2,163 research outputs found
Study of rolling-contact phenomena in magnesium oxide
Study of rolling contact deformation phenomena in magnesium oxide single crystal
Rolling-contact bearing reference summary
Design and performance of rolling contact bearing
Possible use of a Cooper-pair box for low-dose electron microscopy
A transmission electron microscope that takes advantage of superconducting
quantum circuitry is proposed. The microscope is designed to improve image
contrast of radiation-sensitive weak phase objects, in particular biological
specimens. The objective in this setting is to measure the phase shift of the
probe electron wave to a precision within the number of
electrons that does not destroy the specimen. In conventional electron
microscopy scales as , which falls short of the
Heisenberg limit . To approach the latter by using quantum
entanglement, we propose a design that involves a Cooper pair box placed on the
surface of an electrostatic electron mirror in the microscope. Significant
improvement could be attained if inelastic scattering processes are
sufficiently delocalized.Comment: 41 pages, 4 figures; extensively revised, following referee comments;
final version, the main point remains the same as v.
Imagining worse than reality: comparing beliefs and intentions between disaster evacuees and survey respondents
We often credit disasters, and their coverage in the media, with changes in the public perception of risk associated with low-probability, high-consequence events (LPHCs). With a change in perceptions, we also expect changes in beliefs, preferences, and behaviors. Do beliefs and behaviors change in different ways for people who live through these LPHC critical events, as opposed to people who observe them? This study compares hypothetical hurricanes with actual hurricane effects in a survey quasi-experiment. Findings indicate that hypothetical disasters induce stronger reactions than those experienced in the natural world, as Hurricane Katrina bystanders imagine themselves incurring much higher damages, and being much less likely to return to live in their hurricane-damaged homes, than actual Hurricane Katrina evacuees. Ultimately, respondents considering a hypothetical low-probability, high-consequence event exhibit exaggerated beliefs and opposite decisions of those who actually lived through one of these events. Results underline the importance of examining the differences between public perceptions and experiential reality
On the Munn-Silbey approach to polaron transport with off-diagonal coupling
Improved results using a method similar to the Munn-Silbey approach have been
obtained on the temperature dependence of transport properties of an extended
Holstein model incorporating simultaneous diagonal and off-diagonal
exciton-phonon coupling. The Hamiltonian is partially diagonalized by a
canonical transformation, and optimal transformation coefficients are
determined in a self-consistent manner. Calculated transport properties exhibit
substantial corrections on those obtained previously by Munn and Silbey for a
wide range of temperatures thanks to a numerically exact evaluation and an
added momentum-dependence of the transformation matrix. Results on the
diffusion coefficient in the moderate and weak coupling regime show distinct
band-like and hopping-like transport features as a function of temperature.Comment: 12 pages, 6 figures, accpeted in Journal of Physical Chemistry B:
Shaul Mukamel Festschrift (2011
Modeling house price dynamics with heterogeneous speculators
This paper investigates the impact of speculative behavior on house price dynamics. Speculative demand for housing is modeled using a heterogeneous agent approach, whereas ‘real’ demand and housing supply are represented in a standard way. Together, real and speculative forces determine excess demand in each period and house price adjustments. Three alternative models are proposed, capturing in different ways the interplay between fundamental trading rules and extrapolative trading rules, resulting in a 2D, a 3D, and a 4D nonlinear discretetime dynamical system, respectively. While the destabilizing effect of speculative behavior on the model’s steady state is proven in general, the three specific cases illustrate a variety of situations that can bring about endogenous dynamics, with lasting and significant price swings around the ‘fundamental ’ price, as we have seen in many real markets
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