Abstract
The present paper describes the Portuguese National Brain Imaging Network designed to join R&D efforts of four Portuguese universities (Aveiro, Coimbra, Minho and Porto) in this emergent scientific area. This is an open initiative, already funded in 81.3% of its predicted investment (similar to 4.3 million E) for the first 5 years of operation, opened to the participation of other national institutions. This area of neuroscience uses several types of datasets from different medical imaging modalities and biosignals. MRI/MRS and fMRI volumes along with high-resolution EEG are our main targets for the first 5 years of operation and can easily reach the GByte size for a patient study. The Brain Imaging Network Grid (BING) will provide the support to a "neuroscientist-friendly" web portal where neuroscientists can submit brain imaging datasets for different analysis protocols. We will focus the present paper on the description of the consortium, its objectives and the network and Grid services architecture designs that will provide both the computational resources and the federated large data repository for the Portuguese national wide neuroscience scientific community.

Abstract
This paper presents a formal model for a multi-purpose, strategical coordination layer. Based on previous work developed for the RoboCup Soccer simulation, small-size, middle-size, legged leagues and RoboCup Rescue simulation league, a generic coordination model was built that allows the management of collaborative networks of heterogeneous agents. The model uses a multi-level hierarchical approach with the following concepts: strategy, tactics, formations, suh-tactics and roles, from high to low level. Hybrid methods, are used to switch formations and tactics. In order to test the model, two strategy instances, for RoboCup Rescue Simulation and RoboCup Soccer, were developed. Strategies are designed with the help of a graphical tool. Results achieved by the team in RoboCup Rescue and Soccer Simulation competitions demonstrate the usefulness of his approach.

Abstract

Abstract
Question Answering (QA) has been an area of interest for researchers, in part motivated by the international QA evaluation forums, namely the Text REtrieval Conference (TREC), and more recently, the Cross Language Evaluation Forum (CLEF) through QA@CLEF, that since 2004 includes the Portuguese language. In these forums, a collection of written documents is provided, as well as a set of questions, which are to be answered by the participating systems. Each system is evaluated by its capacity to answer the questions, as a whole, and there are relatively few results published that focus on the performance of its different components and their influence on the overall system performance. That is the case of the Information Retrieval (IR) component, which is broadly used in QA systems. Our work concentrates on the different options of preprocessing Portuguese text before feeding it to the IR component, evaluating their impact on the IR performance in the specific context of QA, so that we can make a sustained choice of which options to choose. From this work we conclude the clear advantage of the basic preprocessing techniques: case folding and removal of punctuation marks. For the other techniques considered, stop word removal enhanced the performance of the IR system but that was not the case as far as Stemming and Lemmatization are concerned. © 2007 ACM.

Abstract
In this paper, we study the performance of the optimum receiver for nonlinear distorted OFDM signals in RoF applications, which is composed by a demodulator followed by an ML detector. The demodulator observes the various intermodulation products to compute a set of sufficient statistics, while the detector observes the sufficient statistics to compute an estimate of the original data. Particularly, we concentrate on the uplink of intensity modulation/direct detection RoF system where the OFDM signal suffers from linear distortion (fading), nonlinear distortion and noise. We demonstrate that the optimum receiver outperforms the conventional OFDM receiver by several orders of magnitude.

Abstract
This article reports the study of fractional dynamics during the evolution of a Particle Swarm Optimization (PSO) algorithm. Some initial swarm particles are randomly changed, for stimulating the system response, and its effect is compared with a non-perturbed reference. The perturbation effect in the PSO evolution is observed in the perspective of the fitness time behavior of the best particle. The dynamics is represented through the median of a sample of experiments, while adopting the Fourier analysis for describing the phenomena. The influence of the PSO parameters influence upon the global dynamics is also analyzed.