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The problem of reconstructing a piecewise constant function from a finite number of its Fourier coefficients perturbed by noise is considered. A reconstruction method, based on the computation of the Padè approximants to the Z-transform of the sequence of the noisy Fourier coefficients is proposed… |
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The ability of Well-Balanced (WB) schemes to capture very accurately
steady-state regimes of non-resonant hyperbolic systems of
balance laws has been thoroughly illustrated since its introduction
by Greenberg and LeRoux (1996) [15] (see also the anterior WB
Glimm scheme in E, 1992 [8]). This paper… |
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We study a quasilinear parabolic equation of forward-backward type, under assumptions on the nonlinearity which hold for a wide class of mathematical models, using a pseudo-parabolic regularization of power type.We prove existence and uniqueness of positive solutions of the regularized problem in a… |
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Nonparametric univariate regression via wavelets is usually implemented under the assumptions of dyadic sample size, equally spaced fixed sample points, and i.i.d. normal errors. In this work, we propose, study and compare some wavelet based nonparametric estimation methods designed to recover a… |
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The Smoothed Particle Hydrodynamics (SPH) method, often used for the modelling of the Navier-
Stokes equations by a meshless Lagrangian approach, is revisited from the point of view of Large
Eddy Simulation (LES). To this aim, the LES filtering procedure is recast in a Lagrangian framework
by… |
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A shear-improved Smagorinsky model is introduced based on recent results concerning shear effects in wall-bounded turbulence by Toschi et al. (2000). The Smagorinsky eddy-viscosity is modified subtracting the magnitude of the mean shear from the magnitude of the instantaneous resolved strain-rate… |
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Mass currents in astrophysics generate gravitomagnetic fields of enormous complexity. Gravitomagnetic
helicity, in direct analogy with magnetic helicity, is a measure of entwining of the gravitomagnetic field
lines. We discuss gravitomagnetic helicity within the gravitoelectromagnetic (GEM)… |
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