Question: optimization here's the information from the textbook including iterations 1 & 2. so i need help with the next 2 iterations. 2. Read example in

optimization

optimization here's the information from thehere's the information from the textbook including iterations 1 & 2. so i need help with the next 2 iterations.

optimization here's the information from theoptimization here's the information from theoptimization here's the information from theoptimization here's the information from the

2. Read example in page 582 in Hillier, F. S., \& Lieberman, G. J. (2010). Introduction to operations research. In the following linearly constrained convex programming problem Maximize f(x)=5x1x12+8x22x22, subject to 3x1+2x26 and x10,x20 Apply the Frank-Wolfe algorithm up to four iterations. Note that the first two iterations are shown in the textbook. Show detailed work for the third and fourth iteration. Maximize f(x)=5x1x12+8x22x22, subject to 3x1+2x26 and x10,x20. Note that x1f=52x1,x2f=84x2, so that the unconstrained maximum x=(25,2) violates the functional constraint. Thus, more work is needed to find the constrained maximum. Iteration 1: Because x=(0,0) is clearly feasible (and corresponds to the initial BF solution for the linear programming constraints), let us choose it as the initial trial solution x(0) for the Frank-Wolfe algorithm. Plugging x1=0 and x2=0 into the expressions for the partial derivatives gives c1=5 and c2=8, so that g(x)=5x1+8x2 is the initial linear approximation of the objective function. Graphically, solving this linear programming problem (see Fig. 12.17a) yields xLP(1)=(0,3). For step 3 of the first iteration, the points on the line segment between (0,0) and (0,3) shown in Fig. 12.17a are expressed by (x1,x2)=(0,0)+t[(0,3)(0,0)] for 0t1 =(0,3t) as shown in the sixth column of Table 12.6. This expression then gives h(t)=f(0,3t)=8(3t)2(3t)2 FIGURE 12.17 Illustration of the Frank-Wolf algorithm. TABLE 12.6 Application of the Frank-Wolfe algorithm to the example so that the value t=t that maximizes h(t) over 0t1 may be obtained in this case by setting dtdh(t)=2436t=0, so that t=32. This result yields the next trial solution x(1)=(0,0)+32[(0,3)(0,0)]=(0,2), which completes the first iteration. Iteration 2: To sketch the calculations that lead to the results in the second row of Table 12.6, note that x(1)=(0,2) gives c1=52(0)=5,c2=84(2)=0. For the objective function g(x)=5x1, graphically solving the problem over the feasible region in Fig. 12.17a gives xLP(2)=(2,0). Therefore, the expression for the line segment between x(1) and xLP(2) (see Fig. 12.17a) is x=(0,2)+t[(2,0)(0,2)]=(2t,22t) so that h(t)=f(2t,22t)=5(2t)(2t)2+8(22t)2(22t)2=8+10t12t2 Setting dtdh(t)=1024t=0 yields t=125. Hence, x(2)=(0,2)+125[(2,0)(0,2)]=(65,67), which completes the second iteration. Figure 12.17b shows the trial solutions that are obtained from iterations 3,4 , and 5 as well. You can see how these trial solutions keep alternating between two trajectories that appear to intersect at approximately the point x=(1,23). This point is, in fact, the optimal solution, as can be verified by applying the KKT conditions from Sec. 12.6. 2. Read example in page 582 in Hillier, F. S., \& Lieberman, G. J. (2010). Introduction to operations research. In the following linearly constrained convex programming problem Maximize f(x)=5x1x12+8x22x22, subject to 3x1+2x26 and x10,x20 Apply the Frank-Wolfe algorithm up to four iterations. Note that the first two iterations are shown in the textbook. Show detailed work for the third and fourth iteration. Maximize f(x)=5x1x12+8x22x22, subject to 3x1+2x26 and x10,x20. Note that x1f=52x1,x2f=84x2, so that the unconstrained maximum x=(25,2) violates the functional constraint. Thus, more work is needed to find the constrained maximum. Iteration 1: Because x=(0,0) is clearly feasible (and corresponds to the initial BF solution for the linear programming constraints), let us choose it as the initial trial solution x(0) for the Frank-Wolfe algorithm. Plugging x1=0 and x2=0 into the expressions for the partial derivatives gives c1=5 and c2=8, so that g(x)=5x1+8x2 is the initial linear approximation of the objective function. Graphically, solving this linear programming problem (see Fig. 12.17a) yields xLP(1)=(0,3). For step 3 of the first iteration, the points on the line segment between (0,0) and (0,3) shown in Fig. 12.17a are expressed by (x1,x2)=(0,0)+t[(0,3)(0,0)] for 0t1 =(0,3t) as shown in the sixth column of Table 12.6. This expression then gives h(t)=f(0,3t)=8(3t)2(3t)2 FIGURE 12.17 Illustration of the Frank-Wolf algorithm. TABLE 12.6 Application of the Frank-Wolfe algorithm to the example so that the value t=t that maximizes h(t) over 0t1 may be obtained in this case by setting dtdh(t)=2436t=0, so that t=32. This result yields the next trial solution x(1)=(0,0)+32[(0,3)(0,0)]=(0,2), which completes the first iteration. Iteration 2: To sketch the calculations that lead to the results in the second row of Table 12.6, note that x(1)=(0,2) gives c1=52(0)=5,c2=84(2)=0. For the objective function g(x)=5x1, graphically solving the problem over the feasible region in Fig. 12.17a gives xLP(2)=(2,0). Therefore, the expression for the line segment between x(1) and xLP(2) (see Fig. 12.17a) is x=(0,2)+t[(2,0)(0,2)]=(2t,22t) so that h(t)=f(2t,22t)=5(2t)(2t)2+8(22t)2(22t)2=8+10t12t2 Setting dtdh(t)=1024t=0 yields t=125. Hence, x(2)=(0,2)+125[(2,0)(0,2)]=(65,67), which completes the second iteration. Figure 12.17b shows the trial solutions that are obtained from iterations 3,4 , and 5 as well. You can see how these trial solutions keep alternating between two trajectories that appear to intersect at approximately the point x=(1,23). This point is, in fact, the optimal solution, as can be verified by applying the KKT conditions from Sec. 12.6

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