https://repository.sustech.edu/handle/123456789/1150 Tue, 01 Sep 2026 15:12:15 GMT 2026-09-01T15:12:15Z http://repository.sustech.edu:80/jspui/retrieve/059899eb-f844-4922-ad99-f93a64c6e2d2/ https://repository.sustech.edu/handle/123456789/1150 https://repository.sustech.edu/handle/123456789/28494 Title: Development of Electromagnetic Field Exposure Model for Multi-Technology Mobile Networks using Optimal Weighted Antenna Angle Authors: Mohammed, Mohammed Suleiman Elbasheir; Supervisor, Rashid Abdelhaleem Saeed; Co-Supervisor, Salaheldin Mohamed Ibrahim Edam Abstract: Mobile networks are expanding quickly as a result of development in wireless technologies, especially with the recent introduction of the Fifth Generation New Radio (5G NR). The growth in mobile networks requires the installation of massive number of base stations (BSs) that bring concerns about increasing overall electromagnetic field (EMF) radiation exposure levels. The International Commission on Non-Ionizing Radiation Protection (ICNIRP) has published guidelines that have been adopted by many regulators in many countries to control the overall radiation from EMF transmitters. This research started with comprehensive review for recent works focused on BS EMF radiation assessment for BSs from different perspectives including review for standard limits. An enhanced formula is developed and proposed to accurately calculate the compliance distance (CD) considering more factors such as power reduction factor and system load. In situ measurements are conducted to validate the formula. The results show that CD has shorter distances when the power factor is considered. Also, the study investigated the compliance distance of shared sites by a group of Mobile Network Operators (MNO). The results shows that, compared with a single MNO, the CD increased by 41% in the case of two MNOs, 73% for three MNOs, and 100% for four MNOs. Additionally, sharing scale-up formula is driven and proposed to estimate the increase in CDs for N number of MNOs assuming that all MNOs use the same site configuration. Finally, a design model is developed and proposed to de-concentrate and reduce the total exposure ration (TER) from sectorized antennas of the multi-technology BS with no drawbacks on site coverage level and capacity. The model applies the concept of weighted antenna’s azimuth to spread the total exposure among the horizontal direction. A set of simulations and field measurements were done in a life network to validate the proposed solution. The pre-and-post results show the TER and CD are reduced after applying the proposed model. Overall, the system records show no significant impacts were observed on site’s coverage level and capacity. Tue, 01 Oct 2024 00:00:00 GMT https://repository.sustech.edu/handle/123456789/28494 2024-10-01T00:00:00Z https://repository.sustech.edu/handle/123456789/28493 Title: An Optimized Energy-Aware Stable Election Protocol for Heterogeneous Internet of Underwater Things (IoUT) Networks Authors: Mohamed, Elmustafa Sayed Ali Ahmed Abstract: Internet of Underwater of Things (IoUT) networks offer real-time monitoring and data collection capabilities in marine environments for many application. However, the unique challenges of underwater acoustic communication and energy constraints requires a development of intelligent, adaptive and energy-efficient protocols. The thesis addresses these energy challenges particularly in IoUT heterogeneous networks by proposes an energy-aware clustering protocol to optimizing the cluster heads (CH) management and inter-cluster route decision based on Stable election protocol (SEP) computations. Two approaches are proposed, the first is hybrid Artificial Bee Colony (ABC) and Q-learning (QL) based energy-aware Stable Election Protocol (ABCQL-EASE) and its improved version as an energy-aware and Quality of Service (QoS) driven by Underwater Vehicles (UVs) relaying integrated Stable Election Protocol (EQURI-SE). The ABCQL-EASE presents intelligence approach that combines the ABC algorithms with the adaptive decision-making by QL and multi-criteria decision-making (MCDM) approach. This integration enables the dynamic CHs management based on underwater nodes (UNs) status. The protocol continuously learns from network observations, balancing exploration and exploitation to avoid premature convergence and extend network lifetime. Building upon this foundation, EQURI-SE further enhances energy efficiency by incorporating UVs as mobile relays between CHs. To improve the selection of UVs, a comprehensive framework proposed which integrates Neural Network (NN) and Genetic Algorithm (GA) with MCDM to evaluate UV candidates based on energy, depth, distance and signal quality. A dynamic cooldown mechanism ensures fair usage of UV relaying and prevents overuse of any single UV, thereby extending relay availability and system lifetime. Results show that, ABCQL-EASE reduces the energy consumption and dead UNs approximate between 30% and 61% compared to the baseline and benchmark studies. The EQURI-SE achieves a significant reduction in energy consumption compared to conventional protocols, substantially contributing to extending network lifetime while maintaining high throughput and achieving superior network efficiency. Compared to ABCQL-EASE, the EQURI-SE reduces energy consumption by up to 48%. Both ABCQL-EASE and EQURI-SE provides higher network efficiency compared to baseline given between 92% and 95%. Fri, 01 May 2026 00:00:00 GMT https://repository.sustech.edu/handle/123456789/28493 2026-05-01T00:00:00Z https://repository.sustech.edu/handle/123456789/28379 Title: Modeling of PID Controller for an Auto-Pilot Aircraft Pitch Control Authors: Mokhtar, Omar Mohamed Osman Alradi; Supervisor, -Ebtihal H. G. Yousif Abstract: An aircraft contains three rotational motions like pitch, yaw and roll. The pitch motion is controlled by the elevators that are present on the part of the tail, at the rear of an aircraft. An autopilot is a software or tool that can only manage the aircraft under certain conditions using the vehicle’s hydraulic, mechanical and electronic systems. This system, which can follow the flight plan, can stabilize speed and height as well as the location of the front of the aircraft (heading). Pilots mostly lead the aircraft in a controlled manner by autopilot except for departure and landing. Autopilot is mostly used on passenger aircrafts. In this research, elevators are considered as plant and its transfer function is used in modeling of the controller. The proportional integral derivative (PID) controller was used in the modeling of the control system to find the best performance for the aircraft (pitch motion). The comparison was made before and after adding the PID controller and the performance parameters are as follows. Before adding the controller, the rise time was 0.285s, the peak time was 0.143s, the settling time was 0.914s, the overshoot was 137 and the steady state error was. 0.065. After adding the PID controller it was found that at the selected point (-3.7915-0.0466i), from the geometric locus of the roots, achieves the best performance of the aircraft (pitch motion). The rise time is 0.0021s, the peak time is 0.0045s, the settling time is 0.0124s, the overshoot is 8.6561 and the steady state error is zero. It’s noted from comparison that adding the PID controller led to better performance for the aircraft in terms of the stability which the required in flight until we reach safe and comfortable flight and fewer accidents Description: Thesis Wed, 10 Aug 2022 00:00:00 GMT https://repository.sustech.edu/handle/123456789/28379 2022-08-10T00:00:00Z https://repository.sustech.edu/handle/123456789/28338 Title: Mitigation of cement Alkali Silica Reactivity in Hydropower Concrete Structures Authors: Ibrahim, Abdel Hannan Omer; Supervisor, -Mashair Abdelrahim Mohammed Abstract: The research focuses on the mitigation of cement alkalis and siliceous of aggregates reactivity (ASR) influence in hydropower concrete structures and takes Merowe Dam Project (MDP) and Dam Complex of Upper Atbara Project (DCUAP) as case study. The research aims to find out methodology, for mitigating alkali silica reaction that may occur in hydropower concrete structures and to compare, the laboratory testing results obtained, with the international standard requirements for compliance. The results of the cement material; OPC and GGBS used in both projects, Merowe Dam Project (MDP) and Dam Complex of Upper Atbara (DCUAP), were of low level alkali content, less than 0.6% of Na2O equivalent. The results of crushed and natural aggregates; combined with moderate and high levels of alkali content cement for expansion test, were of low level reactive aggregates. Based on the laboratory testing results obtained from petrographic examination, chemical tests, mortar bar tests and accelerated mortar bar tests concerning alkali silica reaction for fine and coarse aggregates used in concrete and mortar production for construction of MDP & DCUAP projects, all the results fulfilled and verified the standard requirements and limits stated for mitigating alkali content in the cement material and the siliceous found in the aggregates materials, therefore, the concrete and mortar produced from such materials were mitigated from deleterious expansion and damage due to alkali silica reaction. Using of supplementary cementitious material (SCM) Fly Ash to replace 25% of the Cement used in concrete mixes not only for minimizing risk of any probable Alkali-Silica Reactivity mitigation reason, but also for reducing heat of hydration, as a filler to reduce seepage, to increase workability of concrete and as a benefit by reducing the cost of concrete production. It is obvious, from the testing results obtained; to mitigate alkali silica reactivity; there are two options: combine innocuous aggregate with even high level alkali content cement will fulfill the standard requirements for mitigating ASR or combine reactive natural sand with low level alkali content, also will mitigate ASR. The recommendations of this research for future study had been stated as to: establish visual inspection system for existing concrete structures of dams, bridges, water tanks and similar concrete structures which were exposed to wetting environment, establish service record for aggregates quarries which have been used in concrete production for dams, bridges and similar concrete constructed from the same aggregate quarries and further study of local natural pozzolan from Buyda desert central volcanic field. Description: Thesis Thu, 12 Jan 2023 00:00:00 GMT https://repository.sustech.edu/handle/123456789/28338 2023-01-12T00:00:00Z