301 research outputs found
Microscopic Dynamics of Hard Ellipsoids in their Liquid and Glassy Phase
To investigate the influence of orientational degrees of freedom onto the
dynamics of molecular systems in its supercooled and glassy regime we have
solved numerically the mode-coupling equations for hard ellipsoids of
revolution. For a wide range of volume fractions and aspect ratios
we find an orientational peak in the center of mass spectra
and about one decade
below a high frequency peak. This orientational peak is the counterpart of a
peak appearing in the quadrupolar spectra and
. The latter peak is almost insensitive on
for close to one, i.e. for weak steric hindrance, and broadens strongly
with increasing . Deep in the glass we find an additional peak between
the orientational and the high frequency peak. We have evidence that this
intermediate peak is the result of a coupling between modes with and
, due to the nondiagonality of the static correlators.Comment: 6 figures, 12 page
A Tableaux Calculus for Reducing Proof Size
A tableau calculus is proposed, based on a compressed representation of
clauses, where literals sharing a similar shape may be merged. The inferences
applied on these literals are fused when possible, which reduces the size of
the proof. It is shown that the obtained proof procedure is sound,
refutationally complete and allows to reduce the size of the tableau by an
exponential factor. The approach is compatible with all usual refinements of
tableaux.Comment: Technical Repor
Dynamical precursor of nematic order in a dense fluid of hard ellipsoids of revolution
We investigate hard ellipsoids of revolution in a parameter regime where no
long range nematic order is present but already finite size domains are formed
which show orientational order. Domain formation leads to a substantial slowing
down of a collective rotational mode which separates well from the usual
microscopic frequency regime. A dynamic coupling of this particular mode into
all other modes provides a general mechanism which explains an excess peak in
spectra of molecular fluids. Using molecular dynamics simulation on up to 4096
particles and on solving the molecular mode coupling equation we investigate
dynamic properties of the peak and prove its orientational origin.Comment: RevTeX4 style, 7 figure
A Tree Based Language for Music Score Description.
International audienceThe presented work is part of the INScore project, an environment for the design of augmented interactive music scores, oriented towards unconven-tional uses of music notation and representation, including real-time symbolic notation capabilities. This environment is fully controllable using Open Sound Control [OSC] messages. INScore scripting language is an extended textual version of OSC messages that allows you to design scores in a modular and incre-mental way. This article presents a major revision of this language, based on the description and manipulation of trees
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