Báo cáo toán học: "An Analogue of Covering Space Theory for Ranked Posets" pot

... t) the electronic journal of combinatorics 8 (2001), #R32 9 An Analogue of Covering Space Theory for Ranked Posets Michael E. Hoffman Dept. of Mathematics U. S. Naval Academy, Annapolis, MD 21402 meh@usna.edu Submitted: ... X. In this paper we develop a theory of covering maps for ranked posets. More precisely, we define covering maps of “weighted-relation” poset...

Ngày tải lên: 07/08/2014, 06:22

... and only if J ⊂ K. Proof. A theorem of Lucas (see, for example, [GKP, ex. 61, p. 248]), permits us to de- termine the parity of  n m  in terms of the binary expansion of n and m as follows: ... #R30 5 2 Some self-similar matrices. The theory of partially ordered sets (posets in the remaining of this paper) will guide us to produce an analogue of equation (1) involving ou...

Ngày tải lên: 07/08/2014, 15:22

... and predicting the performance is also the target of the cognitive controller built using multilayer feed-forward neural network [13]. The controller performs this task for different channels ... in the fact that the combination of a dynamical learning of context information and user preferences could be exploited in a later stage for the selection of the most appropriate ne...

Ngày tải lên: 20/06/2014, 20:20

Ngày tải lên: 05/08/2014, 09:46

... L 12 .Then (f 1 ,H j ) (f 1 ,H q−1 ) = (f 2 ,H j ) (f 2 ,H q−1 ) for all j ∈{1, , n},sof 1 ≡ f 2 (as in the proof of Theorem 1). This is a contradiction. Thus, we have L sv = ∅ for all 1  s<v 3. Then for any 1  s<v 3, there ... have completed the proof of Theorem 2.  Acknowledgements. The second author would like to thank Professor Do Duc Thai for valuable discussions,...

Ngày tải lên: 06/08/2014, 05:20

... involution g,andifg exchanges colors of vertices of Z, then the number of matchings of Z is the square of the number of matchings of Z/g. For example, the surface of a Rubik’s cube satisfies these ... number of matchings is the square of the number of matchings of the quotient graph. 2. The number of matchings of the edge graph of a graph with vertices of degr...

Ngày tải lên: 07/08/2014, 06:22

... {d l (m)} m l=0 forms a log concave sequence. Unfortunately Proposition 4.1 does not settle this question. For example, for m = 15 the sequence of signs in d j+1 (15) − 2d j (15) + d j−1 (15), for 1 ≤ ... sufficient condition for log concavity of a polynomial is given by the location of its zeros: if all the zeros of a polynomial are real and negative, then it is log concave and...

Ngày tải lên: 07/08/2014, 06:22

... application of extended submodularity is in the study of Rayleigh properties of the multivariate Tutte polynomial of matroids. Following Sokal [13], we define the multivariate Tutte polynom ial of a ... (2011), #P113 22 2. For all disjoint P, R ⊆ E, the sets P and ∅ are R-modular in M. We further know of the following instances of R-submodularity for a matroid M(E, ρ). The fir...

Ngày tải lên: 08/08/2014, 14:23

... transformation does not affect the global run-time behaviour of LR parsing. More serious are the consequences for the size of the parser: the required number of LR states for the transformed ... characterisations. (Proofs of statements in this section are omitted for reasons of space. ) Let G = (N, T, P, S) be a head grammar. To be used below, we introduce a special ki...

Ngày tải lên: 31/03/2014, 06:20

... elegant formalization of the augmented context-free grammars characteristic of most current NLP systems. It is more general than members of the family of unification-based grammar formalisms ... finite set of string categories; T a finite set of terminal symbols; P a finite set of productions or rewriting rules of the form X ~t~, Xe N, ae (NUT)*; and S a distinguished sym...

Ngày tải lên: 01/04/2014, 00:20