Resultats de la cerca198 resultats
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Building of a Motion Feedback Roller Coaster Simulatior: a Case Study
Expósito, Sánchez, M. A.; García fernández, I.; Gamón, M. A.; Pla castells, M.; Martínez Durá, R. J.
(2010). ArticlePROC OF ISC. 2010.
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Modelling and Simulation of Several Interacting Cellular Automata
Pla Castells, M.; García Fernández, I.; Martínez Durá, R. J.
(2010). ArticlePROC. OF ISC. 2010. Cellular Automata are used for modelling and simulation of many systems. In some applications, the system is formed by a set of subsystems that can be modelled separately, but, in such cases, the existence of interactions between these subsystems requires additional modelling and computer programming. In this paper we propose a modelling methodology for the simulation of a set of Cellular Automata models that interact with each other. The modelling methodology is described, together with an insight on implementation details. Also, it is applied to a particular Cellular Automata model, the Sanpile Model, to illustrate its use and to obtain some example simulations.
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Accelerating consensus gossip algorithms: Sparsifying networks can be good for you
Asensio, C.; Beferull-Lozano, B.
(2010). ArticleIn this paper, we consider the problem of improving the convergence speed of an average consensus gossip algorithm by sparsifying a sufficiently dense network graph. Thus, instead of adding links, as usually proposed in the literature, or globally optimizing the mixing matrix of the gossip algorithm for a given network, which requires global knowledge at every node, we find a sparser network that has better spectral properties and faster convergence than the original denser one. This allows to reduce simultaneously both the convergence time and the communication cost involved in the execution of the gossip algorithm. We first show why it is possible to sparsify a network while increasing...
In this paper, we consider the problem of improving the convergence speed of an average consensus gossip algorithm by sparsifying a sufficiently dense network graph. Thus, instead of adding links, as usually proposed in the literature, or globally optimizing the mixing matrix of the gossip algorithm for a given network, which requires global knowledge at every node, we find a sparser network that has better spectral properties and faster convergence than the original denser one. This allows to reduce simultaneously both the convergence time and the communication cost involved in the execution of the gossip algorithm. We first show why it is possible to sparsify a network while increasing its convergence rate and also that there exists an optimal fraction of links to be removed. As a benchmark, we devise a centralized method that selects in an optimal way the set of links to be removed from the original network. Then, we propose a low complexity and scalable decentralized protocol requiring only local information at each node, which also generates a sparser network having a substantially better convergence rate. Simulation results are presented to verify and show clearly the efficiency of our approach.
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Finding Sparse Connectivity Patterns in Power-Constrained Ad-hoc Networks for accelerating consensus algorithms
Asensio, C.; Beferull-Lozano, B.
(2010). ArticleIn this paper, we show how to critically sparsify a given network while improving the convergence rate of the associated average consensus algorithm. Thus, instead of adding new links or reallocating them, we propose novel distributed methods to nd much sparser networks with better convergence results than the original denser ones. We propose two distributed algorithms; a) in the first one, each node solves a local optimization problem using only its two-hop neighborhood, b) the second one is a distributed algorithm based on using, at each node, the power method. As compared with previous work, the reduction in the number of active links is doubled while improving the convergence rate and...
In this paper, we show how to critically sparsify a given network while improving the convergence rate of the associated average consensus algorithm. Thus, instead of adding new links or reallocating them, we propose novel distributed methods to nd much sparser networks with better convergence results than the original denser ones. We propose two distributed algorithms; a) in the first one, each node solves a local optimization problem using only its two-hop neighborhood, b) the second one is a distributed algorithm based on using, at each node, the power method. As compared with previous work, the reduction in the number of active links is doubled while improving the convergence rate and having a much lower power consumption. Simulation results are presented to verify and show clearly the eciency of our approach.
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On Multiterminal source coding for temperature sensing
Beferull-Lozano, B.; Konsbruck, R.
(2010). ArticleWe study the source coding problem in sensor networks deployed to monitor the evolution of spatio-temporal temperature distributions. The sensors sample the temperature field, quantize the samples and transmit the encoded samples through digital channels to some central unit, which computes an estimate of the original temperature field. Our analysis is based on the heat kernel's spectral properties, which are induced by the physics of heat diffusion. We determine rate distortion functions for various source coding schemes. In particular, we compare centralized coding, independent coding, Berger-Tung coding, and predictive quantization.
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CGVR'09: Integrating Virtual Environments with Multimedia contents in a Web Application
Vera, Lucía; Coma, Inmaculada; Talón, Rubén; Fernández, Marcos
(2009). ArticleIn the present paper a system architecture for the combination, interaction and synchronization between different technologies is presented. Our system integrates 3D interactive virtual environments, 2D animations and games, avatars, form applications and documents, videos based in Chroma Key technology and other multimedia components. All of this inside a unique web application with a special objective, developing an interactive game for people who would like to become a self-employed worker. As the legal procedure (focused in the Spanish model) to start to be a sole trader is difficult and hard, we have developed a very intuitive, easy to use and enjoyable game to cover all information...
In the present paper a system architecture for the combination, interaction and synchronization between different technologies is presented. Our system integrates 3D interactive virtual environments, 2D animations and games, avatars, form applications and documents, videos based in Chroma Key technology and other multimedia components. All of this inside a unique web application with a special objective, developing an interactive game for people who would like to become a self-employed worker. As the legal procedure (focused in the Spanish model) to start to be a sole trader is difficult and hard, we have developed a very intuitive, easy to use and enjoyable game to cover all information needed by these collective of people. The authors describe all the components of the architecture, the technologies used for developing each module and the combination and interaction between them to finally obtain this interactive game integrated inside a web application.
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JOREVIR'09: Interacción con Entornos Virtuales en Teléfonos Móviles
Gimeno, Jesús; Coma, Inmaculada; Fernández, Marcos; Morillo, Pedro; Vera, Lucía
(2009). ArticleEn este trabajo presentamos un sistema para la navegación en entornos virtuales 3D sobre teléfonos móviles. Tradicionalmente la interacción con el teléfono móvil se ha realizado utilizando el teclado como dispositivo de interacción. Sin embargo, gracias a las capacidades de los nuevos terminales es posible aprovechar dispositivos como la cámara incorporada o los acelerómetros para implementar interacciones basadas en movimientos naturales del usuario. En el presente trabajo hemos tratado de crear un mecanismo de interacción con entornos virtuales que sea adaptable a las tecnologías incorporadas en el teléfono, de forma que se pueda interaccionar bien interacción mediante las teclas, o bien...
En este trabajo presentamos un sistema para la navegación en entornos virtuales 3D sobre teléfonos móviles. Tradicionalmente la interacción con el teléfono móvil se ha realizado utilizando el teclado como dispositivo de interacción. Sin embargo, gracias a las capacidades de los nuevos terminales es posible aprovechar dispositivos como la cámara incorporada o los acelerómetros para implementar interacciones basadas en movimientos naturales del usuario. En el presente trabajo hemos tratado de crear un mecanismo de interacción con entornos virtuales que sea adaptable a las tecnologías incorporadas en el teléfono, de forma que se pueda interaccionar bien interacción mediante las teclas, o bien capturar los movimientos del usuario haciendo uso de los acelerómetros o las imágenes capturadas por la cámara de vídeo. Para estimar el movimiento a partir de las imágenes capturadas se ha utilizado un algoritmo diferencial. Por último se ha diseñado un entorno 3D que permite el acceso a contenidos Web y multimedia.
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IPCV'09: A Device-Independent 3D User Interface for Mobile Phones Based on Motion and Tracking Techniques
Gimeno, Jesús; Morillo, Pedro; Coma, Inmaculada; Fernández, Marcos
(2009). ArticleThe user interaction in mobile phones has been traditionally based on key behaviors that users have adapted around their mobile devices. Although this type of interaction could be suitable for some contents, it could be improved from the point of view of the usability. In this paper we present a new user interface based on 3D navigation oriented to mobile phones. To enhance the user experience, we have developed a new interface based on 3D real-time graphics where users interact by means of natural movements of their devices. The goals of this development consist in enhancing the user interaction and accessibility to web content or interactive multimedia applications by means of avoiding a...
The user interaction in mobile phones has been traditionally based on key behaviors that users have adapted around their mobile devices. Although this type of interaction could be suitable for some contents, it could be improved from the point of view of the usability. In this paper we present a new user interface based on 3D navigation oriented to mobile phones. To enhance the user experience, we have developed a new interface based on 3D real-time graphics where users interact by means of natural movements of their devices. The goals of this development consist in enhancing the user interaction and accessibility to web content or interactive multimedia applications by means of avoiding a key-based, or a mouse-based, navigation and proposing a software solution adaptable to multiple and different mobile devices. In this sense, the user inputs can be detected by different input devices such as accelerometers or cameras, as well as the traditional keypads. Since mobile phones with on-board digital cameras are now widely available at low cost, the proposed 3D user interface exploits the acquisition capabilities of these input devices. In this sense, a differential algorithm has been applied in order to estimate phone movements from video images. The results of the performance evaluation of the 3D user interface shows that the proposed algorithm not only obtains a motion and tracking under extreme lighting conditions, but also adds an insignificant overhead to the system performance. Finally, a 3D environment has been designed to evaluate the performance of the presented approach, which has been successfully tested in actual users.
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