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AIList Digest Volume 6 Issue 014
AIList Digest Friday, 22 Jan 1988 Volume 6 : Issue 14
Today's Topics:
Seminars - DSRS: Distributed/Parallel Discrete-Event Simulation (SU) &
Virtual Environment Systems (SU) &
Solving Dynamic-Input Interpretation Problems (Unisys) &
Generate, Text and Debug for Planning (AT&T) &
Distributing Backward-Chaining Deductions (BBN),
Course & Conference - Mathematical Logic (Bulgaria)
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Date: Fri, 15 Jan 88 12:07:20 PST
From: Bruce L Hitson <hitson@Pescadero.stanford.edu>
Subject: Seminar - DSRS: Distributed/Parallel Discrete-Event
Simulation (SU)
DISTRIBUTED/PARALLEL DISCRETE-EVENT SIMULATION: A SURVEY
Marc Abrams - Stanford University
DSRS: Distributed Systems Research Seminar (CS548)
Thursday, January 21, 4:15pm
Margaret Jacks Hall 352
Work has increased through the last decade on algorithms to execute
discrete-event simulations on distributed and, more recently, multiprocessor
computer systems. Some simple ways of exploiting parallelism were quickly
proposed -- running independent sequential simulation replicas in parallel,
and distributing the support functions of a simulation. However progress
beyond this in executing two or more events in parallel is only beginning to
be demonstrated. This talk surveys the current state of research in the
field. Proposed simulation algorithms are discussed. Performance
characterizations of the algorithms obtained through theoretical analysis,
simulation, and measurement of implementations are summarized. The talk
concludes with some encouraging directions for future research.
------------------------------
Date: Fri, 15 Jan 88 13:45:24 PST
From: Susan Gere <susan@umunhum.stanford.edu>
Subject: Seminar - Virtual Environment Systems (SU)
EE380---Computer Systems Colloquium
Title: Virtual Environment Display Systems
Speaker: Scott Fisher
From: NASA/Ames Research Center
Time: 4:15 p.m. on Wednesday, January 20
Place: Skilling Auditorium
Abstract
The presentation will describe recent research trends toward development
of virtual interactive simulation environments for aerospace and commercial
applications. The primary focus will be the Virtual Environment Workstation
(VIEW) developed at NASA Ames Research Center. This system provides a
multisensory, interactive display environment in which a user can virtually
explore a 360-degree synthesized or remotely sensed environment and can
viscerally interact with its components through use of head-mounted,
stereoscopic displays, tactile input gloves and 3D sound technology.
Applications for Telepresence, Telerobotics and Spatial Data Management
will also be discussed.
Scott S. Fisher is a Research Scientist in the Aerospace Human Factors
Research Division at NASA/Ames Research Center, Moffett Field, California.
------------------------------
Date: Mon, 18 Jan 88 22:43:31 EST
From: finin@PRC.Unisys.COM (Tim Finin)
Subject: Seminar - Solving Dynamic-Input Interpretation Problems
(Unisys)
AI Seminar
UNISYS Knowledge Systems
Paoli Research Center
Paoli PA
SOLVING DYNAMIC-INPUT INTERPRETATION PROBLEMS
Kathleen D. Cebulka
Computer and Information Sciences
University of Delaware
Newark, DE 19716
Many AI problems can be viewed as interpretation problems which have the
common goal of producing a solution that "explains" a given input. The
solution usually takes the form of a set of beliefs called a hypothesis.
Although a number of researchers have developed strategies for handling the
static case where the input is fixed, there are many problems where the
input is received dynamically in relatively small increments. Usually the
problem solver is interacting with a user who expects a timely response
after every input, so it can not postpone forming a solution while it waits
for more complete information. As a result, the problem solver must rely
on default reasoning and belief revision techniques since new evidence may
reveal that the current hypothesis is not the final answer.
This talk describes a characterization of the solution of dynamic-input
interpretation problems as a search through a hypothesis space. A domain
independent algorithm, called the Hypothesize-Test-Revise algorithm, is
presented and contrasted with the traditional static approach. An
advantage of this algorithm is a more efficient strategy for generating and
revising hypotheses in a dynamic environment.
2:00pm Wednesday, January 20
BIC Conference Room
Unisys Paloi Research Center
Route 252 and Central Ave.
Paoli PA 19311
-- non-Unisys visitors who are interested in attending should --
-- send email to finin@prc.unisys.com or call 215-648-7446 --
------------------------------
Date: Tue, 19 Jan 11:54:54 1988
From: dlm%research.att.com@RELAY.CS.NET
Subject: Seminar - Generate, Text and Debug for Planning (AT&T)
Generate, Test and Debug: a Paradigm for
Solving Interpretations and Planning Problems
Reid Simmons
Massachusetts Institute of Technology
January 21, 1988, AT&T Bell Labs-Murray Hill 3D-473, 11:00 am
January 22, 1988, AT&T Bell Labs-Holmdel 4C-513, 10:30 am
ABSTRACT
We describe how the Generate, Test and Debug (GTD) paradigm
solves interpretation and planning problems, and why its
combination of associational and causal reasoning
techniques enables it to achieve efficient and robust
performance. The Generator constructs hypotheses using
domain dependent rules. The Tester verifies hypotheses and
supplies the Debugger with causal explanations if the test
fails, and the Debugger uses domain-independent algorithms to
repair hypotheses by analyzing the causal explanations and
models of the domain. The GTD paradigm has been implemented
and tested in the domains of geologic interpretation, the
blocks world, and the Tower of Hanoi problem.
Sponsor: Ron Brachman
------------------------------
Date: Thu 21 Jan 88 10:16:21-EST
From: Marc Vilain <MVILAIN@G.BBN.COM>
Subject: Seminar - Distributing Backward-Chaining Deductions (BBN)
BBN Science Development Program
AI Seminar Series Lecture
DISTRIBUTING BACKWARD-CHAINING DEDUCTIONS TO MULTIPLE PROCESSORS
Vineet Singh
Stanford University, and SPAR
(VSINGH@SPAR-20.SPAR.SLB.COM)
BBN Labs
10 Moulton Street
2nd floor large conference room
10:30 am, Friday January 29th
The talk presents PM, a parallel execution model for backward-chaining
deductions. PM exploits more parallelism than other execution models
that use data-driven control and non-shared memory architectures. The
talk also presents an application-independent, compile-time allocation
strategy for PM that is both fast and effective. Effectiveness is
demonstrated by comparing speedups obtained from an implementation of
the allocator to an unreachable upper bound and speedups obtained from
random allocations. The resource allocator uses probabilistic
techniques to predict the amount of communication and the parallelism
profile; this should be useful for other allocation strategies as well.
------------------------------
Date: 12 Jan 88 21:04:23 GMT
From: mcvax!inria!geocub!farinas@uunet.uu.net (Luis Farinas)
Subject: Course & Conference - Mathematical Logic (Bulgaria)
CURRENT ANNOUNCEMENT AND CALL FOR PAPERS
----------------------------------------
SUMMER SCHOOL & CONFERENCE ON MATHEMATICAL LOGIC
honourably dedicated to the 90th anniversary of Arend Heyting
September 13-23, 1988
Chaika near Varna (BULGARIA)
ORGANIZED BY:
Sofia University, Bulgarian Academy of Sciences
TOPICS of the meeting:
* recursion theory
* modal and non-classical logics
* intuitionism and constructivism
* related applications to computer science
* life and work of Arend Heyting (1898-1980)
INVITED LECTURERS:
M.Cresswell V.Lifschitz G. Sacks
D.de Jongh L.Maksimova D.Skordev
A. Ditchev G.Mints G.Takeuti
D.Harel A.Muchnik A.Toelstra
M.Kanovich H.Nishimura D.van Dalen
A.Kechris D.Normann A.Visser
B.Kushner H.Ono S.Wainer
Submission to the conference are invited from the above areas and will be
evaluated by the Programme Commitee. We shall expect 5 copies of a draft full
paper (in English) of no more than 15 double spaced pages, containing original
contributions. Papers should reach the PC chairman by the deadline below,
accompanied by a one page abstract.
DEADLINES :
March, 15: Submission
June,15: Notification
August,15: final version for publication in the proceedings
ORGANIZATION COMMITTEE :
Valentin Goranko : local arragements
Lyubomir Yvanov : Treasurer
Solomon Passy: Secretary
Petio Petkov: Chairman
Tinko Tinchev
Please send all correspondence to the appropriate member of the organization
committee.
HEYTING'88
Sector of Logic
Mathematics Faculty
boul. Anton Ivanov 5
SOFIA 1126
BULGARIA
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End of AIList Digest
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