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On the spectrum of a holomorphic operator-valued function with applications to absorptive photonic crystals

We study electromagnetic wave propagation in a periodic and frequency dependent material characterized by a space- and frequency-dependent complex-valued permittivity. The spectral parameter relates to the time-frequency, leading to spectral analysis of a holomorphic operator-valued function. We apply the Floquet transform and show for a fixed quasi-momentum that the resulting family of spectral p

On a method to reduce uncertainties in bulk property measurements of two-component composites

For two-component composites, we address the inverse problem of estimating the structural parameters and decrease measurement errors in bulk property measurements. A measurement of the effective permittivity at one frequency gives microstructural information about the composite that is used in cross-property bounds to estimate the effective permittivity at other frequencies. We use this informatio

Meshless eigenvalue analysis for resonant structures based on the radial point interpolation method

Meshless methods are a promising field of numerical methods recently introduced to computational electromagnetics. The potential of conformal and multi-scale modeling and the possibility of dynamic grid refinements are very attractive features that appear more naturally in meshless methods than in classical methods. The Radial Point Interpolation Method (RPIM) uses radial basis functions for the a

On the spectrum of an operator pencil with applications to wave propagation in periodic and frequency dependent materials

We study wave propagation in periodic and frequency dependent materials when the medium in a frequency interval is characterized by a real-valued permittivity. The spectral parameter relates to the quasi momentum, which leads to spectral analysis of a quadratic operator pencil where frequency is a parameter. We show that the underlying operator has a discrete spectrum, where the eigenvalues are sy

Computations of lossy Bloch waves In two-dimensional photonic crystals

In this article we compute lossy Bloch waves in two-dimensional photonic crystals with dispersion and material loss. For given frequencies these waves are determined from non-linear eigenvalue problems in the wave vector. We applied two numerical methods to a demanding test case, a photonic crystal with embedded quantum dots that exhibits very strong and anamolous dispersion. The first method is b

Inverse bounds of two-component composites

A method is presented for estimating microstructural parameters from permittivity measurements of two-component composites. This structural information is described by a particular positive measure in the Stieltjes integral representation of the effective permittivity. The dependence on the geometrical structure can be reduced to the problem of calculating the moments of the measure. We present a

Inverse bounds and bulk properties of complex-valued two-component composites

The bulk properties of composites are known to depend strongly on the microstructure. This dependence can be quantified in terms of a representation introduced by D. Bergman, which factorizes the geometry dependence from the contrast. Based on this analytic representation of the effective permittivity, we present a general scheme to estimate the microstructural parameters such as the volume fracti

Bounds on effective anisotropic material parameters

A new method to estimate the micro-structural parameters of anisotropic two-phase composite material is derived. The parameters are estimated using information from measurements or from numerical experiments. The method is used to derive new bounds on the effective tensor that incorporates information from measurements of a related parameter. These new bounds are called cross-property bounds.

Bounds on the effective tensor and the structural parameters for anisotropic two-phase composite material

This paper is concerned with the estimation of macroscopic properties such as the permittivity or the thermal conductivity of a composite material from the microstructure. A new method of estimating the microstructural parameters, such as the volume fraction of anisotropic two-phase composite material, is derived. The parameters are estimated using information from measurements of the random mater

Vad händer med historien när vi kan chatta med de döda?

AI-appar Vad skulle du vilja fråga Julius Caesar, Virginia Woolf, Adolf Hitler? På senare tid har flera AI- tjänster dykt upp som tillåter användaren att samtala med avlidna kändisar. Så inleds ett nytt kapitel i den både uråldriga och fåfänga drömmen om att kommunicera med de döda.

Prevalence of serious bacterial infections and management of febrile infants ≤60 days in Swedish Pediatric Emergency Departments

BACKGROUND. The reported prevalence of serious bacterial infections (SBI: urinary tract infection (UTI), bacteremia, and meningitis) among febrile infants ≤60 days of age varies from 8% to 23%. There are indications that the prevalence of infections differs between the sexes. Infants with fever at home but afebrile at the pediatric emergency department (PED) might have a lower risk of SBIs. Furthe

Bringing Sociology of Law back into Pierre Bourdieu’s Sociology: Elements of Bourdieu’s Sociology of Law and Dispute Transformation

The academic response to Bourdieu's sociology of law has mainly followed his Weberian focus on the role of legal professionals in state transformations. However, rereading Bourdieu's “The Force of Law” through the lens of its references and relating it to the sociology of law “of the moment” (i.e. that of the 1980s), it becomes clear that Bourdieu's sociology of law is more sophisticated than has