Fuzzy Sets Bring Ideas Into Focus

This article describes how using fuzzy logic, computers are coping with some of the vaguer terms in an engineer's vocabulary: ideas like very or slightly. Using fuzzy logic, expert systems are being designed for the interpretation of soil data, and the design of language for damage assessment. Other applications include assessing the safety of earth dams, metal fatigue, structural durability, water quality, waste management, treatment of abandoned mines, human error, and many facets of earthquake engineering. Many factors are not well defined quantitatively. The attributes of a building for example, can be numerically ranked by experts using questionnaires and reviews. This information can then be processed using approximate reasoning techniques and fuzzy logic. Engineers now can put their opinions and judgments into what were previously cold hard numbers by fuzzy means. Uncertainties may one day be dealt with using a unified theory that combines probabilistic and fuzzy set methods.