Browsing by Subject "Airplanes"
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Item A cost-benefit analysis of alternative device configurations for aviation checked baggage security screening(Texas Tech University, 2004-05) Ritchie, LynseyIn the two years since the terrorist attacks of September 11, 2001, the security of our nation's civil aviation system has assumed renewed urgency, and efforts to strengthen aviation security have received a great deal of congressional attention (GAO-03-1150T). As of early 2003, an estimated 1,100 explosive detection systems (EDS) and 6,000 explosive trace detection machines (ETD) had been deployed to ensure 100% checked baggage screening (GAO-04-440T). These two explosive detection technologies are an integral part of the security strategies currently being used in US airports. However, the prohibitive costs associated with deploying and operating such devices and machines has led the TSA to evaluate the cost, effectiveness, maturity, and efficiency of these devices to ensure that they achieve the maximum pay-off in improved security for funds spent (Jacobson et al. 2003b). In addition to the evaluation of cost effectiveness of current explosive detection devices, research into advanced screening equipment and associated technologies has also become a priority. The main objective of this thesis is to evaluate the cost effectiveness of the explosive detection technologies currently in US airports supplemented with evaluations of the newest technologies which could possibly be used to screen checked baggage in the fixture. The research analyzes both single device systems in addition to several cascading sequences of devices. In particular, the expected annual direct cost of using these devices for 100% screening under various checked baggage screening scenarios is obtained. The tradeoffs between using single device strategies and sequenced combinations of the devices are also studied. Lastly, the expected number of successful threats under the different checked baggage screening scenarios with 100% checked baggage screening is studied. The results indicate that for the current security setup, with current device cost and probability parameters, single device systems are less costly and give optimal successful threat values. The cost model introduced provides an effective tool for the execution of cost-benefit analyses of alternative device configurations for aviation checked baggage security screening. Butler and Poole (2002) and Poole and Passantino (2003) feel that a risk-based system is a superior approach to aviation security. If the US implements this type of security system, this cost model will be a valuable tool in developing the optimal device configuration.Item Prediction of energy absorption of extruded tubes(Texas Tech University, 2000-12) Sun, JunningIn this study, the FE crush analysis was carried out using LS-DYNA. It is an advanced general purpose nonlinear FE program. LS-DYNA is suited to handle the large deformations, sophisticated material models, and complex contact interactions required to analyze crash simulations. The objective of this study was to investigate the effect of five parameters on the energy absorption of extruded tubes. The five parameters considered were: imperfection location, cross-section, impact velocity, cutout size, cutout location, and impact mass size. It was shown that the circular and hexagonal extrusions had a high energy absorption efficiency compared to triangular ones. However, the triangular extrusions had the lowest crush peak force. Additionally, cutouts introduced in the sides of the extrusions lowered the crush peak force. Increasing the kinetic energy of the impacting mass was shown to increase the crushing distance, while also increasing the peak force slightly. Finally, it was further showm that cutout and imperfection location influenced the tube folding pattern.Item Uncommon ground: aviation collections and the lack of standardized collection management practices(Texas Tech University, 2000-12) Tidwell, Robert WilliamIt is the hypothesis of this thesis that there are no standardized collections management methods for aviation collections. Moreover, this thesis will verify that the lack of standardized collections management policies is due to lack of attention to the special needs of aircraft collections (especially in the areas of conservation and restoration). This thesis will be substantiated by presenting different collections management issues relevant to aircraft and demonstrating the varying means by which aviation museums respond to these issues, as well as the factors that influence each museum's response. The thesis is divided into four chapters. Due to the integrated nature of collections management, many of the sections will have a degree of overlap.