Qiwei Zhu

Date of Award


Degree Type


Degree Name

Doctor of Philosophy


Expert systems are knowledge based computer programs that offer the possibility of combining theories with heuristic expertise, and are therefore capable of solving domain-specific problems. However, little is known about how human knowledge can be effectively and precisely transferred into computer programs. In addition, the lack of a seamless man-machine interface also causes reduced general acceptance of expert systems. In this thesis, the process of knowledge acquisition and the role of the user interface in expert systems are investigated. Results are presented that describe the development of two prototypic expert systems: SPILLexpert and GSMSdiagnosis.;The knowledge domain matrix (KDM) is an alternative knowledge encoding mechanism that provides a causal knowledge model to be followed in the phases of knowledge extraction and interpretation. The results from the causal analysis are arranged into knowledge tables from which representation to a computer data structure, in this work production rules can be easily achieved. The KDM approach is flexible and effective in the subsequent development phases when the knowledge base is under frequent modification and/or expansion. Knowledge bases developed in this way are portable and can be readily transferred to other expert system shells.;The ACexpert graphical user interface was developed in the Microsoft Windows 3.1 environment. It provides an intuitive access to these systems through the use of graphics and pull down menus, which can be activated by either point-and-click or key stroke. This user interface has been implemented in both the SPILLexpert and GCMSdiagnosis programs.;SPILLexpert is the first expert system application of its kind developed to assist in the response to chemical spills. The importance of this work is two fold. First, an expert system holding heuristics is interfaced with a database structure that retains factual information. Second, the finished program provides a systematic and integrated approach to the development of the most appropriate response to be chosen following an environmental emergency.;GCMSdiagnosis is a diagnostic expert system for trouble-shooting operational problems with the quadrupole ion-trap GC-MS instrument. This work demonstrates the possibility of developing portable expert systems to enhance the 'intelligence' of modern analytical instruments.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.