THE UNIQUENESS OF THE DECOMPOSITION OF QUADRATIC LIE ALGEBRAS

In this paper, we consider the decomposition of a quadratic Lie algebra and the main result is that the decomposition of a quadratic Lie algebra into irreducible nondegenerate ideals is unique up to an isometry (Theorem 3.1). As a corollary, we obtain the uniqueness of the decomposition of an arbitrary Lie algebra into indecomposable ideals up to an isomorphism (Corollary 3.5.4).     

A CLASS OF QUADRATIC DIFFERENTIAL SYSTEM WITH A THIRD ORDER WEAK FOCUS

This paper discusses the uniqueness of the limit cycle of quadratic differential system with a third order weak focus.     

协方差的二次型容许估计

本文研究方差的二次型估计的容许性,在平方损失下,我们给出了一个二次型估计在二次型估计类中是协方差的容许估计的充要条件。     

三项式xn-bx+a的二次不可约因式

本文研究了三项式f(x)=xn-bx a的二次不可约因式,利用Lucas数本原素因数的存在性的结果,对于n≥max(30,(|b| 1)/2)的情况,得到了所有含有首项系数等于1的二次整系数不可约因式的f(x).     

一类通有二次哈密顿系统的环性(英文)

1 IntroductionConsider the fOllowing system:t'here E is a small parameter, H(I, y) is a polynomial of degree (n + 1 ) ? f(I, y)and g(x, y) are polynomials of degree S n. The corresponding Abelian integrallswhere b(h) is a compact leve1 curve H--'(h) of (1.l) when E = 0, for h lyingbetween criticaI values of H. The Hilbert-Arnold prob1em (weakend Hilbert16th problern) is to find an upper boulld of the nurnber of zeros of (l.2) forfixed n 2 2 and for al1 H, f and g. In this paper, we tvi11…     

关于一类二阶矩阵方程的敏度分析

In this paper, the sensitivity of the solution for a class of quadratic matrix equation which arises in the analysis of structural systems and vibration problems is discussed. With Brouwer fixed piont theory, the perturbation of the quadratic matrix equation is analyzed and two computational perturbation bounds are derived. Then a Rice condition number of some kind of solutions is given using the analytic expansion method. Two examples are presented in the last part.     

凸二次交叉规划的等价形式

利用参数规划逆问题考虑凸二次交叉规划与多目标规划的关系 ,把交叉规划转变为同变量规划组 ,再把同变量规划组变为多目标规划 ,证明了凸二次交叉规划的均衡解与多目标规划的最优解的关系。     

具有参数的不带有导数的平方收敛的迭代法

1.引 言 考虑数值求解非线性方程 f(x)=0, (1)其中实值函数f(x)在实零点x*的某邻域U(x*)内连续可微且f'(x)≠0. 牛顿法是科学与工程计算中数值求解(1)的常用数值方法.虽然它一般至少是二阶收敛的,但它需要调用导数值,这使其应用受到限制.我们修改牛顿法,用割线代替切线可得不带     

大整数因子分解中的二次筛法优化

本文研究了大整数因子分解中的二次筛法，提出了算法选择，参数选择，硬件选取和过程控制上的优化途径，直接影响RSA密码系统，推动信息安全的发展。     

二次剩余问题的一个新定理

研究了二次剩余问题,利用整数分类的办法,给出了|Jn|和|Qn|的公式(这里n是奇合数,Jn是Zn*中有Jacobi符号为1的所有元素的集合,Qn是模n的所有二次剩余的集合) .基于这些结果,可以得出当a对模n的Jacobi符号等于1时,正确猜测a为模n的二次剩余的可能性,从而推广了[1]p .74中的结果.     

UNIQUENESS AND DISTRIBUTION OF LIMIT CYCLES FOR BOUNDED QUADRATIC SYSTEM

1 IntroductionAs we know, any given quadratic system which may have limit cycle (LC,fOr abbreviation) can be written in the fOllowing fOrm (see [1] 512)where 6, l, m, n, a, 6 are all real parameters.If all trajectories of a quadratic system remain bounded fOr t 2 0, we saythat the system is bounded, and fOr abbreviation denote by BQS in this paper.The research work for BQS begin with Dickson-Perko [3]. And then, in [4],they made use of the conclusions of [51 to give a detailed classifica…     

实二次域Tame核的阶的3-整除性

本文证明了对某类实二次域,其类数能被3整除当且仅当其Tame核的阶能被3整除,同时给出 了Browkin关于Tame核的3整除性的结果的一个不同证明．     

DERIVATIVES OF EIGENPAIRS OF SYMMETRIC QUADRATIC EIGENVALUE PROBLEM

Derivatives of eigenvalues and eigenvectors with respect to parameters in symmetric quadratic eigenvalue problem are studied. The first and second order derivatives of eigenpairs are given. The derivatives are calculated in terms of the eigenvalues and eigenvectors of the quadratic eigenvalue problem, and the use of state space representation is avoided, hence the cost of computation is greatly reduced. The efficiency of the presented method is demonstrated by considering a spring-mass-damper system.     

ON A CONJECTURE CONCERNING THE NON-EXISTENCE OF LIMIT CYCLES FOR QUADRATIC DIFFERENTIAL SYSTEMS

Aconjecturewasgivenin[l]asfollows:Ifforthesystemoftypeill(i.e.,6/0):wehavewhereW=(n b)(l n)'--a'(6 ZI n),thenthereisnolicestcycle(LC,forabbreviation)aroundO(0,0).Noticethatcondition(2)canbedividedintothefollowingfoursub-cases:i)m=0,a(b ZI)/0,n)a=0,m(l n)/0,iii)W=0,WI/0,tv)m--sa=2a2 n(l Zn)=0,a/0,WI/0.(3)Non-existenceofLCunderi)orn)hasbeenprovedin[2]515,Theorem15.1and15.2;andthatunderWI/0,6=0hasbeenprovedin[2]514.Ifiniii)m(l n)>0then[3]hasprovedthenon-existenceofLCaroundObytheDulacfun…     

SHARP BOUNDS FOR NEUMAN-SANDOR MEAN IN TERMS OF THE CONVEX COMBINATION OF QUADRATIC AND FIRST SEIFFERT MEANS

In this article, we prove that the double inequality
αP（a,b）＋（1-α）Q（a,b）〈M（a,b）〈βP（a,b）＋（1-β）Q（a,b）
holds for any a,b 〉 0 with a ≠ b if and only if α≥1/2 and β≤[π（√2 lov （1＋√2）-1]/[√2π-2） log （1＋√2）]=0.3595…,where M（a, b）, Q（a, b）, and P（a, b） ave the Neuman-Sandor, quadratic, and first Seiffert means of a and b, respectively.     

多参数二次特征值问题重特征值的灵敏度分析

本文研究解析依赖于多参数的二次特征值问题重特征值的灵敏度分析,得到了重特征值的方向导数,证明了相应的特征向量矩阵和特征值平均值的解析性,给出了其一阶偏导数的表达式．然后以这些结论为基础,定义了二次特征值问题重特征值及其不变子空间的灵敏度,并给出了确定二次特征值问题所含矩阵中敏感元素的方法．     

非线性特征值问题的二次近似方法

本文研究求解非线性特征值问题的数值方法.基于矩阵值函数的二次近似,将非线性特征值问题转化为二次特征值问题,提出了求解非线性特征值问题的逐次二次近似方法,分析了该方法的收敛性.结合求解二次特征值问题的Arnoldi方法和Jacobi-Davidson方法,给出求解非线性特征值问题的一些二次近似方法.数值结果表明本文所给算法是有效的.     

二次性能指标下的随机控制问题

<正> 随机控制中的二次性能指标是一种十分重要的情况,对离散时间并对状态是线性的系统,问题已得到彻底解决.对连续时间系统,也已多有讨论,但迄今给出的证明还并不完满,所要求的条件也太强. 设(Ω,,P)是概率空间,{},0≤t≤T是以中的零测集完备了的非降     

A FIXED POINT APPROACH TO THE STABILITY OF A GENERALIZED APOLLONIUS TYPE QUADRATIC FUNCTIONAL EQUATION

Using the fixed point method, this article proves the Hyers-Ulam-Rassias stability of a generalized Apollonius type quadratic functional equation in Banach spaces. The conditions of these results are demonstrated by the quadratic functional equation of Apollonius type.     

PHASE-PORTRAIT OF A CERTAIN INTEGRABLE QUADRATIC DIFFERENTIAL SYSTEM WITH CENTER

In [1] we have proved that the quadratic differential system:has a center O(0, 0), which satisfies the last conditions of [2] 512 Theorem 12.3:Aside from O, (1) has a second finite critical point N(0, 1/n), it is an unstablenode. In [3], this is the case (7) in P.16, with bifurcation curve C12 in Fig.4.1and phase-portrait V32 in P.11.Now, put n = I, thenand (l) becomes:From [1] we know that (4) has a quadratic algebraic integral curveIt is a non--degenerate parabola with symetrical axis x…