Algorithm 3: an algorithm to calculate single numerical crisp value of AQI

Input: H denotes the belief degree of the referential value ‘Hazardous’ of the consequent attribute ‘AQI’; U denotes the belief degree of ‘Unhealthy’ referential value, and G denotes the belief degree of ‘Good’ referential value of the consequent attribute.

Output: The crisp value of AQI (Q).

Begin

1 if ((H > U) and (H > G)) then

2 Q = (201 + 299*H) + ((200*U)/2)

3 else if ((G > H) and (G > U)) then

4 Q = (100*(1 − G)) + ((200*U)/2)

5 else if ((U > H) and (U > G)) then

6 if (H > G) then

7  Q = (101 + 99*U) + ((500*H)/2)

8 else if (G > H) then

9  Q = (101 + 99*U) + ((100*G)/2)

10 return Q

End