Documentos de conferencia

URI permanente para esta colección

https://hdl.handle.net/10784/28716

Examinar

Mostrando 1 - 20 de 64

Observations about an approximate algorithm for the point robot motion planning problem
(IEEE Computer Society, 2002-01-01) Trefftz, C.; Trefftz, H.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
Observations about an approximate parallel algorithm for the point robot motion planning problem are presented. The algorithm solves not only the original problem, but related problems as well. © 2002 IEEE.
Achieving object persistence in an augmented reality indoor environment
(2003-01-01) Gutiérrez, M.D.; Márquez, A.M.; Trefftz, H.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
In this paper we present a system for achieving object persistence in Augmented Reality Indoors Environments. In AR systems based on the Augmented Reality toolkit without object persistence, virtual objects appear and disappear as the corresponding pattern gets in and out of the user's field of view. Object persistence allows the environment to remember the relative position and orientation of virtual objects, making them appear more stable to the user. We describe object persistence as a series of transformations applied to the objects in a simple indoor environment. We then present the results of a quantitative experiment that shows how interactivity is improved by the use of object persistency.
Dynamic server allocation in virtual environments, using quadtrees for dynamic space partition
(2003-01-01) Restrepo, A.; Montoya, A.; Trefftz, H.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
In actual applications of virtual environments, one of the problems that has received attention is the way to assign computational resources to those who participate in the system. In most cases, static resource allocation is used. Static allocation is simple but has several limitations, among them, the missutilization of resources. In this paper we present a proof-of-concept of a new system and report the results of experiments with a system that accomplishes dynamic resource allocation by using Quadtrees for space partitioning, in a Shared Virtual Environment.
Agents as tutors in augmented reality
(2003-01-01) Álvarez, N.; Trefftz, H.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
Interaction between virtual entities and human beings should be similar to the normal interaction between human beings. Verbal interaction is the usual way of interaction among humans, but the interfaces that allow verbal communication between a human being and an agent (virtual human) have a limited vocabulary, need a lot of training and are expensive. In this paper we propose an Augmented Reality System with an unidirectional interface between an agent and a person. By using gestures, animations and adequate texts the agent can show a user how to perform a simple task. We hope that the tests to be conducted will show how useful this unidirectional interface is.
Handling heterogeneity in networked virtual environments
(MIT PRESS, 2003-02-01) Trefftz, H; Marsic, I; Zyda, M; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
The availability of inexpensive and powerful graphics cards as well as fast Internet connections make networked virtual environments viable for millions of users and many new applications. It is therefore necessary to cope with the growing heterogeneity that arises from differences in computing power, network speed, and users' preferences. This paper describes an architecture that accommodates the heterogeneity while allowing a manager to define systemwide policies. One of the main objectives of our scheme is to allow slower nodes to participate in the session by preventing fast nodes from flooding slow nodes with too many messages. Policies and users' preferences can be expressed as simple linear equations forming a model that describes the system as a whole as well as its individual components. When solutions to this model are mapped back to the problem domain, viable solutions that accommodate heterogeneity and system policies are obtained. For example, slower nodes may receive less frequent updates than faster ones for one or several information streams. The results of our experiments with a proof-of-concept system are described.
Combinatory multicast for differentiated data transmission in distributed virtual environments
(ACTA PRESS, 2004-01-01) Quiroz, A; Trefftz, H; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
The shortage of multicast addresses is a factor that limits their use in Intemet-based applications. Since multicast plays a very important role in supporting resource heterogeneity among users of applications with a high demand of computational resources, such as Distributed Virtual Environments, the sparing use of these addresses is of great importance. This paper suggests a scheme for the combination of multicast groups for differentiated data transmission, based on layered multicast, with which the number of different levels of service that can be provided to users of a shared virtual environment with a fixed number of groups is multiplied. For applications where the levels of service correspond to different transmission rates, the scheme also significantly reduces bandwidth utilization. We present a basic method for its implementation and describe preliminary tests to prove its functionality.
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 Comunicaciones
In 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.
BDNG: A dublin core-based architecture for digital libraries
(2005-01-01) Montoya, E.; Ruiz, M.; Giraldo, J.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
Digital Libraries will be one of the main ways to access structured information through the Internet. Information related to resources or objects is known as metadata. Several metadata models have been proposed; however, the model proposed by the Dublin Core Metadata Initiative (DCMI) [1] has demonstrated great utility in digital libraries. The simplicity and generality of DCMI has facilitated the deployment of digital libraries and their interoperability. This paper proposes DCMI as metadata model in our own Digital Library Architecture (Biblioteca Digital de Nueva Generación -BDNG). We have extended DCMI and used some elements of DC-Library application profile (DC-Lib) [2] in addition to new elements not previously considered. This paper presents the metadata models for the following applications: digital library of EAFIT University (BDEeafit), integration of digital or referential libraries (BDMetaLib) and digital library for E-Learning systems (BDEI). This paper also describes the general architecture of BDNG.
Collaborative and distributed augmented reality in teaching multi-variate calculus
(2006-01-01) Orozco, C.; Esteban, P.; Trefftz, H.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
This article presents the first results of using an Augmented Reality (AR) tool, designed to support tutoring sessions in multi-variate calculus. The tool is used either in a face-to-face setting in which the instructor and the students are collocated or in a distance setting, in which the instructor and students are physically in remote places. The tool was used with two groups of students of Differential Calculus. The students had not been exposed to the concept of equations involving 3 variables and the corresponding surfaces in space. The experience explored how students generalized 2D graphics and equations with their 3D surfaces counterparts with the help of the tool.
Collaborative virtual environments for teaching physics
(SPRINGER, 2007-01-01) Giraldo, F.; Rojas, Á.M.J.; Esteban, P.; Trefftz, H.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
Eafit University created a Telepresence application for distance education. It supports bidirectional audio and video and a shared virtual environment that allows the instructor and students to manipulate virtual objects in a collaborative manner, thereby reinforcing the learning process. In this paper we report the experience of creating new contents and deploying the tool in a Physics course at Universidad del Quindío. The tool was improved an extended in order to include new functionality and make it easier for development teams to create new content. Teaching for Understanding was used as pedagogical framework for course creation and also as a guide to develop the interviews that were used to capture user's perceptions and to asses the improvements in the learning process. The results showed that the use of the tool had a positive impact on the students' understanding of the topics at hand. © 2007 Springer.
Understanding Math Concepts Through Computer-Modeled Virtual Objects
(SPRINGER, 2008-01-01) Trujillo, J.; Esteban, P.; Montoya, E.; Giraldo, R.; Montoya, A.; Mejia, J.; Trefftz, H.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
Information and Communication Technologies (ICT) can be used in order to motivate students to establish links between the classroom material and real life situations by modeling those situations through the course equations. This article describes the results of an experience involving a group of Multivariable Calculus at Eafit University. 3D-Universal is the program developed for the experience, which runs on Pocket PC. It allows students to interact and communicate inside the classroom. At each stage of the experience, students were asked to establish links between the classroom-covered material and real objects in their environment.
Remote teaching functional and anatomical concepts skeletal muscle system
(SPRINGER, 2008-01-01) Leon, C.A.D.; Trefftz, H.; Pineda, F.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
In this paper we present the results of using a virtual content developed inside a telepresence application. The application combines video-conference with networked virtual environment allowing an instructor and a group of students to manipulate a virtual object in a collaborative manner. The virtual environment describes bones and muscular structures in order to support teaching of musculoskeletical concepts in a remote physiology class. The virtual environment simulates the movement of flexion and extension of the elbow and the muscular contraction. Current preliminary results show that the content developed within telepresence application can compensate for the lack of physical presence of the instructor in the classroom. © Springer-Verlag Berlin Heidelberg 2007.
Remote teachings of anatomical concepts and collaborative musculoskeletal structure systems
(SPRINGER, 2008-01-01) Diaz, C. A.; Trefftz, H.; Pineda, F.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
In this paper we present the results of using a virtual content developed inside a telepresence application. The application combines video-conference with networked virtual environment allowing an instructor and a group of students to manipulate a virtual object in a collaborative manner. The virtual environment describes bones and muscular structures in order to support teaching of musculoskeletical concepts in a remote physiology class. The virtual environment simulates the movement of flexion and extension of the elbow and the muscular contraction. Current preliminary results show that the content developed within telepresence application can compensate for the lack of physical presence of the instructor in the classroom.
A reconfigurable array based prototype of a specialised string lookup chip
(2008-01-01) Pejovic, V.; Gómez, R.; Bojanic, S.; Lalinde, J.G.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
Different strategies for performing string lookups have been developed and deployed during the evolutionary scientific process. These are the results of both the development of technology and the need for improvement of previously existing solutions. Hence, the string lookup problem has been well studied and the respectful amount of good solutions is present. Due to nature of the problem, most of the solutions are software based. Nevertheless, in the modern computing environments, in which the amount of data to be searched trough is increasingly growing, the problem re-arises demanding for the different type of approaches that could target multi-gigabit throughput rates so as to perform close to real-time string lookups. In that light, this paper studies the potential of migrating, a well-known and widely used, Boyer-Moore string lookup algorithm to a hardware specific device capable of satisfying the demanded throughput, by proposing and characterising the initial implementation option on a reconfigurable platform. © 2008 IEEE.
Understanding math concepts through computer-modeled virtual objects
(SPRINGER, 2008-01-01) Trujillo, J.; Esteban, P.; Montoya, E.; Giraldo, R.; Montoya, A.; Mejía, J.; Trefftz, H.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
Information and Communication Technologies (ICT) can be used in order to motivate students to establish links between the classroom material and real life situations by modeling those situations through the course equations. This article describes the results of an experience involving a group of Multivariable Calculus at Eafit University. 3DUniversal is the program developed for the experience, which runs on Pocket PC. It allows students to interact and communicate inside the classroom. At each stage of the experience, students were asked to establish links between the classroom-covered material and real objects in their environment. © Springer Science+Business Media B.V. 2008.
Multiobjective model for multicast overlay networks over IP/MPLS using MOEA
(2008-01-01) Montoya, J.; Donoso, Y.; Montoya, E.; Echeverri, D.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
Multicast plays an important role in supporting a new generation of applications. At present and for different reasons, technical and non-technical, multicast IP hasn't yet been totally adopted for Internet. During recent years, an active area of research is that of implementing this kind of traffic in the application layer where the multicast functionality isnt a responsibility of the routers but that of the hosts, which we know as Multicast Overlay Networks (MON). In this article, routing in an MON is put forward as a multiobjective optimization problem (MOP) where two functions are optimized: 1) the total end to end delay of the multicast tree and 2) the maximum link utilization. The simultaneous optimization of these two functions is an NP-Complete problem and to solve this we suggest using Multiobjective Evolutionary Algorithms (MOEA), specifically NSGA-II.
Poster: Collaborative data exploration using two navigation strategies
(IEEE COMPUTER SOC, 2009-01-01) Gomez, Omar; Trefftz, Helmuth; Boulanger, Pierre; Bischof, Walter F.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
Virtual collaborative systems are vital tools for accessing and sharing scientific data visualizations. This paper shows how two different modes of collaboration can affect user performance in a specific exploration task. Experiments with groups of users that are working in pairs showed that the lack of mobility can affect the ability to achieve specific exploration goals in a virtual environment. Our analysis reveals that the task was completed more efficiently when users were allowed to move freely and independently instead of working with limited mobility. In these systems, users adapted their own abilities and minimized theeffect of mobility restrictions. ©2009 IEEE.
Simulating soft tissues using a GPU approach of the mass-spring model
(2010-01-01) Leon, C.A.D.; Eliuk, S.; Gomez, H.T.; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
The recent advances in the fields such as modeling bio-mechanics of living tissues, haptic technologies, computational capacity, and graphics realism have created conditions necessary in order to develop effective surgical training using virtual environments. However, virtual simulators need to meet two requirements, they need to be real-time and highly realistic. The most expensive computational task in a surgical simulator is that of the physical model. The physical model is the component responsible to simulate the deformation of the anatomical structures and the most important factor in order to obtain realism. In this paper we present a novel approach to virtual surgery. The novelty comes in two forms: specifically a highly realistic mass-spring model, and a GPU based technique, and analysis, that provides a nearly 80x speedup over serial execution and 20x speedup over CPU based parallel execution. ©2010 IEEE.
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 Comunicaciones
Many 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.
Simulating Soft Tissues using a GPU approach of the Mass-Spring Model
(IEEE COMPUTER SOC, 2010-01-01) Diaz Leon, Christian Andres; Eliuk, Steven; Trefftz Gomez, Helmuth; Universidad EAFIT. Departamento de Ingeniería de Sistemas; I+D+I en Tecnologías de la Información y las Comunicaciones
The recent advances in the fields such as modeling bio-mechanics of living tissues, haptic technologies, computational capacity, and graphics realism have created conditions necessary in order to develop effective surgical training using virtual environments. However, virtual simulators need to meet two requirements, they need to be real-time and highly realistic. The most expensive computational task in a surgical simulator is that of the physical model. The physical model is the component responsible to simulate the deformation of the anatomical structures and the most important factor in order to obtain realism. In this paper we present a novel approach to virtual surgery. The novelty comes in two forms: specifically a highly realistic mass-spring model, and a GPU based technique, and analysis, that provides a nearly 80x speedup over serial execution and 20x speedup over CPU based parallel execution.

Examinar

Examinando Documentos de conferencia por Fecha de publicación

Resultados por página

Opciones de ordenación