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Ítem Distributed local search based on a parallel neighborhood exploration for the rooted distance constrained mínimum spanning-tree problem(Universidad Icesi, 2019-01-01) Aristizábal, Andrés; Tamura Morimitsu, Gabriel; Asesor Tesis; Asesor TesisEl Rooted Distance Constrained Minimum Spanning-Tree Problem, Problema de Árbol de Recubrimiento Mínimo Acotado por Distancia con Raíz Fija, RDCMST por sus iniciales en inglés, es un problema de optimización conocido por ser NP-hard cuya solución se puede aplicar al diseño de redes de telecomunicaciones, entre otros. Investigaciones previas para resolver el problema RDCMST han propuesto soluciones que van desde algoritmos exactos, como los modelos clásicos de programación lineal, hasta métodos heurísticos que incluyen el uso de búsquedas locales. Por lo que sabemos, el estado del arte de este problema tiene al menos dos carencias importantes. Por un lado, no existen aproximaciones paralelas que hayan sido diseñadas para aprovechar varias unidades de procesamiento. Por el otro lado, las aproximaciones existentes están limitadas a instancias del problema de unos pocos miles de vértices.
Ítem SNR estimation for on body communications in MB OFDM Ultra Wide Band communications(Ieee Computer Society, 2010-04-12) Navarro Cadavid, AndrésIn this paper a new signal to noise ratio estimator algorithm based on the moments of the received signal is presented. The novel algorithm has been designed for Ultra Wide Band communications based on Multi Band Orthogonal Frequency Division Multiplexing (MB-OFDM) communication systems. In this proposal, we analyze the behavior of ultra wide band channels when the time and frequency fading have fast changes. Hence, different time coherence values were considered and all the frequency fading models are based in real measurements made in an anechoic chamber. It is remarkable that all the measurement campaigns were focused on body communications. We conclude that the proposed model can be used for SNR estimation in adaptive modulation and channel estimation and link quality control in MB OFDM systems. The performance of the proposed SNR estimation algorithm and its comparison with other SNR estimators was achieved through simulations based on real channel measurements.Ítem Performance evaluation of Vertical Handoff Algorithms(IEEE, 2010-10-10) Navarro Cadavid, AndresDifferent Vertical Handoff Algorithms (VHA) have been proposed in the literature recently. However, there is no consensus on how to evaluate performance of different VHA at the research community. Although some models have been proposed for evaluation of the VHA, this issue is a challenge because the VHA have evolved to become more sophisticated, thus the evaluation models must consider a variety of parameters. In this paper, we propose a new evaluation model for VHA that has been designed based on specific concepts taken from the multi-criteria evaluation and operational reliability. The proposed evaluation model allows analyzing VHA using measured values of some defined parameters, which can be obtained from simulating VHA on a network simulation tool. We present as a case study an evaluation of two VHA that shows the new model functionality and results. © 2010 IEEE.Ítem Machine learning algorithms for inter-cell interference coordination(Universidad Icesi, 2018-07-01) Trejo Narváez, Omar AlbeiroThe current LTE and LTE-A deployments require larger efforts to achieve the radio resource manage - ment. This, due to the increase of users and the constantly growing demand of services. For this reason, the automatic op - timization is a key point to avoid issues such as the inter-cell interference. This paper presents several proposals of machi - ne-learning algorithms focused on this automatic optimization problem. The research works seek that the cellular systems achieve their self-optimization, a key concept within the self-organized networks, where the main objective is to achieve that the networks to be capable to automatically respond to the particular needs in the dynamic network traffic scenarios.Ítem Algoritmos de planificación en redes de paquetes(Universidad Icesi, 2010-03-24T23:27:25Z) Cuéllar Quiñonez, Juan CarlosThis article presents the mechanisms and processes required in order for a router to provide QoS in packet networks and it presents the state of the art in the subject of scheduling algorithms use in this kind of networks.Ítem Análisis de irradiación electromagnética en las inmediaciones de una radio base sectorizada en condiciones andinas(Universidad Icesi, 2006-10-11) García Ariza, Alexis PaoloFor more than a year now, the Radio GIS Research Group, assisted by the Schools of Electrical, Electronic and Telecommunications Engineering (E3T) at UIS, together with other local research groups (i.e. ICESI´s I2T, UFPS’s GIDT, and UDI’s MAXWELL, and the Colombian Ministry of Communications have been conducting a number of studies on high-frequency electromagnetic radiation under outdoor conditions to determine acceptable human exposure levels to this kind of radiation. These studies are driven not only by academic interest in this subject, but also by concerns raised by communities in the city of Bucaramanga and other regions in Colombia with respect to the installation of a large number of radiocommunications stations. With this paper, the Radio GIS group makes some contributions, which will hopefully benefit both the population in general and the regulatory agencies, aiming at establishing control policies based on concrete theoretical and technical studies. The results of the studies discussed in this paper derive from previous research conducted in the field of electromagnetic propagationÍtem Lentes mágicas : Una herramienta de apoyo para la visualización en 3D(Universidad Icesi, 2008-03-27) Ortiz, Carlos Humberto; Popó, José Ricardo; Herrera Botero, Francisco Julián; Navarro Newball, Andrés AdolfoMagic lenses are tools which allow changing a work area according to specific selections and properties. This paper describes the work done aimed to extend the concept of magic lenses to allow seeing inside 3D models which are uploaded from an example application. In order to implement the lenses a ray tracing algorithm for image synthesis was used.Ítem Una evaluación comparativa de la eficiencia de los algoritmos de ML supervisados en la clasificación de tráfico de NFV(Universidad Icesi, 2017-07-01) Vergara Reyes, Juliana Alejandra; Caicedo Rendón, Oscar Mauricio; Martínez Ordoñez, María CamilaThe implementation of NFV allows improving the flexibility, efficiency, and manageability of networks by leveraging virtualization and cloud computing technologies to deploy computer networks. The implementation of autonomic management and supervised algorithms from Machine Learning [ML] become a key strategy to manage this hidden traffic. In this work, we focus on analyzing the traffic features of NFV-based networks while performing a benchmarking of the behavior of supervised ML algorithms, namely J48, Naïve Bayes, and Bayes Net, in the IP traffic classification regarding their efficiency; considering that such an efficiency is related to the trade-off between time-response and precision. We used two test scenarios (an NFV-based SDN and an NFV-based LTE EPC). The benchmarking results reveal that the Naïve Bayes and Bayes Net algorithms achieve the best performance in traffic classification. In particular, their performance corroborates a good trade-off between precision and time-response, with precision values higher than 80 % and 96 %, respectively, in times less than 1,5 sec.Ítem Implementación de técnicas de Data Mining, para la predicción de la deserción de los estudiantes del programa de ingeniería industrial de la Universidad Icesi(Universidad Icesi, 2016-01-01) Polo Saa, Eduardo José; Quintero Moreno, Fernando; Asesor TesisEn Colombia, la deserción que se presenta en las universidades, llega a rondar el 45% del total de estudiantes, dato bastante preocupante, como el 32.6% que se presenta para el Programa de Ingeniera Industrial de la Universidad Icesi. Son muchos los esfuerzos que brindan, tanto universidades como gobierno, en términos de educación, pero la deserción termina causando que gran parte de todo ello se pierda. Data Mining, que traduce Minería de Datos, es aplicado en este proyecto, para identificar patrones e información relevante en todos aquellos estudiantes desertores, para entonces, proporcionar herramientas que puedan predecir la probabilidad de deserción de un estudiante. Así mismo, mediante técnicas estadísticas, se proporcionan varios datos de referencia, que permiten evidenciar el panorama que se presenta en términos de deserción, mostrando el rol de diferentes atributos del estudiante. El proyecto empezó con el análisis de 38 atributos del estudiante, hasta que se redujo a 10, y mediante el algoritmo J48, se logró generar un modelo de predicción de la deserción para los estudiantes del Programa de Ingeniería Industrial de la Universidad Icesi, el cual conto con una asertividad del 74.23%, dato obtenido mediante una validación cruzada.Ítem Aprendizaje basado en retos con mediación de las TIC, una oportunidad para desarrollar el pensamiento computacional(Universidad Icesi, 2020-01-01) Rivera Morcillo, Ivo Albeiro; Quesada Hurtado, Jorge Alberto; Asesor TesisMediante las metodologías inductivas se intervienen las clases de matemáticas del grado 6° de la Institución Educativa Santa Marta del municipio de Suárez para desarrollar las capacidades matemáticas de los niños, a través del desarrollo del pensamiento computacional mediante el lenguaje de programación Scratch y simultáneamente desarrollar competencias siglo XXI.
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