clarke@utcsri.UUCP (06/11/87)
(SF = Sandford Fleming Building, 10 King's College Road)
SUMMARY:
A.I. SEMINAR, Tuesday, June 16, 3 pm, SF1105 -- David Waltz:
"AI on the Connection Machine"
SYSTEMS SEMINAR, Thursday, June 18, 11 am, SF1101 -- Edward D. Lazowska:
"Interconnecting Heterogeneous Computer Systems"
A.I. SEMINAR, Friday, June 19, 11 am, SF1101 -- Yoav Shoham:
"Nonmonotonic Temporal Reasoning and Causation"
----------------
A.I. SEMINAR, Tuesday, June 16, 3 pm, SF1105
Professor David Waltz
Thinking Machines Incorporated
``AI on the Connection Machine"
SYSTEMS SEMINAR, Thursday, June 18, 11 am, SF1101
Professor Edward D. Lazowska
University of Washington
``Interconnecting Heterogeneous Computer Systems"
The Department of Computer Science at the University of Washington is con-
ducting a research and development project whose goal is to simplify the
interconnection of heterogeneous computer systems. In almost every
advanced computing environment, the proliferation of different machines and
operating systems is proving to be a major obstacle to the efficient use of
networks of personal computers and mainframes. In our view, the solution
to this problem is to design a software infrastructure whose specific goal
is to decrease the marginal cost of adding a new type of system to an
existing computing environment, and at the same time to increase the set of
common services that its users can expect to share. We are demonstrating
the feasibility of this approach by producing detailed designs and proto-
types. Our approach involves three key services - file access, mailing,
and remote computation - which are constructed using two underlying facili-
ties - a remote procedure call (RPC) mechanism and a naming service. This
talk provides a technical overview of the project and a more detailed look
at our heterogeneous RPC facility.
A.I. SEMINAR, Friday, June 19, 11 am, SF1101
Professor Yoav Shoham
Stanford University
``Nonmonotonic Temporal Reasoning and Causation"
We define two problems that arise from the conflicting goals of rigor and
efficiency in temporal reasoning, called the qualification problem and the
extended prediction problem, which subsume the infamous frame problem. We
then offer solutions to those. The solution relies on making nonmonotonic
inferences. We present our very simple, semantical approach to nonmonotonic
logics. We then define a particular nonmonotonic logic, called the logic
of chronological ignorance, which combines elements elements of temporal
logic and the modal logic of knowledge. We illustrate how the logic can be
used to solve the qualification problem. (In the unlikely event of time
permitting, we will do the same for the extended prediction problem).
Although the logic of chronological ignorance is, in general, badly
undecidable, we identify a restricted class of theories, called causal
theories, which have very nice properties: They each have a model that is
(in a certain sense) unique, and that is (in a certain sense) easily com-
putable. We argue that the above analysis offers an attractive account of
the concept of causation, and of its central role in common sense reasoning.
--
Jim Clarke -- Dept. of Computer Science, Univ. of Toronto, Canada M5S 1A4
(416) 978-4058
{allegra,cornell,decvax,linus,utzoo}!utcsri!clarke