77,056 research outputs found

    Automatic Classification of Text Databases through Query Probing

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    Many text databases on the web are "hidden" behind search interfaces, and their documents are only accessible through querying. Search engines typically ignore the contents of such search-only databases. Recently, Yahoo-like directories have started to manually organize these databases into categories that users can browse to find these valuable resources. We propose a novel strategy to automate the classification of search-only text databases. Our technique starts by training a rule-based document classifier, and then uses the classifier's rules to generate probing queries. The queries are sent to the text databases, which are then classified based on the number of matches that they produce for each query. We report some initial exploratory experiments that show that our approach is promising to automatically characterize the contents of text databases accessible on the web.Comment: 7 pages, 1 figur

    The impact of an emotionally expressive writing intervention on eating pathology in female students

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    © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.Introduction: Previous research demonstrating emotional influences on eating and weight suggest that emotionally expressive writing may have a significant impact on reducing risk of eating pathology. This study examined the effects of writing about Intensely Positive Experiences on weight and disordered eating during a naturalistic stressor. Method: Seventy-one female students completed an expressive or a control writing task before a period of exams. Both groups were compared on BMI (kg/m2) and the Eating Disorder Examination – Questionnaire (EDE-Q) before the writing task and at 8-week follow-up. A number of secondary analyses were also examined (to identify potential mediators) including measures of attachment, social rank, self-criticism and self-reassurance, stress and mood. Results: There was a significant effect of intervention on changes in the subscales of the EDE-Q (p = .03). Specifically, expressive writers significantly reduced their dietary restraint while those in the control group did not. There was no significant effect of the intervention on changes in BMI or the other subscales of the EDE-Q (Eating, Weight and Shape Concern). There was also no effect of writing on any of the potential mediators in the secondary analyses. Discussion: Emotionally expressive writing may reduce the risk of dietary restraint in women but these findings should be accepted with caution. It is a simple and light touch intervention that has the potential to be widely applied. However, it remains for future research to replicate these results and to identify the mechanisms of action.Peer reviewedFinal Published versio

    Study of transition temperatures in superconductors Final report, 11 Mar. 1968 - 10 Mar. 1970

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    Thermodynamic and electrical properties of niobium stannide and other superconductor

    An Experimental Evaluation of Oil Pumping Rings

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    The design and construction of a reciprocating test vehicle to be used in evaluating hydrodynamic oil pumping rings are discussed. In addition, experimental test data are presented for three pumping ring designs that were constructed from Tin-Based Babbitt (SAE 11), Bearing Bronze (SAE 660), and Mechanical Carbon Graphite (Union Carbide Grade CNF-J). Data of pumped flow rate versus delivered pressure, as well as friction loss, are reported for the following conditions: frequencies of 10, 35 and 45 Hz; strokes of 25.4 mm (1.00 in.), 38.1 mm (1.50 in.) and 50.8 mm (2.00 in.) oil inlet temperature of 49 degrees (120 degrees); and pumping ring close-in pressures of 10.3 MPa (1500 lb/square inch. A 20W40 automotive oil was used for all tests. The maximum delivered pressure was 11 MPa (1600 lb/square inch. An analysis of hydrodynamic oil pumping rings was performed and the results of the analysis were compared to measured test data

    First-principles investigation of 180-degree domain walls in BaTiO_3

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    We present a first-principles study of 180-degree ferroelectric domain walls in tetragonal barium titanate. The theory is based on an effective Hamiltonian that has previously been determined from first-principles ultrasoft-pseudopotential calculations. Statistical properties are investigated using Monte Carlo simulations. We compute the domain-wall energy, free energy, and thickness, analyze the behavior of the ferroelectric order parameter in the interior of the domain wall, and study its spatial fluctuations. An abrupt reversal of the polarization is found, unlike the gradual rotation typical of the ferromagnetic case.Comment: Revtex (preprint style, 13 pages) + 3 postscript figures. A version in two-column article style with embedded figures is available at http://electron.rutgers.edu/~dhv/preprints/index.html#pad_wal

    Heteronuclear ionizing collisions between laser-cooled metastable helium atoms

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    We have investigated cold ionizing heteronuclear collisions in dilute mixtures of metastable (2 3S1) 3He and 4He atoms, extending our previous work on the analogous homonuclear collisions [R. J. W. Stas et al., PRA 73, 032713 (2006)]. A simple theoretical model of such collisions enables us to calculate the heteronuclear ionization rate coefficient, for our quasi-unpolarized gas, in the absence of resonant light (T = 1.2 mK): K34(th) = 2.4*10^-10 cm^3/s. This calculation is supported by a measurement of K34 using magneto-optically trapped mixtures containing about 1*10^8 atoms of each species, K34(exp) = 2.5(8)*10^-10 cm^3/s. Theory and experiment show good agreement.Comment: 8 pages, 6 figure

    The instability of stellar structures intermediate between white dwarfs and neutron stars

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    Instability of stellar structures intermediate between dwarfs and neutron star

    Solar wind radiation damage effects in lunar material

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    The research on solar wind radiation damage and other effects in lunar samples which was conducted to understand the optical properties of lunar materials is reported. Papers presented include: solar radiation effects in lunar samples, albedo of the moon, radiation effects in lunar crystalline rocks, valence states of 3rd transition elements in Apollo 11 and 12 rocks, and trace ferric iron in lunar and meteoritic titanaugites

    First-principles study of stability and vibrational properties of tetragonal PbTiO_3

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    A first-principles study of the vibrational modes of PbTiO_3 in the ferroelectric tetragonal phase has been performed at all the main symmetry points of the Brillouin zone (BZ). The calculations use the local-density approximation and ultrasoft pseudopotentials with a plane-wave basis, and reproduce well the available experimental information on the modes at the Gamma point, including the LO-TO splittings. The work was motivated in part by a previously reported transition to an orthorhombic phase at low temperatures [(J. Kobayashi, Y. Uesu, and Y. Sakemi, Phys. Rev. B {\bf 28}, 3866 (1983)]. We show that a linear coupling of orthorhombic strain to one of the modes at Gamma plays a role in the discussion of the possibility of this phase transition. However, no mechanical instabilities (soft modes) are found, either at Gamma or at any of the other high-symmetry points of the BZ.Comment: 8 pages, two-column style with 3 postscript figures embedded. Uses REVTEX and epsf macros. Also available at http://www.physics.rutgers.edu/~dhv/preprints/index.html#ag_pbt

    New Challenges For Wind Shock Models: The Chandra Spectrum Of The Hot Star Delta Orionis

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    The Chandra spectrum of delta Ori A shows emission lines from hydrogen- and helium-like states of Si, Mg, Ne, and O, along with N VII Lyalpha and lines from ions in the range Fe XVII-Fe XXI In contrast to the broad lines seen in zeta Pup and zeta Ori (850 +/- 40 and 1000 +/- 240 km s(-1) half-width at half-maximum [HWHM], respectively), these lines are broadened to only 430 +/- 60 km s(-1) HWHM. This is much lower than the measured wind terminal velocity of 2000 km s(-1). The forbidden, intercombination, and resonance (fir) lines from He-like ions indicate that the majority of the X-ray line emission does not originate at the base of the wind, in agreement with the standard wind shock models for these objects. However, in that model the X-ray emission is distributed throughout an expanding, X-ray-absorbing wind, and it is therefore surprising that the emission lines appear relatively narrow, unshifted, and symmetric. We compare the observed line profiles to recent detailed models for X-ray line pro le generation in hot stars, but none of them offers a fully satisfactory explanation for the observed line profiles
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