1,065 research outputs found

    The Climate Change Awareness Among Senior High School Students in Sorsogon Province, Philippines

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    The researchers of this study determined the climate change awareness of senior high school students in Sorsogon Province Division during 2022-2023. The subjects of this study were 412 officially enrolled Grade 11 and Grade 12 Academic and Technical Vocational Livelihood students of Juban National High School and J.P. Laurel High School. The researchers utilized descriptive survey design and used adapted research questionnaires. Moreover, the researchers applied weighted mean and ranking and also used other researchers’ works in explaining the gathered data. Findings revealed that the senior high school students are neutral on climate change mitigation and agree on the effects of climate change. Additionally, internet, television, school, and radio are the major sources of information of senior high school students relative to climate change. The researchers recommended that the senior high school students must continue in educating through the different available sources of information in order to improve their views on climate change which are useful in taking actions in connection with mitigation

    A Framework to Synergize Partial Order Reduction with State Interpolation

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    We address the problem of reasoning about interleavings in safety verification of concurrent programs. In the literature, there are two prominent techniques for pruning the search space. First, there are well-investigated trace-based methods, collectively known as "Partial Order Reduction (POR)", which operate by weakening the concept of a trace by abstracting the total order of its transitions into a partial order. Second, there is state-based interpolation where a collection of formulas can be generalized by taking into account the property to be verified. Our main contribution is a framework that synergistically combines POR with state interpolation so that the sum is more than its parts

    Symbolic Partial-Order Execution for Testing Multi-Threaded Programs

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    We describe a technique for systematic testing of multi-threaded programs. We combine Quasi-Optimal Partial-Order Reduction, a state-of-the-art technique that tackles path explosion due to interleaving non-determinism, with symbolic execution to handle data non-determinism. Our technique iteratively and exhaustively finds all executions of the program. It represents program executions using partial orders and finds the next execution using an underlying unfolding semantics. We avoid the exploration of redundant program traces using cutoff events. We implemented our technique as an extension of KLEE and evaluated it on a set of large multi-threaded C programs. Our experiments found several previously undiscovered bugs and undefined behaviors in memcached and GNU sort, showing that the new method is capable of finding bugs in industrial-size benchmarks.Comment: Extended version of a paper presented at CAV'2

    Direct measurement of stellar angular diameters by the VERITAS Cherenkov Telescopes

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    The angular size of a star is a critical factor in determining its basic properties. Direct measurement of stellar angular diameters is difficult: at interstellar distances stars are generally too small to resolve by any individual imaging telescope. This fundamental limitation can be overcome by studying the diffraction pattern in the shadow cast when an asteroid occults a star, but only when the photometric uncertainty is smaller than the noise added by atmospheric scintillation. Atmospheric Cherenkov telescopes used for particle astrophysics observations have not generally been exploited for optical astronomy due to the modest optical quality of the mirror surface. However, their large mirror area makes them well suited for such high-time-resolution precision photometry measurements. Here we report two occultations of stars observed by the VERITAS Cherenkov telescopes with millisecond sampling, from which we are able to provide a direct measurement of the occulted stars' angular diameter at the 0.1\leq0.1 milliarcsecond scale. This is a resolution never achieved before with optical measurements and represents an order of magnitude improvement over the equivalent lunar occultation method. We compare the resulting stellar radius with empirically derived estimates from temperature and brightness measurements, confirming the latter can be biased for stars with ambiguous stellar classifications.Comment: Accepted for publication in Nature Astronom

    Evidence for proton acceleration up to TeV energies based on VERITAS and Fermi-LAT observations of the Cas A SNR

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    We present a study of γ\gamma-ray emission from the core-collapse supernova remnant Cas~A in the energy range from 0.1GeV to 10TeV. We used 65 hours of VERITAS data to cover 200 GeV - 10 TeV, and 10.8 years of \textit{Fermi}-LAT data to cover 0.1-500 GeV. The spectral analysis of \textit{Fermi}-LAT data shows a significant spectral curvature around 1.3±0.4stat1.3 \pm 0.4_{stat} GeV that is consistent with the expected spectrum from pion decay. Above this energy, the joint spectrum from \textit{Fermi}-LAT and VERITAS deviates significantly from a simple power-law, and is best described by a power-law with spectral index of 2.17±0.02stat2.17\pm 0.02_{stat} with a cut-off energy of 2.3±0.5stat2.3 \pm 0.5_{stat} TeV. These results, along with radio, X-ray and γ\gamma-ray data, are interpreted in the context of leptonic and hadronic models. Assuming a one-zone model, we exclude a purely leptonic scenario and conclude that proton acceleration up to at least 6 TeV is required to explain the observed γ\gamma-ray spectrum. From modeling of the entire multi-wavelength spectrum, a minimum magnetic field inside the remnant of Bmin150μGB_{\mathrm{min}}\approx150\,\mathrm{\mu G} is deduced.Comment: 33 pages, 9 Figures, 6 Table

    Measurement of the cross-section ratio sigma_{psi(2S)}/sigma_{J/psi(1S)} in deep inelastic exclusive ep scattering at HERA

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    The exclusive deep inelastic electroproduction of ψ(2S)\psi(2S) and J/ψ(1S)J/\psi(1S) at an epep centre-of-mass energy of 317 GeV has been studied with the ZEUS detector at HERA in the kinematic range 2<Q2<802 < Q^2 < 80 GeV2^2, 30<W<21030 < W < 210 GeV and t<1|t| < 1 GeV2^2, where Q2Q^2 is the photon virtuality, WW is the photon-proton centre-of-mass energy and tt is the squared four-momentum transfer at the proton vertex. The data for 2<Q2<52 < Q^2 < 5 GeV2^2 were taken in the HERA I running period and correspond to an integrated luminosity of 114 pb1^{-1}. The data for 5<Q2<805 < Q^2 < 80 GeV2^2 are from both HERA I and HERA II periods and correspond to an integrated luminosity of 468 pb1^{-1}. The decay modes analysed were μ+μ\mu^+\mu^- and J/ψ(1S)π+πJ/\psi(1S) \,\pi^+\pi^- for the ψ(2S)\psi(2S) and μ+μ\mu^+\mu^- for the J/ψ(1S)J/\psi(1S). The cross-section ratio σψ(2S)/σJ/ψ(1S)\sigma_{\psi(2S)}/\sigma_{J/\psi(1S)} has been measured as a function of Q2,WQ^2, W and tt. The results are compared to predictions of QCD-inspired models of exclusive vector-meson production.Comment: 24 pages, 8 figure

    Measurement of neutral current e+/-p cross sections at high Bjorken x with the ZEUS detector

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    The neutral current e+/-p cross section has been measured up to values of Bjorken x of approximately 1 with the ZEUS detector at HERA using an integrated luminosity of 187 inv. pb of e-p and 142 inv. pb of e+p collisions at sqrt(s) = 318GeV. Differential cross sections in x and Q2, the exchanged boson virtuality, are presented for Q2 geq 725GeV2. An improved reconstruction method and greatly increased amount of data allows a finer binning in the high-x region of the neutral current cross section and leads to a measurement with much improved precision compared to a similar earlier analysis. The measurements are compared to Standard Model expectations based on a variety of recent parton distribution functions.Comment: 39 pages, 9 figure

    Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

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    The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured
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