HHT has not been put forward for long time, so it contains some theoretical problems, such as envelop and mean curve fit, boundary effect, modes mix and so on.

HHT刚提出不久，其理论本身还存在不少问题，如包络线和均值曲线的拟合、边界效应和模态混叠等问题。

youdao

There are 6 interconnected crossing Bridges (one is preserved) and among them there is one special large bridge. The circular min mean curve is 1000 meters and the Max slope is 3%.

全线设有互通立交6处(其中一处预留)，特大桥一座，最小平曲线半径1000米，最大纵坡3%。

youdao

You know it's automatically OK because if you have a closed curve, then the vector field is, I mean, if a vector field is defined on the curve it will also be defined inside.

它必然成立，因为如果给出一条闭合曲线，然后向量空间是…，我是指，向量空间在曲线上有定义，当然在区域内部也有定义。

youdao

And even when the engineering is perfect, Mars itself can throw mean curve balls.

MSN: History littered with failed Mars probes

He did, however, acknowledge that the huge amount of flexibility does mean that the learning curve is steeper.

ENGADGET

In a bell curve, the median and mean are the same.

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