7,967 research outputs found

    Labor Productivity in Britain and America During the Nineteenth Century

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    A number of writers have recently questioned whether labor productivity or per capita incomes were ever higher in the United Kingdom than in the United States. We show that although the United States already had a substantial labor productivity lead in industry as early as 1840, especially in manufacturing, labor productivity was broadly equal in the two countries in agriculture, while the United Kingdom was ahead in services. Hence aggregate labor productivity was higher in the United Kingdom, particularly since the United States had a larger share of the labor force in low value-added agriculture. U.S. overtaking occurred decisively only during the 1890s, as labor productivity pulled ahead in services and the share of agricultural employment declined substantially. Labor force participation was lower in the United States, so that the United Kingdom's labor productivity advantage in the mid-nineteenth century translated into a larger per capita income lead.

    Maximum-entropy Surrogation in Network Signal Detection

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    Multiple-channel detection is considered in the context of a sensor network where raw data are shared only by nodes that have a common edge in the network graph. Established multiple-channel detectors, such as those based on generalized coherence or multiple coherence, use pairwise measurements from every pair of sensors in the network and are thus directly applicable only to networks whose graphs are completely connected. An approach introduced here uses a maximum-entropy technique to formulate surrogate values for missing measurements corresponding to pairs of nodes that do not share an edge in the network graph. The broader potential merit of maximum-entropy baselines in quantifying the value of information in sensor network applications is also noted.Comment: 4 pages, submitted to IEEE Statistical Signal Processing Workshop, August 201

    Letter, Stephen A. Douglas to M. Lewis Clark, August 7, 1852

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    This handwritten letter, dated August 7, 1852, is written from Stephen A. Douglas to M. Lewis Clark requesting that Clark send Douglas a true and perfect copy of a survey of tract of land at the mouth of the Chicago River. The back of the letter contains a summary of the request and states that made out copies of field notes and plat of Falcott\u27s survey on 16 August 1852.https://scholarsjunction.msstate.edu/fvw-manuscripts-original-manuscripts/1137/thumbnail.jp

    The Luminosity Function of Galaxies in the Las Campanas Redshift Survey

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    We present the RR-band luminosity function for a sample of 18678 galaxies, with average redshift z=0.1z = 0.1, from the Las Campanas Redshift Survey. The luminosity function may be fit by a Schechter function with M=20.29±0.02+5loghM^* = -20.29 \pm 0.02 + 5 \log h, α=0.70±0.05\alpha = -0.70 \pm 0.05, and $\phi^* = 0.019 \pm 0.001 \ h^3 Mpc~Mpc^{-3},forabsolutemagnitudes, for absolute magnitudes -23.0 \leq M - 5 \log h \leq -17.5.Wecompareourluminosityfunctiontothatfromotherredshiftsurveys;inparticularournormalizationisconsistentwiththatoftheStromloAPMsurvey,andisthereforeafactoroftwobelowthatimpliedbythe. We compare our luminosity function to that from other redshift surveys; in particular our normalization is consistent with that of the Stromlo-APM survey, and is therefore a factor of two below that implied by the b_J \approx 20brightgalaxycounts.Ournormalizationthusindicatesthatmuchmoreevolutionisneededtomatchthefaintgalaxycountdata,comparedtominimalevolutionmodelswhichnormalizeat bright galaxy counts. Our normalization thus indicates that much more evolution is needed to match the faint galaxy count data, compared to minimal evolution models which normalize at b_J \approx 20.Also,weshowthatourfaintendslope. Also, we show that our faint-end slope \alpha = -0.7,thoughshallowerthantypicalpreviousvalues, though ``shallower'' than typical previous values \alpha = -1,resultsprimarilyfromfittingthedetailedshapeoftheLCRSluminosityfunction,ratherthanfromanyabsenceofintrinsicallyfaintgalaxiesfromoursurvey.Finally,using[OII]3727equivalentwidth, results primarily from fitting the detailed shape of the LCRS luminosity function, rather than from any absence of intrinsically faint galaxies from our survey. Finally, using [OII] 3727 equivalent width W_{\lambda} = 5 A˚ asthedividingline,wefindsignificantdifferencesintheluminosityfunctionsofemissionandnonemissiongalaxies,particularlyintheir~\AA \ as the dividing line, we find significant differences in the luminosity functions of emission and non-emission galaxies, particularly in their \alphavalues.EmissiongalaxieshaveSchechterparameters values. Emission galaxies have Schechter parameters M^* = -20.03 \pm 0.03 + 5 \log hand and \alpha = -0.9 \pm 0.1,whilenonemissiongalaxiesaredescribedby, while non-emission galaxies are described by M^* = -20.22 \pm 0.02 + 5 \log hand and \alpha = -0.3 \pm 0.1$. (abridged abstract)Comment: 41 pages, including 13 postscript figures, uses AASTEX v4.0 style files. Important clarification of R-band definition, plus correction of luminosity densities and updated references. Main conclusions unchanged. Final version to appear in Ap

    Driver vs. manager perceptions of commonly used safety practices in commercial motor vehicle operations

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    This research investigated the perceptions of Commercial Motor Vehicle Operators and Safety Professionals regarding 35 commonly implemented practices used to improve operating safety. Several differences were found in how drivers of different backgrounds rated various practices, and between the drivers and safety managers. These differences were found to be persistent even when combined with measures of safety performance and experience. Managers tended to overvalue (relative to drivers) practices related to hiring, while drivers tended to overvalue (relative to managers) practices related to company support and reward systems. Motor Carriers, insurers, and regulators could consider areas of agreement with respect to high value practices as actionable for increased investment of resources. At the same time, resources allocated toward areas of low perceived value could be reduced

    Safety attitudes and behavioral intentions of municipal waste disposal drivers

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    The Theory of Planned Behavior was used to study factors useful for predicting Behavioral Intentions to commit unsafe acts while driving for commercial drivers working for municipal waste management operations centers. The Theory of Planned Behavior was found to be moderately effective in predicting behavioral intentions, particularly through the constructs of Attitude and Perceived Control. Driver perceptions of safety climate, self-assessed personal safety performance, risk aversion, and attitudes toward behavioral factors associated with engaging in risky behaviors while operating motor vehicles were studied. Risk aversion and driver perception of their own safety performance were also useful predictors of intention
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