Based on gradient descent rule, the BP ( Back Propagation ) algorithm is a local optimization algorithm.

Gradient descent algorithm using momentum BP network training.

采用动量梯度下降算法训练BP网络.

It can be solved by iteration of gradient descent.

它通过梯度下降迭代求得最小值.

Heart attack, also called myocardial infraction, can occur as much as20 years later in women.

心脏突发事件也称心肌梗死，女性常发生年龄可能推迟20年之久。

Malformations that occur as a baby develops in its mother's womb.

发生畸形婴儿的开发在其母亲的子宫内。

She then talks about health issues and the physical damage that can occur as a result of dieting.

她还说到了节食会导致的健康问题和身体损伤。

Cause to happen or to occur as a consequence.

作为结果发生或者出现。

Consequently, no polarization will occur as our productive forces become developed over the next 20 to 30 years.

再过二十年、三十年，我国生产力发展起来了，也不会两极分化。

Delays may occur as a result of the fog.

由于雾的原因，有可能要延迟。

We watched explosive eruptions occur as frequently as several times per day.

我们观察到爆炸式的喷发频繁到每天有多次。

The next one will occur as soon as the lessons of the last one are forgotten.

前一个泡沫的教训一旦被人遗忘，下一个泡沫就将诞生。

Cramping can occur as a protective mechanism following an injury.

抽筋可以在受伤后起到保护机制的作用。

The recursive nature of the approach allows decomposition to occur as many times as needed to identify atomic system elements.

在需要分解以确定原子级系统元素时，此方法的递归性质让分解尽可能多次的发生。

The transition zone between Structure 4 and Structure 5 occur as faulted and oblique anticline.

4号、5号构造过渡区为断裂斜歪背斜。

Dioxins occur as a complex mixture in the environment and in food.

二恶英在环境和食品中以一种复杂的混合物形式出现。

This discussion must occur as you consider platforms, because some programs are platform specific.

此讨论必须在考虑平台时进行，因为有些程序是特定于平台的。

Dual nationality can occur as the result of a variety of circumstances.

双重国籍造成的原因有多种。

Finally, hair loss may occur as part of an underlying disease, such as lupus or diabetes.

最后，可能会出现脱发的一部分，一个潜在疾病，如狼疮性或糖尿病。

Due to the time jumps that occur as daylight saving time comes and goes.

来计划，因为在夏令时开始和结束时会出现时间跳跃。

It can occur as a result of poor quality fuel.

造成爆震的原因可能是燃油质量不佳。

These changes, imperceptible to the human eye, occur as the heart pumps blood through the body.

这些人类眼睛无法知觉的变化发生在心脏将血液泵向全身的时候。