Membership Functions

A membership function defines the degree of membership (degree of truth) of a given real-world value in the membership function. From our QoS example, we have a membership function over the set of link utilization (see Figure 9.2).

From Figure 9.2, we've defined two segments, with a third centered between what exists as our target. The low range can be defined programmatically as shown in Equation 9.1:

(9.1)  

The high range can then be defined as shown in Equation 9.2:

(9.2)