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2D simulation pipeline implementing the Lattice-Boltzmann method
(TRANS TECH PUBLICATIONS LTD, 2013-09-01) Gomez, Rodrigo Orlando; Gomez, Rodrigo Orlando; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
3D Collaborative Virtual Environment for Real-Time GUI Sketching
(2011-07-01) Trefftz, Helmuth; Trefftz, Helmuth; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
A Debugging Scheme of Functional Logic Programs
(Elsevier BV, 2002-01-01) Correa, Francisco Jose; Universidad EAFIT. Departamento de Ciencias; Lógica y Computación
A FIRST-ORDER TIME CONSTANT ESTIMATION FOR NONLINEAR DIFFUSION PROBLEMS
(TAYLOR & FRANCIS INC, 2014-06-03) Simon, Laurent; Ospina, Juan; Universidad EAFIT. Departamento de Ciencias; Lógica y Computación
A Laplace transform-based procedure was proposed to calculate the effective time constant for a class of nonlinear diffusion problems. The governing mathematical representation was first estimated with a linear model by omitting the nonlinear term. The solution to this problem was later introduced into the original equation, which was solved with Laplace transforms, resulting in a first-order approximation of the real system's behavior. A time constant was calculated using frequency-domain expressions. Two case studies were considered to illustrate the methodology. As the rate of heat supplied to a rod is raised, the speed at which the temperature reached an equilibrium value decreased. Increasing the maximum velocity in reaction-diffusion transport by a factor of three lowered the time constant by only 1.7%. The applications of this method range from biosensor dynamics to process control. © 2014 Copyright Taylor and Francis Group, LLC.
A three-dimensional semi-analytical solution for predicting drug release through the orifice of a spherical device
(ELSEVIER SCIENCE BV, 2016-07-25) Simon, L.; Ospina, J.; Universidad EAFIT. Departamento de Ciencias; Lógica y Computación
Three-dimensional solute transport was investigated for a spherical device with a release hole. The governing equation was derived using the Fick's second law. A mixed Neumann-Dirichlet condition was imposed at the boundary to represent diffusion through a small region on the surface of the device. The cumulative percentage of drug released was calculated in the Laplace domain and represented by the first term of an infinite series of Legendre and modified Bessel functions of the first kind. Application of the Zakian algorithm yielded the time-domain closed-form expression. The first-order solution closely matched a numerical solution generated by Mathematica (R). The proposed method allowed computation of the characteristic time. A larger surface pore resulted in a smaller effective time constant. The agreement between the numerical solution and the semi-analytical method improved noticeably as the size of the orifice increased. It took four time constants for the device to release approximately ninety-eight of its drug content. © 2016 Elsevier B.V. All rights reserved.
Adaptive learning objects in the context of eco-connectivist communities using learning analytics
(Elsevier BV, 2019-11-01) Diego, Mosquera; Carlos, Guevara; Jose, Aguilar; Diego, Mosquera; Carlos, Guevara; Jose, Aguilar; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
Eco-connectivist communities are groups of individuals with similar characteristics, which emerge in a connectivist learning process within a knowledge ecology. ARMAGAeco-c is a reflexive and autonomic middleware for the management and optimization of eco-connectivist knowledge ecologies using description, prediction and prescription models. Adaptive Learning Objects are autonomic components that seek to personalize Learning Objects according to certain contextual information, such as learning styles of the learner's, technological restrictions, among other aspects. MALO is a system that allows the management of Adaptive Learning Objects. One of the main challenges of the connectivist learning process is the adaptation of the educational context to the student needs. One of them is the learning objects. For this reason, this work has two objectives, specifying a data analytics task to determine the learning style of a student in an eco-connectivist community and, adapting instances of Adaptive Learning Objects using the learning styles of the students in the communities. We use graph theory to identify the referential member of each eco-connectivist community, and a learning paradigm detection algorithm to identify the set of activities, strategies, and tools that Adaptive Learning Objects instances should have, according to the learning style of the referential member. To test our approach, a case study is presented, which demonstrates the validity of our approach.
Adaptive System for the Generation of Emerging Behaviors in Serious Emerging Games
(Instituto Politecnico Nacional, 2020-01-01) Aguilar, Jose; Altamiranda, Junior; Diaz, Francisco; Aguilar, Jose; Altamiranda, Junior; Diaz, Francisco; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
A video game adaptation system (SAV) for serious emergent games (JSE), allows emergent behaviors in the game, such as the appearance of environments, events, narratives and characters, among others, in order to adapt to the context in the one that is developing. In previous articles the architecture of a JSE engine has been proposed. Furthermore, a first subsystem has been proposed that allows the emergence of a JSE according to the objectives of the environment, based on the ant colony optimization algorithm (ACO). In the present work, the second component of said architecture is specified, the SAV, which allows its dynamic adaptation (during the JSE). The SAV is made up of the sub-layers of strategies, sequences and properties, which manage each of these types of possible emergencies in a JSE, with the intention of dynamically adapting it to the context-domain where the game is being played. Furthermore, in this work the behavior of these sublayers is analyzed in a specific case study, showing very encouraging results of SAV in the educational context of an intelligent classroom (SaCI).
Adequation of a Virtual Immersive Environment for a Learning-Teaching Interaction Using the Limem 3d Method.
(2015-01-01) TORRES, DAVID MAURICIO; Gomez, H.T.; TORRES, DAVID MAURICIO; Gomez, H.T.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
Over the past thirty years, since the advent of the Web, the potential use of virtual environments for teaching-learning processes has undergone an exponential increase, leading us quickly from the use of web pages to social networks, and fro
Advanced fuzzy-logic-based context-driven control for HVAC management systems in buildings
(Institute of Electrical and Electronics Engineers Inc., 2020-01-01) Morales Escobar L.; Aguilar J.; Garces-Jimenez A.; Gutierrez De Mesa J.A.; Gomez-Pulido J.M.; Morales Escobar L.; Aguilar J.; Garces-Jimenez A.; Gutierrez De Mesa J.A.; Gomez-Pulido J.M.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
Control in HVAC (heating, ventilation and air-conditioning) systems of buildings is not trivial, and its design is considered challenging due to the complexity in the analysis of the dynamics of its nonlinear characteristics for the identification of its mathematical model. HVAC systems are complex since they consist of several elements, such as heat pumps, chillers, valves, heating/cooling coils, boilers, air-handling units, fans, liquid/air distribution systems, and thermal storage systems. This article proposes the application of LAMDA (learning algorithm for multivariable data analysis) for advanced control in HVAC systems for buildings. LAMDA addresses the control problem using a fuzzy classification approach without requiring a mathematical model of the plant/system. The method determines the degree of adequacy of a system for every class and subsequently determines its similarity degree, and it is used to identify the functional state or class of the system. Then, based on a novel inference method that has been added to LAMDA, a control action is computed that brings the system to a zero-error state. The LAMDA controller performance is analyzed via evaluation on a regulation problem of an HVAC system of a building, and it is compared with other similar approaches. According to the results, our method performs impressively in these systems, thereby leading to a trustable model for the implementation of improved building management systems. The LAMDA control performs very well for disturbances by proposing control actions that are not abrupt, and it outperforms the compared approaches. © 2013 IEEE.
AIR-MODELLING: A tool for gesture-based solid modelling in context during early design stages in AR environments
(ELSEVIER SCIENCE BV, 2015-01-01) Arroyave-Tobon, Santiago; Osorio-Gomez, Gilberto; Cardona-McCormick, Juan F.; Universidad EAFIT. Departamento de Ciencias; Lógica y Computación
Augmented reality (AR) technologies are just being used as interface in CAD tools allowing the user to perceive 3D models over a real environment. The influence of the use of AR in the conceptualization of products whose configuration, shape and dimensions depend mainly on the context remains unexplored. We aimed to prove that modelling in AR environments allows to use the context in real-time as an information input for making the iterative design process more efficient. In order to prove that, we developed a tool called AIR-MODELLING in which the designer is able to create virtual conceptual products by hand gestures meanwhile he/she is interacting directly with the real scenario. We conducted a test for comparing designers' performance using AIR-MODELLING and a traditional CAD system. We obtained an average reduction of 44% on the modeling time in 76% of the cases. We found that modelling in AR environments using the hands as interface allows the designer to quickly and efficiently conceptualize potential solutions using the spatial restrictions of the context as an information input in real-time. Additionally, modelling in a natural scale, directly over the real scene, prevents the designer from drawing his/her attention on dimensional details and allows him/her to focus on the product itself and its relation with the environment. © 2014 Elsevier B.V. All rights reserved.
Algebraic analysis of social networks for bio-surveillance: the cases of SARS-Beijing-2003 and AH1N1 influenza-Mexico-2009.
(SPRINGER-VERLAG BERLIN, 2011-01-01) Hincapié D; Ospina J; Universidad EAFIT. Departamento de Ciencias; Lógica y Computación
Algebraic analysis of social networks exhibited by SARS-Beijing-2003 and AH1N1 flu-Mexico-2009 was realized. The main tools were the Tutte polynomials and Maple package Graph-Theory. The topological structures like graphs and networks were represented by invariant polynomials. The evolution of a given social network was represented like an evolution of the algebraic complexity of the corresponding Tutte polynomial. The reduction of a given social network was described like an involution of the algebraic complexity of the associated Tutte polynomial. The outbreaks of SARS and AH1N1 Flu were considered like represented by a reduction of previously existing contact networks via the control measures executed by health authorities. From Tutte polynomials were derived numerical indicators about efficiency of control measures.
Ambientes de Aprendizaje en el Siglo XXI
(2008-11-01) CORREA, FRANCISCO JOSE; CORREA, FRANCISCO JOSE; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
Ambientes de Aprendizaje en el Siglo XXI
(2008-11-01) Correa, Francisco Jose; Universidad EAFIT. Departamento de Ciencias; Lógica y Computación
Ambientes de Aprendizaje para el tercer milenio
(1997-01-01) ATUESTA, MARIA DEL ROSARIO; ATUESTA, MARIA DEL ROSARIO; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
An integrated framework for the diagnosis and correction of rule-based programs
(ELSEVIER SCIENCE BV, 2010-10-29) Alpuente, M.; Ballis, D.; Correa, F.; Falaschi, M.; Universidad EAFIT. Departamento de Ciencias; Lógica y Computación
We present a generic scheme for the declarative debugging of programs that are written in rewriting-based languages that are equipped with narrowing. Our aim is to provide an integrated development environment in which it is possible to debug a program and then correct it automatically. Our methodology is based on the combination (in a single framework) of a semantics-based diagnoser that identifies those parts of the code that contain errors and an inductive learner that tries to repair them, once the bugs have been located in the program. We develop our methodology in several steps. First, we associate with our programs a semantics that is based on a (continuous) immediate consequence operator, TR, which models the answers computed by narrowing and is parametric w.r.t. the evaluation strategy, which can be eager or lazy. Then, we show that, given the intended specification of a program R, it is possible to check the correctness of R by a single step of TR. In order to develop an effective debugging method, we approximate the computed answers semantics of R and derive a finitely terminating bottom-up abstract diagnosis method, which can be used statically. Finally, a bug-correction program synthesis methodology attempts to correct the erroneous components of the wrong code. We propose a hybrid, top-down (unfolding-based) as well as bottom-up (induction-based), correction approach that is driven by a set of evidence examples which are automatically produced as an outcome by the diagnoser. The resulting program is proven to be correct and complete w.r.t. the considered example sets. Our debugging framework does not require the user to provide error symptoms in advance or to answer difficult questions concerning program correctness. An implementation of our debugging system has been undertaken which demonstrates the workability of our approach. © 2010 Elsevier B.V. All rights reserved.
Análisis comparativo entre: «el análisis exploratorio de datos» y los modelos de «árboles de decisión» y «kmeans » en el diagnóstico de la malignidad en algunos exámenes de cáncer de mama. Un estudio de caso
(Revista Espacios, 2018-01-01) Sánchez Zuleta, C.C.; Giraldo Marín, L.M.; Piedrahita Escobar, C.C.; Bonet, I.; Lochmüller, C.; Tabares Betancur, M.S.; Peña, A.; Sánchez Zuleta, C.C.; Giraldo Marín, L.M.; Piedrahita Escobar, C.C.; Bonet, I.; Lochmüller, C.; Tabares Betancur, M.S.; Peña, A.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
The exponential growth of medical data has generated the need to implement new techniques of information analysis that support decision making. The objective of this article is to identify the aggregated value that data mining models have in decision making in the information given by exploratory analysis. It was used a case study methodology for two data sets, that look to determine the malignity of detected masses, in the breasts of patients, through the interpretation of attributes registered from the mases. The results show a complementary behavior of both techniques. © 2018.
Approximated analytical solution to an Ebola optimal control problem
(Board Members, 2016-01-01) Hincapié-Palacio, D.; Ospina, J.; Torres, D.F.M.; Universidad EAFIT. Departamento de Ciencias; Lógica y Computación
An analytical expression for the optimal control of an Ebola problem is obtained. The analytical solution is found as a first-order approximation to the Pontryagin Maximum Principle via the Euler-Lagrange equation. An implementation of the method is given using the computer algebra system Maple. Our analytical solutions confirm the results recently reported in the literature using numerical methods.
Arboles de forzamiento semantico
(Fondo Editorial Universidad EAFIT, 2001-01-01) Sierra, Manuel Hernando; Universidad EAFIT. Departamento de Ciencias; Lógica y Computación
Arboles de forzamiento semántico para el sistema básico con afirmación y negación alternas
(2006-01-01) Sierra, Manuel Hernando; Universidad EAFIT. Departamento de Ciencias; Lógica y Computación
Arboles de forzamiento semántico para operaciones entre conjuntos
(2017-01-01) Sierra, Manuel Hernando; Universidad EAFIT. Departamento de Ciencias; Lógica y Computación

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