6,116 research outputs found

    On including quality in applied automatic gait recognition

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    Many gait recognition approaches use silhouette data. Imperfections in silhouette extraction have a negative effect on the performance of a gait recognition system. In this paper we extend quality metrics for gait recognition and evaluate new ways of using quality to improve a recognition system. We demonstrate use of quality to improve silhouette data and select gait cycles of best quality. The potential of the new approaches has been demonstrated experimentally on a challenging dataset, showing how recognition capability can be dramatically improved. Our practical study also shows that acquiring samples of adequate quality in arbitrary environments is difficult and that including quality analysis can improve performance markedly

    Curvature condensation and bifurcation in an elastic shell

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    We study the formation and evolution of localized geometrical defects in an indented cylindrical elastic shell using a combination of experiment and numerical simulation. We find that as a symmetric localized indentation on a semi-cylindrical shell increases, there is a transition from a global mode of deformation to a localized one which leads to the condensation of curvature along a symmetric parabolic crease. This process introduces a soft mode in the system, converting a load-bearing structure into a hinged, kinematic mechanism. Further indentation leads to twinning wherein the parabolic crease bifurcates into two creases that move apart on either side of the line of symmetry. A qualitative theory captures the main features of the phenomena and leads to sharper questions about the nucleation of these defects.Comment: 4 pages, 5 figures, submitted to Physical Review Letter

    The engagement of further and higher education with the London 2012 Olympic and Paralympic Games

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    Podium commissioned the Centre for Sport, Physical Education & Activity Research (SPEAR) at Canterbury Christ Church University to carry out research to capture the engagement of the further and higher education sectors and related stakeholders with the past, current and future opportunities presented by the London 2012 Olympic and Paralympic Games. The full report was released on 15 March 2011 to mark 500 days to go until the start of London 2012

    The Casimir force on a surface with shallow nanoscale corrugations: Geometry and finite conductivity effects

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    We measure the Casimir force between a gold sphere and a silicon plate with nanoscale, rectangular corrugations with depth comparable to the separation between the surfaces. In the proximity force approximation (PFA), both the top and bottom surfaces of the corrugations contribute to the force, leading to a distance dependence that is distinct from a flat surface. The measured Casimir force is found to deviate from the PFA by up to 15%, in good agreement with calculations based on scattering theory that includes both geometry effects and the optical properties of the material

    Neutron, electron and X-ray scattering investigation of Cr1-xVx near Quantum Criticality

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    The weakness of electron-electron correlations in the itinerant antiferromagnet Cr doped with V has long been considered the reason that neither new collective electronic states or even non Fermi liquid behaviour are observed when antiferromagnetism in Cr1−x_{1-x}Vx_{x} is suppressed to zero temperature. We present the results of neutron and electron diffraction measurements of several lightly doped single crystals of Cr1−x_{1-x}Vx_{x} in which the archtypal spin density wave instability is progressively suppressed as the V content increases, freeing the nesting-prone Fermi surface for a new striped charge instability that occurs at xc_{c}=0.037. This novel nesting driven instability relieves the entropy accumulation associated with the suppression of the spin density wave and avoids the formation of a quantum critical point by stabilising a new type of charge order at temperatures in excess of 400 K. Restructuring of the Fermi surface near quantum critical points is a feature found in materials as diverse as heavy fermions, high temperature copper oxide superconductors and now even elemental metals such as Cr.Comment: 6 pages, 6 figures. Accepted to Physical Review

    A TaqMan qPCR method for detecting kdr resistance in Aphis gossypii demonstrates improved sensitivity compared to conventional PCR–RFLP

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    © 2015, Springer-Verlag Berlin Heidelberg. Cotton aphid, Aphis gossypii Glover, has emerged as a prominent pest in Australian cotton production, and monitoring pesticide resistance including pyrethroids in field populations is crucial for its sustainable management. We examined the distribution of kdr resistance in 35 field-collected A. gossypii populations and used TaqMan qPCR assays with pooled samples. The study demonstrated proof of concept that pooled insect qPCR methodology provided effective detection with better sensitivity than individual PCR–RFLP genotyping techniques for the kdr resistance allele. The practical outcome is that routine resistance monitoring can examine more sites while increasing the likelihood of detecting incipient resistance at those sites. More importantly, the method is adaptable to any genetically caused resistance and so not limited to A. gossypii or even insect control. It cannot be overstressed that the ability to detected resistance at very low frequencies is critical to all sustainable resistance management. Early detection of resistance provides critical time for the modification of chemical use prior to potential insecticide control failure

    Reconstruction Mechanism of FCC Transition-Metal (001) Surfaces

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    The reconstruction mechanism of (001) fcc transition metal surfaces is investigated using a full-potential all-electron electronic structure method within density-functional theory. Total-energy supercell calculations confirm the experimental finding that a close-packed quasi-hexagonal overlayer reconstruction is possible for the late 5dd-metals Ir, Pt, and Au, while it is disfavoured in the isovalent 4dd metals (Rh, Pd, Ag). The reconstructive behaviour is driven by the tensile surface stress of the unreconstructed surfaces; the stress is significantly larger in the 5dd metals than in 4dd ones, and only in the former case it overcomes the substrate resistance to the required geometric rearrangement. It is shown that the surface stress for these systems is due to dd charge depletion from the surface layer, and that the cause of the 4th-to-5th row stress difference is the importance of relativistic effects in the 5dd series.Comment: RevTeX 3.0, 12 pages, 1 PostScript figure available upon request] 23 May 199
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