Brachman, R.J., McGuinness, D.L., Patel-Schneider, P.F., Borgida, A. (1999). "Reducing" CLASSIC to practice: Knowledge representation theory meets reality. Artifical Intelligence 114:203-237.  Home/Search   Document Not in Database   Summary   Related Articles   Check

.... early formal investigations into the complexity of reasoning in DLs showed that most DLs do not have polynomial time inference problems [18, 63] As a reaction, the implementors of the Classic system (the first industrial strength DL system) carefully restricted the expressive power of their DL [69, 17]. Phase 2 (1990 1995) started with the introduction of a new algorithmic paradigm into DLs, so called tableau based algorithms [75, 32, 48] They work on propositionally closed DLs (i.e. DLs with full Boolean operators) and are complete also for expressive DLs. To decide the consistency of a ....

R. J. Brachman. "reducing" CLASSIC to practice: Knowledge representation meets reality. In Proc. of the 3rd Int. Conf. on the Principles of Knowledge Representation and Reasoning (KR-92), pages 247--258. Morgan Kaufmann, Los Altos, 1992. 18

.... cNZ.setAdministrativeDivisionSetKnown(false) rNZ.setAs admin divisionKnown(false) Similar mechanisms for handling incomplete knowledge have been used in knowledge representation systems LOOM [19] which includes :closed world and :open world relation properties) and CLASSIC [20] (which allows roles to be declared to be closed ) This notion has also been formalised in description logic by the use of epistemic operators that modify roles, and in AI planning by the use of local closed world formulae [21] The notClosedOn property used in this work should also include a ....

R. J. Brachman, D. L. McGuinness, P. F. Patel-Schneider, and A. Borgida. "Reducing" CLASSIC to practice: Knowledge representation theory meets reality. Artificial Intelligence, 114(1--2):203--237, 1999.

.... constructors [23] Therefore, they cannot express di erent categories of analyst concepts such as entities, relationships, processes, objects [15] Specialised semantic systems They provide specialised deductive services (e.g. concept classi cation) other than semantic consistency check [20, 5]. However, although they represent a substantial improvement over general purpose semantic systems, they fail to provide distinct versions of them on a category basis. Only in a few cases some speci c customisation mechanisms exist which can give rise to the expected inferential behaviour [3] ....

R. J. Brachman et al. Reducing CLASSIC to Practice: Knowledge Representation Meets Reality. Articial Intelligence, 114(12):203237, 1999.

....been such an lcw formula, the agent would have concluded that it didn t know. 15 1.3. 4 Local Closed World Reasoning The notion of closed world reasoning is not new; the information in L lcw database is equivalent to the closed roles found in knowledge representation systems such as classic [2] and loom [3] to predicate completion axioms [8, 46] and, as we mentioned, circumscription axioms [59, 56] However, none of the earlier work was well suited to the needs of a planner based agent, i.e. the ability to express and efficiently reason about the changes to the agent s closed world ....

R. Brachman. "Reducing" classic to Practice: Knowledge Representation Theory Meets Reality. In Proc. 3rd Int. Conf. on Principles of Knowledge Representation and Reasoning, October 1992.

....showed the incompleteness of the (polynomial) structural subsumption algorithms. One reaction to these results (e.g. by the designers of Back and Loom) was to call the incompleteness of the subsumption algorithm a feature rather than a bug of the DL system. The designers of the Classic system [42, 9] followed another approach: they carefully chose a restricted DL that still allowed for an (almost) complete polynomial structural subsumption algorithm [8] Phase 3: Tableau algorithms for expressive DLs and thorough complexity analysis. For expressive DLs (in particular, DLs allowing for ....

Ronald J. Brachman. "Reducing" CLASSIC to practice: Knowledge representation meets reality. In Proc. of KR-92, pages 247--258. Morgan Kaufmann, 1992.

....can easily have hundreds of ramifications. It was complicated applications such as these that drove our work on access to information. We have discussed some of the above mentioned usability issues in separate papers, and they have played at prominent role in at least one major presentation [ 6 ] , but there are new issues and new insights in this paper, springing from our continued experience in the use of the classic family of applications. This paper brings together these issues in one place and directly comments on their role in the usability of knowledge representation systems. 2 ....

Ronald J Brachman. "Reducing" CLASSIC to practice: Knowledge representation theory meets reality. In Proceedings of the Third International Conference on Principles of Knowledge Representation and Reasoning, pages 247--258, Cambridge, Massachusetts, October 1992. Morgan Kaufmann.

.... To solve this problem we utilize an explicit database of meta level sentences such as I know all the files in kr94, which encode local closed world information (LCW) The information in this database is equivalent to the closed roles found in knowledge representation systems such as classic [2], loom [3] to predicate completion axioms [4, 20] and to circumscription axioms [26, 23] Indeed, work on autoepistemic logic (e.g. 27, 22] and circumscription (e.g. 19, 8, 33] has investigated the logic of closed world reasoning over arbitrary first order theories, but without considering ....

R. Brachman. "Reducing" classic to Practice: Knowledge Representation Theory Meets Reality. In Proceedings of KR-92, October 1992.

....(# linked with entity) 3.2 Implementation GenEd is implemented in Common Lisp using the Common Lisp Object System (CLOS) and the Common Lisp Interface Manager (CLIM) as interface toolkit. The classification of concepts and individuals takes place by using the lisp implementation of Classic [ 6; 7 ] as DL system. GenEd consists of 28 modules with a total of about 300 KB source code (without CLIM, CLOS, and Classic) 3.3 User Interface The general procedure for working with GenEd is as follows. The user loads a domain dependent knowledge base (KB) into GenEd. This KB has to comply to ....

R.J. Brachman, ""Reducing" CLASSIC to Practice: Knowledge Representation Theory Meets Reality ", in Principles of Knowledge Representation and Reasoning, Third International Conference, Cambridge, Mass., Oct. 25-29, 1992, Oct. 1992, pp. 247--258.

.... this problem we utilize an explicit database of meta level sentences such as I know the lengths of all files in kr94, which encode local closed world information (LCW) The information in this database is equivalent to the closed roles found in knowledgerepresentation systems such as classic (Brachman 1992) and loom (Brill 1991) to predicate completion axioms (Clark 1978; Kowalski 1978) and to circumscription axioms (McCarthy 1980; Lifschitz 1985) Indeed, there is a large body of previous work on the logic of closed world reasoning (e.g. Konolidge 1982; Etherington 1988; Reiter 1982; Moore ....

R. Brachman. "Reducing" classic to Practice: Knowledge Representation Theory Meets Reality. In Proc. 3rd Int. Conf. on Principles of Knowledge Representation and Reasoning, October 1992.

....such as I know all the files in kr94. The sentences describe the limited instances over which the information in M is in fact a complete model of the external world. The information in the LCW database is equivalent to the closed roles found in knowledge representation systems such as classic [2] and loom [3] to predicate completion axioms [6, 27] and to circumscription axioms [33, 32] Our contributions include: ffl A sound and efficient calculus for answering queries based on the LCW database. The calculus answers queries such as: if the agent is familiar with all the files in the ....

R. Brachman. "Reducing" classic to Practice: Knowledge Representation Theory Meets Reality. In Proc. 3rd Int. Conf. on Principles of Knowledge Representation and Reasoning, October 1992.

....First of all, the study of the computational behavior of concept languages has led to a clear understanding of the properties of the language constructs and their interaction. This is not only valuable from a theoretical viewpoint, but gives insights to the designer of a TKRS (see for example (Brachman, 1992)) with clear indications of the language constructs or their combinations that are difficult to deal with and general methods to cope with them. Second, the complexity results have been obtained by exploiting a general technique for satisfiability checking, which relies on a form of tableaux ....

Brachman, R. J. (1992). "Reducing" CLASSIC to practice: Knowledge representation meets reality. In Proceedings of the Third International Conference on the Principles of Knowledge Representation and Reasoning (KR-92), pages 247--258. Morgan Kaufmann, Los Altos.

....results in a more informed situation. Note that situations should desirably satisfy other domain dependent properties like persistency of the objects, coherence of the trajectories according to speed laws, etc. not addressed here. 3 Representing actions 3. 1 Modeling choices Following classical approaches in Plan Recognition [Kautz, Cohen] plans are seen as collections of actions together with temporal constraints. We implicitly rely on the definition of plan specificity of [Weida Litman] As opposed to plans, actions will capture only time invariant knowledge about the situations 1 ....

....of qualitative attitudes. Instead, if the trajectories were qualitatively invariant during the observation period of the situation then the same qualitative attitudes would be recognized in any sub situation and the situation and its sub situations would have the same MSA s. We slightly extend the classical notion of homogeneity time invariance to a monotonicity condition of the qualitative attitudes. Definition 5 Let E be a typed environment. A situation S in E is said homogeneous iff: 8(o 1 ; t 1 ; p 1 ) 2 S; 8(o 2 ; t 2 ; p 2 ) 2 S; 8q 1 2 P; 8q 2 2 P; q 1 p 1 ; q 2 p 2 ) RA(p ....

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R.Brachman, "Reducing" CLASSIC to Practice: Knowledge Representation Theory Meets Reality, KR'92, pp 247-58, 1992.

....be saved in and loaded from a file. 3.2 Implementation GenEd is implemented in Common Lisp using the Common Lisp Object System (CLOS) and the Common Lisp Interface Manager (CLIM) as interface toolkit. The classification of concepts and the parsing of actual drawings take place by using CLASSIC [9, 10] as DL system. CLASSIC is also implemented in Common Lisp. GenEd consists of 28 modules with a total of about 300 KB source code (without CLIM, CLOS, and CLASSIC) GenEd is fully implemented with the features described in this paper. 3.3 Example Session We demonstrate two visual notations whose ....

R.J. Brachman, ""Reducing" CLASSIC to Practice: Knowledge Representation Theory Meets Reality", in Principles of Knowledge Representation and Reasoning, Third International Conference, Cambridge, Mass., Oct. 25-29, 1992, Oct. 1992, pp. 247--258.

....percent AI. The AI is critical but we cannot ignore the context into which it is embedded. Patrick Winston has called this the raisin bread model of AI. If we want to bake raisin bread, we cannot focus exclusively on the raisins. 2 Operating on a shoestring budget, we have been able 2 See (Brachman 1992) for an account of the massive re engineering necessary to transform an intelligent first knowledge representation system into a usable one. BargainFinder Rodney Sims InfoManifold Rodney Simon MetaCrawler ILA Occam Ahoy ShopBot Occam Figure 2: The Softbot Family Tree. The black boxes ....

Brachman, R. 1992. "Reducing" classic to Practice: Knowledge Representation Theory Meets Reality. In Proc. 3rd Int. Conf. on Principles of Knowledge Representation and Reasoning.

....sentences such as I know all the files in kr94. The sentences describe the limited instances over which M is in fact a complete theory of the external world. The information in the LCW database is equivalent to the closed roles found in knowledge representation systems such as classic [2] and loom [3] to predicate completion axioms [6, 30] and to circumscription axioms [36, 35] 1.1 Contributions While the notion of closed world reasoning appears in previous work, our novel contributions include the following: ffl A sound and incomplete calculus for answering queries based on ....

R. Brachman. "Reducing" classic to Practice: Knowledge Representation Theory Meets Reality. In Proc. 3rd Int. Conf. on Principles of Knowledge Representation and Reasoning, October 1992.

....First of all, the study of the computational behavior of concept languages has led to a clear understanding of the properties of the language constructs and their interaction. This is not only valuable from a theoretical viewpoint, but gives insights to the designer of a TKRS (see for example [Bra92] with clear indications of the language constructs or their combinations that are difficult to deal with and general methods to cope with them. Second, the complexity results have been obtained by exploiting a general technique for satisfiability checking, which relies on a form of tableaux ....

Ronald J. Brachman. "Reducing" CLASSIC to practice: Knowledge representation meets reality. In Proceedings of the Third International Conference on the Principles of Knowledge Representation and Reasoning (KR-92), pages 247--258. Morgan Kaufmann, Los Altos, 1992.

....rule admits polynomial algorithms for consistency testing [53, 35] Both ideas received great attention both from the theoretical and from the applicationoriented community. The limited expressiveness strategy underlies the whole database approach. The CLASSIC Knowledge Representation system [4, 5], built at AT T and currently used in an industrial environment, uses both strategies. CLASSIC adopts a restricted language thus avoiding some sources of intractability but allows constructors that lead to intractable reasoning problems. Such constructors are dealt with incomplete inference ....

R. J. Brachman. "Reducing" CLASSIC to practice: Knowledge representation theory meets reality. In Proceedings of the Third International Conference on the Principles of Knowledge Representation and Reasoning (KR-92), pages 247--258, 1992.

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Ronald J. Brachman. \Reducing" CLASSIC to practice: Knowledge representation theory meets reality. In Nebel et al. [36], pages 247-258.

No context found.

Ronald J. Brachman, Alex Borgida, Deborah L. McGuinness, and Peter F. Patel-Schneider. "Reducing" CLASSIC to Practice: Knowledge Representation Theory Meets Reality. In Artificial Intelligence 114(1-2) pages 203-237, October, 1999. http://www.ksl.stanford.edu/people/dlm/papers/aij99-abstract.html.

.... have been the subject of continued attention in Arti cial Intelligence, both as a subject of theoretical studies (Borgida, 1994; Baader, 1996; Baader Sattler, 2000; Giacomo Lenzerini, 1996; Calvanese, Giacomo, Lenzerini, 1999b) and in applications (Artale, Franconi, Guarino, Pazzi, 1996; Brachman, McGuinness, Patel Schneider, Borgida, 1999; McGuinness Patel Schneider, 1998) More impressively, DLs have found applications in other areas involving information processing, such as databases (Borgida, 1995; Calvanese, Lenzerini, Nardi, 1999) semi structured data (Calvanese, Giacomo, Lenzerini, 1998, 1999a) information ....

Brachman, R., McGuinness, D., Patel-Schneider, P., & Borgida, A. (1999). \Reducing" CLASSIC to Practice: Knowledge Representation Theory Meets Reality. Articial Intelligence, 114 (1-2), 203-237.

No context found.

Brachman, R.J., McGuinness, D.L., Patel-Schneider, P.F., Borgida, A. (1999). "Reducing" CLASSIC to practice: Knowledge representation theory meets reality. Artifical Intelligence 114:203-237.

No context found.

Ronald J. Brachman. "Reducing" CLASSIC to practice: Knowledge representation theory meets reality. In Nebel et al. [19] , pages 247--258.

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