1,466 research outputs found

    Millimetre wave person recognition: hand-crafted vs learned features

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    Imaging using millimeter waves (mmWs) has many advantages including ability to penetrate obscurants such as clothes and polymers. Although conceal weapon detection has been the predominant mmW imaging application, in this paper, we aim to gain some insight about the potential of using mmW images for person recognition. We report experimental results using the mmW TNO database consisting of 50 individuals based on both hand-crafted and learned features from Alexnet and VGG-face pretrained CNN models. Results suggest that: i) mmW torso region is more discriminative than mmW face and the entire body, ii) CNN features produce better results compared to hand-crafted features on mmW faces and the entire body, and iii) hand-crafted features slightly outperform CNN features on mmW torsoThis work has been partially supported by project CogniMetrics TEC2015-70627-R (MINECO/FEDER), and the SPATEK network (TEC2015-68766-REDC). E. GonzalezSosa is supported by a PhD scholarship from Universidad Autonoma de Madrid. Vishal M. Patel was partially supported by US Office of Naval Research (ONR) Grant YIP N00014-16-1-3134. Authors wish to thank also TNO for providing access to the databas

    Agricultura urbana y periurbana como contribución a la estrategia de conservación de la biodiversidad de Heliconias en la región central de Cuba

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    New ways of sustainable production on urban and peri- urbans areas have contributed to the conservation of species diversity, as to ornamentals plants that belong to family: Heliconiaceae. For this reason we recorded nine species of Heliconia as new accessions from Central Region of Cuba, that were prospected in gardens and yards of national reference as well as from three botanical gardens in central provinces of Cuba (Cienfuegos, Villa Clara and Santi Spíritus), located in forested mountain areas. Molecular corroboration of the species collected was included, as well as a brief description of the morphological and ecological characteristics of these accessions. We show the high commercial potential they have for the island and the contribution to the territorial expansion of these species. In the propagation strategy we considered the micropropagation through biotechnological techniques of tissue culture and in vitro conservation in Cienfuegos Biofactory. The collaboration of universities and the municipal government of Cuba Central region together with the active participation of the farmers have allowed the development of new areas, gardens and home gardens, despite limited resources

    Absence of Face-specific Cortical Activity in the Complete Absence of Awareness: Converging Evidence from Functional Magnetic Resonance Imaging and Event-related Potentials

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    In this study, we explored the neural correlates of perceptual awareness during a masked face detection task. To assess awareness more precisely than in previous studies, participants employed a 4-point scale to rate subjective visibility. An event-related fMRI and a high-density ERP study were carried out. Imaging data showed that conscious face detection was linked to activation of fusiform and occipital face areas. Frontal and parietal regions, including the pre-SMA, inferior frontal sulcus, anterior insula/frontal operculum, and intraparietal sulcus, also responded strongly when faces were consciously perceived. In contrast, no brain area showed face-selective activity when participants reported no impression of a face. ERP results showed that conscious face detection was associated with enhanced N170 and also with the presence of a second negativity around 300 msec and a slow positivity around 415 msec. Again, face-related activity was absent when faces were not consciously perceived. We suggest that, under conditions of backward masking, ventral stream and fronto-parietal regions show similar, strong links of face-related activity to conscious perception and stress the importance of a detailed assessment of awareness to examine activity related to unseen stimulus events

    ZnO (Ag-N) Nanorods Films Optimized for Photocatalytic Water Purification

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    ZnO nanorods (NRs) films, nitrogen-doped (ZnO:N), and ZnO doped with nitrogen and decorated with silver nanostructures (ZnO:N-Ag) NRs films were vertically supported on undoped and N doped ZnO seed layers by a wet chemical method. The obtained films were characterized structurally by X-ray diffraction. Morphological and elemental analysis was performed by scanning electron microscopy, including an energy dispersive X-ray spectroscopy facility and their optical properties by Ultraviolet-Visible Spectroscopy. Analysis performed in the NRs films showed that the nitrogen content in the seed layer strongly affected their structure and morphology. The mean diameter of ZnO NRs ranged from 70 to 190 nm. As the nitrogen content in the seed layer increased, the mean diameter of ZnO:N NRs increased from 132 to 250 nm and the diameter dispersion decreased. This diameter increase occurs simultaneously with the incorporation of nitrogen into the ZnO crystal lattice and the increase in the volume of the unit cell, calculated using the X-ray diffraction patterns and confirmed by a slight shift in the XRD angle. The diffractograms indicated that the NRs have a hexagonal wurtzite structure, with preferential growth direction along the c axis. The SEM images confirmed the presence of metallic silver in the form of nanoparticles dispersed on the NRs films. Finally, the degradation of methyl orange (MO) in an aqueous solution was studied by UV-vis irradiation of NRs films contained in the bulk of aqueous MO solutions. We found a significant enhancement of the photocatalytic degradation efficiency, with ZnO:N-Ag NRs film being more efficient than ZnO:N NRs film, and the latter better than the ZnO NRs film. View Full-Text
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