Combinatorial incremental problems

We study the class of Incremental Combinatorial optimization problems, where solutions are evaluated as they are built, as opposed to only measuring the performance of the final solution. Even though many of these problems have been studied, it has' usually been in isolation, so the first objective of this document is to present them under the same framework. We present the incremental analog of several classic combinatorial problems, and present efficient algorithms to find approximate solutions to some of these problems, either improving, or giving the first known approximation guarantees. We present unifying techniques that work for general classes of incremental optimization problems, using fundamental properties of the underlying problem, such as monotonicity or convexity, and relying on algorithms for the non-incremental version of the problem as subroutines. In Chapter 2 we give an e-approximation algorithm for general incremental minimization problems, improving the best approximation guarantee for the incremental version of the shortest path problem. In Chapter 3 we show constant approximation algorithms for several subclasses of incremental maximization problems, including e/2e-1approximation for the maximum weight matching problem, and a e/e+1 approximation for submodular valuations. In Chapter 4 we introduce a discrete-concavity property that allows us to give constant approximation guarantees to several problems, including an asymptotic 0.85-approximation for the incremental maximum flow with unit capacities, and a 0.9-approximation for incremental maximum cardinality matching, incremental maximum stable set in claw free graphs and incremental maximum size common independent set of two matroids.

Name thesis:degree_name

Doctoral

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Mathematics

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2018

Author dc:creator

• Unda Surawski, Francisco T.

Advisor dc:contributor.advisor

• Michel X. Goemans.

• Mathematics.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/122890

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/122890