Results 31 to 40 of about 6,654 (223)

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

Power on digraphs

Operations Research and Decisions, 2016
OPERATIONS RESEARCH AND DECISIONS; ISSN 2081 ...
Peters, Hans, Timmer, Judith, van den Brink, Rene   +2 more
openaire   +8 more sources

Neutrosophic Digraph with Generalized Modus Tollens [PDF]

, 2022
In this paper, we generalize modus tollens method for neutrosophic digraph by using neutrosophic ruleand define degree of a vertex in neutrosophic digraph, Indegree of a vertex in neutrosophic digraph, out degree ofa vertex in neutrosophic digraph and ...
Elsayed Badr, Shokry Nada, Ashraf ELrokh, Hoda Mostafa
core   +1 more source

Antistrong digraphs

Journal of Combinatorial Theory, Series B, 2017
An antidirected trail in a digraph is a trail (a walk with no arc repeated) in which the arcs alternate between forward and backward arcs. An antidirected path is an antidirected trail where no vertex is repeated. We show that it is NP-complete to decide whether two vertices $x,y$ in a digraph are connected by an antidirected path, while one can decide
Jørgen Bang-Jensen, Stéphane Bessy, Bill Jackson, Matthias Kriesell   +3 more
openaire   +4 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, Dalfó Cristina, Martínez-Barona Berenice   +2 more
doaj   +1 more source

Infinite digraphs isomorphic with their line digraphs

Journal of Combinatorial Theory, Series B, 1976
In this paper we give a structural characterization of the digraphs that are isomorphic with their line digraphs.
Lowell W. Beineke, Robert L. Hemminger
openaire   +1 more source

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, Sánchez-López Rocío   +1 more
doaj   +1 more source

Antipodal graphs and digraphs

International Journal of Mathematics and Mathematical Sciences, 1993
The antipodal graph of a graph G, denoted by A(G), has the same vertex set as G with an edge joining vertices u and v if d(u,v) is equal to the diameter of G.
Garry Johns, Karen Sleno
doaj   +1 more source

Xk-Digraphs

Journal of Combinatorial Theory, Series B, 1981
AbstractLet G be a directed graph on n vertices (single loops allowed) such that there are λ directed paths of length k from P to Q for any distinct pair of vertices (P, Q). We prove that if n > 2 and k > 2, G is regular. The regular case is also discussed.
William G. Bridges, R. A. Mena
openaire   +2 more sources

On New Knot Tables

ITM Web of Conferences, 2018
The quasi-pseudo metrics on the vertices of a digraph induces a unique bitopology. In this work, we obtained that a bitopology is associated with any knot km, where k is crossing points of knot and m = 1,2 by using quasi-pseudo metrics on the vertices of
Elmali Ceren Sultan, Uğur Tamer, Kunduraci Tuǧçe   +2 more
doaj   +1 more source