Statistics and Probability Commons^™

On The Exponentiated Weibull Rayleigh Distribution, Mohammed Elgarhy, Ibrahim Elbatal, Gholamhossein G. Hamedani, Amal Hassan

Mathematical and Statistical Science Faculty Research and Publications

A new four-parameter probability model, referred to the exponentiated Weibull Rayleigh (EWR) distribution, is introduced. Essential statistical properties of the distribution are considered. The maximum likelihood estimators of population parameters are given in case of complete sample. Simulation study is carried out to estimate the model parameters of EWR distribution. Additionally, parameter estimators are given in case of Type II censored samples. We come up with two applications to confirm the usefulness of the proposed distribution.

Genome-Wide Systems Genetics Of Alcohol Consumption And Dependence, Kristin Mignogna

Theses and Dissertations

Widely effective treatment for alcohol use disorder is not yet available, because the exact biological mechanisms that underlie this disorder are not completely understood. One way to gain a better understanding of these mechanisms is to examine the genetic frameworks that contribute to the risk for developing this disorder. This dissertation examines genetic association data in combination with gene expression networks in the brain to identify functional groups of genes associated with alcohol consumption and dependence.

The first study took advantage of the behavioral complexity of human samples, and experimental capabilities provided by mouse models, by co-analyzing gene expression networks …

A Multilayer Exponential Random Graph Modelling Approach For Weighted Networks, Alberto Caimo, Isabella Gollini

Articles

A new modelling approach for the analysis of weighted networks with ordinal/polytomous dyadic values is introduced. Specifically, it is proposed to model the weighted network connectivity structure using a hierarchical multilayer exponential random graph model (ERGM) generative process where each network layer represents a different ordinal dyadic category. The network layers are assumed to be generated by an ERGM process conditional on their closest lower network layers. A crucial advantage of the proposed method is the possibility of adopting the binary network statistics specification to describe both the between-layer and across-layer network processes and thus facilitating the interpretation of the …

Numeracy And Social Justice: A Wide, Deep, And Longstanding Intersection, Kira Hamman, Victor Piercey, Samuel L. Tunstall

Numeracy

We discuss the connection between the numeracy and social justice movements both in historical context and in its modern incarnation. The intersection between numeracy and social justice encompasses a wide variety of disciplines and quantitative topics, but within that variety there are important commonalities. We examine the importance of sound quantitative measures for understanding social issues and the necessity of interdisciplinary collaboration in this work. Particular reference is made to the papers in the first part of the Numeracy special collection on social justice, which appear in this issue.

Cronbach’S Alpha Under Insufficient Effort Responding: An Analytic Approach, Stephen W. Carden, Trevor R. Camper, Nicholas S. Holtzman

Psychology: Faculty Publications

Surveys commonly suffer from insufficient effort responding (IER). If not accounted for, IER can cause biases and lead to false conclusions. In particular, Cronbach’s alpha has been empirically observed to either deflate or inflate due to IER. This paper will elucidate how IER impacts Cronbach’s alpha in a variety of situations. Previous results concerning internal consistency under mixture models are extended to obtain a characterization of Cronbach’s alpha in terms of item validities, average variances, and average covariances. The characterization is then applied to contaminating distributions representing various types of IER. The discussion will provide commentary on previous simulation-based investigations, …

Mefenamic Acid – Hpmc As Hg Amorphous Solid Dispersions: Dissolution Enhancement Using Hot Melt Extrusion Technology, Ashay Shukla

Electronic Theses and Dissertations

Mefenamic acid, a BCS class II drug, displays high permeability and low solubility, thereby exhibiting a poor dissolution profile. Hence to improve the solubility and dissolution rate of Mefenamic acid, Hot Melt Extrusion (HME) technique was employed. The amorphous solid dispersion matrix exhibited enhanced dissolution with desired release characteristics. Hydroxypropylmethylcellulose acetate succinate (AquaSolve™ HPMC-AS HG) was used as a carrier with the poloxamer (Kolliphor P407). The drug load was varied from 20% to 40% within the blend. Drug and polymers were blended using a twin shell V-blender for 10 minutes and extruded using an 11mm twin-screw co-rotating extruder (ThermoFisher Scientific, …

Improved N-Dimensional Data Visualization From Hyper-Radial Values, Todd J. Paciencia, Trevor J. Bihl, Kenneth W. Bauer

Faculty Publications

Higher-dimensional data, which is becoming common in many disciplines due to big data problems, are inherently difficult to visualize in a meaningful way. While many visualization methods exist, they are often difficult to interpret, involve multiple plots and overlaid points, or require simultaneous interpretations. This research adapts and extends hyper-radial visualization, a technique used to visualize Pareto fronts in multi-objective optimizations, to become an n-dimensional visualization tool. Hyper-radial visualization is seen to offer many advantages by presenting a low-dimensionality representation of data through easily understood calculations. First, hyper-radial visualization is extended for use with general multivariate data. Second, a method …

On The Modified Burr Xii-Power Distribution: Development, Properties, Characterizations And Applications, Fiaz Ahmad Bhatti, Gholamhossein G. Hamedani, Mustafa Ç. Korkmaz, Munir Ahmad

Mathematical and Statistical Science Faculty Research and Publications

In this paper, a flexible lifetime distribution with increasing, decreasing and bathtub hazard rate called the Modified Burr XII-Power (MBXII-Power) is developed on the basis of the T-X family technique. The density function of the MBXII-Power is arc, exponential, left-skewed, right-skewed, J, reverse-J and symmetrical shaped. Descriptive measures such as moments, moments of order statistics, incomplete moments, inequality measures, residual life functions and reliability measures are theoretically established. The MBXII-Power distribution is characterized via different techniques. Parameters of the MBXII-Power distribution are estimated using maximum likelihood method. The simulation study is performed on the basis of graphical results to see …

The Exponentiated Generalized Topp Leone-G Family Of Distributions: Properties And Applications, Hesham Mohammed Reyad, Morad Alizadeh, Farrukh Jamal, Soha Othman, Gholamhossein G. Hamedani

Mathematical and Statistical Science Faculty Research and Publications

In this paper, we propose a new class of continuous distributions called the exponentiated generalized Topp Leone-G family that extends the Topp Leone-G family introduced by Al-Shomrani et al. (2016). We derive explicit expressions for certain mathematical properties of the new family such as; ordinary and incomplete moments, generating functions, reliability analysis, Lorenz and Bonferroni curves, Rényi entropy, stress strength model, moment of residual and reversed residual life, order statistics, extreme values and characterizations. We discuss the maximum likelihood estimates and the observed information matrix for the model parameters. Two real data sets are used to illustrate the flexibility of …

On The Generalized Log Burr Iii Distribution: Development, Properties, Characterizations And Applications, Fiaz Ahmad Bhatti, Gholamhossein Hamedani, Azeem Ali, Munir Ahmad

Mathematical and Statistical Science Faculty Research and Publications

In this paper, we present a generalized log Burr III (GLBIII) distribution developed on the basis of a generalized log Pearson differential equation (GLPE). The density function of the GLBIII is exponential, arc, J, reverse-J, bimodal, left-skewed, right- skewed and symmetrical shaped. The hazard rate function of GLBIII distribution has various shapes such as constant, increasing, decreasing, increasing-decreasing, upside- down bathtub and modified bathtub. Descriptive measures such as quantile function, sub- models, ordinary moments, moments of order statistics, incomplete moments, reliability and uncertainty measures are theoretically established. The GLBIII distribution is characterized via different techniques. Parameters of the GLBIII distribution …

The Impacts Of Race, Residence, And Prenatal Care On Infant Mortality, Mary Christine Dorley

Walden Dissertations and Doctoral Studies

Tennessee ranks high for infant mortality (IM) in the United States. Despite public health efforts, the IM rate for Blacks is twice that of Whites mimicking what is observed nationally. Several risk factors for IM have been identified; however, it was still unclear how places of residence and prenatal care (PNC) affect IM for Tennesseans. The purpose of this study was to assess the relationship between places of residence (conceptualized by rurality and racial concentration), PNC, and IM among racial groups across Tennessee and to determine if race modified these associations. This was a cross-sectional study using data from the …

The Role Of Glucose Level On The Performance Of The Framingham Risk Score, Uohna June Thiessen

Walden Dissertations and Doctoral Studies

Cardiovascular diseases (CVD) are responsible for more deaths than any other disease, continue to threaten the quality of life for many, and is a major burden to the health care system. The Framingham Heart Study (FHS) identified the major CVD risk factors that became essential to effective CVD screening strategies and the Framingham Risk Score (FRS), is used to assess CVD risk. Based on the concepts of the health behavior model and CVD as a cardiometabolic disorder, multivariate logistic regression analysis was used to evaluate the association between fasting blood glucose (FBG) levels and a CHD event, and to determine …

Wellness Paradigms In Predicting Stress And Burnout Among Beginning Expatriate Teachers, Kimala Proctor

Walden Dissertations and Doctoral Studies

Research indicates that the current teacher shortage is in part due to stress and burnout. A topic that has not been examined is beginning expatriate English medium teachers (EMTs) with 5 years or less of teaching experience in the United Arab Emirates and the relationship between using individualized, self-initiated wellness paradigms and stress, job burnout, and intent to leave the teaching profession. The transactional model of stress and coping, Maslach's multidimensional theory of burnout, and the health promotion model were used to evaluate the moderating effects of the EMTs' burnout and stress levels on their wellness and intent to leave. …

Regression Tree Construction For Reinforcement Learning Problems With A General Action Space, Anthony S. Bush Jr

College of Graduate Studies: Theses & Dissertations

Part of the implementation of Reinforcement Learning is constructing a regression of values against states and actions and using that regression model to optimize over actions for a given state. One such common regression technique is that of a decision tree; or in the case of continuous input, a regression tree. In such a case, we fix the states and optimize over actions; however, standard regression trees do not easily optimize over a subset of the input variables\cite{Card1993}. The technique we propose in this thesis is a hybrid of regression trees and kernel regression. First, a regression tree splits over …

Data Patterns Discovery Using Unsupervised Learning, Rachel A. Lewis

College of Graduate Studies: Theses & Dissertations

Self-care activities classification poses significant challenges in identifying children’s unique functional abilities and needs within the exceptional children healthcare system. The accuracy of diagnosing a child's self-care problem, such as toileting or dressing, is highly influenced by an occupational therapists’ experience and time constraints. Thus, there is a need for objective means to detect and predict in advance the self-care problems of children with physical and motor disabilities. We use clustering to discover interesting information from self-care problems, perform automatic classification of binary data, and discover outliers. The advantages are twofold: the advancement of knowledge on identifying self-care problems in …

Variable Selection In Accelerated Failure Time (Aft) Frailty Models: An Application Of Penalized Quasi-Likelihood, Sarbesh R. Pandeya

College of Graduate Studies: Theses & Dissertations

Variable selection is one of the standard ways of selecting models in large scale datasets. It has applications in many fields of research study, especially in large multi-center clinical trials. One of the prominent methods in variable selection is the penalized likelihood, which is both consistent and efficient. However, the penalized selection is significantly challenging under the influence of random (frailty) covariates. It is even more complicated when there is involvement of censoring as it may not have a closed-form solution for the marginal log-likelihood. Therefore, we applied the penalized quasi-likelihood (PQL) approach that approximates the solution for such a …

Statistical Inference For The Transformed Rayleigh Lomax Distribution With Progressive Type-Ii Right Censorship, Amani Alghami, Wei Ning, Arjun K. Gupta

Mathematics and Statistics Faculty Publications

In this paper, we study the transformed Rayleigh Lomax (Trans-RL) distribution which belongs to a certain family of two parameters lifetime distributions given by Wang et al (2010). Confidence intervals and inverse estimators of the Trans-RL parameters are derived in terms of order statistics. A simulation study is conducted to report the coverage probabilities, the average biases and the average relative mean square errors for the maximum likelihood, L-moments and inverse estimators. We compare the performance of these methods under different schemes of progressively Type-II right censoring. Finally, an illustrative example is provided to demonstrate the proposed methods.

Exploring New Statistical Frontiers At The Intersection Of Survey Science And Big Data: Convergence At "Bigsurv18", Craig A. Hill, Paul Biemer, Trent Buskirk, Mario Callegaro, Analucía Córdova Cazar, Adam Eck, Lilli Japec, Antje Kirchner, Stas Kolenikov, Lars Lyberg, Patrick Sturgis

Mathematics and Statistics Faculty Publications

Held in October 2018, The Big Data Meets Survey Science conference, also known as “Big- Surv18,” provided a first-of-its-kind opportunity for survey researchers, statisticians, computer scientists, and data scientists to convene under the same roof. At this conference, scientists from multiple disciplines were able to exchange ideas about their work might influence and enhance the work of others. This was a landmark event, especially for survey researchers and statisticians, whose industry has been buffeted of late by falling response rates and rising costs at the same time as a proliferation of new tools and techniques, coupled with increasing availability of …

Quasi-Likelihood Ratio Tests For Homoscedasticity Of Variance In Linear Regression, Lili Yu, Varadan Sevilimedu, Robert Vogel, Hani Samawi

Biostatistics, Epidemiology & Environmental Health Sciences: Faculty Publications

Two quasi-likelihood ratio tests are proposed for the homoscedasticity assumption in the linear regression models. They require few assumptions than the existing tests. The properties of the tests are investigated through simulation studies. An example is provided to illustrate the usefulness of the new proposed tests.

The Effect Of Neonicotinoids On Apis Mellifera: A Revisit, Qingchen Liang

Master's Theses and Doctoral Dissertations

Colony collapse disorder (CCD), which has caused high colony mortality rates in the European honeybee (Apis mellifera), is a pressing economical and ecological problem. I revisited Woodcock et al.'s (2017a) paper, "Country-specic Effects of Neonicotinoid Pesticides on Honey Bees and Wild Bees", in light of unsound statistical methods used in the original study. In the first part of this paper, I attempted to replicate the analysis underlying key findings in the original paper. In the second part, I reanalyzed the data using mostly non-parametric methods in order to obtain robust results. I did not find any evidence for a harmful …