• 대한수학회보
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• 제52권1호
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• pp.287-299
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• 2015

A theta graph is the union of three internally disjoint paths that have the same two distinct end vertices. We show that every graph of order $n{\geq}12$ and size at least ${\lfloor}\frac{11n-18}{2}{\rfloor}$ contains three disjoint theta graphs. As a corollary, every graph of order $n{\geq}12$ and size at least ${\lfloor}\frac{11n-18}{2}{\rfloor}$ contains three disjoint cycles of even length.

• Kyungpook Mathematical Journal
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• 제54권1호
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• pp.23-30
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• 2014

For two positive integers r and s, $\mathcal{G}$(n; r; ${\theta}_s$) denotes to the class of graphs on n vertices containing no r of edge disjoint ${\theta}_s$-graphs and f(n; r; ${\theta}_s$) = max{${\varepsilon}(G)$ : G ${\in}$ $\mathcal{G}$(n; r; ${\theta}_s$)}. In this paper, for integers r, $k{\geq}2$, we determine f(n; r; ${\theta}_{2k+1}$) and characterize the edge maximal members in G(n; r; ${\theta}_{2k+1}$).