UWSpace is currently experiencing technical difficulties resulting from its recent migration to a new version of its software. These technical issues are not affecting the submission and browse features of the site. UWaterloo community members may continue submitting items to UWSpace. We apologize for the inconvenience, and are actively working to resolve these technical issues.
 

Iterative Rounding Approximation Algorithms in Network Design

Thumbnail Image

Files

Shea_Marcus.pdf (743.55 KB)

Date

2010-05-21T19:46:39Z

Authors

Shea, Marcus

Journal Title

Journal ISSN

Volume Title

Publisher

University of Waterloo

Abstract

Iterative rounding has been an increasingly popular approach to solving network design optimization problems ever since Jain introduced the concept in his revolutionary 2-approximation for the Survivable Network Design Problem (SNDP). This paper looks at several important iterative rounding approximation algorithms and makes improvements to some of their proofs. We generalize a matrix restatement of Nagarajan et al.'s token argument, which we can use to simplify the proofs of Jain's 2-approximation for SNDP and Fleischer et al.'s 2-approximation for the Element Connectivity (ELC) problem. Lau et al. show how one can construct a (2,2B + 3)-approximation for the degree bounded ELC problem, and this thesis provides the proof. We provide some structural results for basic feasible solutions of the Prize-Collecting Steiner Tree problem, and introduce a new problem that arises, which we call the Prize-Collecting Generalized Steiner Tree problem.

Description

Keywords

iterative rounding, approximation algorithms, network design, degree bounded, prize collecting, fractional tokens

LC Keywords

Citation

URI

http://hdl.handle.net/10012/5239

Collections

Theses
Combinatorics and Optimization