19,293 research outputs found

    Global logistics indicators, supply chain metrics, and bilateral trade patterns

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    Past research into the determinants of international trade highlighted the importance of the basic spatial gravity model augmented by additional variables representing sources of friction. Studies modeled many sources of friction using various proxies, including indices based on expert judgment in some cases. This paper focuses on logistics friction and draws on a data set recently compiled by the World Bank with specific quantitative metrics of logistics performance interms of time, cost, and variability in time. It finds that the new variables that relate directly to logistics performance have a statistically significant relationship with the level of bilateral trade. It also finds that a single logistics index can capture virtually all of the explanatory power of multiple logistics indicators. The findings should spur public and private agencies that have direct or indirect power over logistics performance to focus attention on reducing sources of friction so as to improve their country's ability to compete in today's global economy. Moreover, since the logistics metrics are directly related to operational performance, countries can use these metrics to target actions to improve logistics and monitor their progress.Common Carriers Industry,Transport and Trade Logistics,Economic Theory&Research,Free Trade,Trade Policy

    Time Domain Studies of X-ray Shot Noise in Cygnus X-1

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    We investigate the variability of Cygnus X-1 in the context of shot moise models, and employ a peak detection algorithm to select individual shots. For a long observation of the low, hard state, the distribution of time intervals between shots is found to be consistent with a purely random process, contrary to previous claims in the literature. The detected shots are fit to several model templates and found to have a broad range of shapes. The fitted shots have a distribution of timescales from below 10 milliseconds to above 1 second. The coherence of the cross spectrum of light curves of these data in different energy bands is also studied. The observed high coherence implies that the transfer function between low and high energy variability is uniform. The uniformity of the tranfer function implies that the observed distribution of shot widths cannot have been acquired through Compton scattering. Our results in combination with other results in the literature suggest that shot luminosities are correlated with one another. We discuss how our experimental methodology relates to non-linear models of variability.Comment: Accepted for publication in Astrophysical Journal on July 16, 200

    Technology utilization in a non-urban region - A measurement of the impact of the Technology Use Studies Center Final report

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    Technology utilization in agricultural areas and measurement of impact of technology use studies cente

    SPAN: Astronomy and astrophysics

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    The Space Physics Analysis Network (SPAN) is a multi-mission, correlative data comparison network which links science research and data analysis computers in the U.S., Canada, and Europe. The purpose of this document is to provide Astronomy and Astrophysics scientists, currently reachable on SPAN, with basic information and contacts for access to correlative data bases, star catalogs, and other astrophysic facilities accessible over SPAN

    Scanner observations of selected cool stars

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    Photoelectric spectral scans at 30-A resolution of 9 dwarfs, 10 giants and 6 supergiants with spectral types GO to M5 were presented. All stars were observed every 4 A from wavelength 3300 to wavelength 7000. Absorption features at this resolution coincide with: strong atomic lines of Fe 1,11, Ca 1,11, Mg 1, and Na 1; vibrational bands of the electronic transitions of TiO, MgH, CaH, SiH, AlH, Cn, Ch, C2, OH, and NH. The dependence of the wavelength 3740 Fe 1 blend and the wavelength 3440 depression on temperature is discussed

    Nuclear War

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    Test results of the Chrysler upgraded automotive gas turbine engine: Initial design

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    The upgraded engine as built to the original design was deficient in power and had excessive specific fuel consumption. A high instrumented version of the engine was tested to identify the sources of the engine problems. Analysis of the data shows the major problems to be low compressor and power turbine efficiency and excessive interstage duct losses. In addition, high HC and CO emission were measured at idle, and high NOx emissions at high energy speeds

    Flows and Non-thermal Velocities in Solar Active Regions Observed with the Extreme-ultraviolet Imaging Spectrometer on Hinode: A Tracer of Active Region Sources of Heliospheric Magnetic Fields?

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    From Doppler velocity maps of active regions constructed from spectra obtained by the Extreme-ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft we observe large areas of outflow (20-50 km/s) that can persist for at least a day. These outflows occur in areas of active regions that are faint in coronal spectral lines formed at typical quiet Sun and active region temperatures. The outflows are positively correlated with non-thermal velocities in coronal plasmas. The bulk mass motions and non-thermal velocities are derived from spectral line centroids and line widths, mostly from a strong line of Fe XII at 195.12 Angstroms. The electron temperature of the outflow regions estimated from an Fe XIII to Fe XII line intensity ratio is about 1.2-1.4 MK. The electron density of the outflow regions derived from a density sensitive intensity ratio of Fe XII lines is rather low for an active region. Most regions average around 7E10+8 cm(-3), but there are variations on pixel spatial scales of about a factor of 4. We discuss results in detail for two active regions observed by EIS. Images of active regions in line intensity, line width, and line centroid are obtained by rastering the regions. We also discuss data from the active regions obtained from other orbiting spacecraft that support the conclusions obtained from analysis of the EIS spectra. The locations of the flows in the active regions with respect to the longitudinal photospheric magnetic fields suggest that these regions might be tracers of long loops and/or open magnetic fields that extend into the heliosphere, and thus the flows could possibly contribute significantly to the solar wind.Comment: one tex file, 11 postscript figure file
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