The International Conference on Principles of Knowledge Representation and Reasoning is an A* conference with focus on knowledge representation and reasoning methods for AI like automated planning, natural language understanding, robotics, semantic web and the development of software agents. Our following two papers have been accepted for publication:
Tjitze Rienstra, Claudia Schon, Steffen Staab: Concept contraction in the description logic EL.
In this paper we study the problem of concept contraction for the description logic EL. Concept contraction is concerned with the following question: Given two concepts C and D (with the interesting case being that D subsumes C) how can we find a generalisation of C that is not subsumed by D but is otherwise as similar as possible to C? We take an AGM-style approach and model this problem using the notion of a concept contraction operator. We consider constructive definitions as well as sets of postulates for concept contraction, and link the two by means of representation theorems.
Nico Potyka: Bipolar abstract argumentation with dual attacks and supports.
Bipolar abstract argumentation frameworks allow modeling decision problems by defining pro and contra arguments and their relationships. In some popular bipolar frameworks, there is an inherent tendency to favor either attack or support relationships. However, for some applications, it seems sensible to treat attack and support equally. Roughly speaking, turning an attack edge into a support edge, should just invert its meaning. We look at a recently introduced bipolar argumentation semantics and two novel alternatives and discuss their semantical and computational properties. Interestingly, the two novel semantics correspond to stable semantics if no support relations are present and maintain the computational complexity of stable semantics in general bipolar frameworks.