<html><head><meta http-equiv="Content-Type" content="text/html charset=iso-8859-1"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">Dear John,<div><br></div><div>for your reference, the final version (with some improvements over the first version) of my joint paper with Michele Monaci on Proximity Search is now printed on</div><div><span style="text-align: justify; font-size: medium;"><br></span></div><div><span style="text-align: justify; font-size: medium;">M. Fischetti, M. Monaci, "Proximity Search for 0-1 Mixed-Integer Convex Programming", </span><i style="text-align: justify; font-size: medium;">Journal of Heuristics</i><span style="text-align: justify; font-size: medium;"> 20 (6), 709-731, 2014. DOI: 10.1007/s10732-014-9266-x</span></div><font size="3"><font size="3"><font size="3"><font size="3"><div style="margin-left: 36pt; text-align: justify;"><br></div></font></font></font></font><div><br></div><div>@article{</div><div>year={2014},</div><div>issn={1381-1231},</div><div>journal={Journal of Heuristics},</div><div>volume={20},</div><div>number={6},</div><div>doi={10.1007/s10732-014-9266-x},</div><div>title={Proximity search for 0-1 mixed-integer convex programming},</div><div>url={<a href="http://dx.doi.org/10.1007/s10732-014-9266-x">http://dx.doi.org/10.1007/s10732-014-9266-x</a>},</div><div>publisher={Springer US},</div><div>keywords={Mixed-integer convex optimization; Proximal methods; Primal methods; Heuristics},</div><div>author={Fischetti, Matteo and Monaci, Michele},</div><div>pages={709-731},</div><div>language={English}</div><div>}</div><div> </div><div>Best</div><div><br></div><div>Matteo</div><div><br></div><div><br><div><div>Il giorno 21/nov/2012, alle ore 13:11, John Forrest <<a href="mailto:john.forrest@fastercoin.com">john.forrest@fastercoin.com</a>> ha scritto:</div><br class="Apple-interchange-newline"><blockquote type="cite">
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<font>I am pleased to say that I have spent a very
small amount of time implementing the Proximity Search heuristic
by Fischetti and Monaci.<br>
<br>
At present it is only in Cbc trunk and by default is off. The
simplest way to switch it on using stand-alone version is
"-proximity on".<br>
<br>
Proximity Search is the new "No-Neighborhood Search" 0-1 MIP
refinement heuristic recently proposed by Fischetti and Monaci
(2012). The idea is to define a sub-MIP without additional
constraints but with a modified objective function intended to
attract the search in the proximity of the incumbent. The approach
works well for 0-1 MIPs whose solution landscape is not too
irregular (meaning the there is reasonable probability of finding
an improved solution by flipping a small number of binary
variables), in particular when it is applied to the first
heuristic solutions found at the root node. Feedback about
(un)successful applications are very welcome, and can be send
directly to Matteo Fischetti (<a class="moz-txt-link-abbreviated" href="mailto:matteo.fischetti@unipd.it">matteo.fischetti@unipd.it</a>)<br>
<br>
Feedback about unsuccessful applications may also be sent to me as
I may need to improve my implementation.<br>
<br>
John Forrest<br>
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<div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div><br class="Apple-interchange-newline">---</div><div>Prof. Matteo Fischetti<br>DEI, University of Padova<br>via Gradenigo 6/A<br>I-35131 Padova (Italy)<br>e-mail: <a href="mailto:matteo.fischetti@unipd.it">matteo.fischetti@unipd.it</a><br>web: <a href="http://www.dei.unipd.it/~fisch">www.dei.unipd.it/~fisch</a><br>reports: <a href="http://www.dei.unipd.it/~fisch/papers">www.dei.unipd.it/~fisch/papers</a></div><div><br></div></div><br class="Apple-interchange-newline" style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;"><br class="Apple-interchange-newline">
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