## ASU Electronic Theses and Dissertations

This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.

In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.

Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.

Resource Type
Date Range
2004 2020

## Recent Submissions

According to the World Health Organization, cancer is one of the leading causes of death around the world. Although early diagnostics using biomarkers and improved treatments with targeted therapy have reduced the rate of cancer related mortalities, there remain many unknowns regarding the contributions of the tumor microenvironment to cancer progression and therapeutic resistance. The tumor microenvironment plays a significant role by manipulating the progression of cancer cells through biochemical and biophysical signals from the surrounding stromal cells along with the extracellular matrix. As such, there is a critical need to understand how the tumor microenvironment influences the molecular mechanisms …

Contributors
Truong, Danh, Nikkhah, Mehdi, LaBaer, Joshua, et al.
Created Date
2018

In the upcoming decade, powerful new astronomical facilities such as the James Webb Space Telescope (JWST), the Square Kilometer Array (SKA), and ground-based 30-meter telescopes will open up the epoch of reionization to direct astronomical observation. One of the primary tools used to understand the bulk astrophysical properties of the high-redshift universe are empirically-derived star-forming laws, which relate observed luminosity to fundamental astrophysical quantities such as star formation rate. The radio/infrared relation is one of the more mysterious of these relations: despite its somewhat uncertain astrophysical origins, this relation is extremely tight and linear, with 0.3 dex of scatter over …

Contributors
Monkiewicz, Jacqueline, Bowman, Judd, Scowen, Paul, et al.
Created Date
2019

Social skill impairments and executive dysfunctions caused by epilepsy adversely affect the social, psychological, and cognitive wellbeing of children and their families. Studies show that children with epilepsy are exposed to social, emotional, academic, personality, and behavioral problems when compared to healthy peers. This study focused on identifying the gaps between social skills and executive functioning among children with PCDH-19. The researcher relied on the responses from the sampled population to create reliable findings, discussions, conclusions, and recommendations for this project. The study used quantitative design and self-report approach whereby the participants completed survey that was comprised of various rating …

Contributors
Smith, Lourdes G, DiGangi, Samuel, Bryce, Crystal, et al.
Created Date
2019

Until the second half of the 20th century, publications on breathing techniques for woodwinds have been scarce and often failed to adequately address this aspect of performance and pedagogy. It is through various sensory experiences and because of recent technological advances that academics recognize a gap in the existing literature and have since included studies using various methods, as well as modern technical devices and experiments into the woodwind literature and teaching. These studies have proven to be of great importance to confirm ideas and hypotheses on the matter. The aim of this project is to collect woodwind journal publications …

Contributors
Jevtic-Somlai, Csaba, Spring, Robert, Gardner, Joshua, et al.
Created Date
2019

My Critical Yoga Studies investigation maps from the early 20th century to present day how yoga has become white through U.S. law and cultural productions, and has enhanced white privilege at the expense of Indian and people of color bodies. I position Critical Yoga Studies at the intersection of Yoga Studies, Critical Race Theory, Indigenous Studies, Mobilities Studies, and transnational American Studies. Scholars have linked uneven development and racial displacement (Soja, 1989; Harvey, 2006; Gilmore, 2007). How does racist displacement appear in historic and current contexts of development in yoga? In my dissertation, I use yoga mobilities to explain ongoing …

Contributors
Singh, Roopa, Lomawaima, K. Tsianina, Aggarwal, Rimjhim, et al.
Created Date
2019

Participatory approaches to policy-making and research are thought to “open up” technical decision-making to broader considerations, empower diverse public audiences, and inform policies that address pluralistic public goods. Many studies of participatory efforts focus on specific features or outcomes of those efforts, such as the format of a participatory event or the opinions of participants. While valuable, such research has not resolved conceptual problems and critiques of participatory efforts regarding, for example, their reinforcement of expert perspectives or their inability to impact policy- and decision-making. I studied two participatory efforts using survey data collected from participants, interviews with policy makers …

Contributors
Weller, Nicholas A, Childers, Daniel L, Bennett, Ira, et al.
Created Date
2019

The problem of multiple object tracking seeks to jointly estimate the time-varying cardinality and trajectory of each object. There are numerous challenges that are encountered in tracking multiple objects including a time-varying number of measurements, under varying constraints, and environmental conditions. In this thesis, the proposed statistical methods integrate the use of physical-based models with Bayesian nonparametric methods to address the main challenges in a tracking problem. In particular, Bayesian nonparametric methods are exploited to efficiently and robustly infer object identity and learn time-dependent cardinality; together with Bayesian inference methods, they are also used to associate measurements to objects and …

Contributors
Moraffah, Bahman, Papandreou-Suppappola, Antonia, Bliss, Daniel W., et al.
Created Date
2019

Imagine you live in a place without any storm water or wastewater systems! Wastewater and storm water systems are two of the most crucial systems for urban infrastructure. Water resources have become more limited and expensive in arid and semi-arid regions. According to the fourth World Water Development Report, over 80% of global wastewater is released into the environment without adequate treatment. Wastewater collection and treatment systems in the Kingdom of Saudi Arabia (KSA) covers about 49% of urban areas; about 25% of treated wastewater is used for landscape and crop irrigation (Ministry of Environment Water and Agriculture [MEWA], 2017). …

Contributors
Alfaisal, Faisal Mohammed, Mays, Larry W., Mascaro, Giuseppe, et al.
Created Date
2019

Part I – I analyze a database of Smoothed Particle Hydrodynamics (SPH) simulations of collisions between planetary bodies and use the data to define semi-empirical models that reproduce remant masses. These models may be leveraged when detailed, time-dependent aspects of the collision are not paramount, but analytical intuition or a rapid solution is required, e.g. in ‘N-body simulations’. I find that the stratification of the planet is a non-negligible control on accretion efficiency. I also show that the absolute scale (total mass) of the collision may affect the accretion efficiency, with larger bodies more efficiently disrupting, as a function of …

Contributors
Gabriel, Travis Saint James, Asphaug, Erik I, Hardgrove, Craig, et al.
Created Date
2019

Droplet-structure interactions play a pivotal role in many engineering applications as droplet-based solutions are evolving. This work explores the physical understanding of these interactions through systematic research leading to improvements in thermal management via dropwise condensation (DWC), and breathable protective wearables against chemical aerosols for better thermoregulation. In DWC, the heat transfer rate can be further increased by increasing the nucleation and by optimally ‘refreshing’ the surface via droplet shedding. Softening of surfaces favor the former while having an adverse effect on the latter. This optimization problem is addressed by investigating how mechanical properties of a substrate impact relevant droplet-surface …

Contributors
Phadnis, Akshay, Rykaczewski, Konrad, Wang, Robert, et al.
Created Date
2019

This dissertation combines three research projects to examine the people affecting and affected by urban environmental change across multiple scales of decision making. In the Phoenix Metropolitan area and the Colorado River Basin, I study the social influence around the implementation of water use innovations among city-level stakeholders (Chapter 2) and I emphasize that water insecurity still exists in wealthy cities (Chapter 3). In Chapter 4, I ultimately consider grassroots solutions for achieving resource security alongside positive social change in a historically underserved community. In this dissertation, I have conceptualized my research questions by envisioning urban change as an opportunity …

Contributors
DeMyers, Christine, Wutich, Amber, White, Dave, et al.
Created Date
2019

Several key, open questions in astrophysics can be tackled by searching for and mining large datasets for transient phenomena. The evolution of massive stars and compact objects can be studied over cosmic time by identifying supernovae (SNe) and gamma-ray bursts (GRBs) in other galaxies and determining their redshifts. Modeling GRBs and their afterglows to probe the jets of GRBs can shed light on the emission mechanism, rate, and energetics of these events. In Chapter 1, I discuss the current state of astronomical transient study, including sources of interest, instrumentation, and data reduction techniques, with a focus on work in the …

Contributors
Strausbaugh, Robert, Butler, Nathaniel, Jansen, Rolf, et al.
Created Date
2019

One strategic objective of the National Aeronautics and Space Administration (NASA) is to find life on distant worlds. Current and future missions either space telescopes or Earth-based observatories are frequently used to collect information through the detection of photons from exoplanet atmospheres. The primary challenge is to fully understand the nature of these exo-atmospheres. To this end, atmospheric modeling and sophisticated data analysis techniques are playing a key role in understanding the emission and transmission spectra of exoplanet atmospheres. Of critical importance to the interpretation of such data are the opacities (or absorption cross-sections) of key molecules and atoms. During …

Contributors
Gharib-Nezhad, Ehsan, Line, Michael R., Lyons, James R., et al.
Created Date
2019

I propose a new approach for the analysis of social transformations within the context of colonialism. Drawing on concepts used by historical sociologists, combined with insights from historians and archaeologists, I forge a synthesis of relational mechanisms that concatenated into processes of categorical change. Within the social sciences, mechanisms are formally defined as specific classes of events or social interactions that are causally linked and tend to repeat under specific conditions, potentially resulting in widespread social transformations. Examples of mechanisms include formal inscription through spatial segregation and adjustments in individual position through socioeconomic mobility. For New Spain, historians have identified …

Contributors
Eschbach, Krista, Stark, Barbara L, Smith, Michael E, et al.
Created Date
2019

As the microelectronics industry continues to decrease the size of solder joints, each joint will have to carry a greater current density, making atom diffusion due to current flow, electromigration (EM), a problem of ever-increasing severity. The rate of EM damage depends on current density, operating temperature, and the original microstructure of the solder joint, including void volume, grain orientation, and grain size. While numerous studies have investigated the post-mortem effects of EM and have tested a range of current densities and temperatures, none have been able to analyze how the same joint evolves from its initial to final microstructure. …

Contributors
Branch Kelly, Marion, Chawla, Nikhilesh, Ankit, Kumar, et al.
Created Date
2019

Extracellular Vesicles (EVs), particularly exosomes, are of considerable interest as tumor biomarkers since tumor-derived EVs contain a broad array of information about tumor pathophysiology including its metabolic and metastatic status. However, current EV based assays cannot distinguish between EV biomarker changes by altered secretion of EVs during diseased conditions like cancer, inflammation, etc. that express a constant level of a given biomarker, stable secretion of EVs with altered biomarker expression, or a combination of these two factors. This issue was addressed by developing a nanoparticle and dye-based fluorescent immunoassay that can distinguish among these possibilities by normalizing EV biomarker level(s) …

Contributors
Rodrigues, Meryl, Hu, Tony, Nikkhah, Mehdi, et al.
Created Date
2019

This dissertation details the development of an open source, frequency domain multiplexed (FDM) readout for large-format arrays of superconducting lumped-element kinetic inductance detectors (LEKIDs). The system architecture is designed to meet the requirements of current and next generation balloon-borne and ground-based submillimeter (sub-mm), far-infrared (FIR) and millimeter-wave (mm-wave) astronomical cameras, whose science goals will soon drive the pixel counts of sub-mm detector arrays from the kilopixel to the megapixel regime. The in-flight performance of the readout system was verified during the summer, 2018 flight of ASI's OLIMPO balloon-borne telescope, from Svalbard, Norway. This was the first flight for both LEKID …

Contributors
Gordon, Samuel, Mauskopf, Philip, Groppi, Christopher, et al.
Created Date
2019

In many social-ecological systems, shared resources play a critical role in supporting the livelihoods of rural populations. Physical infrastructure enables resource access and reduces the variability of resource supply. In order for the infrastructure to remain functional, institutions must incentivize individuals to engage in provision and maintenance. The objective of my dissertation is to understand key formal and informal institutions that affect provision of shared infrastructure and the policy tools that may improve infrastructure provision. I examine these questions in the context of irrigation systems in India because infrastructure maintenance is a persistent challenge and system function is critical for …

Contributors
Vallury, Sechindra, Abbott, Joshua K, Anderies, John M, et al.
Created Date
2019

The presence of police officers is not an assurance of safety for everyone. Yet, modern concerns for school safety suggest there is a need for more police officers in schools. Over the last 70 years of School Resource Officer (SRO) programs, the variations of SRO program implementation and the expectation of roles and responsibilities has produced conflicting research on benefits or harms of police in the school environment. The purpose of police in schools has shuffled from relationship-building ambassadors for the community, to educators on crime prevention and drug use, to law enforcement officers for punitive juvenile sanctions, to counselors …

Contributors
Herbert, Jessica L., Sweeten, Gary, Decker, Scott, et al.
Created Date
2019

Layered chalcogenides are a diverse class of crystalline materials that consist of covalently bound building blocks held together by van der Waals forces, including the transition metal dichalcogenides (TMDCs) and the pnictogen chalcogenides (PCs) among all. These materials, in particular, MoS2 which is the most widely studied TMDC material, have attracted significant attention in recent years due to their unique physical, electronic, optical, and chemical properties that depend on the number of layers. Due to their high aspect ratios and extreme thinness, 2D materials are sensitive to modifications via chemistry on their surfaces. For instance, covalent functionalization can be used …

Contributors
Li, Duo, Wang, Qing Hua, Green, Alexander A., et al.
Created Date
2019

This dissertation advances the capability of water infrastructure utilities to anticipate and adapt to vulnerabilities in their systems from temperature increase and interdependencies with other infrastructure systems. Impact assessment models of increased heat and interdependencies were developed which incorporate probability, spatial, temporal, and operational information. Key findings from the models are that with increased heat the increased likelihood of water quality non-compliances is particularly concerning, the anticipated increases in different hardware components generate different levels of concern starting with iron pipes, then pumps, and then PVC pipes, the effects of temperature increase on hardware components and on service losses are …

Contributors
Bondank, Emily Nicole, Chester, Mikhail V, Ruddell, Benjamin L, et al.
Created Date
2019

Functional brain imaging experiments are widely conducted in many fields for study- ing the underlying brain activity in response to mental stimuli. For such experiments, it is crucial to select a good sequence of mental stimuli that allow researchers to collect informative data for making precise and valid statistical inferences at minimum cost. In contrast to most existing studies, the aim of this study is to obtain optimal designs for brain mapping technology with an ultra-high temporal resolution with respect to some common statistical optimality criteria. The first topic of this work is on finding optimal designs when the primary …

Contributors
Alghamdi, Reem, Kao, Ming-Hung, Fricks, John, et al.
Created Date
2019

With the fast pace of globalization and the rise of encounters in digital spaces, CALL scholars have become increasingly interested in how digital tools mediate intercultural encounters. However, despite their evident success in connecting students from around the world, current online intercultural exchanges continue to present problems such a promotion of positive experiences over deep intercultural learning and lack of real-life value (O’ Dowd, 2018). In addition, digitally-mediated intercultural learning research is based on the same theoretical approaches to learning that guide CALL research (Firth & Wagner, 1997; Lafford, 2017). Although such frameworks are successful in allowing researchers to conceive …

Contributors
Ocando Finol, Maria Virginia, Lafford, Barbara, Cuya Gavilano, Lorena, et al.
Created Date
2019

This dissertation focuses on three different efficiency enhancement methods that are applicable to handset applications. These proposed designs are based on three critical requirements for handset application: 1) Small form factor, 2) CMOS compatibility and 3) high power handling. The three presented methodologies are listed below: 1) A transformer-based power combiner architecture for out-phasing transmitters 2) A current steering DAC-based average power tracking circuit for on-chip power amplifiers (PA) 3) A CMOS-based driver stage for GaN-based switched-mode power amplifiers applicable to fully digital transmitters This thesis highlights the trends in wireless handsets, the motivates the need for fully-integrated CMOS power …

Contributors
Moallemi, Soroush, Kitchen, Jennifer, Kiaei, Sayfe, et al.
Created Date
2019

Membrane based technology is one of the principal methods currently in widespread use to address the global water shortage. Pervaporation desalination is a membrane technology for water purification currently under investigation as a method for processing reverse osmosis concentrates or for stand-alone applications. Concentration polarization is a potential problem in any membrane separation. In desalination concentration polarization can lead to reduced water flux, increased propensity for membrane scaling, and decreased quality of the product water. Quantifying concentration polarization is important because reducing concentration polarization requires increased capital and operating costs in the form of feed spacers and high feed flow …

Contributors
Mann, Stewart Conrad, Lind, Mary Laura, Walker, Shane, et al.
Created Date
2019

Aromatic compounds have traditionally been generated via petroleum feedstocks and have wide ranging applications in a variety of fields such as cosmetics, food, plastics, and pharmaceuticals. Substantial improvements have been made to sustainably produce many aromatic chemicals from renewable sources utilizing microbes as bio-factories. By assembling and optimizing native and non-native pathways to produce natural and non-natural bioproducts, the diversity of biochemical aromatics which can be produced is constantly being improved upon. One such compound, 2-Phenylethanol (2PE), is a key molecule used in the fragrance and food industries, as well as a potential biofuel. Here, a novel, non-natural pathway was …

Contributors
Machas, Michael Stafford, Nielsen, David R, Haynes, Karmella, et al.
Created Date
2019

This research investigates teachers' understanding of and feelings about transdisciplinary education and the International Baccalaureate's Primary Years Programme (PYP) as utilized by two remote schools in the province of Papua, Indonesia on the island of New Guinea. A goal of transdisciplinary education is to make learning through inquiry authentic, broad, student-centered, and relevant to the real world. In this study I examine educators’ perspectives of how transdisciplinary education is manifested in the two different and yet related elementary schools. Both schools are supported by a multinational mining company. One school is for expatriate students and the language of instruction is …

Contributors
Erikson, Anita Elice, Stauffer, Sandra L, Sullivan, Jill M, et al.
Created Date
2019

This dissertation aims at developing novel materials and processing routes using alkali activated aluminosilicate binders for porous (lightweight) geopolymer matrices and 3D-printing concrete applications. The major research objectives are executed in different stages. Stage 1 includes developing synthesis routes, microstructural characterization, and performance characterization of a family of economical, multifunctional porous ceramics developed through geopolymerization of an abundant volcanic tuff (aluminosilicate mineral) as the primary source material. Metakaolin, silica fume, alumina powder, and pure silicon powder are also used as additional ingredients when necessary and activated by potassium-based alkaline agents. In Stage 2, a processing route was developed to synthesize …

Contributors
ALGHAMDI, HUSSAM SUHAIL, Neithalath, Narayanan, Rajan, Subramaniam, et al.
Created Date
2019

The world of speculative fiction infuses the soul with the hope of the imaginary. My dissertation examines Afrofuturistic liminal imaginary space and the ways it is experienced as life-giving spaces. The imaginary and the aesthetics it births are formularies for art forms that speak to the hope of a transformed future. Speculative fiction, although in the realm of the imaginary, is an enlivened approach to express in the present collective possibilities and hopes of the people within those very imagined futures. During the past three decades, particularly, Black speculative fiction has been increasingly at the core of the new cultural …

Contributors
Young-Scaggs, Sakena De, Martinez, Jacqueline M, Anderson, Lisa M, et al.
Created Date
2019

Phenotypic and molecular profiling demonstrates a high degree of heterogeneity in the breast tumors. TP53 tumor suppressor is mutated in 30% of all breast tumors and the mutation frequency in basal-like subtype is as high as 80% and co-exists with several other somatic mutations in different genes. It was hypothesized that tumor heterogeneity is a result of a combination of neo-morphic functions of specific TP53 driver mutations and distinct co-mutations or the co-drivers for each type of TP53 mutation. The 10 most common p53 missense mutant proteins found in breast cancer patients were ectopically expressed in normal-like mammary epithelial cells …

Contributors
Pal, Anasuya, LaBaer, Joshua, Roberson, Robert, et al.
Created Date
2019

This dissertation studies two outstanding microscale fluid mechanics problems: 1) mechanisms of gas production from the nanopores of shale; 2) enhanced mass flow rate in steady compressible gas flow through a micro-conduit. The dissertation starts with a study of a volumetric expansion driven drainage flow of a viscous compressible fluid from a small capillary and channel in the low Mach number limit. An analysis based on the linearized compressible Navier-Stokes equations with no-slip condition shows that fluid drainage is controlled by the slow decay of the acoustic wave inside the capillary and the no-slip flow exhibits a slip-like mass flow …

Contributors
SHEN, DI, Chen, Kangping, Herrmann, Marcus, et al.
Created Date
2019

Images are ubiquitous in communicating complex information about the future. From political messages to extreme weather warnings, they generate understanding, incite action, and inform expectations with real impact today. The future has come into sharp focus in recent years. Issues like climate change, gene editing, and smart cities are pushing policy makers, scientists, and designers to rethink how society plans and prepares for tomorrow. While academic and practice communities have increasingly turned their gaze toward the future, little attention is paid to how it is depicted and even less to the role visualization technologies play in depicting it. Visualization technologies …

Contributors
Selkirk, Kaethe, Selin, Cynthia, Wylie, Ruth, et al.
Created Date
2019

My research centers on the design and fabrication of biomolecule-sensing devices that combine top-down and bottom-up fabrication processes and leverage the unique advantages of each approach. This allows for the scalable creation of devices with critical dimensions and surface properties that are tailored to target molecules at the nanoscale. My first project focuses on a new strategy for preparing solid-state nanopore sensors for DNA sequencing. Challenges for existing nanopore approaches include specificity of detection, controllability of translocation, and scalability of fabrication. In a new solid-state pore architecture, top-down fabrication of an initial electrode gap embedded in a sealed nanochannel is …

Contributors
Sadar, Joshua Stephen, Qing, Quan, Lindsay, Stuart, et al.
Created Date
2019

On the Antichrist (CPG 3946) is an eschatological sermon historically attributed to Efrem the Syrian. Composed in Koine Greek, On the Antichrist is not an authentic Efremic sermon but is attributed to the construct Greek Efrem, often called in the literature ‘Ephraem Graecus’. Sometime around the 12th century, Slavic Christians translated the work into Old Church Slavonic. As its goal, this study employs On the Antichrist to investigate how religions (e.g. Christianity) employ religio-cultural constructs and either refine, or redefine, them for new audiences and circumstances. To accomplish this, the author transcribes and translates one of the most important manuscript …

Contributors
McAvoy, Shawn, Clay, J. Eugene, Moore, Moses, et al.
Created Date
2019

Eigenvalues of the Gram matrix formed from received data frequently appear in sufficient detection statistics for multi-channel detection with Generalized Likelihood Ratio (GLRT) and Bayesian tests. In a frequently presented model for passive radar, in which the null hypothesis is that the channels are independent and contain only complex white Gaussian noise and the alternative hypothesis is that the channels contain a common rank-one signal in the mean, the GLRT statistic is the largest eigenvalue $\lambda_1$ of the Gram matrix formed from data. This Gram matrix has a Wishart distribution. Although exact expressions for the distribution of $\lambda_1$ are known …

Contributors
Jones, Scott, Cochran, Douglas, Berisha, Visar, et al.
Created Date
2019

Network analysis is a key conceptual orientation and analytical tool in the social sciences that emphasizes the embeddedness of individual behavior within a larger web of social relations. The network approach is used to better understand the cause and consequence of social interactions which cannot be treated as independent. The relational nature of network data and models, however, amplify the methodological concerns associated with inaccurate or missing data. This dissertation addresses such concerns via three projects. As a motivating substantive example, Project 1 examines factors associated with the selection of interaction partners by students at a large urban high school …

Contributors
Bates, Jordan Taylor, Maroulis, Spiro J, Kang, Yun, et al.
Created Date
2019

Continuing and increasing reliance on fossil fuels to satisfy our population’s energy demands has encouraged the search for renewable carbon-free and carbon-neutral sources, such as hydrogen gas or CO2 reduction products. Inspired by nature, one of the objectives of this dissertation was to develop protein-based strategies that can be applied in the production of green fuels. The first project of this dissertation aimed at developing a controllable strategy to incorporate domains with different functions (e. g. catalytic sites, electron transfer modules, light absorbing subunits) into a single multicomponent system. This was accomplished through the rational design of 2,2’-bipyridine modified dimeric …

Contributors
Alcala-Torano, Rafael de Jesus, Ghirlanda, Giovanna, Moore, Ana L, et al.
Created Date
2019

The depth richness of a scene translates into a spatially variable defocus blur in the acquired image. Blurring can mislead computational image understanding; therefore, blur detection can be used for selective image enhancement of blurred regions and the application of image understanding algorithms to sharp regions. This work focuses on blur detection and its application to image enhancement. This work proposes a spatially-varying defocus blur detection based on the quotient of spectral bands; additionally, to avoid the use of computationally intensive algorithms for the segmentation of foreground and background regions, a global threshold defined using weak textured regions on the …

Contributors
Andrade Rodas, Juan Manuel, Spanias, Andreas, Turaga, Pavan, et al.
Created Date
2019

Causality analysis is the process of identifying cause-effect relationships among variables. This process is challenging because causal relationships cannot be tested solely based on statistical indicators as additional information is always needed to reduce the ambiguity caused by factors beyond those covered by the statistical test. Traditionally, controlled experiments are carried out to identify causal relationships, but recently there is a growing interest in causality analysis with observational data due to the increasing availability of data and tools. This type of analysis will often involve automatic algorithms that extract causal relations from large amounts of data and rely on expert …

Contributors
Wang, Hong Xiang, Maciejewski, Ross, He, Jingrui, et al.
Created Date
2019

There are more than 20 active missions exploring planets and small bodies beyond Earth in our solar system today. Many more have completed their journeys or will soon begin. Each spacecraft has a suite of instruments and sensors that provide a treasure trove of data that scientists use to advance our understanding of the past, present, and future of the solar system and universe. As more missions come online and the volume of data increases, it becomes more difficult for scientists to analyze these complex data at the desired pace. There is a need for systems that can rapidly and …

Contributors
Kerner, Hannah Rae, Bell, James F, Ben Amor, Heni, et al.
Created Date
2019

The main objective of mathematical modeling is to connect mathematics with other scientific fields. Developing predictable models help to understand the behavior of biological systems. By testing models, one can relate mathematics and real-world experiments. To validate predictions numerically, one has to compare them with experimental data sets. Mathematical modeling can be split into two groups: microscopic and macroscopic models. Microscopic models described the motion of so-called agents (e.g. cells, ants) that interact with their surrounding neighbors. The interactions among these agents form at a large scale some special structures such as flocking and swarming. One of the key questions …

Contributors
Jamous, Sara Sami, Motsch, Sebastien, Armbruster, Dieter, et al.
Created Date
2019

Machine learning has demonstrated great potential across a wide range of applications such as computer vision, robotics, speech recognition, drug discovery, material science, and physics simulation. Despite its current success, however, there are still two major challenges for machine learning algorithms: limited robustness and generalizability. The robustness of a neural network is defined as the stability of the network output under small input perturbations. It has been shown that neural networks are very sensitive to input perturbations, and the prediction from convolutional neural networks can be totally different for input images that are visually indistinguishable to human eyes. Based on …

Contributors
Yao, Houpu, Ren, Yi, Liu, Yongming, et al.
Created Date
2019

Population growth, social interaction, and environmental variability are interrelated facets of the same complex system. Tracing the flow of food, water, information, and energy within these social-ecological systems is essential for understanding their long-term behavior. Leveraging an archaeological perspective of how past societies coevolved with their natural environments will be critical to anticipating the impact of impending climate change on farming communities in the developing world. However, there is currently a lack of formal, quantitative theory rooted in first principles of human behavior that can predict the empirical regularities of the archaeological record in semiarid regions. Through a series of …

Contributors
Gauthier, Nicolas, Barton, C Michael, Anderies, John M, et al.
Created Date
2019

Evidence suggests that Augmented Reality (AR) may be a powerful tool for alleviating certain, lightly held scientific misconceptions. However, many misconceptions surrounding the theory of evolution are deeply held and resistant to change. This study examines whether AR can serve as an effective tool for alleviating these misconceptions by comparing the change in the number of misconceptions expressed by users of a tablet-based version of a well-established classroom simulation to the change in the number of misconceptions expressed by users of AR versions of the simulation. The use of realistic representations of objects is common for many AR developers. However, …

Contributors
Henry, Matthew McClellan, Atkinson, Robert K, Johnson-Glenberg, Mina C, et al.
Created Date
2019

This dissertation reports three studies of the relationships between meanings teachers hold and meanings their students construct. The first paper reports meanings held by U.S. and Korean secondary mathematics teachers for teaching function notation. This study focuses on what teachers in U.S. and Korean are revealing their thinking from their written responses to the MMTsm (Mathematical Meanings for Teaching secondary mathematics) items, with particular attention to how productive those meanings would be if conveyed to students in a classroom setting. This paper then discusses how the MMTsm serves as a diagnostic instrument by sharing a teacher’s story. The data indicates …

Contributors
Yoon, Hyunkyoung, Thompson, Patrick W, Roh, Kyeong Hah, et al.
Created Date
2019

Zwitterionic polymers, due to their supurior capability of electrostatically induced hydration, have been considered as effective functionalities to alleviate bio-fouling of reverse osmosis (RO) membranes. Bulk modification of polysulfone-based matrices to improve hydrophilicity, on the other hand, is favored due to the high membrane performance, processibility, and intrinsic chlorine resistance. Here a novel synthetic method was demonstrated to prepare zwitterionic poly(arylene ether sulfone) (PAES) copolymers, which was blended with native polysulfone (PSf) to fabricate free-standing asymmetric membranes via non-solvent induced phase separation process. Both the porosity of the support layer and surface hydrophilicity increased drastically due to the incorporation of …

Contributors
Yang, Yi, Green, Matthew D, Lin, Jerry Y.S., et al.
Created Date
2019

Self-control has been shown to be an important influence behind a variety of risk and protective behaviors, such as substance abuse. Although prior research points to the existence of multiple dimensions of self-control, this concept is not consistently defined and frequently only studied as a conglomerate in clinical research. The current study sought to examine how two experimental manipulations of subcomponents of self-control (motivation and self-efficacy) affect real-world consumptive behavior after accounting for executive function. Additionally, the validity and reliability of a brief state survey measure of perceived self-control capacity, internal motivation, and external motivation was tested. The goal was …

Contributors
Papova, Anna, Corbin, William R, Brewer, Gene, et al.
Created Date
2020

Water has shaped the surface of Mars, recording previous environments and inspiring the search for extinct life beyond Earth. While conditions on the Martian surface today are not conducive to the presence of liquid water, ancient erosional and depositional features indicate that this was not always so. Quantifying the regional and global history of water on Mars is crucial to understanding how the planet evolved, where to focus future exploration, and implications for water on Earth. Many sites on Mars contain layered sedimentary deposits, sinuous valleys with delta shaped deposits, and other indications of large lakes. The Hypanis deposit is …

Contributors
Adler, Jacob, Bell, James, Christensen, Philip, et al.
Created Date
2019

The transport of hydrogen to the Earth’s deep interior remains uncertain. The upper mantle minerals have very low hydrogen solubilities (hundreds of ppm). The hydrogen storage capability in the transition zone minerals (2 wt%) is high compared to those of the upper mantle. The hydrogen storage in the lower mantle is not well known. The main minerals in the lower mantle bridgmanite and ferropericlase have very low hydrogen storage capacities (less than 20 ppm). In order to further understand the hydrogen storage in the lower mantle, a series of experiments had been conducted to simulate the environment similar to the …

Contributors
Chen, Huawei, Shim, Sang-Heon, Garnero, Edward, et al.
Created Date
2019

Silicon photovoltaics is the dominant contribution to the global solar energy production. As increasing conversion efficiency has become one of the most important factors to lower the cost of photovoltaic systems, the idea of making a multijunction solar cell based on a silicon bottom cell has attracted broad interest. Here the potential of using dilute nitride GaNPAs alloys for a lattice-matched 3-terminal 2-junction Si-based tandem solar cell through multiscale modeling is investigated. To calculate the electronic band structure of dilute nitride alloys with relatively low computational cost, the sp^3 d^5 s^* s_N tight-binding model is chosen, as it has been …

Contributors
Zou, Yongjie, Goodnick, Stephen M., Honsberg, Christiana B., et al.
Created Date
2019