Sciweavers

Share
warning: Creating default object from empty value in /var/www/modules/taxonomy/taxonomy.module on line 1416.
ALGORITHMICA
2011
12 years 28 days ago
Crossing Numbers of Graphs with Rotation Systems
We show that computing the crossing number and the odd crossing number of a graph with a given rotation system is NP-complete. As a consequence we can show that many of the well-k...
Michael J. Pelsmajer, Marcus Schaefer, Daniel Stef...
WG
2010
Springer
12 years 4 months ago
Colouring Vertices of Triangle-Free Graphs
The vertex colouring problem is known to be NP-complete in the class of triangle-free graphs. Moreover, it remains NP-complete even if we additionally exclude a graph F which is n...
Konrad Dabrowski, Vadim V. Lozin, Rajiv Raman, Ber...
LATIN
2010
Springer
12 years 4 months ago
The Interval Constrained 3-Coloring Problem
Abstract In this paper, we settle the open complexity status of interval constrained coloring with a fixed number of colors. We prove that the problem is already NP-complete if th...
Jaroslaw Byrka, Andreas Karrenbauer, Laura Sanit&a...
IPL
2008
91views more  IPL 2008»
12 years 5 months ago
Well-balanced orientations of mixed graphs
We show that deciding if a mixed graph has a well-balanced orientation is NP-complete.
Attila Bernáth, Gwenaël Joret
DAM
2008
78views more  DAM 2008»
12 years 6 months ago
Semi-preemptive routing on trees
We study a variant of the pickup-and-delivery problem (PDP) in which the objects that have to be transported can be reloaded at most d times, for a given d N. This problem is kno...
Sven Oliver Krumke, Dirk Räbiger, Rainer Schr...
DAM
2008
139views more  DAM 2008»
12 years 6 months ago
Covering symmetric semi-monotone functions
We define a new set of functions called semi-monotone, a subclass of skew-supermodular functions. We show that the problem of augmenting a given graph to cover a symmetric semi-mo...
Roland Grappe, Zoltán Szigeti
CORR
2010
Springer
94views Education» more  CORR 2010»
12 years 6 months ago
Complexity dichotomy on partial grid recognition
Deciding whether a graph can be embedded in a grid using only unitlength edges is NP-complete, even when restricted to binary trees. However, it is not difficult to devise a numbe...
Vinícius G. P. de Sá, Guilherme Dias...
books