Universidad Tecnológica de Bolívar
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On the Convergence of the Milky Way and M31 Kinematics from Cosmological Simulations
No full textThe kinematics of the Milky Way (MW) and M31, the dominant galaxies in the Local Group (LG), can be used to estimate the LG total mass. New results on the M31 proper motion have recently been used to improve that estimate. Those results are based on kinematic priors that are sometimes guided and evaluated using cosmological N-body simulations. However, the kinematic properties of simulated LG analogs could be biased due to the effective power spectrum truncation induced by the small size of the parent simulation. Here we explore the dependence of LG kinematics on the simulation box size to argue that cosmological simulations need a box size on the order of 1 Gpc in order to claim convergence on the LG kinematic properties. Using a large enough simulation, we find M31 tangential and radial velocities relative to the MW to be in the range v tan = 105 − 59 + 94 km s − 1 and v rad = − 108 − 81 + 68 km s − 1 , respectively. This study highlights that LG kinematics derived from N-body simulations have to be carefully interpreted, taking into account the size of the parent simulation. © 2022. The Author(s). Published by the American Astronomical Society
Control de un convertidor DC-DC con puentes duales activos para adaptar niveles de tensión en microrredes de DC usando linealización por realimentación
No full textEn este trabajo, se propone una estrategia de control para un convertidor DC-DC con puentes duales activos que interconecta dos alimentadores de una microrred de DC. La estrategia de control propuesta, permite regular la tensión de salida del convertidor y asegurar que el valor medio de la corriente en el primario y el secundario del transformador de alta frecuencia sea nulo con el fin de evitar su saturación. El convertidor se modela usando la técnica de modelado promediado en espacio de estados generalizado y el controlador es diseñado mediante una estrategia de control no lineal basada en linealización por realimentación entrada-salida. El desempeño de la estrategia de control propuesta es validada mediante resultados de simulación
team UTB-NLP at finances 2023: financial targeted sentiment analysis using a phonestheme semantic approach
No full textSentiment analysis in the financial domain is a challenging task that plays a crucial role in understanding public opinion, monitoring market trends, and assessing the impact of news on economic agents. In this shared task, we address targeted sentiment analysis in the financial domain, focusing on identifying the main economic target in news headlines and determining the sentiment polarity towards such targets. We propose a methodology that combines transformer-based models and phonestheme embeddings to extract meaningful features from the text, which are then used in a support vector machine (SVM) classifier for sentiment classification. Our approach shows promising results, outperforming the baseline with an F1-score of 0.529229 in Task 1. This research contributes to financial sentiment analysis by addressing the complexity of financial language and considering multiple economic agents' perspectives.Universidad Tecnológica de Bolíva
Presidential preferences in Colombia through Sentiment Analysis
No full textThis work carries out the sentiment analysis of the social network Twitter regarding the presidential debate on May 23, where a hashtag was left open so viewers could give their points of view on these three candidates: Gustavo Petro, Federico Gutierrez, and Rodolfo Hernández. Once we extracted these Tweets contained in the hashtag, they were manually classified. They then went through all the pre-processing and elimination of special characters, links, URLs, images, or videos. Next, the TextVectorization layer from the TensorFlow library was used to convert these tweets to vectors and finally to go through the two models. The results show the best results for the BERT model with an accuracy of 76% and an F1 score of 85%
MAINTENANCE CENTERED ON EXERGY AND EXERGOECONOMIC INDICATORS OF A PREHEAT TRAIN OF A CRUDE OIL DISTILLATION UNIT
No full textEstablished or create new ones to plan the cleaning tasks of the heat exchangers. In this work, a maintenance strategy is developed for a preheating train under the Maintenance Centered on Energy Efficiency (MCEE) philosophy, where it is sought to integrate the information of the principles of the second law of thermodynamics with economic variables to use parameters. The modification of the maintenance justification parameter (J) is proposed, adding to the introduction of two new maintenance indicators (W and X). Each one seeks to evaluate an essential criterion for the maintenance area: economic viability, technical feasibility, and benefits. Towards the other exchangers in the network after cleaning a specific component. A criticality diagram and a criticality matrix are used. The heat exchangers are grouped into sub-assemblies, with the leading group consisting of the key heat exchangers (KHEX), the elements of which have a significant impact on the efficiency of the preheat train. For their part, the regions are composed of components whose performance is less considerable than that of the KHEX. In total, 34 maintenance activities will be carried out, distributed among the 25 interchanges of the network. The planning of a program of cleaning activities according to the maintenance strategy based on the philosophy of the MCEE establishes a substantial scientific contribution due to the almost null existence of exergetic studies applied to the management of maintenance tasks and focused mainly on the preheating of trains. Copyright © 2022 by ASME
Towards gender equality in engineering programs : A case study
No full textThe low participation of women in STEM fields is considered a critical issue in our society. We analyzed the student population by gender of the school of engineering at Universidad TecnolÓgica de Bolívar. We found that the share of female first-time students shows a decreasing trend since 2015 and was only 24% in 2020. Gender gaps are wider in electrical, electronic, systems, mechanic, and mechatronic engineering. We also observed that females have lower access to engineering programs, especially in the last three years. The effects of the COVID-19 pandemic have been observed as a reduction of the share of enrolled students vs applicants. In order to increase the participation of women in the programs with higher gender gaps, we developed several activities in 2020 specially designed for secondary students with the participation of female instructors as role models
Fortalecimiento de los proyectos de vida de los habitantes del corregimiento de Ñanguma, María la Baja (Bolívar) a través de una estrategia de comunicación para el cambio social
No full textEste proyecto de comunicación nació de la necesidad de contribuir al mejoramiento y fortalecimiento de los proyectos de vida de niños(a) y adolescentes del corregimiento de Ñanguma, ubicado en el municipio de María la Baja, a través de una estrategia de comunicación para el cambio socialla base de ejecución del proyecto fue capacitar y educar en diferentes aspectos de la comunicación a la comunidad Ñanguma, en especial a los niños y jóvenes, pero más adelante se fueron sumando algunos adultos interesados en las capacitaciones con otros intereses y acordes a otras necesidades del corregimiento de Ñanguma. Esto con el fin de que pensaran en la construcción autónoma para su proceso de formación en competencias para la vida laboral. Así mismo, lograr que los jóvenes establecieran un compromiso consigo mismos y con su comunidad, para lo cual desarrollamos una estrategia de comunicación, aplicada en diferentes fases.
Determination of the optimal range of the compressor inlet air temperature in a power plant with stig cycle through of advanced exergetic analysis
No full textConventional exergy analysis identifies the more inefficient components; however, this doesn’t regard interaction between components, neither real improvement potential to each component of the system, this information is providing for the advanced exergy analysis. In this paper was developed an advanced exergy analysis to determine the optimal range of the compressor inlet air temperature, to compensate the power loss in a power plant with Stig cycle and an air cooling system. This plant without cooling system at ISO conditions produce 52 MW, while in local conditions (32 °C, 80%RH) its productions decreases to 44.3MW. The results showed that for every degree centigrade that the air temperature decreases at inlet compressor the power output increases in 0.17 MW and total destroyed exergy increases 0.23 MW. It was determined that for the optimal range of compressor inlet air temperature is between 10 and 12°C; at this range were obtained the highest power output values, and the values of the avoidable and endogenous exergy destroyed are diminished in 0.28 MW and 0.20 MW respectively compared to those given in local operating conditions. Copyright © 2019 ASME
Analysis in circular economy research in Latin America: A bibliometric review
No full textCircular Economy (CE) plays a crucial role in Latin America, where the transition to new economic development models poses significant challenges. This study conducts a bibliometric analysis of CE research in the region to identify critical areas of development, influential authors, organizations, and future research trends. This analysis aims to highlight the progress made in the CE field in Latin America and identify areas for improvement to promote sustainable development. Using the Scopus database, we analyzed 632 research papers, and the rising number of CE publications in Latin America suggests a continuous growth trajectory, expected to reach over 2500 studies by 2026. The analysis reveals that Brazil leads CE research with 274 publications, Waste Management being the most studied topic. The study highlights the region's growing trend towards implementing innovative and sustainable solutions for waste management and resource utilization, such as bioengineering and biochemistry processes, which could positively impact the region's economy and environment. The findings of this study provide valuable insights for policymakers and researchers aiming to promote sustainable development in Latin America
Classification of Cognitive Evoked Potentials for ADHD Detection in Children using Recurrence Plots and CNNs
No full textAttention-deficit/hyperactivity disorder (ADHD) is a common childhood-onset condition characterized by difficulty paying attention and hyperactivity. The diagnosis of ADHD is made from psychological tests and electroencephalography (EEG). However, patient cooperation is necessary, which is a challenge with ADHD children. This work proposes a method for classification of ADHD and control cases from cognitive event-related potentials using recurrence plots and deep learning. A total of 44 children were included in this study (22 children with ADHD and 22 case controls). The signals were processed by a high-pass filter to eliminate DC components, wavelets transform with six decomposition levels, and synchronized averaging for each of the six channels (F3, AF3, F4, AF4, F7 and F8). Subsequently, the recurrence plot of each of the processed signals was obtained and used as inputs for two convolutional neural networks (CNN). The proposed models showed accuracies of 69.44% and 77,78%. © 2021 IEE