Discipline: Mathematics and Statistics
Subcategory: Mathematics and Statistics
Omoikhefe Eboreime - Texas Southern University
Co-Author(s): Christie Nelson, Rutgers University, NJ; Dexter Harris, Morgan State University, MD
Walk through metal detectors (WTMDs) are used in a variety of applications including at large stadiums, as a tool to counter possible security threats. With WTMDs at large stadium venues being the focal point of this research, we examined WTMD effectiveness in detecting real stadium contraband items. Contraband items were loaned to us by a sports stadium, as was use of current field-used WTMDs. Experiments were performed to identify factors affecting detection of contraband items. Some factors include height and orientation of the real contraband object passing through and speed of the person walking through the metal detector. In total about 5,900 experiments were performed. In addition, field observations of security screening patrons with WTMDs were observed at a large stadium venue. Data collected from our observations at these events helped us to validate the types of contraband items actually found, along with conversations with stadium security personnel. I. INTRODUCTION Stadium security use walk-through metal detectors (WTMD) to ensure the safety of the stadium patrons during an event. As a result, they are faced with the challenge of keeping patrons safe while simultaneously giving them a positive fan experience. This research focuses on identifying real fan contraband, then determining which factors impact WTMD detection in order to inform stadium security. To begin this research, experimental designs were created and several factors were identified. These factors were considered to possibly affect the detection of specified contraband items by WTMDs. These factors include; speed of the person walking through, the height and orientation of the test object, shielding of the test object and walking through with multiple test objects. This paper begins with a detailed explanation on the background of our research, highlighting the real life applications of walk through metal detectors, use of WTMDs in stadiums, acceptance testing, and WTMD standards. Finally, the paper gives an overview of each experiment and a short summary of results. II. BACKGROUND A. Walk-Through Metal Detectors in Stadium Venues WTMDs are usually stationed outside the gates at stadiums where they are used as a way to prevent contraband items from entering the venue. Due to a large number of spectators, there exists a conflict in trying to balance aspects of sensitivity of the WTMD with the throughput rate of the machine [2]. This is because a higher sensitivity level would trigger an alarm of a larger range of objects, thereby affecting the throughput by slowing it down. On the other hand, a lower sensitivity would trigger an alarm for a smaller range of objects, which in turn increases throughput of the machine. B. Walk-Through Metal Detector Standards WTMD standards govern the way metal detectors are operated in different environments. These standards serve as requirements that need to be satisfied by each individual WTMD in order to guarantee they work as presumed, and to be certified as meeting a specific standard. One WTMD standard is the NILECJ 0601.00 [5] standard, which was created in 1974. The NILECJ 0601.00 has five security levels ranked based on their strictness in detection. In later years, several updates for the NILECJ 0601.00 were made by NIJ. These updates include the NIJ 0601.01 written in 2000, NIJ 0601.02 written in 2003, and NIJ 0601.03 [6] [7].desired contraD. Acceptance Testing Acceptance testing is a form of testing that involves using actual contraband item, replicas of those items, or items shaped like the desired contraband items. WTMD standards call these items test objects, and there are strict requirements for those test items. In our acceptance testing, contraband items are placed on the body of the person who is to walk through the metal detector [1]. In similar acceptance testing scenarios (e.g. in schools), trials typically are repeated 20 times for each object being tested to ensure accurate results [1]. In this particular acceptance testing [1], the test object would be successful in the experiment if at least 19 out of 20 times. A success or failure has the object cause an alarm or fails to cause an alarm, depending on the testing objective. III. EXPERIMENTAL APPROACH A. Contraband Research Research was done to identify items that are likely to be prohibited at stadium as well as actual prohibited items peculiar to various sports stadiums. A list was then compiled, acting as a directory for prohibited items at stadium venues. In the laboratory testing, twelve contraband items corresponding to the list were used in order to determine the impact of varying factors on WTMDs. IV Overview of Results The results obtained from each experiment were determined as a pass for an individual test when contraband objects are detected at least 95% of the time (or passing at least 19 out of 20 trials). When the item fails to fulfill this criteria, it is said to have failed that test.
Abstract- IEEE-11-1-2016 (1).docxFunder Acknowledgement(s): DIMACS ; CCICADA
Faculty Advisor: Christie Nelson, christie.l.nelson.phd@gmail.com
Role: Created three experimental designs to understand the detection of stadium contraband items on two brands of field-used WTMD. Performed field observations of a large venue's patron screening process and collected data on contraband items, their detection, and the deterrence effect of WTMDs.