Tecnura

12-23

Authors: Pedro Guevara López, Jorge Salvador Valdez Martínez, Jesús Audelo González, Gustavo Delgado Reyes

In the biological environment, there has been created epidemiological models that attempt to explain the spread dynamics of an epidemic in a population to predict the behavior of possible epidemics that can affect humanity. Based on that, this paper focused on the study of epidemics worms because they can spread by themselves from one infected host to the entire network of susceptible hosts. In this paper we analyzed the susceptible-infected (SI) model which assumes that in a community with n individuals, the number of individuals in the susceptible state S(t) are in direct contact with the number of individuals that are in infected state I(t). These last individuals can spread the infection or switch to an infectious state with the factor β as a speed of infection. This model is based on differential equations so it cannot be implemented directly on a computer. Due to the complexity of this model, it is proposed an approximate model based on finite different equations to achieve a simulation of the epidemic using a set theory and cardinality obtaining an iterative numerical method which consists on basics arithmetic operations. Additionally, having in mind this is an approximate model, it will be presented an error due to truncation or rounding. At the end of this paper it will be presented a case of study developed in Simulink of Matlab software, and the results of the model based on difference equations is compared with the finite-difference approximate model including the analysis of approximation errors.

38-52

Authors: Sebastián Rodríguez Páez, Arturo Fajardo Jaimes, Carlos Iván Páez Rueda

This paper presents the design, implementation and evaluation of a miniaturized Rat-race hybrid implemented in substrate CER-60 with microstrip transmission lines in a novel space-filling curve. This circuit is the main research´s result of the project PS 3206funded by the Pontificia Universidad Javeriana. The hybrid achieves a miniaturization of 73 %, it operates in the 2.4 GHz ISM band, with an optimum operating frequency 2.56 GHz and a fractional band width of 17.15 %.

65-77

Authors: César Augusto Hernández Suárez, Víctor Alfonso Gómez Saavedra, Robín Alejandro Peña Lote

This paper presents the design and implementation of a data acquisition system to identify the different vector groups of the triphase transformer DL1080. This design is based on computational tools in hardware and software such as Microchips and Labview respectively. Consequently, the prototype has a high-level algorithm. It is able to perform vector analysis of voltage in the transformer which established national and international regulations. This project also allows an interactive environment with the user through graphical tools such as a liquid crystal display with their respective buttons and software developed in Labview called “indices Horarios”. This is useful to illustrate: vector diagrams, winding configurations, real time voltage, among others. This academic application is a tool in learning and strengthening areas such as: electromagnetic conversion, electrical machines and power systems. Therefore, teachers and students can reinforce their knowledge

90-102

Authors: César Augusto García Ubaque, María Camila García Vaca, Carlos Fernando Agudelo Rodríguez

Mining extraction of building materials increased from the 19th century until the early 20th century in Bogotá D.C. (Secretaría Distrital de Ambiente, 2007) and in this period, population rapid growth, poor mining practices and legislation without concepts on sustainable development, generated numerous environmental liabilities due to: abandoned mining installations, mass removalsexposed areas, which currently generate severe negative impacts that affect the population and ecosystems. This article use Gómez Orea Environmental Impact Assessment Methodology to diagnose and analyze environmental liabilities in Villa Gloria quarry located in Ciudad Bolivar (Bogotá D.C.), and to determine the possible mitigation works allowing to give a new use to this area such as: green areas and/or areas of recreation (Secretaría Distrital de Ambiente, 2007)

114-125

Authors: Paulo Alonso Gaona García, Ana Fermoso García, Salvador Sánchez Alonso, Elvis Eduardo Gaona García

In this paper, it is presented a study to evaluate and compare the effectiveness of eight different interfaces based on visualization techniques to carry out searching digital resources according to knowledge area and knowledge representation scheme. The navigation structure is based on hierarchical taxonomic representation through the use of Art and Architecture Thesaurus (AAT). It was adopted principles of Human Computer Interaction (HCI) for the development of search interfaces through information visualization techniques. Finally, it will be presented preliminary results in order to evaluate the most representative aspects to carry out the development of visual search interfaces of learning objects in digital repositories, according to principles of visualization techniques and hierarchic taxonomic classification.