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Tourist behaviour and dynamics of domestic tourism in times of COVID-19
Get PDFThe purpose of this study was to determine the changes and consequences in travel plans due to Covid-19 and characterize the behaviour of domestic tourism in Costa Rica after the confinement through an online survey. The respondents expressed their intention to travel in the first six months, mostly two nights, and accompanied by their family members. Factors related to safety and security appear as key drivers affecting travel decisions. Protected areas and nature-based tourism are the preferred destinations to visit after the lockdown with a clear concentration in the most visited protected areas of Costa Rica.Moya Calderón, Michael-will be generated-orcid-0000-0002-6766-4392-600Chavarría Esquivel, Kevin-will be generated-orcid-0000-0003-4483-4990-600Arrieta García, María MargaritaBarriocanal Lozano, Carlo
Digital analog converter for the extraction of test signals from mixed integrated circuits
Get PDFThe construction of integrated circuits involves testing the correct operation of its internal blocks. For this, a common practice is the integration of functional blocks to stimulate the internal subsystems and extract the responses to those stimuli. In this article, the design and simulation of a circuit for the extraction of the response signals of the devices under test in analog and mixed-signal integrated circuits is presented. The extraction block is a 2-stage 5-bit segmented A/D converter, operating at a sampling frequency of 10 MHz, implemented in a 0.12 µm technological process, which can be powered with 1.5 Vdc. This proposal offers a reduction in the area consumed, by requiring fewer comparators than other similar solutions found in the literature.Simancas-García, José L.MELÉNDEZ, FARID-will be generated-orcid-0000-0001-7007-0109-600R. González, Ramón E.Cárdenas, César-will be generated-orcid-0000-0001-6662-6899-60
GAD-7 Generalised Anxiety Disorder scale in Colombian medical professionals during the COVID-19 pandemic: construct validity and reliability
Get PDFIntroduction: The detection of anxiety symptoms among health workers who care for patients infected with COVID-19 is a current priority. Fast and valid instruments are required for this population group. The objective is to establish the construct validity and reliability of the Generalised Anxiety Disorder (GAD-7) scale in Colombian doctors during the COVID-19 lockdown. Methods: E-health study, in which cross-sectional data were collected online (n = 1,030) from 610 COVID doctors and 420 non-COVID doctors, during the Colombian lockdown, between 20 April and 10 August 2020. Each subject was contacted, and they confirmed their participation, identity and professional role. Results: A single factor factorial structure was found, made up of the 7 items of the instrument, which managed to explain 70% of the variance. The goodness of fit indices (RMSEA = 0.080; CFI = 0.995; SRMR = 0.053; p 0.070. Finally, the internal consistency of the instrument was good, with a Cronbach's alpha of 0.920 (95%IC, 8.80-9.71). Conclusions: The GAD-7 is an instrument that presents adequate indicators of validity and reliability. It is an excellent tool that is reliable and easy and fast to use for the detection of generalised anxiety symptoms in medical personnel caring (or not) for patients infected with COVID-19.Camargo, Loida-will be generated-orcid-0000-0003-0056-6832-600Herrera-Pino, Jorge Alfredo-will be generated-orcid-0000-0002-2690-4791-600Shelach, Salomon-will be generated-orcid-0000-0003-0314-423X-600Soto-Añari, Marcio-will be generated-orcid-0000-0002-9121-3284-600Porto, Maria F.Alonso, Monica-will be generated-orcid-0000-0001-6683-5957-600González, MiguelContreras, Oscar-will be generated-orcid-0000-0001-9808-9776-600Caldichoury, NicoleRamos-Henderson, Miguel-will be generated-orcid-0000-0003-1045-6872-600GARGIULO, Pascual-will be generated-orcid-0000-0003-2962-4346-600López, Norma
Engineering of novel fe-based bulk metallic glasses using a machine learning-based approach
Get PDFA broad range of potential chemical compositions makes difficult design of novel bulk metallic glasses (BMGs) without performing expensive experimentations. To overcome this problem, it is very important to establish predictive models based on artificial intelligence. In this work, a machine learning (ML) approach was proposed for predicting glass formation in numerous alloying compositions and designing novel glassy alloys. The results showed that our ML model accurately predicted the glass formation and critical thickness of MGs. As a case study, the ternary Fe–B–Co system was selected and effects of minor additions of Cr, Nb and Y with different atomic percentages were evaluated. It was found that the minor addition of Nb and Y leads to the significant improvement of glass-forming ability (GFA) in the Fe–B–Co system; however, a shift in the optimized alloying composition was occurred. The experimental results on selective alloying compositions also confirmed the capability of our ML model for designing novel Fe-based BMGs. © 2021, King Fahd University of Petroleum & Minerals.Tzu-Chia, ChenRajiman, RajimanElveny, Marischa-will be generated-orcid-0000-0003-2014-6173-600Grimaldo Guerrero, John William-will be generated-orcid-0000-0002-1632-5374-600Lawal, Adedoyin Isola-will be generated-orcid-0000-0001-8295-1560-600Acwin Dwijendra, Ngakan Ketutaravindhan, surendar-will be generated-orcid-0000-0002-2421-9192-600Danshina, Svetlana-will be generated-orcid-0000-0002-9467-078X-600ZHU, Yu-will be generated-orcid-0000-0003-2204-0946-60
Construcción de paz, reconciliación y derechos humanos: estudios científicos interdisciplinarios
No full textLuego de la firma del Acuerdo de Paz entre el gobierno colombiano y las Fuerzas Armadas Revolucionarias de Colombia, en el año 2016, inicia una era de nuevas expectativas en torno a la paz y la reconciliación en el país. No obstante, se ha visto que aún queda mucho camino por recorrer; han existido diversas críticas y dificultades que han llevado a catalogar el proceso como una paz imperfecta (Rodríguez, 2019). En este sentido, se entendería que una vez cesa la guerra, nace la paz; sin embargo, es necesario reconocer que la paz es un constructo cultural complejo que se circunscribe a la interacción cotidiana entre individuos y la confluencia de las diversas formas de manejar el conflicto. Se infiere que para lograr la paz es necesario vislumbrar aquellos escenarios intrínsecos a partir de los cuales se gesta el diálogo, la participación social, la reconciliación y el respeto por los derechos humanos, como elementos indispensables en la armonía de los territorios. Lo anterior, permite rescatar el reconocimiento de diversos espacios para construir paz y en los que confluyen actores sociales, estatales, académicos y civiles en el abordaje del conflicto, sus manifestaciones, repercusiones y formas de prevención y mitigación para la convivencia y la paz territorial.
En este contexto, el presente libro surgió con el interés de ampliar el conocimiento científico en torno a la construcción de paz desde diversos escenarios, pues “estudiar la paz desde la paz misma permite la posibilidad de aportar a la construcción de cultura de paz, desde la concepción de expertos e investigadores en el tema quienes se aproximan a el (Hernández, Luna y Cadena, 2017, p. 1). Por lo anterior, esta obra comprende estudios científicos interdisciplinarios sobre la construcción de paz, reconciliación y derechos humanos
The nexus between co2 emission, economic growth, trade openness: evidences from middle-income trap countries
No full textIn recent years, the carbon dioxide emissions generated by the massive consumption of fossil energy have been increasing year by year, resulting in more and more obvious greenhouse effect, and the occurrence of climate disasters around the world has become more and more frequent. This study analyses the long-term effects of economic growth, trade, foreign direct investment (FDI) and gross domestic product (GDP) on carbon dioxide (CO2) emissions in Latin American countries that are in the middle-income trap (MIT). Using annual time-series data for the period 2000–2020, the results of middle-income countries of Latin America are compared with higher-income countries (Singapore, the United States, and South Korea) and an upper-middle-income country, China. Specifically, we examine the role of sector value addition to GDP on the CO2 emission nexus for middle-income economies, controlling for the effects on GDP, FDI, and trade. Using regression and path analysis (multiple regression) we find that for higher-income countries FDI, GDP and trade are the important variables that have a strong positive impact on CO2 emission, but that positive impact is weak in MIT countries, which makes this study significant as it highlights important variables needed for MIT countries to remain focused. Autoregressive distributed lag (ARDL) model results also explore that FDI, GDP growth and trade variables can significantly accelerate the environmental quality by CO2 emission, while tourism/travel services and education do not much impact the environment. Hence, our paper provides solid ground for developing a sustainable and pro-growth policy for MIT countries because they are plagued by the decline or stagnation of economic growth
Bibliometric analysis of global trends around hydrogen production based on the scopus database in the period 2011–2021
No full textGiven the increase in population and energy demand worldwide, alternative methods have been adopted for the production of hydrogen as a clean energy source. This energy offers an alternative energy source due to its high energy content, and without emissions to the environment. In this bibliometric analysis of energy production using electrolysis and taking into account the different forms of energy production. In this analysis, it was possible to evaluate the research trends based on the literature in the Scopus database during the years 2011–2021. The results showed a growing interest in hydrogen production from electrolysis and other mechanisms, with China being the country with the highest number of publications and the United States TOP in citations. The trend shows that during the first four years of this study (2011–2014), the average number of publications was 74 articles per year, from 2015 to 2021 where the growth is an average of 209 articles, the journal that published the most on this topic is Applied Energy, followed by Energy, contributing with almost 33% in the research area. Lastly, the keyword analysis identified six important research points for future discussions, which we have termed clusters. The study concludes that new perspectives on clean hydrogen energy generation, environmental impacts, and social acceptance could contribute to the positive evolution of the hydrogen energy industry
Los Hongos Micorrícicos Arbusculares (HMA) y sus posibilidades para una producción más limpia de zarzamora
No full textIntroduction— Blackberry (Rubus glaucus Benth) is among the promising fruit trees of great commercial importance in Colombia, and although it is proposed that the use of mycorrhizae in blackberry plays an important role in sustainable agroecosystems, there is no updated information on the subject. Objective— To provide comprehensive and updated information on arbuscular mycorrhizal fungi in interaction with fruit species with emphasis on the cultivation of blackberry (Rubus sp.). Methodology— A documentary investigation of articles was carried out with updated information that indicated the approach to Arbuscular Mycorrhizal Fungi (AMF) in blackberry, using as units of analysis the articles published by national and international journals and the databases selected during the period. from 2010 to 2020. Results— A total of 20 original articles published were found, distributed like this: national magazines, 6 articles; international magazines, 7 articles; and in databases, 7 articles. Conclusions— The use of AMF in fruit trees is encouraging in Colombia and to a certain extent also in the cultivation of blackberry, however, it is necessary to deepen on aspects related to the response capacity of each crop to mycorrhizal symbiosis, turning this into an obstacle to the larger-scale application of this biotechnology, as well as increasing scientific research on native AMF species and their mycorrhizal potential for achieving cleaner and more sustainable agriculture.Introducción— La mora (Rubus glaucus Benth) se encuentra entre los frutales promisorios de gran importancia comercial en Colombia, y aunque se plantea que el uso de micorrizas en mora juega un papel importante en agroecosistemas sostenibles, no existe información actualizada sobre el tema. Objetivo— Proporcionar información completa y actualizada sobre hongos micorrízicos arbusculares en interacción con especies frutales con énfasis en el cultivo de mora (Rubus sp.). Metodología— Se realizó una investigación documental de artículos con información actualizada que indicaran el abordaje de los Hongos Micorrízicos Arbusculares (HMA) en zarzamora, utilizando como unidades de análisis los artículos publicados por revistas nacionales e internacionales y las bases de datos seleccionadas durante el periodo. de 2010 a 2020. Resultados— Se encontraron un total de 20 artículos originales publicados, distribuidos así: revistas nacionales, 6 artículos; revistas internacionales, 7 artículos; y en bases de datos, 7 artículos. Conclusiones— El uso de HMA en frutales es alentador en Colombia y en cierta medida también en el cultivo de mora, sin embargo, es necesario profundizar en aspectos relacionados con la capacidad de respuesta de cada cultivo a la simbiosis micorrízica, convirtiéndose esto en un obstáculo para la aplicación a mayor escala de esta biotecnología, así como incrementar la investigación científica sobre las especies nativas de HMA y su potencial micorrízico para lograr una agricultura más limpia y sostenible
Modelo de inteligencia artificial y aprendizaje automático para la predicción espacial y temporal de eventos de sequía en el departamento del Magdalena, Colombia
No full textIntroduction— Drought is one of the most critical hydrometeorological phenomenon in terms of its impacts on society. Although Colombia is a tropical country, there are areas of the territory which have periods of drought, and this causes significant economic damage. Objective— Due to recent advances in terms of the spatial and temporal resolutions of remote sensing, and artificial intelligence techniques, it is possible to develop automatic learning models supported by historical information. Methodology— In this study, a Random Forest (RF) and Bagged Decision Tree Classifier (DTC) model was built to perform spatial and temporal drought prediction in the department of Magdalena using the following features: Normalized Difference Vegetation Index (NDVI), land surface temperature (LST), precipitation, Normalized Difference Water Index (NDWI), Normalized Multiband Drought Index (NMDI), evapotranspiration (ET), surface soil moisture (SSM), subsurface soil moisture (SUSM), Multivariate ENSO Index (MEI), Southern Oscillation Index (SOI), and Oceanic Niño Index (ONI). Results— For labelling, which allows one to train and evaluate the model, the Standardized Precipitation Index (SPI) was used to identify drought events. Conclusions— The implementation of the developed model can allow governmental entities to take actions to mitigate impacts generated by recurring droughts in their territories.Introducción— La sequía es uno de los fenómenos hidrometeorológicos más críticos por sus impactos en la sociedad. A pesar de que Colombia es un país tropical, existen zonas del territorio que presentan periodos de sequía, lo que ocasiona importantes perjuicios económicos. Objetivo— Debido a los recientes avances en cuanto a las resoluciones espaciales y temporales de la teledetección, y a las técnicas de inteligencia artificial, es posible desarrollar modelos de aprendizaje automático apoyados en información histórica. Metodología— En este estudio se construyó un modelo clasificador de Bosque Aleatorio (RF) y Árbol de Decisión en Bolsa (DTC) para realizar la predicción espacial y temporal de sequía en el departamento del Magdalena utilizando las siguientes características: Índice de Vegetación de Diferencia Normalizada (NDVI), temperatura de la superficie terrestre (LST), precipitación, Índice de Agua de Diferencia Normalizada (NDWI), Índice de Sequía Multibanda Normalizada (NMDI), evapotranspiración (ET), humedad superficial del suelo (SSM), humedad subsuperficial del suelo (SUSM), Índice ENSO Multivariado (MEI), Índice de Oscilación del Sur (SOI) e Índice del Niño Oceánico (ONI). Resultados— Para el etiquetado, que permite entrenar y evaluar el modelo, se utilizó el Índice de Precipitación Estandarizado (SPI) para identificar los eventos de sequía. Conclusiones— La implementación del modelo desarrollado puede permitir a las entidades gubernamentales tomar acciones para mitigar los impactos generados por sequías recurrentes en sus territorios
Material culture of the amphibian habitat: a case study of Bocas del Atrato in Colombia
No full textLos hábitats anfibios son ecosistemas naturales en los que conviven los grupos humanos entre agua y tierra e inundación y sequía. El problema es la falta de estudio, ya que desde los autores de referencia hay una brecha de 10 años en los que son necesarios enunciar el asentamiento, tipología de vivienda con materiales y sistemas constructivos. El objetivo consistió en identificar las afectaciones por el cambio climático en una comunidad rural del corregimiento de Bocas del Atrato de Turbo en Antioquia (Colombia), a través de una investigación colaborativa entre la comunidad, el sector público y la academia por medio de la metodología participativa en construcción “Acciones Transformadoras”. Como resultado se obtuvo la proyectación conceptual de estrategias basadas en la naturaleza y se concluyó que aún deben seguirse estudiando en estos paisajes anfibios en territorios similares para generar diferentes rutas a explotar desde el conocimiento del saber local y la academia, a través del emprendimiento.Amphibian habitats are natural ecosystems in which human groups coexist between water and land and flood and drought. The problem is the lack of study, since from the reference authors there is a gap of 10 years in which it is necessary to state the settlement, housing typology with materials and constructive systems. The objective was to identify the effects of climate change in a rural community in the village of Bocas del Atrato in Turbo-Antioquia (Colombia), through a collaborative research between the community, the public sector and academia by means of the participatory methodology in construction “Transforming Actions”. As a result, the conceptual projection of strategies based on nature was obtained and it was concluded that these amphibious landscapes in similar territories still need to be studied in order to generate different routes to be exploited from the knowledge of local knowledge and academia, through entrepreneurship