clarke@utcsri.UUCP (Jim Clarke) (10/18/85)
(SF = Sandford Fleming Building, 10 King's College Road)
(GB = Galbraith Building, 35 St. George Street)
SYSTEMS SEMINAR, Thursday, October 24, 11 am, SF1105
Professor Adrian E. Conway
University of Ottawa
"Computational Algorithms for the Analysis of Queueing Networks'
Abstract
Networks of queues are widely used models in system performance
evaluation; two current applications are to distributed computer systems
and local area networks. An important factor in their adoption has been
the discovery of the class of so-called "product-form" networks for which
the state probability distribution is known. Despite the knowledge of this
distribution, it is not a simple matter to compute the mean performance
measures, which are the quantities that are of most interest in practice,
since the state-space of queueing networks is, in general, extremely large.
In recent years, much attention has been paid to this problem of obtaining
the measures of interest in an efficient manner.
There are two principal algorithms that have been developed which are
efficient: the Convolution Algorithm and Mean Value Analysis. Both of
these algorithms have exponential space/time complexity in the number of
"closed routing chains". In this talk, we present a new algorithm, by the
name of RECAL (Recursion by chain algorithm), which has polynomial complex-
ity in the number of routing chains. This algorithm extends the range of
queueing networks which can be analyzed efficiently by exact means. We
shall also present an efficient algorithm for the analysis of so-called
"semi-homogeneous" networks which arise in the modelling of local area net-
works.
COLLOQUIUM, Tuesday, October 29, 11 am, SF 1105
Professor E. Tulving
Dept. of Psychology, University of Toronto.
"What is Memory?"
THEORETICAL ASPECTS SEMINAR, Thursday, Oct. 31, 4pm, GB248
Professor Johan Hastad
Laboratory for Computer Science, MIT.
"Improvements of Yao's Results on Parity Circuits"
--
Jim Clarke -- Dept. of Computer Science, Univ. of Toronto, Canada M5S 1A4
(416) 978-4058
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