531 research outputs found

    Domain wall dynamics in an optical Kerr cavity

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    An anisotropic (dichroic) optical cavity containing a self-focusing Kerr medium is shown to display a bifurcation between static --Ising-- and moving --Bloch-- domain walls, the so-called nonequilibrium Ising-Bloch transition (NIB). Bloch walls can show regular or irregular temporal behaviour, in particular, bursting and spiking. These phenomena are interpreted in terms of the spatio-temporal dynamics of the extended patterns connected by the wall, which display complex dynamical behaviour as well. Domain wall interaction, including the formation of bound states is also addressed.Comment: 15 pages Tex file with 11 postscript figures. Resubmitted to Phys. Rev.

    Utilización de la didáctica del juego como práctica pedagógica para preservar el medio ambiente, en el grado 5º de la Institución Educativa Municipal Normal Superior de Pasto

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    El proyecto de investigación está encaminado al uso de la didáctica del juego con el fin de preservar el medio ambiente, para ello se aplican tres juegos relacionados con la temática ambiental para así determinar la influencia que tienen estos respecto a la preservación de la naturaleza con estudiantes de grado quinto de la Institución Educativa Municipal Normal Superior de Pasto. En la investigación se pretende que el juego tomado como una estrategia pedagógica permite dejar en los estudiantes a aprendizaje significativo suscitando en ellos una actitud ecologista de igual manera para el grupo de investigación ayuda a fortalecer su proceso de enseñanza en las ciencias naturales y la educación ambiental. La investigación se estructura en cuatro capítulos, primero es el acercamiento a la realidad, donde se indaga las problemáticas existentes tras las observaciones, segundo capítulo, es la fundamentación teórica y recolección de información, tal información se analiza e interpreta en el capítulo tres y finalmente en el capítulo cuatro, se elabora una propuesta a partir de los hallazgos de la investigación tomando en cuenta dos aspectos importantes, los juegos tradicionales y la conservación ambiental

    Incorporación de n-gramas discriminativos para mejorar un reconocedor de idioma fonotáctico basado en i-vectores

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    Este artículo describe una nueva técnica que permite combinar la información de dos sistemas fonotácticos distintos con el objetivo de mejorar los resultados de un sistema de reconocimiento automático de idioma. El primer sistema se basa en la creación de cuentas de posteriorgramas utilizadas para la generación de i-vectores, y el segundo es una variante del primero que tiene en cuenta los n-gramas más discriminativos en función de su ocurrencia en un idioma frente a todos los demás. La técnica propuesta permite obtener una mejora relativa de 8.63% en Cavg sobre los datos de evaluación utilizados para la competición ALBAYZIN 2012 LRE

    Low-resource language recognition using a fusion of phoneme posteriorgram counts, acoustic and glottal-based i-vectors

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    This paper presents a description of our system for the Albayzin 2012 LRE competition. One of the main characteristics of this evaluation was the reduced number of available files for training the system, especially for the empty condition where no training data set was provided but only a development set. In addition, the whole database was created from online videos and around one third of the training data was labeled as noisy files. Our primary system was the fusion of three different i-vector based systems: one acoustic system based on MFCCs, a phonotactic system using trigrams of phone-posteriorgram counts, and another acoustic system based on RPLPs that improved robustness against noise. A contrastive system that included new features based on the glottal source was also presented. Official and postevaluation results for all the conditions using the proposed metrics for the evaluation and the Cavg metric are presented in the paper

    Method to Calculate the Electricity Generated by a Photovoltaic Cell, Based on Its Mathematical Model Simulations in MATLAB

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    This paper presents a practical method for calculating the electrical energy generated by a PV panel (kWhr) through MATLAB simulations based on the mathematical model of the cell, which obtains the “Mean Maximum Power Point” (MMPP) in the characteristic V-P curve, in response to evaluating historical climate data at specific location. This five-step method calculates through MMPP per day, per month, or per year, the power yield by unit area, then electrical energy generated by PV panel, and its real conversion efficiency. To validate the method, it was applied to Sewage Treatment Plant for a Group of Drinking Water and Sewerage of Yucatan (JAPAY), México, testing 250 Wp photovoltaic panels of five different manufacturers. As a result, the performance, the real conversion efficiency, and the electricity generated by five different PV panels in evaluation were obtained and show the best technical-economic option to develop the PV generation project

    Language identification based on a discriminative text categorization technique

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    In this paper, we describe new results and improvements to a lan-guage identification (LID) system based on PPRLM previously introduced in [1] and [2]. In this case, we use as parallel phone recognizers the ones provided by the Brno University of Technology for Czech, Hungarian, and Russian lan-guages, and instead of using traditional n-gram language models we use a lan-guage model that is created using a ranking with the most frequent and discrim-inative n-grams. In this language model approach, the distance between the ranking for the input sentence and the ranking for each language is computed, based on the difference in relative positions for each n-gram. This approach is able to model reliably longer span information than in traditional language models obtaining more reliable estimations. We also describe the modifications that we have being introducing along the time to the original ranking technique, e.g., different discriminative formulas to establish the ranking, variations of the template size, the suppression of repeated consecutive phones, and a new clus-tering technique for the ranking scores. Results show that this technique pro-vides a 12.9% relative improvement over PPRLM. Finally, we also describe re-sults where the traditional PPRLM and our ranking technique are combined

    Unidad Técnica de Biblioteca y Documentación de la Estación Experimental de Aula Dei (CSIC) (Z-EEAD)

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    2 Pag. A-3, 1 Fot., 1 Map.Información actualizada de la Unidad Técnica de Biblioteca y Documentación (UTBD) de la Estación Experimental de Aula Dei (EEAD-CSIC), una de las 78 Bibliotecas que conforman la Red de Bibliotecas CSIC, en consonancia con la proporcionada en reciente Plan Estratégico CSIC 2010-2013. Incluye relación de Prestaciones de servicio ofrecidas para el período 2010-2013.Peer reviewe

    Occurrence of melatonin and indolic compounds derived from L-tryptophan yeast metabolism in fermented wort and commercial beers

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    Melatonin and serotonin are bioactive compounds present in foods and beverages and related to neuroprotection and anti-angiogenesis, among other activities. They have been described in wines and the role of yeast in their formation is clear. Thus, this study evaluates the content of these bioactives and other related indolic compounds in beer. For this purpose, commercial beers were analyzed by a validated UHPLC-HRMS method and sample treatment optimized due to the low concentrations expected. Moreover, a wort was fermented with different commercial beer yeast (Abbaye, Diamond, SafAle, SafLager) in order to monitor the formation of these bioactives during the elaboration process. Results show that indolic compounds such as N-acetylserotonin and 3-indoleacetic acid are produced during the alcoholic fermentation of wort. Moreover, the occurrence of four indolic compounds (5-hydroxytryptophan, N-acetylserotonin, 3-indoleacetic acid, L-tryptophan ethyl ester) in commercial beers is reported for the first time.Ministerio de Economía y Competitividad AGL2013-47300-C3-2-R, AGL2016-77505-C3-2-
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