Combinatorial Optimization and Logistics

The Combinatorial Optimization and Logistics (CSLog) group at the University of Bremen focuses on the analysis of discrete algorithmic problems that are computationally difficult. We analyze the structure of such problems and design efficient algorithms with provable performance guarantees for solving them. We are also interested in combinatorial optimization problems where the input is revealed only incrementally or where there is uncertainty in the parameters, and we develop online, stochastic or robust solution methods.

Combinatorial optimization is related to theoretical computer science, discrete mathematics, operations research, algorithm theory and computational complexity theory and has important applications in several fields. In our group we develop theoretic results and apply them to complex real-world environments. Typical applications include scheduling, production planning, logistics, network design, communication and routing in networks, and health care.

Contact

Combinatorial Optimization and Logistics
Faculty 3 - Mathematics and Computer Science
Prof. Dr. Nicole Megow

Bibliothekstr. 5
28359 Bremen

Secretary office
n.n.
Telefon: +49 (0) 421 218 63580

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Research topics

  • approximation algorithms
  • online optimization
  • stochastic dynamic optimization
  • explorable uncertainty
  • learning-augmented algorithms
  • scheduling and resource management
  • network design and routing
  • logistics applications
Zuhörer in einem vollen Hörsaal.
BHACO

BHACO

Bremen-Hamburg Initiative on Algorithms, Combinatorics and Optimization

ALPS

Algorithms with Predictions

Open-source project dedicated to maintaining a repository for papers and links related to learning-augmented algorithms.

Guests

An overview of our guests

Researchers

Nicole Megow

Prof. Dr. Nicole Megow

Bild von Dr. Felix Hommelsheim

Dr. Felix Hommelsheim

Picture of Vijayaragunathan Ramamoorthi

Vijayaragunathan Ramamoorthi

Bild von Alex Lindermayr

M.Sc. Alexander Lindermayr

Jens Schlöter

Dr. Jens Schlöter

Zhenwei Liu

Zhenwei Liu

  • Go to page: Deutsche Forschungsgemeinschaft
  • Go to page: Emmy Noether
  • Go to page: Mind Media Machines
  • Go to page: Logdynamics
  • Go to page: Data Science Center
  • Go to page: Invasic

News

Jan 23-26, 2024: Excited to have Moritz Buchem, Franziska Eberle and Jose Verschae as guests in Bremen for a small Workshop on Stochastic Scheduling.

Jan 22, 2024: Our paper Fast Combinatorial Algorithms for Efficient Sortation (Madison Van Dyk, Jochen Koenemann, Nicole Megow, Kim Klause) has been accepted for IPCO 2024.

Nov 10, 2023: Jens Schlöter successfully defended his PhD. Congratulations!

October 11, 2023: Our paper "Santa Claus meets Makespan and Matroids: Algorithms and Reductions" (Étienne Bamas, Alexander Lindermayr, Nicole Megow, Lars Rohwedder, Jens Schlöter) got accepted at SODA 2024!

July 4, 2023: Nicole won the University of Bremen award for outstanding PhD student supervision. Congratulations!

June 25, 2023: Our paper "Improved Approximation Algorithms for the Expanding Search Problem" (Svenja M. Griesbach, Felix Hommelsheim, Max Klimm, Kevin Schewior) got accepted at ESA 2023.

June 24, 2023: Our group is at Open Campus with a talk and combinatorics games in the pagoda.

June 23-26, 2023: Guochuan Zhang from Zhejiang University is visiting us.

June 21-22, 2023: We have the pleasure of hosting the DFG Fachkollegium Informatik.

June 12-14, 2023: We are excited to have Sanjoy BaruahAlberto Marchetti-Spaccamela, and Leen Stougie as guests in Bremen for a small Workshop on Integrating Predictions in Real-time Scheduling.

May 10, 2023: Zhenwei Liu joins our group. Welcome!

April 25, 2023: Our paper "Speed-Oblivious Online Scheduling: Knowing (Precise) Speeds is not Necessary" (Alexander Lindermayr, Nicole Megow, Martin Rapp) got accepted at ICML 2023.

April 25, 2023: Our paper "Minimalistic Predictions to Schedule Jobs with Online Precedence Constraints" (Alexandra Lassota, Alexander Lindermayr, Nicole Megow, Jens Schlöter) got accepted at ICML 2023.

April 24, 2023: Nicole is co-organizer of the ICALP 2023 Satellite Workshop: Workshop on Recent Trends in Online Algorithms (with Thomas ErlebachKazuo IwamaChung-Shou Liao). Please consider to participate!

April 21, 2023: Our paper "Matching Augmentation via Simultaneous Contractions" (Mohit Garg, Felix Hommelsheim, Nicole Megow) got accepted at ICALP 2023.

April 20, 2023: Our Paper "Sorting and Hypergraph Orientation under Uncertainty with Predictions" (Thomas Erlebach, Murilo Santos de Lima, Nicole Megow, Jens Schlöter) got accepted at IJCAI 2023 (acceptance rate 15%).

April 6, 2023: DFG granted our project on "Optimization under Explorable Uncertainty".

April 5, 2023: Nicole is the PC chair of APPROX 2023. Please consider submitting. Deadline is May 5.

Feb 21, 2023: Lukas Nölke successfully defended his PhD. Congratulations!

Feb 21, 2023: We are hosting the Bremen Day on Combinatorial Optimization: Approximate Flows and Allocations with talks by Sven Krumke (Kaiserslautern), Franziska Eberle (London), Daniel Schmand (Bremen) and the PhD Defense of Lukas Nölke. More details here

Feb 5-10, 2023: We are having a great time at the wonderful Dagstuhl Seminar 23061 on Scheduling with a focus on beyond-worst case analysis, learning, and stochastic models. 

Feb 1, 2023: The full version of our paper "Speed-robust scheduling: sand, bricks, and rocks" (Eberle, Hoeksma, Megow, Nölke, Schewior, Simon) appeared in Mathematical Programming.