Using Ontologies to Structure Ontology-Centric Multi-Agent Systems (OCMAS)

Abstract

Designing a multi-agent system requires complete knowledge regarding the domain. A methodology is required that allows us to adapt to the changes in the system without restructuring it. Due to ever changing system requirements the behavior of the agents may need to change frequently. Such changes often require costly system redesigning and coding. Therefore a framework (OCMAS) is proposed to define the behavior of agents in a frame-based ontology where agents are created with a set number of abilities. The behavior or manner of exactly how they do their job is defined in the ontology. When initialized an agent looks up into the ontology which defines exactly how the behavior is executed. However, the actual realization of an agent‟s behavior is implemented in a rule-engine that is configured from the ontology. We described a group of agent abilities and collaboration mechanisms in an ontology and then tested it by altering the behavior through editing the ontology. Two prototype multi-agent auction systems have been developed as proof of concept. One uses the conventional JADE approach and the second uses the proposed model which allows the creation of reconfigurable agent behaviors at real-time from one auction protocol to another. The evaluation showed that system has the potential to successfully change the agent‟s behavior. In terms of system performance, the results indicated that with sufficient resources in terms of memory and CPU, the system works reasonably efficiently.