Gesellschaft für Operations Research e.V.

gor

Piecing Together the Tree of Life — with Tropical Geometry

by Dr. Andrei Comăneci (Winner of YRA 2025)

How do we find consensus when multiple evolutionary trees tell different stories? In computational biology, phylogenetic trees often conflict due to noise, differing data, or model assumptions. Classical methods like majority-rule consensus work by retaining only those branches shared by most trees—but they ignore branch lengths and often break down in the presence of “rogue taxa,” species that jump around in the tree.

My research introduces a novel approach based on tropical geometry, a field where “addition” is defined as taking the maximum, and “multiplication” becomes addition. This sounds strange, but it enables a new geometric structure—tropical convexity—that is surprisingly well-suited to modeling phylogenetic trees.

Instead of “voting” on branches, we treat trees as points in a tropical space and ask: what tree lies closest to all input trees under a tropical distance? This reframes consensus as a location problem. I proved that for a broad class of tropical distances, the optimal consensus always lies in the tropical convex hull of the inputs—preserving shared structure, while reducing sensitivity to rogue taxa.

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Methoden der gemischt-ganzzahligen Optimierung für robuste Bilevel-Probleme mit „here-and-now“-Followern

von Dr. Yasmine Beck (Gewinnerin des GOR Dissertationspreises 2025)

Optimierungsmodelle sind ein zentrales Werkzeug zur Unterstützung von Entscheidungsträgern in komplexen Entscheidungsprozessen. In der klassischen, einstufigen Optimierung wird angenommen, dass eine einzige Person oder Instanz alle Entscheidungen trifft – ein geeigneter Rahmen für viele Anwendungen in der Praxis, aber eben nicht für alle. In zahlreichen realen Situationen treffen mehrere Akteure Entscheidungen, die sich gegenseitig beeinflussen können. Ein Entscheidungsträger muss dabei oft antizipieren, wie andere auf seine Wahl reagieren werden. Zum Beispiel legt ein Unternehmen Preise für Waren oder Dienstleistungen fest, welche die Nachfrage der Kunden beeinflussen können. Im Verkehrsmanagement bestimmen Behörden Mautgebühren, auf deren Grundlage Reisende ihre Routen anpassen. Beim Schutz kritischer Infrastrukturen müssen Schutzmechanismen so gewählt werden, dass Systeme auch in Ausnahmesituationen wie Naturkatastrophen, technischen Ausfällen oder terroristischen Angriffen funktionsfähig bleiben.

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Joint International Conference on Computational Logistics (ICCL2025) and EURO Mini Conference on Maritime Optimization and Logistics (EuroMar2025), Delft / Rotterdam 

Save the date: September 8-10, 2025

Delft University of Technology and Erasmus University Rotterdam, in Delft & Rotterdam, the Netherlands. https://www.iccl2025.org/

The International Conference on Computational Logistics and EURO Mini Conference on Maritime Optimization and Logistics (EuroMar) will be held on September 8-10, 2025 at Delft University of Technology and Erasmus University Rotterdam, in Delft & Rotterdam, the Netherlands. In the tradition of the ICCL conference series, ICCL focuses on the theory and applications of operations research, artificial intelligence, and management science to problems in logistics.The EuroMar aims to explore, discuss, and advance all those relevant research areas in the interplay between maritime and port logistics and optimization. 

Topics of the joint conference include among others:

  1. Operations Research and Management in logistics
  2. Routing problems
  3. Maritime logistics
  4. Port operations
  5. Shipping operations
  6. Port call optimization
  7. Emergency logistics
  8. Reverse logistics
  9. Crowd logistics
  10. Freight transportation
  11. Green supply chain
  12. Metropolitan/city logistics
  13. Uncertainty modeling in planning and control
  14. Learning-based optimization in logistics
  15. Large-scale evolutionary optimization in logistics
  16. Multi-agent systems in logistics
  17. Self-organizing logistics
  18. Internet of things in smart logistics
  19. Artificial Intelligence in logistics
  20. Machine learning applications in supply chain
  21. Last-generation ICT networks
  22. Land and maritime smart logistics
  23. ICT in logistics
  24. Computational issues in foreign trade supply chains
  25. Facility (re-)layout decision problems

Important Dates

January 6, 2025: Opening of submission system 
February 21, 2025: Submission deadline for proposal special sessions
March 6, 2025: Notification of acceptance session proposals
May 1, 2025: Submission deadline full papers (conference proceedings) 
June 12, 2025: Submission deadline abstracts for presentation only
June 26, 2025: Notifications of acceptance (for both full papers and abstracts)
July 15, 2025: Deadline for submission of camera-ready paper
August 14, 2025: End of early registration (reduced conference fee)

Guidelines for special session proposals

Session proposals (length up to 400 words) should be submitted to f.schulte@tudelft.nl by  February 21, 2025, and should cover the following points:

  1. Session title.
  2. The organizer(s). Include names, addresses, and affiliations, and indicate the main responsible person. 
  3. A brief summary of the scope/topic.

Guidelines for paper submission 

Two kinds of submissions are invited, that is, a proposal can be submitted for:

  1. Conference papers for publication in Springer’s Lecture Notes in Computer Science (LNCS). 
  2. Abstracts for presentation only.

Publication 

Conference papers will be published in Lecture Notes in Computer Sciences (LNCS), Springer.

Selected papers will be invited to a post-conference special issue for ICCL and EuroMar’25.

ICCL Conference Chairs

  1. Frederik Schulte (Delft University of Technology)
  2. Lóri Tavasszy (Delft University of Technology)
  3. Rob Zuidwijk (Erasmus University Rotterdam)
  4. Rommert Dekker (Erasmus University Rotterdam)
  5. Stefan Voß (University of Hamburg)

EuroMar Conference Chairs

  1. Dario Pacino (Technical University of Denmark)
  2. Rosa G. Gonzalez-Ramirez (University of the Andes)
  3. Çağatay Iris (University of Liverpool)
  4. Eduardo Lalla-Ruiz (University of Twente)
  5. Frederik Schulte (Delft University of Technology)

OR 2025 Bielefeld: Quantitative approaches for a complex world

The International Conference on Operations Research, the annual conference of the German Operations Research Society (GOR), looks forward to welcoming you to Bielefeld, Germany.

The conference is an opportunity for academics, researchers and practitioners to discuss methods and applications of operations research, management science, data science and analytics. How can quantitative methods help to find solutions to problems in a closely networked world? This often requires interdisciplinary approaches typical of operations research applications. The conference will take place from September 2-5, 2025 at Bielefeld University.

We invite academics, researchers and practitioners from all over the world to participate in this inspiring OR 2025 conference and to submit an abstract and optionally a paper for the proceedings. The conference language is English.

Timeline:

  • February 1, 2025
    Abstract submission opens
  • April 1, 2025
    Registration opens
  • April 30, 2025
    Abstract submission deadline     Submissions will still be accepted until the early registration deadline
  • May 15, 2025
    Abstract notification
  • May 31, 2025
    Early-bird registration deadline
  • June 15, 2025
    Presenting author registration deadline
  • July 15, 2025
    Operations Research Proceedings
    submissions deadline (optional)
  • September 2, 2025
    Pre-conference doctoral program Dokt!OR
  • September 3-5, 2025
    Conference

PLENARY Speakers:

  • Ruben Ruiz (Amazon Web Services & Universitat Politècnica de València)
  • David Pisinger (Technical University of Denmark)

SEMI-PLENARY Speakers:

  • Ana Paula Barbosa Póvoa (University of Lisbon)
  • Jan C. Fransoo (Tilburg University)
  • Paul Harper (Cardiff University)
  • Ton de Kok (Eindhoven University of Technology)
  • Manuel López-Ibáñez (University of Manchester)
  • Ruth Misener (Imperial College London)
  • Hana Rudová (Masaryk University)
  • Sibel Salman (Koç University)
  • Eduardo Uchoa (Fluminense Federal University, INRIA International Chair (2022 – 2026))

SOCIAL PROGRAM:

  • Join us for hors d’oeuvres and drinks for a relaxed Get Together at Bielefeld University Mensa X.
  • Welcome Reception in the heart of Bielefeld at the exhibition hall of the city’s Stadthalle.
  • Conference Dinner: Experience Bielefeld’s past as a center of the linen garment industry in the unique surroundings of the Hechelei, where linen was spun and woven until the the destruction of the factory in the Second World War. Enjoy a walk through the adjacent Ravensberger Park before or after your meal.

For further information, visit https://or2025.de/ .

International Conference on Optimization and Decision Science 2025 (ODS 2025), Milano (Italy)

Dear Colleagues,

the International Conference on Optimization and Decision Science 2025 (ODS 2025), organized by AIRO, the Italian Operations Research Society will be held in Milan (Italy) on September 1st – 4th, 2025.

ODS 2025 is entitled „Mathematics, algorithms and the art and science of decision-making“.

The conference scope includes operations research, optimization, problem solving, decision making and their applications.
This edition will draw inspiration, ideas, and cross-disciplinary influences from the fields of applied mathematics, computer science, engineering, and economics.
The conference will favor the gathering of scholars and experts from these disciplines, the mutual fertilization of their approaches and methodologies, and the exploration of their challenges.

ODS 2025 aims to be a venue for academics, professionals, private corporations, public stakeholders, industries, and freelance decision-makers to propose attempts and solutions, engage in knowledge sharing and showcase applications.

Methodological contributions as well as reports on relevant applied research projects are welcome.

On the website http://www.airoconference.it/ods2025/ all relevant information is regularly updated.

Participants can submit either short papers or abstracts. Each registered participant can present at most one work.

  • Short papers (8-10 pages, including front matter and references) will undergo a review process by anonymous referees.
    Accepted papers will be included in a special volume of the AIRO Springer Series, indexed in main scientific databases.
  • Abstracts (max 2000 characters, space included) will be selected by the ODS2025 Program Committee to be included in the conference e–book of abstracts.

For all submission details please refer to:
https://www.airoconference.it/ods2025/call-for-papers

Important Dates:

  • (Strict) Deadline for abstracts and short papers: April 29th, 2025
  • Acceptance notification: By May 30th, 2025
  • Deadline for early registration: May 30th, 2025
  • Deadline for camera-ready papers: June 16th, 2025
  • Registration deadline for inclusion in the final program: August 1st,
    2025
  • Conference: September 1st – 4th, 2025

*** Please, note that, due to the overlapping with related conferences‘
deadlines, some dates have been updated. ***

Contact Information
OptLab, Dept. of Computer Science, University of Milan, ods2025@airoconference.it

The Organizing Committee of ODS 2025