Báo cáo toán học: "On a conjecture concerning the Petersen graph" ppt

... or (iii) B has all attachments in N ′ 2 ∪N ′ 3 ∪N ′ 4 , and each of N ′ 2 , N ′ 3 and N ′ 4 contains at least one such attachment. Proof of Claim 6: If j = 4 and x 2 and x j are not adjacent, then ... such that at most two pair of them are adjacent. Therefore, no non-edge-bridge can have attachments in more than two N ′ i ’s, and if it has atta chments in two N ′ i ’s, say in N ′ i and in .....

Ngày tải lên: 08/08/2014, 12:23

... totally dyadic representation A. A dyadic oriented matriod is dyadic of order k if it has a totally dyadic representation A with full row rank and with the property that for each pair of adjacent ... Louisville. scobee@louisville.edu Submitted: January 7, 1999; Accepted: March 30, 1999 Abstract A rational matrix is totally dyadic if all of its nonzero subdeterminants are in {±2 k :...

Ngày tải lên: 07/08/2014, 06:20

... discussions with Eva Czabarka, Ida Kantor, Gyula O.H. Ka t ona, Nathan Lemons, Bal´azs Patk´os, L´aszl´o Sz´ekely, and Jacques Verstra¨ete. The author thanks the NSF for funding her and IPAM for hosting ... hosting her while she was a core participant in the CMA 2009 program. The author also thanks the US State Department and the Hungarian Fulbright Commission for funding her an...

Ngày tải lên: 08/08/2014, 14:22

... + y)(X + y) On a Class of Constant Weight Codes Mihai Caragiu Institute of Mathematics Bucharest and Department of Mathematics, Pennsylvania State University E-mail: caragiu@math.psu.edu Submitted: ... constant weight for their codewords. Note that whenever we take off the first row and the first column of a normalized Hadamard matrix of order 4t, the set of all the rows of the rem...

Ngày tải lên: 07/08/2014, 06:20

... questions. 2 The Main Theorem We begin with some preliminaries about partitions and their conjugates. For a given partition π with parts each  N,wedenotebyf i (π) the number of appearances of i as a part ... in the following be dealing with partitions whose parts are all  some given N.Welet¯π be that partition made up of the parts of π that are <N. In light of (11) we see tha...

Ngày tải lên: 07/08/2014, 08:22

... if a i and a j are adjacent in G. These additional edges are always drawn between two vertices having degree 2 in the copies (that is, copies of a 1 , a 2 , or a 3 ). It is easy to see that Z ... hypohamiltonian graph has at least three non-2-faces. Proof. Let D be an arbitrary cubic planar hypohamiltonian gr aph. If D has only 2-faces, then the deletion of any vertex gives a...

Ngày tải lên: 08/08/2014, 14:23

... 7 On a Generalization of Meyniel’s Conjecture on the Cops and Robbers Game Noga Alon ∗ Tel Aviv University and Institute for Advanced Study, Princeton nogaa@tau.ac.il Abbas Mehrabian Department ... mean a pair (x, y) of vertices with x ∈ X and y ∈ N A s (x). We call x the head and y the tail of the pair. By the remark, the set A ∩ N(x) has at most m elements, and propert...

Ngày tải lên: 08/08/2014, 12:23

... C. Evans, Partial Diff. Equations, American Math. Society, 1998. 5. C. Vargas an d M. Zuluaga, On a Nonlinear Dirichlet Problem Type at Resonance and Bifurcation, Partial Differential Equations, ... notice that the problem Dirichlet for the system (1.1) in a bounded smooth domain have been studied by Zuluaga in [6]. Throughout the paper, (., .)and. denotes the usual scalar product...

Ngày tải lên: 06/08/2014, 05:20

... distances in spaces of random variables, Math. Uspekhi 101 (1976) 417–454 (Russian). 28. V.M. Zolotarev, Ideal metrics in the problems of probability theory and mathe- matical statistics, Austral. ... Introduction During the last several decades the probability metric approach has risen to become one of the most important tools available for dealing with certain types of large scale p...

Ngày tải lên: 06/08/2014, 05:20

... have all n non-terminal symbols, we give a combinatorial interpretation for the transformation L (r) w . After the application of L (r) w to A, the last step is the placement of r + 1 copies of the ... construction for the Stockhausen sequences. Although only known tech- niques [G] are used, these are sophisticated, and the problem serves as a useful study of these techniqu...

Ngày tải lên: 07/08/2014, 06:20