Sufficient Conditions for a Digraph to be Supereulerian

A (di)graph is supereulerian if it contains a spanning eulerian sub(di)graph. This property is a relaxation of hamiltonicity. Inspired by this analogy with hamiltonian cycles and by similar results in supereulerian graph theory, we analyze a number of sufficient Ore type conditions for a digraph to be supereulerian. Furthermore, we study the following conjecture due to Thomassé and the first author: if the arc‐connectivity of a digraph is not smaller than its independence number, then the digraph is supereulerian. As a support for this conjecture we prove it for digraphs that are semicomplete multipartite or quasitransitive and verify the analogous statement for undirected graphs.     

Vertex-disjoint rainbow triangles in edge-colored graphs

Let $G$ be an edge-colored graph of order $n$. The minimum color degree of $G$, denoted by ${\delta }^c\left(G\right)$, is the largest integer $k$ such that for every vertex $v$, there are at least $k$ distinct colors on edges incident to $v$. We say that an edge-colored graph is rainbow if all its edges have different colors. In this paper, we consider vertex-disjoint rainbow triangles in edge-colored graphs. Li (2013) showed that if ${\delta }^c\left(G\right)\ge (n+1)∕2$, then $G$ contains a rainbow triangle and the lower bound is tight. Motivated by this result, we prove that if $n\ge 20$ and ${\delta }^c\left(G\right)\ge (n+2)∕2$, then $G$ contains two vertex-disjoint rainbow triangles. In particular, we conjecture that if ${\delta }^c\left(G\right)\ge (n+k)∕2$, then $G$ contains $k$ vertex-disjoint rainbow triangles. For any integer $k\ge 2$, we show that if $n\ge 16k-12$ and ${\delta }^c\left(G\right)\ge n∕2+k-1$, then $G$ contains $k$ vertex-disjoint rainbow triangles. Moreover, we provide sufficient conditions for the existence of $k$ edge-disjoint rainbow triangles.     

一个基于相邻像素兼容度的模糊加权平均滤波器

在文献[1]的基础上，提出几个改进的模糊加权平均滤波器。本文的方案不仅同时考虑了相邻像素对中心像素的兼容性以及中心像素对相邻像素的兼容性，而且还考虑到了权系数对局部环境的适应性。实验结果表明，该方法相比文献[1]中的模糊加权平均滤波器以及标准的均值滤波器、中值滤波器在噪声消除与边缘保留方面具有更好的性能。     

The Chang-Łoś-Suszko theorem in a topological setting

The Chang-Łoś-Suszko theorem of first-order model theory characterizes universal-existential classes of models as just those elementary classes that are closed under unions of chains. This theorem can then be used to equate two model-theoretic closure conditions for elementary classes; namely unions of chains and existential substructures. In the present paper we prove a topological analogue and indicate some applications.     

可重构制造系统重组过程中设备选择模型的研究

根据生产任务选择加工设备进行制造资源重组是实现可重构制造系统的关键问题之一，由于设备的选择涉及到多种因素，既有定量指标，又有定性指标，传统的依靠人工经验的方法显得力不从心。本文首先结合实际情况，提出了一套设备选择评价体系，通过对模糊判断矩阵采用最小对数二乘法确定各评价因素的权重系数，针对定性指标和定量指标采用不同的方法确定其性能指标值，通过模糊积分对评判指标进行综合评判，最后进行了实例研究。所提出的方法有效地简化了决策过程，为可重构制造系统设备选择提供了一套行之有效的方法。     

面向21世纪课程教材对地方综合大学电工学教学改革的影响--广西大学使用面向21世纪电工学课程系列教材的实践与探索

阐述了我校使用“面向21世纪”电工学课程系列教材的实践与探索过程，以及对我校电工学教学所产生的转折性影响和积极的导向作用，最后对教材提出了几点建议。     

图有分数因子的度条件

本文研究了图有分数因子的度条件,得到了下面的结果：令k(?)1是一个整数,G是一个连通的n阶图,n(?)4k-3且最小度δ(G)(?)k,若对于每一对不相邻的顶点u,v∈V(G)都有max{d_G(u),d_G(v)}(?)n/2,则G有分数k-因子．并指出该结果在一定意义上是最好可能的。     

双纠缠原子在耗散腔场中的纠缠动力学

研究了能量损耗腔中,两纠缠二能级原子与单模辐射场相互作用过程中原子的纠缠动力学.结果表明:双纠缠原子的纠缠度演化特性决定于初始两原子间的纠缠度、纠缠形式、腔场的平均光数、腔场的衰变系数.当原子初始处于一特定纠缠态时,其纠缠度可以放大,并且不受腔场损耗的影响. 关键词： 二能级原子 纠缠度 密度算符 单模辐射场     

K_(1,n)-free图具有给定性质的[a,b]-因子的一个充分条件

图G称为K1,n-free图,如果它不含K1,n作为其导出子图.对K1,n-free图具有给定性质的[a,b]-因子涉及到最小度条件进行了研究,得到一个充分条件.