• Title/Summary/Keyword: planar graphs

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CHARACTERIZATION THEOREMS AND 4-ORDERABILITY ON INFINITE MAXIMAL PLANAR GRAPHS

  • Jung Hwan-Ok
    • Journal of applied mathematics & informatics
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    • v.22 no.1_2
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    • pp.577-587
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    • 2006
  • We present several properties concerning infinite maximal planar graphs. Results related to the infinite VAP-free planar graphs are also included. Finally, we extend the result of W. Goddard, who showed that every finite 4-connected maximal planar graph is 4-ordered, to infinite strong triangulations.

A STRUCTURE THEOREM AND A CLASSIFICATION OF AN INFINITE LOCALLY FINITE PLANAR GRAPH

  • Jung, Hwan-Ok
    • Journal of applied mathematics & informatics
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    • v.27 no.3_4
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    • pp.531-539
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    • 2009
  • In this paper we first present a structure theorem for an infinite locally finite 3-connected VAP-free planar graph, and in connection with this result we study a possible classification of infinite locally finite planar graphs by reducing modulo finiteness.

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PLANE EMBEDDING PROBLEMS AND A THEOREM FOR INFINITE MAXIMAL PLANAR GRAPHS

  • JUNG HWAN OK
    • Journal of applied mathematics & informatics
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    • v.17 no.1_2_3
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    • pp.643-651
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    • 2005
  • In the first part of this paper we investigate several statements concerning infinite maximal planar graphs which are equivalent in finite case. In the second one, for a given induced $\theta$-path (a finite induced path whose endvertices are adjacent to a vertex of infinite degree) in a 4-connected VAP-free maximal planar graph containing a vertex of infinite degree, a new $\theta$-path is constructed such that the resulting fan is tight.

ON TWO GRAPH PARTITIONING QUESTIONS

  • Rho, Yoo-Mi
    • Journal of the Korean Mathematical Society
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    • v.42 no.4
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    • pp.847-856
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    • 2005
  • M. Junger, G. Reinelt, and W. R. Pulleyblank asked the following questions ([2]). (1) Is it true that every simple planar 2-edge connected bipartite graph has a 3-partition in which each component consists of the edge set of a simple path? (2) Does every simple planar 2-edge connected graph have a 3-partition in which every component consists of the edge set of simple paths and triangles? The purpose of this paper is to provide a positive answer to the second question for simple outerplanar 2-vertex connected graphs and a positive answer to the first question for simple planar 2-edge connected bipartite graphs one set of whose bipartition has at most 4 vertices.

ON THE TIGHTNESS CONDITIONS FOR MAXIMAL PLANAR GRAPHS

  • HWAN-OK JUNG
    • Journal of applied mathematics & informatics
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    • v.4 no.1
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    • pp.235-242
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    • 1997
  • We characterize the tight structure of a vertex-accumula-tion-free maximal planar graph with no separating triangles. Together with the result of Halin who gave an equivalent form for such graphs this yields that a tight structure always exists in every 4-connected maximal planar graph with one end.

(An O(log n) Parallel-Time Depth-First Search Algorithm for Solid Grid Graphs (O(log n)의 병렬 시간이 소요되는 Solid Grid 그래프를 위한 Depth-First Search 알고리즘)

  • Her Jun-Ho;Ramakrishna R.S.
    • Journal of KIISE:Computer Systems and Theory
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    • v.33 no.7
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    • pp.448-453
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    • 2006
  • We extend a parallel depth-first search (DFS) algorithm for planar graphs to deal with (non-planar) solid grid graphs, a subclass of non-planar grid graphs. The proposed algorithm takes time O(log n) with $O(n/sqrt{log\;n})$ processors in Priority PRAM model. In our knowledge, this is the first deterministic NC algorithm for a non-planar graph class.

5-CYCLABILITY IN INFINITE PLANAR GRAPHS

  • JUNG HWAN-OK
    • Journal of applied mathematics & informatics
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    • v.19 no.1_2
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    • pp.537-543
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    • 2005
  • A graph is k-cyclable if given k vertices there is a cycle that contains the k vertices. Sallee showed that every finite 3-connected planar graph is 5-cyclable. In this paper Sallee's result is extended to 3-connected infinite locally finite VAP-free plane graphs containing no unbounded faces.

ENERGY OF PLANAR GRAPHS

  • Pirzada, S.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.12 no.1
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    • pp.7-11
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    • 2008
  • The energy of a graph is the sum of the absolute values of its eigen values. We obtain some bounds for the energy of planar graphs in terms of its vertices, edges and faces.

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