L-模糊偏序集上的核算子与核系统

定义L-模糊偏序集上的L-核系统,给出了任一L-模糊偏序集上的L-核算子与L-核系统之间的一一对应关系,从而推广了有界完备L-模糊偏序集的情形,并使得模糊的情况与分明的情况更加协调。另外,也给出了L-闭包算子与L-闭包系统的相关结论。     

FS-偏序集和连续L-偏序集

引入了FS-偏序集和连续L-偏序集概念,探讨了FS-偏序集和连续L-偏序集的性质.主要结果有(1)每一FS-偏序集都是有限上集生成的,因而是Scott紧的;(2)证明了FS-偏序集(连续L-偏序集)的定向完备化是FS-偏序集(连续L-偏序集);(3)一个偏序集是一个FS-Domain当且仅当它为Lawson紧的FS-偏序集;(4)FS-偏序集(连续L-偏序集)去掉部分极大元后还是FS-偏序集(连续L-偏序集).     

L-余拓扑Vs.广义粗集

引入L-余覆盖广义粗集的概念,证明研究该广义粗集的上、下近似与研究L-余拓扑的余子基生成的闭包和内部是等价的,并且以此为基础,讨论该广义粗集的性质.     

定向闭包空间的若干性质

拓扑空间X称为定向闭包空间(简称DC空间),若它是T₀的，且其任一既约闭集都是某定向子集的闭包，此处X赋予特殊化序。本文讨论了定向闭包空间的一些基本性质，证明了偏序集赋予Alexandroof拓扑所得空间和其Smyth幂空间都是DC空间；偏序集赋予上拓扑是quasisober空间当且仅当它是DC空间；DC性对开子空间遗传，但对饱和子空间一般不遗传；对T₀空间X,其Smyth幂空间是DC空间一般不蕴含X是DC空间。     

逆半群半格上的自然偏序关系

首先讨论逆半群Sa的半上的自然偏序与各Sa上的自然偏序之间的关系，然后讨论逆半群Sa的半格S的幂等元集Ea的闭包限制在Sa上与Ea的闭包的关系．     

L-偏序集中L_k-素闭包算子和L_k-素内部算子

本文在完备剩余格上引入了L-偏序集,给出了L-偏序集上L_k-素闭包算子和L_k-素内部算子的概念及其等价刻画,在此基础上推广得出了n重L_k-素闭包算子和n重L_k-素内部算子的概念及其等价刻画。     

L-闭包空间的βc-紧性

在L-闭包空间中给出了βc-开集、La-βc-开覆盖的概念,引入了βc-紧集和βc-紧空间.证明它保持了L-拓扑空间中的主要结论:如闭遗传性、好的推广和弱拓扑不变性等好的性质.     

正整数集上的闭包函数

解答了P.C.Hammer于1960年提出的问题:设h是在正整数集M的幂集上以集乘积来定义的闭包函数,c是幂集上的补余函数,问可否在集M中找出子集A,使A在h与c的任意作用下,恰可衍生出14个不同的集合?并给出各种不同的例子.     

L-可定义集与L-粗糙概念格

对基于剩余格L的L-广形式背景引入了L-可定义集概念,研究L-可定义集的性质及其与L-粗糙概念之间的关系.培出L-广可定义集的刻画;得到常值L-案均为L-可定义集的若干等价条件;证明全体L-可定义集在L-集包含序下是相应L-幂集格及L-粗糙概念格的子完备格;给出全体L-可定义集恰为全体L-粗糙概念外延的一个充要条件.     

L-闭包空间的βc-连通性

在L-闭包空间中定义了βc-连通性和βc-连通空间的概念,并给出了其等价刻画,讨论了它的若干好的性质:弱拓扑不变性、L-好的推广等     

决策信息系统中的拓扑学方法

在决策信息系统中引入拓扑结构,借助拓扑学的基本概念(拓扑、内部和闭包等)研究决策问题,用它们刻画决策信息系统中的一些重要概念(决策协调集、决策约简集、下近似协调集、下近似约简集、上近似协调集、上近似约简集),并利用它们把这些重要概念推广到最一般的情况,建立起相应的约简理论.     

Quasi-concave functions on meet-semilattices

This paper deals with maximization of set functions defined as minimum values of monotone linkage functions. In previous research, it has been shown that such a set function can be maximized by a greedy type algorithm over a family of all subsets of a finite set. In this paper, we extend this finding to meet-semilattices.We show that the class of functions defined as minimum values of monotone linkage functions coincides with the class of quasi-concave set functions. Quasi-concave functions determine a chain of upper level sets each of which is a meet-semilattice. This structure allows development of a polynomial algorithm that finds a minimal set on which the value of a quasi-concave function is maximum. One of the critical steps of this algorithm is a set closure. Some examples of closure computation, in particular, a closure operator for convex geometries, are considered.     

An Extension Principle for Fuzzy Logics

Let S be a set, P(S) the class of all subsets of S and F(S) the class of all fuzzy subsets of S. In this paper an “extension principle” for closure operators and, in particular, for deduction systems is proposed and examined. Namely we propose a way to extend any closure operator J defined in P(S) into a fuzzy closure operator J* defined in F(S). This enables us to give the notion of canonical extension of a deduction system and to give interesting examples of fuzzy logics. In particular, the canonical extension of the classical propositional calculus is defined and it is showed its connection with possibility and necessity measures. Also, the canonical extension of first order logic enables us to extend some basic notions of programming logic, namely to define the fuzzy Herbrand models of a fuzzy program. Finally, we show that the extension principle enables us to obtain fuzzy logics related to fuzzy subalgebra theory and graded consequence relation theory. Mathematics Subject Classification : 03B52.     

Some classes of abstract simplicial complexes motivated by module theory

In this paper we analyze some classes of abstract simplicial complexes relying on algebraic models arising from module theory. To this regard, we consider a left-module on a unitary ring and find models of abstract complexes and related set operators having specific regularity properties, which are strictly interrelated to the algebraic properties of both the module and the ring.Next, taking inspiration from the aforementioned models, we carry out our analysis from modules to arbitrary sets. In such a more general perspective, we start with an abstract simplicial complex and an associated set operator. Endowing such a set operator with the corresponding properties obtained in our module instances, we investigate in detail and prove several properties of three subclasses of abstract complexes.More specifically, we provide uniformity conditions in relation to the cardinality of the maximal members of such classes. By means of the notion of OSS-bijection, we prove a correspondence theorem between a subclass of closure operators and one of the aforementioned families of abstract complexes, which is similar to the classic correspondence theorem between closure operators and Moore systems. Next, we show an extension property of a binary relation induced by set systems when they belong to one of the above families.Finally, we provide a representation result in terms of pairings between sets for one of the three classes of abstract simplicial complexes studied in this work.     

L-Fuzzy闭包算子的扩张原理

Ｆｕｚｚｙ闭包算子的扩张原理揭示了Ｆｕｚｚｙ闭包算子与经典闭包算子之间的密切关系,是利用传统学科已有结论研究Ｆｕｚｚｙ数学相关理论的有效工具。本文讨论了当Ｌ为有限分配格时,Ｌ－Ｆｕｚｚｙ闭包算子与闭包系统的扩张问题,并给出一种具体的由经典闭包算子生成Ｌ－Ｆｕｚｚｙ闭包算子的方法及其部分性质。     

Fuzzifying闭包系统的研究

在Fuzzifying(模糊化)数学的框架下,建立了Fuzzifying闭包系统和Birkhoff型Fuzzifying闭包算子的概念; 引入了Fuzzifying闭包空间范畴和Fuzzifying闭包系统空间范畴,并从范畴论的角度证明Birkhoff型Fuzzifying闭包算子与Fuzzifying闭包系统是协调的.最后文中还得到Fuzzifying闭包空间范畴和Fuzzifying闭包系统空间范畴可以嵌入到Birkhoff型L-闭包空间范畴这一重要结果.     

Degree conditions on induced claws

We introduce a closure concept for a superclass of the class of claw-free graphs defined by a degree condition on end vertices of induced claws. We show that the closure of a graph is the line graph of a triangle-free graph, and that the closure operation preserves the length of a longest path and cycle. These results extend the closure concept for claw-free graphs introduced by Ryjá?ek.     

指数多项式在半带形中的闭包

该文对一类复指数多项式组成的线性空间$M(\Lambda )$ 在Banach 空间 H_α中的不完备性给出了充分必要条件, 其中 H_α为在半带形 I_α={z=x+iy: x≥ 0, |y|≤α} (α > 0 )中连续, 在I_α的内部解析且当 x→∞时, f(x+ iy)在I_α中关于 y 一致地 趋向 0 的函数 f(x+ iy)全体, 其范数为上确界范数. 同时指出, 如果$M(\Lambda )$ 在 H_α中不完备, 则它的闭包cl$(M(\Lambda ))$中所有的函数都可以延拓为由Dirichlet级数表示的解析函数.     

The closure of the set of roots of strongly connected reliability polynomials is the entire complex plane

The strongly connected reliabilityscRel(D,p) of a digraph D is the probability that the spanning subgraph of D consisting of the operational arcs is strongly connected, given that the vertices always operate, but each arc is independently operational with probability p∈[0,1]. We show that the closure of the set of roots of strongly connected reliability polynomials is the whole complex plane.     

Conditional independence structure and its closure: Inferential rules and algorithms

In this paper, we deal with conditional independence models closed with respect to graphoid properties. Such models come from different uncertainty measures, in particular in a probabilistic setting. We study some inferential rules and describe methods and algorithms to compute efficiently the closure of a set of conditional independence statements.