Navegando por Assunto "Processamento paralelo"

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Acesso aberto (Open Access)
Desenvolvimento de Interface gráfica como suporte para soluções numéricas das equações de Maxwell em coordenadas gerais – 3D
(Universidade Federal do Pará, 2011-05-03) COLARES, Adolfo Francesco de Oliveira; SOUZA SOBRINHO, Carlos Leônidas da Silva; http://lattes.cnpq.br/1450994881555781; OLIVEIRA, Rodrigo Melo e Silva de; http://lattes.cnpq.br/4768904697900863
In this work, we have implemented a graphical user interface (GUI) by using the Nokia Qt library (version 3.0). The interface is designed to simplify the creation of scenarios for executing parallel E.M. Simulations by using the numerical technique Local Non-Orthogonal Finite Difference Time-Domain (LN-FDTD) method, applied to solve Maxwell's equations. The simulator was developed by using the C programming language and parallelized by using threads. This way, the pthread library was employed. The 3D visualization of the scenario and of the corresponding mesh to be simulated is performed by a specially developed program based on the OpenGL specification. In order to improve the development and to achieve the goals of computational design, we have used concepts of software engineering, such as the process model for software prototyping. Depriving the user to interact directly with the source code of the simulation program, the probability of human errors while performing the constructing process of scenarios is minimized. In order to demonstrate the operation of the developed tool, a study regarding lightning-induced voltages on low voltage lines with catenaries is performed. Induced voltages inside a small building (a residence) are also studied.
Acesso aberto (Open Access)
Modelagem do mCSEM no domínio do tempo usando transformada discreta de Fourier
(Universidade Federal do Pará, 2009) MIRANDA, Diego da Costa; RÉGIS, Cícero Roberto Teixeira; http://lattes.cnpq.br/7340569532034401
The mCSEM modelling is usually done in the frequency domain, from its theoretical formulation to the analysis of the results. However, the time domain approach is, in principle, capable of providing equivalent information about the geo-electric structure of the subsurface. In this work, we model frequency domain mCSEM data in 1-D environments, then we perform the discrete Fourier transform to obtain time domain results. We simulated marine geological environments with and without the resistive layer that represents the hydrocarbon reservoir. We verified that the time domain data are significantly different when calculated for models with and without hydrocarbons in almost all model configurations. We calculated the results considering variations in the sea depth, in the position of the receivers and in the resistivity of the hydrocarbon layer. We observed the influence of the airwave, even at sea depths greater than 1000m, and although a simple separation of this influence on data is not possible, the time domain allowed us to do an analysis of its effects on the survey. As part of the preparation for the 2-D and 3-D modelling, we also have studied the gain in performance from the use of parallel processing in our task.