null function

It is shown that sufficient and necessary condition for the networks obtaining null error cost function is proved to be R ( Y) R ( X).

证明了网络获得零代价全局最小解的充要条件是R（Y）R（X）。

In this paper, a clear expression of the null distribution function of the likelihood ratio test statistics U that is considered by Hawkins ( 1977) is derived when σ 2 is known. The numerical tables of the distribution funtion are given.

本文对σ~2为已知的情况，导出了由Hawkins（1977）提出的似然比检验统计量U的简明且便于计算的分布函数表达式，并建立了分布函数的数值表。

Then from normal statistic model, a reasonable and simple estimation method is given. A clear expression of the null distribution function of statistics U is also derived.

从正态统计模型出发，对均值变点的位置提供了一种合理、简单的估计方法，对其统计量进行推导，得到关于统计量U的分布函数的定理。

By employing the pole-null representation, we demonstrate that the lateral shift is closely related to the null of the reflection function.

利应用极点-零点描述理论，我们发现光束的位移与光束在该结构中的反射系数函数的零点密切相关。