Towards a non monotonic description logics model

In order to deal with the Ontology Change problem and considering an environment where Description Logics (DLs) are used to describe ontologies, the question of how to integrate distributed ontologies appears to be in touch with Belief Revision since DL terminologies may define same concept descriptions of a not necessarily same world model. A possible alternative to reason about these concepts is to generate unique concept descriptions in a different terminology. This new terminology needs to be consistently created, trying to deal with the minimal change problem, and moreover, yielding a non-monotonic layer to express ontological knowledge in order to be further updated with new distributed ontologies.VII Workshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

On the use of belief revision to merge description logic terminologies

Distributed ontologies expressed as description logics may define repeated information. To reason about concepts that these ontologies express, a possible option is to generate unique concept definitions in a different terminology or TBox. The creation of a new terminology from different ontologies need to be consistent, and expressed with non-monotonic logics to be further updated with new distributed ontologies. The model AGM of theory change seems to be an interesting framework to be studied in conjunction with description logics and generate a new non-monotonic description logics model.Eje: Agentes y Sistemas InteligentesRed de Universidades con Carreras en Informática (RedUNCI

Datalog± Ontology Consolidation

Knowledge bases in the form of ontologies are receiving increasing attention as they allow to clearly represent both the available knowledge, which includes the knowledge in itself and the constraints imposed to it by the domain or the users. In particular, Datalog ± ontologies are attractive because of their property of decidability and the possibility of dealing with the massive amounts of data in real world environments; however, as it is the case with many other ontological languages, their application in collaborative environments often lead to inconsistency related issues. In this paper we introduce the notion of incoherence regarding Datalog± ontologies, in terms of satisfiability of sets of constraints, and show how under specific conditions incoherence leads to inconsistent Datalog ± ontologies. The main contribution of this work is a novel approach to restore both consistency and coherence in Datalog± ontologies. The proposed approach is based on kernel contraction and restoration is performed by the application of incision functions that select formulas to delete. Nevertheless, instead of working over minimal incoherent/inconsistent sets encountered in the ontologies, our operators produce incisions over non-minimal structures called clusters. We present a construction for consolidation operators, along with the properties expected to be satisfied by them. Finally, we establish the relation between the construction and the properties by means of a representation theorem. Although this proposal is presented for Datalog± ontologies consolidation, these operators can be applied to other types of ontological languages, such as Description Logics, making them apt to be used in collaborative environments like the Semantic Web.Fil: Deagustini, Cristhian Ariel David. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; ArgentinaFil: Martinez, Maria Vanina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; ArgentinaFil: Falappa, Marcelo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; ArgentinaFil: Simari, Guillermo Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; Argentin

Towards a non monotonic description logics model

In order to deal with the Ontology Change problem and considering an environment where Description Logics (DLs) are used to describe ontologies, the question of how to integrate distributed ontologies appears to be in touch with Belief Revision since DL terminologies may define same concept descriptions of a not necessarily same world model. A possible alternative to reason about these concepts is to generate unique concept descriptions in a different terminology. This new terminology needs to be consistently created, trying to deal with the minimal change problem, and moreover, yielding a non-monotonic layer to express ontological knowledge in order to be further updated with new distributed ontologies.VII Workshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

Tableau calculi for description logics revision

Focusing on the Ontology Change problem, we consider an environment where Description Logics (DLs) are the logical formalization to express knowledge bases, and the integration of distributed ontologies is developed under new extensions and modifications of the Belief Revision theories yielded originally in [2]. When using tableaux algorithms to reason about DLs, new information is yielded from the models considered in order to achieve knowledge satisfiability. Here a whole new theory have to be reinforced in order to adapt belief revision definitions and postulates to properly react over beliefs on extensions generated from these DL’s reasoning services. In this text we give a brief background of these formalisms and comment the research lines to be taken in our way to this goal.Eje: Agentes y Sistemas InteligentesRed de Universidades con Carreras en Informática (RedUNCI

On the use of belief revision to merge description logic terminologies

Distributed ontologies expressed as description logics may define repeated information. To reason about concepts that these ontologies express, a possible option is to generate unique concept definitions in a different terminology or TBox. The creation of a new terminology from different ontologies need to be consistent, and expressed with non-monotonic logics to be further updated with new distributed ontologies. The model AGM of theory change seems to be an interesting framework to be studied in conjunction with description logics and generate a new non-monotonic description logics model.Eje: Agentes y Sistemas InteligentesRed de Universidades con Carreras en Informática (RedUNCI

Ontology merging using belief revision and defeasible logic programming

We combine argumentation, belief revision and description logic ontologies for extending the -ontologies framework to show how to merge two ontologies in which the union of the strict terminologies could lead to inconsistency. To solve this problem, we revisit a procedure presented by Falappa et al. in which part of the o ending terminologies are turned defeasible by using a kernel revision operator.Eje: Workshop Agentes y sistemas inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

A preliminary investigation on a revision-based approach to the status of warrant

In this article we are presenting a new perspective on the matter of belief revision by its relation to argumentation systems. Our approach is based on the argumentative formalism Defeasible Logic Programming, and therefore we propose a revision of a defeasible logic program by an argument. The revision operators here introduced are de ned as prioritized, since they ensure warrant of the conclusion of the argument being added to the program following a particular minimal change principle. To achieve this, we give two different approaches: one regarding arguments in the classical sense, whereas the other considers the revision by arguments that also include strict rules and facts. Finally, a brief discussion about the relation between our approach and the basic theory of belief revision is exposed, along with a description of other possible minimal change principles.Red de Universidades con Carreras en Informática (RedUNCI

An comparative analysis of different models of belief revision using information from multiple sources

In this work we analyze the problem of knowledge representation in a collaborative multi-agent system where agents can obtain new information from others through communication. Namely, we analyze several approaches of belief revision in multi-agent systems. We will describe different research lines in this topic and we will focus on Belief Revision using Information from Multiple Sources. For this, we are going to accomplish a comparative analysis of different models of belief revision that use information from multiple sources.Workshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

Handling inconsistency on ontologies through a generalized dynamic argumentation framework

In this article we present a generalized dynamic argumentation framework that handles arguments expressed in an abstract language assumed to be some first order logic fragment. Once the formalism is presented, we propose a reification to the description logic ALC with the intention to handle ontology debugging. In this sense, since argumentation frameworks reason over graphs that relate arguments through attack, our methodology is proposed to bridge ontological inconsistency sources to attack relations in argumentation. Finally, an argumentation semantics is proposed as a consistency restoration tool to cope with the ontology debugging.Workshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI