(New page: ECE QE AC-3 August 2011 1. (20 pts) Consider the optimization problem,                   maximize x           &n...)
 
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ECE QE AC-3 August 2011  
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= ECE QE AC-3 August 2011 =
  
1. (20 pts) Consider the optimization problem,  
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===== 1. (20 pts) Consider the optimization problem, =====
  
                  maximize x
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&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; maximize &nbsp;&nbsp;<math>-x_{1}^{2}+x_{1}-x_{2}-x_{1}x_{2}</math>
  
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; subject to  
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&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; subject to &nbsp;&nbsp;<math>x_{1}\geq0, x_{2}\geq0</math>
  
(i) Characterize feasible directions at the point  
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===== (i) Characterize feasible directions at the point &nbsp;<math>x^{*}=\left[ \begin{array}{c} \frac{1}{2} \\ 0 \end{array} \right]</math>  =====
  
(ii) Write down the second-order necessary condition for . Does the point satisfy this condition?
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<span class="texhtml">''d''</span>&nbsp;is a feasible direction at&nbsp;<math>x^{*}(d\in\Re_{2}, d\neq0)</math>, if &nbsp;<math>\exists\alpha_{0}</math>&nbsp; that &nbsp;<math>\left[ \begin{array}{c} \frac{1}{2} \\ 0 \end{array} \right] + \alpha\left[ \begin{array}{c} d_{1} \\ d_{2} \end{array} \in\Omega \right]</math>&nbsp; for all&nbsp;<math>0\leq\alpha\leq\alpha_{0}</math><br>
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===== (ii) Write down the second-order necessary condition for . Does the point satisfy this condition? =====

Revision as of 16:16, 21 June 2012

ECE QE AC-3 August 2011

1. (20 pts) Consider the optimization problem,

                  maximize   $ -x_{1}^{2}+x_{1}-x_{2}-x_{1}x_{2} $

                  subject to   $ x_{1}\geq0, x_{2}\geq0 $

(i) Characterize feasible directions at the point  $ x^{*}=\left[ \begin{array}{c} \frac{1}{2} \\ 0 \end{array} \right] $

d is a feasible direction at $ x^{*}(d\in\Re_{2}, d\neq0) $, if  $ \exists\alpha_{0} $  that  $ \left[ \begin{array}{c} \frac{1}{2} \\ 0 \end{array} \right] + \alpha\left[ \begin{array}{c} d_{1} \\ d_{2} \end{array} \in\Omega \right] $  for all $ 0\leq\alpha\leq\alpha_{0} $

 


(ii) Write down the second-order necessary condition for . Does the point satisfy this condition?

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