clarke@utcsri.UUCP (11/26/87)
(SF = Sandford Fleming Building, 10 King's College Road)
(GB = Galbraith Building, 35 St. George Street)
SUMMARY:
COMBINATORICS SEMINAR, Monday, November 30, 3 pm, SF1102 -- Rudi Mathon:
"Transformations on Designs"
SYSTEMS SEMINAR, Tuesday, December 1, 11 am SF1105 -- Kai Li:
"Shared Virtual Memory on Loosely-Coupled Multiprocessors"
A.I. SEMINAR, Tuesday, December 1, 2 pm, GB244 -- David Poole:
"Defaults and Conjectures: Hypothetical Reasoning for Explanation and Prediction
-------------
COMBINATORICS SEMINAR, Monday, November 30, 3 pm, SF1102
Professor Rudi Mathon
University of Toronto
"Transformations on Designs"
SYSTEMS SEMINAR, Tuesday, December 1, 11 am SF1105
Professor Kai Li
Princeton University
"Shared Virtual Memory on Loosely-Coupled Multiprocessors"
This talk presents the methods for designing a shared virtual memory on a
loosely-coupled multiprocessor, and demonstrates via a working implementa-
tion that such a memory system is practical. The talk includes algorithms
for solving memeory coherence problems in the shared virtual memory, basic
mechanisms for concurrent process control (including process migration),
and special considerations for memory management. A prototype shared vir-
tual memory on an Apollo ring is then described. The system can be used to
run parallel programs on any number of processors. Experiments show that
such a system can indeed utilize the computing power of conventional dis-
tributed workstations, achieving order-of-magnitude speed-ups over a
uniprocessor.
A.I. SEMINAR, Tuesday, December 1, 2 pm, GB244
Professor David Poole
University of Waterloo
"Defaults and Conjectures:
Hypothetical Reasoning for Explanation and Prediction"
Classical logic has been criticised as a language for common sense reason-
ing as it is monotonic. In this talk I wish to argue that the problem is
not with logic, but with how logic is used. An alternate way to use logic
is by using theory formation; logic tells us what a theory implies, an
inconsistency means that the theory cannot be true of the world. I show how
the simplest form of theory formation, namely where the user supplies the
possible hypotheses, can be used as a basis for default reasoning and
model-based diagnosis. This is the basis of the "Theorist" system being
built at the University of Waterloo. I will discuss what we have learned
from building and using our system. I will also discuss distinctions which
we have found to be important in practice, such as between explaining
observations and making predictions; and between normality conditions
(defaults) and abnormality conditions (prototypes, conjectures, diseases).
The effects of these distinctions on recognition and prediction problems
will be presented along with algorithms, theorems and examples.
--
Jim Clarke -- Dept. of Computer Science, Univ. of Toronto, Canada M5S 1A4
(416) 978-4058
{allegra,cornell,decvax,linus,utzoo}!utcsri!clarke