Date of Award
1994
Degree Type
Dissertation
Degree Name
Doctor of Philosophy
Abstract
Atomic Absorption Expert (AAexpert) is an expert system dealing with automated analysis for trace metals by atomic absorption spectrometry (AAS). This program consists of several stand-alone expert systems, each performing a specific task associated with the analysis.;In this thesis, the design and implementation of three important modules of AAexpert have been studied. These are (a) AAdiagnosis - detects problems associated with analytical data of poor quality and instrument malfunction, (b) AA-Quality Control (AA-QC) - provides a real-time assessment of the quality of measured absorbance values, and (c) AAmethods - selects a method of analysis from a method selection database and a rulebase.;The focal points of the work presented here are (a) the transfer of human expertise to a computer program, and (b) the requirements for totally unattended automated analyses.;In the transfer of human expertise, knowledge acquisition has been stressed and the development of a knowledge table has been described. The developer of the expert system assembles the chemical knowledge as case histories. The knowledge table generates rules that represent the acquired knowledge. This approach of knowledge acquisition would greatly assist chemists in the generation, expansion, and portability of their knowledge bases. The implementation of the knowledge table has been demonstrated in AAdiagnosis in which the developer gathers knowledge as a matrix of symptoms (rows) and the underlying causes (columns).;The goal towards totally automated analysis has been described in AA-QC. This module closely interacts with AAcontrol, a module responsible for solution handling and acquisition of data by flame AAS (FAAS). It has been shown that by modelling the detector response (the absorption profile), it is possible to detect a few common and simple problems associated with analysis by FAAS. AA-QC uses a training set based on the numerical analysis of the absorption profile for a set of standard solutions. AA-QC uses production rules to detect problems associated with the analysis.;The use of an expert database system has been studied in AAmethods. The use of rules to suggest a "closest match" method of analysis contained in an "expert database" has been demonstrated.
Recommended Citation
Lahiri, Sharbari, "Design And Implementation Of Expert Systems In Trace Metal Analysis" (1994). Digitized Theses. 2428.
https://ir.lib.uwo.ca/digitizedtheses/2428