Problems and their solutions in representing fuzzy sets and logic in software systems are discussed in this article.

Fuzzy set theory is getting to be widely used as a tool for managing uncertainty in complicated systems. Interactions of fuzzy set theory and information processing is called ‘fuzzy information processing’, where software representation of fuzzy sets and logic is an important subject. Fuzzy information processing is an important area of research but is not fully investigated. This is because it has some problems. For one thing, a fuzzy set can be represented with various kinds of complicated data structures. Another problem is that there are effectively infinite number of operations defined on fuzzy sets.

Some fuzzy logic based systems have been proposed, like fuzzifications of Pro- log, fuzzy control shells, and specially designed languages for fuzzy set processing. But they are not fully acceptable as a uniform platform of fuzzy information pro- cessing. The trade-off of flexibility, convenience and performance remains.

Object-orientation can be a key to solve these problems. Because object- orientation has the ability of data abstraction and information hiding, it is suitable for fuzzy information processing which needs manipulation on complicated data structures. An object-oriented fuzzy set manipulation system named FOPS was developed on such ideas. Two basic classes for fuzzy sets, ArrayedFuzzySet and PairedFuzzySet, are provided and they can be used interchangeably. With its support for fuzzy logic and development environment, FOPS can serve as a good starting point of fuzzy logic based software. Outline of the system and internal data structures are discussed in this article.


Membership Function Fuzzy Logic Fuzzy Control Fuzzy Relation Certainty Factor 


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Copyright information

© Kluwer Academic Publishers 1994

Authors and Affiliations

  • Sozo Yamamoto
    • 1
  1. 1.Central Research LaboratoriesMatsushita Electric Industrial Co., Ltd.OsakaJapan

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