A tricky situation, but all you need to consider is this: the player taking the kick must be clearly identified, and having received your signal, he must kick the ball forward.

没错，这个是一个复杂的情况，但是你所要做的就是考虑以下情况：罚球队员是明确的，收到了你的指令，并且将球向前踢了。

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It provides a valve ball or disk position for a specific input signal.

该类型定位器能按特定的输入信号使阀球或阀板停留在特定位置。

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The vibration signal is modeled and analyzed by using the technique of time series analysis, and the main factors of the surface waviness which cause the ball bearing vibration are detected.

该方法利用时间序列分析技术，对滚动轴承振动信号进行建模和谱分析，找出引起轴承振动的表面因素。

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Hawk-Eye's system uses seven cameras to track the movement of the ball and sends a signal -- within a second -- to watches worn by match officials when a goal is scored.

CNN: England on course for goal-line history

Thompson turned around in time to watch it fly toward a row of defenseless photographers sitting on the baseline, and then raised his hand to signal it was his team's ball since he hadn't touched it last.

WSJ: One NBA Player's Life of Constant Rejection: Tristan Thompson

If the system detects that the ball has crossed the goal line a central computer transmits a signal to the referee via either a watch or earpiece.

CNN: Does football need technology?