Results 31 to 40 of about 34,890 (227)

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, Bessy, Stéphane, Havet, Frédéric, Yeo, Anders   +3 more
core   +5 more sources

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

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

The existence of subdigraphs with orthogonal factorizations in digraphs

AIMS Mathematics, 2021
Let $G$ be a $[0,k_1+k_2+\cdots+k_m-n+1]$-digraph and $H_1,H_2,\cdots,H_r$ be $r$ vertex-disjoint $n$-subdigraphs of $G$, where $m,n,r$ and $k_i$ ($1\leq i\leq m$) are positive integers satisfying $1\leq n\leq m$ and $k_1\geq k_2\geq\cdots\geq k_m\geq r ...
Sizhong Zhou, Quanru Pan
doaj   +1 more source

On the digraph of a unitary matrix

, 2003
Given a matrix M of size n, a digraph D on n vertices is said to be the digraph of M, when M_{ij} is different from 0 if and only if (v_{i},v_{j}) is an arc of D.
Grössing Gerhard, Gudder Stanley, Prisner Erich, Simone Severini, Terras Audrey, Tutte W.   +5 more
core   +2 more sources

Disimplicial arcs, transitive vertices, and disimplicial eliminations [PDF]

, 2014
In this article we deal with the problems of finding the disimplicial arcs of a digraph and recognizing some interesting graph classes defined by their existence.
Eguía, Martiniano, Soulignac, Francisco J.   +1 more
core   +3 more sources

Perfect directed codes in Cayley digraphs

AIMS Mathematics
A perfect directed code (or an efficient twin domination) of a digraph is a vertex subset where every other vertex in the digraph has a unique in- and a unique out-neighbor in the subset. In this paper, we show that a digraph covers a complete digraph if
Yan Wang , Kai Yuan , Ying Zhao
doaj   +1 more source

Some Results on 4-Transitive Digraphs

Discussiones Mathematicae Graph Theory, 2017
Let D be a digraph with set of vertices V and set of arcs A. We say that D is k-transitive if for every pair of vertices u, v ∈ V, the existence of a uv-path of length k in D implies that (u, v) ∈ A.
García-Vázquez Patricio Ricardo, Hernández-Cruz César   +1 more
doaj   +1 more source

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