P. Liberatore and M. Schaerf. Brels: A system for the integration of knowledge bases. In A. Cohn, F. Giunchiglia, and B. Selman, editors, Proceedings of the Seventh International Conference on the Principles of Knowledge Representation and Reasoning, pages 145--152. Morgan Kaufmann Publishers, 2000.  Home/Search   Document Details and Download   Summary   Related Articles   Check

.... data (e.g. 14, 41] are often based on a paraconsistent reasoning process, such as LFI [13] annotated logics [30, 40] or other non classical proof systems [5, 37] Coherent (consistency base) methods, in which the amalgamated data is revised in order to restore consistency (see, e.g. [6, 8, 11, 25, 31]) In many cases the underlying formalism of these approaches are closely related to the theory of belief revision [1, 23] In the context of database systems the idea is to construct consistent databases that are as close as possible to the original database. These repaired instances of the ....

....and or useless. For instance, the inconsistency in (D; IC) fp; q; rg; f:pg) may be removed by deleting every element in D, but this is certainly not the optimal way of restoring consistency in this case. Set inclusion is also considered in [3, 11, 14, 25] cardinality is considered, e.g. in [31] Note that if DB is consistent, and the preference criterion is a partial order that is monotonic in the total size of the repairs components (as in Def. 6) then R(DB; fDBg, so there is nothing to repair, as expected. It is usual to refer to the preferred databases of DB as the consistent ....

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P.Liberatore, M.Schaerf. BReLS: a system for the integration of knowledge bases. Proc. KR'2000 , pp.145-152, 2000.

....tractable restrictions seems a hard task since intractability is still the case in many restricted situations. Finally, our results show that some syntaxbased merging operators (based on set inclusion in However, 4 d H ;sum;sum ) 2 2 can be recovered from a complexity result given in [Liberatore and Schaerf, 2000] , page 151. Table 4: Complexity results (d = dHq ) max sum stead of cardinality and located at the 2 nd level of PH) cannot be encoded in polynomial time as distancebased operators (unless PH collapses) 5 LOGICAL PROPERTIES Since we aim ....

P. Liberatore and M. Schaerf. Brels: a system for the integration of knowledge bases. In Proc. of KR'00, pages 145-152, 2000.

....la hi erarchie polynomiale ne s effondre) Notre cadre fournit donc une vision diff erente des op erateurs de fusion que la dichotomie habituelle modelbased syntax based . Bien que (4 d H ;sum;sum IC (E) j= ff) 2 Delta 2 puisse etre retrouv e a partir de r esultats de complexit e de [18]. 5 Caract erisation axiomatique des op erateurs Donner la d efinition de nouveaux op erateurs n est pas suffisant si l on n indique pas leurs propri et es logiques. En effet, pour pouvoir choisir tel ou tel op erateur pour une application pr ecise, il faut pouvoir avoir une id ee du ....

P. Liberatore and M. Schaerf. Brels: a system for the integration of knowledge bases. In Proc. of KR'00, pages 145--152, 2000.

....that what is obtained would properly re ect the combination of the distributed data on one hand , and would still be coherent (in terms of consistency) on the other hand. Coherent integration and proper representation of amalgamated data is extensively studied in the literature (see, e.g. [1, 3, 7, 13, 14, 20 23, 26, 29]) Common approaches for dealing with this task are based on techniques of belief revision [20] methods of resolving contradictions by quantitative considerations (such as majority vote [21] or qualitative ones (e.g. de ning priorities on di erent sources of information or preferring certain ....

....coherent (in terms of consistency) on the other hand. Coherent integration and proper representation of amalgamated data is extensively studied in the literature (see, e.g. 1, 3, 7, 13, 14, 20 23, 26, 29] Common approaches for dealing with this task are based on techniques of belief revision [20], methods of resolving contradictions by quantitative considerations (such as majority vote [21] or qualitative ones (e.g. de ning priorities on di erent sources of information or preferring certain data over another [2, 4, 5] Other approaches are based on rewriting rules for representing ....

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P.Liberatore, M.Schaerf. BReLS: a system for the integration of knowledge bases. Proc KR'2000 , 145-152, 2000.

....that we call belief extrapolation. This operator takes a sequence of observations assumed to hold for certain and projects these observations forwards and backwards, assuming that fluents tend to persist throughout time. Such operators are not completely new (they have been considered in [3] and [17] see the related work Section) The basic assumptions for extrapolation operators are the following two ones: 1. the agent can only observe some properties at some time points, but does not have the ability of performing actions; furthermore, if events occur, they are perceived by the agent ....

....beliefs across time should involve both of them. This helps us assessing the respective positions of belief update and belief extrapolation in Sandewall s taxonomy of logically represented dynamical systems. Connections with several other works, including pioneering works on extrapolation [3] and [17], are investigated in Section 6. 2 BELIEF EXTRAPOLATION 2.1 SCENARIOS AND TRAJECTORIES Let L be a propositional language built from a finite set of propositional variables V = fv 1 ; v ng, the usual connectives, and the Boolean constants (tautology) and (contradiction) M = 2 is the ....

[Article contains additional citation context not shown here]

P. Liberatore and M. Schaerf. Brels: A system for the integration of knowledge bases. In Proc. of KR'00, pages 145--152, 2000.

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P. Liberatore and M. Schaerf. Brels: A system for the integration of knowledge bases. In A. Cohn, F. Giunchiglia, and B. Selman, editors, Proceedings of the Seventh International Conference on the Principles of Knowledge Representation and Reasoning, pages 145--152. Morgan Kaufmann Publishers, 2000.

No context found.

P. Liberatore and M. Schaerf. Brels: A system for the integration of knowledge bases. In A. Cohn, F. Giunchiglia, and B. Selman, editors, Proceedings of the Seventh International Conference on the Principles of Knowledge Representation and Reasoning, pages 145--152. Morgan Kaufmann Publishers, 2000.

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