Re: [Swarm-Modelling] Literature on modeling concurrency

[Chris Landauer]

hihi, all -

there is an enormous number of papers on scheduling concurrent events in the
communication protocol simulation and verification literature

many properties of complex networks are much easier to prove for asynchronous
behaviors, since the associated mathematics is more powerful and somewhat more
well-developed, even though it might seem otherwise, since the behaviors are
more closely connected

some of this literature dates back to the 1970's, with languages for
expression concurrency, and the difference between truly ``concurrent''
systems, in which events can partially overlap, and ``fake'' concurrency, in
which it is assumed that they do not overlap, so that only one event can
occur at one time (this is the usual assumption for discrete event simulation
systems such as swarm and many others) - it is provable that the latter
approach cannot correctly model situations in which events can in fact overlap

there is also a fair amount of theory - names like nancy lynch, amir pneuli,
zohar manna, leslie lamport, and terms like branching time, linear time, and
such - i will try to dig up some of the references (they are buried in boxes
in the garage, unless the rats ate them) - i would also like to see any more
recent references that anyone finds

i used to pull a trick in my own discrete event simulations (i implemented
gpss once this way, in the 1960's): among all events that are scheduled to
occur at the same time, select them randomly - that precludes any zero-time
information transfers based on knowing that the time at which an event was
scheduled determines its position in the future events set (a common
simulation implementor's trick)

more soon,
cal


Chris Landauer
Aerospace Integration Science Center
The Aerospace Corporation
address@hidden