scholarly journals Multiparameter two-dimensional inversion of scattered teleseismic body waves 2. Numerical examples

2001 ◽  
Vol 106 (B12) ◽  
pp. 30783-30793 ◽  
Author(s):  
J. Shragge ◽  
M. G. Bostock ◽  
S. Rondenay
Keyword(s):  
Body Waves ◽  
Two Dimensional ◽  
Numerical Examples

Numerical solution of two-dimensional first kind Fredholm integral equations by using linear Legendre wavelet

2016 ◽  
Vol 14 (01) ◽  
pp. 1650004 ◽  
Author(s):  
M. Tahami ◽  
A. Askari Hemmat ◽  
S. A. Yousefi
Keyword(s):  
Integral Equation ◽  
Tensor Product ◽  
Numerical Solution ◽  
Fredholm Integral Equation ◽  
Fredholm Integral Equations ◽  
Wavelet Basis ◽  
Two Dimensional ◽  
Legendre Wavelets ◽  
Numerical Examples ◽  
One Dimensional

In one-dimensional problems, the Legendre wavelets are good candidates for approximation. In this paper, we present a numerical method for solving two-dimensional first kind Fredholm integral equation. The method is based upon two-dimensional linear Legendre wavelet basis approximation. By applying tensor product of one-dimensional linear Legendre wavelet we construct a two-dimensional wavelet. Finally, we give some numerical examples.

Statistical properties of Rayleigh waves due to scattering by topography

1967 ◽  
Vol 57 (1) ◽  
pp. 83-90
Author(s):  
J. A. Hudson ◽  
L. Knopoff
Keyword(s):  
Surface Waves ◽  
Rayleigh Waves ◽  
Seismic Noise ◽  
Forward Scattering ◽  
Statistical Properties ◽  
Body Waves ◽  
Simplified Model ◽  
Two Dimensional ◽  
Especial Reference ◽  
The Earth

abstract The two-dimensional problems of the scattering of harmonic body waves and Rayleigh waves by topographic irregularities in the surface of a simplified model of the earth are considered with especial reference to the processes of P-R, SV-R and R-R scattering. The topography is assumed to have certain statistical properties; the scattered surface waves also have describable statistical properties. The results obtained show that the maximum scattered seismic noise is in the range of wavelengths of the order of the lateral dimensions of the topography. The process SV-R is maximized over a broader band of wavelengths than the process P-R and thus the former may be more difficult to remove by selective filtering. An investigation of the process R-R shows that backscattering is much more important than forward scattering and hence topography beyond the array must be taken into account.

scholarly journals Parameter Identification in the Two-Dimensional Riesz Space Fractional Diffusion Equation

2020 ◽  
Vol 4 (3) ◽  
pp. 39
Author(s):  
Rafał Brociek ◽  
Agata Chmielowska ◽  
Damian Słota
Keyword(s):  
Differential Equation ◽  
Diffusion Equation ◽  
Parameter Identification ◽  
Fractional Diffusion ◽  
Riesz Space ◽  
Fractional Diffusion Equation ◽  
Two Dimensional ◽  
Numerical Examples ◽  
Space Fractional Diffusion Equation ◽  
Swarm Intelligence Algorithm

This paper presents the application of the swarm intelligence algorithm for solving the inverse problem concerning the parameter identification. The paper examines the two-dimensional Riesz space fractional diffusion equation. Based on the values of the function (for the fixed points of the domain) which is the solution of the described differential equation, the order of the Riesz derivative and the diffusion coefficient are identified. The paper includes numerical examples illustrating the algorithm’s accuracy.

Two‐dimensional acoustic modeling by a hybrid method

Geophysics ◽  
1985 ◽  
Vol 50 (8) ◽  
pp. 1273-1284 ◽  
Author(s):  
V. Shtivelman
Keyword(s):  
Wave Propagation ◽  
Wave Field ◽  
Inhomogeneous Medium ◽  
Hybrid Method ◽  
Wave Scattering ◽  
Acoustic Modeling ◽  
Two Dimensional ◽  
Numerical Techniques ◽  
Numerical Examples ◽  
Field Computation

This paper follows previous work (Shtivelman, 1984) in which a hybrid method for wave‐field computation was developed. The method combines analytical and numerical techniques and is based upon separation of the processes of wave scattering and wave propagation. The method is further developed and improved; particularly, it is generalized for the case of an inhomogeneous medium above scattering objects (provided the inhomogeneity is weak, i.e., the effects of scattering can be neglected) and is represented by a simpler and more convenient form. Several numerical examples illustrating application of the method to the problems of two‐dimensional acoustic modeling are considered.

A Design Method and the Performance of Two-Dimensional Turbine Cascades for High Subsonic Flow

1971 ◽  
Author(s):  
A. Uenishi
Keyword(s):  
Approximate Solution ◽  
Pressure Distribution ◽  
Subsonic Flow ◽  
Design Method ◽  
Two Dimensional ◽  
Hodograph Method ◽  
Numerical Examples ◽  
Turbine Cascades ◽  
Measured Pressure ◽  
High Subsonic Flow

This paper deals with a hodograph method for design of turbine cascades in high subsonic flow and an approximate solution to a gas, specific heat ratio γ = −1 (the Karman-Tsien approximation) and γ > 1 (the gas obeying the adiabatic law). Numerical examples and a comparison of theoretical and measured pressure distribution for profiles designed by this method are given. Further, a better criterion for design to improve cascade efficiency is also presented.

scholarly journals A Two Dimensional Discrete Mollification Operator and the Numerical Solution of an Inverse Source Problem

Axioms ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 89 ◽  
Author(s):  
Manuel Echeverry ◽  
Carlos Mejía
Keyword(s):  
Inverse Problem ◽  
Source Term ◽  
Fractional Diffusion ◽  
Inverse Source Problem ◽  
Two Dimensional ◽  
Regularization Procedure ◽  
Numerical Examples ◽  
Convergence Results ◽  
Time Fractional Diffusion Equation ◽  
Operator Convergence

We consider a two-dimensional time fractional diffusion equation and address the important inverse problem consisting of the identification of an ingredient in the source term. The fractional derivative is in the sense of Caputo. The necessary regularization procedure is provided by a two-dimensional discrete mollification operator. Convergence results and illustrative numerical examples are included.

Solution of Plane Problems of Elasticity Utilizing Partitioning Concepts

1973 ◽  
Vol 40 (3) ◽  
pp. 767-772 ◽  
Author(s):  
O. L. Bowie ◽  
C. E. Freese ◽  
D. M. Neal
Keyword(s):  
Analytic Function ◽  
Power Series ◽  
Collocation Method ◽  
Stress Function ◽  
Function Theory ◽  
Series Expansions ◽  
Two Dimensional ◽  
Numerical Examples ◽  
Power Series Expansions

A partitioning plan combined with the modified mapping-collocation method is presented for the solution of awkward configurations in two-dimensional problems of elasticity. It is shown that continuation arguments taken from analytic function theory can be applied in the discrete to “stitch” several power series expansions of the stress function in appropriate subregions of the geometry. The effectiveness of such a plan is illustrated by several numerical examples.

scholarly journals A High-Order Compact 2D FDFD Method for Waveguides

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Gang Zheng ◽  
Bing-Zhong Wang
Keyword(s):  
Boundary Condition ◽  
Finite Difference ◽  
Surface Impedance ◽  
Transverse Field ◽  
High Order ◽  
Impedance Boundary Condition ◽  
Two Dimensional ◽  
Dispersion Characteristics ◽  
Impedance Boundary ◽  
Numerical Examples

A high-order compact two-dimensional finite-difference frequency-domain (2D FDFD) method is proposed for the analysis of the dispersion characteristics of waveguides. A surface impedance boundary condition (SIBC) for the high-order compact 2D FDFD method is also given to model lossy metal waveguides. Four transverse field components are involved in the final eigenequation. Numerical examples are given, which show that this high-order compact 2D FDFD method is more efficient than the low-order compact 2D FDFD method and has a less storage cost.

A Quadratic Contact Element Passing the Patch Test

2016 ◽  
Vol 681 ◽  
pp. 47-85
Author(s):  
Duc Tue Nguyen ◽  
Gast Rauchs ◽  
Jean Philippe Ponthot
Keyword(s):  
Patch Test ◽  
Contact Pressure ◽  
Penalty Method ◽  
Contact Element ◽  
Two Dimensional ◽  
Penalty Parameter ◽  
Contact Modeling ◽  
Numerical Examples ◽  
Contact Surfaces ◽  
High Penalty

For the two dimensional contact modeling, the standard node-to-segment quadratic contact elements are known to exhibit oscillations of the contact pressure. This situation is particularly critical when using the penalty method with a high penalty parameter because the amplitude of the oscillations increase with increasing penalty parameter. The aim of this article is to present a method for removing the oscillations of contact pressure observed while using quadratic contact element. For this purpose, the nodal forces at the slave and at the master nodes need to be evaluated appropriately. One possibility is to develop a suitable procedure for computing the nodal forces. In that sake, we selected the approach first proposed in [35] in an appropriate manner. After presenting the improved quadratic contact element, some numerical examples are illustrated in this paper to comparethe standard quadratic node-to-segment element with the proposed element. The examples show that the proposed element can strongly reduce the oscillating contact pressure for both plane and curved contact surfaces.

scholarly journals Runge-Kutta and Block by Block Methods to Solve Linear Two-Dimensional Volterra Integral Equation with Continuous Kernel

2016 ◽  
Vol 11 (10) ◽  
pp. 5705-5714
Author(s):  
Abeer Majed AL-Bugami
Keyword(s):  
Integral Equation ◽  
Volterra Integral Equation ◽  
Existence And Uniqueness ◽  
Uniqueness Of Solution ◽  
Two Dimensional ◽  
Block Method ◽  
Numerical Examples ◽  
Block Methods ◽  
Runge Kutta ◽  
Method R

In this paper, the existence and uniqueness of solution of the linear two dimensional Volterra integral equation of the second kind with Continuous Kernel are discussed and proved.RungeKutta method(R. KM)and Block by block method (B by BM) are used to solve this type of two dimensional Volterra integral equation of the second kind. Numerical examples are considered to illustrate the effectiveness of the proposed methods and the error is estimated.

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