47,326 research outputs found
High field fractional quantum Hall effect in optical lattices
We consider interacting bosonic atoms in an optical lattice subject to a
large simulated magnetic field. We develop a model similar to a bilayer
fractional quantum Hall system valid near simple rational numbers of magnetic
flux quanta per lattice cell. Then we calculate its ground state, magnetic
lengths, fractional fillings, and find unexpected sign changes in the Hall
current. Finally we study methods for detecting these novel features via shot
noise and Hall current measurements.Comment: 4 pages, 4 figures, accepted by PR
High Energy Colliders
We consider the high energy advantages, disadvantages and luminosity
requirements of hadrons, leptons and photon-photon colliders. Technical
problems in obtaining increased energy in each type of machine are presented.
The machines relative size are also discussed.Comment: LaTeX, 27 pages, 8 figures (eps, ps). Submitted to the Proceedings of
the Princeton's 250th Anniversary Conference on Critical Problems in Physic
High Luminosity Muon Collider Design
Muon Colliders have unique technical and physics advantages and disadvantages
when compared with both hadrons and electron machines. They should be regarded
as complementary. Parameters are given of a 4 TeV high luminosity muon-muon
collider, and of a 0.5 TeV demonstration machine. We discuss the various
systems in such muon collider.Comment: LaTeX 5 pages 4 figure
Future Colliders
The high energy physics advantages, disadvantages and luminosity requirements
of hadrons, of leptons and photon-photon colliders are considered. Technical
arguments for increased energy in each type of machine are presented. Their
relative size, and the implications of size on cost are discussed.Comment: LaTeX, 10 pages, 10figure
The effect of three practice conditions on the consistency of chronic dysarthric speech
This study investigated whether it is possible for people with chronic dysarthria to adjust their articulation in three practice conditions. A speaker dependent, speech recognition system was used to compare participants' practice attempts with a model of a word made from previous recordings to give a recognition score. This score was used to indicate changes in production of practice words with different conditions. The three conditions were reading of written target words, visual feedback, and an auditory model followed by visual feedback. For eight participants with dysarthria, the ability to alter speech production was shown, together with a differential effect of the three conditions. Copying an auditory target gave significantly better recognition scores than just repeating the word. Visual feedback was no more effective than repetition alone. For four control participants, visual feedback did produce significantly better recognition scores than just repetition of written words, and the presence of an auditory model was Significantly more effective than visual feedback. Possible reasons for differences between conditions are discussed
Error estimation in the histogram Monte Carlo method
We examine the sources of error in the histogram reweighting method for Monte
Carlo data analysis. We demonstrate that, in addition to the standard
statistical error which has been studied elsewhere, there are two other sources
of error, one arising through correlations in the reweighted samples, and one
arising from the finite range of energies sampled by a simulation of finite
length. We demonstrate that while the former correction is usually negligible
by comparison with statistical fluctuations, the latter may not be, and give
criteria for judging the range of validity of histogram extrapolations based on
the size of this latter correction.Comment: 7 pages including 3 postscript figures, typeset in LaTeX using the
RevTeX macro packag
Threat perception while viewing single intruder conflicts on a cockpit display of traffic information
Subjective estimates of the threat posed by a single intruder aircraft were determined by showing pilots photographs of a cockpit display of traffic information. The time the intruder was away from the point of minimum separation was found to be the major determinant of the perception of threat. When asked to choose a maneuver to reduce the conflict, pilots selected maneuvers with a bias toward those that would have kept the intruders in sight had they been visible out the cockpit window
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