直接最优化方法的收敛性与不动点

最优化方法中的直接法是仅仅利用目标函数值(或者通过试验结果)的信息,试图去寻求最优解.直接法迭代步骤简单,特别当目标函数的解析表达式十分复杂,甚至写不出来时,那些要求计算目标函数的偏导数的方法(称为解析方法)就无能为力了.然而,多因     

图论与矩形对角线法在钻井布局优化设计中的应用

本对钻井布局问题的研究,首先给出图论模型对问题1得出最多可利用4口旧井,井号为2、4、5、10。利用矩形对角线法对问题2得出最多可利用6口旧井,井号为1、6、7、8、9、11。同时利用矩形对角线法给出判定这些井均可利用的条件和算法。     

二维非线性对流扩散方程的非振荡特征差分方法

１．引言 近十几年来,双曲守恒律问题的高分辨率格式已取得很大发展,具有局部自适应选取节点的非振荡插值算法（如 ＵＮＯ［１］, ＥＮＯ［２］等）在这些格式的构造中起着重要的作用．特征差分法是求解对流扩散问题的一种较为有效方法,但在求解具有陡峭前线问题时,也会产生非物理振荡阻（见４）．本文将把特征差分法与非振荡插值算法相结合构造对流扩散问题的高分辨率差分格式． ［１］中的 ＵＮＯ及［２］中的 ＥＮＯ插值都是一维的,有关讨论二维 ＵＮＯ及ＥＮＯ插值的文章还不多见,本文将构造二维基于六节点的二次非振荡插值以及…     

应用功的互等定理法求立方体的位移解

本文推广功的互等定理法于求解弹性力学空间问题.首先,我们给出作为基本系统的六面固定的立方体的基本解,然后在受单位集中载荷作用的基本系统与已知表面位移的实际系统之间应用功的互等定理,从而求得实际系统的位移解.     

SOLVING COLORED YANG-BAXTER EQUATION BY WU＇S METHOD

In this article, we discuss nonsymmetric solutions of the colored Yang-Baxter equation dependent on spectral as well as colored parameters and give all seven-vertex solutions by Wu＇s method. It is also proved that the solutions are composed of six groups of basic solutions up to five solution transformations. Moreover, al l solutions can be classified into two categories called Baxter type and free-fermion type.     

牛顿迭代法与几种改进格式的效率指数

研究牛顿迭代、牛顿弦截法以及它们的六种改进格式的计算效率,计算了它们的效率指数,得到牛顿迭代、改进牛顿法、弦截法和改进弦截法(即所谓牛顿迭代的P.C格式)、二次插值迭代格式、推广的牛顿迭代法、调和平均牛顿法和中点牛顿法的效率指数分别为0.347/n、0.3662/n、0.4812/n、0.4812/n、0.347/n、0.3662/n、0.3662/n、0.3662/n.我们的结果显示,利用抛物插值多项式推出的迭代格式和改进弦截法并没有真正提高迭代的计算效率.此外,我们还证明了改进弦截法与牛顿弦截法等价,并利用这一结论给出了改进弦截法收敛阶为2.618的一个简化证明.     

(19, 9, 4) Hadamard designs and their residual designs

In this paper we study (19, 9, 4) Hadamard designs and their residual designs. We prove that there are precisely six non-isomorphic solutions of (19, 9, 4) designs and that these six designs give rise to in all twenty-one mutually non-isomorphic residual designs.     

基于主客观信息综合判断的非线性拉开档次法

针对以最大程度的拉开被评价对象间差异的综合评价问题,通过分析线性拉开档次法存在的局限性,本文提出了一种基于主客观信息综合判断的非线性拉开档次法,旨在进一步丰富和完善拉开档次法的理论知识。首先对线性拉开档次法进行简单的介绍,并分析了线性拉开档次法的局限性;然后提出前提假设,给出非线性因子选取的原则以及确定指标序关系的方法,并给出排序后相邻指标重要程度比值的选取方法,根据评价原则利用规划模型求解各评价指标的权重系数,利用求得的指标权重采用非线性集结模型计算最终的评价结果;最后用一个算例验证了方法的有效性。     

Convex central configurations for the n-body problem

We give a simple proof of a classical result of MacMillan and Bartky (Trans. Amer. Math. Soc. 34 (1932) 838) which states that, for any four positive masses and any assigned order, there is a convex planar central configuration. Moreover, we show that the central configurations we find correspond to local minima of the potential function with fixed moment of inertia. This allows us to show that there are at least six local minimum central configurations for the planar four-body problem. We also show that for any assigned order of five masses, there is at least one convex spatial central configuration of local minimum type. Our method also applies to some other cases.     

三次系统存在一类双纽线分界线环充要条件

给出了中心对称三次系统存在一类双纽线分界线环的充要条件，并举出此系统至少还存在四个极限环的（2．2）分布的例子．还举出了中心对称三次系统至少存在六个极限环作（3.3）分布以及五个极限环，其中一个极限环包围作（2．2）分布的四个极限环的例子．     

On the boomerang uniformity of permutations of low Carlitz rank

Finding permutation polynomials with low differential and boomerang uniformity is an important topic in S-box designs of many block ciphers. For example, AES chooses the inverse function as its S-box, which is differentially 4-uniform and boomerang 6-uniform. Also there has been considerable research on many non-quadratic permutations which are modifications of the inverse function. In this paper, we give a novel approach which shows that plenty of existing modifications of the inverse function are in fact affine equivalent to permutations of low Carlitz rank, and those modifications cannot be APN. We also present the complete list of permutations of Carlitz rank 3 having the boomerang uniformity six, and give the complete classification of the differential uniformities of permutations of Carlitz rank 3. As an application, we provide all the involutions of Carlitz rank 3 having the boomerang uniformity six.     

THREE KIRCHHOFFIAN INDICES OF THE CACTUS GRAPHS

In this paper we give six explicit formulae to compute the Kirchhoff index,the multiplicative degree-Kirchhoff index and the additive degree-Kirchhoff index of the k-cactus chain and the cactus graph which can be obtained from a k-cactus chain by expanding each of the cut-vertices to a cut edge.     

Determinants and Algebraic Identities Associated with the Root Systems of Classical Lie Algebras

Burnside asked questions about periodic groups in his influential paper of 1902. The study of groups with exponent six is a special case of the study of the Burnside questions on which there has been significant progress. It has contributed a number of worthwhile aspects to the theory of groups and in particular to computation related to groups. Finitely generated groups with exponent six are finite. We investigate the nature of relations required to provide proofs of finiteness for some groups with exponent six. We give upper and lower bounds for the number of sixth powers needed to define the largest 2-generator group with exponent six. We solve related questions about other groups with exponent six using substantial computations which we explain.     

网络服务中非线性多重两阶段定价策略

本文在基于流量的定价策略基础上,结合非线性定价方法给出了一种多重两阶段定价模型,并结合原单一定价策略构造混合定价,通过分析生产者剩余和消费者剩余,推出该模型存在帕累托改进并给出了具体的改进方法。     

美式期权隐含波动率校准问题的研究

研究的是美式期权的隐含波动率校准问题.首先提出一个正则化的最小二乘方法,在对其惩罚问题研究后找到最小二乘问题的最优条件,并给出美式期权波动率校准问题的算法.最后,通过数值算例说明了方法的有效性.     

On the Coordinate of a Singular Point of the Time Correlation Function for a Spin System on a Simple Hypercubic Lattice at High Temperatures

Using the d ^–1 expansion method (d is the space dimension), we estimate the coordinate of the time-dependent autocorrelation function singular point on the imaginary time axis for the spin 1/2 Heisenberg model on a simple hypercubic lattice at high temperatures. We represent the coefficients of the time expansion (the spectral moments) for the autocorrelation function as the sums of the weighted lattice figures in which the trees constructed from the double bonds give the leading contributions with respect to d ^–1 and the same trees with the built-in squares from six bonds or diagrams with the fourfold bonds give the contribution of the next-to-leading order. We find the corrections to the coordinate of the autocorrelation function singular point that are due to the latter contributions.     

A bibliography of ATM related papers

In this paper, we give a list of ATM related papers. This is not a complete list. Rather, it represents the bulk of the references in this ever-growing area. For easier use of this reference list, we have classified the papers into the following six categories: general, source characterization, switching, congestion control, routing, and transport.     

Globalizing a nonsmooth Newton method via nonmonotone path search

We give a framework for the globalization of a nonsmooth Newton method. In part one we start with recalling B. Kummer’s approach to convergence analysis of a nonsmooth Newton method and state his results for local convergence. In part two we give a globalized version of this method. Our approach uses a path search idea to control the descent. After elaborating the single steps, we analyze and prove the global convergence resp. the local superlinear or quadratic convergence of the algorithm. In the third part we illustrate the method for nonlinear complementarity problems.     

最佳逼近的正交化算法

In the present paper,we shall give a new algorithm of the best approximation in Hilbert spaces by using Gram-Schmidt orthogonalization and give some examples to show that the new method is simple and convenient.And we also point out that the best approximation have a wonderful superposition property by using orthogonal method.