Gafar Matanmi Oyeyemi
@unilorin.edu.ng
Professor of Statistics, Head of Department, Department of Statistics, Faculty of Physical Sciences
Department of Statistics, University of Ilorin
RESEARCH, TEACHING, or OTHER INTERESTS
Statistics and Probability, Statistics, Probability and Uncertainty
4
Scopus Publications
496
Scholar Citations
11
Scholar h-index
11
Scholar i10-index
Scopus Publications
- On development of four-parameters exponentiated generalized exponential distribution
- On discrimination procedure with mixtures of continuous and categorical variables
Gafar Matanmi Oyeyemi, George Chinanu Mbaeyi, Saheed Ishola Salawu, and Bernard Olagboyega Muse
Informa UK Limited
ABSTRACT A discrimination procedure, based on the location model is described and suggested for use in situation where the discriminating variables are mixtures of continuous and binary variables. Some procedures that have been previously employed, in a similar situation, like Fisher's linear discriminant function and the logistic regression were compared with this method using error rate (ER). Optimal ERs for these procedures are reported using real and simulated data for the case of varying sample size and number of continuous and binary variables and were used as a measure for assessing the performance of the various procedures. The suggested procedure performed considerably better in the cases considered and never did produce a result that is poor when compared with other procedures. Hence, the suggested procedure might be considered for such situations. - Trace elements; Copper, zinc and selenium, in breast cancer afflicted female patients in LAUTECH Osogbo, Nigeria
ML Adeoti, AS Oguntola, EO Akanni, OS Agodirin, and GM Oyeyemi
Medknow
BACKGROUND There is an indication of the possibility of the direct or indirect influence of trace element in the development and prevention of malignant diseases, the contribution of the trace elements in the etiology of breast cancer has been under scrutiny. AIMS The aim of this study was to determine the serum concentration of trace element in serum of female patients with breast cancer in comparison with healthy controls. SETTINGS Breast Clinic of the Department of Surgery LAUTECH University teaching hospital Osogbo, in south-western Nigeria. MATERIALS AND METHODS A cross-sectional age matched controlled prospective study wherein the venous blood sample of 30 patients with breast cancer and 30 healthy volunteers as controls were analyzed using atomic absorption spectrophotometry. The collected data were analyzed using statistical package for the social sciences (SPSS Inc) 16. RESULT The mean serum concentration of the copper, zinc and selenium were 95.3 ± 4.9 ug/dl and 65.2 ± 15 ug/dl, 62.7 ± 15.7 ug/dl and 93.5 ± 7.2 ug/dl, 45.0 ± 4.6 ug/l and 76.4 ± 8.9 ug/l in the two groups respectively. The concentrations of copper and copper-zinc ratio (C/Z) were significantly higher in the cancer bearing group compared to the controls (C/Z 1.6 ± 0.5 against 0.70 ± 0.14 the P < 0.01). The concentration of zinc and selenium in the venous blood of the breast cancer patients showed inverse relationship while that of the control showed a direct relationship (-0.03 against 0.09). In the breast cancer patients the correlation of copper and zinc, copper and selenium and zinc and selenium showed inverse relationships, none of the relationships was statistically significant. CONCLUSION We found a significant association between the serum concentration of trace elements and breast cancer. - An examination of some safety issues among commercial motorcyclists in Nigeria: A case study
Godwin Tunde Arosanyin, Adekunle Taiwo Olowosulu, and Gafar Matanmi Oyeyemi
Informa UK Limited
The reduction of road crashes and injuries among motorcyclists in Nigeria requires a system inquiry into some safety issues at pre-crash, crash and post-crash stages to guide action plans. This paper examines safety issues such as age restriction, motorcycle engine capacity, highway code awareness, licence holding, helmet usage, crash involvement, rescue and payment for treatment among commercial motorcyclists. The primary data derived from a structured questionnaire administered to 334 commercial motorcyclists in Samaru, Zaria were analysed using descriptive statistics and logistic regression technique. There was total compliance with age restriction and motorcycle engine capacity. About 41.8% of the operators were not aware of the existence of the highway code. The odds of licence holding increased with highway code awareness, education with above senior secondary as the reference category and earnings. The odds of crash involvement decreased with highway code awareness, earnings and mode of operation. About 84% of the motorcyclists did not use crash helmet, in spite of being aware of the benefit, and 65.4% of motorcycle crashes was found to be with other road users. The promotion of safety among motorcyclists therefore requires strict traffic law enforcement and modification of road design to segregate traffic and protect pedestrians.
RECENT SCHOLAR PUBLICATIONS
- A new reduced contagious zero-inflated model: An application to count data
MI Adarabioyo, GM Oyeyemi
ABUAD International Journal of Natural and Applied Sciences 3 (2), 1-15 2023 - ALTERNATIVE ESTIMATOR IN THE ANALYSIS OF VARIANCE TECHNIQUE IN THE PRESENCE OF OUTLIERS
AK Odior, GM Oyeyemi
The Journals of the Nigerian Association of Mathematical Physics 65, 217-224 2023 - REVIEW OF SOME ROBUST ESTIMATORS IN MULTIPLE LINEAR REGRESSIONS IN THE PRESENCE OF OUTLIER (s)
T Alanamu, GM Oyeyemi, RO Olaniran, KO Adetunji
African Journal of Mathematics and Statistics Studies 2023 - Combined exponential-type estimators for finite population mean in two-phase sampling
GM Oyeyemi, I Muhammad, AO Kareem
Asian Journal of Probability and Statistics 21 (2), 44-58 2023 - Performance of Generalized Autoregressive Conditional Heteroscedasticity (GARCH) Models in Modeling Volatility of Brent Crude Oil Price
SD Gbolagade, GM Oyeyemi, AO Abidoye, TJ Adejumo, AI Okegbade
Ilorin Journal of Science 9 (1), 20-32 2022 - Spatial Analysis of Distribution of Inmates in Nigeria Prisons
GM Oyeyemi, AO Kareem, EEO Alemika, AB Ibraheem, OM Oladuti
Ilorin Journal of Science 8 (1), 21-35 2021 - REGULARIZATION TECHNIQUES IN MULTIPLE LINEAR REGRESSION IN THE PESENCE OF MULTICOLLINEARITY
OA Oyegoke, GM Oyeyemi, MO Adeleke, RO Kolawole
FULafia Journal of Science and Technology 6 (1), 48-53 2020 - PROPOSED HOTELLING’S T2 CONTROL CHARTS BASED ON LOCATION AND SCATTER MATRIX
OS Obafemi, GM Oyeyemi, FA Bolarinwa
2020 - An Empirical Study on the Run Length Properties of the Side-Sensitive Modified Group Runs Double Sampling (SSMGRDS) Control Chart for Monitoring the Process Mean Shifts
AA Umar, SS Abubakar, HG Dikko, A Yahaya, GM Oyeyemi, JY Falgore, ...
Academic Research Society of Malaysia 2020 - A Comparison of some Discriminant Techniques in Predicting Blood Pressure
T Yussuf, BL Adeleke, GM Oyeyemi, MO Adeleke, AO Kareem
Faculty of Science, University of Ibadan, Nigeria 2019 - Comparison of Some Spike-and-Slab Priors for Bayesian Variable Selection in Multiple Linear Regression
GM Oyeyemi, YA Olanrewaju, RO Kolawole
Akamai University, USA 2019 - ON THE ESTIMATION OF EMPTY CELL PROBABILITIES IN A CONTINGENCY TABLE
GM Oyeyemi, GC Mbaeyi
Annals. Computer Science Series 16 (1) 2018 - Stand-in Procedure to Multivariate Behrens-Fisher Problem
GM Oyeyemi, PO Adebayo
European Journal of Statistics and Probability 6 (1), 16-28 2018 - Alternative estimator for multivariate location and scatter matrix in the presence of outlier
OS Obafemi, GM Oyeyemi
Anale Seria Informatica 2018 - Heteroscedasticity in One Way Multivariate Analysis of Variance
GM Oyeyemi, PO Adebayo, BL Adeleke
J Phys Math 9 (270), 2090-0902.1000270 2018 - Parametric and Pattern Recognition Models for Credit Scoring in Banking System
S Oyeyemi, G. M. and Issa
Journal of the Nigerian Association of Mathematical Physics 44 (1), 163 - 174 2018 - An Alternative Least Trimmed Squares Estimation of Regression Parameters in the Presence of Outliers in the Independent Variables
AK Oyeyemi, G. M. and Odior
Journal of the Nigerian Association of Mathematical Physics 44 (1), 163 - 174 2018 - An Alternative Solution to Hotelling T Square under the Heteroscedasticity of the Dispersion Matrix
PO Adebayo, GM Oyeyemi
Department of Statistics, University of Ilorin, Ilorin, Nigeria. The Pacific 2018 - Pak. J. Statist. 2018 Vol. 34 (4), 331-358 ON DEVELOPMENT OF FOUR-PARAMETERS EXPONENTIATED GENERALIZED EXPONENTIAL DISTRIBUTION
A Bukoye, GM Oyeyemi
Pak. J. Statist 34 (4), 331-358 2018 - A new robust method for estimating linear regression model in the presence of outliers
T Alanamu, GM Oyeyemi
Pacific Journal of Science and Technology 19 (1), 125-132 2018
MOST CITED SCHOLAR PUBLICATIONS
- On performance of shrinkage methods–a Monte Carlo Study
GM Oyeyemi, EO Ogunjobi, AI Folorunsho
International Journal of Statistics and Applications 5 (2), 72-76 2015
Citations: 66 - Trace elements; copper, zinc and selenium, in breast cancer afflicted female patients in LAUTECH Osogbo, Nigeria
ML Adeoti, AS Oguntola, EO Akanni, OS Agodirin, GM Oyeyemi
Indian journal of cancer 52 (1), 106-109 2015
Citations: 65 - Employment generation and earnings in the informal transport sector in Nigeria
GT Arosanyin, AT Olowosulu, GM Oyeyemi
International Business and Management 2 (2), 139-148 2011
Citations: 55 - Compliance with Road Safety Regulations Among Commercial Motorcyclists in Nigeria/Conformite a la Reglementation de la Securite Routiere Parmi Les Motocyclistes Au Nigeria
AG Tunde, OA Taiwo, OG Matanmi
Canadian Social Science 8 (1), 92 2012
Citations: 45 - Complex survey data analysis: a comparison of SAS, SPSS and STATA
GM Oyeyemi, AA Adewara, RA Adeyemi
Asian J Math Stat 3, 33-9 2010
Citations: 33 - Comparison of outlier detection procedures in multiple linear regressions
GM Oyeyemi, A Bukoye, I Akeyede
American Journal of Mathematics and Statistics 5 (1), 37-41 2015
Citations: 32 - On the estimation of power and sample size in test of independence
GM Oyeyemi, AA Adewara, FB Adebola, SI Salau
nil 2010
Citations: 31 - An examination of some safety issues among commercial motorcyclists in Nigeria: a case study
GT Arosanyin, AT Olowosulu, GM Oyeyemi
International journal of injury control and safety promotion 20 (2), 103-110 2013
Citations: 26 - How effective is the treatment of locally advanced and metastatic breast cancer in developing centres?: A retrospective review
O Agodirin, S Olatoke, G Rahman, M Adeoti, G Oyeyemi, A Durojaiye, ...
Ethiopian journal of health sciences 25 (4), 337-344 2015
Citations: 16 - Poverty in the urban informal sector of Kwara state, Nigeria
GT Ijaiya, RA Bello, GT Arosanyin, GM Oyeyemi, UA Raheem, AT Yakubu
Department of Economics, Faculty of Social Sciences, University of Ilorin 2015
Citations: 12 - A robust method of estimating covariance matrix in multivariate data analysis
GM Oyeyemi, RA Ipinyomi
African Journal of Mathematics and Computer Science Research 3 (1), 1-18 2010
Citations: 12 - Principal component chart for multivariate statistical process control
GM Oyeyemı
TOJSAT 1 (2), 22-31 2011
Citations: 9 - Combined exponential-type estimators for finite population mean in two-phase sampling
GM Oyeyemi, I Muhammad, AO Kareem
Asian Journal of Probability and Statistics 21 (2), 44-58 2023
Citations: 8 - An evaluation of savings culture among commercial motorcyclists in Nigeria: A case study
GT Arosanyin, AT Olowosulu, HI Mobolaji
Management Journal 15 (2), 229-249 2014
Citations: 7 - Comparison of bootstrap and jackknife methods of re-sampling in estimating population parameters
GM Oyeyemi
Global Journal of Pure and Applied Sciences 14 (2), 217-220 2008
Citations: 7 - Pak. J. Statist. 2018 Vol. 34 (4), 331-358 ON DEVELOPMENT OF FOUR-PARAMETERS EXPONENTIATED GENERALIZED EXPONENTIAL DISTRIBUTION
A Bukoye, GM Oyeyemi
Pak. J. Statist 34 (4), 331-358 2018
Citations: 6 - Performance of Generalized Autoregressive Conditional Heteroscedasticity (GARCH) Models in Modeling Volatility of Brent Crude Oil Price
SD Gbolagade, GM Oyeyemi, AO Abidoye, TJ Adejumo, AI Okegbade
Ilorin Journal of Science 9 (1), 20-32 2022
Citations: 4 - A new robust method for estimating linear regression model in the presence of outliers
T Alanamu, GM Oyeyemi
Pacific Journal of Science and Technology 19 (1), 125-132 2018
Citations: 4 - A note on the precision of stratified systematic sampling
AO Kareem, IO Oshungade, GM Oyeyemi
Open Journal of Statistics 5 (02), 104 2015
Citations: 4 - A note on the efficiency of geographic stratification
AO Kareem, GM Oyeyemi, B Aiyelabegan Adijat
International Journal of Mathematics and Statistics Invention 3 (4), 1-10 2015
Citations: 4