Digital Commons Network^™

Who Are We Now? Examining Internal Organizational Communication During Crisis, Elizabeth England

Open Access Theses

Organizational Communication scholars have thoroughly researched communicative processes and phenomena during times of organizational crisis. However, little research aims to understand the extremely important employee perspective during such hardships. In this study, through in-depth qualitative interviews, I investigated employees’ reports of their roles in renegotiating organizational identity, preferred sensemaking tactics, and dissemination of communication during their company’s private financial crisis. I found employees generally failed to recognize their roles in renegotiating organizational identity, instead viewing organizational identity maintenance as a responsibility of leadership. Employees also reported engaging in a number of sensemaking tactics to understand their crisis situation, such as …

Genetics And Genomics Of Golden Eagle Populations With Contrasting Demographic Histories, Nadia B. Fernandez

Open Access Theses

Most species are constrained by geographic barriers to dispersal and geneflow, and such limitations have demographic and genetic consequences. We tested whether a highly vagile bird of prey, the golden eagle (GOEA; Aquila chrysaetos), exhibits disparate genetic signatures among island (Channel Islands, California, USA), peninsular (Baja California Peninsular region, USA) and mainland (California, USA) regions given the contrasting demography and phylogeography among regions. We utilized a SNP assay to estimate heterozygosity, inbreeding coefficients, and the effective population sizes (Ne) of GOEAs. In addition, we sequenced six GOEA genomes to obtain comprehensive measures of homozygosity (i.e., runs of homozygosity, ROHs) burden …

Activity Markers And Horse Riding In Mongolia: Entheseal Changes Among Bronze And Iron Age Human Skeletal Remains, Matthew R. Fuka

Open Access Theses

The emergence of horse riding in Mongolia has recently gained attention in archaeological research (e.g. Houle 2016; Makarewicz et al 2018; Taylor and Tuvshinjargel 2018). Most of this research consists of zooarchaeological studies examining evidence of riding through osteological analyses of horse skeletal remains. This thesis represents an exploratory study on entheseal changes in human skeletal remains from the Bronze and Iron Age of Mongolia (c. 2500 BCE – c. 200 CE) to investigate patterns of repetitive physical activity that may be suggestive of horse riding. Entheseal changes refer to morphological alterations to bone caused by repetitive physical activity that …

Power Management Modeling Of Electric Machine Converter Systems, Drummond R. Fudge

Open Access Theses

The control of power and energy sources to optimize a performance metric (i.e. maximize efficiency, minimize energy storage) has received considerable attention with the emergence of microgrids. In this research, power management models have been developed for two classes of electric machine/converter systems. Specifically, in the first class, a wound rotor synchronous machine/diode rectifier connected to a fixed DC output is considered. Relationships between commanded DC power, mechanical input power, and field winding current are established. In the second class, a buried magnet synchronous machine connected to an inverter is considered. The relationship between the mechanical power, AC power, and …

Aerosol Impacts On Simulated Supercell Thunderstorms In Vortex2 And Vortex-Se, Mingyang Guo

Open Access Theses

Environmental factors are found to strongly affect aerosol impacts on convective thunderstorms. In this study, the storm sensitivity to cloud condensation nuclei (CCN) concentration is explored in five aspects: general storm development, hydrometeor, updraft, precipitation and cold pool from a microphysics point of view. Idealized simulations of the 31 March 2016 and 30 April 2016 cases from the Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX)-Southeast (SE) field campaign, and the 5 June 2009 and 9 June 2009 cases from VORTEX2 field campaign are conducted at 6 CCN concentrations (100-3000 cm-3) with the Advanced Regional Prediction System (ARPS) …

"The Effects Of Oxidative Stress On Exosome Release In Human Skeletal Muscle Satellite Cells", Zachary R. Hettinger

Open Access Theses

In aging, cellular senescence contributes to the impaired capacity of progenitor cells to repair tissue. Decreased regenerative capabilities in skeletal muscle increase with age, where senescence is postulated to contribute to this phenotype. Activation of senescence is accompanied by a secretory network termed the senescence-associated secretory phenotype (SASP) that propagates tissue remodeling and senescent signaling. In skeletal muscle, there are currently no reports of secretory activity following activation of senescence. We hypothesized that by isolating satellite cells from human skeletal muscle and activating senescence in vitro, we could measure the secretory activity of skeletal muscle satellite cells (SkMSCs). Specifically, we …

The Effects Of Agronomic Management And 40 Years Of Variety Release On Soybean Seed Fill And Yield Components, Kathryn Graf

Open Access Theses

Soybean [Glycine max (L.) Merr.] management strategies have become more intensive in recent history in attempt to maximize yields, but how these treatments influence yield components is not well understood. Soybean yield can be simplified into the number of seeds per area and seed size. Seed size is the product of seed growth rate and seed fill duration. The objectives of this research were to determine the effects of agronomic management, through fertilization and foliar application of fungicide and insecticide, across cultivars from 3 decades (1970, 1990, and 2010) on seed growth and pod distribution throughout the soybean canopy. Six …

The Female Threat: Reactions To Increased Representation Of Women In Traditionally Male-Dominated Domains, Laura Hildebrand

Open Access Theses

A burgeoning literature indicates that people experience threat when presented with information about increasing diversity. Yet, most of this literature has focused on increasing racial diversity. In the present research, we examine how people respond to increased representation of women in traditionally male-dominated domains, including (a) what type of threat is elicited and (b) who is most likely to experience this threat. Men and women participants completed several sexism measures and read that the number of women was increasing (versus a neutral condition) in politics (Study 1) and engineering (Study 2). Then participants completed measures of realistic, group status, prototypicality, …

Understanding The Collaboration Difficulties Between Ux Designers And Developers In Agile Environments, Yun-Han Huang

Open Access Theses

With the growing number of UX designers in tech companies in the U.S., the collaboration between UX designers and developers in Agile environments has become a new challenge in the industry. This research study aims to understand the collaboration difficulties between UX designers and developers in Agile environments and further provides insights from the results. The research method was semi-structured interview. A total of five professional UX designers and five professional developers in the industry were interviewed about topics surrounding their collaboration difficulties. The results indicated that UX designers integrating in Agile environments and factors related of organizational context are …

Quasi-One Dimensional Modeling Of Rotational Detonation Engines, Jenna A. Humble

Open Access Theses

Due to stagnation in performance gain in rocket engines, rotating detonation engines (RDEs) have received renewed interest in recent years. This alternate engine cycle presents a large theoretical engine performance gain over constant pressure combustion engines; however, the complex flow fields in RDEs present significant challenges when attempting to determine engine performance for a given engine geometry and feed conditions. Currently in the literature, no simplified model exists to determine engine performance while taking into account the characteristic non-steady behavior of the injection system and the detonation propagation. The objective of this study was to determine if a quasi-one dimensional …

Co-Designing With Refugees: Addressing Challenges To Healthcare Access, Liz Irk

Open Access Theses

This master’s research study aims to contribute to the general body of HCI research focused on resettled refugees. No study in this field has been conducted with resettled refugees from Indianapolis, Indiana. There are many challenges and barriers that resettled refugees face before, during and after resettlement. This qualitative study explores the challenges that refugees in Indianapolis face after resettlement when they seek healthcare resources and services, and how technology and design can be used to help address those challenges by conducting co-design workshops. This research compares the perceptions of service providers with the perceptions of resettled refugees to discover …

The Multi-Market Effects Of Ethanol Policy Under Imperfect Competition, Toni Jankovski

Open Access Theses

The literature on the effects of ethanol policies on agricultural markets is vast and thorough. The overwhelming majority of this literature examines global and national markets. Yet, several studies have documented the fact that corn procurement by ethanol plants is highly geographically localized, suggesting that analyses at the national level may masquerade substantial heterogeneity at the local level. This thesis examines how the structure of local corn markets shape policy pass-through, and its implications on welfare. We do so by combining a partial equilibrium displacement model with a conjectural variations approach, which allows us to accommodate potential market power exertion …

Truck-Drone Hybrid Delivery Routing: Payload-Energy Dependency And No Fly Zones, Ho Young Jeong

Open Access Theses

The truck-drone hybrid delivery system uses a truck as a station for drones in addition to its delivery function and is getting attention because the strengths of these individual vehicles can be selectively and synergistically exploited. In this study, the previous vehicle routing models are extended to the hybrid delivery systems by taking into account two important practical issues: the effect of parcel weight on drone energy consumption and prohibited flying areas. The flight range of the drones is heavily susceptible to the loaded weight due to the limited battery life. Drones are also not allowed to fly over sensitive …

Stochastic Techno-Economic Analysis Of Electricity Produced From Poplar Plantations In Indiana, Dawoon Jeong

Open Access Theses

This study evaluates the feasibility of a 100% biomass direct firing biopower plant in Indiana. As a major biomass fuel, short-rotation coppice (SRC) poplar (Populus spp.) is chosen because of its high biomass productivity. The poplar plantation yield and moisture content data were collected from an actual field trial conducted in southern Indiana (Southwest Purdue Agricultural Center, SWPAC) beginning in 2013. Biomass Bubbling Fluidized Bed (BBFB) boiler and steam-turbine technology is used as the electricity-generating unit. For the three stochastic parameters (yield, moisture content, and planting costs), we estimate the system break-even price distribution through Monte Carlo simulation. We find …

Phosphorus Sorption In Drainage Channel-Floodplain Systems In Agricultural Watersheds, Alexander N. Johnson

Open Access Theses

The two-stage channel is an in-stream conservation practice that creates inset floodplains in agricultural drainage channels and stabilizes streambanks. Inset floodplains are excavated adjacent to the channel, hydrologically reconnecting it to the main channel and tripling the reactive surface area during high flow events. It is uncertain what effect these channel designs have on complex phosphorus (P) dynamics in the stream and in the floodplain, both during baseflow and when channels are flooded. In order to evaluate these practices as a P management strategy, we took soil and water samples from streambed sediments and floodplain soils in 10 two-stage channels …

Take All You Want, But Eat All You Take: Effectiveness Of A Financial Incentive On Individual Food Waste, Nina Jovanovic

Open Access Theses

This study investigates the effect of a fixed financial incentive on students’ food consumption and food wastage behavior. We hypothesize that students will change their behavior under financial incentive with respect to the (1) amount of food taken and (2) associated plate waste. To test our hypothesis, we conduct a randomized control trial experiment at an all-you-can-eat university dining hall, and employ digital photography method to collect daily consumption and waste data for each student. We estimate the amount of food taken on the plate and the amount of plate waste to the nearest 10%. The results indicate the financial …

Mitigating Multi-Stage Attacks In Software Defined Network-Based Distributed Systems, Subramaniyam Kannan

Open Access Theses

Multi-layer distributed systems, such as those found in enterprise networks, are often the target of multi-stage attacks (MSA). In MSA, an attacker compromises external-facing services and then penetrates progressively into deeper services in a stepping-stone manner, by using elevated privileges at each system component, until finally the attacker gains access to the crown jewel of the system (such as, some protected data). Under such attacks, it is difficult to identify the upstream attacker’s identity from a downstream victim machine because of the mixing of multiple network flows. This thesis presents TOPHAT, a system that solves such attribution problems for multi-stage …

Conditioned Medium From Dysfunctional Endothelial Cells Negatively Regulates Satellite Cell Expansion And Differentiation, Christopher Kargl

Open Access Theses

Dysfunction of the endothelial lining of the cardiovascular system is a hallmark symptom of both cardiovascular disease (CVD) and type II diabetes mellitus (T2DM). The dysfunctional endothelial cell phenotype is characterized by an increase in production and release of inflammatory cytokines and reactive oxygen species (ROS) and a decrease in nitric oxide (NO) and growth factor secretion. Evidence has emerged showing a close relationship between endothelial cells and skeletal muscle satellite/progenitor cells. Skeletal muscle cell growth and differentiation are impaired in oxidative environments and many endothelial dysfunction-related diseases. The purpose of the current study is to determine the impact that …

Extrusion Deposition Additive Manufacturing For High Temperature Tooling, Sushrut Karmarkar

Open Access Theses

The Extrusion Deposition Additive Manufacturing (EDAM) process finds a prominent application for composite tooling and prototyping. Estimation of tool deformation and tool shape compensation is essential in designing tools for composite parts manufactured with autoclave and oven cure cycles at high temperatures. Tool shape compensation is a challenge in additively manufactured tool due to the inherent anisotropy of the material and printing parameters based properties of the tool. The simulation tools developed by the Additive Manufacturing Group for the Composite Additive Manufacturing Research Instrument (CAMRI) at Purdue University were used to design the tool shape for the step section of …

Dielectrically-Accurate Tissue Simulating Materials For A Heterogeneous Breast Mri Phantom, Liesl A. Krause

Open Access Theses

Phantoms, which are non-biological test objects, are used to validate a variety of biomedical imaging modalities for accuracy and safety. In MRI, phantoms can be used, specifically, to test safety with regards to SAR and RF heating. This is of particular importance when developing new imaging protocols related to a specific anatomy, MRI use, or other software or hardware updates. Discussed in this thesis is the creation of an anatomically accurate breast phantom for safety testing before use of novel MRI protocols for breast cancer diagnostic imaging. Previous MRI breast phantoms are either homogeneous or have barriers between tissue types, …

Experimental Investigation Of Foam-Phase Change Material Interactions For Thermal Energy Storage, Prahlad Kulkarni

Open Access Theses

High-density electronics and avionics such as Insulated gate bipolar transistor (IJBTs) and transistors, as well as vehicles themselves, generate excess heat, which must be dissipated to prevent overheating and failure. Phase change materials (PCMs) both rapidly dissipate heat through melting and can store this useful thermal energy for future use. The effectiveness of PCMs is limited by low thermal conductivity, thus, high conductivity metal foams are often introduced to improve the thermal storage performance. In the first part of this thesis, the melting and solidification behavior of a phase change material in a single millimeter-scale cavity is investigated with high …

A Core Calculus For Data Refinement, Paul M. Krogmeier

Open Access Theses

A hallmark of modern programming languages is the strict isolation guarantees they provide to clients and creators of data abstractions, guarantees which are backed by decades-old foundational proofs of representation independence. Recent program synthesis frameworks have exploited these guarantees to ensure that clients are protected from any algorithmic and data structure choices made when producing an implementation from a high-level specification. By their nature, such specifications admit a large number of behaviors, introducing a formal gap between the functional correctness guarantees provided by the synthesis engine and the data abstraction guarantees provided by the programming language. To bridge the gap, …

Direct Numerical Simulation Of Kelvin-Helmholtz Instability And Interfacial Stress Tensor Modeling, Jinpin Lin

Open Access Theses

The development of the Kelvin-Helmholtz instability for the stratified, large density ratio flow in rectangular channels is investigated and the models for the interfacial shear stress and interfacial pressure of small-amplitude waves based on the linear analysis are derived. A reduced geometrical model is adopted, and the 2D and 3D simulation results are compared with previous experiments. It is shown that the generation and development of the Kelvin-Helmholtz instability are successfully captured. The numerical simulation tends to underestimate the wave length. The onset of the instability for the experiment is earlier than that in the 2D simulation, while it is …

Study Of Identifying Jaywalkers By Analyzing Camera Data, Yifan Li

Open Access Theses

Jaywalking is an unlawful pedestrian behavior. In the United States, jaywalking leads to hundreds of pedestrian fatalities each year [1]. Existing studies analyzed pedestrian behaviors by computer vision platforms. However, many of those existing platforms were not capable of detecting the single pedestrian in crowded traffic scenes. Those platforms were implemented based on the motion-based pedestrian detector, and the motion-based detector cannot detect pedestrians who are partially occluded or close to other moving objects. Furthermore, those existing platforms did not focus on jaywalker identification; those platforms need manual annotation to distinguish jaywalkers among all pedestrians.

This study proposes a jaywalker-identifying …

Fatigue Damage Modeling Approach Based On Moving Power Spectrum Density, Zhui Li

Open Access Theses

Fatigue damage estimation has long been treated as an important area of research in order to design machines and structures dependably during their entire lifetime. The durability of engineering components and structures under expected vibrational environment must be assessed to meet design requirements for the reliability and safety in the service life. In past decades, fatigue damage estimation approaches in both time domain and frequency domain have been developed to simulate the operational life of the structures under severe vibrations.

Current frequency fatigue prediction methods for accelerated vibration loading conditions, however, are based on stationary Power Spectral Density (PSD) inputs. …

Design And Analysis Of A Body-Powered Underactuated Prosthetic Hand, Hun Chan Lee

Open Access Theses

As affordable and efficient 3-D printers became widely available, researchers are focusing on developing prosthetic hands that are reasonably priced and effective at the same time. By allowing anyone with a 3-D printer to build their body powered prosthetic hands, many people could build their own prosthetic hand. However, one of the major problems with the current designs is the user must bend and hold their wrist in an awkward position to grasp an object.

The primary goal of this thesis is to present the design process and analysis of a mechanical operated, underactuated prosthetic hand with a novel ratcheting …

Controlled Drainage: Assessment Of Yield Impacts And Education Effectiveness, Amanda Locker

Open Access Theses

Controlled drainage is the practice of using a water control structure to hold water in agricultural fields during periods when drainage is unnecessary. The use of this practice may increase crop yields compared to subsurface drainage because during the growing season controlled drainage can capture water from precipitation, and raise the water table for crop use. Results from published studies of controlled drainage impacts on crop yields have been mixed, and the effects of field characteristics and annual weather variation on these impacts are not well understood. For widespread adoption of controlled drainage, more information on how controlled drainage impacts …

Development Of High Frequency Virtual Thermocouples, Shengqi Lu

Open Access Theses

This thesis is dedicated in development of temperature measurement technique based on K-type thermocouple. Assessment of thermocouple response is conducted with the assistance of complete conjugate heat transfer simulations. Numerical results are acquired from an instantaneous solution of heat transfer between the interface of fluid and solid. Enormous CFD cases are analyzed with variations of gas temperature, gas pressure and wall temperature for a series of thermocouples at 6µm,12µm,25µm, and 50µm. The second-order transfer function is used to characterize the properties of response curves in discrete-time domain. Effect of the different parameters to thermocouple response is concluded in terms of …

Modeling, Simulation, And Design Of A Radial Piston Digital Displacement Unit, James R. Marschand

Open Access Theses

State of the art variable displacement pumps experience a reduction in efficiency when operating at low displacements. Digital pumps using high speed on/off valves to control fluid entering and leaving the displacement chamber can increase efficiency by eliminating the leakage and friction associated with the port plate and swash plate. Because the displacement chamber is only pressurized during a portion of the piston stroke, leakages scale with displacement which increases efficiency of these units. The largest increase in efficiency comes at low displacements creating a more efficient pump across the entire operating range. Partial displacement can be achieved using four …

Psychophysiological Correlates Of Childhood Maltreatment And Physical Aggression Perpetration, Andrea Massa

Open Access Theses

Objective: Trauma exposure and symptoms of posttraumatic stress disorder (PTSD) have been consistently linked with aggression perpetration in past research. One theory that has been used to help explain the association between trauma and aggression is the “survival mode” theory, which proposes that traumatized individuals develop an overactive threat detection system, which leads to a greater propensity for anger and aggression. The purpose of the current study was to empirically test the survival mode theory of aggression using a novel methodology. Method: Participants in the current study included 20 undergraduate students from a large university. Participants completed self-report measures of …