Results 231 to 240 of about 8,186 (267)
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Characteristic impedance boundary conditions for the solution of open boundary problems
IEEE Transactions on Magnetics, 1993Open boundary conditions are presented to solve partial differential equations by means of the finite element method. Characteristic impedance boundary conditions are imposed on an artificial boundary to match the external domain with the internal one, avoiding the reflections of the electromagnetic field. An alternative method based on the application
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On the use of the impedance boundary condition with an indirect boundary formulation
IEEE Transactions on Magnetics, 1988The use of the impedance boundary condition (IBC) with an indirect boundary formulation is illustrated. The use of the IBC not only reduces significantly the computation effort but also enables the real nonlinear eB-H characteristic of the material to be presented.
M.T. Ahmed, J.D. Lavers, P.E. Burke
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Impedance boundary method of moments with extended boundary conditions
Journal of Lightwave Technology, 1995An improved impedance boundary method of moments is proposed to accurately and efficiently determine the propagation characteristics of multilayer planar optical waveguides whose refractive index profiles contain large step index changes or a graded-index region combined with step index changes.
K.A. Remley, A. Weisshaar
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Some boundary problems in electrical impedance tomography
Physiological Measurement, 1996Accurate mathematical modelling is important in the development of iterative image reconstruction algorithms for electrical impedance tomography (EIT). In such schemes the forward problem of calculating the electric potential from Neumann boundary data is solved many times.
M, Pidcock, S, Ciulli, S, Ispas
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2000
Although the perfectly conducting ground model is adequate for many applications, it is not universally applicable. A more accurate model is required for surface wave propagation, for correct modelling of reflection effects at vertical polarization or for the modelling of propagation over rough surfaces.
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Although the perfectly conducting ground model is adequate for many applications, it is not universally applicable. A more accurate model is required for surface wave propagation, for correct modelling of reflection effects at vertical polarization or for the modelling of propagation over rough surfaces.
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Impedance boundary conditions for general transient hemodynamics
International Journal for Numerical Methods in Biomedical Engineering, 2014SUMMARYWe discuss the implementation and calibration of a new generalized structured tree boundary condition for hemodynamics. The main idea is to approximate the impedance corresponding to the vessels downstream from a specific outlet. Unlike previous impedance conditions, the one considered here is applicable to general transient flows as opposed to ...
Will Cousins, Pierre A. Gremaud
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Impedance at a rough waveguide boundary
Wave Motion, 1985The impedance at the randomly rough upper boundary of an ocean waveguide is derived. The sound speed of the waveguide is an arbitrary function of depth. The boundary surface height is assumed to be a statistically homogeneous Gaussian process. Integral equations for the Green's function and its normal derivative on the boundary are derived.
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Impedance boundary conditions and effective surface impedance of inhomogeneous metal
SPIE Proceedings, 2003We present nonperturbative results for the effective impedance of strongly inhomogeneous metals valid in the frequency region in which the local impedance (Leontovich) boundary conditions are applicable. The inhomogeneity is due to the properties of the metal and/or the surface roughness.
Alexander M. Dykhne, Inna M. Kaganova
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Inverse Scattering for the Problem with Impedance-type Boundary
Journal of Partial Differential Equations, 2000Summary: This paper deals with inverse scattering problems for the Helmholtz equation with impedance boundary condition. It aims at reconstructing the unknown impedance coefficient from the knowledge of scattered wave fields. We generalize the concept of Classic Solution (CS) to Optimal Solution (OS) by a nonlinear optimization problem.
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Mathematical Notes, 2003
The authors study the problem of nonstationary diffraction of electromagnetic waves with impedance boundary condition. The main goal of this paper is to prove theorems on the existence of solutions for the problems mentioned above. The solution of the problem is expressed in terms of retarded surface potentials of the first and second kinds. The unique
Lytova, A. Yu., Chudinovich, I. Yu.
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The authors study the problem of nonstationary diffraction of electromagnetic waves with impedance boundary condition. The main goal of this paper is to prove theorems on the existence of solutions for the problems mentioned above. The solution of the problem is expressed in terms of retarded surface potentials of the first and second kinds. The unique
Lytova, A. Yu., Chudinovich, I. Yu.
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