193 research outputs found

    Asociación entre bajo peso al nacer y ganancia de peso durante el embarazo en gestantes con sobrepeso - obesidad del hospital distrital el esfuerzo de Florencia de mora, Trujillo, 2019

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    Ante la elevada prevalencia de sobrepeso - obesidad en mujeres a nivel nacional y que más de la mitad de las gestantes inicia el embarazo con exceso de peso. Asimismo, este grupo es el que tiene mayor proporción de excesiva ganancia de peso en el embarazo. Este trabajo tendrá como objetivo determinar la asociación de bajo peso al nacer y ganancia de peso materno en puérperas con sobrepeso -obesidad del Hospital Distrital El Esfuerzo de Florencia de Mora en el período 2020 mediante un estudio observacional, analítico, retrospectivo, transversal. Se obtendrá un tamaño muestral de 80 sujetos por cada grupo y se diseñará un instrumento de recolección según las variables de interés. La asociación entre los grupos se demostrará mediante el hallazgo de diferencia de medias o medianas de ganancia de peso en el embarazo entre presencia o no de bajo peso al nacer. Se obtendrá el Odds Ratio de presentar recién nacido con peso <2500 en insuficiente y excesiva GPE comparado con adecuada ajustándolo con edad, paridad y edad gestacional. Este proyecto iniciará en Julio 2020 y se completará en febrero 2021.Tesis de segunda especialida

    A Comparative Study of Simple Online Learning Strategies for Streaming Data

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    Since several years ago, the analysis of data streams has attracted considerably the attention in various research fields, such as databases systems and data mining. The continuous increase in volume of data and the high speed that they arrive to the systems challenge the computing systems to store, process and transmit. Furthermore, it has caused the development of new online learning strategies capable to predict the behavior of the streaming data. This paper compares three very simple learning methods applied to static data streams when we use the 1-Nearest Neighbor classifier, a linear discriminant, a quadratic classifier, a decision tree, and the Na¨ıve Bayes classifier. The three strategies have been taken from the literature. One of them includes a time-weighted strategy to remove obsolete objects from the reference set. The experiments were carried out on twelve real data sets. The aim of this experimental study is to establish the most suitable online learning model according to the performance of each classifie

    The underground economy in times of crisis: an analysis of undeclared work in Europe

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    Este estudio analiza el trabajo no declarado como pieza fundamental en la economía sumergida en la UE-28, haciendo especial énfasis en su cuantificación y evolución, estructura, variabilidad por países y determinantes. Con este objetivo, se aplican métodos de regresión lineal y modelos de elección discreta con variable dependiente binaria sobre la base de los microdatos correspondientes a los Eurobarómetros especiales dedicados al análisis del fenómeno del trabajo no declarado en los años 2007 y 2013. Los resultados muestran la importancia que tienen sobre el trabajo no declarado (i) el grado de aceptación individual del propio fenómeno; (ii) la percepción del riesgo de sanciones; (iii) la situación laboral del sujeto; y (iv) la propia situación macroeconómica. Las implicaciones de estos resultados para el espectro de políticas disponibles para combatir la economía sumergida son también discutidas en este trabajo.This study analyzes undeclared work as a key portion of the shadow economy in the EU-28, with special focus on its incidence, dynamics, structure, differences across countries and underlying determinants. To this end, linear regression and binary discrete choice models are applied to microdata drawn from 2 special Eurobarometers which are designed to explore undeclared work phenomenon in the years 2007 and 2013. Our results stress the importance of (i) the individual assessment of irregular and individualistic behaviours; (ii) the perceived risk of being detected undertaking paid undeclared work; (iii) the occupation; and (iv) the aggregated conditions, as determinants of undeclared work. The implications of these results for the existing policy options for dealing with the shadow economy are also discussed

    Trademarks and their association with Kirznerian entrepreneurs

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    Although trademarks are the most widely used form of Intellectual Property Rights (IPRs) by firms across all economic sectors worldwide, this indicator is a much less exploited information resource in empirical analysis compared with patents. Our work addresses this gap by investigating the relationship between trademark registration and entrepreneurial activity using data for 33 European countries. Our empirical results show a positive and significant relationship between the share of the self-employed workforce in a given country that can be considered ‘entrepreneurial’ –which we associate with the share of Kirznerian entrepreneurs– and trademark registration at the country level. These results have important implications for scholars, practitioners and policy makers, which are discussed in this work.Ministerio de Economía y Competitividad: Proyectos de I+D+i ECO2017-86305-C4-2-R y ECO2017-86402-C2-2-R. Junta de Andalucía: Grupo de investigación SEJ-487 Spanish Entrepreneurship Research Group – SERG. Universidad de Huelva: Estrategia de Política de Investigación y Transferencia.Departamento de Economía General y Estadístic

    One-Sided Prototype Selection on Class Imbalanced Dissimilarity Matrices

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    In the dissimilarity representation paradigm, several prototype selection methods have been used to cope with the topic of how to select a small representation set for generating a low-dimensional dissimilarity space. In addition, these methods have also been used to reduce the size of the dissimilarity matrix. However, these approaches assume a relatively balanced class distribution, which is grossly violated in many real-life problems. Often, the ratios of prior probabilities between classes are extremely skewed. In this paper, we study the use of renowned prototype selection methods adapted to the case of learning from an imbalanced dissimilarity matrix. More specifically, we propose the use of these methods to under-sample the majority class in the dissimilarity space. The experimental results demonstrate that the one-sided selection strategy performs better than the classical prototype selection methods applied over all classes

    Evaluación de impacto de dos programas de formación del SENA.

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    Abstract. Este documento presenta la evaluación de dos programas ejecutados por el SENA - Formación Técnica y Tecnológica (FTyT) y Formación Especializada del Recurso Humano Vinculado a las Empresas (FE). En el caso de FTyT se emplea un enfoque cuantitativo mientras que en el caso de FE se emplea adicionalmente un enfoque cualitativo. Se encuentra que el programa de FTyT del SENA ha tenido un impacto positivo y significativo algunos aspectos relacionados con las condiciones laborales de sus beneficiarios, por ejemplo en empleabilidad, en calidad del empleo y en movilidad relativa de ingresos. También se encuentra que los beneficiarios son menos propensos a continuar estudios universitarios. No se encuentra un efecto significativo en nivel de ingresos, en movilidad ocupacional ni en condiciones de vida. No obstante el hallazgo de efectos positivos, se recomienda contraponer los resultados de este estudio con un análisis costo-beneficio que incorpore los costos directos e indirectos del programa. La evaluación de impacto cualitativa del programa de FE permite concluir que, en promedio, las empresas del grupo de control observaron un mayor índice de rotación laboral a pesar que tanto el número promedio de empleados nuevos, así como el número promedio de empleados desvinculados son menores en comparación con los promedios observados para el caso de las empresas del grupo de empresas beneficiarias del programa. La metodología de diferencias en diferencias muestra que el índice de rotación laboral es significativo a un nivel de confianza del 90%, lo que permite corroborar parcialmente y en términos estadísticos el análisis descrito previamente. Sin embargo, el soporte común sobre el cual se realizan las estimaciones es bajo (10 empresas), y el resultado no puede ser validado estadísticamente. Sobre la promoción de actividades de capacitación, se establece a partir de las pruebas de comparación de medias que sólo para la variable que mide el número de empleados existen diferencias estadísticamente significativas entre ambos grupos.Evaluación de impacto, Formación ocupacional, Formación para el trabajo, Empleo, SENA, Colombia.

    Exploring early classification strategies of streaming data with delayed attributes

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    In contrast to traditional machine learning algorithms, where all data are available in batch mode, the new paradigm of streaming data poses additional difficulties, since data samples arrive in a sequence and many hard decisions have to be made on-line. The problem addressed here consists of classifying streaming data which not only are unlabeled, but also have a number l of attributes arriving after some time delay. In this context, the main issues are what to do when the unlabeled incomplete samples and, later on, their missing attributes arrive; when and how to classify these incoming samples; and when and how to update the training set. Three different strategies (for l = 1 and constant) are explored and evaluated in terms of the accumulated classification error. The results reveal that the proposed on-line strategies, despite their simplicity, may outperform classifiers using only the original, labeled-and-complete samples as a fixed training set. In other words, learning is possible by properly tapping into the unlabeled, incomplete samples, and their delayed attributes. The many research issues identified include a better understanding of the link between the inherent properties of the data set and the design of the most suitable on-line classification strateg

    On-line learning from streaming data with delayed attributes: A comparison of classifiers and strategies

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    In many real applications, data are not all available at the same time, or it is not affordable to process them all in a batch process, but rather, instances arrive sequentially in a stream. The scenario of streaming data introduces new challenges to the machine learning community, since difficult decisions have to be made. The problem addressed in this paper is that of classifying incoming instances for which one attribute arrives only after a given delay. In this formulation, many open issues arise, such as how to classify the incomplete instance, whether to wait for the delayed attribute before performing any classification, or when and how to update a reference set. Three different strategies are proposed which address these issues differently. Orthogonally to these strategies, three classifiers of different characteristics are used. Keeping on-line learning strategies independent of the classifiers facilitates system design and contrasts with the common alternative of carefully crafting an ad hoc classifier. To assess how good learning is under these different strategies and classifiers, they are compared using learning curves and final classification errors for fifteen data sets. Results indicate that learning in this stringent context of streaming data and delayed attributes can successfully take place even with simple on-line strategies. Furthermore, active strategies behave generally better than more conservative passive ones. Regarding the classifiers, it was found that simple instance-based classifiers such as the well-known nearest neighbor may outperform more elaborate classifiers such as the support vector machines, especially if some measure of classification confidence is considered in the process.This work has been supported in part by the Spanish Ministry of Education and Science under grants CSD2007-00018 Consolider Ingenio 2010 and TIN2009-14205, and by Fundació Caixa Castelló—Bancaixa under grant P1-1B2009-04

    Assessment of the Extrusion Process and Printability of Suspension-Type Drug-Loaded AffinisolTM Filaments for 3D Printing

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    Three-dimensional (3D) printing technology enables the design of new drug delivery systems for personalised medicine. Polymers that can be molten are needed to obtain extruded filaments for Fused Deposition Modelling (FDM), one of the most frequently employed techniques for 3D printing. The aim of this work was to evaluate the extrusion process and the physical appearance of filaments made of a hydrophilic polymer and a non-molten model drug. Metformin was used as model drug and Affinisol™ 15LV as the main carrier. Drug-loaded filaments were obtained by using a single-screw extruder and, subsequently, their printability was tested. Blends containing up to a 60% and 50% drug load with 5% and 7.5% of auxiliary excipients, respectively, were successfully extruded. Between the obtained filaments, those containing up to 50% of the drug were suitable for use in FDM 3D printing. The studied parameters, including residence time, flow speed, brittleness, and fractal dimension, reflect a critical point in the extrusion process at between 30–40% drug load. This finding could be essential for understanding the behaviour of filaments containing a non-molten component

    Estudio de las poblaciones de Corbicula fluminea (Müller, 1774) en el curso medio del río Ebro, tramo Tudela-Zaragoza (Navarra Aragón).

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    Corbicula fluminea es una especie exótica invasora que ya ha colonizado casi toda la Cuenca del Ebro (CE). Es una especie que ha mostrado una gran capacidad para colonizar diferentes ecosistemas. Para conocer mejor su comportamiento en la CE, la Confederación Hidrográfica del Ebro (CHE), inició una campaña para el control y vigilancia de la almeja asiática en el eje del río Ebro y en sus afluentes principales. El presente trabajo se centra en analizar la zona con mayor concentración de C. fluminea de toda la CE. Para ello, se ha delimitado el tramo de la CE entre Tudela y Zaragoza para realizar una caracterización del hábitat y de las poblaciones de almeja asiática distribuidas en 16 estaciones y 7 ríos diferentes. En cuanto a los resultados obtenidos, respecto años anteriores, se observa un declive en las poblaciones del Ebro, con una densidad media actual de 3.054 indiv/m2 y un aumento en las poblaciones de los afluentes, con una densidad media actual de 295 indiv/m2. Sin embargo, en el contexto global de la CE, las poblaciones tienen una tendencia positiva tanto para el Ebro como para los afluentes. Los datos parecen indicar que las poblaciones más grandes de C. fluminea están alcanzando el límite de su capacidad de carga, provocando una cierta mortalidad intraespecífica. <br /
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