https://ijmso.unilag.edu.ng/issue/feed International Journal of Mathematical Sciences and Optimization: Theory and Applications 2025-08-20T14:25:59+00:00 Jaiyeola, T. G. tgjaiyeola@unilag.edu.ng Open Journal Systems <p>The International Journal for Mathematical Sciences and Optimization: Theory and Applications is an open access peer-reviewed international Journal that publishes original articles in the broad range of Mathematical Sciences and Optimization, including articles that relate directly and indirectly to Mathematical Sciences and Optimization. Consequently, good and original articles relating to Computer Sciences, Statistics, Modeling, Artificail Intelligence, Differential Equations, Algorithms, Iterative processes etc. are also publishable in the Journal.</p> <p>The Journal, published by the University of Lagos in collaboration with the Association of Mathematical Sciences and Optimization, is domiciled at the University of Lagos.</p> <p>Articles in this Journal are indexed in Society of African Journal Editors, African Journal Online (AJOL), Google Scholars,&nbsp;</p> https://ijmso.unilag.edu.ng/article/view/2696 A Deterministic Model Analysis for Youth Involvement in Yahoo-Yahoo (Cybercrime) and Yahoo+ (Ritualism) 2025-08-20T14:25:59+00:00 O. M. Ogunmiloro oluwatayo.ogunmiloro@eksu.edu.ng <p>The rising involvement of young people in yahoo-yahoo (cybercrime) and yahoo+ (ritualism) has become a major societal concern, particularly in Nigeria, where economic instability and peer pressure drive vulnerable individuals into these illicit activities. This study develops a deterministic compartmental model to analyze the transition of youths through different stages: vulnerability, engagement in yahoo-yahoo, progression into yahoo+ (ritualism), and recovery through rehabilitation. The model accounts for key factors such as recruitment rates, peer influence, the probability of transitioning to ritualistic practices, rehabilitation effectiveness, and relapse risks. A stability analysis of the equilibrium points, which are the yahoo-free and endemic, provides insight into long-term trends based on the basic reproduction number,&nbsp;<span class="katex"><span class="katex-mathml">R0</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord"><span class="mord mathnormal">R</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist"><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">0</span></span></span><span class="vlist-s">​</span></span></span></span></span></span></span></span>, determining whether yahoo-yahoo (cybercrime) and yahoo+ (ritualism) persist or decline. Numerical simulations reveal potential strategies to reduce youth participation in these activities. Based on the model’s findings, the study offers policy recommendations to support sustainable youth development and mitigate this growing societal threat.</p> 2025-08-13T09:48:41+00:00 Copyright (c) 2025 Author https://ijmso.unilag.edu.ng/article/view/2697 Hyper-Homomorphisms in Obic Algebras 2025-08-13T16:21:31+00:00 E. Ilojide ilojidee@funaab.edu.ng O. O. George oogeorge@unilag.edu.ng <p class="ds-markdown-paragraph">In this paper, hyper-homomorphisms of Obic algebras, which are generalizations of homomorphisms in Obic algebras, are introduced. Their properties are investigated. It is shown that homomorphisms of Obic algebras preserve oscillation. Furthermore, it is established that with a suitably defined binary operation, the collection of hyper-homomorphisms in Obic algebras is also an Obic algebra. Moreover, monics, regular and preserving maps of Obic algebras are studied through their hyper-homomorphisms.</p> <p class="ds-markdown-paragraph">&nbsp;</p> 2025-08-13T11:46:36+00:00 Copyright (c) 2025 Author https://ijmso.unilag.edu.ng/article/view/2699 Optimizing Neural Networks with Linearly Combined Activation Functions: A Novel Approach to Enhance Gradient Flow and Learning Dynamics 2025-08-13T16:21:31+00:00 S. O. Essang sammykmf@gmail.com Ante J. E. jackson.ante@topfaith.edu.ng S. E. Fadugba sunday.fadugba@eksu.edu.ng J. T. Auta jauta@aust.edu.ng J. N. Ezeorah reverendjohnmary@gmail.com R. E. Francis runyifrancis@fedpolyugep.edu.ng A. O. Otobi otobiaugustine@unical.edu.ng <p>Activation functions are crucial for the efficacy of neural networks as they introduce non-linearity and affect gradient propagation. Traditional activation functions, including Sigmoid, ReLU, Tanh, Leaky ReLU, and ELU, possess distinct advantages but also demonstrate limits such as vanishing gradients and inactive neurons. This research introduces an innovative method that linearly integrates five activation functions using linearly independent coefficients to formulate a new hybrid activation function. This integrated function seeks to harmonize the advantages of each element, alleviate their deficiencies, and enhance network training and generalization. Our mathematical study, graphical visualization, and hypothetical tests demonstrate that the combined activation function provides enhanced gradient flow in deeper layers, expedited convergence, and improved generalization relative to individual activation functions. Quantitative metrics demonstrate enhanced gradient flow, expedited convergence, and improved generalization relative to individual activation functions. Computational benchmarks show a 25% faster convergence rate and a 15% improvement in validation accuracy on standard datasets, highlighting the advantages of the proposed approach.</p> 2025-08-13T12:47:13+00:00 Copyright (c) 2025 Author https://ijmso.unilag.edu.ng/article/view/2700 A Note on Transmuted Exponentiated Inverse Exponential Distribution and Application to Breast Cancer Data 2025-08-13T12:38:58+00:00 O. I. Oseghale innocentoseghale@gmail.com V. E. Laoye laoyevictoriae@gmail.com <p class="ds-markdown-paragraph">The Transmuted Exponentiated Inverse Exponential (TEIE) Distribution has been derived using Exponentiated Inverse Exponential (EIE) distribution and the Quadratic Rank Transmutation Map (QRTM). The developed distribution is more flexible and adaptable in modeling data exhibiting different shapes of the hazard function than its sub-models. The mathematical expressions and shapes of the distribution function, probability density function, hazard rate function, and reliability function are studied. The parameters of the TEIE distribution are estimated by the method of maximum likelihood. Finally, the TEIE distribution is applied to breast cancer data set and found to have a better fit than the Transmuted Inverse Exponential (TIE) distribution and the Inverse Exponential (IE) distribution.</p> <p class="ds-markdown-paragraph">&nbsp;</p> 2025-08-13T00:00:00+00:00 Copyright (c) 2025 Author https://ijmso.unilag.edu.ng/article/view/2703 On Quasi-Nilpotents in Finite Partial Transformation Semigroups 2025-08-13T13:00:11+00:00 B. Ali bali@nda.edu.ng M. Yahuza myahuza85@gmail.com A. T. Imam atimam@abu.edu.ng <p class="ds-markdown-paragraph">Let&nbsp;<span class="katex"><span class="katex-mathml">Xn</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord"><span class="mord mathnormal">X</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist"><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">n</span></span></span><span class="vlist-s">​</span></span></span></span></span></span></span></span>&nbsp;be the finite set&nbsp;<span class="katex"><span class="katex-mathml">{1,2,3,⋯ ,n}</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mopen">{</span><span class="mord">1</span><span class="mpunct">,</span><span class="mord">2</span><span class="mpunct">,</span><span class="mord">3</span><span class="mpunct">,</span><span class="minner">⋯</span><span class="mpunct">,</span><span class="mord mathnormal">n</span><span class="mclose">}</span></span></span></span>&nbsp;and&nbsp;<span class="katex"><span class="katex-mathml">Pn</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord"><span class="mord mathcal">P</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist"><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">n</span></span></span><span class="vlist-s">​</span></span></span></span></span></span></span></span>&nbsp;be the partial transformation on&nbsp;<span class="katex"><span class="katex-mathml">Xn</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord"><span class="mord mathnormal">X</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist"><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">n</span></span></span><span class="vlist-s">​</span></span></span></span></span></span></span></span>. A transformation&nbsp;<span class="katex"><span class="katex-mathml">α</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathnormal">α</span></span></span></span>&nbsp;in&nbsp;<span class="katex"><span class="katex-mathml">Pn</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord"><span class="mord mathcal">P</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist"><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">n</span></span></span><span class="vlist-s">​</span></span></span></span></span></span></span></span>&nbsp;is called quasi-nilpotent if when&nbsp;<span class="katex"><span class="katex-mathml">α</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathnormal">α</span></span></span></span>&nbsp;is raised to some certain power it reduces to a constant map, i.e.,&nbsp;<span class="katex"><span class="katex-mathml">αm</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord"><span class="mord mathnormal">α</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist"><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">m</span></span></span></span></span></span></span></span></span></span>&nbsp;reduces to a constant map for&nbsp;<span class="katex"><span class="katex-mathml">m≥1</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathnormal">m</span><span class="mrel">≥</span></span><span class="base"><span class="mord">1</span></span></span></span>. We characterize quasi-nilpotents in&nbsp;<span class="katex"><span class="katex-mathml">Pn</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord"><span class="mord mathcal">P</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist"><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">n</span></span></span><span class="vlist-s">​</span></span></span></span></span></span></span></span>&nbsp;and show that the semigroup&nbsp;<span class="katex"><span class="katex-mathml">Pn</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord"><span class="mord mathcal">P</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist"><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">n</span></span></span><span class="vlist-s">​</span></span></span></span></span></span></span></span>&nbsp;is quasi-nilpotent generated. Moreover, if&nbsp;<span class="katex"><span class="katex-mathml">K(n,r)</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathnormal">K</span><span class="mopen">(</span><span class="mord mathnormal">n</span><span class="mpunct">,</span><span class="mord mathnormal">r</span><span class="mclose">)</span></span></span></span>&nbsp;is the subsemigroup of&nbsp;<span class="katex"><span class="katex-mathml">Pn</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord"><span class="mord mathcal">P</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist"><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">n</span></span></span><span class="vlist-s">​</span></span></span></span></span></span></span></span>&nbsp;consisting of all elements of height&nbsp;<span class="katex"><span class="katex-mathml">r</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathnormal">r</span></span></span></span>&nbsp;or less, where the height of an element&nbsp;<span class="katex"><span class="katex-mathml">α</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathnormal">α</span></span></span></span>&nbsp;is defined as&nbsp;<span class="katex"><span class="katex-mathml">∣imα∣</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord">∣</span><span class="mord mathnormal">im</span><span class="mord mathnormal">α</span><span class="mord">∣</span></span></span></span>, we obtain the quasi-nilpotent rank of&nbsp;<span class="katex"><span class="katex-mathml">K(n,r)</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathnormal">K</span><span class="mopen">(</span><span class="mord mathnormal">n</span><span class="mpunct">,</span><span class="mord mathnormal">r</span><span class="mclose">)</span></span></span></span>, that is, the cardinality of a minimum quasi-nilpotent generating set for&nbsp;<span class="katex"><span class="katex-mathml">Pn</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord"><span class="mord mathcal">P</span><span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist"><span class="sizing reset-size6 size3 mtight"><span class="mord mathnormal mtight">n</span></span></span><span class="vlist-s">​</span></span></span></span></span></span></span></span>, as the Stirling number of the second kind&nbsp;<span class="katex"><span class="katex-mathml">S(n+1,r+1)</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathnormal">S</span><span class="mopen">(</span><span class="mord mathnormal">n</span><span class="mbin">+</span></span><span class="base"><span class="mord">1</span><span class="mpunct">,</span><span class="mord mathnormal">r</span><span class="mbin">+</span></span><span class="base"><span class="mord">1</span><span class="mclose">)</span></span></span></span>, which is the same as its idempotent rank.</p> <p class="ds-markdown-paragraph">&nbsp;</p> 2025-08-12T00:00:00+00:00 Copyright (c) 2025 Author https://ijmso.unilag.edu.ng/article/view/2705 Mathematical Model for Ions Transport Optimization in an Animal Cell Using MATLAB 2025-08-13T16:21:31+00:00 K. J. M. Karimi kkarimi@karu.ac.ke T. Rotich tisesko@yahoo.com <p class="ds-markdown-paragraph">The increasing world population has raised significant concerns about matching food production to demand, prompting extensive research in scientific fields aimed at enhancing plant and animal productivity. However, some of these advances have introduced unintended consequences, such as uncontrolled cell growth that leads to cancer. Effective regulation of cell size is essential to maintaining organismal health. This study focuses on the utilization of a numerical method to develop a mathematical model that optimizes ion transport within an animal cell as a mechanism to ensure a physiologically healthy cell. Through this model, optimal ion concentrations were identified using MATLAB-SIMULINK. The results were validated using experimental data to ensure that they promote healthy cell growth and stability. The results provide valuable insights for treating disorders associated with abnormal cell growth initiated by unregulated ions concentration. This research contributes to understanding cellular homeostasis and lays the groundwork for future bioengineering applications.</p> 2025-08-13T00:00:00+00:00 Copyright (c) 2025 Author https://ijmso.unilag.edu.ng/article/view/2706 On the Fixed Points of Springer Varieties in Type A 2025-08-13T13:22:54+00:00 O. J. Felemu olasupo.felemu@aaua.edu.ng <p class="ds-markdown-paragraph">Springer varieties are sub-varieties of the full (complete) flag variety <span class="katex"><span class="katex-mathml">Fℓn(C)</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathcal">F</span><span class="mord">ℓ<span class="msupsub"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist"><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">n</span></span></span></span><span class="vlist-s">​</span></span></span></span></span><span class="mopen">(</span><span class="mord mathbb">C</span><span class="mclose">)</span></span></span></span>, which can be thought of as the fiber over&nbsp;<span class="katex"><span class="katex-mathml">X</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathnormal">X</span></span></span></span>&nbsp;of the Springer resolution of singularities of the cone of nilpotent endomorphisms&nbsp;<span class="katex"><span class="katex-mathml">X:V⟶V</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathnormal">X</span><span class="mrel">:</span></span><span class="base"><span class="mord mathnormal">V</span><span class="mrel">⟶</span></span><span class="base"><span class="mord mathnormal">V</span></span></span></span>, where&nbsp;<span class="katex"><span class="katex-mathml">X</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathnormal">X</span></span></span></span>&nbsp;is a nilpotent endomorphism in its Jordan canonical form of type&nbsp;<span class="katex"><span class="katex-mathml">λ</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathnormal">λ</span></span></span></span>&nbsp;and&nbsp;<span class="katex"><span class="katex-mathml">V</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathnormal">V</span></span></span></span>&nbsp;is an&nbsp;<span class="katex"><span class="katex-mathml">n</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathnormal">n</span></span></span></span>-dimensional vector space over&nbsp;<span class="katex"><span class="katex-mathml">C</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathbb">C</span></span></span></span>&nbsp;(<span class="katex"><span class="katex-mathml">V=Cn</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathnormal">V</span><span class="mrel">=</span></span><span class="base"><span class="mord"><span class="mord mathbb">C</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist"><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">n</span></span></span></span></span></span></span></span></span></span></span>&nbsp;for convenience). The geometry of Springer varieties is reviewed in this article, along with their&nbsp;<span class="katex"><span class="katex-mathml">Sk</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord"><span class="mord mathnormal">S</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist"><span class="sizing reset-size6 size3 mtight"><span class="mord mtight"><span class="mord mathnormal mtight">k</span></span></span></span></span></span></span></span></span></span></span>-fixed points. We accomplish this by briefly reviewing nilpotent orbits in type&nbsp;<span class="katex"><span class="katex-mathml">A</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord mathnormal">A</span></span></span></span>&nbsp;within the framework of integer partitions.</p> 2025-08-11T00:00:00+00:00 Copyright (c) 2025 Author https://ijmso.unilag.edu.ng/article/view/2708 Assessing Asset Value Changes Using a System of Stochastic Models with Constant Terms and Periodic Drift Coefficients 2025-08-13T16:21:31+00:00 C. P. Ogbogbo cpnogbogbo@ug.edu.gh I. U. Amadi innocent.amadi@portharcourtpoly.edu.ng L. C. Nnoka nnokalove@gmail.com T. Katsekpor tkatsekpor@ug.edu.gh <p class="ds-markdown-paragraph">The Stochastic Differential Equation (SDE) is a well-known mathematical tool used for estimating asset values over time. This paper focuses on stochastic systems with an emphasis on variations in stock parameters. The problems were solved analytically using Itô's method, providing precise measures for assessing asset values. The study empirically analyzes the behavior of asset values under increasing volatility, presenting results in tables and graphs. Key findings include: increased volatility decreases asset values, periodic parameters cause fluctuations in asset assessments, and the average asset value over time impacts financial markets in time-varying investments. This work introduces a novel approach by modeling stock drift coefficients with constants and periodic event parameters, offering unique insights for financial market investors.</p> 2025-08-21T00:00:00+00:00 Copyright (c) 2025 Author https://ijmso.unilag.edu.ng/article/view/2710 Fixed Point Theorems for Some Iteration Processes with Generalized Zamfirescu Mappings in Uniformly Convex Banach Spaces 2025-08-13T16:12:40+00:00 A. O. Bosede aolubosede@yahoo.co.uk S. A. Raji rajisa@lasued.edu.ng S. A. Wusu ashiribo.wusu@lasu.edu.ng S. O. Ayodele rajisa@lasued.edu.ng O. K. Adewale adewalekayode2@yahoo.com A. C. Loyinmi loyinmiac@tasued.edu.ng <p class="ds-markdown-paragraph">This paper establishes fixed point theorems for certain iteration processes in uniformly convex Banach spaces using generalized Zamfirescu mappings. The results improve upon recent findings in the literature. The study focuses on iterative schemes such as Mann and Ishikawa, demonstrating their strong convergence to fixed points under generalized Zamfirescu contractive conditions. The work contributes to the broader understanding of fixed point theory in uniformly convex Banach spaces and provides a foundation for further research in this area.</p> 2025-08-12T00:00:00+00:00 Copyright (c) 2025 Author https://ijmso.unilag.edu.ng/article/view/2711 On the Solutions of Optimal Control Problems Constrained by Ordinary Differential Equations with Vector-Matrix Coefficients Using FICO Xpress Mosel 2025-08-13T16:20:03+00:00 A. S. Afolabi asafolabi@futa.edu.ng A. A. Oyewale Oyewaleadedamola10@gmail.com <p class="ds-markdown-paragraph">This study addresses a general class of quadratic optimal control problems (OCPs) constrained by ordinary differential equations (ODEs) with vector-matrix coefficients. Due to the intractability of analytical solutions for complex dynamic systems, the focus is on developing and comparing efficient numerical methods. An analytical framework is first established by applying first-order optimality conditions to the Hamiltonian, yielding a system of first-order ODEs. The associated Riccati differential equation is then solved using a state transformation approach. For numerical solutions, the objective functional is discretized using Simpson's&nbsp;<span class="katex"><span class="katex-mathml">13</span><span class="katex-html" aria-hidden="true"><span class="base"><span class="mord"><span class="mfrac"><span class="vlist-t vlist-t2"><span class="vlist-r"><span class="vlist"><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">3</span></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">1</span></span></span><span class="vlist-s">​</span></span></span></span></span></span></span></span>&nbsp;rule, and the system dynamics are approximated using a fifth-order implicit integration scheme. The discretized problem is reformulated as an unconstrained optimization problem via the Augmented Lagrangian Method and solved using both the CGM and FICO Xpress Mosel. Comparative results reveal that FICO Xpress Mosel provides faster convergence and greater numerical stability, especially for high-dimensional problems. These findings underscore the effectiveness of commercial solvers like FICO Xpress Mosel in solving large-scale quadratic OCPs with enhanced accuracy and efficiency.</p> 2025-08-13T00:00:00+00:00 Copyright (c) 2025 Author