Sökresultat

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

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

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

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

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.

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

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.

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

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

The pre-dispute phase, during which justiciable problems may or may not emerge and transform into legal cases, is complex. Based on a meta-ethnography of 572 articles, all of which apply or refer to Felstiner et al.’s pioneering linear framework of naming, blaming, and claiming, we analysed the many sorting mechanisms that are at play in the pre-dispute phase. We identified the institutional, poli

The recital is focused on my research involving contemporary voice. My approach to singing research is becoming more systematic as the result of beginning to work on concepts central to the extra-normal voice, term coined by Michael Edward Edgerton. This approach to voice is based on voice science, the aims of which are to investigate the boundaries and/or limits of vocal sound production. In this

Induced polarization (IP) is a common method in ore exploration. IP spectra measured over a wide frequency range can be used to characterize material properties of ores, slags and other residual material from mines and processing facilities. Previous studies have shown that IP parameters are sensitive to type, content or grain size of electronically conductive or semi-conductive minerals. Up to no