Statistics and Probability Commons^™

Rfviz: An Interactive Visualization Package For Random Forests In R, Christopher Beckett

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Random forests are very popular tools for predictive analysis and data science. They work for both classification (where there is a categorical response variable) and regression (where the response is continuous). Random forests provide proximities, and both local and global measures of variable importance. However, these quantities require special tools to be effectively used to interpret the forest. Rfviz is a sophisticated interactive visualization package and toolkit in R, specially designed for interpreting the results of a random forest in a user-friendly way. Rfviz uses a recently developed R package (loon) from the Comprehensive R Archive Network (CRAN) to create …

Relationships Between Social Network Characteristics, Alcohol Use, And Alcohol-Related Consequences In A Large Network Of First-Year College Students: How Do Peer Drinking Norms Fit In?, Graham T. Diguiseppi, Matthew K. Meisel, Sara G. Balestrieri, Miles Q. Ott, Melissa A. Clark, Nancy P. Barnett

Statistical and Data Sciences: Faculty Publications

A burgeoning area of research is using social network analysis to investigate college students' substance use behaviors. However, little research has incorporated students' perceived peer drinking norms into these analyses. The present study investigated the association between social network characteristics, alcohol use, and alcohol-related consequences among first-year college students (N 1,342; 81% of the first-year class) at one university. The moderating role of descriptive norms was also examined. Network characteristics and descriptive norms were derived from participants' nominations of up to 10 other students who were important to them; individual network characteristics included popularity (indegree), network expansiveness (outdegree), relationship reciprocity, …

Innate Immunity, The Hepatic Extracellular Matrix, And Liver Injury: Mathematical Modeling Of Metastatic Potential And Tumor Development In Alcoholic Liver Disease., Shanice V. Hudson

Electronic Theses and Dissertations

The overarching goals of the current work are to fill key gaps in the current understanding of alcohol consumption and the risk of metastasis to the liver. Considering the evidence this research group has compiled confirming that the hepatic matrisome responds dynamically to injury, an altered extracellular matrix (ECM) profile appears to be a key feature of pre-fibrotic inflammatory injury in the liver. This group has demonstrated that the hepatic ECM responds dynamically to alcohol exposure, in particular, sensitizing the liver to LPS-induced inflammatory damage. Although the study of alcohol in its role as a contributing factor to oncogenesis and …

Role Of Misclassification Estimates In Estimating Disease Prevalence And A Non-Linear Approach To Study Synchrony Using Heart Rate Variability In Chickens, Dola Pathak

Department of Statistics: Dissertations, Theses, and Student Research

Infectious disease assays can be imperfect. When estimating disease prevalence, these imperfections are accounted for by incorporating assay sensitivity and specificity into point and variance estimates. Unfortunately, these accuracy measures are often treated as fixed constants, rather than acknowledging that they are estimates from an assay validation process. The purpose of this study is to show the detrimental effect of not taking into account this sampling variability when samples are obtained through group testing (aka, pooled testing). We show that confidence interval coverage can dramatically decline as the sample size increases for the main sample of interest. As a remedy …

Quantitative Microbial Risk Assessment For Parts, Ground, And Msc Poultry Product Including Intervention Analysis And Exploration Of Enterobacteriaceae As An Indicator Organism In Poultry Processing, Leigh Ann Parette

Graduate Theses and Dissertations

Samples collected at five different large bird poultry processing facilities over a period of 7 months from prescald to post debone locations were enumerated for Enterobacteriaceae, Salmonella spp., and Campylobacter spp. and the results were used to create Quantitative Microbial Risk Analyses (QMRA) models for parts, ground, and mechanically separated chicken (MSC) products. Sensitivity analyses indicated the points in the process at which reductions would be most advantageous to the endpoint and simulation models were run to test reductions required to meet the current USDA performance standards.

These data were analyzed to determine the reductions from one node (location) to …

Budget-Constrained Regression Model Selection Using Mixed Integer Nonlinear Programming, Jingying Zhang

Graduate Theses and Dissertations

Regression analysis fits predictive models to data on a response variable and corresponding values for a set of explanatory variables. Often data on the explanatory variables come at a cost from commercial databases, so the available budget may limit which ones are used in the final model.

In this dissertation, two budget-constrained regression models are proposed for continuous and categorical variables respectively using Mixed Integer Nonlinear Programming (MINLP) to choose the explanatory variables to be included in solutions. First, we propose a budget-constrained linear regression model for continuous response variables. Properties such as solvability and global optimality of the proposed …

Spatio-Temporal Reconstruction Of Remote Sensing Observations, Kamrul Khan

Graduate Theses and Dissertations

The USDA Forest Service aims to use satellite imagery for monitoring and predicting changes in forest conditions over time within the country. We specifically focus on a 230, 400 hectares region in north-central Wisconsin between 2003 - 2012. The auxiliary data collected from the satellite imagery of this region are relatively dense in space and time and can be used to efficiently predict how the forest condition changed over that decade. However, these records have a significant proportion of missing values due to weather conditions and system failures. To fill in these missing values, we build spaciotemporal models based on …

Text Analytics Approach To Extract Course Improvement Suggestions From Students’ Feedback, Swapna Gottipati, Venky Shankararaman, Jeff Rongsheng Lin

Research Collection School Of Computing and Information Systems

In academic institutions, it is normal practice that at the end of each term, students are required to complete a questionnaire that is designed to gather students’ perceptions of the instructor and their learning experience in the course. Students’ feedback includes numerical answers to Likert scale questions and textual comments to open-ended questions. Within the textual comments given by the students are embedded suggestions. A suggestion can be explicit or implicit. Any suggestion provides useful pointers on how the instructor can further enhance the student learning experience. However, it is tedious to manually go through all the qualitative comments and …

Comparing Performance Of Gene Set Test Methods Using Biologically Relevant Simulated Data, Richard M. Lambert

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Today we know that there are many genetically driven diseases and health conditions. These problems often manifest only when a set of genes are either active or inactive. Recent technology allows us to measure the activity level of genes in cells, which we call gene expression. It is of great interest to society to be able to statistically compare the gene expression of a large number of genes between two or more groups. For example, we may want to compare the gene expression of a group of cancer patients with a group of non-cancer patients to better understand the genetic …

Statistical Methods To Account For Gene-Level Covariates In Normalization Of High-Dimensional Read-Count Data, Lauren Holt Lenz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The goal of genetic-based cancer research is often to identify which genes behave differently in cancerous and healthy tissue. This difference in behavior, referred to as differential expression, may lead researchers to more targeted preventative care and treatment. One way to measure the expression of genes is though a process called RNA-Seq, that takes physical tissue samples and maps gene products and fragments in the sample back to the gene that created it, resulting in a large read-count matrix with genes in the rows and a column for each sample. The read-counts for tumor and normal samples are then compared …

The Power Law Distribution Of Agricultural Land Size, Lauren Chamberlain

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper demonstrates that the distribution of county level agricultural land size in the United States is best described by a power-law distribution, a distribution that displays extremely heavy tails. This indicates that the majority of farmland exists in the upper tail. Our analysis indicates that the top 5% of agricultural counties account for about 25% of agricultural land between 1997-2012. The power-law distribution of farm size has important implications for the design of more efficient regional and national agricultural policies as counties close to the mean account for little of the cumulative distribution of total agricultural land. This has …

Surviving A Civil War: Expanding The Scope Of Survival Analysis In Political Science, Andrew B. Whetten

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Survival Analysis in the context of Political Science is frequently used to study the duration of agreements, political party influence, wars, senator term lengths, etc. This paper surveys a collection of methods implemented on a modified version of the Power-Sharing Event Dataset (which documents civil war peace agreement durations in the Post-Cold War era) in order to identify the research questions that are optimally addressed by each method. A primary comparison will be made between a Cox Proportional Hazards Model using some advanced capabilities in the glmnet package, a Survival Random Forest Model, and a Survival SVM. En route to …

Concentrations Of Criteria Pollutants In The Contiguous U.S., 1979 – 2015: Role Of Model Parsimony In Integrated Empirical Geographic Regression, Sun-Young Kim, Matthew Bechle, Steve Hankey, Elizabeth (Lianne) A. Sheppard, Adam A. Szpiro, Julian D. Marshall

UW Biostatistics Working Paper Series

BACKGROUND: National- or regional-scale prediction models that estimate individual-level air pollution concentrations commonly include hundreds of geographic variables. However, these many variables may not be necessary and parsimonious approach including small numbers of variables may achieve sufficient prediction ability. This parsimonious approach can also be applied to most criteria pollutants. This approach will be powerful when generating publicly available datasets of model predictions that support research in environmental health and other fields. OBJECTIVES: We aim to (1) build annual-average integrated empirical geographic (IEG) regression models for the contiguous U.S. for six criteria pollutants, for all years with regulatory monitoring data …

Risk Factors Associated With Low Birth Weight, Mohammad Zen Rahfiludin, Yudhy Dharmawan

Kesmas

Neonatal deaths are associated with preterm birth complications. The aim of this study was to analyze risk factors associated with LBW. This was a crosssectional study held in Bulu Primary Health Care, Temanggung, Central Java, Indonesia. The sample size required for this study was 69 based on the Slovin formula. Data were collected using questionnaires and semi-quantitative Food Frequency Questionnaire forms. Data on infant birth weight was taken from midwives’ delivery cohort records. Mid upper arm circumference (MUAC), hemoglobin level, blood pressure, maternal age, parity, nutritional intake, and serum transferrin receptor data were taken from the infant’s mother using a …

Family Perception Towards Health Role In Filariasis Countermeasures Using The Health Belief Model Approach In Aceh Besar District, Said Devi Elvin, Mutia Yusuf, Wirda Hayati, Teuku Alamsyah

Kesmas

Aceh Besar District is a filariasis endemic area. This endemic state is strongly influenced by people’s perception of filariasis countermeasures. This study aimed to determine relation between family perceptions towards health role in filariasis countermeasures using the Health Belief Model. An analytical survey was applied with a cross-sectional study approach. The study population was families at three villages that are Lambaro Bileu, Lambaet, and Cot Preh of Kuta Baro Primary Health Care. This represents 1,113 families with a sample of 92 families that were selected using a proportionate stratified random sampling technique. The study instrument was a questionnaire and data …

Work-Related Skin Diseases Among Workers In The Sewing Section At Pt. X Shoe Company In West Java, Hendra Hendra, Eva Nirwana, Marzuki Isahak

Kesmas

Occupational skin diseases are the most common work-related diseases in many countries. Shoe industry workers are potential to be affected by work-related skin diseases (WRSDs). This study aimed to analyze the risk factors associated with WRSDs among workers in the sewing section at a shoe company in West Java. A total of 477 workers were examined and interviewed using the modified Nordic Occupational Skin Questionnaire-2002/LONG from May 2016 to July 2016. Chi-square test and logistic regression were used to analyze the risk factors related to WRSDs. The results showed that 57.7% of the workers suffered from WRSDs. Most of the …

Pizza And Hamburger Consumption To Overweight Among Adolescents In Jambi City, Ummi Kalsum, Sahridayanti Nainggolan, Nawi Ng

Kesmas

Junk food is unhealthy and poor in nutrient quality, and may result in weight gain, obesity, and coronary heart disease, if consumed regularly. The prevalence of overweight in adolescents is 5-10% higher in urban areas. Adolescents undergo lifestyle changes, including in food consumption behavior. This study aimed to determine relation between junk food consumption patterns and overweight in adolescents. This study was conducted based on a cross-sectional design. A total of 137 high school students in Jambi City were involved in this study. Patterns of junk food consumption were assessed using food frequency questionnaires that examined the eating habits of …

Adolescents' Attitude Toward Hiv/Aids Prevention In Yogyakarta, Meysa Tiranda, Nanik Setiyawati, Anita Rahmawati

Kesmas

Acquired immunodeficiency syndrome (AIDS) is the second leading cause of death in adolescent groups in the world. In Indonesia, the rate of human immunodeficiency virus (HIV)-infected adolescents increases annually. Yogyakarta, well-known as the education city, has the highest number of HIV/AIDS cases in the productive age group of 20–29 years old, which means that they have been already infected with HIV since teen age. This study aimed to determine influential factors that affect adolescents' attitude toward HIV/AIDS prevention. The study was an analytic survey research with a cross-sectional design. Stratified random sampling was applied to select a sample size of …

Role Stress, Personality Type, Burnout, And Performance Of Midwives Towards Postnatal Care Program Achievement In Surabaya City, Elita Halimsetiono, Thinni Nurul Rochmah, Dewi Retno Suminar

Kesmas

The coverage of postnatal care program in Surabaya City had declined since 2011–2013 and could not reach the target. This analytic observational study used a cross-sectional design and was conducted during April–May 2015 to analyze the effect of role stress, personality type, and burnout on midwives’ performance towards postnatal care program achievement in Surabaya City. A total sample of 45 midwives was collected from eight primary health care centers in Surabaya City with basic emergency obstetric and neonatal care services. Accidental sampling was used for sample selection. This study indicated that most of the midwives were aged 20–30 years and …

Impact Of Budget Increase On Primary Health Care Performance In The Era Of National Health Insurance: Case Study In Buleleng District, Kadek Suranugraha, Ni Made Sri Nopiyani, Pande Putu Januraga

Kesmas

Since 2014, there has been an increase in funds for primary health care (PHC) coming from the National Health Insurance program capitation funds and the Health Operational Assistance Fund. This study aimed to explore the effect of this budget increase on the health care services at PHC. The case study used a qualitative approach and interviews from 19 PHC health workers with the highest and lowest budget. Data were analyzed using thematic analysis and supported by quantitative data. The positive impact of the increasing PHC budget was felt by PHC staff due to the addition of operational equipment and incentives …

Utilization Of Styrofoam As Soundproofing Material With Auditory Frequency Range, Sjahrul Meizar Nasri, Iting Shofwati

Kesmas

The utilization of bricks made of styrofoam is expectedly able to be a soundproof for noise control and as a preventive action to reduce the steadily increasing prevalence of hearing loss. This study aimed to assess the use of sound absorption material in which styrofoam was utilized to reduce the noise exposure. In this study, fine aggregates (sand and styrofoam) were made with a mixture of cement with a composition of 1:4 and 1:6, also the addition of polystyrene waste with a percentage of 0%, 20%, 40%, 60%, and 80%. Determination of acoustical property of the mixture was done by …

Health Promotion Toward Knowledge And Intention For Early Detection Of Cervical Cancer In Commercial Sex Workers, Desi Rusmiati, Tiurlan Yunetty Silitonga, Warendi Warendi

Kesmas

Cervical cancer is one of the cancer types that become a haunting danger for many women in the world. In Indonesia, the prevalence rate reached 0.8% or an estimated 98,692 patients. Its prevalence increased to 10% in the commercial sex worker group. This study aimed to explain the effect of health promotion on knowledge and intention for early detection of cervical cancer using the inspection of visual acetate method in the commercial sex workers. This study was quantitative with a quasi-experimental type, one group of pretest and posttest design. The population sample included the commercial sex workers at Genteng Subvillage, …

Inpatient And Outpatient Infection As A Trigger Of Cardiovascular Disease: The Aric Study, Logan Cowan, Pamela L. Lutsey, James S. Pankow, Kunihiro Matsushita, Junichi Ishigami, Kamakshi Lakshminarayan

Biostatistics, Epidemiology & Environmental Health Sciences: Faculty Publications

Background

Acute infections are known cardiovascular disease (CVD) triggers, but little is known regarding how CVD risk varies following inpatient versus outpatient infections. We hypothesized that in‐ and outpatient infections are associated with CVD risk and that the association is stronger for inpatient infections.

Methods and Results

Coronary heart disease (CHD) and ischemic stroke cases were identified and adjudicated in the ARIC (Atherosclerosis Risk in Communities Study). Hospital discharge diagnosis codes and Medicare claims data were used to identify infections diagnosed in in‐ and outpatient settings. A case‐crossover design and conditional logistic regression were used to compare in‐ and outpatient …

Learning Statistics Through Guided Block Play: A Pre-Curriculum In Statistical Literacy, Robert P. Giebitz

Organization, Information and Learning Sciences ETDs

Learning to use data to investigate the world and make decisions has become an essential skill for all citizens. Play and curiosity are powerful motivators for learning. Inquiry – the process of asking questions and seeking answers – can engage the natural curiosity of young learners and motivate early learning. Recent research in statistics education has shown that children as young as 4 and 5 years old can learn to collect, organize, and interpret data they acquire through observation, counting, and measuring in a process of guided inquiry. Guided block play has been used for over 100 years to enable …

The Impact Of Sample Size In Cross-Classified Multiple Membership Multilevel Models, Hyewon Chung, Jiseon Kim, Ryoungsun Park, Hyeonjeong Jean

Journal of Modern Applied Statistical Methods

A simulation study was conducted to examine parameter recovery in a cross-classified multiple membership multilevel model. No substantial relative bias was identified for the fixed effect or level-one variance component estimates. However, the level-two cross-classification multiple membership factor variance components were substantially biased with relatively fewer groups.

Flowgraph Models For Clustered Multistate Time To Event Data, Kristin Hall

USF Tampa Graduate Theses and Dissertations

Healthcare systems have multistate processes. Such processes may be modeled using flowgraphs, which are directed graphs. Flowgraph models support a variety of transition time distributions, easily handle reversibility between states and allow alternate paths to the event or state of interest to be taken. However, estimation of flowgraph and first passage time distribution parameters can lead to incorrect inferences when interdependent data are treated as independent.

In this dissertation, we expand the flowgraph model to accommodate nested and correlated data structures. We develop a framework to incorporate random effects into transition probability and transition time components of a flowgraph model. …

An Introduction To Psychological Statistics, Garett C. Foster, David Lane, David Scott, Mikki Hebl, Rudy Guerra, Dan Osherson, Heidi Zimmer

Open Educational Resources Collection

This work has been superseded by Introduction to Statistics in the Psychological Sciences available from https://irl.umsl.edu/oer/25/.

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We are constantly bombarded by information, and finding a way to filter that information in an objective way is crucial to surviving this onslaught with your sanity intact. This is what statistics, and logic we use in it, enables us to do. Through the lens of statistics, we learn to find the signal hidden in the noise when it is there and to know when an apparent trend or pattern is really just randomness. The study of statistics involves math and relies …

The Compensation For Few Clusters In Clustered Randomized Trials With Binary Outcomes, Lily Stalter

Mathematics & Statistics ETDs

Cluster randomized trials are increasingly popular in epidemiological and medical research. When analyzing the data from such studies it is imperative that the hierarchical structure of the data be taken into account. Multilevel logistic regression is used to analyze clustered data with binary outcomes. Previous literature shows that a greater number of clusters is more important than a large number of subjects per cluster. This paper investigates if it is possible to compensate for the increased bias found for parameter estimates when the number of clusters is decreased. A simulation study was conducted where the absolute percent relative bias for …

Genome-Wide Analysis Of Alternative Rna Splicing In Children With Acute Myeloid Leukemia (Aml), Xichen Li

Shared Knowledge Conference

The pediatric Acute Myeloid Leukemia (AML) is a high-risk and hard-to-treat childhood cancer that originates in the bone marrow from immature white blood cells. Recently, more and more evidence indicates that aberrant splicing of genes is a common characteristic for AML. Gene expression profiles have proved extremely useful for identifying genes that are associated with clinical characteristics and survival outcome of cancer patients. However, conventional gene expression profiles do not account for the differences observed in expressed isoforms when alternative RNA splicing is analyzed. Alternative RNA splicing can generate dozens of distinct transcripts from individual genes and the expressions of …

Analysis Of Ranked Gene Tree Probability Distributions Under The Coalescent Process For Detecting Anomaly Zones, Anastasiia Kim

Shared Knowledge Conference

In phylogenetic studies, gene trees are used to reconstruct species tree. Under the multispecies coalescent model, gene trees topologies may differ from that of species trees. The incorrect gene tree topology (one that does not match the species tree) that is more probable than the correct one is termed anomalous gene tree (AGT). Species trees that can generate such AGTs are said to be in the anomaly zone (AZ). In this region, the method of choosing the most common gene tree as the estimate of the species tree will be inconsistent and will converge to an incorrect species tree when …