一类平面二次系统的（0,1）分布

本文讨论二次系统的极限环的（0，1）分布问题．本文的主要结果是当系统（1）满足定理的条件时，那末它的权限环是（0，1）分布的．     

A computationally efficient method for bootstrapping systems of demand equations: A comparison to traditional techniques

The solution to a Liapunov matrix equation (LME) has been proposed to estimate the parameters of the demand equations derived from the Translog, the Almost Ideal Demand System and the Rotterdam demand models. When compared to traditional scemingly unrelated regression (SUR) methods the LME approach saves both computer time and space, and it provides parameter estimates that are less likely to suffer from round-off error. However, the LME method is difficult to implement without the use of specially written computer programs and, unlike traditional SUR methods, it does not automatically provide an estimate of the covariance of the parameters. This paper solves these two problems, the first by providing a simplified solution to the Liapunov matrix equation which can be written in a few lines of code in computer languages such as SAS PROC MATRIX/IML^TM or GAUSS^TM; the second, by bootstrapping the parameter covariance matrix.     

半线性椭圆方程径向正解的非存在性及解的振荡性和有界性的充分条件

设r=sum from i=1 to (x_i~2),Ω={r|0≤r相似文献   

一阶时滞微分方程解的渐近性态

探讨了一阶时滞微分方程解的渐近性,并得到了这类方程解的渐近性的几个充分条件。     

ON THE INVARIANCE OF ISOMETRY UNDER UNEQUAL SCALE CHANGES

Isometry is the independence of a size variable G(X) and shape. This note characterizes G(X) =γΦX^b1_i as the only continuous size variable for which isometry with respect to G can continue to hold for all unequal changes of scale of the variables X_i, assuming some conditions on the ranges of the X_i.     

对双自由边界Stefan问题的进一步讨论

本文讨论了双自由边界 Stefan 问题的解对于初始条件的单调相依性,以及该解和一个Volterra 型的非线性积分方程组的等价关系。本文所得结果,是对 R.Canno,D.Hill 及 A.Friedman 相应结果的推广。     

用状态变量法计算TSC的投入过程

状态变量法是近代对网络的过渡过程进行分析计算的一种重要方法,随着计算机的发展,日益获得重视。本文应用状态方程推导出TSC投入过程中电流、电容电压的变化规律。     

解析几何中的轨迹问题

本文举例说明各种轨迹问题的解法,并对参数解法的合理性给以证明.     

确定收益模式下证券投资组合研究

在理论与实践中,证券投资组合问题的研究已取得了辉煌的成果。本文通过运用非线性倒向随机微分方程,研究当投资者以将来某一时刻获取一定数额确定性收益为投资目标时,如何确定当前证券投资组合中各证券的投资比例。文中运用非线性倒向随机微分方程给出证券组合的模型,并给出了相应的解的形式。     

一类半线性偏差分方程解的振动性

本文讨论了一类半线性偏差分方程解的振动性，得到了这类方程解的振动性的一些充分条件。