Search results for "resolution."
showing 10 items of 1825 documents
New computational techniques for finite-difference Weighted Essentially Non-Oscillatory schemes and related problems
2014
High-Resolution Shock-Capturing (HRSC) schemes constitute the state of the art for computing accurate numerical approximations to the solution of many hyperbolic systems of conservation laws, especially in computational fluid dynamics. A drawback of these schemes is that most of them use the spectral decomposition of the Jacobian matrix of the system to compute the numerical approximations by local projections to characteristic fields. The numerical solutions obtained are often excellent in terms of resolution, but the computational effort needed may be too high for some problems, especially those for which the spectral information of the flux Jacobian matrix is not available or is quite di…
Transformaciones multiescala no lineales
2013
La transformada wavelet y la multirresolución à la Harten son dos herramientas matemáticas que han sido aplicadas con éxito al tratamiento de señales digitales. En los últimos años, este campo ha experimentado un creciente interés debido a sus múltiples aplicaciones como, entre otras, la compresión de imágenes, eliminación de ruido, reconocimiento de patrones, recuperación de fotografías, en campos tan diversos como la Informática, Física, Medicina o Ingeniería. Iniciamos esta tesis con la revisión de estos conceptos. En 1993 A. Harten, [A. Harten. Discrete multiresolution analysis and generalized wavelets. J. Appl. Numer. Math., 12:153–192 (1993)], generaliza un cierto tipo de wavelets bio…
Measurement of inclusive jet and dijet cross sections in proton-proton collisions at 7 TeV centre-of-mass energy with the ATLAS detector
2011
Jet cross sections have been measured for the first time in proton-proton collisions at a centre-of-mass energy of 7 TeV using the ATLAS detector. The measurement uses an integrated luminosity of 17 nb−1 recorded at the Large Hadron Collider. The anti-k t algorithm is used to identify jets, with two jet resolution parameters, R=0.4 and 0.6. The dominant uncertainty comes from the jet energy scale, which is determined to within 7% for central jets above 60 GeV transverse momentum. Inclusive single-jet differential cross sections are presented as functions of jet transverse momentum and rapidity. Dijet cross sections are presented as functions of dijet mass and the angular variable χ. The res…
Problemas multiplicativos relacionados con la división de fracciones : un estudio sobre su enseñanza y aprendizaje
2013
Los estudiantes tienen dificultades para asociar el enunciado de un problema multiplicativo con la operación que permite resolverlo; esta investigación identifica los tipos de problemas multiplicativos que los estudiantes reconocen como de división de fracciones. Mediante el análisis histórico-epistemológico de textos de enseñanza sobre tres épocas históricas y ocho períodos diferentes, se obtiene un listado de variables de enseñanza (algoritmos, sentidos de uso de fracción y de división de fracciones, representaciones, problemas), así como los valores de dichas variables. Se localizan en los textos consultados algunas reglas particulares y seis algoritmos generales, cuyo predominio ha vari…
The BRICS Centres of Dispute Resolution: causes, state of the art, and prospects
2023
The idea of an enhanced cooperation and exchange of knowledge and best practices among its member states in the fields of trade, commerce, and investments -among others- is at the heart of BRICS. In fact, intra-BRICS trade has nearly tripled over the last decade, supported by an increase in intra-regional trade for all member countries. Thanks to their influential and remarkable progress in promoting local currency (for de-dollarisation purposes), regional FDI, and regional trade, the BRICS economies have emerged and have taken a new space in the twenty-first century. This reinforced one of the core objectives pursued by BRICS which is that of enhancing the five developing economies’ role i…
Acceso a la Justicia de los Consumidores a través del ADR y del ODR
2018
El avance de las tecnologías de información y la comunicación nos ha llevado a cambiar nuestra forma de relacionarnos tanto entre nosotros, como con las administraciones. Además, la adquisición de bienes de consumo a través del medio online es cada día más importante para en la economía global y doméstica. Todo ello, llevó a la Unión Europea a la creación del llamado Mercado Único Digital, donde se estableció como uno de los objetivos prioritarios mejorar la tutela efectiva de los ciudadanos comunitarios que realizan compras a través de internet. El presente trabajo tiene por objeto realizar un análisis sobre las facilidades y dificultades que encuentran los consumidores a la hora de accede…
Pulsating in Unison at Optical and X-Ray Energies: Simultaneous High Time Resolution Observations of the Transitional Millisecond Pulsar PSR J1023+00…
2019
PSR J1023+0038 is the first millisecond pulsar discovered to pulsate in the visible band; such a detection took place when the pulsar was surrounded by an accretion disk and also showed X-ray pulsations. We report on the first high time resolution observational campaign of this transitional pulsar in the disk state, using simultaneous observations in the optical (TNG, NOT, TJO), X-ray (XMM-Newton, NuSTAR, NICER), infrared (GTC) and UV (Swift) bands. Optical and X-ray pulsations were detected simultaneously in the X-ray high intensity mode in which the source spends $\sim$ 70% of the time, and both disappeared in the low mode, indicating a common underlying physical mechanism. In addition, o…
Scientific Merits and Analytical Challenges of Tree‐Ring Densitometry
2019
X-ray microdensitometry on annually resolved tree-ring samples has gained an exceptional position in last-millennium paleoclimatology through the maximum latewood density (MXD) parameter, but also increasingly through other density parameters. For 50 years, X-ray based measurement techniques have been the de facto standard. However, studies report offsets in the mean levels for MXD measurements derived from different laboratories, indicating challenges of accuracy and precision. Moreover, reflected visible light-based techniques are becoming increasingly popular, and wood anatomical techniques are emerging as a potentially powerful pathway to extract density information at the highest resol…
GEOV1: LAI, FAPAR essential climate variables and FCOVER global time series capitalizing over existing products. Part 2: Validation and intercomparis…
2013
International audience; This paper describes the scientific validation of the first version of global biophysical products (i.e., leaf area index, fraction of absorbed photosynthetically active radiation and fraction of vegetation cover), namely GEOV1, developed in the framework of the geoland-2/BioPar core mapping service at 1 km spatial resolution and 10-days temporal frequency. The strategy follows the recommendations of the CEOS/WGCV Land Product Validation for LAI global products validation. Several criteria of performance were evaluated, including continuity, spatial and temporal consistency, dynamic range of retrievals, statistical analysis per biome type, precision and accuracy. The…
Accurate estimation of retinal vessel width using bagged decision trees and an extended multiresolution Hermite model.
2012
We present an algorithm estimating the width of retinal vessels in fundus camera images. The algorithm uses a novel parametric surface model of the cross-sectional intensities of vessels, and ensembles of bagged decision trees to estimate the local width from the parameters of the best-fit surface. We report comparative tests with REVIEW, currently the public database of reference for retinal width estimation, containing 16 images with 193 annotated vessel segments and 5066 profile points annotated manually by three independent experts. Comparative tests are reported also with our own set of 378 vessel widths selected sparsely in 38 images from the Tayside Scotland diabetic retinopathy scre…