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1.
换比萨     
顾丽 《数学大王》2009,(6):27-27
星期天.精灵鼠小弟和爸爸、妈妈去必胜客吃饭,精灵鼠小弟点了一个12寸的比萨,谁知道服务员说没有了,建议给他们一个9寸的外加一个6寸的比萨。爸爸妈妈觉得不错,可精灵鼠小弟不乐意了,坚持叫服务员拿一个9寸的,外加两个6寸的!  相似文献   

2.
本文给出了正定四元数矩阵的定义,同时给出了正定四元数矩阵的一个充要条件,一个必要条件,一个充分条件.  相似文献   

3.
二阶半线性常微分方程Robin边值问题的奇摄动   总被引:15,自引:0,他引:15       下载免费PDF全文
用基本方法讨论了一个半线性奇摄动Robin边值问题.利用微分不等式理论,证明了问题解的存在性,并得到了解的渐近估计.作为应用,给出了两个例子,一个是将结果应用于一个燃烧反应扩散问题的模型,另一个是得到了有关Dirichlet问题的相应结果.  相似文献   

4.
MATCH(14,3,1)-设计的一个构造法   总被引:1,自引:0,他引:1  
一个MATCH(n,k,λ)-设计就是完全图Kn的一个k-匹配集合,使得Kn的每一对独立边恰好出现在λ个k-匹配中。本文构造了一个MATCH(14,3,1)-设计,解决了文献[1]中一个尚未解决的问题,同时还得到一个MATCH(42,3,1)-设计。  相似文献   

5.
对于复平面,我们构造一个一一映射,使复平面上的点能够在一个三维球面上被表示,称为复数的球面几何表示.通过这样一个一一映射,我们可将对平面上的复数的研究转移到一个有限的三维空间上去,并在这个新的空间中讨论复数在其上的一些性质及关系.  相似文献   

6.
图的(g,f)-因子和因子分解   总被引:10,自引:0,他引:10  
刘桂真 《数学学报》1994,37(2):230-237
设G是一个图,g,f是定义在图G的顶点集上的两个整数值函数且图G的一个(g,f)-因子是G的一个支撑子图F使对任意的x∈V(F)有本文给出了一个图(g,f)-可因子化的若干充分条件和一个图是(g,f)-消去图的充分必要条件,并研究了这些条件的应用。  相似文献   

7.
设施选址在整个物流网络中是一个十分重要的决策问题,它决定了整个物流系统的模式,结构和形状。设施选址方法尤其是多设施选址方法的研究已经成为一个备受人们关注的研究领域。本文首先介绍了设施选址的重要性,然后在模糊环境中根据不同的决策标准,建立了三种不同类型的模型,并设计了一个遗传算法来解决其中一个模型。最后给出了一个数值例子。  相似文献   

8.
图的(g,f)-因子和因子分解   总被引:17,自引:0,他引:17  
设G是一个图,g,f是定义在图G的顶点集上的两个整数值函数且图G的一个(g,f)-因子是G的一个支撑子图F使对任意的x∈V(F)有本文给出了一个图(g,f)-可因子化的若干充分条件和一个图是(g,f)-消去图的充分必要条件,并研究了这些条件的应用。  相似文献   

9.
本文证明了如下结果:环R是Artin半单的当且仅当存在一个基数c,使得任意左R-模是一个连续模和一个c-限制的ES-模的直和,也当且仅当存在一个基数c,使得任意左界R-模是一个拟投射模和一个c-限制的ES-模的直和。  相似文献   

10.
对一阶拟线性双曲方程组一类广义Riemann问题,该文在一定条件下证明了,包含一个接触间断和一个中心波以及包含一个接触间断和一个激波的间断解的整体存在性和唯一性.  相似文献   

11.
As early as in 1990, Professor Sun Yongsheng, suggested his students at Beijing Normal University to consider research problems on the unit sphere. Under his guidance and encouragement his students started the research on spherical harmonic analysis and approximation. In this paper, we incompletely introduce the main achievements in this area obtained by our group and relative researchers during recent 5 years (2001-2005). The main topics are: convergence of Cesaro summability, a.e. and strong summability of Fourier-Laplace series; smoothness and K-functionals; Kolmogorov and linear widths.  相似文献   

12.
In this paper we study best local quasi-rational approximation and best local approximation from finite dimensional subspaces of vectorial functions of several variables. Our approach extends and unifies several problems concerning best local multi-point approximation in different norms.  相似文献   

13.
In this paper, we study the commutators generalized by multipliers and a BMO function. Under some assumptions, we establish its boundedness properties from certain atomic Hardy space Hb^p(R^n) into the Lebesgue space L^p with p 〈 1.  相似文献   

14.
15.
<正>August 10-14,2015Beijing,ChinaThe International Congress on Industrial and Applied Mathematics(ICIAM)is the premier international congress in the field of applied mathematics held every four years under the auspices of the International Council for Industrial and Applied Mathematics.From August 10 to 14,2015,mathematicians,scientists  相似文献   

16.
<正>May 26,2014,Beijing Science is a human enterprise in the pursuit of knowledge.The scientific revolution that occurred in the 17th Century initiated the advances of modern science.The scientific knowledge system created by  相似文献   

17.
Let P(z)=∑↓j=0↑n ajx^j be a polynomial of degree n. In this paper we prove a more general result which interalia improves upon the bounds of a class of polynomials. We also prove a result which includes some extensions and generalizations of Enestrǒm-Kakeya theorem.  相似文献   

18.
Shanzhen  Lu  Lifang  Xu 《分析论及其应用》2004,20(3):215-230
In this paper, the authors study the boundedness of the operator [μΩ, b], the commutator generated by a function b ∈ Lipβ(Rn)(0 <β≤ 1) and the Marcinkiewicz integrals μΩ, on the classical Hardy spaces and the Herz-type Hardy spaces in the case Ω∈ Lipα(Sn-1)(0 <α≤ 1).  相似文献   

19.
Given the Laplace transform F(s) of a function f(t), we develop a new algorithm to find an approximation to f(t) by the use of the classical Jacobi polynomials. The main contribution of our work is the development of a new and very effective method to determine the coefficients in the finite series expansion that approximation f(t) in terms of Jacobi polynomials. Some numerical examples are illustrated.  相似文献   

20.
In applications it is useful to compute the local average empirical statistics on u. A very simple relation exists when of a function f(u) of an input u from the local averages are given by a Haar approximation. The question is to know if it holds for higher order approximation methods. To do so, it is necessary to use approximate product operators defined over linear approximation spaces. These products are characterized by a Strang and Fix like condition. An explicit construction of these product operators is exhibited for piecewise polynomial functions, using Hermite interpolation. The averaging relation which holds for the Haar approximation is then recovered when the product is defined by a two point Hermite interpolation.  相似文献   

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