Latin American Journal of Computing
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Estimation of parameters and state variables in an alcoholic fermentation process in a fed-batch bioreactor
Get PDFEnergy consumption in the world is based on two types of sources: fossil fuels and renewable energy. In this case, bioethanol presents itself as an alternative resource to fossil fuels, whose production can occur through specific processes called alcoholic fermentation. In parallel, the growing demand for energy has motivated scientists to develop even more efficient systems and technologies. In this work, mathematical modeling and simulation was performed to represent the kinetics of alcoholic fermentation in a fed-batch bioreactor. The modeling was developed taking into account the microbial inhibition caused by the presence of excess substrate and product through the Tosetto and Hoppe-Hansford models. In the simulation, Bayesian statistics was used as a tool to estimate the kinetic parameters and the state variables of the bioprocess. The estimates were obtained through the use of a particle filter proposed by Liu and West, with 500 particles and experimental measurements from the literature, whose approach presented 99% accuracy and proved to be effective for describing alcoholic fermentation
El Sistema de Gestión de Energía para Edificios Inteligentes utilizando Generación Distribuida: C.B.P
No full textThis paper presents an energy management system for Smart Buildings (SB) using Distributed Generation (DG). The proposal allows reducing the excessive energy consumption of lighting, air conditioning and computing systems at the campus of the administrative building at the University PUCESE. We employ a control system based on the raspberry microcomputer, which allows establishing the working conditions autonomously. The system defines a control algorithm based on different scenarios, where the energy rules for each of the building\u27s services are determined. As a result, there is a 50 % reduction in energy consumption for each of the systems, evidencing a reduction in the energy bill and in the ecological footprint of the building.En este trabajo se presenta un sistema de gestión de energía para Edificios Inteligentes (EI) utilizando Generación Distribuida (GD). La propuesta permite reducir el consumo excesivo de energía que tienen los sistemas de iluminación, climatización y computación en el campus del edificio administrativo de la Universidad PUCESE. Se utiliza un sistema de control basado en el microcomputador raspberry, el cual permite establecer las condiciones de trabajo de manera autónoma. El sistema define un algoritmo de control basado en diferentes escenarios donde se determinan las reglas de energía para cada uno de los servicios del edificio. Como resultado, se reduce el consumo energético en un 50 % para cada uno de los sistemas, evidenciando una reducción en el pliego tarifario, y en la huella ecológica del edificio
Desarrollo de middleware para interconección de una aplicación móvil con un sistema heredado
Get PDFThe modernization of legacy systems is a complex process due to the limitations that they can present when facing of new trends and technologies. Systems such as the “Control Gerencial/Web” (CG/Web) software of the Ecuadorian company “Información Tecnológica del Ecuador S.A.” (“I.T. del Ecuador”) exemplify these challenges. The system architecture, source code, data management and possible bad practices applied are some aspects that engineers must consider when implementing updates of these systems. We develop the CGApp mobile application as a solution to the mobility needs of managerial users of the CG/Web system. However, the development was conditioned by the monolithic architecture of the legacy system, requiring the design and implementation of a middleware as a means of interaction between the mobile component and the elements of the CG/Web. Therefore, we need to perform a legacy system reengineering process, developing methods for data translation, applying security controls and redesigning screens to adapt them to a mobile environment. As a result, it was possible to integrate the mobile application with the legacy system, adding value to the project.El proceso de modernizar un sistema heredado puede llegar a ser complejo debido a limitaciones presentadas frente a las nuevas tendencias y tecnologías. La arquitectura de un sistema, su código fuente, la gestión de datos y la aplicación de malas prácticas son aspectos que los ingenieros deben considerar al implementar actualizaciones sobre estos sistemas. Sistemas como el Control Gerencial/Web (CG/Web) de la empresa ecuatoriana Información Tecnológica del Ecuador S.A. (I.T. del Ecuador) ejemplifican estos retos. Se propuso el desarrollo de la aplicación móvil CGApp como solución a las necesidades de movilidad de los usuarios gerenciales. Sin embargo, su desarrollo fue condicionado por la arquitectura monolítica del sistema heredado, siendo necesario el desarrollo e implementación de un middleware como medio para la interacción entre el componente móvil y los elementos del sistema CG/Web. Por esto, fue necesario aplicar un proceso de reingeniería con base en el sistema heredado, desarrollar métodos para la traducción de datos, aplicar controles de seguridad y rediseñar las pantallas para adaptarlas a un entorno móvil. De esta forma se consiguió integrar la aplicación móvil con el sistema heredado, agregando valor al proyecto.  
The Stiffness Phenomena for the Epidemiological SIR Model: a Numerical Approach
Get PDFMathematical models are among the most successful strategies for predicting the dynamics of a disease spreading in a population. Among them, the so-called compartmental models, where the total population is proportionally divided into compartments, are widely used. The SIR model (Susceptible-Infected-Recovered) is one of them, where the dynamics between the compartments follows a system of nonlinear differential equations. As a result of the non-linearity of the SIR dynamics, it has no analytical solution. Therefore, some numerical methods must be used to obtain an approximate solution. In this contribution, we present simulated scenarios for the SIR model showing its stiffness, a phenomenon that implies the necessity of a small step size choice in the numerical approximation. The numerical results, in particular, show that the stiffness phenomenon increases with higher transmission rates and lower birth and mortality rates . We compare the numerical solutions and errors for the SIR model using explicit Euler, Runge Kutta, and the semi-implicit Rosenbrock methods and analyze the numerical implications of the stiffness on them. As a result, we conclude that any accurate numerical solution of the SIR model will depend on an appropriately chosen numerical method and the time step, in terms of the values of the parameters
A Fractional SIRC Model For The Spread Of Diseases In Two Interacting Populations: Fractional SIRC models in two interacting populations
Get PDFIn this contribution we address the following question: what is the behavior of a disease spreading between two distinct populations that interact, under the premise that both populations have only partial immunity to circulating stains of the disease? Our approach consists of proposing and analyzing a multi-fractional Susceptible (S), Infected (I), Recovered (R) and Cross-immune (C) compartmental model, assuming that the dynamics between the compartments of the same population is governed by a fractional derivative, while the interaction between distinct populations is characterized by the proportion of interaction between susceptible and infected individuals of both populations. We prove the well-posedness of the proposed dynamics, which is complemented with simulated scenarios showing the effects of fractional order derivatives (memory) on the dynamics
Editorial
Get PDFA recognized statement states that change is the only constant in life. Societies, organizations, and people evolve, change, to adapt or anticipate the challenges of their environments. These changes in turn engender new changes, which causes these evolutions to accelerate. To the point at which, the advances that are taking place today have never been so massive or of such magnitude.
It is within this framework that, starting with this issue, I have the pleasure of once again collaborating as co-editor of the Latin American Journal of Computing. I was fortunate to work, until three years ago, under the direction of Jenny Torres Olmedo, PhD., when she was editor-in-chief. And now I have the honor of supporting Denys Flores Arnas, PhD., and his team in this scientific dissemination challenge. The entire team of the journal has worked very hard to bring you this issue, and we have several initiatives that will be implemented in future issues and of which we will have news very soon.
The articles selected for this issue gather interesting contributions from the different fields of computing. Thus, José Sillagana, Daniel Morocho-Lara, Génesis Dayana Pinto and Yennifer Bustos Gamboa present a mixed experimental study focused on the contribution of gamification in the learning of Mathematics in basic education. In their work, these authors report the contributions of the development of web 3.0 authoring resources for Canvas, Liveworksheet and Nearpood.
Luis Pineda, Bayron S. Gutiérrez, Marcos Orellana Cordero and Jorge Luis Zambrano-Martínez present their results on the implementation of layered encryption methods through distributed systems using SOAP. Their work allows to increase the security of the data that is sent from an origin to its destination with a minimum consumption of computational resources in the system.
In their article, Cristhian H. Bastidas Paz and Héctor F. Chinchero Villacís present an energy management system for intelligent buildings using distributed generation. For this, the authors use a control system based on a microcomputer, which defines a control algorithm based on different scenarios where the energy rules for each of the building services are determined. As a result, reductions of about 50% in energy consumption are reported.
Carlos A. Aguirre and Carlos E. Anchundia report the results of the development of a middleware for the interconnection of a mobile application with a legacy system. To do this, the authors worked on a reengineering process for the legacy system, developed methods for data translation, applied security controls, and redesigned user interfaces to adapt them to a mobile environment.
The work of Brian Jordano Cagua Gómez, Julia Edith Pilatasig Caizaguano and Roberto Rodrigo Aguiar Falconí focuses on contributing, through static nonlinear analysis, a method for the evaluation of steel frames. New functionalities of the system for seismic-structural analysis CEINCI LAB are presented.
Sergio Jiménez and Andrés Merino present the application of machine learning models based on CRISP-DM to analyze the levels of depression in students at an Ecuadorian university. The authors conducted a study with 302 students consisting of the Beck Depression Inventory II. From their work, a model with 0.59 accuracy was obtained and it was verified that the variables of gender, age and interpersonal relationships are the most significant when determining the severity of depression.
We hope these articles will be an interesting contribution for our readers. We invite all our audience to continue sending with their contributions. We keep the door open for any concerns and contacts with us and with the authors of the contributions presented in this issue.Un enunciado ampliamente reconocido establece que lo único que es constante en el mundo es el cambio. Las sociedades, organizaciones y personas evolucionan, cambian, para adaptarse o adelantarse a los desafíos de sus entornos. Estos cambios a su vez engendran nuevos cambios, lo que hace que estas evoluciones se aceleren. Al punto en el cual, los avances que se producen en la actualidad nunca han sido tan masivos ni de tal envergadura.
Es en este marco que, desde este número, tengo el gusto de volver a colaborar como co-editor del Latin American Journal of Computing. Tuve la suerte de trabajar, hasta hace tres años, bajo la dirección de Jenny Torres Olmedo, PhD., cuando ella era editora en jefe. Y ahora tengo el honor de apoyar a Denys Flores Arnas, PhD., y a su equipo en este desafío de difusión científica. Todo el equipo de la revista ha trabajo muy fuerte para poder traer el presente número, y tenemos varias iniciativas que se implementarán en futuros números y de las cuales les tendremos noticias muy pronto.
Los artículos seleccionados para el presente número reúnen contribuciones interesantes de los diferentes campos de la computación. Así, José Sillagana, Daniel Morocho-Lara, Génesis Dayana Pinto y Yennifer Bustos Gamboa nos presentan un estudio mixto experimental enfocado en el aporte de la Gamificación en el aprendizaje de Matemática en educación básica. En su trabajo, estos autores reportan los aportes del desarrollo de recursos de autor de la web 3.0 en las aplicaciones Canvas, Liveworksheet y Nearpood.
Luis Pineda, Bayron S. Gutiérrez, Marcos Orellana Cordero y Jorge Luis Zambrano-Martínez presentan sus resultados de la implementación de métodos de cifrado en capas a través de sistemas distribuidos mediante SOAP. Su trabajo permite incrementar la seguridad de los datos que son enviados de un origen hacia su destino con un consumo de recursos computacionales mínimo en el sistema.
En su artículo, Cristhian H. Bastidas Paz y Héctor F. Chinchero Villacís presentan un Sistema de Gestión de Energía para Edificios Inteligentes utilizando Generación Distribuida. Para ello, los autores utilizan un sistema de control basado en un microcomputador raspberry, el cual define un algoritmo de control basado en diferentes escenarios donde se determinan las reglas de energía para cada uno de los servicios del edificio. Como resultado, se reportan reducciones de consumo energético en un 50 %.
Carlos A. Aguirre y Carlos E. Anchundia reportan los resultados del desarrollo de un middleware para la interconección de una aplicación móvil con un sistema heredado. Para ello los autores trabajaron en un proceso de reingeniería con base en el sistema heredado, desarrollaron métodos para la traducción de datos, aplicaron controles de seguridad y rediseñaron las pantallas para adaptarlas a un entorno móvil.
El trabajo de Brian Jordano Cagua Gómez, Julia Edith Pilatasig Caizaguano y Roberto Rodrigo Aguiar Falconí se enfoca en contribuir, mediante análisis no lineal estático, con un método para la evaluación de pórticos de acero. Se presentan nuevas funcionalidades del sistema para el análisis sísmico-estructural CEINCI LAB.
Sergio Jiménez y Andrés Merino presenta la aplicación de modelos de aprendizaje automático basados en CRISP-DM para analizar niveles de depresión en los estudiantes de una universidad ecuatoriana. Los autores realizaron un estudio con 302 estudiantes constituida por el Inventario de Depresión de Beck II. Del trabajo se obtuvo un modelo con 0.59 de exactitud y se verificó que las variables de género, edad y relaciones interpersonales son las más significativas al determinar la severidad de depresión.
Esperamos que estos artículos sean un aporte interesante para nuestros lectores. Invitamos a toda nuestra audiencia a seguir contribuyendo con sus aportes. Mantenemos la puerta abierta para toda inquietud y contacto con nosotros y con los autores de las contribuciones presentadas en este número
Implementation of the SWASH model into HIDRALERTA system
Get PDFEarly warning systems are an important tool for local authorities to detect emergency situations in advance and initiate the necessary safety measure. The To-SEAlert project has the aim of increasing the efficiency, robustness and reliability of the HIDRALERTA early warning system. This study shows a first intent to implement the SWASH model to simulate wave overtopping for the Ericeira prototype. SWASH was implemented for one breakwater profile used to simulate the overtopping discharge and evaluate the associated risk levels. It was compared to the current approach used in HIDRALERTA, which resorts to a neural network trained with a physical modelling database, NN_OVERTOPPING2. Finally, both approaches were compared with previously analyzed video images of the breakwater. The results showed that SWASH generally overestimates overtopping and is not in good agreement with the video images. NN_OVERTOPPING2 has a better agreement with the video images. A possible reason for the overestimation might be the wave direction, which cannot be included in one-dimensional simulations in SWASH
Encripción de Texto a través de Sistemas Distribuidos
Get PDFIn recent years, the exponential growth of interconnections between digital devices has led to a significant increase in cyberattack incidents, often leading to severe and disastrous consequences for an organization by exploiting existing vulne rabilities in emerging technologies. One of the most innovative and effective defense mechanisms is cryptography, considered an essential requirement in the cybersecurity community for data protection. In this paper, we implement encryption methods executed on each machine in a distributed manner through the Simple Object Access Protocol (SOAP) web service for the data that want to be protected. To achieve it, a distributed system was created with virtual machines that host encryption methods such as AES-256, Caesar, and Blowfish, to send encrypted data from a source machine to a destination machine and, in turn, decrypt the encrypted data. The results obtained were excellent because our proposal adds more security to the data, performing it difficult for attackers to obtain the data quickly. In addition, the consumption of computational resources for executing the algorithms in the distributed system is minimal, which is adequate to guarantee its use in any computer with limited resources.En los últimos años, el crecimiento exponencial de las interconexiones entre dispositivos digitales ha provocado un auge significativo de los incidentes de ciberataques. Esto conllevan a consecuencias desastrosas y graves para una organización, mediante la explotación de vulnerabilidades existentes en tecnologías emergentes. Uno de los mecanismos de defensa más innovadores y efectivos en la actualidad es la criptografía, que se considera un requisito esencial en la comunidad de ciberseguridad para la protección de datos. En este trabajo, implementamos métodos de cifrado que se ejecutan independientemente en cada máquina de manera distribuida a través del servicio web denominado protocolo de acceso a objetos simples (SOAP), a los datos que se quieren proteger. Para llevarlo a cabo, se creó un escenario experimental mediante un sistema distribuido con máquinas virtuales que albergan los métodos de cifrado como AES- 256, Cesar, Blowfish, para enviar datos encriptados desde una máquina origen hacia una máquina destino, y a su vez descifrar los datos encriptados. Los resultados obtenidos fueron excelentes debido a que nuestra propuesta agrega más seguridad a los datos que son enviados de un origen hacia su destino, dificultando que el atacante obtenga los datos fácilmente. Además, el consumo de recursos computacionales para la ejecución de los algoritmos en el sistema distribuido es mínimo lo cual es adecuado para garantizar su uso en cualquier computador con muy pocos recursos
Análisis Estático No Lineal de Pórticos de Acero empleando OpenSees y CEINCI LAB
Get PDFStatic nonlinear analysis, called Pushover, is focused on the application of incremental lateral forces to a structure to visualize its probable performance under seismic actions; this is important in countries such as Ecuador, where there is high seismicity. This paper describes the new CEINCI LAB functions for Pushover analysis of steel frames. The CEINCI LAB Computational System is a collection of functions for the seismic-structural analysis. Since 2019, functions have been developed to facilitate data input and presentation of results about non-linear analysis of structures using OpenSees. Our motivation is to present new functions that allow us obtaining animations of the analysis, and to appreciate the level of damage in the structural elements by means of a color code, facilitating the interpretation of the results. Besides, these functions generate an editable file with information on the structural model, type of analysis, results, and other parameters of interest that can be modified on demand. The modeling procedure is illustrated with emphasis on the developed computational functions and their functionality.El análisis no lineal estático, denominado Pushover, consiste en la aplicación de fuerzas laterales incrementales a una estructura para visualizar su probable desempeño ante acciones sísmicas, esto es importante en países como Ecuador donde se tiene una alta sismicidad. En este artículo, se describen las nuevas funciones de CEINCI LAB para el análisis Pushover de pórticos de acero. El Sistema Computacional CEINCI LAB es una colección de funciones para el análisis sísmico-estructural. Desde el año 2019, se han desarrollado funciones para facilitar el ingreso de datos y la presentación de resultados en los análisis no lineales de estructuras empleando OpenSees. Nuestra motivación es presentar nuevas funciones que permitan obtener animaciones del análisis y apreciar el nivel de daño en los elementos estructurales mediante un código de colores, facilitando la interpretación de los resultados. Además, mediante estas funciones se genera un archivo editable con la información del modelo estructural, tipo de análisis, resultados y otros parámetros de interés que pueden ser modificados bajo demanda. Se ilustra el procedimiento de modelado, con énfasis en las funciones computacionales desarrolladas y su funcionalida
Analysis of U-Net Neural Network Training Parameters for Tomographic Images Segmentation
Get PDFImage segmentation is one of the main resources in computer vision. Nowadays, this procedure can be made with high precision using Deep Learning, and this fact is important to applications of several research areas including medical image analysis. Image segmentation is currently applied to find tumors, bone defects and other elements that are crucial to achieve accurate diagnoses. The objective of the present work is to verify the influence of parameters variation on U-Net, a Deep Convolutional Neural Network with Deep Learning for biomedical image segmentation. The dataset was obtained from Kaggle website (www.kaggle.com) and contains 267 volumes of lung computed tomography scans, which are composed of the 2D images and their respective masks (ground truth). The dataset was subdivided in 80% of the volumes for training and 20% for testing. The results were evaluated using the Dice Similarity Coefficient as metric and the value 84% was the mean obtained for the testing set, applying the best parameters considered