Results 31 to 40 of about 783,181 (348)
The Windy Postman Problem on Series-Parallel Graphs [PDF]
Discrete Mathematics & Theoretical Computer Science, 2005 The windy postman problem is the NP-hard problem of finding the minimum cost of a tour traversing all edges of an undirected graph, where the cost of traversal of an edge depends on the direction. Given an undirected graph $G$, we consider the polyhedron
Francisco Javier Zaragoza Martínez
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Testing hereditary properties of nonexpanding bounded-degree graphs [PDF]
, 2007 We study graph properties that are testable for bounded-degree graphs in time independent of the input size. Our goal is to distinguish between graphs having a predetermined graph property and graphs that are far from every graph having that property. It
Christian Sohler +5 more
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On the chromatic number of (P_{5},windmill)-free graphs [PDF]
Opuscula Mathematica, 2017 In this paper we study the chromatic number of \((P_5, windmill)\)-free graphs. For integers \(r,p\geq 2\) the windmill graph \(W_{r+1}^p=K_1 \vee pK_r\) is the graph obtained by joining a single vertex (the center) to the vertices of \(p\) disjoint ...
Ingo Schiermeyer
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Characterising and recognising game-perfect graphs [PDF]
Discrete Mathematics & Theoretical Computer Science, 2019 Consider a vertex colouring game played on a simple graph with $k$ permissible colours. Two players, a maker and a breaker, take turns to colour an uncoloured vertex such that adjacent vertices receive different colours.
Dominique Andres, Edwin Lock
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Nearly perfect sets in the n-fold products of graphs [PDF]
Opuscula Mathematica, 2007 The study of nearly perfect sets in graphs was initiated in [J. E. Dunbar, F. C. Harris, S. M. Hedetniemi, S. T. Hedetniemi, A. A. McRae, R. C. Laskar, Nearly perfect sets in graphs, Discrete Mathematics 138 (1995), 229-246]. Let \(S \subseteq V(G)\). We
Monika Perl
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Perfect edge domination in vague graphs
Ratio Mathematica, 2021 In this paper, we modified undirected vague graphs and edge domination set based on these two concepts. We study the notions of perfect edge domination, connected perfect edge domination of vague graph. Moreover, we investigate some related properties in
M Kaliraja, P Kanibose, Abdul Ibrahim
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Some Variations of Perfect Graphs
Discussiones Mathematicae Graph Theory, 2016 We consider (ψk−γk−1)-perfect graphs, i.e., graphs G for which ψk(H) = γk−1(H) for any induced subgraph H of G, where ψk and γk−1 are the k-path vertex cover number and the distance (k − 1)-domination number, respectively.
Dettlaff Magda +3 more
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Forbidden Structures for Planar Perfect Consecutively Colourable Graphs
Discussiones Mathematicae Graph Theory, 2017 A consecutive colouring of a graph is a proper edge colouring with posi- tive integers in which the colours of edges incident with each vertex form an interval of integers.
Borowiecka-Olszewska Marta +1 more
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Contractions in perfect graphs
Discrete Applied MathematicsIn this paper, we characterize the class of {\em contraction perfect} graphs which are the graphs that remain perfect after the contraction of any edge set. We prove that a graph is contraction perfect if and only if it is perfect and the contraction of any single edge preserves its perfection.
Alexandre Dupont-Bouillard +3 more
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Electronic Notes in Discrete Mathematics, 2013 Abstract In this paper we study a natural generalization for the perfection of graphs to other interesting parameters related with colorations. This generalization was introduced partially by Christen and Selkow in 1979 and Yegnanarayanan in 2001. Let a , b ∈ { ω , χ , Γ , α , ψ } where ω is the clique number, χ is the chromatic ...
Gabriela Araujo-Pardo +1 more
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