910 research outputs found

    VALSE: A Task-independent benchmark for Vision and Language models centered on linguistic phenomena

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    We propose VALSE (Vision And Language Structured Evaluation), a novel benchmark designed for testing general-purpose pretrained vision and language (V&L) models for their visio-linguistic grounding capabilities on specific linguistic phenomena. VALSE offers a suite of six tests covering various linguistic constructs. Solving these requires models to ground linguistic phenomena in the visual modality, allowing more fine-grained evaluations than hitherto possible. We build VALSE using methods that support the construction of valid foils, and report results from evaluating five widely-used V&L models. Our experiments suggest that current models have considerable difficulty addressing most phenomena. Hence, we expect VALSE to serve as an important benchmark to measure future progress of pretrained V&L models from a linguistic perspective, complementing the canonical task-centred V&L evaluations

    VALSE: A Task-independent benchmark for Vision and Language models centered on linguistic phenomena

    Get PDF
    We propose VALSE (Vision And Language Structured Evaluation), a novel benchmark designed for testing general-purpose pretrained vision and language (V&L) models for their visio-linguistic grounding capabilities on specific linguistic phenomena. VALSE offers a suite of six tests covering various linguistic constructs. Solving these requires models to ground linguistic phenomena in the visual modality, allowing more fine-grained evaluations than hitherto possible. We build VALSE using methods that support the construction of valid foils, and report results from evaluating five widely-used V&L models. Our experiments suggest that current models have considerable difficulty addressing most phenomena. Hence, we expect VALSE to serve as an important benchmark to measure future progress of pretrained V&L models from a linguistic perspective, complementing the canonical task-centred V&L evaluations

    Two years of flight of the Pamela experiment: results and perspectives

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    PAMELA is a satellite borne experiment designed to study with great accuracy cosmic rays of galactic, solar, and trapped nature in a wide energy range (protons: 80 MeV-700 GeV, electrons 50 MeV-400 GeV). Main objective is the study of the antimatter component: antiprotons (80 MeV-190 GeV), positrons (50 MeV-270 GeV) and search for antinuclei with a precision of the order of 10810^{-8}). The experiment, housed on board the Russian Resurs-DK1 satellite, was launched on June, 15th15^{th} 2006 in a 350×600km350\times 600 km orbit with an inclination of 70 degrees. In this work we describe the scientific objectives and the performance of PAMELA in its first two years of operation. Data on protons of trapped, secondary and galactic nature - as well as measurements of the December 13th13^{th} 2006 Solar Particle Event - are also provided.Comment: To appear on J. Phys. Soc. Jpn. as part of the proceedings of the International Workshop on Advances in Cosmic Ray Science March, 17-19, 2008 Waseda University, Shinjuku, Tokyo, Japa

    PAMELA results on the cosmic-ray antiproton flux from 60 MeV to 180 GeV in kinetic energy

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    The satellite-borne experiment PAMELA has been used to make a new measurement of the cosmic-ray antiproton flux and the antiproton-to-proton flux ratio which extends previously published measurements down to 60 MeV and up to 180 GeV in kinetic energy. During 850 days of data acquisition approximately 1500 antiprotons were observed. The measurements are consistent with purely secondary production of antiprotons in the galaxy. More precise secondary production models are required for a complete interpretation of the results.Comment: 11 pages, 3 figures, 1 table. Accepted for publication in Physical Review Letter

    A new measurement of the antiproton-to-proton flux ratio up to 100 GeV in the cosmic radiation

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    A new measurement of the cosmic ray antiproton-to-proton flux ratio between 1 and 100 GeV is presented. The results were obtained with the PAMELA experiment, which was launched into low-earth orbit on-board the Resurs-DK1 satellite on June 15th 2006. During 500 days of data collection a total of about 1000 antiprotons have been identified, including 100 above an energy of 20 GeV. The high-energy results are a ten-fold improvement in statistics with respect to all previously published data. The data follow the trend expected from secondary production calculations and significantly constrain contributions from exotic sources, e.g. dark matter particle annihilations.Comment: 10 pages, 4 figures, 1 tabl

    PAMELA Measurements of Cosmic-ray Proton and Helium Spectra

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    Protons and helium nuclei are the most abundant components of the cosmic radiation. Precise measurements of their fluxes are needed to understand the acceleration and subsequent propagation of cosmic rays in the Galaxy. We report precision measurements of the proton and helium spectra in the rigidity range 1 GV-1.2 TV performed by the satellite-borne experiment PAMELA. We find that the spectral shapes of these two species are different and cannot be well described by a single power law. These data challenge the current paradigm of cosmic-ray acceleration in supernova remnants followed by diffusive propagation in the Galaxy. More complex processes of acceleration and propagation of cosmic rays are required to explain the spectral structures observed in our data.Comment: 13 pages, 4 figures, link to SOM (with tables) in the references. This manuscript has been accepted for publication in Science. This version has not undergone final editing. Please refer to the complete version of record at http://www.sciencemag.org/ [www.sciencemag.org

    Planck pre-launch status: Low Frequency Instrument calibration and expected scientific performance

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    We give the calibration and scientific performance parameters of the Planck Low Frequency Instrument (LFI) measured during the ground cryogenic test campaign. These parameters characterise the instrument response and constitute our best pre-launch knowledge of the LFI scientific performance. The LFI shows excellent 1/f1/f stability and rejection of instrumental systematic effects; measured noise performance shows that LFI is the most sensitive instrument of its kind. The set of measured calibration parameters will be updated during flight operations through the end of the mission.Comment: Accepted for publications in Astronomy and Astrophysics. Astronomy & Astrophysics, 2010 (acceptance date: 12 Jan 2010

    Proton-proton elastic scattering at the LHC energy of {\surd} = 7 TeV

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    Proton-proton elastic scattering has been measured by the TOTEM experiment at the CERN Large Hadron Collider at {\surd}s = 7 TeV in dedicated runs with the Roman Pot detectors placed as close as seven times the transverse beam size (sbeam) from the outgoing beams. After careful study of the accelerator optics and the detector alignment, |t|, the square of four-momentum transferred in the elastic scattering process, has been determined with an uncertainty of d t = 0.1GeV p|t|. In this letter, first results of the differential cross section are presented covering a |t|-range from 0.36 to 2.5GeV2. The differential cross-section in the range 0.36 < |t| < 0.47 GeV2 is described by an exponential with a slope parameter B = (23.6{\pm}0.5stat {\pm}0.4syst)GeV-2, followed by a significant diffractive minimum at |t| = (0.53{\pm}0.01stat{\pm}0.01syst)GeV2. For |t|-values larger than ~ 1.5GeV2, the cross-section exhibits a power law behaviour with an exponent of -7.8_\pm} 0.3stat{\pm}0.1syst. When compared to predictions based on the different available models, the data show a strong discriminative power despite the small t-range covered.Comment: 12pages, 5 figures, CERN preprin
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