On -strong distance in strong digraphs

Ping Zhang

Mathematica Bohemica (2002)

  • Volume: 127, Issue: 4, page 557-570
  • ISSN: 0862-7959

Abstract

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For a nonempty set of vertices in a strong digraph , the strong distance is the minimum size of a strong subdigraph of containing the vertices of . If contains vertices, then is referred to as the -strong distance of . For an integer and a vertex of a strong digraph , the -strong eccentricity of is the maximum -strong distance among all sets of vertices in containing . The minimum -strong eccentricity among the vertices of is its -strong radius and the maximum -strong eccentricity is its -strong diameter . The -strong center (-strong periphery) of is the subdigraph of induced by those vertices of -strong eccentricity (). It is shown that, for each integer , every oriented graph is the -strong center of some strong oriented graph. A strong oriented graph is called strongly -self-centered if is its own -strong center. For every integer , there exist infinitely many strongly 3-self-centered oriented graphs of 3-strong radius . The problem of determining those oriented graphs that are -strong peripheries of strong oriented graphs is studied.

How to cite

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Zhang, Ping. "On $k$-strong distance in strong digraphs." Mathematica Bohemica 127.4 (2002): 557-570. <http://eudml.org/doc/249029>.

@article{Zhang2002,
abstract = {For a nonempty set $S$ of vertices in a strong digraph $D$, the strong distance $d(S)$ is the minimum size of a strong subdigraph of $D$ containing the vertices of $S$. If $S$ contains $k$ vertices, then $d(S)$ is referred to as the $k$-strong distance of $S$. For an integer $k \ge 2$ and a vertex $v$ of a strong digraph $D$, the $k$-strong eccentricity $\mathop \{\mathrm \{s\}e\}_k(v)$ of $v$ is the maximum $k$-strong distance $d(S)$ among all sets $S$ of $k$ vertices in $D$ containing $v$. The minimum $k$-strong eccentricity among the vertices of $D$ is its $k$-strong radius $\mathop \{\mathrm \{s\}rad\}_k D$ and the maximum $k$-strong eccentricity is its $k$-strong diameter $_k D$. The $k$-strong center ($k$-strong periphery) of $D$ is the subdigraph of $D$ induced by those vertices of $k$-strong eccentricity $\mathop \{\mathrm \{s\}rad\}_k(D)$ ($_k (D)$). It is shown that, for each integer $k \ge 2$, every oriented graph is the $k$-strong center of some strong oriented graph. A strong oriented graph $D$ is called strongly $k$-self-centered if $D$ is its own $k$-strong center. For every integer $r \ge 6$, there exist infinitely many strongly 3-self-centered oriented graphs of 3-strong radius $r$. The problem of determining those oriented graphs that are $k$-strong peripheries of strong oriented graphs is studied.},
author = {Zhang, Ping},
journal = {Mathematica Bohemica},
keywords = {strong distance; strong eccentricity; strong center; strong periphery; strong distance; strong eccentricity; strong center; strong periphery},
language = {eng},
number = {4},
pages = {557-570},
publisher = {Institute of Mathematics, Academy of Sciences of the Czech Republic},
title = {On $k$-strong distance in strong digraphs},
url = {http://eudml.org/doc/249029},
volume = {127},
year = {2002},
}

TY - JOUR
AU - Zhang, Ping
TI - On $k$-strong distance in strong digraphs
JO - Mathematica Bohemica
PY - 2002
PB - Institute of Mathematics, Academy of Sciences of the Czech Republic
VL - 127
IS - 4
SP - 557
EP - 570
AB - For a nonempty set $S$ of vertices in a strong digraph $D$, the strong distance $d(S)$ is the minimum size of a strong subdigraph of $D$ containing the vertices of $S$. If $S$ contains $k$ vertices, then $d(S)$ is referred to as the $k$-strong distance of $S$. For an integer $k \ge 2$ and a vertex $v$ of a strong digraph $D$, the $k$-strong eccentricity $\mathop {\mathrm {s}e}_k(v)$ of $v$ is the maximum $k$-strong distance $d(S)$ among all sets $S$ of $k$ vertices in $D$ containing $v$. The minimum $k$-strong eccentricity among the vertices of $D$ is its $k$-strong radius $\mathop {\mathrm {s}rad}_k D$ and the maximum $k$-strong eccentricity is its $k$-strong diameter $_k D$. The $k$-strong center ($k$-strong periphery) of $D$ is the subdigraph of $D$ induced by those vertices of $k$-strong eccentricity $\mathop {\mathrm {s}rad}_k(D)$ ($_k (D)$). It is shown that, for each integer $k \ge 2$, every oriented graph is the $k$-strong center of some strong oriented graph. A strong oriented graph $D$ is called strongly $k$-self-centered if $D$ is its own $k$-strong center. For every integer $r \ge 6$, there exist infinitely many strongly 3-self-centered oriented graphs of 3-strong radius $r$. The problem of determining those oriented graphs that are $k$-strong peripheries of strong oriented graphs is studied.
LA - eng
KW - strong distance; strong eccentricity; strong center; strong periphery; strong distance; strong eccentricity; strong center; strong periphery
UR - http://eudml.org/doc/249029
ER -

References

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  2. Strong distance in strong digraphs, J. Combin. Math. Combin. Comput. 31 (1999), 33–44. (1999) MR1726945
  3. On strong distance in strong oriented graphs, Congr. Numer. 141 (1999), 49–63. (1999) MR1744211
  4. Graphs Digraphs, third edition, Chapman Hall, New York, 1996. (1996) MR1408678
  5. Steiner distance in graphs, Čas. Pěst. Mat. 114 (1989), 399–410. (1989) MR1027236

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