Electrical & Electronics Engineering

Permanent URI for this collectionhttp://197.211.34.35:4000/handle/123456789/130

Electrical & Electronics Engineering

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Author: search.filters.author.Mary Adebola Ajiboye

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    ANALYSIS OF SPECTRUM OCCUPANCY PREDICTION RESULTS FOR MAITAMA ABUJA
    (International Conference on Communication and Information Science (ICCIS), 2024) Ajiboye, Johnson Adegbenga; Mary Adebola Ajiboye; Babatunde Araoye Adegboye; Daniel Jesupamilerin Ajiboye; Jonathan Gana Kolo; Abiodun Musa Aibinu
    This research investigates the efficacy of Artificial Neural Networks (ANN) in predicting spectrum occupancy in Maitama, Abuja, Nigeria, focusing on frequency bands ranging from 30 MHz to 300 MHz. The primary objective was to evaluate the accuracy of ANN-based predictions of spectrum usage and compare these predictions with actual measurements. The study employed ANN to forecast spectrum occupancy across various frequency bands, and the predicted data were then compared with empirical measurements to assess the performance of the model. The analysis revealed that prediction errors were generally low across all frequency bands, with most errors falling below 1.5%. Specifically, the 30-47 MHz sub-band demonstrated an average percentage difference between the actual and predicted value of 0.087%, with a maximum error of 1.12% occurring at frequency of 44.65 MHz. For the 47.05-68 MHz band, the average percentage difference was slightly higher at 0.106%, and the maximum error was 2.18% occurring at frequency of 50.2 MHz. In the 68.05-74.8 MHz band, the average percentage error was 0.040%, but with highest error of 0.232% at frequency of 73.95 MHz. The 74.85-87.45 MHz band showed the most accurate predictions with an average error of just 0.010%, and a maximum error of 0.174% at 75.1 MHz. Overall, the highest prediction error was 0.106% in the 47.05-68 MHz band, whereas the lowest was 0.010% in the 74.85-87.45 MHz band. These results highlight the high accuracy of ANN in predicting spectrum usage, demonstrating its potential for effective spectrum management and planning in Maitama, Abuja.
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    Pattern and Feeder Design for the Production of Grey Cast Iron Brackets
    (IUP Journal of Mechanical Engineering, 2013-08-01) Mary Adebola Ajiboye; Matthew Sunday Abolarin; Ajiboye, Johnson Adegbenga
    In this paper, the design and production of sand casting for a gray cast iron bracket was carried out. The bracket was divided into different sections called Appendages A,B,C and D, and Ribs E and F. Efficient feeder design is important so as to minimize casting defects such as porosity and incomplete filling to the barest minimum. The feeder or riser is used to feed metal to the casting as it solidifies; therefore, they are designed and positioned such as to ensure filling the cavity during solidification. The implication of this is that the riser must be designed to be large enough so that it solidifies only after the casting and it should contain a sufficient volume of metal capable of supplying the shrinkage contraction which occurs on cooling from the casting temperature to the completion of solidification. Based on the feeder design in this work, two bracket castings were produced.
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    Design and Implementation of a 5 kVA Inverter
    (IUP Journal of Electrical and Electronic Engineering, 2016-10-01) Ajiboye, Johnson Adegbenga; Chukwuka Anene; Mary Adebola Ajiboye; Abraham U. Usman
    The paper describes the design and construction of a 5 kVA Pulse Width Modulated (PWM) Metal Oxide Semiconductor Field Effect Transistor (MOSFET)-based inverter, which works on the principle of PWM. The inverter uses IC SG3524 and a pair of Twelve MOSFETs to drive the load. The design and implementation starts with the power supply. Component selection was made with the aid of electronics data book, which made the design and calculations very easy. One main feature of this inverter is the monitoring section, and the battery-charging section connected to the inverter circuit. The inverter converts DC supply of the battery into AC power supply required by most electrical appliances/equipment when the AC main is not available; and when the AC main is available, the supply goes to the AC main sensor, the relays and battery charging section of the inverter. This inverter can be used for domestic purpose, and it is not recommended for industrial purpose where high current is required for application, such as starting a heavy-duty motor