Prof. Dr. Stefan Ruzika
Anschrift
Ich leite das Kompetenzzentrum für mathematische Modellierung in MINT-Projekten in der Schule (KOMMS). Besuchen Sie auch die Webseite von KOMMS.
Außerdem bin ich Sprecher des von der Deutschen Forschungsgemeinschaft geförderten Graduiertenkollegs Mathematics of Interdisciplinary Multiobjective Optimization (MIMO), das im Oktober 2024 seine Forschungsarbeit aufnehmen wird. Informationen zum neuen Graduiertenkolleg finden Sie hier.
Aktuelle Lehrveranstaltungen
Im Sommersemester 2025 biete ich folgende Vorlesungen und Seminare an:
Ich betreue außerdem Bachelor- und Masterarbeiten. Wenn Sie hieran Interesse haben, melden Sie sich bitte per E-Mail bei mir.
Forschungsinteressen
- Multikriterielle Optimierung
- Ganzzahlige und kombinatorische Optimierung
- Mathematische Modellierung
- Optimierungsprobleme auf Netzwerken
- Approximationsalgorithmen
Forschungsprojekte
Funktionen (Auswahl)
- seit 2024: Sprecher des DFG-Graduiertenkollegs 2982 "Mathematics of Interdisciplinary Multiobjective Optimization"
- seit 2023: Mitglied des Vorstands der Gesellschaft für Operations Research (GOR); zuständig für den Vorstandsbereich „Arbeitsgruppen“
- seit 2017: Leiter des Kompetenzzentrum für mathematische Modellierung in MINT-Projekten in der Schule (KOMMS)
Curriculum Vitae
- seit 2017: Professor (W3) im Fachbereich Mathematik an der Rheinland-Pfälzischen Technischen Universität Kaiserslautern-Landau (RPTU), ehemals: TU Kaiserslautern
- 2012-2017: Professor für Mathematik (W3), Universität Koblenz-Landau
- 2009-2010: Vertretungsprofessur am Lehrstuhl für Optimierung, Bergische Universität Wuppertal
- 2008-2012: Juniorprofessor für mathematische Optimierung und Anwendungen, TU Kaiserslautern
- 2007: Promotion (Dr.rer.nat.), TU Kaiserslautern
Thesis: On Multiple Objective Combinatorial Optimization
- 2003-2007: Wissenschaftlicher Mitarbeiter, TU Kaiserslautern
- 2003: Diplom in Mathematik, TU Kaiserslautern
- 2002: Master of Science, Clemson University, South Carolina, USA
- 2001-2002: Studium der Mathematik, Clemson University, South Carolina, USA
- 1998-2003: Studium der Mathematik und Informatik, TU Kaiserslautern
Veröffentlichungen
- A. Herzel, S. Helfrich, S. Ruzika, C. Thielen
Approximating biobjective minimization problems using general ordering cones
Journal of Global Optimization (2023) - P. Halffmann, L. E. Schäfer, K. Dächert, K. Klamroth, S. Ruzika
Exact algorithms for multiobjective linear optimization problems with integer variables: A state of the art survey
Journal of Multi-Criteria Decision Analysis 29, pp. 341-363 (2022) - K. Küfer, K. Miettinen, S. Ruzika, S. Sayin
Multi-criteria optimization in industry
OR Spectrum 44, pp. 303-305 (2022) - C. Bazgan, S. Ruzika, C. Thielen, D. Vanderpooten
The power of the weighted sum scalarization for approximating multiobjective optimization problems
Theory of Computing Systems 66, pp. 395-415 (2022) - N. Fröhlich, S. Ruzika
Interdicting facilities in tree networks
Top 30, pp. 95-118 (2022) - S. Helfrich, A. Herzel, S. Ruzika, C. Thielen
An Approximation Algorithm for a General Class of Multi-Parametric Optimization Problems
Journal of Combinatorial Optimization 44, pp. 1459-1494 (2022) - M. Bracke, S. Ruzika
Wie gut ist mein Timing? Modellieren mit realen, selbst erzeugten Daten
MATHEMATIK 5-10 2021, pp. 38-41 (2021) - A. Herzel, S. Ruzika, C. Thielen
Approximation methods for multiobjective optimization problems: A survey
INFORMS Journal on Computing 33, pp. 1284-1299 (2021) - L. Schneider, R. B. Ferri, S. Ruzika
On the influence of knowledge about the ideal-typical modelling processes on individuals’ modelling routes
Quadrante 30, pp. 220-241 (2021) - N. Fröhlich, S. Ruzika
Interdicting facilities in tree networks
TOP, pp. 1-24 (2021) - N. Fröhlich, S. Ruzika
On the hardness of covering-interdiction problems
Theoretical Computer Science 871, pp. 1-15 (2021) - L. E. Schäfer, T. Dietz, M. Barbati, J. R. Figueira, S. Greco, S. Ruzika
The binary knapsack problem with qualitative levels
European Journal of Operational Research (2020) - T. Ullmert, S. Ruzika, A. Schöbel
On the p-hub interdiction problem
Computers & Operations Research 124, pp. 105056 (2020) - T. Dietz, K. Klamroth, K. Kraus, S. Ruzika, L. E. Schäfer, B. Schulze, M. Stiglmayr, M. M. Wiecek
Introducing multiobjective complex systems
European Journal of Operational Research 280, pp. 581-596 (2020) - L. E. Schäfer, T. Dietz, N. Fröhlich, S. Ruzika, J. R. Figueira
Shortest paths with ordinal weights
European Journal of Operational Research 280, pp. 1160-1170 (2020) - L. Streib, M. Kattwinkel, H. Heer, S. Ruzika, R. B. Schäfer
How does habitat connectivity influence the colonization success of a hemimetabolous aquatic insect? - A modeling approach
Ecological Modelling 416, pp. 108909 (2020) - B. Schulze, M. Stiglmayr, L. Paquete, C. M. Fonseca, D. Willems, S. Ruzika
On the rectangular knapsack problem: approximation of a specific quadratic knapsack problem
Mathematical Methods of Operations Research, pp. 1-26 (2020) - F. Gensheimer, T. Dietz, K. Kraft, S. Ruzika, N. Wehn
A Reduced-Complexity Projection Algorithm for ADMM-based LP Decoding
IEEE Transactions on Information Theory (2020) - P. Halffmann, T. Dietz, A. Przybylski, S. Ruzika
An inner approximation method to compute the weight set decomposition of a triobjective mixed-integer problem
Journal of Global Optimization (2020) - A. Herzel, C. Bazgan, S. Ruzika, C. Thielen, D. Vanderpooten
One-exact approximate Pareto sets
Journal of Global Optimization, pp. 1-29 (2020) - L. M. Russo, T. Dietz, J. R. Figueira, A. P. Francisco, S. Ruzika
Sparsifying parity-check matrices
Applied Soft Computing 96, pp. 106601 (2020) - H. Heer, L. Streib, R. B. Schäfer, S. Ruzika
Maximising the clustering coefficient of networks and the effects on habitat network robustness
Plos one 15, pp. e0240940 (2020) - C. Bazgan, A. Herzel, S. Ruzika, C. Thielen, D. Vanderpooten
An approximation algorithm for a general class of parametric optimization problems
Journal of Combinatorial Optimization, pp. 1-31 (2020) - M. Bracke, C. Gomez-Tutor, J. Kuhn, S. Ruzika
Unified Education: Medienbildung entlang der Lehrerbildungskette-Maßnahmen im Rahmen der Qualitätsoffensive Lehrerbildung der TU Kaiserslautern
Mitteilungen der Gesellschaft für Didaktik der Mathematik 45, pp. 33-38 (2019) - H. Heer, L. Streib, M. Kattwinkel, R. B. Schäfer, S. Ruzika
Optimisation Model of Dispersal Simulations on a Dendritic Habitat Network
Scientific Reports 9, pp. 1-11 (2019) - J. R. Figueira, C. M. Fonseca, P. Halffmann, K. Klamroth, L. Paquete, S. Ruzika, B. Schulze, M. Stiglmayr, D. Willems
Easy to say they are Hard, but Hard to see they are Easy - Towards a Categorization of Tractable Multiobjective Combinatorial Optimization Problems
Journal of Multi-Criteria Decision Analysis 24, pp. 82-98 (2017) - T. Kuhn, S. Ruzika
A coverage-based Box-Algorithm to compute a representation for optimization problems with three objective functions
Journal of Global Optimization 67, pp. 581-600 (2017) - P. Halffmann, S. Ruzika, C. Thielen, D. Willems
A General Approximation Method for Bicriteria Minimization Problems
Theoretical Computer Science 695, pp. 1-15 (2017) - A. Giudici, P. Halffmann, S. Ruzika, C. Thielen
Approximation Schemes For the Parametric Knapsack Problem
Information Processing Letters 120, pp. 11-15 (2017) - K. Klamroth, S. Mostaghim, B. Naujoks, S. Poles, R. Purshouse, G. Rudolph, S. Ruzika, S. Sayin, M. M. Wiecek, X. Yao
Multiobjective optimization for interwoven systems
Journal of Multi-Criteria Decision Analysis 24, pp. 71-81 (2017) - C. Torchiani, J. Ohst, D. Willems, S. Ruzika
Shortest Paths with Shortest Detours
Journal of Optimization Theory and Applications 174, pp. 858-874 (2017) - D. H. Biedermann, C. Torchiani, P. M. Kielar, D. Willems, O. Handel, S. Ruzika, A. Borrmann
A hybrid and multiscale approach to model and simulate mobility in the context of public events
Transportation Research Procedia 19, pp. 350-363 (2016) - S. Göttlich, S. Kühn, J. P. Ohst, S. Ruzika
Evacuation modeling: a case study on linear and nonlinear network flow models
EURO journal on computational optimization 4, pp. 219-239 (2016) - T. Kuhn, C. M. Fonseca, L. Paquete, S. Ruzika, M. M. Duarte, J. R. Figueira
Hypervolume subset selection in two dimensions: Formulations and algorithms
Evolutionary Computation 24, pp. 411-425 (2016) - S. Ruzika, C. Torchiani
Comments on: Static and dynamic source locations in undirected networks
TOP 23, pp. 655-659 (2015) - C. Torchiani, M. J. Seitz, D. Willems, S. Ruzika, G. Köster
Fahrgastwechselzeiten von Shuttlebussen
H. TUM-I1517. TU München: Universität Koblenz-Landau 2015 (2015) - T. Vincent, F. Seipp, S. Ruzika, A. Przybylski, X. Gandibleux
Multiple objective branch and bound for mixed 0-1 linear programming: Corrections and improvements for the biobjective case
Computers & Operations Research 40, pp. 498-509 (2013) - A. Borrmann, A. Kneidl, G. Köster, S. Ruzika, M. Thiemann
Bidirectional coupling of macroscopic and microscopic pedestrian evacuation models
Safety science 50, pp. 1695-1703 (2012) - C. Klamler, U. Pferschy, S. Ruzika
Committee selection under weight constraints
Mathematical Social Sciences 64, pp. 48-56 (2012) - J. Gorski, K. Klamroth, S. Ruzika
Generalized multiple objective bottleneck problems
Operations Research Letters 40, pp. 276-281 (2012) - M. Helmling, S. Ruzika, A. Tanatmis
Mathematical programming decoding of binary linear codes: Theory and algorithms
IEEE Transactions on Information Theory 58, pp. 4753-4769 (2012) - S. Ruzika, M. Thiemann
Min-Max quickest path problems
Networks 60, pp. 253-258 (2012) - J. Gorski, K. Klamroth, S. Ruzika
Connectedness of efficient solutions in multiple objective combinatorial optimization
Journal of Optimization Theory and Applications 150, pp. 475-497 (2011) - S. Ruzika, H. Sperber, M. Steiner
Earliest arrival flows on series-parallel graphs
Networks 57, pp. 169-173 (2011) - S. Göttlich, S. Kühn, J. P. Ohst, S. Ruzika, M. Thiemann
Evacuation dynamics influenced by spreading hazardous material
Networks & Heterogeneous Media 6, pp. 443-464 (2011) - J. Gorski, S. Ruzika
On k-max-optimization
Operations Research Letters 37, pp. 23-26 (2009) - M. Ehrgott, S. Ruzika
Improved epsilon-constraint method for multiobjective programming
Journal of Optimization Theory and Applications 138, pp. 375 (2008) - H. W. Hamacher, C. R. Pedersen, S. Ruzika
Finding representative systems for discrete bicriterion optimization problems
Operations Research Letters 35, pp. 336-344 (2007) - H. W. Hamacher, C. R. Pedersen, S. Ruzika
Multiple objective minimum cost flow problems: A review
European Journal of Operational Research 176, pp. 1404-1422 (2007) - H. W. Hamacher, S. Ruzika, S. A. Tjandra
Algorithms for time-dependent bicriteria shortest path problems
Discrete optimization 3, pp. 238-254 (2006) - S. Ruzika
An Exact Algorithm for Solving Weight-Constrained Combinatorial Optimization Problems
Electronic Notes in Discrete Mathematics, pp. 143-144 (2006) - S. Ruzika, M. M. Wiecek
Approximation methods in multiobjective programming
Journal of optimization theory and applications 126, pp. 473-501 (2005) - G. Fadel, Y. Li, S. Konda, M. M. Wiecek, S. Ruzika
Detecting local convexity on the Pareto surface
Journal of Multi-Criteria Decision Analysis 11, pp. 45-54 (2002)
- J. Andersen, M. Baum, C. Dictus, A. Greubel, L. Knippertz, J. Krüger, I. Neumann, B. Priemer, S. Ruzika, J. Schulz, others
Critical Thinking--Gelegenheit für MINT-Lernen in der Zukunft?
Die Zukunft des MINT-Lernens--Band 1: Perspektiven auf (digitalen) MINT-Unterricht und Lehrkräftebildung, Springer Berlin Heidelberg Berlin, Heidelberg, pp. 43-57 (2022) - S. Becker, L. Knippertz, J. Kuhn, L. Kuntz, S. Ruzika
Blickdatenanalyse bei der Interpretation linearer Graphen im mathematischen und physikalischen Kontext
Die Zukunft des MINT-Lernens--Band 1: Perspektiven auf (digitalen) MINT-Unterricht und Lehrkräftebildung, Springer Berlin Heidelberg Berlin, Heidelberg, pp. 181-192 (2022) - K. Kennel, S. Becker, P. Klein, S. Küchemann, J. Kuhn, S. Ruzika
Blickbewegungen beim grafischen Ableiten--Lassen sich Fehler durch Eye-Tracking-Daten vorhersagen und elaborieren?
Eye-Tracking in der Mathematik-und Naturwissenschaftsdidaktik: Forschung und Praxis, Springer, pp. 125-143 (2022) - S. Küchemann, N. Cullmann, S. Kovac, S. Becker, P. Klein, K. Kennel, S. Ruzika, J. Kuhn
Blickverhalten beim Lernen und Problemlösen mit Graphen--Ein Literaturüberblick bis 2020
Eye-Tracking in der Mathematik-und Naturwissenschaftsdidaktik, Springer, pp. 177-192 (2022) - L. E. Schäfer, S. Ruzika
On Variants of the Single-criterion and Multiobjective Near-Shortest Paths Problem
Multikriterielle Optimierung und Entscheidungsunterstützung, Springer Fachmedien Wiesbaden, pp. 17-30 (2019) - K. Küfer, S. Ruzika, P. Halffmann
Multikriterielle Optimierung und Entscheidungsunterstützung: Tagungsband GOR Entscheidungstheorie und-praxis 2018
Springer-Verlag (2019) - S. Ruzika, V. Klöckner, S. Gecks
Wie man einen Testsieger kürt
Digitale Werkzeuge, Simulationen und mathematisches Modellieren, Springer, pp. 229-252 (2018) - D. Willems, O. Zehner, S. Ruzika
On a Technique for Finding Running Tracks of Specific Length in a Road Network
Operations Research Proceedings 2017, Springer, pp. 333-338 (2018) - S. Ruzika, H. Siller, M. Bracke
Evakuierungsszenarien in Modellierungswochen - ein interessantes und spannendes Thema für den Mathematikunterricht
Neue Materialien für einen realitätsbezogenen Mathematikunterricht 3, Springer, pp. 181-190 (2017) - S. Ruzika, H. Siller, M. Bracke
Evakuierungsszenarien in Modellierungswochen--ein interessantes und spannendes Thema für den Mathematikunterricht
Neue Materialien für einen realitätsbezogenen Mathematikunterricht 3, Springer, pp. 181-190 (2017) - S. Göttlich, S. Kühn, J. P. Ohst, S. Ruzika
Influence of Spreading Hazardous Material in Macroscopic Evacuation Dynamics: A Proof of Concept
Pedestrian and Evacuation Dynamics 2012, Springer, pp. 275-282 (2014) - A. Kneidl, M. Thiemann, A. Borrmann, S. Ruzika, H. W. Hamacher, G. Köster, E. Rank
Bidirectional coupling of macroscopic and microscopic approaches for pedestrian behavior prediction
Pedestrian and Evacuation Dynamics, Springer, pp. 459-470 (2011) - K. Leiner, S. Ruzika
Quickest cluster flow problems on tree networks
Network Optimization, Springer, pp. 243-255 (2011) - S. Ruzika, M. Thiemann
Reliable and restricted quickest path problems
Network Optimization, Springer, pp. 309-314 (2011) - H. W. Hamacher, S. Heller, W. Klein, G. Köster, S. Ruzika
A sandwich approach for evacuation time bounds
Pedestrian and Evacuation Dynamics, Springer, pp. 503-513 (2011) - H. W. Hamacher, K. Leiner, S. Ruzika
Quickest cluster flow problems
Pedestrian and Evacuation Dynamics, Springer, pp. 327-336 (2011) - H. W. Hamacher, S. Ruzika
Flach spielen, hoch gewinnen: Fußball und Wissenschaft
Shaker (2010) - S. Ruzika, H. W. Hamacher
A survey on multiple objective minimum spanning tree problems
Algorithmics of Large and Complex Networks, Springer, pp. 104-116 (2009) - S. Ruzika
On multiple objective combinatorial optimization
Verlag Dr. Hut (2007)
- L. Knippertz, S. Becker, J. Kuhn, S. Ruzika
Gaze pattern analysis to reveal student difficulties in interpreting kinematic graphs
Twelfth Congress of the European Society of Research in Mathematics Education (CERME12) (2022) - A. Greubel, H. Siller, S. Ruzika, L. Knippertz
Teaching Mathematical Modeling with Computing Technology: Presentation of a Course based on Evacuations
Proceedings of the 17th Workshop in Primary and Secondary Computing Education, pp. 1-6 (2022) - L. Albert, N. Fröhlich, N. Hausbrand, S. Henninger, T. Maurer, S. Ruzika
Human-biometeorologisch angepasste Routenführungen durch mathematische Optimierung
Mobility, Knowledge and Innovation Hubs in Urban and Regional Development. Proceedings of REAL CORP 2022, 27th International Conference on Urban Development, Regional Planning and Information Society, pp. 427-435 (2022) - M. Stiewing, T. Weber, K. Mangels, S. Ruzika, N. Fröhlich, N. Hausbrandt
„Black Box Babyboomer”--Was kommt auf Kommunen zu? Decision Support System mit Hilfe mathematischer Erreichbarkeitsmodellierung medizinischer Versorgungsstandorte
Mobility, Knowledge and Innovation Hubs in Urban and Regional Development. Proceedings of REAL CORP 2022, 27th International Conference on Urban Development, Regional Planning and Information Society, pp. 131-141 (2022) - L. Schneider, R. B. Ferri, S. Ruzika
How knowledge about ideal-typical modelling processes affects phase transitions in individual modelling routes
Twelfth Congress of the European Society for Research in Mathematics Education (2022) - L. E. Schäfer, T. Dietz, M. V. Natale, S. Ruzika, S. O. Krumke, C. M. Fonseca
The Bicriterion Maximum Flow Network Interdiction Problem in s-t-Planar Graphs
Operations Research Proceedings 2019, pp. 133-139 (2020) - P. Schiewe, A. Schöbel, S. Ruzika
Kosten oder Reisezeit? Bikriterielle Optimierung der integrierten Fahr- und Umlaufplanung
Preprint Heureka'21 (2020) - C. Bazgan, A. Herzel, S. Ruzika, C. Thielen, D. Vanderpooten
An FPTAS for a General Class of Parametric Optimization Problems
International Computing and Combinatorics Conference, pp. 25-37 (2019) - S. Ruzika, L. Schneider
On the role of multicriteria decision support in mathematical modelling
Eleventh Congress of the European Society for Research in Mathematics Education 24 (2019) - F. Gensheimer, T. Dietz, S. Ruzika, K. Kraft, N. Wehn
Improved Maximum-Likelihood Decoding Using Sparse Parity-Check Matrices
2018 25th International Conference on Telecommunications (ICT), pp. 236-240 (2018) - F. Gensheimer, T. Dietz, S. Ruzika, K. Kraft, N. Wehn
A Low-Complexity Projection Algorithm for ADMM-Based LP Decoding
2018 IEEE 10th International Symposium on Turbo Codes & Iterative Information Processing (ISTC), pp. 1-5 (2018) - D. H. Biedermann, C. Torchiani, P. M. Kielar, D. Willems, O. Handel, S. Ruzika, A. Borrmann
A hybrid and multiscale approach to model and simulate mobility in the context of public events
Transportation Research Procedia (19), pp. 350-363 (2016) - F. Gensheimer, S. Ruzika, S. Scholl, N. Wehn
ADMM versus simplex algorithm for LP decoding
9th International Symposium on Turbo Codes and Iterative Information Processing (ISTC), 2016, pp. 211-215 (2016) - F. Gensheimer, S. Ruzika, S. Scholl, N. Wehn
A simplex algorithm for LP decoding hardware
Personal, Indoor, and Mobile Radio Communication (PIMRC), 2014 IEEE 25th Annual International Symposium on, pp. 790-794 (2014) - M. Helmling, E. Rosnes, S. Ruzika, S. Scholl
Efficient maximum-likelihood decoding of linear block codes on binary memoryless channels
Information Theory (ISIT), 2014 IEEE International Symposium on, pp. 2589-2593 (2014) - S. Scholl, F. Kienle, M. Helmling, S. Ruzika
Integer programming as a tool for analysis of channel codes
Systems, Communication and Coding (SCC), Proceedings of 2013 9th International ITG Conference on, pp. 1-6 (2013) - M. Helmling, S. Ruzika
Towards combinatorial LP turbo decoding
2013 IEEE International Symposium on Information Theory Proceedings (ISIT), pp. 1491-1495 (2013) - S. Scholl, F. Kienle, M. Helmling, S. Ruzika
ML vs. BP decoding of binary and non-binary LDPC codes
Turbo Codes and Iterative Information Processing (ISTC), 2012 7th International Symposium on, pp. 71-75 (2012) - A. Tanatmis, S. Ruzika, F. Kienle
A Lagrangian relaxation based decoding algorithm for LTE turbo codes
Turbo Codes and Iterative Information Processing (ISTC), 2010 6th International Symposium on, pp. 369-373 (2010) - M. Punekar, F. Kienle, N. Wehn, A. Tanatmis, S. Ruzika, H. W. Hamacher
Calculating the minimum distance of linear block codes via integer programming
Turbo Codes and Iterative Information Processing (ISTC), 2010 6th International Symposium on, pp. 329-333 (2010) - Y. Ji, F. Seipp, A. Borrmann, S. Ruzika, E. Rank
Mathematical modeling of earthwork optimization problems
Proc. of the International Conference on Computing in Civil and Building Engineering (ICCCBE) (2010) - A. Tanatmis, S. Ruzika, M. Punekar, F. Kienle
Numerical comparison of IP formulations as ML decoders
Communications (ICC), 2010 IEEE International Conference on, pp. 1-5 (2010) - C. Klamler, U. Pferschy, S. Ruzika
Committee selection with a weight constraint based on lexicographic rankings of individuals
International Conference on Algorithmic DecisionTheory, pp. 50-61 (2009) - A. Tanatmis, S. Ruzika, H. W. Hamacher, M. Punekar, F. Kienle, N. Wehn
Valid inequalities for binary linear codes
IEEE International Symposium on Information Theory, 2009. ISIT 2009., pp. 2216-2220 (2009) - A. Tanatmis, S. Ruzika, H. W. Hamacher, M. Punekar, F. Kienle, N. Wehn
A separation algorithm for improved LP-decoding of linear block codes
5th International Symposium on Turbo Codes and Related Topics, 2008, pp. 37-42 (2008) - S. Baumgartner, E. O. Gavriliouk, H. W. Hamacher, T. Meyer, S. Ruzika
Hub location's tool box: Integer programming, heuristics, aggregation, multiobjective optimization
Extended Abstract, ISOLDE X Meeting, Sevilla, Spain (2005)