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- PublicationDesign, development and fabrication of autonomous surface vessel (ASV) shallow water mapping application(2024-07)This thesis explores the development and application of Autonomous Surface Vehi cles (ASVs) as advanced tools in marine technology, specifically addressing the critical need for accurate underwater terrain mapping. Traditional methods often fail in com plex, shallow water environments, impeding scientific, environmental, and maritime operations. By integrating ASVs with advanced sonar systems, this research aims to enhance mapping accuracy and efficiency. The methodology encompasses the devel opment of an ASV capable of wireless navigation and precise depth readings, detail ing the project flow, hardware and software integration, and iterative design processes. Field tests conducted in shallow water environments validated the system’s performance, with data analysis highlighting improvements in navigation accuracy and depth reading precision. These findings demonstrate the potential of ASVs in enhancing underwater mapping and supporting broader scientific, environmental, and navigational applications.
- PublicationDesign of UHF RFID fabric tag antenna(2024-07)Over the past few decades, there has been a growing demand for radio frequency identification (RFID) systems, which offer enhanced performance across various industrial applications and consumers such as object tracking and automatic identification. Despite these developments, the textile retail industry still uses barcodes for product tracking, a technique that relies on human scanning and results in less efficiency. Moreover, the limitations of barcode-based tracking, including vulnerability to theft, highlight the need for more effective alternatives. Implementing RFID technology in these systems enhances efficiency and performance. This project focuses on designing a fabric tag antenna compatible that works under Malaysia's UHF RFID system which is between 919 MHz and 923 MHz. The antenna uses woven conductive fabric for both the radiating patch and ground, with felt fabric as the substrate. The antenna is designed and analyzed using Computer Simulation Technology (CST) Microwave Studio. The prototype of the antenna is manually fabricated to validate its performance and findings. Measurement results show a return loss S11 of -19.17 dB at 921 MHz and a bandwidth of 17 MHz (913.5 - 930.5 MHz). The measured gain reaches 1.51 dB at the same frequency. Overall, the fabricated antenna shows good agreement between measurement and simulation results. Moreover, return loss and gain effects of fabricated antenna under wet and dry conditions were discussed.
- PublicationDesign of rope climbing robot(2024-07)In this ever-evolving field of robotics, innovative solutions are continually being developed to tackle dangerous and hazardous tasks. The climbing robot was developed to help humans reduce the risk of injuries in completing dangerous tasks such as inspections and maintenance in high-rise buildings, towers, cables, and steel bridges. By using a climbing robot, the task efficiency can increase and the cost of labour can be reduced. Some of the climbing robots have a maximum load that exceeds 50 kg, which makes the costs for development and maintenance significantly higher than another climbing robot with a lightweight load. Thus, to reduce the operational costs, the rope climbing robot was designed with a focus on lightweight structure and high efficiency in climbing the rope while functioning as a transportation carrier. For this purpose, the design of the rope climbing robot included a storage compartment that was able to hold multiple light objects, such as first aid kits, tools, and communications devices that were needed for emergency situations, maintenance tasks, and for clearer communication in areas with no signal coverage, such as mountain areas. Based on the results acquired from the experiments conducted, the rope climbing robot can climb the rope in horizontal position, moving forward and backward as well as upward and downward, with a rope at an angle of 15 degrees. By using these motions, the transportation process for carrying light objects is effectively achieved.
- PublicationDesign of ring oscillator with trimming circuit for performance tuning in CMOS 180nm technology(2024-07)Ring oscillator is an important component that used in many electronic circuits as it is able to generate clock frequency for the circuit. The output frequency that generated by the ring oscillator needs to be consistent when the ring oscillator undergo the process, voltage and temperature (PVT) variations. However, the performance of the ring oscillator is affected when undergo the process, voltage and temperature variations as the variations happen is sensitive to the ring oscillator. It will cause the frequency shifting happens in the output of the ring oscillator and degrades its clocking performance. Furthermore, the process variation will provoke uncertainty, voltage variations will cause the deviation in frequency from the ideal operating conditions and the temperature variations will cause the frequency instability. Hence, the trimming circuit is required to tune back the frequency when under PVT variations. A ring oscillator with trimming circuit for performance tuning is designed in this project. This project is constructed by using CMOS 180nm Technology and the Cadence Virtuoso Software is used to design and perform simulation for the designed circuit. An output frequency of 700MHz that obtained from ring oscillator is expected from the results of this project under Process, Variation and Temperature (PVT) variations. In the schematic design of overall circuit, there are 3 sets of capacitors are placed within the ring oscillator, each capacitor is connected to 1 nMOS switch, and each set of capacitors is connected to 1 voltage source. The capacitor and the nMOS switch in the same set have the same properties. Since there are total 3 voltage sources, Vtune1, Vtune2 and Vtune3 are used to control the ON of OFF of each set of capacitors, hence there are total of 8 arrangements of bits used for frequency correction. The simulations are then carried out for all the PVT cases. The arrangements of bits that selected for all cases in the pre- and post-layout simulation are different as the desired frequency is not obtained with the original arrangement of bits that selected in pre-layout simulation. The simulation results of frequency for all PVT cases in post-layout simulation are from 600MHz to 800MHz, all cases have an arrangement of bits able to obtain the desired frequency, 700MHz. The power consumption in pre-layout simulation is 33.1457µW, and in the post-layout simulation is 29.3857µW.
- PublicationDesign of a band gap reference voltage with trimming circuit for performance tuning in CMOS 180nm technology(2024-07)A bandgap voltage reference (BGR) circuit is used to provide a stable output for analog and digital blocks such as A/D and D/A converters. The output needs to be stable across several aspects, including temperature, power, and process variations. The BGR utilizes two quantities with opposite temperature coefficients (TC): PTAT (Proportional To Absolute Temperature) and CTAT (Complementary To Absolute Temperature). These quantities are added through multiplication with the correct weighting factors to achieve stability. However, process, voltage, and temperature (PVT) variations can affect the overall performance of the BGR. Process variation occurs due to the lithography step, while voltage variation is caused by fluctuations in the power supply. Temperature deviations can cause mismatches and functional failures. Hence, a trimming circuit is required to tune the performance of the BGR due to PVT variations. In this project, a bandgap reference voltage with a trimming circuit is designed. The overall circuit is constructed using 180nm CMOS technology. A stable BGR output of 1.2V is expected from this project. A two-stage operational amplifier with a gain higher than 60dB and a phase margin of 45° is required. The workflow of the project starts with identifying the properties of MOSFETs for ease of circuit calculation. Next, the calculation and design of the bandgap voltage reference and the two-stage operational amplifier are carried out. The trimming circuit is built to maintain the performance of the BGR. Simulations for both components are conducted to check the performance of the circuit. At the pre-layout simulation, the two-stage OPAMP achieves a DC gain of 75.2611dB and a phase margin of 77.633°. Across all corners of the pre-layout and post-layout simulations, the output reference voltage is 1.2V, with a temperature coefficient lower than 30ppm/°C.
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- PublicationFactors Influencing Online Gambling Acceptance Among Thai Undergraduate Students(2023-02)This study aims to examine the factors that have impacts on Thai undergraduate students’ behaviour. Thus, the technological, psychological, and personal factors will be used to create a comprehensive model of TAM (Technology Acceptance Model) to explain why Thai undergraduate students tend to gamble online
- PublicationThe Mediating Effect Of Innovation Culture In Computerised Accounting Information System (Cais) Implementation Factors Towards Construction Companies Performance In Iraq(2023-07)The construction industry must implement new technologies, such as computerise accounting information systems (CAIS), to overcome a number of obstacles in order to adapt to the ever-changing construction environment. There is a need to investigate the effect of CAIS contexts on construction companies’ performance and the role of innovation culture as a mediator between CAIS and construction companies’ performance. A thorough evaluation of the literature was done in response to this identified research gap, focusing on the relationship between CAIS and construction companies’ performance. The finding of the literature study showed that CAIS and construction company performance are poorly understood. Empirical research is needed to close this gap and improve CAIS implementation industry practises. This study seeks to investigate the impact of CAIS contexts on the performance of construction companies and the role of innovation culture as a moderator in the relationship between CAIS and performance. The construction companies in Iraq were surveyed for this study using a structured, self-administered questionnaire. From a population of 208 businesses, a non-probability sampling technique was employed, resulting in a 73% response rate. The collected data were analysed to determine the influence of CAIS on the performance of construction companies. The results indicate that none of the three CAIS contexts had a substantial effect on the performance of construction companies.
- PublicationA clinical test for a newly developed direct brain cooling system for the injured brain and pattern of cortical brainwaves in cooling, non-cooling and dead brain(2020)A direct brain cooling system was newly innovated purposedly to ensure direct delivery of therapeutic hypothermia at a selected constant temperature to the injured brain. The practicality, effectiveness and safety of this system were tested clinically in our initial series of fourteen patients with severe head injuries. The patients were randomized into two groups – direct brain cooling at 32°C and the control group. The patients underwent standard decompressive craniectomy. Post operatively, all of them received intracranial pressure, focal brain oxygenation, brain temperature and direct cortical brainwave monitoring. The direct brain cooling group did better in the Extended Glasgow Outcome Scale at the time of discharge and at six months after trauma. This could be due to a trend in the monitored parameters; reduction in intracranial pressure, increment in cerebral perfusion pressure, optimal brainredox regulation, near-normal brain temperature and lessening of epileptic-like brainwave activities are likely reasons for better outcomes in the cooling group. Finally, this manuscript depicts interesting cortical brainwaves during a transition time of being alive to dead. The demonstrated cortical brainwaves are thought as obeying the principles in quantum physics.
- PublicationOptimization of zeolite as filler in polypropylene composite(2009-05-01)Optimization of natural zeolite as filler in polypropylene composite was studied. Two types of coupling agents which are stearic acid and vinyl silane were used in order to study the effect of filler surface treatment on the composite mechanical properties. Prior to mixing process, zeolite was grinded by ring mill into a powder form. Zeolite/polypropylene (PPZ), stearic acid treated zeolite/polypropylene (PPZ SA) and vinyl silane treated zeolite/polypropylene composites (PPZ VS) were prepared using Thermo Haake Polydrive internal mixer and were then compression molded according to standard test specimen. Torque-time curves were plotted to investigate the processing behavior of the composites. The torque value increased with increasing zeolite content from 5 vol. % to 25 vol. % but decreased with the presence of the coupling agents in PPZ composite. Tensile test and impact test were performed to characterize the mechanical properties of PPZ, PPZ SA and also PPZ VS. The obtained experimental values of tensile modulus were then related to the theoretical predictions using a Halpin Tsai equation. The theoretical prediction results in greater values of tensile modulus compared to the experimental values. Fourier Transform Infra red (FTIR) spectra analyses were performed on the composites to study the interaction between the polypropylene and functional group of stearic acid and vinyl silane. Besides, morphological study was done on the tensile fractured surface using a scanning electron microscopy (SEM). It was found that the tensile strength (TS), elongation at break (EAB) and impact strength (IS) decreased but the tensile modulus (E) increased with increasing zeolite content. The addition of coupling agents was proved to enhance the mechanical properties of PPZ. However, stearic acid has little effect in improving the composite mechanical properties in comparison with vinyl silane.
- PublicationPeak flow attenuation using dry pond(2005-04-01)The conventional drainage system increases the storm water runoff and produced larger flow discharge at downstream and causing flash flood. This study shows the function and the effectiveness of the BIOECODS that use infiltration engineering, retaining, treatment, and reducing the flow in order to attenuate the peak flow as suggested in Manual Saliran Mesra Alam (MSMA). In other words, this new method is a new development that is very effective in storm water management using ‘control at source’ method. This study “Peak Attenuation Using Dry Pond” has been carried out to determine the effectiveness of dry pond, one of BIOECODS’s components. Dry pond is calculated in terms of its capability to retain and drain the storm water. From this study it shows that the dry pond perform very well in retaining storm water runoff before draining into the storm water systems, therefore avoiding the occurrence of inundation at the downstream end. The emptying time for Dry Pond C and Dry Pond G is less than 24 hours. The infiltration and sieve analysis also performed to show the effectiveness of dry pond to infiltrate slowly to attenuate the peak flow at downstream. Lastly, hopefully this study may achieve its objectives.
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