Báo cáo toán học: " EVEN KERNELS" doc

... an even kernel. Thus an even kernel may exist nonuniquely. A triangle has no even kernel. u 8 1 u 4 u 2u 3 u 5 u 6 u 7 u 9 u Figure 1. Even kernels in a graph G =(V,E). The notion of an even ... simple path or a simple circuit each have an even kernel if and only if the path or circuit has even length (an even number of edges). The notion of an even kernel is not all th...

Ngày tải lên: 07/08/2014, 06:20

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Ngày tải lên: 05/08/2014, 15:20

... electronic journal of combinatorics 8 (2001), #R13 6 A’s answers, even when we know that the questions do separate. In other works, even knowing that the surviving edges are intersecting, how do ... that this construction may well be valid for much smaller values of p, e.g., p = cn 3/2 or perhaps even p = cn log n (or p = cn for large c?). We have performed some limited computational ex...

Ngày tải lên: 07/08/2014, 06:22

... remainder. • If G = κ and only one or two of a, b,andc is even, then Z(a, b, c) has a central edge e invariant under κ. If one dimension is even, we define Z κ (a, b, c) by deleting e and its vertices ... projective plane and that all faces have an even number of sides, but that G is not bipartite. An equivalent condition is that all contractible cycles in G have even length and all no...

Ngày tải lên: 07/08/2014, 06:23

... (acde,ecad). the electronic journal of combinatorics 9(2)(2002), #R2 5 is a reduct of a homogeneous structure, even though it is not itself a Fra¨ıss´e class, as we have seen. Let (T, r) be a finite rooted binary

Ngày tải lên: 07/08/2014, 07:21

... symmetry classes of points. An even astral configuration is an astral configuration configuration where q and k are both even. This paper completes the classification of all even astral configurations. 1 ... j) (3k−2j) 2k j ,ifj is even and k is odd (the case where j and k are both even is listed in (1)); 3. (6k)#(3k − 2j) j 3k − j 2k ,ifj and k are both odd (the case where j and k are bo...

Ngày tải lên: 07/08/2014, 08:20

... difference.) Abondiseven if it consists of an even number of edges, and odd otherwise. An assignment of directed parities to the even bonds of G is a mapping J from the set of even bonds of G into ... of the even bonds A and B as singled out above, such that G<A ∪ B> is an even duplication of one of the duplications of K 3 or K 4 in Figure 3. By Lemma 16, we nevertheless find e...

Ngày tải lên: 07/08/2014, 13:21

... 2n + 3, then all distances between points of S are even. Proof. We obtain from (1) that, since |S|  3, at least one nonzero distance in S is even. Suppose the other nonzero distance is o dd. ... C 2 ) < n. Since △C 1 AC 2 is isosceles, we have d(A, C 1 ) = d(A, C 2 ) = n/2. Therefore, n is even and |A| = n 2 for all A ∈ S 1 . If d 1 and d 2 are distinct nonzero distances in S 1 , th...

Ngày tải lên: 08/08/2014, 01:20

... an alternative proof for this theorem, us- ing linear programming techniques [6]. See Bell and Stevens [3] for a survey of similar combinatorial problems. 4 Honeycomb arrays We begin this section ... the X-rays of permutations’, Elec. Notes Disc. Math. 20 (2005) 193–203. [3] Jordan Bell and Brett Stevens, ‘A survey of known results and research areas for n-queens’, Discrete Math. 309 (2009) 1...

Ngày tải lên: 08/08/2014, 12:23

... Lyapunov-type inequalities for the following even- order differential equation x (2n) (t) + (−1) n−1 q(t)x(t) = 0. These results improve some existing ones. Keywords: even- order; differential equation; Lyapunov-type ... full text (HTML) versions will be made available soon. Lyapunov-type inequalities for a class of even- order differential equations Journal of Inequalities and Applications...

Ngày tải lên: 20/06/2014, 21:20