Engineering Commons^™

Simulation Of The Objective Occlusion Effect Induced By Bone-Conducted Stimulation Using A Three-Dimensional Finite-Element Model Of A Human Head, Huiyang Xu, Franck Sgard, Kévin Carillo, Éric Wagnac, Jacques De Guise

Études primaires

The occlusion effect (OE) refers to the phenomenon that more bone-conducted physiological sounds are transmitted into the earcanal when it is blocked and may cause discomfort on users of hearing protection devices. Models have been proposed to study the OE as they can help understand the physical mechanisms and can be used to evaluate the individual contribution on the OE of the factors that may affect it (i.e., occlusion device, ear anatomy, and stimulation). The existing finite element models developed to study the OE are limited by their truncated ear geometries. In order to progress in the understanding of the …

Prediction Of Emg Activation Profiles From Gait Kinematics And Kinetics During Multiple Terrains, Erika V. Zabre-Gonzalez, Diego Amieva-Alvarado, Scott A. Beardsley

Biomedical Engineering Faculty Research and Publications

Continuous myoelectric prediction of intended limb dynamics has the ability to provide transparent control of a prosthesis by the user. However, the impact on these models of adding a human user into the control loop is less clear. Here, the ability of a User Response Model (URM) to continuously predict EMG activity from gait kinematics and kinetics collected during three mobility tasks (level-ground walking, stair ascent, and stair descent) was examined. Multiple-input, multiple-output NARX-based URMs were developed with two outputs (ankle plantarflexor and dorsiflexor) and variable inputs (ankle kinetics, and shank and/or ankle kinematics). Accuracy in predicting the tibialis anterior …

Dynamic Optimization Algorithms For Baseload Power Plant Cycling Under Variable Renewable Energy, Rebecca Hyen Hae Kim

Graduate Theses, Dissertations, and Problem Reports (ETD)

The growing deployment of variable renewable energy (VRE) sources, such as wind and solar, is mainly due to the decline in the cost of renewable technologies and the increase of societal and cultural pressures. Solar and wind power generation are also known to have zero marginal costs and fuel emissions during dispatch. Thereby, the VRE from these sources should be prioritized when available. However, the rapid deployment of VRE has heightened concerns regarding the challenges in the integration between fossil-fueled and renewable energy systems. The high variability introduced by the VRE as well as the limited alignment between demand and …

Weed Recognition In Agriculture: A Mask R-Cnn Approach, Sruthi Keerthi Valicharla

Graduate Theses, Dissertations, and Problem Reports (ETD)

Recent interdisciplinary collaboration on deep learning has led to a growing interest in its application in the agriculture domain. Weed control and management are some of the crucial tasks in agriculture to maintain high crop productivity. The inception phase of weed control and management is to successfully recognize the weed plants, followed by providing a suitable management plan. Due to the complexities in agriculture images, such as similar colour and texture, we need to incorporate a deep neural network that uses pixel-wise grouping for identifying the plant species. In this thesis, we analysed the performance of one of the most …

Effects Of Changes In Land Use Land Cover And Climate On Long-Term Total Dissolved Solids Trends In The Mid-Atlantic Region Of The United States, Melaine Edouard Kolimedje

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Mid-Atlantic region (MAR) of the U.S. is subjected to a variety of stressors that affect the headwaters of the major rivers. Some of these stressors are abandoned mine drainage, agriculture, municipal point sources, urban areas, out-of-basin diversions, competing water uses, rapid population growths in the lowlands, alterations in water availability due to climate change and habitat alteration. In addition to these regional stressors, the rapid population growths and energy sources shifting have resulted in changes in land use and land cover (LULC) over the last few decades. The interactive effects of LULC and interannual/long-term climate changes have resulted in …

Quantifying The Impact Of Load-Following On Gas-Fired Power Plants, Yifan Wang

Graduate Theses, Dissertations, and Problem Reports (ETD)

Due to rapid penetration of renewables into the grid, natural gas combined cycle (NGCC) power plants are being forced to cycle their loads more frequently and rapidly than for which they were designed. However, the impact of load-following operation on plant efficiency and equipment health are currently poorly understood. The objective of this work is to quantify the impact of load-following on the gas-fired plants by developing high-fidelity multi-scale dynamic models. There are four main tasks in this project. First, dynamic model of an NGCC power plant has been developed. The main components of the NGCC plants are the gas …

Design Of A Heat Exchanger For A Supercritical Co2 Turbine System, Kehinde Oluwatobi Adenuga

Graduate Theses, Dissertations, and Problem Reports (ETD)

This research aims at designing a shell and tube heat exchanger which will drive a turbine operated on supercritical CO₂. Hot gases from boiler (simulated using air) at 1500 K is introduced into the shell to heat up the supercritical CO₂ at 10 MPa flowing within tubes from 450 K to 1050 K. The design was done using selected shell and tube heat exchanger empirical equations at predefined boundary conditions. The effect of shell and tube diameter on other design parameters was examined. It was observed that the number of tubes, tube external and internal side surface …

Productivity Index For Unconventional Gas Wells, Yousef Khajah

Graduate Theses, Dissertations, and Problem Reports (ETD)

Productivity Index reflects the ability of a well to produce hydrocarbons and is often used to analyze the well's performance. Productivity Index is the ratio of the flow rate to the drawdown pressure under pseudo-steady state flow conditions. The unconventional gas formation such as shale are the main target of the gas exploration and production. The application of horizontal drilling and hydraulic fracturing technologies have been instrumental in development of shale gas resources. The evaluation of the productivity index for unconventional gas wells is however challenging because the production mainly occurs under the transient conditions.

This research aims to evaluate …

Sustainability Key Performance Indicators For Mass Customization, Md Fahid Hasan Pulak

Graduate Theses, Dissertations, and Problem Reports (ETD)

Today’s manufacturers are striving towards a more sustainable and customized product offering in their value chain to satisfy customer demand and compete on the marketplace. By adopting sustainability practices, companies are not only complying with environmental regulations but are strategically addressing the triple bottom line (TBL) of sustainability (environmental, social, and economic). Similarly, mass customization allows a company to better satisfy their customers by creating individualized products economically. Moving forward, it is important to better understand the relationship of these two competitive strategies. In order to assess the sustainability performance of mass customization, it is important to understand the appropriate …

Evaluating Social Media As A Medium Of Private Communication Through Steganographic Images, Kendall Weldon Coles

Graduate Theses, Dissertations, and Problem Reports (ETD)

Social media is a vastly used communication tool with billions of users worldwide. These social networks provide users the ability to share their ideas and thoughts through the messages, videos, and images that they post. The images that are shared can possibly be embedded with private messages through the use of a steganographic tool. The messages are embedded in a fashion that doesn’t change the visual appearance of an image. This allows for these types of images to hide in plain sight, which creates the possibility of someone communicating privately in a public social media setting. This project proved how …

Iot Malicious Traffic Classification Using Machine Learning, Michael Austin

Graduate Theses, Dissertations, and Problem Reports (ETD)

Although desktops and laptops have historically composed the bulk of botnet nodes, Internet of Things (IoT) devices have become more recent targets. Lightbulbs, outdoor cameras, watches, and many other small items are connected to WiFi and each other; and few have well-developed security or hardening. Research on botnets typically leverages honeypots, PCAPs, and network traffic analysis tools to develop detection models. The research questions addressed in this Problem Report are: (1) What machine learning algorithm performs the best in a binary classification task for a representative dataset of malicious and benign IoT traffic; and (2) What features have the most …

Flow Field Measurement And Qualification Of The West Virginia University Environmental Wind Tunnel, Katherine Mary Reid

Graduate Theses, Dissertations, and Problem Reports (ETD)

In 2013 West Virginia University acquired an Environmental Wind Tunnel from Cornell University. Due to the state of the tunnel, elements of the tunnel were redesigned and rebuilt at the West Virginia University Hangar in Morgantown, West Virginia. The motivation of this research was to evaluate and qualify the flow field within the test section of this redesigned and reconstructed wind tunnel. The tunnel has many uses for the university, including outside research opportunities as well as educational purposes for students in the Aerospace Engineering Department. The methods employed for this effort included developing a grid of pitot tubes to …

Deep Models For Improving The Performance And Reliability Of Person Recognition, Sobhan Soleymani

Graduate Theses, Dissertations, and Problem Reports (ETD)

Deep models have provided high accuracy for different applications such as person recognition, image segmentation, image captioning, scene description, and action recognition. In this dissertation, we study the deep learning models and their application in improving the performance and reliability of person recognition. This dissertation focuses on five aspects of person recognition: (1) multimodal person recognition, (2) quality-aware multi-sample person recognition, (3) text-independent speaker verification, (4) adversarial iris examples, and (5) morphed face images. First, we discuss the application of multimodal networks consisting of face, iris, fingerprint, and speech modalities in person recognition. We propose multi-stream convolutional neural network architectures …

Application Of 3d Seismic Signal And Geomechanical Attributes For Subsurface Fracture Characterization: A Case Study In Clearfield County, Central Pennsylvania, Iman F. Zulkapeli

Graduate Theses, Dissertations, and Problem Reports (ETD)

Hydrocarbon exploration in unconventional reservoirs is highly risky due to the nature of the reservoirs and the variability in fractures and reservoir geomechanical properties in the subsurface. The reservoir needs to be fully characterized to avoid any complication such as frac hit, wellbore failure, blowout, or even a dry hole. The Clearfield reservoir produces an exceptionally low amount of gas, compared to the neighboring region in the proximity, which has been poorly understood. This raises the question as to what causes the reservoir to have low productivity.

This study focuses on the natural fracture characterization using high-quality 3D seismic signal …

Real Vs Fake Faces: Deepfakes And Face Morphing, Jacob L. Dameron

Graduate Theses, Dissertations, and Problem Reports (ETD)

The ability to determine the legitimacy of a person’s face in images and video can be important for many applications ranging from social media to border security. From a biometrics perspective, altering one’s appearance to look like a target identity is a direct method of attack against the security of facial recognition systems. Defending against such attacks requires the ability to recognize them as a separate identity from their target. Alternatively, a forensics perspective may view this as a forgery of digital media. Detecting such forgeries requires the ability to detect artifacts not commonly seen in genuine media. This work …

Increasing The Reliability Of Software Systems On Small Satellites Using Software-Based Simulation Of The Embedded System, Matthew D. Grubb

Graduate Theses, Dissertations, and Problem Reports (ETD)

The utility of Small Satellites (SmallSats) for technology demonstrations and scientific research has been proven over the past few decades by governments, universities, and private companies. While the research and technology demonstration objectives that can be provided by these SmallSats are becoming similar to larger spacecraft, their reliability still falls behind. This is in part due to the reduced cost of SmallSat missions in comparison to large spacecraft, which requires cheaper components, rapid development schedules, and accepted risk. In these missions, the importance of the flight software is often overlooked, and the software is rushed through development and not fully …

Erosion And Sediment Controls On Reclaimed Mine Refuse Impoundments, Sara Dalen

Graduate Theses, Dissertations, and Problem Reports (ETD)

To ensure the sustainable use of one of West Virginia’s precious resources, conscientious long-term management of residual waste is of immense importance. This thesis examined two main topics: i) the dewatering process of acid mine drainage (AMD) sludge, and ii) an investigation of soil loss predictions of a reclaimed coal refuse impoundment.

The first aspect of this thesis addresses clarification and remediation of AMD prior to disposal is a prominent component to preventing runoff and seepage of environmentally detrimental byproducts. To examine the effects of flocculation and dewatering more closely by means of geotextiles, an AMD sludge was analyzed. The …

Multimodel Operability Framework For Design Of Modular And Intensified Energy Systems, Vitor Gazzaneo

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this dissertation, a novel operability framework is introduced for the process design of modular and intensified energy systems that are challenged by complexity and highly constrained environments. Previously developed process operability approaches are reviewed and further developed in terms of theory, application, and software infrastructure. An optimization-based multilayer operability framework is introduced for process design of nonlinear energy systems. In the first layer of this framework, a mixed-integer linear programming (MILP)-based iterative algorithm considers the minimization of footprint and achievement of process intensification targets. Then, in the second layer, an operability analysis is performed to incorporate key features of …

The Role Of Structure Evolution For Prbaco2o6-Δ In Oxygen Reduction Reaction Kinetics At Sofc Cathode, Nan Zhang

Graduate Theses, Dissertations, and Problem Reports (ETD)

Mixed ion and electron conductive materials especially those with perovskite-related structures have been widely used as cathode and anode of solid oxide fuel cells (SOFC). Double perovskite LnBaCo₂O_6-δ (Ln=Pr, Nd, Sm, Nd, Y) cathodes have been shown better performance than single perovskite Ln_0.5Ba_0.5CoO_3-δ in SOFC cathode studies. However, the effect of different double perovskite phases on oxygen transport properties has not been investigated. In this study, the electrochemical performance of different double perovskite materials PrBaCo₂O_6-δ (PBCO), NdBaCo₂O_6-δ (NBCO), YBaCo₂O_6-δ (YBCO), and single perovskite …

Floating-Gate Design And Linearization For Reconfigurable Analog Signal Processing, Steven Michael Andryzcik Ii

Graduate Theses, Dissertations, and Problem Reports (ETD)

Analog and mixed-signal integrated circuits have found a place in modern electronics design as a viable alternative to digital pre-processing. With metrics that boast high accuracy and low power consumption, analog pre-processing has opened the door to low-power state-monitoring systems when it is utilized in place of a power-hungry digital signal-processing stage. However, the complicated design process required by analog and mixed-signal systems has been a barrier to broader applications. The implementation of floating-gate transistors has begun to pave the way for a more reasonable approach to analog design. Floating-gate technology has widespread use in the digital domain. Analog and …

Review Of Forecasting Univariate Time-Series Data With Application To Water-Energy Nexus Studies & Proposal Of Parallel Hybrid Sarima-Ann Model, Cory Sumner Yarrington

Graduate Theses, Dissertations, and Problem Reports (ETD)

The necessary materials for most human activities are water and energy. Integrated analysis to accurately forecast water and energy consumption enables the implementation of efficient short and long-term resource management planning as well as expanding policy and research possibilities for the supportive infrastructure. However, the integral relationship between water and energy (water-energy nexus) poses a difficult problem for modeling. The accessibility and physical overlay of data sets related to water-energy nexus is another main issue for a reliable water-energy consumption forecast. The framework of urban metabolism (UM) uses several types of data to build a global view and highlight issues …

Position-Scanning Peptide Libraries As Particle Immunogens For Improving Cd8+ T-Cell Responses, Michael C. Vega

Faculty Articles, Papers, and Other Scholarship

Short peptides reflecting major histocompatibility complex (MHC) class I (MHC-I) epitopes frequently lack sufficient immunogenicity to induce robust antigen (Ag)-specific CD8⁺ T cell responses. In the current work, it is demonstrated that position-scanning peptide libraries themselves can serve as improved immunogens, inducing Ag-specific CD8⁺ T cells with greater frequency and function than the wild-type epitope. The approach involves displaying the entire position-scanning library onto immunogenic nanoliposomes. Each library contains the MHC-I epitope with a single randomized position. When a recently identified MHC-I epitope in the glycoprotein gp70 envelope protein of murine leukemia virus (MuLV) is assessed, only one …

A Comparison Of Aerodynamic Models For Optimizing The Takeoff And Transition Of A Bi-Wing Tailsitter, Ryan Anderson, Jacob Willis, Jacob Johnson, Andrew Ning, Randal Beard

Faculty Publications

Electric vertical takeoff and landing (eVTOL) aircraft take advantage of distributed electric propulsion as well as aerodynamic lifting surfaces to take off vertically and perform long-duration flights. Complex aerodynamic interactions and a hard-to-predict transition maneuver from hover to wing-borne flight are one challenge in their development. To address this, we compare three different interaction models of varying fidelity for optimizing the transition trajectory of a biplane tailsitter. The first model accounts for simplified rotor-on-wing interactions using momentum theory, while the other two account for wing-on-wing interactions using a vortex lattice method and rotor-on-wing aerodynamic interactions using blade element momentum theory. …

Reducing Wind Farm Power Variance From Wind Direction Using Wind Farm Layout Optimization, Bertelsen Gagakuma, Andrew P.J. Stanley, Andrew Ning

Faculty Publications

This paper investigates reducing power variance caused by different wind directions by using wind farm layout optimization. The problem was formulated as a multi-objective optimization. The ε−constraint method was used to solve the bi-objective problem in a two-step optimization framework where two sequential optimizations were performed. The first was maximizing the mean wind farm power alone and the second was minimizing the power variance with a constraint on the mean power. The results show that the variance in power estimates can be greatly reduced, by as much as 30%, without sacrificing mean plant power for the different farm sizes and …

Workshop Outcomes Report: 1st International Workshop On Seismic Resilience Of Arctic Infrastructure And Social Systems, Majid Ghayoomi, Katharine Duderstadt, Alexander Kholodov, Alexander Shiklomanov, Matthew Turner, Elham Ajorlou

Faculty Publications

No abstract provided.

Reducing Environmental Impacts Of Natural Gas Compressor Stations And Applicability Of The Current Regulatory Framework, Scotty Joel Moates

All ETDs from UAB

The natural gas pipeline system is an integral part of the energy structure and critical to meeting energy demand in the United States. Natural gas compressor stations are the heart of the natural gas pipeline industry. Compressor stations compress the gas coming into the station and increase the pressure of the gas to ensure movement down the pipeline at the right operating pressure. This compression process is performed through natural-gas fire engines, such as reciprocating engines and turbines. Natural gas compressor station operations are subject to a wide range of environmental regulations. These regulations seek to mitigate the environmental impacts …

Impact Evaluation Of Major Hurricanes On Designated Southeast Coast Counties Of Usa Using Multivariate Analysis And Forecasting, Mukti Patel

All ETDs from UAB

The study includes four major analyses. Each analysis has its own uniqueness. The Temporal analysis intended to track the economic effect trends of major storms in small counties and large metro regions as well as compare how the percent GDP loss in these locations has affected. The study shows that unfavorable impacts of major storms of the same scale and intensity stood the greatest shift in GDP growth rate percentage along with greatest damage in terms of GDP particularly in the smaller counties during and after major storm event. In addition to that percentage change in population growth rate, personal …

De Novo Generation Of Cardiomyocytes For Regenerative Medicine Treatment, Yawen Tang

All ETDs from UAB

Cardiovascular disease, till now, is still the leading cause of death in the United States. As a consequences of heart attack event, cardiomyocytes death is an irreversible process accompanied with scar formation and loss of heart function. As mammalian cardiomyocytes exit cell cycle shortly after birth, with no replacement of the necrotic cardiomyocytes, the damages caused by heart attack often progress into more severe symptoms such as heart failure. To replenish damaged cardiomyocytes (CMs), many therapies, such as differentiate the induced pluripotent stem cells (iPSCs) into cardiomyocytes and direct reprogram fibroblasts into CMs, have been developed. During this dissertation study, …

Studies On The Influence Of Non-Equilibrium Plasma Irradiation On Polyester Scaffolds: Characterization And Evolution Of New Surface Properties Toward Potential Biomedical Applications, Bernabe Samuel Tucker

All ETDs from UAB

A great need exists for innovative, functional materials. Specifically, functional materials must meet the necessary mechanical and interfacial properties for successful bio-integration for end goals such as medical implants. A gap in the knowledge existed before this work. This work addressed that gap through an experimental approach that employed low-temperature plasma (LTP) processing of fibrous, polyester constructs to produce functional materials. First, atmospheric-pressure plasma processing of electrospun polyester fibers, in a tubular geometry, was reported. Characterization of that system was conducted. Next, the effects of magnetized plasmas were reported. That report was a novel application of magnetized plasma and showed …

Miniaturization Of The Network Analyzer As An Interface Circuit For Wearable Resonance-Based Sensors, Fan Wu

All ETDs from UAB

Readout interface circuits are the essential part of all sensor units. Miniaturing such circuits is a challenging design issue for the future of the Internet of Things, wearable and implantable biomedical devices, sensors for harsh environments, etc. For developing wireless telemetry sensors, Vector Network Analyzer (VNA) is a powerful measurement instrument that can measure scattering parameters (S-Parameters) of single and dual-port networks, as well as Y- and Z-parameters. However, VNAs are expensive and bulky and cannot be carried around, and therefore, they can’t be used as a sensor interface. This thesis aims to design, develop, and implement a miniaturized data …