Papers by Adebayo D Agunbiade
It is important to fit count data with suitable model(s), models such as Poisson Regression, Quas... more It is important to fit count data with suitable model(s), models such as Poisson Regression, Quassi Poisson, Negative Binomial, to mention but a few have been adopted by researchers to fit zero truncated count data in the past. In recent times, dedicated models for fitting zero truncated count data have been developed, and they are considered sufficient. This study proposed Bayesian multi-level Poisson and Bayesian multi-level Geometric model, Bayesian Monte Carlo Markov Chain Generalized linear Mixed Models (MCMCglmms) of zero truncated Poisson and MCMCglmms Poisson regression model to fit health count data that is truncated at zero. Suitable model selection criteria were used to determine preferred models for fitting zero truncated data. Results obtained showed that Bayesian multi-level Poisson outperformed Bayesian multi-level Poisson Geometric model; also MCMCglmms of zero truncated Poisson outperformed MCMCglmms Poisson.
African Journal of Science and Nature, Jun 21, 2017
Funding Nigerian Government owned Institutions has been the responsibility of the Government. Fed... more Funding Nigerian Government owned Institutions has been the responsibility of the Government. Federal institutions have been enjoying the ease flow of cash from the Federal Government. However, State-owned Government Institutions like Olabisi Onabanjo University, as revealed in THE NATION newspaper, has been faced with under-funding from her host Government, hence, calling for creativity for this institution to create or increase the Internally Generated Revenue (IGR). Taking Olabisi Onabanjo University as a case study, this research used a Double Sampling for Regression Statistical Sampling with estimation method to estimate approximate total amount of eight hundred and sixty nine million naira (N869 Million) that the can generate annually from six proposed businesses with reference to the undergraduate population. These six businesses have the following estimate, percentage of contribution to IGR and the corresponding percentage coefficient of variation: Students’ Accommodation (N265 Million: 30.5%: 4.24%),Female Hair do and Male Hair cut (N172 Million: 19.77%: 12.21%), Egg Sales (N64 Million: 7.42%: 5.81%), Fruit Juice (N112 million: 12.90%: 8.56%), Customised Exercise Book (N36 million: 4.15%: 15.69%) and Bread Production (N220 million: 25.2%: 7.77%). It was recommended that Nigerian Institutions should endeavour to do these businesses. Similarly, there is need for Nigerian Institutions to establish the IGR directorate that will be delegated with the objectives on how to strategise on boosting, running and maintaining IGR activities for the institution in the most aggressive and profitable ways.
Journal of Mathematical Sciences: Advances and Applications, 2017
The inconsistent estimators of the parameters resulted from the simultaneity problem when the str... more The inconsistent estimators of the parameters resulted from the simultaneity problem when the structural equations are estimated by ordinary least squares (OLS) approach is of great importance in this research. The study argues that it does not mean that OLS estimation of simultaneous equation models (SEM) is useless; and so examined the empirical analysis of the three categories of estimation techniques: OLS, single equation and system estimation approaches. The asymptotic and small sample properties of the various methods are compared using total absolute bias and the root mean square error. The findings indicated no remarkable and asymptotic pattern in the performance of the estimates of the parameters of each estimator. However, the ranking of the three categories of simultaneous estimation methods differs according to the correlation level of the explanatory variables and the individual equation of the SEM.
Progress in Applied Mathematics, 2012
This paper investigates the effects of heteroscedasticity in the Classical Linear Regression Mode... more This paper investigates the effects of heteroscedasticity in the Classical Linear Regression Model (CLRM) of auditor's remuneration. Several efforts of building a realistic econometric model for Auditor's Remuneration with regards to core banking activities have been undertaken. The work involves the use of White heteroscedasticity and Newey-West test techniques to examine the presence of heteroscedasticity, which shows that heteroscedasticity is an inherent feature of cross-sectional data. The superiority of Weighted Least Squares (WLS) on Ordinary Least Squares (OLS) was put to test in estimating the parameters of Auditor’s Remuneration model designed as:\\ \hspace*{10mm} $ AR_i = \theta_0 + \theta_1 T A_i + \theta_2 T E_i + \theta_3 C D_i + \theta_4 P B T_i + \varepsilon$\\ \hspace*{6mm}And it was established that OLS is not appropriate for estimation if heteroscedasticity is present in research data, and that the model fitted using WLS is the most appropriate that is d...
Double sampling for regression is an advanced sampling and estimation method in Statistics. Sahoo... more Double sampling for regression is an advanced sampling and estimation method in Statistics. Sahoo’s Chain regression in 1993 was a case study of double sampling for regression where two auxiliary variables ( and ) are used. Authors have established that ridge regression performs better than Ordinary Least Squares (OLS) estimation in the presence of collinearity problem in linear regression with more than one independent variable. However, since double sampling for regression with more than one auxiliary variable could as well be faced with collinearity, hence, there is need to verify the validity of ridge regression in estimating the regression coefficient for use in double sampling for regression. This research applied ridge regression estimation method to Sahoo double sampling chain regression estimator when there exists high collinearity between the two auxiliary variables and . The empirical results show that two auxiliary variables maintains higher efficiency over one auxiliary...
International Journal of Mathematics and Computation, 2019
Violation of homoscedasticity assumption in a Panel Data Regression Model (PDRM) implies unequal ... more Violation of homoscedasticity assumption in a Panel Data Regression Model (PDRM) implies unequal variability of error terms, and this creates heterogeneity problem in estimation. This research thus attempts to investigate this phenomenon by extending the works of Baltagi et al. (2010) and Adeboye and Agunbiade (2017) within the context of fitting an audit fee model via a simulated panel data and its estimation through the derivation of a Conditional Lagrange Multiplier (CLM) test for heteroscedasticity given zero first-order serial correlation via a two-way error component model. Monte Carlo simulations were carried out for 27 different variations, of which its design assumed a uniform distribution under a linear heteroscedasticity function. Each of the variation was iterated 1000 times and the assessments of estimators considered are based on Absolute bias (ABIAS) of parameters estimates. Nine (9) different models at different specified conditions were fitted, and the best-fitted m...
The evolution of Information communication Technology (ICT) has cut across all facets of society ... more The evolution of Information communication Technology (ICT) has cut across all facets of society with its prevailing impacts on both academic and non-academic environments. This evolved Social media which has transformed and impacted on communication, learning, research and education in general due to easy access to devices such as smart phones, iPhones, black berry, tablets, iPod and laptops which are connected to the internet. Thus, the objectives of this research is to identify most prevalent factors responsible for the negative and positive effects of ICTinfluenced of social media on student academic performance with the aid of Principal Component Analysis. To achieve this objective, survey was carried out using direct questionnaire method that employed five factors which include; 'social media allows exchange of information', 'social media facilitates smooth interaction with the lecturers', 'social media helps to develop research skills through peer collabor...
The Bulletin of Society for Mathematical Services and Standards, 2013
In recent years, convex programming has become a sophisticated tool of central importance in engi... more In recent years, convex programming has become a sophisticated tool of central importance in engineering, finance, operations research, statistics etc. The goal of this paper is to emphasize modeling and present several convex programming problem formulations especially in optimal design and location theory. We build simple models to address this question, investigate their properties and apply a variant of the Weierstrass theorem to prove the existence of a solution. Our results extend and improve some other comparable results of the author
The Bulletin of Society for Mathematical Services and Standards, 2013
The role of transportation in the promotion of national unity and socio-economic integration in N... more The role of transportation in the promotion of national unity and socio-economic integration in Nigeria cannot be overemphasized. Transport stimulates asense of oneness multi understanding in the cultural diversification of the mostpopulous nation in the sub Sahara of African Continent. it is therefore of interest tostudy using the Autoregressive Moving Average, the transportation system in Nigeriausing Lagos State (being the commercial centre) and also maintains a robust data basethrough the AUTOREG System as a case study by modeling and forecasting theVehicle registration system in terms of types and ownership. The result of theAutoregressive Moving Average (ARMA) approach indicated that there is tendencyfor an increase in the registration of Vehicles in the future. It is therefore suggested that to accommodate an increase in the number of Vehiclesregistration, a robust Vehicle database should be designed across the country forsecurity, research and adequate planning; and Nigerian...
Journal of Modern Mathematics and Statistics, 2011
Violation of homoscedasticity assumption in a Panel Data Regression Model (PDRM) implies unequal ... more Violation of homoscedasticity assumption in a Panel Data Regression Model (PDRM) implies unequal variability of error terms, and this creates heterogeneity problem in estimation. This research thus attempts to investigate the presence and effect of heteroscedasticity in panel data through the estimation of a specified audit fees PDRM using Pooled ordinary least square (POLS, Least square dummy variable (LSDV) technique where all coefficients vary across individual and Random Effect estimator (REM). A conditional Lagrange multiplier test was developed via a two-way error components model, to examine the presence of heteroscedasticity in the fitted POLS model while Hausman test was used to ascertain the suitability of the LSDV Model over Random effect model and vice-versa. The conditional LM test gave a value of 7.1462 with P-value of 0.000000000000446 which shows that there is presence of unequal variance of MA(1) errors among the residuals of the fitted Pooled OLS model, thereby rendered the estimator inconsistent. Both LSDV and RE models were fitted to take care of the challenges posed by the presence of heteroscedasticity and both models captured the goodness of fit better when compared to the Pooled OLS model. However, the Hausman test revealed that random effect model will not be preferable since p-value of the former is less than 0.05.
This research attempts to investigate the effects of heteroscedasticity and periodicity in a Pane... more This research attempts to investigate the effects of heteroscedasticity and periodicity in a Panel Data Regression Model (PDRM) by extending previous works on balanced panel data estimation within the context of fitting PDRM for Banks audit fee. The estimation of such model was achieved through the derivation of Joint Lagrange Multiplier (LM) test for homoscedasticity and zero-serial correlation, a conditional LM test for zero serial correlation given heteroscedasticity of varying degrees as well as conditional LM test for homoscedasticity given first order positive serial correlation via a two-way error component model. Monte Carlo simulations were carried out for 81 different variations, of which its design assumed a uniform distribution under a linear heteroscedasticity function. Each of the variation was iterated 1000 times and the assessment of the three estimators considered are based on Variance, Absolute bias (ABIAS), Mean square error (MSE) and the Root Mean Square (RMSE) o...
It is important to fit count data with suitable model(s), models such as Poisson Regression, Quas... more It is important to fit count data with suitable model(s), models such as Poisson Regression, Quassi Poisson, Negative Binomial, to mention but a few have been adopted by researchers to fit zero truncated count data in the past. In recent times, dedicated models for fitting zero truncated count data have been developed, and they are considered sufficient. This study proposed Bayesian multi-level Poisson and Bayesian multi-level Geometric model, Bayesian Monte Carlo Markov Chain Generalized linear Mixed Models (MCMCglmms) of zero truncated Poisson and MCMCglmms Poisson regression model to fit health count data that is truncated at zero. Suitable model selection criteria were used to determine preferred models for fitting zero truncated data. Results obtained showed that Bayesian multi-level Poisson outperformed Bayesian multi-level Poisson Geometric model; also MCMCglmms of zero truncated Poisson outperformed MCMCglmms Poisson.
Discrete Weibul (DW) is considered to have the ability to capture under and over-dispersion simul... more Discrete Weibul (DW) is considered to have the ability to capture under and over-dispersion simultaneously and also have a closed-form analytical expression of the quantiles of the conditional distribution. There is a need to further investigate how effective the model is, as compared to other competing models in the context of classical and Bayesian technique. In this study, the strength of DW is investigated, for both on frequentist and Bayesian technique. The Bayesian DW adopts parameterization, which makes both parameters of the discrete Weibull distribution to be dependent on the predictors. Bayesian Generalized linear mixed model is also implemented and is compared with the BDW, since Bayesian generalized linear mixed model is known to be robust in handling over-dispersion in count data. A simulation study and real life data was carried out for over and under-dispersed count data. The empirical analysis shows the superiority of Bayesian Generalized linear mixed model over Baye...
This paper employed genetic algorithm to develop a roster table for physicians/medical doctors of... more This paper employed genetic algorithm to develop a roster table for physicians/medical doctors of a hospital in Nigeria. The rostering algorithm involves non-cyclic scheduling process, establishment of hard and soft constraints and choosing of befitting genetic algorithm parameters for generating the medical doctor rostering table. The resultant schedules were analysed with soft constraints using degree of satisfaction nature. KeywordsGenetic algorithm, Constraints, Non-cyclic
Modelling tails of distributions can performed with models such as Weibull, Frechet and Gumbel di... more Modelling tails of distributions can performed with models such as Weibull, Frechet and Gumbel distribution, it can also be modelled with generalized extreme value (GEV); a model which combines the three models. The limitation of GEV model is that it is not sufficient to model some levels of fat tail distributions. To identify the strength of GEV, Simulation study was carried out using both Generalized Pareto distributions (GPD) and GEV models with maximum likelihood estimate (MLE), and comparison was drawn between the models. Empirical results revealed that GPD model is sufficient to model fat tail distributions well irrespective of the data points, On the other hand, GEV models thin tail distribution better than GPD. GPD was modelled using electrical energy dataset and obtained tail risk, while GEV was used to model daily foreign exchange data.
It is important to fit count data with suitable model(s), models such as Poisson Regression, Quas... more It is important to fit count data with suitable model(s), models such as Poisson Regression, Quassi Poisson, Negative Binomial, to mention but a few have been adopted by researchers to fit zero truncated count data in the past. In recent times, dedicated models for fitting zero truncated count data have been developed, and they are considered sufficient. This study proposed Bayesian multi-level Poisson and Bayesian multi-level Geometric model, Bayesian Monte Carlo Markov Chain Generalized linear Mixed Models (MCMCglmms) of zero truncated Poisson and MCMCglmms Poisson regression model to fit health count data that is truncated at zero. Suitable model selection criteria were used to determine preferred models for fitting zero truncated data. Results obtained showed that Bayesian multi-level Poisson outperformed Bayesian multi-level Poisson Geometric model; also MCMCglmms of zero truncated Poisson outperformed MCMCglmms Poisson.
Open Journal of Statistics, 2013
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Papers by Adebayo D Agunbiade