Visualisation in e-Demand: A Grid Service Architecture for Stereoscopic Visualisation

The visualisation strand of the e-Demand project focuses on the use of Grid services to support stereoscopic visualisation in a distributed environment. The architectural design of the framework allows each part of the visualisation pipeline, implemented as a Grid service and communicating in a peer-to-peer manner, to be highly flexible and configurable using the resources most appropriate to the task. An implementation of the framework has been done using Java and a case study has been developed to test it

Intertextualidade e o cânone retórico

Este artigo parte de uma história etimológica dos termos "retórica" e "cânone" para abordar a interdependência de métodos e meios entre a arte literária (produção e crítica) e o tradicional sistema retórico que esteve na base da educação europeia desde a Antiguidade. A intertextualidade é reconhecida como uma "constante literária universal", e são apontados os modos pelos quais o ensino formal teve um papel central na validação do cânone literário na Idade Média e no Renascimento. Ao final, apontam-se caminhos para avaliar, decodificar e relativizar a tradição retórica no contexto da crítica moderna, ressaltando que o processo de desconstrução não deve implicar o desmantelamento das estruturas, mas uma consciente manifestação de cada uma delas.Palavras-chave: arte literária; crítica; intertextualidade; cânone; retórica.Abstract: Starting form an etymological history of the terms "rhetoric" and "canon", the article addresses the interdependence of methods and means between literary art (production and criticism) and the traditional rhetorical system that has been at the basis of European education since Antiquity. Intertextuality is recognized as a "universal literary constant," pointing out the ways in which formal (particularly British) teaching in the Middle Ages and in the Renaissance played a central role in validating the literary canon. In the end, ways to evaluate, decode and relativize the rhetorical tradition in the context of modern criticism are pointed out, emphasizing that the process of deconstruction should not imply the dismantling of structures, but a conscious manifestation of each one of them.Keywords: literary art; criticism; intertextuality; canon; rhetoric

Visualizing ordered bivariate data on node-link diagrams

Node-link visual representation is a widely used tool that allows decision-makers to see details about a network through the appropriate choice of visual metaphor. However, existing visualization methods are not always effective and efficient in representing bivariate graph-based data. This study proposes a novel node-link visual model – visual entropy (Vizent) graph – to effectively represent both primary and secondary values, such as uncertainty, on the edges simultaneously. We performed two user studies to demonstrate the efficiency and effectiveness of our approach in the context of static node-link diagrams. In the first experiment, we evaluated the performance of the Vizent design to determine if it performed equally well or better than existing alternatives in terms of response time and accuracy. Three static visual encodings that use two visual cues were selected from the literature for comparison: Width-Lightness, Saturation-Transparency, and Numerical values. We compared the Vizent design to the selected visual encodings on various graphs ranging in complexity from 5 to 25 edges for three different tasks. The participants achieved higher accuracy of their responses using Vizent and Numerical values; however, both Width-Lightness and Saturation-Transparency did not show equal performance for all tasks. Our results suggest that increasing graph size has no impact on Vizent in terms of response time and accuracy. The performance of the Vizent graph was then compared to the Numerical values visualization. The Wilcoxon signed-rank test revealed that mean response time in seconds was significantly less when the Vizent graphs were presented, while no significant difference in accuracy was found. The results from the experiments are encouraging and we believe justify using the Vizent graph as a good alternative to traditional methods for representing bivariate data in the context of node-link diagrams

Virtual-view adaption for 3D multi-view video streaming

Virtual views in 3D-TV and multi-view video systems are reconstructed images of the scene generated synthetically from the original views. In this paper, we analyze the performance of streaming virtual views over IP-networks with a limited and time-varying available bandwidth. We show that the average video quality perceived by the user can be improved with an adaptive streaming strategy aiming at maximizing the average video quality. Our adaptive 3D multi-view streaming can provide a quality improvement of 2 dB on the average - over non-adaptive streaming. We demonstrate that an optimized virtual view adaptation algorithm needs to be view-dependent and achieve an improvement of up to 0.7 dB. We analyze our adaptation strategies under dynamic available bandwidth in the network