Thesis (M.S. in Aeronautical Engineering) Naval Postgraduate School, June 1997. / Thesis advisor, Robert E. Ball. AD-A329 367. Includes bibliographical references (p. 52-53).

Trespassing behaviour is a problem for railway operations and manifests itself through train-pedestrian collisions, incidents of theft and vandalism to rail infrastructure, as well as encroachment on railway property. The study has consisted of a quantitative and a qualitative part. The quantitative part analyses demographic, temporal and spatial data on train-pedestrian fatalities and injuries, as well as data on occurrences of theft and malicious damage to rail infrastructure in the Cape Town Functional Region between 2015 and 2018. The qualitative part presents the perspective from a diverse group of subject matter experts, having explored opinions on trespassing behaviours and preventative measures. Additionally, the trespassing behaviour at several sites was investigated and a case study evaluation of the efficacy of a pilot Rail Enforcement Unit was carried out. There were 456 railway-related deaths during the study period with 330 of this being train-pedestrian collisions. There were 4715 occurrences of theft and malicious damage to railway assets over the period. Several hot-spot areas were identified via the data and interviews with experts and several sites chosen for further verification. Site visits confirmed widespread trespassing behaviours with the two worst locations recording an average of over 300 persons in a 15-minute period. The case study reviewing the effectiveness of the security and enforcement countermeasure revealed that occurrences of train-pedestrian incidents, as well as security occurrences have increased by 1.4% and 7.5% respectively. Evidence of geographical displacement of crime is evident, suggesting that enforcement countermeasures are temporarily effective and need to be considered in combination with other measures to ensure its durability. In conclusion, this research presents a detailed analysis of railway trespassing and its main effects in order to understand the problem locally. Different approaches are required to combat the various guises of railway trespassing. Certain countermeasures may well be within the rail operator's remit, but essentially, the nature of problems experienced by the rail operator is beyond a rail problem, and requires a systems approach involving multiple authorities

Side-channel leakage, caused by imperfect implementation of cryptographic algorithms in hardware, has become a serious security threat for connected devices that generate and process sensitive data. This side-channel leakage can divulge secret information in the form of power consumption or electromagnetic emissions. The side-channel leakage of a crytographic device is commonly assessed after tape-out on a physical prototype. This thesis presents a methodology called Gate-level Leakage Assessment (GLA), which evaluates the power-based side-channel leakage of an integrated circuit at design time. By combining side-channel leakage assessment with power simulations on the gate-level netlist, GLA is able to pinpoint the leakiest cells in the netlist in addition to assessing the overall side-channel vulnerability to side-channel leakage. As the power traces obtained from power simulations are noiseless, GLA is able to precisely locate the sources of side-channel leakage with fewer measurements than on a physical prototype. The thesis applies the methodology on the design of a encryption co-processor to analyze sources of side-channel leakage. Once the gate-level leakage sources are identified, this thesis presents a logic level replacement strategy for the leakage sources that can thwart side-channel leakage. The countermeasures presented selectively replaces gate-level cells with a secure logic style effectively removing the side-channel leakage with minimal impact in area. The assessment methodology along with the countermeasures demonstrated is a turnkey solution for IP module designers and is also applicable to larger system level designs. / Master of Science / Consider how a lie detector machine works. It looks for subtle changes in a person’s pulse to tell if the person is telling the truth. This unintentional divulgence of secret information is called a side-channel leakage. Integrated circuits reveal secret information in a similar way through their power consumption. This is caused by the transistors, used to build these integrated circuits, switching in concert with the secret data being processed by the integrated circuit. Typically, integrated circuits are evaluated for side-channel leakage only after they have been manufactured into a physical prototype. If the integrated circuit is found vulnerable it is too expensive to manufacture the prototype again with an updated design. This thesis presents a methodology, Gate-level Leakage Assessment (GLA) to evaluate integrated circuits for side-channel leakage during their design process even before they are manufactured. This methodology uses simulations to identify the specific transistors in the design that cause side-channel leakage. Moreover, this thesis presents a technique to selectively replace these problematic transistors in the design with an implementation that thwarts side channel leakage.

Presented in this thesis is the Airborne Countermeasures Ejection and/or Release (ALE)-XX Cockpit Control Unit (CCU) Countermeasures Dispensing System Network Controller (CMDSNC) design. ALE-XX CCU CMDSNC was designed as part of the total ALE-XX system to replace the problematic ALE-40. Fiber optic technology is incorporated into ALE-XX as the communication medium to eliminate Electromagnetic Interference (EMI). ALE-XX CMDSNC uses a star network to solve system operation failures from the existing daisy-chain topology. A comprehensive Built-In-Test (BIT) allows fault diagnose and isolation of hardware problems reported on the CCU Visual Display. Digital electronics replace the electro-mechanical devices, lowers the number of Line Replaceable Units (LRUs), and raises the Mean-Time-Between-Failures (MTBF). The information contained herein could be used as a design aid for future CMDSNCs or other related instrumentation.

The first objective of this thesis is to investigate the effect of several forms of electronic attack (EA) on the radio frequency (RF) sensors used within a boost-phase ballistic missile intercept system. The EA types examined include noise jamming, chaff, radar cross section (RCS) reduction, and expendable decoys. Effects of the EA methods are evaluated by examining the track position error at the sensor fusion output. Sensor fusion architectures investigated include a weighted average sensor fusion; Kalman-filter-based sensor fusion, and joint probabilistic data fusion architecture. A second objective of this thesis is to extend the single-target, single-interceptor analysis and simulation to a multi-target, multi-interceptor scenario to include the formation of an ellipsoidal gating process to correctly correlate the target measurements with the corresponding track file. We show that the most effective EA is the use of noise jamming followed by a RCS reduction of the missile body. We also show that a properly designed sensor fusion process can effectively mitigate the EA techniques that might be used in a boostphase intercept scenario.

Electrical wiring on board aircraft has raised serious weight and safety concerns in the aerospace industry. Wires are antenna. It may also cause interference to radio-based systems on the aircraft, or, in the case of military aircraft, create a "signature" that can be detected by enemy receivers. Wireless application in avionic system helps reducing the total weight and reconfigurable of the aircraft; hence, lower the fuel costs, installation cost and maintenance costs, as well as the “signature” of the aircraft. The focus of this thesis, therefore, is to study the feasibility of different wireless standards, namely Wi-Fi, Bluetooth and ultra-wide band (UWB), on replacing the wired data connection in the EW countermeasure or chaff/flare dispenser systems. The study was constructed under the supervision of the department of Electronic Defense System, Saab AB in Järfalla, Stockholm. The discussion will be based on the resource availability, the reliability, the stability and the security of the wireless system relative to an avionic application; i.e., whether wireless links will negatively affect the overall reliability and safety of the aircrafts. Due to the theoretical studies and results from the simulation, we studied the feasibility issue and concluded that UWB is the most appropriate choice of wireless communication for non-critical aerospace applications, comparing with Wi-Fi and Bluetooth. UWB links can have reasonable immunity to interferences, low interference to other on-board wireless systems, and good security performance.

Thesis (Ph.D)--Mechanical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Rogers, P. H.; Committee Member: Ferri, A. A.; Committee Member: Ruzzene, M.; Committee Member: Smith, M. K.; Committee Member: Trivett, D.; Committee Member: Zinn, B. T. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Human cardiovascular adaptations to microgravity include decreased plasma volume, exercise capacity, baroreflex function as well as decreased orthostatic tolerance upon return to a gravity environment. Several countermeasures have been proposed and tested, although currently none have been developed to prevent post-spaceflight orthostatic intolerance (OI). Artificial gravity (AG) generated by short-radius centrifugation (SRC) has been proposed as a countermeasure to OI as well as other cardiovascular alterations. Methods: Fifteen men and fourteen women underwent three weeks of daily (5 days a week) exposure to intermittent (1.0 to 2.5 Gz) artificial gravity on a 1.9m human powered centrifuge (HPC) at the NASA Ames Research Center. Half the subjects exercised (active) to power the HPC while half rode passively (passive). A combination head-up tilt (HUT) and lower body negative pressure (LBNP) test was used to determine orthostatic tolerance before and after training. Oscillatory LBNP (OLBNP) was used at seven frequencies (0.01 to 0.15 Hz) for two minutes each to assess the dynamic responses of the cardiovascular system to orthostatic stress, before and after AG training. Results: Training improved overall tolerance in the group of subjects by 13% (pandlt;0.05); men were more tolerant than were women (pandlt;0.05); and active subjects were more improved than passive subjects (pandlt;0.05). Mechanisms of improvement appear to be through decreased total peripheral resistance (TPR) and increased stroke volume after training, and increased responsiveness of TPR to fluid shifts (faster changes in TPR to changes in calfcircumference [CC] and OLBNP after training). There was no change in spontaneous baroreflex sensitivity (BRS, calculated by sequence method) or number of sequences per number of heart beats (NNS), although BRS analysis did indicate that stimulation to the cardiac baroreceptors during 1.0 Gz and 2.5 Gz centrifugation was no different than supine control and 70?? HUT, respectively. Taken together, these results suggest that AG training improved tolerance through training of local mechanisms in the peripheral vasculature, or extrinsic control of peripheral vascular resistance, rather than through changes of autonomic control of heart rate.

Many bridges are destroyed or completely failed during floods due to excessive scouring around bridge piers and abutments. Safe bridge design is based on joint consideration of structural, hydraulic, and geotechnical aspects. This study is concerned with the investigation of various types of countermeasures against scouring at bridge sites. The design criteria for various countermeasures are reviewed in terms of hydraulic, hydrologic, constructional, and economical requirements. (Conditions of applicability of these countermeasures are evaluated and designed for different return periods of flow, and hydroeconomic analyses are performed for Esenbosa Bridge). Based on the evaluation of the results of hydroeconomic analyses, combinations of rock riprap and grout filled bags are found to be appropriate measures for piers and abutments against scouring whereas vegetation is observed to be applicable for bank protection.

Thesis (M.S. in Systems Engineering)--Naval Postgraduate School, June 2005. / Thesis Advisor(s): Phillip E. Pace, Murali Tummala. Includes bibliographical references (p.155-158). Also available online.