Physical Sciences and Mathematics Commons^™

Evaluating A Statistical-Based Assessment Tool For Stratifying Risk Among U.S. Air Force Organizations, Tiffany A. Low

Theses and Dissertations

The Air Force Inspection System is a proponent of utilizing a risk-based sampling strategy (RBSS) for conducting inspections from major command levels down to the unit level. The strategy identifies areas deemed most important or risky by commanders and prioritizes them accordingly for an independent assessment by the Inspector General. While Air Force regulation specifies the need to use a RBSS for inspection, the implementation process is delegated to individual commands and, subsequently, wings. The 23rd Wing, the sponsor for this research, directed us to analyze a RBSS tool highlighted as an example from which to adopt for those units …

Data-Driven Analysis Of Drug And Substance Abuse Rates Across The Varying Regions In The United States Of America, Reem Saleh

University Honors Theses

Drugs and substance abuse is one of the leading causes of death for adolescents in the United States. The consequences of using these drugs are profound and can cause both damage to one's physical and psychological health. The rates of drug abuse in the United States continue to increase over the years. This paper analyzes the trends in rates of drug abuse in the four regions in the United States. It looks at the rates in cocaine, cigarettes, marijuana, and tobacco. A preliminary analysis was done to look at the trend in rates followed by an ARIMA time series model …

Unrestricted Factor Analysis: A Powerful Alternative To Confirmatory Factor Analysis, Jan-Benedict E.M. Steenkamp, Alberto Maydeu-Olivares

Faculty Publications

The gold standard for modeling multiple indicator measurement data is confirmatory factor analysis (CFA), which has many statistical advantages over traditional exploratory factor analysis (EFA). In most CFA applications, items are assumed to be pure indicators of the construct they intend to measure. However, despite our best efforts, this is often not the case. Cross-loadings incorrectly set to zero can only be expressed through the correlations between the factors, leading to biased factor correlations and to biased structural (regression) parameter estimates. This article introduces a third approach, which has emerged in the psychometric literature, viz., unrestricted factor analysis (UFA). UFA …

Statistical Modeling Of Longitudinal Medical Cost Data, Shikun Wang

Dissertations & Theses (Open Access)

Projecting the future cancer care cost is critical in health economics research and policy making. An indispensable step is to estimate cost trajectories from an incident cohort of cancer patients using longitudinal medical cost data, accounting for terminal events such as death, and right censoring due to loss of follow-up. Since the cost of cancer care and survival are correlated, a scientifically meaningful quantity for inference in this context is the mean cost trajectory conditional on survival. Many standard approaches for longitudinal and survival analysis are not valid for the problem. The research for my Ph.D. dissertation consists of three …

Why, New York City? Gauging The Quality Of Life Through The Thoughts Of Tweeters, Sheryl Williams

Dissertations, Theses, and Capstone Projects

As a resource for social data, Twitter’s platform has been used to measure the quality of life through sentiment analysis. This capstone project explores another methodological technique—querying Twitter data around specific keyword terms to determine dominant topics, word patterns, and sentiment leanings in a geographical area. Focusing on New York City and Los Angeles for comparative analysis, the keyword term “why” will be used to build a Python analysis around topic modeling and sentiment analysis. Using this approach, the analysis reveals social and cultural differences, the overall sentiment of tweets, and subjects of interest to tweeters.

GitHub Repository for all …

Benign Prostatic Hyperplasia (Bph): A Comprehensive Analysis Of The Malaise And Summarizing Possible Management Options Through Phytotherapeutic Agents, Shan Sasidharan, Kumarapillai Parameswaran Srinivasakumar, Sandeep Poddar, Amiya Bhaumik, Sreemoy Kanti Das, Hareendran Nair J

Kesmas

Benign prostatic hyperplasia (BPH) is a severe illness affecting middle-aged and geriatric male patients. This disease normally occurs at the age of 40 or above and is also associated with sexual dysfunction. Alpha-blockers and 5α-reductase inhibitors are the preferred drugs practiced to treat BPH. However, invasive surgical therapy remains the gold standard for managing the condition in the case of refractory and intricate BPH conditions. Due to the fear of sexual dysfunction and the detrimental influence on their quality of life, most patients seek to avoid synthetic drugs and surgery. For this reason, several patients turn to phytotherapy and other …

Knowledge, Attitudes, And Covid-19 Prevention Practices Of Healthcare Workers In Indonesia: A Mobile-Based Cross-Sectional Survey, Besral Besral, Zulvi Wiyanti, Dion Zein Nurizin, Milla Herdayati, R Sutiawan, Martya Rahmaniati, Popy Yuniar

Kesmas

Knowledge of disease can affect attitudes and prevention practices, and wrong attitudes and practices can directly increase the risk of disease infection. This study aimed to describe the knowledge, attitudes, and COVID-19 prevention practice of healthcare workers in Indonesia and factors associated with prevention practices. A mobile-based cross-sectional survey was conducted in August 2020 with 254 healthcare workers in Indonesia. The self-administered questionnaire consisted of four parts: 1) sociodemographic information, 2) knowledge of COVID-19, 3) attitudes and anxiety toward COVID-19, and 4) COVID-19 prevention practices. The results indicated that healthcare workers in Indonesia had excellent knowledge and positive attitudes about …

Infarct Diameter For Predicting Cognitive Dysfunction In Ischemic Stroke Survivors In West Nusa Tenggara, Indonesia, Herpan Syafii Harahap, Setyawati Asih Putri, Yanna Indrayana, Hasan Amin, Fransisca Ika Mahardika

Kesmas

Cognitive dysfunction is an important consequence of ischemic stroke, which can progress in the first few years and is primarily determined by clinical factors. This study aimed to investigate the clinical determinants of cognitive dysfunction in stroke survivors in West Nusa Tenggara Province, Indonesia. This cross-sectional study assessed 255 ischemic stroke survivors with a mean age of 57.1±9.3 years old and 29–79 years old, recruited consecutively in three main hospitals in West Nusa Tenggara Province between March 2019 and October 2021. Categorical data collected included age, sex, education level, clinical determinants of ischemic stroke, and cognitive status of the patients. …

Determinants Of The Coexistence Dual Form Of Malnutrition In Pairs Of Mother And Child Aged 6 – 59 Months In Bogor District 2019, Maulina Dwi Krismanita, Triyanti Triyanti, Ahmad Syafiq, Trini Sudiarti

Kesmas

The dual form of malnutrition (DFM) is defined as multiple nutritional problems in the same household and time. This study aimed to determine the related factor to DFM incidence in pairs of mothers and children aged 6–59 months in Bogor District in 2019. This cross-sectional study used secondary data on the Nutrition and Health of Babakan Madang Subdistrict Toddlers in 2019 and Nutrition Intake and Stunting of Children Under-Five in Bogor District, West Java Province, involving a total sample of 274 households. The dependent variable in this study was DFM, while the independent variables were maternal age during pregnancy, maternal …

Interprofessional Collaborative Practice And Health Workers Retention At Remote Primary Health Care: Case Study From Nusantara Sehat Team-Based Program, Prastuti Soewondo, Retno Pujisubekti, Ade Widyati Prastyani, Nurul Maretia Rahmayanti

Kesmas

The Nusantara Sehat Team (NST), established in 2015 and consist of multi-professional health workers, implemented to provide comprehensive services at remote primary health cares (PHCs) for two years. This study aimed to explore how the NST leverages the Interprofessional Collaboration (IPC) and its impact on the future career prospects of health workers. Using a qualitative approach, the information was gathered from 48 informants drawn from the current 30 NST recruits and 18 alumni through semi-structured interviews. Of these 48, 20 were clinical practitioners, while the rest were non-clinical health workers. The findings revealed several challenges in promoting collaborative practice, including …

Zoom Fatigue During The Covid-19 Pandemic: Is It Real?, Putri Winda Lestari, Adhila Fayasari

Kesmas

The coronavirus disease 2019 (COVID-19) pandemic has caused drastic changes to social lives moreover the activities done outside, such as work and school. The policy of large-scale social restrictions (LSRR)/Pembatasan Sosial Berskala Besar (PSBB), which makes people stay at home, also plays an important role in changing the face-to-face activity online. As a solution to the major change, people use video conferencing to keep in touch and still feel like doing "offline" activities. The increasing use of video conferencing has raised concerns about the resulting fatigue, termed "Zoom fatigue." This study aimed to describe Zoom fatigue during the COVID-19 pandemic …

Diabetes Mellitus And Mortality Among Covid-19 Patients In Jakarta, March-August 2020, Endang Widuri Wulandari, Sudarto Rotnoatmodjo, Ngabila Salama

Kesmas

Diabetes mellitus (DM) comorbidity is one of the risk factors for coronavirus disease 2019 (COVID-19) mortality. This study aimed to determine the association of comorbid DM and mortality among COVID-19 confirmed cases in DKI Jakarta Province, controlled with confounding variables from March to August 2020. The study design was a retrospective cohort using cox proportional hazard regression, with a total sample of 1,480. The data consisted of 740 COVID-19 cases with and 740 without comorbid DM. The inclusion criteria were COVID-19 confirmed cases with polymerase chain reaction (PCR) laboratory testing reported to the DKI Jakarta Provincial Department of Health, and …

Treatment Adherence And Incidence Of Coronary Heart Disease In Type 2 Diabetes Mellitus Patients, Ahmad Sahlan Baniu, Rani Sauriasari, Woro Riyadina, Pradana Soewondo

Kesmas

Previous studies showed that uncontrolled blood sugar and long-term use of several types of antidiabetic could increase the risk of coronary heart disease (CHD). This study aimed to compare the incidence of CHD in type 2 diabetes mellitus (T2DM) patients showing treatment adherence and non-adherence behavior over four years. This was a retrospective cohort study with data sets obtained from the Bogor Cohort Study of Non-Communicable Disease Risk Factors. All study subjects were not diagnosed with CHD at the beginning of the study. The sample was divided into two groups; one had adhered to treatment from health centers and followed …

Muscle Dysmorphia In Fitness Center Members: Its Affecting Factors And Impacts, Deny Yudi Fitranti, Nurmasari Widyastuti, Etika Ratna Noer, Ayu Rahadiyanti, Fillah Fithra Dieny, Rachma Purwanti, Dewi Kurnia Sandi, Widya Destikasari

Kesmas

Muscle dysmorphia (MD) has several impacts on the decline in social and health functions. This study aimed to determine the correlation between MD with eating behaviors and exercise loading among fitness center members and analyze the factors affecting it. This study used a cross-sectional design with 100 subjects chosen by a consecutive sampling method at three fitness centers in Semarang City. The subjects were all male members of an active fitness center between 17 and 45 years. The data of MD were obtained using the Drive Muscular Scale (DMS), while eating behavior data were obtained using the Eating Attitude Test-40 …

The Influence Of Intrapersonal Constraints On Travel Intention Of People At High Risk From Covid-19 During The New Normal, Dyah Widiyastuti, Ikasari Kusuma Wardhani

Kesmas

Due to the COVID-19 pandemic, tourism constraints have created a challenge for inclusive tourism, especially for older people and people with comorbidities. This study examined intrapersonal constraints’ effect on the travel intentions of people facing fewer opportunities for tourism due to the COVID-19 pandemic, which could disrupt their well-being fulfillment. The data were collected through an online survey of Jakarta citizens aged 46 years and older from the end of June to September 2021, and a total of 337 responses were accumulated. This study applied partial least square structural equation modeling to test the moderating effect of intrapersonal constraints toward …

Local Wisdom Enriching Complementary Feeding Practices During Disaster Situations In Indonesia, Astuti Astuti, Happy Hayati, Fajar Tri Waluyanti, Dessie Wanda

Kesmas

This study aimed to analyze complementary food fulfillment during disaster situations in Indonesia since it frequently experiences natural disasters and young children face unique challenges related to their feeding needs in disaster situations. This qualitative case study based on the Mount Merapi eruption and Sumedang landslide in 2021 collected data using observations, forum group discussions, and in-depth interviews; then, a thematic analysis was conducted. This study involved 17 participants, including Non-governmental Organizations (NGO) activists, health workers, residents involved in making complementary foods, and primary caregivers of children aged 6–24 months. This study found that there were five themes generated from …

Characterization Of A Family Of Rotationally Symmetric Spherical Quadrangulations, Lowell Abrams, Daniel Slilaty

Mathematics and Statistics Faculty Publications

A spherical quadrangulation is an embedding of a graph G in the sphere in which each facial boundary walk has length four. Vertices that are not of degree four in G are called curvature vertices. In this paper we classify all spherical quadrangulations with n-fold rotational symmetry (n ≥ 3) that have minimum degree 3 and the least possible number of curvature vertices, and describe all such spherical quadrangulations in terms of nets of quadrilaterals. The description reveals that such rotationally symmetric quadrangulations necessarily also have a pole-exchanging symmetry.

A Strategy To Identify Event Specific Hospitalizations In Large Health Claims Databases, Joshua Lambert, Harpal Sandhu, Emily Kean, Teenu Xavier, Aviv Brokman, Zachary Steckler, Lee Park, Arnold Stromberg

Statistics Faculty Publications

Background: Health insurance claims data offer a unique opportunity to study disease distribution on a large scale. Challenges arise in the process of accurately analyzing these raw data. One important challenge to overcome is the accurate classification of study outcomes. For example, using claims data, there is no clear way of classifying hospitalizations due to a specific event. This is because of the inherent disjointedness and lack of context that typically come with raw claims data.

Methods: In this paper, we propose a framework for classifying hospitalizations due to a specific event. We then tested this framework in …

A Course In Data Science: R And Prediction Modeling, Adam Kapelner

Open Educational Resources

This is a self-contained course in data science and machine learning using R. It covers philosophy of modeling with data, prediction via linear models, machine learning including support vector machines and random forests, probability estimation and asymmetric costs using logistic regression and probit regression, underfitting vs. overfitting, model validation, handling missingness and much more. There is formal instruction of data manipulation using dplyr and data.table, visualization using ggplot2 and statistical computing.

The Probability Mass Function Of The Kaplan-Meier Product-Limit Estimator, Yuxin Qin, Heather Sasinowska, Lawrence Leemis

Arts & Sciences Articles

Kaplan andMeier’s 1958 article developed a nonparametric estimator of the survivor function from a right censored dataset. Determining the size of the support of the estimator as a function of the sample size provides a challenging exercise for students in an advanced course in mathematical statistics. We devise two algorithms for calculating the support size and calculate the associated probability mass function for small sample sizes and particular probability distributions for the failure and censoring times.

Food Insecurity And Suicidal Behaviors Among Us High School Students*, Andrea D. Brown, Hilary Seligman, Sarah Silwa, Ellen Barnidge, Kathryn L. Krupsky, Zewiditu Demissie, Angela D. Liese

Faculty Publications

BACKGROUND: Food insecurity (FI) rates in the United States are particularly high among households with children. This research set aims to analyze if high school students experiencing FI had higher risk for mental health and suicidal behaviors.

METHODS: Using combined data from 11 states that conducted the 2017 Youth Risk Behavior Survey, a total of 26,962 and24,051 high school students were used to estimate race/ethnicity and sex-stratified prevalence ratios (PRs) from Poissonregression models. A single-question was used to measure the exposure of FI and outcomes of mental health and suicidalbehaviors.

RESULTS: Overall, 10.8% of students reported FI. Students experiencing FI …

Transmission Dynamics Of Covid-19 In Ghana And The Impact Of Public Health Interventions, Sylvia Ofori, Jessica S. Schwind, Kelly L. Sullivan, Benjamin J. Cowling, Gerardo Chowell, Isaac Fung

Department of Biostatistics, Epidemiology, and Environmental Health Sciences Faculty Publications

This study characterized COVID-19 transmission in Ghana in 2020 and 2021 by estimating the time-varying reproduction number (Rt) and exploring its association with various public health interventions at the national and regional levels. Ghana experienced four pandemic waves, with epidemic peaks in July 2020 and January, August, and December 2021. The epidemic peak was the highest nationwide in December 2021 with Rt ≥ 2. Throughout 2020 and 2021, per-capita cumulative case count by region increased with population size. Mobility data suggested a negative correlation between Rt and staying home during the first 90 days of the pandemic. The …

Statistical Characteristics Of High-Frequency Gravity Waves Observed By An Airglow Imager At Andes Lidar Observatory, Alan Z. Liu, Bing Cao

Publications

The long-term statistical characteristics of high-frequency quasi-monochromatic gravity waves are presented using multi-year airglow images observed at Andes Lidar Observatory (ALO, 30.3° S, 70.7° W) in northern Chile. The distribution of primary gravity wave parameters including horizontal wavelength, vertical wavelength, intrinsic wave speed, and intrinsic wave period are obtained and are in the ranges of 20–30 km, 15–25 km, 50–100 m s−1, and 5–10 min, respectively. The duration of persistent gravity wave events captured by the imager approximately follows an exponential distribution with an average duration of 7–9 min. The waves tend to propagate against the local background winds and …

Formal And Informal Styles Of Clothing In The Assessment Of Female Political Candidates, Erma Kurtovic

Master's Theses

Abstract: This study will research the importance of dress code of female candidates on the confidence in leadership.The research question is: How Important is the Formality of Dress Code in the Assessment of Leadership of Female Political Candidates? It is addressed by using an experimental design carried out in India and the United States, using Qualtrics and Amazon Mechanical Turk. This research gathered 400 responses, 200 from each country. Primary data collection was used, with the implementation of two experiments. The experimental design of the two experiments consisted of two conditions, one in which the main political candidate is dressed …

Data Ethics: An Investigation Of Data, Algorithms, And Practice, Gabrialla S. Cockerell

Honors Projects

This paper encompasses an examination of defective data collection, algorithms, and practices that continue to be cycled through society under the illusion that all information is processed uniformly, and technological innovation consistently parallels societal betterment. However, vulnerable communities, typically the impoverished and racially discriminated, get ensnared in these harmful cycles due to their disadvantages. Their hindrances are reflected in their information due to the interconnectedness of data, such as race being highly correlated to wealth, education, and location. However, their information continues to be analyzed with the same measures as populations who are not significantly affected by racial bias. Not …

How Environmental Change Will Impact Mosquito-Borne Diseases, Arsal Khan

Master's Projects and Capstones

Mosquitos, the most lethal species throughout human history, are the most prevalent source of vector-borne diseases and therefore a major global health burden. Mosquito-borne disease incidence is expected to shift with environmental change. These changes can be predicted using species distribution models. With the wide variety of methods used for models, consensus for improving accuracy and comparability is needed. A comparative analysis of three recent modeling approaches revealed that integrating modeling techniques compensates for trade-offs associated with a singular approach. An area that represents a critical gap in our ability to predict mosquito behavior in response to changing climate factors, …

Model Averaging In Agriculture And Natural Resources: What Is It? When Is It Useful? When Is It A Distraction?, Philip M. Dixon

Conference on Applied Statistics in Agriculture and Natural Resources

I use two examples to illustrate three methods for model averaging: using AIC weights, using BIC weights, and fully Bayesian analyses. The first example is a capture-recapture study that estimates the population size by averaging over 4 models for capture probabilities. The second is an analysis of a study of logging impacts on Curculionid weevils using a before-after-control-impact (BACI) study design. The estimated impact is averaged over 4 ecologically relevant models.

Both examples demonstrate the sensitivity of model weights, or posterior model probabilities, to the choice of prior model probabilities and prior distributions for parameters. The model averaged estimates and …

A Novel Correction For The Adjusted Box-Pierce Test, Sidy Danioko, Jianwei Zheng, Kyle Anderson, Alexander Barrett, Cyril S. Rakovski

Mathematics, Physics, and Computer Science Faculty Articles and Research

The classical Box-Pierce and Ljung-Box tests for auto-correlation of residuals possess severe deviations from nominal type I error rates. Previous studies have attempted to address this issue by either revising existing tests or designing new techniques. The Adjusted Box-Pierce achieves the best results with respect to attaining type I error rates closer to nominal values. This research paper proposes a further correction to the adjusted Box-Pierce test that possesses near perfect type I error rates. The approach is based on an inflation of the rejection region for all sample sizes and lags calculated via a linear model applied to simulated …

Intervention Time Series Analysis Of Organ Donor Transplants In The Us, Supraja Malladi

Biology and Medicine Through Mathematics Conference

No abstract provided.

A Robust Clustering Method Using Compositional Data Restrictions: Studying Wood Properties In The Reforestation Of Portugal, Pamela M. Chiroque-Solano, Guido A. Moreira

Conference on Applied Statistics in Agriculture and Natural Resources

Classification of multivariate observations while preserving the data’s natural restriction is a challenge. Special properties such as identifiability, interpretability, and others need to be cared for to build a new approach. To avoid these complications, many transformation algorithms have been developed to use traditional models.In this context, the aim of this work is to propose a robust probabilistic distance algorithm to classify compositional data. Based on the probabilistic distance (PD) clustering approach, the proposal identifies clusters minimizing a joint distance function, JDF, which is part of a dissimilarity measure. This measure combines the PD clustering approach with the density of …