For the unit sphere embedded in a Euclidean space, we obtain quadrature formulas that are exact for spherical harmonics of a fixed order, have nonnegative weights, and are based on function values at scattered points (sites). The number of scattered sites required is comparable to the dimension of the space for which the quadrature formula is required to be exact. As a part of the proof, we der...

In this paper we solve the problem about optimal interval quadrature formula for the class WrF of differentiable periodic functions with rearrangement invariant set F of their derivatives of order r. We prove that the formula with equal coefficients and n node intervals having equidistant midpoints is optimal for considering classes. To this end a sharp inequality for antiderivatives of rearran...

Similar as in the classical case of polynomials, as is known, paraorthogonal rational functions on the unit circle can be used to obtain quadrature formulas of Szegő-type to approximate some integrals. In the present paper we carry out a thorough discussion of the existence of such rational functions in terms of the underlying Borel measure on the unit circle

En medios áridos y semiáridos como el Sureste de la Península Ibérica, para captar las aguas subálveos ramblas, se utilizan sistemas combinados galería presa enterrada. Son complejos hidráulicos que obtienen recursos caudal variable, pero gran calidad. Solo pueden obtener aquellos caudales tras precipitaciones quedan acumulados en los depósitos arenas gravas lechos fluviales, renuevan cada epis...

In this work, we propose a semi-analytical solution for Simple Compartmental Models, more specifically the SIR Model. From system of ordinary differential equations itself, with change variable through an extended domain-based mapping, seek to build sharing solutions paths field function, generated by partial equation. Using characteristic method, obtain exact function in terms arbitrary whose ...

Szegö quadrature formulas represent the analogue on the unit circle of the well-known Gauss–Christoffel quadratures for intervals of the real line. In the present work, Szegö formulas are revised and an application to the computation of the Fourier transform given. 2006 Elsevier Inc. All rights reserved.

In this paper we investigate the Szegő-Radau and Szegő-Lobatto quadrature formulas on the unit circle. These are (n + m)-point formulas for which m nodes are fixed in advance, with m = 1 and m = 2 respectively, and which have a maximal domain of validity in the space of Laurent polynomials. That means that the free parameters (free nodes and positive weights) are chosen such that the quadrature...

Our paper reviews Kallay’s results on a geometric version of the classic Newton-Raphson method, in the context of plane curve queries, e.g. curve-curve intersection, point-curve distance computation. Variants of the geometric Newton-Raphson methods are proposed and empirically verified.

It is well known [28] that a number of important classes of univalent functions (e.g. convex, starlike) are related through their derivatives by functions with positive real part. These functions play an important part in problem from signal theory, in moment problems and in constructing quadrature formulas, see Ronning [97] and the references cited therein for some recent applications. In this...

Since the description of 'alveolar-capillary block' by Austrian, McClement, Renzetti, Donald, Riley, and Cournand (1951), impairment of diffusion across the alveolar-capillary membrane has been regarded as an important factor in the production of low arterial oxygen saturations in patients with diffuse pulmonary disease. However, Luchsinger, Moser, Buhlmann, and Rossier (1957) suggested that re...