Results 41 to 50 of about 4,954 (163)
Discrete Mathematics, 1980 AbstractA digraph is said to be distance-transitive if for all vertices u, v, x, y such that d(u, v) = d(x, y) there is an automorphism π of the digraph such that π(u) = x and π(v) = y. Some examples of distance-transitive digraphs are given in Section 2. Section 3 defines the intersection matrix and gives some of its properties.
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On Vosperian and Superconnected Vertex-Transitive Digraphs [PDF]
Graphs and Combinatorics, 2011 We investigate the structure of a digraph having a transitive automorphism group where every cutset of minimal cardinality consists of all successors or all predecessors of some vertex. We improve most of the existing results in this area.
Hamidoune, Yahya Ould +2 more
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A systematic approach for identifying drivers of critical safety and establishing their hierarchy
The Canadian Journal of Chemical Engineering, Volume 103, Issue 10, Page 4628-4646, October 2025.Abstract Learning from incidents is a crucial step in preventing and mitigating adverse events. Incident databases offer valuable insights for safety management improvements by cause and contributing factors. However, extracting meaningful information from incident investigation reports poses a significant challenge. This study introduces a data‐driven
Mohammad Zaid Kamil +2 more
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Oriented coloring on recursively defined digraphs
, 2019 Coloring is one of the most famous problems in graph theory. The coloring problem on undirected graphs has been well studied, whereas there are very few results for coloring problems on directed graphs. An oriented k-coloring of an oriented graph G=(V,A)
Gurski, Frank +2 more
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Biology, 2013 In this survey paper, we will present a number of core algorithmic questions concerning several transitive reduction problems on network that have applications in network synthesis and analysis involving cellular processes. Our starting point will be the
Satabdi Aditya +2 more
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Number of Subgraphs and Their Converses in Tournaments and New Digraph Polynomials
Journal of Graph Theory, Volume 110, Issue 2, Page 127-131, October 2025.ABSTRACT An oriented graph D is converse invariant if, for any tournament T, the number of copies of D in T is equal to that of its converse − D. El Sahili and Ghazo Hanna [J. Graph Theory 102 (2023), 684‐701] showed that any oriented graph D with maximum degree at most 2 is converse invariant. They proposed a question: Can we characterize all converse
Jiangdong Ai +4 more
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AxiomsAfter the initiation of Jachymski’s contraction principle via digraph, the area of metric fixed point theory has attracted much attention. A number of outcomes on fixed points in the context of graph metric space employing various types of contractions ...
Doaa Filali +2 more
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A Dichotomy Theorem for Γ‐Switchable H‐Colouring on m‐Edge‐Coloured Graphs
Journal of Graph Theory, Volume 110, Issue 2, Page 200-208, October 2025.ABSTRACT Let G be a graph in which each edge is assigned one of the colours 1 , 2 , … , m, and let Γ be a subgroup of S m. The operation of switching at a vertex x of G with respect to an element π of Γ permutes the colours of the edges incident with x according to π.
Richard Brewster +2 more
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Exponents of vertex-transitive digraphs
Discrete Mathematics, 2000 The exponent (respectively, diameter) of a directed graph \(D\) is the least value \(r\) such that for all \(u,v\in V(D)\) there exists a directed \((u\to v)\)-walk of length exactly \(r\) (respectively, \(\leq r\)). These parameters are finite when \(D\) is strongly connected. Many upper bounds are presented for these two parameters in terms of order,
Shen, Jian, Gregory, D.A.
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Precedence‐Constrained Shortest Path
Networks, Volume 86, Issue 3, Page 282-295, October 2025.ABSTRACT We propose a variant of the shortest path problem where the order in which vertices occur in the path is subject to precedence constraints. Precedence constraints are defined in terms of vertex pairs (a,b)$$ \left(a,b\right) $$ which indicate that a vertex a$$ a $$ is the predecessor of a vertex b$$ b $$.
Christina Büsing +2 more
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