Search results for "MATRICE"
showing 10 items of 218 documents
The effects of different basal levels of anxiety on the behavioral shift analyzed in the central platform of the elevated plus maze.
2015
The aim of the present research was to study the effects of different basal levels of anxiety on the behavioral shift studied in the central platform of the elevated plus maze. To this purpose, quantitative and multivariate analyses, the latter based on transition matrix elaboration, were carried out on Wistar and on DA/Han rats the latter belonging to a strain characterized by different reactivity to anxiogenic stimuli. Wistar rats spent 74.11 ± 5.11 s in the central platform, whereas DA/Han significantly more: 127.08 ± 9.87. Per cent distributions evidenced a clear-cut difference in walking activities (46.25% in Wistar, 28.4% in DA/Han rats) and in the sniffing activities (45.82% in Wista…
Associations of IGF-1 and Adrenal Androgens with Cognition in Childhood
2019
<b><i>Background:</i></b> Little is known about the association between adrenarche and cognition in general populations of children. We therefore studied the associations of dehydroepiandrosterone sulfate (DHEAS), androstenedione (A4), testosterone, insulin-like growth factor-1 (IGF-1), and adrenarche with cognition among prepubertal children. <b><i>Methods:</i></b> These cross-sectional analyses are based on baseline data of the Physical Activity and Nutrition in Children Study. A total of 387 children (183 girls, 204 boys) were included in the analyses. Raven’s Coloured Progressive Matrices (CPM) score was used to assess nonverbal reasoning.…
Effects of a Nine-Month Physical Activity Intervention on Morphological Characteristics and Motor and Cognitive Skills of Preschool Children
2020
(1) Background: Regular physical activity (PA) plays an important role during early childhood physical and psychological development. This study investigates the effects of a 9-month PA intervention on physiological characteristics and motor and cognitive skills in preschool children. (2) Methods: Preschool children (n = 132
Longitudinal Associations of Fitness, Motor Competence, and Adiposity with Cognition
2019
Purpose: The purpose of this study was to investigate the longitudinal associations of cardiorespiratory fitness (CRF), motor competence (MC), and body fat percentage (BF%) with cognition in children. Methods: Altogether, 371 children (188 boys and 183 girls) 6–9 yr of age at baseline participated in this 2-yr follow-up study. We assessed CRF by maximal cycle ergometer test, computed the MC score from the z-scores of the 50-m shuttle run, static balance, and box and block test results, measured BF% by dual-energy x-ray absorptiometry, and assessed cognition using the Raven’s Coloured Progressive Matrices (RCPM) score. The associations were studied by linear regression analysis and repeated-…
Algorithms for {K, s+1}-potent matrix constructions
2013
In this paper, we deal with {K, s + 1}-potent matrices. These matrices generalize all the following classes of matrices: k-potent matrices, periodic matrices, idempotent matrices, involutory matrices, centrosymmetric matrices, mirrorsymmetric matrices, circulant matrices, among others. Several applications of these classes of matrices can be found in the literature. We develop algorithms in order to compute {K, s + 1}-potent matrices and {K, s + 1}-potent linear combinations of {K, s + 1}-potent matrices. In addition, some examples are presented in order to show the numerical performance of the method. (C) 2012 Elsevier B.V. All rights reserved.
Implementation of eco-sustainable biocomposite materials reinforced by optimized agave fibers
2018
Abstract Although several works have recently been published in literature about biocomposites, i.e. about composites with polymeric matrix reinforced by natural fibers, only a few articles have been devoted to the implementation of high performance biocomposites for structural and semi-structural applications. The present study aims to give a contribution by considering biocomposites obtained by using an eco-friendly partially bio-based epoxy (green epoxy) and sisal (agave sisalana fibers) obtained by a proper optimization process. Through a systematic experimental analysis, three different types of biocomposites obtained with a suitable manufacturing process, such as random short fiber bi…
How to simulate normal data sets with the desired correlation structure
2010
The Cholesky decomposition is a widely used method to draw samples from multivariate normal distribution with non-singular covariance matrices. In this work we introduce a simple method by using singular value decomposition (SVD) to simulate multivariate normal data even if the covariance matrix is singular, which is often the case in chemometric problems. The covariance matrix can be specified by the user or can be generated by specifying a subset of the eigenvalues. The latter can be an advantage for simulating data sets with a particular latent structure. This can be useful for testing the performance of chemometric methods with data sets matching the theoretical conditions for their app…
A fast 3D dual boundary element method based on hierarchical matrices
2008
AbstractIn this paper a fast solver for three-dimensional BEM and DBEM is developed. The technique is based on the use of hierarchical matrices for the representation of the collocation matrix and uses a preconditioned GMRES for the solution of the algebraic system of equations. The preconditioner is built exploiting the hierarchical arithmetic and taking full advantage of the hierarchical format. Special algorithms are developed to deal with crack problems within the context of DBEM. The structure of DBEM matrices has been efficiently exploited and it has been demonstrated that, since the cracks form only small parts of the whole structure, the use of hierarchical matrices can be particula…
The varieties of bifocal Grassmann tensors
2022
AbstractGrassmann tensors arise from classical problems of scene reconstruction in computer vision. In particular, bifocal Grassmann tensors, related to a pair of projections from a projective space onto view spaces of varying dimensions, generalize the classical notion of fundamental matrices. In this paper, we study in full generality the variety of bifocal Grassmann tensors focusing on its birational geometry. To carry out this analysis, every object of multi-view geometry is described both from an algebraic and geometric point of view, e.g., the duality between the view spaces, and the space of rays is explicitly described via polarity. Next, we deal with the moduli of bifocal Grassmann…
On the consistency of the commodity-based technology in make-use model of production
2001
In the Stone make-use model, the industry-based technology is consistent because his solution can be explained in variational terms inside a circuit. However, the alternative model, the commodity-based technology, is not economically realistic: it never corresponds to a circuit, even if an exact solution can be found when the number of commodities is equal to the number of industries. This model hesitates between a supply-driven and a demand-driven model but when it is converted into a true supply-driven one, it retrieves a consistency.