https://ptsldigital.ukm.my/jspui/handle/123456789/388928 2026-04-27T07:46:34Z 2026-04-27T07:46:34Z Khoir, Aulia Nisa'ul (P111120) https://ptsldigital.ukm.my/jspui/handle/123456789/777866 2025-02-05T04:30:51Z 2023-05-31T00:00:00Z

Title: Distribution pattern of historical and future conditions of biomass burning events over Malaysia - Indonesia Authors: Khoir, Aulia Nisa'ul (P111120) Abstract: Biomass burning haze in Malaysia - Indonesia has become a recurring annual issue. Fire hotspot monitoring and projection are the efforts to control the forest and land fire disasters that cause the biomass burning haze. The study assesses the historical distribution and projected future condition of biomass burning (BB) activities in Malaysia - Indonesia. The study performed Empirical Orthogonal Function (EOF) and Rotated-EOF (REOF) to investigate the historical distribution of biomass burning and Aerosol Optical Depth (AOD) as aerosol emission proxy from 2001 to 2020 years. Climate indices are also included to analyze their impacts on BB and AOD distribution. The future condition of BB events (2041 – 2070 years) is projected by applying the Fire Weather Index (FWI), a hotspot danger rating system based on the future climate projection data from CORDEX-SEA. The future climate projection is performed under two scenarios, business-as-usual (RCP4.5) and worst-case scenario (RCP8.5). The results suggest that the primary regime of BB over Malaysia - Indonesia, represented by the distribution of BB and AOD, comes from the burning activities that primarily occurred in the Kalimantan and Sumatra. The research work also shows that the presence of weather anomalies, namely El Niño South Oscillation (ENSO) and positive Dipole Mode (DM), affect the distribution of the BB events and AOD. Additionally, the projection of fire hotspots shows an overall increase in future fire activities under the RCP4.5 and RCP8.5 scenarios. However, the average percentage increase of FWI in the future (2041 – 2070) under the RCP8.5 scenario is 43.9%, higher than under the RCP4.5 scenario, which is 39.7%. In short, this study explains how the fire events varied over the past two decades Malaysia – Indonesia and the future fire danger rating for mitigating action consideration. Lastly, the study is expected to be one effort to prevent and reduce the impact of BBH haze in Malaysia – Indonesia.

2023-05-31T00:00:00Z Ali Ahmed Musaed, Alya (P115986) https://ptsldigital.ukm.my/jspui/handle/123456789/777865 2025-02-05T04:29:19Z 2023-12-18T00:00:00Z

Title: Metamaterial-based massive mimo antenna array for 5G and beyond wireless communication system Authors: Ali Ahmed Musaed, Alya (P115986) Abstract: Fifth generation (5G) and beyond wireless era has resulted in substantial breakthroughs in various industries, including telecommunications, healthcare, and Internet of Things (IoT). These advances are made feasible by using high-frequency spectrums, which surpass the limitations of traditional communication systems. However, the growing demand for wireless communication services outstrips the capabilities of existing technologies, prompting the development of new technologies. Massive multi-input multi-output (M-MIMO) technology has received much attention in the research community due to its ability to dramatically improve wireless communication system capacity while needing only minor increases in bandwidth or power for transmission. The main goal of this thesis is to develop a M-MIMO antenna array system backed up with several unique metamaterials (MTMs) to meet the requirements of developing 5G and 6G wireless communication systems. Two high-gain planar and non-planar antenna systems based MTM have been designed, fabricated, and measured for the upcoming millimeter wave (mm-wave) 5G applications, whereas a third M-MIMO system for 6G applications is developed. First, the planar M-MIMO antenna is designed with 64 elements which are fed with 16 port, whereas each subarray has 2 × 2 rectangular-shaped patches. However, the second M-MIMO antenna is a non-planar 16-port system built on 3D-octagonal-shaped block geometry with eight broadband sides to involve 360 degrees of the coverage area. Each antenna is made up of 2 × 2 y-shaped radiating patches. Moreover, both planar and non-planar mm-wave M-MIMO antennas has been equipped by the proposed epsilon-negative (ENG) and double-negative (DNG) MTMs to enhance performance. Furthermore, a third non-planar M-MIMO antenna for 6G applications is designed, which is one of the main focuses of this work. A novel 3D cross-shaped M-MIMO system is introduced and loaded with unique MTM to serve terahertz frequencies. The antenna system consists of 16 ports distributed across four sides of a cross-shaped Polyimide substrate, with each side integrating 2×2 MIMO systems that share a common ground and loaded with a near-zero-index epsilon-negative (NZI-ENG) MTM decoupling structure to enhance the isolation between array elements. The parameters of the three developed antenna systems have been optimized using commercial Computer Simulation Technology software (CST). Utilizing the advantages of the proposed ENG/DNG MTMs to the proposed mm-wave M-MIMO antennas resulted with enhanced performance in terms of isolation, gain and efficiency. The performance of the planar M-MIMO antenna, which operates within 25.5-29 GHz, reached an increased efficiency up to 99%, along with lower measured isolation levels of up to 25 dB and a maximum gain of 20 dBi. Whereas the 3D octagonal-shaped antenna system which operates on the frequency span of 24.8-28.6 GHz obtained a high isolation level of 23 dB, a maximum measured gain of 14.9 dBi, and an efficiency of up to 97%. As for the 6G non-planar cross-shaped M-MIMO antenna which operates between 0.24 to 0.40 THz frequency band, the MTM decoupling structure effectively accomplishes an isolation of greater than 24 dB for, boosting antenna performance to reach a maximal gain of 13.2 dBi and an efficiency of 92%. The proposed non-planar 3D-MIMO antenna system has tremendous potential for use in wireless communication applications of the 6G.

2023-12-18T00:00:00Z Md. Ismail Hossain (P108132) https://ptsldigital.ukm.my/jspui/handle/123456789/777864 2025-02-05T04:27:33Z 2024-01-29T00:00:00Z

Title: Ferrite based nanoparticiles synthesized and characterized flexible microwave substrate for multiband wireless applications Authors: Md. Ismail Hossain (P108132) Abstract: Flexible substrate materials with tunable electromagnetic properties are attractive to researchers in modern microwave technology for designing flexible multiband wireless applications like antennas and metamaterials (MTM). The problem addressed in this thesis is the need for advanced and versatile microwave substrates, as current limitations in ferrite-based nanoparticle synthesis and characterization hinder the development of flexible substrates for multiband wireless applications. The motivation behind this research stems from the inherent limitations of existing microwave substrates and the potential benefits offered by ferrite-based nanoparticles. This research is aimed to synthesize and characterize ferrite-based nanoparticles to develop new flexible microwave substrate materials which can be affordable for manipulating electromagnetic properties. Firstly, a single negative (SNG) Stove-shaped metamaterial is developed on MgxZn(1-x)Fe2O4 ferrite-based flexible substrate. The synthesized Mg-Zn ferrite material substrate flexible exhibited maximum 90° bending stability when compared with different conventional substrate materials of Rogers RO3003, Rogers RO4835 LoPro, and FR-4 lossy. The structural, morphological, electromagnetic, and dielectric properties of the proposed MgxZn(1-x)Fe2O4 are investigated. The proposed flexible substrate-based MTM structure can be a potential candidate for wireless communications in the S and C bands. Secondly, an Ox Wheels-shaped (OWS) metamaterial absorber is designed on CaxCo(0.90-x)Al.10.Fe2O4 nanoparticle-based flexible substrate. The structural, morphological, electromagnetic, and dielectric properties of the proposed CaxCo(0.90-x)Al.10.Fe2O4 are investigated. This specific resonance frequency reached the highest 99.61%, 98.03%, and 98.79% absorption, which covers the S, C, and X bands. Finally, a Drone-shaped SNG metamaterial is designed on CaxCo(.9-x)Zn.01Fe2O4-based flexible substrate to investigate the effective parameters for microwave applications. The raw materials are taken according to the chemical formula of CaxCo(.9-x)Zn.01Fe2O4, where X=25%, X=50%, and X=75%, respectively. The structural, morphological, electromagnetic, and dielectric properties of the proposed CaxCo(.9-x)Zn.01Fe2O4 are investigated. The Drone-shaped SNG metamaterial covers S, C, and X band frequency ranges. This study investigated three different materials MgxZn(1-x)Fe2O4, CaxCo(0.90-x)Al.10.Fe2O4, and CaxCo(.9-x)Zn.01Fe2O4 then metamaterials unit cell is fabricated on it for experimental verification through a Vector Network Analyzer (VNA). The dielectric assessment kit assessed the produced samples' loss tangents and dielectric constant values (Schmid & Partner Engineering AG, SPEAG, and DAK 3.5). The results ensure that the ferrite nanoparticle-based flexible microwave substrate offers tunable electromagnetic properties and is suitable for developing metamaterials for flexible microwave technology.

2024-01-29T00:00:00Z Sarah Shaharuddin (P111119) https://ptsldigital.ukm.my/jspui/handle/123456789/563323 2024-09-24T08:40:17Z 2023-07-01T00:00:00Z

Title: Geospatial assesment of a cost-effective IoT-based sensor for multi sensing detection in a campus setting Authors: Sarah Shaharuddin (P111119) Abstract: The emergence of the Internet of Things (IoT) and the smart city concept has revolutionised automation frameworks, enabling the realisation of previously fictional scenarios. In line with this, this research aimed to develop an IoT-based sensor and integrate notification platforms for an early warning system during indoor fire hazards with a specific focus on the UKM campus building, using digital technology, including IoT sensors, actuators, and devices. The primary focus of this study is the application of sensor technology for detecting indoor fire hazards and incorporating a novel approach to assess the data quality produced by the sensor using geospatial analysis techniques. This research comprised seven phases: literature review, prototype development, database establishment, notification platform configuration, system integration, ground simulation, and data processing and geospatial analysis. To achieve this, a physical sensor consisting of temperature, humidity, smoke, and flame sensors was developed and subjected to simulations to assess its functionality. Five series of ground simulations with different time frames were conducted based on the probability of smoke ignition according to the building's attributes. Geospatial analyses, including inverse distance weighting interpolation, density calculation, standard deviational ellipse (SDE), and mathematical graph, were employed to represent and analyse the quality of the generated data. The raster representation indicated that the smoke distribution conformed to the simulation environment on the ground, with high correlation between regions related to the smoke ignition point and the presence of smoke. The analyses considered the wall as a barrier to ensure that the interpolation results closely represented the ground. The smoke density pattern throughout the simulation revealed that the areas related to sensor 5, sensor 6, sensor 7, sensor 9, and sensor 10 were the most intense spots, consistently intense from the beginning to the end. Additionally, the SDE analysis of the smoke data indicated a northwest-southeast distribution, consistent across the simulations despite being divided according to different timelines. Simulation 4 had the largest ellipse size, while simulation 1 represented the smallest. The findings of the study demonstrated that the proposed sensor prototype successfully detected early fire hazards in the UKM campus building. Moreover, the analysis of the sensor data revealed variations in sensitivity among different sensors, as indicated by the density estimation and standard deviation of the data. This research also contributes to the development of a smart campus framework, specifically focusing on the UKM campus building and its existing fire alarm system, which currently employs conventional methods. Overall, this research combines geospatial analysis and IoT-based sensor systems to develop a smart campus environment in UKM capable of early fire detection. The integration of geospatial techniques enhances the assessment of data quality and enables more effective monitoring and management of fire hazards within the UKM campus buildings.

2023-07-01T00:00:00Z