Báo cáo toán học: "Graph products and new solutions to Oberwolfach problems" pps

... Graph products and new solutions to Oberwolfach problems Gloria Rinaldi Dipartimento di Scienze e Metod i dell’Ingegneria Universit`a di Modena e Reggio ... graph is obtained together with a new decomposition. In this paper we show how it can be used to construct infinitely many new solutions to the Oberwolfach problem, in both the classic and the equipartite ... type...

Ngày tải lên: 08/08/2014, 14:22

Ngày tải lên: 05/08/2014, 15:20

... The authors wish to thank the anonymous referees who drew their attention to [9], Lemma 5.5 of [14], and for their invaluable comments. Also, they wish to thank M. Alishahi and M. Iradmusa for ... and P. Hell, Universality of A-mote graphs, European J. Combinatorics, 14 (1993), 23–27. [10] G. Hahn and C. Tardif, Graph homomorphisms: structure and symmetry, in Gra ph Symmetry,...

Ngày tải lên: 08/08/2014, 11:20

... is in a singleton colour class, v is adjacent to both p and q in G, and thus v is adjacent to p or q in G  . Hence v touches pq. Now consider x ∈ S − {v} and pq ∈ E(G  ). Since p and q have distinct ... matchings M a and M b with a 2 and b 2 edges, respectively, that cover all the vertices of K d+1 . Hence M a and M b share exactly one ve rtex. Take two new vertices x a...

Ngày tải lên: 08/08/2014, 12:23

Ngày tải lên: 05/08/2014, 09:46

... combinatorics 4 (1997), #R29 10 6 Acknowledgments We thank Joshua Bao and Jim Propp for helpful suggestions and comments. Special thanks go to Glenn Tesler for helping to draw the tiling pictures and ... Kuperberg, M. Larsen and J. Propp, Alternating-Sign Matrices and Domino Tilings, Journal of Algebraic Combinatorics 1 (1994) p 111-132 and p 219-234. [4] P. John, H. Sachs an...

Ngày tải lên: 07/08/2014, 06:22

... j.Awordw is said to be a shuffle of u and v if w has length r + s and if u and v are both subsequences of w. The shuffle product u ∃ v of u and v is an element of KX and is defined to be the sum of ... appealing to combinatorialists and, for example, [2, 4, 11, 15] study the Klyachko idempotent and its generalizations. Our goal is to introduce a new, broad generalization of...

Ngày tải lên: 07/08/2014, 08:22

... question is to see if it is feasible to extend such relations to directed graphs. In a directed graph, the distance and diameter can be naturally defined: The distance from a vertex u to a vertex ... from u to v.A directed graph is strongly connected if for any two vertices u and v, there is a directed path from u to v. The diameter of a strongly connected directed graph is defi...

Ngày tải lên: 07/08/2014, 13:21

... (D). Factorising digraphs by R a,∞ and R −∞,b , respectively, we can only obtain a few different digraphs. Depending upon these factor graphs with respect to R −∞,b and R a,∞ it is possible to define five ... T 2,2 ↑ Z, T 2,1 ↑ Z and T 1,2 ↑ Z are of types T ± , T − and T + , respectively, and have properties 2 + and 2 − simultaneously. Finally, a chain is of type NT and has pr...

Ngày tải lên: 07/08/2014, 21:21

... a carrier and a purging gas. The TiCl 4 and water were evaporated at 30°C and 20°C, respectively. The cycle consisted of a 1-s exposure to T iCl 4 ,5-sArpurge,1-s exposure to water, and 5-s Ar ... exposure to TiC l 4 ,5-sAr purge, 10-s exposure to HDD, and 50-s Ar purge. The vapor pressure of the Ar in the reactor was maintained at 100 mTorr. The deposited HDD layer was expo...

Ngày tải lên: 20/06/2014, 21:20