The Experts below are selected from a list of 51453 Experts worldwide ranked by ideXlab platform
Patrick Joly - One of the best experts on this subject based on the ideXlab platform.
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Solutions of the time-Harmonic Wave equation in periodic Waveguides : asymptotic behaviour and radiation condition
Archive for Rational Mechanics and Analysis, 2015Co-Authors: Sonia Fliss, Patrick JolyAbstract:In this paper, we give the expression and the asymptotic behaviour of the physical solution of a time Harmonic Wave equation set in a periodic Waveguide. This enables us to define a radiation condition and show well-posedness of the Helmholtz equation set in a periodic Waveguide.
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Domain Decomposition Method for Harmonic Wave Propagation : A General Presentation
1998Co-Authors: Francis Collino, Souad Ghanemi, Patrick JolyAbstract:In this paper we give a general presentation of non overlapping domain decomposition methods for Harmonic Wave propagation models. Our abstract framework lead to concise convergence proofs and contains some recent developments about the use of non local transmission conditions. It also includes applications to acoustic, electromagnetic or elastic Waves, as well as the treatment of space discretization.
Sonia Fliss - One of the best experts on this subject based on the ideXlab platform.
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Time Harmonic Wave propagation in one dimensional weakly randomly perturbed periodic media
SN Partial Differential Equations and Applications, 2020Co-Authors: Sonia Fliss, Laure GiovangigliAbstract:In this work we consider the solution of the time Harmonic Wave equation in a one dimensional periodic medium with weak random perturbations. More precisely, we study two types of weak perturbations: (1) the case of stationary, ergodic and oscillating coefficients, the typical size of the oscillations being small compared to the Wavelength and (2) the case of rare random perturbations of the medium, where each period has a small probability to have its coefficients modified, independently of the other periods. Our goal is to derive an asymptotic approximation of the solution with respect to the small parameter. This can be used in order to construct absorbing boundary conditions for such media.
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Solutions of the time-Harmonic Wave equation in periodic Waveguides : asymptotic behaviour and radiation condition
Archive for Rational Mechanics and Analysis, 2015Co-Authors: Sonia Fliss, Patrick JolyAbstract:In this paper, we give the expression and the asymptotic behaviour of the physical solution of a time Harmonic Wave equation set in a periodic Waveguide. This enables us to define a radiation condition and show well-posedness of the Helmholtz equation set in a periodic Waveguide.
Alexey Agaltsov - One of the best experts on this subject based on the ideXlab platform.
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Uniqueness and non-uniqueness in acoustic tomography of moving fluid
Journal of Inverse and Ill-posed Problems, 2016Co-Authors: Alexey Agaltsov, Roman NovikovAbstract:AbstractWe consider a model time-Harmonic Wave equation of acoustic tomography of moving fluid in an open bounded domain in ℝ
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A global uniqueness result for acoustic tomography of moving fluid
Bulletin Des Sciences Mathematiques, 2015Co-Authors: Alexey AgaltsovAbstract:Abstract We consider a model time-Harmonic Wave equation of acoustic tomography of moving fluid in an open bounded domain in dimension d ≥ 2 . We give global uniqueness theorems for related inverse boundary value problem at fixed frequency.
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A global uniqueness result for acoustic tomography of moving fluid
2015Co-Authors: Alexey AgaltsovAbstract:We consider a model time-Harmonic Wave equation of acoustic tomography of moving fluid in an open bounded domain in dimension $d \geq 2$. We give global uniqueness theorems for related inverse boundary value problem at fixed frequency.
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Finding scattering data for a time-Harmonic Wave equation with first order perturbation from the Dirichlet-to-Neumann map
2015Co-Authors: Alexey AgaltsovAbstract:We present formulas and equations for finding scattering data from the Dirichlet-to-Neumann map for a time-Harmonic Wave equation with first order perturbation with compactly supported coefficients. We assume that the coefficients are matrix-valued in general. To our knowledge, these results are new even for the general scalar case.
Kazuo Shima - One of the best experts on this subject based on the ideXlab platform.
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Mode-filtering analysis of space and time Harmonic Wave components of magnetic fields in rotating machinery
Electrical Engineering in Japan, 2010Co-Authors: Kenji Miyata, Kazumasa Ide, Kazuo ShimaAbstract:We propose a new method for analysis of the Harmonic Wave components of magnetic fields in rotating machinery. Using the magnetic permeability obtained by transient analysis of the nonlinear magnetic field, the Harmonic Wave components of the magnetic field are individually calculated in the spaces of both the rotor and stator subject to the boundary condition that the Harmonic Wave components obtained by the transient analysis are set on the sliding surface. Mode separation of the magnetic field will contribute to research on reducing harmful Harmonic Wave components for rotating machinery. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 172(2): 55–63, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20951
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mode filtering analysis method of space and time Harmonic Wave components of magnetic fields in rotating machinery
Ieej Transactions on Industry Applications, 2008Co-Authors: Kenji Miyata, Kazuo ShimaAbstract:We propose a new analysis method of Harmonic Wave components of magnetic fields in rotating machinery. Using the magnetic permeability obtained by the transient analysis of nonlinear magnetic field, the Harmonic Wave components of the magnetic field are individually calculated both in the spaces of rotor and stator under the boundary condition that the Harmonic Wave components obtained by the transient analysis are set on the sliding surface. The mode separation of magnetic field will contribute to the study of reducing the harmful Harmonic Wave components for the rotating machinery.
Victor M Calo - One of the best experts on this subject based on the ideXlab platform.
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a class of discontinuous petrov galerkin methods part iv the optimal test norm and time Harmonic Wave propagation in 1d
Journal of Computational Physics, 2011Co-Authors: J Zitelli, Ignacio Muga, Leszek Demkowicz, Jay Gopalakrishnan, David Pardo, Victor M CaloAbstract:The phase error, or the pollution effect in the finite element solution of Wave propagation problems, is a well known phenomenon that must be confronted when solving problems in the high-frequency range. This paper presents a new method with no phase errors for one-dimensional (1D) time-Harmonic Wave propagation problems using new ideas that hold promise for the multidimensional case. The method is constructed within the framework of the discontinuous Petrov-Galerkin (DPG) method with optimal test functions. We have previously shown that such methods select solutions that are the best possible approximations in an energy norm dual to any selected test space norm. In this paper, we advance by asking what is the optimal test space norm that achieves error reduction in a given energy norm. This is answered in the specific case of the Helmholtz equation with L^2-norm as the energy norm. We obtain uniform stability with respect to the Wave number. We illustrate the method with a number of 1D numerical experiments, using discontinuous piecewise polynomial hp spaces for the trial space and its corresponding optimal test functions computed approximately and locally. A 1D theoretical stability analysis is also developed.
