19,878 research outputs found
Towards a General Argumentation System based on Answer-Set Programming
Within the last years, especially since the work proposed by Dung in 1995, argumentation has emerged as a central issue in Artificial Intelligence. With the so called argumentation frameworks (AFs) it is possible to represent statements (arguments) together with a binary attack relation between them.
The conflicts between the statements are solved on a semantical level by selecting acceptable sets of arguments. An increasing amount of data requires an automated computation of such solutions.
Logic Programming in particular Answer-Set Programming (ASP) turned out to be adequate to solve problems associated to such AFs.
In this work we use ASP to design a sophisticated system for the evaluation of several types of argumentation frameworks
A Parameterised Hierarchy of Argumentation Semantics for Extended Logic Programming and its Application to the Well-founded Semantics
Argumentation has proved a useful tool in defining formal semantics for
assumption-based reasoning by viewing a proof as a process in which proponents
and opponents attack each others arguments by undercuts (attack to an
argument's premise) and rebuts (attack to an argument's conclusion). In this
paper, we formulate a variety of notions of attack for extended logic programs
from combinations of undercuts and rebuts and define a general hierarchy of
argumentation semantics parameterised by the notions of attack chosen by
proponent and opponent. We prove the equivalence and subset relationships
between the semantics and examine some essential properties concerning
consistency and the coherence principle, which relates default negation and
explicit negation. Most significantly, we place existing semantics put forward
in the literature in our hierarchy and identify a particular argumentation
semantics for which we prove equivalence to the paraconsistent well-founded
semantics with explicit negation, WFSX. Finally, we present a general proof
theory, based on dialogue trees, and show that it is sound and complete with
respect to the argumentation semantics.Comment: To appear in Theory and Practice of Logic Programmin
A QBF-based Formalization of Abstract Argumentation Semantics
Supported by the National Research Fund, Luxembourg (LAAMI project) and by the Engineering and Physical Sciences Research Council (EPSRC, UK), grant ref. EP/J012084/1 (SAsSY project).Peer reviewedPostprin
Improving argumentation-based recommender systems through context-adaptable selection criteria
Recommender Systems based on argumentation represent an important proposal where the recommendation is supported by qualitative information. In these systems, the role of the comparison criterion used to decide between competing arguments is paramount and the possibility of using the most appropriate for a given domain becomes a central issue; therefore, an argumentative recommender system that offers an interchangeable argument comparison criterion provides a significant ability that can be exploited by the user. However, in most of current recommender systems, the argument comparison criterion is either fixed, or codified within the arguments. In this work we propose a formalization of context-adaptable selection criteria that enhances the argumentative reasoning mechanism. Thus, we do not propose of a new type of recommender system; instead we present a mechanism that expand the capabilities of existing argumentation-based recommender systems. More precisely, our proposal is to provide a way of specifying how to select and use the most appropriate argument comparison criterion effecting the selection on the userĀ“s preferences, giving the possibility of programming, by the use of conditional expressions, which argument preference criterion has to be used in each particular situation.Fil: Teze, Juan Carlos Lionel. Consejo Nacional de Investigaciones CientĆficas y TĆ©cnicas. Centro CientĆfico TecnolĆ³gico Conicet - BahĆa Blanca; Argentina. Universidad Nacional del Sur. Departamento de Ciencias e IngenierĆa de la ComputaciĆ³n; Argentina. Universidad Nacional de Entre RĆos; ArgentinaFil: Gottifredi, SebastiĆ”n. Consejo Nacional de Investigaciones CientĆficas y TĆ©cnicas. Centro CientĆfico TecnolĆ³gico Conicet - BahĆa Blanca; Argentina. Universidad Nacional del Sur. Departamento de Ciencias e IngenierĆa de la ComputaciĆ³n; ArgentinaFil: GarcĆa, Alejandro Javier. Consejo Nacional de Investigaciones CientĆficas y TĆ©cnicas. Centro CientĆfico TecnolĆ³gico Conicet - BahĆa Blanca; Argentina. Universidad Nacional del Sur. Departamento de Ciencias e IngenierĆa de la ComputaciĆ³n; ArgentinaFil: Simari, Guillermo Ricardo. Consejo Nacional de Investigaciones CientĆficas y TĆ©cnicas. Centro CientĆfico TecnolĆ³gico Conicet - BahĆa Blanca; Argentina. Universidad Nacional del Sur. Departamento de Ciencias e IngenierĆa de la ComputaciĆ³n; Argentin
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