Electrical & Electronics Engineering

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Electrical & Electronics Engineering

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Cognitive Radio Networks, a Key Technology of Future Wireless Communication: Challenges and Opportunities
(IUP Journal of Telecommunications, 2012-11-01) Ajiboye, Johnson Adegbenga; Yinusa Ademola Adediran
It is a well-known and established fact that the current approach of fixed spectrum allocation, the command-and-control model, makes the spectrum or the finite resource to be grossly underutilized or inefficient. There are so many bands of the spectrum already licensed to users but which in reality are unoccupied at some instance in time thereby creating spectrum holes. These are 'opportunities' that could be harnessed. Cognitive Radio (CR) is a promising technology being envisioned to solve the problem of spectrum underutilization and allows for real-time spectrum management. The CR, in a non-interference basis, opportunistically explores the unused channel, thereby ensuring efficient usage of this 'scarce' resource. The CR is a sure technology for the next generation wireless systems. In a CR, a licensed user, also called a Primary User (PU), has a priority over the Secondary User (SU) which has no spectrum license. Therefore, at the arrival of a PU, an opportunistic SU vacates the occupied channel and seeks another empty channel to be allocated. In this way, spectral efficiency is greatly enhanced. In this work, we examine the challenges that this new technology is bound to face.
Performance Evaluation of Energy-aware Swarm Intelligence Based Routing Protocols for Wireless Sensor Networks Based on Different Radio Models
(International Journal of Computing, Communications and Networking, 2013-12-13) Adamu Murtala Zungeru; Enesi Asizehi Yahaya; Caroline Omoanatse Alenoghena
A routing protocol is the nervous system of any computer network. In a network where hundreds or thousands of nodes are working simultaneously, the job of a routing protocol is to identify/discover one or more path connecting a pair of nodes under a given set of constraints. The prime requirement for a routing protocol is to optimize the network performance. On the other hand, ad hoc networks form a distinct category of networks whereby nodes are wirelessly connected to each other and may be in constant random motion. However, in ad hoc networks like sensor networks, the performance differs with different radio models. This paper present simulation results of the comparative investigation of the performance of swarm based routing protocols for wireless sensor networks (WSNs) based on different radio models using routing modeling application simulation environment (RMASE), an application built on a probabilistic wireless network simulator (PROWLER). Our simulation results indicate that the energy aware routing objectives of Termite-hill, Sensor driven and cost-aware ant routing (SC) and Improved Energy Efficient Ant Based routing (IEEABR) protocols increases the network lifetime for Normal Radio Model (NRM), Radio Model with Signal-to-Interference-plus-Noise Ratio (RMSINR) and Radio Model with Rayleigh Fading (RMRYF)
Performance Characteristics and Double Revolving Theory of Single Phase Induction Motor
(Leonardo Journal of Sciences, 2013-12-23) Yahaya Asizehi ENESI
Single phase induction motors are used in number of applications such as in offices, homes and in factories. Their numerous applications and immense importance lead to the study of the general characteristics of such motors. In this paper the input data of a given single phase induction motor without core loss is obtained from laboratory and the motor equivalent circuit is developed from the input parameters and this circuit helps to obtain the principle of double revolving theory. Determination of the output parameters from input parameters using circuit equations lead to the plotting graphs of the motor performance characteristics for the purpose of illustration. The paper also demonstrates the simulation of the steady-state performance by MATLAB program
Determination of the Wire size of a Three phase Squirrel cage Induction Motor with a Missing Nameplate
(The Nigerian Journal of Engineering and Applied Sciences (NJEAS), 2014-06-29) Enesi Asizehi Yahaya; Mark Nwohu; Ayo Imoru; Tola Omokhafe; Ambafi .G. James
An empty stator of a squirrel cage induction motor rated at 220/380V, 50Hz with a missing nameplate and without winding has been lying down in a factory for so long and now the factory wants to use it for production purposes. This is a motor whose class protection degree is IP44, IP54 or IP55. This paper presents a method of determining the wire size (diameter) required to rewind the motor to its full rating power capacity. With motor nameplate and using National Electrical Code (NEC) and National Manufacturers Association (NEMA) specifications, the diameter of the wire can be determined. In the absence of the nameplate and the windings, the motor is difficult to rewind in order to obtain its desired characteristics. This can be achieved by the measurement of main dimensions of motor stator, using standard rating specifications, standard performance curves and analytical method.
Analysis of non-salient pole synchronous generator using phasor diagrams
(Leonardo Journal of Sciences, 2014-12-25) Yahaya Asizehi ENESI; Adamu Murtala ZUNGERU; Isah Agbogunde ADEMOH
In this paper, various performance equations are derived from phasor diagrams of a three phase non-salient pole (cylindrical rotor) synchronous generator of known armature resistance and of ignored armature resistance for lagging, unity and leading power factor load. These equations are used to calculate the output parameters of non-synchronous generator and to plot the graphs of terminal voltage-armature current, torque angle-armature current, torque angle-terminal voltage, power-torque angle and torque-speed characteristics through simulation by MATLAB program for the purpose of illustration.
Available Transmission Transfer Efficiency (ATTE) as an Index Measurement for Power Transmission Grid Performance
(2015-05-25) Ahmad Abubakar Sadiq; Mark N. Nwohu; Jacob Tsado; Ahmad A. Ashraf; Agbachi E. Okenna; Enesi E. Yahaya; Ambafi James Garba
Transmission system performance analysis is vital to proper planning and operations of power systems in the presence of deregulation. Key performance indicators (KPIs) are often used as measure of degree of performance. This paper gives a novel method to determine the transmission efficiency by evaluating the ratio of real power losses incurred from a specified transfer direction. Available Transmission Transfer Efficiency (ATTE) expresses the percentage of real power received resulting from inter-area available power transfer. The Tie line (Rated system path) performance is seen to differ from system wide (Network response) performance and ATTE values obtained are transfer direction specific. The required sending end quantities with specified receiving end ATC and the receiving end power circle diagram are obtained for the tie line analysis. The amount of real power loss load relative to the available transfer capability gives a measure of the transmission grid efficiency
A Comparison of Code Maintainability in Agile Environment
(IUP Journal of Information Technology, 2016-06-01) Mary Adebola Ajiboye; Matthew Sunday Abolarin; Ajiboye, Johnson Adegbenga
The demand for quick delivery of quality software is becoming high among software clients due to the fast changing technology in the dynamic world. Agile software development meets this demand and has gained appropriate and wide acceptance among software practitioners. However, the quality of such software is greatly impacted by its maintainability. Unfortunately, existing works focused only on the flexibility aspect of maintainability without paying attention to timely delivery. In this work, maintainability as a function of time to correct codes was examined among various categories of software developers. Deliberate errors, ranging from two to nine, were introduced into sets of agile codes written in python programming language and given to 100 programmers, each in the groups of individual junior, individual expert, random, expert pairs, junior pairs and junior expert pairs. The results revealed that random pair programmers spent the highest time of 21.88 min/bug on the average, while individual experts spent the least time of 16.26 min/bug.
Game theoretic data association for multi-target tracking with varying number of targets
(IEEE, 2016-06-23) Abdullahi Daniyan; Yu Gong; Sangarapillai Lambotharan
We investigate a game theoretic data association technique for multi-target tracking (MTT) with varying number of targets. The problem of target state-estimate-to-track data association has been considered. We use the SMC-PHD filter to handle the MTT aspect and obtain target state estimates. We model the interaction between target tracks as a game by considering them as players and the set of target state estimates as strategies. Utility functions for the players are defined and a regret-based learning algorithm with a forgetting factor is used to find the equilibrium of the game. Simulation results are presented to demonstrate the performance of the proposed technique.
4.3 Game-theoretic solutions for resource allocation and tracking
(UDRC, 2018-10-10) Anastasios Deligiannis, Abdullahi Daniyan, Gaia Rossetti, Sangarapillai Lambotharan, Jordi Barr
Spectrum Occupancy Measurement in the VHF Band- Results and Evaluation in the Context of Cognitive Radio
(International Engineering Conference (IEC) 2019, 2019) Ajiboye, Johnson Adegbenga; Adegboye B.A; Aibinu A.M; Kolo J.G
In this paper the results of spectrum occupancy survey in the context of Cognitive Radio was presented. In Cognitive Radio, secondary unlicensed users are allowed to opportunistically use the primary licensed users’ bands with the understanding that there will be no interference i.e Secondary Users (SU) quits at the arrival of Primary Users (PU). A 24-hour measurement survey was carried out at the centre of Minna metropolis in Niger State, Nigeria covering a frequency range of VHF (30-300MHz). Aaronia HF 6065 V4 spectrum analyzer was used for data collection. Results show that the band allocated for Aeronautical Navigation has the highest spectral occupancy of 39.83% followed by the FM band with occupancy of 12.90% while the frequency band meant for Aeronautical Mobile and Space Operation has occupancy of 4.73% and TV Broadcasting 0.09%. The average occupancy of the VHF band is 14.39%.
Review of Spectrum Occupancy Measurements in the Context of Cognitive Radio
(IJIPC 2019, 2019-12) Ajiboye, Johnson Adegbenga; Babatunde Araoye Adegboye; Abiodun Musa Aibinu; Jonathan Gana Kolo
Presently, there is a progressive growth in the proportion of internet users as well as deployment of data intensive applications which has led to higher demand for bandwidth on the usable spectrum space for the unlicensed and licensed frequency bands. Spectrum is a scarce and limited resource, inefficiencies in the management of spectrum has resulted to a recent and unique communication standard for explotting the current licensed spectrum in an opportunistic manner. Cognitive Radio (CR) has proved to be the solution to this seeming highly demanded spectrum Several studies have been conducted on spectrum occupancy across the world in order to observe and determine the bands that have been underutilized so as to make room for the new technological emergences such as CR. This review shows that from previous works done, there is a research gap in the spectrum measurement work for TV band and specifically the VHF band in Nigeria.
Cloud-based IoT monitoring system for poultry farming in Nigeria
(Faculty of Engineering, University of Maiduguri, Maiduguri, Nigeria, 2020-01-04) Gbadamosi, Safiu Abiodun
The monitoring of environmental parameters of poultry farm using IoT applications is no longer a new research area in the field of engineering. However, the cost of implementing most of the reviewed research work seams unaffordable to rural farmers in Nigeria. This could limit the adoption and usage of such devices. In this paper, we present a cost effective cloud-based IoT monitoring system for poultry farming. The system uses two vital weather parameters- temperature and humidity. The methodology adopted, employed the use of DHT11 sensor (a temperature and humidity sensor) to note every change in temperature and humidity data of the farm environment. The sensed data were extracted, sampled and processed by the microcontroller before transmitting the data to a remote cloud server through the WiFi module. The cloud server (Thingspeak) received the sensed data, analysed the data and plot the data graphically. The plotted graph is viewed from a computer or any smart devices. The result indicates that temperature and humidity values range between 33-38°C and 31-33mmHg respectively. Furthermore, the results show that the device is efficient in monitoring the two environmental parameters. Therefore, the efficiency of the system will no doubt provide much quicker and accurate information about change in temperature and humidity data of farm environment.
Air Gap Length and Maximum and Minimum Inductance of A Double-Salient Reluctance Machine (DSRM) using The Developed Analytical Algorithm
(International Journal on Electrical Engineering and Informatics, 2022-03-12) Enesi Asizehi Yahaya; Ajah Victor; Emenike Chinedozi Ejiogu
In this paper an algorithm is developed to predict the maximum and minimum inductance of an optimized pole arc of a fabricated double salient reluctance machine (DSRM). The developed analytical algorithm investigates the air gap length at the maximum and minimum inductances. These are achieved through the machine rotor pole arc, stator pole arc, bore diameter, back iron thickness, rotor yoke thickness, stack length, and rotor pole diameter. The validity of the newly developed analytical procedures for predicting the maximum and minimum inductances was evaluated using the measurements obtained from the machine prototype. There was a good correlation between the analytical and experimental results. Inductances and air gap lengths of 2/2 DSRM of equal stator and rotor pole width and stator pole width greater than the rotor pole width were investigated and analyzed using the developed algorithm. A second existing DSRM with different numbers of stator and rotor poles whose inductances have been known and compared with finite element analysis (FEA) is chosen to verify the algorithm developed. The 2/2 DSRM’s potential to sustain oscillation during energy conversion from mechanical energy to electrical energy is investigated
Interference Avoidance Resource Allocation for D2D-Enabled 5G Narrowband Internet of Things
(IEEE, 2022-06-21) Gbadamosi, Safiu Abiodun,; Hancke Gerhard Petrus; Abu-Mahfouz Adnan M.
In dense, interference-prone 5G narrowband Internet of Things (NB-IoT) networks, device-to-device (D2D) communication can reduce the network bottleneck. We propose an interference-avoidance resource allocation for D2D-enabled 5G NB-IoT systems that consider the less favorable cell edge narrowband user equipment (NUEs). To reduce interference power and boost data rate, we divided the optimization problem into three subproblems to lower the algorithm’s computational complexity. First, we leverage the channel gain factor to choose the probable reuse channel with better Quality of Service (QoS) control in an orthogonal deployment method with channel state information (CSI). Second, we used a bisection search approach to determine an optimal power control that maximizes the network sum rate, and third, we used the Hungarian algorithm to construct a maximum bipartite matching strategy to select the optimal pairing pattern between the sets of NUEs and the D2D pairs. According to numerical data, the proposed approach increases the 5G NB-IoT system’s performance in terms of D2D sum rate and overall network signal-to-interference plus noise ratio (SINR). The D2D pair’s maximum power constraint, as well as the D2D pair’s location, pico-base station (PBS) cell radius, number of potential reuse channels, and D2D pair cluster distance, all influence the D2D pair’s performance. The simulation results demonstrate the efficacy of our proposed scheme.
Wireless Sensor Networks: State of Arts
(IEC 2023, 2023-03-21) Okafor A.C; Dauda U.S; Kolo J.G; Ohize H.O; Ajiboye, Johnson Adegbenga
The enhancement of the Wireless Sensor Network (WSN) have made technology much easier and is impacting on all fields of endeavours. The invention of WSN and the present advancement especially in the field of Engineering is the main focus of this article. The paper has also enlightened the current state of the WSN in data collection procedure. The marketplace of the WSN and its growth has been elaborated in the paper along with the future scope and challenges.
Dynamic Eccentricity Fault Detection in Synchronous Machines Using Principal Component Analysis
(IEEE, 2023-09) Yusuf, Latifa; Ilampari, Thirumarai Chelvan
The paper proposes a new method for detecting dynamic eccentricity faults in a Salient Pole Synchronous Machine (SPSM). Several methods have been documented in the literature for detecting dynamic eccentricity, including using search coils, motor current signature analysis (MCSA), and data-based techniques. The former approach is invasive, thereby increasing installation cost, while MCSA is affected by load variations. A major hurdle in using data-driven methods is the selection of features. To overcome these limitations, the authors propose performing principal component analysis (PCA) on the fundamental sideband frequencies of motor current signals to detect and isolate dynamic eccentricity from static eccentricity faults. Principal Component Analysis (PCA) is a data-driven technique that can extract meaningful features in a dataset by transforming correlated variables into a reduced set of uncorrelated variables through a linear transformation. Experimental data of stator currents from a 2-kW, 208 V, 3-phase SPSM were used for the analysis. Results showed that the method isolated dynamic eccentric faults irrespective of the loading condition of the SPSM.
Pair Programming – Cubic Prediction Model Results for Random Pairs and Individual Junior Programmers
(2023-11-06) Mary Adebola Ajiboye; Matthew Sunday Abolarin; Ajiboye, Johnson Adegbenga; Abraham Usman Usman; Sanjay Misra
Due to the rapidly evolving technology in the dynamic world, there is a growing desire among software clients for swift delivery of high quality software. Agile software development satisfies this need and has been widely and appropriately accepted by software professionals. The maintainability of such software, however, has a significant impact on its quality. Unfortunately, existing works neglected to consider timely delivery and instead concentrated primarily on the flexibility component of maintainability. This research looked at maintainability as a function of time to rectify codes among Individual Junior and Random pair soft ware developers. Data was acquired from an experiment performed on software developers in the agile environment and analyzed to develop the quality model metrics for maintainability which was used for prediction. One hundred programmers each received a set of agile codes created in the Python programming language, with deliberate bugs ranging from one to ten. The cubic regression model was used for predicting time spent on debugging errors above ten bugs. Results show that the random pair programmers spent an average time of 21.88 min/error while the individual programmers spent a lesser time of 16.57min/error.
Interference-Aware and Coverage Analysis Scheme for 5G NB-IoT D2D Relaying Strategy for Cell Edge QoS Improvement
(IEEE, 2024-01-15) Gbadamosi, Safiu Abiodun,; Hancke, Gerhard Petrus; Abu-Mahfouz Adnan M.
In an interference-limited 5G narrowband Internet of Things (NB-IoT) heterogeneous networks (HetNets), device-todevice (D2D) relaying technology can provide coverage expansion and increase network throughput for cell-edge NB-IoT users (NUE). However, as D2D relaying improves the network’s spectral efficiency, it makes interference management and resource allocation more difficult. To improve cell-edge user quality of service (QoS), we propose an interference-aware and coverage analysis scheme for 5G NB-IoT D2D relaying. We divide the optimization problem into three subproblems to reduce the algorithm complexity. First, we use the max-max signal-to-noiseplus-interference ratio (Max-SINR) to select an optimal D2D relay with the highest channel-to-interference-plus-noise ratio (CINR) to relay the source NUE information to the NB-IoT base station (NBS). Second, we optimize the transmit power (TP) of the cell-edge NUE to the relay under the peak interference power constraints using a Lagrange dual approach to ensure the user’s service life. We fixed the TP between the D2D relay and the NBS and then transformed the D2D relay’s coverage problem that maximizes the network uplink data rate into a 0-1 integer programming problem. Then, we propose a heuristic algorithm to obtain the system performance. Due to the high-channel gain between the two communicating devices, the simulation results show that the Max-SINR selection scheme outperforms the other relay selection schemes except for the D2D communication scheme in efficiency, data rate and SINR.
DEVELOPMENT OF AGILE PRODUCTIVITY METRICS OF INDIVIDUAL EXPERT JAVASCRIPT DEVELOPERS FOR SOFTWARE PROJECT MANAGERS
(Humminbird Publications and Research International, 2024-01-29) Abdulgafar A.; Makinde J.K; Ajiboye, Johnson Adegbenga; Ajiboye M.A
Software Project Managers require metrics to measure productivity in team work. Since agile software development require continuous improvement, metrics helps in identifying bottlenecks and inefficiencies thereby enabling teams to refine their processes iteratively. Productivity metrics also helps in effective resource allocation and optimization to ensure timely delivery of software products by Software Project Managers. Although metrics have been developed for traditional software programmers little work has been done in developing metrics for Agile Software Project Managers specifically for JavaScript Program. In this work, metrics for Individual Expert agile software programmers and specifically for JavaScript was developed. Programs in JavaScript was designed and developed to record the time spent in correcting deliberate errors introduced. Experiment was conducted among one hundred programmers' group of Individual Expert pairs with the aim of recording time spent in debugging the codes, The curve fit regression models of time spent in debugging a number of bugs in agile software written in JavaScript programming language for project managers revealed that Cubic model had the highest R squared value of 0.996 which is closely followed by the quadratic model with a value of 0.980 while the compound, growth and exponential models have the least value of 0.868.
Coordination of Flexible Alternating Current Transmission Systems and Distributed Generation in a Synthetic Co-simulation of Transmission and Distribution Network
(Turkish Journal of Electrical Power and Energy Systems (TEPES), 2024-02) Ahmad, Abubakar Sadiq; Yusuf, Latifa; Muhammad, Buhari; Sanusi Sani Adamu; James, Garba Ambafi
In ensuring sustainable power delivery under rapid growth in demand, modern power grids are characterized by advanced solutions such as flexible alternat ing current transmission systems and distributed generation. However, flexible alternating current transmission systems and distributed generations are often planned by their respective system operators, ignoring their coordination and impacting system-wide performance. This paper develops a bi-level optimization approach for flexible alternating current transmission systems and distributed generation coordination in an integrated transmission and distribution network to improve available transfer capability, power losses, and voltage deviation. The approach comprises inner and outer optimization. Inner optimization imple ments a hybrid of particle swarm optimization and Active Power Flow Performance Index for flexible alternating current transmission systems’ planning. At the same time, the outer optimization employs multi-objective particle swarm optimization, which targets distributed generation planning at the distribution network—the integrated transmission and distribution network models’ both transmission and distribution section. To demonstrate the effectiveness of the developed approach, two models of distributed generations, only real power and real and reactive power injections, were separately coordinated with a thyristor-controlled series compensator and static synchronous series compensator. Results show superior available transfer capability enhancement with thyristor-controlled series compensator−power injectionsDG and static synchronous series compensator−power injectionsDG, compared to the non-coordinated scenario. Pareto front plots of available transfer capability, power losses, and voltage deviation are such that after some maximum available transfer capability, the slope of the Pareto approaches zero.