Results 41 to 50 of about 34,890 (227)
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.
Bridges, W.G, Mena, R.A
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The Existence of Planar Hypotraceable Oriented Graphs [PDF]
Discrete Mathematics & Theoretical Computer Science, 2017 A digraph is \emph{traceable} if it has a path that visits every vertex. A digraph $D$ is \emph{hypotraceable} if $D$ is not traceable but $D-v$ is traceable for every vertex $v\in V(D)$.
Susan van Aardt +2 more
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On (4,2)-digraph Containing a Cycle of Length 2 [PDF]
, 2000 A diregular digraph is a digraph with the in-degree and out-degree of all vertices is constant. The Moore bound for a diregular digraph of degree d and diameter k is M_{d,k}=l+d+d^2+...+d^k.
Baskoro, Edy Tri, Iswadi, Hazrul
core
The maximal spectral radius of a digraph with (m+1)^2 - s edges
, 2003 It is known that the spectral radius of a digraph with k edges is \le \sqrt{k}, and that this inequality is strict except when k is a perfect square. For k=m^2 + \ell, \ell fixed, m large, Friedland showed that the optimal digraph is obtained from the ...
Snellman, Jan
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Energy Science &Engineering, EarlyView.The study analyzes barriers to electric vehicle growth in India using DEMATEL and ANP. It distinguishes cause‐and‐effect barriers and ranks them. Major barriers include poor charging infrastructure and high costs. ABSTRACT This study employs a hybrid technique based on the Decision‐Making Trial Evaluation Laboratory (DEMATEL), Analytic Network Process (
Sanjeev Kumar +6 more
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H-kernels by walks in H-colored digraphs and the color-class digraph
AKCE International Journal of Graphs and Combinatorics, 2016 Let H be a digraph possibly with loops and D a finite digraph without loops whose arcs are colored with the vertices of H (D is an H-colored digraph). V(D) and A(D) will denote the sets of vertices and arcs of D respectively.
Hortensia Galeana-Sánchez +1 more
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Graph partitioning: an updated survey
AKCE International Journal of Graphs and Combinatorics, 2023 Graph partitioning problem, which is one of the most important topics in graph theory, usually asks for a partition of the vertex set of a graph into pairwise disjoint subsets with various requirements. It comes from the well-known Max-Cut Problem: Given
Shufei Wu, Jianfeng Hou
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Algebra universalisAbstract Call a finite relational structure k-Słupecki if its only surjective k -ary polymorphisms are essentially unary, and Słupecki if it is k -Słupecki
Kunos, Ádám +2 more
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Subsquares in Random Latin Squares and Rectangles
Journal of Combinatorial Designs, EarlyView.ABSTRACT A k×n $k\times n$ partial Latin rectangle is C‐sparse $C \mbox{-} \mathrm{sparse}$ if the number of nonempty entries in each row and column is at most C $C$ and each symbol is used at most C $C$ times. We prove that the probability a uniformly random k×n $k\times n$ Latin rectangle, where k<(1∕2−α)n $k\lt (1\unicode{x02215}2-\alpha )n ...
Alexander Divoux +3 more
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Toward Wojda's conjecture on digraph packing [PDF]
Opuscula Mathematica, 2017 Given a positive integer \(m\leq n/2\), Wojda conjectured in 1985 that if \(D_1\) and \(D_2\) are digraphs of order \(n\) such that \(|A(D_1)|\leq n-m\) and \(|A(D_2)|\leq 2n-\lfloor n/m\rfloor-1\) then \(D_1\) and \(D_2\) pack.
Jerzy Konarski, Andrzej Żak
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