Autor: Ryjáček, Zdeněk - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Artykuł

Skocz do pozycji: 2.

Tytuł:: The flower conjecture in special classes of graphs
Autorzy:: Ryjáček, Zdeněk
Schiermeyer, Ingo
Powiązania:: https://bibliotekanauki.pl/articles/972046.pdf
Data publikacji:: 1995
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: hamiltonian graphs
flower conjecture
square
claw-free graphs
Opis:: We say that a spanning eulerian subgraph F ⊂ G is a flower in a graph G if there is a vertex u ∈ V(G) (called the center of F) such that all vertices of G except u are of the degree exactly 2 in F. A graph G has the flower property if every vertex of G is a center of a flower. Kaneko conjectured that G has the flower property if and only if G is hamiltonian. In the present paper we prove this conjecture in several special classes of graphs, among others in squares and in a certain subclass of claw-free graphs.
Źródło:: Discussiones Mathematicae Graph Theory; 1995, 15, 2; 179-184
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: On traceability and 2-factors in claw-free graphs
Autorzy:: Fronček, Dalibor
Ryjáček, Zdeněk
Skupień, Zdzisław
Powiązania:: https://bibliotekanauki.pl/articles/744410.pdf
Data publikacji:: 2004
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: traceability
2-factor
claw
degree condition
closure
Opis:: If G is a claw-free graph of sufficiently large order n, satisfying a degree condition σₖ > n + k² - 4k + 7 (where k is an arbitrary constant), then G has a 2-factor with at most k - 1 components. As a second main result, we present classes of graphs ₁,...,₈ such that every sufficiently large connected claw-free graph satisfying degree condition σ₆(k) > n + 19 (or, as a corollary, δ(G) > (n+19)/6) either belongs to $⋃ ⁸_{i=1} _i$ or is traceable.
Źródło:: Discussiones Mathematicae Graph Theory; 2004, 24, 1; 55-71
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 4.

Tytuł:: Distance-Locally Disconnected Graphs
Autorzy:: Miller, Mirka
Ryan, Joe
Ryjáček, Zdeněk
Powiązania:: https://bibliotekanauki.pl/articles/30146681.pdf
Data publikacji:: 2013-03-01
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: neighborhood
distance
locally disconnected
cage
Opis:: For an integer k ≥ 1, we say that a (finite simple undirected) graph G is k-distance-locally disconnected, or simply k-locally disconnected if, for any x ∈ V (G), the set of vertices at distance at least 1 and at most k from x induces in G a disconnected graph. In this paper we study the asymptotic behavior of the number of edges of a k-locally disconnected graph on n vertices. For general graphs, we show that this number is Θ(n²) for any fixed value of k and, in the special case of regular graphs, we show that this asymptotic rate of growth cannot be achieved. For regular graphs, we give a general upper bound and we show its asymptotic sharpness for some values of k. We also discuss some connections with cages.
Źródło:: Discussiones Mathematicae Graph Theory; 2013, 33, 1; 203-215
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 5.

Tytuł:: Factor-criticality and matching extension in DCT-graphs
Autorzy:: Favaron, Odile
Favaron, Evelyne
Ryjáček, Zdenĕk
Powiązania:: https://bibliotekanauki.pl/articles/971953.pdf
Data publikacji:: 1997
Wydawca:: Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:: factor-criticality
matching extension
claw
dominated claw toes
Opis:: The class of DCT-graphs is a common generalization of the classes of almost claw-free and quasi claw-free graphs. We prove that every even (2p+1)-connected DCT-graph G is p-extendable, i.e., every set of p independent edges of G is contained in a perfect matching of G. This result is obtained as a corollary of a stronger result concerning factor-criticality of DCT-graphs.
Źródło:: Discussiones Mathematicae Graph Theory; 1997, 17, 2; 271-278
2083-5892
Pojawia się w:: Discussiones Mathematicae Graph Theory
Dostawca treści:: Biblioteka Nauki

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