Báo cáo toán học: " Local equivalence of transversals in matroids" pptx

... because the content design of the textbooks of the Chinese language is principally based on the HKCEE grading criteria. Virtually, some Hong Kong people hold the point that training in the use of ... the development of Cantonese teaching will not go in the opposite direction. The Position of Cantonese in the Current Education Policy Cantonese ha...

Ngày tải lên: 20/06/2014, 21:20

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Ngày tải lên: 05/08/2014, 10:20

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Ngày tải lên: 05/08/2014, 15:20

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Ngày tải lên: 05/08/2014, 15:20

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Ngày tải lên: 05/08/2014, 15:21

... The transversals of V are in one-to-one correspondence with the matchings in G covering the part N; and a local replacement in this language corresponds to changing a single edge in the matching. Let ... V n of n-tuples of elements of M forms the Hamming graph; two n-tuples being adjacent whenever they differ in only one coordinate. Ev- ery matroid structure on M determin...

Ngày tải lên: 07/08/2014, 06:20

... A Generalisation of Transversals for Latin Squares Ian M. Wanless Christ Church St Aldates Oxford OX1 1DP United Kingdom wanless@maths.ox.ac.uk We define a k-plex to be a partial latin square of ... to be filled. A partial latin square with every cell filled is a latin square. The set of partial latin squares of order n is denoted by PLS(n), and the set of latin squar...

Ngày tải lên: 07/08/2014, 06:23

... n, proving (17) and completing the proof of our theorem.  Acknowledgement. The authors are grateful to Prof. D. Todorov for pointing out a fallacy in an earlier version of the proof of Theorem ... the maximum of the sum of degrees of the vertices of an r-clique, as in the abstract. If G has no r-cliques, we set ∆ r (G)=0. Furthermore, let ∆ r (n, m)= min G=G(n,m) ∆ r (G...

Ngày tải lên: 07/08/2014, 08:22

... Pro- ceedings of the National Academy of Sciences of the United States of America, 75:40– 42, 1978. [13] Curtis Greene and Herbert S. Wilf. Closed form summation of C-finite sequences. Transactions of the ... shift equivalent. 4 Shift Equivalence of P-finite Sequences The algorithm for the P-finite case consists of a case distinction: either the question can be reduced to a...

Ngày tải lên: 07/08/2014, 13:21

... t  2 (m−2−ν)(n−n 0 −···−n 2 m−2 −1)+n 0 +···+n 2 m−2 −1 . Proof. The formulas follow from Corollary 3.2 and simple counting arguments. 4 B n -orbits in Tuples of Dihedral Groups The dihedral group D N of order 2N is given by the ... (2008), #R80 2 Hurwitz Equivalence in Tuples of Generalized Quaternion Groups and Dihedral Groups Xiang-dong Hou Department...

Ngày tải lên: 07/08/2014, 21:20

... Gallai and A. N. Milgra m, Verallgemeinerung eines graphentheoretischen Satzes von R´edei, Acta. Sci. Math. 21 (1960) 181–186. [8] G. Hahn and B. Jackson, A note concerning paths and independence number ... digraph D with stability number k such that deleting the vertices of any k − 1 directed paths in D leaves a digraph with stability number k. In this note, we prove this...

Ngày tải lên: 07/08/2014, 21:21

... the transposition of the remaining two vertices. This implies that the only graphs which have fix(G) = n−1 are the complete graphs and the empty graphs. On the other hand, the graphs with fix(G) ... e), where v and e are a vertex and an edge of G, and v and e are incident. Inf(G) has an edge between (v 1 , e 1 ) and (v 2 , e 2 ) if v 1 = v 2 or e 1 = e 2 . We denote the...

Ngày tải lên: 07/08/2014, 21:21

... between the mutation class of a quiver of type D n and triangulations up to rotation and inverting tags Here we adapt the methods and ideas of [T] to obtain a bijection between the mutation class of ... 1: The mutation class of D 4 . It is know from [FZ3] that the mutation class of a Dynkin quiver Q is finite. An explicit formula for the num...

Ngày tải lên: 07/08/2014, 21:21

... journal of combinatorics 16 (2009), #R95 5 Hurwitz Equivalence in Tuples of Dihedral Groups, Dicyclic Groups, and Semidihedral Groups Charmaine Sia Department of Mathematics Massachusetts Institute ... Gorenstein, Finite Groups, 2nd ed., Chelsea Publishing Company, New York, 1980. [3] X. Hou, Hurwitz equivalence in tuples of generalized quaternion groups...

Ngày tải lên: 08/08/2014, 01:20

... follows. 3 Cyclic partitions of general complete hypergraphs By ˜ K n we denote the complete hyper gr aph on the set of vertices V n , i.e. the hypergraph with the set of edges consisting of all non ... the complete k -uniform hypergraph of order n, 1  k  n−1, i.e. the hypergraph with the set V n = {1, 2, , n} of vertices and the set  V n k  of edges. If there exist...

Ngày tải lên: 08/08/2014, 12:22