10 research outputs found

    Aplicaciones de la expansión de consultas basadas en ontologías de dominio a la búsqueda de objetos de aprendizaje en repositorios

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    Prieto Méndez, Manuel Emilio, codir.En el campo del e-learning se realizan grandes esfuerzos dedicados al mejoramiento del proceso de enseñanza ? aprendizaje, uno de ellos está dirigido a motivar el uso y reutilización de los recursos digitales en repositorios. En un comienzo, los esfuerzos se dirigieron a aumentar la cantidad de recursos disponibles, hoy en día existe una gran cantidad de recursos almacenados en repositorios heterogéneos, por lo tanto el desafío se traslada a mejorar y hacer más eficientes las formas de buscar, seleccionar, localizar y acceder a recursos dispersos y distribuidos en repositorios. Dentro de esta línea, el objetivo de esta tesis es proponer una estrategia para la expansión de consultas basadas en ontologías de dominio que permita al diseñador instruccional obtener, desde un repositorio, objetos de aprendizaje relevantes para el diseño de sus cursos o la composición de otros recursos más complejos. Para lograr este objetivo se analizan las propuestas de expansión de consultas ya sea en el campo de la recuperación de información en general o específicamente, en los repositorios de objetos de aprendizaje. A partir de lo anterior, se establecen los criterios para la expansión de consultas basada en ontologías, se define la forma como serán abordados los problemas detectados, y por último, se formula, diseña e implementa la estrategia de expansión de consultas basada en ontología de dominio aplicada en el contexto de la búsqueda de objetos de aprendizaje en repositorios. Para la evaluación de nuestra propuesta se diseña un experimento dentro del dominio de genética, utilizando la ontología Gene como base de conocimiento y el repositorio MERLOT como proveedor de los objetos de aprendizaje en este dominio. Las consultas de prueba se definen a partir de los contenidos tratados en un conjunto de cursos de genética publicados en la Web por instituciones de educación superior para el año 2009. La evaluación de la relevancia de los resultados es realizada por 3 expertos en el dominio. El análisis de la concordancia y asociación entre las evaluaciones de los expertos es realizado por medio del análisis de Kappa de Cohen y el coeficiente de correlación de Spearman. Finalmente, la efectividad de la propuesta de expansión se evalúa a partir de las métricas de cobertura y novedad aplicadas a los resultados recuperados de las consultas con y sin expansión. La principal aportación de nuestra propuesta es una estrategia para la expansión de consultas basada en ontologías de dominio que permita al diseñador instruccional obtener resultados relevantes que sin la expansión no podrían ser recuperados desde los repositorios de objetos de aprendizaje. Suponemos que en la medida que los diseñadores intruccionales puedan acceder a recursos relevantes es posible contribuir en la calidad de los cursos e-learning o en la calidad de los nuevos recursos creados a partir de ellos. Cabe destacar que la efectividad de nuestra propuesta se ve afectada por el sistema de recuperación utilizado en cada repositorio, la calidad de los recursos almacenados y su etiquetado, así como la completitud y calidad de la base de conocimiento utilizada para la expansión

    Aplicaciones de la expansión de consultas basadas en ontologías de dominio a la búsqueda de objetos de aprendizaje en repositorios

    Get PDF
    Prieto Méndez, Manuel Emilio, codir.En el campo del e-learning se realizan grandes esfuerzos dedicados al mejoramiento del proceso de enseñanza ? aprendizaje, uno de ellos está dirigido a motivar el uso y reutilización de los recursos digitales en repositorios. En un comienzo, los esfuerzos se dirigieron a aumentar la cantidad de recursos disponibles, hoy en día existe una gran cantidad de recursos almacenados en repositorios heterogéneos, por lo tanto el desafío se traslada a mejorar y hacer más eficientes las formas de buscar, seleccionar, localizar y acceder a recursos dispersos y distribuidos en repositorios. Dentro de esta línea, el objetivo de esta tesis es proponer una estrategia para la expansión de consultas basadas en ontologías de dominio que permita al diseñador instruccional obtener, desde un repositorio, objetos de aprendizaje relevantes para el diseño de sus cursos o la composición de otros recursos más complejos. Para lograr este objetivo se analizan las propuestas de expansión de consultas ya sea en el campo de la recuperación de información en general o específicamente, en los repositorios de objetos de aprendizaje. A partir de lo anterior, se establecen los criterios para la expansión de consultas basada en ontologías, se define la forma como serán abordados los problemas detectados, y por último, se formula, diseña e implementa la estrategia de expansión de consultas basada en ontología de dominio aplicada en el contexto de la búsqueda de objetos de aprendizaje en repositorios. Para la evaluación de nuestra propuesta se diseña un experimento dentro del dominio de genética, utilizando la ontología Gene como base de conocimiento y el repositorio MERLOT como proveedor de los objetos de aprendizaje en este dominio. Las consultas de prueba se definen a partir de los contenidos tratados en un conjunto de cursos de genética publicados en la Web por instituciones de educación superior para el año 2009. La evaluación de la relevancia de los resultados es realizada por 3 expertos en el dominio. El análisis de la concordancia y asociación entre las evaluaciones de los expertos es realizado por medio del análisis de Kappa de Cohen y el coeficiente de correlación de Spearman. Finalmente, la efectividad de la propuesta de expansión se evalúa a partir de las métricas de cobertura y novedad aplicadas a los resultados recuperados de las consultas con y sin expansión. La principal aportación de nuestra propuesta es una estrategia para la expansión de consultas basada en ontologías de dominio que permita al diseñador instruccional obtener resultados relevantes que sin la expansión no podrían ser recuperados desde los repositorios de objetos de aprendizaje. Suponemos que en la medida que los diseñadores intruccionales puedan acceder a recursos relevantes es posible contribuir en la calidad de los cursos e-learning o en la calidad de los nuevos recursos creados a partir de ellos. Cabe destacar que la efectividad de nuestra propuesta se ve afectada por el sistema de recuperación utilizado en cada repositorio, la calidad de los recursos almacenados y su etiquetado, así como la completitud y calidad de la base de conocimiento utilizada para la expansión

    Explainable Hopfield Neural Networks Using an Automatic Video-Generation System

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    Hopfield Neural Networks (HNNs) are recurrent neural networks used to implement associative memory. They can be applied to pattern recognition, optimization, or image segmentation. However, sometimes it is not easy to provide the users with good explanations about the results obtained with them due to mainly the large number of changes in the state of neurons (and their weights) produced during a problem of machine learning. There are currently limited techniques to visualize, verbalize, or abstract HNNs. This paper outlines how we can construct automatic video-generation systems to explain its execution. This work constitutes a novel approach to obtain explainable artificial intelligence systems in general and HNNs in particular building on the theory of data-to-text systems and software visualization approaches. We present a complete methodology to build these kinds of systems. Software architecture is also designed, implemented, and tested. Technical details about the implementation are also detailed and explained. We apply our approach to creating a complete explainer video about the execution of HNNs on a small recognition problem. Finally, several aspects of the videos generated are evaluated (quality, content, motivation and design/presentation).University of the Bio-Bio. Vicerrectoria de Investigacion. Facultad de Ciencias Empresariales. Departamento de Sistemas de Informacion

    Detecting Aggressiveness in Tweets: A Hybrid Model for Detecting Cyberbullying in the Spanish Language

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    In recent years, the use of social networks has increased exponentially, which has led to a significant increase in cyberbullying. Currently, in the field of Computer Science, research has been made on how to detect aggressiveness in texts, which is a prelude to detecting cyberbullying. In this field, the main work has been done for English language texts, mainly using Machine Learning (ML) approaches, Lexicon approaches to a lesser extent, and very few works using hybrid approaches. In these, Lexicons and Machine Learning algorithms are used, such as counting the number of bad words in a sentence using a Lexicon of bad words, which serves as an input feature for classification algorithms. This research aims at contributing towards detecting aggressiveness in Spanish language texts by creating different models that combine the Lexicons and ML approach. Twenty-two models that combine techniques and algorithms from both approaches are proposed, and for their application, certain hyperparameters are adjusted in the training datasets of the corpora, to obtain the best results in the test datasets. Three Spanish language corpora are used in the evaluation: Chilean, Mexican, and Chilean-Mexican corpora. The results indicate that hybrid models obtain the best results in the 3 corpora, over implemented models that do not use Lexicons. This shows that by mixing approaches, aggressiveness detection improves. Finally, a web application is developed that gives applicability to each model by classifying tweets, allowing evaluating the performance of models with external corpus and receiving feedback on the prediction of each one for future research. In addition, an API is available that can be integrated into technological tools for parental control, online plugins for writing analysis in social networks, and educational tools, among others

    Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

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    Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

    Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

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    There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Detecting Aggressiveness in Tweets: A Hybrid Model for Detecting Cyberbullying in the Spanish Language

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    In recent years, the use of social networks has increased exponentially, which has led to a significant increase in cyberbullying. Currently, in the field of Computer Science, research has been made on how to detect aggressiveness in texts, which is a prelude to detecting cyberbullying. In this field, the main work has been done for English language texts, mainly using Machine Learning (ML) approaches, Lexicon approaches to a lesser extent, and very few works using hybrid approaches. In these, Lexicons and Machine Learning algorithms are used, such as counting the number of bad words in a sentence using a Lexicon of bad words, which serves as an input feature for classification algorithms. This research aims at contributing towards detecting aggressiveness in Spanish language texts by creating different models that combine the Lexicons and ML approach. Twenty-two models that combine techniques and algorithms from both approaches are proposed, and for their application, certain hyperparameters are adjusted in the training datasets of the corpora, to obtain the best results in the test datasets. Three Spanish language corpora are used in the evaluation: Chilean, Mexican, and Chilean-Mexican corpora. The results indicate that hybrid models obtain the best results in the 3 corpora, over implemented models that do not use Lexicons. This shows that by mixing approaches, aggressiveness detection improves. Finally, a web application is developed that gives applicability to each model by classifying tweets, allowing evaluating the performance of models with external corpus and receiving feedback on the prediction of each one for future research. In addition, an API is available that can be integrated into technological tools for parental control, online plugins for writing analysis in social networks, and educational tools, among others
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