Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "graph coloring" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 95
Tytuł:
Analysis of the efficiency of graph coloring algorithms
Autorzy:
Kubale, Marek
Powiązania:
https://bibliotekanauki.pl/articles/748571.pdf
Data publikacji:
1982
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Computational complexity and efficiency of algorithms
Coloring of graphs and hypergraphs
Graph theory
Opis:
.
This paper discusses the computational efficiency and the number of colors used by the following algorithms for coloring vertices of graphs: sequential coloring and sequential coloring with interchange algorithms for a largest-first and a smallest-last orderings of vertices, the coloring-pairs algorithm, and the approximately maximum independent set algorithm. Each algorithm is supplied with a Pascal-like program, time complexity in terms of the size of a graph, and worst-case behaviour. In conclusion, some computational results are included with support the estimations and suggest the sequential coloring with interchange algorithm for a largest-first vertex ordering as a method which uses the least number of colors for uniformly distributed random graphs.
Źródło:
Mathematica Applicanda; 1982, 10, 19
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Associative graph products and their independence, domination and coloring numbers
Autorzy:
Nowakowski, Richard
Rall, Douglas
Powiązania:
https://bibliotekanauki.pl/articles/972041.pdf
Data publikacji:
1996
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
graph products
independence
domination
irredundance
coloring
Opis:
Associative products are defined using a scheme of Imrich & Izbicki [18]. These include the Cartesian, categorical, strong and lexicographic products, as well as others. We examine which product ⊗ and parameter p pairs are multiplicative, that is, p(G⊗H) ≥ p(G)p(H) for all graphs G and H or p(G⊗H) ≤ p(G)p(H) for all graphs G and H. The parameters are related to independence, domination and irredundance. This includes Vizing's conjecture directly, and indirectly the Shannon capacity of a graph and Hedetniemi's coloring conjecture.
Źródło:
Discussiones Mathematicae Graph Theory; 1996, 16, 1; 53-79
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generalized colorings and avoidable orientations
Autorzy:
Szigeti, Jenő
Tuza, Zsolt
Powiązania:
https://bibliotekanauki.pl/articles/971967.pdf
Data publikacji:
1997
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
hereditary property
graph coloring
Opis:
Gallai and Roy proved that a graph is k-colorable if and only if it has an orientation without directed paths of length k. We initiate the study of analogous characterizations for the existence of generalized graph colorings, where each color class induces a subgraph satisfying a given (hereditary) property. It is shown that a graph is partitionable into at most k independent sets and one induced matching if and only if it admits an orientation containing no subdigraph from a family of k+3 directed graphs.
Źródło:
Discussiones Mathematicae Graph Theory; 1997, 17, 1; 137-145
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Graph colorings with local constraints - a survey
Autorzy:
Tuza, Zsolt
Powiązania:
https://bibliotekanauki.pl/articles/972031.pdf
Data publikacji:
1997
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
graph coloring
list coloring
choice number
precoloring extension
complexity of algorithms
chromatic number
Opis:
We survey the literature on those variants of the chromatic number problem where not only a proper coloring has to be found (i.e., adjacent vertices must not receive the same color) but some further local restrictions are imposed on the color assignment. Mostly, the list colorings and the precoloring extensions are considered.
In one of the most general formulations, a graph G = (V,E), sets L(v) of admissible colors, and natural numbers $c_v$ for the vertices v ∈ V are given, and the question is whether there can be chosen a subset C(v) ⊆ L(v) of cardinality $c_v$ for each vertex in such a way that the sets C(v),C(v') are disjoint for each pair v,v' of adjacent vertices. The particular case of constant |L(v)| with $c_v$ = 1 for all v ∈ V leads to the concept of choice number, a graph parameter showing unexpectedly different behavior compared to the chromatic number, despite these two invariants have nearly the same value for almost all graphs.
To illustrate typical techniques, some of the proofs are sketched.
Źródło:
Discussiones Mathematicae Graph Theory; 1997, 17, 2; 161-228
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The smallest hard-to-color graphs for the classical, total and strong colorings of vertices
Autorzy:
Kubale, M.
Manuszewski, K.
Powiązania:
https://bibliotekanauki.pl/articles/206254.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
optymalizacja
teoria grafów
złożoność obliczeniowa
benchmark
chromatic number
chromatic sum
graph oring
hard-to-color graph
NP-completeness
strong coloring
Opis:
: Let A(G) be the number of colors used by algorithm to color the vertices of graph G. A graph G is said to be hard-to-color (HC) (resp. slightly HC) if for every (resp. some) implementation of the algorithm A we have A(G) > chi(G), where chi(G) is the chromatic number of G. The study of HC graphs makes it possible design improved algorithms trying to avoid hard instances as far possible. Hard-to-color graphs are also good benchmarks for the evaluation of existing and future algorithms and provide an alternative way of assessing their quality. In this paper we demonstrate the smallest HC graphs for the best known coloring heuristics in classical applications, as well as when adapted to the chromatic sum coloring and strong coloring of vertices.
Źródło:
Control and Cybernetics; 1999, 28, 2; 355-365
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Frequency planning and ramifications of coloring
Autorzy:
Eisenblätter, Andreas
Grötschel, Martin
Koster, Arie
Powiązania:
https://bibliotekanauki.pl/articles/743541.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
frequency assignment
graph coloring
Opis:
This paper surveys frequency assignment problems coming up in planning wireless communication services. It particularly focuses on cellular mobile phone systems such as GSM, a technology that revolutionizes communication. Traditional vertex coloring provides a conceptual framework for the mathematical modeling of many frequency planning problems. This basic form, however, needs various extensions to cover technical and organizational side constraints. Among these ramifications are T-coloring and list coloring. To model all the subtleties, the techniques of integer programming have proven to be very useful.The ability to produce good frequency plans in practice is essential for the quality of mobile phone networks. The present algorithmic solution methods employ variants of some of the traditional coloring heuristics as well as more sophisticated machinery from mathematical programming. This paper will also address this issue.Finally, this paper discusses several practical frequency assignment problems in detail, states the associated mathematical models, and also points to public electronic libraries of frequency assignment problems from practice. The associated graphs have up to several thousand vertices and range form rather sparse to almost complete.
Źródło:
Discussiones Mathematicae Graph Theory; 2002, 22, 1; 51-88
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A note on total colorings of planar graphs without 4-cycles
Autorzy:
Wang, Ping
Wu, Jian-Liang
Powiązania:
https://bibliotekanauki.pl/articles/744436.pdf
Data publikacji:
2004
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
total coloring
planar graph
list coloring
girth
Opis:
Let G be a 2-connected planar graph with maximum degree Δ such that G has no cycle of length from 4 to k, where k ≥ 4. Then the total chromatic number of G is Δ +1 if (Δ,k) ∈ {(7,4),(6,5),(5,7),(4,14)}.
Źródło:
Discussiones Mathematicae Graph Theory; 2004, 24, 1; 125-135
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analogues of cliques for oriented coloring
Autorzy:
Klostermeyer, William
MacGillivray, Gary
Powiązania:
https://bibliotekanauki.pl/articles/744524.pdf
Data publikacji:
2004
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
graph coloring
oriented coloring
clique
planar graph
Opis:
We examine subgraphs of oriented graphs in the context of oriented coloring that are analogous to cliques in traditional vertex coloring. Bounds on the sizes of these subgraphs are given for planar, outerplanar, and series-parallel graphs. In particular, the main result of the paper is that a planar graph cannot contain an induced subgraph D with more than 36 vertices such that each pair of vertices in D are joined by a directed path of length at most two.
Źródło:
Discussiones Mathematicae Graph Theory; 2004, 24, 3; 373-387
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some applications of pq-groups in graph theory
Autorzy:
Exoo, Geoffrey
Powiązania:
https://bibliotekanauki.pl/articles/744429.pdf
Data publikacji:
2004
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
Ramsey number
edge coloring
cage
degree
girth
Cayley graph
Opis:
We describe some new applications of nonabelian pq-groups to construction problems in Graph Theory. The constructions include the smallest known trivalent graph of girth 17, the smallest known regular graphs of girth five for several degrees, along with four edge colorings of complete graphs that improve lower bounds on classical Ramsey numbers.
Źródło:
Discussiones Mathematicae Graph Theory; 2004, 24, 1; 109-114
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Defining sets in (proper) vertex colorings of the Cartesian product of a cycle with a complete graph
Autorzy:
Mojdeh, D.
Powiązania:
https://bibliotekanauki.pl/articles/743869.pdf
Data publikacji:
2006
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
graph coloring
defining set
cartesian product
Opis:
In a given graph G = (V,E), a set of vertices S with an assignment of colors to them is said to be a defining set of the vertex coloring of G, if there exists a unique extension of the colors of S to a c ≥ χ(G) coloring of the vertices of G. A defining set with minimum cardinality is called a minimum defining set and its cardinality is the defining number, denoted by d(G,c).
The d(G = Cₘ × Kₙ, χ(G)) has been studied. In this note we show that the exact value of defining number d(G = Cₘ × Kₙ, c) with c > χ(G), where n ≥ 2 and m ≥ 3, unless the defining number $d(K₃×C_{2r},4)$, which is given an upper and lower bounds for this defining number. Also some bounds of defining number are introduced.
Źródło:
Discussiones Mathematicae Graph Theory; 2006, 26, 1; 59-72
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Equitable coloring of graph products
Autorzy:
Furmańczyk, H.
Powiązania:
https://bibliotekanauki.pl/articles/254911.pdf
Data publikacji:
2006
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
equitable coloring
graph product
Opis:
A graph is equitably k-colorable if its vertices can be partitioned into k independent sets in such a way that the number of vertices in any two sets differ by at most one. The smallest k for which such a coloring exists is known as the "equitable chromatic number" of G and denoted by χ=(G). It is interesting to note that if a graph G is equitably k-colorable, it does not imply that it is equitably (k + 1)-colorable. The smallest integer k for which G is equitably k'-colorable for all k' ≥ k is called "the equitable chromatic threshold" of G and denoted by χ*=(G). In the paper we establish the equitable chromatic number and the equitable chromatic threshold for certain products of some highly-structured graphs. We extend the results from [2] for Cartesian, weak and strong tensor products.
Źródło:
Opuscula Mathematica; 2006, 26, 1; 31-44
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On-line -coloring of graphs
Autorzy:
Borowiecki, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/743585.pdf
Data publikacji:
2006
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
on-line algorithm
graph coloring
hereditary property
Opis:
For a given induced hereditary property , a -coloring of a graph G is an assignment of one color to each vertex such that the subgraphs induced by each of the color classes have property . We consider the effectiveness of on-line -coloring algorithms and give the generalizations and extensions of selected results known for on-line proper coloring algorithms. We prove a linear lower bound for the performance guarantee function of any stingy on-line -coloring algorithm. In the class of generalized trees, we characterize graphs critical for the greedy -coloring. A class of graphs for which a greedy algorithm always generates optimal -colorings for the property = K₃-free is given.
Źródło:
Discussiones Mathematicae Graph Theory; 2006, 26, 3; 389-401
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The cost chromatic number and hypergraph parameters
Autorzy:
Bacsó, Gábor
Tuza, Zsolt
Powiązania:
https://bibliotekanauki.pl/articles/743998.pdf
Data publikacji:
2006
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
graph coloring
cost chromatic number
intersection number of a hypergraph
Opis:
In a graph, by definition, the weight of a (proper) coloring with positive integers is the sum of the colors. The chromatic sum is the minimum weight, taken over all the proper colorings. The minimum number of colors in a coloring of minimum weight is the cost chromatic number or strength of the graph. We derive general upper bounds for the strength, in terms of a new parameter of representations by edge intersections of hypergraphs.
Źródło:
Discussiones Mathematicae Graph Theory; 2006, 26, 3; 369-376
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Erdős regular graphs of even degree
Autorzy:
Dobrynin, Andrey
Mel'nikov, Leonid
Pyatkin, Artem
Powiązania:
https://bibliotekanauki.pl/articles/743782.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
vertex coloring
4-critical graph
circulant
regular graph
vertex connectivity
Opis:
In 1960, Dirac put forward the conjecture that r-connected 4-critical graphs exist for every r ≥ 3. In 1989, Erdös conjectured that for every r ≥ 3 there exist r-regular 4-critical graphs. A method for finding r-regular 4-critical graphs and the numbers of such graphs for r ≤ 10 have been reported in [6,7]. Results of a computer search for graphs of degree r = 12,14,16 are presented. All the graphs found are both r-regular and r-connected.
Źródło:
Discussiones Mathematicae Graph Theory; 2007, 27, 2; 269-279
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Grundy number of graphs
Autorzy:
Effantin, Brice
Kheddouci, Hamamache
Powiązania:
https://bibliotekanauki.pl/articles/743619.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
Grundy coloring
vertex coloring
cartesian product
graph product
Opis:
The Grundy number of a graph G is the maximum number k of colors used to color the vertices of G such that the coloring is proper and every vertex x colored with color i, 1 ≤ i ≤ k, is adjacent to (i-1) vertices colored with each color j, 1 ≤ j ≤ i -1. In this paper we give bounds for the Grundy number of some graphs and cartesian products of graphs. In particular, we determine an exact value of this parameter for n-dimensional meshes and some n-dimensional toroidal meshes. Finally, we present an algorithm to generate all graphs for a given Grundy number.
Źródło:
Discussiones Mathematicae Graph Theory; 2007, 27, 1; 5-18
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 95

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies