水面舰艇编队防空问题的建模研究

数学建模在水面舰艇编队防空系统中起到不可估量的作用.通过实例,分析一枚及多枚来袭导弹穿越护卫舰时的数学关系,得出护卫舰100%发现来袭导弹的最大工作半径为25km;并在此基础上建立100%防御成功条件下防御面积最大化的数学模型.计算得出编队的最佳设计阵型为:四艘护卫舰布置在以指挥舰为中心、半径为59km的圆上,各舰相对于指挥舰的方位角分别为45°、95°、145°和195°.根据各战舰拦截导弹过程的运动关系,求得了最优阵型下舰队拦截来袭导弹的最大批次.     

水面舰艇编队防空和信息化战争评估模型

研究了由一艘驱逐舰和四艘护卫舰组成的水面舰艇编队的防空建模问题,建立了突出信息平衡度的修正兰彻斯特战争模型.对于问题1,利用编队与来袭导弹的时变相对位置速度数据求解模型,得到编队最佳队形.对于问题2,建立了来袭导弹对舰艇编队追击问题的几何模型,从单舰到编队的拦截区域分析了编队最小防御纵深的估算方法.对于问题3,采用问题2中类似的方法,计算出有信息支援条件下可拦截来袭导弹15批,相比问题二提高了37.20%.对于问题4,采用聚类分析方法对已知意图的附件数据进行聚类,将分类后的类别中心作为意图识别的模式,采用基于所提出的意图偏差度判别分析方法对空中可疑目标可能的意图作出了识别.对于问题5,在分析信息优势的特征和信息平衡度的重要作用的基础上,根据交战双方对对方作战信息的掌控能力和实时水平,给出了交战双方之间的信息平衡度计算模型.以海湾战争作为案例,结合两类模型进行了对比计算,对修正模型的有效性作出了初步验证.     

水面舰队建立最佳防空编队的数学模型

防空反导是水面舰艇编队最重要的任务之一,我国南海海域辽阔,水面舰艇执行外围岛礁附近海域巡航任务时,往往超出了空中掩护的作战半径,需要自身的对空防御,这时,水面舰艇的编队阵型至关重要.同时,空中目标意图识别是战场态势分析的一个重要部分.以我海军在南海某开阔海域巡逻的水面舰艇编队为例,探究了最佳编队队形的数学模型,并根据所提供的战场空中目标信息,判断目标可能的意图,为威胁判断、火力分配和抗击来袭目标奠定基础.     

平衡型与BP-最优设计

对Lu和Sun[1],Lu等[2]中提出的E(d2)准则进行了扩展,定义了一个新准则,用以评价和构造因子设计.对一个含有k个因子的因子设计,定义了"平衡型"向量B=(B(1),B(2),…,B(k)),其中B(m)表示与m平衡(即强度为m的正交性)的接近程度,m=1,…,b,而B(2)=E(d2).这个新准则(称为"最近平衡准则"),顺序最小化向量B的各个分量.对B(m)得到了下界LB(m),m=1,…,b.证明了当试验单元间的Hamming距离都相等时,平衡型向量的各分量同时达到其下界.试验单元间的Hamming距离都相等的等水平设计称为"正则表".饱和的等水平正交表构成了正则表的一个子类.对2≤q≤7给出了一些q-水平正则表的结果,其中某些是新的.正则表可进一步用于构造具有好性质的设计.     

RECENT PROGRESS ON SPHERICAL HARMONIC APPROXIMATION MADE BY BNU RESEARCH GROUP ——In memory of Professor Sun Yongsheng

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.     

A unified approach to certain problems of best local approximation

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.     

Boundedness for commutators of multipliers on Hardy type spaces

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.     

THE 8~(th) INTERNATIONAL CONGRESS ON INDUSTRIAL AND APPLIED MATHEMATICS

<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     

Towards Excellence in Science Chinese Academy of Sciences

<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     

Bounds for the zeros of polynomials

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.     

Boundedness of commutators related to Marcinkiewicz integrals on hardy type spaces

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).     

Jacobi polynomials used to invert the laplace transform

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.     

Generalization of the interaction between Haar approximation and polynomial operators to higher order methods

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.