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EURO Summer Institute on
“Nonlinear Methods in Combinatorial Optimization”

Klagenfurt, Austria, August 20 – September 4, 2010

The office of the IFORS EURO Vice President is pleased to announce the sponsorship of two
participants to join the EURO Summer Institute on “Nonlinear Methods in Combinatorial Optimization (ESI 2010)” to be held in Klagenfurt, Austria on August 20 – September 4, 2010.

The Euro Summer and Winter Institutes (ESWI) are organized to encourage good social and working relationships among promising young OR scientists in Europe. Thanks to an agreement between EURO and IFORS, IFORS will sponsor travel costs of two delegates to the ESI from other IFORS member societies. Applicants from developing countries will be given preferential treatment for one of the two slots available.
EURO will extend its usual sponsorship (to cover the costs of the scientific program, accommodation, meals, and social activities) to the two IFORS fellows.

The ESIs and EWIs aim to encourage the establishment of a network of promising young researchers (with less than 10 years experience in OR) to encourage future collaborative work. Each ESWI seeks to involve 20-25 participants. The Institute features lectures by invited speakers and the participants themselves will present and discuss their papers. A special issue of an international journal will be produced, based on the papers presented during the ESI. Just as important is the varied social program that is prepared for the participants.

The ESI 2010


Nonlinear methods such as semidefinite optimization or eigenvalue optimization have been successfully applied in the last decade to deal with NP-hard combinatorial optimization problems. A prominent example is furnished by the theta function, introduced by Lovasz (1979), which is a tractable graph parameter separating the clique number from the chromatic number. It can be formulated either in terms of eigenvalue optimization or as the optimal solution of a semidefinite program. Consequently, techniques from convex optimization are increasingly used in combinatorial optimization. On the algorithmic side, this is mostly due to the generalization of the interior-point methodology from linear to semidefinite programming. Even though the interior-point machinery carries over nicely from linear to semidefinite optimization, the computational overhead due to dense linear algebra operations makes it necessary to explore algorithmic alternatives to interior-point methods. The hyperplane rounding idea of Goemans and Williamson has turned out to be a strong theoretical tool in the approximation analysis of algorithms, opening up a new area of research in theoretical computer science. Finally, the new relaxations can also be used to solve problems to optimality. This requires algorithmic engineering to combine (nonlinear) bounding techniques with limited enumeration.

It is the purpose of the summer institute to focus on recent developments in this area. The following topics are of major interest to the ESI.

• Investigation of new relaxations for NP-hard problems,
• Algorithms for large scale semidefinite programs and related other conical relaxations of combinatorial optimization problems,
• Investigation of rounding heuristics, based on these relaxations,
• Investigation of theoretical error estimates of these relaxations,
• Exact solution methods, using semidefinite relaxations in combination with enumeration techniques

Miguel Anjos (University of Waterloo, Canada)
Florian Jarre (Universität Düsseldorf, Germany)
Etienne de Klerk (Tilburg University, The Netherlands)
Christoph Helmberg (Technische Universitaet Chemnitz, Germany)
Veronica Piccialli (Università degli Studi di Roma Tor Vergata, Italy)


The conference will be held at the Alpen-Adria-Universität Klagenfurt, Austria, which is located at the beautiful lake “Wörthersee”.


Members of the local organizing committee are Franz Rendl, Angelika Wiegele and Philipp Hungerländer (all of them belong to the Alpen-Adria-Universität Klagenfurt).


Participation is limited to a group of about 20 students, normally aged 25-35, who have significant experience in the field, and are authors of at least one high-quality paper which has not yet been published, nor submitted for publication. During ESI all participants are invited to give a talk of 30 minutes on their submitted paper.


A special issue of an optimization journal will be produced dedicated to the papers presented at the ESI. Therefore the submitted papers should be suitable for publication and meet selected journal’s standards as described in the corresponding “Notes for Authors”.

For further information and subsequent updates please see also the webpage, or alternatively, send your request by e-mail to

Applications for the IFORS Fellowships:

If you:
1. Have done work along the lines of the ESI 2010;
2. Do not have more than 10 years experience in OR; and
3. Can present your unpublished work and answer questions in English,
you may be the person we are looking for.

Please submit your curriculum vitae, your proposed paper (or at least a two-page abstract of this
work) and a letter of recommendation from one referee (preferably your thesis advisor or head of department) by January 31, 2010 to:

M.Grazia Speranza
IFORS EURO Vice President
(Submission by email is strongly encouraged)
Fax No. +390302400925
Mailing Address:
Dipartimento Metodi Quantitativi
Università degli Studi di Brescia
C.da S.Chiara 50
25122 Brescia

Adjudication of submissions will be done by the IFORS EURO Vice President. The successful candidates will be required to submit full papers (if not done so initially) within two weeks of being notified of their success. The successful IFORS Fellows will be notified by February 28, 2010.