Don't Be Strict in Local Search!
Gaspers, Serge; Kim, Eun Jung; Ordyniak, Sebastian; Saurabh, Saket; Szeider, Stefan (2012), Don't Be Strict in Local Search!, in Selman, Bart; Hoffmann, Jörg, Proceedings of the Twenty-Sixth AAAI Conference on Artificial Intelligence, AAAI Press
Type
Communication / ConférenceExternal document link
http://arxiv.org/abs/1208.1688v3Date
2012Conference title
AAAI 2012Conference date
2012-07Conference city
TorontoConference country
CanadaBook title
Proceedings of the Twenty-Sixth AAAI Conference on Artificial IntelligenceBook author
Selman, Bart; Hoffmann, JörgPublisher
AAAI Press
ISBN
978-1-57735-568-7
Metadata
Show full item recordAuthor(s)
Gaspers, SergeKim, Eun Jung
Laboratoire d'analyse et modélisation de systèmes pour l'aide à la décision [LAMSADE]
Ordyniak, Sebastian
Saurabh, Saket
Szeider, Stefan
Abstract (EN)
Local Search is one of the fundamental approaches to combinatorial optimization and it is used throughout AI. Several local search algorithms are based on searching the k-exchange neighborhood. This is the set of solutions that can be obtained from the current solution by exchanging at most k elements. As a rule of thumb, the larger k is, the better are the chances of finding an improved solution. However, for inputs of size n, a na\"ive brute-force search of the k-exchange neighborhood requires n to the power of O(k) time, which is not practical even for very small values of k. Fellows et al. (IJCAI 2009) studied whether this brute-force search is avoidable and gave positive and negative answers for several combinatorial problems. They used the notion of local search in a strict sense. That is, an improved solution needs to be found in the k-exchange neighborhood even if a global optimum can be found efficiently. In this paper we consider a natural relaxation of local search, called permissive local search (Marx and Schlotter, IWPEC 2009) and investigate whether it enhances the domain of tractable inputs. We exemplify this approach on a fundamental combinatorial problem, Vertex Cover. More precisely, we show that for a class of inputs, finding an optimum is hard, strict local search is hard, but permissive local search is tractable. We carry out this investigation in the framework of parameterized complexity.Subjects / Keywords
combinatorial optimization; Local SearchRelated items
Showing items related by title and author.
-
Kim, Eun Jung; Ordyniak, Sebastian; Szeider, Stefan (2014) Communication / Conférence
-
Kim, Eun Jung; Ordyniak, Sebastian (2012) Chapitre d'ouvrage
-
Kim, Eun Jung; Kratsch, Stefan; Pilipczuk, Marcin; Wahlström, Magnus (2021) Communication / Conférence
-
Kim, Eun Jung; Kratsch, Stefan; Pilipczuk, Marcin; Wahlström, Magnus (2023) Communication / Conférence
-
Ganian, Robert; Kim, Eun Jung; Slivovsky, Friedrich; Szeider, Stefan (2018) Communication / Conférence