76,988 research outputs found
Trick or treat? Adaptation to Italian-accented English speech by native English, Italian, and Dutch listeners
English is spoken worldwide by both native (L1) and nonnative (L2) speakers. It is therefore imperative to establish how easily L1 and L2 speakers understand each other. We know that L1 listeners adapt to foreign-accented speech very rapidly (Clarke & Garrett, 2004), and L2 listeners find L2 speakers (from matched and mismatched L1 backgrounds) as intelligible as native speakers (Bent & Bradlow, 2003). But foreign-accented speech can deviate widely from L1 pronunciation norms, for example when adult L2 learners experience difficulties in producing L2 phonemes that are not part of their native repertoire (Strange, 1995). For instance, Italian L2 learners of English often lengthen the lax English vowel /I/, making it sound more like the tense vowel /i/ (Flege et al., 1999). This blurs the distinction between words such as bin and bean. Unless listeners are able to adapt to this kind of pronunciation variance, it would hinder word recognition by both L1 and L2 listeners (e.g., /bin/ could mean either bin or bean). In this study we investigate whether Italian-accented English interferes with on-line word recognition for native English listeners and for nonnative English listeners, both those where the L1 matches the speaker accent (i.e., Italian listeners) and those with an L1 mismatch (i.e., Dutch listeners). Second, we test whether there is perceptual adaptation to the Italian-accented speech during the experiment in each of the three listener groups. Participants in all groups took part in the same cross-modal priming experiment. They heard spoken primes and made lexical decisions to printed targets, presented at the acoustic offset of the prime. The primes, spoken by a native Italian, consisted of 80 English words, half with /I/ in their standard pronunciation but mispronounced with an /i/ (e.g., trick spoken as treek), and half with /i/ in their standard pronunciation and pronounced correctly (e.g., treat). These words also appeared as targets, following either a related prime (which was either identical, e.g., treat-treat, or mispronounced, e.g., treek-trick) or an unrelated prime. All three listener groups showed identity priming (i.e., faster decisions to treat after hearing treat than after an unrelated prime), both overall and in each of the two halves of the experiment. In addition, the Italian listeners showed mispronunciation priming (i.e., faster decisions to trick after hearing treek than after an unrelated prime) in both halves of the experiment, while the English and Dutch listeners showed mispronunciation priming only in the second half of the experiment. These results suggest that Italian listeners, prior to the experiment, have learned to deal with Italian-accented English, and that English and Dutch listeners, during the experiment, can rapidly adapt to Italian-accented English. For listeners already familiar with a particular accent (e.g., through their own pronunciation), it appears that they have already learned how to interpret words with mispronounced vowels. Listeners who are less familiar with a foreign accent can quickly adapt to the way a particular speaker with that accent talks, even if that speaker is not talking in the listeners’ native language
Equation of State in 2+1 Flavor QCD at High Temperatures
We calculate the Equation of State at high temperatures in 2+1 flavor QCD
using the highly improved staggered quark action. We study the lattice spacing
dependence of the pressure at high temperatures using lattices with temporal
extent and and perform continuum extrapolations. We
also give a continuum estimate for the Equation of State up to temperatures
GeV, which are then compared with results of the weak-coupling
calculations. We find a reasonably good agreement with the weak-coupling
calculations at the highest temperatures.Comment: RevTeX, 16 pages, 16 figures, published versio
Numerical Models for the Diffuse Ionized Gas in Galaxies. II. Three-dimensional radiative transfer in inhomogeneous interstellar structures as a tool for analyzing the diffuse ionized gas
Aims: We systematically explore a plausible subset of the parameter space
involving effective temperatures and metallicities of the ionizing stellar
sources, the effects of the hardening of their radiation by surrounding leaky
HII regions with different escape fractions, as well as different scenarios for
the clumpiness of the DIG, and compute the resulting line strength ratios for a
number of diagnostic optical emission lines.
Methods: For the ionizing fluxes we compute a grid of stellar spectral energy
distributions (SEDs) from detailed, fully non-LTE model atmospheres that
include the effects of stellar winds and line blocking and blanketing. To
calculate the ionization and temperature structure in the HII regions and the
diffuse ionized gas we use spherically symmetric photoionization models as well
as state-of-the-art three-dimensional (3D) non-LTE radiative transfer
simulations, considering hydrogen, helium, and the most abundant metals.
Results: We provide quantitative predictions of how the line ratios from HII
regions and the DIG vary as a function of metallicity, stellar effective
temperature, and escape fraction from the HII region. The range of predicted
line ratios reinforces the hypothesis that the DIG is ionized by (filtered)
radiation from hot stars; however, comparison of observed and predicted line
ratios indicates that the DIG is typically ionized with a softer SED than
predicted by the chosen stellar population synthesis model. Even small changes
in simulation parameters like the clumping factor can lead to considerable
variation in the ionized volume. Both for a more homogeneous gas and a very
inhomogeneous gas containing both dense clumps and channels with low gas
density, the ionized region in the dilute gas above the galactic plane can
cease to be radiation-bounded, allowing the ionizing radiation to leak into the
intergalactic medium.Comment: 21 pages, 9 figures, accepted by A&
Dependence of the thermoluminescent high-temperature ratio (HTR) of LiF:Mg,Ti detectors on proton energy and dose
The high-temperature ratio (HTR) is a parameter quantifying changes of the
shape of the high-temperature part of the LiF:Mg,Ti glow-curve after exposure
to densely ionizing radiation. It was introduced in order to estimate the
effective LET of an unknown radiation field and to correct the decreased
relative TL efficiency for high Linear Energy Transfer (LET) radiation. In the
present work the dependence of HTR on proton energy (14.5 to 58 MeV) and dose
(0.5 to 30 Gy) was investigated. All measured HTR values were at the level of
1.2 or higher, therefore significantly different from the respective value for
gamma rays (HTR is equal to 1), but HTR was found to be insensitive to changes
of proton energy above 20 MeV. As a result the relationship between HTR and
relative TL efficiency is not unequivocal. The HTR was found to be dependent on
absorbed dose even for the lowest studied doses.Comment: Manuscript has been presented at the 17th International Conference on
Solid State Dosimetry, Recife, Brasil, September 22-27,201
Citizens without nations
To broach the question of whether citizenship could exist without (or beyond) community, this paper discusses genealogies of citizenship as membership that binds an individual to the community of birth (of the self or a parent). It is birthright as fraternity that blurs the boundary between citizenship and nationality. After briefly discussing recent critical studies on birthright citizenship (whether it is civic or ethnic or blood or soil) by Ayelet Shachar and Jacqueline Stevens, the paper discusses three critical genealogies of the relationship between birthright and citizenship by Max Weber, Hannah Arendt, and Michel Foucault. Although each provides a critical perspective into the question, Weber reduces citizenship to fraternity with nation and Arendt reduces citizenship to fraternity with the state. It is Foucault who illustrates racialization of fraternity as the connection between citizenship and nationality. Yet, since Foucault limits his genealogical investigations to the 18th and 19th centuries, a genealogy of fraternity of what he calls an immense biblical and Greek tradition remains for Derrida to articulate as a question of citizenship
Aerodynamic influence coefficient method using singularity splines
A numerical lifting surface formulation, including computed results for planar wing cases is presented. This formulation, referred to as the vortex spline scheme, combines the adaptability to complex shapes offered by paneling schemes with the smoothness and accuracy of loading function methods. The formulation employes a continuous distribution of singularity strength over a set of panels on a paneled wing. The basic distributions are independent, and each satisfied all the continuity conditions required of the final solution. These distributions are overlapped both spanwise and chordwise. Boundary conditions are satisfied in a least square error sense over the surface using a finite summing technique to approximate the integral. The current formulation uses the elementary horseshoe vortex as the basic singularity and is therefore restricted to linearized potential flow. As part of the study, a non planar development was considered, but the numerical evaluation of the lifting surface concept was restricted to planar configurations. Also, a second order sideslip analysis based on an asymptotic expansion was investigated using the singularity spline formulation
Heuristic Spike Sorting Tuner (HSST), a framework to determine optimal parameter selection for a generic spike sorting algorithm
Extracellular microelectrodes frequently record neural activity from more than one neuron in the vicinity of the electrode. The process of labeling each recorded spike waveform with the identity of its source neuron is called spike sorting and is often approached from an abstracted statistical perspective. However, these approaches do not consider neurophysiological realities and may ignore important features that could improve the accuracy of these methods. Further, standard algorithms typically require selection of at least one free parameter, which can have significant effects on the quality of the output. We describe a Heuristic Spike Sorting Tuner (HSST) that determines the optimal choice of the free parameters for a given spike sorting algorithm based on the neurophysiological qualification of unit isolation and signal discrimination. A set of heuristic metrics are used to score the output of a spike sorting algorithm over a range of free parameters resulting in optimal sorting quality. We demonstrate that these metrics can be used to tune parameters in several spike sorting algorithms. The HSST algorithm shows robustness to variations in signal to noise ratio, number and relative size of units per channel. Moreover, the HSST algorithm is computationally efficient, operates unsupervised, and is parallelizable for batch processing
The 'gated-diode' configuration in MOSFET's, a sensitive tool for characterizing hot-carrier degradation
This paper describes a new measurement technique, the forward gated-diode current characterized at low drain voltages to be applied in MOSFET's for investigating hot-carrier stress-induced defects at high spatial resolution. The generation/recombination current in the drain-to-substrate diode as a function of gate voltage, combined with two-dimensional numerical simulation, provides a sensitive tool for detecting the spatial distribution and density of interface defects. In the case of strong accumulation, additional information is obtained from interband tunneling processes occurring via interface defects. The various mechanisms for generating interface defects and fixed charges at variable stress conditions are discussed, showing that information complementary to that available from other methods is obtaine
- …