BangJensen, J.
Overview
Works:  4 works in 11 publications in 1 language and 20 library holdings 

Roles:  Author 
Publication Timeline
.
Most widely held works by
J BangJensen
The Julius Petersen graph theory centennial by
L. D Andersen(
)
1 edition published in 2016 in English and held by 11 WorldCat member libraries worldwide
1 edition published in 2016 in English and held by 11 WorldCat member libraries worldwide
On the complexity of colouring by superdigraphs of bipartite graphs by
Simon Fraser University. Centre for Systems Science(
Book
)
3 editions published in 1990 in English and held by 4 WorldCat member libraries worldwide
It follows from the result of Hell and Nesetril that HCOL is NPcomplete whenever H contains the equivalent digraph of a nonbipartite undirected graph. Thus in order to complete the classification of all directed graphs, it remains to consider those digraphs for which the `undirected part' is bipartite; that is, directed graphs obtained from the equivalent digraph of an undirected bipartite graph by adding some arcs. The paper begins by proving some general results, then introduces the family of `partitionable' digraphs, and proves that if H is a partitionable digraph, then HCOL is NPcomplete if H does not admit a homomorphism to the directed twocycle C2, and is polynomial otherwise. This verifies the conjecture for partitionable digraphs
3 editions published in 1990 in English and held by 4 WorldCat member libraries worldwide
It follows from the result of Hell and Nesetril that HCOL is NPcomplete whenever H contains the equivalent digraph of a nonbipartite undirected graph. Thus in order to complete the classification of all directed graphs, it remains to consider those digraphs for which the `undirected part' is bipartite; that is, directed graphs obtained from the equivalent digraph of an undirected bipartite graph by adding some arcs. The paper begins by proving some general results, then introduces the family of `partitionable' digraphs, and proves that if H is a partitionable digraph, then HCOL is NPcomplete if H does not admit a homomorphism to the directed twocycle C2, and is polynomial otherwise. This verifies the conjecture for partitionable digraphs
Local tournaments and proper circular arc graphs by
P Hell(
Book
)
5 editions published in 1990 in English and held by 4 WorldCat member libraries worldwide
A local tournament is a diagraph in which the outset as well as the inset of every vertex is a tournament. These diagraphs have recently been found to share many desirable properties of tournaments. This paper illustrates this property by giving algorithms to find a hamiltonian path and cycle in a local tournament. It mentions several characterizations and recognition algorithms of graphs orientable as local tournaments and it turns out that they are precisely the graphs previously studied as proper circular arc graphs. Thus new recognitions algorithms are obtained for proper circular arc graphs. The paper also gives a more detailed structural characterization of chordal graphs that are orientable as local tournaments
5 editions published in 1990 in English and held by 4 WorldCat member libraries worldwide
A local tournament is a diagraph in which the outset as well as the inset of every vertex is a tournament. These diagraphs have recently been found to share many desirable properties of tournaments. This paper illustrates this property by giving algorithms to find a hamiltonian path and cycle in a local tournament. It mentions several characterizations and recognition algorithms of graphs orientable as local tournaments and it turns out that they are precisely the graphs previously studied as proper circular arc graphs. Thus new recognitions algorithms are obtained for proper circular arc graphs. The paper also gives a more detailed structural characterization of chordal graphs that are orientable as local tournaments
On unitarity of spherical representations by
J BangJensen(
Book
)
2 editions published in 1988 in English and held by 1 WorldCat member library worldwide
2 editions published in 1988 in English and held by 1 WorldCat member library worldwide
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