98 research outputs found

    A Novel Feature Extraction Descriptor for Face Recognition

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    This paper presents a new feature extraction technique for face recognition. The new model, called multi-descriptor, is based on the well-known method of local binary patterns. It involves many different neighborhoods of the central pixel. Its unique advantage is that this descriptor allows the use of different neighborhood sizes instead of only one point. This structure ensures reasonable effectiveness and also provides the possibility to obtain a different distribution of features. Based on the new descriptor, a face recognition model using the pairwise feature descriptor based on the proposed descriptor was developed in this work, and local binary patterns were created to investigate the similarity and dissimilarity between the two models. For both models, the training was done using the support vector machine method on different face databases to overcome face recognition problems such as camera distance, expression, large head size, and illumination variations. The proposed technique achieved perfect accuracy on almost all tested databases including the Extended Yale B and Grimace database

    Detailed Investigation of Glass Balustrade in Kashirskaya Shopping Mall Project

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    Glass balustrade construction, envisaged for architectural considerations, was utilised in Kashirskaya shopping center in Moscow, Russia. Modifications were required in the manufacturer's design, to be further verified by full scale tests, on the most used largest sized panels. 3-D finite element computer model of glass balustrades and connection members were formed and ultimate capacity and service limit calculations were made according to the related regulations. Results were compared with the experiments carried out on full-scale glass balustrades tested at METU Structural Mechanics Laboratory

    Fermi Gamma-ray Space Telescope: High-Energy Results from the First Year

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    The Fermi Gamma-ray Space Telescope (Fermi) was launched on June 11, 2008 and began its first year sky survey on August 11, 2008. The Large Area Telescope (LAT), a wide field-of-view pair-conversion telescope covering the energy range from 20 MeV to more than 300 GeV, is the primary instrument on Fermi. While this review focuses on results obtained with the LAT, the Gamma-ray Burst Monitor (GBM) complements the LAT in its observations of transient sources and is sensitive to X-rays and gamma-rays with energies between 8 keV and 40 MeV. During the first year in orbit, the Fermi LAT has observed a large number of sources that include active galaxies, pulsars, compact binaries, globular clusters, supernova remnants, as well as the Sun, the Moon and the Earth. The GBM and LAT together have uncovered surprising characteristics in the high-energy emission of gamma-ray bursts (GRBs) that have been used to set significant new limits on violations of Lorentz invariance. The Fermi LAT has also made important new measurements of the Galactic diffuse radiation and has made precise measurements of the spectrum of cosmic-ray electrons and positrons from 20 GeV to 1 TeV.Comment: 39 pages, 16 figure

    Childhood emotional trauma and cyberbullying perpetration among emerging adults: a multiple mediation model of the role of problematic social media use and psychopathology

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    Research suggests that a small minority of social media users experience problems as a result of their online use. The purpose of the present study was to examine the association of cyberbullying perpetration and problematic social media use with childhood emotional trauma, Cluster B (narcissistic, histrionic, antisocial, and borderline) personality traits, dissociative experiences (DEs), depression, and self-esteem in a nonclinical undergraduate sample. A total of 344 university students volunteered to complete a questionnaire that included measures on the aforementioned dimensions. Thirty-eight percent of the participants had emotional neglect and 27% had emotional abuse, while 44% of them demonstrated at least one cyberbullying perpetration behavior. Results indicated that cyberbullying perpetrators had higher scores on problematic social media use, dissociative experiences, Cluster B traits, depression and childhood emotional trauma, and lower on self-esteem. Path analysis demonstrated that, while adjusting for gender and age, childhood emotional trauma was directly and indirectly associated with cyberbullying perpetration via Cluster B traits. Moreover, depression and dissociation were directly associated with problematic social media use. The findings of this study emphasize the important direct role of childhood emotional trauma and pathological personality traits on cyberbullying perpetration

    Spawning of bluefin tuna in the black sea: historical evidence, environmental constraints and population plasticity

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    <div><p>The lucrative and highly migratory Atlantic bluefin tuna, <em>Thunnus thynnus</em> (Linnaeus 1758<em>;</em> Scombridae), used to be distributed widely throughout the north Atlantic Ocean, Mediterranean Sea and Black Sea. Its migrations have supported sustainable fisheries and impacted local cultures since antiquity, but its biogeographic range has contracted since the 1950s. Most recently, the species disappeared from the Black Sea in the late 1980s and has not yet recovered. Reasons for the Black Sea disappearance, and the species-wide range contraction, are unclear. However bluefin tuna formerly foraged and possibly spawned in the Black Sea. Loss of a locally-reproducing population would represent a decline in population richness, and an increase in species vulnerability to perturbations such as exploitation and environmental change. Here we identify the main genetic and phenotypic adaptations that the population must have (had) in order to reproduce successfully in the specific hydrographic (estuarine) conditions of the Black Sea. By comparing hydrographic conditions in spawning areas of the three species of bluefin tunas, and applying a mechanistic model of egg buoyancy and sinking rate, we show that reproduction in the Black Sea must have required specific adaptations of egg buoyancy, fertilisation and development for reproductive success. Such adaptations by local populations of marine fish species spawning in estuarine areas are common as is evident from a meta-analysis of egg buoyancy data from 16 species of fish. We conclude that these adaptations would have been necessary for successful local reproduction by bluefin tuna in the Black Sea, and that a locally-adapted reproducing population may have disappeared. Recovery of bluefin tuna in the Black Sea, either for spawning or foraging, will occur fastest if any remaining locally adapted individuals are allowed to survive, and by conservation and recovery of depleted Mediterranean populations which could through time re-establish local Black Sea spawning and foraging.</p> </div

    A search for very high energy gamma-ray emission from the starburst galaxy NGC 253 with H.E.S.S

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    We present the result of 28 hours of observations of the nearby starburst galaxy NGC 253 with the H.E.S.S. detector in 2003. We find no evidence for very high energy gamma-ray emission from this object. Gamma-ray emission above 400 GeV from NGC 253 had been reported by the CANGAROO collaboration in 2002. From the H.E.S.S. data we derive upper limits on the flux above 300 GeV of 1.9 * 10^-12 photons cm^-2 s^-1 for a point-like source and 6.3 * 10^-12 photons cm^-2 s^-1 for a source of radius 0.5 degrees as reported by CANGAROO, both at a confidence level of 99%. These upper limits are inconsistent with the spectrum reported by CANGAROO. The expected very high energy gamma-ray emission from this object is discussed in the framework of a galactic wind propagation model.Comment: 7 pages, 3 figure
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