Knowledge representation in the ontological engineering using conceptual modeling and graph-based reasoning

The process of software engineering follows a few basic stages of development: the business system analysis, the design of the new software solution, the software development with correctness verification and, finally, the software implementation in a user environment. Ontological engineering is also considered through the basic engineering steps. It can be perceived as a support for the process of developing information systems through two aspects: the conceptual modeling and the formal implementation. The conceptual knowledge is a representation of knowledge of considering the business system domain. Tools and languages for building formal ontology support the knowledge representation described with the conceptual model. The integration of ontological engineering in software engineering can be considered as the improvement in the development, implementation and use of the information system.In this paper, the knowledge representation and reasoning formalism of ontology are presented with a graph-based formalism. This formalism is logically founded, and it is a key feature for knowledge representation and reasoning.An ontology lifecycle development starts with competency questions about the domain specification. The specification of concepts and basic relationships by a conceptual graph model are the foundations for the modeling of formal ontology elements such as rules and constraints. Complex queries derived from competency questions are also presented with graph-based formalism. Relations between graphs like specializations and generalization operations, and also mapping like homomorphism, will optimize the ontology structure. The described process of ontology development is applied to a case of education domain modeling.