Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

2021

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 8791 - 8820 of 9975

Full-Text Articles in Engineering

Altered Skeletal Muscle Excitation-Contraction Coupling In The R6/2 Transgenic Mouse Model For Huntington's Disease, Daniel R. Miranda Jan 2021

Altered Skeletal Muscle Excitation-Contraction Coupling In The R6/2 Transgenic Mouse Model For Huntington's Disease, Daniel R. Miranda

Browse all Theses and Dissertations

Huntington’s disease (HD) has classically been categorized as a neurodegenerative disorder. However, the expression of the disease-causing mutated huntingtin gene in skeletal muscle may contribute to the symptoms of HD, namely those that involve involuntary muscle contraction. In the R6/2 transgenic mouse model of HD, we previously observed ion channel defects that could contribute to involuntary muscle contraction. Here, in R6/2 muscle we investigated the consequence of these ion channel defects on action potentials (APs), the first step in excitation-contraction (EC) coupling. We found that the ion channel defects were associated with depolarizing the baseline membrane potential during AP trains. …


Texture-Driven Image Clustering In Laser Powder Bed Fusion, Alexander H. Groeger Jan 2021

Texture-Driven Image Clustering In Laser Powder Bed Fusion, Alexander H. Groeger

Browse all Theses and Dissertations

The additive manufacturing (AM) field is striving to identify anomalies in laser powder bed fusion (LPBF) using multi-sensor in-process monitoring paired with machine learning (ML). In-process monitoring can reveal the presence of anomalies but creating a ML classifier requires labeled data. The present work approaches this problem by printing hundreds of Inconel-718 coupons with different processing parameters to capture a wide range of process monitoring imagery with multiple sensor types. Afterwards, the process monitoring images are encoded into feature vectors and clustered to isolate groups in each sensor modality. Four texture representations were learned by training two convolutional neural network …


Reconfigurable Antenna Array Using The Pin-Diode-Switched Printed Square Spiral Element, Corey M. Stamper Jan 2021

Reconfigurable Antenna Array Using The Pin-Diode-Switched Printed Square Spiral Element, Corey M. Stamper

Browse all Theses and Dissertations

A dual-band array of reconfigurable elements is modeled and simulated. The array consists of four single square spiral microstrip antennas that are corporately fed and are used as a unit cell. The single square spiral uses two PIN diodes as switching elements to achieve reconfiguration. The array has four switch states that can operate over four discrete frequencies in the S and C bands. The unit cell radiation pattern is used with the pattern multiplication model to quickly simulate the array pattern of larger arrays. A 3 x 3 array of the unit cells is modeled with only the center …


Development Of A Robust And Tunable Aircraft Guidance Algorithm, Jacob R. Spangenberg Jan 2021

Development Of A Robust And Tunable Aircraft Guidance Algorithm, Jacob R. Spangenberg

Browse all Theses and Dissertations

A set of guidance control laws is developed for application to a reduced order dynamic aircraft model. A feedback control formulation utilizing a linear quadratic regulator (LQR) is developed, together with methods for easing the design burden associated with gain tuning. Metrics are developed to assess the stability margin of the controller over the full flight envelope of a notional unmanned aerial vehicle (UAV) model. A feedforward control path is then added to the architecture. The performance of the guidance control laws is assessed through time domain step response metrics as well as through execution of a design mission. The …


Texture-Driven Image Clustering In Laser Powder Bed Fusion, Alexander H. Groeger Jan 2021

Texture-Driven Image Clustering In Laser Powder Bed Fusion, Alexander H. Groeger

Browse all Theses and Dissertations

The additive manufacturing (AM) field is striving to identify anomalies in laser powder bed fusion (LPBF) using multi-sensor in-process monitoring paired with machine learning (ML). In-process monitoring can reveal the presence of anomalies but creating a ML classifier requires labeled data. The present work approaches this problem by printing hundreds of Inconel-718 coupons with different processing parameters to capture a wide range of process monitoring imagery with multiple sensor types. Afterwards, the process monitoring images are encoded into feature vectors and clustered to isolate groups in each sensor modality. Four texture representations were learned by training two convolutional neural network …


Augmenting Structure/Function Relationship Analysis With Deep Learning For The Classification Of Psychoactive Drug Activity At Class A G Protein-Coupled Receptors, Hannah Willow Shows Jan 2021

Augmenting Structure/Function Relationship Analysis With Deep Learning For The Classification Of Psychoactive Drug Activity At Class A G Protein-Coupled Receptors, Hannah Willow Shows

Browse all Theses and Dissertations

G protein-coupled receptors (GPCRs) initiate intracellular signaling pathways via interaction with external stimuli. [1-5] Despite sharing similar structure and cellular mechanism, GPCRs participate in a uniquely broad range of physiological functions. [6] Due to the size and functional diversity of the GPCR family, these receptors are a major focus for pharmacological applications. [1,7] Current state-of-the-art pharmacology and toxicology research strategies rely on computational methods to efficiently design highly selective, low toxicity compounds. [9], [10] GPCR-targeting therapeutics are associated with low selectivity resulting in increased risk of adverse effects and toxicity. Psychoactive drugs that are active at Class A GPCRs used …


Utilizing Rotational Energy In Wind Turbine Blades With The Flywheel Mechanism And Predicting The Power Output By Neural Networking, Anamika Mishra Jan 2021

Utilizing Rotational Energy In Wind Turbine Blades With The Flywheel Mechanism And Predicting The Power Output By Neural Networking, Anamika Mishra

Browse all Theses and Dissertations

As we expand and innovate for better and safer living, there will always be a need for new energy sources. By replacing fossil fuels, renewable energy is becoming a viable option for primary power generation. That is why researchers are turning their attention to renewable energy sources and ways of making the most of them. WIND ENERGY is a promising renewable and clean energy source harvested from the wind which is plentiful on the planet. We already have the technology to harvest it, but the efficiency and power output are not optimal. In this thesis, to enhance the energy harvesting …


Evaluating The Performance Of Using Speaker Diarization For Speech Separation Of In-Person Role-Play Dialogues, Raveendra Medaramitta Jan 2021

Evaluating The Performance Of Using Speaker Diarization For Speech Separation Of In-Person Role-Play Dialogues, Raveendra Medaramitta

Browse all Theses and Dissertations

Development of professional communication skills, such as motivational interviewing, often requires experiential learning through expert instructor-guided role-plays between the trainee and a standard patient/actor. Due to the growing demand for such skills in practices, e.g., for health care providers in the management of mental health challenges, chronic conditions, substance misuse disorders, etc., there is an urgent need to improve the efficacy and scalability of such role-play based experiential learning, which are often bottlenecked by the time-consuming performance assessment process. WSU is developing ReadMI (Real-time Assessment of Dialogue in Motivational Interviewing) to address this challenge, a mobile AI solution aiming to …


Mathematical Formula Recognition And Automatic Detection And Translation Of Algorithmic Components Into Stochastic Petri Nets In Scientific Documents, Elisavet Elli Kostalia Jan 2021

Mathematical Formula Recognition And Automatic Detection And Translation Of Algorithmic Components Into Stochastic Petri Nets In Scientific Documents, Elisavet Elli Kostalia

Browse all Theses and Dissertations

A great percentage of documents in scientific and engineering disciplines include mathematical formulas and/or algorithms. Exploring the mathematical formulas in the technical documents, we focused on the mathematical operations associations, their syntactical correctness, and the association of these components into attributed graphs and Stochastic Petri Nets (SPN). We also introduce a formal language to generate mathematical formulas and evaluate their syntactical correctness. The main contribution of this work focuses on the automatic segmentation of mathematical documents for the parsing and analysis of detected algorithmic components. To achieve this, we present a synergy of methods, such as string parsing according to …


Goal Management In Multi-Agent Systems, Venkatsampath Raja Gogineni Jan 2021

Goal Management In Multi-Agent Systems, Venkatsampath Raja Gogineni

Browse all Theses and Dissertations

Autonomous agents in a multi-agent system coordinate to achieve their goals. However, in a partially observable world, current multi-agent systems are often less effective in achieving their goals. In much part, this limitation is due to an agent's lack of reasoning about other agents and their mental states. Another factor is the agent's inability to share required knowledge with other agents and the lack of explanations in justifying the reasons behind the goal. This research addresses these problems by presenting a general approach for agent goal management in unexpected situations. In this approach, an agent applies three main concepts: goal …


Detecting Server-Side Web Applications With Unrestricted File Upload Vulnerabilities, Jin Huang Jan 2021

Detecting Server-Side Web Applications With Unrestricted File Upload Vulnerabilities, Jin Huang

Browse all Theses and Dissertations

Vulnerable web applications fundamentally undermine website security as they often expose critical infrastructures and sensitive information behind them to potential risks and threats. Web applications with unrestricted file upload vulnerabilities allow attackers to upload a file with malicious code, which can be later executed on the server by attackers to enable various attacks such as information exfiltration, spamming, phishing, and spreading malware. This dissertation presents our research in building two novel frameworks to detect server-side applications vulnerable to unrestricted file uploading attacks. We design the innovative model that holistically characterizes both data and control flows using a graphbased data structure. …


The Effect Of Winding Curvature And Core Permeability On The Power Losses And Leakage Inductance Of High-Frequency Transformers, Daniel J. Whitman Jan 2021

The Effect Of Winding Curvature And Core Permeability On The Power Losses And Leakage Inductance Of High-Frequency Transformers, Daniel J. Whitman

Browse all Theses and Dissertations

At the frequencies used in switching dc-dc converters, the skin and proximity effects have a significant effect on both the losses and leakage inductance of the transformers used in these circuits. Analytical expressions that have been derived to calculate ac resistance and leakage inductance have primarily used a 1-D approximation. They also have used Cartesian coordinates or approximations that are equivalent to Cartesian coordinates, as well as usually assuming an ideal core of infinite permeability. The classical result in the case of the resistance/losses is Dowell’s equation, and there are analogous results for leakage inductance. This dissertation derives new equations …


Acute Oxygen-Sensing By The Carotid Bodies : The Thermal Microdomain Model, Ryan Joseph Rakoczy Jan 2021

Acute Oxygen-Sensing By The Carotid Bodies : The Thermal Microdomain Model, Ryan Joseph Rakoczy

Browse all Theses and Dissertations

The carotid bodies (CB) are peripheral chemoreceptors that detect changes in arterial oxygenation and, via afferent inputs to the brainstem, correct the pattern of breathing to restore blood gas homeostasis. Elucidating the “signal” that couples carotid body sensory type I cell (CBSC) hypoxic mitochondrial inhibition with potassium channel closure has proven to be an arduous task; to date, a multitude of oxygen-sensing chemotransduction mechanisms have been described and altercated (Varas, Wyatt & Buckler, 2007; Gao et al, 2017; Rakoczy & Wyatt, 2018). Herein, we provide preliminary evidence supporting a novel oxygen-sensing hypothesis suggesting CBSC hypoxic chemotransductive signaling may in part …


Noninvasive Blood Flow And Oxygenation Measurements In Diseased Tissue, Benjamin S. Rinehart Jan 2021

Noninvasive Blood Flow And Oxygenation Measurements In Diseased Tissue, Benjamin S. Rinehart

Browse all Theses and Dissertations

The research presented in this dissertation focused on the application of optical imaging techniques to establish blood flow and oxygen saturation as effective biomarkers for two disease cases, Autism Spectrum Disorder (ASD) and Huntington’s Disease (HD). The BTBR mouse model of ASD was utilized to validate measurements of cerebral blood flow and oxygenation as biomarkers for autism. The R6/2 mouse model of juvenile HD was utilized to validate measurements of skeletal muscle blood flow following tetanic muscle contractions induced by electrical nerve stimulation. Next, a noncontact, camera-based system to measure blood flow and oxygen saturation maps was implemented to improve …


Tibial Strains And Tray-Bone Micromotions After Total Knee Arthroplasty: Computational Studies Evaluating The Tibial Fixation, Huizhou Yang Jan 2021

Tibial Strains And Tray-Bone Micromotions After Total Knee Arthroplasty: Computational Studies Evaluating The Tibial Fixation, Huizhou Yang

Electronic Theses and Dissertations

Cemented and cementless fixation in total knee arthroplasty (TKA) have been successfully used for decades. As the number of younger and more active patients treated with TKA continues to increase, long-term implant survivorship is of increasing importance. One of the most common complications and hence the reason for revision is mechanical loosening (23.1% of all revised TKA). The loosening mechanisms have been proposed for different fixation types. For cemented fixation, bone remodeling after surgery is regulated by the changes in strain energy density (SED). The recruitment of osteoclasts and osteoblasts is controlled by SED-related signals. Insufficient stimuli can promote bone …


Building Services Engineering January/February Jan 2021

Building Services Engineering January/February

Building Services Engineering

No abstract provided.


Quantifying The Value Of Foam-Based Flexible Floating Solar Photovoltaic Systems, Koami Soulemane Hayibo Jan 2021

Quantifying The Value Of Foam-Based Flexible Floating Solar Photovoltaic Systems, Koami Soulemane Hayibo

Dissertations, Master's Theses and Master's Reports

Distributed generation with solar photovoltaic (PV) technology is economically competitive if net metered in the U.S. Yet there is evidence that net metering is misrepresenting the true value of distributed solar generation so that the value of solar (VOS) is becoming the preferred method for evaluating economics of grid-tied PV. VOS calculations are challenging and there is widespread disagreement in the literature on the methods and data needed. To overcome these limitations, this thesis reviews past VOS studies to develop a generalized model that considers realistic future avoided costs and liabilities. The approach used here is bottom-up modeling where the …


Application Of Carbon Nanotube Thermophones As Duct Noise Cancelling Speakers: Using New Technology With Old Theories, Stephania M. Vaglica Jan 2021

Application Of Carbon Nanotube Thermophones As Duct Noise Cancelling Speakers: Using New Technology With Old Theories, Stephania M. Vaglica

Dissertations, Master's Theses and Master's Reports

Certain materials can produce sound through heat fluctuations. In recent times, the material capable of this was discovered to be Carbon Nanotubes (CNT). The idea is to create a flexible speaker that can be made into any shape or form to create sound. Once a speaker has been created, an active noise control system can be designed to cancel loud sounds in building and pipe ducts. This technology, similar to noise cancelling headphones, allows a user to create a modular system to mitigate noise in everyday life. Thus, the purpose of this research is to illustrate the abilities of a …


Experimental Evaluation And Simulation Of Torque Transmissibility Frequency Response Functions Of Vibration Isolators And Absorbers For Drivetrain Applications, Luke Jurmu Jan 2021

Experimental Evaluation And Simulation Of Torque Transmissibility Frequency Response Functions Of Vibration Isolators And Absorbers For Drivetrain Applications, Luke Jurmu

Dissertations, Master's Theses and Master's Reports

Four studies involving torsional vibration isolation performance of automotive drivetrain components, make up this dissertation. One study features a prototype planetary torsional vibration absorber, a unique device that targets low frequency torsion modes in automotive drivetrains. Two studies feature experiments on several torque converters, clutch locked and open, to validate models of the hardware. The last study details experiments on a centrifugal pendulum absorber in a torque converter, to characterize the viscous friction while submerged in automatic transmission fluid (ATF). The enclosed studies improve the state of the art of drivetrain vibration absorbers and isolators, by introducing a new vibration …


Sliding Mode Control Of A Nonlinear Wave Energy Converter Model, Tania Demonte Gonzalez Jan 2021

Sliding Mode Control Of A Nonlinear Wave Energy Converter Model, Tania Demonte Gonzalez

Dissertations, Master's Theses and Master's Reports

The most accurate wave energy converter models for heaving point absorbers include nonlinearities, which increase as resonance is achieved to maximize energy capture. The efficiency of wave energy converters can be enhanced by employing a control scheme that accounts for these nonlinearities. This project proposes a sliding mode control for a heaving point absorber that includes the nonlinear effects of the Froude-Krylov force. The sliding mode controller tracks a reference velocity that matches the phase of the excitation force to ensure higher energy absorption. This control algorithm is tested in regular linear waves and is compared to a complex-conjugate control …


Exploring Rapid Solidification And Equal Channel Angular Pressing In The Fabrication Of Mg-Based Alloys For Medical Applications, Emily Tom Jan 2021

Exploring Rapid Solidification And Equal Channel Angular Pressing In The Fabrication Of Mg-Based Alloys For Medical Applications, Emily Tom

Dissertations, Master's Theses and Master's Reports

The development of magnesium bioresorbable implants has become increasingly popular due to the increased need for temporary implants and magnesium’s excellent biocompatibility and suitable elastic modulus. Even though magnesium is an excellent candidate, when alloyed with other metals magnesium’s corrosion rate becomes too rapid for bioresorbable medical applications. The investigation into novel processing techniques to control the formation of precipitates to improve mechanical strength and ductility as well as corrosion rates has become of interest. This work investigates the combination of two nonequilibrium processing techniques, rapid solidification (RS) and equal channel angular pressing (ECAP), and the effects it has on …


Development Of Autonomous Vehicle Motion Planning And Control Algorithm With D* Planner And Model Predictive Control In A Dynamic Environment, Somnath Mondal Jan 2021

Development Of Autonomous Vehicle Motion Planning And Control Algorithm With D* Planner And Model Predictive Control In A Dynamic Environment, Somnath Mondal

Dissertations, Master's Theses and Master's Reports

The research in this report incorporates the improvement in the autonomous driving capability of self-driving cars in a dynamic environment. Global and local path planning are implemented using the D* path planning algorithm with a combined Cubic B-Spline trajectory generator, which generates an optimal obstacle free trajectory for the vehicle to follow and avoid collision. Model Predictive Control (MPC) is used for the longitudinal and the lateral control of the vehicle. The presented motion planning and control algorithm is tested using Model-In-the-Loop (MIL) method with the help of MATLAB® Driving Scenario Designer and Unreal Engine® Simulator by Epic Games®. Different …


High Injection Pressure Impinging Diesel Spray Characteristics And Subsequent Soot Formation In Reacting Conditions, Zhihao Zhao Jan 2021

High Injection Pressure Impinging Diesel Spray Characteristics And Subsequent Soot Formation In Reacting Conditions, Zhihao Zhao

Dissertations, Master's Theses and Master's Reports

The spray impingement in diesel engines attracts the attention of engine researchers in recent decades as the physical size of the engine is reduced. Due to the spray impingement, the atomization, vaporizing and air-fuel mixing quality is altered compared to a free spray. For emission control, soot is one of the major particulate emissions from diesel combustion and its formation in an impinged spray is worthy to be investigated.

Firstly, to understand the impinged spray characteristics, the experiments for both non-vaporizing and reacting conditions were conducted in a constant volume combustion vessel. The impinged spray was captured by a high-speed …


Lithium-Ion Battery Recycling Using Mineral Processing Methods, Ruiting Zhan Jan 2021

Lithium-Ion Battery Recycling Using Mineral Processing Methods, Ruiting Zhan

Dissertations, Master's Theses and Master's Reports

The surges in the volume of the retired Li-ion batteries (LIBs) in future motivate Li-ion battery recycling R&D activities worldwide. Within the Li-ion batteries, the most valuable component is cathode active materials that consist of critical minerals and materials such as lithium, cobalt, nickel, manganese. The LIB recycling has been investigated at both the lab scale and industrial scale. There are three existing recycling methods, namely physical separation, pyrometallurgy, and hydrometallurgy. Physical separation methods sort individual battery components without changing materials’ physical properties, while both pyrometallurgical and hydrometallurgical recycling routes aim to recover valuable metals using a high-temperature process and …


Pre-Failure Persistent Scatterer Interferometry (Psi) And Soil Moisture Index (Smi) Analysis Of The Edenville Dam In Midland, Michigan, Ryan Klida Jan 2021

Pre-Failure Persistent Scatterer Interferometry (Psi) And Soil Moisture Index (Smi) Analysis Of The Edenville Dam In Midland, Michigan, Ryan Klida

Dissertations, Master's Theses and Master's Reports

The Edenville Dam was an earth dam located approximately 15 miles northwest of Midland, Michigan. The dam impounded the Tobacco and Tittabawassee Rivers, forming Wixom Lake. On May 19th, 2020, the dam failed after three days of elevated rainfall. Flood waters from Wixom Lake caused the overtopping of the Sanford Dam downstream, and the flooding of the surrounding area. The Edenville Dam was 95 years old at the time of failure and was constructed before modern geotechnical engineering methods were widely practiced. Dam infrastructure similar to Edenville is not uncommon, requiring the need for increased monitoring. A pre-failure …


Telelocomotion—Remotely Operated Legged Robots, Kevin Huang, Divas Subedi, Rahul Mitra, Isabella Yung, Kirkland Boyd, Edwin Aldrich, Digesh Chitrakar Jan 2021

Telelocomotion—Remotely Operated Legged Robots, Kevin Huang, Divas Subedi, Rahul Mitra, Isabella Yung, Kirkland Boyd, Edwin Aldrich, Digesh Chitrakar

Engineering: Faculty Publications

Teleoperated systems enable human control of robotic proxies and are particularly amenable to inaccessible environments unsuitable for autonomy. Examples include emergency response, underwater manipulation, and robot assisted minimally invasive surgery. However, teleoperation architectures have been predominantly employed in manipulation tasks, and are thus only useful when the robot is within reach of the task. This work introduces the idea of extending teleoperation to enable online human remote control of legged robots, or telelocomotion, to traverse challenging terrain. Traversing unpredictable terrain remains a challenge for autonomous legged locomotion, as demonstrated by robots commonly falling in high-profile robotics contests. Telelocomotion can reduce …


Boundary Integral Equation Method For Electrostatic Field Prediction In Piecewise-Homogeneous Electrolytes, Christopher Keith Pratt Jan 2021

Boundary Integral Equation Method For Electrostatic Field Prediction In Piecewise-Homogeneous Electrolytes, Christopher Keith Pratt

Theses and Dissertations--Electrical and Computer Engineering

This thesis presents a method to predict electrostatic fields, potentials, and currents in regions containing piecewise-homogeneous electrolytes. Additionally, an efficient electric field calculation is presented. A boundary integral equation is formulated for the boundary potentials and currents and is discretized using the Locally Corrected Nyström method. Solution convergence with respect to the mesh discretization and basis order is investigated. The techniques are validated through analysis of problems with either analytic solutions, with published data, or with other solution methods.


Electric Power Systems And Components For Electric Aircraft, Damien Lawhorn Jan 2021

Electric Power Systems And Components For Electric Aircraft, Damien Lawhorn

Theses and Dissertations--Electrical and Computer Engineering

Electric aircraft have gained increasing attention in recent years due to their potential for environmental and economic benefits over conventional airplanes. In order to offer competitive flight times and payload capabilities, electric aircraft power systems (EAPS) must exhibit extremely high efficiencies and power densities. While advancements in enabling technologies have progressed the development of high performance EAPS, further research is required.

One challenge in the design of EAPS is determining the best topology to be employed. This work proposes a new graph theory based method for the optimal design of EAPS. This method takes into account data surveyed from a …


Fabrication And Simulation Of Perovskite Solar Cells, Maniell Workman Jan 2021

Fabrication And Simulation Of Perovskite Solar Cells, Maniell Workman

Theses and Dissertations--Electrical and Computer Engineering

Since the dawning of the industrial revolution, the world has had a need for mass energy production. In the 1950s silicon solar panels were invented. Silicon solar panels have been the main source of solar energy production. They have set the standard for power conversion efficiency for subsequent generations of photovoltaic technology. Solar panels utilize light’s ability to generate an electron hole pair. By creating a PN Junction in the photovoltaic semiconductor, the electron and hole are directed in opposing layers of the solar panel generating the electric current. Second generation solar panels utilized different thin film materials to fabricate …


Traveling Wave Fault Location Method For Distribution Systems With Distributed Generation, Oluwafeyisayo Afolabi Jan 2021

Traveling Wave Fault Location Method For Distribution Systems With Distributed Generation, Oluwafeyisayo Afolabi

Theses and Dissertations--Electrical and Computer Engineering

Fault location is an important topic within electric power systems, as accurate fault location techniques will improve the reliability of the system and reduce downtime caused by outages. This paper explores fault location in distribution systems with distributed generation using the traveling wave fault location method. The single-ended and double-ended traveling wave methods are evaluated using a single-circuit distribution system which is modeled using MATLAB SIMULINK. The results are compared using a basis of signals and bus pairs across fault types, sampling rates and fault resistances.