Digital Commons Network^™

End-To-End Hierarchical Reinforcement Learning With Integrated Subgoal Discovery, Shubham Pateria, Budhitama Subagdja, Ah-Hwee Tan, Chai Quek

Research Collection School Of Computing and Information Systems

Hierarchical reinforcement learning (HRL) is a promising approach to perform long-horizon goal-reaching tasks by decomposing the goals into subgoals. In a holistic HRL paradigm, an agent must autonomously discover such subgoals and also learn a hierarchy of policies that uses them to reach the goals. Recently introduced end-to-end HRL methods accomplish this by using the higher-level policy in the hierarchy to directly search the useful subgoals in a continuous subgoal space. However, learning such a policy may be challenging when the subgoal space is large. We propose integrated discovery of salient subgoals (LIDOSS), an end-to-end HRL method with an integrated …

Segment-Wise Time-Varying Dynamic Bayesian Network With Graph Regularization, Xing Yang, Chen Zhang, Baihua Zheng

Research Collection School Of Computing and Information Systems

Time-varying dynamic Bayesian network (TVDBN) is essential for describing time-evolving directed conditional dependence structures in complex multivariate systems. In this article, we construct a TVDBN model, together with a score-based method for its structure learning. The model adopts a vector autoregressive (VAR) model to describe inter-slice and intra-slice relations between variables. By allowing VAR parameters to change segment-wisely over time, the time-varying dynamics of the network structure can be described. Furthermore, considering some external information can provide additional similarity information of variables. Graph Laplacian is further imposed to regularize similar nodes to have similar network structures. The regularized maximum a …

Pickup And Multi-Delivery Problem With Time Windows, Pham Tuan Anh, Aldy Gunawan, Vincent F. Yu, Tuan C. Chau

Research Collection School Of Computing and Information Systems

This paper addresses a new variant of Pickup and Delivery Problem with Time Windows (PDPTW) for enhancing customer satisfaction. In particular, a huge number of requests is served in the system, where each request includes a pickup node and several delivery nodes instead of a pair of pickup and delivery nodes. It is named Pickup and Multi-Delivery Problem with Time Windows (PMDPTW). A mixed-integer programming model is formulated with the objective of minimizing total travel costs. Computational experiments are conducted to test the correctness of the model with a newly generated benchmark based on the PDPTW benchmark instances. Results show …

Quote: Quality-Oriented Testing For Deep Learning Systems, Jialuo Chen, Jingyi Wang, Xingjun Ma, Youcheng Sun, Jun Sun, Peixin Zhang, Peng Cheng

Research Collection School Of Computing and Information Systems

Recently, there has been a significant growth of interest in applying software engineering techniques for the quality assurance of deep learning (DL) systems. One popular direction is deep learning testing, i.e., given a property of test, defects of DL systems are found either by fuzzing or guided search with the help of certain testing metrics. However, recent studies have revealed that the neuron coverage metrics, commonly used by most existing DL testing approaches, are not necessarily correlated with model quality (e.g., robustness, the most studied model property), and are also not an effective measurement on the confidence of the model …

Can Obsessive Thoughts Predict Problematic Alcohol Use Through Thought Suppression?, Laura Pettigrew

Psychology Theses & Dissertations

Alcohol misuse, which is a prevalent issue among college students, often coincides with psychiatric disorders or symptoms. Treatment of one facilitates treatment of the other. Some anecdotal evidence suggests that obsessive-compulsive disorder (OCD), or just obsessive-compulsive symptoms, is connected to alcohol misuse.

This study adapts part of the cognitive control model of OCD, which states that intrusive thoughts will only lead to distress if the individual interprets them in a dysfunctional manner and tries to control them. When the thought control attempt fails, if the individual interprets the failure in a dysfunctional way as well, they will become distressed. If …

Trauma And Crisis Counselor Preparation: The Relationship Of An Online Trauma And Crisis Course And Counseling Self-Efficacy, Julia Leigh Lancaster

Counseling & Human Services Theses & Dissertations

The field of trauma and crisis is growing and ubiquitous to all counseling specialties. Updates in 2009 and 2016 to the Council for Accreditation of Counseling and Related Educational Programs (CACREP) counselor preparation standards added mandated teachings on crisis, trauma, and disaster counseling in counselor preparation programs’ (CPPs) curricula. Since then, some CPPs have created stand-alone crisis courses, while the majority have infused various related content and trainings into already established counseling courses. Research does, in fact, support an increased crisis, trauma, and disaster readiness with more hours dedicated to the study and practice of domain specific content, and confirms …

An Exploration Of Different Motivations Between Stakeholders And Visitors Of The Potomac Heritage National Scenic Trail, Colin Mccormack

Human Movement Studies & Special Education Theses & Dissertations

Visitors have different motivations associated with parks and protected areas, and the people who run those areas are also different from visitors due to their unique positions. This is especially true for the Potomac Heritage National Scenic Trail (POHE), where stakeholders – ranging from park managers and Department of Transportation planners to volunteers of nonprofits and historical societies collaborate to manage sections along the 822-mile extent of the trail. Building on previous work itemizing the diversity of motivations for visitation to parks and protected areas, this study investigates similarities and differences in stakeholder and manager Recreation Experience Preferences by clustering …

Advanced Generalized Predictive Control And Its Application To Tiltrotor Aircraft For Stability Augmentation And Vibration Reduction, Thomas Glen Ivanco

Mechanical & Aerospace Engineering Theses & Dissertations

The goals of this research were to restore generalized predictive control (GPC) capability at NASA and within the community, to better understand GPC and its performance relative to other options, and to improve upon the capability of GPC. Unique to this research is the comparison of GPC with other control options including PID controllers, optimal control theory, and other versions of the similar AutoRegressive moving average model with eXogenous inputs (ARX) models. Similar to GPC, ARX models use an experimentally acquired system identification to characterize the input/output relationship between controls and response measurements. Because this relationship is determined from acquired …

Development And Validation Of A Three-Dimensional Optical Imaging System For Chest Wall Deformity Measurement, Nahom Kidane

Electrical & Computer Engineering Theses & Dissertations

Congenital chest wall deformities (CWD) are malformations of the thoracic cage that become more pronounced during early adolescence. Pectus excavatum (PE) is the most common CWD, characterized by an inward depression of the sternum and adjacent costal cartilage. A cross-sectional computed tomography (CT) image is mainly used to calculate the chest thoracic indices. Physicians use the indices to quantify PE deformity, prescribe surgical or non-surgical therapies, and evaluate treatment outcomes. However, the use of CT is increasingly causing physicians to be concerned about the radiation doses administered to young patients. Furthermore, radiographic indices are an unsafe and expensive method of …

Machine Learning-Based Event Generator, Yasir Alanazi

Computer Science Theses & Dissertations

Monte Carlo-based event generators have been the primary source for simulating particle collision experiments for the study of interesting physics scenarios. Monte Carlo generators rely on theoretical assumptions, which limit their ability to capture the full range of possible correlations between particle’s momenta. In addition, the simulations of the complete pipeline often take minutes to generate a single event even with the help of supercomputers.

In recent years, much attention has been devoted to the development of machine learning event generators. They demonstrate attractive advantages, including fast simulations, data compression, and being agnostic of theoretical assumptions. However, most of the …

Investigation Of Gaas Double Heterostructures For Photonic Heat Engines, Nathan Giannini-Hutchin

Optical Science and Engineering ETDs

The creation of a laser cooled semiconductor device has been a long sought achievement. GaAs-based devices have emerged as a promising candidate for the realization of this goal. Efforts to improve the efficiency of such devices have enabled the material to exhibit external quantum efficiencies (EQE, a measure of the probability that an excitation leads to the emission of a photon) of 99.5\%. Despite this impressive feat, a laser coolable device remains elusive.

To investigate the obstacles to such a device, the material characteristics of GaAs-based double heterostructures (DHS) are theoretically and experimentally examined. Through this study, a GaAs $\vert$ …

Agent-Based Modeling Predicts Rac1 Is Critical For Ovarian Cancer Metastasis, Melanie Rivera, Leslie Toledo-Jacobo, Elsa Romero, Tudor I. Oprea, Melanie E. Moses, Laurie G. Hudson, Angela Wandinger-Ness, Martha M. Grimes

Pathology Research and Scholarship

Experimental and computational studies pinpoint rate-limiting step(s) in metastasis governed by Rac1. Using ovarian cancer cell and animal models, Rac1 expression was manipulated, and quantitative measurements of cell-cell and cell-substrate adhesion, cell invasion, mesothelial clearance, and peritoneal tumor growth discriminated the tumor behaviors most highly influenced by Rac1. The experimental data were used to parameterize an agent-based computational model simulating peritoneal niche colonization, intravasation, and hematogenous metastasis to distant organs. Increased ovarian cancer cell survival afforded by the more rapid adhesion and intravasation upon Rac1 overexpression is predicted to increase the numbers of and the rates at which tumor cells …

Visionary Women Or Suspected Witches: The Shifting Use And Construction Of Reputation In Accusations Of Witchcraft During The High And Late Middle Ages, Megan E. Hattey

History ETDs

Throughout the high and late Middle Ages, an individual’s social acceptance and well-being were heavily dependent upon fama, or reputation, they cultivated within their communities. Women, especially, constructed and molded their reputations to protect themselves from hardship and social ostracization, allowing them a degree of agency in social situations. In this thesis, I argue that the mindful development of one’s fama was key for women to protect themselves from accusations of witchcraft. Through the lives of Hildegard of Bingen, Elisabeth of Schönau, and Jeanne d’Arc, I demonstrate how medieval reputations were built, the trifold nature it could hold, and …

A Suggested Data Structure For Transparent And Repeatable Reporting Of Bibliographic Searching, Neal R. Haddaway, Melissa L. Rethlefsen, Melinda Davies, Julie Glanville, Bethany Mcgowan, Kate Nyhan, Sarah Young

Publications

Academic searching is integral to research activities: (1) searching to retrieve specific information, (2) to expand our knowledge iteratively, (3) and to collate a representative and unbiased selection of the literature. Rigorous searching methods are vital for reliable, repeatable and unbiased searches needed for these second and third forms of searches (exploratory and systematic searching, respectively) that form a core part of evidence syntheses. Despite the broad awareness of the importance of transparency in reporting search activities in evidence syntheses, the importance of searching has been highlighted only recently and has been the explicit focus of reporting guidance (PRISMA-S). Ensuring …

Smartphone Usage Before And During Covid-19: A Comparative Study Based On Objective Recording Of Usage Data, Khansa Chemnad, Sameha Alshakhsi, Mohamed Basel Almourad, Majid Altuwairiqi, Keith Phalp, Raian Ali

All Works

Most studies that claimed changes in smartphone usage during COVID-19 were based on self-reported usage data, e.g., that collected through a questionnaire. These studies were also limited to reporting the overall smartphone usage, with no detailed investigation of distinct types of apps. The current study investigated smartphone usage before and during COVID-19. Our study used a dataset from a smartphone app that objectively logged users’ activities, including apps accessed and each app session start and end time. These were collected during two periods: pre-COVID-19 (161 individuals with 77 females) and during COVID-19 (251 individuals with 159 females). We report on …

Serious Leisure, Job Task Load, & Satisfaction, Carson Matsick

All Theses

The study examined the relationship between degree of leisure seriousness and leisure, job, and life satisfaction, as moderated by perceived job mental workload. Serious leisure has largely been studied in reference to general life satisfaction and health outcomes, and less research exists to examine whether serious leisure participation may influence work. This study tested the following hypothesis: the relationship between serious leisure participation and employee well-being is moderated by mental workload on the job, such that a) as mental workload increases, then serious leisure participation and satisfaction will be less strongly positively correlated, and b) as mental workload decreases, then …

Flexural Bond Strength Of Masonry Assemblies With Lightweight Grout, Benjamin L. Hiner

All Theses

Lightweight grout has many potential benefits in masonry construction, including minimizing mass, improving thermal performance, and potentially reducing shrinkage cracking via internal curing. However, insufficient testing of masonry assemblies with lightweight grout has been conducted to suggest appropriate design modification factors akin to the lambda factor in ACI 318-19. The objective of this paper is to study the tensile bond behavior of masonry assemblies grouted with lightweight grout and to suggest appropriate equations for predicting design capacity. A moment couple test is designed specifically for grouted masonry assemblies and has additional capacity compared to the traditional ASTM 1072 bond wrench …

The Effects Of Tubulin Post-Translational Modifications On The Flagellar Motility Of Trypanosoma Brucei, Katherine Wentworth

All Theses

Trypanosoma brucei is a parasitic kinetoplastid that causes African trypanosomiasis and is transmitted to a mammalian host by the tsetse fly (Glossina spp.). T. brucei relies on its flagellar motility to carry out its morphological changes from the procyclic form (predominant in the fly vector) to the bloodstream form (infectious form in mammals) and navigate the bloodstream of its host. The driving structure within the flagellum is the axoneme, which is composed of microtubules and dynein motor proteins. The tubulin code hypothesis suggests that cells regulate microtubule motor protein activity through post-translational modifications (PTMs) of alpha and beta …

Investigation Of Geopolymer Based Soil Stabilization Methods For Expedient Airfield Pavement Surfaces, Brett Albertson

All Theses

The United States Air Force (USAF) has the unique capability of being able to interdict superior airpower anywhere, at any time. However, superior airpower is only as effective as the amount of time an aircraft can spend in a particular area. The closer an aircraft can get to the mission need, the more time that can be spent in the air, or the less time that must be spent moving in and out of the operational area. Through the use of skilled and experienced men and women, the USAF is able to apply expedient and unsurfaced airfield paving techniques that …

An Economic Impact And Investment Analysis Of Armillaria Root Rot In The United States Peach Industry, Gracie Herrin

All Theses

Peach production in the United States has decreased over the last decade due to increased disease prevalence. Armillaria root rot (ARR) is a lethal root fungus that affects many stone fruits, including peaches, often leading to rapid decline/death of trees and abandonment of orchards. This thesis is divided into four chapters which focus on answering four key questions that, to the best of my knowledge, have not been addressed in previous industry research.

The second chapter determines the magnitude of ARR disease prevalence in the United States and producers’ maximum willingness to pay (WTP) for a theoretical ARR-resistant rootstock. Results …

The Language Of Recruitment: How Minority Status, Racial Minority Centrality, & Linguistic Cues Impact Applicant Perceptions, Clark Waters

Theses and Dissertations

As color-blindness, the intentional denial of racial differences, continues to occupy corporate policy, expressions and consequences of modern racism in the workplace remain pervasive. Color-blind attitudes can be harmful due to their focus on perceived equality, at the expense of actionable, functional equity. Establishing a culture of racial equity in the workplace requires an understanding of how the language used to discuss race can impact potential applicants’ opinions of the company. To attract a diverse pool of job applicants, the language of recruitment is of particular importance in the current study. Using a vignette-style survey design, a diverse sample of …

"The Lady Took Me To The End Of The World!": The Life Of Mrs. N.A. Courtright., Marcus Walker

Faculty and Staff Scholarship

Nellie Almee Courtright was the first female to earn a law degree from the University of Louisville School of Law, but she had an accomplished career before -- and even after -- she stepped foot into a law classroom. This is the account of a woman who made her own way in the world, and made life better for hundreds in doing so.

Brief And Extended Effects Of Modified Competing Stimulus Assessments, Soray Nicole Castro

Theses and Dissertations

Competing stimulus assessments (CSA) are pre-assessment tools that systematically identify stimuli associated with reduced problem behavior. The current study aims to evaluate the effectiveness of an augmented CSA containing components of prompted engagement and response blocking. Results indicated the augmented CSA effectively identified two additional competing items for two of the three participants following prompted engagement. We also evaluated the extended effects of the competing stimuli on item engagement and stereotypy for two participants. Stereotypy reductive effects are maintained for one of the four competing stimuli for Participant 2 and two of the six items for Participant 3.

Employment Transitions From Active-Duty Army Officer To Civilian: An Exploration Of The Knowledge, Skills, And Abilities Possessed By Combat-Experienced, Army Field-Grade Officers, James Daniel Crook

Theses and Dissertations

Two decades of wars in Iraq and Afghanistan have concluded, bringing an end to the longest military conflicts in the history of the United States of America. Following the example of post-war history, the military’s posture is to reduce personnel end-strength. The post-war military requires fewer soldiers, and a significant number of transitioning officers make the journey from military to civilian employment. This quantitative study discovered the knowledge, skills, and abilities of combat-experienced, active-duty, Army field-grade officers and explored the change from military to civilian employment. This study addressed the gap in the literature regarding this specific group of transitioning …

Piper Pa-28-181 Archer Iii Tail #931ec Flight Test Stability, Control And Performance, Steven Allan Sutton

Theses and Dissertations

The following flight test was conducted as part of the culmination requirement for the Master of Science, Flight Test Engineer degree program from Florida Institute of Technology. The flight was conducted to gather data and produce a flight test report on the data gathered. The flight test plan consisted of a series of both Stability and Handling test point as well as basic aircraft performance points. The testing was planned to be accomplished over a single flight, for reasons discussed later in this report. The flight departed on the morning of 26 September, 2022 out of Bob Sikes Airport, KCEW, …

Design Of Ethical Autonomous Agents For Unmanned Aerial Vehicles Using Fuzzy Logic, Gavin Giovanni Smith

Theses and Dissertations

Autonomous systems have, over the years become part of our everyday lives. These systems have been deployed to executed a diverse range of applications in different industries; finance, healthcare, military, and in particular, the flight industry. With the rise of UAVs, new opportunities arose, but with those opportunities came new pitfalls within any industry. For UAVs, one of the pitfalls came in the form of ethical decisionmaking, which led to a variety of questions. Can the Autonomous systems within UAVs be designed with ethics in mind? Which ethical guidelines would we use to implement such a system? How would we …

How Well Do Your Family Members Know You? The Relationship Between Informant Report And Cognitive Performance Of Older Adults, Mairy Yousif

Theses and Dissertations

Introduction: Given the clear impact and prevalence of dementia on the aging population, there is a need for greater research and understanding in this area. As the dementia progresses, medical providers rely heavily on caregiver and family member reports of the patient’s functioning and other aspects of their care. Therefore, it is important to know how accurate caregivers and family members are in judging their loved ones’ cognitive and physical strengths and weaknesses. This study aims to expand upon these previous studies by comparing caregiver/collateral reports of cognitive and functional status on the DSRS to neuropsychological tests and an objective …

Design And Optimization Of High-Power Density Permanent Magnet Motor With Integrated Cooling For Aircraft Propulsion, Aravindakshan Thirumalai Ananthanpillai

Theses and Dissertations

There is a critical need for the electrification of transportation systems. While power density required for ground-based vehicles can, to some extent, be met by current off-the-shelf motors and generators, aircrafts require significant improvements both in terms of power density and efficiency. The concept relies on the tight integration of a high-power density dual-rotor permanent magnet motor, high power density SiC power converters, and a shared closed loop cooling system rejecting the heat in the propulsion ducted fan air stream. The motor is based on a dual-rotor configuration using permanent magnets forming ideal Halbach arrays allowing for high magnetic loading …

Developmental Evaluation Of The B-1b Aircraft, Jonathon Malycke

Theses and Dissertations

The purpose of this test was to perform a Developmental Phase IIA evaluation of the B-1B Lancer for the land-based, long-range, all-weather ground attack mission. One two-hour ground evaluation, one simulator and one flight totaling 7.5 hours was conducted under daylight, visual meteorological conditions from Dyess Air Force Base (AFB) in Abilene, Texas (337th Test and Evaluation Squadron). All test objectives were completed except the low altitude flight evaluation, landing pattern operations, and AFCS operations due to weather, maintenance and time constraints. The test aircraft was representative of a production B-1B aircraft and included a Sniper Targeting Pod and a …

The Relationship Between Hallucinations And Visuospatial Impairment Among Individuals With Dementia, Ruta Sohoni

Theses and Dissertations

Objective: This study examines the neuropsychological functioning, specifically using the Hooper Visual Organization Test (VOT), to understand the impact of hallucinations on the level of impairment in the visuospatial domain.

Method: Archival data obtained over three years from a total of 73 patients from the Health First Memory Disorder Clinic was used in this study. Participants were included in the study if they endorsed experiencing hallucinations, were given the VOT during their brief neuropsychological evaluation, and were diagnosed with dementia or unspecified neurocognitive disorder. The patient’s electronic medical record was used to retrospectively gather additional details regarding their hallucinations and …