KNOWLEDGE REPRESENTATION AND DATABASE MANAGEMENT FOR CAD (CAD/CAM)
Abstract
Problems at the conceptual foundations of conceptual modelling for the design of database and knowledgebase systems are investigated. The irrealist view that "...there are many ways the world is, and every true description captures one of them" GOOD78 , is taken as descriptive of the problems facing design of integrated software systems. The realization that reality is not the problem, but that formulations of descriptions (through computer representational schema) of it are, leads to the investigation of certain formal-logical techniques for modelling descriptions. The relativity of description to a system, a certain way of taking things, implies that database and knowledgebase systems must have access to both the description and the system to make any sense of the reality being modelled. The proposal that constructional systems form a theoretical foundation on which to develop a knowledge representation paradigm for conceptual modelling that allows this is made here, apparently for the first time. Before developing a constructional system approach to conceptual modelling, a consideration of the requirements of CAD database systems is presented in the form of a functional specification. This fills a self-proclaimed gap in the CAD literature on database requirements for design databases EAST81b, SIDL80 . To experiment with the constructional system proposal a new data model, the Object-Relationship-Situation (ORS) model, is presented. ORS is a conceptual modelling tool that collects the information on the objects and relationships to be modelled in a database in another auxiliary database which serves as the conceptual schema. ORS operationalizes some of the aspects of the knowledge representation proposals contained herein, but stops short of providing the full power inherent in a constructional systems approach.
Degree
Ph.D.
Subject Area
Mechanical engineering|Artificial intelligence
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