De Sevilla al Campo de Gibraltar: los itinerarios de Alfonso XI en sus campañas del Estrecho

A lo largo de su reinado, Alfonso XI llegó en cinco ocasiones a las hoy tierras del Campo de Gibraltar; en todas ellas fue acompañado de un ejército más o menos numeroso, pasando siempre por Sevilla y Jerez de la Frontera. Pero el camino seguido entre estas dos ciudades, así como los lugares de acampada elegidos en cada desplazamiento, dependió de circunstancias logísticas y de lo apremiante de la situación. Por su parte, el itinerario que unía Jerez con las tierras del Estrecho se vio afectado, además, por cuestiones relativas a la seguridad del ejército. Unos y otros aspectos se tratan aquí teniendo en cuenta la toponimia actual y la que se cita en las fuentes medievales.During his reign, Alfonso XI visited the area of Gibraltar fi ve times. On each occasion, he came with an army, passing through Seville and Jerez de la Frontera on the way. The routes followed between these two cities and the places chosen to set up camp depended on logistics, how pressing the situation was, and the safety of the army. All of these circumstances are examined in this article, with special attention paid to present-day place names and those mentioned in medieval documents

Revistas argentinas de economía: de tiempos de la colonia a internet

Se compilan las principales experiencias de publicación de revistas cuyo contenido estaba vinculado a la profesión deeconomista o cumplía algún papel en la formación de nuevos economistas. Loscasos considerados van desde 1801 hasta comienzos del siglo actual

The Grand Mastership of Alfonso Méndez de Guzmán in the Order of Santiago (1338-1342)

Alfonso méndez de guzmán became grand master of the order of Santiago through the imposition of alfonso XI, at a time when the king sought to place people of his entire confidence at the head of the military orders. méndez de guzmán responded in great measure to the expectations that the King of Castile had placed in him. He took part in the battle of Salado and in the conquest of alcalá la real. However, we deal here not only with the military activity of the grand master but also his work as administrator at the head of the order. We include a list of the names of his closest collaborators and details of his itinerary. for this we have studied the royal chronicles and documents and in the index we include a particularly interesting document.Alfonso méndez de guzmán fue nombrado maestre de la orden de Santiago como consecuencia de la injerencia de alfonso XI en los asuntos internos de los santiaguistas. El tiempo que méndez de guzmán permaneció al frente de la orden fue corto, pero muy intenso al coincidir su gobierno con la ofensiva de los benimerines y la contraofensiva de alfonso XI que siguió a la batalla del Salado. Pero no sólo tratamos aquí de la actuación del maestre en estos hechos de armas, sino que seguimos su labor administrativa al tiempo de dar a conocer sus colaboradores más cercanos y también su itinerario. Para ello nos hemos apoyado en las crónicas reales y en la documentación, entresacando de ésta el interesante documento que aportamos en el apéndice documental

Anxiety, heart rate variability and performance in a tennis match

Treball Final de Màster Universitari en Investigació en Cervell i Conducta. Codi: SBM024. Curs: 2019/2020.Pre-competitive anxiety may have an impact on performance in a tennis match during real life competition. Heart rate variability (HRV) is a relevant biomarker reflecting cardiac modulation by sympathetic and vagal components of the autonomic nervous system (ANS). This study will analyse, with non-invasive tools, the influence of competition and precompetitive anxiety on psychophysiological activation, as well as its impact on performance outcomes. A sample of 30 players between 14-18 years will be monitored during two firsts round matches and a training day (simulating a match play). RMSSD and High frequency (HF)-HRV (often referred to as respiratory sinus arrhythmia), Revised Competitive State Anxiety Inventory-2 (CSAI-2R) and score-match (outcome of good or bad performance) will be assessed before the tennis match and during the match breaks. According to the literature review, we expect that “losers” will show lower resting HRV and will score higher in anxiety compared to “winners”. Based on our findings, an individualized training program will be implemented in order to improve performance in tennis competition

A Generalized Regression Methodology for Bivariate Heteroscedastic Data

We present a methodology for reducing a straight line fitting regression problem to a Least Squares minimization one. This is accomplished through the definition of a measure on the data space that takes into account directional dependences of errors, and the use of polar descriptors for straight lines. This strategy improves the robustness by avoiding singularities and non-describable lines. The methodology is powerful enough to deal with non-normal bivariate heteroscedastic data error models, but can also supersede classical regression methods by making some particular assumptions. An implementation of the methodology for the normal bivariate case is developed and evaluated

Natural frequencies and damping ratios of multi-layered laminated glass beams using a dynamic effective thickness

Multi-layered laminated glass panels are those with at least three monolithic glass layers and two viscoelastic interlayers. Multi-layered laminated glass panels are commonly used in floors, roofs and other horizontal glazing accessible to the public where a high level of security is required. Although the glass can be consider a linear-elastic material, the viscoelastic interlayers determine a non-linear behaviour of the laminated structure that must be taken into consideration. In this paper, an analytical model based on the effective thickness concept and the Ross, Kerwin and Ungar model is proposed to predict the dynamic behaviour of multi-layered laminated glass beam-like structures with different boundary conditions and at different temperatures. This analytical model allows the simplification of the calculus on this multi-layered laminated components opposite to use time-consuming numeric models. In this work, a study was carried out on a multi-layered laminated glass beam composed of three annealed glass layers and two polymeric interlayers. The analytical predictions are validated by numerical simulations and experimentally using operational modal analysis tests. The proposed model predicts the natural frequencies with errors less than 5% whereas the discrepancies in damping ratios are less than 50%

The geometric representations in the books of text used in the Autonomous Community of Extremadura

Se recogen los principales resultados de una investigación sobre la visualización de la Geometría en libros de texto actuales de Matemáticas de las editoriales de mayor uso en Extremadura (SM, Anaya y Santillana). El estudio se centra en la variedad de representaciones al introducir las figuras y conceptos geométricos, los elementos de las imágenes que puedan derivar en dificultades en el proceso de enseñanza-aprendizaje de la Geometría, la representación plana de figuras tridimensionales y las imágenes reales que se utilizan para aludir a elementos geométricos abstractos.The main results of a research on the visualization of the Geometry in present-day Mathematics text books of the more used editorials in Extremadura (SM, Anaya and Santillana) are collected. Study focuses on the variety of representations in the introduction of the figures and geometrical concepts, the elements of the images which could lead to difficulties in the Geometry teaching-learning process, the plane representation of tridimensional figures and the real images that are used to refer to abstract geometrical elements.peerReviewe

Benjamín Cornejo a cien años de su natalicio · Biografía

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Load-independent characterization of trade-off fronts for operational amplifiers

Abstract—In emerging design methodologies for analog integrated circuits, the use of performance trade-off fronts, also known as Pareto fronts, is a keystone to overcome the limitations of the traditional top-down methodologies. However, most techniques reported so far to generate the front neglect the effect of the surrounding circuitry (such as the output load impedance) on the Pareto-front, thereby making it only valid for the context where the front was generated. This strongly limits its use in hierarchical analog synthesis because of the heavy dependence of key performances on the surrounding circuitry, but, more importantly, because this circuitry remains unknown until the synthesis process. We will address this problem by proposing a new technique to generate the trade-off fronts that is independent of the load that the circuit has to drive. This idea is exploited for a commonly used circuit, the operational amplifier, and experimental results show that this is a promising approach to solve the issue

Improved estimation of Weibull Parameters considering unreliability uncertainties

We propose a linear regression method for estimating Weibull parameters from life tests. The method uses stochastic models of the unreliability at each failure instant. As a result, a heteroscedastic regression problem arises that is solved by weighted least squares minimization. The main feature of our method is an innovative s-normalization of the failure data models, to obtain analytic expressions of centers and weights for the regression. The method has been Monte Carlo contrasted with Benard?s approximation, and Maximum Likelihood Estimation; and it has the highest global scores for its robustness, and performance