Engineering Commons^™

Air Force Pilot's Recognition About The Effectiveness Of Active Noise Cancellation On Hearing Health, Performance, And Aviation Safety, Kyungtaek Hwang

Electronic Theses and Dissertations, 2020-2023

The purpose of this thesis is to suggest the application of Active Noise Cancellation in Air Force pilot headset and helmet not only to reduce noise-induced hearing damage, but also to enhance pilot performance and aviation safety. Despite the recent advances of sound treatment technology, the interior sounds of a military aircraft exceed the damage risk criterion of 8 hrs/day exposure. Air Force pilots are flying under the extreme condition where noise is severe and prevalent. The exposure to noise can lead to permanent hearing loss, stress and fatigue, unintelligible communication, and deterioration of speech perception and recall. With all …

Mixed-Criticality System Design For Real-Time Scheduling And Routing Upon Platforms With Uncertainties, Sudharsan Vaidhun Bhaskar

Electronic Theses and Dissertations, 2020-2023

Unlike typical computing systems, applications in real-time systems require strict timing guarantees. In the pursuit of providing guarantees, the complex dynamic behaviors of these systems are simplified using models to keep the analysis tractable. In order to guarantee safety, such models often involve pessimistic assumptions. While the amount of pessimism was reasonable for simple computing platforms, for modern platforms the pessimism involves ignoring features that improve performance such as cache usage, instruction pipelines, and more. In this work, we explore routing and scheduling problems in real-time systems, where the uncertainties in the operation are carefully accounted for by complex models …

Not All Influence Is Born Equal: On The Effects Of Various Types Of Behavioral Influence Relationships On Social Media, Chathurani Senevirathna

Electronic Theses and Dissertations, 2020-2023

Typically, online social influence is analyzed using a single metric approach. However, social influence is not monolithic; different users exercise different influences in different ways, and influence is correlated with the user and content-specific attributes. One such attribute could be whether the action is an initiation of a new post, a contribution to a post, or a sharing of an existing post. Thus, this dissertation uses this platform-independent action classification and models the influence as multiple entities and examines social networks through the perspective of behavioral influence propagation. Two empirical studies are present in this dissertation. The first study presents …

A Flexible 3d Architecture For Cooling Future Generation Devices, Khan Mohammad Rabbi

Electronic Theses and Dissertations, 2020-2023

Systems that consume and convert energy produce thermal energy as a byproduct. This generation of thermal energy, if not dissipated properly, contributes to the significant temperature rise of the overall system. This temperature rise can lead to reduced efficiency and system-level failure. Future technologies will continue to face such thermal challenges. In fact, next-gen devices will demand flexible thermal management architectures for high-performance operation. To tackle these challenges, innovative liquid cooling technologies and high-speed thermal diagnostic systems must be developed simultaneously. Active and passive pulsation-liquid-cooling techniques are currently an attractive thermal management solution. In an active cooling mode, the influence …

Characterization Of Nanoparticles Using Inductively-Coupled Plasma Mass Spectrometry, Jabez D. Campbell

Graduate Theses/Dissertations

Nanomaterials are a relatively new class of materials that have many applications which span a wide host of fields from medical products to consumer products. The possible compositions and forms of nanomaterials are just as varied as the applications. Therefore, a versatile characterization method is needed for researchers and regulators alike to ensure nanomaterials are properly used. Single Particle Inductively Coupled Plasma Mass Spectrometry (SP-ICP-MS) is a functional method that could fill the characterization need in the nanomaterial research field. Using data from both SP-ICP-MS tests and data from literature established characterization methods, the viability of making SP-ICP-MS the standard …

Synthesis Of Novel Nio/Comn2o4 Heterostructured Nanoparticles And The Effects Of Variable Size And Metal Concentrations On Their Magnetic And Surface Chemical Properties, Farhan Ishrak

Graduate Theses/Dissertations

I studied the effect of core size and metal concentration on the structural, morphological, and magnetic properties of NiO-based magnetic heterostructured nanocrystals (HNCs) generated hydrothermally. The NiO nanocrystals were created by a thermal decomposition technique, while the surrounding Mn and Co-based phases were created through a hydrothermal procedure, with core diameters ranging from 9.31 nm to 24.51 nm and total metal concentrations of 0.05 M and 0.08 M. The resulting inverted AFM-FiM NiO/CoMn2O4 bimagnetic systems make up the heterostructured nanocrystals. The magnetic HNCs were thoroughly characterized using XRD, SEM-EDX, TEM, PPMS magnetometry, and XPS analysis. Investigations into the structure of …

On The Synthesis And Characterization Of Bimagnetic Coo/Nife2o4 Heterostructured Nanoparticles, Muhammad Sharif Uddin

Graduate Theses/Dissertations

Bimagnetic nanoparticles show promise for applications in energy efficient magnetic storage media and magnetic device applications. The magnetic properties, including the exchange bias of nanostructured materials can be tuned by variation of the size, composition, and morphology of the core vs overlayer of the nanoparticles (NPs). The purpose of this study is to investigate the optimal synthesis routes, structure and magnetic properties of novel CoO/NiFe2O4 heterostructured nanocrystals (HNCs). In this work, I aim to examine how the size impacts the exchange bias, coercivity and other magnetic properties of the CoO/NiFe2O4 HNCs. The nanoparticles with sizes ranging from 10 nm to …

Speaker Encoding For Zero-Shot Speech Synthesis, Tristin W. Cory

Graduate Theses/Dissertations

Spoken communication, for many, is an essential part of everyday life. Some individuals can lose or not be born with the ability to speak. To function on a day-to-day basis, these individuals find other ways of communication. Adaptive speech synthesis is one of those ways. It recreates a user’s previous voice or creates a voice that blends with their regional dialect. Current adaptive speech synthesis techniques that achieve human-like speech require thirty minutes, to a few hours of high-quality audio recordings of a target speaker. This amount of recorded audio is not commonly possessed by people in need of a …

Integrating Temperature Dependence Into A Microstructure-Sensitive Fatigue Model For Titanium Alloys, Jared Michael Darius

Masters Theses

This work seeks to integrate temperature dependence into a microstructure-sensitive fatigue model for titanium alloys produced by both extrusion and electron beam melting (EBM) additive manufacturing, revising and enhancing the MultiStage Fatigue (MSF) model as the foundational model framework. Traditional fatigue modeling has required design engineers to conservatively use a lower-bound estimate of fatigue life predictions given a statistically significant spread of experimental data that can span up to two or sometimes three orders of magnitude for a given test condition. This variation in fatigue data has since been accounted for with the advent of the MSF model, linking individual …

A Monolithic Solid-State Interferometer For Real-Time Multi-Environment Measurements, Aaron J. Pung

Space Dynamics Laboratory Publications

The high degree of precision offered by optical interferometry makes it an ideal tool in many applications, including vibration detection, wind tunnel aerodynamics, surface topology measurements, and environmental sensing. In the latter case, real-time measurement of real-world environments is crucial to ensuring the health and safety of individuals operating within domestic and industrial domains. Currently, these measurements are made possible with portable fiber-based interferometer systems – systems that are also limited by high cost, fragility, coupling loss, and low power. This work presents a lightweight free-space interferometer that is versatile, modular, and compact. The interferometer is monolithic, geometrically simple, easy …

Incommensurate Conformable-Type Three-Dimensional Lotka–Volterramodel: Discretization, Stability, And Bifurcation, Feras Yousef, Billel Semmar, Kamal Al Nasr

Computer Science Faculty Research

The classic Lotka–Volterra model is a two-dimensional system of differential equations used to model population dynamics among two-species: a predator and its prey. In this article, we consider a modified three-dimensional fractional-order Lotka–Volterra system that models population dynamics among three-species: a predator, an omnivore and their mutual prey. Biologically speaking, population models with a discrete and continuous structure often provide richer dynamics than either discrete or continuous models, so we first discretize the model while keeping one time-continuous dependent variable in each equation. Then, we analyze the stability and bifurcation near the equilibria. The results demonstrated that the dynamic behaviors …

Development Of A Targeted Drug Delivery System For Intracranial Atheroslerotic Disease, Kirby Fuglsby

Dissertations and Theses

Intracranial atherosclerotic disease (ICAD) remains a leading cause of ischemic events such as stroke. However, the use of drug coated balloons (DCBs) containing paclitaxel (PAT) in the brain vasculature remains limited. This is the result of several factors including particulate shed from polymer excipients, PAT toxicity, and poor blood-brain barrier (BBB) permeability of PAT. Therefore, there is a need for novel PAT and excipient formulations for balloon coatings to improve delivery of PAT to the arterial wall in ICAD while reducing off target drug effects and particulate shed. GM1 has previously been shown to cross the BBB and have high …

Skeletal Modeling Parameters And Clinical Factors Related To Injury Risk In Baseball Pitchers, Aaron Trunt

Dissertations and Theses

ABSTRACT Baseball pitching is a well-studied area of biomechanics partially due to high injury rates in the upper extremity. While current known injury risk factors for pitchers include limited shoulder range of motion (ROM), increased ball velocity, and limited shoulder strength, there has been a lack of scientific evidence linking increased joint kinetics to injury risk. The aims of this research were to (1) explore relationships between known risk factors for injury and joint kinetics, (2) establish more specific biomechanical models of pitchers to calculate joint kinetics with greater precision, and (3) deploy these models prospectively to determine how model …

Integrating Experimental Parameter Space For Granular Flow Within Polygon Tumblers, Michaela Mcmahon

Graduate Research Theses & Dissertations

Granular flows are complex phenomena bridging both fluid and solid mechanics and observed frequently in the natural world. The transitional dynamics of acceleration from solid body motion to rapid flow can affect many aspects including volume flow rates and mixing behaviors. In order to study the combination of both variables together within polygon-shaped tumblers, control systems are necessary with a corresponding user interface. This thesis reports an interface for changing variable inputs to the system. Predictions of rotation rates with corresponding interfaces with hardware connections are described. Results of image analysis verify output performance that incorporates the following variable changes: …

Experimental Analysis Of Flowing Layer Characteristics In Equilateral Triangular Tumblers For Quasi-2d Macro-Particle Flow, Jason Quinn Ostenburg

Graduate Research Theses & Dissertations

Rotating tumblers are used in a wide variety of industrial applications from mixing anddeburring to flow regulation and storage. Almost all model tumblers previously analyzed, both theoretically and experimentally, had circular cross sections that produced consistent flowing layer dimensions and steady state flow. In contrast, tumblers with triangular cross sections produced unsteady flow as a direct result of the dynamic dimensions of the flowing surface. Although unsteady, the flow produced in triangular tumblers is periodic every 120◦ of rotation after an initial mixing period. The mechanisms by which the flow characteristics vary as a triangular tumbler rotates and the number …

Towards Plasmon Mapping Of Sers-Active Ag Dewetted Nanostructures Using Spels, Mohamed Beshr, E. Dexter, Paul E. Tierney, Aidan Meade, Shane Murphy, George Amarandei

Articles

Thermal dewetting of silver thin flm can lead to SERS-active Ag nanoparticles. Here, we report our progress towards using scanning probe energy loss spectroscopy (SPELS) to map the plasmonic behaviour of SERS-active Ag nanoparticles (NP) by investigating NPs produced through the dewetting study of Ag thin flms on SiO2/Si and Ti/SiO2/Si substrates. The nanoparticles size and spatial distribution were controlled by the deposition and thermal annealing parameters. The results of preliminary SPELS measurements of these structures, alongside SERS data show that there is a correlation between the Raman enhancement and the nanoparticle size and interparticle spacing.

A Non-Reacting Passive Scalar Comparison Of Starccm And Openfoam In A Supersonic Cavity Flame Holder, Thomas Nuese

Electronic Theses and Dissertations

The scramjet engine equipped with a modern-day airliner would allow for very quick travel across the United States. The major problem is that designing such an engine and testing it to make sure it is safe would cost millions if not billions of dollars. Computational fluid dynamics allows for complex designs to be tested but can still take many days, weeks, or even months to complete. With the use of computational fluid dynamics (CFD), the scramjet engine can be analyzed to determine a quicker way to test and develop a reliable configuration in addition to analyzing the effects of different …

Allocative Efficiency Of Grid Farming In Urban Green Built Environments, Aaryan Manoj Nair

Publications and Research

As of a 2019 study conducted by the National Urban Gardening Program (National Urban Gardening Program), urban farming accounts for approximately 19% of the total national farming output and is expected to triple to almost 45% by 2025. There is intensive research being conducted on aspects of reduced recidivism, communal health benefits, natural carbon capture systems, improved urban ecology and the necessity for reducing the carbon footprint of food, (informally dubbed “food miles”) there is little substantive research on optimization, and maximation of crop productivity in hyper-urban areas. The article attempts to study allocative efficiency in hyper urban built environments.

Novel Architecture Of Onem2m-Based Convergence Platform For Mixed Reality And Iot, Seungwoon Lee, Woogeun Kil, Byeong Hee Roh, Si-Jung Kim, Jin Suk Kang

College of Engineering Faculty Research

There have been numerous works proposed to merge augmented reality/mixed reality (AR/MR) and Internet of Things (IoT) in various ways. However, they have focused on their specific target applications and have limitations on interoperability or reusability when utilizing them to different domains or adding other devices to the system. This paper proposes a novel architecture of a convergence platform for AR/MR and IoT systems and services. The proposed architecture adopts the oneM2M IoT standard as the basic framework that converges AR/MR and IoT systems and enables the development of application services used in general-purpose environments without being subordinate to specific …

Improving Active Learning Through Advanced Teaching Practices On An Online Course, Jin Ouk O. Choi

UNLV Best Teaching Practices Expo

Since the outbreak of the COVID, there has been a great need to advance learning experiences and opportunities for students when the courses are taught remotely. To address the need, the author incorporated the teaching strategies learned from the Culturally Relevant & Responsive Teaching (CRRT) fellows program supported by the NSF TRANSCEnD project. In Fall 2021, the author implemented multiple new teaching techniques and strategies in the CEM453-653 course, delivered entirely online. The specific teaching practices and technologies are: 1) Delivering lectures both live (synchronous) and recordings (asynchronous); 2) Using adaptive technology (Mentimeter & WebEx Poll) with real-time feedback; 3) …

The Return Of Labor-Based Grading Contracts, Erica J. Marti

UNLV Best Teaching Practices Expo

Despite best attempts, grading can be very subjective when it comes to determining quality. For certain courses, the process is just as important as the product, but often the grade is based mainly on the quality of the product and doesn’t take the labor or process into account. One alternative to standard grade systems is labor-based grading or contract grading. In this system, students meet certain requirements to earn a certain grade. If students meet the criteria for the assignment, it counts toward the contract. If not, they can revise, reflect and resubmit. With this format, students can focus on …

Learning Retention Through Glossary Development, Haroon Stephen

UNLV Best Teaching Practices Expo

The teaching practice is to engage students in glossary development. It is adopted to increase student learning retention of civil engineering terms. Learning retention is the process of transferring new information into long-term memory. This teaching practice was implemented in two courses during summer and fall 2021. The benefits of this practice were assessed using a post-semester survey. The survey responses revealed that this teaching practice increased understanding of the technical terms of 87% of the respondents and increased conceptual understanding of 83% of the respondents.

The Improvement Of The Regional Regulatory Governance System For Radiation Risk Management: Spatial Analysis On Radiation Hazards In South Korea, Sangwon Lee, Jaewon Lim, Chan Goo Yi

Public Policy and Leadership Faculty Research

Since the 2011 Fukushima nuclear power plant accident, nuclear regulators have strength-ened safety standards or decided to decommission the nuclear power plant. The vast majority of radiation is from nuclear power plants, so safety measures are also concentrated in nuclear power plants. Radioactive materials located much closer to the people are scattered around the nation. However, it is difficult for citizens to predict the radiation risk around them because regulatory agencies do not provide adequate information on radiation. The main goal of this study is to analyze the spatial distribution patterns of radioactive materials that serve as indicators for potential …

An Approach For Material Model Identification Of A Composite Coating Using Micro-Indentation And Multi-Scale Simulations, Pouya Shojaei, Riccardo Scazzosi, Mohamed Trabia, Brendan O’Toole, Marco Giglio, Xing Zhang, Yiliang Liao, Andrea Manes

Mechanical Engineering Faculty Research

While deposited thin film coatings can help enhance surface characteristics such as hardness and friction, their effective incorporation in product design is restricted by the limited understand-ing of their mechanical behavior. To address this, an approach combining micro-indentation and meso/micro-scale simulations was proposed. In this approach, micro-indentation testing was conducted on both the coating and the substrate. A meso-scale uniaxial compression finite element model was developed to obtain a material model of the coating. This material model was incorporated within an axisymmetric micro-scale model of the coating to simulate the indentation. The proposed approach was applied to a Ti/SiC metal …

Transdisciplinarity In Experience Design: A Global Survey Of Higher Ed Programs In Exd/Xd, Yvonne Houy

Creative Collaborations

In our age of ubiquitous devices and digital media it is the perceived value of the end-to-end experience that brings people to a place. Designing inspiring and emotionally engaging end-to-end experiences requires experts in a wide range of disciplines committed to an interdisciplinary collaboration that can arrive at transdisciplinary design - the sum becomes greater than its parts.

Civil engineering, hospitality, business, psychology, digital User Experience (UX) design, and experience data analysis need to be seamless integrated with the fine and performing arts and design fields:

• Architecture, interior, landscape and sound design actively engage the senses.

• Graphic and fine arts …

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Review Of Mathematical Modelling Techniques With Applicationsin Biosciences, Ahmed Hasan Alridha, Ahmed Sabah Al-Jilawi, Fouad H. Abd Alsharify

Iraqi Journal for Computer Science and Mathematics

Modelling can provide intellectual frameworks that are necessary to translate data into knowledge.Mathematical modelling has played an important role in many applications, such as ecology, genetics, engineering,psychology, sociology, physics and computer science, in recent years. This study focused on reviewing mathematicalmodelling and its applications to biological systems by tracing many metabolic activities of cellular interactions onthe one hand and between the spread of epidemics and population growth on the other hand. Various mathematicalequations have played fundamental roles in the formation of these systems for model development proceduresby describing them mathematically and establishing relationships that characterise the dynamics of a biologicalphenomenon. …

A Machine Learning Approach To Intended Motion Prediction For Upper Extremity Exoskeletons, Justin Berdell

Graduate Research Theses & Dissertations

A fully solid-state, software-defined, one-handed, handle-type control device built around a machine-learning (ML) model that provides intuitive and simultaneous control in position and orientation each in a full three degrees-of-freedom (DOF) is proposed in this paper. The device, referred to as the “Smart Handle”, and it is compact, lightweight, and only reliant on low-cost and readily available sensors and materials for construction. Mobility chairs for persons with motor difficulties could make use of a control device that can learn to recognize arbitrary inputs as control commands. Upper-extremity exoskeletons used in occupational settings and rehabilitation require a natural control device like …

True-Ed Select: A Machine Learning Based University Selection Framework, Jerry C. Cearley

University of the Pacific Theses and Dissertations

University/College selection is a daunting task for young adults and their parents alike. This research presents True-Ed Select, a machine learning framework that simplifies the college selection process. The framework uses a four-layered approach including the user survey, machine learning, consolidation, and recommendation. The first layer collects both the objective and subjective attributes from users that best characterize their ideal college experience. The second layer employs machine learning techniques to analyze the objective and subjective attributes. The third layer combines the results from the machine learning techniques. The fourth layer inputs the consolidated result and presents a user-friendly list of …

Predictions Of Produced Water Quality And Recycled Water Optimization For Spatially-Distributed Wells In Point Pleasant Formation, Armel Quentin Mbakop

Graduate Theses, Dissertations, and Problem Reports (ETD)

The treatment of produced water as a fracturing fluid is becoming an increasingly important aspect of water management surrounding the booming of the unconventional oil and gas industry. Two main problems facing the oil and gas industry are the availability of water for well drilling and completion and disposal of the produced water. Unconventional well drilling and completion in the Utica shale requires large amounts of water. The wastewater that results after production—containing high levels of organic and inorganic matter— is usually disposed of through deep well injection. A new approach reuses this produced water as part of subsequent fracturing …

Modeling, Simulation, And Hardware-In-The-Loop Implementation Of Distributed Voltage Control In Power Systems With Renewable Energy Sources, Ali Dehghan Banadaki

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation develops and analyzes distributed controllers for power systems with renewable energy sources. A comprehensive state space modeling of voltage source inverters (VSIs) is developed specifically to address the secondary voltage control. This model can be used for simulation and control design. Unlike frequency, voltage is a local phenomenon, meaning that it cannot be controlled from a far distance. Therefore, a voltage zoning matrix that relates the sensitivity of the loads to the sources is proposed. The secondary voltage control is designed by applying the eigenvalue decomposition of the voltage zoning matrix to obtain the reference generators voltages. The …