Search results for "nuit"

Quasihyperbolic boundary conditions and capacity: Hölder continuity of quasiconformal mappings

2001

We prove that quasiconformal maps onto domains which satisfy a suitable growth condition on the quasihyperbolic metric are uniformly continuous when the source domain is equipped with the internal metric. The obtained modulus of continuity and the growth assumption on the quasihyperbolic metric are shown to be essentially sharp. As a tool, we prove a new capacity estimate.

CAD of complex passive devices composed of arbitrarily shaped waveguides using Nyström and BI-RME methods

2004

In this paper, a novel computer-aided design (CAD) tool of complex passive microwave devices in waveguide technology is proposed. Such a tool is based on a very efficient integral-equation analysis technique that provides a full-wave characterization of discontinuities between arbitrarily shaped waveguides defined by linear, circular, and/or elliptical arcs. For solving the modal analysis of such arbitrary waveguides, a modified version of the well-known boundary integral-resonant-mode expansion (BI-RME) method using the Nyström approach, instead of the traditional Galerkin version of the method of moments, is proposed, thus providing significant savings on computational costs and implement…

FDTD characterization of evanescent modes-multimode analysis of waveguide discontinuities

2000

In this paper, a finite-difference time-domain numerical dispersion relation for evanescent waves is derived, and its impact on the modeling accuracy is studied. The numerical evanescent constant is found to differ from the analytical one. As a result, a correction must be used to compute discontinuity parameters. This influences the reference plane chosen for the analysis of propagating modes. Moreover, on calculating multimode transmission and reflection coefficients, the dispersion for evanescent higher order modes is determinant. The dispersive relation is derived, discussed, and used to correct the evanescent constants for the multimode analysis of a waveguide discontinuity.

A rigorous and efficient full-wave analysis of uniform bends in rectangular waveguide under arbitrary incidence

2003

In this paper, a rigorous full-wave analysis of uniform bends in rectangular waveguides is performed. An accurate and efficient method-of-moments solution combined with the generalized-admittance-matrix (GAM) formulation is proposed in order to achieve a full-wave characterization of the analyzed structures. This full-wave modal solution turns out to be necessary for modeling complex microwave devices involving an arbitrary number of discontinuities between curved and straight waveguides, where all the modes of the involved guides are excited. The key feature of the presented method lies in the GAM representation of single and cascaded curved E- and H-plane uniform bends, which allows the c…

Approximation of Baskakov type Pólya–Durrmeyer operators

2017

In the present paper we propose the Durrmeyer type modification of Baskakov operators based on inverse Polya-Eggenberger distribution. First we estimate a recurrence relation by using hypergeometric series. We give a global approximation theorem in terms of second order modulus of continuity, a direct approximation theorem by means of the Ditzian-Totik modulus of smoothness and a Voronovskaja type theorem. Some approximation results in weighted space are obtained. Also, we show the rate of convergence of these operators to certain functions by illustrative graphics using the Maple algorithms.

On a step method and a propagation of discontinuity

2019

In this paper we analyze how to compute discontinuous solutions for functional differential equations, looking at an approach which allows to study simultaneously continuous and discontinuous solutions. We focus our attention on the integral representation of solutions and we justify the applicability of such an approach. In particular, we improve the step method in such a way to solve a problem of vanishing discontinuity points. Our solutions are considered as regulated functions.

Rupture et continuité : la préfecture de la Côte d'or sous la Restauration

2010

Discovery of hard phase lags in the pulsed emission of GRO J1744-28

2016

We report on the discovery and energy dependence of hard phase lags in the 2.14 Hz pulsed profiles of GRO J1744-28. We used data from XMM-Newton and NuSTAR. We were able to well constrain the lag spectrum with respect to the softest (0.3--2.3 keV) band: the delay shows increasing lag values reaching a maximum delay of $\sim$ 12 ms, between 6 and 6.4 keV. After this maximum, the value of the hard lag drops to 7 ms, followed by a recovery to a plateau at 9 ms for energies above 8 keV. NuSTAR data confirm this trend up to 30 keV, but the measurements are statistically poorer, and therefore, less constraining. The lag-energy pattern up to the discontinuity is well described by a logarithmic fun…

Abbandono di rifiuti

2018

The abandonment of waste is a phenomenon that is difficult to control. First of all, there is no certain definition of abandonment and the nature of the concept of waste changes over time. Furthermore, the perpetrators of the crime often remain unknown and the cost of the intervention rests on the administrations. Particularly interesting are the consequences in terms of tenuousness of the fact

Risk Preference Heterogeneity and Multiple Demand for Insurance

2010

We examined the relationship between unobserved risk preferences and four insurance purchase decisions: health Medigap insurance, long-term insurance, life insurance and annuity. Standard economic theory assumes that individuals take decision over a set of risky domains according to their own risk preferences which are stable across decision contexts. This assumption of context-invariant risk preference has caused debate in the literature concerning its validity. Using data from the Health and Retirement Study, we exploit latent class analysis to identify conditional on predicted and realized risk how heterogeneity in risk preferences affects multiple insurance demand. Our results provide e…