Tecnura

20-35

Authors: Maira Cecilia Gasca Mantilla, Luis Leonardo Camargo Ariza, Byron Medina Delgado

This paper presents: the evolution of mobile telephony services in Latin America contextualized in different technology generations, the features of software for mobile devices, and proposes a method for developing mobile applications in Latin America. This method is based on the conceptualization of contemporary telecommunications technologies and the agile software development methodologies. The main objective of this method is to facilitate the creation and evaluation of new applications and services. The method is developed in five steps: the analysis stage, the requirements is obtained and classified and the service is customize; the design stage, in this stage is defined the technological and the solution is structured by some chart or diagram; the development stage, the design is implemented in a software product; the performance test stage, the application is emulates and simulates to adjusting details in the product, the software is installs in real equipment and is evaluated the performance and success; the delivery stage, the distribution channel of the application is defined, in order to adapt the application at the same. Furthermore, the paper presents the results of developing a m-health service in Android and J2ME using the proposed method, service for patients who need or wish to have regular monitoring of measurements of blood pressure and glucose. The service has a satisfactory evaluation with test users.

48-61

Authors: Carlos Alberto Hidalgo Mora, Nelson Leonardo Díaz Aldana, César Leonardo Trujillo Rodríguez

During last two decades, several technologies have developed and improved the high voltage direct current systems. The technological growth in power electronics converters has led to increase flexibility and modularity for interconnections of alternating current and direct current systems. In this sense, high voltage direct current system based on voltage source converters appear as feasible and flexible technology when active and reactive power flow have to be regulated between different power grids. Therefore, for an adequate operation, one of the major challenges is to regulate the direct current voltage and the reactive power flow between the alternating current system and the voltage source converter at the rectifier station. In this document, several methodologies will be explored for modeling, identifying, and designing controllers to regulate the direct current voltage at the common bus, and reactive power flow. In particular, linear techniques such as feedback states are used for the design of controllers. Finally, practical results will be presented on a physical voltage source converter prototype.

71-88

Authors: Mirna Jirón Popova

This article presents part of the results of the research work titled"Technological formation in Colombia in the public university field", particularly at Universidad Distrital Francisco José de Caldas, which was one of the observed institutions. Consequently, we present the findings related to the events that take place from the moment in which Technological Faculty is institutionalized, aiming at offering Technological Higher Education to disadvantaged sectors from the population at Distrito Capital. Special emphasis is made on aspects related to the tensions among resisting or adapting to the regulations of the control mechanisms; conjunction that lastly determines that this faculty would transform its original proposal of Technological Education by Cycles, towards an Engineers Formation by Cycles and, afterwards, to Engineers Formation by Propaedeutic Cycles.

103-114

Authors: scar Ignacio Sánchez, César Alberto Torres, Francisco Santamaría

In order to design an efficient protection system of structures against lightning, a risk assessment shall be made, and damages and losses resulting from that event must be identified. In this sense, the is-sues described in the standard NTC 4552 or the IEC 62305 to perform the risk assessment must be taken into account, and thus evaluate whether a protection system against lightning is needed or if the existing lightning protection system needs modifications. The Colombian standard NTC 4552 "Protection against lightning" is based on the principles described in IEC 62305, published in 2006. However, in the IEC 62305 (2010) changes were made, which significantly change the risk assessment and can generate an incorrect analysis for the Colombian case; in addition, several research results obtained in Colombian and other tropical countries have been incorporated in the NTC 4252, which has led some of the parameters used in the analysis and design of lightning protection systems are different from those used in international standards.

127-142

Authors: Vicente García Díaz, Edward Rolando Núñez Valdez, Jordán Pascual Espada, Cristina Pelayo García Bustelo, Juan Manuel Cueva Lovelle, Carlos Enrique Montenegro Marín

The software crisis is a concept that has started to be used in 1968, at the first conference organized by the North Atlantic Treaty Organization (NATO) on software development. There, Edsger Dijkstra criticized that projects were not completed in compliance with the classic triple constraint of project management (scope, time and cost), since most of them do not reach the expected requirements, are delivered out of time or exceeds the expected cost. Unfortunately, the current reality is that while there have been proposed new methodologies aimed at solving the usual problems related to software development, there is still no reliable method to estimate the development of computer systems. This work introduces the Model-Driven Engineering approach that, according to the experts, will help to solve many of the problems that thousands of software development teams have daily worldwide.