He estimates, for his purposes, and he shows you calculations of the efficient portfolio frontier.

他用自己的角度估算了参数,他还给出了计算有效边界的方法。

耶鲁公开课 - 金融市场课程节选

Crandall later converted and used deregulation to steamroll less nimble competitors with his efficient hub-and-spoke strategy, which feeds regional passengers into a central hub where they can transfer to other American flights.

FORBES: The ghost of Crandall

From therein, the Polish number two gathered his concentration and was efficient in the way he wrapped up victory.

BBC: GB relegated after Davis Cup loss

But I mean all athletes especially endurance athletes, have very efficient cardiovascular systems, in particular the most relevant at the moment Lance Armstrong, is really just extremely efficient and his ability, his body's ability to carry and use oxygen.

BBC: Breakfast with Frost