Statistics and Probability Commons^™

A Phenological Model For A Southern Population Of Mountain Pine Beetle, Catherine E. Wangen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mountain pine beetle (MPB, Dendroctonus ponderosae Hopkins) attacks living Pinus trees across a widespread area of western North America, causing significant ecological and economic damage. The ability to make accurate predictions of how MPB populations across this range will respond to temperatures, which affect MPB progress through life stages, is essential. Northern and southern populations of MPB are genetically different in response to temperature, requiring geographic-specific model parameters. There is not currently a predictive model for the southern MPB life cycle, despite concerns that those populations may be more susceptible to increased numbers of generations per year, which would …

Bayesian Variable Selection Strategies In Longitudinal Mixture Models And Categorical Regression Problems., Md Nazir Uddin

Electronic Theses and Dissertations

In this work, we seek to develop a variable screening and selection method for Bayesian mixture models with longitudinal data. To develop this method, we consider data from the Health and Retirement Survey (HRS) conducted by University of Michigan. Considering yearly out-of-pocket expenditures as the longitudinal response variable, we consider a Bayesian mixture model with $K$ components. The data consist of a large collection of demographic, financial, and health-related baseline characteristics, and we wish to find a subset of these that impact cluster membership. An initial mixture model without any cluster-level predictors is fit to the data through an MCMC …

Statistical Analysis Of Genetic Sequence Variants In Whole Exome Sequencing Data From Patients With Prostate Cancer, Kelvin Ofori-Minta

Open Access Theses & Dissertations

A single variation in the genetic sequence within the DNA of an organism could easily lead to beneficial, detrimental or neutral effects. Most often than not, these effects are detrimental than beneficial. While many biomedical and bioinformatics studies have been conducted to determine the genetic cause of prostate cancer (PrCa) which is still the second leading cause of cancer related death among men in the United States. An appreciable effort in statistical bioinformatics researches has been directed towards this aim. Through statistical analyses of a set of whole exome sequencing data from patients with PrCa obtained via The Cancer Genome …

Integrated Machine Learning Approaches To Improve Classification Performance And Feature Extraction Process For Eeg Dataset, Mohammad Masum

Doctor of Data Science and Analytics Dissertations

Epileptic seizure or epilepsy is a chronic neurological disorder that occurs due to brain neurons' abnormal activities and has affected approximately 50 million people worldwide. Epilepsy can affect patients’ health and lead to life-threatening emergencies. Early detection of epilepsy is highly effective in avoiding seizures by intervening in treatment. The electroencephalogram (EEG) signal, which contains valuable information of electrical activity in the brain, is a standard neuroimaging tool used by clinicians to monitor and diagnose epilepsy. Visually inspecting the EEG signal is an expensive, tedious, and error-prone practice. Moreover, the result varies with different neurophysiologists for an identical reading. Thus, …

Contributions To The Teaching And Learning Of Fluid Mechanics, Ashwin Vaidya

Department of Mathematics Faculty Scholarship and Creative Works

This issue showcases a compilation of papers on fluid mechanics (FM) education, covering different sub topics of the subject. The success of the first volume [1] prompted us to consider another follow-up special issue on the topic, which has also been very successful in garnering an impressive variety of submissions.

As a classical branch of science, the beauty and complexity of fluid dynamics cannot be overemphasized. This is an extremely well-studied subject which has now become a significant component of several major scientific disciplines ranging from aerospace engineering, astrophysics, atmospheric science (including climate modeling), biological and biomedical science …

Decompositions Of Total Causal Effect: A Natural Counterfactual Framework Assessing Mediation And Interaction, Xin Gao

Mathematics & Statistics ETDs

In this work, we developed ten-way decompositions of the total causal effect on continuous outcomes in the presence of two mediators that have mediation and interaction components. We considered a natural counterfactual interaction effect framework that facilitates the decomposition of the total casual effects of the exposure on the outcome attributable to the effects of mediators and their interaction effects with the exposure. We discussed the identification assumptions and provide empirical formulas for estimating the components of the ten-way decompositions. We also developed multiplicative total causal effect decompositions based on risk ratios for binary outcomes, hazard ratios and logarithm survival …

The Uncertainty Of Confidence, Michael J. Leach

Journal of Humanistic Mathematics

This is a free-verse poem about the estimation of population parameters in statistical models. The spacing of words is intended to reflect uncertainty.

Markov Chains For Computer Music Generation, Ilana Shapiro, Mark Huber

Journal of Humanistic Mathematics

Random generation of music goes back at least to the 1700s with the introduction of Musical Dice Games. More recently, Markov chain models have been used as a way of extracting information from a piece of music and generating new music. We explain this approach and give Python code for using it to first draw out a model of the music and then create new music with that model.

Predictors Of Chronic Opioid Therapy In Medicaid Beneficiaries With Hiv Who Initiated Antiretroviral Therapy, Gyeon Oh, Emily S. Brouwer, Erin L. Abner, David W. Fardo, Patricia R. Freeman, Chris Delcher, Daniela C. Moga

Epidemiology and Environmental Health Faculty Publications

The factors associated with chronic opioid therapy (COT) in patients with HIV is understudied. Using Medicaid data (2002-2009), this retrospective cohort study examines COT in beneficiaries with HIV who initiated standard combination anti-retroviral therapy (cART). We used generalized estimating equations on logistic regression models with backward selection to identify significant predictors of COT initiation. COT was initiated among 1014 out of 9615 beneficiaries with HIV (male: 10.4%; female: 10.7%). Those with older age, any malignancy, Hepatitis C infection, back pain, arthritis, neuropathy pain, substance use disorder, polypharmacy, (use of) benzodiazepines, gabapentinoids, antidepressants, and prior opioid therapies were positively associated with …

A Comparison Study Among The High School Students In The Us: Obesity And Overweight Rates Among Racial Minorities—Stress, Dietary Behavior, Sports And Physical Activity Participation, Animesh Dali '24, Naima Shifa

Student Research

Background: The Youth Risk Behavior Surveillance System (YRBSS) collects data on American youth primarily for assessing various health risk factors. This study aims to examine the relationship between demographic, and behavioral variables that we have considered as risk factors and obesity in American youth in 2015 and 2019.

Methods: Data pertaining to obesity risk factors and BMI measurements were obtained from the YRBSS. Cross Tables and linear regression models were constructed and subsequent analyses were used to examine the correlation between risk factors and BMI. Two-sample t-tests were used to explore the difference between the 2015 and 2019 datasets.

Results: …

Treatment Patterns And Outcomes In Elderly Patients With Newly Diagnosed Multiple Myeloma: Results From The Connect® Mm Registry, Hans C. Lee, Sikander Ailawadhi, Cristina J. Gasparetto, Sundar Jagannath, Robert M. Rifkin, Brian G.M. Durie, Mohit Narang, Howard R. Terebelo, Kathleen Toomey, James W. Hardin Ph.D., Lynne Wagner, James L. Omel, Mazaher Dhalla, Liang Liu, Prashant Joshi, Rafat Abonour

Faculty Publications

No abstract provided.

Joint Displays For Mixed Methods Research In Psychology, Matthew T. Mccrudden, Gwen Marchand, Paul A. Schutz

Research & Economic Development Faculty Research

Mixed methods researchers use joint displays for integration at different phases of the research process in psychological research. Joint displays are visual displays that are used to integrate quantitative and qualitative data during data collection, analysis, and interpretation. We discuss different mixing purposes and how joint displays may help researchers integrate the quantitative and qualitative strands of a study. We provide examples of joint displays for data collection and for data analysis, including newer innovations. Finally, we discuss considerations, including benefits and challenges, of using joint displays during data collection and analysis.

An Exploratory Assessment Of Callings: The Importance Of Specialization, Christopher Paul Cain, Lisa Nicole Cain, James A. Busser, Hee Jung Kang

Hospitality Faculty Research

Purpose This study sought to understand how having a calling influenced engagement, work–life balance and career satisfaction for Professional Golfers Association of America (PGA) and Golf Course Superintendent of America (GCSA) professionals. Design/methodology/approach A conceptual model was used to examine callings among golf course supervisors and its impact on their engagement, work–life balance and career satisfaction. This study also explored the moderation effect of employees’ generalized or specialized role on the calling–engagement relationship. Surveys were collected from a single golf management company and partial least squares structural equation modeling (PLS-SEM) was used for data analysis. Findings The results revealed significant …

Causal Mediation Analysis With Multiple Time-Varying Mediators, An-Shun Tai, Sheng-Hsuan Lin, Yu-Cheng Chu, Tsung Yu, Milo A. Puhan, Tyler Vanderweele

Harvard University Biostatistics Working Paper Series

In longitudinal studies with time-varying exposures and mediators, the mediational g-formula is an important method for the assessment of direct and indirect effects. However, current methodologies based on the mediational g-formula can deal with only one mediator. This limitation makes these methodologies inapplicable to many scenarios. Hence, we develop a novel methodology by extending the mediational g-formula to cover cases with multiple time-varying mediators. We formulate two variants of our approach that are each suited to a distinct set of assumptions and effect definitions and present nonparametric identification results of each variant. We further show how complex causal mechanisms (whose …

Physical Activity Barriers And Assets In Rural Appalachian Kentucky: A Mixed-Methods Study, Natalie Jones, Deirdre Dlugonski, Rachel Gillespie, Emily M. Dewitt, Joann Lianekhammy, Stacey A. Slone, Kathryn M. Cardarelli

Sports Medicine Research Institute Faculty Publications

Obesity is an increasing public health concern in the U.S. and a contributor to chronic illness, with trends revealing a rise in adult obesity and chronic disease rates among the most vulnerable and disadvantaged populations, including those in rural communities. A mixed-methods approach was used to examine perspectives on perceived physical activity barriers, resources, and level of community support. Researchers utilized the socioecological model to examine the multiple domains that support physical activity in rural Appalachia. The present study focuses on baseline data, including a cohort survey to assess physical activity, health status, and barriers to physical activity, and five …

Multiple Baseline Interrupted Time Series: Describing Changes In New Mexico Medicaid Behavioral Health Home Patients’ Care, Jessica Reno

Mathematics & Statistics ETDs

In 2016, the CareLink New Mexico behavioral health homes program began enrolling Medicaid recipients with the goal of increasing care coordination, improving access to services, and decreasing long-term costs of care for adults with serious mental illness (SMI) and children with severe emotional disturbance (SED). To evaluate these aims, a retrospective interrupted time series study using Medicaid claims data was designed. First, a comparable subset of non-enrolled individuals was selected from the pool of Medicaid recipients with SMI or SED using propensity score matching. Then, segmented regression was applied to three outcomes: total Medicaid charges, number of outpatient behavioral health …

Investigation And Statistical Modeling Of The Mechanical Properties Of Additively Manufactured Lattices, Derek G. Spear, Anthony N. Palazotto

Faculty Publications

This paper describes the background, test methodology, and experimental results associated with the testing and analysis of quasi-static compression testing of additively manufactured open-cell lattice structures. The study aims to examine the effect of lattice topology, cell size, cell density, and surface thickness on the mechanical properties of lattice structures. Three lattice designs were chosen, the Diamond, I-WP, and Primitive Triply Periodic Minimal Surfaces (TPMSs). Uniaxial compression tests were conducted for every combination of the three lattice designs, three cell sizes, three cell densities, and three surface thicknesses. In order to perform an efficient experiment and gain the most information …

Do Different Relevance Attributes Indicate The Same Conservation Priorities? A Case Study In Caves Of Southeastern Brazil, Maysa F.V.R. Souza, Denizar A. Alvarenga, Marconi Souza-Silva, Rodrigo L. Ferreira

International Journal of Speleology

In the last decade, the scientific community brought to the debate gaps that slow down the advance of knowledge regarding global biodiversity. More recently, this discussion has reached subterranean environments, where these gaps are even more dramatic due to the relict and vulnerable nature of their species. In this context, we tested ecological metrics related to some of these gaps, checking if the biological relevance of the caves would change depending on ecological attributes related to each metric. The study was carried out in caves from southeastern Brazil, located in a region presenting a high richness of troglobitic species restricted …

Optimal Transport Driven Bayesian Inversion With Application To Signal Processing, Elijah F. Perez

Mathematics & Statistics ETDs

This paper will outline a Debiased Sinkhorn Divergence driven Bayesian inversion framework. Conventionally, a Gaussian Driven Bayesian framework is used when performing Bayesian inversion. A major issue with this Gaussian framework is that the Gaussian likelihood, driven by the L2 norm, is not affected by phase shift in a given signal. This issue has been addressed in [1] using a Wasserstein framework. However, the Wasserstein framework still has an issue because it assumes statistical independence when multidimensional signals are analyzed. This assumption of statistical independence cannot always be made when analyzing signals where multiple detectors are recording one event, say …

The Unit Generalized Log Burr Xii Distribution: Properties And Application, Fiaz Ahmad Bhatti, Azeem Ali, Gholamhossein Hamedani, Mustafa Ç. Korkmaz, Munir Ahmad

Mathematical and Statistical Science Faculty Research and Publications

In this paper, a three-parameter bounded unit distribution with a flexible hazard rate called the unit generalized log Burr XII (UGLBXII) distribution is derived. To show the importance of the proposed distribution, we establish some of its mathematical properties such as random number generator, ordinary moments, generalized TL moments, conditional moments, reliability and uncertainty measures. We characterize the UGLBXII distribution via innovative techniques. We also present the bivariate‐ and multivariate‐type distributions via Morgenstern (Mor) family and via Clayton family. Six estimation methods such as the maximum likelihood, maximum product spacings, least squares, weighted least squares, Cramer-von Mises and Anderson-Darling methods …