Digital Commons Network^™

A New Algorithm For Robust Affine-Invariant Clustering, Andrews Tawiah Anum

Open Access Theses & Dissertations

Cluster analysis is an unsupervised machine learning technique commonly employed to partition a dataset into distinct categories referred to as clusters. The k-means algorithm is a prominent distance-based clustering method. Despite its overwhelming popularity, the algorithm is not invariant under non-singular linear transformations and is not robust, i.e., can be unduly influenced by outliers. To address these deficiencies, we propose an alternative clustering procedure based on minimizing a “trimmed” variant of the negative log-likelihood function. We develop a “concentration step”, vaguely reminiscent of the classical Lloyd’s algorithm, that can iteratively reduce the objective function. Multiple real and synthetic datasets are …

Confidence Interval For The Mean Of A Beta Distribution, Sean Rangel

Electronic Theses and Dissertations

Statistical inference for the mean of a beta distribution has become increasingly popular in various fields of academic research. In this study, we developed a novel statistical model from likelihood-based techniques to evaluate various confidence interval techniques for the mean of a beta distribution. Simulation studies will be implemented to compare the performance of the confidence intervals. In addition to the development and study involving confidence intervals, we will also apply the confidence intervals to real biological data that was gathered by the Department of Biology at Stephen F. Austin State University and provide recommendations on the best practice.

Gps-Denied Navigation Using Synthetic Aperture Radar Images And Neural Networks, Teresa White

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Unmanned aerial vehicles (UAV) often rely on GPS for navigation. GPS signals, however, are very low in power and easily jammed or otherwise disrupted. This paper presents a method for determining the navigation errors present at the beginning of a GPS-denied period utilizing data from a synthetic aperture radar (SAR) system. This is accomplished by comparing an online-generated SAR image with a reference image obtained a priori. The distortions relative to the reference image are learned and exploited with a convolutional neural network to recover the initial navigational errors, which can be used to recover the true flight trajectory throughout …

Estimating Treatment Effect On Medical Cost And Examining Medical Cost Trajectory Using Splines And Change Point Techniques., Indranil Ghosh

Electronic Theses and Dissertations

In the world of growing medical needs, other than the clinical outcomes, the cost of healthcare is one of the important aspects to evaluate. The cost of treatment could act as a decisive factor on which one to choose from two equally likely effective treatment options. In literature, the most used quantity for the cost of treatment is cumulative lifetime cost since the diagnosis of a disease. While it provides a bird' eye view of the treatment cost, it fails to capture the underlying pattern of the treatment cost trajectory. We developed a marginal structural functional model (MSFM) using an …

Risk-Based Machine Learning Approaches For Probabilistic Transient Stability, Umair Shahzad

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Power systems are getting more complex than ever and are consequently operating close to their limit of stability. Moreover, with the increasing demand of renewable wind generation, and the requirement to maintain a secure power system, the importance of transient stability cannot be overestimated. Considering its significance in power system security, it is important to propose a different approach for enhancing the transient stability, considering uncertainties. Current deterministic industry practices of transient stability assessment ignore the probabilistic nature of variables (fault type, fault location, fault clearing time, etc.). These approaches typically provide a conservative criterion and can result in expensive …

The Physiological Factors Of Diabetes And Their Effect On The Cognitive And Emotional Functioning In Older Populations: A Secondary Data Analysis, Celeste Anahi Alvidrez

Open Access Theses & Dissertations

Background: The rates of Type 2 Diabetes (T2D) have increased over the past 20 years in all age groups. The physiological factors that underlie T2D could have impact on specific brain pathways that support cognitive and emotional functioning. Aims and Objective: The goal of this study was to examine whether older Mexican American individuals with a history of T2D were more likely to develop later cognitive impairment and/or depression. Hypotheses: It was predicted that elderly participants (mean age at time of interview = 87.87 years) with a history of T2D onset prior to age 65, are more likely to have …

Factors Influencing Intent To Take A Covid-19 Test In The United States, Sheila Rutto

Theses and Dissertations

In 2020, COVID-19 became the first pandemic in the world’s history that brought the entire world to an abrupt and unexpected halt. Since the first reported case of the disease to date, the novel coronavirus has been able to wreak havoc in literary every corner of the globe and left an ever-growing number of unprecedented fatalities. The normal way of life has been disrupted, and the level of uncertainty about the end of this pandemic continues to manifest to many. Due to the urgency to bring this pandemic under control, medical officers have been able to recommend actions that people …

A Healthy Dietary Pattern With A Low Inflammatory Potential Reduces The Risk Of Gestational Diabetes Mellitus, Lotta Pajunen, Liisa Korkalo, Noora Houttu, Outi Pellonperä, Kati Mokkala, Nitin Shivappa Mbbs, Mph, Ph.D., James Hébert Scd, Tero Vahlberg, Kristina Tertti, Kirsi Laitinen

Faculty Publications

Purpose An optimal diet for lowering the risk of gestational diabetes mellitus (GDM) is still to be defined, but may comprise of nutrient intakes, dietary patterns, diet quality, and eating frequency. This study was designed to investigate the contribution of diet in developing GDM in a comprehensive way. Methods The dietary intake of overweight or obese women, a risk group for GDM (n = 351), was assessed using 3-day food diaries and diet quality questionnaires in early pregnancy. Eating frequency and nutrient intakes were calculated, and dietary patterns identified using principal component analysis. The inflammatory potential of the diet was …

Statistical Analysis Based On Adaptive Progressive Hybrid Censored Data From Lomax Distribution, Amal Helu, Hani Samawi

Biostatistics, Epidemiology & Environmental Health Sciences: Faculty Publications

In this article, we consider statistical inferences about the unknown parameters of the Lomax distribution basedon the Adaptive Type-II Progressive Hybrid censoring scheme, this scheme can save both the total test time and the cost induced by the failure of the units and increases the efficiency of statistical analysis. The estimation of the parameters is derived using the maximum likelihood (MLE) and the Bayesian procedures. The Bayesian estimators are obtained based on the symmetric and asymmetric loss functions. There are no explicit forms for the Bayesian estimators, therefore, we propose Lindley’s approximation method to compute the Bayesian estimators. A comparison …

Performance Of A Validated Spontaneous Preterm Delivery Predictor In South Asian And Sub-Saharan African Women: A Nested Case Control Study, Rasheda Khanam, Tracy C. Fleischer, Nansi Boghossian, Imran Nisar, Usha Dhingra, Sayedur Rahman, Angela C. Fox, Muhammad Iiyas, Arup Dutta, Nurun Naher, Ashoka D. Polpitiya, Usma Mehmood, Saikat Deb, Aziz Ahmed Choudhury, Md Bahadur Badsha, Karim Muhammad, Said Mohammed Ali, Salahuddin Ahmed, Durlin E. Hickok, Najeeha Iqbal, Et. Al.

Faculty Publications

Objectives

To address the disproportionate burden of preterm birth (PTB) in low- and middle-income countries, this study aimed to (1) verify the performance of the United States-validated spontaneous PTB (sPTB) predictor, comprised of the IBP4/SHBG protein ratio, in subjects from Bangladesh, Pakistan and Tanzania enrolled in the Alliance for Maternal and Newborn Health Improvement (AMANHI) biorepository study, and (2) discover biomarkers that improve performance of IBP4/SHBG in the AMANHI cohort.

Study design

The performance of the IBP4/SHBG biomarker was first evaluated in a nested case control validation study, then utilized in a follow-on discovery study performed on the same samples. …

The Covid-19 Pandemic: Role Of Coping Humor And Internal Health Locus Of Control On Social Dysfunction And Anxiety & Depression, Muhammad Arief Sumantri, Zahrani Zahrani, Hilda Rosa Ainiyah, Azmul Fuady Idham

Kesmas

The concerns about the impact of social distancing on mental health have been widely discussed. This study aimed to know the predictive effect of coping humor and Internal Health Locus of Control (Internal HLoC) on social dysfunction and anxiety & depression during the implementation of the COVID-19 social distancing agenda. This study was also intended to assess the effect of humor content on coping humor. A quantitative approach was used as the method ofthe study with 243 online-recruited participants, and a PLS-SEM analysis was applied to find out the predictive effect in this study. The results and conclusions showed that …

Are We Passing On Violence To The Next Generation?: Gender Norms And Gender-Based Violence Attitudes Among Early Adolescents In Indonesia, I Gusti A A. Mahendra, Anggriyani Wahyu Pinandari, Ifta Choiriyah, Siswanto Agus Wilopo

Kesmas

Intensification of gender norms during puberty affects adolescents’ perceptions and behavior related to violence. This study examined the association between gender norms and gender-based violence (GBV) among early adolescents considering socio-ecological variables using cross-sectional data from 3,618 Indonesian Global Early Adolescent Study pupils. Chi square tests with simple and multiple logistic regression analyses examined how different factors' levels predict GBV. Among boys, GBV attitudes were found high (53%). Furthermore, they also had high heteronormative expectations, threatened feelings, experiences of violence, porn access, and 5+ adverse childhood experiences (ACEs). Logistic regression results revealed that adolescent boys having one or two scores …

How Risky People Of Getting Covid-19 Based On Their Daily Activities?, Fajar Ariyanti, Mustakim Mustakim, Moch T A Al Ayubi, Desty Pratiwi Marlisman

Kesmas

In Indonesia at the end of 2020, COVID-19 cases were increasing and predicted to continue, as it had not yet passed the peak of the pandemic curve. The government had implemented mobility restrictions to reduce exposure to COVID-19. This study aimed to identify the risk of people getting COVID-19 based on their daily activities. Using a cross-sectional design, this study took 315 respondents under non-probability sampling from September to October 2020. Thedata were analyzed using the Chi-square test with α 0.05. This study showed that the risk percentage of people infected with COVID-19 based on their daily activities was 15.56% …

The Indonesian Strategy To Achieve Universal Health Coverage Through National Health Insurance System: Challenges In Human Resources, Atikah Adyas

Kesmas

Many countries are currently trying to achieve universal health insurance coverage in order to provide health protection for their population. Indonesia has received a strong political commitment to implement national health insurance including government support to finance the poor. The implementation of comprehensive national health insurance requires human resources, each of which has a role in fighting for noble goals for the welfare of all people. This paper is taken from the experience of Indonesia and several other countries as well as guidelines that can be used in exploring the role of human resources for the success of the implementation …

Mental Fatigue And Its Associated Factors Among Coal Mining Workers After One Year Of The Covid-19 Pandemic In Indonesia, Hendra Djamalus, Budi Utomo, I Made Djaja, Sjahrul M. Nasri

Kesmas

Mental fatigue among coal mining operators was related to driving activities that require high concentration. This study aimed to determine factors that contributed to mental fatigue among coal mine operators in Indonesia, specifically in Kalimantan and Sumatra, after a one-year COVID-19 pandemic. This cross-sectional study was conducted among 480 operators from two companies and seven sites. A self-administrated questionnaire in the Google Form was used to measure mental fatigue, the non-work-related factors (age, education, marital status, residence, and stress level), and work-related factors (working periods, shift pattern, type of shift, and work area in mining). The data analyzed using Chi-square …

Breastfeeding Knowledge And Behavior In Lactational Amenorrhea Method (Lam) As A Natural Contraceptive, Mufdlilah Mufdlilah, Reza Bintangdari Johan, Sri Ratna Ningsih

Kesmas

The lactational amenorrhea method (LAM) is a natural contraceptive that is highly effective after the three essential criteria are fulfilled. However, there is a significantly low adoption resulting from poor knowledge and correct practices. This study aimed to determine the correlation between knowledge and behavior of breastfeeding mothers on breastfeeding as a natural contraceptive. This was an analytic observational study with a cross-sectional design involving 89 breastfeeding mothers and was performed from January to March 2018. Furthermore, data were collected using a questionnaire, and the results showed knowledge of breastfeeding mothers to be good (59.6%) and not good (51.7%). However, …

Integrated Model Of A Family Approach And Local Support In Tuberculosis Case Finding Efforts In People With Hiv/Aids, Erni Astutik, Chatarina Umbul Wahyuni, Imelda F E Manurung, Geofrey Ssekalembe

Kesmas

The human immunodeficiency virus (HIV) remains a major global public health problem. People with HIV/acquired immune deficiency syndrome (AIDS) are more susceptible to opportunistic infections such as tuberculosis (TB). Therefore, families and community leaders need to help monitor people living with HIV/AIDS (PLWHA). This study aimed to analyze an integrated family approach and local support model to detect TB cases in PLWHA. This study used a case-control study in Kupang City, East Nusa Tenggara Province, in July 2020. The sample comprised 100 people (50 PLWHA with TB case and 50 controls) using total sampling and random sampling, respectively. The variables …

Predictors Of The Covid-19 Social Distancing Practice Among Undergraduate Health Students In Samarinda City, Indonesia: A Cross-Sectional Study, Siti Hadijah Aspan, Pramon Viwattanakulvanid

Kesmas

Social distancing is a health protocol recommended by the World Health Organization (WHO) for reducing the spread of COVID-19. Undergraduate health students play an important role in the dissemination of accurate information. This study identified predictors that influenced the COVID-19 social distancing practice and examined the sources of social distancing information among undergraduate health students in Samarinda City, Indonesia. This cross-sectionalonline survey study (March-April 2021) involved 422 undergraduate students from medicine, public health, and pharmacy faculties at Mulawarman University. Binary logistic regression was conducted to identify factors associated with the COVID-19 social distancing practice. The results showed that age (AOR …

Knowledge, Attitudes, And Practices Of Health Personnel In Responding To The Covid-19 Pandemic In Indonesia, Dyah Suryani, Suyitno Suyitno, Maretalinia Maretalinia, Elvi Juliansyah, Vernonia Yora Saki, Kraichat Tantrakarnapa

Kesmas

The COVID-19 pandemic, originated in China, has spread to worldwide, including Indonesia. Until July 2021, the growth rate has been gradually increasing, and cases have been found in all 34 provinces of Indonesia. This cross-sectional study aimed to investigate the knowledge, attitude, and practices (KAP) of health personnel in the primary health care towards the COVID-19 pandemic in Indonesia using online self-report questionnaire. A total of 440 respondents contributed to this online survey. The average level of KAP were 7.7 out of 10.0, 14.3 out of 15.0, and 31.9 out of 36.0, respectively. There was no significant association between respondents’ …

The Seroprevalence Of Toxoplasma Gondii In Cats At The House Of Maternal Women With Toxoplasmosis In Badung, Indonesia, Made Subrata, Nyoman Mantik Astawa, Nyoman Tigeh Suryadi, Sang Gede Purnama, Kadek Karang Agustina, Ngakan Putu Anom Harjana, Made Damriyasa

Kesmas

Toxoplasmosis is a zoonotic disease caused by infection with the parasite called Toxoplasma gondii (T. gondii). The health and social impacts of the infectionare enormous, including miscarriage, hydrocephalus, blindness, and mental retardation. The occurrence of toxoplasmosis in maternal women cannot be se parated from cats around their houses. This study aimed to determine the seroprevalence of the parasite in cats found in the human carriers residences and identify the risk factors of toxoplasmosis in maternal women in Badung District, Bali Province, Indonesia. A total of 80 cat serum samples were obtained from two residential groups, 40 from the housing where …

The Effectiveness And Safety Of Favipiravir In Covid-19 Hospitalized Patients At Tertiary Referral Hospital, Bali, Indonesia, Herni Damayanti, I Gede K Sajinadiyasa, Hindun Wilda Risni, Rani Sauriasari

Kesmas

COVID-19 is a major public health problem, with still questionable specific cure. Favipiravir is a COVID-19 antiviral that is potentially a therapy for COVID-19. This study aimed to analyze its effectivity and safety in moderate to critical hospitalized patients. This study was a retrospective cohort in a tertiary referral hospital in Denpasar City, Bali Province, Indonesia, from August 2020 to January 2021. There was a total of 192 patients; 96 in the favipiravir group and 96in the non-favipiravir group (remdesivir/oseltamivir). Effectivity was measured by assessing the clinical condition at the end of the isolation period of 14 days. The favipiravir …

Aggregating Twitter Text Through Generalized Linear Regression Models For Tweet Popularity Prediction And Automatic Topic Classification, Chen Mo, Jingjing Yin, Isaac Chun-Hai Fung, Zion Tse

Biostatistics, Epidemiology & Environmental Health Sciences: Faculty Publications

Social media platforms have become accessible resources for health data analysis. However, the advanced computational techniques involved in big data text mining and analysis are challenging for public health data analysts to apply. This study proposes and explores the feasibility of a novel yet straightforward method by regressing the outcome of interest on the aggregated influence scores for association and/or classification analyses based on generalized linear models. The method reduces the document term matrix by transforming text data into a continuous summary score, thereby reducing the data dimension substantially and easing the data sparsity issue of the term matrix. To …

Characterizing Long Covid: Deep Phenotype Of A Complex Condition, Rachel R. Deer, Madeline A. Rock, Nicole Vasilevsky, Leigh Carmody, Halie Rando, Alfred J. Anzalone, Marc D. Basson, Tellen D. Bennett, Timothy Bergquist, Eilis A. Boudreau, Carolyn T. Bramante, James Brian Byrd, Tiffany J. Callahan, Lauren E. Chan, Haitao Chu, Christopher G. Chute, Ben D. Coleman, Hannah E. Davis, Joel Gagnier, Casey S. Greene, Ramakanth Kavuluru

Institute for Biomedical Informatics Faculty Publications

BACKGROUND: Numerous publications describe the clinical manifestations of post-acute sequelae of SARS-CoV-2 (PASC or "long COVID"), but they are difficult to integrate because of heterogeneous methods and the lack of a standard for denoting the many phenotypic manifestations. Patient-led studies are of particular importance for understanding the natural history of COVID-19, but integration is hampered because they often use different terms to describe the same symptom or condition. This significant disparity in patient versus clinical characterization motivated the proposed ontological approach to specifying manifestations, which will improve capture and integration of future long COVID studies.

METHODS: The Human Phenotype Ontology …

Causal Effects On Low Apgar At 5-Min And Stillbirth In A Malaria Maternal–Fetal Health Outcome Investigation: A Large Perinatal Surveillance Study In The Brazilian Amazon, Julio Abel Seijas-Chávez, Melissa Nolan Ph.D., Mph, Mary K. Lynn, Maria José Francalino Da Rocha, Muana Da Costa Araújo, Fernando Luiz Affonso Fonseca, Gabriel Zorello Laporta

Faculty Publications

Background

Malaria elimination in Brazil poses several challenges, including the control of Plasmodium falciparum foci and the hidden burden of Plasmodium vivax in pregnancy. Maternal malaria and fetal health outcomes were investigated with a perinatal surveillance study in the municipality of Cruzeiro do Sul, Acre state, Brazilian Amazon. The research questions are: what are the causal effects of low birth weight on low Apgar at 5-min and of perinatal anaemia on stillbirth?

Methods

From November 2018 to October 2019, pregnant women of ≥ 22 weeks or puerperal mothers, who delivered at the referral maternity hospital (Juruá Women and Children’s Hospital), …

The Dietary Inflammatory Index Is Not Associated With Gut Permeability Or Biomarkers Of Systemic Inflammation In Hiv Immunologic Non-Responders, Fat Malazogu, Rodney K. Rousseau, Nitin Shivappa Mbbs, Mph, Ph.D., Sanja Huibner, Sharon L. Walmsley, Colin M. Kovacs, Erika Benko, Robert J. Reinhard, Ron Rosenes, James R. Hébert, Rupert Kaul

Faculty Publications

Immunologic non-responders (INRs) are a subset of individuals living with HIV who have suboptimal blood CD4+ T cell recovery despite effective antiretroviral therapy (ART). They are at an increased risk of serious non-AIDS co-morbidities and death, and demonstrate enhanced systemic immune activation. In other populations diet has been correlated with markers of systemic inflammation through the Diet Inflammatory Index (DII), but this association has not been studied in persons living with HIV (PLWH). Blood was collected from 28 INR PLWH with a blood CD4+ T cell count <350/μL despite ≥2 years of effective ART. Participants completed a Canadian Diet History Questionnaire, and their responses were used to calculate the DII. Plasma inflammatory markers (IFNγ, TNF, IL-6, sVCAM, D-dimer, sCD14 and CRP) were assayed by ELISA, cellular immune activation (HLA-DR and CD38 on CD4+ and CD8+ T cells) was quantified using flow cytometry, and small bowel permeability assessed by calculation of the urine LacMan ratio after drinking a mix of lactulose and mannitol. Participants were a median age of 57 years, had been on effective ART for 15 years, and the median DII was −1.91 (range of −3.78 to +2.23). No correlation was observed between DII and plasma markers of inflammation, levels of T cell activation, gut permeability, or the biomarker of bacterial translocation sCD14. Self-reported alcohol intake, a potential confounder of the relationship between diet and inflammatory biomarkers, was also not associated with systemic inflammation or gut permeability. Our findings suggest that other mechanisms, rather than diet, are likely to be the major driver of systemic inflammation in INR individuals.

Association Between Diet Quality Indices And Incidence Of Type 2 Diabetes In The Melbourne Collaborative Cohort Study, Allison M. Hodge, Md Nazmul Karim, James Hébert Scd, Nitin Shivappa Mbbs, Mph, Ph.D., Barbora De Courten

Faculty Publications

Type 2 diabetes mellitus is a common condition whose incidence is increasing worldwide, and for which obesity and diet are important risk factors. The aim of this study was to assess the association of three diet quality scores with diabetes risk and how much of the association was mediated through body size. The Melbourne Collaborative Cohort Study recruited 41,513 men and women aged 40–69 years during 1990–1994. At baseline, data were collected on lifestyle and diet, anthropometric measures were performed. Incident diabetes was assessed by self-report at follow-up surveys in 1994–1998 and 2003–2007. The associations between the dietary inflammatory index …

Classifying Mosquito Presence And Genera Using Median And Interquartile Values From 26-Filter Wingbeat Acoustic Properties, Hernan S. Alar, Proceso L. Fernandez Jr

Department of Information Systems & Computer Science Faculty Publications

Mosquitoes are known to be one of the deadliest creatures in the world. There have been several studies that aim to identify mosquito presence and species using various techniques. The most common ones involve automatic identification of mosquito species from the sounds produced by flapping its wings. The development of these important concepts and technologies can help reduce the spread of mosquito-borne diseases. This paper presents a simple model based on mean and interquartile values that aim to solve the mosquito classification. Despite its simplicity, the proposed model significantly outperforms a Convolutional Neural Network (CNN) model in identifying the mosquito …

Uncertainty Quantification In Deep And Statistical Learning With Applications In Bio-Medical Image Analysis, K. Ruwani M. Fernando

USF Tampa Graduate Theses and Dissertations

Deep Learning (DL) has achieved the state-of-the-art performance across a broad spectrum oftasks. From a statistical standpoint, deep neural networks can be construed as universal function approximators. Although statistical modeling and deep learning methods are well-established as independent areas of research, hybridization of the two paradigms via probabilistic deep networks is an emerging trend. Through development of novel analytical methods under the statistical and deep-learning framework, we address some of the major challenges encountered in the design of intelligent systems which include class imbalance learning, probability calibration, uncertainty quantification and high dimensionality. When modeling rare events, existing methodologies require re-sampling …

Applications And Power Analyzation Of New Multiple Testing Procedures Based On Covering Principle, Yu Zhang

Student Theses and Dissertations

Multiple comparison tests are quite prevalent in clinical trials to increase efficiency and the chance of finding treatment or drug effects. However, making multiple comparisons will lead to the potential inflation of the Type I error rate. How well one test procedure controls the rate of false-positive conclusions becomes the main concern nowadays. A novel method named Covering Principle has been proposed recently. It provides a new approach to designing multiple testing procedures from the angle of rejection regions in the sample space, rather than in the parameter space, which uses in the methods based on the closed testing and …

A 6-Cpg Validated Methylation Risk Score Model For Metabolic Syndrome: The Hypergen And Goldn Studies, Bertha A. Hidalgo, Bre Minniefield, Amit Patki, Rikki Tanner, Minoo Bagheri, Hemant K. Tiwari, Donna K. Arnett, Marguerite Ryan Irvin

Epidemiology and Environmental Health Faculty Publications

There has been great interest in genetic risk prediction using risk scores in recent years, however, the utility of scores developed in European populations and later applied to non-European populations has not been successful. The goal of this study was to create a methylation risk score (MRS) for metabolic syndrome (MetS), demonstrating the utility of MRS across race groups using cross-sectional data from the Hypertension Genetic Epidemiology Network (HyperGEN, N = 614 African Americans (AA)) and the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN, N = 995 European Americans (EA)). To demonstrate this, we first selected cytosine-guanine dinucleotides …