Báo cáo toán học: "Another characterisation of planar graphs" ppt

... alt =""

Ngày tải lên: 05/08/2014, 15:20

... class="bi x0 y0 w1 h 1" alt =""

Ngày tải lên: 05/08/2014, 15:21

...

Ngày tải lên: 05/08/2014, 15:21

... 2-cycles.  Perfect factorisations of bipartite graphs and Latin squares without proper subrectangles I. M. Wanless Department of Mathematics and Statistics University of Melbourne Parkville ... describe a Latin square using a single line of text. We do this by first reducing of order 2 is said to be N 2 and a Latin square without proper subsquares is N...

Ngày tải lên: 07/08/2014, 06:20

... two dimensions of turning games in Chapter 14 of Winning Ways. 2. The Rules of the Game. In this paper, another form of matrix nim is proposed. This form is also a gen- eralization of Wythoff’s Game, ... positions of the form  ab cd  with a =min{a, b, c, d}. Then all L-positions are of the form, a + c<min{b, d}. (7) All R-positions are of the form, a + b<min...

Ngày tải lên: 07/08/2014, 06:23

... member of the second coordinate of the label of y, delete the edge x j y.If the digit of z is 3 and y is not a member of the second coordinate of the label of z, delete the electronic journal of ... Subclaims, the proof of our lemma is complete. 5 Proof of the Main Theorem In this section, we present the proof of the main theorem. Let C be a topologically closed class o...

Ngày tải lên: 07/08/2014, 06:23

... and Motivation The rank of a graph X is the rank of its adjacency matrix A( X). As the rank is such a fundamental algebraic concept, the relationship between the structure of a graph and its rank ... of other matrices associated with a graph, or about the ranks of certain graphs over finite fields (for examples, see Godsil & Royle [7]). In calculating the rank...

Ngày tải lên: 07/08/2014, 07:21

... the lattice structure comes from orientations of the completion. 2 Lattices of Fixed Degree Orientations A plane graph is a planar graph G =(V, E) together with a fixed planar embedding. In particular ... there may exist rigid the electronic journal of combinatorics 11 (2004), #R15 15 Lattice Structures from Planar Graphs Stefan Felsner Technische Universităat Berlin, Institut fău...

Ngày tải lên: 07/08/2014, 08:20

... we have a G =  Q⊆G connected (−1) |Q| = η G (−1) =  R increasing G connected  v∈V −{r} (−1) the electronic journal of combinatorics 12 (2005), #N1 5 A partition of connected graphs Gus Wiseman gus@ nafindix.com Submitted: ... component of G. If G is a rooted connected graph on V with root r, we will call the set partition π = s(G| V −{r} )ofV −{r} the depth-first par...

Ngày tải lên: 07/08/2014, 08:22

... classifying one-factorizations of regular graphs are studied. The smallest open case is currently graphs of order 12; one-factorizations of r -regular graphs of order 12 are here classified for ... One-Factorizations of Degree 2n − 2 and Order 2n Uniqueness of a regular graph of degree 2n − 2 and order 2n follows directly from unique- ness of its complement g...

Ngày tải lên: 07/08/2014, 08:22

... show that the absence of a rainbow n-cycle (again, with n odd) implies the absence of rainbow cycles of lengths  n 2  and 3n − 6. However, the absence of a rainbow cycle of even length does not ... absence of rainbow n-cycles and rainbow m-cycles implies the absence of rainbow (n + m − 2)-cycles. (For example, by this fact alone, the absence of rainbow 3-cycl...

Ngày tải lên: 07/08/2014, 13:21

... in J. Graph Theory. the electronic journal of combinatorics 15 (2008), #R82 9 Irregularity strength of regular graphs Jakub Przybylo AGH University of Science and Technology Al. Mickiewicza ... of G is a map f : E(G) → {1, 2, . . . , w}. An irregularity strength of G, s(G), is the smallest w such that there is a w-weighting of G for which  e:u∈e f(e) =  e:v∈e f(e) for a...

Ngày tải lên: 07/08/2014, 21:20

... s 3 ) for all u r ∈ B − {u i , u j }.  We have found the proof of Theorem 1 during the 7th International Colloquium on Graph Theo r y in Hy`eres in September 2005. Another proof of the theorem ... that  N n  = o( N n ).  the electronic journal of combinatorics 17 (2010), #N11 4 Another abstraction of the Erdos-Szekeres Happy End Theorem Noga Alon Ehsan Chiniforo...

Ngày tải lên: 08/08/2014, 11:20

... 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 ... 05C10 Abstract A new characterisation of planar graphs is presented. It concerns the structure of the cocycle space of a graph, and is motivated by consideration of the...

Ngày tải lên: 08/08/2014, 11:20

... 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