2,879 research outputs found

    Data processing method for a weak, moving telemetry signal

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    Method of processing data from a spacecraft, where the carrier has a low signal-to-noise ratio and wide unpredictable frequency shifts, consists of analogue recording of the noisy signal along with a high-frequency tone that is used as a clock to trigger a digitizer

    Methods of editing cloud and atmospheric layer affected pixels from satellite data

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    The location and migration of cloud, land and water features were examined in spectral space (reflective VIS vs. emissive IR). Daytime HCMM data showed two distinct types of cloud affected pixels in the south Texas test area. High altitude cirrus and/or cirrostratus and "subvisible cirrus" (SCi) reflected the same or only slightly more than land features. In the emissive band, the digital counts ranged from 1 to over 75 and overlapped land features. Pixels consisting of cumulus clouds, or of mixed cumulus and landscape, clustered in a different area of spectral space than the high altitude cloud pixels. Cumulus affected pixels were more reflective than land and water pixels. In August the high altitude clouds and SCi were more emissive than similar clouds were in July. Four-channel TIROS-N data were examined with the objective of developing a multispectral screening technique for removing SCi contaminated data

    Open Space – a collaborative process for facilitating Tourism IT partnerships

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    The success of IT projects depends on the success of the partnerships on which they are based. However past research by the author has identified a significant rate of failure in these partnerships, predominantly due to an overly technical mindset, leading to the question: “how do we ensure that, as technological solutions are implemented within tourism, due consideration is given to human-centred issues?” The tourism partnership literature is explored for additional insights revealing that issues connected with power, participation and normative positions play a major role. The method, Open Space, is investigated for its ability to engage stakeholders in free and open debate. This paper reports on a one-day Open Space event sponsored by two major intermediaries in the UK travel industry who wanted to consult their business partners. Both the running of the event and its results reveal how Open Space has the potential to address some of the weaknesses associated with tourism partnerships

    Intermediate energy cross sections for electron-impact vibrational-excitation of pyrimidine

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    We report differential cross sections (DCSs) and integral cross sections (ICSs) for electron-impact vibrational-excitation of pyrimidine, at incident electron energies in the range 15–50 eV. The scattered electron angular range for the DCS measurements was 15°–90°. The measurements at the DCS-level are the first to be reported for vibrational-excitation in pyrimidine via electron impact, while for the ICS we extend the results from the only previous condensed-phase study [P. L. Levesque, M. Michaud, and L. Sanche, J. Chem. Phys. 122, 094701 (2005)], for electron energies ⩽12 eV, to higher energies. Interestingly, the trend in the magnitude of the lower energy condensed-phase ICSs is much smaller when compared to the corresponding gas phase results. As there is no evidence for the existence of any shape-resonances, in the available pyrimidine total cross sections [Baek et al., Phys. Rev. A 88, 032702 (2013); Fuss et al., ibid. 88, 042702 (2013)], between 10 and 20 eV, this mismatch in absolute magnitude between the condensed-phase and gas-phase ICSs might be indicative for collective-behaviour effects in the condensed-phase results

    Spectral density asymptotics for Gaussian and Laguerre β\beta-ensembles in the exponentially small region

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    The first two terms in the large NN asymptotic expansion of the β\beta moment of the characteristic polynomial for the Gaussian and Laguerre β\beta-ensembles are calculated. This is used to compute the asymptotic expansion of the spectral density in these ensembles, in the exponentially small region outside the leading support, up to terms o(1)o(1) . The leading form of the right tail of the distribution of the largest eigenvalue is given by the density in this regime. It is demonstrated that there is a scaling from this, to the right tail asymptotics for the distribution of the largest eigenvalue at the soft edge.Comment: 19 page

    D/H Ratios on Saturn and Jupiter from Cassini CIRS

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    We present new measurements of the deuterium abundance on Jupiter and Saturn, showing evidence that Saturn's atmosphere contains less deuterium than Jupiter's. We analyzed far-infrared spectra from the Cassini Composite Infrared Spectrometer to measure the abundance of HD on both giant planets. Our estimate of the Jovian D/H = (2.95 ± 0.55) × 10−5 is in agreement with previous measurements by ISO/SWS: (2.25 ± 0.35) × 10−5, and the Galileo probe: (2.6 ± 0.7) × 10−5. In contrast, our estimate of the Saturn value of (2.10 ± 0.13) × 10−5 is somewhat lower than on Jupiter (by a factor of 0.710.15+0.22{0.71}_{-0.15}^{+0.22}), contrary to model predictions of a higher ratio: Saturn/Jupiter = 1.05–1.20. The Saturn D/H value is consistent with estimates for hydrogen in the protosolar nebula (2.1 ± 0.5) × 10−5, but its apparent divergence from the Jovian value suggests that our understanding of planetary formation and evolution is incomplete, which is in agreement with previous work.The US-based authors: J.E.D.P., C.A.N., G.L.B., R.K.A., B.E.H., and F.M.F. were supported by the NASA Cassini Mission during the period when this research was conducted. L.N.F. was supported by a Royal Society Research Fellowship at the University of Leicester. P.G.J.I. was supported by the United Kingdom Science and Technology Facilities Council.Peer-reviewedPublisher Versio

    New Measurements of Fine-Scale CMB Polarization Power Spectra from CAPMAP at Both 40 and 90 GHz

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    We present new measurements of the cosmic microwave background (CMB) polarization from the final season of the Cosmic Anisotropy Polarization MAPper (CAPMAP). The data set was obtained in winter 2004-2005 with the 7 m antenna in Crawford Hill, New Jersey, from 12 W-band (84-100 GHz) and 4 Q-band (36-45 GHz) correlation polarimeters with 3.3' and 6.5' beamsizes, respectively. After selection criteria were applied, 956 (939) hours of data survived for analysis of W-band (Q-band) data. Two independent and complementary pipelines produced results in excellent agreement with each other. A broad suite of null tests as well as extensive simulations showed that systematic errors were minimal, and a comparison of the W-band and Q-band sky maps revealed no contamination from galactic foregrounds. We report the E-mode and B-mode power spectra in 7 bands in the range 200 < l < 3000, extending the range of previous measurements to higher l. The E-mode spectrum, which is detected at 11 sigma significance, is in agreement with cosmological predictions and with previous work at other frequencies and angular resolutions. The BB power spectrum provides one of the best limits to date on B-mode power at 4.8 uK^2 (95% confidence).Comment: 19 pages, 17 figures, 2 tables, submitted to Ap

    Ethyl cyanide on Titan: Spectroscopic detection and mapping using ALMA

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    We report the first spectroscopic detection of ethyl cyanide (C2_2H5_5CN) in Titan's atmosphere, obtained using spectrally and spatially resolved observations of multiple emission lines with the Atacama Large Millimeter/submillimeter array (ALMA). The presence of C2_2H5_5CN in Titan's ionosphere was previously inferred from Cassini ion mass spectrometry measurements of C2_2H5_5CNH+^+. Here we report the detection of 27 rotational lines from C2_2H5_5CN (in 19 separate emission features detected at >3σ>3\sigma confidence), in the frequency range 222-241 GHz. Simultaneous detections of multiple emission lines from HC3_3N, CH3_3CN and CH3_3CCH were also obtained. In contrast to HC3_3N, CH3_3CN and CH3_3CCH, which peak in Titan's northern (spring) hemisphere, the emission from C2_2H5_5CN is found to be concentrated in the southern (autumn) hemisphere, suggesting a distinctly different chemistry for this species, consistent with a relatively short chemical lifetime for C2_2H5_5CN. Radiative transfer models show that most of the C2_2H5_5CN is concentrated at altitudes 300-600 km, suggesting production predominantly in the mesosphere and above. Vertical column densities are found to be in the range (2-5)×1014\times10^{14} cm2^{-2}.Comment: Published in 2015, ApJL, 800, L1

    Triply differential (e,2e) studies of phenol

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    We have measured (e,2e) triple differential cross sections (TDCS) for the electron-impact ionisation of phenol with coplanar asymmetrical kinematics for an incident electron energy of 250 eV. Experimental measurements of the angular distribution of the slow outgoing electrons at 20 eV are obtained when the incident electron scatters through angles of −5◦, −10◦, and −15◦, respectively. The TDCS data are compared with calculations performed within the molecular 3-body distorted wave model. In this case, a mixed level of agreement, that was dependent on the kinematical condition being probed, was observed between the theoretical and experimental results in the binary peak region. The experimental intensity of the recoil features under all kinematical conditions was relatively small, but was still largely underestimated by the theoretical calculations

    TENNISSENSE: A MULTI-SENSORY APPROACH TO PERFORMANCE ANALYSIS IN TENNIS

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    There is sufficient evidence in the current literature that the ability to accurately capture and model the accelerations, angular velocities and orientations involved in the tennis stroke could facilitate a major step forward in the application of biomechanics to tennis coaching (Tanabe & Ito, 2007; Gordon & Dapena, 2006). The TennisSense Project, run in collaboration with Tennis Ireland, aims to create the infrastructure required to digitally capture physical, tactical and physiological data from tennis players in order to assist in their coaching and improve performance. This study examined the potential for using Wireless Inertial Monitoring Units (WIMUs) to model the biomechanical aspects of the tennis stroke and for developing coaching tools that utilise this information
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