A social force approach for the defensive strategy of security guards in a terrorist attack

Abstract

In recent years, the emergence of terrorist attacks all over the world has endangered public security seriously and caused many civilian casualties. The goal of this paper is to develop a general approach for studying the defensive scheme of security guards and reducing civilian casualties in a terrorist attack. When artificial attacks occur in an enclosed public place, pedestrians try to avoid terrorists and escape from the room, security guards want to fight against terrorists and protect pedestrians, but terrorists aim to kill other agents quickly. The new approach consists of two parts. First, a modified social force model is built to simulate the crowd movement of all agents. Second, a novel algorithm is proposed to simulate the process of the fights between security guards and terrorists. Then several defensive strategies and spatial position schemes are proposed for security guards and they are compared and analyzed through computer simulations. It is found that security guards may be more of a hindrance than a help for pedestrians in some cases. Only an appropriate defensive scheme can reduce the number of civilian deaths significantly in terrorist attacks. Furthermore, the positions of security guards within the room should not be too concentrated at the center or too scattered at the corners in the daily work. A moderately scattered position scheme of security guards established beforehand will save civilian lives effectively in terrorist attacks. Our study provides valuable insights to the counterterrorism emergency management.