20 search results - page 1 / 4 » Integrality ratio for group Steiner trees and directed stein... |
SODA
2003
ACM
13 years 6 months ago
2003
ACM
The natural relaxation for the Group Steiner Tree problem, as well as for its generalization, the Directed Steiner Tree problem, is a flow-based linear programming relaxation. We...
ICALP
2009
Springer
14 years 5 months ago
2009
Springer
We improve the approximation ratios for two optimization problems in planar graphs. For node-weighted Steiner tree, a classical network-optimization problem, the best achievable ap...
STOC
2010
ACM
13 years 10 months ago
2010
ACM
The Steiner tree problem is one of the most fundamental ÆÈ-hard problems: given a weighted undirected graph and a subset of terminal nodes, find a minimum weight tree spanning ...
ISAAC
2004
Springer
13 years 10 months ago
2004
Springer
The Steiner tree problem asks for a minimum cost tree spanning a given set of terminals S ⊆ V in a weighted graph G = (V, E, c), c : E → R+ . In this paper we consider a genera...
WADS
2009
Springer
13 years 11 months ago
2009
Springer
Abstract. A central issue in the design of modern communication networks is the provision of Quality-of-Service (QoS) guarantees at the presence of heterogeneous users. For instanc...