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排序方式: 共有1108条查询结果,搜索用时 62 毫秒
951.
We prove that any complete multipartite graph with parts of even size can be decomposed into closed trails with prescribed even lengths. Copyright © 2011 Wiley Periodicals, Inc. J Combin Designs 19:455‐462, 2011 相似文献
952.
A concept called P3BD‐closed set is introduced to describe a set of positive integers which is both PBD‐closed and 3BD‐closed. The theory of P3BD‐closure is developed and a few examples of P3BD‐closed sets are exhibited. In the process, the existence spectrum of OLIQ ?s (overlarge sets of idempotent quasigroups with their own idempotent orthogonal mates) is almost determined. A pair of orthogonal OLIQ ?s is shown to asymptotically exist. The existence of OLIQ s (overlarge sets of idempotent quasigroups with their own orthogonal mates not necessarily specifying idempotency) is also established with only 10 possible exceptions remained. Copyright © 2011 Wiley Periodicals, Inc. J Combin Designs 19:407‐421, 2011 相似文献
953.
本文用概率论的基本方法结合矩阵表示上的置换方法,证明了三维随机 Sierpinski地毯随着保留概率从0到1变化,过程组态经历几个不同的相位,并求出各相位间的临界概率或给出其范围. 相似文献
954.
Pascual Jara 《Czechoslovak Mathematical Journal》2007,57(1):225-241
Lattices of submodules of modules and the operators we can define on these lattices are useful tools in the study of rings
and modules and their properties. Here we shall consider some submodule operators defined by sets of left ideals. First we
focus our attention on the relationship between properties of a set of ideals and properties of a submodule operator it defines.
Our second goal will be to apply these results to the study of the structure of certain classes of rings and modules. In particular
some applications to the study and the structure theory of torsion modules are provided. 相似文献
955.
Received June 6, 1995 / Revised version received May 26, 1998 Published online October 9, 1998 相似文献
956.
We introduce the notion of semigroup with a tight ideal series and investigate their closures in semitopological semigroups,
particularly inverse semigroups with continuous inversion. As a corollary we show that the symmetric inverse semigroup of
finite transformations I
λ
n
of the rank ≤
n is algebraically closed in the class of (semi)topological inverse semigroups with continuous inversion. We also derive related
results about the nonexistence of (partial) compactifications of classes of semigroups that we consider. 相似文献
957.
Akira Hiraki 《Graphs and Combinatorics》2009,25(1):65-79
Let Γ be a distance-regular graph of diameter d ≥ 3 with c
2 > 1. Let m be an integer with 1 ≤ m ≤ d − 1. We consider the following conditions:
In [12] we have shown that the condition (SC)
m
holds if and only if both of the conditions (BB)
i
and (CA)
i
hold for i = 1,...,m. In this paper we show that if a
1 = 0 < a
2 and the condition (BB)
i
holds for i = 1,...,m, then the condition (CA)
i
holds for i = 1,...,m. In particular, the condition (SC)
m
holds. Applying this result we prove that a distance-regular graph with classical parameters (d, b, α, β) such that c
2 > 1 and a
1 = 0 < a
2 satisfies the condition (SC)
i
for i = 1,...,d − 1. In particular, either (b, α, β) = (− 2, −3, −1 − (−2)
d
) or holds. 相似文献
(SC) m : For any pair of vertices at distance m there exists a strongly closed subgraph of diameter m containing them. | |
(BB) m : Let (x, y, z) be a triple of vertices with ∂Γ(x, y) = 1 and ∂Γ(x, z) = ∂Γ(y, z) = m. Then B(x, z) = B(y, z). | |
(CA) m : Let (x, y, z) be a triple of vertices with and |C(z, x) ∩ C(z, y)| ≥ 2. Then C(x, z) ∪ A(x, z) = C(y, z) ∪ A(y, z). |
958.
With every subset selection for posets, there is associated a certain ideal completion . As shown by Erné, such completions help to extend classical results on domains and similar structures in the absence of
the required joins. Some results about –predistributive or –precontinuous posets and –continuous functions are summarized and supplemented. In particular, several central results on function spaces in domain
theory are extended to the setting of productive closed subset selections. The category FSBP, in which objects are finitely separated and upper bounded posets and arrows are continuous functions between them, is shown to be cartesian closed.
This research is supported by the National Natural Science Foundation of China, 10471035. 相似文献
959.
运输问题的退化解及表解中0元的添加 总被引:3,自引:0,他引:3
在运输问题表上作业法中,有时会遇到退化解问题,这样在给调运方案时需要在调运表上添加0元,可是0应添在何处?大多数文献中均未具体给出或给出的结论有误,0元的添加不当有时会导致一系列问题出现,本文将讨论这些问题,且给出一个0元添加的确定的答案. 相似文献
960.
主要构造出了一类sd-集但非Wsd-集.同时,我们使用一种新方法,推广了一些已知的结果.基于这些结果,系统地揭示了sd-尺度函数的傅里叶变换的支集与闭球的关系. 相似文献