Madalina Croitoru

Default Conceptual Graph Rules: Preliminary Results for an Agronomy Application

In this paper, we extend Simple Conceptual Graphs with Reiters default rules. The motivation for this extension came from the type of reasonings involved in an agronomy application, namely the simulation of food processing. Our contribution is many fold: first, the expressivity of this new language corresponds to our modeling purposes. Second, we provide an effective characterization of sound and complete reasonings in this language. Third, we identify a decidable subclass of Reiters default logics. Last we identify our language as a superset of

A Viewpoint Approach to Structured Argumentation

mathcal{SREC}^-

Distinguishing Answers in Conceptual Graph Knowledge Bases

, and provide the lacking semantics for the latter language.

Representing and Reasoning about Different Viewpoints: An Agronomy Application

We introduce in this paper a viewpoint-based argumentation approach in the context of the EcoBioCap project, which requirements are different actor arguments expressed over several criteria, describing the objects of a domain, to support/oppose contradictory goals. A viewpoint is an ASPIC+ argumentation system defined over a subset of rules corresponding to a single criterion. Concepts of conflict between viewpoints, independent viewpoints, and collection of independent viewpoints are the basis of our argumentation approach.

On Ontological Expressivity and Modelling Argumentation Schemes Using COGUI

In knowledge bases (KB), the open world assumption and the ability to express variables may lead to an answer redundancy problem. This problem occurs when the returned answers are comparable. In this paper, we define a framework to distinguish amongst answers. Our method is based on adding contextual knowledge extracted from the KB. The construction of such descriptions allows clarification of the notion of redundancy between answers, based not only on the images of the requested pattern but also on the whole KB. We propose a definition for the set of answers to be computed from a query, which ensures both properties of non-redundancy and completeness. While all answers of this set can be distinguished from others with a description, an open question remains concerning what is a good description to return to an end-user. We introduce the notion of smart answer and give an algorithm that computes a set of smart answers based on a vertex neighborhood distance.

Aide à la décision en ingénierie inverse : une approche s'appuyant sur l'argumentation

Real-world applications are often complex systems where several ways of analysing a given situation can be expressed, depending on actors viewpoints. This paper proposes a semantically sound syntactic extension to Conceptual Graphs, namely Conceptual Graph Assemblies (CGAs), that allows the representation of multiple viewpoints on the same situation. Several reasoning mechanisms, based on the projection operation, corresponding to different strength levels and adapted to multi-viewpoints situations are then demonstrated. Several modelling scenarios are then proposed and our work is put in the context of real world examples from the agri-food domain.

Research and Development in Intelligent Systems XXVII

Knowledge elicitation, representation and reasoning explanation by/to non computing experts has always been considered as a crafty task due to difficulty of expressing logical statements by non logicians. In this paper, we use the COGUI editor in order to elicit and represent Argumentation Schemes within an inconsistent knowledge base. COGUI is a visual, graph based knowledge representation editor compatible with main Semantic Web languages. COGUI allows for default reasoning on top of ontologies. We investigate its use for modelling and reasoning using Argumentation Schemes and discuss the advantages of such representation. We show how this approach can be useful in the practical setting of EcoBioCap where the different Argumentation Schemes can be used to lead reasoning.

Définition de la sémantique des clés dans le Web sémantique : un point de vue théorique

Evaluating food quality is a complex process since it relies on numerous criteria historically grouped into four main types: nutritional, sensorial, practical and hygienic qualities. They may be completed by other emerging preoccupations such as the environmental impact, economic phenomena, etc. However, all these aspects of quality and their various components are not always compatible and their simultaneous improvement is a problem that sometimes has no obvious solution, which corresponds to a real issue for decision making. This paper proposes a decision support method in reverse engineering, i.e. guided by the objectives defined for the end products of an agrifood chain. It is materialized by a backward chaining approach based on argumentation.