基于近似拓扑的近似闭包

粗糙集的拓扑研究具有意义,其中的近似拓扑具有对经典拓扑的双向逼近性.研究基于近似拓扑的近似闭包.定义近似开集确立近似拓扑,建立近似闭集.基于近似闭集,定义近似闭包获得基本性质,分析近似闭包与闭包、闭包近似集、近似集闭包的包含序关系.近似闭包深化了近似拓扑,实现了对经典闭包的逼近与扩张.     

合成信息系统与有限个子信息系统的近似算子研究

信息系统的合成和分解在实际应用中是一个很重要的问题。在文献[13]中讨论了两个信息系统的合成,本文给出了任意有限个对象合成信息系统和有限个属性合成信息系统的概念,分别讨论了它们的上下近似算子与有限个原子信息系统的上下近似算子之间的关系,并通过实例验证了该方法在计算近似算子时可以有效地减少运算时间。     

经典命题逻辑中的近似推理与强近似推理

基于命题逻辑公式之间相似度的概念,在经典命题逻辑系统中提出了两种近似推理模式,得到了它们的一些基本性质。讨论了这两种推理模式与经典推理模式之间的关系。此外,当理论Γ有限时,本文分别给出Γ在α程度上近似推出公式A和理论Σ的充要条件。最后,我们给出公式A与有限理论Γ的结论集D(Γ)之间距离的计算公式。     

关于近似极因子

易知这时H>0(表示H是正定矩阵),并且分解(1)中的Q与H是唯一确定的. 由于极分解在控制论与统计分析等领域中的应用,有关的计算方法与理论分析已经发展起来。 为了计算A的极因子Q与H,通常是先算出Q的近似解X,然后令     

两相可混溶驱动问题中近似压力方程的一种新方法

1　介　　绍ΩR2为凸多边形区域,Ω上的两相可混溶驱动问题可由以下微分方程系统来描述a)-.[a(x,c)(p-r(c)]=.u=q,b)φ(x)ct+u.c-(Dc)=(c-c)q=g(c),(1.1)其中a(x,c)=-k(x)μ(c),k(x)为介质的渗透率,μ(c)为流体的粘度,p为流体的压力,φ(x)为介质的孔隙度,c为一相流体的体积浓度,q为外部流体的体积流速,且满足相容性条件∫Ωqdx=0.D是2×2阶矩阵,D=φ(x)[dmI+|u|(dlE(u)+dtE⊥(u))],E(u)=(uiuj/|u|2)2×2,dm为分子扩散系数,dl,dt分别为横向、纵向弥散系数.系统的边界条件、初始条件:n为边界单位外法向a)u.n=0,(x,t)∈Ω×Jb)2i,j=1Dij(…     

The granular accuracy of approximation for the rough sets

自Pawlak提出粗糙集概念以来,人们一直对粗糙集的近似精度很有兴趣,出现了不少有关近似精度的文献.本文提出了粗糙集的粒度近似精度,讨论了粒度近似精度的性质,并与Pawlak近似精度和基于等价关系图过剩熵的近似精度进行了比较.比较发现粒度近似精度更具合理性.     

粗糙集理论介绍和研究综述

介绍粗糙集理论的基本原理,粗糙集理论中的知识表示以及目前粗糙集理论的研究状况。     

结合代数上的粗糙集

在结合代数上引入粗糙集的理论,给出了结合代数上基于理想的同余关系,研究了结合代数的子空间上下近似的若干粗糙集性质。     

近似凸集的某些性质

主要研究了两类近似凸集的关系和性质.首先,举例说明两类近似凸集没有相互包含关系.其次,在近似凸集(nearly convex)条件下,证明了在一定条件下函数上图是近似凸集与凸集的等价关系.同时,考虑了近似凸函数与函数上图是近似凸集的等价刻画、近似凸函数与函数水平集是近似凸集的必要性,并用例子说明近似凸函数与函数水平集是...     

近似邻近点算法收敛性的一个注记

近似邻近点算法在最优化理论与方法研究中具有重要作用.在不同误差准则下,近似邻近点算法具有不同的收敛性.利用极大单调算子等工具给出了一个具体的例子,解释了在一些误差准则下近似邻近点算法的收敛性.     

On Minty variational principle for nonsmooth vector optimization problems with generalized approximate convexity

In this paper, we consider a nonsmooth vector optimization problem involving locally Lipschitz generalized approximate convex functions and find some relations between approximate convexity and generalized approximate convexity. We establish relationships between vector variational inequalities and nonsmooth vector optimization problem using the generalized approximate convexity as a tool.     

Calculus rules for global approximate minima and applications to approximate subdifferential calculus

We provide calculus rules for global approximate minima concerning usual operations on functions. The formulas we obtain are then applied to approximate subdifferential calculus. In this way, new results are presented, for example on the approximate subdifferential of a deconvolution, or on the subdifferential of an upper envelope of convex functions.     

拟凸多目标优化问题近似解的最优性条件

研究了拟凸多目标优化问题近似弱有效解、近似有效解的最优性条件.首先,在已有拟凸函数次微分的基础上引进4种近似次微分的概念,并给出它们之间的关系.然后,将4种近似次微分的概念应用到拟凸多目标优化问题中,给出了拟凸多目标优化问题近似弱有效解和近似有效解的充分条件和必要条件,并给出实例加以说明.     

基于近似惯性流形的后验Galerkin的方法

１．引言 为提高用数值方法解非线性发展方程及非线性椭圆边值问题的逼近阶,许多学者例如Ｊ．Ｎｏｖｏ和 Ｅ．Ｔｉｔｉ［４］, Ｍａｒｉｏｎ和 Ｔｅｍａｎ［６］,Ｊ．Ｘｕ［７］以及 Ｗ．Ｌａｙｔｏｎ［９］等人,提出了后验Ｇａｌｅｒｋｉｎ方法、近似惯性流形方法、非线性Ｇａｌｅｒｋｉｎ方法、各种区域分裂法、多重网格法等等．本文根据［１］提出了一种新的高精度的后验 Ｇａｌｅｒｋｉｎ方法．它的逼近阶是经典 Ｇａｌｅｒｋｉｎ方法逼近阶的两倍． 考虑非线性椭圆边值问题这里ｎ是按ｄ＝２,３）上具有分段光滑边界ｒ的有界区域,…     

一维3×3非线性系统脉冲波的干扰

利用非线性几何光学的方法,讨论一维情形下3×3半线性偏微分方程具有两个初始脉冲波的干扰问题.证明方程组近似解的存在性,得到脉冲波的干扰出现在一阶项中.通过对近似解进行误差分析,得到精确解的一个好的近似.     

Obtaining exact value by approximate computations

Numerical approximate computations can solve large and complex problems fast.They have the advantage of high efficiency.However they only give approximate results,whereas we need exact results in some fields.There is a gap between approximate computations and exact results. In this paper,we build a bridge by which exact results can be obtained by numerical approximate computations.     

Quantitative Approximation to the Ordered Dirichlet Distribution under Varying Basic Probability Spaces

An approximate expansion of a sequence of ordered Dirichlet densities is given under the set-up with varying dimensions of the relating basic probability spaces. The problem is handled as the approximation to the joint distribution of an increasing number of selected order statistics based on the random sample drawn from the uniform distribution U(0, 1). Some inverse factorial series to the expansion of logarithmic function enable us to give quantitative error evaluations to our problem. With the help of them the relating modified K-L information number, which is defined on an approximate main domain and different from the usual ones, is accurately evaluated. Further, the proof of the approximate joint normality of the selected order statistics is more systematically presented than those given in existing works. Concerning the approximate normality the modified affinity and the half variation distance are also evaluated.     

Approximate duality of g-frames in Hilbert spaces

In this article, we introduce and characterize approximate duality for g-frames. We get some important properties and applications of approximate duals. We also obtain some new results in approximate duality of frames, and generalize some of the known results in approximate duality of frames to g-frames. We also get some results for fusion frames, and perturbation of approximately dual g-frames. We show that approximate duals are stable under small perturbations and they are useful for erasures and reconstruction.     

APPROXIMATE DUALITY OF g-FRAMES IN HILBERT SPACES

In this article, we introduce and characterize approximate duality for g-frames. We get some important properties and applications of approximate duals. We also obtain some new results in approximate duality of frames, and generalize some of the known results in approximate duality of frames to g-frames. We also get some results for fusion frames, and perturbation of approximately dual g-frames. We show that approximate duals are stable under small perturbations and they are useful for erasures and reconstruction.