9,073 research outputs found

    Human transfer characteristics in flight and ground simulation for a roll tracking task

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    Human transfer characteristics in flight and ground simulation for roll tracking tas

    Finite time collapse of N classical fields described by coupled nonlinear Schrodinger equations

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    We prove the finite-time collapse of a system of N classical fields, which are described by N coupled nonlinear Schrodinger equations. We derive the conditions under which all of the fields experiences this finite-time collapse. Finally, for two-dimensional systems, we derive constraints on the number of particles associated with each field that are necessary to prevent collapse.Comment: v2: corrected typo on equation

    Simple computer method provides contours for radiological images

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    Computer is provided with information concerning boundaries in total image. Gradient of each point in digitized image is calculated with aid of threshold technique; then there is invoked set of algorithms designed to reduce number of gradient elements and to retain only major ones for definition of contour

    Advanced study of coastal zone oceanographic requirements for ERTS E and F

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    Earth Resources Technology Satellites E and F orbits and remote sensor instruments for coastal oceanographic data collectio

    First measurements of the flux integral with the NIST-4 watt balance

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    In early 2014, construction of a new watt balance, named NIST-4, has started at the National Institute of Standards and Technology (NIST). In a watt balance, the gravitational force of an unknown mass is compensated by an electromagnetic force produced by a coil in a magnet system. The electromagnetic force depends on the current in the coil and the magnetic flux integral. Most watt balances feature an additional calibration mode, referred to as velocity mode, which allows one to measure the magnetic flux integral to high precision. In this article we describe first measurements of the flux integral in the new watt balance. We introduce measurement and data analysis techniques to assess the quality of the measurements and the adverse effects of vibrations on the instrument.Comment: 7 pages, 8 figures, accepted for publication in IEEE Trans. Instrum. Meas. This Journal can be found online at http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=1

    Pursuing Clean Energy Equitably

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    This is the final version of the report. Available from the publisher via the URL in this record.This paper explores the opportunities for a ‘just transition’ to low carbon and sustainable energy systems; one that addresses the current inequities in the distribution of energy benefits and their human and ecological costs. In order to prioritize policies that address energy poverty alleviation and sustainability concerns, national action and higher levels of international cooperation and coordination are required to steer public policy towards a broader range of public interests. This also implies re-directing the vast sums of private energy finance that currently serve a narrow set of interests. This paper considers how national and global energy governance must adapt and change to ensure a just transition to low carbon and sustainable energy systems. Creating a low carbon and sustainable energy transition will face significant challenges in overcoming opposition from a broad array of interest groups. The challenges of guiding a just transition are amplified by the relinquishing of government control over the energy sector in many countries and the current weak and fragmented state of global energy governance. The necessary changes in energy decision making will entail complex trade-offs and rebound effects that make strong, participatory and transparent institutional arrangements essential in order to govern such challenges equitably. In this respect, procedural justice is critical to achieving distributive justice and to creating a simultaneously rapid, sustainable and equitable transition to clean energy futures

    The Octarepeat Domain of the Prion Protein Binds Cu(II) with Three Distinct Coordination Modes at pH 7.4

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    The prion protein (PrP) binds Cu2+ in its N-terminal octarepeat domain. This unusual domain is comprised of four or more tandem repeats of the fundamental sequence PHGGGWGQ. Previous work from our laboratories demonstrates that at full copper occupancy, each HGGGW segment binds a single Cu2+. However, several recent studies suggest that low copper occupancy favors different coordination modes, possibly involving imidazoles from histidines in adjacent octapeptide segments. This is investigated here using a combination of X-band EPR, S-band EPR, and ESEEM, along with a library of modified peptides designed to favor different coordination interactions. At pH 7.4, three distinct coordination modes are identified. Each mode is fully characterized to reveal a series of copper-dependent octarepeat domain structures. Multiple His coordination is clearly identified at low copper stoichiometry. In addition, EPR detected copper−copper interactions at full occupancy suggest that the octarepeat domain partially collapses, perhaps stabilizing this specific binding mode and facilitating cooperative copper uptake. This work provides the first complete characterization of all dominant copper coordination modes at pH 7.4

    Deep Eyes: Binocular Depth-from-Focus on Focal Stack Pairs

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    Human visual system relies on both binocular stereo cues and monocular focusness cues to gain effective 3D perception. In computer vision, the two problems are traditionally solved in separate tracks. In this paper, we present a unified learning-based technique that simultaneously uses both types of cues for depth inference. Specifically, we use a pair of focal stacks as input to emulate human perception. We first construct a comprehensive focal stack training dataset synthesized by depth-guided light field rendering. We then construct three individual networks: a Focus-Net to extract depth from a single focal stack, a EDoF-Net to obtain the extended depth of field (EDoF) image from the focal stack, and a Stereo-Net to conduct stereo matching. We show how to integrate them into a unified BDfF-Net to obtain high-quality depth maps. Comprehensive experiments show that our approach outperforms the state-of-the-art in both accuracy and speed and effectively emulates human vision systems
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