Scholarly works in the Department of Mathematics
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Item Heat and Mass Transfer Mixed Convective Electrically Conducting Nanomaterial Flow Over a Stretching Sheet(Journal of Multidisciplinary Engineering Science and Technology (JMEST), 2024) Lawal, Muhammad Muhammad; Ogboru, Oghenero Kelvin; Okedoye, Akindele MichaelThe study of heat and mass transfer in electrically conducting nanomaterial flows over a stretching sheet is a complex phenomenon involving fluid mechanics, thermodynamics, and electrical conductivity. The flow of electrically conducting nanomaterials over a stretching sheet is governed by the Navier-Stokes and Maxwell equations, which describe momentum and electric field distributions. The electrical conductivity of the nanomaterials plays a crucial role in the flow behavior, as it affects the electric field distribution and fluid motion. Numerical simulations using the finite volume method were conducted to investigate the effects of electrical conductivity, nanoparticle volume fraction, and stretching velocity on the flow, heat, and mass transfer characteristics. Results showed that electrical conductivity significantly impacts the flow structure, leading to the formation of electrically induced vortices and streamlines. The nanoparticle volume fraction also affects the flow behavior, increasing fluid viscosity and decreasing fluid velocity. These findings have important implications for the design and optimization of nanomaterial-based devices and processes, such as energy harvesting, water purification, and drug delivery.Item Dissipative Non-Slip MHD Nanofluid Flow with Variable Viscousity and Thermal Conductivity in the Presence of Arrhenius Chemical Reaction(European Journal of Theoretical and Applied Science, 2024) Ogboru, Kelvin O.; Lawal, Muhammad M.; Okedoye, Akindele M.This research investigates the intricate dynamics of dissipative nonslip magnetohydrodynamic (MHD) nanofluid flow, characterized by variable viscosity and thermal conductivity, under the influence of an Arrhenius chemical reaction. The inclusion of the Arrhenius chemical reaction adds complexity through heat generation or absorption, impacting temperature and concentration gradients. The study is motivated by the extensive applications of nanofluids in engineering and industrial processes, where precise control of heat and mass transfer is critical. We develop a comprehensive mathematical model that incorporates the variable properties of the nanofluid, the effects of the Lorentz force due to the applied magnetic field, and the temperature-dependent reaction rates dictated by the Arrhenius equation. The formulated governing equations were non-dimensionalised to identify the flow governing parameters. Finite Element Method (FEM), grid generation, solution algorithms, and post-processing to analyse velocity, temperature, and concentration distributions were used to obtain the numerical methods to solve fluid flow problems based on the Navier-Stokes equations, involving concepts of discretization. pdsolve subpackage in Maple 2023 was used to numerically solve PDEs with specific initial and boundary conditions, incorporating the plot and display commands for graphical analysis, and the results are presented and discussed. The findings reveal that the interplay between parameters like Hartmann number, Darcy parameter, and heat generation or absorption profoundly influences flow behaviour and thermal characteristics. The reactivity parameter is crucial, dictating the rate of chemical reactions and affecting system dynamics. This research enhances understanding of the interdependencies among fluid properties, chemical reactions, and external parameters in nanofluid flows.Item Application of the Taylor Series Technique to the Solution of Bratu Problems(FNAS Journal of Mathematical Modeling and Numerical Simulation, 2025) Otaide, I.J; Ugbene I.J.This study presents a numerical solution of the Bratu differential equations (BDE) using Taylor’s series technique. The effectiveness and reliability of the proposed method were further demonstrated by two numerical examples. The outcomes were also compared to other previously published research. Our suggested approach outperforms the Salem and Thanoon (2022) method in terms of approximating the exact solution. The Maple 18 software was used to perform the computationsItem Second kind Chebyshev collocation technique for Volterra-Fredholm fractional order integro-differential equations(J. Nat. Scien. & Math. Res., 2022) Otaide, I.K; Oyedepo, T; Ayoade, A. A; Ayinde, A. M.In this work, we present the numerical solution of fractional order Volterra– Fredholm integro-differential equations using the second kind of Chebyshev collocation technique. First, we transformed the problem into a system of linear algebraic equations, which are then solved using matrix inversion to obtain the unknown constants. Furthermore, numerical examples are used to outline the method’s accurItem Generalized Hyers-Ulam Stability of Second Order Linear Ordinary Differential Equation with Initial Condition(Adv. Inequal, 2014) OTAIDE, I.; MODEBEI, M. I.; OLAIYA, O.O.The stability of ordinary differential equation has been investigated and this investigation is ongoing. In this work, we investigate the stability of second-order linear ordinary differential nonhomogeneous equation with initial condition in the Hyers-Ulam sense.Item A Comparative Analysis Performance of Data Augmentation on Age-Invariant Face Recognition Using Pretrained Residual Neural Network(Journal of Theoretical and Applied Information Technology, 2021) ABERE, REUBEN; OKOKPUJIE, KENNEDY; OFOCHE, JOYCE C.; BIOBELEMOYE, BASUO J.; OKOKPUJIE, IMHADE PRINCESSThere has been an immense improvement in face recognition research. Unfortunately, the accuracy of face recognition systems recognizing the same person over time due to ageing is open research. Minor geometric changes in the face that occur due to ageing contribute to face recognition systems' inaccuracy. Researchers, over subsequent years, have come up with methods to improve the performance of Age Invariant Face Recognition (AIFR) systems, the most recent one being the use of Convolutional Neural Network (CNN) to create face recognition models. The pre-trained residual network (ResNet) is trained and tested using a heterogeneous database to actualize this improvement. The heterogeneous database consists of images from 82 Caucasian subjects in the FG-Net database and 11 African subjects. These obtained images were augmented using geometric transformation and Noise to increase the amount of data for training. Afterwards, a model robust is developed. The Sliding Window framework was used to detect the faces fed into CNN for training and testing. After getting the results from our classification model, an analysis was carried out on the classification models of both the original dataset and augmented datasets. It was observed that the model performed remarkably with the noise-injected dataset and performed worst with the geometric transformation database.Item Effects of Data Resampling on Predicting Customer Churn via a Comparative Tree-based Random Forest and XGBoost(Journal of Computing Theories and Applications, 2024) Abere, Reuben Akporube et. al.Customer attrition has become the focus of many businesses today – since the online market space has continued to proffer customers, various choices and alternatives to goods, services, and products for their monies. Businesses must seek to improve value, meet customers' teething demands/needs, enhance their strategies toward customer retention, and better monetize. The study compares the effects of data resampling schemes on predicting customer churn for both Random Forest (RF) and XGBoost ensembles. Data resampling schemes used include: (a) default mode, (b) random-under-sampling RUS, (c) synthetic minority oversampling technique (SMOTE), and (d) SMOTE-edited nearest neighbor (SMOTEEN). Both tree-based ensembles were constructed and trained to assess how well they performed with the chi-square feature selection mode. The result shows that RF achieved F1 0.9898, Accuracy 0.9973, Precision 0.9457, and Recall 0.9698 for the default, RUS, SMOTE, and SMOTEEN resampling, respectively. Xgboost outperformed Random Forest with F1 0.9945, Accuracy 0.9984, Precision 0.9616, and Recall 0.9890 for the default, RUS, SMOTE, and SMOTEEN, respectively. Studies support that the use of SMOTEEN resampling outperforms other schemes; while, it attributed XGBoost enhanced performance to hyper-parameter tuning of its decision trees. Retention strategies of recency-frequency-monetization were used and have been found to curb churn and improve monetization policies that will place business managers ahead of the curve of churning by customers.Item Assessment of Asymmetric Mangrove Restoration Trials in Ogoniland, Niger Delta, Nigeria: Lessons for Future Intervention(Ecological Restoration, 2016) Nenibarini Zabbey; Franklin B.G. TaneeMangrove restoration has been undertaken with varying degrees of success in many tropical and subtropical marine shorelines around the globe. However, mangrove reforestation in the Niger Delta, Africa’s largest delta and mangrove belt is, at best, rudimentary. Here, we present floristic results on two opportunistic artificial mangrove regeneration case studies aimed at restoring mangrove swamps damaged by oil pollution (Bodo Creek) and colonized by invasive Nypa fruticans (nypa palm) (Kono Creek) in Ogoniland, eastern Niger Delta, Nigeria. Nursery raised seedlings of the delta’s dominant Rhizophora racemosa were planted 1 m apart in zigzag fashion at both locations. Planting at the oil-polluted site was preceded by soil quality investigation and bio-stimulation with fertilizer, whereas at Kono Creek, there was no addition of fertilizer before and after planting. A 3-year post planting evaluation of survival rate, growth, and girth parameters showed better performance of mangroves at the Bodo Creek restoration than at the Kono Creek restoration, with survival rates of 72% and 12%, respectively. In sharp contrast to the Bodo Creek restoration, few stands of the planted mangroves at the Kono Creek restoration had started producing propagules. Investigations of soil quality, and where necessary, followed by remedial treatment, particularly augmenting key nutrients, are critical precursors of successful artificial mangrove regeneration.Item BEHeDaS: A Blockchain Electronic Health Data System for Secure Medical Records Exchange(Journal of Computing Theories and Application, 2024) Abere, Reuben Akporube et. al.Blockchain platforms propagate into every facet, including managing medical services with professional and patient-centered applications. With its sensitive nature, record privacy has become imminent with medical services for patient diagnosis and treatments. The nature of medical records has continued to necessitate their availability, reachability, accessibility, security, mobility, and confidentiality. Challenges to these include authorized transfer of patient records on referral, security across platforms, content diversity, platform interoperability, etc. These, are today – demystified with blockchain-based apps, which proffers platform/application services to achieve data features associated with the nature of the records. We use a permissioned-blockchain for healthcare record management. Our choice of permission mode with a hyper-fabric ledger that uses a world-state on a peer-to-peer chain – is that its smart contracts do not require a complex algorithm to yield controlled transparency for users. Its actors include patients, practitioners, and health-related officers as users to create, retrieve, and store patient medical records and aid interoperability. With a population of 500, the system yields a transaction (query and https) response time of 0.56 seconds and 0.42 seconds, respectively. To cater to platform scalability and accessibility, the system yielded 0.78 seconds and 063 seconds, respectively, for 2500 users.Item Two-Echelon Inventory Model With Service Consideration and Lateral Transshipment(WSEAS TRANSACTIONS on SYSTEMS, 2021) ZELIBE, SAMUEL CHIABOM; BASSEY, UNANAOWO NYONGThis paper considers a two-echelon inventory system with service consideration and lateral transshipment. So far, researchers have not extensively considered the use of lateral transshipment for such systems. Demand arrivals at both echelons follow the Poisson process. We introduce a continuous review base stock policy for the system in steady state, which determined the expected level for on-hand inventory, expected lateral transshipment level and expected backorder level. We showed that the model satisfied convexity with respect to base stock level. Computational experiments showed that the model with lateral transshipment performed better that the model without lateral transshipment.Item Kumaraswamy Alpha Power Inverted Exponential Distribution: Properties and Applications(ISTAT˙ IST˙ IK: JOURNAL OF THE TURKISH STATISTICAL ASSOCIATION, 2019) Zelibe, Samuel Chiabom; Eghwerido, Joseph Thomas; Efe-Eyefia, EferhonoreThis article proposes a four parameter class of lifetime model called Kumaraswamy Alpha Power Inverted Exponential (KAPIE) distribution in the family of the alpha power transformation. Various statistical properties of the KAPIE density including quantile and hazard rate functions, skewness, kurtosis, order statistics and entropies are investigated. The parameters of the KAPIE distribution are estimated by a maximum likelihood. The flexibility and behaviour of the estimators were studied through a simulation. The empirical flexibility of the KAPIE distribution was examined by means of real life data. It was observed that the KAPIE distribution can serve as an alternative model to other existing densities in literature for modeling lifetime data.Item The Concept of Rhotrix Type a Semigroups(Journal of Mathematic Comput. Science., 2022) UGBENE, I. J.; NDUBUISI R. U.; ABUBAKAR, R. B.Several articles exist on rhotrices as associative rhotrix theory and non-associative rhotrix theory. In this paper, we describe the structure of rhotrix type 𝐴 semigroups. Ultimately, we extend the work of Mohammed et al on rhotrix semigroup.Item Theoretical Analysis of the Weibull Alpha Power Inverted Exponential Distribution: Properties and Applications(Gazi University Journal of Science, 2020) ZELIBE, Samuel Chiabom; EFE-EYEFIA, Eferhonore; EGHWERIDO, Joseph ThomasThis article proposed a Weibull-Alpha Power Inverted Exponential (WAPIE) distribution for lifetime processes. Statistical properties of this distribution such as survival, hazard, reversed hazard, cumulative, odd functions, kurtosis, quantiles, skewness, order statistics and the entropies were derived. Parameters of this family of distribution were also obtained by maximum likelihood method. The behaviour of the estimators was studied through simulation. The behavior of the new developed distribution was further examined through real life data. The WAPIE distribution competes favourably well with other distributions.Item Gompertz-Alpha Power Inverted Exponential Distribution: Properties and Applications(Thailand Statistician, 2020) Zelibe, Samuel Chiabom; Eghwerido, Joseph Thomas; Efe-Eyefia, EferhonoreThis article proposes the Gompertz-Alpha power inverted exponential distribution for lifetime processes. The statistical properties of the distribution such as survival, hazard, reversed hazard, cumulative, odd functions, quantiles, order statistics and entropies were derived. The parameters of the new distribution were obtained by maximum likelihood method. A simulation study was performed to test the flexibility of the propose model. However, the flexibility of the new distribution was also examined using two real life data. The goodness-of-fit of the proposed model indicates that the new distribution perform favourably when compare with existing distributions.Item On The Technological Promises and Challenges Facing E-Businesses in Nigeria(Computing, Information Systems & Development Informatics, 2012) UGBENE, Ifeanyichukwu Jeff; UGWU, Ejike; EZE, Everestus ObinwanneThis paper attempts to address the technological promises and challenges facing e-business in Nigeria. E-business represents a major opportunity for developing nations that can access it effectively and a threat to those that cannot. E-business holds great promise and challenges for Nigeria in ten areas: what is really e-business, potential benefits of the internet in Nigeria, the development context in Nigeria, e-business: towards a conceptual understanding, strategies to encourage the ICT infrastructure in Nigeria, technology requirements and components for e-business in Nigeria, technology services, the challenges faced by Nigerians in the use of e-business, the policy challenge for Nigeria and finally, the impact of information technology upon productivity in Nigeria.Item Transient Heat and Mass Transfer of Hydromagnetic Effects on the Flow Past a Porous Medium with Movable Vertical Permeablesheet(International Journal of Applied Mechanics and Engineering, 2020) Okedoye, A.M.; Salawu, S.O.An unsteady flow of heat and species transport through a porous medium in an infinite movable vertical permeable flat surface is considered. The hydromagnetic chemical reactive fluid flow is stimulated by the thermal and solutant convection, and propelled by the movement of the surface. The formulated nonlinear flow equations in time space are solved analytically by asymptotic expansions to obtain solutions for the flow momentum, energy and chemical concentration for various thermo-physical parameters. The existence of flow characteristic is defined with the assistance of the flow parameters. In the study, the impact of some pertinent flow terms is reported and discussed. The study revealed that the species boundary layer increases with a generative chemical reaction and decreases with a destructive chemical reaction. Also, arise in the generative species reaction term reduces the flow momentum for the cooling surface. The impact of other flow governing parameters is displayed graphically as well as the fluid wall friction, wall energy and species gradients. The results of this study are important in chemical thermal engineering for monitoring processes to avoid solution blow up.Item Mathematical Modelling of the Dynamics and Control of Communicable Diseases with Emphasis on Cholera Epidemics(Asian Journal of Applied Science and Technology (AJAST), 2023) Avwerosuo, Anthony Akalusi; Okedoye, Akindele MichaelCholera remains a disease of public health importance, associated with high morbidity and mortality. This research provides a mathematical approach on the effective control and possible eradication of Vibrio cholera causing menace. This was done using a deterministic SPIRB mathematical model, were we defined S-susceptible, P-protected, I-infected, R-recovered and B-bacteria. We carried out mathematical analyses on the model, such as the invariant region analysis, non-negativity of solutions, equilibrium points, basic reproduction number, stability analysis, sensitivity analysis and bifurcation analysis. All solutions of the SPIRB model are positive and there exists an invariant region for the model. Although, the disease-endemic equilibrium of the model is globally asymptomatically stable, the disease-free equilibrium of the model is not globally stable but locally asymptomatically stable. It was also revealed that the recruitment rate into the susceptible class, the probability that each contact is effective enough to cause infection, the contact rate with contaminated environment, the average contribution of each infected individual to the pathogen population of Vibrio cholera, and the progression rate of protected individuals to the susceptible class are the most sensitive parameters. We showed via the bifurcation analysis that if the progression rate of protected individuals to the susceptible class can be kept very close to zero, say between zero and unity, then the disease-free equilibrium can be kept stable. Numerical simulations were conducted to show the effects of some parameters on the classesItem Analyzing the Impact of Heat and Mass Transfer on Unsteady MHD Flow with Thermal Radiation and Binary Chemical Reaction(European Journal of Theoretical and Applied Science, 2024) Okedoye, Akindele M.; Ometan, Sunday O.; Alabi, Mathew O.In this paper, we investigate the combined effects of heat and mass transfer on unsteady oscillatory magnetohydrodynamic (MHD) flow with thermal radiation and binary chemical reaction. The governing equations of the flow field, energy equation, and species concentration equation are derived under the assumptions of incompressible flow, uniform magnetic field, and small amplitude oscillations. The influence of thermal radiation and chemical reaction is incorporated through appropriate boundary conditions. Mathematical formulations are presented for the coupled system of equations, and numerical simulations are conducted to analyze the heat and mass transfer characteristics of the flow. Sensitivity analysis of the governing parameters were conducted and presented through graphs and discussed. The results provide insights into the complex interplay between fluid dynamics, thermal radiation, and chemical reaction in MHD systems and their implications for engineering applications.Item On the Unsteady Free Convective Flow with Radiative Heat Transfer of Sisko Fluid(IJISET - International Journal of Innovative Science, Engineering & Technology, 2015) Okedoye, Akindele MichaelAn approximate numerical solution of an unsteady free convective flow with radiative heat transfer past a flat plate moving through a binary mixture for a Sisco fluid has been obtained by solving the governing equations using numerical technique. Numerical calculations are carried out for different values of dimensionless parameters and an analysis of the results obtained shows that the flow is influenced appreciably by the chemical reaction, heat source, suction/injection at the wall and also the influence of Dufour and Soret in Sisco fluid.Item Mathematical analysis of affinity hemodialysis on T-Cell depletion(Elsevier, 2020) Okedoye, Akindele M.; Salawu, Sulyman O.; Oke, S.I.; Oladejo, N.K.Investigation into the mathematical analysis of affinity hemodialysis on T-cell depletion is considered to give more significant understanding on the infection dynamics of HIV. Our model revealed the possibility of more than two infected equilibriums with the incorporation of recovery through the affinity hemodialysis. The conditions for stable infected equilibrium to prevent full-blown of AIDS are obtained and stated as hypothesis. This work has, therefore, open the way for partnerships among modelers and clinicians to strengthening the insight into the nature and process of viral multiphasic decay noticed in some treated patients. The initial growth of virus, infected cells and glycoprotein as well as possibility of total viral clearance are examined in the study