CoBase: a scalable and extensible cooperative information system

摘要: A new generation of information systems that integrates knowledge base technology with database is presented for providing cooperative (approximate, conceptual, and associative) query answering. Based on the schema application characteristics, data are organized into Type Abstraction Hierarchies (TAHs). The higher levels hierarchy provide a more abstract representation than lower levels. Generalization (moving up in hierarchy), specialization down association between hierarchies) three key operations deriving answers user. context, TAHs can be constructed automatically from databases. An intelligent dictionary/directory system lists location characteristics (e.g., context user type) TAHs. CoBase also has relaxation manager to control relaxations. In addition, an explanation included describe processes quality relaxed answers. uses mediator architecture scalability extensibility. Each module, such as relaxation, association, explanation, TAH management, implemented mediator. Further, directory provided direct requests appropriate service mediators. Mediators communicate each other via KQML. GUI includes map server which allows users specify queries graphically incrementally map, greatly improving querying capabilities. been demonstrated answer imprecise transportation logistic planning applications. Currently, we applying methodology match medical image (X-ray, MRI) features approximate matching emitter signals electronic warfare