clarke@utcsri.UUCP (Jim Clarke) (02/21/86)
(GB = Galbraith Building, 35 St. George Street)
(SF = Sandford Fleming Building, 10 King's College Rd.)
COLLOQUIUM, Tuesday, March 4, 11 am, SF 1105
Professor A. von Staa
Catholic University of Rio de Janeiro
"The Computer Environment in Brazil"
(Abstract below.)
SYSTEMS/AI SEMINAR, Tues. Mar. 4, 3 pm, SF 1105
Dr. Joseph Goguen
SRI International
"Eqlog - the Software Specification and
Logic Programming Language"
(Abstract below.)
THEORY SEMINAR, Tues. Mar. 4, 4 pm, SF 1105
Dr. Erich Kaltofen
Rennselaer Polytechnic Institute
"Computing with Polynomials given a Straight-Line
Programs Theory and Practice"
(Abstract below.)
SYSTEMS SEMINAR, Thurs. Mar. 6, 11 am, GB 220
Yannis Ioannidis
University of California, Berkeley
"Processing Recursion in Deductive Databases"
(Abstract below.)
AI SEMINAR, Thurs., Mar. 6, 3 pm, SF 1101
Edward P. Stabler, Jr.
Quintus Computer Systems
"Restricting Logic Grammars"
(Abstract below.)
SPECIAL ANNOUNCEMENT
This year's Keys Memorial Lecture will be given by Dr. Lewis M. Branscomb,
IBM Chief Scientist and Vice-President on the subject "Smart Machines or
Satisfying Ones: the Promise of Artificial Intelligence", on Monday, 3
March 1986 at 4:00 pm in the George Ignatieff Theatre.
ABSTRACTS
Arndt von Staa
An Assessment and Outlook of the Computer Industry in Brazil
Several years ago Brazil decided to start its own computer industry. For
this purpose import restrictions were enacted, especially with regard to
micro and mini computers. One of the consequences is a growing hardware
industry, where nothing existed before. Computer related activities are
still the fastest growing economical branch in Brazil, even at a time of
severe recession. For example, there are now more than 40 hardware
manufacturers. Some of this hardware is being exported, believe it or not,
to the USA. Hardware and software used in bank automation has been
entirely designed and developed in Brazil. Some people claim that these
systems are the most sophisticated around.
There are also several negative aspects, the worst of them is piracy. Some
people argue though, that piracy would be even worse if no national com-
puter industry existed. Some of the proposed ideas about how to combat
piracy will be presented.
In this talk some of the existing and proposed laws will be described.
Some of the consequences these laws had on the computer industry will be
shown. Computer related education, hardware industry, software industry,
CAD/CAM, industrial control, computer services will be briefly examined,
and an outlook of their evolution will be shown.
Joseph Goguen
Eqlog
Eqlog is a logic programming language for software specification with some
nice applications to artificial intelligence such as problem solving and
natural language.
Erich Kaltofen
Computing with Polynomials given by Straight-Line
Programs Theory and Practice
My talk centers around the theory and practice of a new representation for
multivariate polynomials with exponentially many terms, namely the
representation by straight-line programs. I have shown that theoretically
common polynomial operations are feasible, that is random polynomial-time.
More precisely, given polynomials in straight-line format one can, for
example, compute the greatest common divisor and the irreducible factors -
again in straight-line representation - in random polynomial time (Monte-
Carlo, always fast and probably correct). My lecture will focus on the
factorization algorithm.
We are currently building a system for manipulating polynomials and
rational functions in such a representation. Together with a conversion
procedure back to sparse format, this system can manipulate objects that
previously needed exponential space to represent. I will also demonstrate
our system by showing examples, which underline the practicality of our new
representation as well.
Edward P. Stabler, Jr.
Restricting Logic Grammars
The best-known parser formalisms for logic programming systems have typi-
cally aimed to be expressive and efficient rather than restrictive, but it
is well known that more restrictive formalisms can make the task of grammar
construction easier, whether it is done manually (by a programmer) or
automatically (by a grammar induction system). The ideal would be a parser
formalism for natural languages that is so restricted as to rule out the
definition of just those linguistic structures that do not occur in any
natural language. A restrictive grammar formalism for logic programming
languages will be described that imposes some of the constraints suggested
by recent Chomskian linguistic theory, constraints that are thought to
apply to all human languages. This formalism allows for relatively elegant
characterizations of natural languages that can be translated into reason-
ably efficient top-down backtracking prolog parsers with lookahead.
Yannis Ioannidis
Processing Recursion in Deductive Databases
Recursion appears to be one of the most important features of a database
system enhanced with deductive power. In such an environment, it has trad-
itionally been studied under the formalism of 1-st order logic, focus-
ing on recursive Horn clauses. We reformulate the recursion problem in
operator form, embedding it in a particular algebraic structure. This
enables us to get more information about the mechanics of recursion. In
particular, alternative processing techniques are revealed, which, depend-
ing on the database state, have the potential of being more efficient
than the traditional ones. The importance of including these alternative
algorithms in the strategy space of a recursion optimizer is illus-
trated by some examples.
--
Jim Clarke -- Dept. of Computer Science, Univ. of Toronto, Canada M5S 1A4
(416) 978-4058
{allegra,cornell,decvax,ihnp4,linus,utzoo}!utcsri!clarke