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WG
2004
Springer
15 years 3 months ago
Collective Tree Spanners and Routing in AT-free Related Graphs
In this paper we study collective additive tree spanners for families of graphs that either contain or are contained in AT-free graphs. We say that a graph G = (V, E) admits a sys...
Feodor F. Dragan, Chenyu Yan, Derek G. Corneil
WG
2004
Springer
15 years 3 months ago
Unhooking Circulant Graphs: A Combinatorial Method for Counting Spanning Trees and Other Parameters
It has long been known that the number of spanning trees in circulant graphs with fixed jumps and n nodes satisfies a recurrence relation in n. The proof of this fact was algebra...
Mordecai J. Golin, Yiu-Cho Leung
COCOA
2009
Springer
15 years 4 months ago
A PTAS for Node-Weighted Steiner Tree in Unit Disk Graphs
Abstract. The node-weighted Steiner tree problem is a variation of classical Steiner minimum tree problem. Given a graph G = (V, E) with node weight function C : V → R+ and a sub...
Xianyue Li, Xiao-Hua Xu, Feng Zou, Hongwei Du, Pen...
SODA
2004
ACM
156views Algorithms» more  SODA 2004»
14 years 11 months ago
Approximating Minimum Max-Stretch spanning Trees on unweighted graphs
Given a graph G and a spanning tree T of G, we say that T is a tree t-spanner of G if the distance between every pair of vertices in T is at most t times their distance in G. The p...
Yuval Emek, David Peleg
FCT
2009
Springer
15 years 4 months ago
Martingales on Trees and the Empire Chromatic Number of Random Trees
We study the empire colouring problem (as defined by Percy Heawood in 1890) for maps whose dual planar graph is a tree, with empires formed by exactly r countries. We prove that, ...
Colin Cooper, Andrew R. A. McGrae, Michele Zito