Statistics and Probability Commons^™

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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, …

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 …

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 …