Christian Wulff-Nilsen

Welcome to my home page. Since May 1st 2007, I have been working as a Ph.D. student at the University of Copenhagen, Department of Computer Science. My supervisor is Martin Zachariasen. Below you will find some basic information about my research interests and publications.

How to reach me
Research Interests
Publications

How to reach me

Work address:

Department of Computer Science (DIKU)
University of Copenhagen
Universitetsparken 1
DK-2100 København Ø, Denmark
Phone (direct): +45 35 32 14 38
Phone (switch): +45 35 32 14 00
Fax: +45 35 32 14 01
E-mail: koolooz@diku.dk
Office: 3-0-16
Home address:
Vermlandsgade 78, 3. th.
DK-2300 Copenhagen S, Denmark
Mobile phone: +45 60 83 34 56

Research Interests

My current focus is on planar graphs. I have also been working on metric space and geometric (Euclidean and fixed orientations) graph problems, in particular the Steiner tree and dilation/stretch factor problems.

Publications

G. Borradaile and C. Wulff-Nilsen Min st-Cut Oracle for Planar Graphs with Near-Linear Preprocessing Time.
arXiv:1003.1320v1 [cs.DM], March 2010.

C. Wulff-Nilsen Solving the Replacement Paths Problem for Planar Directed Graphs in O(nlogn) Time.
In proceedings of the Twenty-First Annual ACM-SIAM Symposium on Discrete Algorithms, p. 756-765, 2010.

C. Wulff-Nilsen Minimum Cycle Basis and All-Pairs Min Cut of a Planar Graph in Subquadratic Time.
arXiv:0912.1208v1 [cs.DM], December 2009.

S. Mozes and C. Wulff-Nilsen Shortest Paths in Planar Graphs with Real Lengths in O(nlog2n/loglog n) Time.
arXiv:0911.4963v1 [cs.DM], November 2009.

C. Wulff-Nilsen Girth of a Planar Digraph with Real Edge Weights in O(nlog3n) Time.
arXiv:0908.0697v1 [cs.DM], August 2009.

C. Wulff-Nilsen Solving the Replacement Paths Problem for Planar Directed Graphs in O(nlogn) Time.
Technical Report 09-03, Department of Computer Science, University of Copenhagen, 2009.

C. Wulff-Nilsen Wiener Index and Diameter of a Planar Graph in Subquadratic Time.
Proc. 25th European Workshop on Computational Geometry, Brussels, 2009, p. 25-28.

C. Wulff-Nilsen Computing the dilation of edge-augmented graphs in metric spaces.
Computational Geometry, Volume 43, Issue 2, February 2010, Pages 68-72, Special Issue on the 24th European Workshop on Computational Geometry.

C. Wulff-Nilsen Bounding the Expected Number of Rectilinear Full Steiner Trees.
To appear in Networks (early view).

C. Wulff-Nilsen Wiener Index, Diameter, and Stretch Factor of a Weighted Planar Graph in Subquadratic Time.
Technical Report 08-16, Department of Computer Science, University of Copenhagen, 2008.

C. Wulff-Nilsen Sum of All-Pairs Shortest Path Distances in a Planar Graph in Subquadratic Time.
Technical Report 08-11, Department of Computer Science, University of Copenhagen, 2008.

C. Wulff-Nilsen Computing the Maximum Detour of a Plane Graph in Subquadratic Time.
In S.-H. Hong, H. Nagamochi, and T. Fukunaga (Eds.): ISAAC 2008, LNCS 5369, pp. 740-751, 2008.

J. Luo and C. Wulff-Nilsen Computing Best and Worst Shortcuts of Graphs Embedded in Metric Spaces.
In S.-H. Hong, H. Nagamochi, and T. Fukunaga (Eds.): ISAAC 2008, LNCS 5369, pp. 764-775, 2008.

C. Wulff-Nilsen Computing the Stretch Factor of Paths, Trees, and Cycles in Weighted Fixed Orientation Metrics.
Proc. 20th Canadian Conference on Computational Geometry (CCCG 2008), Montreal, Canada, 2008, p. 59-62.
(full version, 12 pages)

C. Wulff-Nilsen Computing the Maximum Detour of a Plane Graph in Subquadratic Time.
Technical Report 08-07, Department of Computer Science, University of Copenhagen, 2008.

C. Wulff-Nilsen Steiner hull algorithm for the uniform orientation metrics.
Computational Geometry - Theory and Applications, Vol. 40/1, May 2008, pp. 1-13.

M. Brazil, B. K. Nielsen, D. A. Thomas, P. Winter, C. Wulff-Nilsen, and M. Zachariasen. A Novel Approach to Phylogenetic Trees: d-Dimensional Geometric Steiner Trees.
Networks, volume 53, issue 2, pages 104-111, 2008.

C. Wulff-Nilsen Computing the Dilation of Edge-Augmented Graphs in Metric Spaces.
Proc. 24th European Workshop on Computational Geometry, Nancy, 2008, p. 123-126.

C. Wulff-Nilsen A linear bound on the expected number of rectilinear full Steiner tree components spanning a fixed number of terminals.
Proc. 23rd European Workshop on Computational Geometry, Graz, 2007, p. 158-161.

C. Wulff-Nilsen Proximity structures in the fixed orientation metrics.
Proc. 22nd European Workshop on Computational Geometry, Delphi, 2006, p. 153-157