nl-kr-request@CS.ROCHESTER.EDU (NL-KR Moderator Brad Miller) (05/17/88)
NL-KR Digest (5/16/88 17:47:00) Volume 4 Number 49 Today's Topics: Seminar - AURORA -- An Or-Parallel Prolog System (Unisys) Seminar - Nonmonotonic Parallel Inheritance Networks (AT&T) Seminar - Collative Semantics (AT&T) BBN AI Seminar -- Steven Minton Language & Cognition Seminar Harvard AI seminar Lang. & Cognition Seminar From CSLI Calendar, May 5, 3:27 CSLI Reports From CSLI Calendar, May 12, 3:28 Conference - AAAI Workshop on Plan Recognition Submissions: NL-KR@CS.ROCHESTER.EDU Requests, policy: NL-KR-REQUEST@CS.ROCHESTER.EDU ---------------------------------------------------------------------- Date: Sat, 23 Apr 88 12:40 EDT From: Tim Finin <antares!finin@burdvax.prc.unisys.com> Subject: Seminar - AURORA -- An Or-Parallel Prolog System (Unisys) AI SEMINAR UNISYS PAOLI RESEARCH CENTER AURORA - An Or-parallel Prolog System Andrzej Ciepelewski Swedish Institute of Computer Science (SICS) A parallel prolog system has been constructed in a cooperative effort among Argonne National Lab, University of Manchester and SICS. The system has been based on a state of the art sequential Prolog. It runs on multiprocessors with shared memory and is expected to perform better than on e.g. Sequent Symmetry than the commercial Prolog systems available today. The system executes "ordinary" ordinary Prolog programs withs cuts and side effects keeping the semantics of sequential execution. Also programs written in Prolog extended with parallel primitives like "cavalier" commit and unorderd sided-effects can be excuted. The system has been designed for portability and modifiability. It main part, the engine part and the scheduler part are nicely interfaced. Two quite different schedulers have already been tried. Some preliminary performance data has already been collected, running mostly small search and parsing problems. The largest program ran so far have been the parallelised SICStus Prolog compiler and Chat-80. The figures from Sequent Balance 8000 show about 20% parallel overhead in one processor case and close to linear speed-ups. We are waiting with exitement for figures from Sequent Symmetry where the system has been recently ported. In my talk I will mainly discuss implementation decisions and performance figures. 2:00 pm Tuesday, April 26 Paoli Auditorium 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 -- Tim Finin finin@prc.unisys.com Paoli Research Center ..!{psuvax1,sdcrdcf,cbmvax,bpa}!burdvax!finin Unisys Corporation 215-648-7446 (o) PO Box 517, Paoli PA 19301 215-386-1749 (h) ------------------------------ Date: Mon, 25 Apr 88 12:30 EDT From: dlm%research.att.com@RELAY.CS.NET Subject: Seminar - Nonmonotonic Parallel Inheritance Networks (AT&T) Speaker: Chiaki Sakama ICOT, Japan. Time: 10:30, May 2nd, 1988 Room: AT&T Bell Laboratories- Murray Hill 3D-436 Title: Nonmonotonic Parallel Inheritance Networks This paper discusses a formalization of nonmonotonic inheritance reasoning in semantic networks using Reiter's default theory. It enables us to define inheritance rules apart from data in a network, and improves readability or maintenance of a network compared with other approaches. We also present a parallel inheritance algorithm based on this method, which generates a set of properties for an input class. This algorithm is easily realized in a parallel logic programming language GHC (Guarded Horn Clauses), which is developed as the kernel language of the fifth-generation project at ICOT. Sponsor: David Etherington ether@research.att.com ------------------------------ Date: Mon, 25 Apr 88 12:30 EDT From: dlm%research.att.com@RELAY.CS.NET Subject: Seminar - Collative Semantics (AT&T) Speaker: Dan Fass Computing Research Laboratory, New Mexico State University Title: Collative Semantics: A Semantics for Natural Language Processing Date: Thursday, April 29, 10:30 Place: AT&T Bell Laboratories- Murray Hill 3D-560 Abstract: The main semantic phenomena Collative Semantics (CS) addresses are lexical ambiguity and what are referred to as "semantic relations". Seven kinds of semantic relation investigated are literal, metonymic, metaphorical, anomalous, novel, inconsistent, and redundant relations. The talk will discuss CS and the three main ideas behind it: (1) a linguistic view of knowledge representation which shows how the semantic primitives of a knowledge representation can function like senses of words from natural language; (2) a distinction made between knowledge and coherence; and (3) a large-scale framework of four constructs, two representations and two processes, in which coherence plays a major organising role. CS has four components which are instances of the four constructs: sense-frames and semantic vectors are the two representations, and collation and screening are the two processes. Sense-frames represent lexical ambiguity: they embody the linguistic view of knowledge representation. Collation is a process which discriminates semantic relations: it matches the sense-frames of two word senses and distinguishes semantic relations between the word senses as a complex system of mappings between their sense-frames. Semantic vectors represent semantic relations: they are a "coherence representation" which records the systems of mappings produced by collation. Screening is a process which resolves lexical ambiguity: it selects between pairs of semantic vectors. CS has been implemented in a sentence analysis program called Meta5. Examples will be given of how metaphors and metonymies are distinguished by Meta5. Sponsors: Bruce Ballard (bwb@research.att.com) Ron Brachman (rjb@research.att.com) ------------------------------ Date: Wed, 27 Apr 88 14:23 EDT From: Marc Vilain <MVILAIN@G.BBN.COM> Subject: BBN AI Seminar -- Steven Minton BBN Science Development Program AI Seminar Series Lecture LEARNING EFFECTIVE SEARCH CONTROL KNOWLEDGE: AN EXPLANATION-BASED APPROACH Steven Minton Carnegie-Mellon University (Steven.Minton@cad.cs.cmu.edu) BBN Labs 10 Moulton Street 2nd floor large conference room 10:30 am, Tuesday May 3 In order to solve problems more effectively with accumulating experience, a problem solver must be able to learn and exploit search control knowledge. In this talk, I will discuss the use of explanation-based learning (EBL) for acquiring domain-specific control knowledge. Although previous research has demonstrated that EBL is a viable approach for acquiring control knowledge, in practice EBL may not always generate useful control knowledge. For control knowledge to be effective, the cumulative benefits of applying the knowledge must outweigh the cumulative costs of testing whether the knowledge is applicable. Generating effective control knowledge may be difficult, as evidenced by the complexities often encountered by human knowledge engineers. In general, control knowledge cannot be indiscriminately added to a system; its costs and benefits must be carefully taken into account. To produce effective control knowledge, an explanation-based learner must generate "good" explanations -- explanations that can be profitably employed to control problem solving. In this talk, I will discuss the utility of EBL and describe the PRODIGY system, a problem solver that learns by searching for good explanations. Extensive experiments testing the PRODIGY/EBL architecture in several task domains will be discussed. I will also briefly describe a formal model of EBL and a proof that PRODIGY's generalization algorithm is correct with respect to this model. ------------------------------ Date: Fri, 29 Apr 88 08:51 EDT From: Dori Wells <DWELLS@G.BBN.COM> Subject: Language & Cognition Seminar BBN Science Development Program Language & Cognition Seminar Series METAPHORS, MEMORIES AND MODALITIES: INSIGHTS FROM INFANTS Sheldon H. Wagner Department of Psychology University of Rochester BBN Laboratories Inc. 10 Moulton Street Large Conference Room, 2nd Floor 10:30 a.m., Friday, May 6, 1988 Absract: Human infants are linguistically and experientially immature and yet they show evidence of complex cognitive judgments some of which might be thought solely to be in the province of language users. Examples of these are "metaphorical" recognition of similarities between physically dissimilar events and the recognition of objects presented separately to different modalities. Evidence for these abilities and a putative amodal code that subserves them will be presented along with a model of visual recognition memory that can serve as a useful metric for quantifying the rate of information-processing of infants of varying ages. Concurrrent validity for the model will be examined by comparing performances of infants of varying ages under different experimental conditions and by comparing these results to those obtained from infants born under medically compromising conditions such as birth asphyxia, intraventricular hemorrhage and severe prematurity. ------------------------------ Date: Fri, 29 Apr 88 13:48 EDT From: Ehud Reiter <reiter@harvard.harvard.edu> Subject: Harvard AI seminar Monday, May 9, 1988 4 PM Aiken 101 (Harvard University) (Tea at 3:45 pm, Aiken Main Lobby) Connectionist Representations and Linguistic Inference David S. Touretzky Computer Science Department Carnegie Mellon University DUCS is a neural network architecture for representing and manipulating frame-like structures. Slot names and slot fillers are diffuse patterns of activity spread over a collection of units. The choice of a distributed representation gives rise to certain useful properties not shared by conventional frame systems. One of these is the ability to retrieve a slot even if the slot name is not known precisely. Another is the ability to encode fine semantic distinctions as subtle variations on the canonical pattern for a slot. DUCS combines the flexiblity of parallel distributed processing with the structured flavor of conventional formalisms. but it is only suggestive of the sort of fluid knowledge representations connectionists are really after. In the second half of the talk I will discuss some current problems in connectionist natural language processing. Spreading activation/lateral inhibition architectures are insufficient to handle many interesting linguistic phenomena. For example, metonymy requires not only a rich knowledge representation, but also a flexible inference mechanism. Future connectionist models, employing more sophisticated network architectures, may provide solutions to these difficulties. ------------------------------ Date: Tue, 3 May 88 15:34 EDT From: Dori Wells <DWELLS@G.BBN.COM> Subject: Lang. & Cognition Seminar BBN Science Development Program Language & Cognition Seminar Series ON GLOSSING Alton Becker Dept. of Linguistics University of Michigan BBN Laboratories Inc. 10 Moulton Street Large Conference Room, 2nd Floor 10:30 a.m., Thursday, May 5, 1988 Abstract: While linguists have become very sophisticated in parsing languages, the other basic linguistic act, glossing, is done uncritically almost always, even though to a very great extent glossing determines parsing. In this talk, the pervasive double-headedness construction in Burmese which, I will argue, is untranslatable into single-headed English will be used to illustrate how uncritical glossing has obscured deep syntactic differences between languages. As are all my talks, this one will be yet another plea for nonuniversality. ------------------------------ Date: Thu, 5 May 88 12:20 EDT From: Emma Pease <emma@russell.stanford.edu> Subject: From CSLI Calendar, May 5, 3:27 Reading: "Connectionism and Cognitive Architecture: A Critical Analysis" by Jerry Fodor and Zenon Pylyshyn Cognition, March 1988 Discussion led by Adrian Cussins (cussins.pa@xerox.com) May 5 Fodor and Pylyshyn try to impale connectionism on the horns of a dilemma: either connectionism is a mere implementation theory, or it is a false theory of cognition because it cannot capture the systematicity of thought. Once you adopt Fodor and Pylyshyn's perspective, their argument is very powerful. I will run through their argument, and then show how to adopt a different perspective on connectionist modeling of cognition by showing how to deny their assumption that any psychological theory must model cognition in terms of its conceptual structure. Our question must be: Can we make sense of connectionism's claim to model cognition subsymbolically? -------------- NEXT WEEK'S CSLI TINLUNCH Harman's and Cherniak's Leniency on Agent Rationality Readings: "Change in View: Principles of Reasoning" by Gilbert Harman, chaps. 2 and 3 (MIT Press, 1986) and "Minimal Rationality" by Christopher Cherniak (MIT Press, 1986) Discussion led by Ronald Loui (loui@csli.stanford.edu) May 12 In two short chapters of CHANGE IN VIEW, Gil Harman (1) argues against the "special relevance" of logic to reasoning, and (2) dismisses normative theories that require (probabilistic) degrees of belief. Inconsistency is unavoidable, closure leads to clutter, and sometimes implication is immediate, but not logical. There exists all-or-nothing-belief, and "it is too complicated for mere finite beings to make extensive use of probabilities." Christopher Cherniak is more interested in "how stupid can you be" while still being describable as a rational agent. But he has also tried to let the agent off the normative hook. He argues that a condition of MINIMAL RATIONALITY must be fashioned for any satisfactory cognitive theorizing. Only inferences that are "feasible" and "apparently appropriate" need be made. I will focus on the Harman chapters, but will entertain Cherniak's blurring of the descriptive/normative distinction as well. -------------- NEXT WEEK'S CSLI SEMINAR What is Logic Programming? What is a Logic? Jose Meseguer (meseguer@csl.sri.com) May 12 During the past few years at CSLI, Joseph Goguen and I have proposed a broad view of logic programming that is open to different logics and rejects the identification of logic programming with one of its instances. This point of view has led to the design and implementation of the purely functional logic programming language OBJ, to the design of the Eqlog language that unifies functional and relational programming, and to the FOOPS and FOOPlog languages that extend OBJ and Eqlog with object-oriented capabilities. The development of natural language systems can be made much simpler by adopting this broad view of logic programming. Joseph Goguen has shown how the Goguen-Burstall theory of institutions can be applied to formalize logic programming languages and yields design principles for such languages. In this talk, I will report on some recent work of mine that builds on the previous joint work with Goguen and makes this view axiomatic by giving general axioms that a language should satisfy in order to be called a logic programming language. The question of what a logic programming language is leads us to the more fundamental question about how general logics should be axiomatized. Two main approaches to this question are: 1. A model-theoretic approach that takes the satisfaction relation between models and sentences as basic, and is exemplified by the Barwise axioms for abstract model theory and the Goguen-Burstall axioms for institutions. 2. A proof-theoretic approach that takes the entailment relation between sets of sentences as basic and is exemplified by the work of Tarski on consequence relations and the entailment axioms of Scott. Neither of these approaches is by itself sufficient to axiomatize logic programming. In the talk I will present an axiomatization that unifies both approaches and yields the desired axioms for logic programming. I will also discuss how languages based on higher-order type theory can be included in this framework. ------------------------------ Date: Tue, 10 May 88 01:09 EDT From: Ron Nash <nash@csli.STANFORD.EDU> Subject: CSLI Reports The Spring 1988 catalog of reports published by The Center for the Study of Language and Information at Stanford University is now available online, in HyperCard format (for Macintosh computers). Abstracts are included. This is an update of (not a supplement to) the previous catalog. So if you missed the last edition, this one contains the complete list. The file is available by anonymous ftp from csli.stanford.edu The relevant file is: pub/csli-abstracts.hqx Those without internet access can send a 3.5" disk and a self-addressed envelope to: Publications CSLI Ventura Hall Stanford University Stanford, CA 94305-4115 (CSLI was founded in 1983 by researchers from Stanford University, SRI International, and Xerox PARC to further research and development of integrated theories of language, information, and computation.) Ron Nash Center for the Study of Language and Information Stanford University nash@russell.stanford.edu ------------------------------ Date: Thu, 12 May 88 13:00 EDT From: Emma Pease <emma@russell.stanford.edu> Subject: From CSLI Calendar, May 12, 3:28 Reading: "Even" by Paul Kay Discussion led by Mark Gawron (gawron@csli.stanford.edu) May 19 This is one of several papers assuming the outlook of Construction Grammar, which takes the analysis of the semantic and syntactic properties of constructions as central, and takes the analysis of a sentence to be the unification of the constructions in it. As the primitive grammatical units, constructions here take on the role of lexical items in other linguistic theories. This paper focuses on the semantic and pragmatic properties of the "construction" EVEN; Kay invokes what he calls a scalar model, which he has elsewhere used to explicate the notion of informativeness crucial for Grice's Maxim of Quantity. If Kay's analysis is right, a correct account of the use of EVEN in an utterance will make it an operation on the proposition expressed by that utterance, another proposition Kay calls the context proposition, and a particular scalar model invoked for that occasion. This use of scalar models raises some issues about just what needs to be part of the context that the meaning of a word (or by extension, sentence) needs to operate on. ------------------------------ Date: Wed, 27 Apr 88 14:29 EDT From: Drew Mcdermott <dvm@YALE-BULLDOG.ARPA> Subject: Conference - AAAI Workshop on Plan Recognition CALL FOR PARTICIPATION WORKSHOP ON PLAN RECOGNITION AAAI-88, Minneapolis, Minnesota, Wednesday, August 24. Radisson-St. Paul Hotel Plan recognition is a touchstone issue for Artificial Intelligence, which has generated thorny problems and theoretical results for years. The class of problems we have in mind is to infer a goal-based explanation of the behavior of one or more actors. This class can be extended to closely related problems like inferring an author's plans from a text, inferring a programmer's plans from his code, or inferring explanations of new bug types from case histories. Problems of this sort often seem to lie at the heart of intelligence, because people can apparently select just the right explanatory principles from large knowledge bases. For that reason, this problem area has encouraged interest in nontraditional control structures such as marker passing, parallelism, and connectionism. To date, however, no decisive solutions have been obtained. The workshop will aim at bringing together individuals working in all the active areas related to plan recognition, as well as individuals trying to exploit research results for practical applications. This interaction should prove fruitful for both groups. Contributors interested in participating in this workshop are requested to submit a 1000-2000 word extended abstract of their work, describing its relevance to the topic of plan recognition. The workshop attendance will be limited to 35, and all participants will present their work, either in an oral presentation, or in a poster session. Abstracts will be refereed by the organizing committee. Copies of the chosen abstracts will be sent to each participant prior to the workshop. Presenters shall have the opportunity to expand their abstracts for inclusion in a workshop proceedings to be published later. Extended abstracts should be received prior to June 3, 1988. Mail them to: Jeff Maier TASC 2555 University Blvd. Fairborn, Ohio 45324 (513)426-1040 Authors will be notified of the status of their papers by July 8, 1988. Organizing Committee: Larry Birnbaum, Yale University Doug Chubb, US Army, Center for Signals Warfare Jeff Maier, TASC Drew McDermott, Yale University Bob Wilensky, UC Berkeley Steve Williams, TASC ------------------------------ End of NL-KR Digest *******************