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a physical process of compressing an assembly
of hard particles. As the LSA may need thousands of arithmetic operations even for a few particles,
it is usually carried out on a [[digital computer]].
A physical process of compression often
involves a contracting hard boundary of the container,
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Volume 94 Issue 2, May 1991
http://arxiv.org/PS_cache/cond-mat/pdf/0503/0503627v2.pdf </ref>
in the setting with
[[periodic boundary conditions]]
where the virtual particles were "swelling" or expanding
in a fixed, finite virtual volume without hard boundary.
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the LSA is able to handle particle ensembles
in tens to hundreds of thousands
on today's (2011) standard [[personal computers]].
Only a very limited experience was reported
<ref> Packing Hyperspheres in High-Dimensional Euclidean Spaces," M. Skoge, A. Donev, F.H. Stillinger, and S. Torquato, Phys. Rev. E 74, 041127 (2006)</ref>
in using the LSA in dimensions higher than 3.
== Comments on the algorithm ==
Particle jamming in LSA is achieved via simulating pre-jammed
[[granular flow]].
The flow is rendered as a
[[discrete event simulation]],
the events being particle-particle or particle-boundary collisions
with jamming ideally occurring after infinitely many
collisions and infinitely lengthy calculations.
In practice, the calculations are finite,
they are stopped
when all inter-collision particle runs becomes
smaller than an explicitly specified small threshold
or when they become smaller than an implicit threshold,
such as a threshold implied
by the computing resolution (for example, by the
[[double precision]] resolution).
The key to the algorithm efficiency is that
the calculations are done essentially in an
[[event-driven]] fashion, rather than in a
time-driven fashion. This means that almost
no computation
is wasted on calculating or maintaining the positions and velocities
of the particles between the collisions.
Among the [[event-driven]] algorithms intended for
the same task of simulating [[granular flow]],
like, for example, the algorithm of Rapaport
<ref>
</ref>
the LSA is distinguished by a simpler data structure
and data handling.
For any particle at any stage of calculations
the LSA maintains the record of only two events:
an old, already processed event, which comprises
the processed event time stamp,
the particle state (including
position and velocity), and, perhaps,
another particle or boundary identification,
the one with which the particle collided in the past,
and a new event proposed for a future processing
with a similar set of parameters.
== Examples of use ==
== References ==
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