Repositorio Institucional Universidad EAFIT ::Examinando por Materia "Optimization"

Examinando por Materia "Optimization"

Mostrando 1 - 20 de 84

Accelerated Thermal Simulation for Three-Dimensional Interactive Optimization of Computer Numeric Control Sheet Metal Laser Cutting
(American Society of Mechanical Engineers (ASME), 2018-03-01) Mejia D.; Moreno A.; Arbelaiz A.; Posada J.; Ruiz-Salguero O.; Chopitea R.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Laboratorio CAD/CAM/CAE
In the context of computer numeric control (CNC)-based sheet metal laser cutting, the problem of heat transfer simulation is relevant for the optimization of CNC programs. Current physically based simulation tools use numeric or analytic algorithms which provide accurate but slow solutions due to the underlying mathematical description of the model. This paper presents: (1) an analytic solution to the laser heating problem of rectangular sheet metal for curved laser trajectories and convective cooling, (2) a graphics processing unit (GPU) implementation of the analytic solution for fast simulation of the problem, and (3) an integration within an interactive environment for the simulation of sheet metal CNC laser cutting. This analytic approach sacrifices the material removal effect of the laser cut in the favor of an approximated real-time temperature map on the sheet metal. The articulation of thermal, geometric, and graphic feedback in virtual manufacturing environments enables interactive redefinition of the CNC programs for better product quality, lower safety risks, material waste, and energy usage among others. The error with respect to finite element analysis (FEA) in temperature prediction descends as low as 3.5%. Copyright © 2018 by ASME.
¿Los activos de inversión con criterios ASG generan valor para el inversionista? evidencia a partir de ETF
(Universidad EAFIT, 2022) Hoyos, Jonathan Camilo; Restrepo Ochoa, Diana Constanza
An approach for printing the maximum possible number of images
(Institute of Industrial Engineers, 2017-01-01) Rojas-Santiago M.; Barbosa R.C.; Muthuswamy S.; Hulett M.; Velez-Gallego M.C.; Universidad EAFIT. Departamento de Ingeniería de Producción; Gestión de Producción y Logística
This paper considers a real life application of a printing process in a lithographic company that manufactures food packaging bags. The focus area of this problem is to print a variety of 2D images of bags on a surface area for maximum press layouts, with a constraint that the orientation of all bags is fixed and they should be placed parallel to the edges of the impression material. The problem under study is NP-hard and is an extension of the classical knapsack problem. An algorithm to maximize the number of rectangular images of bags that can be placed within the printing material is proposed. The results were compared with a Particle Swarm Optimization (PSO) metaheuristic. Several numerical experiments show that our procedure outperforms the PSO algorithm and improves the lithography's performance.
Assembly planning with automated retrieval of assembly sequences from CAD model information
(EMERALD GROUP PUBLISHING LIMITED, 2012-01-01) Vigano, Roberto; Osorio Gomez, Gilberto; Universidad EAFIT. Departamento de Ingeniería de Diseño; Ingeniería de Diseño (GRID)
Purpose - The purpose of this paper is to define an approach to extract the liaison graph from a 3D CAD model and analyze a method to find at least a feasible assembly sequence for the product. The method could be useful to search the optimal sequence of assembling for a product, by comparing different sequences extracted in automatic mode from a 3D CAD model. Design/methodology/ approach - The method proposed analyzes the liaison graph extracted, in order to obtain the possible assembly sequences for the product under study. The extraction of the sequences is based on some attributes and parameters of the graph. Findings - By means of the method proposed it is possible to obtain in automatic mode the liaison graph of an assembly 3D CAD model. Moreover, the study of the graph obtained allows the definition of all the assembly sequences for the product. Finally, it is possible to analyse the sequences found to select the optimal sequence. Research limitations/implications - The major limitation of the approach is, actually, the great number of impossible sequences that are extracted. For this, a little intervention by the user is required. Practical implications - The application of the method allows the manufacturer to analyze and study the optimal assembly sequence without the direct use of a CAD system. The approach could be used at the early stage of the design process and by means of the database of the PDM/PLM systems. Originality/value - The approach proposed in the paper is an original method to extract a liaison graph from a 3D CAD model. The approach to extract the assembly sequences was compared with other methods and good results have been obtained. © Emerald Group Publishing Limited.
The Box-Benkhen experimental design for the optimization of the electrocatalytic treatment of wastewaters with high concentrations of phenol and organic matter.
(IWA PUBLISHING, 2009-01-01) GilPavas, Edison; Betancourt, Alejandra; Angulo, Monica; Dobrosz-Gomez, Izabela; Angel Gomez-Garcia, Miguel; GilPavas, Edison; Betancourt, Alejandra; Angulo, Monica; Dobrosz-Gomez, Izabela; Angel Gomez-Garcia, Miguel; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
In this work, the Box-Benkhen experimental Design (BBD) was applied for the optimization of the parameters of the electrocatalytic degradation of wastewaters resulting from a phenolic resins industry placed in the suburbs of Medellin (Colombia). The direct and the oxidant assisted electro-oxidation experiments were carried out in a laboratory scale batch cell reactor, with monopolar configuration, and electrodes made of graphite (anode) and titanium (cathode). A multifactorial experimental design was proposed, including the following experimental variables: initial phenol concentration, conductivity, and pH. The direct electro-oxidation process allowed to reach ca. 88% of phenol degradation, 38% of mineralization (TOC), 52% of Chemical Oxygen Demand (COD) degradation, and an increase in water biodegradability of 13%. The synergetic effect of the electro-oxidation process and the respective oxidant agent (Fenton reactant, potassium permanganate, or sodium persulfate) let to a significant increase in the rate of the degradation process. At the optimized variables values, it was possible to reach ca. 99% of phenol degradation, 80% of TOC and 88% of COD degradation. A kinetic study was accomplished, which included the identification of the intermediate compounds generated during the oxidation process.
Centros de servicios compartidos como estrategia organizacional en áreas financieras
(Universidad EAFIT, 2020) Zúñiga Moreno, Adriana Milena; Hernández Vargas, Karen; Betancur Hurtado, Carlos Mario
Currently, the shared service centers are being a trend in our country, multinational companies have brought their operational processes in order to, standardize, generate efficiencies and above all, obtain cost savings. In our research, we reviewed the characterization of SCC and also analyzed how the financial function has become the most common to be implemented in them. Through surveys, we collect information to understand the perception of users of the financial area in SCC and thus, to identify positive and negative aspects of this organizational strategy.
Class Schedule Assignment Based on Students Learning Rhythms Using A Genetic Algorithm
(Universidad EAFIT, 2013-03-22) Suarez Chilma, Victor F.; Castrillón Gomez, Omar D.; Guerrero Aguirre, Álvaro; Universidad Nacional de Colombia
Combining LR and 2-opt for scheduling a single machine subject to job ready times and sequence dependent setup times
(Institute of Industrial Engineers, 2014-01-01) Rojas-Santiago, M.; Muthuswamy, S.; Vélez-Gallego, M.C.; Montoya-Torres, J.R.; Universidad EAFIT. Departamento de Ingeniería de Producción; Gestión de Producción y Logística
In this research, the job ready times and sequence-dependent setup times of a single machine scheduling problem are considered with the objective of makespan minimization. As the problem is NP-hard, a Lagrangean Relaxation (LR) approach is proposed to find an initial solution and a heuristic based on 2-opt was implemented to improve it. Extensive computational experiments showed that the proposed combination of LR and 2-opt is effective. Wide range of test problems from 25 to 75 jobs was studied. The performance of the proposed approach was compared with the results from a commercial solver.
Comparación de metodologías de optimización de carteras: Markowitz vs. Black-Litterman, para activos financieros colombianos
(Universidad EAFIT, 2016) Montoya Gil, Juan Miguel; Maya Bastidas, Carolina; Almonacid Hurtado, Paula María
Personas naturales y compañías financieras que manejan grandes volúmenes de capital, especialmente fondos de pensiones y aseguradoras, deben tener muy claro tanto el nivel de exposición al riesgo como la rentabilidad esperada de las carteras de activos financieros que conforman para cada uno de sus clientes desde antes de que estos inviertan -- El presente trabajo busca contribuir en este sentido presentando las diferencias y las principales ventajas y desventajas de utilizar los métodos Markowitz y Black-Litterman, para optimizar carteras con activos del mercado de capital colombiano -- Dicha comparación se lleva a cabo mediante el cálculo de la frontera eficiente para cada uno de los métodos -- Los resultados muestran que el método Black-Litterman se ajusta más a las necesidades de diversificación de un inversionista que transa con activos colombianos
Construcción de portafolios de inversión con las alternativas que ofrece el Fondo de Pensiones Voluntarias de la AFP Protección, como una herramienta para asesorar a sus afiliados
(Universidad EAFIT, 2016) Romero Ochoa, Edgar Sebastián; Torres Oke, Sebastián
En el presente trabajo de investigación, se aplica en un primer momento el modelo de Markowitz (1952), en lo referente a la optimización de portafolios de inversión, tomando como insumos las diferentes alternativas de inversión del fondo de pensiones voluntarias de Protección, con la intención de establecer carteras lo suficientemente diversificadas que permitan alcanzar el máximo nivel de rentabilidad disponible para los niveles de riesgo conservador, moderado o crecimiento (menor aversión al riesgo) -- Posteriormente, se realiza una propuesta para hacer más asertivo el cuestionario para identificar el nivel de aversión al riesgo de los inversionistas -- De esta forma, el trabajo pretende servir como una herramienta para mejorar la asesoría financiera realizada por los consultores financieros de esta empresa, teniendo en cuenta el nivel de aversión al riesgo de los afiliados, los rendimientos esperados y el horizonte de tiempo de las inversiones
Decolorization and mineralization of Diarylide Yellow 12 (PY12) by photo-Fenton process: the Response Surface Methodology as the optimization tool.
(IWA PUBLISHING, 2012-01-01) GilPavas, Edison; Dobrosz-Gomez, Izabela; Angel Gomez-Garcia, Miguel; GilPavas, Edison; Dobrosz-Gomez, Izabela; Angel Gomez-Garcia, Miguel; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
The Response Surface Methodology (RSM) was applied as a tool for the optimization of the operational conditions of the photo-degradation of highly concentrated PY12 wastewater, resulting from a textile industry located in the suburbs of Medellin (Colombia). The Box-Behnken experimental Design (BBD) was chosen for the purpose of response optimization. The photo-Fenton process was carried out in a laboratory-scale batch photo-reactor. A multifactorial experimental design was proposed, including the following variables: the initial dyestuff concentration, the H(2)O(2) and the Fe(+2) concentrations, as well as the UV wavelength radiation. The photo-Fenton process performed at the optimized conditions resulted in ca. 100% of dyestuff decolorization, 92% of COD and 82% of TOC degradation. A kinetic study was accomplished, including the identification of some intermediate compounds generated during the oxidation process. The water biodegradability reached a final DBO(5)/DQO = 0.86 value.
Degradación de Colorante Amarillo 12 de Aguas Residuales Industriales utilizando Hierro Cero Valente, Peróxido de Hidrógeno y Radiación Ultravioleta
(Centro de Informacion Tecnologica, 2016-01-01) Gilpavas, E.; Medina, J.; Dobrosz-Gómez, I.; Gómez, M.Á.; Gilpavas, E.; Medina, J.; Dobrosz-Gómez, I.; Gómez, M.Á.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
The Fenton heterogeneous process in a fluidized bed reactor using Zero Valent Iron (ZVI), in the metallic state, for the treatment of textile wastewater has been used an analyzed. The aim of this work was to optimize the following operating parameters: initial dye concentration, H2O2 concentration, pH, amount of ZVI, and UV radiation, for the removal of dye and organic matter. At first, a fractional factorial experimental design allows defining the most influential factors. After that, they were optimized using the Response Surface Methodology coupled to the Box-Behnken experimental design. The optimal conditions were found to be as follows: initial dye concentration, 881 mg/L; pH 5; ZVI concentration, 5,31 g/L; H2O2 concentration, 0,86 mL/L. At these conditions, the degradation kinetics was performed, reaching 100% and 80,83% of dye and chemical oxygen demand respectively, in 150 minutes of reaction.
Degradación y mineralización de tartrazina mediante electrooxidación. Optimización de las condiciones de operación
(Centro de Informacion Tecnologica, 2014-01-01) Gilpavas, E.; Dobrosz-Gómez, I.; Gómez-García, M.Á.; Gilpavas, E.; Dobrosz-Gómez, I.; Gómez-García, M.Á.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
In this work, the operational conditions of the tartrazine electro-oxidation (EO) process were optimized. The batch reactor used has two electrodes: one made of diamond doped with boron and the other one of titanium, working at monopolar configuration. The initial dyestuff concentration (Ci), the current density (i) and the pH were defined as the main factors affecting the EO. Their optimal values were found as follows: Ci=30 ppm, i=5mA/cm2 and pH=6.0. At these conditions, a kinetic analysis was performed in the terms of: the percentage of the dyestuff decolorization (%DC), the percentage of the chemical oxygen demand (%DCOD), and the percentage of the total organic carbon (%TOC). Additionally, the effect of Fe2+ (electro- Fenton process, EF) and Fe2+/UV radiation (electro-photo-Fenton process, EFF) on the studied process were evaluated. The work demonstrates the validity of the hypothesis about the most significant parameters that affect the EO process.
Design and construction of a transducer for bite force registration.
(ELSEVIER SCI LTD, 2009-05-29) Isaza JF; Throckmorton GS; Roldán SI; Universidad EAFIT. Departamento de Ingeniería Mecánica; Bioingeniería GIB (CES – EAFIT)
This study describes the development of a system for quantification of human biting forces by (1) determining the mechanical properties of an epoxy resin reinforced with carbon fiber, (2) establishing the transducer's optimal dimensions to accommodate teeth of various widths while minimizing transducer thickness, and (3) determining the optimal location of strain gages using a series of mechanical resistance and finite element (FE) analyses. The optimal strain gage location was defined as the position that produced the least difference in strain pattern when the load was applied by teeth with two different surface areas. The result is a 7.3-mm-thick transducer with a maximum load capacity beyond any expected maximum bite force (1500N). This system includes a graphic interface that easily allows acquisition and registration of bite force by any health-sciences or engineering professional.
Design and construction of a transducer for bite force registration.
(ELSEVIER SCI LTD, 2009-05-29) Isaza JF; Throckmorton GS; Roldán SI; Universidad EAFIT. Departamento de Ingeniería de Diseño; Ingeniería de Diseño (GRID)
This study describes the development of a system for quantification of human biting forces by (1) determining the mechanical properties of an epoxy resin reinforced with carbon fiber, (2) establishing the transducer's optimal dimensions to accommodate teeth of various widths while minimizing transducer thickness, and (3) determining the optimal location of strain gages using a series of mechanical resistance and finite element (FE) analyses. The optimal strain gage location was defined as the position that produced the least difference in strain pattern when the load was applied by teeth with two different surface areas. The result is a 7.3-mm-thick transducer with a maximum load capacity beyond any expected maximum bite force (1500N). This system includes a graphic interface that easily allows acquisition and registration of bite force by any health-sciences or engineering professional.
Diseño de un modelo de mejora para la reducción de tiempo en la ejecución de proyectos en la compañía Dell Technologies
(Universidad EAFIT, 2024) Arias Linares, Jhon Alexander; Marciales Camacho, Harold Andrés; Gómez Salazar, Elkin Arcesio
Diseño de una cartera de inversión eficiente administrada por el fondo del “Giving Day” de la Universidad EAFIT para generar un impacto positivo en el acceso a la educación superior y el bienestar estudiantil
(Universidad EAFIT, 2023) Hernández Mora, María Camila; Londoño Agudelo, Simón; Luján Jaramillo, Alejandra María
Dynamic server allocation in virtual environments, using quadtrees for dynamic space partition
(2003-01-01) Restrepo, A.; Montoya, A.; Trefftz, H.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
In actual applications of virtual environments, one of the problems that has received attention is the way to assign computational resources to those who participate in the system. In most cases, static resource allocation is used. Static allocation is simple but has several limitations, among them, the missutilization of resources. In this paper we present a proof-of-concept of a new system and report the results of experiments with a system that accomplishes dynamic resource allocation by using Quadtrees for space partitioning, in a Shared Virtual Environment.
Economic Dispatch in Microgrids with Renewable Energy Using Interior Point Algorithm and Lineal Constrainst
(Universidad EAFIT, 2017-04-24) Arango, Dario; Urrego, Ricardo; Rivera, Sergio; Universidad Nacional de Colombia
Electrochemical Degradation of Acid Yellow 23 by Anodic OxidationOptimization of Operating Parameters
(American Society of Civil Engineers (ASCE), 2016-11-01) GilPavas, Edison; Dobrosz-Gomez, Izabela; Angel Gomez-Garcia, Miguel; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
In this study, the electrochemical oxidation (EO) process was implemented and optimized to effectively decolorize and degrade wastewater containing Acid Yellow 23 (Y23). The experiments were carried out in a laboratory-scale batch cell reactor, with monopolar configuration of electrodes, made of graphite (anode) and titanium (cathode). The response surface methodology (RSM), coupled with Box-Behnken experimental design (BBD), was used to evaluate the single and interactive effects of different variables of the EO process on (1)degradation percentages of both chemical oxygen demand (%DCOD) and color (%DC) and (2)energy consumption (EC). Thus, the following experimental factors were considered: initial dye concentration (40-100mg/L), current density (10-20mA/cm2), and conductivity (1,000-4,000S/cm). Thus, the subsequent conditions were found to be optimal for decolorization and degradation of Y23: initial dye concentration = 100mg/L; current density = 20mA/cm2; and conductivity = 4,000S/cm. At these conditions, the EO process allowed to reach approximately 99% of color degradation and 76% of COD degradation. Because NaCl was used as an electrolyte, chorine formation was monitored, and its effect on %DC and %DCOD was also evaluated.

Examinando por Materia "Optimization"

Resultados por página

Opciones de ordenación