Papers by Kazeem A Adepoju
Journal of Modern Applied Statistical Methods, May 1, 2015
The Kumaraswamy exponential distribution, a generalization of the exponential, is developed as a ... more The Kumaraswamy exponential distribution, a generalization of the exponential, is developed as a model for problems in environmental studies, survival analysis and reliability. The estimation of parameters is approached by maximum likelihood and the observed information matrix is derived. The proposed models are applied to three real data sets.
A three parameter probability model which serves as a generalization of the Exponential distribut... more A three parameter probability model which serves as a generalization of the Exponential distribution was studied. The new model is named Exponentiated Generalized Exponential (EGE) distribution. The shape of the model could be increasing, decreasing or unimodal (depending on the value of the parameters). Explicit expressions are provided for the moments and generating functions, reliability function and failure rate. The method of maximum likelihood estimation (MLE) was proposed for the estimation of the parameters. An application to two real data sets was provided in order to assess the flexibility of the proposed model over some models in the literature.
On the Log-Gamma Exponentiated Weibull Regression Model: An Application to Recurrence of Bank Failure in Nigeria
Abstract: This study is focused on combining Nakagami distribution and beta distribution with a v... more Abstract: This study is focused on combining Nakagami distribution and beta distribution with a view to obtaining a distribution that is better than each of them individually in terms of the estimate of their characteristics and parsimonious in their parameters using the logit of beta (the link function of the Beta generalized distribution by Jones (2004)). The resulting model, beta Nakagami distribution is better in terms of its flexibility and shape. The statistical properties of the proposed distribution such as moments, moment generating function, the asymptotic behavior among others were investigated. Our findings showed that beta Nakagami apart from being flexible, has better representation of data than Nakagami distribution. It therefore describes situations better than the Nakagami distribution.
Mathematics and Statistics
We propose the Kumaraswamy-F (KUMAF) distribution which is a generalization of the conventional F... more We propose the Kumaraswamy-F (KUMAF) distribution which is a generalization of the conventional Fisher Snedecor (F-distribution). The new distribution can be used even when one or more of the regular assumptions are violated. It is obtained with the addition of two shape parameters to a continuous F-distribution which is commonly used to test the null hypothesis in the Analysis of Variance (ANOVA test). The statistical properties of the proposed distribution such as moments, moment generating function, the asymptotic behavior among others were investigated. The method of maximum likelihood is used to estimate the model parameters and the observed information matrix is derived. The distribution is found to be more flexible and robust to regular assumptions of the conventional F-distribution. In future research, the flexibility of this distribution as well as its robustness using a real data set will be examined. The new distribution is recommended for used in most applications where the assumption underlying the use of conventional F distribution for one-way analysis of variance are violated such as homogeneity of variance or normality assumption probably as result of the presence of outlier(s). It is instructive to note that the new distribution preserves the originality of the data without transformation.
In this paper, an optimal estimator for estimating the population mean is proposed. This is ach i... more In this paper, an optimal estimator for estimating the population mean is proposed. This is ach ieved by minimizing the coefficient of variation (C x ) of the au xiliary variable in the Mean Square Error (MSE) fro m the existing estimators. Using well analyzed data to illustrate the procedure for both the Ratio and Product estimators, a min imu m of 10 percent reduction in the MSE were observed from each of the existing estimators considered. The proposed optimal estimators is unifo rmly better than all other estimators and thus most preferred over the existing modified ratio and product estimators for the use in practical applicat ions for certain population with peculiar characteristics
This research work presents new development in the field of natural science, where comparison is ... more This research work presents new development in the field of natural science, where comparison is made theoretically on the efficiency of both classical regression models and that of artificial neural network models, with various transfer functions without data consideration. The results obtained based on variance estimation indicates that ANN is better which coincides with the results of Authors in the past on the efficiency of ANN over the traditional regression models. The certain conditions required for ANN efficiency over the conventional regression models were noted only that the optimal number of hidden layers and neurons needed to achieve minimum error is still open to further investigation. Key words Artificial neural network models; Transfer functions; Hidden layers; Regression models
This article focuses on developing a new modified ratio estimator of population mean of the study... more This article focuses on developing a new modified ratio estimator of population mean of the study variable using the linear combination of known values of Median, Coefficient of Kurtosis and Quartile deviation of the auxiliary variable. Comparison of the Mean square error and bias of the proposed estimator will be made with that of Yan and Tian (2010), Subramani, et.al G. (2012), and Jeelani et. al (2013) estimators. We demonstrate numerically that the proposed estimator is more efficient than some of the existing modified ratio estimators. Keywords: Ratio, Product, Estimator, Parameter, Mean Square error
American Journal of Mathematics and Statistics, 2013
In this paper, an estimator wh ich is robust in the present of outlier and Skewness is proposed. ... more In this paper, an estimator wh ich is robust in the present of outlier and Skewness is proposed. This is achieved by incorporating median, a good measure of location in this regard to the modified ratio estimator developed as in(22). Using well analy zed data to illustrate the procedure for the Ratio estimator, its Mean square error was observed the minimu m of the existing estimators considered. The proposed modified estimator is uniformly better than all other estimators and thus most preferred over the existing modified ratio estimators for the use in practical applications for certain population with peculiar characteristics
American Scientific Research Journal for Engineering, Technology, and Sciences, 2016
In this paper, two new outlier generating mechanisms for the detection of outliers in multivariat... more In this paper, two new outlier generating mechanisms for the detection of outliers in multivariate time series setting were derived. This is achieved by specifying two-variable vector autoregressive models and assuming additive and convolution effect of outliers on time series data. The magnitude and variance of outlier were derived for the generating models by method of least squares. Also a modified test statistics were developed to detect single outliers both in the response and explanatory variables. In order to establish the validity and efficiency of the derived models, the models were applied to both simulated and existing data. The results from the analysed data were also compared to some existing models and the result showed that the convolution model is best in terms of the number of outliers detected and the residual variance. This result confirms the finding in previous studies of outlier detection in univariate time series.
Journal of modern applied statistical methods: JMASM
One of the bases for assessment of wind energy potential for a specified region is the probabilit... more One of the bases for assessment of wind energy potential for a specified region is the probability distribution of wind speed. Thus, appropriate and adequate specification of the probability distribution of wind speed becomes increasingly important. Several distributions have been proposed for describing wind distribution. Among the most popular distributions is the Weibull whose choice is due to its flexibility. An exponentiated Weibull distribution is proposed as an alternative to model wind speed data with a view to comparing it with the existing Weibull distribution. Results indicate that the proposed distribution outperforms the existing Weibull distribution for modeling wind speed data in terms of minimum Akaike information criterion (AIC) and likelihood function. Thus, the exponentiated Weibull can be used as an alternative distribution that adequately describe the wind speed and thereby provide better representation of the potentials of wind energy. Keywords: Wind power, Wei...
American Journal of Mathematics and Statistics, 2013
In this paper, an optimal estimator for estimating the population mean is proposed. This is ach i... more In this paper, an optimal estimator for estimating the population mean is proposed. This is ach ieved by minimizing the coefficient of variation (Cx) of the au xiliary variable in the Mean Square Error (MSE) fro m the existing estimators. Using well analyzed data to illustrate the procedure for both the Ratio and Product estimators, a min imu m of 10 percent reduction in the MSE were observed from each of the existing estimators considered. The proposed optimal estimators is unifo rmly better than all other estimators and thus most preferred over the existing modified ratio and product estimators for the use in practical applicat ions for certain population with peculiar characteristics Ratio estimation involves the use of known population totals for auxiliary variables to improve the weighting from sample values to population estimates of interest. It operates by comparing the samp le estimate for an au xiliary variab le with the known population total for the same variable on the ...
We propose adding one parameter to a continuous distribution called the Nakagami-m distribution (... more We propose adding one parameter to a continuous distribution called the Nakagami-m distribution (or simply the Nakagami distribution) that was proposed for modeling the fading of radio signals by (Nakagami, 1960) and recently extended by Shittu and Adepoju (2013). The exponentiated Nakagami (ENAK) distribution has been proposed as a generalization of the classical Nakagami distribution. The distribution is more flexible than beta-Nakagami distribution developed by Shittu and Adepoju (2013). The statistical properties of the proposed distribution such as moments, moment generating function, the asymptotic behavior among others were investigated. The method of maximum likelihood is used for estimating the model parameters and the observed information matrix is derived. A real data set is used to compare the new model with the class of Nakagami distributions. Our findings showed that Exponentiated Nakagami has better representation of data than other class of Nakagami distribution. Key...
On the Exponentiated Weibull Distribution for Modeling Wind Speed in South Western Nigeria
Journal of Modern Applied Statistical Methods
On the Efficiency of Some Modified Ratio and Product Estimators – The Optimal Cx Approach
On the Efficiency of Ratio Estimator Based on Linear Combination of Median, Coefficients of Skewness and Kurtosis
American Journal of Mathematics and Statistics, 2013
On the Beta-Nakagami Distribution
Progress in Applied Mathematics, 2013
The Beta Power Exponential Distribution
Journal of Statistical Science and Application, 2014
The Beta- Fisher Snedecor Distribution with Applications to Cancer Remission Data
On the Development of an Exponentiated F Test for One-Way Anova in the Presence of Outlier(S)
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Papers by Kazeem A Adepoju