
148 Chapter 5 Fuzzy LogiC
vague parameters. Type-2 fuzzy systems (T2 FS) take us one more step to-
ward the goal of “computing with words,” or using computers to represent
human perception. Zadeh (1999) presents that perceptions of size, health,
and comfort cannot be modeled by traditional mathematical techniques
and that fuzzy logic is more suitable. Since T2 FS are based on fuzzy sets
whose membership grades are noncrisp, fuzzy membership functions, they
can model perceptions more effectively than the T1 FS (John & Coupland
2007; Mendal 2007). That is, a T1 FS has a grade of membership that is crisp,
whereas a T2 FS has grades ...