条件概率中的“条件”与事件发生的“条件”的关系剖析

在解答条件概率问题的过程中,厘清条件概率中的“条件”与事件发生的“条件”是关键一环,解题者往往对条件概率中的“条件”与事件发生的“条件”之间的关系分析不到位,认识不明晰,导致问题的关系不清,解答产生意想不到的错误．下文对条件概率中的“条件”与事件发生的“条件”的常见关系举例剖析,供读者参考．     

隐含条件:审题教学的一项重要任务

数学问题的条件,一般有显性条件和隐含条件之分.所谓显性条件,就是文本或图形直接给予的条件,这类条件一读就能发现;而隐含条件则隐藏于题目的文本与图形之中,需要对题中的已知条件进行深度解读、开发,才能发现.直观、明显是显性条件的特点,所以对这类条件的教学往往是教师审题教学的主要内容.而隐含条件的内隐性往往使其在审题教学中被边缘化,成为陪衬,这样的审题教学生态显然是失衡的.笔者认为,审题教学不仅要重视显性条件分析,还应关注隐含条件的剖析,要将其放在培养和发展学生审题能力的高度上加以     

有限Boole语义中公式的条件随机真度

基于条件概率的思想,利用赋值集的随机化方法,在有限Boole语义中引入公式的条件随机真度,证明了条件随机真度的MP规则和HS规则。引入公式间的条件相似度和条件伪距离,建立了条件随机逻辑度量空间,证明了条件随机逻辑度量空间中逻辑运算的连续性,并初步研究了给定条件下的近似推理理论。     

n值G?del命题逻辑系统中公式的条件随机真度

基于条件概率的思想,利用赋值集的随机化方法,在n值命题G(o|¨)del逻辑系统中引入公式的条件随机真度,证明了条件随机真度的MP规则和HS规则.引入公式间的条件随机相似度和条件伪距离,建立了条件随机逻辑度量空间,证明了条件随机逻辑度量空间中二元运算的连续性.     

条件加序设计的性质与数据分析

条件加序设计在试验中应用广泛,但对于条件加序设计的研究却很少.本文定义了条件加序设计的成对有序因子条件主效应,研究了成对有序因子条件主效应的正交性,提出了条件加序模型.最后利用实例说明其数据分析方法.     

已有降维方法的推广

SAVE,PHD和SIRⅡ已被证明是有效的降维方法,这些方法基于下面的两个假设1线性条件和常数方差条件.但是,常数方差条件非常强.当常数方差不成立时,即使线性条件成立,SAVE,PHD和SIRⅡ经常会找到中心空间之外的方向.通过去掉了常数方差条件,在较弱条件下推广了SAVE,PHD和SIRⅡ从而使得在较弱的条件下,能得到中心空间的正确估计.     

条件独立性与条件回归独立性

引入随机变量条件独立、强条件回归独立、逐对条件回归独立、连续条件回归独立、邻对条件回归独立、累积条件回归独立诸定义,证明它们之间的等价关系.     

非全局Lipschitz条件下随机延迟微分方程Euler方法的收敛性

大多数随机延迟微分方程数值解的结果是在全局Lipschitz条件下获得的.许多延迟方程不满足全局Lipschitz条件,研究非全局Lipschitz条件下的数值解的性质,具有重要的意义.本文证明了漂移系数满足单边Lipschitz条件和多项式增长条件,扩散系数满足全局Lipschitz条件的一类随机延迟微分方程的Eul...     

关于一类二层规划问题的一阶最优性条件研究

本文针对一类具有特定结构的二层规划问题, 将下层问题用其KKT条件代替, 把二层规划问题转化成带有互补约束的单层优化问题.然后利用Fritz-John条件,在适当的条件下,得到了二层优化问题的一阶最优性条件.本文所给条件简单、容易验证,并且不同于[1]的条件.     

注意挖掘隐含条件

有些数学题目中,常有一些条件隐含在题意中没有明确给出,这些条件就是所谓的隐含条件,而利用好这些隐含条件,可以简捷地解题,下面通过几个例子加以说明.     

Matrix representations of Sturm‐Liouville problems with coupled eigenparameter‐dependent boundary conditions and transmission conditions

We study matrix representations of Sturm‐Liouville problems with coupled eigenparameter‐dependent boundary conditions and transmission conditions. Meanwhile, given any matrix eigenvalue problem with coupled eigenparameter‐dependent boundary conditions and transmission conditions, we construct a class of Sturm‐Liouville problems with given boundary conditions and transmission conditions such that they have the same eigenvalues.     

Partial uniform boundedness of solutions of systems of differential equations with partly controlled initial conditions

We introduce the notion of partial uniform boundedness of solutions with partially controlled initial conditions in the general case, that is, the case in which the part of variables with respect to which the boundedness of solutions is studied is a subset of the part of variables with respect to which the initial conditions are controlled. We obtain a criterion for the partial uniform boundedness of solutions with partly controlled initial conditions. We introduce the notion of partial total boundedness of solutions with partly controlled initial conditions. We obtain a sufficient condition for the partial total boundedness of solutions with partly controlled initial conditions.     

On a nonclassical interpretation of the dirichlet problem for a fourth-order pseudoparabolic equation

For a fourth-order pseudoparabolic equation with nonsmooth coefficients in a rectangular domain, we consider the Dirichlet problem with nonclassical conditions that do not require matching conditions. We justify the equivalence of these conditions and the classical boundary conditions for the case in which the solution of the problem is sought in a Sobolev space.     

Well-posedness of a problem with initial conditions for hyperbolic differential-difference equations with shifts in the time argument

We study a problem with initial conditions on the half-line for a differentialdifference equation of the hyperbolic type with deviations of the time argument. We obtain sufficient conditions for the well-posed solvability of the problem in Sobolev spaces with an exponential weight. In terms of the spectrum of the problem operator, we obtain necessary conditions for the well-posed solvability of the problem, sufficient conditions for the absence of solutions, and sufficient conditions for the nonuniqueness of the solution.     

带随机初值的随机偏微分方程整体解的存在性

研究了一类带随机初值并且由分数次Brownian运动驱动的随机偏微分方程.借助于Kolmogorov准则,建立了整体Lipschitz条件下此类随机偏微分方程的一个解.同时证明了局部Lipschitz条件下整体解的存在性.     

Immersed Interface Finite Element Methods for Elasticity Interface Problems with Non-Homogeneous Jump Conditions

<正>In this paper,a class of new immersed interface finite element methods (IIFEM) is developed to solve elasticity interface problems with homogeneous and non-homogeneous jump conditions in two dimensions.Simple non-body-fitted meshes are used.For homogeneous jump conditions,both non-conforming and conforming basis functions are constructed in such a way that they satisfy the natural jump conditions. For non-homogeneous jump conditions,a pair of functions that satisfy the same non-homogeneous jump conditions are constructed using a level-set representation of the interface.With such a pair of functions,the discontinuities across the interface in the solution and flux are removed;and an equivalent elasticity interface problem with homogeneous jump conditions is formulated.Numerical examples are presented to demonstrate that such methods have second order convergence.     

集值优化问题的高阶最优性条件(借助Studniarski导数)(英文)

本文研究的是约束集值优化问题的高价最优性条件.首先通过借助集值映射的Stud-niarski导数和严格局部有效性,讨论了集值优化问题的高阶必要条件和充分条件.对于充分条件,初始空间必须是有限维的.其次在初始空间和目标空间是有限维的以及集值映射是m阶稳定的条件下,也得到了此约束集值优化问题的高阶最优性条件.     

On the possible dimensions of subspace intersections

A problem concerning the dimensions of the intersections of a subspace in the direct sum of a finite number of the finite-dimensional vector spaces with the pairwise sums of direct summands, provided that the subspace intersection with these direct summands is zero has been discussed. The problem is naturally divided into two ones, namely, the existence and representability of the corresponding matroid. Necessary and sufficient conditions of the existence of a matroid with the specified ranks of some subsets of the base set have been given. Using these conditions, necessary conditions of the existence of a matroid with a base set composed of a finite series of pairwise disjoint sets of the full rank and the given ranks of their pairwise unions have been presented. A simple graphical representation of the latter conditions has also been considered. These conditions are also necessary for the subspace to exist. At the end of the paper, a conjecture that these conditions are sufficient has also been stated.     

Generalized impedance boundary conditions for the maxwell equations as singular perturbations problems

In this paper the Maxwell equations in an exterior domain with generalaized impedance boundary conditions of Engquist-Nédélec are considered. The particular form of the assumed boundary conditions can be considered to be a singular perturbation of the Dirichlet boundary conditions. The convergence of the solution of the Maxwell equations with these generalized impedance boundary conditions to that of the corresponding Dirichlet problem is proven. The proof uses a new integral equations method combined with results dealing with singular perturbation problems of a class of pseudo-differential operators.     

Generalized Farkas' theorem and optimization of infinitely constrained problems

This note is concerned with the generalization of Farkas' theorem of the alternative and its application to derive the necessary optimality conditions for min-max problems with satisfaction conditions. Farkas' theorem is generalized to a system of linear inequalities with max operations. The problems studied require a solution at which the worst objective value attains its minimum over a set of solutions fulfilling satisfaction conditions. The satisfaction conditions claim that plural performance criteria should be kept below the permissible level, whatever disturbances may happen or whatever opponents' decisions may be taken. We present a generalized Farkas' theorem in order to derive the necessary optimality conditions for the problems of this class.