1,721,153 research outputs found
Punción seca para el tratamiento de fascitis plantar
No full textRando Rivas, Alejandro; director de proyecto: Pérez Gurbindo, Ignacio2024-2025Grado en PodologíaFacultad de Ciencias de la Salu
Semiclassical matrix elements for a chaotic propagator in the scar function basis
No full textA semiclassical approximation for the matrix elements of a quantum chaotic propagator in the scar function basis has been derived. The obtained expression is solely expressed in terms of canonical invariant objects. For our purpose, we have used the recently developed, semiclassical matrix elements of the propagator in coherent states, together with the linearization of the flux in the neighborhood of a classically unstable periodic orbit of chaotic two-dimensional systems. The expression derived here is successfully verified to be exact for a (linear) cat map, after the theory is adapted to a discrete phase space appropriate to a quantized torus.Fil: Rivas, Alejandro Mariano Fidel. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigaciones y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Constituyentes); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Educación en cuarentena
No full textUNCiencia podcasts. Contenido del audio.
¿Qué es educar y qué es aprender?
Los sistemas educativos ante la virtualidad.
Las desigualdades sociales y la educación virtual.
En este momento la escuela debe privilegiar los vínculos.La pandemia ha trastocado todo lo conocido. Según el último reporte de la Unesco, 190 países suspendieron en forma total o parcial las clases. Esto afectó a 1.500 millones de alumnos, que representan el 90% de la población estudiantil actual.
Dentro de este fenómeno sin precedentes, la respuesta fue una forzada migración inmediata a lo digital, pero la sociedad no estaba preparada para eso.Fil: Ludueña, Diego. Universidad Nacional de Córdoba. Prosecretaría de Comunicación Institucional. UNCiencia; Argentina.Fil: Pisarello, Andrea. Centro Educativo Nivel Medio Adultos, Anexo Yapeyú del Coronel Olmedo, Córdoba; Argentina.Fil: Rivas, Alejandro. Centro Educativo Nivel Medio Adultos N° 168, Córdoba; Argentina
Semiclassical coherent-states propagator
No full textIn this work, we derived a semiclassical approximation for the matrix elements of a quantum propagator in coherent states (CS) basis that avoids complex trajectories; it only involves real ones. For that purpose, we used the symplectically invariant semiclassical Weyl propagator obtained by performing a stationary phase approximation (SPA) for the path integral in the Weyl representation. After that, for the transformation to CS representation SPA is avoided; instead a quadratic expansion of the complex exponent is used. This procedure also allows us to express the semiclassical CS propagator uniquely in terms of the classical evolution of the initial point without the need of any root search typical of van Vleck–Gutzwiller-based propagators. For the case of chaotic Hamiltonian systems, the explicit time dependence of the CS propagator has been obtained. The comparison with a realistic chaotic system that derives from a quadratic Hamiltonian, the cat map, reveals that the expression here derived is exact up to quadratic Hamiltonian systems.Fil: Rivas, Alejandro Mariano Fidel. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Diffusion behavior of Cr diluted in bcc and fcc Fe: Classical and quantum simulation methods
No full textAbstract We characterize the atomic mobility behavior driven by vacancies, in bcc and fcc Fe-Cr diluted alloys, using a multi-frequency model. We calculate the full set of the Onsager coefficients and the tracer self and solute diffusion coefficients in terms of the mean jump frequencies. The involved jump frequencies are calculated using a classical molecular static (CMS) technique. For the bcc case, we also perform quantum calculations based on the density functional theory (DFT). There, we show that, in accordance with Bohr's correspondence principle, as the size of the atomic cell (total number of atoms) is increased, quantum results with DFT recover the classical ones obtained with CMS calculations. This last ones, are in perfect agreement with available experimental data for both, solute and solvent diffusion coefficients. For high temperatures, in the fcc phase where no experimental data are yet available, our CMS calculations predict the expected solute and solvent diffusion coefficients.Fil: Ramunni, Viviana Patricia. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rivas, Alejandro Mariano Fidel. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Dos décadas de intervencionismo en la Educación Superior Colombiana
No full textEl texto realiza un análisis sobre cómo son trascendentales los temas que debe abordar una reforma al sistema de educación superior, y que aún no se han cubierto adecuadamente, enumerando las falencias y deudas históricas del Estado colombiano en el tema particular de la Educación Superio
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