Displaying 201 – 220 of 234

Showing per page

Correctors and field fluctuations for the pϵ(x)-laplacian with rough exponents : The sublinear growth case

Silvia Jimenez (2013)

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

A corrector theory for the strong approximation of gradient fields inside periodic composites made from two materials with different power law behavior is provided. Each material component has a distinctly different exponent appearing in the constitutive law relating gradient to flux. The correctors are used to develop bounds on the local singularity strength for gradient fields inside micro-structured media. The bounds are multi-scale in nature and can be used to measure the amplification of applied...

Costruzione di spike-layers multidimensionali

Andrea Malchiodi (2005)

Bollettino dell'Unione Matematica Italiana

Si studiano soluzioni positive dell’equazione - ϵ 2 Δ u + u = u p in Ω , dove Ω R n , p > 1 ed ϵ è un piccolo parametro positivo. Si impongono in genere condizioni al bordo di Neumann. Quando ϵ tende a zero, dimostriamo esistenza di soluzioni che si concentrano su curve o varietà.

Covariant differential operators and Green's functions

Miroslav Engliš, Jaak Peetre (1997)

Annales Polonici Mathematici

The basic idea of this paper is to use the covariance of a partial differential operator under a suitable group action to determine suitable associated Green’s functions. For instance, we offer a new proof of a formula for Green’s function of the mth power Δ m of the ordinary Laplace’s operator Δ in the unit disk found in a recent paper (Hayman-Korenblum, J. Anal. Math. 60 (1993), 113-133). We also study Green’s functions associated with mth powers of the Poincaré invariant Laplace operator . It turns...

Crack detection using electrostatic measurements

Martin Brühl, Martin Hanke, Michael Pidcock (2001)

ESAIM: Mathematical Modelling and Numerical Analysis - Modélisation Mathématique et Analyse Numérique

In this paper we extend recent work on the detection of inclusions using electrostatic measurements to the problem of crack detection in a two-dimensional object. As in the inclusion case our method is based on a factorization of the difference between two Neumann-Dirichlet operators. The factorization possible in the case of cracks is much simpler than that for inclusions and the analysis is greatly simplified. However, the directional information carried by the crack makes the practical implementation...

Crack detection using electrostatic measurements

Martin Brühl, Martin Hanke, Michael Pidcock (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

In this paper we extend recent work on the detection of inclusions using electrostatic measurements to the problem of crack detection in a two-dimensional object. As in the inclusion case our method is based on a factorization of the difference between two Neumann-Dirichlet operators. The factorization possible in the case of cracks is much simpler than that for inclusions and the analysis is greatly simplified. However, the directional information carried by the crack makes the practical...

Currently displaying 201 – 220 of 234