Elaboración de una guía de planificación técnica y financiera para el cultivo de la cebolla de bulbo (Allium ceppa). Estudio de caso

92 páginas : ilustraciones, fotografías, tablas y gráficas.El trabajo plantea la importancia, la elaboración e implementación de una guía de planificación técnica y financiera para cultivos transitorios como la cebolla de bulbo para los pequeños productores con el objetivo de planificar la producción y atender mercados constantes.Bibliografía y citaciones: páginas 89-92,Incluye notas de pie de página y anexos.PregradoAdministrador de Empresas Agropecuaria

Attention-based deep recurrent neural network to forecast the temperature behavior of an electric arc furnace side-wall

Structural health monitoring (SHM) in an electric arc furnace is performed in several ways. It depends on the kind of element or variable to monitor. For instance, the lining of these furnaces is made of refractory materials that can be worn out over time. Therefore, monitoring the temperatures on the walls and the cooling elements of the furnace is essential for correct structural monitoring. In this work, a multivariate time series temperature prediction was performed through a deep learning approach. To take advantage of data from the last 5 years while not neglecting the initial parts of the sequence in the oldest years, an attention mechanism was used to model time series forecasting using deep learning. The attention mechanism was built on the foundation of the encoder–decoder approach in neural networks. Thus, with the use of an attention mechanism, the long-term dependency of the temperature predictions in a furnace was improved. A warm-up period in the training process of the neural network was implemented. The results of the attention-based mechanism were compared with the use of recurrent neural network architectures to deal with time series data, such as Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU). The results of the Average Root Mean Square Error (ARMSE) obtained with the attention-based mechanism were the lowest. Finally, a variable importance study was performed to identify the best variables to train the model.This work has been funded by the Colombian Ministry of Science through grant number 786, “Convocatoria para el registro de proyectos que aspiran a obtener beneficios tributarios por inversión en CTeI”. This work has been partially funded by the Spanish Agencia Estatal de Investigación (AEI)—Ministerio de Economía, Industria y Competitividad (MINECO), and the Fondo Europeo de Desarrollo Regional (FEDER) through the research project DPI2017-82930-C2-1-R, and by the Generalitat de Catalunya through the research project 2017-SGR-388.Peer ReviewedPostprint (published version

Metodología para determinar la viabilidad de generación de energía eléctrica por medio del recurso eólico

Objetivo: Describir una metodología para determinar la viabilidad de producción de energía eléctrica mediante el aprovechamiento de la energía eólica, teniendo en cuenta los datos del recurso eólico y el uso de un aerogenerador comercial de baja potencia para realizar la conversión de energía. Metodología: Se evaluaron los datos suministrados por la estación meteorológica del aeropuerto Camilo Daza de la ciudad de Cúcuta, en un periodo de 5 años, comprendido entre los años 2010-2014. Resultados: Con base en los datos suministrados por la estación, se seleccionó el aerogenerador comercial WINDSPOT 7,5 kW para establecer la producción de energía. Conclusión: El análisis de los datos proporcionados determinó que no es viable la implementación de una estación eólica en dicha zona, dado que  las velocidades del viento no están en el rango recomendado, el cual debe ser superior a 5 m/s

Diplomado de profundización cisco diseño e implementación de soluciones integradas LAN / WAN.

Evidencias del desarrollo en el simuladorDesarrollo de prácticas mediante el uso de la herramienta de simulación PACKET TRACER, con el fin de realizar los procesos de configuración de dispositivos de Networking.Development of practices throug the use of the PACKET TRACER, simulation tool, in order to carry out the configuration processes of Networking

Optimización del proceso de ferroxidación para la eliminación de metales pesados de agua residual

Se buscó optimizar un proceso de remoción de arsénico, cromo y vanadio disueltos en agua residual industrial, mediante ferroxidación con viruta de (Fe (0)). Aplicando un diseño factorial 2k, se analizaron cuatro parámetros: concentración de contaminantes, tamaño y cantidad de viruta de hierro y tiempo de residencia. Solo el tiempo de residencia afectó significativamente la eficiencia. A partir concentraciones iniciales de 14.16 mg As/L, 12.82 mg Cr/L y 13.53 mg V/L, se obtuvieron remociones de más del 98%, con 8 h y 16 h de tiempo de retención. Cuando se evaluaron tiempos menores a 8 h, en 4 h se observó una remoción mayor al 98% en As y 100% en V, sin embargo, la remoción de Cr sólo fue cercana al 90%, lo que implicó concentraciones finales que rebasan los límites de la NOM-001-SEMARNAT-1996, por lo que se propone combinar la ferroxidación con un proceso de precipitación química.We aimed to optimize a process of removal of arsenic, chromium and vanadium dissolved in industrial wastewater by ferroxidation with Fe (0) chips. Applying a 2k factorial design, four parameters were analyzed: pollutant concentration, size and amount of iron chips of and residence time. Only the residence time significantly affected efficiency. From initial concentrations of 14.16 mg As/L, 12.82 mg Cr/L and 13.53 mg V/L, were removals of more than 98%, with 8 h and 16 h of retention time. When retention times were less than 8 h, in 4 h we observed 98% As and 100% V removals, however, the removal of Cr was only close to 90%, which meant final concentrations that exceed the limits of the NOM-001-SEMARNAT-1996, it was therefore proposed to combine the ferroxidation with a chemical precipitation process

What Is the Support for Conspiracy Beliefs About COVID-19 Vaccines in Latin America? A Prospective Exploratory Study in 13 Countries

Conspiracy theories about COVID-19 began to emerge immediately after the first news about the disease and threaten to prolong the negative impact of the COVID-19 pandemic by limiting people’s willingness of receiving a life-saving vaccine. In this context, this study aimed to explore the variation of conspiracy beliefs regarding COVID-19 and the vaccine against it in 5779 people living in 13 Latin American countries (Argentina, Bolivia, Chile, Colombia, Cuba, Ecuador, El Salvador, Guatemala, Mexico, Paraguay, Peru, Uruguay and Venezuela) according to sociodemographic variables such as gender, age, educational level and source of information about COVID-19. The study was conducted during the COVID-19 pandemic between September 15 and October 25, 2021. The Spanish-language COVID-19 Vaccine Conspiracy Beliefs Scale (ECCV-COVID) and a sociodemographic survey were used. The results indicate that, in most countries, women, people with a lower educational level and those who receive information about the vaccine and COVID-19 from family/friends are more supportive of conspiracy ideas regarding the COVID-19 vaccine. In the case of age, the results vary by country. The analysis of the responses to each of the questions of the ECCV-COVID reveals that, in general, the countries evaluated are mostly in some degree of disagreement or indecision regarding conspiratorial beliefs about COVID-19 vaccines. The findings could help open further study which could support prevention and treatment efforts during the COVID-19 pandemic

Design and Cross-Cultural Invariance of the COVID-19 Vaccine Conspiracy Beliefs Scale (COVID-VCBS) in 13 Latin American Countries

"Aims: Over the past 2 years, the vaccine conspiracy beliefs construct has been used in a number of different studies. These publications have assessed the determinants and outcomes of vaccine conspiracy beliefs using, in some cases, pooled data from different countries, and compared the results across these contexts. However, studies often do not consider measurement invariance as a necessary requirement for comparative analyses. Therefore, the aim of this study was to develop and evaluate the crosscultural MI of the COVID-19 Vaccine Conspiracy Beliefs Scale (COVID-VCBS) in 12 Latin American countries. Methods: Confirmatory factor analysis, item response theory analysis and alignment method were applied to test measurement invariance in a large number of groups. Results: The COVID-VCBS showed robust psychometric properties and measurement invariance for both factor loadings and crosstabs. Also, a higher level of acceptance of conspiracy beliefs about vaccines is necessary to respond to higher response categories. Similarly, greater acceptance of conspiracy beliefs about COVID-19 vaccines was related to a lower intention to be vaccinated. Conclusion: The results allow for improved understanding of conspiracy beliefs about COVID-19 vaccines in the countries assessed; furthermore, they provide researchers and practitioners with an invariant measure that they can use in cross-cultural studies in Latin America. However, further studies are needed to test invariance in other countries, with the goal of developing a truly international measure of conspiracy beliefs about COVID-19 vaccines.

Network analysis of the relationships between conspiracy beliefs towards COVID-19 vaccine and symptoms of fear of COVID-19 in a sample of latin american countries

The present study examined how conspiracy beliefs about COVID-19 vaccines specifically relate to symptoms of fear of COVID-19 in a sample of four South American countries. A total of 1785 people from Bolivia, Colombia, Ecuador, and Peru participated, responding to a sociodemographic survey, the Fear of COVID-19 scale (FCV-19 S) and the Vaccine Conspiracy Beliefs Scale-COVID-19 (VCBS-COVID-19). Network analysis identified the most important symptoms of fear and conspiracy beliefs about COVID-19 vaccines (nodes) and the associations between them (edges). In addition, the robustness of the network of these indicators of centrality and the possible differences in the structure and connectivity of the networks between the four countries were evaluated. The results suggest that the nodes with the highest centrality were items 2 and 5 of the FCV-19 S and item 2 of the VCBS-COVID-19. Likewise, item 6 is the belief that most predicts conspiracy beliefs about vaccines against COVID-19; while item 6 was the symptom that most predicts fear of COVID-19. The findings strongly support cross-cultural similarities in the networks across the four countries rather than differences. Although it was expected that a higher presence of symptoms of fear of COVID-19 may lead people to compensate for their fear by believing in conspiratorial ideas about vaccines and, consequently, rejecting the COVID-19 vaccine, the results do not clearly show this relationship. This could lead other researchers to generate evidence to explain the differences between Latin American countries and countries in other contexts in terms of vaccination rates. This evidence could be useful to develop policies favoring vaccination against COVID-19 that are more contextualized to the Latin American region, characterized by social instability and economic recession during the pandemic

Network analysis of the relationships between conspiracy beliefs towards COVID-19 vaccine and symptoms of fear of COVID-19 in a sample of latin american countries

"The present study examined how conspiracy beliefs about COVID-19 vaccines specifcally relate to symptoms of fear of COVID-19 in a sample of four South American countries. A total of 1785 people from Bolivia, Colombia, Ecuador, and Peru participated, responding to a sociodemographic survey, the Fear of COVID-19 scale (FCV-19 S) and the Vaccine Conspiracy Beliefs Scale-COVID-19 (VCBS-COVID-19). Network analysis identifed the most important symptoms of fear and conspiracy beliefs about COVID-19 vaccines (nodes) and the associations between them (edges). In addition, the robustness of the network of these indicators of centrality and the possible diferences in the structure and connectivity of the networks between the four countries were evaluated. The results suggest that the nodes with the highest centrality were items 2 and 5 of the FCV-19 S and item 2 of the VCBS-COVID-19. Likewise, item 6 is the belief that most predicts conspiracy beliefs about vaccines against COVID-19; while item 6 was the symptom that most predicts fear of COVID-19. The fndings strongly support cross-cultural similarities in the networks across the four countries rather than diferences. Although it was expected that a higher presence of symptoms of fear of COVID-19 may lead people to compensate for their fear by believing in conspiratorial ideas about vaccines and, consequently, rejecting the COVID-19 vaccine, the results do not clearly show this relationship. This could lead other researchers to generate evidence to explain the diferences between Latin American countries and countries in other contexts in terms of vaccination rates. This evidence could be useful to develop policies favoring vaccination against COVID-19 that are more contextualized to the Latin American region, characterized by social instability and economic recession during the pandemic.

COVID-19 anxiety, psychological well-being and preventive behaviors during the COVID-19 pandemic in Latin America and the Caribbean: relationships and explanatory model

This study assesses the relationship between COVID-19 anxiety and subjective well-being in terms of the mediating role of COVID-19 preventive behaviors. Additionally, the contribution of sociodemographic factors (sex and age) and risk perception on COVID-19 anxiety and its potential measurement invariance was tested in 5655 participants from 12 countries in Latin America and the Caribbean. A mixture of both latent and observable variables were analyzed using a system of structural equations. The Coronavirus Anxiety Scale (CAS), Preventive COVID-19 Infection Behaviors Scale (PCIBS) and single-item measures were used to assess the perceived probability of death, perceived severity and concern about transmitting COVID-19. The results indicated that there is a significant and relevant direct effect of COVID-19 anxiety on participants' well-being. Furthermore, COVID-19 anxiety significantly predicted both preventive behavior (β =.29, p <.01) and well-being (β = –.32, p <.01). The effects of COVID anxiety and preventive behavior explained 9.8% of the variance in well-being (R-square =.098); whereas, 8.4% of the variance in preventive behavior was associated with COVID anxiety (R-square =.084). Likewise, perceived likelihood of death from COVID, perceived severity of COVID, and concerns about COVID transmission were positively related to anxiety. Age was negatively related to anxiety, with men being less anxious than women. The results are invariant by country, i.e., the broad relationships found in the combined sample are also present in each individual country. The findings indicate that, although the exact relationships between variables may vary between countries, there are enough similarities to provide useful information about the impact of the COVID-19 pandemic in each of the countries included in the study