5,434 research outputs found

    A framework for forensic face recognition based on recognition performance calibrated for the quality of image pairs

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    Recently, it has been shown that performance of a face recognition system depends on the quality of both face images participating in the recognition process: the reference and the test image. In the context of forensic face recognition, this observation has two implications: a) the quality of the trace (extracted from CCTV footage) constrains the performance achievable using a particular face recognition system; b) the quality of the suspect reference set (to which the trace is matched against) can be judiciously chosen to approach optimal recognition performance under such a constraint. Motivated by these recent findings, we propose a framework for forensic face recognition that is based on calibrating the recognition performance for the quality of pairs of images. The application of this framework to several mock-up forensic cases, created entirely from the MultiPIE dataset, shows that optimal recognition performance, under such a constraint, can be achieved by matching the quality (pose, illumination, and, imaging device) of the reference set to that of the trace. This improvement in recognition performance helps reduce the rate of misleading interpretation of the evidence

    What affects international migration of European science and engineering graduates?

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    In public policy, international migration of scientists and engineers is often seen as achance of recruiting the most talented and productive workers. However, it can alsobe a risk in terms of loosing a country’s talented workers. In this paper, we analysemigration of graduates from science and engineering studies from nine Europeancountries. Using a dataset with information on personal characteristics, previousmigration experience, as well as study- and work-related variables, we analyse thedeterminants of migrating to the country of the first job and to the country of subsequentjobs after graduation. We find that not only wage gains are driving the migrationdecision. Differences in labour market opportunities related to R&D spending area strong predictor of future migration. Furthermore, past migration experiences arerelated to a higher probability of labour migration. Moreover, we find evidence ofselective migration: the best graduates are most likely to migrate. Contrary to ourexpectation, qualitative aspects of the job match such as the utilisation of skills in thejob and involvement in innovation hardly seem to matter in the decision whetheror not to migrate. Interestingly, the wage level affects migration towards countriesin continental Europe, whereas Anglo-Saxon countries seem to attract migrants duetheir larger R&D intensity.education, training and the labour market;

    A story about standardization for design of glass works

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    This contribution attempts to give an overview of the European standardization framework which is related to the design and calculation of glass works in buildings. The different work levels, institutions, technical committees and workgroups, and the various types of documents and their statute will be introduced, explaining the difference between draft, experimental and final standards, between harmonized, support and design standards, the general and particular meaning of harmonization and implementation. The standardization framework is explained firstly from the point of view of European standardization policy and history, and secondly regarding the standardization framework in Belgium. In particular, an attempt is made to highlight some particularities existing in harmonization efforts of design methods and codes for glass works

    Controlling percolation with limited resources

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    Connectivity - or the lack thereof - is crucial for the function of many man-made systems, from financial and economic networks over epidemic spreading in social networks to technical infrastructure. Often, connections are deliberately established or removed to induce, maintain, or destroy global connectivity. Thus, there has been a great interest in understanding how to control percolation, the transition to large-scale connectivity. Previous work, however, studied control strategies assuming unlimited resources. Here, we depart from this unrealistic assumption and consider the effect of limited resources on the effectiveness of control. We show that, even for scarce resources, percolation can be controlled with an efficient intervention strategy. We derive this strategy and study its implications, revealing a discontinuous transition as an unintended side-effect of optimal control.Comment: 5 pages, 4 figures, additional supplemental material (19 pages

    Discrete hierarchy of sizes and performances in the exchange-traded fund universe

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    Using detailed statistical analyses of the size distribution of a universe of equity exchange-traded funds (ETFs), we discover a discrete hierarchy of sizes, which imprints a log-periodic structure on the probability distribution of ETF sizes that dominates the details of the asymptotic tail. This allows us to propose a classification of the studied universe of ETFs into seven size layers approximately organized according to a multiplicative ratio of 3.5 in their total market capitalization. Introducing a similarity metric generalising the Herfindhal index, we find that the largest ETFs exhibit a significantly stronger intra-layer and inter-layer similarity compared with the smaller ETFs. Comparing the performance across the seven discerned ETF size layers, we find an inverse size effect, namely large ETFs perform significantly better than the small ones both in 2014 and 2015

    Micro-transition cascades to percolation

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    We report the discovery of a discrete hierarchy of micro-transitions occurring in models of continuous and discontinuous percolation. The precursory micro-transitions allow us to target almost deterministically the location of the transition point to global connectivity. This extends to the class of intrinsically stochastic processes the possibility to use warning signals anticipating phase transitions in complex systems.Comment: 5 pages, 4 figures (main text) + 14 figures and 8 figures (supplementary materials). Accepted for publication by Physical Review Letter

    Multiframe Scene Flow with Piecewise Rigid Motion

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    We introduce a novel multiframe scene flow approach that jointly optimizes the consistency of the patch appearances and their local rigid motions from RGB-D image sequences. In contrast to the competing methods, we take advantage of an oversegmentation of the reference frame and robust optimization techniques. We formulate scene flow recovery as a global non-linear least squares problem which is iteratively solved by a damped Gauss-Newton approach. As a result, we obtain a qualitatively new level of accuracy in RGB-D based scene flow estimation which can potentially run in real-time. Our method can handle challenging cases with rigid, piecewise rigid, articulated and moderate non-rigid motion, and does not rely on prior knowledge about the types of motions and deformations. Extensive experiments on synthetic and real data show that our method outperforms state-of-the-art.Comment: International Conference on 3D Vision (3DV), Qingdao, China, October 201
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