Zobrazeno 1 - 10
of 305
pro vyhledávání: '"BOJAN MOHAR"'
Autor:
BOJAN MOHAR, HEHUI WU
Publikováno v:
Forum of Mathematics, Sigma, Vol 4 (2016)
The dichromatic number of a graph $G$ is the maximum integer $k$ such that there exists an orientation of the edges of $G$ such that for every partition of the vertices into fewer than $k$ parts, at least one of the parts must contain a directed
Externí odkaz:
https://doaj.org/article/c365064a067649b282527c431ed7305c
Publikováno v:
Discrete Mathematics & Theoretical Computer Science, Vol DMTCS Proceedings vol. AE,..., Iss Proceedings (2005)
An $L(2,1)$-labeling of a graph is a mapping $c:V(G) \to \{0,\ldots,K\}$ such that the labels assigned to neighboring vertices differ by at least $2$ and the labels of vertices at distance two are different. Griggs and Yeh [SIAM J. Discrete Math. 5 (
Externí odkaz:
https://doaj.org/article/c1f2f6812ce249f7b4e8388fbe7026b0
Publikováno v:
Discrete Mathematics & Theoretical Computer Science, Vol DMTCS Proceedings vol. AE,..., Iss Proceedings (2005)
The minor crossing number of a graph $G$, $rmmcr(G)$, is defined as the minimum crossing number of all graphs that contain $G$ as a minor. We present some basic properties of this new minor-monotone graph invariant. We give estimates on mmcr for some
Externí odkaz:
https://doaj.org/article/3a3d35b960024ecf8ee50668179e9a83
Publikováno v:
Journal of Combinatorial Theory, Series B. 161:63-85
The proper chromatic number $\Vec{\chi}(G)$ of a graph $G$ is the minimum $k$ such that there exists an orientation of the edges of $G$ with all vertex-outdegrees at most $k$ and such that for any adjacent vertices, the outdegrees are different. Two
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8ca126b157135f627aa66c726b237a6f
https://doi.org/10.1016/j.jctb.2023.02.003
https://doi.org/10.1016/j.jctb.2023.02.003
Publikováno v:
Combinatorica. 42:701-728
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::f551cc6ff502ce842d5eb37006447e1c
https://doi.org/10.1007/s00493-021-4285-3
https://doi.org/10.1007/s00493-021-4285-3
Publikováno v:
Journal of Combinatorial Theory, Series B. 152:415-452
The atom-bond connectivity (ABC) index is a degree-based molecular descriptor that found diverse chemical applications. Characterizing trees with minimum ABC-index remained an elusive open problem even after serious attempts and is considered by some
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c06afed52f4c07882ccb7c4d690e9a17
https://doi.org/10.1016/j.jctb.2021.07.001
https://doi.org/10.1016/j.jctb.2021.07.001
Autor:
Seyyed Aliasghar Hosseini, Fiachra Knox, Bruce Reed, Sebastián González Hermosillo de la Maza, Bojan Mohar
Publikováno v:
Theoretical Computer Science. 857:166-176
The game of cops and robbers is a well-known game played on graphs. In this paper we consider the straight-ahead orientations of 4-regular quadrangulations of the torus and the Klein bottle and we prove that their cop number is bounded by a constant.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::76a1228d1a4e6d822de4c42950cd1f21
https://doi.org/10.1016/j.tcs.2021.01.012
https://doi.org/10.1016/j.tcs.2021.01.012
Publikováno v:
Polytopes and Discrete Geometry. :125-147
Hopcroft a Wong v roku 1974 navrhli lineárny algoritmus na zjišťování isomorfismu polyherálních grafů. V příspěvku navrhneme modifikovaný algoritmus na řešení tohoto problému s lineárnou složitostí. Práce obsahuje detaily nevyhnut
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::cd735840781da0d46d8c806276978384
https://doi.org/10.1090/conm/764/15358
https://doi.org/10.1090/conm/764/15358
Autor:
Fiachra Knox, Bojan Mohar
Publikováno v:
Journal of Combinatorial Theory, Series B. 144:95-118
It is proved that every connected graph G on n vertices with χ ( G ) ≥ 4 has at most k ( k − 1 ) n − 3 ( k − 2 ) ( k − 3 ) k-colourings for every k ≥ 4 . Equality holds for some (and then for every) k if and only if the graph is formed f
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::7e2f6543b00f076efc803ef16b29131e
https://doi.org/10.1016/j.jctb.2020.01.002
https://doi.org/10.1016/j.jctb.2020.01.002
Publikováno v:
Discrete & Computational Geometry. 64:229-232
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::60ce28ccf1c00f472d4bdefbbd2254e2
https://doi.org/10.1007/s00454-020-00214-y
https://doi.org/10.1007/s00454-020-00214-y