Digital Commons Network^™

Nanomaterials For Cardiovascular Engineering, Roya Bagheri

Dissertations, Master's Theses and Master's Reports

Cardiovascular diseases and disorders (i.e., those related to heart and blood vessels) are the main reasons for mortality worldwide. Nanomaterials, with their unique morphologies and properties, have a great potential for advancing cardiovascular engineering to treat diseases and disorders. In this dissertation, several cardiovascular applications of conductive nanomaterials were investigated. First, a conductive nanomaterial was explored to fabricate biohybrid nanomaterial-cardiomyocyte (CM – heart muscle cell) systems. Using Carbon Nanotube (CNT) forest as a 3D porous and conductive scaffold was investigated. The influence of the CNT forest on the viability, attachment, and spreading of CMs and their genetic information was …

Memory Optimizations For High-Throughput Computer Systems, Zhiyuan Lu

Dissertations, Master's Theses and Master's Reports

The emergence of new non-volatile memory (NVM) technology and deep neural network (DNN) inferences bring challenges related to off-chip memory access. Ensuring crash consistency leads to additional memory operations and exposes memory update operations on the critical execution path. DNN inference execution on some accelerators suffers from intensive off-chip memory access. The focus of this dissertation is to tackle the issues related to off-chip memory in these high performance computing systems.

The logging operations, required by the crash consistency, impose a significant performance overhead due to the extra memory access. To mitigate the persistence time of log requests, we introduce …

Altering The Environment: The Effects Of Light And Music On Vigilance Performance And Affective State, Lauren Sprague

Dissertations, Master's Theses and Master's Reports

Vigilance, otherwise known as a state of alert watchfulness, is a phenomenon that occurs when someone is sustaining their attention on a particular task or environment. Largely, tasks that require a state of vigilance induce negative mood outcomes, result in loss of performance over time, and cause increased disengagement from the task. These tasks involve detecting critical signals which are buried among more frequently occurring neutral signals. While little can be done to change the base nature of the vigilance task, altering the physical environment of the operator may improve working conditions to a point where there are fewer losses …

The Impact Of Pre-Experiment Walking On Distance Perception In Vr, Soheil Sepahyar

Dissertations, Master's Theses and Master's Reports

While individuals can accurately estimate distances in the real world, this ability is often diminished in virtual reality (VR) simulations, hampering performance across training, entertainment, prototyping, and education domains. To assess distance judgments, the direct blind walking method—having participants walk blindfolded to targets—is frequently used. Typically, direct blind walking measurements are performed after an initial practice phase, where people become comfortable with walking while blindfolded. Surprisingly, little research has explored how such pre-experiment walking impacts subsequent VR distance judgments. Our initial investigation revealed increased pre-experiment blind walking reduced distance underestimations, underscoring the importance of detailing these preparatory procedures in research—details …

The Hidden Role Of The “Co-” Paradigm In The Conceptualization And Application Of Living Labs, Madelina E. Dilisi

Dissertations, Master's Theses and Master's Reports

In the past two decades, the living lab has emerged as an innovative approach for addressing a wide range of issues. Living labs challenge traditional top-down research and development approaches in an array of subjects including climate change and sustainability, healthcare, information communication technology, and urban planning. Despite their growth, the current conceptualization of living labs is incomplete. The conceptual ambiguity surrounding living labs prevents researchers and practitioners from appreciating their true value, limitations, and appropriate applications. My thesis builds on Dekker et al.’s (2020) living lab research by including key concepts from the “co” paradigm literature that includes the …

A Search For Compact Object Dark Matter In The Universe Utilizing Gravitational Millilensing Of Gamma-Ray Bursts, Oindabi Mukherjee

Dissertations, Master's Theses and Master's Reports

In this dissertation, I explore the existence of Compact Object (CO) Dark Matter (DM), examining its predicted millilensing impact on the light curves of Gamma-Ray Bursts (GRBs). The hypothesis under investigation is that if CO DM exists, it will act as a gravitational lens, influencing light emanating from GRBs and creating a measurable gravitational echo. The detection of this echo is conditional on several factors, including the spatial alignment of the observer, lens, and source and the mass of the CO DM.

Recent studies have reported the potential detection of millilensing in several GRBs, including GRB 950830, GRB 081122A, GRB …

Multilevel Computational Investigation Into The Catalytic Mechanisms Of Matrix Metalloproteinase-1 And Fat Mass And Obesity-Associated Enzyme, Ann Varghese

Dissertations, Master's Theses and Master's Reports

Enzymes are biological macromolecules, typically proteins, that efficiently accelerate the rate of chemical reactions. Their remarkable catalytic power plays a vital role in essential processes across all kingdoms of life. Nowadays, computational chemistry methods provide valuable insights into enzymatic functions aiding our understanding of biological processes and providing advancements in fields such as biomedical sciences, biomimetic catalysis, drug design and biotechnology. This dissertation employs multilevel computational chemistry methods to investigate the structure-function relationships and the catalytic mechanisms of two metalloenzymes -Zn(II)-dependent matrix metalloproteinase-1 (MMP-1) and non-heme Fe(II)/2-oxoglutarate (2OG) dependent fat-mass and obesity-associated (FTO) enzyme. Chapter 2 explores the role of …

Using Artificial Intelligence To Understand Environmental Policy Innovation Labs' Contribution To The Sustainable Development Goals, Sidney M. Mechling

Dissertations, Master's Theses and Master's Reports

Policy innovation labs (PILs) serve as centers of experimental innovation pursued by governmental, private, and non-profit entities that employ design-thinking methodology, scientific experimentation, and user-centric approaches (Wellstead et al., 2021). The multi-disciplinary expertise of policy innovation labs in social and economic topics equips them to offer policy recommendations addressing public issues, including environmental concerns. When designing innovative solutions, it is customary for policy innovation labs to provide substantial information and reports detailing their progress and methods. However, the wealth of information available becomes a challenge to fully divest in comprehending a lab's contribution to solving global issues. This report addresses …

Investigating Collaborative Explainable Ai (Cxai)/Social Forum As An Explainable Ai (Xai) Method In Autonomous Driving (Ad), Tauseef Ibne Mamun

Dissertations, Master's Theses and Master's Reports

Explainable AI (XAI) systems primarily focus on algorithms, integrating additional information into AI decisions and classifications to enhance user or developer comprehension of the system's behavior. These systems often incorporate untested concepts of explainability, lacking grounding in the cognitive and educational psychology literature (S. T. Mueller et al., 2021). Consequently, their effectiveness may be limited, as they may address problems that real users don't encounter or provide information that users do not seek.

In contrast, an alternative approach called Collaborative XAI (CXAI), as proposed by S. Mueller et al (2021), emphasizes generating explanations without relying solely on algorithms. CXAI centers …

Novel Bayesian Neural Networks And Uncertainty Quantification Of Computational Mechanics Models, Ponkrshnan Thiagarajan

Dissertations, Master's Theses and Master's Reports

Computational and data-driven models suffer from a wide range of uncertainties that impact the reliability of such models. Given the exponential proliferation of machine learning models in real-world systems, establishing a degree of confidence in their predictions becomes paramount. Reliability in predictions takes on utmost significance in domains such as autonomous driving, medical image analysis, etc., where human lives are involved, and inaccuracies in predictions could lead to disastrous outcomes. For these reasons, comprehending and quantifying uncertainties in computational and data-driven models is of utmost importance. A number of techniques have been developed to quantify uncertainties in machine learning models. …

Physical, Optical, And Chemical Properties Of Light Absorbing Aerosols And Their Climatic Impacts, Susan Mathai

Dissertations, Master's Theses and Master's Reports

Aerosols are particles suspended in the atmosphere; they are emitted during natural phenomena such as dust storms, wildfires, and volcanic eruptions, and during anthropogenic activities like household wood burning, vehicles operations, and industrial productions, or they can form in the atmosphere from gas to particle partition. Aerosols impact earth’s weather and climate by absorbing and scattering the incoming solar and the outgoing earth thermal radiation and interacting with clouds. The optical properties of aerosols evolve as the chemical and physical properties vary during their residence in the atmosphere. In addition, the aerosols’ properties strongly depend on the vertical distribution in …

On Examining Solvation And Dielectric Constants Of Polar And Ionic Liquids Using The Stockmayer Fluid Model, Cameron J. Shock

Dissertations, Master's Theses and Master's Reports

We develop Stockmayer fluid (SF) models to predict and analyze dielectric properties of polar solvents, ionic liquids, and polyermized ionic liquids. A Stockmayer fluid treats molecules as simple Lennard-Jones spheres with dipole moments and point charges. With this model we calculate the solvation energies of 26 ions in 7 polar solvents and compare with experiment. There is qualitative agreement and we find that the SF model can account for the effects of dielectric saturation, which the commonly used Born solvation energy equation lacks. We also calculate the dielectric constants of these 7 solvents and find quantitative agreement with experiment. We …

Deep Learning For Medical Image Segmentation Using Prior Knowledge And Topology, Chen Zhao

Dissertations, Master's Theses and Master's Reports

Image segmentation refers to the division of a digital image into distinct segments or groups of pixels/voxels. However, most of the existing deep learning approaches lack the utilization of prior knowledge, such as shape information, which could improve segmentation accuracy. In addition, conventional image segmentation frequently falls short in preserving intricate spatial details, motivating the innovation of strategies for multi-scaled feature integration. Furthermore, traditional image segmentation methods primarily concentrate on pixel-level or region-level analysis. However, given the inherent morphological similarities among various image objects, the significance of topology information surpasses that of pixel-level data in the realm of medical image …

Surface Reconstruction In Iron Garnets, Sushree Dash

Dissertations, Master's Theses and Master's Reports

This dissertation presents the results of a study investigating the physical mechanisms underlying an unexpectedly large increase in magneto-optic efficiency observed in iron garnet. Such materials are technologically important for telecommunications due to their nonreciprocal optical action. In the past, our group had found evidence of an enhanced Faraday rotation in bismuth-substituted iron garnet films less than 50 nm thick. Subsequent investigation revealed that this enhancement could be traced to surface effects. This is significant because understanding these phenomena could be used to formulate engineering solutions for device miniaturization. In this dissertation, we present the result of a research project …

Making Scientific Information Usable: Development And Assessment Of A Novel Intervention To Boost Healthy Lifestyle Decision-Making, Brittany Nelson

Dissertations, Master's Theses and Master's Reports

Context—Improving diet can reduce the risk of chronic health conditions such as cancer and heart disease. However, people continue to make poor dietary health decisions. A novel intervention based on the science of behavior change and incorporating Human-Centered Design (HCD) methodology is needed to boost informed dietary decision-making.

Objective—This research presents a Behavior Change Wheel (BCW), Human-Centered Design (HCD) approach to develop a novel high-usability video intervention that will increase informed decision-making for whole-grain dietary decisions. The intervention will target college students, improving habits that can carry on throughout later adulthood.

Design—Study 1 consisted of preliminary data …

Effects Of Downwash When Measuring Gas Concentration With Uav-Mounted Gas Sensors, Jacob Lane Brinkman

Doctoral Dissertations

"This research concludes that the downwash region of a rotary-wing unmanned aerial vehicle (UAV) does not produce pressure variations substantial enough to cause significant changes in density-based gas concentration measurements. US regulations evaluate gas concentration as a function of gas density, and accurate concentration measurements are critical for protecting health and safety, which means evaluation of actual downwash effects on measured gas concentration is essential.

During experimentation, the UAV was fixed to a stand in a sealed chamber filled with NOx (NO and NO₂) of constant concentration. The UAV rotors ran at hovering speeds, and gas concentrations were …

Fiber Optic Sensors For Liquid Identifications, Wassana Naku

Doctoral Dissertations

"The fiber optic Fabry-Perot interferometer (FPI) is a widely utilized sensing configuration, offering numerous advantages over conventional electronic sensors, including high accuracy, distributed sensing capabilities, immunity to electromagnetic interference, and compact size. In this study, we propose a remarkably simple fiber optic-tip sensor system combined with machine learning techniques for the identification of pure and volatile organic liquids (VOLs).

A liquid droplet forms an extrinsic FPI (EFPI), with its effective reflectance being a function of the droplet's length. As the droplet evaporates, its length decreases. We conducted immersion tests using optical fiber tip sensors and monitored the time-transient responses of …

Characterization And Improvement Of Powder Properties Through Plasma Spheroidization For Use In The Laser Powder Bed Fusion Process, M. Hossein Sehhat

Doctoral Dissertations

"This research was conducted to characterize the powder properties using different characterization techniques to enhance the powder behavior in the Laser Powder Bed Fusion (LPBF) process. One of the shortcomings of LPBF process is the high cost of gas-atomized powder feedstock. To overcome this downside, the cheaper water-atomized powder was characterized and used in LPBF process, and its performance was compared with those of gas-atomized powder. Also, the plasma spheroidization process was used to improve the powder characteristics; if the spheroidized powder could function as well as the virgin powder, plasma spheroidization process could be applied to the used powders …

Sustainable Development: A Data Analysis Investigation For A New Conceptual Model, Case Study Comparison And Validation Techniques, Tiffanie Marie Toles

Doctoral Dissertations

"The three pillars model for sustainability, often represented with three intersecting circles described as economic, environmental, and social factors with sustainability being at the center is a complex and philosophically open model [1]. As society promotes efforts to reduce carbon impacts, there becomes a need to critically review the models employed for understanding. This research presents a validated methodology, an updated conceptual configuration of sustainability for overall use, as well as a sustainable development performance measurement system. Using the 2020 Sustainable Development Goals Index Data, 232 indicators from 193 countries were used to evaluate the efficacy of using more than …

Recurrent Event Data Analysis With Mismeasured Covariates, Ravinath Alahakoon Mudiyanselage

Doctoral Dissertations

"Consider a study with n units wherein every unit is monitored for the occurrence of an event that can recur with random end of monitoring. At each recurrence, p concomitant variables associated to the event recurrence are recorded with q (q ≤ p) collected with errors. Of interest in this dissertation is the estimation of the regression parameters of event time regression models accounting for the covariates. To circumvent the problem of bias and consistency associated with model's parameter estimation in the presence of measurement errors, we propose inference for corrected estimating functions with well-behaved roots under additive measurement errors …

Nuclear Weapons In Japanese Strategic Culture, Logan Joseph Douglas Campbell

Graduate Theses/Dissertations

Acquiring nuclear weapons of its own has been inconsistent with Japan’s post-Cold War strategic culture, which is heavily based on an identity and associated norms grounded in nuclear pacifism. However, Japan’s strategic culture has been evolving with changing threat perceptions, eroding international nuclear nonproliferation norms, and declining confidence in US security guarantees. As Japan’s strategic culture shifts towards a more pragmatic interpretation of its national interests, acquiring nuclear weapons may become a more easily legitimized option, one that would be entirely consistent with a remilitarized strategic culture. Scholarship on Japanese strategic culture is vast but lacks a strategic culture explanation …

A Part From You, Kenneth Rick Briggenhorst Jr.

Graduate Theses/Dissertations

I invite empathy through art that is technologically assisted to find alternative interpretations for nontheologically informed faith. The sudden passing of my dearest friend, Jimmy, encouraged me to dig through my archives of data, to cherish all the bytes that remain of him. In this endeavor, I find that death is not the end, but a post-physical state of being. I express this sentiment in a part from you, where the work utilizes inanimate constructs to place your faith in, to make sense of the complexities of grief in a digitally tethered way of life. This life that allows many …

Right Turn At Reality: A Rhetorical Analysis Of Right Wing Negotiations On Race And Masculinity In Online Spaces, Andrew R.J. Hart

Graduate Theses/Dissertations

The effects of right wing politically charged violence are more visible now than at any other point in recent American history. The Internet, and social media more specifically, has become a crucial nexus point in the dissemination of decentralized Alt-Right propaganda. The visual nature of social media has increased the importance of images a means of communication. Through this thesis, I analyze artifacts coming out of these spaces representing a conversation between creators and audiences, and how they work dialogically to introduce and reify symbols of white masculine supremacy within this subgroup. Through this process, I find multiple recurring patterns …

Thawing Interests: The Arctic In U.S. Grand Strategy, Benjamin S. Murray

Graduate Theses/Dissertations

The thawing Arctic is subject to increasing activity, attention, and a renewal of interests in the region from around the globe. National interests have compelled strategic planning in the Arctic region and are connected to global geopolitics. A concept of grand strategy is distilled from theories of past authors, understood within the modern context. That concept includes a terminological framework consisting of interests and threats to inform an ends, ways, and means design of strategy, composed of all instruments of state power, blending policy with strategy, and across the peace-war continuum. Then fundamental precepts of existing U.S. grand strategy are …

Syncretistic Religiosity In The Mausoleums Of Bangladesh: Exploring The Possibility Of A Blended Religious Identity, Sadia Afrin

Graduate Theses/Dissertations

Firstly, this thesis investigates the syncretistic religious nature of Bangladeshi mausoleums, along with the historical background of the Sufi mausoleums and the flourishment of this syncretistic religiosity. The study explores the contribution of Sufis to the spread of Islam in Bengal. It discusses how the liberal attitude of mausoleum enshrined Sufis toward their followers of diverse faiths patronized syncretism. The study here hypothesizes that the religious practices of Bangladeshi mausoleums are syncretistic; they are neither exclusively Muslim nor Hindu but present a blended identity. It demonstrates how religious syncretism is an undeniable phenomenon in the mausoleums of Bangladesh and how …

Analysis Of K-Food Franchises In Thai Market Focusing On The Consumption Behavior Of Thai Generation Y And Generation Z In Bangkok Metropolitan Region, Vajirawit Siripiyaphat

Chulalongkorn University Theses and Dissertations (Chula ETD)

These days, fans everywhere are enamored with the Korean Wave (Hallyu). South Korean administrations have highlighted Korean cuisine (K-food) as one of their exported cultural products. Localizing K-food abroad might cause misunderstandings among foreigners. Accordingly, franchising has the potential to maintain food authenticity. Thus, the purpose of this thesis was to examine the consumption behavior of Thai Generation Y and Z in relation to Korean franchise businesses in the Bangkok Metropolitan Region (BMR). The first analysis used the theory of planned behavior (TPB) together with a new variable regarding the food consumption behaviors of Koreans and Thais. Then, the examination …

K-Pop Idol Trainees Selection Process In Thailand, Chamapat Rattanaphansri

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research employed qualitative methods, utilizing an in-depth interview approach with a total of eleven individuals, including three Thai and Korean Staff Members at K-Labels, four Former Thai K-Pop Idols, and four Former Thai K-Pop Trainees for primary data. Additionally, secondary data was gathered through document research via twenty YouTube video interviews. The study aims to investigate the methods, evaluation principles, and factors influencing the K-Pop Idol Trainees Selection Process in Thailand and provide recommendations for implementing a trainee selection process in the T-Pop Industry. The findings revealed that the K-Pop Idol Trainee Selection Process in Thailand comprised three main …

Study Of Nationalism And Consolidation Of Democracy In South Korea : 1987-1993, Nura-Arnis Kitkongpat

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study aimed to examine the factors that contributed to the consolidation of democracy in the Republic of Korea (South Korea) during 1987–1993. The research employed the threshold definition of the consolidation of democracy as the only game in town and focused on South Korean nationalist sentiment that influenced the movement within and outside the National Assembly. It also minimized the risk of democratic interruption and stabilized the democratic government. According to the findings, the South Korean people diverted their focus to the pride of the nation. The Seoul Olympic Games in 1988, Nordpolitik, economic success, and democratization during the …

The Popularity Of Thai Y Series In Japan, Taiki Yamamoto

Chulalongkorn University Theses and Dissertations (Chula ETD)

The burgeoning popularity of the Thai Y series within Japan presents a captivating case study of cultural diffusion and media influence in the contemporary era. This paper explores the underlying dynamics behind this phenomenon, focusing on the interplay between social media's role in content propagation, the narrative appeal of the series to Japanese audiences, and the unique charm of Thai actors that captivates the same demographic. The research employs a multifaceted approach which incorporates examination of key media platforms, storytelling analysis, interview, and analysis of actors’ appeal. The findings reveal insights into the cultural, and social impact of the Thai …

Cultural Destination Branding For Doi Mae Salong : Stakeholders’ Perspectives, Shu Ma

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study uses qualitative and quantitative methods to propose and develop Doi Mae Salong's destination branding. Here are the research goals: This research aims to: 1) investigate the community identity, destination resources, and significance of Doi Mae Salong ; 2) collect data on Doi Mae Salong's tourism resources and current tourism situation ; 3) identify the stakeholders' destination branding goals for Doi Mae Salong ; and 4) develop Doi Mae Salong's brand based on its resources and stakeholders' perspectives. During the quantitative phase, on-site visitors completed a questionnaire with an IOC score of 0.896 between August 8 and September 8, …