Lista de Projetos

Este projecto de investigação pretende analisar e compreender um aspecto particular da relação entre tecnologia e sociedade. Procura-se investigar a forma como as tecnologias da informação e da comunicação (TIC) estão a ser integradas e utilizadas na escola e nos processos de ensino e aprendizagem no ensino secundário.

Future satellite communications systems face a challenge to provide higher bitrates, together with improved QoS (quality of service) guarantees, to more GT (ground terminals). Moreover, this should be achieved with higher spectral and power efficiencies, with less energy.This project considers future very high bitrate LEO (Low Earth Orbit) satellite systems with satellite MPR (multipacket reception), compatible with low-cost portable GTs. A cross-layered approach is proposed: a physical layer team will handle the signal design, the synchronization and estimation issues, and the receiver design, including MPR development; a data link layer team will handle the Multiple Access control protocol design and the scheduling algorithm to support different QoS (Quality of Service) classes, and the interaction with the network layers. Both teams will be involved in the design and test of the cross-layering features involving both layers, required to provide guaranteed QoS, even during satellite handover.In this project we will develop OQPSK-type schemes with reduced envelope fluctuations and high power and spectral efficiencies and compatible with an efficient and low cost power amplification. To further improve the overall system power efficiency we also consider schemes with spectral overlapping between different frequency channels. With respect to the receiver design, the main goal is an efficient multipacket detection technique able to cope with collisions, already shown by the research team to allow significant improvements in personal area networks. We will consider turbo frequency-domain equalizers suitable to cope with time-dispersion effects and able to handle spectral overlapping between frequency channels. Hybrid ARQ/FEC (Automatic Repeat reQuest/Forward Error Correction), namely with packet combining, will be proposed to handle fading for the most demanding QoS classes and control packets. To cope with Doppler effects, suitable synchronization and channel estimati...

Este estudo teve como objetivo inventariar, catalogar e analisar o trabalho de Equipas sucessivas que pertenciam às estruturas dos Ministérios das Colónias e mais tarde do Ultramar (doravante designados ministérios no exterior) e que eram responsáveis pelo projeto arquitetónico faz parte de uma abordagem mais abrangente estudar sobre a cidade e a arquitetura produzida nos antigos territórios coloniais, cujo objetivo é promover o conhecimento do património intelectual e construído gerado pelos portugueses e disponibilizá-lo ao público em geral por meio de um sistema de consulta online .

The goal of the project is to advance the state of the art in criteria and algorithms for solving imaging inverse problems. The research fronts that we aim to push forward are the following: a) In standard photography, and even more in computational photography (CP), deconvolution plays a key role. In the standard case, deblurring is used to compensate lens softness, while in many CP applications (e.g., coded aperture) deconvolution is itself responsible for producing the images. Even with the CP ''friendly'' direct operators, prior knowledge (regularization) is required to solve the IP. In this work front, we will develop new regularization criteria, beyond the currently used sparseness-inducing 1-norm and total-variation. In particular, we will consider: compound regularizers; criteria that adapt automatically to the intrinsic complexity and/or the local structure of the underlying image; non-local regularization (which has only been used for pure denoising problems, with excellent results).b) Realistically, full knowledge about the convolution operator is seldom available: the exact motion causing a motion blur is of course unknown; coded aperture imaging is highly sensitive to the exact knowledge of the aperture, which is usually obtained by a previous careful calibration procedure. These observations stress the general importance of blind deconvolution. In this topic, we willresearch criteria for blind deconvolution, for problems with varying degrees of uncertainty about the direct operator. In particular, we will take steps towards the ''holly grail'' of blind deconvolution: an objective function whose minimization yields optimal image and convolution estimates.c) Some of the currently fastest algorithms for CS and image deconvolution under standard regularizers were developed by researchers in the project team. The new criteria mentioned in (a) and (b) will result in new, more challenging optimization problems, requiring new algorithms. This will be the third...

A pesquisa a desenvolver visa contribuir para compreender e explicar a complexa realidade da reintegração social de dependentes de substâncias psicoactivas, após a passagem por um processo de tratamento numa comunidade terapêutica. Através da articulação entre diferentes perspectivas teóricas pretende-se identificar tendências e factores que conduzam a uma efectiva reintegração social, abandonando o consumo de substâncias psicoactivas. Pretende-se desenvolver um modelo de análise que equacione diferentes dimensões analíticas dando conta dos factores de reforço versus vulnerabilidade que poderão influenciar as trajectórias de reintegração social destes indivíduos. Constituem objectivos centrais da pesquisa captar regularidades e singularidades sociais presentes nas estratégias de reintegração dos indivíduos e associadas a padrões sociais, familiares, individuais, a competências adquiridas durante o processo terapêutico, ou resultantes da apropriação de medidas institucionais.