1,878 research outputs found

    Monitoreo de la contaminación del aire urbano utilizando dispositivos sensores de bajo costo

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    Ilustraciones, gráficas, tablasThe study of urban air pollution holds paramount significance within the realms of environmental science and public health. Urban areas are epicenters of diverse human activities, industrial operations, and vehicular traffic, collectively contributing to elevated concentrations of air pollutants. As the use of LCS devices becomes more prevalent in citizen science initiatives, educational purposes, rise of information and awareness, it is crucial to establish their performance characteristics and evaluation metrics for air pollution monitoring. This thesis focuses on evaluating the performance of Low-cost sensors (LCS) in the monitoring of PM2.5 concentrations in outdoor urban environments in Colombia using data mining and machine learning models. The results show that the polynomial regression and Artificial Neural Networks models present a better enhancing in the accuracy and precision of the measurements of the different models of LCS used in this study compared with simple linear regression and other machine learning models. Lastly, the project endeavors to demonstrate the applicability of LCS devices for monitoring PM2.5 concentration in various transportation modes within the city of Medellin. This research contributes to the broader understanding of LCS devices' potential in enhancing air quality monitoring and their suitability for citizen-driven initiatives in regions lacking regulatory-grade instruments.El estudio de la contaminación del aire urbano tiene una importancia fundamental en los ámbitos de la ciencia ambiental y la salud pública. Las áreas urbanas son epicentros de diversas actividades humanas, operaciones industriales y tráfico vehicular, contribuyendo colectivamente a concentraciones elevadas de contaminantes atmosféricos. A medida que el uso de dispositivos LCS se vuelve más frecuente en iniciativas de ciencia ciudadana, con fines educativos, aumento de información y conciencia, es crucial establecer sus características de rendimiento y métricas de evaluación para el monitoreo de la contaminación del aire. Esta tesis se centra en evaluar el rendimiento de los sensores de bajo costo (LCS) en el monitoreo de las concentraciones de PM2.5 en entornos urbanos al aire libre en Colombia mediante la minería de datos y modelos de aprendizaje automático. Los resultados muestran que los modelos de regresión polinómica y redes neuronales artificiales mejoran la precisión y la exactitud de las mediciones de los diferentes modelos de LCS utilizados en este estudio en comparación con la regresión lineal simple y otros modelos de aprendizaje de máquinas. Por último, el proyecto pretende demostrar la aplicabilidad de los dispositivos LCS para monitorear la concentración de PM2.5 en diversos modos de transporte dentro de la ciudad de Medellín. Esta investigación contribuye a una comprensión más amplia del potencial de los dispositivos LCS para mejorar el monitoreo de la calidad del aire y su idoneidad para iniciativas impulsadas por ciudadanos en regiones que carecen de instrumentos de calidad regulatoria. (text tomado de la fuente)Colciencias Convocatoria 727 doctorados nacionalesDoctoradoDoctor en IngenieríaInvestigación de operacionesÁrea Curricular de Ingeniería de Sistemas e Informátic

    Housing, Health and Happiness

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    Despite the importance of housing for people’s well-being, there is little evidence on the causal impact of housing and housing improvement programs on health and welfare. In this paper, we help to fill this gap by investigating the impact of a large-scale effort by the Mexican Government to replace dirt floors with cement floors on child health and adult happiness. We find that replacing dirt floors with cement floors significantly improves the health of young children. Specifically, we find significant decreases in the incidence of parasitic infestations, diarrhea, and the prevalence of anemia, and an improvement in children’s cognitive development. Additionally, we find that replacing dirt floors by cement floors significantly improves adult welfare, as measured by increased satisfaction with their housing and quality of life, as well as by lower scores on depression and perceived stress scales.

    Métodos de Previsão da Geração de Ácido a Partir de Resíduos Mineiros

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    Os testes laboratoriais utilizados para determinar o potencial de geração de ácido podem ser de natureza estática ou dinâmica. Um teste estático determina simultaneamente, a partir de uma amostra, a capacidade total de geração de ácido bem como o potencial total de neutralização desse ácido. A capacidade total de geração de ácido é determinada ou como a diferença entre estes valores ou como o seu quociente. A partir desses resultados pretende-se inferir se existirá ou não geração de ácido quando da exposição dos resíduos aos agentes meteóricos. Estes testes não determinam a cinética da geração de ácido mas apenas o potencial de produção. Os testes estáticos são conduzidos de forma expedita e apresentam custos pouco relevantes. Os testes cinéticos pretendem simular, a uma velocidade acelerada, o que acontece nos locais mineiros. Exigem um tempo de realização superior e têm um custo superior. Os dados obtidos a partir destes testes podem ser utilizados para classificar os resíduos de acordo com o seu potencial de geração de ácido. Esta informação, quando recolhida e avaliada durante o próprio estudo de viabilidade de um novo empreendimento mineiro ou de construyção civil, permite projectar medidas de mitigação desde o início do projecto. A principal distinção operatória, a nível laboratorial, entre os dois tipos de testes reside no facto que os ensaios estáticos correspondem a uma única determinação temporal enquanto que os ensaios cinéticos recorrem a vários ciclos repetitivos de exposição da amostra a várias cargas de soluções aquosas. Os testes cinéticos permitem simultaneamente inferir a composição iónica dos lixiviados. De uma modo genérico pode-se afirmar que sob o ponto de vista metodológico os ensaios estáticos, devido à sua rapidez e baixo custo, podem ser efectuados com um grande número de amostras constituintes de várias unidades litológicas representativas, enquanto que os ensaios dinâmicos serão efectuados sobre uma ou duas amostras, geralmente compósitas e com uma composição sugerida pelos resultados obtidos com os testes estáticos. Os autores submeterem amostras dos resíduos do tratamento de minérios de duas explorações mineiras portuguesas em actividade a vários destes testes estáticos e dinâmicos, comparando-os entre si

    Housing, health, and happiness

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    Despite the importance of housing for people's well-being, there has been little work done to assess the causal impact of housing and housing improvement programs on health and welfare. In this paper the authors help fill this gap by investigating the impact of a large-scale effort by the Mexican government to replace dirt floors with cement floors on child health and adult happiness. They find that replacing dirt floors with cement floors significantly reduces parasitic infestations in young children, reduces diarrhea, reduces anemia, and improves cognitive development. Finally, they also find that this program leave adults substantially better off, as measured by satisfaction with their housing and quality of life and by their significantly lower rates of depression and perceived stress.Health Monitoring&Evaluation,Disease Control&Prevention,Housing&Human Habitats,Access to Finance,Construction Industry

    Identification of helpful and not helpful online reviews within an eWOM community using text-mining techniques

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    Resumen de la comunicación[EN] Consumers represent today a significant source of information to learn about products and services quality thanks to the proliferation of user-generated content in the form of online reviews. It is thus of paramount to understand what makes online reviews helpful to consumers as this evaluation might affect their purchase decisions. In this regard, this research has applied textmining techniques by extracting the characteristics from online reviews' texts of an eWOM community, and further utilized these characteristics to train a logistic classifier using three classes: helpful, neutral and not helpful. The aim is identifying which unique attributes determine whether an online review is helpful or not. Findings reveal that there are much more unique attributes classified as helpful than attributes classified as not helpful. Additionally, the unique attributes associated to helpful reviews exhibit more objective appraisal while those associated to not helpful reviews show more subjective appraisal. The proposed methodology can be used to predict the helpfulness of posted reviews and to obtain their unique attributes.Olmedilla, M.; Martinez-Torres, R.; Toral, SL. (2018). Identification of helpful and not helpful online reviews within an eWOM community using text-mining techniques. En 2nd International Conference on Advanced Reserach Methods and Analytics (CARMA 2018). Editorial Universitat Politècnica de València. 250-250. https://doi.org/10.4995/CARMA2018.2018.8304OCS25025

    Pain and painkillers

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    El dolor es algo que todos nosotros a lo largo de nuestra vida sufrimos o padecemos y por ello es muy importante saber como reaccionar ante este tipo de situaciones para intentar calmar la zona afectada. Todos no tenemos el mismo tipo de dolor ya que varían según las características y factores que o condicionan, por eso debemos saber como actuar para así poder acudir al médico o farmacéutico de confianza para que ellos nos guíen.Pain is something all of us throughout our lives suffer or suffer and it is very important to know how to react to these situations to try to calm the affected area. All do not have the same kind of pain as they vary according to the characteristics and factors or condition, so we know how to act in order to go to the doctor or pharmacist of confidence so that they guide us
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