Digital Commons Network^™

Cloth-Air Partitioning Of Oxybenzone, Jonathan T. Hill

Masters Theses

"Clothing has been proven to be a significant accumulator of chemicals from the air. Semi-volatile organic compounds (SVOCs) have a high affinity towards textiles, and measuring the equilibrium partition coefficient between cloth and air (K_cloth-air) for SVOCs is crucial in predicting human exposure to these compounds. This study aims to quantify K_cloth-air for oxybenzone to contribute to a larger human exposure experiment carried out at the Technical University of Denmark (DTU). K_cloth-air for oxybenzone was calculated using data collected from the exposure chamber at DTU and from performing extractions of oxybenzone in fabric samples from the …

Personalizing Education With Algorithmic Course Selection, Tyler Morrow

Masters Theses

"The work presented in this thesis utilizes context-aware recommendation to facilitate personalized education and assist students in selecting courses (or in non-traditional curricula, topics or modules) that meet curricular requirements, leverage their skills and background, and are relevant to their interests. The original research contribution of this thesis is an algorithm that can generate a schedule of courses with consideration of a student's profile, minimization of cost, and complete adherence to institution requirements. The research problem at hand - a constrained optimization problem with potentially conflicting objectives - is solved by first identifying a minimal sets of courses a student …

Leveraging Knowledge At Startups, Amruta Anil Ranade

Masters Theses

"Startups contribute to the economy and job creation in the United States. One of the primary assets of startups is tacit knowledge of the employees of the startup. Technical communicators can help startups capture, share, and leverage the tacit knowledge at startups. Technical communicators could benefit from learning how knowledge management initiatives at startups work. The current study is an ethnographic case-study that was conducted at a fast-growing startup in California.

The data for the study was collected through observations, informal and semi-structured formal interviews with participants, and feedback from customers of the startup. The collected data was analyzed based …

Novel Approaches For Efficient Stochastic Computing, Ramu Seva

Masters Theses

"This thesis is comprised of two papers, where the first paper presents a novel approach for parallel implementation of SC using FPGA (Field Programmable Gate Array). This paper makes use of the distributed memory elements of FPGAs (i.e., look-up-tables -LUTs) to achieve this. An attempt has been made to build the stochastic number generators (SNGs) by using the proposed LUT approach. The construction of these SNGs has been influenced by the Quasi-random number sequences, which provide the advantage of reducing the random fluctuations present in the pseudo-random number generators such as LFSR (Linear Feedback Shift Register) as well as the …

Impact Of Framing And Priming On Users' Behavior In Cybersecurity, Kavya Sharma

Masters Theses

"This research examines the impact of framing and priming on users' behavior (i.e., action) in a cybersecurity setting. It also examines perceptual outcomes (i.e., confidence, perceived severity, perceived susceptibility, trust, and fear) associated with the users' cybersecurity action. The research draws on prospect theory in the behavioral economics literature and instance-based learning theory in the education literature to generate the hypotheses for the research. A between-subject experimental design (N=129) was used. The results suggest that priming users to cybersecurity risks reduces their risk-taking behavior associated with cybersecurity whereas negative framing of messages associated with cybersecurity has no significant effect on …

Decodable Network Coding In Wireless Network, Junwei Su

Masters Theses

"Network coding is a network layer technique to improve transmission efficiency. Coding packets is especially beneficial in a wireless environment where the demand for radio spectrum is high. However, to fully realize the benefits of network coding two challenging issues that must be addressed are: (1) Guaranteeing separation of coded packets at the destination, and (2) Mitigating the extra coding/decoding delay. If the destination has all the needed packets to decode a coded packet, then separation failure can be averted. If the scheduling algorithm considers the arrival time of coding pairs, then the extra delay can be mitigated. In this …

Evaluation Of Swelling And Re-Swelling Of Preformed Particle Gels (Ppg) When Exposed To Co₂, Sujay Suresh

Masters Theses

"Long term water/gas flooding induces high permeability channels in reservoirs. Reservoir heterogeneity becomes the most prominent challenge faced in mature oil fields. Gel treatment has been a proven solution to counter the problem of reservoir heterogeneity, to provide in-depth treatment and improve the sweep efficiency for reservoirs. Preformed particle gels (PPGs) were developed as an alternative to in-situ gels as they preferentially penetrate and shutoff high permeability zones, leaving the low permeability zones undamaged. These gels have been predominantly used in water flooding projects, but have not been employed in carbon dioxide (CO₂) flooding projects. CO₂ Resistant …

Data Analysis Of Lane Merge And Lane Shift Sign Configurations In A Freeway Workzone, Satwinder Singh Thind

Masters Theses

"In this study, driver responses to alternative lane shift and lane merge signs are analyzed and compared using a driving simulation system. In particular, driver responses to the lane merge signs proposed by the Missouri Department of Transportation (MoDOT) are compared to the current lane merge signs recommended by the Manual on Uniform Traffic Control Devices (MUTCD) and driver responses to the lane shift signs proposed by MoDOT are compared to current lane shift signs recommended by MUTCD. The driving simulation system is composed of a driving simulator and a PC with data recording program such that the position coordinates, …

Extending Time Series Forecasting Methods Using Functional Principal Components Analysis, Isaac Michael Wagner-Muns

Masters Theses

"Traffic volume forecasts are used by many transportation analysis and management systems to better characterize and react to fluctuating traffic patterns. Most current forecasting methods do not take advantage of the underlying functional characteristics of the time series to make predictions. This paper presents a methodology that uses Functional Principal Components Analysis (FPCA) to create smooth and differentiable daily traffic forecasts. The methodology is validated with a data set of 1,813 days of 15 minute aggregated traffic volume time series. Both the FPCA based forecasts and the associated prediction intervals outperform traditional Seasonal Autoregressive Integrated Moving Average (SARIMA) based methods"--Abstract, …

Characterization Of The Rectification Behaviour Of In-Amps And Estimating The Near Field Coupling From Smps Circuits To A Nearby Antenna Using Dipole Moments, Chunyu Wu

Masters Theses

"This thesis discusses two parts.

In the first part, the rectification behavior of popular instrumentation amplifiers is measured in both common mode and single-ended RF noise injection. It is recommended that AD8221 be used in common mode RF noise injection environment. And AD8220 and AD8429 are recommended in single-ended RF noise injection environment. The mechanism of RF noise rectification inside in-amps is also discussed. It is verified that rectification mainly happens at the non-inverting input of two op-amps in the first stage of an in-amp. The DC voltage difference between inverting input and non-inverting input of the in-amp is further …

Dc-Dc Converter Based Photovoltaic Simulator With A Double Current Mode Controller, Weichao Zhang

Masters Theses

"This thesis presents the performance of a DC-DC converter based with current mode controller photovoltaic (PV) simulator which emulates the output characteristics of a real PV module. A portable PV simulator prototype of 85 W is examined in terms of its steady state IV curve matching capacity and the convergence time corresponding to step change in current source load, voltage source load, and insolation levels. The current-voltage (IV) characteristics of the PV module are implemented as a look-up-table (LUT) which determines the reference output current from measured output voltage. A Thevenin Equivalent Method approach to PV arrays analysis is also …

A Physics-Based Approach For Power Integrity In Multi-Layered Pcbs, Biyao Zhao

Masters Theses

"Developing a power distribution network (PDN) for ASICs and ICs to achieve the low-voltage ripple specifications for current digital designs is challenging with the high-speed and low-voltage ICs. Present methods are typically guided by best engineering practices for low impedance looking into the PDN from the IC. A pre-layout design methodology for power integrity in multi-layered PCB PDN geometry is proposed in the thesis. The PCB PDN geometry is segmented into four parts and every part is modelled using different methods based on the geometry details of the part. Physics-based circuit models are built for every part and the four …

Processing, Microstructure, And Properties Of Engineered Diboride Structures, Connor Charles Wittmaier

Masters Theses

"The mechanical properties and processing parameters of boride ceramics in foam and laminate architectures were evaluated. The ceramic reticulated foam was produced through a polymer substrate replication technique and the hardness and compressive strength were tested. The laminate structure was tested to evaluate the flexure strength and work of fracture as a function of temperature.

The foam architecture was produced using a TiB₂ slurry coating on a polyurethane reticulated foam preform. Foams sintered to 2150⁰C displayed an average grain size of 8.9 ± 7.3 µm, and a hardness of 17.3 ± 2.4 GPa. Crush testing foams were sintered at …

Multi Stage Recovery From Large Scale Failure In Interdependent Networks, Maria Angelin John Bosco

Masters Theses

"Node and link failures that usually cause limited damage in a single network, may cascade into large scale disasters in the case of interdependent networks, due to the dependencies that exist between them. Recovery from such failures may require multiple stages or steps for complete restoration of connection or flow between them. When critical services are disrupted, the order in which the broken elements are repaired affects the earliest possible recovery time of vital services. In a flow network, one order of restoration may restore more flow at an earlier stage than another. The paper aims to model an efficient …

Comparison Of Voltage Regulation Between Sst And Conventional Transformers In High Penetration Pv Power Systems, Gautham Ashokkumar

Masters Theses

"Solid state transformers (SST) are power electronic transformers combined with high-frequency conventional transformers and control circuitry capable of delivering high performance and flexible power control capabilities. This thesis focuses on analyzing the performance of SSTs in a distribution system with photovoltaic (PV) injection. In order to validate the performance of SSTs, average value models are used on the IEEE 34 bus distribution feeder network scaled to 12.47 kV. SST voltage profiles on the load side are analyzed and the unity power factor capabilities are demonstrated. This is followed by the study of voltage profiles on the primary side of the …

Development Of A Variogram Approach To Spatial Outlier Detection Using A Supplemental Digital Elevation Model Dataset, Zane Daniel Helwig

Masters Theses

"When developing a ground water model, the quality of the dataset should first be evaluated. Spatial outliers can lead to predictions which are not representative of actual conditions. In order to isolate misrepresentative points, a method is presented which examines the experimental variogram of a ground water elevation dataset. To define a threshold variance between pairs of ground water elevation measures, ground elevation values from a digital elevation model (DEM) are used to determine a maximum reasonable variance expected to occur on the experimental variogram. To determine appropriate DEM parameters, a separate study was also done which observed characteristic behavior …

Imaging In Karst Terrain Using The Electrical Resistivity And Multichannel Analyses Of Surface Wave Methods, Ragab W. Jaafar

Masters Theses

"Electrical resistivity tomography and multi-channel analyses of surface waves data were acquired at a study area in Phelps County in the south-central part of Missouri. The objectives of the investigation were fourfold: 1) to image the subsurface in the study area to a depth of 70 feet; 2) to compare the ERT images generated using both the dipole-dipole and Wenner-Schlumberger arrays; and 3) to assess how variations in the MASW array configuration affected MASW data quality; and 4) to compare the ERT-estimated depth to top-of-rock and the MASW-generated depth to top-of-rock.

The subsurface in the study area was imaged to …

Application Of Millimeter-Wave Differential Probe For Crack Detection On Riveted Structures, Kuang Ping Ying

Masters Theses

"This thesis proposes the use of a W-band wideband differential probe for crack detection on riveted structures, such as aircraft fuselage lap joints. Detection of crack at its early stage (surface-breaking) is particularly important to prevent the development of a fatigue crack. This probe utilizing millimeter-wave frequencies serves as a viable candidate on detecting surface-breaking cracks, as it can be employed in measurements in a non-contact fashion, while allowing for high spatial-resolution images and the abilities to penetrate through dielectric materials (paint), making it attractive for detecting small cracks. In previous works, a V-band differential probe has shown promise for …

Crustal Thickness And Vp/Vs Ratio Of Yellowstone, Eastern Snake River Plain, Wyoming Province, And The Northern Basin And Range Province Through Receiver Function Analysis, Avikant Dayma

Masters Theses

"For decades, numerous studies have been conducted and contradictory results were achieved about the origin and evolution of the Yellowstone supervolcano and the Eastern Snake River Plain. Whether the 640 km long time-progressive chain of rhyolitic calderas was formed due to mantle-plume or a result of lithospheric extension allowing the emergence of melt on the surface is still a debate. Using receiver function analyses, this study determines the crustal thickness and the Vp/Vs ratio below the Yellowstone Plateau, Wyoming Province (WP), Idaho Batholith (IB), Eastern Snake River Plain (ESRP), and the northern Basin and Range Province (BRP). The thickness is …

Study Of Surface Complexation And Mineral Dissolution During Water-Rock Interaction In High Salinity Waterflooding At Elevated Temperatures, Sameer Salasakar

Masters Theses

"High salinity waterflooding for carbonate reservoirs is efficient and cheap method used for improved oil recovery. Various mechanisms have been proposed including adsorption/desorption on rock surface, mineral dissolution and precipitation, multicomponent ion exchange, interfacial tension reduction, fine migration and double layer expansion. These all process alter the wettability which leads to improved oil recovery.

Objective of this study was to understand processes that occur during water-rock interaction when high salinity water is flooded into the reservoir. In this work, effect of temperature on water-rock interaction is studied along with effect of pH and specific surface areas of calcite at normal …

Effect Of Fracture Heterogeneity On Proppant Transport And Settling Mechanism, Dhurgham Abdulameer Kadhim

Masters Theses

"Proppant transport modeling through fractures with slickwater fluid systems assumes uniform and homogeneous fracture widths by implying constant fluid behavior at wall boundaries. Hydraulic fracturing mineback operations have demonstrated that induced fractures are heterogeneous and varying in width. This work investigates the impact of fracture width heterogeneity, roughness, and leak-off on ceramic proppant transport and settling, using proppant distribution concepts of Equilibrium Dune Level (EDL) and equilibrium Dune Length (EDX). Experimental work was conducted to investigate the impact of fracture width heterogeneity by varying fracture width along two plexiglass sheets. To mimic actual hydraulic fractures, the injection side was designed …

Nuclei Segmentation Using Level Set Method And Data Fusion For The Cin Classification, Ravali Edulapuram

Masters Theses

"This paper deals with the automation of the detection of the cervical cancer through histology images. This process is divided into two parts, corresponding to segmentation and data fusion. The segmentation and classification of the cervical epithelium images is done using hybrid image processing techniques. The digitized histology images provided have a pre-cervical cancer condition called cervical intraepithelial neoplasia (CIN) by expert pathologists. Previously, image analysis studies focused on nuclei-level features to classify the epithelium into the CIN grades. The current study focuses on nuclei segmentation based on the level set segmentation and fuzzy c-means clustering methods. Morphological post-processing operations …

The Fourth Amendment In A Digital World, Laura K. Donohue

Georgetown Law Faculty Publications and Other Works

Fourth Amendment doctrines created in the 1970s and 1980s no longer reflect how the world works. The formal legal distinctions on which they rely—(a) private versus public space, (b) personal information versus third party data, (c) content versus non-content, and (d) domestic versus international—are failing to protect the privacy interests at stake. Simultaneously, reduced resource constraints are accelerating the loss of rights. The doctrine has yet to catch up with the world in which we live. A necessary first step for the Court is to reconsider the theoretical underpinning of the Fourth Amendment, to allow for the evolution of a …

A Regulatory Theory Of Legal Claims, J. Maria Glover

Georgetown Law Faculty Publications and Other Works

Procedural law in the United States seeks to achieve three interrelated goals in our system of litigation: efficient processes that achieve “substantive justice” and deter wrongdoing, accurate outcomes, and meaningful access to the courts. For years, however, procedural debate, particularly in the context of due process rights in class actions, has been redirected toward more conceptual questions about the nature of legal claims—are they more appropriately conceptualized as individual property or as collective goods? At stake is the extent to which relevant procedures will protect the right of individual claimants to exercise control over their claims. Those with individualistic conceptions …

Chinese International Students In A Northwest University: Investigating Cultural Academic Learning And Teaching Preferences, Michael L. Bevis

Theses and Dissertations

As Chinese international students on American university campuses continue to rise, the importance of these institutions to accommodate the students in adapting to a different academic culture has become more critical. On a public, coeducational research university located in the Pacific Northwest, a concurrent triangulated mixed method research design was implemented to investigate cultural factors with preferred learning and teaching styles of Chinese international students along with what corroborative descriptions these students provide as effective learning experiences in American college classrooms.

The study brought attention to Chinese international students’ differing cultural values from the previous literature understanding, it supported previous …

Evaluating The Attitudes Of Preservice Teachers Toward Multicultural Competence, Angela D. Marshall

Theses and Dissertations

Changes in the ethnicity of the student population across the nation necessitated a change in teacher education curricula. This explanatory, sequential, mixed-method study examined how a group of preservice teachers viewed the importance of multicultural competence before and after student teaching. Specifically, an evaluation of preservice teachers’ attitudes about their own multicultural preparedness was made prior to and after being given full responsibility for an ethnically diverse classroom.

The study employed quantitative and qualitative measures to assess preservice teachers’ levels of multicultural competence as well as their awareness of self-perceptions of multicultural competence that contribute to attitudes toward teaching an …

Effects Of A Peer-Tutoring System Utilizing Students With Emotional Behavioral Disorders As Tutors And Students With Intellectual Disabilities As Tutees, Vicki Koslin Howell

Theses and Dissertations

High school students with intellectual disabilities often find appropriate ways and times to socialize with their peers. In self-contained settings, students are often limited to interacting with only those within the classroom. In addition, students with emotional behavioral disorders often have deficits in social domains and in self-esteem. Improving socializations of students with disabilities has always been a concern of both parents and teachers. Peer-mediated learning has been a proven effective way to instruct students with disabilities. Placing a student with an emotional behavioral disorder in the position of a peer tutor allows them to feel more secure in their …

Course Quality And Hosting Platforms: Implications For Massively Open Online Course (Mooc) Design And Delivery, Rita Diane Schmallegger

Theses and Dissertations

Massive open online courses (MOOCs) began as an experiment in connectivist learning in 2008 (Downes, 2012). While the number of MOOCs offered has risen, as has the number of universities offering MOOCs (Brown, Costello, Donkon, & Giolla-Mhichill, 2015), perceptions of the quality of MOOCs have been mixed (Bali, 2014; Peterson, 2014). From a perspective of Merrill’s first principles of instruction (2013), this qualitative study examined MOOC delivery platforms to determine what learning platforms and what specific characteristics may best promote and sustain MOOC quality. MOOCs selected for this study include those offered in English, open to anyone with Internet access, …

Examining The Relationship Between Virtual School Size And Student Achievement, Sherrill Waddell

Theses and Dissertations

The purpose of this study is to examine the relationship between virtual school size and student achievement in virtual schools in a southwestern state. Enrollment size and the following areas were studied in an attempt to determine student achievement: STAAR English Language Arts/Reading, STAAR Math, STAAR Science, and STAAR Social Studies testing scores in regards to race. This quantitative study used nonexperimental research utilizing a distribution approach. The effect of virtual school size on student achievement in a southwestern state was examined. Specifically, student achievement was defined by student passing rates on individual tests of the STAAR examination. This research …

Factors In The Admissions Process Influencing Persistence In A Master’S Of Science Program In Marine Science, Melissa L. Dore

Theses and Dissertations

Factors in the Admissions Process Influencing Persistence in a Master’s of Science Program in Marine Science. Melissa L. Dore, 2017: Applied Dissertation, Nova Southeastern University, Abraham S. Fischler College of Education. Keywords: academic persistence, admission counseling, graduate students, marine science education, examinations This applied dissertation was conducted to provide the graduate program in marine sciences a valid predictor for success in the admissions scoring systems that include the general Graduate Record Exam. The dependent variable was persistence: successfully graduating from the marine sciences master’s programs. This dissertation evaluated other values including the applicant’s age, gender, undergraduate GPA, letters of recommendation, …