Ω-模糊可补子半环

给定一个集合Ω,引入了可补半环的Ω-模糊可补子半环的概念,研究了它的一些基本性质。给出了可补半环的Ω-模糊可补子半环的等价刻画,证明了可补半环的Ω-模糊可补子半环的交、同态像与同态原像等也是可补半环的Ω-模糊可补子半环。最后,通过在SΩ上定义运算+,×,-,得到可补半环(SΩ,+,×,-),并研究了与其相关的模糊可补子半环与Ω-模糊可补子半环。     

可补半环上的同余

研究可补丰环上的同余关系,得出一些重要性质.并证明了一个半环R是可补半环当且仅当它是某个布尔环和布尔代数的直积,因而可补半环必是来法可交换的.     

可除半环的伪理想与同余

引入可除半环的伪理想,它与同余互相唯一决定,在可除半环中利用理想作商是可行的,并证明了同态基本定理.     

一类平坦半环生成的簇

平坦半环是一类重要的加法幂等元半环,它在半环簇理论的研究中扮演着重要的角色.主要研究了次直不可约的平坦半环,以及一类平坦半环生成的簇.给出了次直不可约的nil-平坦半环的等价刻画,证明了当n小于4时,平坦半环S(x1x2…xn)均是有限基底的.     

可除闭半环

本文讨论了可除闭半环的分类、无限超积、元素的闭包和嵌入定理，这些结果为研究与应用可除半环提供了有用的基础。     

关于一个加法幂等元半环簇的有限基底问题

研究了由x2≈x确定的加法幂等元半环簇和xy≈zt确定的加法幂等元半环簇的并W (即包含上述两个簇的并集的最小的簇)的有限基底问题.证明了W是有限基底的,且W的子簇格是阶为312的分配格.     

关于一类半环上的格林关系的若干研究

研究了加法半群是带,乘法半群是完全正则半群的半环上的格林关系,给出了˙L∧+D(+L,+R)是同余关系的充分必要条件,证明了由这些同余关系所决定的半环类都是半环簇,并给出了这些半环簇的Mal′cev积分解.     

纯整环并半环的半群结构

环并半环称为纯整环并半环, 若其加法幂等元集是一个带半环. 若纯整环并半环的加法幂等元集是一个T带半环, 称为$T$纯整环并半环. 研究了纯整环并半环以及一些$T$纯整环并半环的半群结构.     

关于拟正则半环上可除半环同余的注记

研究了拟正则半环上的同余,给出了拟正则半环上一类理想的性质,并利用这类理想给出了拟正则半环上可除半环同余的几种等价形式.     

基于可减的实半环与实素理想

半环R被称为实半环,若对于任意的n∈N,方程x1^2＋…＋xn^2=0在R中只有零解：x1=…=xn=0.为了刻画实半环,引入了实理想和极小素理想的概念,利用同余的方法,得到了可减半环类中实半环的结构定理.     

Cancellable Elements of the Lattice of Epigroup Varieties

We completely describe all commutative epigroup varieties that are cancellable elements of the lattice EPI of all epigroup varieties. In particular, we prove that a commutative epigroup variety is a cancellable element of the lattice EPI if and only if it is a modular element of this lattice.     

Varieties of idempotent semirings with commutative addition

The multiplicative reduct of an idempotent semiring with commutative addition is a regular band. Accordingly there are 13 distinct varieties consisting of idempotent semirings with commutative addition corresponding to the 13 subvarieties of the variety of regular bands. The lattice generated by the these 13 semiring varieties is described and models for the semirings free in these varieties are given. Received April 22, 2004; accepted in final form June 3, 2005.     

Tropical Arithmetic and Matrix Algebra

This article introduces a new structure of commutative semiring, generalizing the tropical semiring, and having an arithmetic that modifies the standard tropical operations, i.e., summation and maximum. Although our framework is combinatorial, notions of regularity and invertibility arise naturally for matrices over this semiring; we show that a tropical matrix is invertible if and only if it is regular.     

Locally Closed Semirings and Iteration Semirings

Locally closed semirings, iteration semirings and Conway semirings play an important role in the algebraic theory of semirings and theoretical computer science. Z. ésik and W. Kuich showed that a locally closed commutative semiring is an iteration semiring (is also a Conway semiring). By study of polynomial semirings and matrix semirings, we obtain new expressions of certain polynomials and show that all matrix semirings over a locally closed semiring are also locally closed, and so a locally closed semiring (which need not be commutative) is an iteration semiring.     

Locally Closed Semirings and Iteration Semirings

Locally closed semirings, iteration semirings and Conway semirings play an important role in the algebraic theory of semirings and theoretical computer science. Z. ésik and W. Kuich showed that a locally closed commutative semiring is an iteration semiring (is also a Conway semiring). By study of polynomial semirings and matrix semirings, we obtain new expressions of certain polynomials and show that all matrix semirings over a locally closed semiring are also locally closed, and so a locally closed semiring (which need not be commutative) is an iteration semiring.     

Diameters of commuting graphs of matrices over semirings

We calculate the diameters of commuting graphs of matrices over the binary Boolean semiring, the tropical semiring and an arbitrary nonentire commutative semiring. We also find the lower bound for the diameter of the commuting graph of the semigroup of matrices over an arbitrary commutative entire antinegative semiring.     

Determinants of matrices over semirings

In this paper, the concept of determinants for the matrices over a commutative semiring is introduced, and a development of determinantal identities is presented. This includes a generalization of the Laplace and Binet–Cauchy Theorems, as well as on adjoint matrices. Also, the determinants and the adjoint matrices over a commutative difference-ordered semiring are discussed and some inequalities for the determinants and for the adjoint matrices are obtained. The main results in this paper generalize the corresponding results for matrices over commutative rings, for fuzzy matrices, for lattice matrices and for incline matrices.     

Cyclic semirings with idempotent noncommutative addition

The article discusses the structure of cyclic semirings with noncommutative addition. In the infinite case, the addition is idempotent and is either left or right. Addition of a finite cyclic semirings can be either idempotent or nonidempotent. In the finite additively idempotent cyclic semiring, addition is reduced to the addition of a cyclic subsemiring with commutative addition and an absorbing element for multiplication and the addition of a cycle that is a finite semifield.