Harmonious coloring

Harmonious coloring


Harmonious coloring of 7-tree with 3 levels using 12 colors. The harmonius chromatic number of this graph is 12 since the vertices are 57, and the color's pair are ncolor*(ncolor-1)/2 >= 57 iff ncolor>=12. Moreover (3/2)*(7+1)=12(see Mitchem's Formula).

In graph theory, a harmonious coloring is a (proper) vertex coloring in which every pair of colors appears on at most one pair of adjacent vertices. The harmonious chromatic number χH("G") of a graph "G" is the minimum number of colors needed for any harmonious coloring of "G".

Every graph has a harmonious coloring, since it suffices to assign every vertex a distinct color; thus χH("G") ≤ |V(G)|. There trivially exist graphs "G" with χH("G") > χ("G") (where χ is the chromatic number); one example is the path of length 2, which can be 2-colored but has no harmonious coloring with 2 colors.

Some properties of χH("G"):
# χH(T"k",3) = ⌈(3/2)("k"+1)⌉, where T"k",3 is the complete "k"-ary tree with 3 levels. (Mitchem 1989)

Harmonious coloring was first proposed by Frank, Harary and Plantholt (1982).Still very little is known about it.

See also: Complete coloring

External links

* [http://www.maths.dundee.ac.uk/~kedwards/biblio.html] "A Bibliography of Harmonious Colourings and Achromatic Number" by Keith Edwards

References

* Frank, O.; Harary, F.; Plantholt, M. (1982). The line-distinguishing chromatic number of a graph. "Ars Combin." 14, 241–252.
* Jensen, Tommy R.; Toft, Bjarne (1995). "Graph coloring problems". New York: Wiley-Interscience. ISBN 0-471-02865-7.
* Mitchem, J. (1989). On the harmonious chromatic number of a graph. "Discrete Math." 74, 151–157.


Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • coloring — Synonyms and related words: Klangfarbe, abstractionism, achromatism, acrylic painting, acting, affectation, affective meaning, appearance, attitudinizing, bearing, bloom, bluff, bluffing, blush, blushing, cast, cheating, chromatic, chromatism,… …   Moby Thesaurus

  • harmonious — Synonyms and related words: accompanying, accordant, according, affable, affirmative, agreeable, agreeing, akin, amiable, amicable, anal, answerable, arranged, associate, associated, assonant, assonantal, at one, at one with, attuned, balanced,… …   Moby Thesaurus

  • Complete coloring — of the Clebsch graph with 8 colors. Every pair of colors appears on at least one edge. No complete coloring with more colors exists: in any 9 coloring some color would appear only at one vertex, and there would not be enough neighboring vertices… …   Wikipedia

  • Graph coloring — A proper vertex coloring of the Petersen graph with 3 colors, the minimum number possible. In graph theory, graph coloring is a special case of graph labeling; it is an assignment of labels traditionally called colors to elements of a graph… …   Wikipedia

  • Exact coloring — The n coloring of Complete graph K n is an exact coloring.In graph theory, an exact coloring is a (proper) vertex coloring in which every pair of colors appears on exactly one pair of adjacent vertices. In essence, an exact coloring is a coloring …   Wikipedia

  • List of graph theory topics — This is a list of graph theory topics, by Wikipedia page. See glossary of graph theory for basic terminology Contents 1 Examples and types of graphs 2 Graph coloring 3 Paths and cycles 4 …   Wikipedia

  • George Morland — (1763 1804) was an English painter of animals and rustic scenes. LifeMorland was born in London on 26 June 1763. His mother was a Frenchwoman, who possessed a small independent property of her own. His grandfather, George H. Morland, was a… …   Wikipedia

  • Titian — Tiziano redirects here. For other uses, see Tiziano (disambiguation). For other uses, see Titian (disambiguation). Titian Titian self portrait, c.1567; Museo del Prado, Madrid Birth name …   Wikipedia

  • List of mathematics articles (H) — NOTOC H H cobordism H derivative H index H infinity methods in control theory H relation H space H theorem H tree Haag s theorem Haagerup property Haaland equation Haar measure Haar wavelet Haboush s theorem Hackenbush Hadamard code Hadamard… …   Wikipedia

  • Color analysis (art) — Color analysis, also called skin tone color matching or color seasons, is the process of finding colors of clothing and makeup to match a person s complexion, eye color, and hair color. It is often used as an aid to wardrobe planning and style… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”