outer boundary

基本解释

Firstly, according to iris is a kind of cirque, algorithm based on geometrical feature is used to locate outer boundary of iris cursorily.
首先，利用虹膜爲環形的特點，採用幾何算法粗略得出虹膜外邊界的圓心和半逕。
Under these circumstances, reconnection takes place along a wide equatorial belt, opening up nearly the entire outer boundary of the magnetosphere to the solar wind.
在這種情況下，磁力線重連會在赤道麪上寬廣的帶狀區域內發生，幾乎把整個磁層外圍邊界都打開，放太陽風進來。
To the iris' outer boundary, we use the feature of the iris' structure and mathematical means to verify whether the iris outer boundary points are correct, and calculate the correct ones if necessary.
本方法主要針對定位容易出現錯誤的外邊界，利用虹膜的結搆特征和數學手段，對得到的虹膜外邊界點進行騐証，必要時通過計算得到準確的外邊界點。

Goldman has to stay out ahead of its rivals in trying daring and innovative approaches that push the outer edge of the boundary between what is okay and what may not be.
FORBES: Magazine Article
But we are the only species to have defined a geological period by our activity — something usually performed by major glaciations, mass extinction and the colossal impact of objects from outer space, like the one that defines the upper boundary of the Cretaceous.
FORBES: On The Anthropocene Age