Engineering Commons^™

Emitter Selection Optimization For Passive Synthetic Aperture Radar, Mu Kim

Theses and Dissertations

Widely distributed modern communication networks provide excellent opportunities to share the spectrum for passive radar systems, of which emitter selection is a major consideration factor. This research introduces emitter selection problem space, which consists of three SAR processing domains, namely, Data Collection, Image and Mission Performance Domains. Quantitative links between these domains are critical to formulate an optimal emitter selection problem in the Data Collection Domain and/or Image Domain, which satisfies given mission requirements in Mission Performance Domain. This research examines the properties of the SAR processing domains to develop performance metrics in the Data Collection and Image Domains, whose …

Mixed-Criticality Scheduling Using Reinforcement Learning, Omar Elseadawy

Theses and Dissertations

Mixed-criticality (MC) scheduling is necessary for many safety-critical real-time embedded systems, as a failure of high-criticality jobs could lead to fatal accidents. With the emergence of software technologies in software-defined vehicles in the automotive and avionics industries, studying Mixed-Critically (MC) systems is essential to their safety standards, similar to ISO26262. The real-time operation of MC systems makes it an inherently online problem, such that the scheduler is only aware of the jobs that are currently released at any point in time and has no knowledge of future jobs. Due to the overhead cost of preemption, this study focuses on enforcing …

Enhancing Construction Safety Training Of Bridges Using Augmented Reality And Virtual Reality, Mohamed Sherif Elrifaee

Theses and Dissertations

Infrastructure development projects are widely acknowledged as some of the most complex and challenging projects to undertake. The construction of bridges, in particular, has proven to be a significant safety risk for workers, with a considerable number of accidents reported on construction sites. There is a lack of comprehensive training programs specifically designed for bridge construction safety, and only a few studies have explored the use of both AR and VR to enhance safety training in construction. As such, this research aims to improve the safety of bridge construction sites through the implementation of Augmented Reality (AR) and Virtual Reality …

The Feasibility Of Using High Strength Stainless Steel In Pre-Stressing Applications, Rana Khaled Morsy

Theses and Dissertations

This paper evaluates the applicability of using a corrosion-resistant reinforcement high strength stainless steel strands (HSSS) Duplex 2205 in pre-stressing applications. HSSS-Duplex 2205 is a high performance steel which can be used as an alternative to the conventional carbon steel strands, for a better service life. The high strength and corrosion resistance of the material allows it to show its impressive performance in marine structural applications. Although the use of HSSS-Duplex 2205 could be initially costly; however, the improved durability and extended service life of the concrete structures using HSSS would require less life-cycle cost. Although there is a gap …

Computational Study On The Acoustic Footprint Of Stenosis In Larger Arteries, Ahmed Abdelnabi

Theses and Dissertations

We identify a new (acoustic) frequency-stenosis relations whose frequencies fall within the recommended auscultation threshold for stethoscopy (< 120 Hz) in this study. We demonstrate that these relations can be used to extend the application of phonoangiography (the measurement of the degree of stenosis from bruits) to stethoscopes that are broadly available. The First relationship is successfully identified using an analysis limited to the acoustic signature of the von Karman vortex street, which we automatically isolate using a metric based on an area-weighted average of the Q-criteria for the post-stenotic region. Specifically, we conduct LES-CFD simulations on simplified 2D internal flow geometries that represent blood vessels with varying degrees of stenosis. Then, using the Ffowcs Williams-Hawkings (FW-H) equation, we extract their emitted acoustic signals, which we subtract from a pure signal (stenosis-free) at the same heart rate. Next, we transform this differential signal to the frequency domain and meticulously classify its acoustic signatures according to six stenosis-invariant flow phases of a cardiac cycle. Using our Q-criterion-based metric, we then automatically restrict our acoustic analysis to the noises emitted by the von Karman vortex street (phase 4). Our analysis of its acoustic signature demonstrates a strong linear relationship between the degree of steno- sis and its dominant frequency, which differs significantly from the break frequency and heart rate (previously identified dominant frequencies). For the Second relationship, we develop a frequency-stenosis scaling law for particularly supravalvular aortic stenosis that falls within the preferred frequency range (30-120 Hz) for echocardiography. We expand to 3D patient specific geometry using Simulia’s Living Heart Human Model (LHHM), which has an anatomically accurate aorta geometry. This LHHM geometry is modified with stenoses ranging from 30 to 80 percent (moderate to severe). For physiologically consistent hemodynamic boundary conditions, we expand the study to employ the Windkessel model, which has been implemented on Fluent using UDF. We demonstrate that physiological boundary conditions reduce simulation time significantly compared to static boundary conditions. The FW-H model extracted the flow-generated acoustic signal of the stenotic geometries and analysed it at clinically relevant receiver locations. A preferred receiver location consistent with clinical practise is determined, and a correlation between the degree of stenosis and the prevalent acoustic frequency (within the frequency range of 70-120 Hz) is established. The obtained second scaling law is shown to be clinically reliable in assessing stenotic severity. Future research will investigate incorporating the vibroacoustic role of adjacent organs and tissue to expand the clinical applicability of our findings. Expansion of clinical and numerical datasets will be pursued in future research to enhance the reliability of our scaling law, possibly by leveraging much-needed ML-based acceleration schemes.

Exploring Senior Chemical Engineering Students’ Approach To Process Safety Decision Making, Jeffrey Saunders Stransky

Theses and Dissertations

Despite investments in chemical process safety education, evidence suggests that engineers’ decision making may contribute to process safety incidents. Currently, limited educational endeavors in process safety decision making exist, raising the need for a better understanding of how to prepare chemical engineering students for industry decisions. This dissertation fortifies current process safety education through three studies involving senior chemical engineering students. Study One developed the Engineering Process Safety Research Instrument (EPSRI) through exploratory and confirmatory factor analyses. Educators may use the EPSRI to evaluate their students’ moral development. Study Two evaluated a digital process safety game, Contents Under Pressure, on …

Estimating The Impact Of Intersection Traffic On Air Quality Emissions At Camden Cooper Medical Health Intersection Through The Integration Of Vissim/Moves Models, Kourtney Nicole Arena

Theses and Dissertations

Traffic emissions near intersections can increase significantly due to idling as well as stop-and-go traffic conditions. Increased emissions of pollutants like particulate matter (PM), nitrogen oxides (NOx), carbon monoxide (CO), and polycyclic aromatic hydrocarbons (PAHs) found in traffic exhaust deteriorate the health of the population that is exposed to them. Since general traffic emissions are increased by the stop-and-go conditions produced at intersections, PAH traffic emissions should also increase from intersection driving conditions. The intersection of Dr. Martin Luther King Jr. Blvd and Haddon Ave in Camden, NJ was identified as an ideal site to study PAH traffic emissions. To …

Morphogenetic Engineering Of Synthetic Protocell Systems, Qinyu Zhu

Theses and Dissertations

Observing and studying how life forms behave, i.e., their movement, adaptability, and so on, have enabled human beings to develop new technologies or optimize existing ones. One of the more noticeable phenomena in Nature is morphogenesis. Morphogenetic processes exist in different stages of biological development, from cellular division to tissue and organ formation. It is easy to observe shape development during mophogenesis due to emerging imaging techniques. However, it is hard to understand this process due to its complex organization, and the morphogenetic responses can be induced by a variety of chemicals or mechanical stresses and are subject to the …

Methods For Designing Compact And Deployable Origami-Inspired Flat-Foldable Spacecraft Antennas And Other Systems, Collin Ryan Ynchausti

Theses and Dissertations

There are times when it is desirable for devices to be stowed compactly, ``transported'' to the location of their desired use, and then deployed to another stable shape or configuration to perform their designed function. Origami-based mechanisms are beneficial in these cases due to their compact, folded nature and large deployments. Unlike traditional mechanical design, compliant mechanism and origami-based design approaches inherently have coupled characteristics, creating complex design problems. The research presented here discusses metrics, methods, and designs to aid in the design of origami-adapted and compliant mechanisms, focusing on the design case of deployable space systems. First, the hexagonal …

Development Of A Modular Agricultural Robotic Sprayer, Paolo Rommel P. Sanchez

Theses and Dissertations

Precision Agriculture (PA) increases farm productivity, reduces pollution, and minimizes input costs. However, the wide adoption of existing PA technologies for complex field operations, such as spraying, is slow due to high acquisition costs, low adaptability, and slow operating speed. In this study, we designed, built, optimized, and tested a Modular Agrochemical Precision Sprayer (MAPS), a robotic sprayer with an intelligent machine vision system (MVS). Our work focused on identifying and spraying on the targeted plants with low cost, high speed, and high accuracy in a remote, dynamic, and rugged environment. We first researched and benchmarked combinations of one-stage convolutional …

Towards Optimal Operation And Control Of Emerging Electric Distribution Networks, Jimiao Zhang

Theses and Dissertations

The growing integration of power-electronics converters enabled components causes low inertia in the evolving electric distribution networks, which also suffer from uncertainties due to renewable energy sources, electric demands, and anomalies caused by physical or cyber attacks, etc. These issues are addressed in this dissertation. First, a virtual synchronous generator (VSG) solution is provided for solar photovoltaics (PVs) to address the issues of low inertia and system uncertainties. Furthermore, for a campus AC microgrid, coordinated control of the PV-VSG and a combined heat and power (CHP) unit is proposed and validated. Second, for islanded AC microgrids composed of SGs and …

High-Speed Photonic Signal Processing For Free Space Optical Stealth Communication And Interference Management, Yang Qi

Theses and Dissertations

This dissertation focuses on free space optical stealth communication and wideband interference management techniques. The coexistence of multiple high-speed wireless communication systems generates wideband interference, which poses a challenge to the contemporary framework of signal processing. To protect the security and privacy of users' communications, stealth communication techniques that hide and recover private information against eavesdropping attacks are necessary. The main challenge in stealth information recovery and interference management is to separate the signal of interest from noise and wideband interference [1]. This dissertation proposes and experimentally demonstrates various techniques for stealth communication and wideband interference management using photonic signal …

Flexural Wave Manipulation By Non-Hermitian Planar Elastic Metasurface, Katerina Stojanoska

Theses and Dissertations

It has been demonstrated that metasurfaces with spatially asymmetric inner geometry exhibit unidirectional scattering effects, which can be used to control waves in a directional fashion. In this thesis, a planar Non-Hermitian elastic metasurface exhibiting unidirectional focusing of flexural waves is proposed. Asymmetrically loaded piezoelectric disks and metallic blocks comprise the unit cells. By using a negative capacitance shunting, a tunable material loss is embedded into the system. With suitable engineering of the induced loss profile, resonating building blocks are designed, which are capable of independently accessing unidirectional zero reflection. A planar metasurface is then created so that constructive interference …

Enhanced Throughput Of Aligned Polyacrylonitrile Nanofiber Manufacturing Via High-Speed Centrifugal Spinning, Jason Glen Ippolito

Theses and Dissertations

Centrifugal spinning is noteworthy due to its high fiber throughput rate compared to other nanofiber manufacturing platforms. It is capable of producing fibers in the nanoscale diameter range from a multitude of polymers, such as polyacrylonitrile (PAN). With a traditional centrifugal spinner, fiber can be rapidly spun and collected on static posts. However, the use of static posts inevitably forms a dense ring of fiber after a short period of time, and this fiber build up can halt the spinning process. In this work, the factors that influence the throughput and scalability of highly aligned centrifugally spun PAN fibers are …

A Graph-Based Approach For Adaptive Serious Games, Nidhi G. Patel

Theses and Dissertations

Traditional education systems are based on the one-size-fits-all approach, which lacks personalization, engagement, and flexibility necessary to meet the diverse needs and learning styles of students. This encouraged researchers to focus on exploring automated, personalized instructional systems to enhance students’ learning experiences. Motivated by this remark, this thesis proposes a personalized instructional system using a graph method to enhance a player’s learning process by preventing frustration and avoiding a monotonous experience. Our system uses a directional graph, called an action graph, for representing solutions to in-game problems based on possible player actions. Through our proposed algorithm, a serious game integrated …

Adaptive Large Neighborhood Search Algorithm – Performance Evaluation Under Parallel Schemes & Applications, Sandip Kumar

Theses and Dissertations

Adaptive Large Neighborhood Search (ALNS) is a fairly recent yet popular single-solution heuristic for solving discrete optimization problems. Even though the heuristic has been a popular choice for researchers in recent times, the parallelization of this algorithm is not widely studied in the literature compared to the other classical metaheuristics. To extend the existing literature, this study proposes several different parallel schemes to parallelize the basic/sequential ALNS algorithm. More specifically, seven different parallel schemes are employed to target different characteristics of the ALNS algorithm and the capability of the local computers. The schemes of this study are implemented in a …

Effects Of Alternative Jet Fuels On Aerospace-Grade Composites: Experimental And Modeling Studies, Naoufal Harich

Theses and Dissertations

The aviation industry aims to reduce its environmental impact through innovation and research. The usage of composite materials for multiple primary structures represents one such measure. Several alternative fuels were approved and used along with the Federal Aviation Administration (FAA). These alternative fuels are produced from wastes and biomasses. Some alternative fuels were initially only approved as drop-in fuels, meaning they must be blended with conventional fuels to operate. Fuel tanks are usually embedded into the wing structure, which is mainly made of composite materials. These composites tend to absorb fluids it encounters through their matrix phase. The absorption behavior …

Evaluation Of Conservation Practices Effect On Water Quality Using The Swat Model, Vivek Venishetty

Theses and Dissertations

The deterioration of water quality due to human-driven alternations has an adverse effect on the environment. More than 50% of surveyed surface water bodies in the United States (US) are classified as impaired waters as per the Clean Water Act. The pollutants affecting the water quality in the US are classified as point and non-point sources. Pollutant mitigation strategies such as the selective implementation of best management practices (BMPs) based on the severity of the pollution could improve water quality by reducing the amounts of pollutants. Quantifying the efficiency of a specific management practice can be difficult for large watersheds. …

A Screening Tool For The Implementation Of Electric And Thermal Energy Storage Systems At Commercial And Industrial Facilities, Mckenna P. Amerson

Theses and Dissertations

The integration of on-site renewable systems with energy storage devices is an important topic in improving energy management for commercial buildings and industrial facilities. Energy storage technologies have the ability to impact the end user’s power reliability while creating measurable energy and cost savings. However, the potential yet remains to increase the application of these systems. To determine the feasibility of renewables and energy storage in commercial and industrial applications, a pre-screening software tool is developed using data-driven algorithms to complete an energy, cost, and carbon savings analysis of storage implementation. A case study of a standalone retail building is …

Understanding Vascular Calcification Through The Lens Of Canonical Wnt Signaling, Karlee Mcneel

Theses and Dissertations

Every 37 seconds, someone in the United States dies from cardiovascular disease. Vascular calcification is one of the underlying causes of these fatal events. Medial calcification develops following arteriosclerosis, or hardening of the arteries. Medial calcification is characterized by the deposition of hydroxyapatite in the medial layer of the arteries after normal vascular smooth muscle cells undergo a phenotypic switch to resemble osteoblast-like cells. It is hypothesized that this switch is caused by the wingless related (WNT)-Signaling pathway. The WNT-Signaling pathway, upon activation, causes the upregulation of osteogenic markers for the development of osteoblast-like cells. Current treatments alleviate consequences of …

Risk Assessments And Modeling Of Driver By Using Risk Potential Theory, Riku Kikuta

Theses and Dissertations

Recently, various self-driving and driving assistance systems such as Advanced Driver Assistance System (ADAS) have been developed with the intent to reduce the number of motor vehicle accidents. While self-driving systems have been proven to reduce traffic accidents, the systems sometimes make other drivers confused because of their mechanical behavior. To avoid confusion and possible error, it is necessary to construct self-driving systems that exhibit human-like behaviors. Risk Potential theory has been used to construct models that successfully represent driver behavior, especially expert behavior. This project uses Risk Potential theory to construct and evaluate a collision avoidance driver model which …

Synthesis Of Biomass-Based Graphene Nanomaterials For Aqueous Heavy Metal Removal And Cement-Based Composite Property Enhancement, Tharindu N. Karunaratne

Theses and Dissertations

Utilizing biomass such as lignin, bamboo, soybean, corn stalk, rice husk, etc., as a carbon source to produce graphene-based nanomaterials has been reported recently. However, the potential of using such nanomaterials for engineering and environmental applications has not been realized. This dissertation investigates the use of graphene-based nanomaterials synthesized from using biomass as a carbon source for water remediation and cement-based composites’ (CBCs) property enhancement.

The first chapter introduces graphene and graphene-based nanomaterials, as well as the synthesis and application of graphene-based nanomaterials for removing heavy metals in an aqueous solution and for property enhancement in CBCs. The experimental investigation …

The Effect Of Four Decades Of Deregulation On Competition And Productivity Of The U.S. Freight Transportation Industry, Seungjae Shin

Theses and Dissertations

This study reviews the competition and productivity of the U.S. freight transportation industry for the past 41 years. This study investigated the trends of HHI market concentration index values and labor productivity values of rail and truck sectors and tried to find any relationships between the two values in the separate periods before and after the abolishment of the ICC. This study also investigated how the existence of a regulatory body impacted productivity of the freight transportation industry by using a Cobb Douglas production function on annual financial statement data in the U.S. stock exchange market. This study found that: …

The Use Of Lidar To Measure Water Surface Elevations In Froude-Scaled Physical Hydraulic Models, Gary L. Bell

Theses and Dissertations

Light detection and ranging (LiDAR) instrumentation is becoming more diverse in our world of today. One challenge in scaled physical hydrodynamic models in a laboratory setting is obtaining high resolution water surface elevation data while maintaining accuracy requirements. Accurate water surface elevations are a primary parameter in hydraulic models as they are a means of controlling/monitoring the physical model’s boundary conditions, analyzing model experiment results, and informing model conclusions. This study focuses on laser scanners that have ranging accuracies of at least +/-10 millimeters (mm) or better for the purpose of attaining LiDAR water surface elevation measurements in scaled physical …

An Investigation Into Perceptions, Expectations, And Development Of Professional Skills In Engineering Students, Morgan Kathryn Green

Theses and Dissertations

Upon graduation from an undergraduate institution, engineering graduates are expected to have a baselevel skill in technical skills related to their discipline. Teaching technical skills comes naturally to engineering programs as the conceptual understanding of the material form the foundation of engineering ability. However, engineering graduates also are expected to have a baselevel of professional skills, which are more subjective in nature and do not have a standardized approach for teaching or assessing them at the undergraduate level. An investigation into current perceptions of professional skills by relevant parties is an initial step in providing more structure to professional skills …

Where Did They Come From? Why Did They Go? How Engineering Students’ Perceptions Cultivate Experiences And Influence Behaviors, Sara Campbell Vick

Theses and Dissertations

Engineering undergraduate students have opinions and perceptions of engineering disciplines and engineering undergraduate students do not always matriculate and graduate in precisely the same discipline. Understanding how these two characteristics of engineering undergraduate students interact to inform behaviors is important for engineering educators and administrators to increase and improve recruitment and retention among their students.

This dissertation approached each characteristic of engineering students, first separately and then together. A nationwide survey of undergraduate engineering students found significant differences in how students perceive various engineering disciplines along several paired-term anchored scales. These differences were equally significant when scores were considered in …

Robotic Cotton Harvesting With A Multi-Finger End-Effector: Research, Design, Development, Testing, And Evaluation, Hussein Gharakhani

Theses and Dissertations

Cotton is harvested with large and heavy machines that are very efficient but have some disadvantages. They can harvest the crop only once at the end of the growing season. Since cotton bolls do not mature uniformly, the early opened bolls expose their fiber to weather for extended periods, reducing lint quality. In addition, the machines can also compact the soil, reducing water and fertilizer usage efficiencies and crop yields in the following years. Robotic cotton harvesting offers a promising solution to these issues. Smaller robotic harvesters could go to the field multiple times during the season to pick cotton …

Mitigating Adverse Impacts Of Increased Electric Vehicle Charging On Distribution Transformers, Akansha Jain

Theses and Dissertations

There is a growing interest in electric transportation, and the number of electric vehicles (EVs) is increasing. The resulting increase in EV charging power demand has an adverse impact on the existing power grids, especially the distribution transformers. The repeated and continued overloading caused by EV charging can significantly reduce their operational life. This dissertation aims to comprehensively study the adverse impacts of EV charging on distribution transformers and provide robust and practical solutions to mitigate it. A typical North American secondary distribution system with different EV penetration levels and four realistic residential EV charging scenarios are used for the …

A Step Toward Understanding Software Development In The Public Sector: A Study Of A Department Of Defense Research And Development Organization, Joshua Q. Church

Theses and Dissertations

This paper focuses on the importance of effective software development processes and a foundational understanding of success factors in the public sector. Although there has been significant investment in information technology, not all public sector software projects result in a successful return on investment. This study explores the crucial factors, referred to as Critical Success Factors (CSFs), that enable the success of public sector software development projects. Additionally, this study aims to discover if the CSFs, the Software Development Life Cycle (SDLC), or its methodologies are more impactful for the success of software projects. This study aims to also identify …

Design Of High-Power Ultra-High-Speed Permanent Magnet Machine, Md Khurshedul Islam

Theses and Dissertations

The demand for ultra-high-speed machines (UHSM) is rapidly growing in high-tech industries due to their attractive features. A-mechanically-based-antenna (AMEBA) system is another emerging application of UHSM. It enables portable wireless communication in the radio frequency (RF)-denied environment, which was not possible until recently. The AMEBA system requires a high-power (HP) UHSM for its effective communication performance. However, at the expected rotational speed range of 0.5 to 1 million rpm, the power level of UHSM is limited, and no research effort has succeeded to improve the power level of UHSM.

The design of HP-UHSM is highly iterative, and …