Research Interests:

  • Integer and Combinatorial Multiobjective Optimization
  • Mathematical Modelling
  • Operations Research in Health Care Management

Publications:

  • Helfrich, S., Ruzika, S., Thielen, C. Efficiently Constructing Convex Approximation Sets in Multiobjective Optimization Problems. INFORMS Journal on Computing (online first) (2024). https://doi.org/10.1287/ijoc.2023.0220
  • Helfrich, S., Prinz, K. & Ruzika, S. The Weighted p-Norm Weight Set Decomposition for Multiobjective Discrete Optimization Problems. Journal of Optimization Theory and Applications 202, 1187–1216 (2024). https://doi.org/10.1007/s10957-024-02481-8
  • Helfrich, S., Herzel, A., Ruzika, S. et al. Using scalarizations for the approximation of multiobjective optimization problems: towards a general theory. Mathematical Methods of Operations Research 100, 27–63 (2024). https://doi.org/10.1007/s00186-023-00823-2
  • Helfrich, S. Approximation and Scalarization in Multiobjective Optimization. Verlag Dr. Hut. (2023).
  • Helfrich, S., Perini, T., Halffmann, P. et al. Analysis of the weighted Tchebycheff weight set decomposition for multiobjective discrete optimization problems. Journal of Global Optimization 86, 417–440 (2023). https://doi.org/10.1007/s10898-023-01284-x
  • Herzel, A., Helfrich, S., Ruzika, S. et al. Approximating biobjective minimization problems using general ordering cones. Journal of Global Optimization 86, 393–415 (2023). https://doi.org/10.1007/s10898-023-01276-x
  • Helfrich, S., Herzel, A., Ruzika, S. et al. An approximation algorithm for a general class of multi-parametric optimization problems. Journal of Combinatorial Optimization 44, 1459–1494 (2022). https://doi.org/10.1007/s10878-022-00902-w