Universidad Tecnológica de Bolívar

About: Universidad Tecnológica de Bolívar is a education organization based out in Cartagena, Colombia. It is known for research contribution in the topics: AC power & Computer science. The organization has 507 authors who have published 724 publications receiving 3900 citations. The organization is also known as: UTB & Utb.

Análisis Multivariado y Aprendizaje Automático en la evaluación y pronóstico de los perfiles financieros en el sector de Telecomunicaciones en Colombia

Abstract: En esta investigacion se desarrolla un metodo apoyado en las tecnicas de Aprendizaje automatico para evaluar y pronosticar perfiles financieros en el sector de Telecomunicaciones en Colombia. Lo anterior soportado en elementos conceptuales relacionados con el Analisis multivariado y herramientas de Aprendizaje automatico. Para lo anterior, se utilizo informacion relacionada con los rublos financieros de 75 empresas, informacion que sirvio para calcular indicadores financieros y de productividad. Seguidamente se aplico la tecnica de analisis de conglomerados que permitio identificar y clasificar las empresas en tres grupos caracteristicos del sector lograndose un nivel de homogeneidad de 0,,527 y heterogeneidad de 1,358. A partir de lo anterior se aplico el algoritmo GLMNET asociado a las tecnicas de Aprendizaje automatico, lograndose un modelo que predice de manera correcta la pertenencia a los grupos identificados con un 98% de precision. En general se valora el metodo que integra el analisis de conglomerados y el algoritmo de GLMNET para evaluar y pronosticar perfiles financieros y de productividad en el sector de telecomunicaciones en Colombia.

Performance Benchmarking of Stochastic and Deterministic Representation Bases with Compressive Sensing in Computerized Tomography Images

Abstract: Computerized tomography is a procedure that emits X-rays rotating around the body, projecting signals to be processed and converted to images. X-rays radiation in people may cause cardiovascular diseases, malformations in prenatal babies, and increasing the development of cancer cells. The tomography device has coded-aperture to block some X-rays and it uses recovery computational techniques to getting a tomographic image from less radiation. One useful technique for such reconstruction is compressive sensing, which can recovery images from sparse signals. Usually, the sparsity of the images is obtained through transforming it into some basis matrix. This work compares from computational models the performance of two representation bases: one deterministic and one stochastic. The tomography images dataset was represented in every one of the bases and compressive sensing was applied to decreasing the information contained in each image. Then we apply the GPSR algorithm to reconstruction. Results showed that: both representation bases combined with compressive sensing reduce the samples number of the image available for its reconstruction without significantly affecting its quality. Also, the stochastic base presented a better performance concerning the Peak Signal to Noise Ratio (PSNR), this is 4.815% higher than the deterministic counterpart. On the other hand, it was identified that the image reconstruction is possible from 50 % or higher of the compression, i.e., the minimal samples percentage required for reconstruction is 50 %. We conclude that the stochastic base outperforms the deterministic equivalent mainly regarding quality image reconstructed while the differences considering the computational time and samples nurmber are not significantly,

Diseño del chasis de un vehículo eléctrico autónomo para la ciudad de Cartagena de Indias (SETA-tren del Caribe) usando elementos finitos y la técnica de Shell

Abstract: This document contains the chassis design for an autonomous electric vehicle. First, a fatigue failure analysis should be done to the underside of the chassis under fluctuating loads. Subsequently, the methodology of the shell technique or plate technique is applied to make the structural analysis by finite elements of the complete structure. The results show a satisfactory design that meets all the criteria used.

A MLPG Formulation for Stress Analysis in Bi-dimensional Elastic Bodies

Abstract: In this work, a meshfree method known as Meshless Local Petrov-Galerkin was implemented in a bidimensional linear elasticity problem. Bidimensional MLS shape functions were used in the polynomial approximation of the displacement and stress fields. The numerical integration was carried out by the Gauss-Legendre scheme and the quadrature points were located using the cartesian coordinate system. The local integration domain and the influence domain had circular shapes. A comparison with the analytical solutions of a plate with a circular hole subjected to traction was done. Numerical results showed a good agreement in the displacement and stress fields. Some schemes for improving the accuracy of the solutions were proposed.

Are There Differences in the Academic Performance between Men and Women in Colombia?: A Regional Analysis

Abstract: This paper aims to explore the gender gap in the academic performance in the secondary school in the Colombian regions using data from the SABER-11 2009, a test administered by the ICFES. This data has been analyzed using mean differences and through the student’s quantile regressions, focusing on the math and language components. This analysis shows that men obtain a better performance on the math component than women but this result is not homogenous in the country. Central-Eastern part of the country exhibit the wider differences. Solely in the Caribbean and Pacific region there were women having better performance in language.