Description
Leader of the group Networks and Optimization: Guido Schäfer.
In today’s society, complex systems surround us. From transport and traffic, to behavioral economics and operations management, real-world applications often demand that we identify simple, optimal solutions among a huge set of possibilities. Our research group Networks and Optimization (N&O) does fundamental research to tackle such challenging optimization problems.
We develop algorithmic methods to solve complex optimization problems efficiently. Our research provides efficient algorithms to some of the most challenging problems, for example, in planning, scheduling and routing. To come up with the best optimization algorithms, we combine and extend techniques from different disciplines in mathematics and computer science.
N&O covers a broad spectrum of optimization aspects. Our expertise ranges from discrete to continuous optimization and applies to centralized and decentralized settings. We focus on both problem-specific methods and universal toolkits to solve different types of optimization problems. The key in our investigations is to understand and exploit combinatorial structures, such as graphs, networks, lattices and matroids. Our research is of high scientific impact and contributes to various fields.
In several cooperations with industry partners, the algorithmic techniques that we develop in our group have proven useful to solve complex real-world problems. We are always interested in new algorithmic challenges arising in real-world applications and are open to new cooperations.
Watch our group video to get a glimpse of our activities.
Video about our collaboration with ProRail (in Dutch)
Vacancies
2-year Postdoc, within the research project OPTIMAL
Centrum Wiskunde & Informatica (CWI) has a vacancy in the Networks and Optimization research group for a talented 2-year Postdoc, within the research project OPTIMAL. OPTIMAL (Optimization for and with Machine Learning) is a Dutch ENW-groot project funded by NWO (2019-2025), offering 5 PhD and 6 PostDoc positions in the Netherlands, starting from September 2020 or later.
Postdoc on the subject of Towards a Quantitative Theory of Integer Programming.
Centrum Wiskunde & Informatica (CWI) has a vacancy in the Networks & Optimization research group for a talented Postdoc, on the subject of Towards a Quantitative Theory of Integer Programming.
News
Daniel Dadush and Samarth Tiwari receive Best Paper Award at CCC'20
Daniel Dadush and Samarth Tiwari from CWI's Networks and Optimization research group receive the Best Paper Award at the Computational Complexity Conference 2020 for their work 'On the Complexity of Branching Proofs'.
Daniel Dadush receives prestigious Van Dantzig Prize
Daniel Dadush has been awarded the Van Dantzig Prize, which is considered the highest Dutch award in statistics and operations research. It is awarded by the VVSOR once every five years.
CWI researchers involved in two NWO-Groot grants
In the NWO Open Competition ENW-GROOT programme, four CWI researchers received in total two grants to study machine learning and neural networks: Nikhil Bansal, Monique Laurent, Benjamin Sanderse and Leen Stougie.
QuSoft/CWI team earns 4th place in Benelux Algorithm Programming Contest 2019
On Saturday 19 October 2019, Arjan Cornelissen, Farrokh Labib and Ruben Brokkelkamp formed a combined QuSoft/CWI team in the BAPC 2019 programming contest. They earned the 4th place, competing against companies such as ASML, Booking.com, Ortec and Sioux.
Members
Associated Members
Publications
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Huizing, D, Schäfer, G, van der Mei, R.D, & Bhulai, S. (2020). The median routing problem for simultaneous planning of emergency response and non-emergency jobs. European Journal of Operational Research. doi:10.1016/j.ejor.2020.02.002
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de Klerk, E, & Laurent, M. (2020). Convergence analysis of a Lasserre hierarchy of upper bounds for polynomial minimization on the sphere. Mathematical Programming, 2020. doi:10.1007/s10107-019-01465-1
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Abiad, A, Gribling, S.J, Lahaye, D.J.P, Mnich, M, Regts, G, Vena, L, … Zwaneveld, P.J. (2020). On the complexity of solving a decision problem with flow-depending costs: The case of the IJsselmeer dikes. Discrete Optimization. doi:10.1016/j.disopt.2019.100565
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Bansal, N, Dadush, D.N, Garg, S, & Lovett, S. (2019). The Gram-Schmidt Walk: A Cure for the Banaszczyk Blues. Theory of Computing, 15. doi:10.4086/toc.2019.v015a021
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Bansal, N, Böhm, M, Eliáš, M, Koumoutsos, G, & Umboh, S.W. (2019). Nested convex bodies are chaseable. Algorithmica. doi:10.1007/s00453-019-00661-x
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Brokkelkamp, K.R, Polak, S.C, Schäfer, G, & Velaj, Y. (2019). Approximate pricing in networks: How to boost the betweenness and revenue of a node. In 30th International Symposium on Algorithms and Computation (pp. 13:1–13:15). doi:10.4230/LIPIcs.ISAAC.2019.13
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de Klerk, E, & Laurent, M. (2019). A survey of semidefinite programming approaches to the generalized problem of moments and their error analysis. In World Women in Mathematics 2018 (pp. 17–56). doi:10.1007/978-3-030-21170-7_1
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Bansal, N, Svensson, O, & Trevisan, L. (2019). New notions and constructions of sparsification for graphs and hypergraphs. In Proceedings of FOCS (pp. 910–928). doi:10.1109/FOCS.2019.00059
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Bansal, N, Chalermsook, P, Laekhanukit, B, Nanongkai, D, & Nederlof, J. (2019). New Tools and Connections for Exponential-Time Approximation. Algorithmica, 81(10), 3993–4009.
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Gribling, S.J. (2019, September 30). Applications of optimization to factorization ranks and quantum information theory. Center dissertation series. Retrieved from http://dx.doi.org/10.26116/center-lis-1925
Current projects with external funding
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Continuous Methods in Discrete Optimization ()
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Wiskundecluster DIAMANT ()
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Smart Heuristic Problem Optimization
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Mixed-Integer Non-Linear Optimisation Applications (MINOA)
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Optimization for and with Machine Learning (OPTIMAL)
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Polynomial Optimization, Efficiency through Moments and Algebra (POEMA)
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Vóórkomen en voorkómen van incidenten op het spoor (PPS Prorail)
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Towards a Quantitative Theory of Integer Programming (QIP)
Related partners
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Alma Mater Studiorum-Universita di Bologna
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Alpen-Adria-Universität Klagenfurt
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CNR Pisa
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CNRS
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Dassault Systèmes B.V.
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IBM
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INRIA
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Prorail
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Rheinische Friedrich-Wilhelmus Universitaet Bonn
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Technische Universität Dortmund
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Tilburg University
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Tromsø, Norway
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Universita degli Studi di Firenze
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Universität Konstanz
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University of Birmingham
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Universiteit van Tilburg