Fuzzy Modeling and Genetic Algorithms for Data Mining and Exploration

5.8 Review

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We are using the centroid — or center-of-gravity (COG) — defuzzifi-

cation to find the predicted product price. This involves finding the bal-

ance point on the membership curve and dropping a “plumb line” to

a value on the fuzzy set’s domain. The vertical line under the outcome

fuzzy set in Figure 5.45 is the point of defuzzification. When applied to

the outcome fuzzy set, the model returns a price of $24.13, with a degree

of evidence (the compatibility index) of [0.5039].

5.8 Review

Fuzzy systems replace the crispness of Boolean logic with the elasticity

of fuzzy logic. In this chapter we examined the principles underlying

fuzzy rule-based models to show how the use of fuzzy logic provides

a more flexible, more robust, and less brittle approach ...