Báo cáo toán học: "Movable (n4) Configurations" pps

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Ngày tải lên: 05/08/2014, 09:46

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Ngày tải lên: 05/08/2014, 15:20

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Ngày tải lên: 05/08/2014, 15:20

... modules are weak supplemented, hence closed weak supplemented. So we have the following implications: local ⇒ hollow ⇒ weak supplemented ⇒ closed weak supplemented. But a closed weak supplemented ... M closed weak supple- mented and N non-singular. Then N is closed weak supplemented. 4. Cl osed Weak Supplemented Ring AringR is called closed weak supplemented i...

Ngày tải lên: 06/08/2014, 05:20

... Between Weakly d-Koszul Modules and Classical d-Koszul and Koszul Modules In this section, we will investigate the relations between weakly d-Koszul modules and classical d-Koszul and Koszul modules. ... among weakly d-Koszul modules, d-Koszul modules and Koszul modules. Corollary 3.10. Let M be a weakly d-Koszul module. Then (1) All the 2n th syzygies of G(M...

Ngày tải lên: 06/08/2014, 05:20

... square-counting or an interlacing argument, one can show that the max- imum number of vertices in an independent set in the Hoffman-Singleton graph is 15. If S is an independent set of size 15 in this ... Then H is the Hoffman-Singleton graph. Note that we may view the vertices in S as points and the vertices not in S as lines, with a point and line incident if the corresponding verti...

Ngày tải lên: 07/08/2014, 06:20

... with double-ended queues, parallel stacks and parallel queues, Proc. ACM Symp. Theory of Computing 5 (1973), 268–277. [13] Wilf H S: private communication, 1995. Priority Queues and Multisets M.D. ... Linton L.A. Walker Department of Mathematical and Computational Sciences University of St. Andrews North Haugh, St. Andrews KY16 9SS, Scotland {sal,mda,louise}@dcs.st -and. ac.uk Subm...

Ngày tải lên: 07/08/2014, 06:20

... chromatic number of the forbidden subgraph). Our results provide bounds that are remarkably accurate for small forbidden configurations but we still have some small forbidden configurations for which ... the work begun by Anstee, Griggs and Sali on small forbidden configurations. In the notation of (0,1)-matrices, we consider a (0,1)-matrix F (the forbidden conguration), an m ì n...

Ngày tải lên: 07/08/2014, 06:22

... 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

... 3 q }. This coloring is easy to show not to have any rainbow arithmetic progressions of length at least 3. It turns out that in order to force a rainbow AP(k) we need to ensure that for each color ... A 5 and i is odd, C otherwise. (4) the electronic journal of combinatorics 11 (2004), #R1 6 On rainbow arithmetic progressions Maria Axenovich Department of Mathematics Iowa State Uni...

Ngày tải lên: 07/08/2014, 08:20

... 9: An astral type 1 configuration (30 2 , 10 6 ) 4 Astral [4, 4] configurations Astral configurations of class [4, 4] — that is, astral (n 4 ) configurations — have been characterized completely, ... from the astral [6, 4] 1 configurations 30#8 1 10 7 13 12 and 30#10 1 11 6 14 13 . Theorem 10.9. Polars of mixed astral [6, 5] 2 configurations are astral [5, 6] 2 configura- tio...

Ngày tải lên: 07/08/2014, 08:20

... symbol of σ.Sincen +1>m, we can select a random subsequence of σ of length m by first throwing out one of the n + 1 symbols of σ at random and then randomly selecting a subsequence of length ... the following theorem of Stromquist. We give a proof which is somewhat shorter than the proof in [1], both for its own interest and because we will reuse the method of proof when stu...

Ngày tải lên: 07/08/2014, 08:22

Ngày tải lên: 07/08/2014, 13:21

... columns in order to have the resulting matrix to be simple. If we wish to remove row i, then we can force the resulting (m − 1)-rowed matrix to be simple by deleting the columns associated with ... Subject Classification: 05D05 Abstract The present paper continues the work begun by Anstee, Ferguson, Griggs and Sali on small forbidden configurations. We define a matrix to be simple if it is a...

Ngày tải lên: 07/08/2014, 15:23

... given in [3], where it was shown that there are no astral 5-configurations with dihedral symmetry. The existence of astral 5-configurations with only cyclic symmetry is still unsettled but is highly ... line passes through five points. We describe how to construct the first known family of 5-configurations with chiral (that is, only rotational) symmetry, and prove that the constructi...

Ngày tải lên: 08/08/2014, 11:20