广义字典序积的自同态幺半群

讨论了图的广义字典序积的自同态幺半群的性质,给出了广义字典序积图X[Yz|x∈V（X）]的自同态幺半群与X,Yx(x∈V(X))的自同态幺半群的圈积相等的充要条件。     

图的P-正则自同态幺半群

刻划了具有Ｐ－正则自同态幺半群的二分图,讨论了字典序积图的自同态幺半群的Ｐ－正则性。     

图的强收缩核与图的强自同态幺半群的正则性

本文研究图及其强自同态幺半群．首先刻画了图的强自同态幺半群的正则元，然后给出了此幺半群正则的充要条件．这推广了［１］和［２］中关于有限图的强自同态幺半群正则的结果．     

Generalized Quasi—Variational Inequalities on Paracompact Sets

Ｔｈｉｓｐａｐｅｒｉｓｃｏｎｔｉｎｕａｔｉｏｎｓｏｆ［１］，ｗｅｓｔｉｌｌｔｏｕｓｅｍａｒｋｓａｎｄｔｅｒｍｓｉｎ［１］ａｎｄｔｈｅｏｔｈｅｒｔｅｒｍｓａｇｒｅｅｗｉｔｈ［２］ａｎｄ［３］．ＬｅｔＥａｎｄＦｂｅｔｗｏＨａｕｓｄｏｒｆｆｔｏｐｏｌｏｇｉｃａｌｖｅｃｔｏｒｓｐａｃｅｓ，ＸＥ，ＹＦｂｅｔｗｏｎｏｎｅｍｐｔｙｓｅｔｓ，ＦｂｅｔｈｅｄｕａｌｓｐａｃｅｏｆＦ，Ａ：Ｘ→２ＹａｎｄＢ：Ｙ→２Ｆｂｅｔｗｏｓｅｔ－ｖａｌｕｅｄｍａｐｐｉｎｇ，Ｔ：Ｙ→Ｘｂｅｉｎｖｅｒｔｉｂｌｅ．Ｉｎｔｈｉｓｐ…     

半群上Rees矩阵半群的半格的结构

推广了Ｍ．Ｐｅｔｒｉｃｈ在文［１］中所用的方法，得到了幺半群上Ｒｅｅｓ矩阵半群的半格的一个结构定理．研究了单幂幺半群上Ｒｅｅｓ矩阵半群的半格的性质并给出了矩形单幂幺半群的半格的若干等价刻划．     

图的完全正则自同态

作为图的代数分析的一部分，对图的自同态幺半群的研究近年来有一定的进展（参见［３］及［４］）。这类研究的主要目的在于将半群理论应用于图论。文献［５］研究了图的正则自同态及其逆。在此基础上本文进一步描述了图的完全正则自同态的组合特征；同时对含有完全正则自同态ｆ的极大子群，文中也明确给出了其单位元素及ｆ的逆     

分裂图的自同态幺半群的正则性

对自同态么半群正则的分裂图进行了刻划，从而关于分裂图回答了Ｋｎａｕｅｒ提出的一个公开问题［１］。     

具有弱滑脊性质序列空间上的HelingerToeplitz定理

设Ｅ（Ｘ）和Ｆ（Ｙ）是向量值序列空间并且Ｅ（Ｘ）具有弱滑脊性质．Ａ＝［Ａｉｊ］是一个算子值无穷矩阵并且映Ｅ（Ｘ）进入Ｆ（Ｙ）．如果（Ｘ，Ｙ）有Ｂａｎａｃｈ－Ｓｔｅｉｎｈａｕｓ性质，那么Ａ是σ（Ｅ（Ｘ），Ｅ（Ｘ）βＹ）－σ（Ｆ（Ｙ），Ｆ（Ｙ）βＹ）连续的．     

H~＊－有理模和右Smash积A＃~R_HH~＊ 

本文对Ｈ￣＊上的有理模Ｍ做了一些讨论，刻划了此类模的某些性质，并利用这些性质得到了右Ｓｍａｓｈ积Ａ＃［ｋＧ］上模Ｍ是完全可约模的条件。     

右（左）逆半群的半直积及圈积

给出了两个幺半群的半直积及圈积为右（左）逆半群的充分必要条件，从而推广了[2]中两个幺半群的半幺直积和圈积为逆半群的充分必要条件．     

Graphs whose endomorphism monoids are regular

In this paper, we give several approaches to construct new End-regular (-orthodox) graphs by means of the join and the lexicographic product of two graphs with certain conditions. In particular, the join of two connected bipartite graphs with a regular (orthodox) endomorphism monoid is explicitly described.     

The rank of the endomorphism monoid of a uniform partition

The rank of a semigroup is the cardinality of a smallest generating set. In this paper we compute the rank of the endomorphism monoid of a non-trivial uniform partition of a finite set, that is, the semigroup of those transformations of a finite set that leave a non-trivial uniform partition invariant. That involves proving that the rank of a wreath product of two symmetric groups is two and then use the fact that the endomorphism monoid of a partition is isomorphic to a wreath product of two full transformation semigroups. The calculation of the rank of these semigroups solves an open question.     

On unretractive graphs

The present paper proves necessary and sufficient conditions for both lexicographic products and arbitrary graphs to be unretractive. The paper also proves that the automorphism group of a lexicographic product of graphs is isomorphic to a wreath product of a monoid with a small category.     

On wreathed lexicographic products of graphs

This paper proves a necessary and sufficient condition for the endomorphism monoid of a lexicographic product G[H] of graphs G,H to be the wreath product of the monoids and . The paper also gives respective necessary and sufficient conditions for specialized cases such as for unretractive or triangle-free graphs G.     

Endomorphism monoids and topological subgraphs of graphs

We prove, that, given a finite graph Y there exists a finite monoid (semigroup with unity) M such that any graph X whose endomorphism monoid is isomorphic to M contains a subdivision of Y. This contrasts with several known results on the simultaneous prescribability of the endomorphism monoid and various graph theoretical properties of a graph. It is also related to the analogous problems on graphs having a given permutation group as a restriction of their automorphism group to an invariant subset.     

Lexicographic Products of Half Linearly Ordered Groups

The notion of the half linearly ordered group (and, more generally, of the half lattice ordered group) was introduced by Giraudet and Lucas [2]. In the present paper we define the lexicographic product of half linearly ordered groups. This definition includes as a particular case the lexicographic product of linearly ordered groups. We investigate the problem of the existence of isomorphic refinements of two lexicographic product decompositions of a half linearly ordered group. The analogous problem for linearly ordered groups was dealt with by Maltsev [5]; his result was generalized by Fuchs [1] and the author [3]. The isomorphic refinements of small direct product decompositions of half lattice ordered groups were studied in [4].     

Endomorphism monoids of free acts and O-wreath products of monoids

Monoids and acts which may have zero elements are considered. In Section 1 we construct a O-wreath product of monoids. In 2 we prove the theorem that the endomorphism monoid of a free act over a monoid with zero can be represented as a O-wreath product. Considering monoids with tero we are interested in their annihilator properties. In 3 we give necessary and sufficient conditions for a O-wreath product of monoids to be a right (left) Baer (Rickart) monoid. In 4 we obtain as a consequence corresponding conditions for the endomorphism monoid of a free act over a monoid with zero.     

图的字典积的非零整数流(英文)

充分利用图的字典积的结构证明了以下结论:如果图G_1的每连通分支都非平凡,图G_2的阶数大于3,那么它们的字典积G_1[G_2]具有非零3-流.     

Graphs whose strong endomorphism monoids are regular

Let X be a graph, S End X be its strong endomorphism monoid. It is proved that S End X is a regular monoid if and only if the canonical strong factor graph U of X contains no proper subgraph which is isomorphic to U. The result generalizes that of U. Knauer about the regularity of strong endomorphism monoids of graphs.