Báo cáo toán học: "Colouring planar mixed hypergraphs" potx
Báo cáo toán học: "Colouring planar mixed hypergraphs" potx
... graph as a planar embedding of a maximal hypergraph such that the faces of the graph correspond to the edges of the hypergraph. 3 Colouring planar mixed hypergraphs Let H =(V,C, D) be a mixed hypergraph. ... colouring properties of general planar mixed hypergraphs was first raised in [13] (problem 8, p.43). It is evident that every planar D-hypergraph is colourable, just as every...
Ngày tải lên: 07/08/2014, 06:22
Báo cáo toán học: "On Planar Mixed Hypergraphs" pps
... A planar mixed hypergraph may not have a strong embedding. We prove an easy lemma on the number of faces of size two in an embedding of a planar mixed hypergraph: Lemma 1 Let H be any planar mixed ... of planar mixed hypergraphs — similar properties of planar mixed hypergraphs were already used in [10, 15]. We address properties of feasible sets and existence of strict col...
Ngày tải lên: 07/08/2014, 06:22
Báo cáo toán học: "Colouring 4-cycle systems with specified block colour patterns: the case of embedding P3-designs" ppsx
... c (××✷✷, two-coloured of pattern 2 + 2), type d (×✷ × ✷, mixed two-coloured), type e (××✷, three-coloured of pattern 2 + 1 + 1), type f (×✷ ×, mixed three-coloured), type g (×✷♦, four-coloured or ... (××✷✷, two-coloured of pattern 2 + 2), type d (×✷ × ✷, mixed two-coloured), type e (××✷, three-coloured of pattern 2 + 1 + 1), type f (×✷ ×, mixed three-coloured), type g (×✷♦, four...
Ngày tải lên: 07/08/2014, 06:22
Báo cáo toán học: "Chromatically Unique Multibridge Graphs" potx
... 1994) 307-316. [12] C.D. Wakelin and D.R. Woodall, Chromatic polynomials, polygon trees and outer- planar graphs, J. Graph Theory 16 (1992) 459-466. [13] S.J. Xu, Classes of chromatically equivalent
Ngày tải lên: 07/08/2014, 08:20
