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．     

半群的半直积及其同余

给出了两个幺半群的半直积是Ｃｌｉｆｏｒｄ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．     

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.     

The Monoid of Hypersubstitutions of Type (n)

A hypersubstitution of type (n) is a map which takes the n-ary operation symbol f to an n-ary term (f). Any such can be inductively extended to a map on the set of all terms of type (n), and any two such extensions can be composed in a natural way. Thus, the set Hyp(n) of all hypersubstitutions of type (n) forms a monoid. For n = 2, many properties of this monoid were described by Denecke and Wismath [5]. In this paper, we study the semigroup properties of Hyp(n) for arbitrary n 2. In particular, we characterize the projection, dual and idempotent hypersubstitutions, and describe the classes of these elements under Greens relations.AMS Subject Classification (1991): 08B15 20M07Research supported by NSERC, Canada     

伴随型Renner幺半群的阶

In this paper, we find the orders of the Renner monoids for J-irreducible monoids K＊p（G）, where G is a simple algebraic group over an algebraically closed field K, and p ： G → GL（V） is the irreducible representation associated with the highest root.     

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     

A Presentation of the Singular Part of the Symmetric Inverse Monoid#

We give a semigroup presentation of the singular part of the symmetric inverse monoid on a finite set. Along the way, we derive a monoid presentation of the monoid of all order-preserving injective partial transformations on a finite chain, which differs from the presentation discovered by Fernandes.     

Ideal Structure of the Kauffman and Related Monoids

The generators of the Temperley-Lieb algebra generate a monoid with an appealing geometric representation. It has been much studied, notably by Louis Kauffman. Borisavljevi?, Do?en, and Petri? gave a complete proof of its abstract presentation by generators and relations, and suggested the name “Kauffman monoid”. We bring the theory of semigroups to the study of a certain finite homomorphic image of the Kauffman monoid. We show the homomorphic image (the Jones monoid) to be a combinatorial and regular *-semigroup with linearly ordered ideals. The Kauffman monoid is explicitly described in terms of the Jones monoid and a purely combinatorial numerical function. We use this to describe the ideal structure of the Kauffman monoid and two other of its homomorphic images.     

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.     

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.     

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.     

Brauer and Jones tied monoids

We introduce a ramified monoid, attached to each Brauer–type monoid, that is, to the symmetric group, to the Jones and Brauer monoids among others. Ramified monoids correspond to a class of tied monoids arising from knot theory and are interesting in themselves. The ramified monoid attached to the symmetric group is the Coxeter-like version of the so–called tied braid monoid. We give a presentation of the ramified monoid attached to the Brauer monoid. Also, we introduce and study two tied-like monoids that cannot be described as ramified monoids. However, these monoids can also be regarded as tied versions of the Jones and Brauer monoids.     

Brauer Characters of Finite Monoids

We introduce the concept of a Brauer character of a representation of a finite monoid M in characteristic p>0. When p does not divide the order of any subgroup of M, we develop a theory of p-monoid quivers. We apply our results to the full transformation semigroup.     

On Retractable S-Acts

In this paper we introduce a class of right S-acts called retractable S-acts which are right S-acts with homomorphisms into their all subacts. We also give some classifications of monoids by comparing such acts with flatness properties.     

INVERSE MONOIDS OF GRAPHS

. IntroductionGraph endomorphism and its regularity property have been investigated in some literatures (of. [1--41 for examples). The invertibility is a stronger algebraic property thanregUlarity in semigroup theory. It is commonly agreed that inverse semigroups are the mostpromising class of semigroups for study. In this paper we first present a combinatorial characterization of an inverse monoid of a graph (Theorem 2.3). Then using this we prove thata bipartite graph with an inverse monoi…     

用条件(Pw)刻画的幺半群

本文引入了条件（P_w）,讨论了条件（P_w）与条件（P）、条件（P_E）之间的关系,刻画了幺半群上S-系的平坦性.