Your Perfect Assignment is Just a Click Away
We Write Custom Academic Papers

100% Original, Plagiarism Free, Customized to your instructions!

glass
pen
clip
papers
heaphones

Linear Programming Assignment

Linear Programming Assignment

Problem 1. (Degeneracy)

Consider the following dictionary, which we may have encountered when solving an LP with the simplex method.
ζ   =     c1*x1 + c3*x3 + d3*w3 + c4*x4
w1 = 5  -6*x1 + 2*x3   “ w3 “ 3*x4
w2 = 2 +4*x1  -6*x3 + 2*w3 – 2*x4
x2 =  0  +3*x1          -w3 +2*x4
where
c1 = -361
c3 = 0
d3 = 0
c4 = -1083
Determine these parameters and write down the resulting dictionary. We denote it by (EXAM-Dict).
We use (P-sol) and (D-sol) to respectively denote the primal and dual basic solutions given in (EXAM-Dict). Answer the following questions:
i. Write the components of (P-sol) and (D-sol). Is the dictionary (EXAM-Dict) primal feasible? Is it dual feasible?
ii. Is (EXAM-Dict) primal degenerate? Why?
iii. If (EXAM-Dict) is primal degenerate, show how to find an alternative dual feasible basic solution (denoted by (D-sol-alt)) such that (P-sol) and (D-sol-alt) have complementary slackness. Moreover, show how to find yet another dual feasible solution (D-sol-3) such that (P-sol) and (D-sol-3) have complementary slackness; (D-sol-3) should be different from both (D-sol) and (D-sol-alt).
iv. Is (EXAM-Dict) dual degenerate? Why?
v. If (EXAM-Dict) is dual degenerate, show how to find an alternative primal feasible basic solution (denoted by (P-sol-alt)) such that (P-sol-alt) and (D-sol) have the same objective function value. Then find another primal feasible solution (different from both (P-sol) and (P-sol-alt)) that also has the same objective function value.
Problem 2 (lexicographic simplex method)
Consider the following LP

max 4×1 + x2 + 5×3 +3×4
s.t. -6×1 + x2-x3-2×4 <= 0    (-17/8)x2 - 6x3 + (13/8)x4 <= 1    4x1 + 2x2 + 2x3 <= 0 x1,x2,x3,x4 >=0
Now solve the LP with the perturbation/lexicographic variant of the primal simplex method to ensure that no degeneracy can occur.
In each iteration of the simplex method, clearly write down the following things: dictionary, current basic feasible solution (BFS), current objective value, the entering variable, the leaving variable, how you did the ratio test (noting in particular the features of the perturbation/lexicographic method), the basic variables, the non-basic variables.

Order Solution Now