Results 71 to 80 of about 8,697 (224)
When a digraph and its line digraph are connected and cospectral [PDF]
, 1998 In this paper we characterize all digraphs each one of which is cospectral with its line digraph and both the digraph and its line digraph are connected. Some related enumeration problems are also considered.
Lin, Guoning, Zhang, Fuji
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Journal of Algebra Combinatorics Discrete Structures and Applications, 2022 A $(0,1)$-labelling of a set is said to be {\em friendly} if approximately one half the elements of the set are labelled 0 and one half labelled 1. Let $g$ be a labelling of the edge set of a graph that is induced by a labelling $f$ of the vertex set. If both $g$ and $f$ are friendly then $g$ is said to be a {\em cordial} labelling of the graph.
Beasley, LeRoy B. +3 more
openaire +2 more sources
Allocation of Indivisible Items With a Common Preference Graph: Minimizing Total Dissatisfaction
Networks, EarlyView.ABSTRACT Allocating indivisible items among a set of agents is a frequently studied discrete optimization problem. In the setting considered in this work, the agents' preferences over the items are assumed to be identical. We consider a very recent measure for the overall quality of an allocation which does not rely on numerical valuations of the items.
Nina Chiarelli +6 more
wiley +1 more source
When the arc-colored line digraph of a cayley colored digraph is again a cayley colored digraph [PDF]
, 1992 Let D6(G) be the Cayley colored ügraph of a finite group G generated by A. The arc-colored line digraph of a Cayley colored digraph ie obtained by appropriately coloring the arcs of its line digraph.
Fiol Mora, Maria Lluïsa +2 more
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Frucht’s Theorem for the Digraph Factorial
Discussiones Mathematicae Graph Theory, 2013 To every graph (or digraph) A, there is an associated automorphism group Aut(A). Frucht’s theorem asserts the converse association; that for any finite group G there is a graph (or digraph) A for which Aut(A) ∼= G.
Hammack Richard H.
doaj +1 more source
Discrete Mathematics, 2004 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Boland, James +2 more
openaire +3 more sources
Interdiction Models and Heuristics for Graph Propagation
Networks, EarlyView.ABSTRACT Given a graph G=(V,E)$$ G=\left(V,E\right) $$ and a set S⊂V$$ S\subset V $$ of activated/infected nodes, we consider the problem of determining the set of c$$ c $$ nodes that minimizes the network propagation on the subgraph that results from the removal of those c$$ c $$ nodes. To measure network propagation, we assume that a node i$$ i $$ is
Agostinho Agra, José Maria Samuco
wiley +1 more source
Journal of Research of the National Institute of Standards and Technology, 2014 A digraph whose degree sequence has a unique vertex labeled realization is called threshold. In this paper we present several characterizations of threshold digraphs and their degree sequences, and show these characterizations to be equivalent. One of the characterizations is new, and allows for a shorter proof of the equivalence of the two known ...
Brian Cloteaux +3 more
openaire +4 more sources
Simultaneous Network Design With Restricted Link Usage
Networks, EarlyView.ABSTRACT Given a digraph with two terminal vertices s$$ s $$ and t$$ t $$ as well as a conservative cost function and several not necessarily disjoint color classes on its arc set, our goal is to find a minimum‐cost subset of the arcs such that its intersection with each color class contains an s$$ s $$‐t$$ t $$ dipath.
Naonori Kakimura +3 more
wiley +1 more source
The homology digraph of a preordered space [PDF]
, 2023 This paper studies a notion of directed homology for preordered spaces, called the homology digraph. We show that the homology digraph is a directed homotopy invariant and establish variants of the main results of ordinary singular homology theory for ...
Kahl, Thomas, Faustino, Catarina
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