Like making a key for a lock you've never seen, designing an uber-specific microscopic agent to track down an "unknown threat" may prove slightly difficult.

就如同为一只你从未见过的锁，制作一把钥匙一样。要想设计这样一种超级具体的微型代理装置去追查“未知的威胁”，将会是有难度的。

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But identifying previously unknown malware is difficult, and keeping track of different variants of existing viruses makes it harder.

不过辨认未知的恶意软件是困难的，继续了解现存各种病毒的差别将更加困难。

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When the inertial parameters are unknown, two adaptive control schemes are proposed based on the results for a free- floating space manipulator system to track the desired trajectory in workspace.

在此基础上，给出了系统参数未知时由空间机械臂末端惯性空间期望轨迹产生机械臂关节铰期望角速度、角加速度的增广自适应控制算法。

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Unlike newspapers though, which are of unknown origin, each track in Undersound will have a birth-place, giving added meaning.

ENGADGET: Undersound, a way to trade music on the London Underground

Most mobile robots do this using a technique called SLAM (simultaneous localisation and mapping), whereby they build up a map of their unknown environment, using various sensors, whilst keeping track of their current position at the same time.

BBC: NEWS | Technology | 'Guessing' robots find their way

Barzelay has never been afraid to turn a pop song into a mission statement: For proof, check out Clem Snide's masterful "I Love the Unknown, " which Barzelay helpfully tacks on as a bonus track to Lose Big.

NPR: Eef Barzelay: A Blueprint For Finding Love