Báo cáo toán học: "Counting Triangulations of Planar Point Sets" pps

... we need to count the triangulations of the hole of the 6-vint, and of the holes of the potential 8-vints. We first claim that in any of these triangulations, exactly one of the edges bc and ao ... number of triangulations of the portion to the right of aq, times the maximal number of triangulations of the po rt io n to its left). Table 6 lists the possible cases fo...

Ngày tải lên: 08/08/2014, 14:22

... and at least one of them contains an end of an edge of A  i ∩ B  since at least one of G[X i ∩ Y ] and G[X i ∩ Y ] contains an end of an edge of A i ∩ B. the electronic journal of combinatorics ... characterisation of planar graphs is presented. It concerns the structure of the cocycle space of a graph, and is motivated by consideration of the dual of an elementary...

Ngày tải lên: 08/08/2014, 11:20

... trees of a 5- wheel 3 A bijection between slope vectors and complement- reducible graphs In this section we count the points of S 2 (K n ), the slope variety of K n over F 2 . The points of F ( n 2 ) 2 have ... spanning tree of W . Proof. (⇐) Suppose that H a is a coupled spanning tree of W . When τ W is written in the form of equation (1), over F 2 , it is the sum of all coup...

Ngày tải lên: 08/08/2014, 12:23

Ngày tải lên: 05/08/2014, 09:46

Ngày tải lên: 05/08/2014, 10:20

Ngày tải lên: 05/08/2014, 15:20

... some results on mid -point sets of two linear sets in the light of the Lebesgue density. In the present paper the authors restrict their investigations into mid -point sets of sets of natural numbers ... In this paper the authors study some properties of the mid -point sets of sets of natural numbers using upper (lower) asymptotic density of sets of natural numbers. In th...

Ngày tải lên: 06/08/2014, 05:20

... number of orientations. If this problem is pursued based on the proof of this paper then a first step is finding an algorithm for generating the ideals of a poset in time proportional to the number of ... topological sort of the maximum directed subgraph of G corresponds to an acyclic orientation of G. Pruesse and Ruskey [1] showed that the prism of AO(G) is Hamiltonian in the c...

Ngày tải lên: 07/08/2014, 06:20

... first proof of (13) appears in [2]. It may be viewed as the first non- commutative extension of Euler’s evaluation of ζ(2n). Theorem 2 Let n be a positive integer, and let I denote the set of all ... identities of the form (17), then the number of (linearly independent) relations of this type can be computed via P´olya Theory (see, e.g., [8]) as the number of orbits in the actio...

Ngày tải lên: 07/08/2014, 06:22

... 3.1, 3.3 and 3.4 comprise the first steps of Bouc’s proof of Theorem 1.1. At this point our proof departs from Bouc’s and follows a path analogous to that of Friedman and Hanlon [4] for the chessboard ... rational eigenvalues of the Laplacian (over any field of characteristic 0) of any simplicial complex are nonnegative. This fact follows from the positive semidefinitness of the...

Ngày tải lên: 07/08/2014, 06:23