An expert system shell for aerospace applications

REX is an object-oriented, asynchronous, real-time expert system shell that can handle continuous streams of data, represent temporal knowledge, and perform process monitoring. REX has been developed to meet the challenges of the dynamic aerospace environment. The system´s distinguishing feature is a semantically rich temporal representation facility for both data and knowledge. It handles the matching and firing of two rule types for encoding temporal knowledge: clock synchronized rules and spanning rules. To handle simultaneous, disjointed events, we have adopted a multiple rule-firing model. Also, in REX, rules are objects-and they are stored, retrieved, and managed exactly like data objects-unlike conventional object-oriented expert system shells, where rules operate on top of objects and are treated differently from objects.<>