1,354 research outputs found
Methodological issues in measures of imitative reaction times
Ideomotor (IM) theory suggests that observing someone else perform an action activates an internal motor representation of that behaviour within the observer. Evidence supporting the case for an ideomotor theory of imitation has come from studies that show imitative responses to be faster than the same behavioural measures performed in response to spatial cues. In an attempt to replicate these findings, we manipulated the salience of the visual cue and found that we could reverse the advantage of the imitative cue over the spatial cue. We suggest that participants utilised a simple visuomotor mechanism to perform all aspects of this task, with performance being driven by the relative visual salience of the stimuli. Imitation is a more complex motor skill that would constitute an inefficient strategy for rapid performance
Interconnect fatigue design for terrestrial photovoltaic modules
The results of comprehensive investigation of interconnect fatigue that has led to the definition of useful reliability-design and life-prediction algorithms are presented. Experimental data indicate that the classical strain-cycle (fatigue) curve for the interconnect material is a good model of mean interconnect fatigue performance, but it fails to account for the broad statistical scatter, which is critical to reliability prediction. To fill this shortcoming the classical fatigue curve is combined with experimental cumulative interconnect failure rate data to yield statistical fatigue curves (having failure probability as a parameter) which enable (1) the prediction of cumulative interconnect failures during the design life of an array field, and (2) the unambiguous--ie., quantitative--interpretation of data from field-service qualification (accelerated thermal cycling) tests. Optimal interconnect cost-reliability design algorithms are derived based on minimizing the cost of energy over the design life of the array field
Universality and the five-dimensional Ising model
We solve the long-standing discrepancy between Monte Carlo results and the
renormalization prediction for the Binder cumulant of the five-dimensional
Ising model. Our conclusions are based on accurate Monte Carlo data for systems
with linear sizes up to L=22. A detailed analysis of the corrections to scaling
allows the extrapolation of these results to L=\infinity. Our determination of
the critical point, K_c=0.1139150 (4), is more than an order of magnitude more
accurate than previous estimates.Comment: 6 pages LaTeX, 1 PostScript figure. Uses cite.sty (included) and
epsf.sty. Also available as PostScript and PDF file at
http://www.tn.tudelft.nl/tn/erikpubs.htm
Relaxed Local Correctability from Local Testing
We cement the intuitive connection between relaxed local correctability and
local testing by presenting a concrete framework for building a relaxed locally
correctable code from any family of linear locally testable codes with
sufficiently high rate. When instantiated using the locally testable codes of
Dinur et al. (STOC 2022), this framework yields the first asymptotically good
relaxed locally correctable and decodable codes with polylogarithmic query
complexity, which finally closes the superpolynomial gap between query lower
and upper bounds. Our construction combines high-rate locally testable codes of
various sizes to produce a code that is locally testable at every scale: we can
gradually "zoom in" to any desired codeword index, and a local tester at each
step certifies that the next, smaller restriction of the input has low error.
Our codes asymptotically inherit the rate and distance of any locally
testable code used in the final step of the construction. Therefore, our
technique also yields nonexplicit relaxed locally correctable codes with
polylogarithmic query complexity that have rate and distance approaching the
Gilbert-Varshamov bound.Comment: 18 page
The Chandra Dust Scattering Halo of Galactic Center transient Swift J174540.7-290015
We report the detection of a dust scattering halo around a recently
discovered X-ray transient, Swift J174540.7-290015, which in early February of
2016 underwent one of the brightest outbursts (F_X ~ 5e-10 erg/cm^2/s) observed
from a compact object in the Galactic Center field. We analyze four Chandra
images that were taken as follow-up observations to Swift discoveries of new
Galactic Center transients. After adjusting our spectral extraction for the
effects of detector pileup, we construct a point spread function for each
observation and compare it to the GC field before the outburst. We find
residual surface brightness around Swift J174540.7-290015, which has a shape
and temporal evolution consistent with the behavior expected from X-rays
scattered by foreground dust. We examine the spectral properties of the source,
which shows evidence that the object transitioned from a soft to hard spectral
state as it faded below L_X ~ 1e36 erg/s. This behavior is consistent with the
hypothesis that the object is a low mass X-ray binary in the Galactic Center.Comment: Accepted for publication in Ap
Constrained action selection in children with developmental coordination disorder
The effect of advance (‘precue’) information on short aiming movements was explored in adults, high school children, and primary school children with and without developmental coordination disorder (n = 10, 14, 16, 10, respectively). Reaction times in the DCD group were longer than in the other groups and were more influenced by the extent to which the precue constrained the possible action space. In contrast, reaction time did not alter as a function of precue condition in adults. Children with DCD showed greater inaccuracy of response (despite the increased RT). We suggest that the different precue effects reflect differences in the relative benefits of priming an action prior to definitive information about the movement goal. The benefits are an interacting function of the task and the skill level of the individual. Our experiment shows that children with DCD gain a benefit from advance preparation in simple aiming movements, highlighting their low skill levels. This result suggests that goal-directed RTs may have diagnostic potential within the clinic
Critical Surface Free Energies and Universal Finite-Size Scaling Amplitudes of Three-Dimensional XY Models by Direct Monte Carlo Sampling
Direct Monte Carlo sampling is employed to obtain estimates of excess surface free energies of three-dimensional XY models at criticality. Results for simple-cubic and body-centered-cubic lattices are consistent with universality of finite-size scaling amplitudes. The results are used to estimate the magnitude of the thinning effect, mediated by the incipient long-ranged correlations, on liquid-helium films at the λ point
Surface Free Energies of Three-Dimensional Ising Models and Universality of Finite-Size Scaling Amplitudes by Direct Monte Carlo Sampling
Direct Monte Carlo sampling is employed to obtain estimates of excess surface free energies of three-dimensional Ising models at criticality. Results for simple and body-centered-cubic lattices provide strong evidence for the universality of finite-size scaling amplitudes and in particular the related interaction per unit area, mediated via the incipient long-ranged correlations, of two free surfaces a finite distance apart
La importancia de la evaluación docente
Cuando hablamos de evaluación de la docencia debemos tener presente que, más allá de la importancia y la actualidad, abordamos un asunto de indudable complejidad. En los últimos diez años, y como respuesta a las directrices europeas, la Universidad española ha puesto en marcha diferentes mecanismos y procedimientos de aseguramiento de la calidad. Uno de los más conocidos es el Programa de Apoyo a la Evaluación de la Actividad Docente del Profesorado Universitario (DOCENTIA), desarrollado por ANECA y las distintas agencias de evaluación autonómicas. Un programa que ha tratado de revertir una situación histórica en nuestra Universidad. Y es que, tradicionalmente, la Universidad española ha otorgado un mayor peso a las funciones investigadoras del profesorado que a la propia acción docente. El profesorado ha sido evaluado periódicamente por sus “méritos” de investigación –los cuales han servido para su promoción–, mientras que su actividad docente ha sido evaluada automáticamente –como reflejo de su antigüedad en la institución–, siendo en muchos casos un verdadero lastre para “lo que de verdad cuenta”: la investigación. Un hecho que ha sido puesto en evidencia en numerosas ocasiones y desde diferentes ángulos, entre ellos los estudiantes, quienes reclaman de manera reiterada mecanismos de evaluación docente que permitan detectar las malas praxis y establecer medidas para corregir tales situaciones
Thermodynamics predicts how confinement modifies hard-sphere dynamics
We study how confining the equilibrium hard-sphere fluid to restrictive one-
and two-dimensional channels with smooth interacting walls modifies its
structure, dynamics, and entropy using molecular dynamics and transition-matrix
Monte Carlo simulations. Although confinement strongly affects local
structuring, the relationships between self-diffusivity, excess entropy, and
average fluid density are, to an excellent approximation, independent of
channel width or particle-wall interactions. Thus, thermodynamics can be used
to predict how confinement impacts dynamics.Comment: 4 pages, 4 figure
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