To determine the practical significance. For example, in economic management and social management, we can use the existing "objective scale"
Is the membership degree of fuzzy sets. Here is an example.
If the universe X represents machines and equipment, and fuzzy set A = "Equipment in good condition" is defined on X, you can use "set".
"Preparation rate" is the membership degree of A. If X represents a product, the fuzzy set A = "stable quality" is defined on X,
The "authentic rate" of products can be used as the membership degree of A. If X represents family, the fuzzy set A can be defined on X..
= "family poverty", then "Engel coefficient = food consumption/total consumption" can be used as the membership degree of A.
In addition, for some fuzzy sets, it is sometimes difficult to give the membership directly, but the so-called
"Binary contrast sorting method", that is, first determine the corresponding membership degree of two elements through pairwise comparison.
Order, and then through mathematical methods to deal with, get the required membership function.
For details, please refer to the fuzzy mathematics of Baidu Encyclopedia.