Abstract: Civil aviation security check is an important part of air defense security, and it is the last line of defense to prevent passengers and their carry-on luggage from carrying prohibited items into the aircraft. TheInternational Air Transport Association (IATA) proposed“future security checkpoint”, through a series of security inspection equipment alone or in combination, combined with the passenger information for risk assessment, and allocated differentiated security channel for passengers with different risk levels. At present, most airports in the United States have begun to use the double equipment combination of walk-through metal detector and millimeter wave human body imaging equipment, where walk-through metal detector is the first stage of inspection, and millimeter wave human body imaging equipment is the second stage of inspection. This paper intends to study this double equipment system.
   In the process of passenger personal inspection, two types of errors will occur when the security inspection equipment is running: false alarm and false clear. The false clear leads to passengers carrying contraband into the aircraft, and the false alarm takes up the security inspection resources. The two types of errors affect the security of the system and cause waste of security costs. Because the two types of errors generated by the security inspection system can’t be eliminated, it is of great significance to optimize the security cost within the acceptable range of the two types of errors in the system. This paper studies a dual-device system based on walk-through metal detector and millimeter wave body imaging device, and optimizes the security cost on the premise of ensuring system security. Personal security equipment produces the two types of errors: false alarm and false release when checking passengers. The response of the security equipment is simulated by normal distribution, and the probability of the two types of errors is controlled by the equipment alarm threshold. After all passengers pass through the first-stage walk through metal door, the second-stage millimeter wave body imaging device is checked according to the alarm of the walk-through metal detector. The combined alarm of the two devices determines the system alarm and system clear. Security rule 1: all the first-stage and second-stage equipment alarms lead to the security system alarm; the security system release refers to the situation where the first-stage equipment does not raise the alarm, or the first-stage equipment sounds the alarm but the second-stage equipment does not sound the alarm. Security rule 2: the first-stage equipment raises the alarm, or the first-stage equipment does not raise the alarm but the second-stage equipment sounds the alarm; the security system clear refers to the situation where the first-stage and second-stage equipment do not raise the alarm. The security of the two security rules is analyzed within the acceptable range of the two types of errors, and the best security rules for strict and common security channels are determined. Aiming at the two kinds of security rules, the nonlinear programming models of security cost are established respectively with the two kinds of system errors as the constraints, and finally solved by Monte Carlo simulation method.
   Compared with the existing research, the innovation in this paper is mainly reflected in the following: this paper simulates the response of security equipment as a normal distribution, and considers the variability of the two kinds of error probabilities of the equipment with the threshold; it analyzes the security and applicability of the two kinds of security rules. By comparing their respective advantages, the best security rules are assigned to the common and strict security channels. The results show that security rule 1 is suitable for the common security channel, and security rule 2 is suitable for the strict security channel. The minimum security cost of the two rules is similar, and the per capita security cost of security rule 1 is lower than that of security rule 2.

Key words: passenger security cost, two types of errors, two security rules, Monte Carlo simulation

摘要： 为了节约机场旅客人身安检成本,研究基于通过式金属门和毫米波人体成像设备的双设备系统,在确保系统安全性的前提下,对安检成本进行优化。人身安检设备在检查旅客时会产生错误报警和错误放行两类错误,通过正态分布模拟安检设备的响应,利用设备报警阈值控制两类错误发生的概率。所有旅客经过一阶段通过式金属门检查后,然后根据通过式金属门的报警情况确定是否进行二阶段毫米波人体成像设备检查,组合双设备的报警情况确定系统报警和系统放行。在两类错误可接受范围内分析两种安检规则的安全性,确定严格和普通安检通道最佳的安检规则。针对两种安检规则,以系统两类错误为限制条件,分别建立安检成本的非线性规划模型,最后利用蒙特卡罗模拟法求解。结果表明:安检规则1适合普通安检通道,安检规则2适合严格安检通道;两种规则的最低安检成本相近,安检规则1的人均安检成本低于安检规则2。

关键词: 安检成本, 两类错误, 安检规则, 蒙特卡罗模拟