A Stochastic Approach to Modeling Aviation Security Problems Using the KNAPSACK Problem

Designers, operators, and users of multiple-device, access control security systems are challenged by the false alarm, false clear tradeoff. Given a particular access control security system, and a prespecified false clear standard, there is an optimal (minimal) false alarm rate that can be achieved. The objective of this research is to develop methods that can be used to determine this false alarm rate. Meeting this objective requires knowledge of the joint conditional probability density functions for the security device responses. Two sampling procedures, the static grid estimation procedure and the dynamic grid estimation procedure, are proposed to estimate these functions. The concept of a system response function is introduced and the problem of determining the optimal system response function that minimizes the false alarm rate, while meeting the false clear standard, is formulated as a decision problem and proven to be NP-complete. Two heuristic procedures, the Greedy algorithm and the Dynamic Programming algorithm, are formulated to address this problem. Computational results using simulated security data are reported. These results are compared to analytical results, obtained for a prespecified system response function form. Suggestions for future research are also included.