Search results for "circle"
showing 10 items of 122 documents
Inversion Formulas for the Discretized Hilbert Transform on the Unit Circle
1998
A discrete version of the Hilbert transform on the unit circle is considered. Its Moore--Penrose inverse with respect to suitable scalar products is derived for different side conditions. Furthermore, stability of the pseudo-inverse is studied. These results allow the efficient computation of approximate solutions of singular integral equations with Hilbert kernel. Furthermore, the stability analysis of such methods becomes much easier even for graded meshes which are useful for weakly singular solutions.
Improved Method for Orbital Elements Differential Correction.
1990
As was pointed out by IAU in 1976, an important problem in fundamental astronomy is the improvement of the vernal equinox and equator positions. To this aim, it is necessary to know the accurate values of minor planets orbital elements. The classical methods of orbital elements differential corrections are based on linking the observations at different epochs considering equal derivatives respect to the initial and osculating elements. In this paper we present an improved method in which the least squares matrix coefficients is calculated from the integration of the Lagrange planetary equations and its derivatives.
Conceptualización y medición del valor percibido: consensos y controversias
2019
[ES] Estudiar el concepto Valor resulta ser necesario y útil en Marketing por ser un concepto endémico para la disciplina y relevante para la profesión. Sin embargo, a pesar de décadas de investigación, la doctrina se lamenta de un cierto círculo vicioso sobre las dificultades conceptuales y de medición del Valor. Este trabajo revisa estas dificultades y las categoriza en torno a acuerdos y controversias, evidenciando sus efectos en la compleja red nomológica construida a lo largo de los años en torno al Valor. Además, explora empíricamente tres modelos causales de relaciones entre dimensiones de Valor, Satisfacción y Lealtad, testados con PLS sobre una muestra de 340 clientes de hotel. Los…
Photoproduction of $\eta$ $\pi$ pairs off nucleons and deuterons
2016
Quasi-free photoproduction of $\pi\eta$-pairs has been investigated from threshold up to incident photon energies of 1.4 GeV, respectively up to photon-nucleon invariant masses up to 1.9 GeV. Total cross sections, angular distributions, invariant-mass distributions of the $\pi\eta$ and meson-nucleon pairs, and beam-helicity asymmetries have been measured for the reactions $\gamma p\rightarrow p\pi^0\eta$, $\gamma n\rightarrow n\pi^0\eta$, $\gamma p\rightarrow n\pi^+\eta$, and $\gamma n\rightarrow p\pi^-\eta$ from nucleons bound inside the deuteron. For the $\gamma p$ initial state data for free protons have also been analyzed. Finally, the total cross sections for quasi-free production of $…
Ultrametricity property of energy landscapes of multidisperse packing problems
2009
We consider the problem of finding the densest closed packing of hard disks with proposed different radii in a circular environment, such that the radius of the circumcircle is minimal. The subspace of the quasioptimum configurations of this problem exhibits the property of ultrametricity.
Thin plastic shell x-ray optics: an update
2003
We present new results from a program to develop large area X-ray telescopes that are made from thin plastic shells. We use multi-shell cylindrical lenses in a point-to-point configuration to form full aperture images of the small focal spot in a an X-ray tube on a microchannel plate detector. The image data are analyzed to yield radial profiles and encircled energy curves. The derived parameters can be extrapolated to the case of a telescope that is a conical approximation to Wolter 1 optics. The plastic shells can be coated with suitable mono- or multilayers that allow for a wideband coverage of X-ray energies. Our current program is focused on the development of a large area, hard X-ray …
Calibration of the Solar-B x-ray optics
2005
The Solar-B X-ray telescope (XRT) is a grazing-incidence modified Wolter I X-ray telescope, of 35 cm inner diameter and 2.7 m focal length. XRT, designed for full sun imaging over the wavelength 6-60 Angstroms, will be the highest resolution solar X-Ray telescope ever flown. Images will be recorded by a 2048 X 2048 back-illuminated CCD with 13.5 μm pixels (1 arc-sec/pixel ) with full sun field of view. XRT will have a wide temperature sensitivity in order to observe and discriminate both the high (5-10 MK) and low temperature (1-5 MK) phenomena in the coronal plasma. This paper presents preliminary results of the XRT mirror calibration performed at the X-ray Calibration Facility, NASA-MSFC,…
Nación, emoción y fantasía. La España melodramática de Ayguals de Izco = Nation, Emotion and Fantasy. Ayguals de Izco's Melodramatic Spain
2017
El artículo analiza las novelas por entregas de Wenceslao Ayguals de Izco (1801-1873) desde su dimensión melodramática para señalas de qué modo participaron en la creación de los imaginarios, las narrativas sociales y políticas y la "comunidad emocional" del radicalismo democrático español de mediados del siglo XIX. Posteriormente examino una serie de "fantasías nacionales" que se repiten con insistencia en estas novelas melodramáticas: la unión matrimonial como metáfora de la plenitud nacional, el mártir por la patria y el "ángel de salvación" que socorre a los desfavorecidos. Todas estas fantasías se fundan en la diferencia sexual (al tiempo que la construyen) y permiten la identificación…
Exact Voronoi diagram of smooth convex pseudo-circles: General predicates, and implementation for ellipses
2013
International audience; We examine the problem of computing exactly the Voronoi diagram (via the dual Delaunay graph) of a set of, possibly intersecting, smooth convex \pc in the Euclidean plane, given in parametric form. Pseudo-circles are (convex) sites, every pair of which has at most two intersecting points. The Voronoi diagram is constructed incrementally. Our first contribution is to propose robust and efficient algorithms, under the exact computation paradigm, for all required predicates, thus generalizing earlier algorithms for non-intersecting ellipses. Second, we focus on \kcn, which is the hardest predicate, and express it by a simple sparse $5\times 5$ polynomial system, which a…
ERMENEUSI E DIRITTO
2013
This essay discusses Heidegger’s hermeneutical phenomenology and hermeneutical circle through juridical interpretation. The purpose is to show how jurists, judges and lawmakers can make, by means of juridical interpretation, more prolific the same hermeneutical circle. It’s about the vitality opposed to static nature of opus magnum Sein und Zeit’s hermeneutical circle. New perspective examines in depth Heidegger’s hermeneutical phenomenology, compared to Husserl’s understanding, and develops in different fields of study, such as theology, psychoanalysis, and the same law.