Zobrazeno 1 - 10
of 41
pro vyhledávání: '"Dean G. Hoffman"'
Publikováno v:
Graphs and Combinatorics. 35:1585-1596
It is shown that whenever the edges of a connected simple graph on n vertices are colored with $$n-1$$ colors appearing so that no cycle in G is rainbow, there must be a monochromatic edge cut in G. From this it follows that such colorings of G can b
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::01c854c640e72aa583daf23378a1b1bc
https://doi.org/10.1007/s00373-019-02102-6
https://doi.org/10.1007/s00373-019-02102-6
Publikováno v:
Journal of Combinatorial Theory, Series A. 130:26-41
We generalize a theorem of M. Hall Jr., that an r × n Latin rectangle on n symbols can be extended to an n × n Latin square on the same n symbols. Let p, n, ? 1 , ? 2 , ? , ? n be positive integers such that 1 ? ? i ? p ( 1 ? i ? n ) and ? i = 1 n
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::dccccd2e6f5d0bd78d32c1cc02a62134
https://doi.org/10.1016/j.jcta.2014.10.007
https://doi.org/10.1016/j.jcta.2014.10.007
Autor:
Dean G. Hoffman, Dan Roberts
Publikováno v:
Journal of Combinatorial Designs. 22:161-170
A k-star is the complete bipartite graph . Let G and H be graphs, and let be a partial H-decomposition of G. A partial H-decomposition, , of another graph is called an embedding of provided that and G is a subgraph of . We find an embedding of a part
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::3e289d2b2e8ff4199975cbd5738a176b
https://doi.org/10.1002/jcd.21353
https://doi.org/10.1002/jcd.21353
Publikováno v:
Theory and Applications of Graphs, Vol 4, Iss 2 (2017)
An extremal result about vertex covers, attributed by Hajnal to Erdős and Gallai, is applied to prove the following: If n, k, and t are integers satisfying n ≥ k ≥ t ≥ 3 and k ≤ 2t - 2, and G is a graph with the minimum number of edges among
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f4ec0708b7b93801a7d523e72735a9dd
https://digitalcommons.georgiasouthern.edu/tag/vol4/iss2/1
https://digitalcommons.georgiasouthern.edu/tag/vol4/iss2/1
Publikováno v:
Discrete Mathematics. 311:2423-2427
A 6-cycle system of a graph G is an edge-disjoint decomposition of G into 6-cycles. Graphs G , for which necessary and sufficient conditions for existence of a 6-cycle system have been found, include complete graphs and complete equipartite graphs. A
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::497778b27c19d45bdf508fc8fc190c3d
https://doi.org/10.1016/j.disc.2011.06.026
https://doi.org/10.1016/j.disc.2011.06.026
Publikováno v:
Combinatorica. 30:617-625
Let (X, C) be a k-cycle system of order n, with vertex set X (of cardinality n) and collection of k-cycles C. Suppose n=kq+r where r
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::e360c64a1c9664ac4a7da69d283bd307
https://doi.org/10.1007/s00493-010-2525-z
https://doi.org/10.1007/s00493-010-2525-z
Publikováno v:
Graphs and Combinatorics. 27:161-170
If the complete graph K n has vertex set X, a maximum packing of K n with 4-cycles, (X, C, L), is an edge-disjoint decomposition of K n into a collection C of 4-cycles so that the unused edges (the set L) is as small a set as possible. Maximum packin
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ef47ad79fc430c159a5c25d700a16afa
https://doi.org/10.1007/s00373-010-0967-0
https://doi.org/10.1007/s00373-010-0967-0
Publikováno v:
Discrete Mathematics. 308(13):2844-2853
The complete multipartite graph Kn(m) with n parts of size m is shown to have a decomposition into n-cycles in such a way that each cycle meets each part of Kn(m); that is, each cycle is said to be gregarious. Furthermore, gregarious decompositions a
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::96ed8ca982cdf57b138ec57177e50f83
Publikováno v:
Discrete Mathematics. 308(5-6):696-714
A 4-cycle decomposition of a complete multipartite graph is said to be gregarious if each 4-cycle in the decomposition has its vertices in four different partite sets. Here we exhibit gregarious 4-cycle decompositions of the complete equipartite grap
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::896a8b7366f70376710541b1547a18b2
Publikováno v:
Discrete Mathematics. 307(13):1659-1667
A k-cycle decomposition of a complete multipartite graph is said to be gregarious if each k-cycle in the decomposition has its vertices in k different partite sets. Equipartite gregarious 3-cycle systems are 3-GDDs, and necessary and sufficient condi
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::58ff7ecd7be94cbe8fab09aaf9409311