Digital Commons Network^™

Hybrid Beamforming With Deep Learning For Large-Scale Antenna Arrays, Rentao Hu, Lijun Jiang, Ping Li

Electrical and Computer Engineering Faculty Research & Creative Works

The emergence of highly directional beamforming technology makes millimeter wave frequency band communication possible in future wireless communication networks. Based on the multipath characteristics of millimeter wave frequency communication, a high-precision multipath channel estimation algorithm based on signal subspace is proposed. In the mobile terminal, an iterative heuristic radiofrequency combination algorithm based on spatial points is proposed. The analog precoding at the base station uses deep learning to accelerate the calculation, and then the multi-user communication is modeled to design the digital precoding. The simulation results show that the multi-channel estimation algorithm can estimate 4 paths with an error of …

Mining Haul Road Defect Detection -- Advancement In Automated Road Extent And Response Calibration For Improved Maintenance, Alexander David Douglas

Doctoral Dissertations

Mine haul roads degrade rapidly due to extremely heavy loads on sub optimal construction materials. This research tests two methods of defect detection to determine limitations to current technology: optical detection and vehicle vibration response. Optical defect detection was found to have the least significant limitations for surface defect detection and vehicle vibration response modeling has the least significant limitations for subsurface defects. This research proposes novel methods to eliminate the critical limitations of both technologies.

Unmanned Aerial Vehicles (UAV) equipped with GPS and a high-resolution camera is used to create a 3-D point cloud using a structure-from-motion algorithm. This …

Instrumentation, Modeling, And Sound Metamodeling Foundations For Complex Hybrid Systems, Natasha Amelia Jarus

Doctoral Dissertations

Many of our critical infrastructures, from power grids to water distribution networks, are complex hybrid systems that use software to control their non-trivial physical dynamics. These systems must be able to capably serve their purpose, while also being reliable, dependable, safe, secure, and efficient. Representation and analysis of these features requires the creation of several distinct models. These models may encode design goals or be derived from collected instrumentation data, reflecting both how a system ought to operate and how it does operate. It is essential to ensure that all of these models consistently and accurately describe the same system. …

Sensor Data Based Adaptive Models For Assembly Worker Training In Cyber Manufacturing, Md. Al-Amin

Doctoral Dissertations

“Production innovations are occurring faster than ever leading conventional production systems towards cyber manufacturing. Manufacturing workers thus need to frequently learn new methods and skills. In fast-changing, largely uncertain production systems, manufacturers with the ability to comprehend workers’ behavior and assess their operational performance in near real-time will achieve better performance than peers. Recognizing worker actions in near real-time while performing the assembly can serve this purpose. However, reliably recognizing the assembly actions performed by the workers is challenging, because the actions for assembly are complex and workers are not only heterogeneous but sensitive to the variation of the work …

Data And Resource Management In Wireless Networks Via Data Compression, Gps-Free Dissemination, And Learning, Xiaofei Cao

Doctoral Dissertations

“This research proposes several innovative approaches to collect data efficiently from large scale WSNs. First, a Z-compression algorithm has been proposed which exploits the temporal locality of the multi-dimensional sensing data and adapts the Z-order encoding algorithm to map multi-dimensional data to a one-dimensional data stream. The extended version of Z-compression adapts itself to working in low power WSNs running under low power listening (LPL) mode, and comprehensively analyzes its performance compressing both real-world and synthetic datasets. Second, it proposed an efficient geospatial based data collection scheme for IoTs that reduces redundant rebroadcast of up to 95% by only collecting …

Designing Transition Metal Chalcogenides Electrocatalyst Surfaces For High-Efficiency Water Oxidation, Umanga De Silva

Doctoral Dissertations

”The rising demand for energy security and reducing fossil fuel dependence has prompted researchers to search for a clean, sustainable, and efficient energy generation system with low environmental impact. Water electrolysis has been identified as one of the most important processes satisfying the above needs to generate hydrogen as a clean fuel. Two half-cell reactions of oxygen evolution reaction (OER) at the anode and hydrogen evolution reaction (HER) at the cathode comprise the main process of water electrolysis. However, the oxygen evolution reaction is the most crucial step for efficient water splitting. Traditionally, metal oxides have been utilized as catalysts …

Fiber-Optic And Coaxial-Cable Extrinsic Fabry-Perot Interferometers For Sensing Applications, Chen Zhu

Doctoral Dissertations

”The fiber-optic extrinsic Fabry-Perot interferometer (EFPI) is one of the simplest sensing configurations and is widely used in various applications due to its prominent features, such as high sensitivity, immunity to electromagnetic interference, and remote operation capability. In this research, a novel one-dimensional wide-range displacement sensor and a three-dimensional displacement sensor based on fiber-optic EFPIs are demonstrated. These two robust and easy-to-manufacture sensors expand the application scope of the fiber-optic EFPI sensor devices, and have great potential in structural health monitoring, the construction industry, oil well monitoring, and geo-technology.

Furthermore, inspired by the fiber-optic EFPI, a novel and universal ultra-sensitive …

High Throughput Analysis To Study Emerging Pollutants And Nanoparticle Fate In Biological Systems, Xiaolong He

Doctoral Dissertations

”The increasing applications of emerging and fugitive contaminants (EFCs) and engineered nanoparticles (ENPs) attract significant research interest for their potential risks to human health and the environment. In order to assess the health risks of these emerging contaminants, rapid and reliable analytical methods to measure the concentrations and fates of these contaminants are imperative. This dissertation focuses on the developments of advanced analytical methods and their applications to study those emerging contaminants in crop plant and simulated gastric fluid (SGF). Three types of mass spectrometry based methodologies have been developed, one is freeze-thaw/centrifugation extraction followed by high performance liquid chromatography …

Development Of Intelligent Stimuli-Responsive Biomaterials And Nanodevices, Shuo Yang

Doctoral Dissertations

"Structural DNA nanotechnology utilizes DNA molecules as building blocks to fabricate ordered artificial nanostructures at the molecular level. Among all DNA-based techniques, DNA origami has been considered as one of the most powerful tools for constructing artificial nanostructures with excellent programmability and addressability. Currently, most DNA origami nanostructures are static and do not have the ability to response to environmental stimulation. The development of environmental-responsive DNA origami nanostructures is a critical step towards the realization of intelligent dynamic DNA origami-based nanodevices. This research focuses on the design and fabrication process of both static and dynamic DNA origami nanostructures and their …

Design And Development Of A Variable Resistance Hand Exerciser Using A Compliant Mechanism, Jyothi Komatireddy

Masters Theses

"Rehabilitation exercise plays a vital role in recovering from an injury or illness condition by improving flexibility and restoring muscle strength. If not done correctly, exercising can cause more damage to the health condition than in healing. Understanding the muscle’s resistance level while performing an exercise helps design the exercising equipment not to overstrain the muscle during operation. This research presents a methodology to develop a variable-resistance hand exerciser by using a compliant cam-follower mechanism. The proposed design comprised a compliant follower and a rigid cam. The rigid cam is synthesized using the human hand force-deflection profile as an input …

Relationships Among Mineralogy, Geochemistry, And Oil And Gas Production In The Tuscaloosa Marine Shale, Hayley Roxana Beitel

Masters Theses

"The Tuscaloosa Marine Shale (TMS) is an unconventional shale reservoir located in southeast Louisiana and southwest Mississippi. Limited mineralogical and geochemical data for the TMS have been published. The data that do exist indicate that the formation is heterogeneous. Consequently, previous investigators and oil and gas companies have not managed to effectively link mineralogical and chemical changes to oil and gas production in the TMS. These linkages are critical to establish for future exploration efforts. In this study, we attempt to establish these relationships by gathering all existing mineralogical and chemical data in the TMS, including newly acquired data from …

Projectile Generator Design For Underground Coal Mine Seal Testing, Ethan Allan Steward

Masters Theses

"Underground coal mines have several dangers, one of the most hazardous of which is the possibility of an explosion caused by the ignition of methane gas. To reduce ventilation costs, coal mines have the option to close off abandoned areas that are no longer active with structural seals to keep an explosion from propagating into working areas of the mine. Though seals have been designed to resist the overpressure, none have been evaluated for their resistance to the impact of heavy objects. Underground explosions produce high velocity gasses that, traveling through mine openings, may propel objects in the mine at …

A Simple Background Elimination Method For Miniaturized Fiber-Optic Raman Probe, Bohong Zhang

Masters Theses

"Raman scattering is called a photonic - molecular interaction based on the kinetic model of the analytic. Due to the uniqueness of the Raman scattering technique, it can provide a unique fingerprint signal for molecular recognition. However, a serious challenge often encountered in Raman measurement comes from the requirements of fast, real-time remote sensing, background fluorescence suppression, and micro-environmental detection.

A new Miniaturized Fiber-Optic Raman Probe (MFORP) for Raman spectroscopy, used especially for eliminating background fluorescence and enhancing sampling, is presented. Its main purpose is to provide an overview of excellent research on the detection of very small substances and …

Predator Scent And Presence Alter Mammal Assemblages In The Missouri Ozarks, Usa, Cara Jean Yocom-Russell

Masters Theses

"Species that are vulnerable to predation exhibit a host of behavioral and physiological adaptations toward the avoidance of this outcome: Heightened awareness of surroundings through visual, olfactory, and auditory senses are common ways in which these species avoid detection by predators. While links between direct predator-prey relationships are well established, less is known about how predators can shape overall community structure or the populations of secondary or less frequently consumed prey items. As humans expand into rural areas, the frequency of wildlife conflicts rises. In response, humans look to prevent these events with a variety of methods. One such method …

Early Wildfire Detection By Air Quality Sensors On Unmanned Aerial Vehicles: Optimization And Feasibility, Doaa Rjoub

Masters Theses

“Millions of acres of forests are destroyed by wildfires every year, causing ecological, environmental, and economical losses. The recent wildfires in Australia and the Western U.S. smothered multiple states with more than fifty million acres charred by the blazes. The warmer and drier climate makes scientists expect increases in the severity and frequency of wildfires and the associated risks in the future. These inescapable crises highlight the urgent need for early detection and prevention of wildfires. This work proposed an energy management framework that integrated unmanned aerial vehicle (UAV) with air quality sensors for early wildfire detection and forest monitoring. …

Multiple Generations Of Phlogopite In An Alnöite Diatreme: Insights Into The Petrogenesis Of The Avon Alkaline Igneous Province, Missouri, Nathan Gregory Limbaugh

Masters Theses

“Alkaline Ultramafic Carbonatite (AUC) complexes, although rare, are valued for diamonds and REEs, and as windows into subcontinental and mantle processes as recorded by rock fabrics, mineral spatial relationships, and mineral compositions. We report specifically on olivine and phlogopite petrographic relationships and compositions from the Devonian alnoite diatreme-facies of the Avon Alkaline Igneous Province, Missouri. The diatreme alnoite is a mixture of domains of olivine magmaclasts (OM) set in a crystal-rich melilite matrix. OM are highly fractured, serpentinized olivine pseudomorphs with variable amounts of pristine olivine fragments. Larger olivine domains typically exhibit clear crystal faces and irregular “channels” indicative of …

Bond Graph Modeling Of Critical Infrastructures For Cyber-Physical Security Implementation, Michele Jane White

Masters Theses

“In developed societies, there exists infrastructure vital to everyday life. This includes water and power systems. Technology is quickly evolving and being implemented on these utilities. This technology can range from smart metering in neighborhoods to volume sensors in local waste water treatment facilities. When networking, sensing, monitoring, or control devices are integrated with infrastructure it is considered a cyber physical system, or CPS. When information about an important physical system is connected to the virtual world, it is opened up to security risks. Cyber security can be provided to the CPS by monitoring the physical state of the system …

A Compact Wavelength Meter Using A Multimode Fiber, Ogbole Collins Inalegwu

Masters Theses

“Wavelength meters are very important for precision measurements of both pulses and continuous-wave optical sources. Conventional wavelength meters employ gratings, prisms, interferometers, and other wavelength-sensitive materials in their design. Here, we report a simple and compact wavelength meter based on a section of multimode fiber and a camera. The concept is to correlate the multimodal interference pattern (i.e., speckle pattern) at the end-face of a multimode fiber with the wavelength of the input lightsource. Through a series of experiments, specklegrams from the end face of a multimode fiber as captured by a charge-coupled device (CCD) camera were recorded; the images …

Biochemical Assay Invariant Attestation For The Security Of Cyber-Physical Digital Microfluidic Biochips, Fredrick Eugene Love Ii

Masters Theses

“Due to the devastating global impact that infectious diseases have had, especially in developing countries, the demand for access to adequate resources to combat sickness continues to be a heavy burden. Reliable and affordable diagnostics is a vital first line of defense in fighting outbreaks and providing accurate treatment. Digital microfluidics biochips capable of running multiple diagnostic tests on a single platform are an emerging technology that are increasingly being evaluated as a viable platform for rapid diagnosis and point-of-care field deployment. Although these systems offer many benefits, processing errors are inherent. Therefore, cyber-physical digital biochips are being investigated that …

Analysis And Design Of Dc-Link Capacitor In Cascaded H-Bridge Multilevel Active Front-End Converter, Muhammad Shehroz Malik

Masters Theses

Medium-voltage grid-tied systems often use a cascaded H-bridge multi-level active front-end. In this converter, dc link bus capacitors play an important role in stabilizing the converter and enabling both active and reactive power injections. The present work provides analytical expressions for the capacitor current, which are essential for optimizing system design (especially capacitor size vs. lifetime). Then, the expression is incorporated into the grid connected bidirectional power system model. Consequently, this work contributes to the guiding principles to choose accurate dc link capacitor ratings against grid-side power delivery requirements.

DC-link capacitors come with an expiration date which is dependent on …

Computer Gamification: Addressing Symptoms Of Inattentive Adhd In Children, Shavonne Victoria Halterman

Masters Theses

“Computer gamification has the potential to help meet the educational needs of children with Inattentive Attention Deficit/Hyperactivity disorder (ADHD). The elements of computer gamification are mapped to distinct kinds of interventions for Inattentive ADHD and show certain types of computer gamified learning are better than others for those who experience Inattentive ADHD”--Abstract, page iii.

Research And Development Of A Laser Hot Wire Deposition Process, Christopher Croft

Masters Theses

“Laser hot wire directed energy deposition (DED) is an increasingly popular method for improving deposition rates and overall reduction of build times in DED processing. While there is clear benefit, it is important to fully understand the impact of preheating the wire. This work focuses on developing a model that describes bead geometry output using all factors including the wire preheat. The model was fit with over 150 data points that explored a large range of each factor. The resulting model was then leveraged to evaluate a process control variable. The technique chosen used feedback from the hot wire system …

Airbnbs In The Rural Midwest: Optimizing Listing Content For User’S Decision-Making Processes, Mary Catherine Kosacki

Masters Theses

This research examines the effectiveness of rural Airbnb listing content in influencing user decision-making. The peer-to-peer economy has been rapidly growing over the past decade, providing new opportunities for individuals to offer goods and services to other individuals through corporate platforms. Specifically, the Airbnb platform has rapidly grown, becoming the largest online platform for peer-to-peer property rentals, and one of the largest companies in the peer-to-peer sector of the economy. Previous research on the Airbnb platform has focused primarily on urban areas; however, Airbnbs have a proportionally large impact on local economies in rural areas.

Several methods were employed to …

Physics-Based Modeling Of Lithium-Ion Batteries For Control And Estimation Applications, Brody J. C. Riemann

Masters Theses

“Lithium-ion batteries are extensively used in many application areas like consumer electronics, electric vehicles, and microgrids. As the world moves towards further electrification of vehicles and more widespread use of renewable energy sources, the need for large-scale battery storage systems will grow. To effectively replace conventional methods, batteries will need to be charged quickly while accounting for degradation to maximize lifetime. Further, larger batteries require more detailed safety monitoring, which is implemented using a battery management system (BMS). A BMS is responsible for state of charge (SOC) estimation, state of health (SOH) estimation, cell balancing, regulating voltage and current according …

Values Of Trust In Ai In Autonomous Driving Vehicles, Ru Lian

Masters Theses

“Automation with artificial intelligence technology is an emerging field and is widely used in various industries. With the increasing autonomy, learning, and adaptability of intelligent machines such as self-driving cars, it is difficult to regard them as simple tools in human hands. At the same time, a series of problems and challenges such as predictability, interpretability, and causality arise. Trust in self-driving technology will impact the adoption and utilization of autonomous driving technology. A qualitative research methodology, Value-Focused Thinking, is used to identify the values of trust in autonomous driving vehicles and analyze the relationship between these values”--Abstract, page iii.

A Systematic Analysis Of Eye-Tracking Metrics For Sleepiness, Debasis Roy

Masters Theses

”Sleepiness or sleep deprivation is a serious hazard that can be life-threatening in carrying out certain tasks (e.g., when driving or executing attention-critical tasks). Eye movement can provide cues on sleepiness. Hence, eye-tracking metrics have the potential to detect sleepiness.

In this research, we used a systematic analysis approach to identify eye-tracking metrics for sleepiness. We used several databases to identify independent experimental studies that have used eye-tracking metrics to assess sleepiness. We identified 25 studies that included 674 participants where the participants’ data were captured both in an alert state and in a sleep-deprived state. In the analysis, we …

A Meta-Analysis: Gamification In Education, Yalin Wang

Masters Theses

“Gamification has been used in a variety of contexts including education. In order to understand the effects of gamification in education, a meta-analysis was conducted. A bottom-up approach was used to analyze the effects of game design elements on learning outcomes found in the literature search. The result suggests that gamification can enhance student learning outcomes. Elements such as points, leaderboards, competitions, progress bars, feedback, and collaboration have medium to large effect sizes. Gamification also has larger effects on young children in elementary education than learners at other education levels. The study offers suggestions and guidelines for educators on the …

Prediction Intervals For Fractionally Integrated Time Series And Volatility Models, Rukman Ekanayake

Doctoral Dissertations

"The two of the main formulations for modeling long range dependence in volatilities associated with financial time series are fractionally integrated generalized autoregressive conditional heteroscedastic (FIGARCH) and hyperbolic generalized autoregressive conditional heteroscedastic (HYGARCH) models. The traditional methods of constructing prediction intervals for volatility models, either employ a Gaussian error assumption or are based on asymptotic theory. However, many empirical studies show that the distribution of errors exhibit leptokurtic behavior. Therefore, the traditional prediction intervals developed for conditional volatility models yield poor coverage. An alternative is to employ residual bootstrap-based prediction intervals. One goal of this dissertation research is to develop …

Thermomechanical Simulation And Process Optimization For Hot Rolling Of Steel, Shouvik Ganguly

Doctoral Dissertations

"Hot rolling is a manufacturing process that involves large material deformation, complicated geometries, contact conditions and non-uniform temperature gradients. Steel industries are motivated to prevent hot rolled steel products to be defect free and with desired shape and size. In order to simulate the process accurately, it is essential that the material model for steel accounts for the viscoplasticity and changes in properties that occur in steel at elevated temperatures as grain growth and recrystallization.

The healing of existing voids during hot rolling was investigated using finite element simulations. Voids are highly undesirable as they not only degrade the product …

Convective-Diffusive Transport In Krogh Cylinders: A Model For Pharmacokinetics, Xianjie Qiu

Doctoral Dissertations

"Drug delivery to inside of the tumor is the important problem. The dynamics of drug delivery is presented here. Previously and particularly for directed delivery, a stirred tank model has been used, which appears to have worked well when compared to experiments. However, the stirred tank models do not include all the mass transfer resistances and towards that end we have used a distributed system called Krogh cylinder. This study focuses on the Krogh cylinder model simulation, both on the fluid flow and the mass transfer. The capillary network is broken down into cylindrical cells, each containing a capillary and …