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Showing 1 to 20 of 101 for “"Kirchhoff"”.
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Kirchhoff approximation for rough surface scattering
Thesis: M.S., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 1993
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Kirchhoff Common Offset Migration Velocity Analysis via Differential Semblance
… velocity analysis are introduced: NMO-based and Kirchhoffbased. For each version, both the efficiency and effectiveness are discussed. For NMObased differential semblance, the application is illustrated on both synthetic data set and field data set to invert both ID and 2D velocity models. For …
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On the zeta Kirchhoff index of several graph transformations
1 PDF file (vi, 85 pages)
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2.5D downward continuation of the seismic wavefield using Kirchhoff data mapping
Includes bibliographical references (pages 129-131).
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Rough surface scattering under Gaussian beam illumination and the Kirchhoff approximation
… under illumination by a Gaussian beam using the Kirchhoff approximation is presented. The analysis assumes a source distribution which yields a Gaussian beam solution as a radiated field. This field is used to excite a current density on the surface using the Kirchhoff approximation. A vector …
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Elemento finito para placas e cascas usando a teoria de Kirchhoff-Love
… for plates and shells using the theory of Kirchhoff-Love. ln arder to guarantee the continuity of rotations for the middle surface normal vectors, it was used Hermite interpolation functions for the transverse displacements and incomplete quadratic polinomials for the in-plane …
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Estudo da validade da hipótese de Kirchhoff-Love na Teoria das Placas
… conditions from the classical theory due to Kirchhoff-Love and the refined Reissner theory were obtained by using the linear theory of elasticity and standard energy variational principles. Analytical expressions of deflections and resultant stresses are treated for rectangular plates …
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Detection and Kirchhoff-type migration of seismic events by use of a new characteristic function
The classical method of seismic event localization is based on the picking of body wave arrivals, ray tracing and inversion of travel time data. Travel time picks with small uncertainties are required to produce reliable and accurate results with this kind of source localization. Hence recordings, …
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On models of Kirchhoff Equations with damping terms: existence results and asymptotic behaviour of solutions
The abstract will be viewed from the PDF to distortion Mathematical Formulas.
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Free and Forced Vibration of Linearly Elastic and St. Venant-Kirchhoff Plates using the Third Order Shear and Normal Deformable Theory
Employing the Finite Element Method (FEM), we numerically study three problems involving free and forced vibrations of linearly and nonlinearly elastic plates with a third order shear and normal deformable theory (TSNDT) and the three dimensional (3D) elasticity theory. We used the commercial …
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Acoustic scattering from sand dollars (Dendraster excentricus) : modeling as high aspect ratio oblate objects and comparison to experiment
… methods. Using an approximation to the Helmholtz-Kirchhoff integral, the Kirchhoff method gives an analytic integral expression to the backscattering from an object. This integral was first solved analytically for a disk and a spherical cap, two high aspect ratio oblate shapes which simplify the …
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Acoustic scattering from sand dollars (Dendraster Excentricus) : modeling as high aspect ratio oblate objects and comparison to experiment
… methods. Using an approximation to the Helmholtz-Kirchhoff integral, the Kirchhoff method gives an analytic integral expression to the backscattering from an object. This integral was first solved analytically for a disk and a spherical cap, two high aspect ratio oblate shapes which simplify the …
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High-frequency electromagnetic wave scattering from rough surfaces
… (PO) theory. The SBR method improves on the Kirchhoff approximation by considering the mutual interactions between the irregularities of the surface (i.e., shadowing and multiple scattering are accounted for). In addition, the SBR technique is more efficient than the Method of Moments (MoM) …
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Cavity flow past an obstacle including gravity effects
… facilitate numerical computation. The Helmholtz-Kirchhoff cavity model is used in this study, with sixteen primary cases analyzed. The computer results are plotted and the computer listing is given. From the results, it is found that the Helmholtz-Kirchhoff model is not applicable because no …
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Innovative Acoustic Reflection Imaging Techniques And Application To Clinical Breast Tomography
… from UST data. We have extended the planar Kirchhoff migration method used in geophysics, and combined it with sound speed and attenuation data obtained from the transmission signals to create reflection ultrasound images that are corrected for refractive and attenuative effects. </p> <p>The …
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Stationary Configurations of Point Vortices (Morse Theory, Hamiltonian Systems, Fluid Mechanics)
… which was given a Hamiltonian formulation by Kirchhoff. Stationary configurations are those which remain self-similar throughout the motion, and are of considerable physical interest.
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Predicting Surface Scatter Using A Linear Systems Formulation Of Non-paraxial Scalar Diffraction
… perturbation method) and Beckmann-Kirchoff (Kirchhoff approximation) theories are commonly used to predict surface scatter effects. In addition, Harvey and Shack developed a linear systems formulation of surface scatter phenomena in which the scattering behavior is characterized by a surface …
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Results on the interaction between atomistic and continuum models
… for the first and second atomistic Piola--Kirchhoff stress tensors. An interesting feature of the atomistic first Piola--Kirchhoff stress tensor is the absence of a kinetic contribution, which in the atomistic Cauchy stress tensor accounts for thermal fluctuations. We show that this effect …
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Bending of a Flat Circular Plate With a Central Hole Due to Evenly Spaced Bending Moments at the Outside.
… the use of the boundary conditions formulated by Kirchhoff. A Fourier Series was used to represent the applied bending moments at the outer boundary.
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