378 research outputs found

    UFPR-Periocular: A Periocular Dataset Collected by Mobile Devices in Unconstrained Scenarios

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    Recently, ocular biometrics in unconstrained environments using images obtained at visible wavelength have gained the researchers' attention, especially with images captured by mobile devices. Periocular recognition has been demonstrated to be an alternative when the iris trait is not available due to occlusions or low image resolution. However, the periocular trait does not have the high uniqueness presented in the iris trait. Thus, the use of datasets containing many subjects is essential to assess biometric systems' capacity to extract discriminating information from the periocular region. Also, to address the within-class variability caused by lighting and attributes in the periocular region, it is of paramount importance to use datasets with images of the same subject captured in distinct sessions. As the datasets available in the literature do not present all these factors, in this work, we present a new periocular dataset containing samples from 1,122 subjects, acquired in 3 sessions by 196 different mobile devices. The images were captured under unconstrained environments with just a single instruction to the participants: to place their eyes on a region of interest. We also performed an extensive benchmark with several Convolutional Neural Network (CNN) architectures and models that have been employed in state-of-the-art approaches based on Multi-class Classification, Multitask Learning, Pairwise Filters Network, and Siamese Network. The results achieved in the closed- and open-world protocol, considering the identification and verification tasks, show that this area still needs research and development

    Robust Iris Segmentation Based on Fully Convolutional Networks and Generative Adversarial Networks

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    The iris can be considered as one of the most important biometric traits due to its high degree of uniqueness. Iris-based biometrics applications depend mainly on the iris segmentation whose suitability is not robust for different environments such as near-infrared (NIR) and visible (VIS) ones. In this paper, two approaches for robust iris segmentation based on Fully Convolutional Networks (FCNs) and Generative Adversarial Networks (GANs) are described. Similar to a common convolutional network, but without the fully connected layers (i.e., the classification layers), an FCN employs at its end a combination of pooling layers from different convolutional layers. Based on the game theory, a GAN is designed as two networks competing with each other to generate the best segmentation. The proposed segmentation networks achieved promising results in all evaluated datasets (i.e., BioSec, CasiaI3, CasiaT4, IITD-1) of NIR images and (NICE.I, CrEye-Iris and MICHE-I) of VIS images in both non-cooperative and cooperative domains, outperforming the baselines techniques which are the best ones found so far in the literature, i.e., a new state of the art for these datasets. Furthermore, we manually labeled 2,431 images from CasiaT4, CrEye-Iris and MICHE-I datasets, making the masks available for research purposes.Comment: Accepted for presentation at the Conference on Graphics, Patterns and Images (SIBGRAPI) 201

    Paradoxos da ‚Äúidentidade nacional‚ÄĚ nos discursos arquitet√īnicos de Lucio Costa e Sylvio de Vasconcellos

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    n the debate about the period and the architectural style that represented the national identity in the historiography of Brazilian architecture, in the first decades of the twentieth century, different agents took place in the consolidation of the architectural heritage idea. Important characters in cultural preservation policies, such as Rodrigo Melo Franco de Andrade and M√°rio de Andrade, integrated the public space emphasizing their positions of organic intellectuals in cultural policies. Given this fact, this article focuses on the consolidation in the social imaginary of eighteenth-century architecture as an effective representation of national architecture, consolidating itself as a style/period with the largest number of buildings listed until 1970. Understanding the different subjects involved in this process, this article focuses on the effective political action of Lucio Costa and Sylvio Vasconcellos on the defense of colonial heritage, based on texts and interventions in the overturned cities throughout Brazil, shaping and consolidating their strategies around an ideology of heritage and nation. In addition, we seek to understand the direct relationship established by both agents between the ‚Äúelected‚ÄĚ national heritage architecture and the precepts of the new architectural practice linked to the Modern Movement, to which they were adherents. Justifying the new from the primitive, in a perfect relationship where everything can be explained and fitted, the eclectic architecture was treated as a copy of styles, exacerbation of ornaments and link to foreignism, in opposition at the claimed nation project. We should always review concepts and guidelines, dealing more truthfully and fairly with our eclectic heritage, and consequently with our architectural historiography.No debate em torno do per√≠odo e do estilo arquitet√īnico que representassem a identidade nacional na historiografia da arquitetura brasileira, nas primeiras d√©cadas do s√©culo XX, diferentes agentes tomaram lugar na consolida√ß√£o do ide√°rio patrimonial arquitet√īnico. Figuras marcantes √†s pol√≠ticas de preserva√ß√£o cultural, tais como Rodrigo Melo Franco de Andrade e M√°rio de Andrade, integraram o espa√ßo p√ļblico ressaltando suas posi√ß√Ķes de intelectuais inerentes √†s pol√≠ticas culturais. Tendo em vista tal fato, este artigo se debru√ßa sobre a consolida√ß√£o no imagin√°rio social da arquitetura setecentista enquanto efetiva representa√ß√£o da arquitetura nacional, concretizando-se enquanto estilo/per√≠odo com o maior n√ļmero de edifica√ß√Ķes tombadas at√© 1970. Compreendendo os diferentes sujeitos envolvidos nesse processo, centra-se, assim, na efetiva a√ß√£o pol√≠tica de Lucio Costa e Sylvio Vasconcellos na defesa em torno do patrim√īnio colonial, a partir de textos e interven√ß√Ķes nas cidades tombadas Brasil afora, conformandoe consolidando suas estrat√©gias em torno de um ide√°rio de patrim√īnio e na√ß√£o. Al√©m disso, busca-se compreender a rela√ß√£o direta estabelecida por ambos os agentes entre a arquitetura ‚Äúeleita‚ÄĚ patrim√īnio nacional e os preceitos do novo fazer arquitet√īnico vinculado ao Movimento Moderno, ao qual eram adeptos. Justificando o novo a partir do primitivo, numa rela√ß√£o perfeita em que tudo se explica e se encaixa, a arquitetura ecl√©tica foi tratada como c√≥pia de estilos, exacerba√ß√£o de ornamentos e vincula√ß√£o ao estrangeirismo, se opondo assim ao projeto de na√ß√£o pleiteado. Devemos sempre rever conceitos e diretrizes, tratando de forma mais verdadeira e justa o nosso patrim√īnio ecl√©tico, e em consequ√™ncia, nossa historiografia arquitet√īnica

    The status of the Quijote multi-frequency instrument

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    The QUIJOTE-CMB project has been described in previous publications. Here we present the current status of the QUIJOTE multi-frequency instrument (MFI) with five separate polarimeters (providing 5 independent sky pixels): two which operate at 10-14 GHz, two which operate at 16-20 GHz, and a central polarimeter at 30 GHz. The optical arrangement includes 5 conical corrugated feedhorns staring into a dual reflector crossed-draconian system, which provides optimal cross-polarization properties (designed to be < -35 dB) and symmetric beams. Each horn feeds a novel cryogenic on-axis rotating polar modulator which can rotate at a speed of up to 1 Hz. The science driver for this first instrument is the characterization of the galactic emission. The polarimeters use the polar modulator to derive linear polar parameters Q, U and I and switch out various systematics. The detection system provides optimum sensitivity through 2 correlated and 2 total power channels. The system is calibrated using bright polarized celestial sources and through a secondary calibration source and antenna. The acquisition system, telescope control and housekeeping are all linked through a real-time gigabit Ethernet network. All communication, power and helium gas are passed through a central rotary joint. The time stamp is synchronized to a GPS time signal. The acquisition software is based on PLCs written in Beckhoffs TwinCat and ethercat. The user interface is written in LABVIEW. The status of the QUIJOTE MFI will be presented including pre-commissioning results and laboratory testing

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Detection chain and electronic readout of the QUBIC instrument

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    The Q and U Bolometric Interferometer for Cosmology (QUBIC) Technical Demonstrator (TD) aiming to shows the feasibility of the combination of interferometry and bolometric detection. The electronic readout system is based on an array of 128 NbSi Transition Edge Sensors cooled at 350mK readout with 128 SQUIDs at 1K controlled and amplified by an Application Specific Integrated Circuit at 40K. This readout design allows a 128:1 Time Domain Multiplexing. We report the design and the performance of the detection chain in this paper. The technological demonstrator unwent a campaign of test in the lab. Evaluation of the QUBIC bolometers and readout electronics includes the measurement of I-V curves, time constant and the Noise Equivalent Power. Currently the mean Noise Equivalent Power is ~ 2 x 10‚ĀĽ¬Ļ‚Ā∂ W/‚ąöHz
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