1,889 research outputs found

    Systematic performance of the ASKAP Fast Radio Burst search algorithm

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    Detecting fast radio bursts (FRBs) requires software pipelines to search for dispersed single pulses of emission in radio telescope data. In order to enable an unbiased estimation of the underlying FRB population, it is important to understand the algorithm efficiency with respect to the search parameter space and thus the survey completeness. The Fast Real-time Engine for Dedispersing Amplitudes (FREDDA) search pipeline is a single pulse detection pipeline designed to identify radio pulses over a large range of dispersion measures (DM) with low latency. It is used on the Australian Square Kilometre Array Pathfinder (ASKAP) for the Commensal Real-time ASKAP Fast Transients (CRAFT) project . We utilise simulated single pulses in the low- and high-frequency observation bands of ASKAP to analyse the performance of the pipeline and infer the underlying FRB population. The simulation explores the Signal-to-Noise Ratio (S/N) recovery as a function of DM and the temporal duration of FRB pulses in comparison to injected values. The effects of intra-channel broadening caused by dispersion are also carefully studied in this work using control datasets. Our results show that for Gaussian-like single pulses, >85%> 85 \% of the injected signal is recovered by pipelines such as FREDDA at DM < 3000 pc cm−3\mathrm{pc\ cm^{-3}} using standard boxcar filters compared to an ideal incoherent dedispersion match filter. Further calculations with sensitivity implies at least ∼10%\sim 10\% of FRBs in a Euclidean universe at target sensitivity will be missed by FREDDA and HEIMDALL, another common pipeline, in ideal radio environments at 1.1 GHz.Comment: 11 pages 13 figures. Accepted for MNRAS; Data and simulation code available onlin

    Moby: Addressing Coastal Litter on Nantucket Through Functional Art

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    Artists around the world have created captivating sculptures to raise awareness of the growing problem of marine litter and pollution. In this vein, we collaborated with the Nantucket Department of Public Works and the Marine Mammal Alliance Nantucket to design a functional public sculpture in the image of a sperm whale called Moby. This iconic sculpture will serve as an attractive receptacle for trash and recyclables and encourage people to collect and dispose of coastal litter found on the beach. The Moby project will spread awareness of the impact litter has on the marine environment and its wildlife through informational signage, local outreach, and the symbolic image of marine litter filling the body of a whale

    Enseignement de l'échographie au chevet à l'aide d'une technique de visioconférence

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    Implication Statement Point-of-care ultrasound (POCUS) has usually been taught using a hands-on, in-person approach. We present a novel approach to delivering POCUS virtually using a dual image videoconferencing technique. We outline an easily implementable approach and summarize medical students’ experience and feedback. This form of delivery has potential to improve instructional delivery in resource restricted settings or during pandemic restrictions where a hands-on approach may not be possible.Énoncé des implications de la recherche L'échographie au chevet fait généralement l’objet d’un enseignement pratique, en personne. Nous présentons une nouvelle approche, virtuelle, pour son enseignement, par visioconférence à double flux vidéo. L’approche que nous décrivons est facile à mettre en œuvre. Nous résumons l'expérience et les commentaires des étudiants en médecine sur cette modalité qui est susceptible d'améliorer l'enseignement dans des contextes où les ressources sont limitées ou en cas de pandémie, lorsque l’approche pratique n'est pas possible

    End-to-End Physics Event Generator

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    We apply generative adversarial network (GAN) technology to build an event generator that simulates particle production in electron-proton scattering that is free of theoretical assumptions about underlying particle dynamics. The difficulty of efficiently training a GAN event simulator lies in learning the complicated pat- terns of the distributions of the particles physical properties. We develop a GAN that selects a set of transformed features from particle momenta that can be generated easily by the generator, and uses these to produce a set of augmented features that improve the sensitivity of the discriminator. The new Feature-Augmented and Transformed GAN (FAT-GAN) is able to faithfully reproduce the distribution of final state electron momenta in inclusive electron scattering, without the need for input derived from domain-based theoretical assumptions. The developed technology can play a significant role in boosting the science of the Jefferson Lab 12 GeV program and the future Electron-Ion Collider.https://digitalcommons.odu.edu/gradposters2021_sciences/1006/thumbnail.jp

    Impact of two rounds of praziquantel mass drug administration on Schistosoma mansoni infection prevalence and intensity: a comparison between community wide treatment and school based treatment in western Kenya

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    AbstractThis study compared the effectiveness of the community-wide treatment and school-based treatment approaches in the control of Schistosoma mansoni infections in villages with ⩾25% prevalence in western Kenya. Stool samples from first year students, 9–12year olds and adults (20–55years) were analyzed by the Kato–Katz technique for S. mansoni eggs. After two rounds of treatment, S. mansoni prevalence and intensity levels significantly declined in both treatment approaches. Prevalence comparisons between the two approaches did not show any significant differences following treatment. However, infection intensity levels in the 9–12year old school-attending pupils were significantly higher in the community-wide treatment arm than in the school-based treatment arm. Nevertheless, significant reductions in S. mansoni infection prevalence and intensity levels were achieved among school-age children regardless of the treatment approach used

    Design and Functional Validation of a Mechanism for Dual-Spinning CubeSats

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    The mission of the Micro-sized Microwave Atmospheric Satellite (MicroMAS) is to collect useful atmospheric images using a miniature passive microwave radiometer payload hosted on a low-cost CubeSat platform. In order to collect this data, the microwave radiometer payload must rotate to scan the ground-track perpendicular to the satellite's direction of travel. A custom motor assembly was developed to facilitate the rotation of the payload while allowing the spacecraft bus to remained fixed in the local-vertical, local-horizontal (LVLH) frame for increased pointing accuracy. This paper describes the mechanism used to enable this dual-spinning operation for CubeSats, and the lessons learned during the design, fabrication, integration, and testing phases of the mechanism's development lifecycle
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