LAUTECH Journal of Engineering and Technology

Performance evaluation and redesign of Offa garage roundabout in Ilorin, Nigeria using microscopic simulation

H. A. Salami, S. ABAYOMI, O. O. Adeleke — Mon, 02 Dec 2024 00:00:00 +0000

An urban traffic system is a composite network, which consists of varying types of intersections. In this paper, the focal point is on a heterogeneous traffic system, In this paper, the focus is on a heterogeneous traffic system featuring a non-signalized intersection (roundabout), with the aim of replacing it with a signalized one

It has always been a difficult process to carry out Traffic analysis, with the ever increasing volume of vehicles and densely populated roadways. it is definitely difficult to suggest an alternative answer especially in developing countries like Nigeria. This paper analyses an intersection in the city of Ilorin Kwara State Nigeria. The intersection is modelled with the VISSIM 21, which is a traffic microscopic simulation software that has been extensively used in assessing traffic conditions. The paper also simulates the modelled intersection and determines the possibility of installing a traffic signal at the skewed T- intersection and checks its usefulness by comparing the Level of service, Queue length and carbon emission when the signals is installed and after.

Affordable energy-saving switch control system for homes with disabled persons

O. V. Abhulimen, O. O. Afolabi, M. O. Obatale — Tue, 03 Dec 2024 12:38:24 +0000

The need for energy conservation has become increasingly urgent in today's world, especially as energy costs continue to rise and the demand for sustainable living grows. For persons with physical disabilities, simple tasks like turning light switches on and off can be challenging, resulting in higher energy usage, increased electricity bills, and increased physical strain. Existing solutions often prioritize energy efficiency but overlook affordability and accessibility, making them impractical for low-income households. To address these issues, this paper proposes an affordable automated energy-saving lighting switch control system using Arduino Uno, ultrasonic sensors for human presence detection, and a relay to control lighting. A person-counter mechanism ensures accurate operation based on room occupancy. Experimental results shows that the proposed system achieves 100% accuracy in detecting human presence in a room, effectively reducing energy consumption from 0.4 kWh to 0.2 kWh per day, which corresponds to 50% energy savings. Additionally, it is 42.41% less expensive than the most affordable system compared in the paper. These findings underscore the system’s potential to offer an affordable, accessible, and energy-efficient solution that enhances the convenience and comfort of disabled persons while contributing to energy conservation efforts.

Analysis of dimensionality reduction on ransomware detection using machine learning techniques

A. O. Olalouwa, E. Amusan, O. Adeosun — Tue, 03 Dec 2024 12:54:38 +0000

Ransomware attacks continue to evolve as a pervasive threat to cybersecurity such as data loss, financial losses, and potential disruption of critical services which have prompted the need for robust detection mechanisms. Leveraging on machine learning techniques for ransomware detection has gained recognition; however, the high-dimensional nature of feature spaces has posed some challenges in model efficiency and effectiveness. This research therefore explores the impact of two well-known dimensionality reduction methods that may enhance ransomware detection using five popularly used machine learning algorithms which are K-Nearest Neighbor (KNN), Decision Tree (DT), Random Forest (RF), Support Vector Machine (SVM) and Naive Bayes (NB). Through comprehensive analysis and experimentation, two well-known dimensionality reduction techniques, Linear Discriminant Analysis (LDA) and Principal Component Analysis (PCA) were examined on the selected machine learning algorithms using a Ransomware PE Header Feature Dataset (publicly available on online data repository) with 1028 features. Metrics such as Accuracy, Recall, Precision and F1-Score were used to evaluate the classifiers. The comparative analysis of LDA and PCA reveals a discernible preference for one classifier over another. From the results, it is observed that the performance of classifiers with PCA is better than that of with LDA. Also, Decision Tree and Random Forest classifiers outperform the other three algorithms without using dimensionality reduction as well as with both PCA and LDA.

A Simulation study of the output characteristics of freestanding Triboelectric nanogenerators with interdigitated electrodes for self-powered sensing application

K. E. Ojo — Fri, 06 Dec 2024 00:00:00 +0000

Diverse forms of mechanical energy are available in environmental routine activities. These energy forms can be harvested, measured and converted to produce electricity at nanogenerator (NG) and micro-scale levels based on the phenomenon of triboelectrification. These motivate this work to develop a self-powered sensing device to detect and monitor static and dynamic processes associated with mechanical activities. The significance is to study the output characteristics of freestanding mode triboelectric nanogenerator (TENG) with multiple units of metal and dielectric electrodes. The integrated modeling environment of COMSOL Multiphysics software was employed for the simulation study of the proposed TENG. The system output responses considered for analysis includes, open circuit electric potential and short circuit surface charge density. For the open circuit, the electric potential was achieved at maximum value of 10kV, while for short circuit surface charge density, the electric potential was achieved at maximum value of 27 Cm^-2. The study results revealed that the input parameter of contact displacement of electrodes is proportional to the output electrical potential of the system. Hence, the efficiency of TENG can be deployed for energy harvesting and sensing of mechanical variables.

31W Linear broadband 3.4 to 4.4 GHZ high power class-j GaN HEMT amplifier

C. N. Akwuruoha — Fri, 06 Dec 2024 13:19:49 +0000

The recent upsurge in wireless communication systems requiring high-power transmitters for numerous applications such as electronic warfare (EW), RADAR, Satellite and optical communications has further underscored the importance of linear broadband high-power Class-J power amplifiers. This paper proposes a 31W linear broadband 3.4 to 4.4 GHz high-power Class-J GaN HEMT(gallium nitride high electron mobility transistor)amplifier. The power amplifier was designed based on Cree's commercially available 10WGaN HEMT power transistor device (CGHV40010F) using Keysight Advanced Design System (ADS) software and simulated. The transistor was biased withadrain supply voltage of 48V at aquiescent drain-to-source current of 0.58A,which makes the power transistor suitable for high voltage transmitter operations and foreclosed the need for voltage upgrade, thereby reducing thecost of operation. The power amplifier (PA) operates from 3.4 to 4.4 GHz with a centre frequency of 3.9 GHz. The PA has an output power of 31W, drain efficiency of 36.3%, power added efficiency of 35.3% and power gain of 12.9 dB at an input power of 32 dBm. The PA small signal gain stood at 10.6 dB at acentre frequency of 3.9 GHz. The PA maintained a peak envelope power of 56.2W at aninput power of 31 dBm at atwo-tone Frequency of 3.895 GHz. The proposed PA will find applications in wireless communications, military and aviation transmitters.