Báo cáo toán học: "Cubical Convex Ear Decompositions" pot

... rank-selected subposets of posets with convex ear decompositions have a convex ear decomposition? Are there any other useful constructions that preserve having a convex ear decomposition and/or EL- ced? ... has a convex ear decomposition. 2. L is doubly Cohe n-Macaulay. 3. Every interval o f L is complemented. Note 4.2. A construction very much like Schweig’s convex ear de...

Ngày tải lên: 08/08/2014, 01:20

... in G (or simply gregarious when G is clear) if each of its vertices lies in a different partite set of G. In order to apply this definition, it must be clear what the partite sets of G are. With ... path, then due to the cyclic nature of the decomposition of 2λK n , each vertex in 2(K n ∗ K λ ) appears as an endpoint of exactly two paths in the set X(G i ) (resp ectively, X(H i )). Since there...

Ngày tải lên: 08/08/2014, 01:20

Ngày tải lên: 05/08/2014, 09:46

Ngày tải lên: 05/08/2014, 15:20

Ngày tải lên: 05/08/2014, 15:20

... L(4,n) by Athreya, Pranesachar and Singhi [1]. General formulae for L(n, n) appear in [3], [8] and [10], but do not appear useful for either exact or asymptotic com- putation. The asymptotic value ... ,s n } and E(G)={c i s j | column i contains symbol j}. We will call this graph the template of R. Clearly, many Latin rectangles may have the same template; for example, every Latin square of o...

Ngày tải lên: 07/08/2014, 06:20

... by the addition of no more than two ears, and no 2 -ear addition can be replaced by a pair of 1 -ear additions. The latter clause shows that in the case of a 2 -ear addition there is no alternating ... graph has an ear decomposition (G 0 ,G 1 , ,G n ) in which, for each i>0, the graph G i is obtained from G i−1 by a 1- or 2 -ear addition. In view of Theorem 1, let us define an ear d...

Ngày tải lên: 07/08/2014, 06:20

... A 0 6 (n)isthesetof all paths from (0, 0) to (n, n) that use step set S 6 . An interesting solution appears in [3, vol. 90]. References [1] J. Bonin, L. Shapiro, R. Simion, Some q-analogues of the Schr¨oder ... J. Stat. Plann. and Infer., 34 (1993) 291–303 [6] R.A. Sulanke, The Narayana distribution, to appear in J. Stat. Plann. and Infer. the electronic journal of combinatorics 7 (2000), #R4...

Ngày tải lên: 07/08/2014, 06:20

... appear, can be found in the reference for [Sch90], on page 23 of this article. T HE E LECTRONIC J OURNAL OF C OMBINATORICS 4 (NO.2) (1997), # R17 23 [Es86] George A. Escher, "Potato ... played the game with his father.) Two pieces of cut potato can serve as the medium on which to carve the motif and its reflected image, and then these potato stamps are inked and used to produce...

Ngày tải lên: 07/08/2014, 06:22

... grant of Derek Corneil and the Fields Institute. † This research is supported by NSERC Canada OGP007621 and the Fields Institute. ‡ This research is supported by NSERC Canada OGP007621, OGP007268 ... a and once to b. For 4. it now suffices to prove the reverse implication, so suppose that ABC appears twice. If AB and AC are not repeated, then the two faces ABC are connected by exactly two edges...

Ngày tải lên: 07/08/2014, 06:22