2,121 research outputs found

    Multivariate Nonparametric Estimation of the Pickands Dependence Function using Bernstein Polynomials

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    Many applications in risk analysis, especially in environmental sciences, require the estimation of the dependence among multivariate maxima. A way to do this is by inferring the Pickands dependence function of the underlying extreme-value copula. A nonparametric estimator is constructed as the sample equivalent of a multivariate extension of the madogram. Shape constraints on the family of Pickands dependence functions are taken into account by means of a representation in terms of a specific type of Bernstein polynomials. The large-sample theory of the estimator is developed and its finite-sample performance is evaluated with a simulation study. The approach is illustrated by analyzing clusters consisting of seven weather stations that have recorded weekly maxima of hourly rainfall in France from 1993 to 2011

    Association of mid-infrared solar plages with Calcium K line emissions and magnetic structures

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    Solar mid-IR observations in the 8-15 micrometer band continuum with moderate angular resolution (18 arcseconds) reveal the presence of bright structures surrounding sunspots. These plage-like features present good association with calcium CaII K1v plages and active region magnetograms. We describe a new optical setup with reflecting mirrors to produce solar images on the focal plane array of uncooled bolometers of a commercial camera preceded by germanium optics. First observations of a sunspot on September 11, 2006 show a mid-IR continuum plage exhibiting spatial distribution closely associated with CaII K1v line plage and magnetogram structures. The mid-IR continuum bright plage is about 140 K hotter than the neighboring photospheric regions, consistent with hot plasma confined by the magnetic spatial structures in and above the active regionComment: 5 pages, 4 figures. Accepted by PAS

    Comparison of 30 THz impulsive burst time development to microwaves, H-alpha, EUV, and GOES soft X-rays

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    The recent discovery of impulsive solar burst emission in the 30 THz band is raising new interpretation challenges. One event associated with a GOES M2 class flare has been observed simultaneously in microwaves, H-alpha, EUV, and soft X-ray bands. Although these new observations confirm some features found in the two prior known events, they exhibit time profile structure discrepancies between 30 THz, microwaves, and hard X-rays (as inferred from the Neupert effect). These results suggest a more complex relationship between 30 THz emission and radiation produced at other wavelength ranges. The multiple frequency emissions in the impulsive phase are likely to be produced at a common flaring site lower in the chromosphere. The 30 THz burst emission may be either part of a nonthermal radiation mechanism or due to the rapid thermal response to a beam of high-energy particles bombarding the dense solar atmosphere.Comment: accepted to Astronomy and Astrophysic

    La enseñanza del fútbol sala en la formación de futuros profesionales de la Educación Física: la aproximación entre la teoría y la práctica

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    El trabajo describe una actividad realizada en la asignatura de fútbol sala del curso de formación de profesorado en Educación Física de la Universidade de Caxias do Sul (UCS) en Brasil. Los estudiantes impartieron clases de fútbol sala para niñas con edad entre los 11 y los 14 años en los centros de enseñanza de la ciudad de Caxias do Sul y su región. El objetivo de la actividad fue proporcionar a los futuros profesionales un mayor acercamiento a la realidad con la cual se deberán enfrentar en un futuro muy cercano, produciendo una formación más significativa y relevante. Al final del curso, después de los 18 partidos semanales previstos, más las clases para las chicas, los estudiantes respondieron un pequeño cuestionario adaptado en la escala de Likert sobre la importancia de la experiencia práctica para su formación. Los resultados determinaron que 7% de los alumnos del curso consideraron que la experiencia de enseñanza con las chicas presentó poca importancia para su formación como profesionales de Educación Física. Por otra parte 16% han considerado importante la actividad práctica. 37% dijeron que la experiencia fue bastante importante y 40% han respondido que la actividad fue de fundamental importancia. Ninguno contestó que la actividad fue nada importante. Así, concluimos que la utilización de esa metodología y experiencia didáctica ha permitido la reducción de las discrepancias entre la teoría y práctica existentes en las asignaturas de carácter práctico en los cursos de formación del profesorado

    Advanced 3D modeling versus Building Information Modeling: the case study of Palazzo Ettoreo in Sacile (Italy)

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    This paper presents an experience of 3D modeling starting from laser scanning data and following two alternative approaches: the first one, called \u201cAdvanced 3D modeling\u201d, based on an original meshing algorithm, while the second make use of Revit BIM software. The case study in Palace Ettoreo in Sacile (Pordenone, Italy), constructed in Renaissance Venetian style in the 16th century: it has a trapezoid plan and is developed on three floors, with the ground one endowing a portico on two fa\ue7ades. The palace has been surveyed by two terrestrial laser scanners: a Riegl Z420i for 5 external scans and a FARO Photon 120 for 53 internal scans; also a topographic surveying of 270 targets have been carried out. The final TLS cloud has 1,4 billions of points. The Advanced 3D modeling has produced a \u201csmart\u201d mesh, allowing also to model the elements with deformations (out of plumb, bulges and troughs). Moreover, this model drastically reduce the stored data: the whole palace is modeled by 111.496 polygons only. The modeling with Revit follows the classical flowchart where the principal architectonical elements are gradually composed: this HBIM process has required a strong manual work in exploiting the available parametric objects and/or in the definition of new objects. Comparing the two models with respect the points cloud, both have evidenced advantages and limitations: therefore, the best solution is a process involving their combination. At the beginning, the Advanced 3D modeling is performed onto the points cloud, so well exploiting the segmentation tools and the smart meshing of the surfaces preserving any geometrical irregularity. Such obtained model allows metrical and morphological evaluation on the various structural and architectonical elements. Afterwards, this very light model becomes the entry data for the modeling in BIM environment, where also the shape of irregular elements are so imported

    Spatial variability of nitrogen dioxide and formaldehydeand residential exposure of children in the industrial area of Viadana, Northern Italy

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    Chipboard production is a source of ambient air pollution. We assessed the spatial variability of outdoor pollutants and residentialexposure of children living in proximity to the largest chipboard industry in Italy and evaluated the reliability of exposureestimates obtained from a number of available models. We obtained passive sampling data on NO2and formaldehyde collectedby the Environmental Protection Agency of Lombardy region at 25 sites in the municipality of Viadana during 10 weeks (2017-2018) and compared NO2measurements with average weekly concentrations from continuous monitors. We compared interpo-lated NO2and formaldehyde surfaces with previous maps for 2010. We assessed the relationship between residential proximity tothe industry and pollutant exposures assigned using these maps, as well as other available countrywide/continental models basedon routine data on NO2, PM10, andPM2.5. The correlation between NO2concentrations from continuous and passive samplingwas high (Pearson'sr= 0.89), although passive sampling underestimated NO2especially during winter. For both 2010 and 2017-2018, we observed higher NO2and formaldehyde concentrations in the south of Viadana, with hot-spots in proximity to theindustry. PM10and PM2.5exposures were higher for children at 3.5 km to theindustry, whereas NO2exposure was higher at 1-1.7 km to the industry. Road and population densities were also higher close tothe industry. Findings from a variety of exposure models suggest that children living in proximity to the chipboard industry inViadana are more exposed to air pollution and that exposure gradients are relatively stable over time

    Chronic bronchitis without airflow obstruction, asthma and rhinitis are differently associated with cardiovascular risk factors and diseases

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    Cardiovascular and respiratory diseases can frequently coexist. Understanding their link may improve disease management. We aimed at assessing the associations of chronic bronchitis (CB), asthma and rhinitis with cardiovascular diseases and risk factors in the general population
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