Digital Commons Network^™

Towards Predictor Adaptive Robust Control And Inference Of Cyber-Physical Systems With Applications To Aerospace Systems, Jayaprakash “Suraj” Nandiganahalli

Open Access Dissertations

The simultaneous presence of factors such as uncertain plant parameters (e.g., inertia variations, change of damping coefficient), time-varying disturbances (e.g., imprecise mathematical models, uncertain nonlinearities), input delay (e.g., due to transport phenomenon, computation latencies, communication lags), and inaccessibility of the plant states of an nth− order dynamical system present a challenge to the formal control design and to its closed loop stability and performance guarantees. It is well-known that input delays can cause negative phase shifts, limiting the control bandwidth which when coupled with system uncertainties can potentially shift the system into an unstable region of operation. This is especially …

Quantifying The Relations Among Neurophysiological Responses, Dimensional Psychopathology, And Personality Traits., Takakuni Suzuki

Open Access Dissertations

The Research Domain Criteria (RDoC) model, one of the transdiagnostic dimensional models of psychopathology proposed by the National Institute of Mental Health, emphasizes the integration of basic biological science into clinical research. The event-related negativity (ERN), a deflection in electroencephalogram after making an error, is a promising neurophysiological indicator for such endeavor. However, RDoC model posits that ERN is related to three of the five broad dimensions without any indication of how ERN relates differently across the dimensions. Recent research indicate that ERNs elicited from different tasks do not elicit the exact same ERNs. Therefore, constructing theoretically guided tasks and …

Essays On Aspects Of International Finance: Cross-Border Asset Sales And Return Premium On Multinational Firms, Xue Wang

Open Access Dissertations

This dissertation consists of two independent chapters.

The first chapter examines the role of foreign institutional investors in the corporate asset sales market. Using data in 44 developed and emerging markets over 2001-2016, I document that foreign institutional ownership is positively related to the probability of cross-border asset sales. Compared to domestic asset sales, cross-border asset sales deliver higher abnormal returns for shareholders of the selling firms. These effects are robust to a variety of control variables and fixed effects. The documented effects are stronger in smaller firms and are driven by independent institutional investors. The evidence together suggests that …

Quantum Transport In Threedimensional Topological Insulators, Yang Xu

Open Access Dissertations

In this thesis, I will describe our electrical transport approach in studying three-dimensional topological insulators (3D TIs). A 3D TI is a quantum material characterized by a gapped bulk and gapless surface states that are topologically protected by time reversal symmetry, thus immune to backscattering. It provides an excellent platform to pursue a plethora of exotic physics and novel device applications such as spintronics. However, in most of the prototypical 3D TIs (like Bi2Se3, Bi2Te3, and Sb2Te3), the bulk carriers always unavoidably present and overwhelm the surface conduction in transport measurements.

Here, taking advantage of material engineering, we have successfully …

A Model And Measure Of Parental Vaccine Hesitancy: A Basis For The Development Of Future Health Campaigns, Jessica Hample

Open Access Dissertations

The “anti-vaccination,” or vaccine hesitancy, phenomenon has attracted the attention of many researchers in recent years. A significant amount of research has focused on identifying, categorizing, and measuring the beliefs common to vaccine-hesitant individuals. However, prior attempts to identify these beliefs have suffered from potential biases that call into question both the validity and comprehensiveness of our existing understanding of vaccine hesitancy. This dissertation project attempts to improve our understanding of vaccine hesitancy by systematically collecting beliefs held by vaccine-hesitant parents in the USA and using those beliefs to create a measure and model of vaccine hesitancy. Exploratory and confirmatory …

Incorporating Multicultural Education Into A Church Small Group Bible Study, Shalyse Iseminger

Open Access Dissertations

The purpose of this dissertation research was to understand how a group of Evangelical Christians made meaning of their experiences in a small group Bible study that employed a multicultural education curriculum focused on race and ethnicity. In this research, I used a case study as the methodology for data collection. Over the course of twelve weeks, I explored the experiences of the participants through interviews, observations, and document analysis. After analyzing the data through the lenses of Critical Whiteness studies and Critical Race Theory, I found that although participants acknowledged racism and the existence of White privilege and recognized …

Divide And Recombine For Large And Complex Data: Model Likelihood Functions Using Mcmc And Trmm Big Data Analysis, Qi Liu

Open Access Dissertations

Divide & Recombine (D&R) is a powerful and practical statistical framework for the analysis of large and complex data. In D&R, big data are divided into subsets, each analytic method is applied to subsets with no communication among subsets, and the outputs are recombined to form a result of the analytic method for the entire data. This enables deep analysis and practical computational performance. The aim of this thesis is to provide an innovative D&R procedure to model likelihood of the generalized linear model for large data sets using Markov chain Monte Carlo (MCMC) methods and to present an analysis …

Quantifying Arctic Terrestrial Ecosystem Carbon Dynamics Using Mechanistically-Based Biogeochemistry Models And In Situ And Satellite Data, Zhou Lyu

Open Access Dissertations

Terrestrial ecosystems of northern mid-to-high latitudes (45°-90°N) play a critical role in global carbon cycling and climate system feedbacks, given the massive carbon storage in the region and the amplification effects due to year-round and seasonal snow covering. This region has vast area of peatlands with a large amount of soil organic carbon. It has experienced dramatic climatic and environmental changes in recent decades, and the changes are expected to continue. This dissertation aims to quantify the Arctic carbon dynamics under these changes using mechanistically-based biogeochemistry models and in situ and remotely sensed data.

In the Arctic, snow pack modifies …

Synthesis Of Stable Open-Shell Moieties And Polymers For Charge Transfer Applications, Varad Vinayak Agarkar

Open Access Theses

Open-shell small molecules and non-conjugated polymers containing open-shell moieties as pendant groups have been of significant interest lately with regards to liquid crystalline materials, polymerization initiators, and in electrical conductivity applications. The research presented in this thesis focuses on the latter application and especially on tuning the optoelectronic properties of a novel class of small molecules viz. the 6-oxoverdazyl radicals and, as a result, is broadly divided into two parts.

The former part consists of designing a low glass transition temperature polymer for attainment of high electrical conductivity values not reported previously for non-conjugated pendant radical polymers. The high conductivity …

Changes In Audiovisual Word Perception During Mid-Childhood: An Erp Study, Elizabeth Ancel

Open Access Theses

Throughout school-age years, speech perception is an important skill that often relies on the child’s ability to combine both auditory and visual information from the speaker. In order to better understand the development of multisensory speech perception during mid-childhood, we analyzed audiovisual word perception in three groups of participants: 8-9-year olds, 11-12-year olds, and adults. Participants matched visually-perceived articulatory movements with corresponding auditory words. In “congruent” trials, the auditory word matched the subsequently presented silent visual articulation. In “incongruent” trials, the words presented differed on the initial phoneme. From this task, we evaluated specific neural components —the N400 and the …

Additive Manufacturing For Aerodynamic Diffuser Designs In A Centrifugal Compressor, Ruben Adkins-Rieck

Open Access Theses

The primary objective of this research was to develop a facility capable of testing the aerodynamic performance of vaned diffusers in a centrifugal compressor. The research utilizes stereolithography to 3D-print a vaned diffuser flow path which can then be tested directly in the Purdue Centrifugal Stage for Aerodynamic Research (CSTAR) facility at the Purdue Compressor Research Lab. This compressor is representative of a compressor that would form the rear stage of an axi-centrifugal compressor in a gas turbine aero-engine.

Several components were designed and manufactured to accept the printed plastic diffuser in the CSTAR facility. A printed diffuser flow path …

Experimental Study Of A Transcritical Thermoacoustic Device, Dayle N. Alexander

Open Access Theses

A prototype transcritical thermoacoustic engine has been constructed and tested, yielding thermoacoustic results. Three different thermoacoustic “stack” designs have been evaluated in the present study. All three show damped acoustic oscillations as a temperature gradient is produced along the stack and a non-linear perturbation is induced. Spontaneously instabilities at much lower frequency were observed in the device with one of the “stacks”. These instabilities grew to a limit cycle amplitude that was maintained until heat was removed. Data are presented for both types of instabilities over a range of operating conditions.

Mr-Compatible Electrophysiology Recording System For Multimodal Imaging, Nishant B. Barbaria

Open Access Theses

Simultaneous acquisition of functional magnetic resonance imaging (fMRI) and electrophysiological recordings is an emerging multimodal neuroimaging strategy for studying brain functions. However, the strong magnetic field generated during fMRI greatly degrades the electrophysiological signal quality during simultaneous acquisition. Here, I developed a low powered, miniaturized, system – “ECHO” which delivers a hardware and software solution to overcome the challenges presented by multimodal imaging. The device monitors fluctuations in electromagnetic field during fMRI and synchronizes amplification and sampling of electrophysiological signals to minimize effects of gradient and RF artifacts (electromagnetic artifacts). Furthermore, I introduced a concept of wirelessly transmitting recorded data …

Effects Of A Mobile Tablet Device And An Augmentative And Alternative Communication (Aac) Application On Individuals With An Acquired Communication Disorder: Influence On Communication Abilities And Quality Of Life, Yamini Balasubramanian

Open Access Theses

The purpose of this study was to evaluate the effects of a mobile tablet device and an Augmentative and Alternative Communication (AAC) application on the communicative abilities and quality of life of individuals with acquired communication disorders. A preexperimental single subject research design was replicated across one client with progressive dysarthria, and two clients with non-fuent aphasia to investigate effects of specifc communicative abilities (message intelligibility for the client with dysarthria and correct information units for the clients with aphasia) in addition to quality of life. Results suggest that improvements were noted in percent message intelligibility and correct information units …

Evaluating The Effects Of Education On Student Knowledge, Attitudes, And Behavior Regarding Food Waste, Rebecca Busse

Open Access Theses

Food waste is a growing global environmental, economic, and social issue. One proposed method for reducing food waste is to increase awareness through education. This study is the first to evaluate the effects of environmentally focused lesson plans on student knowledge, attitudes, and behavior regarding food waste. The study was conducted with second and fifth grade classrooms in two Indiana elementary schools. Student responses were assessed using pre/post surveys and interviews, and by measuring student plate waste. Teacher interviews were also conducted to determine existing perceptions and uses of food waste education in the classroom, and to assess reactions to …

Demonstrator For Selectively Compliant Morphing Systems With Multi-Stable Structures, David M. Boston

Open Access Theses

The field of morphing wings presents significant potential for increasing the efficiency of aircraft. Conventional designs used in the industry limit the adaptability of aerodynamic surfaces to address an engineering trade-off between load-carrying and compliance. This same trade-off remains a factor in morphing wings, which must also balance weight considerations while attempting to remain competitive with conventional designs. The current state-of-the-art in morphing wings is briefly described in this work. This is followed by an investigation into a new application of the principle of selective stiffness, by which local changes in stiffness may be applied to affect the global structural …

High Resolution Temperature Measurement Using Ters, Qian Cao

Open Access Theses

Heat is a functional importance in nanoscale devices. It will affect the function and performance of the device if not distributed properly. Since the development of nano-science, various studies have been issued on nanoscale temperature mapping utilizing a variety of techniques. Among them, optical methods are preferred due to its noninvasive characteristic. Especially, Tip Enhanced Raman Spectroscopy (TERS) performs as a tool with high spatial resolution in temperature mapping.

In this work, a homemade TERS system based on AFM is utilized as the tool for nanoscale temperature mapping. Bismuth thin film is used as nanoscale thermometer due to the characteristic …

Effects Of Supplemental Nutrition Assistance Program (Snap) On Adults' Diet Quality, Kaiyan Chen

Open Access Theses

The objective of this research is to understand the effects of the Supplemental Nutrition Assistance Program (SNAP) on adult participants’ diet quality. We use National Health and Nutrition Examination Survey (NHANES) data from 2007–2014 to compare diet quality and food choices between current SNAP participants and non-current participants. The overall diet quality measures include the Healthy Eating Index-2010 (HEI-2010), energy density, and a nutrition index. We also consider HEI-2010 components to evaluate several important aspects of diet quality, including whole grains, various types of vegetables and fruits, dairy, and protein etc. The food choice analysis compares food intakes between current …

The Approach To Ridge Regression For Big Data: An Examination, Wan-Chih Chiang

Open Access Theses

Ridge regression is a technical method to deal with highly correlated data when using regression model for analysis. Like other traditional techniques, one common limitation happens when the data size is bigger than the storage capacity of the memory or taking most of the memory storage. The analysis can’t complete because of memory error, either happening in loading the data into the memory or during the calculation step. Sampling or extending the memory storage capacity may be two possible solutions to avoid the problem. However, it probably brings unknown bias when the population is enormous or high costs in establishing …

Modeling And Parameter Characterization Of A Betavoltaic Cell, Darrell S. Cheu

Open Access Theses

Betavoltaic cells are a type of nuclear battery where kinetic energy from beta particles are converted into electricity. The goal of this research is to evaluate betavoltaic cell electrical performance and predict its response to temperature changes for potential implementation. To achieve this goal, three tasks were performed: betavoltaic cells were electrically characterized under temperature, critical betavoltaic semiconductor parameters were experimentally determined, and the Shockley-Diode model was used to predict electrical performance and compared to experimental results.

Betavoltaic cells were evaluated from -30◦Cto70◦C. I-V curves were gathered at each temperature step in order to determine open circuit voltage and short …

Prevalence And Control Of Listeria Monocytogenes And S. Enterica In Retail Produce Environments, John Lawrence Burnett

Open Access Theses

There has been a notable increase in produce-related foodborne illness attributed to L. monocytogenes and S. enterica. Recent studies show retail environments may be a source for L. monocytogenes contamination of deli meat; however, environmental prevalence of both L. monocytogenes and S. enterica in retail produce remains largely uncharacterized. Studies aiming to decrease the prevalence of L. monocytogenes in retail delicatessens have not shown significant successes. The first goal of this study was to determine the prevalence of Listeria monocytogenes and Salmonella enterica in retail produce environments and to elucidate their possible ecological niches. Thirty environmental samples per store were …

Care Givers: Motivating And Enhancing Non-Profit Caregivers’ Experiences, Mingchu Cong

Open Access Theses

The challenges of the aging world population continue to become more and more serious. Caregivers play a very important role in the caregiving system. There are different types of caregivers: family caregivers, who are typically a patient's family member; and professional caregivers, who are trained and paid to care for their assigned patients. Another group yet are volunteer caregivers, the primary targeted user group of this research. Volunteer caregivers are both dramatically overlooked and making significant contributions to society. People who work as volunteer caregivers are mostly motivated by their kindness. Volunteer caregiving is typically a part-time job provided by …

Chocolate Almond Milk Consumption Changes Salivaryproline-Rich Protein Expression, Whichalterastringencyandbitterness, Ciera Crawford

Open Access Theses

In this work we analyze how humans experience sensations from polyphenols, focusing particularly on chocolate flavonoids. First, we investigated how people use terms to describe the “astringent” sensation of these compounds, determining that the words “dry, rough” may be a feasible alternative to the poorer understood term “astringent.” Next, we investigated how human salivary proteomes may influence the sensations of chocolate flavonoids, and whether those proteomes change after exposure to the compounds in chocolate milk for a week. In this larger six-week study design, subjects alternated each week between consuming a low polyphenol diet and consuming one of three different …

Hyperspectral Modeling Of Relative Water Content And Nitrogen Content In Sorghum And Maize, Valerie Cross

Open Access Theses

Sorghum and maize are two of the most important cereal grains worldwide. They are important industrially, and also serve as staple crops for millions of people across the world. With climate change, increasing frequencies of droughts, and crops being planted on more marginal land, it is important to breed sorghum and maize cultivars that are tolerant to drought and low fertility soils. However, one of the largest constraints to the breeding process is the cycle time between cultivar development and release. Early evaluation of cultivars with increased the ability to maintain water status under drought and increases nitrogen contents under …

Detection And Management Of Diabetes Mellitus (Type -Ii), Ridhi Deo

Open Access Theses

Diabetes is a life threatening disease. Diabetes is also hereditary and its incidence depends on factors pertaining to the health, lifestyle and family background of an individual. Gestational Diabetes Mellitus (GDM) is a special case in diabetes which occurs only during pregnancy. The aim of the author’s thesis is to mathematically model the risk factors for diabetes (type -2). The factors are modeled to predict if an individual will have diabetes. The model is aimed at being beneficial to patients so that they can determine if their current lifestyle habits are healthy. The purpose of the thesis is to explore …

Liquid-Vapor Imaging In Fuel Sprays Using Lifetime-Filtered Planar Laser-Induced Fluorescence, Alber Douglawi

Open Access Theses

Many performance parameters in combustion systems are heavily dependent on the fuel injection process. Liquid-vapor imaging in spray applications has proven to be difficult because of the dominance of the liquid phase signal due to its higher number density. This work addresses this issue by employing temporal filtering in Planar Laser-Induced Fluorescence (PLIF) imaging. Temporal filtering takes advantage of the fact that although the vapor signal tends to be weaker, its fluorescence signal persists longer than the liquid signal under the same conditions. An experimental setup was designed with the capability to supply a two-phase flow in a controlled environment …

Development Of Tools To Reduce Risk Of Nosocomial And Foodborne Pathogens Exposure, Paula A. Duarte-Guevara

Open Access Theses

Transmission pathways of pathogenic bacteria are one of the most relevant fields of research because of its direct impact not only on the public health but also on the economy. Identifying the critical factors for bacteria spreading through the population provide new tools for the prevention of disease and risk management. Clostridium difficile is the primary causative of antibiotic-associated diarrhea in healthcare settings. C. difficile infection (CDI) symptoms range from mild diarrhea to pseudomembranous colitis and can result in death. Awareness of the microorganism is extremely low, and the understanding of it is far from complete. Because of this, the …

Biodynamic Imaging System: A Novel, Noninvasive Method For Assessing Embryo Viability., Natalie Ehmke

Open Access Theses

In vitro embryo production is the foundation of most assisted reproductive technologies, yet efficiency of these technologies is relatively low due to the lack of a reliable method for measuring embryo viability. Current methods to evaluate the viability of in vitro derived embryos are invasive or expensive to perform. In order to create a reliable system to assess the developmental potential of the embryo, a novel optical approach known as BioDynamic Imaging (BDI) has been proposed for application. BDI is able to measure dynamic processes inside an embryo encompassing a broad range of motions that relate directly to functional developmental …

Electrostatic Regulation Of Phospholipase C Beta Enzymes, Candi Michelle Esquina

Open Access Theses

Phospholipase C (PLC) proteins cleave phosphatidylinositol lipids from cellular membranes to produce the second messengers inositol triphosphate (IP3) and diacylglycerol (DAG). The PLCb subfamily is among the best characterized of the PLC enzymes and is crucial for normal cardiovascular function. Under basal conditions, PLCb has low activity and is partitioned between the plasma membrane and the cytoplasm. However, it is unclear how this low activity state is maintained from a molecular standpoint. One known autoinhibitory element is the X–Y linker, a loop within the catalytic domain that forms a lid over the active site and which is displaced through interfacial …

Parental Restrictive Feeding With Latino Adolescents: Examining The Role Of Adolescent Self-Regulation In Associations With Body Mass Index, Carly Danae Evich

Open Access Theses

Latino adolescents in the U.S. are disproportionately affected by obesity compared to adolescents of other racial and ethnic backgrounds. Previous studies have suggested that parental restrictive feeding may serve as a modifiable risk factor. However, given that obesity in youth often develops as a function of a child’s susceptibility for weight gain interacting with their environment, the suggested negative effects of parental restrictive feeding may not generalize across all Latino adolescents. One marker of susceptibility for weight gain in youth is poor self-regulation, which can lead to reliance on others to help regulate eating behavior. However, the potential for self-regulation …