1,143 research outputs found

    Auditory Decision Aiding in Supervisory Control of Multiple Unmanned Aerial Vehicles

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    This paper investigates the effectiveness of sonification, continuous auditory alert mapped to the state of a monitored task, in supporting unmanned aerial vehicle (UAV) supervisory control. Background: UAV supervisory control requires monitoring each UAV across multiple tasks (e.g., course maintenance) via a predominantly visual display, which currently is supported with discrete auditory alerts. Sonification has been shown to enhance monitoring performance in domains such as anesthesiology by allowing an operator to immediately determine an entity's (e.g., patient) current and projected states, and is a promising alternative to discrete alerts in UAV control. However, minimal research compares sonification to discrete alerts, and no research assesses the effectiveness of sonification for monitoring multiple entities (e.g., multiple UAVs). Method: An experiment was conducted with 39 military personnel, using a simulated setup. Participants controlled single and multiple UAVs, and received sonifications or discrete alerts based on UAV course deviations and late target arrivals. Results: Regardless of the number of UAVs supervised, the course deviation sonification resulted in 1.9 s faster reactions to course deviations, a 19% enhancement from discrete alerts. However, course deviation sonification interfered with the effectiveness of discrete late arrival alerts in general, and with operator response to late arrivals when supervising multiple vehicles. Conclusions: Sonifications can outperform discrete alerts when designed to aid operators to predict future states of monitored tasks. However, sonifications may mask other auditory alerts, and interfere with other monitoring tasks that require divided attention.US Army through a Small Business Innovation Research led by Charles River Analytics, Inc

    Trapping of Projectiles in Fixed Scatterer Calculations

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    We study multiple scattering off nuclei in the closure approximation. Instead of reducing the dynamics to one particle potential scattering, the scattering amplitude for fixed target configurations is averaged over the target groundstate density via stochastic integration. At low energies a strong coupling limit is found which can not be obtained in a first order optical potential approximation. As its physical explanation, we propose it to be caused by trapping of the projectile. We analyse this phenomenon in mean field and random potential approximations. (PACS: 24.10.-i)Comment: 15 page

    The Confined-Deconfined Interface Tension in Quenched QCD using the Histogram Method

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    We present results for the confinement-deconfinement interface tension σcd\sigma_{cd} of quenched QCD. They were obtained by applying Binder's histogram method to lattices of size L2×Lz×LtL^2\times L_z\times L_t for Lt=2L_t=2 and L=8,10,12\mbox{ and }14 and various Lz[L,4L]L_z\in [L,\, 4\, L]. The use of a multicanonical algorithm and rectangular geometries have turned out to be crucial for the numerical studies. We also give an estimate for σcd\sigma_{cd} at Lt=4L_t=4 using published data.Comment: 15 pages, 9 figures (of which 2 are included, requiring the epsf style file), preprint HLRZ-93-

    The interaction of a gap with a free boundary in a two dimensional dimer system

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    Let \ell be a fixed vertical lattice line of the unit triangular lattice in the plane, and let \Cal H be the half plane to the left of \ell. We consider lozenge tilings of \Cal H that have a triangular gap of side-length two and in which \ell is a free boundary - i.e., tiles are allowed to protrude out half-way across \ell. We prove that the correlation function of this gap near the free boundary has asymptotics 14πr\frac{1}{4\pi r}, rr\to\infty, where rr is the distance from the gap to the free boundary. This parallels the electrostatic phenomenon by which the field of an electric charge near a conductor can be obtained by the method of images.Comment: 34 pages, AmS-Te

    Sixteen years of social and ecological dynamics reveal challenges and opportunities for adaptive management in sustaining the commons

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    Efforts to confront the challenges of environmental change and uncertainty include attempts to adaptively manage social–ecological systems. However, critical questions remain about whether adaptive management can lead to sustainable outcomes for both ecosystems and society. Here, we make a contribution to these efforts by presenting a 16-y analysis of ecological outcomes and perceived livelihood impacts from adaptive coral reef management in Papua New Guinea. The adaptive management system we studied was a customary rotational fisheries closure system (akin to fallow agriculture), which helped to increase the biomass of reef fish and make fish less wary (more catchable) relative to openly fished areas. However, over time the amount of fish in openly fished reefs slowly declined. We found that, overall, resource users tended to have positive perceptions about this system, but there were negative perceptions when fishing was being prohibited. We also highlight some of the key traits of this adaptive management system, including 1) strong social cohesion, whereby leaders played a critical role in knowledge exchange; 2) high levels of compliance, which was facilitated via a “carrot-and-stick” approach that publicly rewarded good behavior and punished deviant behavior; and 3) high levels of participation by community actors

    Transnational environmental crime threatens sustainable development

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    Transnational environmental crime has become the largest financial driver of social conflict, with severe implications for peace and security. Sustainable-development frameworks need to overtly recognize and mitigate the risks posed by transnational environmental crime to environmental security

    PTF11iqb: cool supergiant mass-loss that bridges the gap between Type IIn and normal supernovae

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    The supernova (SN) PTF11iqb was initially classified as a Type IIn event caught very early after explosion. It showed narrow Wolf–Rayet (WR) spectral features on day 2 (as in SN 1998S and SN 2013cu), but the narrow emission weakened quickly and the spectrum morphed to resemble Types II-L and II-P. At late times, H? exhibited a complex, multipeaked profile reminiscent of SN 1998S. In terms of spectroscopic evolution, we find that PTF11iqb was a near twin of SN 1998S, although with somewhat weaker interaction with circumstellar material (CSM) at early times, and stronger interaction at late times. We interpret the spectral changes as caused by early interaction with asymmetric CSM that is quickly (by day 20) enveloped by the expanding SN ejecta photosphere, but then revealed again after the end of the plateau when the photosphere recedes. The light curve can be matched with a simple model for CSM interaction (with a mass-loss rate of roughly 10?4 M? yr?1) added to the light curve of a normal SN II-P. The underlying plateau requires a progenitor with an extended hydrogen envelope like a red supergiant at the moment of explosion, consistent with the slow wind speed (<80?km?s?1) inferred from narrow H? emission. The cool supergiant progenitor is significant because PTF11iqb showed WR features in its early spectrum – meaning that the presence of such WR features does not necessarily indicate a WR-like progenitor. Overall, PTF11iqb bridges SNe IIn with weaker pre-SN mass-loss seen in SNe II-L and II-P, implying a continuum between these types

    PTF11iqb: cool supergiant mass-loss that bridges the gap between Type IIn and normal supernovae

    No full text
    The supernova (SN) PTF11iqb was initially classified as a Type IIn event caught very early after explosion. It showed narrow Wolf–Rayet (WR) spectral features on day 2 (as in SN 1998S and SN 2013cu), but the narrow emission weakened quickly and the spectrum morphed to resemble Types II-L and II-P. At late times, H? exhibited a complex, multipeaked profile reminiscent of SN 1998S. In terms of spectroscopic evolution, we find that PTF11iqb was a near twin of SN 1998S, although with somewhat weaker interaction with circumstellar material (CSM) at early times, and stronger interaction at late times. We interpret the spectral changes as caused by early interaction with asymmetric CSM that is quickly (by day 20) enveloped by the expanding SN ejecta photosphere, but then revealed again after the end of the plateau when the photosphere recedes. The light curve can be matched with a simple model for CSM interaction (with a mass-loss rate of roughly 10?4 M? yr?1) added to the light curve of a normal SN II-P. The underlying plateau requires a progenitor with an extended hydrogen envelope like a red supergiant at the moment of explosion, consistent with the slow wind speed (<80?km?s?1) inferred from narrow H? emission. The cool supergiant progenitor is significant because PTF11iqb showed WR features in its early spectrum – meaning that the presence of such WR features does not necessarily indicate a WR-like progenitor. Overall, PTF11iqb bridges SNe IIn with weaker pre-SN mass-loss seen in SNe II-L and II-P, implying a continuum between these types

    GDGMV Borehole Database Interface User Guide

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    This report is the published product of a collaboration between the British Geological Survey (BGS) and the General Department of Geology and Minerals Vietnam (GDGMV) and Ministry of Natural Resources and Environment (MONRE) as part of the Hanoi Urban Geology Project. The project has been ongoing since 2016, funded through the by BGS NC-ODA: Geoscience for Sustainable Futures Programme. The project delivers against three priority themes: 1) Development of Digital Systems and Workflows 2) Urban Geology for Planning Policy and Construction 3) Training, Knowledge Exchange and Stakeholder Engagement These tasks are delivering new digital data technology, new working practices, and increased institutional capacity with respect to urban geoscience. The GDGMV Borehole Database Interface outlined in this document is one of many systems developed and put in place. This report should be used in conjunction with the other reports related to this collaboration, including: OR/21/019 – GDGMV Lexicon Database User Guide OR/20/55 – Considerations for Borehole Coding and Coded Borehole Data Checking There is also a toolbox of documents, data tools, and workflows available
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