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Ítem A collaborative tool for synchronous distance education(2004-01-01) Agudelo, A.; Escobar, L.; Restrepo, J.; Quiroz, A.; Trefftz, H.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las ComunicacionesIn this paper we report results of the use of a telepresence application in a simulated distance education setting. The application combines video-conference with a networked virtual environment in which the instructor and the students can experiment with virtual object in a collaborative manner. The teaching for Understanding (TFU) framework is used as the pedagogical approach. Current preliminary results show that the combination of the telepresence application with TFU, can compensate for the lack of physical presence of the instructor in the classroom.Ítem Design and implementation of a low-cost projected virtual reality system to support learning processes(Springer Verlag, 2011-01-01) Gómez, R.; Trefftz, H.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las ComunicacionesVirtual Reality technologies have been successfully incorporated into the learning processes and potential new applications in education are explored continuously. We found that one of the difficulties to popularize its use in the educational context, in countries with emerging and developing economies, is the cost of hardware required to generate satisfactory immersive experience. In this work we considered virtual reality from the perspective of human-computer interaction to support learning processes. The characteristics of low-cost projected virtual reality system (PVR) proposed, combines study and integration of available technology solutions, the development of an image synchronization routine that enables the use of a single video projector and the design of a printable pattern that preserve the state of polarization on the projection screen. © 2011 Springer-Verlag.Ítem A domain-specific modeling framework for attack surface modeling(SciTePress, 2020-01-01) Sun, T.N.; Drouot, B.; Golra, F.R.; Champeau, J.; Guerin, S.; Le Roux, L.; Mazo, R.; Teodorov, C.; Van Aertryck, L.; L'Hostis, B.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las ComunicacionesCybersecurity is becoming vital as industries are gradually moving from automating physical processes to a higher level automation using cyber physical systems (CPS) and internet of things (IoT). In this context, security is becoming a continuous process that runs in parallel to other processes during the complete life cycle of a system. Traditional threat analysis methods use design models alongside threat models as an input for security analysis, hence missing the life-cycle-based dynamicity required by the security concern. In this paper, we argue for an attacker-aware systems modeling language that exposes the systems attack surfaces. For this purpose, we have designed Pimca, a domain specific modeling language geared towards capturing the attacker point of view of the system. This study introduces the formalism along with the Pimca workbench, a framework designed to ease the development and manipulation of the Pimca models. Finally, we present two relevant use cases, serving as a preliminary validation of our approach. © Copyright 2020 by SCITEPRESS - Science and Technology Publications, Lda. All rights reserved.Ítem Exhaustive community enumeration on a cluster(Institute of Electrical and Electronics Engineers Inc., 2018-01-01) Trefftz C.; McGuire H.; Kurmas Z.; Scripps J.; Pineda J.D.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las ComunicacionesA parallelization based on MPI and OpenMP of an algorithm that evaluates and counts all the possible communities of a graph is presented. Performance results of the parallelization of the algorithm obtained on a cluster of workstations are reported. Load balancing was used to improve the speedups obtained on the cluster. Two different kinds of load balancing approaches were used: One that involved only MPI and a second one in which MPI and OpenMP were combined. The reason for the load imbalance is described. © 2018 IEEE.Ítem An immersive virtual reality training system for mechanical assembly(2011-01-01) Peniche, A.; Diaz, C.; Trefftz, H.; Paramo, G.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las ComunicacionesGiven the growing evolution of technology, machinery and manufacturing techniques, conventional methodologies for training the workforce are not enough for the current needs. Therefore methodologies capable to accelerate the training process and able to train the trainee in a wide range of scenarios are claimed for the industrial sector. Virtual reality offers an alternative that has been successfully implemented in other industries, and virtual reality based training systems have numerous advantages over the conventional methodologies, making it a very good option. Based on that premise, this paper explores the implementation of an immersive training system for mechanical assembly based on virtual reality for improving the training process. This system was proved to be as effective as the conventional methodology.Ítem Improving the business processes management from the knowledge management(Association for Computing Machinery, 2016-01-01) Marta S. Tabares; Giraldo, Liliana; Aguilar, Luis; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las ComunicacionesThis paper proposes a model that integrates the knowledge management to the business processes management in order to improve the process performance. The proposal defines the knowledge management flow as an element that interacts with part workflows and provides rules and actions in the BPMN elements in order to improve the BPM. To achieve the aim, first, a survey was made in forty Colombian' companies in order to identify the state of the practice about business process management, knowledge management and their use through the workflows; then, different elements were identified and characterized in order to achieve the integration model proposed. This was experimented in forty business workflows of the companies analyzed. A use case shows how the interactions among model elements are, and how these can improve the process performance. This experience allowed to measuring the effect that the integration had in the business process management by means of a new metric that involve the knowledge management in the workflow. Finally, it was possible conclude that the knowledge management must be part to the BPM impacting directly the workflow, in order to improve the result offered to the organizational actors and customers.Ítem Solving large systems of linear equations on GPUs(Springer Verlag, 2018-01-01) Llano-Ríos T.F.; Ocampo-García J.D.; Yepes-Ríos J.S.; Correa-Zabala F.J.; Trefftz C.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las ComunicacionesGraphical Processing Units (GPUs) have become more accessible peripheral devices with great computing capacity. Moreover, GPUs can be used not only to accelerate the graphics produced by a computer but also for general purpose computing. Many researchers use this technique on their personal workstations to accelerate the execution of their programs and have often encountered that the amount of memory available on GPU cards is typically smaller than the amount of memory available on the host computer. We are interested in exploring approaches to solve problems with this restriction. Our main contribution is to devise ways in which portions of the problem can be moved to the memory of the GPU to be solved using its multiprocessing capabilities. We implemented on a GPU the Jacobi iterative method to solve systems of linear equations and report the details from the results obtained, analyzing its performance and accuracy. Our code solves a system of linear equations large enough to exceed the card’s memory, but not the host memory. Significant speedups were observed, as the execution time taken to solve each system is faster than those obtained with Intel® MKL and Eigen, libraries designed to work on CPUs. © Springer Nature Switzerland AG 2018.Ítem Technological tools to learn calculus(Institute of Electrical and Electronics Engineers Inc., 2015-12-02) Gómez, G.P.P.; Restrepo, C.M.Z.; Duarte, P.V.E.; Rivera, L.F.Z.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las ComunicacionesOnline learning tools have allowed professors to carry out their classes in an interactive way, synchronic as well as asynchronic, giving them the opportunity to explore from different points of view specific themes or concepts, achieving greater dynamism in their classes through the active participation of students. This article presents the results of the implementation of an software tool for massive use designed with the objective of allowing Engineering students to strengthen their basic mathematical knowledge as well as to improve their results in courses such as Calculus I and Mathematics I. These courses are part of the first semesters of the syllabus for all undergraduate programs of the School of Engineering, and are basic courses in the formation of an engineer at Universidad EAFIT (Medellin, Colombia). This software tool for massive use allows students to self-diagnose, to solve exercises with different levels of complexity and difficulty, to visualize academic contents such as video classes and virtual resources, and to know their evolution in the understanding of basic concepts in calculus. On one hand, this facilitates the beginning of their studies at the university. On the other, it gives the professor an initial diagnose of the level students have to start the course so that continuous analytics can be performed based on the learning process of the student. Furthermore, this article shows the results of a comparative analysis done to two groups of students, a Control group and an Experimental group, that took Calculus I as part of their undergraduate studies. The experiment lasted two months with testing done at the beginning and at the end of the course. The objective was to register the level of knowledge acquired by the students and compare the differences between the two groups, control and experimental. The testing also allowed the progress of the student between tests to be measured, taking into account that the experimental group had the opportunity to explore the platform during this two-month period. Therefore, the analysis performed served to gather information useful for evaluating the effectiveness of the proposed system in the learning process of the students at the University. © 2015 IEEE.Ítem Unravelling the widening of the earliest Andean northern orogen: Maastrichtian to early Eocene intra-basinal deformation in the northern Eastern Cordillera of Colombia(Wiley-Blackwell Publishing Ltd, 2020-07-21) Bayona G.; Baquero M.; Ramírez C.; Tabares M.; Salazar A.M.; Nova G.; Duarte E.; Pardo A.; Plata A.; Jaramillo C.; Rodríguez G.; Caballero V.; Cardona A.; Montes C.; Gómez Marulanda S.; Cárdenas-Rozo A.L.; Universidad EAFIT. Departamento de Ciencias; Biodiversidad, Evolución y ConservaciónThe onset of deformation in the northern Andes is overprinted by subsequent stages of basin deformation, complicating the examination of competing models illustrating potential location of earliest synorogenic basins and uplifts. To establish the width of the earliest northern Andean orogen, we carried out field mapping, palynological dating, sedimentary, stratigraphic and provenance analyses in Campanian to lower Eocene units exposed in the northern Eastern Cordillera of Colombia (Cocuy region) and compare the results with coeval succession in adjacent basins. The onset of deformation is recorded in earliest Maastrichtian time, as terrigenous detritus arrived into the basin marking the end of chemical precipitation and the onset of clastic deposition produced by the uplift of a western source area dominated by shaly Cretaceous rocks. Disconformable contacts within the upper Maastrichtian to middle Palaeocene succession document increasing supply of quartzose sandy detritus from Cretaceous quartzose rocks exposed in eastern source areas. The continued unroofing of both source areas produced a rapid shift in depositional environments from shallow marine in Maastrichtian to fluvial-lacustrine systems during the Palaeocene-early Eocene. Supply of immature Jurassic sandstones from nearby western uplifts, together with localized plutonic and volcanic Cretaceous rocks, caused a shift in Palaeocene sandstones composition from quartzarenites to litharenites. Supply of detrital sandy fragments, unstable heavy minerals and Cretaceous to Ordovician detrital zircons, were derived from nearby uplifted blocks and from SW fluvial systems within the synorogenic basin, instead of distal basement rocks. The presence of volcanic rock fragments and 51–59 Ma volcanic zircons constrain magmatism within the basin. The Maastrichtian–Palaeocene sequence studied here documents crustal deformation that correlates with coeval deformation farther south in Ecuador and Peru. Slab flattening of the subducting Caribbean plate produced a wider orogen (>400 km) with a continental magmatic arc and intra-basinal deformation and magmatism. © 2020 International Association of Sedimentologists and European Association of Geoscientists and Engineers and John Wiley - Sons LtdÍtem WeSketch: A 3D real time collaborative virtual environment that improves the GUI sketching task(2010-01-01) Hernández, H.A.; Trefftz, H.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las ComunicacionesMany tools help GUI designers to produce prototypes of their future applications, but when this job requires the collaboration with geographically dispersed partners some problems arise like lack awareness of the others' work, concurrent manipulation of virtual objects and non-fluent communication of actions and intentions. We Sketch allows a small geographically distributed group to build GUI prototypes in a highly participative manner, keeping everyone aware of what is going on. A 3D virtual round table, virtual sheets simulating sketches, avatars representing users, an audio communication system and a shared view of sketches are the pieces that allow designers to discuss and co-design GUIs in real time offering a comfortable and pleasant experience. This paper describes the tool and the results of a set of experiments conducted in order to validate the hypothesis: "WeSketch allows a small group of designers who are geographically dispersed to be more efficient and feel more motivated during the GUI Sketching task than they do with current tools". © 2011 IEEE.