Results 211 to 220 of about 139,638 (260)
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Journal of Graph Theory, 1992
AbstractWe give a new condition involving degrees sufficient for a digraph to be hamiltonian.
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AbstractWe give a new condition involving degrees sufficient for a digraph to be hamiltonian.
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Directed Graphs and Substitutions
Theory of Computing Systems, 2001zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Holton, C., Zamboni, L. Q.
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SIAM Journal on Discrete Mathematics, 1999
A property \(P\) of graphs is called monotone if it is preserved under the deletion of edges. Let \(\Delta^P_n\) denote the simplicial complex whose simplices are edge sets of \(n\)-vertex graphs having a monotone property \(P\). Topological properties of complexes of undirected graphs recently have been studied in a number of papers (see references in
Björner, Anders, Welker, Volkmar
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A property \(P\) of graphs is called monotone if it is preserved under the deletion of edges. Let \(\Delta^P_n\) denote the simplicial complex whose simplices are edge sets of \(n\)-vertex graphs having a monotone property \(P\). Topological properties of complexes of undirected graphs recently have been studied in a number of papers (see references in
Björner, Anders, Welker, Volkmar
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SIAM Journal on Algebraic Discrete Methods, 1985
This very interesting paper introduces the concept of graceful directed graphs as follows. A digraph D with e arcs is numbered by assigning a distinct integer value h(v) from \(\{\) 0,1,...,e\(\}\) to each node v. Each arc (u,v) receives a value \(h(u,v)=h(v)-h(u)\) (mod e\(+1)\).
Bloom, G. S., Hsu, D. F.
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This very interesting paper introduces the concept of graceful directed graphs as follows. A digraph D with e arcs is numbered by assigning a distinct integer value h(v) from \(\{\) 0,1,...,e\(\}\) to each node v. Each arc (u,v) receives a value \(h(u,v)=h(v)-h(u)\) (mod e\(+1)\).
Bloom, G. S., Hsu, D. F.
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SIAM Journal on Discrete Mathematics, 1999
A ranking of a (di)graph is a colouring of the vertex set with positive integers in such a way that every (di)path between two vertices of the same colour has a vertex of larger colour. The \(k\)-ranking problem is as follows: given a (di)graph \(G\) and an integer \(k\), check whether \(G\) has a ranking with \(k\) colours. This problem is known to be
Kratochvíl, Jan, Tuza, Zsolt
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A ranking of a (di)graph is a colouring of the vertex set with positive integers in such a way that every (di)path between two vertices of the same colour has a vertex of larger colour. The \(k\)-ranking problem is as follows: given a (di)graph \(G\) and an integer \(k\), check whether \(G\) has a ranking with \(k\) colours. This problem is known to be
Kratochvíl, Jan, Tuza, Zsolt
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Decomposition of Directed Graphs
SIAM Journal on Algebraic Discrete Methods, 1982A composition for directed graphs which generalizes the substitution (or X-join) composition of graphs and digraphs, as well as the graph version of set-family composition, is described. It is proved that a general decomposition theory can be applied to the resulting digraph decomposition.
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Cut-primitive directed graphs versus clan-primitive directed graphs
Advances in Pure and Applied Mathematics, 2010Summary: Given a directed graph \(G= (V, A)\), a subset \(X\) of \(V\) is a clan of \(G\) provided that for \(a,b\in X\) and \(x\in V\setminus X\), \((a, x)\in A\) if and only if \((b, x)\in A\), and similarly for \((x, a)\) and \((x, b)\). For instance, \(\emptyset\), \(V\) and \(\{x\}\), where \(x\in V\), are clans of \(G\), called trivial.
Boudabbous, Youssef, Ille, Pierre
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