Ann-Kathrin Wiertz

On a Tractable Single-Level Reformulation of a Multilevel Model of the European Entry-Exit Gas Market with Market Power

  • Veronika Grimm
  • Julia Grübel
  • Martin Schmidt
  • Alexandra Schwartz
  • Gregor Zöttl
  • Ann-Kathrin Wiertz
    • Categories Complementarity and Variational Inequalities, Energy Tags , , ,

    We propose a framework that allows to quantitatively analyze the interplay of the different agents involved in gas trade and transport in the context of the European entry-exit system. Previous contributions have focused on the case of perfectly competitive buyers and sellers of gas, which allows to replace the respective market equilibrium problem by a … Read more

    Algorithms for the Clique Problem with Multiple-Choice Constraints under a Series-Parallel Dependency Graph

  • Andreas Bärmann
  • Patrick Gemander
  • Maximilian Merkert
  • Ann-Kathrin Wiertz
  • Francisco Javier Zaragoza Martínez
    • Categories Dynamic Programming, Graphs and Matroids, Polyhedra Tags , , , ,

    The clique problem with multiple-choice constraints (CPMC), i.e. the problem of finding a k-clique in a k-partite graph with known partition, occurs as a substructure in many real-world applications, in particular scheduling and railway timetabling. Although CPMC is NP-complete in general, it is known to be solvable in polynomial time when the so-called dependency graph … Read more