841 research outputs found

    Motion tracking of iris features to detect small eye movements

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    The inability of current video-based eye trackers to reliably detect very small eye movements has led to confusion about the prevalence or even the existence of monocular microsaccades (small, rapid eye movements that occur in only one eye at a time). As current methods often rely on precisely localizing the pupil and/or corneal reflection on successive frames, current microsaccade-detection algorithms often suffer from signal artifacts and a low signal-to-noise ratio. We describe a new video-based eye tracking methodology which can reliably detect small eye movements over 0.2 degrees (12 arcmin) with very high confidence. Our method tracks the motion of iris features to estimate velocity rather than position, yielding a better record of microsaccades. We provide a more robust, detailed record of miniature eye movements by relying on more stable, higher-order features (such as local features of iris texture) instead of lower-order features (such as pupil center and corneal reflection), which are sensitive to noise and drift

    Discrimination of Helicobacter pullorum and Campylobacter lari by analysis of whole cell fatty acid extracts

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    Helicobacter pullorum and Campylobacter lari are rarely isolated from humans with acute enteritis. Hitherto the two species could only be identified by genotypic techniques. Gas liquid chromatography of whole cell fatty acid extracts is described as the first phenotypic method for discrimination of the two species. Cholesteryl glucoside, a characteristic feature of the genus Helicobacter, but seldom found in other bacteria, could not be detected in Helicobacter pullorum. Therefore, rapid determination of this glycolipid may serve as a discrimination marker for Helicobacter pullorum from most other Helicobacter specie

    Discrimination of Helicobacter pullorum and Campylobacter lari by analysis of whole cell fatty acid extracts

    Get PDF
    Helicobacter pullorum and Campylobacter lari are rarely isolated from humans with acute enteritis. Hitherto the two species could only be identified by genotypic techniques. Gas liquid chromatography of whole cell fatty acid extracts is described as the first phenotypic method for discrimination of the two species. Cholesteryl glucoside, a characteristic feature of the genus Helicobacter, but seldom found in other bacteria, could not be detected in Helicobacter pullorum. Therefore, rapid determination of this glycolipid may serve as a discrimination marker for Helicobacter pullorum from most other Helicobacter species

    Privacy-Preserving Eye Videos using Rubber Sheet Model

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    Video-based eye trackers estimate gaze based on eye images/videos. As security and privacy concerns loom over technological advancements, tackling such challenges is crucial. We present a new approach to handle privacy issues in eye videos by replacing the current identifiable iris texture with a different iris template in the video capture pipeline based on the Rubber Sheet Model. We extend to image blending and median-value representations to demonstrate that videos can be manipulated without significantly degrading segmentation and pupil detection accuracy.Comment: Will be published in ETRA 20 Short Papers, June 2-5, 2020, Stuttgart, Germany Copyright 2020 Association for Computing Machiner

    Direct Measurement of Quantum Confinement Effects at Metal to Quantum-Well Nanocontacts

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    Model metal-semiconductor nanostructure Schottky nanocontacts were made on cleaved heterostructures containing GaAs quantum wells (QWs) of varying width and were locally probed by ballistic electron emission microscopy. The local Schottky barrier was found to increase by ∼0.140 eV as the QW width was systematically decreased from 15 to 1 nm, due mostly to a large (∼0.200 eV) quantum-confinement increase to the QW conduction band. The measured barrier increase over the full 1 to 15 nm QW range was quantitatively explained when local "interface pinning" and image force lowering effects are also considered

    Nanometer-resolution measurement and modeling of lateral variations of the effective work function at the bilayer Pt/Al/SiO2 interface

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    A ballistic electron emission microscopy (BEEM) comparison of the dependence on gate voltage of the average energy barrier of a metal bilayer Pt/Al/ SiO2 /Si sample and a Pt/ SiO2 /Si sample suggests that the metal/oxide interface of the Pt/Al/ SiO2 /Si sample is laterally inhomogeneous at nm length scales. However, BEEM images of the bilayer sample do not show significantly larger lateral variations than observed on a (uniform) Pt/ SiO2 /Si sample, indicating that any inhomogeneous "patches" of lower-energy barrier height have size smaller than the lateral resolution of BEEM, estimated for these samples to be ???10nm. Finite element electrostatic simulations of an assumed inhomogeneous interface with nm size patches of different effective work function can fit the experimental data of the bilayer sample much better than an assumed homogenous interface, indicating that the bilayer film is laterally inhomogeneous at the nm scale.open2

    Evaluating equity in European climate change mitigation pathways

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    This short report presents a systematic consideration of equity in emissions pathways at the level of the European Union. The study starts from a framework of international environmental law principles that inform national fair shares and from principles that are highlighted in European Climate Law. Building from this normative position, allocation approaches that can be considered ‘fair’ are described and indicators that allow their operationalization are identified. The implications of the various fairness approaches for the EU are quantified and compared with stylistic European climate mitigation pathways

    Effect of inclined quantum wells on macroscopic capacitance-voltage response of Schottky contacts: Cubic inclusions in hexagonal SiC

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    Finite-element calculations of Schottky diode capacitance-voltage (C-V) curves show that an array of subsurface inclined quantum wells (QWs) produce negligible change in shape and slope of C-V curves, but significantly reduce the intercept voltage. This is particularly important for hexagonal SiC, in which current- or process-induced cubic inclusions are known to behave as electron QWs. These calculations naturally explain the surprisingly large effect of cubic inclusions on the apparent 4H-SiC Schottky barrier determined by C-V measurements, and together with the measured C-V data indicate the QW subband energy in the inclusions to be ~0.51 eV below the host 4H-SiC conduction band.open151
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