Báo cáo toán học: "Phytophthora species in oak forests of north-east France" pptx

... term dynamics of oak ecosystems: assessment of the role of root pathogens and environmental constraints as interacting decline inducing factors" (PATHOAK). References [1 ] ... hosts, including oak, and it was isolated from fine roots and collar stripe cankers on oak in Germany [17]. Its ecological role remains unclear. It is an interest-...

Ngày tải lên: 08/08/2014, 14:21

Ngày tải lên: 05/08/2014, 09:46

Ngày tải lên: 05/08/2014, 15:20

... See http://mathworld.wolfram.com/BernsteinPolynomial.html the electronic journal of combinatorics 10 (2003), #R15 17 A Discontinuity in the Distribution of Fixed Point Sums Edward A. Bender Department of Mathematics University of ... an interesting steep drop from r = n to r = n + 1, and this paper arose in providing a quantification of the observed plunge. We think that this pro...

Ngày tải lên: 07/08/2014, 07:21

... vertex in Q k (x)containsk+1 vertices in Q k (x). A ball centered on some vertex in a Q k (y) such that d(y, x) = 1 contains exactly one vertex in Q k (x). We consider γ theminimumnumberofverticesofthecodewecanfindinaQ k (x). Let ... perfect binary single-error correcting code of length k is a perfect code on the hypercube Q k ,and a tiling of the grid Z n by balls of radius 1 is...

Ngày tải lên: 07/08/2014, 13:21

... The set of incidence vectors of the matchings of G have a convex hull which is equal to the polytope containing all x ∈ R E which satisfy the following the electronic journal of combinatorics ... matching (or one-factor) of G is a subgraph of G in which each vertex has degree at most one. A basic question in combinatorial optimization is, “What is the size of a maximum match...

Ngày tải lên: 07/08/2014, 13:21

... search. In this paper, a new method of constructing fifteen in nite classes of integral graphs is presented. In getting the results we proceed as follows: firstly, we give the construction of the (in nite) ... Cao, Integral trees of diameter R (3 ≤ R ≤ 6) (in Chinese), Heilongjiang Daxue Ziran Kexue Xuebao (2) (1988) 1-3, 95. [4] Z.F. Cao, Introductory Diophantine Equations (in C...

Ngày tải lên: 07/08/2014, 15:22

... generating functions for the number of words π of length n over the alphabet [a] according to the numb er of occurrences of τ = 22 · · ·21 in π and according to the number of occurrences of τ in ... patterns, includ ing all words of length 3. In addition, we find simple explicit formulas for the total number of occurrences of the patterns in q uestion within all the p...

Ngày tải lên: 08/08/2014, 11:20

... generalization of the Gallai-Roy theorem, Graphs and Combinatorics 17 (2001) 681-685. [6] C. Lin, Simple proofs of results on paths representing all colors in proper vertex- colorings, Graph and Combinatorics ... u and v in T (G, v) is called an ancestor of u. By Theorem 6.6 of [2], in every DFS tree if w and w ′ are adjacent, then one of them is a ncestor of another. In a...

Ngày tải lên: 08/08/2014, 12:23

... constraint in the structure of trees or indeed all higher plants. If we seek meaning in the list as a whole there remains the task of “seeing the wood for the trees”, selecting and arranging them into ... Gradients But the intended purpose of the rules was to aid the discovery of basic principles of tree architecture. In this the rules have individual roles, but also roles i...

Ngày tải lên: 08/08/2014, 14:22