17,784 research outputs found
Meditation and Lucid Dreams
Eighteen regular meditators in various meditative traditions completed a 30—day: dream diary and gave information regarding previous dream experience and meditative practice. They rated each dream as lucid, partially lucid, control or none of these, and for each dream indicated whether they had actually heard voices, heard other sounds or felt bodily movement
System for the measurement of ultra-low stray light levels
An apparatus is described for measuring the effectiveness of stray light suppression light shields and baffle arrangements used in optical space experiments and large space telescopes. The light shield and baffle arrangement and a telescope model are contained in a vacuum chamber. A source of short, high-powered light energy illuminates portions of the light shield and baffle arrangement and reflects a portion of same to a photomultiplier tube by virtue of multipath scattering. The resulting signal is transferred to time-channel electronics timed by the firing of the high energy light source allowing time discrimination of the signal thereby enabling the light scattered and suppressed by the model to be distinguished from the walls and holders around the apparatus
Phase transition in a log-normal Markov functional model
We derive the exact solution of a one-dimensional Markov functional model
with log-normally distributed interest rates in discrete time. The model is
shown to have two distinct limiting states, corresponding to small and
asymptotically large volatilities, respectively. These volatility regimes are
separated by a phase transition at some critical value of the volatility. We
investigate the conditions under which this phase transition occurs, and show
that it is related to the position of the zeros of an appropriately defined
generating function in the complex plane, in analogy with the Lee-Yang theory
of the phase transitions in condensed matter physics.Comment: 9 pages, 5 figures. v2: Added asymptotic expressions for the
convexity-adjusted Libors in the small and large volatility limits. v3: Added
one reference. Final version to appear in Journal of Mathematical Physic
Hopping Conduction and Bacteria: Transport in Disordered Reaction-Diffusion Systems
We report some basic results regarding transport in disordered
reaction-diffusion systems with birth (A->2A), death (A->0), and binary
competition (2A->A) processes. We consider a model in which the growth process
is only allowed to take place in certain areas--"oases"--while the rest of
space--the "desert"--is hostile to growth. In the limit of low oasis density,
transport is mediated through rare "hopping" events, necessitating the
inclusion of discreteness effects in the model. By first considering transport
between two oases, we are able to derive an approximate expression for the
average time taken for a population to traverse a disordered medium.Comment: 4 pages, 2 figure
K3-fibered Calabi-Yau threefolds I, the twist map
A construction of Calabi-Yaus as quotients of products of lower-dimensional
spaces in the context of weighted hypersurfaces is discussed, including
desingularisation. The construction leads to Calabi-Yaus which have a fiber
structure, in particular one case has K3 surfaces as fibers. These Calabi-Yaus
are of some interest in connection with Type II -heterotic string dualities in
dimension 4. A section at the end of the paper summarises this for the
non-expert mathematician.Comment: 31 pages LaTeX, 11pt, 2 figures. To appear in International Journal
of Mathematics. On the web at
http://personal-homepages.mis.mpg.de/bhunt/preprints.html , #
Hopping Transport in the Presence of Site Energy Disorder: Temperature and Concentration Scaling of Conductivity Spectra
Recent measurements on ion conducting glasses have revealed that conductivity
spectra for various temperatures and ionic concentrations can be superimposed
onto a common master curve by an appropriate rescaling of the conductivity and
frequency. In order to understand the origin of the observed scaling behavior,
we investigate by Monte Carlo simulations the diffusion of particles in a
lattice with site energy disorder for a wide range of both temperatures and
concentrations. While the model can account for the changes in ionic activation
energies upon changing the concentration, it in general yields conductivity
spectra that exhibit no scaling behavior. However, for typical concentrations
and sufficiently low temperatures, a fairly good data collapse is obtained
analogous to that found in experiment.Comment: 6 pages, 4 figure
Design of automatic milking system for use in pasture-based systems
End of Project ReportA commercial vision system was successful in identifying target artificial teats in various and demanding scenarios, but the system is very prone to making false identifications.
A robotic manipulator capable of the simultaneous handling of four milking cups has been designed.
The end-effector profile is sufficiently compact to allow access between the rear legs of the cow while enabling full access to all four teats for application of milking cups.
The positioning response of the end-effecter is satisfactory for accommodating small changes in teat position during milking cup application
Structure of 10N in 9C+p resonance scattering
The structure of exotic nucleus 10N was studied using 9C+p resonance
scattering. Two L=0 resonances were found to be the lowest states in 10N. The
ground state of 10N is unbound with respect to proton decay by 2.2(2) or 1.9(2)
MeV depending on the 2- or 1- spin-parity assignment, and the first excited
state is unbound by 2.8(2) MeV.Comment: 6 pages, 4 figures, 1 table, submitted to Phys. Lett.
The direct Cu NQR Study of the Stripe Phase in the Lanthanum Cuprates
Using Cu NQR in Eu-doped La_(2-x)Sr_xCuO_4 we find the evidence of the pinned
stripe phase at 1.3K for 0.08<x<0.18. The pinned fraction increases by one
order of magnitude near hole doping x=1/8. The NQR lineshape reveals three
inequivalent Cu positions. A dramatic change of the NQR signal for x > 0.18
correlating with the onset of bulk superconductivity corresponds to the
depinning of the stripe phase.Comment: 4 pages, 3 figures, to appear in Physica C, Proceedings of the 6th
International Conference on Materials and Mechanisms of Superconductivity,
Houston, February 200
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