一种改进的Heaviside函数与Dirac函数的C-V图像分割研究

C-V模型中Heaviside函数和Dirac函数正则化逼近影响对目标图像的分割,根据Heaviside函数和Dirac函数的性质,提出了新的正则化Heaviside函数和Dirac函数.首先分析了C-V模型中正则化的Heaviside函数和Dirac函数在图像分割中所起的作用,在此基础上提出了新的正则化的Heaviside函数和Dirac函数,改进了C-V模型.实验结果表明,运用正则化的Heaviside函数和Dirac函数的图像分割效果较好.     

分段函数的分类及分离型分段函数与初等函数之间的关系

将分段函数划分为连结型分段函数 ,分离型分段函数和它们的组合形式三种类型 ,得到了分离型分段函数是初等函数的充分必要条件 ,完整地解决了分离型分段函数与初等函数之间的关系 ,并且给出了初等函数在其任一截取集上的限制函数 (截取函数 )仍然是初等函数的结果     

绝对值函数的一致光滑逼近函数

绝对值函数是一个非光滑函数,研究了绝对值函数的光滑逼近函数.给出了绝对值函数的上方一致光滑逼近函数和下方一致光滑逼近函数,分别研究了其性质,并通过图像展示了逼近效果.     

例谈函数定义域对研究函数性质的影响

函数是高中阶段的重点内容．函数的定义域、解析式和值域统称为函数的三要素,其中定义域和解析式决定了函数的值域．许多同学在学习函数时总是比较重视函数的解析式,忽略函数的定义域,从而造成很多错解．实际上,函数的定义域改变了,函数也就改变了,它是函数不可忽视的重要组成部分,下面举例说明．     

工程项目施工状态诊断模型

文章提出了工程项目施工的投资状态函数、进度状态函数、质量状态函数和环境状态函数，并以状态函数为基础，建立了项目施工状态诊断模型。文章给出各层次中的状态函数，理出了施工状态量化诊断的思路，对各层次中状态诊断函数的描述作了探索。     

Walsh函数的一种新定义及快速算法设计

传统的Walsh函数是以Rademacher函数为基函数生成 .本文运用对称复制的观点 ,定义了一种新函数 G函数 ,并以G函数为基础 ,定义了四种序的Walsh函数 ,同时 ,运用序码分析方法 ,实现了两种序Walsh变换的快速算法设计 .     

P-可测函数的构造性质

可测函数的构造性质是定义它关于测度μ的积分的理论基础.为了在P-测度空间上定义P-积分,借鉴可测函数的构造性质,引入了P-示性函数、P-简单函数、P-初等函数以及P-可测函数的概念,在此基础上系统地研究了P-实可测函数、有界P-实可测函数和非负P-可测函数与P-简单函数序列及P-初等函数序列的收敛关系;找出了P-实可测的充分必要条件;证明了实P-可测函数正部和负部都是非负P-实可测函数,最终得出任何P-实可测函数均可以表示为二非负P-可测函数之差,为定义P-积分提供了理论依据.     

亚纯函数多项式与其导函数分担小函数的唯一性

利用Nevanlinna理论与多项式加权和的概念研究了一类亚纯函数多项式与其导函数分担小函数的唯一性.在分担小函数的条件下,得到了亚纯函数的特征函数与计数函数之间的一个不等式,并研究了亚纯函数多项式与其k阶导数分担小函数的唯一性问题,所得到的定理补充,改进与推广了一些已有的结果.     

巧用单调性妙解竞赛题

函数的单调性是函数的重要性质,掌握了一个函数的单调性就意味着我们从总体上把握了函数的变化趋势,函数的单调性是画函数图象求函数极值、最值的重要依据．有些数学问题特别是数学竞赛题,若能自觉运用函数思想构造函数,     

一道大学生数学竞赛题的联想

通过对一个正弦函数不等式的类比,给出了余弦函数、正切函数、双曲正弦函数、双曲余弦函数、反正弦函数、反双曲正弦函数的不等式.     

Toposes for semigroups: an invitation

This is an expository paper in which we explain the basic ideas of topos theory in connection with semigroup theory. We focus mainly on the classifying topos of an inverse semigroup or pseudogroup, and to some extent on creating a dictionary between the language of semigroups and topos theory. We begin with the algebraic theory having to do with inverse semigroups, and then turn to an analysis of pseudogroups using sheaf theory. Our work includes some new material on wide semigroup homomorphisms and their geometric morphisms.

     

On equivalency of martingales and related problems

We study some almost everywhere convergence problems for martingales. We establish various equivalency theorems, which show that in some problems of martingales theory the general martingales can be replaced by Haar martingales. Some applications of the obtained results to the theory of differentiation of integrals and convergence of Riemann sums are also discussed.     

Conformal field theory and elliptic cohomology

In this paper, we use conformal field theory to construct a generalized cohomology theory which has some properties of elliptic cohomology theory which was some properties of elliptic cohomology. A part of our presentation is a rigorous definition of conformal field theory following Segal's axioms, and some examples, such as lattice theories associated with a unimodular even lattice. We also include certain examples and formulate conjectures on modular forms and Monstrous Moonshine related to the present work.     

Pseudocomplementation and minimal prime ideals in semirings

In Section 2 of the present paper, we introduce the concept of pseudocomplementation for semirings and show the semiring version of some known results in lattice theory. We also introduce semirings with pc-functions and prove some interesting results for minimal prime ideals of such semirings. In Section 3, some classical results for minimal prime ideals in ring theory are generalized in the context of semiring theory.     

From Riemann and Kodaira to Modern Developments on Complex Manifolds

We survey the theory of complex manifolds that are related to Riemann surface, Hodge theory, Chern class, Kodaira embedding and Hirzebruch–Riemann–Roch, and some modern development of uniformization theorems, Kähler–Einstein metric and the theory of Donaldson–Uhlenbeck–Yau on Hermitian Yang–Mills connections. We emphasize mathematical ideas related to physics. At the end, we identify possible future research directions and raise some important open questions.     

Asymptotic linearity of the mapping class group and a homological version of the Nielsen–Thurston classification

We study the action of the mapping class group on the integral homology of finite covers of a topological surface. We use the homological representation of the mapping class to construct a faithful infinite-dimensional representation of the mapping class group. We show that this representation detects the Nielsen–Thurston classification of each mapping class. We then discuss some examples that occur in the theory of braid groups and develop an analogous theory for automorphisms of free groups. We close with some open problems.     

A retrospective view of fuzzy control systems

One of the most active areas for the application of fuzzy set theory has been in process control. We trace the development of this research, from the first papers by Zadeh to current efforts in both theory and practice. We review some themes that appear in this corpus and suggest some directions for future work. In particular, we suggest that by adopting some concepts from artificial intelligence, existing approaches to fuzzy control system design could be significantly enhanced.     

Elliptic system with some singular nonlinearity

We investigate multiplicity of solutions for elliptic systems with singular non-linearities. We obtain a theorem which shows that elliptic systems with some singular non-linearities have infinitely many solutions. We get this result by using the variational method, critical point theory and homology theory.     

Several Jordan-algebraic aspects of optimization†

We describe some concepts from the theory of Euclidean Jordan algebras and their use in optimization theory. This includes: primal-dual algorithms, optimality conditions, convexity of spectral functions, proof of some inequalities and a Jordan-algebraic version of Horn–Schur theorem     

Dimension of compact metric spaces

We give a survey of old and new results in dimension theory of compact metric spaces. Most of the relatively new results presented in the survey are based on the cohomological dimension approach. We complement the survey by stating the basics of cohomological dimension theory and listing some of its applications beyond the dimension theory.