调度问题中两类分离约束传播算法的比较及一种改进算法

约束传播算法是求解约束满足问题的一种重要方法。调度问题是一种特殊的约束满足问题。本介绍了调度问题中的Edge-Finding和Energy-Reasoning两种分离约束传播算法，并对它们进行了比较，中最后给出了一种结合Energy-Reasoning的Edge-Finding改进算法。     

一道平面解析几何问题的再探究

<正>《中学生数学》2020年10月上期登载一文"一道平面解析几何问题想到的",此文对圆锥曲线中动点在x轴问题做了一般化的推广.读后深受启发,对文中问题的实质做了进一步的探究,以供参考研究.     

圆锥曲线的一组有趣性质

文[1]、文[2]研究了圆锥曲线的弦对一些特殊定点张直角的问题，笔者最近对这一问题作了一些探究，得到了一组优美的结论，现介绍如下．     

带分布参数一阶系统的最佳控制问题

在[1]中对一阶柯娃律夫斯卡婭型方程组提出了若干类的最佳控制问题,并对一类特殊的线性方程作了一些探讨。本文拟对稍一般的线性方程另一类最佳控制问题作些研究,给出一种求解的方法。§1.问题的提出     

关于Steiner最小树问题

在本刊第二卷第二期上,我们曾发表了黄光明的《最短网络》一文,对Steiner最小树问题在当时的发展情况作了一些介绍。最近由于他与堵丁柱共同解决了Gilbert和Pallak在1968年所提出的一个猜想,不少读者对于这一问题产生了兴趣。为此,我们组写了这篇文章,目的在于使读者对这一问题的历史和连带产生的问题以及目前的发展状况有一较确切的和较全面的了解。     

不等式约束二次规划的一新算法

文献[1]提出了一般等式约束非线性规划问题一种求解途径．文献[2]应用这一途径给出了等式约束二次规划问题的一种算法，本文在文献[1]和[2]的基础上对不等式约束二次规划问题提出了一种新算法．     

用POT方法估计损失分布尾部的效应分析

在再保险中,对高超额层选取及定价等问题的讨论有着重要意义,从而引出对如何选取好的统计模型来拟合大的观测值这一问题的讨论。针对这一问题,我们考虑了POT方法(peaks over thoreholdapproach),即根据极值理论(EVT),用模拟的方法对这一方法进行评价,指出了POT方法的若干优缺点陷。     

分类问题的模糊决策分析

本文对群体决策中分类问题给出了一种新的有效算法:贴近度分析法。对贴近度概念做了修正,给出了一种一般表达式,并针对分类问题提出了对称贴近度和非对称贴近度概念。     

一维波动方程联合反演的分步正则化法

本文只用一个纵波信息,对一维波动方程的速度和震源函数进行联合反演.并考虑到波动方程的反问题是一不适定问题,对震源函数和波速分别用正则化法分步迭代求解,大大减少了反问题的计算工作量,改善了该反问题的计算稳定性.为计算实际一维地震数据提供了一种方法.文中给出了只用一个反问题补充条件同时进行多参数反演的详细公式,并对相应的数值算例进行了分析和比较.     

敏感性问题抽样调查的应用注记

本文对敏感性问题抽样调查在应用中发现的一些问题作了初步探索，考虑了同时调查多个敏感性问题时，用每个问题分别独立地随机化回答敏感性问题与之配对的另一问题的方法，此时估计每个敏感性问题的相关性，给出了极大似估估计及贝叶斯估计，另外，还考虑了用一次随机化回答几个敏感性问题或与之配对的另几个问题的情形。     

What is quasiconvex analysis?

We endeavour to answer the question of the title, or rather the question of how much one can extend convex analysis to a wider framework in which some convexity features remain. Subdifferential calculus and duality are the main directions we consider     

数量特征敏感性问题随机化回答的改进模型

研究数量特征敏感性问题的调查方法,设计了一种数量特征敏感性问题的随机化回答改进模型,计算了改进模型的估计量及其方差,并对改进模型进行了分析,得出改进模型具有较好的精度．     

Critical orbits of polynomials with a periodic point of specified multiplier

Mathematische Zeitschrift - Answering a question posed by Adam Epstein, we show that the collection of conjugacy classes of polynomials admitting a parabolic fixed point and at most one infinite...     

The Northwest corner rule revisited

Under which conditions can one permute the rows and columns in an instance of the transportation problem, such that the Northwest corner rule solves the resulting permuted instance to optimality? And under which conditions will the Northwest corner rule find the optimal solution for every possible permutation of the instance?We show that the first question touches the area of NP-completeness, and we answer the second question by a simple characterization of such instances.     

钻井布局模型

本文的关键思想是找出在变化中的不变量 .对于第一小题 ,作者发现可以把所有的点“移到”一个方格中 ,而它们相对网格结点的距离不变 ,这样问题就得到了大大的简化 .对于第二题 ,本文发现坐标变换时各点之间的欧氏距离不变 ,利用各点的距离关系 ,给出一系列的判定条件 ,最后用优化算法 (充要条件 )判定 .第二题的算法对于第三题也是通用的 ,因此第三题应用第二题的方法来解决     

亚纯函数的正规族

In this paper, we deal with the problem of normal families concerning share-values. The results extend and improve some theorems put forward by Miranda, Pang, Chen, Hua and Fang. Moreover, we answer one question posed by Gu, Pang, Fang and so on.     

The last temptation of William T. Tutte

In 1999, at one of his last public lectures, Tutte discussed a question he had considered since the times of the Four Color Conjecture. He asked whether the 4-coloring complex of a planar triangulation could have two components in which all colorings had the same parity. In this note we answer Tutte’s question contrary to his speculations by showing that there are triangulations of the plane whose coloring complexes have arbitrarily many even and odd components.     

An embedding theorem for affine resolvable designs

In this note, we consider a question raised by S.S. Shrikhande [6] concerning the embedding of an ARD with deficiency d into ARBIBD. We show that such an embedding is always possible if we assume that and in addition that there is one good class.     

Invariance property of proximity conditions in nonlinear subdivision

Proximity conditions are used extensively in the analysis of smoothness and approximation order properties of subdivision schemes for manifold-valued data. While these properties under question are independent of choice of coordinates on the manifold, it is not known whether the proximity condition itself is invariant under arbitrary change of coordinates. In this note, we answer this question to the affirmative, i.e. we prove that the proximity condition is satisfied in one coordinate system if and only if it is satisfied in any other coordinate system. In passing, we prove a connection between the general proximity condition and an alternate proximity condition used in the interpolatory case. This interpolatory proximity condition also enjoys the same invariance under change of coordinates.     

Is the inf-convolution of law-invariant preferences law-invariant?

We analyze the question of whether the inf-convolution of law-invariant risk functionals (preferences) is still law-invariant. In other words, we try to understand whether the representative economic agent (after risk redistribution) only cares about the distribution of the total risk, assuming all individual agents do so. Although the answer to the above question seems to be affirmative for many examples of commonly used risk functionals in the literature, the situation becomes delicate without assuming specific forms and properties of the individual functionals. We illustrate with examples the surprising fact that the answer to the main question is generally negative, even in an atomless probability space. Furthermore, we establish a few very weak conditions under which the answer becomes positive. These conditions do not require any specific forms or convexity of the risk functionals, and they are the richness of the underlying probability space, and monotonicity or continuity of one of the risk functionals. We provide several examples and counter-examples to discuss the subtlety of the question on law-invariance.