1,227 research outputs found

    On the stability of persistent entropy and new summary functions for Topological Data Analysis

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    Persistent entropy of persistence barcodes, which is based on the Shannon entropy, has been recently defined and successfully applied to different scenarios: characterization of the idiotypic immune network, detection of the transition between the preictal and ictal states in EEG signals, or the classification problem of real long-length noisy signals of DC electrical motors, to name a few. In this paper, we study properties of persistent entropy and prove its stability under small perturbations in the given input data. From this concept, we define three summary functions and show how to use them to detect patterns and topological features

    Country knowledge and familiarity effects on consumer perceived risk and rejection of foreign-made products

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    Las preocupaciones de los consumidores por los productos fabricados en el extranjero plantean interrogantes sobre lo que éstos conocen acerca del país de origen y la medida en que ese conocimiento se traduce en su rechazo de los productos extranjeros. El presente estudio examina tres tipos de variables de conocimiento acerca del país de origen que, junto con la experiencia de uso/familiaridad, actúan como antecedentes potenciales del riesgo percibido y, a su vez, de la reticencia de los consumidores españoles a comprar y de la (no) posesión de productos chinos. Los resultados revelan que el conocimiento medioambiental del país genera riesgo de auto-imagen/social, mientras que la experiencia de uso/familiaridad reduce tanto el riesgo de auto-imagen/social como el riesgo de rendimiento. Ambos tipos de riesgo afectan significativamente (positivamente) a la reticencia de los consumidores a comprar y (negativamente) a la posesión de productos extranjeros. Se discuten las implicaciones teóricas.Consumer concerns about foreign-made products raise questions about what consumers know about the COO and the extent to which such knowledge translates into their rejection of foreign products. The present examines three types country knowledge variables, along with familitarity/usage experience, as potential antecedents of perceived risk and, in turn, of Spanish consumers’ reluctance to buy and (non-)ownership of Chinese apparel products. The findings reveal that environmental country knowledge can engender self-image/social risk, whereas familiarity/usage experience reduces both self-image/social and performance risks. As expected, the two distinct risk types considered here significantly contributed to consumers’ reluctance to buy (positively) and product ownership (negatively). Theoretical implications are discussed

    Simulations of Melting of Encapsulated CaCl2·6H2O for Thermal Energy Storage Technologies

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    We present in this work simulations using the finite difference approximation in 2D for the melting of an encapsulated phase-change material suitable for heat storage applications; in particular, we study CaCl2·6H2O in a cylindrical encapsulation of internal radius 8 mm. We choose this particular salt hydrate due to its availability and economic feasibility in high thermal mass building walls or storage. Considering only heat conduction, a thermostat is placed far from the capsule, providing heat for the melting of the phase-change material (PCM), which is initially frozen in a water bath. The difference in density between the solid and liquid phases is taken into account by considering a void in the solid PCM. A simple theoretical model is also presented, based on solving the heat equation in the steady state. The kinetics of melting is monitored by the total solid fraction and temperatures in the inner and outer surfaces of the capsule. The effect of different parameters is presented (thermostat temperature, capsule thickness, capsule conductivity and natural convection in the bath), showing the potential application of the method to select materials or geometries of the capsule

    Characterising epithelial tissues using persistent entropy

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    In this paper, we apply persistent entropy, a novel topological statis- tic, for characterization of images of epithelial tissues. We have found out that persistent entropy is able to summarize topological and geomet- ric information encoded by -complexes and persistent homology. After using some statistical tests, we can guarantee the existence of signi cant di erences in the studied tissues.Ministerio de Economía y Competitividad MTM2015-67072-

    Persistent entropy: a scale-invariant topological statistic for analyzing cell arrangements

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    In this work, we develop a method for detecting differences in the topological distribution of cells forming epithelial tissues. In particular, we extract topological information from their images using persistent homology and a summary statistic called persistent entropy. This method is scale invariant, robust to noise and sensitive to global topological features of the tissue. We have found significant differences between chick neuroepithelium and epithelium of Drosophila wing discs in both, larva and prepupal stages. Besides, we have tested our method, with good results, with images of mathematical tesselations that model biological tissues

    Charged and neutral current neutrino induced nucleon emission reactions

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    By means of a Monte Carlo cascade method, to account for the rescattering of the outgoing nucleon, we study the charged and neutral current inclusive one nucleon knockout reactions off nuclei induced by neutrinos. The nucleon emission process studied here is a clear signal for neutralcurrent neutrino driven reactions, and can be used in the analysis of future neutrino experiments.Nieves Pamplona,Juan Miguel, [email protected] ; Vicente Vacas, Manuel Jose, [email protected]

    Accidentes de trabajo derivados de la exposición a la bacteria Legionella pneumophila

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    La legionelosis es una enfermedad que puede afectar al ámbito laboral. El análisis de las sentencias que se realiza en este artículo pone de manifiesto este hecho. De ahí que sea necesario el estudio del agente biológico produ ctor de la enfermedad, desde el punto de vista de la prevención de riesgos laborales

    Light flavor and heavy quark spin symmetry in heavy meson molecules

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    We propose an effective field theory incorporating light SU(3)-flavor and heavy quark spin symmetry to describe charmed meson-antimeson bound states. At lowest order the effective field theory entails a remarkable simplification: it only involves contact range interactions among the heavy meson and antimeson fields. We show that the isospin violating decays of the X(3872) can be used to constrain the interaction between the D and a (D) over bar* mesons in the isovector channel. As a consequence, we can rule out the existence of an isovector partner of the X(3872). If we additionally assume that the X(3915) and Y(4140) are D*(D) over bar* and D*(s)(D) over bar*(s) molecular states, we can determine the full spectrum of molecular states with isospin I = 0, 1/2 and 1

    Universidad de Alcalá: de la escuela de magisterio a la facultad de educación

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    La implantación del Espacio Europeo de Educación Superior (EEES) ha causado una profunda transformación de los estudios universitarios. Entre los principales cambios que afectan a todos los grados podemos encontrar: el énfasis en el desarrollo de competencias, la aparición de los ECTS (European Credit Transfer and Accummulation System) o el desarrollo de un trabajo Fin de Grado. En este artículo se han descrito y analizado los cambios más importantes que se han producido al pasar de una diplomatura de tres años a un grado de cuatro años de duración en los estudios de Magisterio de la Universidad de AlcaláThe implementation of the European Higher Education Area (EHEA) has caused a deep transformation of the university studies. The emphasis on competences development, the emergence of the ECTS (European Credit Transfer and Accumulation System) or the development of a Final Degree Work can be found among these major changes affecting all the degrees. This article describes and analyses the impact of the changes produced going from a three year general degree to a four year bachelor degree in Teacher Education studies of the University of Alcal
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