1,105 research outputs found
Expectancy effects in the EEG during joint and spontaneous word-by-word sentence production in German
Our aim in the present study is to measure neural correlates during spontaneous interactive sentence production. We present a novel approach using the word-by-word technique from improvisational theatre, in which two speakers jointly produce one sentence. This paradigm allows the assessment of behavioural aspects, such as turn-times, and electrophysiological responses, such as event-related-potentials (ERPs). Twenty-five participants constructed a cued but spontaneous four-word German sentence together with a confederate, taking turns for each word of the sentence. In 30% of the trials, the confederate uttered an unexpected gender-marked article. To complete the sentence in a meaningful way, the participant had to detect the violation and retrieve and utter a new fitting response. We found significant increases in response times after unexpected words and â despite allowing unscripted language production and naturally varying speech material â successfully detected significant N400 and P600 ERP effects for the unexpected word. The N400 EEG activity further significantly predicted the response time of the subsequent turn. Our results show that combining behavioural and neuroscientific measures of verbal interactions while retaining sufficient experimental control is possible, and that this combination provides promising insights into the mechanisms of spontaneous spoken dialogue
Multi-objective optimisation of machine tool error mapping using automated planning
Error mapping of machine tools is a multi-measurement task that is planned based on expert knowledge. There are no intelligent tools aiding the production of optimal measurement plans. In previous work, a method of intelligently constructing measurement plans demonstrated that it is feasible to optimise the plans either to reduce machine tool downtime or the estimated uncertainty of measurement due to the plan schedule. However, production scheduling and a continuously changing environment can impose conflicting constraints on downtime and the uncertainty of measurement. In this paper, the use of the produced measurement model to minimise machine tool downtime, the uncertainty of measurement and the arithmetic mean of both is investigated and discussed through the use of twelve different error mapping instances. The multi-objective search plans on average have a 3% reduction in the time metric when compared to the downtime of the uncertainty optimised plan and a 23% improvement in estimated uncertainty of measurement metric when compared to the uncertainty of the temporally optimised plan. Further experiments on a High Performance Computing (HPC) architecture demonstrated that there is on average a 3% improvement in optimality when compared with the experiments performed on the PC architecture. This demonstrates that even though a 4% improvement is beneficial, in most applications a standard PC architecture will result in valid error mapping plan
Einstein A Coefficients and Oscillator Strengths for the A 2Î -X2ÎŁ+ (Red) and B 2ÎŁ+-X2ÎŁ+ (Violet) Systems and Rovibrational Transitions in the X2ÎŁ+ State of CN
Line strengths have been calculated in the form of Einstein A coefficients and f-values for a large number of bands of the A 2Î -X 2ÎŁ+ and B 2ÎŁ+-X 2ÎŁ+ systems and rovibrational transitions within the X 2ÎŁ+ state of CN using Western\u27s PGOPHER program. The J dependence of the transition dipole moment matrix elements (the Herman-Wallis effect) has been taken into account. Rydberg-Klein-Rees potential energy functions for the A 2Î , B 2ÎŁ+ , and X 2ÎŁ+ states were computed using spectroscopic constants from the A 2Î -X 2ÎŁ+ and B 2ÎŁ+-X 2ÎŁ+ transitions. New electronic transition dipole moment functions for these systems and a dipole moment function for the X 2ÎŁ+ state were generated from high level ab initio calculations and have been used in Le Roy\u27s LEVEL program to produce transition dipole moment matrix elements (including their J dependence) for a large number of vibrational bands. The program PGOPHER was used to calculate Einstein A coefficients, and a line list was generated containing the observed and calculated wavenumbers, Einstein A coefficients and f-values for 290 bands of the A 2Î -X 2ÎŁ + transition with vâČ = 0-22, vâł = 0-15, 250 bands of the B 2ÎŁ+-X 2ÎŁ+ transition with vâČ = 0-15, vâł = 0-15 and 120 bands of the rovibrational transitions within the X 2ÎŁ+ state with v = 0-15. The Einstein A coefficients have been used to compute radiative lifetimes of several vibrational levels of the A 2Î and B 2ÎŁ + states and the values compared with those available from previous experimental and theoretical studies. © 2014. The American Astronomical Society
Comment on: "Estimating the Hartree-Fock limit from finite basis set calculations" [Jensen F (2005) Theor Chem Acc 113:267]
We demonstrate that a minor modification of the extrapolation proposed by
Jensen [(2005): Theor Chem Acc 113:267] yields very reliable estimates of the
Hartree-Fock limit in conjunction with correlation consistent basis sets.
Specifically, a two-point extrapolation of the form
yields HF limits
with an RMS error of 0.1 millihartree using aug-cc-pVQZ and
aug-cc-pV5Z basis sets, and of 0.01 millihartree using aug-cc-pV5Z and
aug-cc-pV6Z basis sets.Comment: Theoretical Chemistry Accounts, in pres
Low-mass lithium-rich AGB stars in the Galactic bulge: evidence for Cool Bottom Processing?
Context: The stellar production of the light element lithium is still a
matter of debate.
Aims: We report the detection of low-mass, Li-rich Asymptotic Giant Branch
(AGB) stars located in the Galactic bulge.
Methods: A homogeneous and well-selected sample of low mass, oxygen-rich AGB
stars in the Galactic bulge has been searched for the absorption lines of Li.
Using spectral synthesis techniques, we determine from high resolution UVES/VLT
spectra the Li abundance in four out of 27 sample stars, and an upper limit for
the remaining stars.
Results: Two stars in our sample have a solar Li abundance or above; these
stars seem to be a novelty, since they do not show any s-element enhancement.
Two more stars have a Li abundance slightly below solar; these stars do show
s-element enhancement in their spectra. Different scenarios which lead to an
increased Li surface abundance in AGB stars are discussed.
Conclusions: Of the different enrichment scenarios presented, Cool Bottom
Processing (CBP) is the most likely one for the Li-rich objects identified
here. Self-enrichment by Hot Bottom Burning (HBB) seems very unlikely as all
Li-rich stars are below the HBB mass limit. Also, the ingestion of a low mass
companion into the stars' envelope is unlikely because the associated
additional effects are lacking. Mass transfer from a former massive binary
companion is a possible scenario, if the companion produced little s-process
elements. A simple theoretical estimation for the Li abundance due to CBP is
presented and compared to the observed values.Comment: 5 pages, 3 figures, accepted by A&A Letter
ExoMol molecular line lists - XIV: The rotation-vibration spectrum of hot SO2
Sulphur dioxide is well-known in the atmospheres of planets and satellites, where its
presence is often associated with volcanism, and in circumstellar envelopes of young
and evolved stars as well as the interstellar medium. This work presents a line list of 1.3
billion 32S
16O2 vibration-rotation transitions computed using an empirically-adjusted
potential energy surface and an ab initio dipole moment surface. The list gives complete
coverage up to 8000 cmâ1
(wavelengths longer than 1.25 ”m) for temperatures below
2000 K. Infrared absorption cross sections are recorded at 300 and 500 C are used to
validated the resulting ExoAmes line list. The line list is made available in electronic
form as supplementary data to this article and at www.exomol.com
ExoMol molecular line lists - XIV. The rotation-vibration spectrum of hot SO<sub>2</sub>
Sulphur dioxide is well-known in the atmospheres of planets and satellites,
where its presence is often associated with volcanism, and in circumstellar
envelopes of young and evolved stars as well as the interstellar medium. This
work presents a line list of 1.3 billion SO
vibration-rotation transitions computed using an empirically-adjusted potential
energy surface and an ab initio dipole moment surface. The list gives complete
coverage up to 8000 cm (wavelengths longer than 1.25 m) for
temperatures below 2000 K. Infrared absorption cross sections are recorded at
300 and 500 C are used to validated the resulting ExoAmes line list. The line
list is made available in electronic form as supplementary data to this article
and at www.exomol.com.Comment: Submitted to MNRA
The implications of unconfounding multisource performance ratings
The reliability of job performance ratings is a divisive topic in applied psychology because commonly reported reliability estimates are low and because such reliability estimates are often used to correct validity coefficients (LeBreton, Scherer, & James, 2014). In previous research, attention has been given to the multifaceted nature of multisource job performance ratings. However, measurement-design-relevant effects have been confounded in previous research on this topic. In separate samples from 2 different applications and measurement designs, we unconfounded effects relevant to multisource performance ratings using a Bayesian generalizability theory approach. Our results suggest that the main contributors to reliability in multisource ratings are source-related and general performance effects. Conservative estimates for reliability based on our results were in the range of .81 to .84. We raise questions for future research about corrections for validity coefficients based on criterion unreliability and about reconsidering the measurement design formally applied to multisource ratings
Solar neutrino-electron scattering as background limitation for double beta decay
The background on double beta decay searches due to elastic electron
scattering of solar neutrinos of all double beta emitters with Q-value larger
than 2 MeV is calculated, taking into account survival probability and flux
uncertainties of solar neutrinos. This work determines the background level to
be [1-2]E-7 counts /keV/kg/yr, depending on the precise Q-value of the double
beta emitter. It is also shown that the background level increases dramatically
if going to lower Q-values. Furthermore, studies are done for various detector
systems under consideration for next generation experiments. It was found that
experiments based on loaded liquid scintillator have to expect a higher
background. Within the given nuclear matrix element uncertainties any approach
exploring the normal hierarchy has to face this irreducible background, which
is a limitation on the minimal achievable background for purely calorimetric
approaches. Large scale liquid scintillator experiments might encounter this
problem already while exploring the inverted hierarchy. Potential caveats by
using more sophisticated experimental setups are also discussed
Discovery of a TiO emission band in the infrared spectrum of the S star NP Aurigae
We report on the discovery of an infrared emission band in the Spitzer
spectrum of the S-type AGB star NP Aurigae that is caused by TiO molecules in
the circumstellar environment. We modelled the observed emission to derive the
temperature of the TiO molecules (\approx 600 K), an upper limit on the column
density (\approx 10^17.25 cm^{-2}) and a lower limit on the spatial extent of
the layer that contains these molecules. (\approx 4.6 stellar radii). This is
the first time that this TiO emission band is observed. A search for similar
emission features in the sample of S-type stars yielded two additional
candidates. However, owing to the additional dust emission, the identification
is less stringent. By comparing the stellar characteristics of NP Aur to those
of the other stars in our sample, we find that all stars with TiO emission show
large-amplitude pulsations, s-process enrichment, and a low C/O ratio. These
characteristics might be necessary requirements for a star to show TiO in
emission, but they are not sufficient.Comment: 4 pages, 4 figures, letter to the edito
- âŠ