180 research outputs found
Sobre la Factibilidad del Soporte Factual Externo como Métrica de Calidad para Wikipedia
Developing metrics to estimate the information quality of Wikipedia articles is an interesting and important research area. In this article, we propose and analyse the feasibility, of a new quality metric based on the “external factual support” of an article. The rationale behind this metric is identified, a formal definition of the metric is presented and some implementation aspects are introduced. Preliminary results show the feasibility of our proposal and its potential to discriminate high quality versus low quality Wikipedia’s articles.El desarrollo de métricas para estimar la calidad de información de los artículos de Wikipedia es un área de investigación interesante e importante. En este artículo, se propone una nueva métrica de calidad basada en el “soporte factual externo” de un artículo y se analiza su viabilidad. Los motivos que dan sustento a esta métrica son identificados, se presenta una definición formal de la misma y también se dan detalles de su implementación. Los resultados preliminares obtenidos, muestran la viabilidad de nuestra propuesta y su potencial para discriminar entre artículos de alta y baja calidad en Wikipedia
Introducción a la microeconomía
1 archivo PDF (251 páginas)Consta de seis capítulos, coinciden con los temas que conforman el curso de Introducción a la Teoría Económica', cada capítulo está integrado por el desarrollo teórico, una sección de ejercicios resueltos, un resumen y un listado de los conceptos más importantes de cada capítulo. Los temas de los capítulos son: conceptos básicos de la teoría económica; herramientas básicas; producción especialización e intercambio; demanda, oferta y equilibrio de mercado; elasticidades y aplicaciones e historia de la ciencia económica
Can children use the A-not a test?
Sensory scientists have adapted several sensory methods to fit children's cognitive abilities. Although several discrimination methods have been reported with children, the A-not-A test has not been studied yet. The aims of this work were to: (i) evaluate the feasibility of using the A-Not-A test with school-aged children, and (ii) compare how the framing of the question (overall differences vs. differences in liking) may influence the results. A total of 126 children were involved in the study. They participated in three sessions, each composed of a familiarization task with a visual stimuli and sample tasting with one of three dairy products (vanilla milk desserts, chocolate-flavored milk, and vanilla-flavored yogurt). Half of the children evaluated the samples in terms of overall differences and the other half in terms of differences in liking. Results from the familiarization step showed that children correctly identified the visual reference in the A-not-A test regardless of how the question was framed, suggesting that they were able to understand the methodology. In the case of tasting samples, children were significantly more likely to correctly identify the reference in two of the three studied dairy products, when the question was based on liking, as compared to the framing based on overall differences.publishedVersio
Assertividade e consumo de drogas em estudantes mexicanos
The aim of this study was to assess the relationship between low assertiveness and illicit drug use among high school students, and to determine which of the assertive characteristics such as behavioral control, recognition and acceptance of others, effective coping with problems and interpersonal differences, perceived self-efficacy in problem solving, verbal expression skills and positive affect in dealing with problems, acted as predictors of consumption. The research used a non- experimental cross-sectional and ex post facto design. By means of a non-probabilistic sampling technique, 1492 high school students were selected from schools located in high risk areas for drug consumption and were surveyed through the Assertive Factors Assessment Scale [EFA for its Spanish acronym], validated with Mexican adolescent population. The students were divided in two groups, the Illicit Drug users and the Non-drug users. After comparing the assertive characteristics between both groups, it was found that Non-drug users have more effective strategies for coping with problems, a perception of higher self-efficacy in solving problems, higher behavioral control, greater recognition and acceptance of others, better verbal expression skills and a more effective emotional management. It also found by logistic regression analysis that behavioral control and recognition and acceptance of others were factors most likely to serve as protective factors of illicit drug use. Results confirm the importance of communication skills, impulse control and emotional management for establishing more satisfying relationships and coping with access to tobacco, alcohol or illicit drugs.El estudio persiguió evaluar la relación entre una baja asertividad y el uso de drogas ilícitas entre estudiantes mexicanos, así como identificar si alguna de las características asertivas como control conductual, reconocimiento y aceptación de los demás, enfrentamiento eficaz de los problemas y diferencias interpersonales, percepción de autoeficacia en la resolución de problemas, habilidades en la expresión verbal y afectos positivos asociados al enfrentamiento de problemas, predicen probabilísticamente el consumo de drogas ilícitas. Se utilizó un diseño no experimental, transversal, ex post facto, y con un muestreo por conveniencia, se encuestó a 1.492 estudiantes de escuelas secundarias localizadas en zonas de alto riesgo para el consumo de drogas utilizando la escala de Evaluación de Factores Asertivos (EFA), validada en población mexicana adolescente. De los estudiantes participantes se conformaron dos grupos: el de Usuarios de drogas ilícitas y el de No usuarios de drogas. Al comparar las características asertivas entre ambos grupos, se encontró que los No usuarios cuentan con estrategias de enfrentamiento más eficaces a los problemas, perciben mayor autoeficacia en su resolución, tienen mayor control conductual, mayor reconocimiento y aceptación de los demás, presentan más habilidades de expresión verbal y tienen un mejor manejo de sus afectos. Asimismo, se identificó mediante un análisis de regresión logística que el control conductual y el reconocimiento y aceptación de los demás son elementos con mayor probabilidad de fungir como elementos protectores del consumo de drogas ilícitas. Los hallazgos confirman la relevancia de las habilidades comunicativas, el control de impulsos y el manejo de emociones, para el establecimiento de relaciones más satisfactorias y en el enfrentamiento ante la oferta de tabaco, alcohol u otras drogas.O estudo buscou avaliar a relação entre uma baixa assertividade e o uso de drogas ilícitas entre estudantes mexicanos; assim como identificar se alguma das características assertivas como controle da conduta, reconhecimento e aceitação dos outros, enfrentamento eficaz dos problemas e diferença interpessoais, percepção de auto eficácia na solução de problemas, habilidades na expressão verbal e afetos positivos associados ao enfrentamento de problemas, predizem probabilisticamente o consumo de drogas ilícitas. Através de um desenho não experimental, transversal, ex post facto, e com uma amostragem por conveniência, foram entrevistados 1.492 estudantes de escolas secundárias localizadas em zonas de alto risco para o consumo de drogas utilizando a escala de Avaliação de Fatores Assertivos (EFA), validada na população mexicana adolescente. Dos estudantes participantes foram formados dois grupos, o de Usuários de drogas ilícitas e o de Não usuários de drogas. Ao comparar as características assertivas entre os grupos, encontrou-se que os Não usuários contam com estratégias de enfrentamento mais eficazes aos problemas, percebem maior auto eficácia em sua resolução, têm maior controle de conduta, maior reconhecimento e aceitação dos outros, apresentam mais habilidades de expressão verbal e têm um melhor controle de seus afetos. Da mesma forma identificou-se mediante uma análise de regressão logística que o controle de conduta e o reconhecimento e aceitação dos outros são elementos com maior probabilidade de atuar como elementos protetores do consumo de drogas ilícitas. Os descobrimentos confirmam a relevância das habilidades comunicativas, o controle de impulsos e o controle das emoções, para o estabelecimento de relações mais satisfatórias e no enfrentamento diante da oferta de tabaco, álcool ou outras drogas
Data-driven mapping of hourly wind speed and its potential energy resources: A sensitivity analysis
Renewable energies play a significant role to mitigate the impacts of climate change. In countries like Spain, there is a significant potential of wind energy production which might be a key resource. In this research, we obtain wind power at 80 meters height and wind turbine energy (assuming a specific turbine). To achieve this objective we produce an optimal mapping of the hourly “instantaneous surface wind speed” (height 10 m), based on the available data. An extensive region (Granada Province, south Spain) is studied with a spatial resolution of 300 m, during a long period (1996-2016). It allows us to assess the intra- and inter-daily variability of wind energy resources. Several interpolation approaches are tested and a cross validation experiment is applied to identify the optimal approach. The obtained maps were compared with the results obtained in the stations with two common frequency distributions (Rayleigh and Weibull). This is the first time that this sensitivity integrated analysis is performed over an extensive region (12600 km2) for a long time period (20 years) at fine spatiotemporal resolution (300 m, hourly scale). The results can be very valuable for a preliminary analysis of potential optimal location of wind energies facilities
Endophytic colonisation of tomato by the entomopathogenic fungus Beauveria bassiana: the use of different inoculation techniques and their effects on the tomato leafminer Tuta absoluta (Lepidoptera: Gelechiidae)
Fungal entomopathogens can naturally regulate populations of various insects. The entomopathogen Beauveria bassiana (Bals.- Criv.) Vuill. is also able to endophytically colonize different plants. Endophytic colonization by entomopathogens may provide a source of indirect interactions between fungi and insects and has been associated with the ability of the fungus to control insect pests. The tomato leaf miner, Tuta absoluta (Meyrick) is considered one of the most devastating pests of tomato (Solanum lycopersicum L.) and its difficult control is due to its miner habit, short life cycle, and high reproductive capacity. The aims of this study were: (i) to use three different techniques, i.e. leaf spraying, seed immersion and root dipping, for the endophytic inoculation of B. bassiana in tomato plants; and (ii) to assess the effect of B. bassiana on tomato leaf consumption and mortality of T. absoluta after inoculation. The percentage of colonization by B. bassiana was assessed 7, 14 and 28 days after inoculation. All inoculation techniques employed allowed the recovery of B. bassiana, although our results showed significant differences between techniques. Leaf spraying was the most effective, with the highest percentage of colonization recorded 7 days after inoculation. We also evaluated (i) the effect on the mortality of T. absoluta by direct contact with conidia of B. bassiana, and (ii) the effect on tomato leaf consumption and mortality by indirect contact through ingestion of inoculated plant tissues with B. bassiana. Mortality bioassays showed that B. bassiana infected T. absoluta, either by direct contact or indirectly, via ingestion of inoculated tomato leaves. Direct contact showed a higher percentage of mortality and a lower median survival time (MST) than indirect contact. Significant differences in the mortality percentages of T. absoluta after exposure with B. bassiana were found among the treatments and the control. Our results suggest that the endophytic inoculation of B. bassiana in tomato crops provides the basis for further investigation, which should focus on the virulence of the endophytic B. bassiana against T. absoluta.Facultad de Ciencias Naturales y MuseoInstituto de Botánica "Dr. Carlos Spegazzini"Centro de Estudios Parasitológicos y de Vectore
Reflexiones en torno al escenario de la tutoría en la universidad. El caso de México.
This article includes a series of reflections on the scope and limitations of tutoring in Higher Education Institutions in Mexico. It offers theoretical conceptual statements about the purpose of academic tutoring. Besides, it emphasizes the role of the faculty as a tutor, bearing in mind the current demands of his / her role as a facilitator in the training and academic development of the student.
It recognizes the pedagogical implications of the coaching process that occurs from tutoring in order to promote the achievement of moral and intellectual autonomy of university students. Furthermore, it samples some results of the impact of tutoring in Mexico and concludes by sharing some considerations that should be kept in mind in the tutoring action to favor the integral education of the 21st century university students.Este artículo muestra una serie de reflexiones en torno al alcance y limitaciones de las tutorías en las Instituciones de Educación Superior en México. Ofrece argumentos teórico-conceptuales sobre la finalidad de las tutorías académicas. Enfatiza el rol del docente como tutor, al considerar las demandas actuales de su función facilitadora en el trayecto formativo y académico del estudiante.
Reconoce las implicaciones pedagógicas del proceso de acompañamiento que se da a partir de las tutorías, a fin de promover el logro de la autonomía moral e intelectual de los estudiantes universitarios y concluye compartiendo algunas consideraciones que se deben tener presentes en la acción tutorial, para favorecer la formación integral del estudiante universitario del siglo XXI.
 
El aumento del crimen y la disminución de la participación laboral en el ingreso en México
The growth of crime and the decline of wage share are two trends that have characterized the Mexican economy since the late seventies until the present. However, in the economy research, the causes of these trends are studied in a separated way. In contrast, in this paper is proposed a model of efficiency wages in framework of demand-constrained equilibrium, finding that the growth in the crime supply and the decrease of wage share have a common cause: the diminution of the opportunities for workers to insert themselves and remain employed in the labor market.El crecimiento del crimen y la reducción del ingreso salarial como parte del ingreso nacional son dos fenómenos que han caracterizado a la economía mexicana desde finales de la década de los setenta hasta la actualidad. Sin embargo, usualmente, en la literatura económica se estudian las causas que originan estos fenómenos de forma separada. En contraste, en este artículo se propone un modelo de salarios de eficiencia en un contexto de equilibrio restringido por demanda, encontrando que ambos fenómenos tienen una causa común: la disminución en las oportunidades de los trabajadores de insertarse y permanecer empleados en el mercado laboral
A PSO-based clustering approach assisted by initial clustering information
Clustering of short texts is an important research area because of its applicability in information retrieval and text mining. To this end was proposed CLUDIPSO, a discrete Particle Swarm Optimization algorithm to cluster short texts. Initial results showed that CLUDIPSO has performed well in small collections of short texts. However, later works showed some drawbacks when dealing with larger collections. In this paper we present a hybridization of CLUDIPSO to overcome these drawbacks, by providing information in the initial cycles of the algorithm to avoid a random search and thus speed up the convergence process. This is achieved by using a pre-clustering obtained with the Expectation-Maximization method which is included in the initial population of the algorithm. The results obtained with the hybrid version show a significant improvement over those obtained with the original version.Eje: Workshop Bases de datos y minería de datos (WBDDM)Red de Universidades con Carreras en Informática (RedUNCI
Global Assessment of Seawater Intrusion Problems (Status and Vulnerability)
In this research paper we propose a novel method to perform an integrated analysis of the status and vulnerability of coastal aquifers to seawater intrusion (SWI). The method is based on a conceptual approach of intrusion that allows to summarised results in a visual way at different spatial scales, moving from steady pictures (corresponding to instantaneous or mean values in a period) including maps and 2D conceptual crosssections and temporal series of lumped indices. Our aim is to help in the identification of coastal groundwater bodies at risk of not achieving good chemical status according to the Water Framework Directive. The indices are obtained from available information about aquifer geometry and historical monitoring data (chloride concentration and hydraulic head data). This method may be applied even in cases where a reduced number of data are available. It does not require complex modelling and has been implemented in a GIS tool that encourages its use in other cases. Analysis of the evolution of historical time series of these indices can be used to assess resilience and trends with respect to SWI problems. This method can be also useful to compare intrusion problems in different aquifers and temporal periods
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