Matches in SemOpenAlex for { <https://semopenalex.org/work/W2005943912> ?p ?o ?g. }
Showing items 1 to 57 of
57
with 100 items per page.
- W2005943912 endingPage "91" @default.
- W2005943912 startingPage "82" @default.
- W2005943912 abstract "Let G be a simple digraph. The dicycle packing number of G , denoted ν c ( G ) , is the maximum size of a set of arc-disjoint directed cycles in G . Let G be a digraph with a nonnegative arc-weight function w . A function ψ from the set C of directed cycles in G to R + is a fractional dicycle packing of G if ∑ e ∈ C ∈ C ψ ( C ) ⩽ w ( e ) for each e ∈ E ( G ) . The fractional dicycle packing number , denoted ν c * ( G , w ) , is the maximum value of ∑ C ∈ C ψ ( C ) taken over all fractional dicycle packings ψ . In case w ≡ 1 we denote the latter parameter by ν c * ( G ) . Our main result is that ν c * ( G ) - ν c ( G ) = o ( n 2 ) where n = | V ( G ) | . Our proof is algorithmic and generates a set of arc-disjoint directed cycles whose size is at least ν c ( G ) - o ( n 2 ) in randomized polynomial time. Since computing ν c ( G ) is an NP-Hard problem, and since almost all digraphs have ν c ( G ) = Θ ( n 2 ) our result is a FPTAS for computing ν c ( G ) for almost all digraphs. The result uses as its main lemma a much more general result. Let F be any fixed family of oriented graphs. For an oriented graph G , let ν F ( G ) denote the maximum number of arc-disjoint copies of elements of F that can be found in G , and let ν F * ( G ) denote the fractional relaxation. Then, ν F * ( G ) - ν F ( G ) = o ( n 2 ) . This lemma uses the recently discovered directed regularity lemma as its main tool. It is well known that ν c * ( G , w ) can be computed in polynomial time by considering the dual problem. We present a polynomial algorithm that finds an optimal fractional dicycle packing. Our algorithm consists of a solution to a simple linear program and some minor modifications, and avoids using the ellipsoid method. In fact, the algorithm shows that a maximum fractional dicycle packing with at most O ( n 2 ) dicycles receiving nonzero weight can be found in polynomial time." @default.
- W2005943912 created "2016-06-24" @default.
- W2005943912 creator A5003622145 @default.
- W2005943912 creator A5026016357 @default.
- W2005943912 date "2007-01-01" @default.
- W2005943912 modified "2023-09-27" @default.
- W2005943912 title "Packing directed cycles efficiently" @default.
- W2005943912 cites W1965059628 @default.
- W2005943912 cites W2005616548 @default.
- W2005943912 cites W2018732791 @default.
- W2005943912 cites W2029575996 @default.
- W2005943912 cites W2040831377 @default.
- W2005943912 cites W2058108962 @default.
- W2005943912 cites W2083580384 @default.
- W2005943912 cites W2090962863 @default.
- W2005943912 cites W2103985627 @default.
- W2005943912 cites W2155295958 @default.
- W2005943912 cites W2951773826 @default.
- W2005943912 doi "https://doi.org/10.1016/j.dam.2006.04.033" @default.
- W2005943912 hasPublicationYear "2007" @default.
- W2005943912 type Work @default.
- W2005943912 sameAs 2005943912 @default.
- W2005943912 citedByCount "8" @default.
- W2005943912 countsByYear W20059439122012 @default.
- W2005943912 countsByYear W20059439122015 @default.
- W2005943912 countsByYear W20059439122019 @default.
- W2005943912 countsByYear W20059439122022 @default.
- W2005943912 crossrefType "journal-article" @default.
- W2005943912 hasAuthorship W2005943912A5003622145 @default.
- W2005943912 hasAuthorship W2005943912A5026016357 @default.
- W2005943912 hasBestOaLocation W20059439121 @default.
- W2005943912 hasConcept C114614502 @default.
- W2005943912 hasConcept C33923547 @default.
- W2005943912 hasConceptScore W2005943912C114614502 @default.
- W2005943912 hasConceptScore W2005943912C33923547 @default.
- W2005943912 hasIssue "2" @default.
- W2005943912 hasLocation W20059439121 @default.
- W2005943912 hasLocation W20059439122 @default.
- W2005943912 hasOpenAccess W2005943912 @default.
- W2005943912 hasPrimaryLocation W20059439121 @default.
- W2005943912 hasRelatedWork W1974891317 @default.
- W2005943912 hasRelatedWork W1978042415 @default.
- W2005943912 hasRelatedWork W2017331178 @default.
- W2005943912 hasRelatedWork W2044189972 @default.
- W2005943912 hasRelatedWork W2069964982 @default.
- W2005943912 hasRelatedWork W2313400459 @default.
- W2005943912 hasRelatedWork W2976797620 @default.
- W2005943912 hasRelatedWork W3086542228 @default.
- W2005943912 hasRelatedWork W4225152035 @default.
- W2005943912 hasRelatedWork W4245490552 @default.
- W2005943912 hasVolume "155" @default.
- W2005943912 isParatext "false" @default.
- W2005943912 isRetracted "false" @default.
- W2005943912 magId "2005943912" @default.
- W2005943912 workType "article" @default.