Temat: graph labelling - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Strongly multiplicative graphs
Autorzy:: Beineke, L.
Hegde, S.
Powiązania:: https://bibliotekanauki.pl/articles/743424.pdf
Data publikacji:: 2001
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: graph labelling
multiplicative labelling
Opis:: A graph with p vertices is said to be strongly multiplicative if its vertices can be labelled 1,2,...,p so that the values on the edges, obtained as the product of the labels of their end vertices, are all distinct. In this paper, we study structural properties of strongly multiplicative graphs. We show that all graphs in some classes, including all trees, are strongly multiplicative, and consider the question of the maximum number of edges in a strongly multiplicative graph of a given order.
Źródło:: Discussiones Mathematicae Graph Theory; 2001, 21, 1; 63-75
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Difference labelling of cacti
Autorzy:: Sonntag, Martin
Powiązania:: https://bibliotekanauki.pl/articles/743380.pdf
Data publikacji:: 2003
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: graph labelling
difference graph
cactus
Opis:: A graph G is a difference graph iff there exists S ⊂ IN⁺ such that G is isomorphic to the graph DG(S) = (V,E), where V = S and E = {{i,j}:i,j ∈ V ∧ |i-j| ∈ V}.
It is known that trees, cycles, complete graphs, the complete bipartite graphs $K_{n,n}$ and $K_{n,n-1}$, pyramids and n-sided prisms (n ≥ 4) are difference graphs (cf. [4]). Giving a special labelling algorithm, we prove that cacti with a girth of at least 6 are difference graphs, too.
Źródło:: Discussiones Mathematicae Graph Theory; 2003, 23, 1; 55-65
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Cyclic decompositions of complete graphs into spanning trees
Autorzy:: Froncek, Dalibor
Powiązania:: https://bibliotekanauki.pl/articles/744515.pdf
Data publikacji:: 2004
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: graph factorization
graph labelling
spanning trees
Opis:: We examine decompositions of complete graphs with an even number of vertices, $K_{2n}$, into n isomorphic spanning trees. While methods of such decompositions into symmetric trees have been known, we develop here a more general method based on a new type of vertex labelling, called flexible q-labelling. This labelling is a generalization of labellings introduced by Rosa and Eldergill.
Źródło:: Discussiones Mathematicae Graph Theory; 2004, 24, 2; 345-353
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 4.

Tytuł:: An upper bound for maximum number of edges in a strongly multiplicative graph
Autorzy:: Adiga, Chandrashekar
Smitha, Mahadev
Powiązania:: https://bibliotekanauki.pl/articles/743941.pdf
Data publikacji:: 2006
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: graph labelling
strongly multiplicative graphs
Opis:: In this note we give an upper bound for λ(n), the maximum number of edges in a strongly multiplicative graph of order n, which is sharper than the upper bounds given by Beineke and Hegde [3] and Adiga, Ramaswamy and Somashekara [2], for n ≥ 28.
Źródło:: Discussiones Mathematicae Graph Theory; 2006, 26, 2; 225-229
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 5.

Tytuł:: Difference labelling of digraphs
Autorzy:: Sonntag, Martin
Powiązania:: https://bibliotekanauki.pl/articles/744591.pdf
Data publikacji:: 2004
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: graph labelling
difference digraph
oriented tree
Opis:: A digraph G is a difference digraph iff there exists an S ⊂ N⁺ such that G is isomorphic to the digraph DD(S) = (V,A), where V = S and A = {(i,j):i,j ∈ V ∧ i-j ∈ V}.For some classes of digraphs, e.g. alternating trees, oriented cycles, tournaments etc., it is known, under which conditions these digraphs are difference digraphs (cf. [5]). We generalize the so-called source-join (a construction principle to obtain a new difference digraph from two given ones (cf. [5])) and construct a difference labelling for the source-join of an even number of difference digraphs. As an application we obtain a sufficient condition guaranteeing that certain (non-alternating) trees are difference digraphs.
Źródło:: Discussiones Mathematicae Graph Theory; 2004, 24, 3; 509-527
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 6.

Tytuł:: Total edge irregularity strength of trees
Autorzy:: Ivančo, Jaroslav
Jendrol', Stanislav
Powiązania:: https://bibliotekanauki.pl/articles/743612.pdf
Data publikacji:: 2006
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: graph labelling
tree
irregularity strength
total labellings
total edge irregularity strength
Opis:: A total edge-irregular k-labelling ξ:V(G)∪ E(G) → {1,2,...,k} of a graph G is a labelling of vertices and edges of G in such a way that for any different edges e and f their weights wt(e) and wt(f) are distinct. The weight wt(e) of an edge e = xy is the sum of the labels of vertices x and y and the label of the edge e. The minimum k for which a graph G has a total edge-irregular k-labelling is called the total edge irregularity strength of G, tes(G). In this paper we prove that for every tree T of maximum degree Δ on p vertices
tes(T) = max{⎡(p+1)/3⎤,⎡(Δ+1)/2⎤}.
Źródło:: Discussiones Mathematicae Graph Theory; 2006, 26, 3; 449-456
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 7.

Tytuł:: On constant-weight TSP-tours
Autorzy:: Jones, Scott
Kayll, P.
Mohar, Bojan
Wallis, Walter
Powiązania:: https://bibliotekanauki.pl/articles/743167.pdf
Data publikacji:: 2003
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: graph labelling
complete graph
travelling salesman problem
Hamilton cycle
one-factor
two-factor
k-factor
constant-weight
local matching conditions
edge label growth-rate
Sidon sequence
well-spread sequence
Opis:: Is it possible to label the edges of Kₙ with distinct integer weights so that every Hamilton cycle has the same total weight? We give a local condition characterizing the labellings that witness this question's perhaps surprising affirmative answer. More generally, we address the question that arises when "Hamilton cycle" is replaced by "k-factor" for nonnegative integers k. Such edge-labellings are in correspondence with certain vertex-labellings, and the link allows us to determine (up to a constant factor) the growth rate of the maximum edge-label in a "most efficient" injective metric trivial-TSP labelling.
Źródło:: Discussiones Mathematicae Graph Theory; 2003, 23, 2; 287-307
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

Artykuł

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