Fabrication error Indexed eXamples and Solutions: FIXS

Abstract

The major goal of the Regional/National Bridge Fabrication Error Expert System research project is to develop a sharable and well reasoned bridge fabrication error repair database which can be used by several state: DOTs within a geographical,. region. This report focuses on the enhancement of the knowledge base and improvement of the system performance based on the initial work of Fabrication error Indexed examples and Solutions (FIXS). FIXS is a knowledge-based system in the domain of steel bridge fabrication errors using both rule-based reasoning and casebased reasoning. To expand the knowledge base to cover errors experienced by multiple DOTs and to improve the system effectiveness, 38 new cases were solicited from the North Central States Consortium and the Repair Database Task Group of the AASHTONSBA Steel Bridge Collaboration. The new cases, along with the existing 120 rule solutions and 112 case solutions in the knowledge base, were reviewed by the Task Group members. The sketches and instructions summarized from actual cases and the comments obtained from the Task Group members were implemented in the ,, software to provide graphical and instructive information for case solutions. In addition, generic problems and corrections were also collected and implemented in the software as a tutorial tool for common fabrication errors. To improve the accuracy of similar case retrieval, the case-based reasoning shell SCBR was revised by introducing continuous feature evaluation for numeric features, replacing the simple match approach in the first version of FIXS. The explanation facility was also improved.