An object oriented canonical form for reusable knowledge bases /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1991.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | An object-oriented Canonical Form (CF) is proposed to facilitate reuse of knowledge bases (KBs). The research described focuses specifically on KBs created with the aid of commercial expert system building tools (ESBTs). Two types of knowledge reuse are of particular interest. Knowledge transfer occurs when an entire source KB constructed with one ESBT is translated into a target KB suitable for another ESBT. In knowledge cooperation two ESs exchange knowledge while collaborating on a solution for some problem. One difficulty for knowledge transfer is that all knowledge must be translated from the source KB to the target KB. When KBs include unique features from ESBTs, the developer will probably be required to tune the target KB further before it is operational. Knowledge cooperation, however, could reuse all knowledge contained in the KBs of cooperating ESs if communication is limited to simple exchanges that reflect responses to complex questions. Various arguments are given to justify knowledge reuse and especially why an object-oriented approach is desirable. The CF serves as an intermediate representation through which knowledge is translated when reused. The immediate benefit from using a CF is that the number of knowledge translators needed is reduced from N(N-1) to 2N. Knowledge representation features of several representative ESBTs were thoroughly analyzed as a prelude to designing the CF. Features investigated include lexical characteristics, data types, facts, and rules. Findings from this analysis are described in detail. Overlap in knowledge representation features of ESBTs chiefly determines the software architecture for the CF. Prototype automatic knowledge translators were written to verify the suitability of the CF for reusing knowledge. Knowledge from a sample KB was transferred with prototype translators between ESBTs. Results show that the object-oriented CF and knowledge translators are useful tools for reusing knowledge. As expected, knowledge transfer is hindered when ES builders rely on unique ESBT features. An additional contribution of this research is identification of guidelines which, if followed, maximize portability of transferred KBs. Indications are that knowledge cooperation is less affected by ESBT differences. Recommendations for future research include refinement of the CF and translators, as well as implementation of a prototype environment for testing the CF with cooperating ESs. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Computer Science." |
| Physical Description: | xvii, 277 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |