• Publications
  • Influence
On the Computation of Fully Proportional Representation
TLDR
We investigate the parameterized complexity of winner determination of the two classical and two new rules with respect to several parameters. Expand
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Unweighted Coalitional Manipulation under the Borda Rule Is NP-Hard
TLDR
The Borda voting rule is a positional scoring rule where, for m candidates, for every vote the first candidate receives m- 1 points, the second m- 2 points and so on. Expand
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Separator-based data reduction for signed graph balancing
TLDR
Polynomial-time data reduction is a classical approach to hard graph problems. Expand
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Towards a dichotomy for the Possible Winner problem in elections based on scoring rules
  • N. Betzler, B. Dorn
  • Mathematics, Computer Science
  • J. Comput. Syst. Sci.
  • 18 November 2009
TLDR
We show that Possible Winner is NP-complete for all pure scoring rules except plurality, veto, and the scoring rule defined by the scoring vector (2,1,...,1,0). Expand
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Fixed-parameter algorithms for Kemeny rankings
TLDR
The computation of Kemeny rankings is central to many applications in the context of rank aggregation. Expand
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Experiments on data reduction for optimal domination in networks
TLDR
We present empirical results on computing optimal dominating sets in networks by means of data reduction through efficient preprocessing rules. Expand
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Parameterized Algorithms and Hardness Results for Some Graph Motif Problems
We study the NP-complete Graph Motif problem: given a vertex-colored graph G= (V,E) and a multiset Mof colors, does there exist an Si¾? Vsuch that G[S] is connected and carries exactly (also withExpand
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Towards a Dichotomy of Finding Possible Winners in Elections Based on Scoring Rules
TLDR
In this work, we consider the computational complexity of Possible Winner for the broad class of voting protocols defined by scoring rules. Expand
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Probabilistic Possible Winner Determination
TLDR
We study the computational complexity of the counting version of the POSSIBLE-WINNER problem, a special case of the MANIPULATION problem. Expand
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Parameterized Algorithmics for Finding Connected Motifs in Biological Networks
TLDR
We study the NP-hard LIST-COLORED GRAPH MOTIF problem which, given an undirected list-colored graph G = (V, E) and a multiset M of colors, asks for maximum-cardinality sets S ⊆ V and M' ⊇ M such that G[S] is connected and contains exactly (with respect to multiplicity) the colors in M'. Expand
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