Results 21 to 30 of about 48,688 (228)
On some subclasses of interval catch digraphs
Electronic Journal of Graph Theory and Applications, 2022 A digraph G = (V, E) is an interval catch digraph if for each vertex v ∈ V, one can associate an interval on real line and a point within it (say (Iv, pv)) in such a way that uv ∈ E if and only if pv ∈ Iu. It was introduced by Maehara in 1984.
Sanchita Paul, Shamik Ghosh
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The non-negative spectrum of a digraph
Open Mathematics, 2020 Given the adjacency matrix A of a digraph, the eigenvalues of the matrix AAT constitute the so-called non-negative spectrum of this digraph. We investigate the relation between the structure of digraphs and their non-negative spectra and associated ...
Alomari Omar +2 more
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Interplay of time-delay and velocity alignment in the Cucker-Smale model on a general digraph [PDF]
, 2018 We study dynamic interplay between time-delay and velocity alignment in the ensemble of Cucker-Smale (C-S) particles(or agents) on time-varying networks which are modeled by digraphs containing spanning trees.
Jiu‐Gang Dong +2 more
semanticscholar +1 more source
A digraph fourier transform with spread frequency components [PDF]
IEEE Global Conference on Signal and Information Processing, 2017 We study the problem of constructing a graph Fourier transform (GFT) for directed graphs (digraphs), which decomposes graph signals into different modes of variation with respect to the underlying network.
Rasoul Shafipour +3 more
semanticscholar +1 more source
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
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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.
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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
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Subset sum problems with digraph constraints [PDF]
Journal of combinatorial optimization, 2016 We introduce and study optimization problems which are related to the well-known Subset Sum problem. In each new problem, a node-weighted digraph is given and one has to select a subset of vertices whose total weight does not exceed a given budget.
L. Gourvès, J. Monnot, Lydia Tlilane
semanticscholar +1 more source
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
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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
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