English
Related papers

Related papers: Eigenrays in 3D heterogeneous anisotropic media: P…

200 papers

Following the theory presented in Part I, where we derived the Euler-Lagrange, nonlinear, second-order kinematic ray tracing equation for smooth heterogeneous general anisotropic media, this part is devoted for its numerical finite-element…

Geophysics · Physics 2020-03-23 Zvi Koren , Igor Ravve

In this part, we apply the same finite-element approach, used in Part III for the vanishing first traveltime variation (to obtain the stationary rays), for the second traveltime variation, in order to compute the dynamic characteristics…

Geophysics · Physics 2020-03-26 Igor Ravve , Zvi Koren

The form of the Lagrangian proposed in Part I of this study has been previously used for obtaining stationary ray paths between two endpoints in isotropic media. We extended it to general anisotropy by replacing the isotropic medium…

Geophysics · Physics 2020-03-23 Zvi Koren , Igor Ravve

Considering 3D heterogeneous anisotropic media, in Part III of this study we obtain the finite-element solution for the stationary ray path between two fixed endpoints using the finite element approach. It involves computation of the global…

Geophysics · Physics 2020-03-24 Igor Ravve , Zvi Koren

Parts V, VI and VII of this study are dedicated to the computation of paraxial rays and dynamic characteristics along the stationary rays obtained numerically in Part III. In this part (Part V), we formulate the linear, second-order, Jacobi…

Geophysics · Physics 2020-03-24 Igor Ravve , Zvi Koren

In Part V of this study, we presented an original Lagrangian approach for computing the dynamic characteristics along stationary rays, by solving the linear, second-order Jacobi differential equation, considering four sets of initial…

Geophysics · Physics 2020-03-24 Igor Ravve , Zvi Koren

We present an original, generic, and efficient approach for computing the first and second partial derivatives of ray velocities along ray paths in general anisotropic elastic media. These derivatives are used in solving kinematic problems,…

Geophysics · Physics 2021-12-01 Zvi Koren , Igor Ravve

An efficient procedure using a novel semi-analytical forward solver for identifying heterogeneous and anisotropic elastic parameters from only one full-field measurement is proposed and explored. We formulate the inverse problem as an…

Numerical Analysis · Mathematics 2025-06-19 Xiaopeng Zhu , Zhongyi Huang

A two-point ray-tracing technique for 3D smoothly heterogeneous, weakly transversely-isotropic media is based on Fermat's principle and takes advantage of global Chebyshev approximation of both the model and curved rays. This approximation…

Geophysics · Physics 2019-02-07 Vladimir Grechka , George A. McMechan

This paper mainly investigates the classic resonant cavity problem with anisotropic and nonconductive media, which is a linear vector Maxwell's eigenvalue problem. The finite element method based on edge element of the lowest-order and…

Numerical Analysis · Mathematics 2020-12-02 Wei Jiang , Jie Liu

In magnetized plasmas of fusion devices the strong magnetic field leads to highly anisotropic physics where solution scales along field lines are much larger than perpendicular to it. Hence, regarding both accuracy and efficiency, a…

Numerical Analysis · Mathematics 2020-01-29 Benedict Dingfelder , Florian J. Hindenlang

We consider two classes of linear kinetic equations: with constant collision frequency and constant mean free path of gas molecules (i.e., frequency of molecular collisions, proportional to the modulus molecular velocity). Based homogeneous…

Mathematical Physics · Physics 2014-07-29 A. V. Latyshev , A. D. Kurilov

Analyzing the fluid velocity gradients in a Lagrangian reference frame provides an insightful way to study the small-scale dynamics of turbulent flows, and further insight is provided by considering the equations in the eigenframe of the…

Fluid Dynamics · Physics 2023-07-19 Maurizio Carbone , Michele Iovieno , Andrew D Bragg

The transmission eigenvalue problem arises from the inverse scattering theory for inhomogeneous media and has important applications in many qualitative methods. The problem is posted as a system of two second order partial differential…

Numerical Analysis · Mathematics 2020-01-16 Bo Gong , Jiguang Sun , Tiara Turner , Chunxiong Zheng

Wavefield travel time tomography is used for a variety of purposes in acoustics, geophysics and non-destructive testing. Since the problem is non-linear, assessing uncertainty in the results requires many forward evaluations. It is…

Geophysics · Physics 2023-08-21 James Ludlam , Katherine Tant , Victorita Dolean , Andrew Curtis

Motivated by the study of uniaxial crystal optics, we consider a coupled system of $3D$ anisotropic wave equations, in which they have the same speed only in one direction but distinct speeds in the other directions. Moreover, this system…

Analysis of PDEs · Mathematics 2023-03-08 Xuecheng Wang

This work presents a novel methodology for deriving stationary and axially symmetric solutions to Einstein field equations using the 1+3 tetrad formalism. This approach reformulates the Einstein equations into first order scalar equations,…

General Relativity and Quantum Cosmology · Physics 2024-12-23 J. Ospino , J. L. Hernández-Pastora , A. V. Araujo-Salcedo , L. A. Núñez

We present two applications of the integro-differential volume equation for the eigenstrain, building on Eshelby's inclusion method [15,16], in the contexts of both static and dynamic linear elasticity. The primary objective is to address…

Analysis of PDEs · Mathematics 2025-03-25 Drossos Gintides , Leonidas Mindrinos

In present article we consider the problems of concentrated point force which is moving with constant velocity and oscillating with cyclic frequency in unbounded homogeneous anisotropic elastic two-dimensional medium. The properties of…

Mathematical Physics · Physics 2009-11-10 G. Iovane , A. V. Nasedkin , M. Ciarletta

We present a collection of well-conditioned integral equation methods for the solution of electrostatic, acoustic or electromagnetic scattering problems involving anisotropic, inhomogeneous media. In the electromagnetic case, our approach…

Numerical Analysis · Mathematics 2018-05-15 Lise-Marie Imbert-Gerard , Felipe Vico , Leslie Greengard , Miguel Ferrando
‹ Prev 1 2 3 10 Next ›