127 research outputs found

    Applicability of the strategies for the elastic seismic analysis of cable-stayed bridges

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    En este trabajo se proponen estrategias de análisis y de modelado optimizadas para abordar el estudio sísmico de puentes atirantados que mantienen sus materiales en rango elástico, ofreciendo al diseñador un rango de errores esperables en cada caso en función del tipo de torre de atirantamiento, luz principal y terreno de cimentación, entre otras características. Para ello, se ha realizado un estudio comparativo de diferentes procedimientos de cálculo dinámico aplicados al análisis sísmico elástico de un gran número de puentes atirantados, y se han relacionado las desviaciones observadas con las simplificaciones introducidas en el planteamiento matemático de los mismos. Entre los métodos considerados se encuentra el cálculo modal espectral, el análisis modal dinámico y la integración directa del sistema acoplado de la dinámica. Además, el efecto del impacto del tablero contra las torres en dirección transversal ha sido analizado por medio de elementos de contacto. Se ha concluido que el cálculo modal espectral ofrece resultados que están del lado de la inseguridad, alrededor de un 20%, respecto del cálculo modal dinámico de referencia, el cual es el más preciso.Several optimized analysis and modelling strategies are provided in this work in order to address the seismic behaviour of cable-stayed bridges in the elastic range, including the expected error ranges in terms of the tower shape, the main span or the stiffness associated with the foundation soil, among other project features. This valuable information for the designer is obtained through the comparative study of different analysis methodologies applied to a large number of cable-stayed bridge models, relating the observed deviations with the simplifications introduced in their mathematical developments. Both the widespread response spectrum analysis, the modal time history analysis and the direct integration of the coupled system of dynamics have been considered. Furthermore, the direct integration has been employed to address the effect of possible contacts and impacts between the deck and the towers during the earthquake in transverse direction. It is concluded that spectrum calculations provide results that are usually 20% lower than the reference modal time history analysis, which is the most precise method.Peer Reviewe

    Revisión de los beneficios físicos de la electroestimulación integral

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    La electroestimulación integral (WB-EMS) está cobrando gran relevancia debido a la irrupción de esta tecnología en el sector del fitness y a la propagación viral de multitud de centros que ofertan este sistema que promueven una serie de beneficios asociados al uso de WB-EMS que consideramos no están lo suficientemente justificados o fundamentados. El objetivo de esta revisión es valorarlos y razonar sobre su práctica. Observamos que las investigaciones sobre EMS no apoyan los beneficios que estos promueven más allá de los relacionados principalmente con los parámetros de fuerza. Investigaciones sobre WB-EMS tampoco apoyan estos beneficios siendo además poco extensibles debido a que se han realizado con poblaciones específicas. Asimismo, los resultados de estos son muy modestos, especialmente en el gasto energético que, sumado al máximo tiempo que puede practicarse (20 minutos, dos veces por semana), no se aconseja ni como alternativa ni como sustitutivo a la actividad física tradicional

    Revisió dels beneficis físics de l’electroestimulació integral

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    L’electroestimulació integral (WB-EMS) està cobrant gran rellevància a causa de la irrupció d’aquesta tecnologia en el sector del fitnes i a la propagació viral de multitud de centres que ofereixen aquest sistema, els quals promouen una sèrie de beneficis associats a l’ús de WB-EMS que considerem que no estan prou justificats o fonamentats. L’objectiu d’aquesta revisió és valorar-los i raonar sobre la seva pràctica. Observem que les investigacions sobre EMS no fonamenta els beneficis que promouen més enllà dels relacionats principalment amb els paràmetres de força. Investigacions sobre WB-EMS tampoc fonamenten aquests beneficis i a més a més són poc extensibles pel fet que s’han dut a terme amb poblacions específiques. Així mateix, els resultats d’aquests són molt modestos, especialment en la despesa energètica que, sumat al màxim temps que pot practicar-se (20 minuts, dues vegades per setmana), no s’aconsella ni com a alternativa ni com substitutiu a l’activitat física tradicional

    Heavy Metals and Trace Elements in Human Breast Milk from Industrial/Mining and Agricultural Zones of Southeastern Spain

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    © 2021 The authors. This document is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by /4.0/ This document is the published version of a published work that appeared in final form in International Journal of Environmental Research and Public Health.Human breast milk is the most complete foodstuff for infants but can also be a potential source of exposure to toxic chemicals. The aim of this study was to assess the levels of metal pollution in the breast milk of women living in agricultural and industrial/mining areas of the Region of Murcia (Spain) that are well known for their cases of environmental pollution. Human milk samples were collected from 50 mothers and inorganic contaminants were analyzed using inductively coupled plasma mass spectrometry (ICP‐MS). The mean or maximum concentrations of the different inorganic elements analyzed in breast milk, with the exception of manganese, exceeded the maximum limits established by the WHO and could constitute a high risk for pregnant mothers and their children. The breast milk of women living in the industrial/mining zone presented the highest levels of aluminum, zinc, arsenic, lead, mercury and nickel. On the contrary, the highest concentrations of manganese, chromium and iron were determined in the milk of women living in the agricultural zone. These results suggested and confirmed different profiles of environmental contamination of these areas

    Study of time-frequency characteristics of single snores: extracting new information for sleep apnea diagnosis

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    Obs tructive sleep apnea (OSA) is a highly prevalent chronic disease, especially in elderly and obese population . Despite constitut ing a huge health and economic problem, most patients remain undiagnosed due to limitations in current strategies. Therefore, it is essential to find cost - effective diagnostic alternatives. One of these novel approaches is the analysis of acoustic snoring signals. Snoring is an early symptom of OSA which carr ies pathophysiological information of high diagnostic value. For this reason, the main objective of this work is to study the characteristics of single snores of different types, from healthy and OSA subjects. To do that, we analyzed snoring signals from p revious databases and developed an experimental protocol to record simulated OSA - related sounds and characterize the response of two commercial tracheal microphones. Automatic programs for filtering, downsampling, event detection and time - frequency analysi s were built in MATLAB. We found that time - frequency maps and spectral parameters (central, mean and peak frequency and energy in the 100 - 500 Hz band) allow distinguishing regular snores of healthy subjects from non - regular snores and snores of OSA subject s. Regarding the two commercial microphones, we f ound that one of them was a suitable snoring sensor, while the other had a too restricted frequency response. Future work shall include a higher number of episode s and subjects , but our study has contributed to show how important the differences between regular and non - regular snores can be for OSA diagnosis, and how much clinically relevant information can be extracted from time - frequency maps and spectral parameters of single snoresPeer ReviewedPostprint (published version

    TASS 2015 – La evolución de los sistemas de análisis de opiniones para español

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    El análisis de opiniones en microblogging sigue siendo una tarea de actualidad, que permite conocer la orientación de las opiniones que minuto tras minuto se publican en medios sociales en Internet. TASS es un taller de participación que tiene como finalidad promover la investigación y desarrollo de nuevos algoritmos, recursos y técnicas aplicado al análisis de opiniones en español. En este artículo se describe la cuarta edición de TASS, resumiendo las principales aportaciones de los sistemas presentados, analizando los resultados y mostrando la evolución de los mismos. Además de analizar brevemente los sistemas que se presentaron, se presenta un nuevo corpus de tweets etiquetados en el dominio político, que se desarrolló para la tarea de Análisis de Opiniones a nivel de Aspecto.Sentiment Analysis in microblogging continues to be a trendy task, which allows to understand the polarity of the opinions published in social media. TASS is a workshop whose goal is to boost the research on Sentiment Analysis in Spanish. In this paper we describe the fourth edition of TASS, showing a summary of the systems, analyzing the results to check their evolution. In addition to a brief description of the participant systems, a new corpus of tweets is presented, compiled for the Sentiment Analysis at Aspect Level task.This work has been partially supported by a grant from the Fondo Europeo de Desarrollo Regional (FEDER), REDES project (TIN2015-65136-C2-1-R) and Ciudad2020 (INNPRONTA IPT-20111006) from the Spanish Government

    Science production of pesticide residues in honey research: A descriptive bibliometric study

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    © 2020, Elsevier B.V.. This document is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the accepted version of a published work that appeared in final form in Environmental Toxicology and PharmacologyThis work aims to provide a comprehensive study of the available research information on pesticide residues in honey through literature analysis. The research advancements within this research field from 1948 to 2019 are addressed using the Web of Science database. The results from the 685 articles analyzed indicate that this research field is in the focus of interest nowadays (Price index: 47.5 %). The yearly production increased steadily from 2001 on, and authors, journals, and institutions followed Lotka's law. On the other hand, Pico, Y (Spain) (2.5 %), Journal of Chromatography A (5.8 %), the USA (15.0 %) and Agricultural Research Service (USA) (4.0 %) were the most productive author, journal, country and institution, respectively. The research hotspots of this field, according to keyword analysis, are related to the chromatographic techniques for the determination of pesticides such as imidacloprid, neonicotinoids, or coumaphos in honey and derivate products such as propolis and wax

    2019 National survey of fitness trends in Spain

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    En 2016 y 2017 se han realizado las primeras Encuestas Nacionales sobre Tendencias en Fitness en España, reproduciendo la metodología de las encuestas internacionales sobre tendencias globales de fitness promovidas por el Colegio Americano de Medicina del Deporte (ACSM) desde 2006. Este estudio presenta los resultados de la tercera Encuesta Nacional sobre Tendencias en Fitness para el año 2019. Su objetivo ha sido identificar las principales tendencias y su relevancia en el sector del fitness español para ese año. Se recogió la opinión de 600 profesionales del sector del fitness sobre 46 potenciales tendencias mediante un cuestionario online. Las tendencias más relevantes para 2019 en el contexto español son «personal formado, cualificado y experimentado», «entrenamiento funcional», «ejercicio y pérdida de peso», «entrenamiento personal», «entrenamiento interválico de alta intensidad», y «entrenamiento con el peso corporal». Las tendencias en el sector del fitness en España para 2019 han resultado ser muy estables con respecto a las tendencias que emergieron en el top 20 en la encuesta de 2018, con solo 2 tendencias nuevas y apenas cambios en sus posiciones en ranking. Sin embargo, las diferencias son mucho mayores cuando se comparan con el top 20 de la encuesta internacional de 2018, con 8 tendencias diferentes (un 40%). Esto indica cierta divergencia de las tendencias de fitness en nuestro país y las tendencias globales del sector, mostrando una dinámica propia en el sector españolIn 2016 and 2017 the first National Surveys on Fitness Trends was carried out in Spain reproducing the methodology of the worldwide surveys about global fitness trends endorsed by the American College of Sport Medicine (ACSM) since 2006. This study shows the findings of the third National Survey of Fitness Trends aimed at identifying the main trends in the Spanish fitness sector and their relevance in 2019. The opinion of 600 professionals in the fitness sector about 46 potential trends were gathered via an online questionnaire. The more relevant trends in the Spanish context for 2019 were «educated, certified and experienced fitness professionals», «functional training», «exercise and weight loss», «personal training», «high intensity interval training» and «body weight training». Trends in the Spanish fitness sector have been very stable in 2019 compared to those emerged in the top 20 in the 2018 survey, with only 2 new trends whereas the others remained almost unchanged in their ranking positions. However, differences were much greater when compared with the top 20 of the global survey of 2018, with 8 different trends (40%). This points to some divergences of fitness trend in our country and the global trends of the sector, showing a dynamic of its own in the Spanish secto

    Dynamic Federated Learning Model for Identifying Adversarial Clients

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    Federated learning, as a distributed learning that conducts the training on the local devices without accessing to the training data, is vulnerable to dirty-label data poisoning adversarial attacks. We claim that the federated learning model has to avoid those kind of adversarial attacks through filtering out the clients that manipulate the local data. We propose a dynamic federated learning model that dynamically discards those adversarial clients, which allows to prevent the corruption of the global learning model. We evaluate the dynamic discarding of adversarial clients deploying a deep learning classification model in a federated learning setting, and using the EMNIST Digits and Fashion MNIST image classification datasets. Likewise, we analyse the capacity of detecting clients with poor data distribution and reducing the number of rounds of learning by selecting the clients to aggregate. The results show that the dynamic selection of the clients to aggregate enhances the performance of the global learning model, discards the adversarial and poor clients and reduces the rounds of learning.Comment: 11 pages, 6 figure

    Análisis de la movilidad peatonal urbana para personas con diversidad funcional a través del uso de Información Geográfica Voluntaria.

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    La desigualdades de los espacios urbanos se recrean en la accesibilidad a la red de movilidad peatonal urbana y su interacción con las personas con diversidad funcional, tanto sillas de ruedas como invidentes. Los distritos municipales de Las Fuentes y San José, Zaragoza (España), presenta un contexto demográfico envejecido y un marco urbanístico susceptible de ser inaccesible. Los avances tecnológicos y la Información Geográfica Voluntaria (IGV) permiten la implementación de una base de datos abierta con información relativa a la accesibilidad. Sobre esta base, OpenStreetMap (OSM), se ha realizado un análisis de red para diagnosticar la vialidad de las aceras y los pasos de peatones.<br /
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