当今社会是一个人口高度密集、相互关系高度复杂的社会,自从美国911后,社会所面临的各种突发事件和异常事件越来越多,因而安防监控的难度与重要性也越来越突出。为此,世界各国政府和学者都在研 Today’s society is a highly populated and highly interdependent society. Since the United States was in the wake of the Sept.11 attacks on various kinds of emergencies and anomalies, the difficulty and importance of security surveillance became more and more prominent . To this end, the world’s governments and scholars are studying