Engineering Commons^™

Tractor Instrumentation System: Hitch And Pto, And Row Crop Tractor Electrification Considerations, Andrew Donesky

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Power sources used for vehicles are advancing at a fast pace. Electric batteries are becoming more power dense, thus allowing them to be used with electric motors in place of a diesel or gas powered systems. There are several ways that energy use and storage size can be computed for agricultural field operations, such as planting, using theoretical predictions, gathering engine load data from tractor’s Controller Area Network (CAN) bus, or integrating the CAN data to determine the actual power used by implements.

While measuring data from the CAN bus is a great way to capture actual tractor use information, …

Adaptive Activations And Shift Invariance In Shallow Convolutional Neural Networks, Chinmay Appa Rane

Electrical Engineering Dissertations - Archive

Deep learning training training algorithms are a huge success in recent years in many fields including speech, text,image video etc. Deeper and deeper layers are proposed with huge success with resnet structures having around 152 layers. Shallow convolution neural networks(CNN's) are still an active research, where some phenomena are still unexplanined. CNN's are assumed to be invariant to shift due to its architecture, but recent studies have shown other wise. Apart from shift invariance, activation functions used in the network are of utmost importance, as they provide non linearity to the networks. Relu's are the most commonly used activation function. …

New Infeed Correction Methods For Distance Protection In Distribution Systems, Fahd Hariri, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

The reliability and security of power systems may be jeopardized by the increase in the amounts of renewable generation and the uncertainties produced by these devices. In particular, the protection schemes of traditional power systems have been challenged by the integration of distributed generation (DG) resources. Distance relays (DRs), which have been mainly employed to protect transmission systems, are increasingly proposed as one of the solutions to protect distribution systems with a heavy penetration of DGs. However, conventional distance protection faces several drawbacks that might lead to maloperation. One of those challenges is the "infeed effect", which causes the impedance …

The Development Of Micro-Gas Chromatography System With Integrated Photonic Crystal Sensors, Priyanka Biswas

Electrical Engineering Dissertations - Archive

Miniaturization of gas chromatography (GC) systems have made it possible to utilize the analytical technique in on-site applications without having to compromise data reliability offered by the conventional benchtop GC. Various types of miniaturized microsensors and nanosensors have been developed for a micro-gas chromatography (µGC) system. However, integration of an appropriate detector in µGC systems still face significant challenge. We present a solution to the problem through integration of µGC with photonic crystal slab (PCS) sensors using transfer printing technology. This integration offers an opportunity to utilize the advantages of optical sensors such as high sensitivity, immunity to electromagnetic interference, …

Object Classication, Detection And State Estimation Using Yolo V3 Deep Neural Network And Sensor Fusion Of Stereo Camera And Lidar, Kamalkumar Bharatkumar Mehta

Mechanical and Aerospace Engineering Theses - Archive

Real-time object classification, localization, and detection with region-based convolution neural network (R-CNN) require high computational power, or it consumes a tremendous amount of time with the use of the available onboard computer system. Therefore, either of those ways is not practical in real-time object detection. In contrast, the YOLO-v3 network, which stands for you only look once, that uses the YOLO algorithm seems to be practical in live object classification, localization, and detection, since the YOLO algorithm seems to work faster than the sliding window algorithm used by R-CNN. Sensor fusion in this context requires estimation and association of information …

Development Of Eam And Rf-Meam Interatomic Potential For Zirconium Diboride, Bikash Timalsina

Graduate Theses/Dissertations

Embedded Atom Method (EAM) and Modified-EAM (MEAM) interatomic potentials were developed for zirconium diboride (ZrB₂). The EAM and “Reference Free” (RF) version of the Modified Embedded Atom Method (RFMEAM) potentials have been fitted by utilizing Density Functional Theory (DFT)-based datasets including lattice deformations and high-temperature ab-initio molecular dynamics (AIMD) simulation results. The occupancies of phonons for acoustic phonon modes from the density functional theory calculation shows that these modes of vibration, mostly due to heavier mass element (Zr), which occur below 8.711 THz, while a slight underestimation to that of DFT calculation predicted by EAM below 8.439 THz …

Interprofessional Inconsistencies In The Diagnosis Of Shoulder Instability: Survey Results Of Physicians And Rehabilitation Providers, Constantine P. Nicolozakes, Xinning Li, Timothy L. Uhl, Guido Marra, Nitin B. Jain, Eric J. Perreault, Amee L. Seitz

Physical Therapy Faculty Publications

Background: Clinicians of many specialties within sports medicine care for athletes with shoulder instability, but successful outcomes are inconsistent. Consistency across specialties in the diagnosis of shoulder instability is critical for care of the athlete, yet the extent of divergence in its diagnosis is unknown.

Hypothesis: Physicians differ from rehabilitation providers in which findings they deem clinically important to differentiate shoulder instability from impingement, and in how they diagnose athlete scenarios with atraumatic shoulder instability.

Study Design: Cross-sectional study.

Methods: Physicians (orthopaedic surgeons, primary care sports medicine physicians) and rehabilitation providers (physical therapists, athletic trainers) were asked via an online …

Background Flow Influence On Impulsive Jet-Driven Micro Droplet Dispersal, Vaishak Thiruvenkitam

Doctoral Dissertations and Master's Theses

Accurately predicting the airborne spread of infectious diseases is crucial in controlling the COVID­19 pandemic today. Studies have shown the spread of expiratory droplets depends on ambient thermodynamic conditions and flow properties of the jet emitted by the activity. However, the droplet spread in conditions of background flow is not yet comprehensively understood. This study uses the Eulerian­-Lagrangian model with k−ω turbulence modelling to simulate spread of particles and study the factors affecting it in a closed environment with a background flow. Respiratory activities are modeled as a non-­isothermal jet of air with droplets suspended in them in a predetermined …

Active Control Of Coherent Structures In An Axisymmetric Jet, Michael Marques Goncalves

Doctoral Dissertations and Master's Theses

The primary objective of this work is to develop high-fidelity simulation model for jet noise control predictions and quantify the sound reduction when an external source frequency mode excitation is imposed on the jet flow. Whereas passive approaches using mixing devices, such as chevrons, have been shown to reduce low-frequency noise in jet engines, such approaches incur a performance penalty since they result in a reduced thrust. To avoid a performance penalty in reducing jet noise, the current work investigates a open-loop active noise control (ANC) system that utilizes a unsteady microjet actuator on the nozzle lip in the downstream …

Shape Optimization Of A Sandwich Composite Plate With Low-Velocity Impact Loading And Effect Of Finite Difference Sensitivity Analysis, Utsav Shah

Doctoral Dissertations and Master's Theses

The structural design of spacesuits is essential in an advancing future of both Lunar and Martian space exploration. A typical spacesuit is made of sandwich composite material and designed to withstand various pressure and loading conditions while also considering the safety and comfort of the astronauts. One of the critical load cases in spacesuit design is a low-velocity impact (LVI) which may occur due to tool drop and other similar scenarios. The objectives of this work were (a) to create a finite element (FE) model of a component of a spacesuit, (b) validation of the FE model through experiments, (c) …

Design, Development, And Testing Of Research Payloads On Various Suborbital Flight-Test Platforms, Vijay Vishal Duraisamy

Doctoral Dissertations and Master's Theses

With recent advances in the commercial space industry, suborbital payload launches have become more common and accessible to researchers actively seeking solutions for problems involving prolonged space travel and future missions to Moon and Mars. Suborbital payload missions compared to orbital launches are less expensive and offer faster turnaround times; however, the novelty of this domain provides unique challenges. This multidisciplinary research effort aims to tackle some of these challenges by detailing the design, development, and testing techniques followed in the successful launch and recovery of payload experiments in currently active and upcoming suborbital launch vehicles. The research methodology involves …

Durability And Damage Analysis Of Hybrid Multiscale Composites, Suma Ayyagari

Doctoral Dissertations and Master's Theses

In this dissertation, an effort was carried out to enhance the mechanical performance of fiber reinforced composites (FRPs) by modification of the fibers’ surface morphologies. The effects of various surface alterations of a plain-woven carbon fiber fabric surface, on the fiber/epoxy interface were investigated. The alterations were mostly achieved by growing different nanofillers like zinc oxide nanorods (ZnO NR), carbon nanotubes (CNTs), and metal organic frameworks (MOFs) on the fiber surface. While the growth techniques for ZnO NR and CNTs place restrictions on the size of the fabricated composites, MOFs route is uniform, affordable, and can be readily scaled up …

A Reduced-Order Model Bi-Modal Excitation Of A Supersonic Planar Jet, Benjamin Malczewski

Doctoral Dissertations and Master's Theses

This work analytically and numerically examines the effects of bi-modal excitation on a Mach 1.5 heated planar jet. Starting with the Navier-Stokes equations, triple decomposition is applied to the flow components. A reduced order model is derived, turning the Navier-Stokes partial differential equations into a set of coupled ordinary differential equations, relating the momentum thickness and amplitudes of a fundamental and subharmonic mode to the streamwise location along the jet. Computational fluid dynamics data from the minor plane of a Mach 1.5 heated rectangular jet is used to verify a hyperbolic tangent profile for the mean flow at various streamwise …

Envelope Analysis Of Speed-Controlled Evtol Urban Air Mobility Vehicles, David J. Thompson

Doctoral Dissertations and Master's Theses

There are many vehicles being developed which rely on electrically driven propellers/rotors for both control and propulsion. Based on these vehicles, it is hypothesized that there exists a size limit for speed-controlled propellers/rotors in terms of propeller/rotor diameter. To investigate this, a scaling method was created to allow for a vehicle to be created without being based on a specific mission or passenger/cargo requirement. Relationships were developed to size both the physical vehicle and the weight of the vehicle based on the propeller/rotor diameter. A simulation of a quadcopter was created for the vehicle and scaled with both propeller/rotor diameter …

Intelligent System For Laparoscopic Surgery Suturing Skill Assessment, Mohammed Yasser Al-Gailani

Dissertations

In laparoscopic surgery, which is also referred to as minimally invasive surgery (MIS), surgeons carry out surgical procedures with the assistance of a video camera and several surgical instruments. Laparoscopic surgeons should possess excellent eye-hand coordination capabilities, strong cognitive knowledge, case and problem management, and manual dexterity skills. Such skills can be acquired through simulation using a basic, low-fidelity setup, such as the surgical box-trainer. General surgeons must pass a set of tests on a Fundamentals of Laparoscopic Surgery (FLS) Trainer device.

One pivotal skill for a successful operation is developing a sense of the applied forces on the tissue …

Performance Evaluation Of Transportation Systems For Sustainability And Smart-Growth Of Cities: An Integrated Assessment Of Health Impacts, Ahmad Feizi

Dissertations

The performance of transportation systems is a significant component that influences the quality of life. The performance evaluation refers to a process of determining how well transportation systems perform regarding their intended goals and objectives. The advancement of information and communication technology and the integration between transportation systems and advanced technologies have directed more attention to the concept of smart cities. Smart cities are constituted of several interrelated components. Therefore, this offers comprehensive and integrated frameworks to evaluate the transportation performance and understanding of multifaceted interactions between the components from a transportation engineering perspective in four sections.

In the first …

Relationship Between Standardization Critical Success Factors (Csfs) And Project Performance, Binit Kumar Shrestha

UNLV Theses, Dissertations, Professional Papers, and Capstones

Facility standardization strategy is defined as the development and use of consistent designs to align project stakeholders, objectives, and scope to capture and optimize schedule, cost, and value. The implementation and proper execution of this strategy can lead to considerable benefits, such as design once and reuse multiple times, along with learning curve benefits in fabrication, operations, and construction, as well as accelerated responds to schedule needs. Although standardization strategy is not a new idea; capital projects have failed to achieve high levels of facility standardization. The primary reason for this is the industry’s struggle to execute standardized projects successfully. …

Forecasting Pedestrian Trajectory Using Deep Learning, Arsal Syed

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this dissertation we develop different methods for forecasting pedestrian trajectories. Complete understanding of pedestrian motion is essential for autonomous agents and social robots to make realistic and safe decisions. Current trajectory prediction methods rely on incorporating historic motion, scene features and social interaction to model pedestrian behaviors. Our focus is to accurately understand scene semantics to better forecast trajectories. In order to do so, we leverage semantic segmentation to encode static scene features such as walkable paths, entry/exits, static obstacles etc. We further evaluate the effectiveness of using semantic maps on different datasets and compare its performance with already …

Photocatalytic And Photochemical Decomposition Of Various Per- And Polyfluoroalkyl Substances (Pfas) In Water, Nusrat Chowdhury

Civil Engineering Dissertations - Archive

Per- and polyfluoroalkyl substances (PFAS) are anthropogenic compounds comprised of a perfluoroalkyl backbone and a terminal functional group. Their detrimental health effects of in humans, like other halogenated chemicals, have been well documented and thus the frequent occurrence of PFAS in the water environment is a recent global concern. After US Environmental Protection Agency (EPA) released a drinking water health advisory for the two most detected long chain PFAS (such as perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS)), industrial production and application of short chain PFAS continues to rise. Feasible and sensible treatment strategies are in dire need for environmental …

Application Of In Situ And Ex Situ Characterization Of Atomic Layer Deposition Processes For Gallium Phosphide And Sodium Fluoride, Sara Rose Kuraitis

Boise State University Theses and Dissertations

Atomic layer deposition (ALD) is a vapor deposition technique for synthesizing thin films with nanometer thickness control. ALD films are deposited on a substrate surface in a cyclic layer-by-layer fashion utilizing alternating doses of highly reactive chemical precursors. Precursors are selected to undergo self-limiting chemical reactions with the surface, and desired film thickness is achieved by varying the number of ALD cycles accordingly. Optimization of ALD process parameters and precursor chemistry enables conformal coating of arbitrary substrate geometries, including high aspect ratio features such as trenches. In the decades since its introduction, ALD has been used for applications across many …

Narrow Band Active Contour Attention Model For Medical Segmentation, Ngan Le, Toan Bui, Viet-Khao Vo-Ho, Kashu Yamazaki, Khoa Luu

Computer Science and Computer Engineering Faculty Publications and Presentations

Medical image segmentation is one of the most challenging tasks in medical image analysis and widely developed for many clinical applications. While deep learning-based approaches have achieved impressive performance in semantic segmentation, they are limited to pixel-wise settings with imbalanced-class data problems and weak boundary object segmentation in medical images. In this paper, we tackle those limitations by developing a new two-branch deep network architecture which takes both higher level features and lower level features into account. The first branch extracts higher level feature as region information by a common encoder-decoder network structure such as Unet and FCN, whereas the …

Biotransformation Of Trace Organic Compounds Via Microbial Ammonia Oxidation In Biofiltration Systems For Water Reuse, Nicholas Babcock

UNLV Theses, Dissertations, Professional Papers, and Capstones

The use of ozone-biofiltration (BAF) for water reuse has recently been viewed as an attractive option due its low cost and ability to achieve high quality effluent. However, one challenge that is particularly problematic for ozone-biofiltration is the occurrence of trace organic compounds (TOrCs), such as pharmaceuticals and personal care products, in domestic wastewater, primarily due to their uncertain public health impacts. These TOrCs might be degraded by three ammonia oxidizing microorganisms (AOMs), including ammonia oxidizing bacteria (AOBs), ammonia oxidizing archaea (AOAs), and Comammox that have been found in biofiltration systems. Cometabolism, the fortuitous biodegradation of compounds by enzymes used …

Analysis Of Microscopic Objects Using Computer Vision Methods, Yuan Dao

UNLV Theses, Dissertations, Professional Papers, and Capstones

As an essential and powerful tool to observe living organisms, three-dimensional fluorescence microscopy is widely used in biological research and diagnosis. The 4D fluorescence microscopy data can be obtained using time-lapsed videos of 3D images. To analyze and extract useful information from the increasingly large and complex biological image dataset, efficient and effective computational tools are in need but still lagging behind. In analyzing biological data, two major challenges are faced. First, time-lapsed fluorescence microscopic images typically have a low SNR. Second, biological objects often change their morphology and internal structure frequently. As such, conventional image processing methods may not …

Modeling Capacity: Multiple Weaving Areas, Sheida Khademi

Civil Engineering Dissertations - Archive

Systematic, well-designed research provides the most effective approach to the solution of many problems facing highway administrators and engineers. Traffic congestion on freeway systems is one significant concern in urban areas throughout the U.S.A. In this era, building new freeways to reduce congestion is less feasible due to the high capital and social costs. Thus, the effective management and operation of existing freeway facilities has become a preferred approach to reduce traffic congestion. A weaving section is a common design on major highway facilities that always has been an interest to researchers. Weaving areas are characterized by frequent lane changes, …

Mechanical Response Of Chemically Treated Sulfate-Rich Clay Under Multiple Triaxial Stress Path, Azadeh Asghariastaneh

Civil Engineering Dissertations - Archive

Expansive clayey soils, which are abundant in arid and semi-arid areas, including the state of Texas, can lead to excessive distress in pavements, foundations, embankments, earth retaining systems and other civil infrastructure that is either made of or supported by this type of soils. Calcium-based stabilizers, such as lime, cement and fly ash, have become popular soil stabilizers due to their ready availability and relatively low cost; however, myriad cases of failures of pavements and foundation built over sulfate-rich treated clay have led researchers to search for more efficient substitutes for calcium-based stabilizers. A very limited number of studies, however, …

Aerial Flight Paths For Communication, Alisha Bevins

School of Computing: Dissertations, Theses, and Student Research

This body of work presents an iterative process of refinement to understand naive perception of communication using the motion of an unmanned aerial vehicle (UAV). This includes what people believe the UAV is trying to communicate, and how they expect to respond through physical action or emotional response. Previous work in this area sought to communicate without clear definitions of the states attempting to be conveyed. In an attempt to present more concrete states and better understand specific motion perception, this work goes through multiple iterations of state elicitation and label assignment. The lessons learned in this work will be …

Local Style Preservation In Improved Gan-Driven Synthetic Image Generation For Endoscopic Tool Segmentation, Yun Hsuan Su, Wenfan Jiang, Digesh Chitrakar, Kevin Huang, Haonan Peng, Blake Hannaford

Engineering: Faculty Publications

Accurate semantic image segmentation from medical imaging can enable intelligent vision-based assistance in robot-assisted minimally invasive surgery. The human body and surgical procedures are highly dynamic. While machine-vision presents a promising approach, sufficiently large training image sets for robust performance are either costly or unavailable. This work examines three novel generative adversarial network (GAN) methods of providing usable synthetic tool images using only surgical background images and a few real tool images. The best of these three novel approaches generates realistic tool textures while preserving local background content by incorporating both a style preservation and a content loss component into …

Mixed Metal Oxide Nanowires Via Solid State Alloying., Veerendra Atla

Electronic Theses and Dissertations

Mixed metal oxide materials with composition control find applications in energy conversion and storage processes such as heterogenous catalysis, photoelectrochemical catalysis, electrocatalysis, thermal catalysis, and lithium-ion batteries. Mixed metal oxides and/or complex oxides with composition control and in one-dimensional form as nanowires could be interesting to various catalysis applications due to control on single crystal surfaces, active sites, acidity versus basicity site density, and oxygen vacancies. The major challenge is to synthesize mixed metal oxide nanowires beyond binary oxides with composition control. In this dissertation, solid state alloying of binary oxide nanowires with solid and liquid precursors is studied to …

Passive Method For 3d Reconstruction Of Human Jaw: Theory And Application., Mohamad Ghanoum

Electronic Theses and Dissertations

Oral dental applications based on visual data pose various challenges. There are problems with lighting (effect of saliva, tooth dis-colorization, gum texture, and other sources of specularity) and motion (even inevitable slight motions of the upper/ lower jaw may lead to errors far beyond the desired tolerance of sub-millimeter accuracy). Nowadays, the dental CAM systems have become more compromised and accurate to obtain the geometric data of the jaw from the active sensor (laser scanner). However, they have not met the expectations and the needs of dental professionals in many ways. The probes in these systems are bulky { even …

Methane Emission Treatment And Potential Upcycling Using Methylomicrobium Alcaliphilum, Jace Parkinson

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Anthropogenic methane emissions are harmful to the environment and can be difficult to treat. Use of M. alcaliphilum for bioremediation of methane looks to be one of the most promising methods of reducing the negative environmental impacts of methane emissions while simultaneously providing an economic incentive. Successful bioreactor design for M. alcaliphilum based methane treatment requires biokinetic constants and microbial growth information. Methods were established for determining biokinetic constants, including growth rate, biomass yield, specific methane consumption rate, and a correlation between methane oxidation and carbon dioxide production for M. alcaliphilum. Values determined for these constants were used to …