منابع مشابه
Obtaining Uniformly Dense Graphs
Let G be a non-trivial, loop-less multi-graph and for each non-trivial sub-graph H of G, let g(H) = |E(H)| |V (H)|−ω(G) . G is said to be uniformly dense if and only if γ(G), the maximum among g(H) taken over all non-trivial subgraphs H of G is attained when H = G. This quantity γ(G) is called the fractional arboricity of G and was introduced by Catlin, Grossman, Hobbs and Lai [4]. γ(G)− g(G) m...
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LetG be a graph with vertex set V (G) and edge setE(G). A labeling f : V (G) → {0, 1} induces an edge labeling f ∗ : E(G) → {0, 1}, defined by f ∗(xy) = |f (x) − f (y)| for each edge xy ∈ E(G). For i ∈ {0, 1}, let ni(f ) = |{v ∈ V (G) : f (v) = i}| and mi(f )=|{e ∈ E(G) : f ∗(e)= i}|. Let c(f )=|m0(f )−m1(f )|.A labeling f of a graphG is called friendly if |n0(f )−n1(f )| 1. A cordial labeling ...
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We present an expected polynomial time algorithm to generate a labeled planar graph uniformly at random. To generate the planar graphs, we derive recurrence formulas that count all such graphs with vertices and edges, based on a decomposition into 1-, 2-, and 3-connected components. For 3-connected graphs we apply a recent random generation algorithm by Schaeffer and a counting formula by Mulli...
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The area of approximation algorithms for the Steiner tree problem in graphs has seen continuous progress over the last years. Currently the best approximation algorithm has a performance ratio of 1.550. This is still far away from 1.0074, the largest known lower bound on the achievable performance ratio. As all instances resulting from known lower bound reductions are uniformly quasi-bipartite,...
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ژورنال
عنوان ژورنال: Ars Mathematica Contemporanea
سال: 2017
ISSN: 1855-3974,1855-3966
DOI: 10.26493/1855-3974.1013.46a