Results 21 to 30 of about 27,993 (181)
Cospectral digraphs from locally line digraphs [PDF]
, 2016 A digraph $\G=(V,E)$ is a line digraph when every pair of vertices $u,v\in V$ have either equal or disjoint in-neighborhoods. When this condition only applies for vertices in a given subset (with at least two elements), we say that $\G$ is a locally line
Dalfó, C., Fiol, M. A.
core +4 more sources
AKCE International Journal of Graphs and Combinatorics, 2020 Let and be two digraphs; without loops or multiple arcs. An coloring of is a function . We say that is an colored digraph. For an arc of , we say that is the color of over the coloring . A directed path in is an path if is a directed walk in .
Hortensia Galeana-Sánchez +1 more
doaj +1 more source
Arc-Disjoint Hamiltonian Cycles in Round Decomposable Locally Semicomplete Digraphs
Discussiones Mathematicae Graph Theory, 2018 Let D = (V,A) be a digraph; if there is at least one arc between every pair of distinct vertices of D, then D is a semicomplete digraph. A digraph D is locally semicomplete if for every vertex x, the out-neighbours of x induce a semicomplete digraph and ...
Li Ruijuan, Han Tingting
doaj +1 more source
Journal of Research of the National Institute of Standards and Technology, 2014 A digraph whose degree sequence has a unique vertex labeled realization is called threshold. In this paper we present several characterizations of threshold digraphs and their degree sequences, and show these characterizations to be equivalent. One of the characterizations is new, and allows for a shorter proof of the equivalence of the two known ...
Cloteaux, Brian +3 more
openaire +3 more sources
Sufficient Conditions for a Digraph to Admit A (1, ≤ ℓ)-Identifying Code
Discussiones Mathematicae Graph Theory, 2021 A (1, ≤ ℓ)-identifying code in a digraph D is a subset C of vertices of D such that all distinct subsets of vertices of cardinality at most ℓ have distinct closed in-neighbourhoods within C. In this paper, we give some sufficient conditions for a digraph
Balbuena Camino +2 more
doaj +1 more source
Are there any good digraph width measures? [PDF]
, 2010 Several different measures for digraph width have appeared in the last few years. However, none of them shares all the "nice" properties of treewidth: First, being \emph{algorithmically useful} i.e.
B. Courcelle +15 more
core +1 more source
From Subkautz Digraphs to Cyclic Kautz Digraphs [PDF]
Journal of Interconnection Networks, 2018 The Kautz digraphs K(d, ℓ) are a well-known family of dense digraphs, widely studied as a good model for interconnection networks. Closely related to these, the cyclic Kautz digraphs CK(d, ℓ) were recently introduced by Böhmová, Huemer and the author, and some of its distance-related parameters were fixed.
openaire +5 more sources
Kernels by Monochromatic Paths and Color-Perfect Digraphs
Discussiones Mathematicae Graph Theory, 2016 For a digraph D, V (D) and A(D) will denote the sets of vertices and arcs of D respectively. In an arc-colored digraph, a subset K of V(D) is said to be kernel by monochromatic paths (mp-kernel) if (1) for any two different vertices x, y in N there is no
Galeana-Śanchez Hortensia +1 more
doaj +1 more source
Double vertex digraphs of digraphs
Discrete Mathematics, 2009 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Gao, Yubin, Shao, Yanling
openaire +1 more source
Out-degree reducing partitions of digraphs [PDF]
, 2017 Let $k$ be a fixed integer. We determine the complexity of finding a $p$-partition $(V_1, \dots, V_p)$ of the vertex set of a given digraph such that the maximum out-degree of each of the digraphs induced by $V_i$, ($1\leq i\leq p$) is at least $k ...
Bang-Jensen, Joergen +3 more
core +5 more sources