其它实时系统则利用一些算法来检测可疑的行为，比如一群人在一条被封住入口的门边徘徊，抑或定位那些看起来被人落下无人看管的行李物品。
Other real-time systems use algorithms to detect suspicious behaviour, such as a group loitering near a door where entry is barred, or to spot items of luggage that seem to have been left unattended.
方法对25例有明确异物吞入史，但X线探查为阴性的患者，运用超声高、低频探头对可疑部位进行探查定位。
Methods 25 patients who had foreign body inside the digestive tract but the X-ray exploration was negative, were exarnined with ultrasonic inspection with high and Iow frequency detecting head.
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