13,060 research outputs found
Man-systems evaluation of moving base vehicle simulation motion cues
A motion cue investigation program is reported that deals with human factor aspects of high fidelity vehicle simulation. General data on non-visual motion thresholds and specific threshold values are established for use as washout parameters in vehicle simulation. A general purpose similator is used to test the contradictory cue hypothesis that acceleration sensitivity is reduced during a vehicle control task involving visual feedback. The simulator provides varying acceleration levels. The method of forced choice is based on the theory of signal detect ability
Anderson-Mott Transition in a Magnetic Field: Corrections to Scaling
It is shown that the Anderson-Mott metal-insulator transition of
paramagnetic, interacting disordered electrons in an external magnetic field is
in the same universality class as the transition from a ferromagnetic metal to
a ferromagnetic insulator discussed recently. As a consequence, large
corrections to scaling exist in the magnetic-field universality class, which
have been neglected in previous theoretical descriptions. The nature and
consequences of these corrections to scaling are discussed.Comment: 5pp., REVTeX, no figs, final version as publishe
Classical Three-Box "paradox"
A simple classical probabilistic system (a simple card game) classically
exemplifies Aharonov and Vaidman's "Three-Box 'paradox'" [J. Phys. A 24, 2315
(1991)], implying that the Three-Box example is neither quantal nor a paradox
and leaving one less difficulty to busy the interpreters of quantum mechanics.
An ambiguity in the usual expression of the retrodiction formula is shown to
have misled Albert, Aharonov, and D'Amato [Phys. Rev. Lett. 54, 5 (1985)] to a
result not, in fact, "curious"; the discussion illustrates how to avoid this
ambiguity.Comment: 10 pages. v4: As published, with corrections and updated reference
Escaping free-energy minima
We introduce a novel and powerful method for exploring the properties of the
multidimensional free energy surfaces of complex many-body systems by means of
a coarse-grained non-Markovian dynamics in the space defined by a few
collective coordinates.A characteristic feature of this dynamics is the
presence of a history-dependent potential term that, in time, fills the minima
in the free energy surface, allowing the efficient exploration and accurate
determination of the free energy surface as a function of the collective
coordinates. We demonstrate the usefulness of this approach in the case of the
dissociation of a NaCl molecule in water and in the study of the conformational
changes of a dialanine in solution.Comment: 3 figure
Heat pipes for spacecraft temperature control: An assessment of the state-of-the-art
Various heat pipe temperature control techniques are critically evaluated using characteristic features and properties, including heat transport capability, volume and mass requirements, complexity and ease of fabrication, reliability, and control characteristics. Advantages and disadvantages of specific approaches are derived and discussed. Using four development levels, the state of-the-art of the various heat pipe temperature control techniques is assessed. The need for further research and development is discussed and suggested future efforts are projected
The effect of hydrogen sulphide on ammonium bisulphite when used as an oxygen scavenger in aqueous solutions
Peer reviewedPostprin
Community learning and development training for professionals engaged in community regeneration and community planning
The study was commissioned by the Scottish Executive Development Department to identify training needs and current provision of community learning and development (CLD) training for a range of professionals (other than those formally qualified in CLD) who are engaged in community regeneration and community planning (Local Government in Scotland Act 2003). It was one of a series of studies emanating from the Scottish Executive response to the review: „Empowered to Practice – the future of community learning and development training in Scotland‟. One of the themes of the report taken up by the Scottish Executive was the need for; „wider opportunities for joint training with other disciplines such as teachers, librarians, college lecturers, health workers and social workers‟
Metal-superconductor transition at zero temperature: A case of unusual scaling
An effective field theory is derived for the normal metal-to-superconductor
quantum phase transition at T=0. The critical behavior is determined exactly
for all dimensions d>2. Although the critical exponents \beta and \nu do not
exist, the usual scaling relations, properly reinterpreted, still hold. A
complete scaling description of the transition is given, and the physics
underlying the unusual critical behavior is discussed. Quenched disorder leads
to anomalously strong T_c-fluctuations which are shown to explain the
experimentally observed broadening of the transition in low-T_c thin films.Comment: 4 pp., no figs, final version as publishe
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