Navegando por Assunto "Interpolation"

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Acesso aberto (Open Access)
Comparação entre métodos de aproximação numérica utilizando o programa matlab
(Universidade Federal do Pará, 2017-12) LOPES, Álvaro Pereira; COSTA, Manuel de Jesus dos Santos
This Scientific Initiation article covered with the aid of codes developed an interface of the Matlab program some comparisons between numerical approximation methods and found which one was more effective in certain situations. The polynomial interpolation concepts were presented, addressing the interpolation of Lagrange and Newton, and segmented interpolation, approaching cubic splines. Some applications were developed. First, they compared the methods Lagrange and Newton a practical example, the determination of the width of a river for the construction of a bridge. In another application, it analyzed the Newton polynomial behavior and Cubic Spline interpolation in the Runge function. When analyzing the results, it was concluded that between the Lagrange interpolation and Newton latter is more efficient since it is lighter in terms of computational effort, but it is not suitable for situations where it has many interpolation points ie, where the polynomial interpolation is very high degree. The cubic spline is efficient in these cases shows that it uses several low degree polynomial to form the interpolating curve.
Acesso aberto (Open Access)
Interpolação de eventos de reflexão em traços sísmicos de dados pré-empilhamento usando aproximação de tempo de trânsito SRC-AF
(Universidade Federal do Pará, 2014-06-24) FERNANDES, Alexandre Sodré; CRUZ, João Carlos Ribeiro; http://lattes.cnpq.br/8498743497664023
The seismic method is a well known technique for revealing details of the geological subsurface structures because the seismic data are processed and produce seismic sections, which are images of subsurface structures. The quality of the recorded seismic data depends on factors such as the complexity of the subsurface, level of noise, surface topography of acquisition, heterogeneities in the mantle of weathering, among others. Irregular acquisition, short offsets, low coverage in common points in depth lead to a low quality imaging in subsurface and low resolution in seismic sections. In common reflection surface imaging, the hyperbolic approximation of traveltimes for paraxial rays in the vicinity of a central ray reflected with finite source-receiver offset, function of five kinematic attributes of the wave field, represent better the time field reflection compared to conventional methods. The Common Reflection Surface for Common Offset (CRS-CO) approaches reflection events within the vicinity of the trace with a fixed offset that we want to interpolate, adding correlated events, where the output is defined as the weighted average of the amplitudes along the traveltime approximation SRC-AF, assigning the result to its trace to all points of an common offset section. The specific objective of this work is to model the regularization of temporal sections filling areas lacking seismic data, increasing the signal to noise ratio by interpolation of reflection events in seismic traces based on the approximation of traveltime for Common Reflection Surface for Common Offset (CRS-CO). The algorithm was applied to the seismic acquisition settings Common Source, Common Offset and Common Mid Point for a set of 2D synthetic data, modeled by ray tracing.