Digital Commons Network^™

Spatial Genetic And Distribution Modeling For The Conservation Of Hellbender Salamanders, Emily Boersma Mccallen

Open Access Dissertations

Ecological data is inherently spatial; however, it is still the norm to model ecological data as spatially invariant. Failure to account for spatial structure in response variables and modeled relationships can result in inflated coefficient values, shifts in the relative importance and sign of predictors, cross-scale contradictions in relationships, and reduced predictive power due to the averaging of modeled relationships. When ecological models are used to support conservation decision-making, model error can be costly leading to both misallocation of limited resources and distrust of science-based management.

My dissertation focuses on developing methods to account for spatial structure in two models …

Credit Network Payment Systems: Security, Privacy And Decentralization, Pedro Moreno Sanchez

Open Access Dissertations

A credit network models transitive trust between users and enables transactions between arbitrary pairs of users. With their flexible design and robustness against intrusions, credit networks form the basis of Sybil-tolerant social networks, spam-resistant communication protocols, and payment settlement systems. For instance, the Ripple credit network is used today by various banks worldwide as their backbone for cross-currency transactions. Open credit networks, however, expose users’ credit links as well as the transaction volumes to the public. This raises a significant privacy concern, which has largely been ignored by the research on credit networks so far.

In this state of affairs, …

Visual Analytics To Support Atomistic Simulations Design, Daniel Felipe Mejia Padilla

Open Access Dissertations

Nowadays, complex simulations of a variety of processes are extensively used in academia and industry. Particularly in academia, powerful scientific software tools are constantly developed to simulate complex systems; for instance, simulations of quantum transport using the non-equilibrium greens Function formalism. The potential impact of these scientific tools in industry is huge, but it is hindered by the lack of usability of the software by those who are not deeply familiar with it. Visual analytics is a new field that has shown the positive impact of interactive visualizations in software usability and the cognitive process of the user. This research …

Framework For Assessing The Pavement Surface Evaluation And Rating Method In Pavement Management Plans, Sharlan R. Montgomery

Open Access Dissertations

With the increasing popularity and use of the pavement surface evaluation and rating (PASER) method by local agencies throughout the U.S., the variability inherent in manual condition assessments, and the lack of research pertaining to the PASER method, there is a need to better understand the PASER method and its use by local agencies. This research consisted of three research phases. Phase 1 investigated the relationship between the pavement condition index (PCI) and PASER. Corresponding PCI and PASER data were collected for both asphalt and concrete pavement segments. Both a general linear regression model and an ordered probability model were …

Hybrid Cloud Model Checking Using The Interaction Layer Of Harms For Ambient Intelligent Systems, Mauricio Alejandro Gomez Morales

Open Access Dissertations

Soon, humans will be co-living and taking advantage of the help of multi-agent systems in a broader way than the present. Such systems will involve machines or devices of any variety, including robots. These kind of solutions will adapt to the special needs of each individual. However, to the concern of this research effort, systems like the ones mentioned above might encounter situations that will not be seen before execution time. It is understood that there are two possible outcomes that could materialize; either keep working without corrective measures, which could lead to an entirely different end or completely stop …

Towards Ontology-Based Phishing Detection, Gilchan Park

Open Access Dissertations

Detection of phishing emails is a topic that has received a lot of attention both from academia and industry due to the devastating effects that phishing enabled data breaches have had on private individual and companies. Notwithstanding enormous efforts to detect phishing attacks, phishing still remains a major threat in information security, and the damages from it are not forecasted to disappear in the near future. One of the reasons is the diversity of attacks, especially within spear phishing and whaling. Another reason is that the natural language part of the detectors is usually devoid of semantics. Many of the …

Corporate Social Responsibility Of Construction And Real Estate Development Companies In Developing Countries: An Assessment Model, Ahmed Nabil Abdel-Salam

Open Access Dissertations

Corporate Social Responsibility (CSR) contributes significantly to the community development which is based on the principles of fairness, social justice, participation, and continuous learning with core emphasis on educating, enabling, and empowering community members. CSR not only helps to develop the community but also contributes toward sustainable development of business. Companies involved in the construction industry are serving several stakeholders internally and externally. In this dissertation, CSR, with regard to two stakeholders (company employees and the community) is studied to assess the mutual impacts between the company and the community.

The main objective of this research is to develop guidelines …

Hispanic Children Thrown Into Limbo: Language Ideologies Of Spanish Heritage Speakers And Their English Peers In A Monolingual And A Bilingual School In Indiana, Carmen Octavio

Open Access Dissertations

Spanish heritage speakers are a growing and heterogeneous population that shares a status of inequality within society regarding their language and culture. This study explored the language ideologies of Spanish heritage speakers and their English peers in two different settings: an urban monolingual school and a sub-urban bilingual school with a Dual-Immersion language program in Indiana.

The focus for heritage language students in US schools is usually on the linguistic components of bilingual or English monolingual development and does not focus on ideologies or climate within classrooms where heritage students are taught. With little to no focus on ideologies or …

Electrolytic Microsystems For Biomedical Applications, Satya V.R.V. Tejasvi Parupudi

Open Access Dissertations

With an American dying each minute due to cancer and with a global burden of over $170 billion by 2020, there is a critical need for alternate solutions, especially for deep-seated, inoperable tumors in the liver and brain. Systemic chemotherapy has side effects and radiation is expensive. Challenges of current technologies for treating the liver include poor performance near vascular structures and the inability to treat multiple nodular tumors. Brain tumor treatment suffers from inadequate intra-cerebral drug concentration and uncontrollable drug delivery. These difficulties motivate the development of low-cost solutions that have fractionated application and are localized, monitored, and compatible …

Residual Dimension Of Finitely Generated Nilpotent Groups, Mark A. Pengitore

Open Access Dissertations

In previous work, the author claimed an effective characterization for residual finiteness and lower asymptotic bounds for conjugacy separability of all finitely generated nilpotent groups. However, a counterexample to the characterization of residual finiteness for finitely generated nilpotent groups was communicated to the author which also had consequences to the lower asymptotic bound provided for conjugacy separability for the class of finitely generated nilpotent groups. Subsequently, the statements of the asymptotic characterization of residual finiteness and the asymptotic lower bound for conjugacy separability for the same class of groups along with their proofs are incorrect. In this article, we provide …

Low Temperature Simulations Framework For Quantum Dots And Point Contacts., Harshad Sahasrabudhe

Open Access Dissertations

Quantum computing is becoming increasingly important due to its potential in solving complex optimization problems such as protein folding, and the ability to model correlated electronic systems. Designing of semiconductor based quantum computers is challenging due to the vast number of parameters that need to be optimized from fabrication to their operation. Simulations of these devices could help with the design process. A computational modeling framework is presented that can model quantum point contacts and quantum dots, which are the building blocks of semiconductor based quantum computers. Care was taken to minimize the number of parameters, and use only those …

Online Data Cleaning, Elkindi Rezig

Open Access Dissertations

Data-centric applications have never been more ubiquitous in our lives, e.g., search engines, route navigation and social media. This has brought along a new age where digital data is at the core of many decisions we make as individuals, e.g., looking for the most scenic route to plan a road trip, or as professionals, e.g., analysing customers’ transactions to predict the best time to restock different products. However, the surge in data generation has also led to creating massive amounts of dirty data, i.e., inaccurate or redundant data. Using dirty data to inform business decisions comes with dire consequences, for …

Regulation Of Thermogenic And Inflammatory Response In Adipose Tissue By 18-C Fatty Acids, Sunhyue Shin

Open Access Dissertations

Dietary fatty acids, in particular long-chain fatty acids (LCFA), are involved in the regulation of metabolic, oxidative, and inflammatory responses. This is a mechanism by which fatty acids participate in the regulation of energy homeostasis and impact development of obesity, type 2 diabetes, and cardiovascular diseases. White and brown adipose tissue play a significant role in energy storage and expenditure through fatty acid uptake and oxidation. LCFA, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have been reported to induce thermogenesis by activating brown and beige adipocytes to oxidize more fuel molecules. However, the effects of 18-carbon (18-C) LCFA with …

A Study Of Techniques And Mechanisms Of Vagus Nerve Stimulation For Treatment Of Inflammation, Jesse P. Somann

Open Access Dissertations

Vagus nerve stimulation (VNS) has been on the forefront of inflammatory disorder research for the better part of the last three decades and has yielded many promising results. There remains, however, much debate about the actual biological mechanisms of such treatments, as well as, questions about inconsistencies in methods used in many research efforts.

In this work, I identify shortcomings in past VNS methods and submit new developments and findings that can progress the research community towards more selective and relevant VNS research and treatments. In Aim 1, I present the most recent advancements in the capabilities of our fully …

Design And Characterization Of Optical Fiber-To-Chip Edge Couplers And On-Chip Mode Division Multiplexing Devices, Min Teng

Open Access Dissertations

Integrated silicon photonics has recently emerged as a promising solution to data interconnection in large data centers, which are characterized by short-range (0.5 – 2 km) and high bandwidth, i.e. 400 Giga-bit-per-second. Light from an external laser is first coupled to a silicon photonic chip, splits and modulated to carry data, and then multiplexed and coupled out to one or more optical fibers to take advantage of their large data bandwidth over their electric counterparts. However, short-range optical communication is still faced with several technical challenges. First, the difficulty to couple light between optical fibers and chips leads directly to …

Non-Suicidal Self-Injury In First-Year College Students: The Testing Of A Nonlinear Integrated Model, Natasha Pryde Trujillo

Open Access Dissertations

Non-suicidal self-injury (NSSI) is an increasing concern among college students (Whitlock, Muehlenkamp, & Eckenrode, 2008). First-year college students, who are in the midst of transitioning to the college environment, are often at increased risk for problematic behaviors or maladaptive coping as they adjust to the varied changes that take place during this crucial developmental phase (Chickering & Reisser, 1993, Fromme, Corbin, & Krause, 2008). First-year college students may be at particular risk for NSSI engagement because of the developmental, interpersonal, and intrapersonal demands that accompany the transition to college. Further, first-year students who have experienced aversive life events connected to …

Environmental Life Cycle Impact And Complexity Assessment Of Rare Earth Production, Ehsan Vahidi Movassagh

Open Access Dissertations

Rare Earth Elements (REEs) find applications in clean energy technology, including wind turbines, electric vehicles, and high efficiency lighting therefore, as the renewable energy market expands, demand of REEs is anticipated to rise. However, it is well known that the production of REEs carries large environmental burden and as a result, reducing environmental footprints of REE production becomes critical. The first action towards reducing the environmental degradation during production of REEs is the thorough examination of the energy requirements and environmental emissions. To date, Life Cycle Assessment (LCA) is the standard methodology to evaluate the environmental performance of a system, …

Program Transformation For Secure And Sustainable Web Applications, Weihang Wang

Open Access Dissertations

Web advertising is a multi-billion-dollar industry. As a primary source of income for many Internet companies, web advertising (ads) has a profound impact on the security and sustainability of today’s web ecosystem. Web advertising, however, is extremely complex and highly vulnerable to attacks. In fact, attackers using the web advertising system as a channel to spread malware has become some of today’s largest web-based attacks. To protect users from malicious advertising, we develop a memory randomization system, PAD, that effectively prevents malicious advertising (malvertising) attacks exploiting zero-day vulnerabilities.

To reduce the risk of malicious ads and remove unwanted ads, recent …

Materials Design With Molecular Dynamics: Novel Properties In Martensitic Alloys Through Free Energy Landscape Engineering, Samuel Temple Reeve

Open Access Dissertations

Novel properties in martensitic alloys are predicted using molecular dynamics (MD) simulations, the uncertainty from input models in MD is explored and quantified, and new data infrastructure for MD is developed.

The possible regimes of material properties are extended through free energy landscape engineering (FELE), where coherent, epitaxial integration of two materials at the nanoscale can result in metamaterials with fundamentally different behavior. Free energy as a function of strain is calculated using MD simulations and analytically combined to predict potential new properties for a Ni 63% - Al 37% martensitic alloy combined with B2 NiAl, shown to be an …

Parental Divorce, Parental Conflict Dimensions, Perception Of Gains, Growth, And Parent-Child Relationship In College Students, Matthew M. Welsh

Open Access Dissertations

The primary focus of this study was to examine the possible associations among perceptions of pre-divorce parental conflict, perceived gains of parental divorce, posttraumatic growth, and current relationship quality with parents. The literature review focuses on college student development, empirical studies related to negative and positive outcomes for children, adolescents, and college students of divorce, and factors related to negative and positive outcomes for children, adolescents, and college students of divorce. Findings are based on data I collected from 430 participants from Purdue University. I addressed my questions and tested the associated hypotheses through the use of MANOVA and hierarchical …

Functional Analysis Of Er-Localized Ubac2 And Ubac2-Interacting Proteins From Arabidopsis, Zhe Wang

Open Access Dissertations

Selective autophagy targets specific cargo by autophagy receptors through interaction with ATG8 (autophagy-related protein 8)/MAP1LC3 (microtubule associated protein 1 light chain 3) for degradation in the vacuole. Here, we report the identification and characterization of three related ATG8-interacting proteins (AT1G17780/ATI3A, AT2G16575/ATI3B and AT1G73130/ATI3C) from Arabidopsis. ATI3 proteins contain a WxxL LC3-interacting region (LIR) motif at the C terminus required for interaction with ATG8. ATI3 homologs are found only in dicots but not in other organisms including monocots. Disruption of ATI3A does not alter plant growth or development but compromises both plant heat tolerance and resistance to the necrotrophic fungal pathogen …

The Dark Side Of High-Quality Lmx: Relational Tensions And Their Impacts On Leaders And Members, Lusi Wu

Open Access Dissertations

As one of the most popular approaches to study leadership, the leader-member exchange (LMX) theory focuses on the dyadic relationship between a leader and a member (Gerstner & Day, 1997; Graen & Uhl-Bien, 1995). It posits that supervisors develop different forms of exchange relationships with followers (Sparrowe & Liden, 1997). Low quality LMX is more like economic exchange based on mutually agreed on duties, while high quality LMX is characterized by trust, support, loyalty, and commitment (Uhl-Bien & Maslyn, 2003). Past LMX studies have documented and supported many positive outcomes for high-quality LMX subordinates, such as higher job satisfaction, organizational …

Mapping Underground Utilities With Complex Spatial Configurations Using Ground Penetrating Radar, Chenxi Yuan

Open Access Dissertations

Records of the locations, measures, and properties of over 20 million mileage underground utility networks in the US are incomplete, inaccurate, and many times unavailable. This lack of information of underground pipes and cables is a primary reason for over six million of utility interruptions every year that cause injuries, fatalities, property damages, and environmental pollutions, amounting to over eight billions of dollars in loss. It also poses a critical challenge to maintaining and upgrading the ageing underground infrastructure with a D+ score according to the American Society of Civil Engineers’ Report Card. There is a critical need for accurately …

A Comprehensive Analysis Of Estimating Land Use Change Emissions Induced By Global Aviation Biofuels Production Using Economic Equilibrium Models, Xin Zhao

Open Access Dissertations

This dissertation is comprised of three independent but closely related essays, which provide new insights on estimating biofuels induced land use (ILUC) change and related emissions from distinct perspectives. The first essay in this dissertation developed the framework for estimating aviation biofuels induced land use change emissions using GTAP-BIO and its coupled emission model, AEZ-EF. We translate International Energy Agency (IEA) projections into appropriate shock sizes by region and pathway. We make modifications in GTAP-BIO to introduce the aviation biofuels pathways and update AEZ-EF based on new data. Twelve aviation biofuels pathways, produced using four technologies including Hydroprocessed Esters and …

Adaptive Communication For Wireless Massive Mimo Systems, Ahmed A. Ibrahim

Open Access Dissertations

The demand for high data rates in wireless communications is increasing rapidly. One way to provide reliable communication with increased rates is massive multiple-input multiple-output (MIMO) systems where a large number of antennas is deployed. We analyze three systems utilizing a large number of antennas to provide enhancement in the performance of wireless communications. First, we consider a general form of spatial modulation (SM) systems where the number of transmitted data streams is allowed to vary and we refer to it as generalized spatial modulation with multiplexing (GSMM). A Gaussian mixture model (GMM) is shown to accurately model the transmitted …

Laboratory Safety Training Design And Evaluation For Aeronautical Engineering Technology Students In Part 147 Program, Xun Zhao

Open Access Dissertations

The FAA Part 147 program at Purdue University requires students in Aeronautical Engineering Technology (AET) major to take 1125 hours of laboratory works. Students are required to work in several different laboratory environments including airframe, powerplant, aircraft sheet metal processing, composite materials processing, electricity and electronics, non-destructive testing, aircraft system, maintenance practices and advanced manufacturing. Although course instructors emphasize laboratory safety, there is currently no pre-laboratory training for all students before they log any laboratory hours. Starting from 2004, occupational injuries and illness rates in the air transportation industry were shown to be much higher than the average for private …

Early Turn-Taking Prediction For Human Robot Collaboration, Tian Zhou

Open Access Dissertations

To enable natural and fluent human robot collaboration, it is critical for a robot to comprehend their human partners’ on-going actions, predict their behaviors in the near future, and plan its actions accordingly. Specifically, the capability of making early predictions can allow robots to determine the precise timing of turn-taking events and start planning and executing preparative tasks to take the turn. Such proactive behavior would save waiting time and increase efficiency and naturalness in collaborative tasks.

To that end, this dissertation presents the design and implementation of an early turn-taking prediction framework, centered around physical human robot collaboration tasks. …

Websites For Physics Demonstrations And Computer Simulations: A Non-Educational Quality Evaluation, Zheng Zhou

Open Access Dissertations

Scientific disciplines including mathematics, physics, and chemistry tend to adopt online resources, including websites and web applications, to demonstrate physical experiments and simulate scientific phenomena that are hard to observe and investigate in real world. The present study examined the existing collections of the websites and web applications created in academics for physics demonstrations and computer simulations. The present study discovered the existing collections of websites lack update and more recent resources. The present study conducted a state-of-the-art literature review to amend, update, and supplement the existing collection of the websites for physics demonstrations and computer simulations to a comprehensive …

Throughput And Efficiency Analysis Of Network-Coded Harq For Two-Way Wireless Systems, Hongyi Zhu

Open Access Dissertations

Due to the explosive increase of wireless subscribers, it becomes more crucial to efficiently use the limited spectrum resources. To improve spectral efficiency, this study explores network-coded (NCed) automatic repeat request (ARQ) in two-way wireless systems. NCed-ARQ has been proved effective in multi-cast and broadcast channels by utilizing the side-information overheard during retransmissions. However, most wireless networks are two-way where each node transmits and receives. In two-way wireless systems, more side-information can be used to enhance the throughput performance with network coding, which has not received much attention. In this study, we propose a new NCed-ARQ scheme with reverse-link assistance …

Modeling The Behavioral Landscape Ecology Of A Reintroduced Carnivore, Casey C. Day

Open Access Dissertations

The American marten (Martes Americana) is an endangered forest carnivore native to the Upper Midwestern United States and culturally significant to local Ojibwe tribes. In this region, the marten faces a number of potential threats to its persistence, including competition, predation, lack of prey availability, lack of recruitment, and lack of population connectivity. To evaluate how marten behavior affects the conservation and management of this species, I developed an individual-based model to simulate marten dispersal and home range establishment. In Chapter 2, I describe the model and the process of calibrating it to perform comparably to real-world martens. I also …