<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><P>Hi,</P>
<P>Thank you for your attention to this E-mail. In the paper "Adaptive Barrier Strategies for </P>
<P>Nonlinear Interior Methods" part 5 "A Globalization Method" presents a globalization procedure:</P>
<P>As long as the adaptive primal-dual steps make sufficient progress towards the solution, the </P>
<P>algorithm is free to choose a new value for the barrier parameter at every iteration. We call </P>
<P>this the free mode. However, if the iteration fails to maintain progress, then the algorithm </P>
<P>reverts to a monotone mode, in which a Fiacco-McCormick strategy is applied. Here, the value of</P>
<P>the barrier parameter remains fixed, and a robust globalization technique (e.g., based on</P>
<P>a merit function or a filter) is employed to ensure progress for the corresponding barrier</P>
<P>problem. Once the barrier problem is approximately minimized, the barrier parameter is</P>
<P>decreased. The monotone mode continues until an iterate is generated that makes sufficient</P>
<P>progress for the original problem, at which point the free mode resumes. Is this procedure</P>
<P>applied in current version of IPOPT?</P>
<P>Sincerely.</P>
<P>From Wei. <BR></P>