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

Engineering Commons

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

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 40021 - 40050 of 196041

Full-Text Articles in Engineering

A Probabilistic Perspective Of Human-Machine Interaction, Mustafa Canan, Mustafa Demir, Samuel Kovacic Jan 2022

A Probabilistic Perspective Of Human-Machine Interaction, Mustafa Canan, Mustafa Demir, Samuel Kovacic

Engineering Management & Systems Engineering Faculty Publications

Human-machine interaction (HMI) has become an essential part of the daily routine in organizations. Although the machines are designed with state-of-the-art Artificial Intelligence applications, they are limited in their ability to mimic human behavior. The human-human interaction occurs between two or more humans; when a machine replaces a human, the interaction dynamics are not the same. The results indicate that a machine that interacts with a human can increase the mental uncertainty that a human experiences. Developments in decision sciences indicate that using quantum probability theory (QPT) improves the understanding of human decision-making than merely using classical probability theory (CPT). …


Theorizing The Initial Response Of Countries In Bringing Covid-19 Pandemic Under Control: The Effect Of Change Readiness Of Countries, M. Mahdi Moeini Gharagozloo, Farinaz Sabz Ali Pour, Chen Chen, Mozhgan Moeini Gharagozloo Jan 2022

Theorizing The Initial Response Of Countries In Bringing Covid-19 Pandemic Under Control: The Effect Of Change Readiness Of Countries, M. Mahdi Moeini Gharagozloo, Farinaz Sabz Ali Pour, Chen Chen, Mozhgan Moeini Gharagozloo

Engineering Management & Systems Engineering Faculty Publications

Pandemic crises can bring the biggest and deepest shocks to countries around the world. In the first quarter of 2020, a global pandemic named “COVID-19” spread all over the world and not only took so many lives and created so much fear but also brought a tremendous financial pain as a result of shutting down economies to fight with this unknown contagious virus. This paper examines how countries’ change readiness enables them to bring the spread of an international crisis under control. We propose that higher levels of change readiness would help countries to cope with risks and uncertainties generated …


What Makes An Expert? Characterizing Perceptions Of Expertise And Intuition Among Early-Career Engineers, Caroline Bolton Jan 2022

What Makes An Expert? Characterizing Perceptions Of Expertise And Intuition Among Early-Career Engineers, Caroline Bolton

Honors Theses

This thesis seeks to characterize if and how practicing engineers’ perceptions of expertise development, decision-making processes, and engineering intuition vary by aspects of identity, specifically gender and career stage. This thesis is built from ongoing work of the Miskioğlu group on the relationship between expertise and intuition in engineering. Intuition is a characteristic of experts used in decision-making, and the importance of experience in the development of expertise is well documented in literature. There is a gap around how intuition relates to experience, prompting the need to compare the perceptions of early career engineers and mid-to-late career engineers. This thesis …


Zips Racing Electric 2022 Brakes Subsystem Design, Nicholas Thomas Jan 2022

Zips Racing Electric 2022 Brakes Subsystem Design, Nicholas Thomas

Williams Honors College, Honors Research Projects

This project will include the design, manufacture, and assembly of the entire brakes subsystem for the Zips Racing Electric (ZRE) 2022 car. Goals of the brakes system include a lightweight, modular, machinable, and rigid design. The project will begin in the Fall semester with the design of the pedals and rotors as well as calculations to specify master cylinders, calipers, pads, etc. Software such as SolidWorks CAD, SolidWorks FEA, and Mastercam CAM will be employed. Next, the second semester will involve manufacturing or purchasing necessary components. Prototype pedals will be manufactured for physical testing.

The project will be completed individually. …


Effect Of Room Air Exposure On The Field Emission Performance Of Uv Light Irradiated Si-Gated Field Emitter Arrays, Ranajoy Bhattacharya, Mason Cannon, Rushmita Bhattacharjee, Jim Browning Jan 2022

Effect Of Room Air Exposure On The Field Emission Performance Of Uv Light Irradiated Si-Gated Field Emitter Arrays, Ranajoy Bhattacharya, Mason Cannon, Rushmita Bhattacharjee, Jim Browning

Electrical and Computer Engineering Faculty Publications and Presentations

Field emission cathodes are promising candidates in nanoscale vacuum channel transistors and are used in microwave vacuum electron devices. Prior research has shown that UV light exposure as well as 350 °C vacuum bake can desorb water vapor from Si field emission tips, resulting in lower work function and improved emission performance. However, after long exposure to room air (greater than 24 h), the improved performance is lost as water adsorbs on the tips. In this study, experiments were carried on two sets of 1000 × 1000 Si-gated field emitter arrays to determine the length of time that emitters can …


Handwritten English Word Recognition Using A Deep Learning Based Object Detection Architecture, Riktim Mondal, Samir Malakar, Elisa H. Barney Smith, Ram Sarkar Jan 2022

Handwritten English Word Recognition Using A Deep Learning Based Object Detection Architecture, Riktim Mondal, Samir Malakar, Elisa H. Barney Smith, Ram Sarkar

Electrical and Computer Engineering Faculty Publications and Presentations

Handwriting is used to distribute information among people. To access this information for further analysis the page needs to be optically scanned and converted to machine recognizable form. Due to unconstrained writing styles along with connected and overlapping characters, handwriting recognition remains a challenging task. Most of the methods in the literature use lexicon-based approaches and train their models on large datasets having near 50 K word samples to achieve good results. This results in high computational requirements. While these models use around 50 K words in their dictionary when recognizing handwritten English text, the actual number of words in …


Predicting Radiated Emissions From A Cable Harness Through Component Level Tests, Fuwei Ma Jan 2022

Predicting Radiated Emissions From A Cable Harness Through Component Level Tests, Fuwei Ma

Masters Theses

“In this work, a procedure is developed to predict the radiated emissions from a cable harness using component-level tests. Direct measurement on the engine control unit is utilized to accurately characterize the equivalent common mode source voltages and impedance associated with the device. The cable harness geometry is reduced using the equivalent cable bundle approach by lumping wires according to the source and load impedance compared with characteristic impedance of the harness, which dramatically reduces the measurement effort and allows practical 3D full-wave simulation of the radiated emissions. Radiated emissions are predicted from an engine control unit (ECU) and an …


Am Surface Roughness And Its Impact On Drag, Jackson Landry Chandler Jan 2022

Am Surface Roughness And Its Impact On Drag, Jackson Landry Chandler

Honors Academy

“The main goal of this thesis is to quantify additive manufacturing (AM) surface roughness, as a precursor to identifying its impact on unsteady transient flow properties. Experimental data using the Hirox optical microscopes and SEM imaging collected from the nylon and stainless-steel lattice structures contained an inherent level of surface roughness at the finer scale. Surface Roughness have a negative effect on additively manufactured materials and as such should be mitigated whenever possible. Surface roughness increases unwanted features such as the level of drag, skin friction, negative heat transfer/mass transfer properties, and other unwanted unsteady transitional flow characteristics. Though exceptions …


Atomistic-Continuum Membrane And Machine Learning Models For Two-Dimensional Materials, Upenda Yadav Jan 2022

Atomistic-Continuum Membrane And Machine Learning Models For Two-Dimensional Materials, Upenda Yadav

Dissertations, Master's Theses and Master's Reports

“What could we do with layered structures with just the right layers?” asked Richard Feynman in his famous 1959 lecture, “There’s plenty of room at the bottom.” With the help of the amazing developments of the past several years, we are coming close to answering that question. In 2004, graphene was first isolated from graphite and only six short years later it won the Nobel Prize in Physics. Graphene is one atomic layer of Carbon, it is the thinnest and yet the strongest materials we have ever seen. It is 200 times stronger than its equivalent weight in steel and …


Ransombuster Iot: A Intrusion Detection And Dataset Creation Tool For Ransomware Attacks Within Iot Networks, Jackson M. Walker Jan 2022

Ransombuster Iot: A Intrusion Detection And Dataset Creation Tool For Ransomware Attacks Within Iot Networks, Jackson M. Walker

Cybersecurity Undergraduate Research Showcase

The proposed research follows the design-science guidelines(Hevner, 2004). This paper uses these design-science methods for developing the guidelines for the implementation of the proposed architecture, understanding previous research contributions, and evaluating of research. This paper proposes a network artifact for studying ransomware IoT intrusion detection techniques and offers a proposed network architecture to serve as a framework for creating a publicly available dataset for IoT research on ransomware.


Deepfakes: Ai Technology Of The Future, Hosanna Root Jan 2022

Deepfakes: Ai Technology Of The Future, Hosanna Root

Cybersecurity Undergraduate Research Showcase

Deepfakes technology’s danger stems from its ability to create realistic but fake synthesized media that people often identify as something that is real. With this powerful technology in the wrong hands, deepfakes can cause devastating havoc through information warfare, election campaign disruptions, and more, creating distrust in society. Disinformation is already rampant today, even without wide deployments of deepfakes, which is concerning given the fact that deepfakes’ nefarious full potentials are yet to be reached.


Cell Mechanics In Cardiovascular Disease And Electrospun Scaffold For Vascular Tissue Engineering, Alex Park Rickel Jan 2022

Cell Mechanics In Cardiovascular Disease And Electrospun Scaffold For Vascular Tissue Engineering, Alex Park Rickel

Dissertations and Theses

Cardiovascular disease (CVD) is the leading cause of death worldwide. Atherosclerosis, one of the primary CVDs, is characterized as a chronic inflammatory disease. In the initial stages of atherosclerosis, there is a buildup of cholesterol and lipoproteins that triggers monocytes to enter the arterial wall and begin accumulating lipids. Vascular smooth muscle cells (VSMCs) begin to detach and migrate from the media toward the intima in a process known as phenotypic switching. Phenotypic switching transitions VSMCs from a contractile to synthetic phenotype and they gain the capacity for migration, proliferation, and secretion of extracellular matrix (ECM) proteins. Synthetic VSMCs experience …


Modeling And Simulation Of A Power Plant Boiler Including The Dynamics Of Swell And Shrink, Richard Perman Jan 2022

Modeling And Simulation Of A Power Plant Boiler Including The Dynamics Of Swell And Shrink, Richard Perman

Electronic Theses and Dissertations, 2020-2023

Renewables such as photovoltaics and wind turbines have seen consistent growth in markets across the globe. While renewables increase grid capacity and reduce the use of fossil fuels, their generation rates fluctuate subject to external factors. As the ratio of renewables to nonrenewables increases, so does variability of net load on intermediate and peaking power plants. Power plants with heat recovery steam generators (HRSG) constitute a significant proportion in these categories. There are several interconnected systems within HRSGs, including drum boilers which exhibit interesting transient phenomena known as swell and shrink. Improved understanding, dynamic modeling, and real-time simulation (RTS) of …


Flame-Generated Turbulence For Flame Acceleration And Detonation Transition, Rachel Hytovick Jan 2022

Flame-Generated Turbulence For Flame Acceleration And Detonation Transition, Rachel Hytovick

Electronic Theses and Dissertations, 2020-2023

Detonations are a supersonic mode of combustion witnessed in a variety of applications, from next-generation propulsion devices to catastrophic explosions and the formation of supernovas. Detonations are typically initiated through the deflagration to detonation transition (DDT), a detailed process where a subsonic flame undergoes rapid acceleration increasing compressibility until a hotspot forms on the flame front inciting a detonation wave to form. Due to the complex nature of the phenomena, DDT is commonly investigated in three stages – (i) preconditioning, (ii) detonation onset, and (iii) wave propagation and stability. The research presented explores each of these stages individually, with a …


Design And Analysis Of A Foldable Propeller Blade, Annan Mashin Jan 2022

Design And Analysis Of A Foldable Propeller Blade, Annan Mashin

Electronic Theses and Dissertations, 2020-2023

Deployable structures have made an immense impact in the engineering world. The concept of the deployable structure has been able to reduce costs and sizing limits across a variety of use cases. However, sizing and cost reduction are not the only reasons that deployable structures are prominent. There are unique propeller blades that have entered into the world of deployable structures, where the ability to be stowed away and deployed to a much larger diameter can increase launch flexibility, and the engine efficiencies of aircraft. Although, most of the deployable propeller blades that have been designed in studies have the …


Experimental And Computational Heat Transfer Study Of Sco2 Single Jet Impingement, John Richardson Jan 2022

Experimental And Computational Heat Transfer Study Of Sco2 Single Jet Impingement, John Richardson

Electronic Theses and Dissertations, 2020-2023

The present study experimentally investigates the heat transfer capability of supercritical carbon dioxide (sCO2) single-jet impingement. The evaluated jet Reynolds number range is between 80,000 and 1,000,000, with a non-dimensional jet-to-target surface spacing of 2.8. CO2-impinging jet stagnation conditions were maintained at approximately 20 MPa and a temperature of 673 K for most experiments. The goal is to understand how changes in the aforementioned parameters influence heat transfer between the working fluid and the heated surface. Additionally, due to the elevated Reynolds numbers and difference in thermodynamic properties between air and CO2, air-derived impingement correlations may not be appropriate for …


Computational Modeling Of Respiratory Airflow In Human Distal Airways Using Hybrid Lung Model, Adnan Islam Jan 2022

Computational Modeling Of Respiratory Airflow In Human Distal Airways Using Hybrid Lung Model, Adnan Islam

Electronic Theses and Dissertations, 2020-2023

A major challenge in the Computational Fluid Dynamics (CFD) modeling of the human respiratory system is the complex variation of geometric scale from the trachea to the peripheral airways. The current literature on image-based lung flow analysis is limited to a few (typically 5) generations beyond the trachea. Such studies, which are limited largely by computational intensity and computational cost, also have limited accuracy. In this study we propose a hybrid methodology that enables CFD analysis from the middle to the distal airways through to the alveolar level. A hybrid lung model is generated where the middle airways are reconstructed …


Detecting And Tracking Vulnerable Road Users' Trajectories Using Different Types Of Sensors Fusion, Zhongchuan Wang Jan 2022

Detecting And Tracking Vulnerable Road Users' Trajectories Using Different Types Of Sensors Fusion, Zhongchuan Wang

Electronic Theses and Dissertations, 2020-2023

Vulnerable road user (VRU) detection and tracking has been a key challenge in transportation research. Different types of sensors such as the camera, LiDAR, and inertial measurement units (IMUs) have been used for this purpose. For detection and tracking with the camera, it is necessary to perform calibration to obtain correct GPS trajectories. This method is often tedious and necessitates accurate ground truth data. Moreover, if the camera performs any pan-tilt-zoom function, it is usually necessary to recalibrate the camera. In this thesis, we propose camera calibration using an auxiliary sensor: ultra-wideband (UWB). USBs are capable of tracking a road …


Extreme-Pressure Ignition Studies Of Methane And Natural Gas With Co2 With Applications In Rockets And Gas Turbines, Cory Kinney Jan 2022

Extreme-Pressure Ignition Studies Of Methane And Natural Gas With Co2 With Applications In Rockets And Gas Turbines, Cory Kinney

Electronic Theses and Dissertations, 2020-2023

Although concerns about carbon dioxide (CO2) emissions and their impact on climate change has led to an increase in renewable energy electricity generation, natural gas power plants remain the dominant source of electricity generation in the United States. Until the capacity of renewable energy sources can meet growing electricity demand, natural gas power generation will likely remain an important source of electricity generation. Supercritical CO2 (sCO2) power generation cycles offer an alternative to traditional gas turbines by reusing and sequestering CO2 from the combustion process to prevent its release into the atmosphere. This study seeks to understand natural gas ignition …


Studies On Copper Indium Based Oxide Transparent Semiconducting Thin Films., Giji Skaria Jan 2022

Studies On Copper Indium Based Oxide Transparent Semiconducting Thin Films., Giji Skaria

Electronic Theses and Dissertations, 2020-2023

Transparent Conducting Oxides (TCOs) have unique optoelectronic properties which allow visible light to pass through while having reasonably high electrical conductivity. TCOs find a variety of applications ranging from uses in solar cells, optical displays, reflective coatings, light emission devices, low-emissivity windows, electrochromic mirrors, UV sensors, and windows, defrosting windows, electromagnetic shielding, and transparent electronics. The conductivity of TCOs can be tuned from insulating via semiconducting to conducting as well as their transparency adjusted depending on the donor/acceptor levels as well as the bandgap of the material. This enables the realization of both n-type and p-type TCOs which make them …


Big Data Processing Attribute Based Access Control Security, Anne Tall Jan 2022

Big Data Processing Attribute Based Access Control Security, Anne Tall

Electronic Theses and Dissertations, 2020-2023

The purpose of this research is to analyze the security of next-generation big data processing (BDP) and examine the feasibility of applying advanced security features to meet the needs of modern multi-tenant, multi-level data analysis. The research methodology was to survey of the status of security mechanisms in BDP systems and identify areas that require further improvement. Access control (AC) security services were identified as priority area, specifically Attribute Based Access Control (ABAC). The exemplar BDP system analyzed is the Apache Hadoop ecosystem. We created data generation software, analysis programs, and posted the detailed the experiment configuration on GitHub. Overall, …


High Fidelity Injury Severity Analysis Using Econometric Modeling Approaches, Ahmed Kabli Jan 2022

High Fidelity Injury Severity Analysis Using Econometric Modeling Approaches, Ahmed Kabli

Electronic Theses and Dissertations, 2020-2023

Crash severity models are typically developed using police reported injury severity databases. However, several research studies have identified various challenges associated with police reported data. Therefore, the current dissertation is focusing on developing high resolution crash severity models based on medical professional driver injury severity reported using Abbreviated Injury Scale for eight body regions. The dissertation focused on developing a disaggregate injury severity modeling framework that can enhance the estimation accuracy of independent variable impacts on severity. Within this broad research vision, the dissertation has multiple objectives. First, a joint random parameters multivariate model structure with as many dimensions as …


Improving The Performance And Durability Of Metal Contacts In Crystalline Silicon Solar Cells Using Advanced Characterization, Nafis Iqbal Jan 2022

Improving The Performance And Durability Of Metal Contacts In Crystalline Silicon Solar Cells Using Advanced Characterization, Nafis Iqbal

Electronic Theses and Dissertations, 2020-2023

Solar energy is one of the fastest growing forms of energy generation due to its low cost, lack of emissions, minimal maintenance, and excellent durability. However, like any other technology, it is also not free from defects and degradation, which limit its performance in the real world. Most of the degradation is related to metal contacts, which also happens to be one of the most expensive items in manufacturing, comprising almost half of the cost of converting a silicon wafer into a photovoltaic (PV) cell. Therefore, studying contact degradation to make them reliable and free of defects is the key …


Direct Laser Writing Below The Diffraction Limit By Exploring Multi-Pulse-Induced Physics, Boyang Zhou Jan 2022

Direct Laser Writing Below The Diffraction Limit By Exploring Multi-Pulse-Induced Physics, Boyang Zhou

Electronic Theses and Dissertations, 2020-2023

Ultrafast laser ablation has enabled high-precision processing of a wide range of materials including metals, semiconductors, dielectrics, and polymers. Several laser nanostructuring methods exist, including those based on optical near-fields, special material properties, surface plasmons, and multiphoton absorption (MPA). Among these methods, the MPA method has the potential for nanoscale direct laser writing by using a simple experimental setup. However, the understanding of the fundamental mechanism involved in the laser ablation process is still incomplete, and it remains challenging to obtain a feature size much smaller than the diffraction-limited spot size. The goal of this research is to understand how …


A Study Of Microgravity On Fluid Transport Through Porous Structures In Microfluidic Devices, Sylvain Le Henaff Jan 2022

A Study Of Microgravity On Fluid Transport Through Porous Structures In Microfluidic Devices, Sylvain Le Henaff

Electronic Theses and Dissertations, 2020-2023

The objective of this study is to refine the understanding of micro-fluidics subject to micro-gravity in an attempt to support future space exploration efforts. A combination of experimental and numerical approaches were utilized to build a validated assessment approach. A quasi-pore geometry, inspired by CT scans of rat bones, was used in lieu of human bone structures. A quasi-1D assessment of the conservation of momentum was used to identify the dominant forces acting on the fluid at the operating length-scales. The dominant forces were surface tension, gravity, and shear stress. Experiments were conducted to visualize the flow moving through the …


Synchronous Raman Microspectroscopy And Laser Beam Induced Current Measurements As A Metrology Tool For Solar Cells And Optoelectronic Devices, Jeya Prakash Ganesan Jan 2022

Synchronous Raman Microspectroscopy And Laser Beam Induced Current Measurements As A Metrology Tool For Solar Cells And Optoelectronic Devices, Jeya Prakash Ganesan

Electronic Theses and Dissertations, 2020-2023

This works developed synchronous Raman microspectroscopy with laser beam induced current (LBIC) measurements to generate insights into structure-property correlations in finished solar cell modules. Raman spectroscopy is a powerful, non-destructive technique to examine phase and composition of materials where a laser beam excites characteristic vibrational modes of chemical bonds in a material. Conducting Raman spectroscopy under a microscope (i.e., Raman microspectroscopy) with confocal capabilities allows the chemical constituents to be mapped with high spatial resolution in the x, y and z directions. Simultaneously, the excitation laser from Raman can also generate photocarriers in a semiconductor. In a solar cell, these …


Machine Learning Algorithms For Forecasting The Impacts Of Connected And Automated Vehicles On Highway Construction Costs, Amirsaman Mahdavian Jan 2022

Machine Learning Algorithms For Forecasting The Impacts Of Connected And Automated Vehicles On Highway Construction Costs, Amirsaman Mahdavian

Electronic Theses and Dissertations, 2020-2023

A multitude of externalities affects transport efficiency and numbers of trips. Population expansion, urban development, political issues, fiscal trends, and growth in the field of connected, automated, shared, and electric (CASE) vehicles have all played prominent roles. While the market is keenly aware of the upcoming shift to the CASE vehicles, the transformation itself is reliant upon the development of technologies, customer outlook, and guidelines. The purpose of this research is to establish an overview of the possible network design problems, as well as potential consequences to vehicle automation systems by employing machine learning and system dynamics analysis. Finally, the …


Davydov-Split Aggregates Of Cyanine Dyes For Bovine Serum Albumin Detection, Yiping Ma Jan 2022

Davydov-Split Aggregates Of Cyanine Dyes For Bovine Serum Albumin Detection, Yiping Ma

Electronic Theses and Dissertations, 2020-2023

The p-conjugated supramolecular aggregates have gained significant interest in recent years. The cyanine dye aggregates are particularly interesting due to their unique optical and excitonic properties, which cannot be found in individual molecules. Cyanine dyes can form different kinds of aggregates. H-aggregates are formed when dye molecules are packed in a face-to-face fashion, which gives rise to a blue-shift absorption band and strong emission quenching compared to the monomer. J-aggregates are composed of individual dye molecules in a head-to-tail stacking, which leads to a red-shift absorption band and a sharp intense emission band with a small Stoke shift compared with …


Data-Driven Diagnostics And Prognostics For Complex Systems: Methods And Applications, Junchuan Shi Jan 2022

Data-Driven Diagnostics And Prognostics For Complex Systems: Methods And Applications, Junchuan Shi

Electronic Theses and Dissertations, 2020-2023

Recent advances in artificial intelligence or machine learning have the potential to significantly improve the effectiveness and efficiency of diagnostic and prognostic techniques. The objective of this research is to develop novel data-driven predictive models with machine learning and deep learning algorithms that allow one to model the degradation, detect the faults, as well as predict the remaining useful life (RUL) of complex systems, including bearings, gearboxes, and Lithium-ion (Li-ion) batteries. First, an enhanced ensemble learning algorithm is developed to improve the accuracy of RUL prediction by selecting diverse base learners and features at different degradation stages. The proposed method …


A Study Of Autorotation: Samara Seed Pods And Tethered Autogyros, Jonathan Mcconnell Jan 2022

A Study Of Autorotation: Samara Seed Pods And Tethered Autogyros, Jonathan Mcconnell

Electronic Theses and Dissertations, 2020-2023

This work presents an exploration of autorotational behavior, observing naturally occurring structures to provide insight into the stability and design of autorotative mechanisms. A rotor is said to be in autorotation when, in the presence of airflow, a natural rotation generates lift to either suspend or slow the descent of a rotor. This phenomenon is observed in nature in the form of samaras, a seed pod morphology evolved in parallel by maple trees and many other organisms around the world. Simulation and experimental observation of samara vertical descent behavior provides insight into the stability of naturally evolved autorotative structures. A …