角的转化变形策略分析

角的变形有四种:1.将一个角拆成两个角的和或差;2.对角进行换元;3.将所求式的角凑成条件式中两已知角的和或差;4.用未知角表示已知角.变形的目的是充分用已知条件,简化解题过程.一、将一个角拆成两角和或差     

时变退化时滞微分系统的变易公式

本文将研究时变退化时滞微分系统.给出了该类系统的变易公式.这将在进一步研究退化时滞微分系统时十分有用.     

时变退化时滞微分系统的变易公式

本文将研究时变退化时滞微分系统.给出了该类系统的变易公式.这将在进一步研究退化时滞微分系统时十分有用.     

基于熵权法的三维动态灰关联优化算法

考虑不同属性及不同时间对于对象的影响,将灰关联决策模型进行拓展.首先,采用熵权法确定不同时刻各属性的权重,将偏差与灰熵结合确定不同时间的权重.其次将其与邓氏关联分析模型结合,综合集成熵权法及灰色关联决策模型的优点,构建三维动态多属性灰关联决策模型的优化算法.最后将方法运用于河南省农业发展状况评价.结果表明:方法计算简便,分辨率高,且能更好的反映实际.     

HPM视角下“三等分角”习题课教学与思考

一、数学史话将数学史与数学融合在一起共同促进学生的发展是HPM(Historyand Pedagogyof Mathematics)研究的一个主要涵义.我们知道,三等分角是古希腊三大几何问题之一.即在尺规作图(即用没有刻度的直尺和圆规作图)的前提下,无法将一个给定的角三等分.若将条件放宽,却可以引发三等分的作法.比如历史上关于"三等分角"的故事的版本很多,其中有一段是与阿基米德有关.这里简要概述这段故事.     

0.2一点也不小

2011年3月11日,日本气象厅表示,日本于当地时间11日14时46分发生里氏7.9级地震,震中位于宫城县以东太平洋海域,震源深度20公里.东京有强烈震感.美国地质勘探局将日本当天发生的地震震级从里氏7.9级修正为里氏8.8级.北京小部分区域有震感,对中国大陆不会有明显影响.不过,此次地震可能引发的海啸将影响太平洋大部分地区.北京时间3月13日,日本气象厅再次将震级修改为9.0级.     

区间MDEA模型及其求解

将一种改进的DEA模型-MDEA模型[1]拓展到区间投入产出情形,得到区间MDEA模型.定义了一种反映决策者满意度的区间数序关系,当决策者给定一满意度水平,将区间MDEA中的区间不等式约束转化为确定型约束.研究了该满意度水平的另一层含义,即决策者对除被评价决策单元外的其它决策单元的偏好程度,据此将区间MDEA中的区间等式约束和区间目标函数转化为确定型.最终将区间MDEA转化为某一满意度水平下的确定型MDEA,并进行求解.最后给出算例分析.     

基于高斯伪谱的最优控制求解及其应用

研究一种基于高斯伪谱法的具有约束受限的最优控制数值计算问题.方法将状态演化和控制规律用多项式参数化近似,微分方程用正交多项式近似.将最优控制问题求解问题转化为一组有约束的非线性规划求解.详细论述了该种近似方法的有效性.作为该种方法的应用,讨论了一个障碍物环境下的机器人最优路径生成问题.将机器人路径规划问题转化为具有约束条件最优控制问题,然后用基于高斯伪谱的方法求解,并给出了仿真结果.     

例说对等式的观察

观察能力是人们认识世界的一种重要能力 .在数学解题中 ,对题设条件的仔细观察 ,往往是解决问题的关键 .本文将通过一组实例来说明观察在解竞赛题中的作用 .例 1　对于自然数ｍ ,规定如下 3种操作 :①将ｍ除以 2 ;②将ｍ乘以 3后再加1;③将ｍ乘以 3后再减 1.求证 :对任何自然数ｎ ,均可经过有限次上述操作后变为 1.分析　考察题设中的条件和结论 .结论是将ｎ变为 1,这是一种下降的变化 .在 3种操作中 ,操作①是将自然数下降 ,而操作② ,③是将自然数上升 ,因此要保证总体成下降的趋势 ,可在每排一次上升操作后连续安排2次下降的操作 .简解　…     

耦合的Fitz-Hugh-Nagumo模型的初边值问题

首先研究了具有耦合的Fitz-Hugh-Nagumo模型初值问题的渐近性.其次,所对应的平衡态方程解的基本性态也将被讨论.最后,该模型的初边值问题古典解的最大吸引子的存在性将首次被证明.     

Priority centralization of the one period multi-location inventory system

In this paper, we will examine a multi-center one-period inventory system. The usual penalty cost for being out of stock will be replaced by an assurance of service constraint at each location. That is, we will constrain our inventory size to meet a specific maximum probability of being out of stock at each location. The centralized system we shall propose will define a priority rule which will cause us to satisfy the entire demand of high priority locations before we begin satisfying the demands of lower priority locations. This will allow us to find a minimum initial inventory level for the centralized system that will meet all of the assurance of service constraints. We will look at the special case where the variance of the total demand of several locations is non-decreasing in locations included in the total. In this case, we will show the computations required for finding the optimal centralized priority system are minimal. Finally, we will show that such a system is superior to a decentralized system.     

A new method for similarity measures for pattern recognition

This paper points out three questionable areas in the realm of similarity measures and then provides a new method that will rectify the problem. The purpose of this paper is fourfold. First, we will propose a scenario where the three similarity measures proposed by Hung and Yang (2004) [1] are helpless in aiding a decision maker in deciding pattern recognition problem. Second, we will present our method for solving the dilemma. Third, we will show that our proposed similarity measures satisfy the axioms for well defined similarity measures. Fourth, we will prove that our method could solve pattern recognition problems. Our findings will help researchers handle similarity problems under intuitionistic fuzzy sets environment.     

考虑罚金政策的众包物流服务质量网络均衡模型

为优化众包物流服务质量,考虑平台罚金政策,构建了包括发包方、众包平台和接包方在内的三层众包物流服务网络模型,并进行算例分析。结果表明,众包平台实施罚金政策并加大自身服务质量投入成本会促使接包方改善自身的服务质量,众包平台的服务质量和利润随之增大,但一味的增大罚金不但会使得接包方利润下降,众包平台的服务质量和利润也呈稍微下降趋势,因此平台应该选择合适的罚金区间;平台在竞争的同时也要进行一定的合作,因为平台间同步协调改进罚金政策以及质量投入会取得更大的收益和更高的平均服务质量。     

Convex- and Monotone-Transformable Mathematical Programming Problems and a Proximal-Like Point Method

The problem of finding the singularities of monotone vectors fields on Hadamard manifolds will be considered and solved by extending the well-known proximal point algorithm. For monotone vector fields the algorithm will generate a well defined sequence, and for monotone vector fields with singularities it will converge to a singularity. It will also be shown how tools of convex analysis on Riemannian manifolds can solve non-convex constrained problems in Euclidean spaces. To illustrate this remarkable fact examples will be given.     

Numerical solution of singularly perturbed fifth order two point boundary value problem

We will consider Adomain decomposition method and the homotopy method to solve a fifth order singularly perturbed BVP arising in viscoelastic flows. The success and pitfalls of the methods will be investigated. Numerical testing will be provided to show the efficiency of the methods proposed. Comparison with the work of others will also be done.     

Restricted expected multivariate least squares

A new approach of estimating parameters in multivariate models is introduced. A fitting function will be used. The idea is to estimate parameters so that the fitting function equals or will be close to its expected value. The function will be decomposed into two parts. From one part, which will be independent of the mean parameters, the dispersion matrix is estimated. This estimator is inserted in the second part which then yields the estimators of the mean parameters. The Growth Curve model, extended Growth Curve model and a multivariate variance components model will illustrate the approach.     

基于格子Boltzmann方法的液滴撞击具有不同润湿性孔板的研究

基于格子Boltzmann方法,对液滴撞击不同湿润性节流孔板表面进行了数值模拟.主要研究了在液滴撞击过程中,Weber数(We)、孔板表面湿润性和孔板尺寸对液滴通过孔板时不同状态的影响.数值模拟结果表明:孔板为亲水特性时,在较低We下,液滴不会与孔板表面脱离,而是附着在孔板下表面,并且在毛细作用下液滴会在孔道中上升一段...     

Multiscale asymptotic expansion and finite element methods for the mixed boundary value problems of second order elliptic equation in perforated domains

In this paper, we will discuss the mixed boundary value problems for the second order elliptic equation with rapidly oscillating coefficients in perforated domains, and will present the higher-order multiscale asymptotic expansion of the solution for the problem, which will play an important role in the numerical computation . The convergence theorems and their rigorous proofs will be given. Finally a multiscale finite element method and some numerical results will be presented. This work is Supported by National Natural Science Foundation of China (grant # 10372108, # 90405016), and Special Funds for Major State Basic Research Projects( grant # TG2000067102)     

Stieltjes Functions and Hurwitz Stable Entire Functions

The concept of stability, originally introduced for polynomials, will be extended to apply to the class of entire functions. This generalization will be called Hurwitz stablility and the class of Hurwitz stable functions will serve as the main focus of this paper. A first theorem will show how, given a function of either of the Stieltjes classes, a Hurwitz stable function might be constructed. A second approach to constructing Hurwitz stable functions, based on using additional functions from the Laguerre-Pólya class, will be presented in a second theorem.     

不确定条件下多属性决策的比较因素法(英文)

本文针对不确定条件下多属性决策问题,扩展了原有多属性决策的概念,引入了比较因素与次比较因素,获得了其一些代数性质以及相应的定理。在此基础上,给出了不确定条件下多属性决策的比较因素法。