Báo cáo toán học: "An extension of matroid rank submodularity and the Z-Rayleigh property" pptx

... 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 first of these was communicated to us by Noble [10]. Recall that the ... under duality, and we get the following corollary. Corollary 45. The matroids F ∗ 7 and (F − 7 ) ∗ are Z-Rayleigh. 5 Summary and open probl ems We introduced R -subm...

Ngày tải lên: 08/08/2014, 14:23

Ngày tải lên: 05/08/2014, 09:46

... functions f and g on the complex plane C, if they have the same inverse images for five distinct values, then f = g,andthatg is a special type of a linear fractional tran- formation of f if they have the ... the proof of Theorem 2.  Acknowledgements. The second author would like to thank Professor Do Duc Thai for valuable discussions, the Universit´e de Bretagne Occidental...

Ngày tải lên: 06/08/2014, 05:20

... 8 (2001), #R30 5 We now restate Theorem 2.2 in terms of the coefficients of P . Theorem 2.3 Let 0 ≤ a 0 ≤ a 1 ···≤a m be a sequence of real numbers and n ∈ . Then the sequence q j := q j (m, n)= m  k=j a k  k j  n k−j (2) is ... Acknowledgements The work presented here was part of a SIMU project at the University of Puerto Rico at Humacao. The authors wish to thank Herb...

Ngày tải lên: 07/08/2014, 06:22

... .l_k>}. The correctness of this acceptance condition is a consequence of the invariant. 3. Extension to S-attributed Grammars The chief element of the extension of the algorithm is a change in the ... show that the attribute occurrences on the right-hand side a of the production have already been evaluated. Hence, evaluation of the attribute occurr...

Ngày tải lên: 01/04/2014, 00:20

... terms of QoS, and more specifically in terms of bitrate, and on user preferences, in terms of user satisfaction for the achieved QoS, given the service, the time and the location of the user. ... and its frequent update constitute the basis of this technique. The update of these relies on approaches suggested in [36, 38–40]. To begin with, using the Sh...

Ngày tải lên: 20/06/2014, 20:20

... under the antipo- dal map, the 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 degree at ... a coboundary. Following the terminology of the proof, the curvature of any weighting is a cobound- ary, because it is the sum (in the sense of “”)...

Ngày tải lên: 07/08/2014, 06:22

... Let be the set of circular necklaces made of beads of k colors: a rank- m element of is a necklace with m beads, and the least element is the empty necklace ∅. For a rank- (m − 1) necklace p and a rank- m ... example, if P is the poset of partitions ordered by inclusion of their Young diagrams, then the universal cover  P is the poset of standard Young tablea...

Ngày tải lên: 07/08/2014, 06:22

... hand, the recursion above is precisely the one that describes the relationship between the Hasse matrices of the posets B l and B l+1 , and H(l) is indeed the Hasse matrix of B l . On the other hand, ... the Hasse matrix of a poset, we mean the incidence matrix of its Hasse diagram, viewed as a directed graph: The rows and the columns of this matrix are i...

Ngày tải lên: 07/08/2014, 15:22

... characterised by vertical and horizontal wind speed) and gas (water vapour, CO 2 and other bio- genic gases) content of the air. Heat and gas contents of the air are called “scalars” because they are characterised by ... interception and sources in case of the emission of thermal infra red radiation. Scattering processes at the surface of the organs depends on wa...

Ngày tải lên: 08/08/2014, 14:22