|August 2014 - Present||Professor, Georgia Southern University ‐ Public Health, Jiann-Ping Hsu College of|
|February 2013 - Present||Affiliate, Institute for Interdisciplinary STEM Education, Georgia Southern University ‐ Institute for Interdisciplinary STEM Education|
|Present||Professor, Georgia Southern University ‐ Biostatistics, Epidemiology and Environmental Health Sciences, Department of|
|August 2008 - June 2016||Director of Karl E. Center for Biostatistics, Georgia Southern University|
|September 2007 - July 2014||Associate Professor, Department of Biostatistics, Jiann-Ping Hsu College of Public Health, Georgia Southern University|
|August 2006 - August 2007||Assistant Professor, Department of Biostatistics, Jiann-Ping Hsu College of Public Health, Georgia Southern University|
Honors and Awards
- Academic Outstanding Award, Yarmouk University, Outstanding Performance in Master Degree (1986)
- Henry Award for Outstanding Performance on Ph.D. Qualifying Examination, University of Iowa (1990)
- Award for Scholarship, Jiann-Ping Hsu College of Public Health, Georgia Southern University (2012-2013)
- Georgia Southern University Award for Excellence in Research Nominee (2013, 2014, 2015)
- Award Recipient for Excellence in Research/Creative Scholarly Activity, Georgia Southern University (2017-2018)
- Bayesian Statistics I (BIOS 9231)
- Statistical Consultation (BIOS 9130)
- Data Analysis with SAS (BIOS 7535)
- Regression Analysis in Biostatistics (BIOS 6331)
- Biostatistics I (PUBH 6541 online)
- Advanced Topics in Biostatistics (PUBH 8130 blended online)
- Experimental Design in Biostatistics (BIOS 6332)
- Data Management for Biostatistics (BIOS 7534)
- Advance Statistical Inference Biostatistics I (BIOS 9131)
- Advance Statistical Inference Biostatistics II (BIOS 9133)
- Meta-Analysis (BIOS 9331)
- Probability (MATH 3337)
- Stat and Prob for K-8 Teachers (MATH 5130)
- Biostatistics I (PUBH 6541)
- Selected Topics in Public Hlth (PUBH 7090)
- Introduction to Statistics I (STAT 2231)
- Sampling & Survey Methods (STAT 5130)
- Sampling & Survey Methods (STAT 5130G)
- Statistical Methods I (STAT 5531)
- Statistical Methods I (STAT 5531G)
- Design of Experiments I (STAT 7231)
- Actuarial Mathematics (STAT 7430)
|1994||Ph.D. in Biostatistics, University of Iowa|
|1991||M.S. in Applied Statistics, University of Iowa|
|1986||M.S. in Statistics, Yarmouk University|
|1981||B.S. in Mathematics/Statistics, Yarmouk University|
PO Box 8015
Statesboro, GA 30460
Phone: (912) 478-1345
Office: Hendricks Hall
Refereed Journal Articles (108)
Notes on Kernel Based Mode Estimation Using More Efficient Sampling Designs Computational Statistics (2018)
The mode is a measure of the central tendency as well as the most probable value. Additionally, the mode is not influenced by the tail of the distribution. In the literature the properties and the ...
Response to Comments by Pablo Martínez-Camblor on “Notes on Overlap Measure as an Alternative to Youden Index: How Are They Related?” Statistics in Medicine (2018)
We enjoyed reading comments made by Pablo Martínez‐Camblor on our recently published paper “Notes on Overlap Measure as an Alternative to Youden Index: How are they related?” We think that the author has misinterpreted the ...
On Quantiles Estimation Based on Different Stratified Sampling With Optimal Allocation Communications in Statistics - Theory and Methods (2018)
This work considers the problem of estimating a quantile function based on different stratified sampling mechanism. First, we develop an estimate for population quantiles based on stratified simple random sampling (SSRS) and extend the discussion ...
On Inference of Multivariate Means Using Efficient Sampling Designs Communications for Statistical Applications and Methods (2018)
In many studies, a researcher attempts to describe a population where units are measured for multiple outcomes, or responses. In this paper, we present an efficient procedure based on ranked set sampling to estimate and ...
A Simpler Approach for Mediation Analysis for Dichotomous Mediators in Logistic Regression Journal of Statistical Computation and Simulation (2018)
Mediation is a hypothesized causal chain among three variables. Mediation analysis for continuous response variables is well developed in the literature, and it can be shown that the indirect effect is equal to the total ...
Increased Fisher's Information for Parameters of Association in Count Regression via Extreme Ranks Communications in Statistics - Theory and Methods (2018)
The article details a sampling scheme which can lead to a reduction in sample size and cost in clinical and epidemiological studies of association between a count outcome and risk factor. We show that inference ...
Methods Improving the Estimate of Diagnostic Odds Ratio Communications in Statistics - Simulation and Computation (2018)
Diagnostic odds ratio is defined as the ratio of the odds of the positivity of a diagnostic test results in the diseased population relative to that in the non-diseased population. It is a function of ...
On Estimation of Overlapping Measures for Exponential Populations Under Progressive First Failure Censoring Quality Technology and Quantitative Management (2018)
Overlapping coefficient is a direct measure of similarity between two distributions which is recently becoming very useful in many fields of applications including microarray analysis for the purpose of identifying differentially expressed biomarkers, especially in ...
Reducing Sample Size Needed for Accelerated Failure Time Model Using More Efficient Sampling Methods Journal of Statistical Theory and Practice (2018)
Survival data are time-to-event data, such as time to death, time to appearance of a tumor, or time to recurrence of a disease. Accelerated failure time (AFT) models provide a linear relationship between the log ...
Notes on the Overlap Measure as an Alternative to the Youden Index: How Are They Related? Statistics in Medicine (2017)
The receiver operating characteristic (ROC) curve is frequently used to evaluate and compare diagnostic tests. As one of the ROC summary indices, the Youden index measures the effectiveness of a diagnostic marker and enables the ...
On Marginal Distributions Under Progressive Type II Censoring: Similarity/Dissimilarity Properties Open Journal of Statistics (2017)
Currently, progressive censoring is intensively investigated by several researchers due to its ability to remove subjects from the experiment before the final termination point, thus saving time and cost. The closed form of marginal density ...
On Kernel Density Estimation Based on Different Stratified Sampling With Optimal Allocation Communications in Statistics - Theory and Methods (2017)
Kernel density estimation is probably the most widely used non parametric statistical method for estimating probability densities. In this paper, we investigate the performance of kernel density estimator based on stratified simple and ranked set ...
Using Ranked Auxiliary Covariate as a More Efficient Sampling Design for ANCOVA Model: Analysis of a Psychological Intervention to Buttress Resilience Communications for Statistical Applications and Methods (2017)
Drawing a sample can be costly or time consuming in some studies. However, it may be possible to rank the sampling units according to some baseline auxiliary covariates, which are easily obtainable, and/or cost efficient. ...
On Stratified Ranked Set Sampling for Regression Estimators Journal of Statistics and Management Systems (2017)
Two types of stratified regression estimators for the population mean, the separate and the combined estimators, are investigated using stratified random sampling scheme (SSRS) and stratified ranked set sampling (SRSS). We derived mean and variance ...
Estimates for Cell Counts and Common Odds Ratio in Three-Way Contingency Tables by Homogeneous Log-Linear Models with Missing Data AStA Advances in Statistical Analysis (2017)
Missing observations often occur in cross-classified data collected during observational, clinical, and public health studies. Inappropriate treatment of missing data can reduce statistical power and give biased results. This work extends the Baker, Rosenberger and ...
More Efficient Logistic Analysis Using Moving Extreme Ranked Set Sampling Journal of Applied Statistics (2017)
Logistic regression is the most popular technique available for modeling dichotomous-dependent variables. It has intensive application in the field of social, medical, behavioral and public health sciences. In this paper we propose a more efficient ...
On Stratified Bivariate Ranked Set Sampling with Optimal Allocation for Naïve and Ratio Estimators Journal of Applied Statistics (2017)
The purpose of the current work is to introduce stratified bivariate ranked set sampling (SBVRSS) and investigate its performance for estimating the population mean using both naïve and ratio methods. The properties of the proposed ...
Evaluating the Efficiency of Treatment Comparison in Crossover Design by Allocating Subjects Based On Ranked Auxiliary Variable Communications for Statistical Applications and Methods (2016)
The validity of statistical inference depends on proper randomization methods. However, even with proper randomization, we can have imbalanced with respect to important characteristics. In this paper, we introduce a method based on ranked auxiliary ...
Estimation of P(X > Y) When X and Y Are Dependent Random Variables Using Different Bivariate Sampling Schemes Communications for Statistical Applications and Methods (2016)
The stress-strength models have been intensively investigated in the literature in regards of estimating the reliability θ = P (X > Y) using parametric and nonparametric approaches under different sampling schemes when X and Y ...
Rank-Based Kernel Estimation of the Area Under the ROC Curve Statistical Methodology (2016)
In medical diagnostics, the ROC curve is the graph of sensitivity against 1-specificity as the diagnostic threshold runs through all possible values. The ROC curve and its associated summary indices are very useful for the ...
Improved Estimation of Optimal Cut-Off Point Associated with Youden Index Using Ranked Set Sampling Biometrical Journal (2016)
A diagnostic cut-off point of a biomarker measurement is needed for classifying a random subject to be either diseased or healthy. However, the cut-off point is usually unknown and needs to be estimated by some ...
A Test of Symmetry Based on the Kernel Kullback-Leibler Information with Application to Base Deficit Data Biometrics and Biostatistics International Journal (2016)
The assumption of the symmetry of the underlying distribution is important to many statistical inference and modeling procedures. This paper provides a test of symmetry using kernel density estimation and the Kullback-Leibler information. Based on ...
Balanced Bayesian LASSO for Heavy Tails Journal of Statistical Computation and Simulation (2016)
Regression procedures are not only hindered by large p and small n, but can also suffer in cases when outliers are present or the data generating mechanisms are heavy tailed. Since the penalized estimates like ...
Correction of Verication Bias using Log-Linear Models for a Single Binaryscale Diagnostic Tests Journal of Biometrics and Biostatistics (2015)
In diagnostic medicine, the test that determines the true disease status without an error is referred to as the gold standard. Even when a gold standard exists, it is extremely difficult to verify each patient ...