Search results for " statistics"
showing 10 items of 1891 documents
Advances in blind source separation for spatial data
2021
Viele Datensaetze bestehen aus multivariaten Messungen, die an verschiedenen geographischen Orten durchgefuehrt wurden. Typischerweise besitzen solche Datensaetze die Eigenschaft, dass Messungen in unmittelbarer Naehe aehnlicher sind als Messungen, die eine hohe Entfernung aufweisen. In der statistischen Analyse solcher raeumlichen Daten sollte diese spezielle Eigenschaft beruecksichtigt werden. In letzter Zeit wurde in der statistischen Literatur die sogenannte Blind Source Separation Methode auf raeumliche Daten erweitert. In diesem Model wird angenommen, dass die Daten aus Linearkombinationen von unbeobachteten Variablen bestehen, und das Ziel ist diese latenten Variablen zu bestimmen. D…
Effects of Polyphenol, Measured by a Biomarker of Total Polyphenols in Urine, on Cardiovascular Risk Factors After a Long-Term Follow-Up in the PREDI…
2016
Several epidemiological studies have shown an inverse association between the consumption of polyphenol-rich foods and risk of cardiovascular diseases. However, accuracy and reliability of these studies may be increased using urinary total polyphenol excretion (TPE) as a biomarker for total polyphenol intake. Our aim was to assess if antioxidant activity, measured by a Folin-Ciocalteu assay in urine, is correlated with an improvement in cardiovascular risk factors (blood pressure and serum glucose, cholesterol, HDL-cholesterol, LDL-cholesterol, and triglyceride concentrations) in an elderly population at high risk. A longitudinal study was performed with 573 participants (aged 67.3 ± 5.9) f…
One-dimensional heterogeneous solids with uncertain elastic modulus in presence of long-range interactions: Interval versus stochastic analysis
2013
The analysis of one-dimensional non-local elastic solids with uncertain Young's modulus is addressed. Non-local effects are represented as long-range central body forces between non-adjacent volume elements. For comparison purpose, the fluctuating elastic modulus of the material is modeled following both a probabilistic and a non-probabilistic approach. To this aim, a novel definition of the interval field concept, able to limit the overestimation affecting ordinary interval analysis, is introduced. Approximate closed-form expressions are derived for the bounds of the interval displacement field as well as for the mean-value and variance of the stochastic response.
Coherence between brain activation and speech envelope at word and sentence levels showed age-related differences in low frequency bands
2021
Abstract Speech perception is dynamic and shows changes across development. In parallel, functional differences in brain development over time have been well documented and these differences may interact with changes in speech perception during infancy and childhood. Further, there is evidence that the two hemispheres contribute unequally to speech segmentation at the sentence and phonemic levels. To disentangle those contributions, we studied the cortical tracking of various sized units of speech that are crucial for spoken language processing in children (4.7–9.3 years old, N = 34) and adults (N = 19). We measured participants’ magnetoencephalogram (MEG) responses to syllables, words, and…
Measuring High-Order Interactions in Rhythmic Processes Through Multivariate Spectral Information Decomposition
2021
Many complex systems in physics, biology and engineering are modeled as dynamical networks and described using multivariate time series analysis. Recent developments have shown that the emergent dynamics of a network system are significantly affected by interactions involving multiple network nodes which cannot be described using pairwise links. While these higher-order interactions can be probed using information-theoretic measures, a rigorous framework to describe them in the frequency domain is still lacking. This work presents an approach for the spectral decomposition of multivariate information measures, capable of identifying higher-order synergistic and redundant interactions betwee…
Extropy: Complementary Dual of Entropy
2015
This article provides a completion to theories of information based on entropy, resolving a longstanding question in its axiomatization as proposed by Shannon and pursued by Jaynes. We show that Shannon's entropy function has a complementary dual function which we call "extropy." The entropy and the extropy of a binary distribution are identical. However, the measure bifurcates into a pair of distinct measures for any quantity that is not merely an event indicator. As with entropy, the maximum extropy distribution is also the uniform distribution, and both measures are invariant with respect to permutations of their mass functions. However, they behave quite differently in their assessments…
Radiocarbono y estadística Bayesiana: aportaciones a la cronología de la Edad del Bronce en el extremo oriental del sudeste de la península Ibérica
2014
La investigación arqueológica desarrollada en las últimas décadas ha permitido evaluar que en los valles de los ríos Segura y Vinalopó se dirimió el contacto entre dos sociedades de la Edad del Bronce de la península Ibérica: el grupo Argárico y el grupo del Prebético Meridional Valenciano. Las excavaciones realizadas en tres yacimientos de este ámbito - Terlinques, Cabezo Pardo y Cabezo Redondo- y las dotaciones de radiocarbono obtenidas permiten por primera vez evaluar la diacronía del proceso histórico que envolvió el desarrollo de ambos grupos arqueológicos a lo largo del II milenio cal BC, así como determinar diversos momentos socialmente significativos en su devenir histórico. Para el…
La circulation des objets métalliques à l'âge du Bronze entre Rhône et Saône: utilisation d'une transformation cartographique linéaire
2006
In order to gain a better understanding of circulation flows of metal objects during the Bronze Age, and move beyond traditional distribution maps of archaeological discoveries, the authors propose a more quantitative and concise method of graphic representation, namely cartographic linear transformation. The value of the method was tested on the Saône-Rhône axis. Bronze axes, swords and daggers were recorded along a 50 km strip either side of the river axis, in order to estimate the frequency and mass of objects in “circulation”.
Burnout Syndrome in municipal health managers
2016
Resumo Introdução Os gestores municipais da saúde devem responder às demandas de suas equipes e dos pacientes do Sistema Único de Saúde, enfrentando cotidianamente situações potencialmente estressoras. A sobrecarga no trabalho pode levar à exaustão física e mental, com esgotamento dos recursos emocionais, e desencadear a Síndrome de Burnout (SB), cujas consequências podem atingir o serviço gerenciado, uma vez que, ao desempenhar essa atividade laboral, tomam-se decisões determinantes nas ações em saúde que afetam muitas pessoas. Este estudo verificou a presença da SB nos gestores municipais de saúde do Estado de São Paulo. Métodos Estudo do tipo transversal no qual foram coletados dados soc…
A Geometric Algorithm for Ray/Bézier Surfaces Intersection Using Quasi-Interpolating Control Net
2008
In this paper, we present a new geometric algorithm to compute the intersection between a ray and a rectangular Bezier patch. The novelty of our approach resides in the use of bounds of the difference between a Bezier patch and its quasi-interpolating control net. The quasi-interpolating polygon of a Bezier surface of arbitrary degree approximates the limit surface within a precision that is function of the second order difference of the control points, which allows for very simple projections and 2D intersection tests to determine sub-patches containing a potential intersection. Our algorithm is simple, because it only determines a 2D parametric interval containing the solution, and effici…