可压缩欧拉-泊松方程组平衡解的存在性

可压缩欧拉-泊松方程组描述的是具自引力势能气态星体内部气体的运动变化.对于满足质量守恒和能量守恒的一些速度场,本文在熵函数的光滑性较弱的条件下研究欧拉-泊松方程组平衡解的存在性.在本文中,作者应用变分方法得到6/5＜γ＜2时方程组平衡解的存在性结果.该结果减弱了关于非旋转星体欧拉-泊松方程组平衡解存在的条件,从而适用于更一般的物理环境.     

一类拟线性双曲型方程组混合初-边值问题的半整体C~1解

本文证明了具零特征且形式更广泛的一类拟线性双曲型方程组的具有一般非线性边界条件的混合初 一边值问题半整体C1解的存在唯一性.     

一类拟线性双曲型方程组混合初-边值问题的半整体C1解

本文证明了具零特征且形式更广泛的一类拟线性双曲型方程组的具有一般非线性边界条件的混合初-边值问题半整体C1解的存在唯一性.     

具非线性扩散系数的中立双曲型阻尼偏微分方程组解的振动性

研究一类具非线性扩散系数的中立双曲型阻尼偏微分方程组的振动性.通过利用R iccati变换、微积分技巧,获得了该方程组在两类边值条件下解振动的一些充分条件.     

拟线性对称双曲组具有特征边界的初边值问题

拟线性对称双曲组在数学物理中有广泛的应用.例如,流体力学方程组就可化为拟线性对称双曲组进行讨论.在文[1,2]中,对于拟线性对称双曲组具非特征边界的初边值问题已作了完整的讨论,但对于边界为特征的情形,附加了方程组中未知函数导数项的系数不依赖于u的要求.在等熵、初速为亚音速,初始密度接近于常数的固壁边界问题,     

具阻尼和源项的非线性粘弹热方程组解的爆破

考虑一个具阻尼和源项的非线性粘弹热方程组的初边值问题.建立一个正初始能量下方程组解的爆破结果.     

高维非线性守恒律方程组

本文根据高维非线性守恒律方程组的研究历程将这一领域的研究大体分为四个阶段: 局部经典解、具扇状波结构弱解、具花状波结构弱解、整体解与混合型方程. 本文据此线索回顾与介绍多年来在该领域所获得的主要成果与进展, 并提出今后所面临的一些未解决的重要问题及困难.     

一维Dirac-Klein-Gordon方程组解的存在时间

本文研究具弱衰减、小初值初始条件的一维Dirac－Klein－Gordon方程组解的存在时间估计问题，结果表明这类问题解的存在时间几乎比e－4大初值的弱衰减条件使得通常的方法不能使用，在此，通过利用Delort曾用过的方程组特征的曲率性质以及2次微局部椭圆正则性解决了该问题.     

当绝热指数很大时气体的一种非定常平面平行运动的渐近解

文献[1]在气体的速度分量只与极角θ及时间t有关,而与极距r无关的条件下求解理想气体的非定常平面平行具势运动方程组(1.2)～(1.3).文献[1]指出,在一般的情况下,不能得到解的显式表示式,只是对于二种特殊情况得到了显式解.本文研究了文献[1]的同样问题.第一部分,对音速作了一些补充限制,从而得到了方程组的显式解.第二部分,假设气体的绝热指数γ>>1,求得了方程组的一级近似解.     

半空间上具耦合非线性边界扩散系统的爆破性质

考虑半空间上具耦合非线性边界条件的热方程组解的爆破估计. 给出了爆破速率的上界和下界估计, 得到了具零初值解的惟一性和非惟一性结果.     

Some properties of singular integral operators over an open curve Dedicated to the 85th birthday of Prof.Lu Jinake

In this paper, the stability properties, the endpoint behavior and the invertible relations of Cauchy-type singular integral operators over an open curve are discussed. If the endpoints of the curve are not special, this type of operators are proved to be stable. At the endpoints, either the singularity or smoothness of the operators are exactly described. And the function sets or spaces on which the operators are invertible as well as the corresponding inverted operators are given. Meanwhile, some applications for the solution of Cauchy-type singular integral equations are illustrated.     

Depth notions for orthogonal regression

Global depth, tangent depth and simplicial depths for classical and orthogonal regression are compared in examples, and properties that are useful for calculations are derived. The robustness of the maximum simplicial depth estimates is shown in examples. Algorithms for the calculation of depths for orthogonal regression are proposed, and tests for multiple regression are transferred to orthogonal regression. These tests are distribution free in the case of bivariate observations. For a particular test problem, the powers of tests that are based on simplicial depth and tangent depth are compared by simulations.     

Some properties of singular integral operators over an open curve Dedicated to the 85th birthday of Prof. Lu Jianke

In this paper, the stability properties, the endpoint behavior and the invertible relations of Cauchy-type singular integral operators over an open curve are discussed. If the endpoints of the curve are not special, this type of operators are proved to be stable. At the endpoints, either the singularity or smoothness of the operators are exactly described. And the function sets or spaces on which the operators are invertible as well as the corresponding inverted operators are given. Meanwhile, some applications for the solution of Cauchy-type singular integral equations are illustrated.     

Some properties of complex matrix-variate generalized Dirichlet integrals

Dirichlet integrals and the associated Dirichlet statistical densities are widely used in various areas. Generalizations of Dirichlet integrals and Dirichlet models to matrix-variate cases, when the matrices are real symmetric positive definite or hermitian positive definite, are available [4]. Real scalar variables case of the Dirichlet models are generalized in various directions. One such generalization of the type-2 or inverted Dirichlet is looked into in this article. Matrix-variate analogue, when the matrices are hermitian positive definite, are worked out along with some properties which are mathematically and statistically interesting.     

Matrix-valued polynomials generated by the scalar-type Rodrigues’ formulas

The properties of matrix-valued polynomials generated by the scalar-type Rodrigues’ formulas are analyzed. A general representation of these polynomials is found in terms of products of simple differential operators. The recurrence relations, leading coefficients, completeness are established, as well as, in the commutative case, the second order equations for which these polynomials are eigenfunctions and the corresponding eigenvalues, and ladder operators.A new, direct proof is given to the conjecture of Durán and Grünbaum that if the weights are self-adjoint and positive semidefinite then they are necessarily of scalar type.Commutative classes of orthogonal polynomials (corresponding to weights that are self-adjoint but not positive semidefinite) are found, which satisfy all the properties usually associated to orthogonal polynomials, and are not of scalar type.     

Stability of random impulsive coupled systems on networks with Markovian switching

Abstract

This article is intended to study global asymptotical stability in probability for random impulsive coupled systems on networks with Markovian switching. Two cases are considered. (1) Continuous dynamics are stable while impulses are unstable; (2) impulses are stable while continuous dynamics are unstable. To begin with, based on Lyapunov method as well as graph-theoretic technique, several new stability criteria in two cases are derived, that are, the Lyapunov-type criteria and the coefficients-type criteria. Then main results are used for a class of random impulsive coupled oscillators. Finally, the effectiveness of the obtained results is verified by numerical simulations.     

秩为1矩阵的性质及应用

给出了秩1矩阵的结构,讨论了这类矩阵在矩阵运算、对角化、标准型等方面的性质,推广和改进了文[1]的一些相关结果,并指出了它的若干应用,重点讨论了一类矩阵,得到了有关结论和方法.     

混合位置分布中分量参数的统计推断

对混合位置分布族,当混合比已知时,提出了关于分量参数的假设检验和区间估计方法,所提出的方法基于广义枢轴模型.在一定的条件下,检验的实际水平等于名义水平,且各置信域的实际覆盖率等于名义覆盖率.在更一般的场合,检验是相合的,并且各置信域的实际覆盖率趋于名义覆盖率.模拟显示所给的方法是令人满意的.     

Scheduling jobs with different,job-dependent earliness and tardiness penalties using the SLK method

The single machine job scheduling problem, where due dates are assigned using the SLK due date determination method, is examined assuming different penalties for the early and tardy jobs. These penalties are assumed to be job-dependent, proportional to the processing times of jobs raised to an integer, non-negative power. The objective function is the total weighted lateness. Several cases are examined and four algorithms providing the optimal sequences for these cases are presented. Examples are given and conclusions are drawn.