610 resultados para calcul variationnel
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Analisar a associação entre excesso de peso e diferentes fatores de risco familiares em adolescentes da região oeste do estado de São Paulo. Estudo transversal com 1779 adolescentes de ambos os sexos, e idade compreendida entre 11 e 17 anos. Calculou-se o índice de massa corporal e os fatores de risco familiares foram analisados por meio de questionário. O excesso de peso foi associado com o sexo masculino (RC=1,55 [1,22-1,97]), estudar em escola particular (RC=2,14 [1,56-2,94]) e maior escolaridade materna (RC=0,52 [0,33-0,83]). Iniciativas de combate à obesidade devem ser instauradas em meio escolar e atingir toda a estrutura familiar, bem como levar em consideração particularidades decorrentes do sexo.
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Incluye Bibliografía
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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A ideia de se medir, ainda que parcialmente, a heterogeneidade por meio do diferencial de produtividade, traz em si um problema, que é o de como calculá-la. Utilizar a receita bruta, ou o valor da transformação industrial, por exemplo, superestima a produtividade, na medida em que ficam encobertos todos os contratos de terceirização. Desse modo, uma mesma receita (ou produto) pode ser gerada com menos pessoas ocupadas, elevando a medida de produtividade artificialmente. No caso deste artigo, que trata da heterogeneidade regional, foram buscadas duas bases de informação que dessem conta, inclusive, da parcela informal da economia: para tanto, foi utilizada a base das Contas Regionais do Brasil, de 1996 a 2008 (calculada pelo Instituto Brasileiro de Geografia e Estatística − IBGE e pelos institutos estaduais de estatística), que fornece o valor adicionado para cada Unidade da Federação (UF), e confrontá-la com a base de pessoal ocupado fornecida pelas Pesquisas Nacionais por Amostra de Domicílios (Pnads), também para cada UF. Com isso, agrupam-se tanto as parcelas formais quanto as informais da economia.
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Se analiza la evolución de la desigualdad injusta en el Brasil (1995-2009) mediante un enfoque no paramétrico de la estimación de la función de ingresos. Se utilizaron las medidas de entropía de Li, Maasoumi y Racine (2009) a fin de cuantificar separadamente las diferencias de ingresos para cada variable de esfuerzo. Se calculó un coeficiente de Gini de desigualdad injusta basado en los valores ajustados de la estimación no paramétrica, analizándose la robustez para las estimaciones, incluyendo variables de circunstancias. La evolución de las entropías mostró reducción de la diferencia de ingresos atribuida a la educación como factor determinante. Las variables de horas trabajadas y situación en el mercado laboral explican significativamente las diferencias de salarios imputadas al esfuerzo individual, pero la variable migratoria reveló escaso poder explicativo. Finalmente, el análisis de robustez demostró la plausibilidad de los resultados de cada etapa de la ejecución empírica.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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On the field of the projects of hydraulic systems exists a lot of worries when we talk about the calculate of hydraulic pumps. In this case some facts must be considerate: length of tubes, fluid characteristics, height gauge, temperature, pressure, characteristics of tubes, flow required and others. For that mathematic calculates must be developed with the objective to optimize hydraulic pumps and agree to find an ideal machine (that don't requires more energy than necessary or less energy than it requires; that is the more critical case, cause exists the risk that the fluid pumped do not agree to become in your destiny). The wrong calculate of this machine can super-size its, bringing an excessive energy consumption. Actually it's an important subject because we are in the age of lack of energy what turn it more expensive. So the correct sizing of a hydraulic pump is connected with the fact that you have to uses the enough energy resources avoiding waste. The calculate of ideal pump in the pumping system is studied during years and a lot of specialists in this subject develop equations and theories to calculate its. Some researches study about this subject and all of them become to the same conclusion: to find the ideal pump we have to know the characteristics of fluid (cinematic viscosity), the required flow , overall yield (overall of motor x overall of pump) the high gauge or discharge pressure and the loss of repression. The pressure drop can be calculated with different theories: using Hazen-Williams, Darcy e Weisbach or Chézy (1775 - that starts the researches to calculate the pressure drop). Although the most used theory and what is most near to reality is the Darcy's equation. So, in this job the Darcy's equation were choice to calculate the drop pressure that consider what kind of flow we are studying: laminar or turbulent. The determination of the best pump to be used in the ... ( complete abstract click eletronic access below)
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Dans ces dernières années, plusieurs méthodes de dimensionnement d'ouvrages de soutènement en sol renforcé ont été développés, mais la doute c’est où l'utilisation de chacun d'eux se révèle plus avantageux? Ce travail a été conçu avec l'objectif de faire une étude d’un cas historiques d'un mur en remblais renforcé avec parement végétal de 27,6 mètres de haut, dont la conception a été analysé en utilisant une méthode de calcul et des logiciels informatiques spécifiques à l’utilisation dans le domaine géotechnique. Avec cette étudesont attendus de résultats capable de présenter les principales caractéristiques de chaque méthode et où il peut le mieux être appliquée
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Cosmic radiation has been identi ed as one of the main hazard to crew, aircraft and sensitive equipments involved in long-term missions and even high-altitude commercial ights. Generally, shields are used in spatial units to avoid excessive exposure, by holding the incident radiation. Unfortunatelly, shielding in space is problematic, especially when high-energy cosmic particles are considered, due to the production of large number of secondary particles, mainly neutrons, protons and alpha particles, caused by spallation reactions and quasi-elastic processes of the corpuscular radiation with the shield. Good parameters for checking the secondary particle production at target material are diferential cross section and energy deposited in the shield. Addition experiments, some computer codes based on Monte Carlo method show themselves a suitable tool to calculate shield parameters, due to have evaluated nuclear data libraries implemented on the algorithm. In view of this, the aim of this work is determining the parameters evaluated in shielding materials, by using MCNPX code, who shows good agreement with experimental data from literature. Among the materials, Aluminium had lower emission and production of secondary particles
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The most common sleep disorder is obstructive sleep apnea syndrome (OSAS), that is characterized by repeated pauses in breathing during sleep, resulting in partial or complete obstruction of the upper airway. It is associated with systemic arterial hypertension and obesity. Objective: To assess the frequency of OSAS in the adult population of Botucatu by the Berlin questionnaire. Method: Transveral study was performed in which the sample size was estimated at 385 individuals. The Berlin questionnaire was administered to adults randomly on the streets, supermarkets and local shops. Data were analyzed taking into account age, gender, "high risk for OSAS", hypertension, obesity and correlations for OSAS. Results: 468 people interviewed were aged between 18 and 95 years, average of 59 years. 166 (35.25%) individuals were identified as "high risk for OSAS", being more frequent in the population above 40 years. Obesity was present in 23.3%, more common in women (60.2%). 83.5% of the population obese also had a "high risk for OSAS". Hypertension was observed in 27.3%, of these 71.9% were at "high risk for OSAS". Conclusion: The study showed a high frequency of "high risk for OSAS" in the adult population. Despite the dissemination by the media about sleep apnea, patients are not investigated, even under medical care for hypertension.
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Observations of cosmic rays arrival directions made with the Pierre Auger Observatory have previously provided evidence of anisotropy at the 99% CL using the correlation of ultra high energy cosmic rays (UHECRs) with objects drawn from the Veron-Cetty Veron catalog. In this paper we report on the use of three catalog independent methods to search for anisotropy. The 2pt-L, 2pt+ and 3pt methods, each giving a different measure of self-clustering in arrival directions, were tested on mock cosmic ray data sets to study the impacts of sample size and magnetic smearing on their results, accounting for both angular and energy resolutions. If the sources of UHECRs follow the same large scale structure as ordinary galaxies in the local Universe and if UHECRs are deflected no more than a few degrees, a study of mock maps suggests that these three method can efficiently respond to the resulting anisotropy with a P-value = 1.0% or smaller with data sets as few as 100 events. using data taken from January 1, 2004 to July 31, 2010 we examined the 20, 30, ... , 110 highest energy events with a corresponding minimum energy threshold of about 49.3 EeV. The minimum P-values found were 13.5% using the 2pt-L method, 1.0% using the 2pt+ method and 1.1% using the 3pt method for the highest 100 energy events. In view of the multiple (correlated) scans performed on the data set, these catalog-independent methods do not yield strong evidence of anisotropy in the highest energy cosmic rays.
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Mach number and thermal effects on the mechanisms of sound generation and propagation are investigated in spatially evolving two-dimensional isothermal and non-isothermal mixing layers at Mach number ranging from 0.2 to 0.4 and Reynolds number of 400. A characteristic-based formulation is used to solve by direct numerical simulation the compressible Navier-Stokes equations using high-order schemes. The radiated sound is directly computed in a domain that includes both the near-field aerodynamic source region and the far-field sound propagation. In the isothermal mixing layer, Mach number effects may be identified in the acoustic field through an increase of the directivity associated with the non-compactness of the acoustic sources. Baroclinic instability effects may be recognized in the non-isothermal mixing layer, as the presence of counter-rotating vorticity layers, the resulting acoustic sources being found less efficient. An analysis based on the acoustic analogy shows that the directivity increase with the Mach number can be associated with the emergence of density fluctuations of weak amplitude but very efficient in terms of noise generation at shallow angle. This influence, combined with convection and refraction effects, is found to shape the acoustic wavefront pattern depending on the Mach number.
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Atmospheric conditions at the site of a cosmic ray observatory must be known for reconstructing observed extensive air showers. The Global Data Assimilation System (GDAS) is a global atmospheric model predicated on meteorological measurements and numerical weather predictions. GDAS provides altitude-dependent profiles of the main state variables of the atmosphere like temperature, pressure, and humidity. The original data and their application to the air shower reconstruction of the Pierre Auger Observatory are described. By comparisons with radiosonde and weather station measurements obtained on-site in Malargue and averaged monthly models, the utility of the GDAS data is shown. (C) 2012 Elsevier B.V. All rights reserved.
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The Pierre Auger Observatory is a facility built to detect air showers produced by cosmic rays above 10(17) eV. During clear nights with a low illuminated moon fraction, the UV fluorescence light produced by air showers is recorded by optical telescopes at the Observatory. To correct the observations for variations in atmospheric conditions, atmospheric monitoring is performed at regular intervals ranging from several minutes (for cloud identification) to several hours (for aerosol conditions) to several days (for vertical profiles of temperature, pressure, and humidity). In 2009, the monitoring program was upgraded to allow for additional targeted measurements of atmospheric conditions shortly after the detection of air showers of special interest, e. g., showers produced by very high-energy cosmic rays or showers with atypical longitudinal profiles. The former events are of particular importance for the determination of the energy scale of the Observatory, and the latter are characteristic of unusual air shower physics or exotic primary particle types. The purpose of targeted (or "rapid") monitoring is to improve the resolution of the atmospheric measurements for such events. In this paper, we report on the implementation of the rapid monitoring program and its current status. The rapid monitoring data have been analyzed and applied to the reconstruction of air showers of high interest, and indicate that the air fluorescence measurements affected by clouds and aerosols are effectively corrected using measurements from the regular atmospheric monitoring program. We find that the rapid monitoring program has potential for supporting dedicated physics analyses beyond the standard event reconstruction.