377 research outputs found

    Word-frequency effect in lexical decision: finding a frequency-based component

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    Journal ArticleSubjects making lexical decisions are reliably faster in responding to high-frequency words than to low-frequency words. This is known as the word frequency effect. We wished to demonstrate that some portion of this effect was due to frequency differences between words rather than to other dimensions correlated with word frequency. Three groups of subjects (10 engineers, 10 nurses, and 10 law students) made lexical decisions about 720 items, half words and half nonwords, from six different categories (engineering, medical, low-frequency nontechnical, medium-frequency nontechnical, and two groups of high-frequency nontechnical). Results of t w o analyses of variance revealed a crossover interaction such that engineers were faster in responding to engineering words than to medical words, whereas nurses were faster in responding to medical words than to engineering words. The engineering and medical words were equally long and equally infrequent by standard word counts. We take this as support for a frequency-based component in the word frequency effect. The practical implications of this research for estimating the readability of technical text are discussed

    Combinatorial Voter Control in Elections

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    Voter control problems model situations such as an external agent trying to affect the result of an election by adding voters, for example by convincing some voters to vote who would otherwise not attend the election. Traditionally, voters are added one at a time, with the goal of making a distinguished alternative win by adding a minimum number of voters. In this paper, we initiate the study of combinatorial variants of control by adding voters: In our setting, when we choose to add a voter~vv, we also have to add a whole bundle Îş(v)\kappa(v) of voters associated with vv. We study the computational complexity of this problem for two of the most basic voting rules, namely the Plurality rule and the Condorcet rule.Comment: An extended abstract appears in MFCS 201

    Instability-induced fermion production in quantum field theory

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    Nonequilibrium instabilities are known to lead to exponential amplification of boson occupation numbers for low momentum modes on time scales much shorter than the asymptotic thermal equilibration time. We show for Yukawa-type interactions that this growth induces very efficient fermion production, which proceeds with the maximum primary boson growth rate. The description is based on a 1/N expansion of the 2PI effective action to NLO including boson-fermion loops, which are crucial to observe this phenomenon. For long enough amplification in the boson sector, fermion production terminates when the thermal occupancy is reached in the infrared. At higher momenta, where boson occupation numbers are low, the fermion modes exhibit a power-law regime with exponent two.Comment: 19 pages, 16 figures, Phys.Rev.D version, minor correction

    A close look into the carbon disk at the core of the planetary nebula CPD-568032

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    We present high spatial resolution observations of the dusty core of the Planetary Nebula with Wolf-Rayet central star CPD-568032. These observations were taken with the mid-infrared interferometer VLTI/MIDI in imaging mode providing a typical 300 mas resolution and in interferometric mode using UT2-UT3 47m baseline providing a typical spatial resolution of 20 mas. The visible HST images exhibit a complex multilobal geometry dominated by faint lobes. The farthest structures are located at 7" from the star. The mid-IR environment of CPD-568032 is dominated by a compact source, barely resolved by a single UT telescope in a 8.7 micron filter. The infrared core is almost fully resolved with the three 40-45m projected baselines ranging from -5 to 51 degree but smooth oscillating fringes at low level have been detected in spectrally dispersed visibilities. This clear signal is interpreted in terms of a ring structure which would define the bright inner rim of the equatorial disk. Geometric models allowed us to derive the main geometrical parameters of the disk. For instance, a reasonably good fit is reached with an achromatic and elliptical truncated Gaussian with a radius of 97+/-11 AU, an inclination of 28+/-7 degree and a PA for the major axis at 345+/-7 degree. Furthermore, we performed some radiative transfer modeling aimed at further constraining the geometry and mass content of the disk, by taking into account the MIDI dispersed visibilities, spectra, and the large aperture SED of the source. These models show that the disk is mostly optically thin in the N band and highly flared.Comment: Paper accepted in A&

    Observing other pedestrians: Investigating the typical distance and duration of fixation

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    After dark, road lighting should enhance the visual component of pedestrians’ interpersonal judgements such as evaluating the intent of others. Investigation of lighting effects requires better understanding of the nature of this task as expressed by the typical distance at which the judgement is made (and hence visual size) and the duration of observation, which in past studies have been arbitrary. Better understanding will help with interpretation of the significance of lighting characteristics such as illuminance and light spectrum. Conclusions of comfort distance in past studies are not consistent and hence this article presents new data determined using eye-tracking. We propose that further work on interpersonal judgements should examine the effects of lighting at a distance of 15 m with an observation duration of 500 ms

    Bottomonium in the plasma: Lattice results

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    We present results on the heavy quarkonium spectrum and spectral functions obtained by performing large-scale simulations of QCD for temperatures ranging from about 100 to 500 MeV, in the same range as those explored by LHC experiments. We discuss our method and perspectives for further improvements towards the goal of full control over the many systematic uncertainties of these studies

    Comparative Study of Quarkonium Transport in Hot QCD Matter

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    This document summarizes the efforts of the EMMI Rapid Reaction Task Force on "Suppression and (re)generation of quarkonium in heavy-ion collisions at the LHC", centered around their 2019 and 2022 meetings. It provides a review of existing experimental results and theoretical approaches, including lattice QCD calculations and semiclassical and quantum approaches for the dynamical evolution of quarkonia in the quark-gluon plasma as probed in high-energy heavy-ion collisions. The key ingredients of the transport models are itemized to facilitate comparisons of calculated quantities such as reaction rates, binding energies, and nuclear modification factors. A diagnostic assessment of the various results is attempted and coupled with an outlook for the future.Comment: 54 pages, 19 figure

    The BRICS in the Global Order: A New Political Agenda?

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    Regarding the BRICS (Brazil, Russia, India, China and South Africa) it’s important to analyze comparatively the new power cycle in order to understand not only the impact of the world crisis as well as the relationship between the official political discourses and the economic instability. Actually, the trade liberalization and economic interdependence accompanied with an uncertain international system are putting pressure to the BRICS with their own agendas for global order in seeking for a balance and also to regain a new political and economical dynamic for the promotion of new strategies
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