Some results on projection of planar sets

In this paper we define certain types of projections of planar sets and study some properties of such projections.     

一个命题的多种证明

在解答某文献中的一个问题的过程中,得到了一个命题.用不同的方法给出了该名题的多种证明.     

Local set theory

In 1945, Eilenberg and MacLane introduced the new mathematical notion of category. Unfortunately, from the very beginning, category theory did not fit into the framework of either Zermelo—Fraenkel set theory or even von Neumann—Bernays—Gödel set-class theory. For this reason, in 1959, MacLane posed the general problem of constructing a new, more flexible, axiomatic set theory which would be an adequate logical basis for the whole of naïve category theory. In this paper, we give axiomatic foundations for local set theory. This theory might be one of the possible solutions of the MacLane problem.Translated from Matematicheskie Zametki, vol. 77, no. 2, 2005, pp. 194–212.Original Russian Text Copyright © 2005 by V. K. Zakharov.This revised version was published online in April 2005 with a corrected issue number.     

REGULARITY OF ENTROPY SOLUTIONS TO NONCONVEX SCALAR CONSERVATION LAWS WITH MONOTONE INITIAL DATA

We prove that for a given strictly increasing initial datum in Ck, the solution of the initial value problem is piecewise Ck smooth except for flux functions of nonconvex conservation laws in a certain subset of C^k＋1 of first category, defined in the range of the initial datum.     

Not every -set is perfectly meager in the transitive sense

We prove the following theorems:

1.

It is consistent with ZFC that there exists a - set which is not perfectly meager in the transitive sense.

2.

Every set which is perfectly meager in the transitive sense has the property.

3.

The product of two sets perfectly meager in the transitive sense has also that property.

     

Borsuk''''s Problem in a Special Normed Space

Borsuk's problem is a famous problem in combinatorial geometry. It deals with the problem of partitioning a set into parts of smaller diameter. The problem was posed by the well-known Polish mathematician K. Borsuk in 1933. Many results have been obtained since then. In this paper, we discuss the Borsuk's problem in the     

Geometric Realisations of Cubical Sets with Connections, and Classifying Spaces of Categories

We investigate the category of cubical sets with some additional degeneracies called connections. We prove that the realisation of a cubical set with connections is independent, up to homotopy, of whether we collapse those extra degeneracies or not and that any cubical set which is Kan admits connections. Using this type of cubical sets we define the cubical classifying space of a category and prove that this is equivalent to the simplicial one.     

限制性集合矩阵的计数公式

In this paper, we consider the counting problem of matrix of set (Aij)k×n which satisfies k∪i=1 n∪j=1 Aij={a1,a2,…,am} and other conditions, and obtain some computational formulas which extend all the results in [1].     

Strongly meager sets and their uniformly continuous images

We prove the following theorems:

(1) Suppose that is a continuous function and is a Sierpinski set. Then

(A)

for any strongly measure zero set , the image is an -set,

(B)

is a perfectly meager set in the transitive sense.

(2) Every strongly meager set is completely Ramsey null.

     

模糊集范畴及集合范畴上的模

本文构造了在完备格上模糊集范畴.利用极小扩展原则和范畴的性质,获得了函子Uα构成集合范畴上的模结构,推广了P.Eklund的结论.     

Hybrid Approach for Solving Multiple-Objective Linear Programs in Outcome Space

Various difficulties arise in using decision set-based vector maximization methods to solve a multiple-objective linear programming problem (MOLP). Motivated by these difficulties, some researchers in recent years have begun to develop tools for analyzing and solving problem (MOLP) in outcome space, rather than in decision space. In this article, we present and validate a new hybrid vector maximization approach for solving problem (MOLP) in outcome space. The approach systematically integrates a simplicial partitioning technique into an outer approximation procedure to yield an algorithm that generates the set of all efficient extreme points in the outcome set of problem (MOLP) in a finite number of iterations. Some key potential practical and computational advantages of the approach are indicated.     

广义区间空间中参数型非紧KKM定理及其在经济平衡问题上的应用

在不具线性结构的拓扑空间———广义区间空间———中证明了集值映像参数型非紧的 KKM定理,用本文结果研究了极大极小问题和拓扑型广义经济Shafer Sonneischein平衡存在问题.     

填充Jnlia集与Mandelbrot集的面积与直径

本文用单叶函数中的面积定理及Ｇａｒａｂｅｄｉａｎ－Ｓｃｈｉｆｆｅｒ不等式的有关推论．给出了求多项式的填充Ｊｕｌｉａ集及Ｍａｎｄｅｌｂｒｏｔ集面积的方法及直径的上界估计，从而给Ａ．Ｄｏｕａｄｙ所提的有关问题一个回答．     

一类非单调二阶锥互补问题解集的非空性与有界性

本文在二阶锥上引入一类新的映射,称之为笛卡尔P_*(κ)映射,它是单调映射的推广.文中讨论涉及这类映射的二阶锥互补问题的解的存在性和解集的有界性.主要结论为:如果所考虑的互补问题是严格可行的,那么它的解集是非空有界的.     

一类覆盖问题的组合学分析

从组合学的角度研究了一类随机选取集合中元素的覆盖问题,得到了重复性地、随机独立地、等概地选取某个有限集合中的元素,不遗漏地取遍所有元素所需的次数的期望,给出了理论和实验的数据结果.并且分析了该问题在现实世界中的一些实例.而且对于该问题的扩展模型—每次抽取集合中t个不同元素—进行了一些探讨.     

Group of Self-Equivalences of Sum Object

In general category, the group of self-equivalences of sum object can decompose as the product of its two subgroups under certain conditions and also several split short exact sequences are obtained. Subsequently, we apply the above results to the category of space under a space and get some results which are dual to those in fibrewise category.     

关于余极限范畴(英文)

本文研究了余极限范畴.利用余完备Abel范畴的定义,证明了余完备Abel范畴A的余极限范畴Acl是余完备的Abel范畴,并得到一类等价于模范畴的余极限范畴,从而推广了文献[9]中的一些结果.     

Category and dimensions for cut-out sets

In this paper, we study the modified box dimensions of cut-out sets that belong to a positive, nonincreasing and summable sequence. Noting that the family of such sets is a compact metric space under the Hausdorff metric, we prove that the lower modified box dimension equals zero and the upper modified box dimension equals the upper box dimension for almost all cut-out set in the sense of Baire category.     

Meromorphic Functions That Share Three Sets

In this paper we study the problem of meromorphic functions sharing three sets and obtain some theorems which are the extension and complement of some known relative results given by Yi Hongxun and others.     

非光滑多目标规划的最优性

本文给出了一种新的右上导数定义,利用这一右上导数定义了几类广义凸性条件,进而讨论了非光滑多目标规划的最优性．包括Ｆｒｉｔｚ－Ｊｏｈｎ条件和Ｋｕｈｎ－Ｔｕｃｋｅｒ条件．