Rudarski radovi br 4 2011 - Institut za rudarstvo i metalurgiju Bor
Rudarski radovi br 4 2011 - Institut za rudarstvo i metalurgiju Bor
Rudarski radovi br 4 2011 - Institut za rudarstvo i metalurgiju Bor
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μ ( x)<<strong>br</strong> />
=<<strong>br</strong> />
B<<strong>br</strong> />
⎧ y − 8, 8 ≤ y ≤ 9 ⎫<<strong>br</strong> />
⎨ ⎬<<strong>br</strong> />
⎩ − y + 10, 9 ≤ x ≤ 10 ⎭<<strong>br</strong> />
Odrediti: C = A+ B<<strong>br</strong> />
Da bi izvršili naznačene operacije nad<<strong>br</strong> />
datim trougaonim fuzzy <strong>br</strong>ojevima potrebno<<strong>br</strong> />
je odrediti levu i desnu granicu intervala<<strong>br</strong> />
poverenja <strong>za</strong> svaki nivo uverenja<<strong>br</strong> />
α ∈[<<strong>br</strong> />
0,<<strong>br</strong> />
1]<<strong>br</strong> />
. Drugim rečima potrebno je<<strong>br</strong> />
odrediti ekstremne vrednosti u α preseku<<strong>br</strong> />
fuzzy <strong>br</strong>ojeva A i B.<<strong>br</strong> />
Leva granična vrednost fuzzy <strong>br</strong>oja<<strong>br</strong> />
A <strong>za</strong> nivo uverenja α ∈[<<strong>br</strong> />
0,<<strong>br</strong> />
1]<<strong>br</strong> />
dobija se<<strong>br</strong> />
prema izrazu α x L :<<strong>br</strong> />
1<<strong>br</strong> />
x α α α<<strong>br</strong> />
L − 3 = → xL<<strong>br</strong> />
= 6 + 2α<<strong>br</strong> />
2<<strong>br</strong> />
Desna granična vrednost fuzzy <strong>br</strong>oja<<strong>br</strong> />
A <strong>za</strong> nivo uverenja [ ] α α ∈ 0 , 1 ⋅ xR<<strong>br</strong> />
dobija<<strong>br</strong> />
se prema izrazu :<<strong>br</strong> />
1 α<<strong>br</strong> />
α<<strong>br</strong> />
− x R + 5 = α → xR<<strong>br</strong> />
= 10 − 2α<<strong>br</strong> />
2<<strong>br</strong> />
α presek fazi <strong>br</strong>oja je :<<strong>br</strong> />
1 [ α α<<strong>br</strong> />
α = L , R ] = [ 6 + 2α<<strong>br</strong> />
, 10 − 2α<<strong>br</strong> />
]<<strong>br</strong> />
2<<strong>br</strong> />
x x A<<strong>br</strong> />
Analogno prethodnom dobijamo <strong>za</strong> α<<strong>br</strong> />
presek fuzzy <strong>br</strong>oja B :<<strong>br</strong> />
Na sličan način se računa i razlika,<<strong>br</strong> />
proizvod i količnik fuzzy <strong>br</strong>ojeva.<<strong>br</strong> />
Ako su aktivnosti Ai, čije je trajanje ti<<strong>br</strong> />
fuzzy <strong>br</strong>oj, prika<strong>za</strong>ne pomoću krugova ili<<strong>br</strong> />
Sl. 2. Fuzzy <strong>br</strong>ojevi A, B, C<<strong>br</strong> />
[ α α<<strong>br</strong> />
y ] = [ 8 + α,<<strong>br</strong> />
− α ]<<strong>br</strong> />
B α = L , yR<<strong>br</strong> />
10<<strong>br</strong> />
Izračunajmo zbir fuzzy <strong>br</strong>ojeva A i B<<strong>br</strong> />
koji je označen sa C . Fuzzy <strong>br</strong>oj C se<<strong>br</strong> />
formalno <strong>za</strong>pisuje C = { z, μ ( z)<<strong>br</strong> />
} .<<strong>br</strong> />
C<<strong>br</strong> />
Prema pravilu o sabiranju trouglastih<<strong>br</strong> />
fuzzy <strong>br</strong>ojeva sledi:<<strong>br</strong> />
C = [ (6 + 2 α) + (8 + α),(10- α) + (10 − 2α]<<strong>br</strong> />
=<<strong>br</strong> />
= [ 14 + 3 α,20 −3α]<<strong>br</strong> />
Jednačine koje predstavljaju levu i<<strong>br</strong> />
desnu stranu fuzzy <strong>br</strong>oja C:<<strong>br</strong> />
α 1 α 14<<strong>br</strong> />
14 + 3α<<strong>br</strong> />
= z → α = z −<<strong>br</strong> />
3 3<<strong>br</strong> />
α 1 α 20<<strong>br</strong> />
20 − 3α<<strong>br</strong> />
= z → α = − z −<<strong>br</strong> />
3 3<<strong>br</strong> />
Funkcija pripadnosti fuzzy <strong>br</strong>oja C je<<strong>br</strong> />
takođe oblika trougla i formalno se predstavlja<<strong>br</strong> />
analitičkim izrazom:<<strong>br</strong> />
⎧ 1 14 ⎫<<strong>br</strong> />
z − , 14 ≤ z ≤ 17<<strong>br</strong> />
⎪ 3 3<<strong>br</strong> />
⎪<<strong>br</strong> />
μ ( z ) =<<strong>br</strong> />
C ⎨ ⎬<<strong>br</strong> />
⎪ 1 20<<strong>br</strong> />
− z + , 17 ≤ z ≤ 20 ⎪<<strong>br</strong> />
⎪⎩ 3 3<<strong>br</strong> />
⎪⎭<<strong>br</strong> />
A i B Fuzzy <strong>br</strong>ojevi kao i njihov zbir, tj.<<strong>br</strong> />
fuzzy <strong>br</strong>oj C prika<strong>za</strong>ni su na slici 2.<<strong>br</strong> />
pravougaonika (precedence dijagram),<<strong>br</strong> />
onda se vremena njihovih najranijih i najkasnijih<<strong>br</strong> />
<strong>za</strong>vršetaka RZi I RKi izračunavaju<<strong>br</strong> />
pomoću sledećih izra<strong>za</strong>:<<strong>br</strong> />
Broj 4,<strong>2011</strong>. 150<<strong>br</strong> />
RUDARSKI RADOVI