7,089 research outputs found

    Independent AND-parallel implementation of narrowing

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    We present a parallel graph narrowing machine, which is used to implement a functional logic language on a shared memory multiprocessor. It is an extensión of an abstract machine for a purely functional language. The result is a programmed graph reduction machine which integrates the mechanisms of unification, backtracking, and independent and-parallelism. In the machine, the subexpressions of an expression can run in parallel. In the case of backtracking, the structure of an expression is used to avoid the reevaluation of subexpressions as far as possible. Deterministic computations are detected. Their results are maintained and need not be reevaluated after backtracking

    Modelling the Degree of Emotional Concern: COVID-19 Response in Social Media

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    The massive impact caused by the COVID-19 pandemic has left no one indifferent, becoming an unprecedented challenge. The use of protections such as sanitary masks has become increasingly common, restrictions in our daily lives, such as social distancing or confinements, have had serious consequences on the economy and our welfare state. Although the measures imposed throughout the world follow the same pattern, they have been applied with different criteria depending on the country. Over extended periods of time, people tend to change their perception of an event and its magnitude, or in other words, they stop being so concerned despite the seriousness of the matter. In this paper, we introduce a new metric to quantify the degree of emotional concern of people being affected by a topic, and we confirm how populations from different countries follow this trend of downplaying the effect of the pandemic and reach a state of indifference. To do this, we propose a method to analyze the social media stream over time extracting the different emotional states from the Russel Circumplex plane and computing the shifting created by the tragic event—the pandemic. We complete this metric by incorporating searching behavior to reflect not only push contents but also pull inquiries. The resulting metric establishes a relationship between the pandemic and the emotional response by defining the degree of Emotional Concern. Although the method can be applied to any location with a significant and varied amount of geo-localized social media streams, the scope of this paper covers the most representative cities in Europe

    Algunos resultados recientes en polinomios ortogonales de Sobolev

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    En este trabajo expondré algunos resultados recientes acerca de polinomios ortogonales con respecto a un producto escalar no estándar que involucra medidas de soporte no acotado

    Las bibliotecas universitarias y los Programas de evaluación de la ANECA: una propuesta para la Universidad de Almería: trabajo para el Curso Selectivo de Promoción Interna A1 de la Universidad de Almería

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    Análisis de los Programas de la ANECA relativos a la evaluación de las titulaciones y a la evaluación del profesorado a fin de identificar los requisitos indicados para las bibliotecas universitarias y determinar oportunidades y acciones de mejora para la Biblioteca de la Universidad de Almería

    Efectos de un entrenamiento de fuerza de corta duración sobre la capacidad de salto vertical en jugadores de voleibol de elite durante la temporada

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    The aim of this study was to describe the effects of 6 weeks of combined strength and jump training which incorporated modera te loads and high intensity contractions on the vertical jump ability (VJ), loaded jumps and velocity of execution in full squat in a group of professional male volleyball players during the competition season. It was hypothesized that the VJ improved by cross combined strength and jump training both characterized by high velocity of execution (>1m/s). The participants in this study were twelve players who competed in the fir st national division of the Spanish National League during the 2011-2012 season. The neuromuscular performance was estimated by unloaded (CMJ) and load ed countermovement jumps (CMJ loaded ) height (cm); and by velocity of displacement in the concentric phase of full squat (FS) (m/s). There was a significant increase in CMJ and CMJ loaded after 6-week of training (5%, p<0.01; and 5.7%, p<0.05; respectively). These changes were accompanied by a small and moderate value of Effect Size (0.47, and 0.67; respectively). No significant differences were observed for velocity of displacement in FS. The linear correlation analysis showed a single moderate correlation statistically significant between the changes in CMJ-CMJ loaded and CMJ-FS (r=0.62 and r=0.59, p<0.05; respectively). Albeit speculative, our results suggest that the use of moderate loads could be enough to im prove the vertical jump performance, since in our study a load equivalent to 60% 1RM in the FS was not exceeded and jumping exercises were performed wi th light loads.El objetivo de este estudio fue describir los efectos de 6 semanas de entrenamiento combinado de fuerza y salto, el cual incorpora cargas moderadas e intensidades de contracción altas, sobre la capacidad de salto vertical, saltos con cargas y la velocidad de ejecución en el ejercicio de sentadilla en un grupo de jugadores profesionales de voleibol durante la temporada de competición. Se estableció la hipótesis de que el sa lto vertical mejoro por el uso combinado de entrenamiento de fuerza y salto, ambos caracterizados por una alta velocidad de ejecución (>1m/s). El rendimie nto neuromuscular fue estimado por la altura (cm) del salto sin cargas (CMJ), salto con cargas (CMJ loaded ), y por la velocidad (m/s) de desplazamiento en la fase concéntrica en la sentadilla completa (FS). Tuvo lugar un incremento significativo en CMJ y CMJ loaded después de 6 semanas de entrenamientos (5%, p<0.01; y 5.7%, p<0.05; respectivamente). Estos cambios fueron acompañados por un valor de Tamaño del Efecto pequeño y moderado (0.47, and 0.67 ; respectivamente). No se observaron diferencias significativas en la velocidad de desplazamiento en FS. El análisis de correlación lineal mostró una correlación moderada estadísticamente significativa entre los cambios en CMJ-CMJ loaded y CMJ-FS (r=0.62; y r=0.59, p<0.05; respectivamente). Aunque algo especulativo, nuestros resultados sugieren que el uso de cargas moderadas podría ser suficiente para mejorar el rendimiento del salto vertical, ya que en nuestro estudio no se excedió una carga equivalente al 60% de 1RM en FS y los ejercicios de saltos también fueron realizados con cargas ligeras

    One- and two-photon scattering from generalized V-type atoms

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    The one- and two-photon scattering matrix S is obtained analytically for a one-dimensional waveguide and a point-like scatterer with N excited levels (generalized V -type atom). We argue that the two-photon scattering matrix contains sufficient information to distinguish between different level structures which are equivalent for single-photon scattering, such as a V -atom with N = 2 excited levels and two two-level systems. In particular, we show that the scattering with the V -type atom exhibits a destructive interference effect leading to two-photon Coupled-Resonator-Induced Transparency, where the nonlinear part of the two-photon scattering matrix vanishes when each incident photon fulfills a single-photon condition for transparency

    Single photons by quenching the vacuum

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    Heisenberg's uncertainty principle implies that the quantum vacuum is not empty but fluctuates. These fluctuations can be converted into radiation through nonadiabatic changes in the Hamiltonian. Here, we discuss how to control this vacuum radiation, engineering a single-photon emitter out of a two-level system (2LS) ultrastrongly coupled to a finite-band waveguide in a vacuum state. More precisely, we show the 2LS nonlinearity shapes the vacuum radiation into a nonGaussian superposition of even and odd cat states. When the 2LS bare frequency lays within the band gaps, this emission can be well approximated by individual photons. This picture is confirmed by a characterization of the ground and bound states, and a study of the dynamics with matrix product states and polaron Hamiltonian methods.Comment: 9 pages, 10 figure
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