COGS Thesis and Dissertations
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- PublicationSimulating the effects of remote tsunami waves induced by earthquake on transmission tower: A real case study(2020)
;G. Nelvindran S. GovindasamyThe Manila Trench subduction zone is an active convergent plate margin between the South China Sea and northern Philippines. In recent events, Manila subduction zone has been distinguished as a high hazardous tsunamigenic earthquake source region within the South China Sea where no earthquake larger than Mw = 7.6 has been recorded in the past 100 years. However, there are probability for larger earthquakes in the future anticipated to affect neighbouring countries such as Malaysia as historical data are not reliable. These large earthquakes could potentially trigger the generation of tsunami that will propagate towards South China Sea and reach East Coast of Peninsular Malaysia. Hence, this study investigates the severity of tsunami and its impact on power plant structure located near the coastal areas, which in this case a transmission tower. The potential disastrous impact of tsunami waves on a power plant causes loss of lives, damage to assets, and loss of electricity for the coastal communities similar to year 2011 Tohoku tsunami in Japan. Therefore, application of shallow water equation (SWE) in tsunami modelling namely generation and propagation phase and nonlinear shallow water equation (NSWE) for run-up and inundation phase of a tsunami event are pertinent in simulating various scenarios of tsunami. In this study, simulations were carried out at earthquake intensities of moment magnitude Mw 7.0, Mw 8.0, and Mw 9.3. These ranges of earthquake intensities were chosen to illustrate the significant difference in the capacity of earthquake induce tsunami investigated in this study. The worst-case scenario of Mw = 9.3 was found to cause the state of Terengganu to experience a wave height ranging at 0.51m-1.54m with arrival time of 9-12hrs. Meanwhile, the inundation depth at power plant in Paka, Terengganu was found to reach up to 1.25m and resulted to tsunami force of 164.81kN as lateral load. This lateral load is then applied to a 275-kV transmission tower using Linear Static Analysis, where the maximum lateral force, Fx was determined. Based on the modelled transmission tower, beam number 395 and node number 274 exhibited the maximum value of Fx = 6442.28kN was obtained which produced a factor of safety for compression capacity of 4.61 that can be concluded as unsafe for compressive design. Hence, an additional member is recommended to be added at this critical beam and node in order to improve its compression and tension capacities and withstand lateral load from tsunami event. Gusset plate capacity and bolt resistance of critical members were, however, found to be able to withstand effects from tsunami force at Mw 9.3. Thus, this study has established that tsunami inundation depth and waves velocity were the parameters found to highly influence the stability of affected transmission tower. - PublicationSIMULATION AND PERFORMANCE ANALYSIS OF MEMRISTOR BASED RING OSCILLATOR TRUE RANDOM NUMBER GENERATOR FOR HARDWARE SECURITY(2021-05-30)
;NOOR ALIA BINTI NOR HASHIMThe world is evolving where there is a huge reliance on the internet and online transactions which makes hardware security exposed to security attacks. Software operations are easily targeted which makes it very important to update the hardware security. It is crucial to investigate all new and improved solutions in particular using memristors. This research presented a memristor-based ring oscillators TRNG (MROTRNG) using CMOS technology. The memristor possesses characteristics such as memory-like behaviour, relatively small in size and is compatible to be used in CMOS fabrication. These characteristics are suitable to be implemented in the true random number generator (TRNG) design and be applied for hardware security purposes. By implementing memristor in the TRNG design of the ring oscillators, the oscillation frequency can be more random and affects the process variations of the entropy source circuit. The memristor based ring oscillators was designed to oscillate around 100MHz with a voltage supply of 1.8V using SilTerra‟s 180nm CMOS technology. The randomness value was calculated to be 1.6769 for MRO. Performance metric were calculated and analyzed in terms of uniqueness, uniformity, and bit-aliasing with an ideal value of 50% for each metric. In addition, the National Institute Statistical Test Suite (NIST) was used to evaluate the performance results of the TRNG. There are three scenarios that were used to compare the performance of the TRNG designs. These are 1 st scenario: TRNG with inverters of NMOS and PMOS transistors, 2nd scenario: TRNG with common source with resistive load as inverters and 3rd scenario: TRNG with common source with memristive load as inverters. Each scenario of the design passes the performance metric calculation but the best results was based on 2nd scenario with the smallest percentage error of 0.208% with 49.986%, 49.03% and 49.03% of uniqueness, uniformity and bit-aliasing respectively when data is 10000 bits in size. Although, the TRNG design in 2nd scenario produces the best results and passed 10 out of 12 of the NIST tests compared to other scenarios, the design in 3rd scenario showed that the output also demonstrates randomness in the output. The proposed memristor based ring oscillator TRNG was implemented with four different memristor window functions to observe any changes that might occur in the output bits. All of the TRNG design in different memristor window function passed 10 out of 12 of the NIST tests when data size is 2000 bits. This research has proved that the memristor based ring oscillator TRNG has the potential to produce output that demonstrates randomness characteristics suitable as solution to security.