Gerald Onwuka - Academia.edu (original) (raw)

Papers by Gerald Onwuka

International Journal of Advanced Research

This research work investigated with error process. The auto covariance function maximum likeliho... more This research work investigated with error process. The auto covariance function maximum likelihood methods, iterative method and chi-squares test statistics is used to develop SARIMA model corrupted with error process that is used to estimate the true parameter of the SARIMA model. The forecast performance measurement and properties of error with different value are also investigated. Test of seasonal unit roots are also carried out in the work. The simulation, and real data of Zamfara state monthly Rain fall from 1998 to 2022 is used to validate the results with R - Statistical software version 4.1.1 and mini tab statistical software version 14. The result showed a significance p- value of 0.000, the proposed model provides a generalization and more flexible specification than the existing models of AR (1) error and ARMA (1,1) error in fitting time series processes in the presence of errors . Hence, the studies showed that, the finding is closely to the true parameter of the proce...

International Journal of Science for Global Sustainability, Oct 31, 2023

This study focused on creating a binary logistic regression model to evaluate the risk factors fo... more This study focused on creating a binary logistic regression model to evaluate the risk factors for hepatitis B viral disease in the Gusau Local Government of Zamfara State, Nigeria. Secondary data was utilised, and the model identified independent predictors of hepatitis-b disease based on variables with a P-value < 0.05 and a 95% confidence interval for the odds ratio not less than 1. The results indicated that marital status, history of blood transfusion, multiple sex partners, and alcohol consumption were statistically associated with hepatitis-B virus infection, while gender and having an infected family member were not. Model selection criteria, including Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC), favoured a model with only significant predictors, revealing the existence of Hepatitis-B virus infection risk factors in patients from Gusau Local Government of Zamfara State.

International Journal of Science for Global Sustainability, Oct 31, 2023

In sampling theory, it is a popular trend to use auxiliary information to obtain more efficient e... more In sampling theory, it is a popular trend to use auxiliary information to obtain more efficient estimators for the population parameters to increase the precision of the estimator. Estimators obtained using auxiliary information are supposed to be more efficient than the estimators obtained without using auxiliary information. The ratio, regression, product and difference methods take advantage of the auxiliary information at the estimation stage. Therefore, this study considered a generalized class of log-type estimators of finite population mean based on correlation coefficient as the proposed estimator for estimating the population mean of the study variable. It has been shown that the generalized class of log-type estimators has lesser mean square errors (MSEs) under the optimum values of the characterizing scalar as compared to some of the commonly used related estimators available in the literature. Further, an extension of the proposed generalized class of log-type estimators using multiple auxiliary variables such as coefficient of variation () X C , coefficient of kurtosis () () 2 x  , and correlation coefficient () xy . have also base initiated in this dissertation. The expressions for the properties of the proposed family of estimators, that is; Bias and Mean Square Error (MSE), were derived to the first degree of approximation. We also obtained the optimum Mean Square Error (MSEopt.), and theoretical comparisons were made with the related existing estimators in literature. Following theoretical comparisons, it was demonstrated that the proposed family of estimators was more efficient than various related existing estimators compared with, under the obtained conditions.

Asian Journal of Probability and Statistics, Oct 1, 2023

From the previous literature, there had been various research on models with error processes espe... more From the previous literature, there had been various research on models with error processes especially, the time series model with corrupted error processes. The gap to be filled here was the extension of such a model to the SARIMA model with corruption error processes. Thus, this research work focused on parameter estimates with a corrupted AR(1)error process. Auto-covariance functions were used to estimate the variances of error terms that characterized the SARIMA model. The forecast performance measurement was investigated and properties of errors with different values of parameters were examined. A test of seasonal unit root was carried out and the result revealed a seasonality effect. Simulation with R Statistical software was used to prove the findings. In addition, the monthly temperature data of Zamfara State from 1998 to 2020 was used to validate the results using the iteration procedure and chi-square statistic.The results from the study showed that the research findings were very significant to the error process and would be useful to researchers in the prediction and handling of natural calamities.

International Journal of Advanced Research

Asian Journal of Probability and Statistics, Nov 13, 2023

Generalized additive model was used to analyse data from Nigeria standard demographic and health ... more Generalized additive model was used to analyse data from Nigeria standard demographic and health survey (NDHS) 2018. The sample consists of 10609 children aged 6-59 months who were tested for malaria parasitemia through the rapid diagnostic test (RDT). Child mortality data was obtained by calculating the difference between the number of children ever born and the proportion of children alive during the survey. The analysis was carried out in R version 4.1.1 via mgcv package. The results obtained indicated linear and nonlinear effects of malaria risk factors on child mortality. The findings also revealed mosquito bed net usage, wealth index, maternal education, type of place of residence and malaria test outcome as significant predictors of child malaria mortality.

Equity Journal of Science and Technology, 2013

This paper focuses on one of the six child-hood deadly diseases in the country- measles in partic... more This paper focuses on one of the six child-hood deadly diseases in the country- measles in particular, in order to ascertain its prevalence in this part of the country. Data on reported cases of measles in Sokoto State from January to May 2011 were collected. Cluster Analysis and Principal Component Analysis were used to analyze the data collected. The result shows similarity in occurrence of this disease in 5 clusters of the local government areas under review. Principal Component Analysis technique shows variations in occurrence in different month from the total variation.

Journal of mathematical sciences & computational mathematics, Oct 3, 2022

International journal of statistics and applications, 2017

This research examined the long range dependency comportment of apparent temperature in BirninKeb... more This research examined the long range dependency comportment of apparent temperature in BirninKebbi metropolis, using hourly data for a period of two years from 2013 to 2014. We found that the data points are highly correlated, there is a sense of return of a particular characteristic after some hours and this depicts seasonality traits and fractional integrated d series suspected. Autoregressive Fractional Integrated Moving Average (ARFIMA) modelrevealed that the series for the periods investigated is fractionally integrated with high-lag correlation structure, d=0.495. The long range dependency which describes the number of days for the return characteristics of persistence of the shock in a very long time period after it occurs was estimated to be three hundred and twelve days (312) days approximately a year; thus, once a shock is felt on apparent temperature, it will go on for about a year before the pattern or structure will be repeated.

Fudma Journal of Sciences, Aug 18, 2022

This study deals with using calibration estimation approaches to modified the combined ratio esti... more This study deals with using calibration estimation approaches to modified the combined ratio estimator in stratified random sampling. Calibration distance measures with their associate constraints were used to modify combined ratio estimator. In stratified random sampling, new sets of optimum calibration weights are created and used to obtain new calibration estimators of population mean. Empirical study through simulation was conducted to look into the efficiency of the suggested estimators obtained. The suggested calibration estimators are more efficient than other existing estimators investigated in the study, according to the findings.

Equity Journal of Science and Technology, 2016

In this paper a class of ratio-type estimator has been proposed by using unknown constant to esti... more In this paper a class of ratio-type estimator has been proposed by using unknown constant to estimate population mean of the study variable. The proposed estimator includes a number of estimators. The particular cases of proposed estimator have been discussed. The expression for bias and the MSE of the proposed estimator were derived up to the first order of approximation. The efficiency of the proposed estimator has been compared with the estimators that are particular cases of proposed estimator and condition under which the proposed estimator is more efficient is derived. Appropriate Numerical illustrations are used to determine the efficiency of proposed estimator and existing estimators.

© 2013 Int. j. eng. sci. All rights reserved for TI Journals. Introduction Childbirth (also calle... more © 2013 Int. j. eng. sci. All rights reserved for TI Journals. Introduction Childbirth (also called labour, birth, partus or parturition) is the culmination of a human pregnancy or gestation period with the expulsion of one or more newborn infants from a woman's uterus (Columbia Encyclopedia, 2006) [5]. Birth with minimal intervention or without technical or medical intervention is considered to be normal (Duff, 2002) [1]. A focus on normalizing birth results in better quality, safer care for mothers and their babies with an improved experience. Increasing normal births and reducing c-section deliveries is associated with shorter (or no) hospital stays, fewer adverse incidents and admissions to neonatal units and better health outcomes for mothers. It is also associated with higher rates of successful breastfeeding and a more positive birth experience. These changes benefit not only women and their families but also maternity staff. The process of normal human childbirth is categorized in three stages of labour: the shortening and dilation of the cervix, descent and birth of the infant, and birth of the placenta. In many cases, with increasing frequency, childbirth is achieved through caesarean section, the removal of the neonate through a surgical incision in the abdomen, rather than through vaginal birth. The WHO recommends that the caesarean section rate should not be higher than 10% to 15%. The most recent data (2008/09) reports a national c-section rate of 24.6%, a significant rise compared to 12% in 1990. There is significant variation in the c-section rate across maternity units, ranging from 12.5% to 34.6% (NHS Institute, 2007) [4]. Moreover, caesarean delivery was associated with high maternal and neonatal complication rates and increased care costs. Medical professional policy makers find that induced births and elective cesarean can be harmful to the fetus and neonate without benefit to the mother, and have established strict guidelines for non-medically indicated induced births and elective cesarean before 39 weeks.Although caesarean section rates vary widely between different facilities and different countries, caesarean section rates have risen consistently over time (Warwick, 2001) [6]. An operative vaginal birth rate of 10.8% in 2000, 10.3% in 2001 and 9.6% in 2002 indicates a normal birth rate of 68.4 % in 2000, 67.6% in 2001, 67.7% in 2002 (Ministry of Health, 2003 & 2004) [3]. Background of Study The need for this study is necessitated by the need to find an appropriate time series model to forecast normal deliveries with a view to developing the best model for the series and to use the best chosen model to forecast normal birth in future years. Materials and Methods Data for the study The data used was collected on a monthly basis for a period of 13 years (from January 1999 to December 2011) from Maryam Abacha Women and Children Hospital Sokoto, North-Western Nigeria.. Focus is placed on ACF, PACF, ARIMA model and time plots. Investigating Urban Water Supply Output in Nigeria: The Case Study of Benin City Internat ional Journal of Engineeri ng Sciences, 2(4) Apri l 2013 101 Methodology Statistical methods applied to time series data were originally developed mainly in econometrics, and then used in many other fields, such as ecology, physics and engineering. In the original application, the focus was in prediction, and the aim was to produce an accurate forecast of future measurements given an observed series. The standard statistical approaches adopted for this purpose usually rely on autoregressive moving average (ARIMA) and related models. Recently, the time series design has been exploited also in biomedical data, due to the availability of routinely collected series of administrative or medical data, such as mortality or morbidity counts, and air pollution or temperature measurements. The various methods used for the study include, the Box-Jenkins Model Identification to determine the adequate model from ARIMA family models. Also other Model identification tool were used. Discussion of Results Figure 1.1 below shows the time plot of the normal delivery outcome which if we were to draw the mean line; we will have a curve shape line indicating that the mean is not stationary. The variability among the swings appears almost the same but to further confirm if the variance is stationary or not, the series would be subjected to log transformation. 0 20 40 60 80 100 120 14

Oriental Journal of Physical Sciences

Some existing estimators based on auxiliary attribute have been proposed by many authors. In this... more Some existing estimators based on auxiliary attribute have been proposed by many authors. In this paper, we use the concept of power transformation to modify some existing estimators in order to obtain estimators that are applicable when there is positive or negative correlation between the study and auxiliary variable. The properties (Biases and MSEs) of the proposed estimators were derived up to the first order of approximation using Taylor series approach. The efficiency comparison of the proposed estimators over some existing estimators considered in the study were established. The empirical studies were conducted using existing population parameters to investigate the proficiency of the proposed estimators over some existing estimators. The results revealed that the proposed estimators have minimum Mean Square Errors and higher Percentage Relative Efficiencies than the conventional and other competing estimators in the study. These implies that the proposed estimators are more ...

Oriental Journal of Physical Sciences

This study considered modification of combined ratio type calibration estimators in stratified ra... more This study considered modification of combined ratio type calibration estimators in stratified random sampling using calibration estimation approaches. The estimators of population mean in stratified random sampling depends on the strata estimated sample means. However, the means are sensitive to the extreme values or outliers in the sample observations of the study variables and strata sizes respectively. A new sets of calibration weights and property of the suggested combined calibration estimators of population mean in stratified sampling were derived. Empirical study through simulation was conducted to investigate the efficiency of the modified combined ratio-type calibration estimators of population mean obtained and the results revealed that the suggested estimators of population mean performed better than some existing estimators considered in the study.

DOI: 10.35629/5252-0401565571 Impact Factor value 7.429 | ISO 9001: 2008 Certified Journal Page 5... more DOI: 10.35629/5252-0401565571 Impact Factor value 7.429 | ISO 9001: 2008 Certified Journal Page 565 Multivariate Logistic Regression Modeling for Assessing the Risk Factors of Diabetes in Gusau Zamfara State, Nigeria Gerald Ike Onwuka , Wasiu Babayemi , and Mubarak Hassan Augie Faculty of Physical Science, Department of Mathematics, Statistics Unit. Kebbi State University of Science and Technology, Aliero. Kebbi state, Nigeria.

This study describes a procedure employing Gaussian elimination method in matrix algebra to balan... more This study describes a procedure employing Gaussian elimination method in matrix algebra to balance chemical equations from easy to relatively complex chemical reactions. The result shows that 2 atom of sodium (Na), 6 atoms of oxygen (O), 4 atoms of Hydrogen (H), and 1 atom of sulfur (S) each on both the reactants and products makes the chemical equation balance. This result satisfies the law of conservation of matter and confirms that there is no contradiction to the existing way(s) of balancing chemical equations.

International Journal of TROPICAL DISEASE & Health

Nigeria’s effort to reduce under-five mortality has been biased in favour of childhood mortality ... more Nigeria’s effort to reduce under-five mortality has been biased in favour of childhood mortality to the neglect of neonates and as such the literature is short of adequate information on the determinants of neonatal mortality, whereas studies have shown that about half of infant deaths occur in the neonatal period. Knowledge of the determinants of neonatal mortality is essential for the design of intervention programmes that will enhance neonatal survival. Therefore, this study was conducted to investigate the trends in neonatal mortality in Nigeria. It also proposed a Poisson based continuous probability distribution called Poisson-Lindley distribution to neonatal mortality rate in Nigeria. Some properties of the new model and other relevant measures were obtained. The unknown parameters of the model were also estimated using the method of maximum likelihood. The fitness of the proposed model to the neonatal mortality rate was considered using a dataset on neonatal mortality rate f...

International Journal of Scientific and Research Publications (IJSRP)

Journal of Natural Sciences Research, 2015

Fertility behavior is conditioned by both biological and social factors. Knowledge of fertility p... more Fertility behavior is conditioned by both biological and social factors. Knowledge of fertility pattern gives insight into drivers of human fertility. The paper investigated the birth pattern of women in Kebbi State, North Western Nigeria. A total of 2,256 questionnaires were distributed to the women of child bearing age using simple random sampling across five local government areas. The aim of the study was to analyze the pattern of fertility among age group of women of childbearing age and the effects of some exogenous variables on the fertility of women in the state. Poisson regression was applied for the positive count value recorded. The results from the analysis revealed that experience of birth or history of birth, financial reliant, obesity, individual age are highly significant to the study and have direct impact on fertility. Despite our ability to breed continuously, all human populations exhibit variation in reproduction.

International Journal of Advanced Research

International Journal of Science for Global Sustainability, Oct 31, 2023

Asian Journal of Probability and Statistics, Oct 1, 2023

International Journal of Advanced Research

Asian Journal of Probability and Statistics, Nov 13, 2023

Equity Journal of Science and Technology, 2013

Journal of mathematical sciences & computational mathematics, Oct 3, 2022

International journal of statistics and applications, 2017

Fudma Journal of Sciences, Aug 18, 2022

Equity Journal of Science and Technology, 2016

Oriental Journal of Physical Sciences

International Journal of TROPICAL DISEASE & Health

International Journal of Scientific and Research Publications (IJSRP)

Journal of Natural Sciences Research, 2015