Statistics and Probability Commons^™

Fundamental Tradeoffs In Estimation Of Finite-State Hidden Markov Models, Justin Le

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hidden Markov models (HMMs) constitute a broad and flexible class of statistical models that are widely used in studying processes that evolve over time and are only observable through the collection of noisy data. Two problems are essential to the use of HMMs: state estimation and parameter estimation. In state estimation, an algorithm estimates the sequence of states of the process that most likely generated a certain sequence of observations in the data. In parameter estimation, an algorithm computes the probability distributions that govern the time-evolution of states and the sampling of data. Although algorithms for the two problems are …

Bi-Directional Testing For Change Point Detection In Poisson Processes, Moinak Bhaduri

UNLV Theses, Dissertations, Professional Papers, and Capstones

Point processes often serve as a natural language to chronicle an event's temporal evolution, and significant changes in the flow, synonymous with non-stationarity, are usually triggered by assignable and frequently preventable causes, often heralding devastating ramifications. Examples include amplified restlessness of a volcano, increased frequencies of airplane crashes, hurricanes, mining mishaps, among others. Guessing these time points of changes, therefore, merits utmost care. Switching the way time traditionally propagates, we posit a new genre of bidirectional tests which, despite a frugal construct, prove to be exceedingly efficient in culling out non-stationarity under a wide spectrum of environments. A journey surveying …

Prostate Cancer Survival Among Hispanics: A Surveillance, Epidemiology, And End Results (Seer) Population-Based Cohort Study, David Rivas

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hispanics are now the youngest, largest, and fastest growing minority group in the U.S. Prostate cancer (PC) is the most commonly diagnosed cancer in men and is the second-leading cause of cancer deaths among Hispanics. For the first time, we examined PC-specific survival among distinct Hispanic groups that include Mexicans, Cubans, Dominicans, Puerto Ricans, as well as Central and South Americans. We compared these groups to the main reference population in the U.S., non-Hispanic Whites (NHW), after adjustment for prognostic factor risk categories (prostate-specific antigen (PSA) level, Gleason score, and tumor stage), as well as sociodemographic covariates (e.g., health insurance, …

Using Computational Bayesian Statistics To Analyze Parameters In A Differential Equation Model, Jacob Menix

Mahurin Honors College Capstone Experience/Thesis Projects

The purpose of this project is to use Bayesian statistics to analyze values of parameters for a previously developed system of differential equations which describes the healing process of diabetic foot ulcers. The model describes the relationships between matrix metalloproteinases (MMPs), their inhibitors (TIMPs), and extracellular matrix (ECM). A Bayesian approach is used when the availability of data is sparse, as it is in this case. Delayed Rejection Adaptive Metropolis (DRAM), a MATLAB implementation of a Metropolis-Hastings algorithm, is used to estimate parameters. This approach with the individual patient data allows us to estimate and compare parameters and their pairwise …

Re-Evaluating Performance Measurement: New Mathematical Methods To Address Common Performance Measurement Challenges, Jordan David Benis

Electronic Theses and Dissertations

Performance Measurement is an essential discipline for any business. Robust and reliable performance metrics for people, processes, and technologies enable a business to identify and address deficiencies to improve performance and profitability. The complexity of modern operating environments presents real challenges to developing equitable and accurate performance metrics. This thesis explores and develops two new methods to address common challenges encountered in businesses across the world. The first method addresses the challenge of estimating the relative complexity of various tasks by utilizing the Pearson Correlation Coefficient to identify potentially over weighted and under weighted tasks. The second method addresses the …

Designing A Calibration Set In Spectral Space For Efficient Development Of An Nir Method For Tablet Analysis, Md Anik Alam

Electronic Theses and Dissertations

Designing a calibration set is the first step in developing a spectroscopic calibration method for quantitative analysis of pharmaceutical tablets. This step is critical because successful model development depends on the suitability of the calibration data. For spectroscopic-based methods, traditional concentration based techniques for designing calibration sets are prone to have redundant information while simultaneously lacking necessary information for a successful calibration model. The traditional method also follows the same design approach for different spectroscopic techniques and different formulations, thereby lacks the optimizing capability to be technique and formulation specific.

A method for designing a calibration set in the Near …

Low-Fat Abiraterone Food Effect Is Of Little Consequence, Jill M. Kolesar, Glenn X. Liu

Pharmacy Practice and Science Faculty Publications

No abstract provided.

Fast Identification Of Components Commonly Used In Homemade Explosives By Spectroscopic And Chemometric Methods, Deidre Day Vandenbos, Huggins Msimanga, Christopher Dockery

Master of Science in Chemical Sciences Theses

Homemade explosives (HMEs) have become a global pandemic. This forensic research focuses on developing identification methods that can provide quick, cost effective, non-destructive analysis using portable instrumentation. These capabilities would be invaluable to first responders, military, and security officials to establish an evidentiary link between a suspect and a reference in cases of HMEs, IEDs, arson and environmental contamination.

Modern methods for quick identification of the fuels and oxidant sources used in manufacturing HMEs, include Fourier Transform Infrared (FT-IR) and Raman spectroscopy. Visual confirmation alone, however, is not strong enough to discriminate chemicals with nearly identical spectra, which occurs when …

Discrete Ranked Set Sampling, Heng Cui

Statistical Science Theses and Dissertations

Ranked set sampling (RSS) is an efficient data collection framework compared to simple random sampling (SRS). It is widely used in various application areas such as agriculture, environment, sociology, and medicine, especially in situations where measurement is expensive but ranking is less costly. Most past research in RSS focused on situations where the underlying distribution is continuous. However, it is not unusual to have a discrete data generation mechanism. Estimating statistical functionals are challenging as ties may truly exist in discrete RSS. In this thesis, we started with estimating the cumulative distribution function (CDF) in discrete RSS. We proposed two …

Pooling Of Variances: The Skeleton In The Mixed Model Closet?, Philip M. Dixon

Conference on Applied Statistics in Agriculture and Natural Resources

I explore three related issues concerning pooling of error variances: when is it appropriate (or not) to pool, how best to evaluate equality of variances, and whether there is a cost to never pooling. I focus on pooling decisions in a combined analysis of a multi-site experiment. A-priori, sites should have different error variances. My primary question is whether an analysis that ignores unequal variances is wrong.

I find that ignoring heteroscedasticity between sites maintains, or provides slightly conservative, tests of average treatment effects and treatment-by-site interactions. Models with site-specific variances do provide more powerful tests when variances are different. …

Data On The Risk Perceptions Of Beach Water Safety In Coastal Georgia, Jeffery A. Jones, Asli Aslan, Rakhi Trivedi, Maria I. Olivas, Mikayla Hoffmann

Biostatistics, Epidemiology & Environmental Health Sciences: Faculty Publications

These data reflect the perceptions of beach water quality drawn from a convenience sample of 238 visitors to Georgia (USA) beaches collected in June–July 2017 and are related to the research article entitled “Water quality and the perception of risk: a study of Georgia, USA, beachgoers” (Jones et al., 2018) [1]. Data were collected both via an online survey distributed through Facebook and through in-person questionnaires collected directly on the beaches.

Golden Arm: A Probabilistic Study Of Dice Control In Craps, Donald R. Smith, Robert Scott Iii

UNLV Gaming Research & Review Journal

This paper calculates how much control a craps shooter must possess on dice outcomes to eliminate the house advantage. A golden arm is someone who has dice control (or a rhythm roller or dice influencer). There are various strategies for dice control in craps. We discuss several possibilities of dice control that would result in several different mathematical models of control. We do not assert whether dice control is possible or not (there is a lack of published evidence). However, after studying casino-legal methods described by dice-control advocates, we can see only one realistic mathematical model that describes the resulting …

Statistical Modeling Of Financial Time Series, Ranju Karki

Student Theses and Dissertations

This thesis presents a comprehensive report of my research in financial time series analysis from Fall 2017 to Spring 2018. It is focused on two main topics: clustering and modeling of financial time dependent information. The weighted five-day moving arc length is used as a measure of volatility, and we applied self-organizing maps to cluster the subject information. We perform a clustering procedure of financial time dependent information using several lag values, and Apple Incorporation and Google as the leading stocks. As a result, we discovered that there are others financial time dependent information present in the same cluster with …

Evaluating Preexisting Qualitative Research Data For Secondary Analysis, Victoria Sherif

Educational Leadership Studies Faculty Publications

In this article, I explore the nature of secondary analysis and provide a brief history of the method. Qualitative secondary analysis is a relatively under-used method in education and the social sciences, often due to the lack of easily accessible, relevant, trustworthy, and complete data. I address some of the potentials and limitations that influence its use and explore criteria for assessing the quality and sufficiency of preexisting qualitative research data. Qualitative secondary analysis has important implications for qualitative researchers, students and practitioners interested in generating new knowledge via unobtrusive, reliable, valid, and time/cost effective research through the wider use …

The Relationship Between Stryd Power And Running Economy In Well-Trained Distance Runners 2018, Casey Austin

Master's Theses

A novel running wearable called the Stryd Summit footpod attaches to a runner’s right or left shoe and measures running power output. The developers of the product purport that the footpod’s power and form power measures may correlate with metabolic data gathered in a lab. PURPOSE: Explore the relationship between power output and running economy at threshold pace. METHODS: Seventeen well-trained distance runners, 9 males and 8 females, completed a running protocol at threshold pace. Participants ran two discontinuous four-minute stages: one with their self-selected cadence (SS), and one with cadence lowered by 10% (LC). Metabolic data, power, and form …

Oxidative Stress And Cardiovascular Risk In Type 1 Diabetes Mellitus: Insights From The Dcct/Edic Study, W. Wilson Tang, P. Mcgee, John M. Lachin, D. Li, B. Hoogwerf, S. Hazen, +Several Additional Authors

Epidemiology Faculty Publications

Background--Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus. Methods and Results--A random subcohort of 349 participants was selected from the DCCT/EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT, and 1 to 2 years post-DCCT (EDIC years 1 and …

Resistance To Peer Influence Moderates The Relationship Between Perceived (But Not Actual) Peer Norms And Binge Drinking In A College Student Social Network, Graham T. Diguiseppi, Matthew K. Meisel, Sara G. Balestrieri, Miles Q. Ott, Melissa J. Cox, Melissa A. Clark, Nancy P. Barnett

Statistical and Data Sciences: Faculty Publications

Introduction: Adolescent and young adult binge drinking is strongly associated with perceived social norms and the drinking behavior that occurs within peer networks. The extent to which an individual is influenced by the behavior of others may depend upon that individual’s resistance to peer influence (RPI).

Methods: Students in their first semester of college (N = 1323; 54.7% female, 57% White, 15.1% Hispanic) reported on their own binge drinking, and the perceived binge drinking of up to 10 important peers in the first-year class. Using network autocorrelation models, we investigated cross-sectional relationships between participant’s binge drinking frequency and the perceived …

Simple Approximations To The Renewal Function, Antonio G. Campbell

Theses/Capstones/Creative Projects

In reliability theory, a renewal process is a stochastic model for arrival times or events occurring in a certain system. For a renewal process, it is of interest to be able to estimate the number of events that will occur in the time interval (0, t]. The renewal function, M(t), is the expected value of renewals to occur within the system from (0,t]. It is a solution of the renewal equation. Since closed-form solutions of the renewal equation are mostly non-existent, approximation methods are used. Simpler approximation methods than those currently available are presented and are applied to data. The …

Mindset, Attitudes, And Success In Statistics, Matthew Isaac

Undergraduate Honors Capstone Projects

Students in many disciplines are required to take an introductory statistics course while pursuing a college education. Despite the utility of statistical methods in future research and career pursuits, many students have negative views of statistics. We are interested in how students' mindsets and attitudes towards statistics impact their performance in an undergraduate statistics course. We administered a survey to students in several undergraduate statistics courses at Utah State University. This survey included questions addressing mathematics experience, attitudes towards statistics, mindset, and course performance. We observed that the majority of students indicated the presence of a growth mindset and positive …

A Practical Guide To Big Data, Ekaterina Smirnova, Andrada Ivanescu, Jiawei Bai, Ciprian M. Crainiceanu

Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works

Big Data is increasingly prevalent in science and data analysis. We provide a short tutorial for adapting to these changes and making the necessary adjustments to the academic culture to keep Biostatistics truly impactful in scientific research.