B
Barry O'Sullivan
Researcher at University College Cork
Publications - 324
Citations - 3966
Barry O'Sullivan is an academic researcher from University College Cork. The author has contributed to research in topics: Constraint programming & Constraint satisfaction problem. The author has an hindex of 29, co-authored 312 publications receiving 3610 citations. Previous affiliations of Barry O'Sullivan include Brown University & National University of Ireland.
Papers
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Journal ArticleDOI
A fixed-parameter algorithm for the directed feedback vertex set problem
TL;DR: New algorithmic techniques are developed that result in an algorithm with running time 4k!
Journal ArticleDOI
Finding small separators in linear time via treewidth reduction
TL;DR: A method for reducing the treewidth of a graph while preserving all of its minimal separators up to a certain fixed size is presented, and this technique turns out to be relevant for H-coloring problems as well as cardinality constrained variants of the classical H- Coloring problem.
Journal ArticleDOI
Almost 2-SAT is fixed-parameter tractable
Igor Razgon,Barry O'Sullivan +1 more
TL;DR: This work proposes an algorithm that solves the problem of removing k clauses from a 2-cnf formula in O(15^kxkxm^3) time showing that this problem is fixed-parameter tractable.
Posted Content
Almost 2-SAT is Fixed-Parameter Tractable
Igor Razgon,Barry O'Sullivan +1 more
TL;DR: The fixed-parameter tractability of the 2-CNF deletion problem was shown in this article, where the authors proposed an algorithm that solves this problem in O(15k*k*m^3) time.
Proceedings Article
Finding diverse and similar solutions in constraint programming
TL;DR: A number of different classes of diversity and similarity problems are defined and a number of practical solution methods are proposed, some of which use global constraints for enforcing diversity (or similarity) between solutions.