CGL Meeting Agenda
Wednesday, April 5, 1995
- Location:
- DC 1304
- Time:
- 1:30 PM
- Chair:
- Haroon Sheikh
1. Adoption of the agenda - additions/deletions thereto.
2. Coffee Hour and Next Meeting:
- Coffee hour this week:
- ???
- Coffee hour next week:
- ???
- Next Meeting
-
- Time:
- April 12, 1995
- Location:
- DC 1304
- Chair:
- Jay Steele
- Tech Presentation:
- Stephen Mereu
- Forthcoming: (list next 4 and trades)
-
- Chairs:
- Riston Tapp
- Greg Veres
- Bill Wallace
- Julie Waterhouse
- Tech presentations:
- Andrew Park
- Glenn Paulley
- Randall Reid
- Haroon Sheikh
3. Technical Presentation:
- Presenter:
- Mike McCool
- Title:
-
- Abstract:
-
4. General Discussion Items:
-
5. Action List (remember to update AL_active)
6. Directors Meeting:
7. Seminar(s):
DEPARTMENT OF COMPUTER SCIENCE
UNIVERSITY OF WATERLOO
SEMINAR ACTIVITIES
MASTER'S THESIS PRESENTATION
-Friday, April 7, 1995
Alain Gaudrault, graduate student, Dept. Comp. Sci.,
Univ. Waterloo, will speak on "Load Balancing in a
Distributed Virtual Reality Environment."
TIME: 10:30-12:30 p.m.
ROOM: DC 1302
ABSTRACT
The WAterloo Virtual Environment System (WAVES) has
been designed to provide virtual reality application
developers with the tools to create distributed virtual
worlds without concern for the underlying
implementation. The need to distribute tasks generated
by virtual reality software becomes a necessity if
virtual worlds are to scale up gracefully. By
incorporating load balancing techniques within WAVES,
virtual worlds of great size and fidelity may be
possible. In this paper, load balancing approaches are
reviewed, and an algorithm is developed and
implemented. Simulation software to test the
efficiency of the load balancing algorithm is
described, and results of the testing phase is
included. Future development of both WAVES and the
load balancing scheme is discussed.
April 10. Davis Centre 1331. Noon.
Graeme Hirst, Computer Science Department, University of Toronto.
Existence assumptions in knowledge representation
Abstract. If knowledge representation formalisms are to be suitable for
semantic
interpretation of natural language, they must be more adept with
representations of existence and non-existence than they presently
are. Quantifiers must sometimes scope over non-existent entities. I
review the philosophical background, including Anselm and Kant, and
exhibit some ontological problems that natural language sentences pose
for knowledge representation. The paraphrase methods of Russell and
Quine are unable to deal with many of the problems.
Unfortunately, the shortcomings of the Russell-Quine ontology are
reflected in most current knowledge representation formalisms in AI.
Several alternatives are considered, including some intensional
formalisms and the work of Hobbs, but all have problems. Free logics
and possible worlds don't help either. But useful insights are found
in the Meinongian theory of Parsons, in which a distinction between
nuclear and extranuclear kinds of predicates is made and used to define
a universe over which quantification scopes. If this is combined with
a naive ontology, with about eight distinct kinds of existence, a
better approach to the representation of non-existence can be developed
within Hobbs's basic formalism.
Biography. Graeme Hirst is the author of /Semantic interpretation and the
resolution of ambiguity/ (Cambridge University Press, 1987).
He serves as book review editor of /Computational Linguistics/.
The University of Waterloo
200 University Avenue
Waterloo, Ontario
The Institute for Computer Research (ICR)
Presents a Colloquium on
Uncheatable Benchmarks
by: Dr. Jin-yi Cai
of: Department of Computer Science
SUNY Buffalo
Buffalo, New York
Date: Wednesday, April 12, 1995
Time: 3:30 pm.
Place: William G. Davis Computer Research Centre, Room 1302
Abstract:
Benchmarks have been used to test everything from the speed of a
processor, to the accuracy of computations, to the capacity of a
memory system. The computing community relies heavily on the use
of benchmarks to assess how well a given hardware or software
system operates. The recent fiasco involving the Pentium chips is
an excellent reminder that while certain computations may seem
elementary, adequate testing using good benchmarks is indispens-
able.
Up until now, the study of the art of designing a good benchmark
has focused on making the benchmark ``realistic'' in predicting
how well it will perform for the intended applications; the issue
of making benchmark results trustworthy has been relegated to
``trusted'' or third party agents, and little attention has been
paid to the question of making benchmarks themselves ``uncheat-
able''.
We wish to study the problem of how one can make benchmarks
resistant to tampering and hence more trustworthy. We propose a
framework based on modern cryptography and complexity theory.
Concrete schemes are proposed for different benchmarks: speed of
the processor, memory capacity, sorting, etc. They are ``un-
cheatable'', if certain complexity theory assumptions are true
based on the hardness of factoring and discrete logarithm.
We also present a scheme for matrix multiplication which depends
on the numerical instability of certain floating point arithmet-
ic. If time permits we will present a new scheme which could
have captured the errors in the Pentium chip.
Part of this talk will be based on joint work with R. Lipton, R.
Sedgewick and A. Yao, and also joint work with my students S. Ar
and A. Nerurkar. Supported by NSF grant CCR9319393 and
CCR9057486, and a Sloan fellowship.
Everyone is welcome. Refreshments served.
8. Lab Cleanup (till 2:30pm or 5 minutes, whichever is longer)