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Search Results: 1 - 10 of 9232 matches for " Ezzat Selim;Campos Velho "
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Evaluation of radiances generated by solving the radiative-transfer equation with different approaches
Chalhoub, Ezzat Selim;Campos Velho, Haroldo F. de;Silva Neto, Ant?nio José da;
Journal of the Brazilian Society of Mechanical Sciences and Engineering , 2012, DOI: 10.1590/S1678-58782012000200010
Abstract: radiative transfer is the main phenomenon in the basis of several relevant problems of scientific and technological interest. examples of application of the mathematical and computational modeling of such phenomenon can be found in astronomy, environmental sciences, engineering and medicine among many different areas. the integro-differential equation known as boltzmann equation describes mathematically the interaction of the radiation with the participating medium, i.e. a medium which may absorb, scatter and emit radiation. several methods have been developed for the solution of the bolztmann equation. in the present work we present a comparison of the solutions obtained for the one-dimensional problem with four different methods: (i) monte carlo (mc) method; (ii) discrete ordinates method (sn) combined with a finite difference approximation; (iii) analytical discrete ordinates method (asn); and (iv) laplace transform discrete ordinates method (ltsn). our final objective is to solve the inverse radiative transfer problem and for that purpose, we want to investigate methods that may provide accurate and fast solutions for the direct problem.
Rafael Rott de Campos Velho
Revista Eletr?nica do Curso de Direito da UFSM , 2009, DOI: 10.5902/198136947034
Abstract: O escopo do presente trabalho é demonstrar o quanto os regulamentos expedidos por agências reguladoras independentes s o importantes no cenário hodierno para a garantia da Democracia e dos Direitos Fundamentais. Tais autoridades precisam ser dotadas de relativa independência, haja vista os interesses da sociedade em jogo no processo de tomada de certas decis es técnicas, as quais podem afetar qualquer cidad o. No entanto, o campo de atua o dos entes em quest o deve sofrer limita es com o intuito de garantir a legitima o popular.
Application of GC/EIMS in Combination with Semi-Empirical Calculations for Identification and Investigation of Some Volatile Components in Basil Essential Oil  [PDF]
Mamoun S. M. Abd El-Kareem, Mohamed Abd El Fattah Rabbih, Ezzat Taha Mohamed Selim, Elsherbiny Abd El-monem Elsherbiny, Ayman Yasen El-Khateeb
International Journal of Analytical Mass Spectrometry and Chromatography (IJAMSC) , 2016, DOI: 10.4236/ijamsc.2016.41002
Abstract: Volatile components in the extracts of basil leaves (Ocimum basilicum L.) were identified by gas chromatography/mass spectrometry (GC/MS) with electron ionization (EI) mode. The major volatile components of basil under investigation are α-pinene, sabinene, β-pinene, d-limonene, eucalyptol, l-linalool and estragole. Electron ionization mass spectra of these compounds have been obtained and investigated. Furthermore, the semi-empirical MNDO [Modified Neglect of Diatomic Overlap] method was used to calculate the thermochemical data for the structural properties of these compounds.
A study of low power laser on the regenerative process of Girardia tigrina (Girard,1850) (Turbellaria; Tricladida; Dugesiidae)
Lopes, KAR.;Campos Velho, NMR.;Munin, E.;
Brazilian Journal of Biology , 2009, DOI: 10.1590/S1519-69842009000200013
Abstract: the mechanism of regeneration does not start to restore the wound until its corresponding epimorphic phase. a bioestimulation of tissues and cells by laser radiation depends on the wavelength, on the dose, and on the intensity of the light. the goal of this work was to verify the effect of the low power laser at 660 nm on the regenerative process of girardia tigrina. the specimens were maintained in the laboratory under a temperature ranging from 19° up to 24 °c for 21 days. the planarians were anesthetized by placing them on ice and then cut them with a scalpel. the three treatments were as following: animals individually irradiated with 14 sessions with 1 minute duration (treatment 1), 14 sessions with 3 minutes duration (treatment 2), and without irradiation (control). the planarians were amputated and divided in three study treatments: a control group (without radiation), and two other treatments: irradiated for 1 minute, and irradiated for 3 minutes. the animals were irradiated with diode laser (660 nm) with 3.3 ± 0.3 mw of power, using 0.94 mw.mm-2 power density for each irradiation procedure. during the experiment, 14 irradiation sessions were undertaken. the specimens were fixed in bouin, and stained with hematoxyline and eosin. from observation and histological analysis, it was possible to assess the effects of interaction between laser and tissue. the head fragment after 1 minute of irradiation presented a better organized tissue scheme, when compared with the other treatments. aspects of the body fragments submitted to 3 minutes of light treatment were very similar to fragments that had not been injured. it can be concluded that there are changes in the quality of regeneration when treated with low power laser under the conditions mentioned above.
Hierarquiza o de direitos fundamentais: a doutrina da posi o preferencial na jurisprudência da Suprema Corte Norte-americana
Letícia de Campos Velho Martel
Sequência : Estudos Juridicos e Politicos , 2004,
Abstract: Este ensaio examina a quest o dahierarquiza o dos direitos fundamentais àluz da jurisprudência da Suprema Corte norte-americana. Para tal, explicita a doutrina1da posi o preferencial, suas origens e seusrumos atuais, além de realizar um breveincurso na teoria do compelling interest, doutrinacorrelata àquela, sempre em aten o aosjulgados da Corte Máxima estadunidense.This essay has as main subjectthe Supreme Court preferred positionconstitutional law doctrine. In order toachieve this goal, it first explains theorigins and actual questions concerningthe preferred position doctrine, and afterit operates a brief examination of thecompelling interest doctrine, which isparallel to preferred position.
Indisponibilidade de Direitos Fundamentais: conceito lac nico, consequências duvidosas
Letícia de Campos Velho Martel
Espa?o Jurídico : Journal of Law , 2011,
Abstract: resumo
Neural-estimator for the surface emission rate of atmospheric gases
F. F. Paes,H. F. Campos Velho
Computer Science , 2009,
Abstract: The emission rate of minority atmospheric gases is inferred by a new approach based on neural networks. The neural network applied is the multi-layer perceptron with backpropagation algorithm for learning. The identification of these surface fluxes is an inverse problem. A comparison between the new neural-inversion and regularized inverse solution id performed. The results obtained from the neural networks are significantly better. In addition, the inversion with the neural netwroks is fster than regularized approaches, after training.
Data Mining for Flooding Episode in the States of Alagoas and Pernambuco—Brazil  [PDF]
Heloisa Musetti Ruivo, Haroldo F. de Campos Velho, Fernando M. Ramos, Saulo R. Freitas
American Journal of Climate Change (AJCC) , 2018, DOI: 10.4236/ajcc.2018.73025
Abstract: The increasing volume of data in the area of environmental sciences needs analysis and interpretation. Among the challenges generated by this “data deluge”, the development of efficient strategies for the knowledge discovery is an important issue. Here, statistical and tools from computational intelligence are applied to analyze large data sets from meteorology and climate sciences. Our approach allows a geographical mapping of the statistical property to be easily interpreted by meteorologists. Our data analysis comprises two main steps of knowledge extraction, applied successively in order to reduce the complexity from the original data set. The goal is to identify a much smaller subset of climatic variables that might still be able to describe or even predict the probability of occurrence of an extreme event. The first step applies a class comparison technique: p-value estimation. The second step consists of a decision tree (DT) configured from the data available and the p-value analysis. The DT is used as a predictive model, identifying the most statistically significant climate variables of the precipitation intensity. The methodology is employed to the study the climatic causes of an extreme precipitation events occurred in Alagoas and Pernambuco States (Brazil) at June/2010.
Estimativa do perfil da concentra??o de clorofila em águas naturais através de um perceptron de múltiplas camadas
Dall Cortivo, F.;Chalhoub, E. S.;Campos Velho, H. F.;
TEMA (S?o Carlos) , 2012, DOI: 10.5540/TEMA.2012.013.03.0233
Abstract: in this work the average profile of chlorophyll concentration is estimated from the emitted radiation at the surface of natural waters. this is performed through the use an artificial neural network of multilayer perceptron type to act as the inverse operator. bio-optical models are used to correlate the chlorophyll concentration with the absorption and scattering coefficients. the network training is formulated as an optimization problem, in which the update of the free variables of network (weights, viéses and each slope of the activation functions) is performed through the quasi-newton method.
Data Assimilation by Artificial Neural Networks for an Atmospheric General Circulation Model: Conventional Observation
Rosangela S. Cintra,Haroldo F. de Campos Velho
Physics , 2014,
Abstract: This paper presents an approach for employing artificial neural networks (NN) to emulate an ensemble Kalman filter (EnKF) as a method of data assimilation. The assimilation methods are tested in the Simplified Parameterizations PrimitivE-Equation Dynamics (SPEEDY) model, an atmospheric general circulation model (AGCM), using synthetic observational data simulating localization of balloon soundings. For the data assimilation scheme, the supervised NN, the multilayer perceptrons (MLP-NN), is applied. The MLP-NN are able to emulate the analysis from the local ensemble transform Kalman filter (LETKF). After the training process, the method using the MLP-NN is seen as a function of data assimilation. The NN were trained with data from first three months of 1982, 1983, and 1984. A hind-casting experiment for the 1985 data assimilation cycle using MLP-NN were performed with synthetic observations for January 1985. The numerical results demonstrate the effectiveness of the NN technique for atmospheric data assimilation. The results of the NN analyses are very close to the results from the LETKF analyses, the differences of the monthly average of absolute temperature analyses is of order 0.02. The simulations show that the major advantage of using the MLP-NN is better computational performance, since the analyses have similar quality. The CPU-time cycle assimilation with MLP-NN is 90 times faster than cycle assimilation with LETKF for the numerical experiment.
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