幺半群的半直积及其同余

给出了两个幺半群的半直积是Ｃｌｉｆｆｏｒｄ半群的充要条件及其结构。并讨论了逆半群半直积的Ｇｒｅｅｎ关系、最小群同余和极大幂等元分离同余。     

弱Clifford形正则半群的半直积和圈积

本文给出两个么半群Ｓ和Ｔ的半直积和圈积为弱Ｃｌｉｆｆｏｒｄ拟正则么半群的充要条件和半直积的结构，同时还讨论了弱Ｃｌｉｆｆｏｒｄ拟正则么半群的最小群同余与半直积的最小群同余之间的关系。     

强π-逆半直积

给出两个半群S和T的半直积是强π-逆半群，强π-E-酉逆半群和E-酉逆半群的充要条件，同时还讨论了E-酉逆半群的最小群同余与半直积的最小群同余之间的关系。     

弱Clifford拟正则半群的半直积和圈积

本文给出两个么半群Ｓ和Ｔ的半直积和圈积为弱Ｃｌｉｆｆｏｒｄ拟正则么半群的充要条件和半直积的结构，同时还讨论了弱Ｃｌｉｆｆｏｒｄ拟正则么半群的最小群同余与半直积的最小群同余之间的关系．     

幺半群左正则纯整半直积上的同余

研究了幺半群半直积上的同余，给出了幺半群半直积的所谓同余分解定理，并特别讨论了幺半群左正则纯整半直积及其子类上的同余．     

半群半直积的主投影性质(英文)

本文研究了半群半直积的主投影性质.利用适当半群,获得了右主投影半群半直积的充分和必要条件,推广了半直积的一些结果.     

正则半群上的矩形群同余

文[1]中PetrichM定义了同余的核与迹，用它们描述了逆半群上的同余，Gomes在文[2]中定义了同余的核与超迹并描述了正则半群上的R-幂单(R-unipo-tent)同余，本文利用同余的核与超迹描述正则半群上的另一类重要同余，即矩形群同余．     

π-纯正半群的半直积

给出了两个半群的半直积S×αT是π-纯正半群的充分必要条件,并得到了半直积S×αT是右强π-逆半群的充分必要条件.     

C-rpp半群的半直积

给出了两个幺半群的半直积是C-rpp半群的充要条件及结构。     

LR-C半群的半直积

给出了两个半群的半直积是LR-C半群的充要条件.     

Factorization theory of root closed monoids of small rank

In this note, we investigate ideal and factorization-theoretic properties of some root closed cancellative commutative monoids of rank at most two.     

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．     

Enumeration of symplectic and orthogonal injective partial transformations

In this paper, we compute the generating function of , where a is a real number with a≥1. We then use this function to determine the generating functions of the symplectic and orthogonal Renner monoids. Furthermore, we show that these functions are closely related to Laguerre polynomials.     

On graphs with a given endomorphism monoid

Hedrlín and Pultr proved that for any monoid M there exists a graph G with endomorphism monoid isomorphic to M . In this paper we give a construction G(M) for a graph with prescribed endomorphism monoid M . Using this construction we derive bounds on the minimum number of vertices and edges required to produce a graph with a given endomorphism monoid for various classes of finite monoids. For example we show that for every monoid M , | M |=m there is a graph G with End(G)? M and |E(G)|≤(1 + 0(1))m². This is, up to a factor of 1/2, best possible since there are monoids requiring a graph with \begin{eqnarray*} && \frac{m^{2}}{2}(1 -0(1)) \end{eqnarray*} edges. We state bounds for the class of all monoids as well as for certain subclasses—groups, k‐cancellative monoids, commutative 3‐nilpotent monoids, rectangular groups and completely simple monoids. © 2009 Wiley Periodicals, Inc. J Graph Theory 62, 241–262, 2009     

Resolutions for free partially commutative monoids

We construct a free resolution for a free partially commutative monoid and, using this resolution, estimate the homological dimension of the monoid.     

Eulerian* -polynomial identities on matrix algebras

In this paper we considerably strengthen a result of Ribenboim on noetherian generalised power series rings. While Ribenboim proves his result under the restrictive assumption that the monoid occuring in the definition of the geralised power series ring in cancellative we prove a corresponding result for arbitrary ordered monoids.     

The Symplectic Monoid

In this paper, we describe explicitly the symplectic monoid ? and its Renner monoid ? using elementary methods. We refine the Bruhat–Renner decomposition of ? and analyze in detail the length function on ?. We then show that every element of ? has a unique canonical form decomposition, which is an analogue of the canonical form of elements in Chevalley groups. We also compute the order of ? over a finite field, and as a consequence we obtain a new combinatorial identity.