Digital Commons Network^™

Co-Design Of Reconfigurable And Multifunction Passive Rf/Microwave Components, Mohamed F. Hagag

Open Access Dissertations

In order to meet the market demands, multi-band communication systems that are able to accommodate different wireless technologies to be compatible with different wireless standards should be investigated and realized. Multifunction and multi-band RF front-end components are promising solutions for reducing the size and enhancing the performance of multi-band communication systems. This dissertation focuses on the design and implementation of different multifunction and tunable microwave components for use in multi-standard, flexible transceiver.

For frequency-domain duplexing (FDD) communication systems, in which the uplink and downlink channels are carried on different RF frequencies, a diplexer is an essential component to separate the …

Holostream: High-Accuracy, High-Speed 3d Range Video Encoding And Streaming, Tyler Bell

Open Access Dissertations

In recent decades, three-dimensional (3D) scanning techniques have improved in terms of speed, quality, and usability. These improvements have helped 3D scanning applications become increasingly popular within many different fields and industries, such as entertainment, security, manufacturing, and human computer interaction. However useful, real-time 3D scanning techniques generate large amounts of data, which may limit real-time storage or transmission of acquired 3D data. A platform which can enable high-quality, low-bandwidth 3D video communications could then be very useful within a broad range of applications, for example, telemedicine.

The goal of telemedicine is to use telecommunications technology to remotely diagnose, monitor, …

Interactions Between Sodium Caseinate And Polyglucose In Aqueous Solutions, Angarika Rayate

Open Access Theses

Biopolymers interactions have been widely studied to understand their impact on the texture and shelf life of food products. The effect of addition of sodium caseinate on the physical and rheological properties of solutions containing poly-glucose compounds (dextran, maltodextrin), at neutral pH and varying biopolymer concentrations, have been investigated. Through a combination of characterization tools, the properties for the mixed biopolymer systems are correlated to the nature of the interactions between the two biopolymers involved.

For systems containing sodium caseinate and dextran, biopolymer incompatibility, leading to phase separation, was observed as there were minimal changes detected in the particle size …

The Consequences Of Legalizing Recreational Marijuana: Evidence From Colorado And Washington, Ty Miller

Open Access Dissertations

In December of 2012, Washington and Colorado implemented the legalization of possession and use of marijuana for recreational purposes. Following this, January of 2014, Colorado opened the first recreational marijuana dispensaries in the United States. Although the debate about recreational marijuana has been fought in the public and academic spheres, we have limited empirical data as to the effect of these policies. With this, arguments in regard to whether marijuana should be legalized in the United States have far outpaced reliable scientific research. As more states, and potentially the federal government, begin to vote on whether to legalize, reliable research …

Multi-Dimensional Data Analytics And Deep Learning Via Tensor Networks, Wenqi Wang

Open Access Dissertations

With the booming of big data and multi-sensor technology, multi-dimensional data, known as tensors, has demonstrated promising capability in capturing multidimensional correlation via efficiently extracting the latent structures, and drawn considerable attention in multiple disciplines such as image processing, recommender system, data analytics, etc. In addition to the multi-dimensional nature of real data, artificially designed tensors, referred as layers in deep neural networks, have also been intensively investigated and achieved the state-of-the-art performance in imaging processing, speech processing, and natural language understanding.

However, algorithms related with multi-dimensional data are unfortunately expensive in computation and storage, thus limiting its application when …

The Intimate Partner Violence Experience Of Arab Immigrant Women In The U.S., Aieyat B. Zalzala

Open Access Dissertations

Intimate partner violence (IPV) is a significant problem for immigrant women in the U.S. There are a number of unique risk factors and help-seeking barriers (e.g., patriarchal beliefs, lack of social support, immigration status, language as a barrier, limited knowledge about and access to resources) that contribute to the likelihood of immigrant women being in and remaining in violent relationships. As a result, immigrant women often feel isolated, alone, and silenced in their attempt to address their IPV. However, we know less about the IPV experience of Arab immigrant women in the U.S. as these women hold multiple marginalized identities …

Mesoscale Modeling Of Defects And Phase Transformations In Crystalline Materials, Yifei Zeng

Open Access Dissertations

Strength of nanolayered metallic composite, stacking fault strengthening mechanism in random alloys especially high entropy alloys and solid state amorphization during mechanical milling are investigated in detail using phase field based method. Nanolayered metallic composite are comprised of alternating layers of two or more different metallic phases. It exhibits superior strength and ductility in ambient and extreme environment [1–4]. The key phenomenon characterizing the strength of this material is the slip transmission of single dislocation from one layer to the other. It is observed that both the modulus and the lattice parameters of different phases affect the slip transmission strength. …

Gist Of A Gest: Learning Gestures For The First Time, Maria Eugenia Cabrera Ubaldi

Open Access Dissertations

Humans are able to understand meaning intuitively and generalize from a single observation, as opposed to machines which require several examples to learn and recognize a new physical expression. This trait is one of the main roadblocks in natural human-machine interaction. Particularly, in gestures which are an intrinsic part of human communication. In the aim of natural interaction with machines, a framework must be developed to include the adaptability humans portray to understand gestures from a single observation. This problem is known as one-shot gesture recognition, and it has been researched previously. Nevertheless, most approaches rely heavily on purely numerical …

Producing Nanoscale Laser Spot And Its Applications, Anurup Datta

Open Access Dissertations

Driven by the exponential growth in the field of nanotechnology in the last few decades, there has been a huge impetus in the design and production of subwavelength nanoscale laser spot which has found wide range of applications in different fields such as nanofabrication and data storage, among others. Limited by the diffraction limit of light when using conventional optics, generally metallic nano-apertures and nano-antennas are used for producing sub-100 nm spots. Design of such types of nano structures typically involves the use of surface plasmons to effectively collect and concentrate light below the diffraction limit. This work discusses the …

Pathology Or Neurodiversity?: Cognitive Accessibility And The Rhetorical Construction Of Adhd In Higher Education, Samuel James Dunn

Open Access Dissertations

It is estimated that 2-8% of college students (approximately 1 in 20) report clinically significant diagnoses of attention deficit hyperactivity disorder (ADHD). Typically, those with verifiable diagnoses of ADHD are eligible to receive certain accommodations through the university which, in theory, put them on even footing with their peers; however there has been very little research done to actively address the needs of these students in the context of the composition classroom itself. To address this gap, in this dissertation I discuss the rhetorical positioning and identity construction of ADHD in the contemporary American university and ways in which composition …

Detecting Popularity Of Ideas And Individuals In Online Community, Chien-Yi Hsiang

Open Access Dissertations

Research in the last decade has prioritized the effects of online texts and online behaviors on user information prediction. However, the previous research overlooks the overall meaning of online texts and more detailed features about users’ online behaviors. The purpose of the research is to detect the adopted ideas, the popularity of ideas, and the popularity of individuals by identifying the overall meaning of online texts and the centrality features based on user’s online interactions within an online community.

To gain insights into the research questions, the online discussions on MyStarbucksIdea website is examined in this research. MyStarbucksIdea had launched …

Graphic Design Students' Development Of Adaptive Expertise In Ideation Strategies, Shih-Ping Kuo

Open Access Dissertations

This exploratory study uses the convergent design of mixed methods to integrate adaptive expertise theory to study how individual student participant from graphic design or non-graphic-design majors to solve a novel ideation problem in graphic design. Adaptive expertise includes six dimensions: metacognition, flexibility, dynamic knowledge, ability to welcome challenges, efficiency and deep understanding of the domain knowledge, and multiple perspectives. Those are desired qualities for a learner to stand out in the global market that are constantly changing with complex challenges. Thirty undergraduate students participated in this study. This study aims to answer four questions: types of graphic design tool …

The Mathematical Content Preparation Of Elementary Teachers, Brooke Max

Open Access Dissertations

Prospective elementary teachers’ (PTs) preparation often includes courses focused on deepening K–8 mathematical content knowledge and, in some cases, considering the content from a teacher’s perspective. Standards and recommendations from professional organizations have included attention to mathematical content (e.g., Mathematical Education of Teachers II [MET II]), mathematical processes (e.g., Common Core State Standards for Mathematics: Standards for Mathematical Practice [CCSSM SMPs]), and mathematical proficiency (e.g., Adding It Up). The publication of these documents has raised questions about how mathematics teacher educators (MTEs) incorporate these standards and recommendations in PTs’ coursework, particularly in Mathematics Content for Elementary Teachers (MCfET) courses, which …

Analysis Of Metallic Shielding For Reduction Of Rf Induced Heating Of Electrode During Mri For Active Implants, Krishna M. Singhal

Open Access Dissertations

The options available to patients with implantable devices are limited. It is because there are multiple interactions between the MRI environment and the implantable medical devices. The three main components of MRI systems- static magnet, RF coil, and a gradient coil- interact with the implantable medical devices. These interactions can cause force, torque, device vibrations and RF-induced heating. Among all these potential hazards is the heating caused by the RF electromagnetic field. The lead wires of the implants can act as antennas and pick up the electric field generated by the RF coil. This results in the induced current traveling …

Guided Data Fusion, Romila Pradhan

Open Access Dissertations

While the volume and variety of data furnished by disparate data sources has rocketed over the years, often there is little to no restraint over the quality of data available on the Internet; data sources often provide conflicting information for the same data item (a real-world entity or event).

Recent years have witnessed a number of data fusion systems that propose solutions to consolidate multiple instances of a data item, distinguish correct from incorrect information and present a unified, consistent and meaningful record to users. Most of these fusion systems are focused on automatically identifying correct information for data items. …

Evaluation Of Economic Improvement In United States And China Pork Industry Through Modeling And Genetic Tools, Jian Cheng

Open Access Theses

The overall objective of this research was to improve pork production economics in United States and China through modeling and genetics. The first study was to estimate the impact of accuracy in which pigs are sorted for market on the optimal market carcass weight (CW) and economic returns. Two types of errors were evaluated, BW estimation error (BWEE) and percentage of pigs not visually evaluated (PNVE). Four levels of BWEE with SD’s of 0, 4, 6 and 8% of BW and four levels of PNVE (0, 8, 16, and 24%) were simulated. Initially, pigs were marketed in three marketing cuts …

Micropropulsion Trade Study And Investigation For Attitude Control Of Nanosatellites, Katherine L. Fowee

Open Access Theses

Since their inception two decades ago, CubeSats have become dominant in the small satellite market, enabling new mission architectures, technology development, and education opportunities. However, the limited mass, power, and volume inherent in this small platform, constrains the on board subsystems and thus the capabilities compared to larger satellites. Attitude control is essential to maximizing the potential of CubeSats and other nanosatellites, though traditional momentum control systems such as reaction wheels are not feasible on the smallest CubeSats. Micropropulsion is an intriguing alternative to traditional methods, and many miniaturization efforts have been made for chemical and electrical propulsion systems. One …

Physical Environments Of Boutique Hotels: A Scale For Evaluation, Hwijin Jeon

Open Access Theses

Boutique hotels refer to small hotels and independent. Boutique hotels have been growing over the world because nowadays travelers expect unique experiences during their stay. Moreover, the aesthetics of boutique hotels, including unique designs or décor, appealing themes, and interesting entertainment have captured travelers’ eyes. Travelers prefer to stay at boutique hotels rather than at homogeneous chain hotels due to special experience through the architectural designs, unique theme, and entertainment during a stay. Since boutique hotels have been popular not only for travelers but also scholars in academia, scholars also have conducted studies regarding boutique hotels. Researchers found that “unique …

Efficacy Of Listeria Phage In Reducing Listeria Monocytogenes Under Both Experimental And Food Processing Conditions, Jia Liu

Open Access Theses

Listeria monocytogenes (L. monocytogenes) is a foodborne pathogen able to flourish in different food processing environments. Bacteriophages are viruses that target bacteria and may be effective in controlling bacterial contamination in different environments. In 2006, the US Food and Drug Administration approved a six-Listeria phage product for use as a food additive in controlling Listeria contamination in ready-to-eat meat and poultry products. In this study, we evaluated the efficacy of bacteriophages in controlling Listeria monocytogenes growth on non-food contact surfaces under different conditions.

Stainless steel coupons or sterilized bags were inoculated with Listeria monocytogenes (LM94 or LM-GFP) and a cocktail …

Designing Agricultural Input Subsidy Programs: A System Dynamics Informed Optimization Approach For Zambia, Mrunal Shah

Open Access Theses

Input subsidies have been introduced in many of the sub-Saharan countries to increase the agricultural productivity. However, these programs are very expensive and they continue to operate with no end in sight. There have been many studies evaluating of the subsidy programs, but there is a need to develop a formal design model for input subsidies. This Thesis provides a proof of concept design model for a time-bounded input subsidy program. A system dynamic framework was developed based on the in depth literature review of the learnings from the past subsidy programs. Using the relationships in the system dynamic framework, …

Chromatin Remodeling In Early Embryogenesis, Bethany Weldon

Open Access Theses

Epigenetic marks are globally remodeled during mammalian embryo development. Chromatin remodeling mediated by the SWI/SNF (Switch/Sucrose non-fermentable) complexes can participate in epigenetic remodeling during cleavage development. SWI/SNF complexes are multi-subunit complexes that contain a core catalytic subunit (SMARCA4 or SMARCA2) and a collection of additional subunits that guide the complexes to their appropriate loci. It has been reported that discrete SWI/SNF subunits adopt different intracellular localization patterns as porcine embryos proceed through cleavage development. In the work presented here, we investigated how these SWI/SNF subunits are trafficked during embryo development. We hypothesized that the localization patterns of the SWI/SNF chromatin …

Effects Of Carbon Nanotubes On Microbial Growth And Horizontal Gene Transfer, Ran Chen

Open Access Theses

Carbon nanotubes (CNTs) have widely studied in various fields since its discovery. The wide research and application of CNTs may result in the occurrence of CNTs in natural environment and their nanotoxicity has been widely recognized. Moreover, a less frequently studied effect of CNTs is the promotion of spread of antibiotic resistance. CNTs may function as a reservoir of antibiotic resistance genes (ARGs) and pose additional health risks associated with the spread of ARGs in natural environment, but no previous studies have been reported on the effects of CNTs on horizontal gene transfer. The objective of this study was to …

Environmental And Genetic Considerations For The Conservation Of An Arboreal Species: Phascolarctos Cinereus, Kendra C. Hodge

Open Access Theses

Many factors have been shown to affect mating behavior (e.g. day length, age, genotype). For instance, genes of the major histocompatibility complex (MHC) are known to influence mate choice in a wide variety of vertebrate species. The genetic management of captive populations can be confounded if intrinsic mate choice reduces or eliminates reproductive success between carefully chosen breeding pairs. For example, the San Diego Zoo (SDZ) koala colony only has a 45\% copulation rate for matched individuals. In order investigate if MHC had an effect on mating success in this population, we first had to characterize it in the koala, …

Effects Of Hydrostatic Pressure On The Stability Of Liquid Storage Tanks Subjected To Wind Loading, Pin-Hsuan Wu

Open Access Theses

The relationship between the liquid height, buckling behavior and uplift deformation of empty and partially filled steel aboveground storage tanks subjected to wind load were numerically investigated using finite element analysis (FEA). Aboveground storage tanks are prone to be influenced by wind pressure, especially for the empty state or at the partial filled configurations due to their thin-walled circular cylindrical steel shell walls which may buckle at stress levels much less than the yield stress of steel material. Buckling behavior is a common and undesirable failure mode experienced by the tank shell subjected to wind load. Furthermore, because tanks are …

Three Essays On Skill Heterogeneity In Frictional Labor Markets, Jacklyn R. Buhrmann

Open Access Dissertations

This dissertation is composed of three essays using labor search models to explore the role of skill mismatch in the labor market. The first, “Skill Mismatch in Frictional Labor Markets”, provides theory and evidence on pair-specific skill mismatch in the labor market, defined as the gap between an individual’s skills and the requirements of her job. Employment data from the NLSY97 display some degree of positive sorting into occupations on the basis of cognitive skills, but skill mismatch is pervasive and costly. I develop and estimate a labor search model featuring heterogeneity in worker skills and firm skill requirements that …

Village In The City: Collective Efficacy And Neighborhood Stability On Chicago’S Far Southwest Side, Joy L. Kadowaki

Open Access Dissertations

The theory of collective efficacy highlights the importance of community members’ shared expectations for social control and their trust and cohesion with one another for predicting neighborhood variation in crime and other social outcomes. Researchers have found that neighborhood collective efficacy is largely stable over time and predicts future variation in crime and other social outcomes, independently of neighborhood social composition. An expansive body of quantitative research has made a very compelling case for the durability of collective efficacy as an important neighborhood process, but a number of questions remain regarding the social mechanisms by which it operates. This dissertation …

Genotype By Nitrogen Management Investigations Into Mitigating Stress And Soil Nitrogen Depletion In African Continuous Maize Production, Heather Randolph Pasley

Open Access Dissertations

Adoption of maize (Zea mays L.) hybrids with enhanced drought/heat/low N stress tolerance and increasing the application of N fertilizer have both been proposed as potential solutions for Subsaharan Africa (SSA)’s food insecurity. Neither solution, however, has been able to increase grain yield in SSA at the same rate seen in other parts of the world as drought/heat/low N stress are often not the only yield-limiting factors in SSA. The primary objectives of this study were to determine what stresses are limiting grain yield response to N fertilizer, to evaluate differences among hybrids in terms of their relative stress tolerance …

A Model Based Iterative Reconstruction Approach To Tunable Diode Laser Absorption Tomography, Zeeshan Nadir

Open Access Dissertations

Tunable diode laser absorption tomography (TDLAT) has emerged as a popular nonintrusive technique for simultaneous sensing of gas concentration and temperature. The gas concentration and temperature is computed by making light absorbance measurements using tunable diode lasers. Major challenges of TDLAT imaging include a highly nonlinear measurement process and availability of only a few light absorbance measurements. Therefore, TDLAT imaging of concentration and temperature is an ill-posed, nonlinear inverse problem. Conventional approaches to TDLAT primarily consist of making restrictive assumptions about the gas flow to simplify the problem.

In this thesis, we study the problem of reconstruction of TDLAT measurements …

Proton Doping And Characterization Of Rare Earth Nickelates, Derek Karl Wittenburg Schwanz

Open Access Dissertations

Perovskite rare earth nickelates with formula RNiO3 (R = trivalent rare earth element) feature exceptional electrical behavior and performance in a wide variety of functional applications due to their unique metal-insulator transition. This distinctive phase transition is caused by charge disproportionation as the crystal structure distorts upon temperature change and electron-electron interactions result in a modified band structure. However, electron doping of the same nickelate systems has created a more pronounced phase transition wherein unprecedented resistivity changes on the order of 1010 Ω*cm are achieved through the opening of a wide bandgap. In this work, a new method for inducing …

Electronics And Optoelectronics Devices From Low-Dimensional Systems, Yuqi Zhu

Open Access Dissertations

The notion of low dimensionality becomes more than a pure mathematical ideal, as scaling of modern electronics reaches a state of the art in which electrons are strongly confined at the interface between silicon and the gate oxides in MOSFETs. Moreover, the improvement of material synthesis in the last two decades gives rise to many fascinating materials, in which the electronic states are confined at least for one dimension, like quantum dots (QD) for 0 dimension (0D), carbon nanotubes (CNT) for 1 dimension (1D), graphene and transitional metal dichalcogenides (TMD) as 2 dimensions (2D). In these materials, quantum confinement due …