1,076 research outputs found

    Spelling errors and keywords in born-digital data: a case study using the Teenage Health Freak Corpus

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    The abundance of language data that is now available in digital form, and the rise of distinct language varieties that are used for digital communication, means that issues of non-standard spellings and spelling errors are, in future, likely to become more prominent for compilers of corpora. This paper examines the effect of spelling variation on keywords in a born-digital corpus in order to explore the extent and impact of this variation for future corpus studies. The corpus used in this study consists of e-mails about health concerns that were sent to a health website by adolescents. Keywords are generated using the original version of the corpus and a version with spelling errors corrected, and the British National Corpus (BNC) acts as the reference corpus. The ranks of the keywords are shown to be very similar and, therefore, suggest that, depending on the research goals, keywords could be generated reliably without any need for spelling correction

    Nonmonotonic inelastic tunneling spectra due to surface spin excitations in ferromagnetic junctions

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    The paper addresses inelastic spin-flip tunneling accompanied by surface spin excitations (magnons) in ferromagnetic junctions. The inelastic tunneling current is proportional to the magnon density of states which is energy-independent for the surface waves and, for this reason, cannot account for the bias-voltage dependence of the observed inelastic tunneling spectra. This paper shows that the bias-voltage dependence of the tunneling spectra can arise from the tunneling matrix elements of the electron-magnon interaction. These matrix elements are derived from the Coulomb exchange interaction using the itinerant-electron model of magnon-assisted tunneling. The results for the inelastic tunneling spectra, based on the nonequilibrium Green's function calculations, are presented for both parallel and antiparallel magnetizations in the ferromagnetic leads.Comment: 9 pages, 4 figures, version as publishe

    Prospects for asteroseismology

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    The observational basis for asteroseismology is being dramatically strengthened, through more than two years of data from the CoRoT satellite, the flood of data coming from the Kepler mission and, in the slightly longer term, from dedicated ground-based facilities. Our ability to utilize these data depends on further development of techniques for basic data analysis, as well as on an improved understanding of the relation between the observed frequencies and the underlying properties of the stars. Also, stellar modelling must be further developed, to match the increasing diagnostic potential of the data. Here we discuss some aspects of data interpretation and modelling, focussing on the important case of stars with solar-like oscillations.Comment: Proc. HELAS Workshop on 'Synergies between solar and stellar modelling', eds M. Marconi, D. Cardini & M. P. Di Mauro, Astrophys. Space Sci., in the press Revision: correcting abscissa labels on Figs 1 and

    Design of Experiments for Screening

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    The aim of this paper is to review methods of designing screening experiments, ranging from designs originally developed for physical experiments to those especially tailored to experiments on numerical models. The strengths and weaknesses of the various designs for screening variables in numerical models are discussed. First, classes of factorial designs for experiments to estimate main effects and interactions through a linear statistical model are described, specifically regular and nonregular fractional factorial designs, supersaturated designs and systematic fractional replicate designs. Generic issues of aliasing, bias and cancellation of factorial effects are discussed. Second, group screening experiments are considered including factorial group screening and sequential bifurcation. Third, random sampling plans are discussed including Latin hypercube sampling and sampling plans to estimate elementary effects. Fourth, a variety of modelling methods commonly employed with screening designs are briefly described. Finally, a novel study demonstrates six screening methods on two frequently-used exemplars, and their performances are compared

    Scale issues in soil moisture modelling: problems and prospects

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    Soil moisture storage is an important component of the hydrological cycle and plays a key role in land-surface-atmosphere interaction. The soil-moisture storage equation in this study considers precipitation as an input and soil moisture as a residual term for runoff and evapotranspiration. A number of models have been developed to estimate soil moisture storage and the components of the soil-moisture storage equation. A detailed discussion of the impli cation of the scale of application of these models reports that it is not possible to extrapolate processes and their estimates from the small to the large scale. It is also noted that physically based models for small-scale applications are sufficiently detailed to reproduce land-surface- atmosphere interactions. On the other hand, models for large-scale applications oversimplify the processes. Recently developed physically based models for large-scale applications can only be applied to limited uses because of data restrictions and the problems associated with land surface characterization. It is reported that remote sensing can play an important role in over coming the problems related to the unavailability of data and the land surface characterization of large-scale applications of these physically based models when estimating soil moisture storage.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Previously unpublished Odonata records from Sarawak, Borneo, part VI: Miri Division including checklists for Niah, Lambir Hills, Loagan Bunut and Pulong Tau National Parks

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    Recods of Odonata made from 2005 to 2020 in Miri Division in Sarawak are presented, including records from Lambir Hills, Loagan Bunut, Niah and Pulong Tau National Parks. Primary types of Odonata originating from Miri Division are listed. Surveys of more than one day duration in Miri Division and covered here are tabulated with the funding source where appropriate; four of the surveys covered here were funded by the International Dragonfly Fund. One hundred and eighty-eight species are listed based on surveys made by the authors, of which Macromia jucunda Lieftinck, 1955, had not been recorded from Borneo before, Burmagomphus arthuri Lieftinck, 1953 is a new record for Miri Division and Camacinia gigantea (Brauer, 1867) has only been recorded from the Division re-cently with the only published record in a difficult to access publication (Choong (2020)). At least 48 more of the species listed were recorded from Miri Division for the first time in surveys covered in this report, although the records have been published (in most cases with no details beyond division and district in Dow (2021)) before. Two forms of Xiphi-agrion cyanomelas Selys, 1876 are recorded and the likelihood that they represent different species is discussed. A possibly new, large sized, species of Macromia allied to M. westwoodii Selys, 1874 is recorded and discussed. Other notable records not published with details before include Rhinocypha stygia Förster, 1897, Rhinoneura caerulea Kimmins, 1936, Dysphaea lugens (Selys, 1873), Euphaea ameeka van Tol & Norma-Rashid, 1995, Euphaea basalis (Laidlaw, 1915), Amphicnemis new sp. cf mariae Lieftinck, 1940 (previously recorded from Usun Apau National Park), Anaciaeschna jaspidea (Burmeister, 1839), Heliaeschna uninervulata Martin, 1909, Borneogomphus sp., Heliogomphus borneensis Lieftinck, 1964, Ictinogomphus acutus (Laidlaw, 1914), Chlorogomphus sp., Macromia corycia Laidlaw, 1922, Idionyx montana Karsch, 1891, Hylaeothemis clementia Ris, 1909, Orchithemis xanthosoma Laidlaw, 1911, Rhyothemis fulgens Kirby, 1889, Rhyothemis regia (Brauer, 1867), Tetrathemis sp. cf platyptera Selys, 1878, Tramea phaeoneura Lieftinck, 1953 and Tramea sp. cf virginia (Rambur, 1842). The habitat preferences of Dysphaea lugens are discussed. A male-male tandem of Coeliccia nigrohamata Laidlaw, 1918 is reported. The somewhat peculiar distribution of Argiocnemis rubescens rubeola Selys, 1877 and Pseudothemis jorina Förster, 1904 in Sarawak is discussed. Activity of the apparently normally crepuscular Heliaeschna uninervulata in the middle of the day is reported. An interesting morphological detail of some female Chlorogomphus from Sarawak is discussed. The likelihood that Macromia corycia is a junior synonym of M. gerstaeckeri Krüger, 1899 is discussed. The possibility that the range of Rhyothemis regia is expanding in Sarawak is remarked upon. The identity of Tramea sp. cf virginia is discussed. With the records presented here at least 222 species of Odonata are known from Miri Division and with the addition of Macromia jucunda to the known fauna, 309 species have now been recorded from Sarawak. More detailed specimen records are given in Appendix 1 and a revised checklist of Odonata from Lambir Hills National Park and the first checklis from Loagan Bunut, Niah and Pulong Tau National Parks are given in Appendix 2

    Previously unpublished Odonata records from Sarawak, Borneo, part VI: Miri Division including checklists for Niah, Lambir Hills, Loagan Bunut and Pulong Tau National Parks.

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    Recods of Odonata made from 2005 to 2020 in Miri Division in Sarawak are presented, including records from Lambir Hills, Loagan Bunut, Niah and Pulong Tau National Parks. Primary types of Odonata originating from Miri Division are listed. Surveys of more than one day duration in Miri Division and covered here are tabulated with the funding source where appropriate; four of the surveys covered here were funded by the International Dragonfly Fund. One hundred and eighty-eight species are listed based on surveys made by the authors, of which Macromia jucunda Lieftinck, 1955, had not been recorded from Borneo before, Burmagomphus arthuri Lieftinck, 1953 is a new record for Miri Division and Camacinia gigantea (Brauer, 1867) has only been recorded from the Division re-cently with the only published record in a difficult to access publication (Choong (2020)). At least 48 more of the species listed were recorded from Miri Division for the first time in surveys covered in this report, although the records have been published (in most cases with no details beyond division and district in Dow (2021)) before. Two forms of Xiphi-agrion cyanomelas Selys, 1876 are recorded and the likelihood that they represent different species is discussed. A possibly new, large sized, species of Macromia allied to M. westwoodii Selys, 1874 is recorded and discussed. Other notable records not published with details before include Rhinocypha stygia Förster, 1897, Rhinoneura caerulea Kimmins, 1936, Dysphaea lugens (Selys, 1873), Euphaea ameeka van Tol & Norma-Rashid, 1995, Euphaea basalis (Laidlaw, 1915), Amphicnemis new sp. cf mariae Lieftinck, 1940 (previously recorded from Usun Apau National Park), Anaciaeschna jaspidea (Burmeister, 1839), Heliaeschna uninervulata Martin, 1909, Borneogomphus sp., Heliogomphus borneensis Lieftinck, 1964, Ictinogomphus acutus (Laidlaw, 1914), Chlorogomphus sp., Macromia corycia Laidlaw, 1922, Idionyx montana Karsch, 1891, Hylaeothemis clementia Ris, 1909, Orchithemis xanthosoma Laidlaw, 1911, Rhyothemis fulgens Kirby, 1889, Rhyothemis regia (Brauer, 1867), Tetrathemis sp. cf platyptera Selys, 1878, Tramea phaeoneura Lieftinck, 1953 and Tramea sp. cf virginia (Rambur, 1842). The habitat preferences of Dysphaea lugens are discussed. A male-male tandem of Coeliccia nigrohamata Laidlaw, 1918 is reported. The somewhat peculiar distribution of Argiocnemis rubescens rubeola Selys, 1877 and Pseudothemis jorina Förster, 1904 in Sarawak is discussed. Activity of the apparently normally crepuscular Heliaeschna uninervulata in the middle of the day is reported. An interesting morphological detail of some female Chlorogomphus from Sarawak is discussed. The likelihood that Macromia corycia is a junior synonym of M. gerstaeckeri Krüger, 1899 is discussed. The possibility that the range of Rhyothemis regia is expanding in Sarawak is remarked upon. The identity of Tramea sp. cf virginia is discussed. With the records presented here at least 222 species of Odonata are known from Miri Division and with the addition of Macromia jucunda to the known fauna, 309 species have now been recorded from Sarawak. More detailed specimen records are given in Appendix 1 and a revised checklist of Odonata from Lambir Hills National Park and the first checklis from Loagan Bunut, Niah and Pulong Tau National Parks are given in Appendix 2

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

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    Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
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