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Transportation Simplex Method. Transportation Simplex Method. If the problem is unbalanced, balance it Use one of the methods described in section 7.2 to find a bfs
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Transportation Simplex Method • If the problem is unbalanced, balance it • Use one of the methods described in section 7.2 to find a bfs • Use the fact that u1=0 and ui+ vj =cij for all basic variable to find the [u1 u2 … um v1 v2 …vn] for the current bfs • If ui + vj – cij ≤ 0 for all nonbasic variable, then the current bfs is optimal. If this is not the case, enter the variable with the most positive ui + vj – cijinto the basis using pivot procedure. This yield a new bfs • Using the new bfs, return to step 3 and 4
For maximization problem replace 4 by 4’ 4’. If ui + vj – cij≥ 0 for all nonbasic variable, then the current bfs is optimal. If this is not the case, enter the variable with the most negative ui + vj – cij into the basis using pivot procedure.
Bagaimanamelakukan Pivot dalamMasalahTransportasi • Tentukanvariabel yang harusmasuksebagai basis • Temukan loop (pastihanyaadasatu loop) yang berkaitandengan entering variable danbeberapa basic variable • Hitunghanyasel yang adadalam loop. Labelisel yang ditemukanpadalangkah 2 mulaidari entering variable: yang merupakanbilangangenapkitalabelisebagaiselgenapdan yang merupakanbilanganganjilkitalabelisebagaiselganjil. • Temukanselganjil yang memilikinilaiterkecil (sebutnilaiinisebagai. Variabelpadaseliniakanmeninggalkan basis. Turunkannilaidarisetiapselganjildantingkatkannilaisetiapselgenap
Definition An ordered sequence of at least four different cells is called loop if • Any two consecutive cells lie in either the same row or same column • No three consecutive cells lie in the same row or column • The last cell in the sequence has a row or column in common with the first cell in the sequence
Example Powerco Problem using North West Corner Method 35 10 20 20 10 10
Basic Variable x11=35 x21=10 x22=20 X23=20 x33=10 x34=30 Hitung[u1 u2u3v1 v2v3 v4] dari u1 = 0 ui+ vj =cijuntuksemua basic variable x11u1+v1=c11=8 v1= 8 x21u2+v1=c21=9 u2=1 x22u2+v2=c22=12 v2=11 x23u2+v3=c23=13 v3=12 x33u3+v3=c33=16 u3=4 x34u3+v4=c34=5 v4=1
Hitung ij= ui+vj– cijuntuksemuanonbasic variable 12 = 0 +11 – 6 = 5 13 = 0 +12 -10 = 2 14 = 0 +1 – 9 = -8 24 = 1 +1 – 7 =-5 31 = 4 +8 – 14 = -2 2 = 4 +11 – 9 = 6 Terdapat yang positif. 2 paling positifsehingga x32masuksebagai basis Gunakanprosedur looping Loop yang mencakup x32danbeberapa basic variabeladalah (3,2) – (3,3) – (2,3) – (2,2)
35 10 20 20 10 10
Odd cell : (3,3) dan (2,2) X33 =10 x22 = 20 = 10 X33 dan x22dikurangi 10, x32dan x23ditambah 10 SehinggadidapatTabel 2
35 10 10 30 30 10