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Abstract

Given a point set \(P\) in the Euclidean plane and a parameter \(t\), we define an \emph{oriented \(t\)-spanner} \(G\) as an oriented subgraph of the complete bi-directed graph such that for every pair of points, the shortest closed walk in \(G\) through those points is at most a factor \(t\) longer than the shortest cycle in the complete graph on \(P\). We investigate the problem of computing sparse graphs with small oriented dilation. As we can show that minimising oriented dilation for a given number of edges is NP-hard in the plane, we first consider one-dimensional point sets. While obtaining a \(1\)-spanner in this setting is straightforward, already for five points such a spanner has no plane embedding with the leftmost and rightmost point on the outer face. This leads to restricting to oriented graphs with a one-page book embedding on the one-dimensional point set. For this case we present a dynamic program to compute the graph of minimum oriented dilation that runs in \(O(n^7)\) time for \(n\) points, and a greedy algorithm that computes a \(5\)-spanner in \(O(n\log n)\) time. Expanding these results finally gives us a result for two-dimensional point sets: we prove that for convex point sets the greedy triangulation results in a plane oriented \(t\)-spanner with \(t=19 \cdot t_g\), where \(t_g\) is a upper bound on the dilation of the greedy triangulation.

Details

1009240
Identifier / keyword
Title
Oriented Spanners
Publication title
arXiv.org; Ithaca
Publication year
2024
Publication date
Dec 9, 2024
Section
Computer Science
Publisher
Cornell University Library, arXiv.org
Source
arXiv.org
Place of publication
Ithaca
Country of publication
United States
University/institution
Cornell University Library arXiv.org
e-ISSN
2331-8422
Source type
Working Paper
Language of publication
English
Document type
Working Paper
Publication history
 
 
Online publication date
2024-12-10
Milestone dates
2023-06-29 (Submission v1); 2023-07-28 (Submission v2); 2024-06-12 (Submission v3); 2024-12-09 (Submission v4)
Publication history
 
 
   First posting date
10 Dec 2024
ProQuest document ID
2831652537
Document URL
https://www.proquest.com/working-papers/oriented-spanners/docview/2831652537/se-2?accountid=208611
Full text outside of ProQuest
Copyright
© 2024. This work is published under http://arxiv.org/licenses/nonexclusive-distrib/1.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.
Last updated
2024-12-11
Database
2 databases
  • ProQuest One Academic
  • ProQuest One Academic