Received: from AI.AI.MIT.EDU (CHAOS 3130) by MC.LCS.MIT.EDU 22 Jan 88 04:15:41 EST Received: from KL.SRI.COM (TCP 1200200002) by AI.AI.MIT.EDU 22 Jan 88 04:07:46 EST Date: Thu 21 Jan 1988 23:03-PST From: AIList Moderator Kenneth Laws Reply-to: AIList@SRI.COM US-Mail: SRI Int., 333 Ravenswood Ave., Menlo Park, CA 94025 Phone: (415) 859-6467 Subject: AIList V6 #14 - Seminars, Mathematical Logic Conference To: AIList@SRI.COM 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) ---------------------------------------------------------------------- Date: Fri, 15 Jan 88 12:07:20 PST From: Bruce L Hitson 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 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 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 ------------------------------ End of AIList Digest ********************