Báo cáo toán học: "Induced complete h-partite graphs in dense clique-less graphs" pptx

... remain in each U i this procedure can be applied repeatedly, thus finding at least (1 − 1 2 ) c a vertex disjoint induced copies of K(h, a) in each copy of K(h, c). Since there are at the beginning ... and R. Yuster, Almost H-factors in dense graphs, Graphs and Combi- natorics 8 (1992), 95–102. [3] N. Alon and R. Yuster, H-factors in dense graphs, J. of Combinatorial Theory Se...

Ngày tải lên: 07/08/2014, 06:20

... Since each edge in C(x) is contained in some K 5 andthusisacenteredgeinsomeW 4 , by Lemma 2.3 and Lemma 2.5-(1), G 2 admits a 3-NZF, a contradiction. Claim 3. No degree 2 vertex is contained in ... is contained in a circuit of length 3 or 4. By contradiction. Let G 1 be the graph obtained from G by deleting the edge e and adding a new vertex y  and a new edge xy  .SinceG contains no...

Ngày tải lên: 07/08/2014, 07:21

... vertices in graphs, IEEE Transactions on Information Theory, vol 44, pp. 599-611, 1998. [6] A. Lobstein, Bibliography on identifying and locating-dominating codes in graphs, http://www.infres.enst.fr/∼lobstein/debutBIBidetlocdom.pdf [7] ... are the minimal graphs for the subgraph relationship in the class of 2-connected, r-twin-free graphs. But in this case, the result cannot be...

Ngày tải lên: 07/08/2014, 15:22

... following classes: C B is the class of graphs in G 1 with a distinguished block, C v is the class of graphs in G 1 with a distinguished vertex, and C Bv is the class of graphs in G 1 with a distinguished ... graph in C B is obtained in a unique way by taking a block in G 2 and attaching at each vertex of the block a vertex-pointed connected graph in C  , which yields C B...

Ngày tải lên: 07/08/2014, 21:21

... products can be very useful tools in finding decompositions of complete equipartite graphs. This is the key approach in many papers, including: [2, 3 , 6] and indeed this paper. Much work on cycle ... and preliminary lemmas In this section we introduce some notation, including the idea of weak and strong paths. These are the building blocks for our constructions in the next section....

Ngày tải lên: 08/08/2014, 12:22

Ngày tải lên: 05/08/2014, 15:21

... graphs, In: Combinatorial Geometry and Graph Theory (Proc. of Indo- nesia-Japan Joint Conf., September 13 – 16, 2003, Bandung, Indonesia) 185–199, Lecture Notes in Computer Science 3330, Springer, ... E)is called a complete split graph if every u ∈ I is adjacent to every v ∈ K. The notion of split graphs was introduced in 1977 by F¨oldes and Hammer [4]. These graphs are interestin...

Ngày tải lên: 06/08/2014, 05:20

... graph Φ (i.e., with gains in GF(3) + ) based on K n . A theory of switching classes and triple covering graphs, analogous to that of signed complete graphs (and of two -graphs) is developed. The ... of minimal balancing edge sets; hence the frustration index l(Σ) = minimum size of a member of the blocker. Ch. 5: Graphs without odd-K 5 minors”, i.e., signed graphs without −K 5 as a m...

Ngày tải lên: 07/08/2014, 05:23

... edge corresponding to it would be distinguished, and G is not a multilink. Thus the center is a node, and that node cannot represent a multilink, since, again, its endpoints would be distinguished in G. ... is ordinary in G.Thus,B e is also simple, locally finite and 3-connected. We must show that B e = G α . Let η be a link in T joining α with, say, β,andletT  be the component of T−α c...

Ngày tải lên: 07/08/2014, 06:20

... cubic graphs for girths 14, 15 and 16. Introduction We consider the problem of finding smallest regular graphs with given girth and degree: the cage problem. This problem has a prominent place in ... Computer Science Indiana State University Terre Haute, IN 47809 Submitted: September 20, 1996; Accepted: September 26, 1996 Abstract A method for constructing cubic graphs with girths i...

Ngày tải lên: 07/08/2014, 06:20