26 research outputs found
Concrete bridge deck assessment using thermography and radar
No full textThesis (M.S.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1987.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.Bibliography: leaves 263-272.by W. M. Kim Roddis.M.S
Heuristic, qualitative, and quantitative reasoning about steel bridge fatigue and fracture
No full textThesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil Engineering, 1989.Includes bibliographical references.by W.M. Kim Roddis.Ph.D
Comparison of QPE and QSIM as Qualitative Reasoning Techniques
No full textQualitative reasoning predicts and explains the behavior of physical systems using the system's structure through modeling and simulation. There are several approaches to qualitative reasoning. Two of the most prominent software implementations are QPE (Qualitative Process Engine) by Forbus and QSIM (Qualitative Simulation) by Kuipers. A comparison of the two systems is done on the basis of representation and reasoning ability of physical systems. The standard examples in qualitative reasoning and examples in fatigue and fracture in metals are used in the comparison. The fatigue and fracture domain of study can serve as a prototype for other related models of material behavior. A thorough comparison of QSIM and QPE identifies future directions of qualitative reasoning development
Fabrication error Indexed eXamples and Solutions: FIXS
No full textThe 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
