Team

Prof. Dr. Kathrin Klamroth (Uni Wuppertal)
Dr. Andreia Guerreiro (INESC-ID Lisbon)

Prof. Dr. José Rui Figueira (IST Lisbon)
Prof. Dr. Carlos Fonseca (Universität Coimbra)
Philipp Herrmann (RPTU Kaiserslautern-Landau)
Prof. Dr. Luís Paquete (Universität Coimbra)
Prof. Dr. Stefan Ruzika (RPTU Kaiserslautern-Landau)
PD Dr. Michael Stiglmayr (Uni Wuppertal)
Dr. Julia Sudhoff Santos (Uni Wuppertal)

Projekt

Ordinal combinatorial optimization (OCO) problems can be best motivated by an application example. Consider the problem of planning safe and convenient bicycle routes for every-day travel. In this context, we distinguish between safe streets (green: reserved for cyclists), medium-safe streets (orange: having a reasonably safe bicycle lane), and unsafe streets (red: busy streets without a bicycle lane). Assuming that green is better than orange, and that orange is better than red, a path with one green and one orange edge (g,o) is clearly preferred over a path with one green and one red edge (g,r). However, when comparing a path with orange, orange (o,o) with a path with green, red (g,r), a ranking depends on the individual preferences of the decision maker. Ordinal combinatorial optimization is concerned with the modelling and analysis of ordering relations in the presence of ordinal criteria, the derivation of ordinally nondominated solutions, and the development as well as implementation of efficient solution methods for different classes of combinatorial optimization problems including shortest paths, network flows, knapsack problems, and assignment problems, among others.

The scientific goal of this project is to advance the theoretical understanding and the algorithmic solution of ordinal combinatorial optmization problems by combining state-of-the-art methods from Computer Science and from Mathematical Optimization for mutual benefit. Simultaneously, we establish and advance an international and cross-disciplinary collaboration between the Universities at Coimbra, Lissabon, Kaiserslautern, and Wuppertal. The project promotes the scientific careers of young and promising researchers by supporting research stays at the respective partner organizations and by integrating master students though the joint supervision of master theses.

Workshop, Meetings, Forschungsaufenthalte

• 22.–28.9.2024 in Coimbra und Lissabon (Stefan Ruzika und Philipp Herrmann)
• 21.–25.10.2014 in Coimbra und Lissabon (Kathrin Klamroth und Michael Stiglmayr)

Konferenz-Vorträge

1. J. Sudhoff Santos: "A Divide-And-Conquer Approach for Polyhedral Dominance Cones: Bridging the Gap from General Order Relations to Practical Problem Solving", MCDM 2024, Hammamet, June 6, 2024
2. K. Klamroth: "Ordinal Location Problems and Consistent Multiobjective Shortest Paths", MCDM 2024, Hammamet, June 6, 2024

Abschlussarbeiten

• Renée Lamsfuß: "Ordinal Location Problems with Consistent Multiobjective Shortest Paths". Master Thesis, Bergische Universität Wuppertal, April 2024