AG Optimierung

Prof. Dr. Stefan Ruzika

Anschrift

Paul-Ehrlich-Straße
Gebäude 14 , Raum 457
67663 Kaiserslautern

Postfach 3049
67653 Kaiserslautern

Kontakt

Tel.: +49 631 205 4423
Fax: +49 631 205 4737
E-Mail: ruzika@mathematik.uni-kl.de


Forschungsinteressen

  • Multikriterielle Optimierung
  • Ganzzahlige und kombinatorische Optimierung
  • Mathematische Modellierung
  • Optimierungsprobleme auf Netzwerken
  • Approximationsalgorithmen

Aktuelle Vorlesungen

Im aktuellen Semester biete ich folgende Vorlesung an:

Location Theory (Standortplanung)

Veröffentlichungen

Journal Papers

  • Shortest Paths with Ordinal Weights
    L. E. Schäfer, T. Dietz, N. Fröhlich, S. Ruzika, J. Figueira,
    arXiv preprint arXiv:1808.09410 (2018)

  • Approximation schemes for the parametric knapsack problem
    A. Giudici, P. Halffmann, S. Ruzika, C. Thielen,
    Information Processing Letters 120, pp. 11-15 (2017)

  • A general approximation method for bicriteria minimization problems
    P. Halffmann, S. Ruzika, C. Thielen, D. Willems,
    Theoretical Computer Science 695, pp. 1-15 (2017)

  • Easy to say they are Hard, but Hard to see they are Easy—Towards a Categorization of Tractable Multiobjective Combinatorial Optimization Problems
    J. Figueira, C. M. Fonseca, P. Halffmann, K. Klamroth, L. Paquete, S. Ruzika, B. Schulze, M. Stiglmayr, D. Willems,
    Journal of Multi-Criteria Decision Analysis 24, pp. 82-98 (2017)

  • Multiobjective optimization for interwoven systems
    K. Klamroth, S. Mostaghim, B. Naujoks, S. Poles, R. Purshouse, G. Rudolph, S. Ruzika, S. Sayin, M. M. Wiecek, X. Yao,
    Journal of Multi-Criteria Decision Analysis 24, pp. 71-81 (2017)

  • A coverage-based Box-Algorithm to compute a representation for optimization problems with three objective functions
    T. Kuhn, S. Ruzika,
    Journal of Global Optimization 67, pp. 581-600 (2017)

  • Shortest Paths with Shortest Detours
    C. Torchiani, J. Ohst, D. Willems, S. Ruzika,
    Journal of Optimization Theory and Applications 174, pp. 858-874 (2017)

  • A hybrid and multiscale approach to model and simulate mobility in the context of public events
    D. H. Biedermann, C. Torchiani, P. M. Kielar, D. Willems, O. Handel, S. Ruzika, A. Borrmann,
    Transportation Research Procedia 19, pp. 350-363 (2016)

  • Evacuation modeling: a case study on linear and nonlinear network flow models
    S. Göttlich, S. Kühn, J. Ohst, S. Ruzika,
    EURO journal on computational optimization 4, pp. 219-239 (2016)

  • Hypervolume subset selection in two dimensions: Formulations and algorithms
    T. Kuhn, C. M. Fonseca, L. Paquete, S. Ruzika, M. M. Duarte, J. Figueira,
    Evolutionary Computation 24, pp. 411-425 (2016)

  • Fahrgastwechselzeiten von Shuttlebussen
    C. Torchiani, M. J. Seitz, D. Willems, S. Ruzika, G. Köster,
    (2015)

  • Comments on: Static and dynamic source locations in undirected networks
    S. Ruzika, C. Torchiani,
    TOP 23, pp. 655-659 (2015)

  • Multiple objective branch and bound for mixed 0-1 linear programming: Corrections and improvements for the biobjective case
    T. Vincent, F. Seipp, S. Ruzika, A. Przybylski, X. Gandibleux,
    Computers & Operations Research 40, pp. 498-509 (2013)

  • Bidirectional coupling of macroscopic and microscopic pedestrian evacuation models
    A. Borrmann, A. Kneidl, G. Köster, S. Ruzika, M. Thiemann,
    Safety science 50, pp. 1695-1703 (2012)

  • Generalized multiple objective bottleneck problems
    J. Gorski, K. Klamroth, S. Ruzika,
    Operations Research Letters 40, pp. 276-281 (2012)

  • Mathematical programming decoding of binary linear codes: Theory and algorithms
    M. Helmling, S. Ruzika, A. Tanatmis,
    IEEE Transactions on Information Theory 58, pp. 4753-4769 (2012)

  • Committee selection under weight constraints
    C. Klamler, U. Pferschy, S. Ruzika,
    Mathematical Social Sciences 64, pp. 48-56 (2012)

  • Min-Max quickest path problems
    S. Ruzika, M. Thiemann,
    Networks 60, pp. 253-258 (2012)

  • Evacuation dynamics influenced by spreading hazardous material
    S. Göttlich, S. Kühn, J. Ohst, S. Ruzika, M. Thiemann,
    Networks & Heterogeneous Media 6, pp. 443-464 (2011)

  • Connectedness of efficient solutions in multiple objective combinatorial optimization
    J. Gorski, K. Klamroth, S. Ruzika,
    Journal of Optimization Theory and Applications 150, pp. 475-497 (2011)

  • Earliest arrival flows on series-parallel graphs
    S. Ruzika, H. Sperber, M. Steiner,
    Networks 57, pp. 169-173 (2011)

  • On k-max-optimization
    J. Gorski, S. Ruzika,
    Operations Research Letters 37, pp. 23-26 (2009)

  • Improved epsilon-constraint method for multiobjective programming
    M. Ehrgott, S. Ruzika,
    Journal of Optimization Theory and Applications 138, pp. 375 (2008)

  • Finding representative systems for discrete bicriterion optimization problems
    H. W. Hamacher, C. Pedersen, S. Ruzika,
    Operations Research Letters 35, pp. 336-344 (2007)

  • Multiple objective minimum cost flow problems: A review
    H. W. Hamacher, C. Pedersen, S. Ruzika,
    European Journal of Operational Research 176, pp. 1404-1422 (2007)

  • An Exact Algorithm for Solving Weight-Constrained Combinatorial Optimization Problems
    S. Ruzika,
    Electronic Notes in Discrete Mathematics, pp. 143-144 (2006)

  • Algorithms for time-dependent bicriteria shortest path problems
    H. W. Hamacher, S. Ruzika, S. A. Tjandra,
    Discrete optimization 3, pp. 238-254 (2006)

  • Approximation methods in multiobjective programming
    S. Ruzika, M. M. Wiecek,
    Journal of optimization theory and applications 126, pp. 473-501 (2005)

  • Detecting local convexity on the Pareto surface
    G. Fadel, Y. Li, S. Konda, M. M. Wiecek, S. Ruzika,
    Journal of Multi-Criteria Decision Analysis 11, pp. 45-54 (2002)

Proceedings

  • Improved Maximum-Likelihood Decoding Using Sparse Parity-Check Matrices
    F. Gensheimer, T. Dietz, S. Ruzika, K. Kraft, N. Wehn,
    2018 25th International Conference on Telecommunications (ICT), pp. 236-240 (2018)

  • ADMM versus simplex algorithm for LP decoding
    F. Gensheimer, S. Ruzika, S. Scholl, N. Wehn,
    Turbo Codes and Iterative Information Processing (ISTC), 2016 9th International Symposium on, pp. 211-215 (2016)

  • A simplex algorithm for LP decoding hardware
    F. Gensheimer, S. Ruzika, S. Scholl, N. Wehn,
    Personal, Indoor, and Mobile Radio Communication (PIMRC), 2014 IEEE 25th Annual International Symposium on, pp. 790-794 (2014)

  • Efficient maximum-likelihood decoding of linear block codes on binary memoryless channels
    M. Helmling, E. Rosnes, S. Ruzika, S. Scholl,
    Information Theory (ISIT), 2014 IEEE International Symposium on, pp. 2589-2593 (2014)

  • Towards combinatorial LP turbo decoding
    M. Helmling, S. Ruzika,
    Information Theory Proceedings (ISIT), 2013 IEEE International Symposium on, pp. 1491-1495 (2013)

  • Integer programming as a tool for analysis of channel codes
    S. Scholl, F. Kienle, M. Helmling, S. Ruzika,
    Systems, Communication and Coding (SCC), Proceedings of 2013 9th International ITG Conference on, pp. 1-6 (2013)

  • ML vs. BP decoding of binary and non-binary LDPC codes
    S. Scholl, F. Kienle, M. Helmling, S. Ruzika,
    Turbo Codes and Iterative Information Processing (ISTC), 2012 7th International Symposium on, pp. 71-75 (2012)

  • Mathematical modeling of earthwork optimization problems
    Y. Ji, F. Seipp, A. Borrmann, S. Ruzika, E. Rank,
    Proc. of the International Conference on Computing in Civil and Building Engineering (ICCCBE) (2010)

  • Calculating the minimum distance of linear block codes via integer programming
    M. Punekar, F. Kienle, N. Wehn, A. Tanatmis, S. Ruzika, H. W. Hamacher,
    Turbo Codes and Iterative Information Processing (ISTC), 2010 6th International Symposium on, pp. 329-333 (2010)

  • A Lagrangian relaxation based decoding algorithm for LTE turbo codes
    A. Tanatmis, S. Ruzika, F. Kienle,
    Turbo Codes and Iterative Information Processing (ISTC), 2010 6th International Symposium on, pp. 369-373 (2010)

  • Numerical comparison of IP formulations as ML decoders
    A. Tanatmis, S. Ruzika, M. Punekar, F. Kienle,
    Communications (ICC), 2010 IEEE International Conference on, pp. 1-5 (2010)

  • Committee selection with a weight constraint based on lexicographic rankings of individuals
    C. Klamler, U. Pferschy, S. Ruzika,
    International Conference on Algorithmic DecisionTheory, pp. 50-61 (2009)

  • Valid inequalities for binary linear codes
    A. Tanatmis, S. Ruzika, H. W. Hamacher, M. Punekar, F. Kienle, N. Wehn,
    Information Theory, 2009. ISIT 2009. IEEE International Symposium on, pp. 2216-2220 (2009)

  • A separation algorithm for improved LP-decoding of linear block codes
    A. Tanatmis, S. Ruzika, H. W. Hamacher, M. Punekar, F. Kienle, N. Wehn,
    Turbo Codes and Related Topics, 2008 5th International Symposium on, pp. 37-42 (2008)

  • Hub location’s tool box: Integer programming, heuristics, aggregation, multiobjective optimization
    S. Baumgartner, E. O. Gavriliouk, H. W. Hamacher, T. Meyer, S. Ruzika,
    Extended Abstract, ISOLDE X Meeting, Sevilla, Spain (2005)
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