents
An Emulator Toolbox to Approximate Radiative Transfer Models with Statistical Learning
2015
Physically-based radiative transfer models (RTMs) help in understanding the processes occurring on the Earth’s surface and their interactions with vegetation and atmosphere. When it comes to studying vegetation properties, RTMs allows us to study light interception by plant canopies and are used in the retrieval of biophysical variables through model inversion. However, advanced RTMs can take a long computational time, which makes them unfeasible in many real applications. To overcome this problem, it has been proposed to substitute RTMs through so-called emulators. Emulators are statistical models that approximate the functioning of RTMs. Emulators are advantageous in real practice because…
Customer Value Framework and Recommendation Intention: The Moderating Role of Customer Characteristics in an Online Travel Community
2019
The aim of this study was to develop and test a model that examined the interactions among the customer value framework, recommendation intention and customer characteristics in an online travel community (OTC). Data were obtained using Amazon Mechanical Turk from 251 members of an OTC as a sample. The partial least squares method was used to analyse the data. We found that all the variables of the customer value framework, including functional value, hedonic value and social value, were positively related to recommendation intention. In addition, using multi-group analyses, the study found differences between how different customer segments perceive each of the value dimensions and their e…
Optimal Spectral Wavelengths for Discriminating Orchard Species Using Multivariate Statistical Techniques
2019
Sustainable management of orchard fields requires detailed information about the tree types, which is a main component of precision agriculture programs. To this end, hyperspectral imagery can play a major role in orchard tree species mapping. Efficient use of hyperspectral data in combination with field measurements requires the development of optimized band selection strategies to separate tree species. In this study, field spectroscopy (350 to 2500 nm) was performed through scanning 165 spectral leaf samples of dominant orchard tree species (almond, walnut, and grape) in Chaharmahal va Bakhtiyari province, Iran. Two multivariable methods were employed to identify the optimum wavelengths:…
Measuring the perceived value of rural tourism: a field survey in the western Sicilian agritourism sector
2016
Rural tourism constitutes a valuable tool for the sustainable development of many rural areas. This paper examines the concept of perceived value in rural tourism. A quantitative field survey was carried out in some main Western Sicilian holiday farms (agritourisms) during the Spring 2014. A theoretical model of the tourists’ perceived value in this specific context was developed and validated, using a 22-item scale. Using Partial Least Squares Path Modelling a theoretical structural model of the multidimensional structure of the RTPV was tested, assessing intensity and direction of the causal relationships among RTPV and its dimensions. Five dimensions were identified as forming the constr…
Structural Parameters under Partial Least Squares and Covariance-Based Structural Equation Modeling : A Comment on Yuan and Deng (2021)
2023
In their article, Yuan and Deng argue that a structural parameter under partial least squares structural equation modeling (PLS-SEM) is zero if and only if the same structural parameter is zero under covariance-based structural equation modeling (CB-SEM). Yuan and Deng then conclude that statistical tests on individual structural parameters assessing the null hypothesis of no effect can achieve the same purpose in CB-SEM and PLS-SEM. Our response to their article highlights that the relationship they find between PLS-SEM and CB-SEM structural parameters is not universally valid, and that consequently, tests on individual parameters in CB-SEM and PLS-SEM generally do not fulfill the same pur…
El entorno del servicio -Artscape- y su influencia en el comportamiento del asistente de artes escénicas
2015
La presente tesis doctoral propone un modelo teórico que explica la relación entre el servicescape y la respuesta del consumidor en términos de valor percibido, satisfacción y lealtad, con el añadido de interpretar estas relaciones a través del papel moderador que ejercen las emociones. Para nuestro análisis del servicescape, éste se ha definido como un constructo de tercer orden compuesto formativamente por dos dimensiones: la referente a las características físicas –elementos exteriores e interiores- y la referente a aquellas cuestiones relacionadas con la relación social establecida entre los actores de la prestación del servicio, es decir, consumidores y organización –características de…
Computing Difficulties for Deriving Poverty Indices from Some Functional Forms of Lorenz Curves
2014
We examine three families of classical one-parameter functional forms for estimating a Lorenz curve: the power form (Pareto, elementary form), the exponential form (Gupta, elementary form) and fractional form (Rohde). For the first time, we systematically study these functions not for their ability to be estimated but on the point of view of the possibility of deriving poverty indices, which implies first determining the headcount ratio (i.e., the percentage of poor). We show that computing difficulties have been largely underestimated. Two forms, the most simple ones, pose no problem: the elementary power and exponential forms. However, the Pareto functional form poses problem with a restr…
Exploiting ongoing EEG with multilinear partial least squares during free-listening to music
2016
During real-world experiences, determining the stimulus-relevant brain activity is excitingly attractive and is very challenging, particularly in electroencephalography. Here, spectrograms of ongoing electroencephalogram (EEG) of one participant constructed a third-order tensor with three factors of time, frequency and space; and the stimulus data consisting of acoustical features derived from the naturalistic and continuous music formulated a matrix with two factors of time and the number of features. Thus, the multilinear partial least squares (PLS) conforming to the canonical polyadic (CP) model was performed on the tensor and the matrix for decomposing the ongoing EEG. Consequently, we …
Higher-order Nonnegative CANDECOMP/PARAFAC Tensor Decomposition Using Proximal Algorithm
2019
Tensor decomposition is a powerful tool for analyzing multiway data. Nowadays, with the fast development of multisensor technology, more and more data appear in higherorder (order > 4) and nonnegative form. However, the decomposition of higher-order nonnegative tensor suffers from poor convergence and low speed. In this study, we propose a new nonnegative CANDECOM/PARAFAC (NCP) model using proximal algorithm. The block principal pivoting method in alternating nonnegative least squares (ANLS) framework is employed to minimize the objective function. Our method can guarantee the convergence and accelerate the computation. The results of experiments on both synthetic and real data demonstrate …
Exploring User Acceptance of Free Wireless Fidelity Public Hot Spots : An Empirical Study
2008
Research regarding commercial and free wireless fidelity (Wi-Fi) public hot spots acceptance and adoption is sketchy. Therefore, it has become imperative to understand the critical factors that affect their acceptance. The focus of this study is free Wi-Fi public hot spot users, with the objective to better understand their user acceptance. In doing so, this study integrated two well-established initial acceptance models, specifically, the technology acceptance model and the diffusion of innovation theory. This study was conducted using an on-line survey that collected data from 129 users. It uses the Partial Least Square (PLS) technique to examine the relationship between variables. The re…