Fiuza F.,University of Lisbon |
Fonseca R.A.,University of Lisbon |
Fonseca R.A.,Instituto Universitario Of Lisbon |
Tonge J.,University of California at Los Angeles |
And 2 more authors.
Physical Review Letters | Year: 2012
The formation of nonrelativistic collisionless shocks in the laboratory with ultrahigh intensity lasers is studied via ab initio multidimensional particle-in-cell simulations. The microphysics behind shock formation and dissipation and the detailed shock structure are analyzed, illustrating that the Weibel instability plays a crucial role in the generation of strong subequipartition magnetic fields that isotropize the incoming flow and lead to the formation of a collisionless shock, similar to what occurs in astrophysical scenarios. The possibility of generating such collisionless shocks in the laboratory opens the way to the direct study of the physics associated with astrophysical shocks. © 2012 American Physical Society. Source
Mostafa M.M.,Instituto Universitario Of Lisbon
Expert Systems with Applications | Year: 2013
Blogs and social networks have recently become a valuable resource for mining sentiments in fields as diverse as customer relationship management, public opinion tracking and text filtering. In fact knowledge obtained from social networks such as Twitter and Facebook has been shown to be extremely valuable to marketing research companies, public opinion organizations and other text mining entities. However, Web texts have been classified as noisy as they represent considerable problems both at the lexical and the syntactic levels. In this research we used a random sample of 3516 tweets to evaluate consumers' sentiment towards well-known brands such as Nokia, T-Mobile, IBM, KLM and DHL. We used an expert-predefined lexicon including around 6800 seed adjectives with known orientation to conduct the analysis. Our results indicate a generally positive consumer sentiment towards several famous brands. By using both a qualitative and quantitative methodology to analyze brands' tweets, this study adds breadth and depth to the debate over attitudes towards cosmopolitan brands. © 2012 Elsevier Ltd. All rights reserved. Source
Almeida M.S.C.,University of Lisbon |
Almeida M.S.C.,Instituto Universitario Of Lisbon |
Figueiredo M.A.T.,University of Lisbon
IEEE Transactions on Image Processing | Year: 2013
Image deblurring (ID) is an ill-posed problem typically addressed by using regularization, or prior knowledge, on the unknown image (and also on the blur operator, in the blind case). ID is often formulated as an optimization problem, where the objective function includes a data term encouraging the estimated image (and blur, in blind ID) to explain the observed data well (typically, the squared norm of a residual) plus a regularizer that penalizes solutions deemed undesirable. The performance of this approach depends critically (among other things) on the relative weight of the regularizer (the regularization parameter) and on the number of iterations of the algorithm used to address the optimization problem. In this paper, we propose new criteria for adjusting the regularization parameter and/or the number of iterations of ID algorithms. The rationale is that if the recovered image (and blur, in blind ID) is well estimated, the residual image is spectrally white; contrarily, a poorly deblurred image typically exhibits structured artifacts (e.g., ringing, oversmoothness), yielding residuals that are not spectrally white. The proposed criterion is particularly well suited to a recent blind ID algorithm that uses continuation, i.e., slowly decreases the regularization parameter along the iterations; in this case, choosing this parameter and deciding when to stop are one and the same thing. Our experiments show that the proposed whiteness-based criteria yield improvements in SNR, on average, only 0.15 dB below those obtained by (clairvoyantly) stopping the algorithm at the best SNR. We also illustrate the proposed criteria on non-blind ID, reporting results that are competitive with state-of-the-art criteria (such as Monte Carlo-based GSURE and projected SURE), which, however, are not applicable for blind ID. © 1992-2012 IEEE. Source
Agency: Cordis | Branch: FP7 | Program: MC-CIG | Phase: FP7-PEOPLE-2013-CIG | Award Amount: 100.00K | Year: 2014
The proposed research program is designed to investigate the embodied mechanisms that ground cognition, in first (L1) and second (L2) language. We suggest that different languages shape our thinking, perceiving and feeling of the world. More importantly, they are grounded differently. We argue that whereas L1 is embodied, this is not the case for L2, or at least not to the same degree. The proposed experiments are designed to systematically compare L1/L2 related differences in performance as well as psychophysiological indicators in a number of paradigms presented to early (EB) and late (LB) bilinguals. To our knowledge these are among the first studies on embodiment with bilingual samples. The suggestion that L1 and L2 are unlikely to be equally embodied will be investigated in a study designed to furnish a direct examination of how L1 and L2 are somatically grounded (a neglected feature of both the embodied literature as well as bilingualism research). Studies 2 to 4 investigate how embodied simulation may drive specific phenomena such language congruence effects, modality switching costs and false memories in L1 and L2. Studies 5 & 6 will provide a more ecologically valid indication of how affective and interpersonal states are manifested in spontaneous linguistic representations when using L1 and L2. Our findings are likely to advance our understanding of a number of central issues pertinent to the emerging field of embodiment and may lend additional support to the assumptions that cognition and language are grounded on bodily states. Second, this research will identify the constraints of such assumptions in an increasingly multilingual and multicultural world where the daily use of a second language for professional, recreational and interpersonal purposes is often required. This is likely to inform research and policies designed to address the current challenges posed by participating in two or more linguistic communities.
Agency: Cordis | Branch: H2020 | Program: RIA | Phase: PHC-04-2015 | Award Amount: 5.95M | Year: 2016
The overarching aim of INHERIT is to define effective inter-sectoral policies and interventions that promote health and well being across the social gradient by tackling key environmental stressors and related inequalities in the areas of living, consuming and moving. INHERIT will bring together relevant stakeholders from different sectors, including the private sector. It will support inter-sectoral cooperation between environment, climate and health by: a) Analysing existing scientific knowledge on key environmental stressors to health and approaches to address these; b) Identifying existing promising inter-sector policies and interventions that enable conditions for more healthy and environmentally sustainable behaviours, in three main areas: living, consuming and moving; c) Developing a Common Analytical Framework using impact assessment tools and quantitative and qualitative indicators to assess the social, environmental and health benefits and the economic value in promising inter-sectoral interventions; d) Developing targets and future visions while considering overall economic and politics contexts and global trends (i.e. participatory back-casting, stakeholder and citizen consultations and household surveys); e) Implementing, testing and evaluating pilot interventions in different European contexts; f) Enhancing the leadership skills of public health professionals in inter-sectoral work to address key environmental stressors to health and promote healthy and environmentally sustainable lifestyles; g) Translating evaluation findings into models of good practice for effective inter-sectoral work and evidence based tools for policy development to contribute to the global and European environment, health and sustainable development policy agenda. The novelty of INHERIT lies in its support for health, environment and climate sectors to jointly pursue the inter-related goals of improving health and well-being of the population while preserving the environment.