Báo cáo toán học: "Nowhere-zero k-flows of supergraphs" docx
Báo cáo toán học: "On Certain Eigenspaces of Cographs" docx
... multiplicities of eigenvalues
0 and −1 of G. Observe that two vertices of G belong to the same cluster (or to the
set of isolated vertices) exactly if the corresponding leaves of T have a common ... fixed vertex of M,
• −1 in turn to exactly one other vertex of M,
• 0 to all other vertices of G.
Then the constructed vectors constitute a simply structured basis of Eig(−1; G)....
Báo cáo toán học: "Nowhere-zero k-flows of supergraphs" docx
... v
i
v
i
v
j
v
j
and a segment of C form a cycle in G of
the electronic journal of combinatorics 8 (2001), #R20 3
Nowhere-zero k-flows of supergraphs
Bojan Mohar
∗
and Riste
ˇ
Skrekovski
∗
Department of Mathematics,
University ... in Q is of length ≥ 6, we can color at least
6
7
of the edges of Q using
colors 1 and 2. Color every edge of the 1-factor E(G) − E(Q) by color...
Báo cáo toán học: "On the Theory Of Pfaffian Orientations. II. T -joins, k-Cuts, and Duality of Enumeration" potx
... of all vertices of T and even splitting of
all vertices of V − T. If the edge f
of G
s
is the image of the edge f of G then we let
x
s
f
= x
f
. We let x
s
e
=1for the remaining edges e of ... functions of T -joins and k-cuts of graphs.
A graph is a pair G =(V,E)whereV is a set and E is a set of unordered pairs of
elements of V . The elements of V are called ve...
Báo cáo toán học: "On the symmetry of the distribution of k-crossings and k-nestings in graphs" pot
... chain of length k of the filling is a selection of rows r
1
< · · · < r
k
and
columns c
1
< · · · < c
k
such that the cells (r
i
, c
i
) are nonempty. A ne chain of length k of
the ... adjacency matrix of a graph on [n] in the
diagram ∆
n
= (n−1, n−2, . . . , 2, 1) (this encoding was used by Krattenthaler in [2] to give
alternative proofs of some of the results of...
Báo cáo toán học: "A refinement of the formula for k-ary trees and the Gould-Vandermonde’s convolution" pps
... noncombinatorial proof of (2) by a modified
Riordan array theorem derived from theorems in Sprugnoli et al. [5]. Also we refine the
formula for C
β,γ
(n) with aids of a Gould classes of inverse relation ... supported by the 973 Project, the PCSIRT Project of the
Ministry of Education, the Ministry of Science and Technology and the National Science
Foundation of China.
References
[...
Báo cáo toán học: "A Paintability Version of the Combinatorial Nullstellensatz, and List Colorings of k-partite k-uniform Hypergraphs" pps
... concept
of list colorings. This generalization is based on a different point of view. Instead of
assigning color lists L
v
of size ℓ
v
to the vertices v of a (hyper)graph, we assign sets of
vertices ... introduction of paintability of graphs in
[Scha2] and the purely combinatorial proof of the Alon-Tarsi List Coloring Theorem in
[Scha3]. We also point out that, beside our pai...
Báo cáo khoa học: "Optimal k-arization of Synchronous Tree-Adjoining Grammar" ppt
... of either α
or β produces a k of size at least m, the later removal
of fragments of size less than m cannot affect the k
found by the algorithm. Due to validity preservation,
removal of any of ... node n
1
of γ
L
, we let π(n
1
) de-
note the stripe of adjacent rows of π addressed by
substring σ(n
1
) of σ(n
L
). If n
1
dominates n
2
in γ
L
,
we let π(n
1
, n
2
) denote th...
Báo cáo toán học: " Structure-property relations of co-doped bismuth layer-structured Bi3.25La0.75(Ti1-xMox)3O12 ceramics" pptx
... conductivity values of
BLTM were lower than those of undoped BLT ceramic regardless of measurement
frequency. This seemed to be the effect of the donor dopant on the electrical
conductivity of a p-type ... properties of (1 – x)PMN–xPZT ferroelectric ceramics.
Phys Solid State 2000, 42:936-943.
21. Baudry L: Theoretical investigation of the influence of space charges on
f...
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