An automatic accident detection method based on traffic flow parameters will be accessed, through simulating the physical environment of urban tunnel with traffic simulation software VISSIM.
采用VISSIM交通仿真软件，对城市隧道内的物理环境进行仿真，可设计出一种基于交通流参数的交通事故自动检测方法。
The method for locking frequency according to CPT line is studied. The model of frequency detection for physical package is attained according to analysis the course of detection.
进而研究根据CPT谱线实现原子钟锁频的数学过程，并通过对激光调制过程中物理鉴频系统的信号流分析得到物理系统的鉴频模型。
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