| 1 |
Author(s):
S. A. Jimoh, Ebenezer Ajomole, E. C. Ajila.
Page No : 1-15
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Transient Dynamics of Timoshenko Beams Subjected to Moving Loads in Turbulent Environments.
Abstract
This paper investigates the transient response of Timoshenko beams under moving loads in turbulent environments. The study incorporates the effects of shear deformation, rotary inertia, and dynamic aerodynamic forces caused by turbulence. The governing equations are derived from Timoshenko beam theory and coupled with an aerodynamic force model that accounts for mean and fluctuating wind velocities. A spectral representation of turbulent forces is employed to simulate realistic wind-induced forces. Numerical simulations are conducted using both the spectral element method (SEM) and the finite element method (FEM), enabling a comparison of their accuracy and computational efficiency. Results are presented for various load velocities and turbulence intensities, highlighting the advantages and limitations of each method. This study provides valuable insights into the dynamic behavior of beams in challenging environmental conditions, offering practical applications in civil, mechanical, and aerospace engineering.
| 2 |
Author(s):
Moffat Victoria Ekpedeme, Iseh Matthew Joshua.
Page No : 16-39
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Examining the Influence of Basket of Commodities on Consumer Price Index using Stepwise Regression Analysis.
Abstract
This study adopts the concept of stepwise regression analysis with the aim of generating a model to examine the influence of basket of commodities on consumer price index (CPI) in both rural and urban areas in Nigeria. Data used is gotten from the CBN data bank. The result of analysis shows that (housing, water, electricity, gas and other fuel), (food and non alcoholic beverages), (alcoholic beverage, tobacco and kola) (clothing and foot wear), (health), (furnishing and household equipment maintenance), (restaurant and hotels) and (education) are the variables that mostly affect the urban area. Also, for the Rural area, it is observed that (housing, water, electricity, gas and other fuel), (food and non alcoholic beverages), (alcoholic beverage, tobacco and kola), (clothing and foot wear), (health), (furnishing and household equipment maintenance), (miscellaneous goods and services), and (transport) are the variables that contributes significantly. Therefore, the independent variables that have contributed significantly and common to both urban and rural areas are , , , , , and . However, it was noticed that, among the indicators in the basket of commodities, (restaurant and hotels) and (education) have effect only on the urban area while (miscellaneous goods and services) and (transport) were significant in the rural areas only. On this note, the choice of stepwise regression model has really paid off by distinguishing the cause and effect of basket of commodities on CPI for rural and urban areas.
| 3 |
Author(s):
Olumi Toba Timothy, Lawal Fatai Kolade, Ehimony James Babatunde, Umolo David, Ittah Joseph Babatunde.
Page No : 31-44
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Exchange Rate Volatility Analysis: Evaluating Garch Models for Naira-Dollar Rates.
Abstract
This study examines exchange rate volatility with Generalized Autoregressive Conditional heteroscedastic (GARCH) models using daily exchange rate data obtained from the central bank of Nigeria between 1st January 2017 and 31st December 2019. The ARCH LM test of the mean equation revealed the presence of conditional heteroscedasticity. The returns were modeled using ARCH (3), GARCH (2,2), Exponential Generalized Autoregressive Conditional Heteroscedastic EGARCH (3,2), Threshold Generalized Autoregressive Conditional Heteroscedastic TGARCH(1,1). The results revealed that EGARCH (3,2) was the best since it has the least AIC of -24.3197 and SIC of -24.2741. Diagnostic test of the EGARCH (3,2) model residuals with Ljung-Box and the ARCH LM tests revealed that the models were free from higher order autocorrelation and conditional heteroscedasticity respectively. The parameters of the EGARCH (3,2) model was significant and the positive value of the leverage parameter is an indication of absence of leverage effect in the returns of Naira-Dollar exchange rate. The absence of the leverage effect in the exchange rate indicates that positive shocks increases volatility than negative shocks of equal magnitude. Thus, the implication is that a strengthening Dollar (Weakening Naira) leads to higher period volatility than when the Naira is strengthens by the same amount. It is recommended that the Central bank should put in place long term measures to stabilize the Naira since a weakening Naira increases the uncertainty in the exchange market than a strengthening Naira.
| 4 |
Author(s):
Emwinloghosa Kenneth Guobadia, Jophet Ewere Okoh, Joel Isreal Eviano, Adebisi Ajibola Monsuru.
Page No : 40-47
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A New Triangular Probability Model: A Combinatorial Modification of Probability Distributions.
Abstract
The paper projects innovating means to probability modeling using integration method and the concept of normalization. It brings to light a probability distribution obtained by combining a probability density function of a distribution and a cumulative distribution function of another continuous probability model, to produce a triangular trend and a half bell-curve trend. Gumbel and exponential distributions are the root-distributions used for this development. The properties of the distribution include moments and related measures, and estimation, studied alongside simulation.
| 5 |
Author(s):
Essang Samuel Okon, Kolawole Olamide Michael, Francis Runyi Emmanuel, Ibeh Kingsley Kelechi, Ante Jackson Efiong, Ayuk Philia Agam, Okeke Stephen Ikenna, Otobi Augustine Ogbaji, Akpotuzor Sylvia Adaobi, Urekor Simon Ntol, Essien Daniel Edison, Ita Benedict Iserom, Akpan Christian Solomon.
Page No : 48-66
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On The Novel Damped Oscillatory Logistic Growth Model: A Hybrid Approach.
Abstract
The Damped Oscillatory Logistic Growth (DOLG) Model is introduced as a novel hybrid framework that integrates oscillatory dynamics, damping, and logistic growth into a single differential equation. This model extends classical systems such as the harmonic oscillator, logistic growth equation, and damped systems by combining their key features into a unified framework. Numerical solutions reveal rich dynamical behaviors, including damped oscillations, stabilization to carrying capacity, and phase-dependent growth patterns. The system’s stability is analytically and numerically confirmed, with trajectories converging to the non-trivial equilibrium (x,v) = (K,0) for all parameter regimes. The effects of damping, growth rate, and oscillation frequency are explored through time series and phase portraits, demonstrating the model’s versatility in capturing complex phenomena. Potential applications span ecology, economics and engineering, offering new insights into oscillating populations, cyclical growth, and mechanical systems with growth constraints. This study lays the groundwork for future research on hybrid dynamical systems and their interdisciplinary applications.
| 6 |
Author(s):
Obodo O. E., Umeh E. U..
Page No : 67-84
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Assessing the Variance of Maximum Likelihood Estimates for Truncated Pseudo-Lindley Poisson Distribution: A Simulation-Based Approach.
Abstract
This paper introduces a new lifetime probability distribution called the Truncated Pseudo-Lindley-Poisson Distribution (TPLPD), which generalizes the Pseudo-Lindley Distribution and the Poisson distribution. The distribution is a flexible distribution used to model count data with varying degrees of dispersion. This study also investigates the performance of Maximum Likelihood Estimation (MLE) for estimating the parameters of the Truncated Pseudo Lindley Poisson Distribution (TPLPD) through a simulation-based approach. The variance of MLE estimates is assessed under various sample sizes and parameter combinations. The results of the simulation study reveal that the variance of MLE estimates decreases as the sample size increases, and that the choice of parameter combinations significantly affects the variance.
| 7 |
Author(s):
Alaba Akinleye Obabire, Okiemute Gregory Agadaga.
Page No : 85-96
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The Socio-Economic Contributions of Establishment of Federal Polytechnic, Orogun, Delta State on the Host Community.
Abstract
Chi-square test of independence was used in this study to determine associations between establishment of Federal Polytechnic, Orogun and various important socio-economic determinants. Also, to know the significant contribution of the establishment of the Federal Polytechnic, Orogun on the socio-economic development of Orogun in Ughelli North Local Government Area of Delta State in Nigeria. Questionnaire was administered on 1000 respondents randomly selected from various categories of people in the community. Data collected was presented and analyzed using Statistical Package for Social Science, (SPSS) and Microsoft Excel. Most importantly various socio-economic impacts of this great Polytechnic is established in this study.
| 8 |
Author(s):
Mohammed Anono Zubair, Abubakar Haruna.
Page No : 97-128
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Multivariate Volatility Modelling of Stock Prices For Some Selected Nigerian Solid Minerals.
Abstract
The need to provide an acceptable model and forecast for stock prices of solid minerals in Nigeria is valuable for investors and analysts. It will empower them to better understand and manage the associated risks in stock price movements. This study aims to model and forecast the volatility of stock prices of solid minerals, like gold, tin, and zinc. The data utilized in this study was sourced from the Central Bank of Nigeria and Nigeria Stock Exchange. It is the monthly stock prices for selected solid minerals like; Gold, Tin, and Zinc. Multivariate GARCH models such as the VECH, BEKK, Diagonal VECH and Diagonal BEKK model were employed to provide the needed multivariate volatility modeling. The findings reveal that, on average, investors experienced positive returns, and a non-symmetric distribution. It was also discovered that intricate patterns exist within the volatility dynamics of these stocks. Volatility clustering, ARCH effects, and the persistence of volatility shocks over time was identified, emphasizing the non-random nature of stock returns volatility. It is recommended that investors and analysts carefully consider the implications of volatility clustering, ARCH effects, and persistence in volatility shocks when making investment decisions in the stock market, particularly regarding Gold, Tin, and Zinc stocks.
| 9 |
Author(s):
Atsu J. U., Ante J. E., Ambrose U. U., Essang S. O., Aigberemhon E. M., Oyong S. B., Francis R. E..
Page No : 129-140
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Global Solution Existence and Eventual Stability for Nonlinear Systems with Impulses.
Abstract
In this paper, the existence of maximal solution of a comparison differential system for a class of piecewise continuous Lyapunov function is examined. Also, the eventual stability of nonlinear impulsive differential equations with fixed moments of impulse is examined using the vector Lyapunov functions, which is generalized by a class of piecewise continuous Lyapunov functions. The novelty in the use of the vector Lyapunov functions lies in the fact that the difficulty often encountered by the scalar Lyapunov function is allayed especially for large scale dynamical systems. Together with comparison results, sufficient conditions for eventual stability are presented.
| 10 |
Author(s):
Danjuma Theophilus, Laminu Idris.
Page No : 141-158
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Cost Minimization Problem for Deteriorating Item With Stock Level Dependent Demand and Controllable Deterioration Under Trade Credit and Partial Backlogging.
Abstract
This paper studied cost minimization problem for deteriorating item where demand is stock level dependent, deterioration is controllable, vendor can offer trade credit and shortages are partially backlogged. We derived the objective function which is the total average cost function and solved the optimization problem by using optimization problem solver in MatLab. From the numerical examples and sensitivity analysis, we found that the optimal total average cost and the optimal ordered quantity are sensitive to the reduced deteriorating rate and initial demand parameters.
| 11 |
Author(s):
Halima Usman, Obafemi Omoniyi Raymondjoy.
Page No : 159-176
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Optimized Transport Model for Sokoto City Through Vehicle Routing Problem: A Hybrid Metaheuristic and Mathheuristic Approach.
Abstract
This study presents a pioneering hybrid optimization framework designed to enhance urban transportation efficiency in Sokoto City, leveraging a synergistic combination of population-based algorithms and mathematical refinement techniques. By integrating Metaheuristic approaches (Genetic Algorithm and Ant Colony Optimization) with Mathheuristic methods (Mixed Integer Linear Programming with GurobiPy), the model optimizes bus terminal placement, bus stop allocation, and vehicle routing, utilizing a graph-based road network and real-time traffic data. The results reveal significant improvements, including a 33% reduction in travel time, a 25% decrease in congestion delays, and an 18% fuel cost saving. These findings demonstrate the hybrid model's superiority over traditional routing methods and standalone heuristic techniques, positioning it as a valuable tool for transportation planning in similar urban environments. This research contributes to the advancement of intelligent urban mobility and provides actionable insights for policymakers, transportation authorities, and urban planners in emerging economies.
