What is considered to be an anomaly can vary, but normally, any incident that occurs on frequency greater than or less than two standard deviations from the statistical norm raises an eyebrow.
对于一个异常行为的变化是怎么考虑的呢？一般的来说我们这样的考虑，任何一件（异常的）事发生的次数与标准统计的基线比，是（突然）性频繁增大或者是（突然）性减少。
Categorization norm for human factor accidents and accidental signs and their statistical method are the bases for guaranteeing civil aviation flying safety.
事故与事故征候分类标准和统计方法是民航飞行安全的一项基础性安全管理内容。
How to work out the experimental norm under this new inter national standard are discussed in this paper with the principle of chain transmission and statistical theory.
本文依据链传动基本原理，就如何依据新的国际标准制订试验规范进行了探讨。
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