The Edward Snowden data breach of 2013 clearly illustrates the damage that insiders can do to an organization. An insider's knowledge of an organization allows them legitimate access to the systems where valuable information is stored. Because they belong within an organizations security perimeter, an insider is inherently difficult to detect and prevent information leakage. To counter this, proactive measures must be deployed to limit the ability of an insider to steal information. Email monitoring at the edge is can easily be monitored for large file exaltation. However, USB drives are ideally suited for large-scale file extraction in a covert manner. This work discusses a process for disabling write-access to USB drives while allowing read-access. Allowing read-access for USB drives allows an organization to adapt to the changing security posture of the organization. People can still bring USB devices into the organization and read data from them, but exfiltration is more difficult.

<p> This thesis studies critical zones of automated vehicles. The goal is for the automated vehicle to complete a car-following or lane change maneuver without collision. For instance, the automated vehicle should be able to indicate its interest in changing lanes and plan how the maneuver will occur by using model predictive control theory, in addition to the autonomous vehicle toolbox in Matlab. A test bench (that includes a scenario creator, motion logic and planner, sensors, and radars) is created and used to calculate the parameters of a critical zone. After a trajectory has been planned, the automated vehicle then attempts the car following or lane change while constantly ensuring its safety to continue on this path. If at any point, the lead vehicle brakes or a trailing vehicle accelerates, the automated vehicle makes the decision to either brake, accelerate, or abandon the lane change. </p>

In this thesis, advanced control methods are presented for torque ripple reduction and performance improvement in switched reluctance motor (SRM) drives. Firstly, a comparative evaluation of power electronic converters including asymmetric, N+1, C dump, split AC, and split DC converters is presented for three-phase SRMs in terms of cost, efficiency and control performance. Secondly, two methods are proposed using torque sharing function (TSF) concepts for torque ripple reduction of SRM over a wide speed range. An offline TSF is proposed to minimize the copper loss and the absolute rate of change of flux linkage (ARCFL) with a Tikhonov factor. Then an online TSF is proposed by adding a proportional and integral compensator with torque error to torque reference of the phase with lower ARCFL. Therefore, the total torque of online TSF is determined by the phase with lower ARCFL rather than the phase with higher ARCFL as in conventional TSFs. The maximum torque-ripple-free speed (TRFS) of the offline TSF and online TSF is validated to be 7 times and 10 times as high as the best case in these conventional TSFs, respectively. Thirdly, two methods are proposed to eliminate mutual flux effect on rotor position estimation of SRM drives without a prior knowledge of mutual flux, one is the variable-hysteresis-band current control for the incoming-phase self-inductance estimation and the other is variable-sampling outgoing-phase self-inductance estimation. Compared with the conventional method which neglects the mutual flux effect, the proposed position estimation method demonstrates an improvement in position estimation accuracy by 2º. Fourthly, a fixed-switching-frequency integral sliding mode current controller for SRM drives is presented, which demonstrates high dynamics, strong robustness and none steady-state error. All the proposed control methods are verified by both simulations and experiments with a 2.3 kW, 6000 rpm, three-phase 12/8 SRM operating in both linear magnetic and saturated magnetic regions. / Thesis / Doctor of Philosophy (PhD)

The paper presents a computer-based guide of the effect of layout and loading (tension and torque) on the timing belt life and uses it to show the sensitivity of life to changed conditions in an automotive camshaft drive. The predictions are in line with experience. The guide requires belt property information, such as the tooth and tension member stiffness, the friction coefficient between the belt lands and pulleys and the pitch difference from the pulley, in order to calculate the tooth deflections caused by the belt loadings on the various pulleys in the layout. It also requires information on how the belt life depends on the tooth deflections. Experimental data are presented on the life±deflection relations of a commercial automotive timing belt tested between 100 and 140 8C, although the bulk of the data has been obtained at 120 8C. Four different life laws have been found, depending on whether the failure-initiating deflection occurred on a driver or a driven pulley, and whether at entry to or exit from the pulley. Theoretical analysis of the tooth loading in the partial meshing state shows that, in three cases out of the four, the different life±deflection laws transform to a single relation between the life and the tooth root strain. The exception is failure caused by driven entry conditions; work is continuing to understand better the causes of failure in this circumstance

Variable Frequency Drives (VFDs) are utilized in commercial and industrial facilities to improve motor efficiency and provide process flexibility. VFDs are nonlinear loads that inject harmonic currents into the power system, and result in harmonic voltages across the system impedance. This harmonic distortion can negatively impact the performance of other sensitive loads in the system. If a VFD serves a critical function, it may be necessary to supply the VFD from a Diesel Generator or Uninterruptible Power Supply (UPS). These sources have relatively high impedance when compared to a standard utility source, and will result in greater harmonic voltage distortion. This increases the likelihood of equipment failure due to harmonics. The full extent of the impact, however, is typically unknown until an extensive harmonic analysis is performed or the system is installed and tested. This thesis evaluates the impact that source impedance has on the harmonic voltage distortion that is produced by nonlinear loads such as VFDs. An ideal system of varying source types (Utility, Generator and UPS) and varying VFD rectifier technologies (6-Pulse, 12-Pulse and 18-Pulse) is created to perform this analysis and plot the results. The main output of this thesis is a simplified methodology for harmonic analysis that can be implemented when designing a power system with a VFD serving a critical function and a high impedance source like a generator or UPS. Performing this analysis will help to ensure that other sensitive loads will operate properly in the system. / Master of Science

A shaft and bearing system was developed with natural frequencies in the range of 8,000 to 60,000 rpm for the purpose of determining the practicality of low-speed harmonic excitation of high-speed natural frequencies. The analytical development and analysis utilized SPAR, a finite element program, and a bearing stiffness program to determine frequencies for the first through fourth harmonics of natural frequencies under 60,000 rpm. A misaligned flexible disc coupling was used to input a forcing function with a frequency of N times the running speed and thereby excite the natural frequencies in the Nth harmonic at the running speed. Most of the analytical results had corresponding experimental results; however, many increased vibration levels did not correlate with analytical results. Four frequency response plots are presented. A comparison of these plots and analytical results are presented in the form of a Campbell diagram. Although the experimental results are not supportive enough to be conclusive, they do indicate that low-speed harmonic excitation may be a method of predicting high-speed natural frequencies. Major difficulties were encountered in the experimental program which are described, and some alternative investigations are proposed. / M.S.

Among the different multiphase ac drive solutions, one of the most widely reported in the literature is the six-phase machine. The machines can be realised into two different configurations, symmetrical and asymmetrical. For the symmetrical configuration, the stator winding consists of two sets of three-phase windings that are spatially shifted by 60 degrees where spatial displacement between any two consecutive phases is the same and equal to 60 degrees. For the asymmetrical configuration, the two sets of three-phase windings are spatially shifted by 30 degrees. As a result, the spatial shift between consecutive phases becomes non-equidistant. In this thesis, modulation techniques for both symmetrical and asymmetrical six-phase machines are investigated. The machines are configured in open-end winding configuration where both ends of the stator winding are connected to separate isolated inverters in a topology known as dual-inverter supply. Compared to conventional single-sided supply topology where one end of the winding is connected to an inverter while the other side is star-connected, some additional benefits are offered by the dual-inverter supply topology. First, fault tolerance of the drive is improved, since the supply is realised with two independent inverters. In case one of the inverters is faulted, the other can continue to provide power to the machine. Second, the same phase voltages can be achieved with half the dc-link voltages on the two inverter inputs compared to the single-sided supply, which can be useful in applications such as electric and hybrid electric vehicles and medium sized ships, where the dc voltage levels are limited. Further, due to the nature of the topology, additional diodes and capacitors like in the Neutral Point Clamped (NPC) and Flying Capacitor (FC) VSIs are not required. The latter results in a further advantage - capacitor voltage balancing techniques are not required. Two pulse width modulation (PWM) techniques for control of the dual-inverter supplied six-phase drives are proposed in this thesis. The first is a reference sharing algorithm where the inverters are modulated using reference voltage that is shared equally and unequally between the two modulators. For both symmetrical and asymmetrical six-phase drives, a better performance, in term of total harmonic distortion (THD) of phase voltage is obtained when the reference is shared unequally between the two modulators. The second technique is carrier-based modulation where the modulation of the two inverters is determined by the disposition of the carrier signals. Three variations of carrier signals disposition are investigated namely; the phase disposition (PD-PWM), alternate phase opposition disposition (APOD-PWM) and phase-shifted PWM (PS-PWM). For the symmetrical six-phase drive, the best phase voltage and current THDs are obtained using APOD-PWM while for asymmetrical six-phase drive, the APOD-PWM produces the worst current THD despite having the best voltage THD among the three methods. All the developed modulation techniques are analysed using simulations and experiments undertaken using a laboratory prototypes. The waveforms and spectra of phase voltage and load current obtained from the simulation and experimental works are presented in this thesis together with the THD of both the voltage and current over entire linear modulation range.

The subject of this diploma thesis is designing a way of substituting pneumatic drives with electrical actuators for mechanical movements in a headlights tester. The thesis also contains a theoretical introduction to the issue in the first part. Substitution variants are assessed considering chosen parameters and evaluated using multi-criteria evaluation method. Two final designs are compiled based on the evaluation results and processed into the 3D model of the tester. Drawings are produced for these solutions. In conclusion, a recommendation derived from achieved results is given to the tester manufacturer, ELCOM a.s.

Design and construction of machine respects the needs of the manufactory of delicatessen. In my technical report there were also project several drives and there were described main structural parts of the machine.

<p>Predicting core losses in electromagnetic and electromechanical devices such as electric machines is crucial to avoid overheating or oversizing. This work focuses on predicting core loss under a dc bias condition which results in hysteresis loop distortion and an increase in the core loss. The interest in dc biased materials is to facilitate design of electric drive systems wherein the electric machine core is subject to a dc bias such as in homopolar machines. Owing to their simplicity and ease of use, Steinmetz-based models are considered in this work. Herein, four models based on Steinmetz Equations are studied and compared for dc offset sinusoidal field intensity waveforms. The model parameters are then characterized for a sample of M15 steel. Finally, the four models are compared with regards to their accuracy and performance under saturated conditions.</p>