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FSTTCS
2010
Springer
13 years 9 months ago
Finding Sparser Directed Spanners
A spanner of a graph is a sparse subgraph that approximately preserves distances in the original graph. More precisely, a subgraph H = (V, EH ) is a k-spanner of a graph G = (V, E...
Piotr Berman, Sofya Raskhodnikova, Ge Ruan
COMBINATORICS
2006
221views more  COMBINATORICS 2006»
14 years 14 days ago
Kernels of Directed Graph Laplacians
Abstract. Let G denote a directed graph with adjacency matrix Q and indegree matrix D. We consider the Kirchhoff matrix L = D - Q, sometimes referred to as the directed Laplacian. ...
John S. Caughman IV, J. J. P. Veerman
FSTTCS
2008
Springer
14 years 1 months ago
STCON in Directed Unique-Path Graphs
ABSTRACT. We study the problem of space-efficient polynomial-time algorithms for directed stconnectivity (STCON). Given a directed graph G, and a pair of vertices s, t, the STCON ...
Sampath Kannan, Sanjeev Khanna, Sudeepa Roy
CCCG
2009
14 years 1 months ago
On Directed Graphs with an Upward Straight-line
In this paper we study the problem of computing an upward straight-line embedding of a directed graph G into a point set S, i.e. a planar drawing of G such that each vertex is map...
Carla Binucci, Emilio Di Giacomo, Walter Didimo, A...
SODA
2008
ACM
135views Algorithms» more  SODA 2008»
14 years 1 months ago
Improved algorithms for orienteering and related problems
In this paper we consider the orienteering problem in undirected and directed graphs and obtain improved approximation algorithms. The point to point-orienteering-problem is the f...
Chandra Chekuri, Nitish Korula, Martin Pál
EMMCVPR
2001
Springer
14 years 5 months ago
Grouping with Directed Relationships
Abstract. Grouping is a global partitioning process that integrates local cues distributed over the entire image. We identify four types of pairwise relationships, attraction and r...
Stella X. Yu, Jianbo Shi
TAMC
2009
Springer
14 years 5 months ago
Feasibility of Motion Planning on Directed Graphs
Because of irreversibility of movements, motion planning on directed graphs is much more intricate than that on graphs. Recently we showed that the feasibility of motion planning o...
Zhilin Wu, Stéphane Grumbach
EDBT
2010
ACM
138views Database» more  EDBT 2010»
14 years 5 months ago
How to authenticate graphs without leaking
Secure data sharing in multi-party environments requires that both authenticity and confidentiality of the data be assured. Digital signature schemes are commonly employed for au...
Ashish Kundu, Elisa Bertino
ICALP
2003
Springer
14 years 5 months ago
Similarity Matrices for Pairs of Graphs
Abstract. We introduce a concept of similarity between vertices of directed graphs. Let GA and GB be two directed graphs with respectively nA and nB vertices. We define a nA × nB...
Vincent D. Blondel, Paul Van Dooren
STACS
2005
Springer
14 years 6 months ago
A Polynomial Time Algorithm for Minimum Cycle Basis in Directed Graphs
Abstract. We consider the problem of computing a minimum cycle basis in a directed graph G with m arcs and n vertices. The arcs of G have non-negative weights assigned to them. We ...
Telikepalli Kavitha, Kurt Mehlhorn