Henning Fernau
University of Trier
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Publication
Featured researches published by Henning Fernau.
Algorithmica | 2002
Jochen Alber; Hans L. Bodlaender; Henning Fernau; Ton Kloks; Rolf Niedermeier
Abstract. We present an algorithm that constructively produces a solution to the k -DOMINATING SET problem for planar graphs in time O(c^ \sqrt k n) , where c=4^ 6\sqrt 34 . To obtain this result, we show that the treewidth of a planar graph with domination number γ (G) is O(\sqrt \rule 0pt 4pt \smash γ (G) ) , and that such a tree decomposition can be found in O(\sqrt \rule 0pt 4pt \smash γ (G) n) time. The same technique can be used to show that the k -FACE COVER problem (find a size k set of faces that cover all vertices of a given plane graph) can be solved in O(c1^ \sqrt k n) time, where c1=3^ 36\sqrt 34 and k is the size of the face cover set. Similar results can be obtained in the planar case for some variants of k -DOMINATING SET, e.g., k -INDEPENDENT DOMINATING SET and k -WEIGHTED DOMINATING SET.
SIAM Journal on Computing | 2007
Jianer Chen; Henning Fernau; Iyad A. Kanj; Ge Xia
Determining whether a parameterized problem is kernelizable and has a small kernel size has recently become one of the most interesting topics of research in the area of parameterized complexity and algorithms. Theoretically, it has been proved that a parameterized problem is kernelizable if and only if it is fixed-parameter tractable. Practically, applying a data reduction algorithm to reduce an instance of a parameterized problem to an equivalent smaller instance (i.e., a kernel) has led to very efficient algorithms and now goes hand-in-hand with the design of practical algorithms for solving
ACM Transactions on Algorithms | 2012
Daniel Binkele-Raible; Henning Fernau; Fedor V. Fomin; Daniel Lokshtanov; Saket Saurabh; Yngve Villanger
\mathcal{NP}
scandinavian workshop on algorithm theory | 2000
Jochen Alber; Hans L. Bodlaender; Henning Fernau; Rolf Niedermeier
-hard problems. Well-known examples of such parameterized problems include the vertex cover problem, which is kernelizable to a kernel of size bounded by
IWPEC'06 Proceedings of the Second international conference on Parameterized and Exact Computation | 2006
Henning Fernau
2k
Journal of Computer and System Sciences | 2003
Jochen Alber; Henning Fernau; Rolf Niedermeier
, and the planar dominating set problem, which is kernelizable to a kernel of size bounded by
Algorithmica | 2010
Henning Fernau
335k
Journal of Discrete Algorithms | 2009
Henning Fernau; David F. Manlove
. In this paper we develop new techniques to derive upper and lower bounds on the kernel size for certain parameterized problems. In terms of our lower bound results, we show, for example, that unless
computing and combinatorics conference | 2002
Henning Fernau
\mathcal{P} = \mathcal{NP}
mathematical foundations of computer science | 2001
Jochen Alber; Hongbing Fan; Michael R. Fellows; Henning Fernau; Rolf Niedermeier; Frances A. Rosamond; Ulrike Stege
, planar vertex cover does not have a problem kernel of size smaller than