Engineering Commons^™

Estimating Direction Of Arrival For Multi-Arm Spiral Antennas Using Machine Learning, Samuel Pearson

Honors Theses

Military systems require monitoring a wide frequency range of the RF spectrum to detect and monitor enemy targets. A vital component of that is calculating the direction of arrival of enemy radars. The use of compressive sensing architectures like the Nyquist Folding Receiver (NyFR) allow for computationally cheap capturing of wideband signals; however, these techniques make traditional direction of arrival (DOA) estimation techniques difficult. Given the advantages of compressive sensing, this research aims to apply machine learning (ML) techniques to multi-arm spiral antennas to estimate the incoming DOA. Software like MATLAB was used to simulate the multi-arm spiral antenna and …

Assistive Mobile Manipulator For People With Limited Mobility, Matthew Tognotti

Electrical and Computer Engineering Senior Theses

This project develops a robotic system that allows a mobile manipulator to help individuals with mobility limitations perform daily tasks. The primary goal is to enhance independence by enabling users to retrieve items necessary for daily routines, such as preparing for work or school. The system allows users to interact with the robot using structured voice commands and uses a rule-based approach so that the robot can learn tasks to be repeated in future interactions. An experimental setup is developed to evaluate the proposed system in a pilot study of 10 adult participants. The preliminary results from the pilot study …

Mechanistic Empirical Design Of Flexible Pavements For Biopolymer Treated Soils, Vishweshwaran M

Theses and Dissertations

Cognizing the contamination effects of chemical soil modifiers on soil and groundwater, the assessment of the ability of biopolymers to improve the engineering properties of soils has gained attention in the last decade. As a soil additive, biopolymers have the potential to solve the trilemma of sustainability, price and soil suitability. Two polysaccharides and two protein biopolymers have been adopted in this study to enhance the geotechnical properties of fine-grained soils.

Design thickness catalogues were developed for a three-layered flexible pavement using 3D finite element analysis (FEA) and layered elastic analysis. The catalogue aims to provide structurally reliable thickness values …

Experimental, Computational, And Machine Learning Methods For Prediction Of Residual Stresses In Laser Additive Manufacturing: A Critical Review, Sung Heng Wu, Usman Tariq, Ranjit Joy, Todd Sparks, Aaron Flood, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In recent decades, laser additive manufacturing has seen rapid development and has been applied to various fields, including the aerospace, automotive, and biomedical industries. However, the residual stresses that form during the manufacturing process can lead to defects in the printed parts, such as distortion and cracking. Therefore, accurately predicting residual stresses is crucial for preventing part failure and ensuring product quality. This critical review covers the fundamental aspects and formation mechanisms of residual stresses. It also extensively discusses the prediction of residual stresses utilizing experimental, computational, and machine learning methods. Finally, the review addresses the challenges and future directions …

Insight Into Uniform Filming Of Lif-Rich Interphase Via Synergistic Adsorption For High-Performance Lithium Metal Anode, Yufang He, Li Wang, Aiping Wang, Bo Zhang, Hiep Pham, Jonghyun Park, Xiangming He

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Multi-scale simulation is an important basis for constructing digital batteries to improve battery design and application. Lif-rich solid electrolyte interphase (sei) is experimentally proven to be crucial for the electrochemical performance of lithium metal batteries. However, the lif-rich sei is sensitive to various electrolyte formulas and the fundamental mechanism is still unclear. Herein, the structure and formation mechanism of lif-rich sei in different electrolyte formulas have been reviewed. On this basis, it further discussed the possible filming mechanism of lif-rich sei determined by the initial adsorption of the electrolyte-derived species on the lithium metal anode (lma). It proposed that individual …

Towards A Wearable Device For Measuring Impedance Plethysmography Of The Radial Artery, Pritom Chowdhury

Dartmouth College Master’s Theses

Recent advancements in bioimpedance technology have demonstrated significant promise in the application of cardiac health monitoring. This research explores the design and development of a forearm-based wearable bioimpedance device for non-invasive measurement of heart rate and respiratory rate at an accuracy level comparable to medical-grade monitors. It utilizes a tetrapolar electrode configuration to analyze bioimpedance changes in the radial artery due to blood flow.

An ongoing aspect of this work involves the preliminary development of an embedded framework intended to integrate signal generation, acquisition, and processing within the device to achieve compact and efficient system design, anticipated to contribute to …

Exploring Lstm-Based Attention Mechanisms With Pso And Grid Search Under Different Normalization Techniques For Energy Demands Time Series Forecasting, Andri Pranolo, Xiaofeng Zhou, Yingchi Mao, Bambang Widi Pratolo, Aji Prasetya Wibawa, Agung Bella Putra Utama, Abdoul Fatakhou Ba, Abdullahi Uwaisu Muhammad

Knowledge Engineering and Data Science

Advanced analytical approaches are required to accurately forecast the energy sector's rising complexity and volume of time series data. This research aims to forecast the energy demand utilising sophisticated Long Short-Term Memory (LSTM) configurations with Attention mechanisms (Att), Grid search, and Particle Swarm Optimization (PSO). In addition, the study also examines the influence of Min-Max and Z-Score normalization approaches in the preprocessing stage on the accuracy performances of the baselines and the proposed models. PSO and Grid Search techniques are used to select the best hyperparameters for LSTM models, while the attention mechanism selects the important input for the LSTM. …

Hybrid Method For User Review Sentiment Categorization In Chatgpt Application Using N-Gram And Word2vec Features, Husna Luthfiatun Nisa, Atina Ahdika

Knowledge Engineering and Data Science

The rapid development of Artificial Intelligence (AI) has significantly influenced nearly all aspects of life. One AI product widely used by people worldwide is the Chat Generative Pre-Training Transformer (ChatGPT), which can respond to questions conversationally. Although data indicates that the use of ChatGPT in Indonesia is less widespread than in other countries, a Populix survey reveals that half of the respondents have utilized ChatGPT, using AI more than once a month. This indicates its crucial role among the Indonesian population. ChatGPT is not limited to browsers; it is also available as a downloadable application on the Google Play Store. …

Convolutional Neural Network In Motion Detection For Physiotherapy Exercise Movement, Dika Fikri Laistulloh, Anik Nur Handayani, Rosa Andrie Asmara, Phillip Taw

Knowledge Engineering and Data Science

Physiotherapy focuses on movement and optimal utilization of the patient's potential. Exercise Therapy is a physiotherapy procedure that specifically focuses exercises on active and passive movements. Cerebral Palsy (CP) patients are one of the sufferers of motor disorders of the upper extremities. Cerebral Palsy (CP) patients suffer from disorders in motor functions of the upper extremities. Physiotherapy Exercise Movement has 4 categories of movement exercises for the therapy of people with upper extremity body disorders: Elbow flexor strengthening in sitting using free weights, lifting an object up, reaching diagonally in sitting, and reaching from a low surface to a high …

Optimizing Malaria Control: Granular And Cost-Effective Mosquito Habitat Index In Endemic Areas Through Satellite Imagery, Nur Ainun Daulay, Salwa Rizqina Putri, Arie Wahyu Wijayanto, Ika Yuni Wulansari

Knowledge Engineering and Data Science

Malaria, classified as a tropical disease under the Sustainable Development Goals (SDGs) indicator 3.3, remains a significant global health challenge. In this study, by taking advantage of multiple spectral composite indexes of multisource satellite imagery to capture various geospatial features relevant to the suitability of marsh mosquito habitat, we introduced the Mosquito Habitat Suitability Index (MHSI) to assess potential Anopheles mosquito breeding sites in terms of the vegetation density, water bodies, environment temperature, and humidity in any particular areas. The MHSI integrates the publicly accessible granular level of the normalized difference vegetation index, water index, land surface temperature, and moisture …

Docker Optimization Of An Automotive Sector Virtual Server Infrastructure, Leonel Hernandez, Carlos Eduardo Uc Rios

Knowledge Engineering and Data Science

Server virtualization is a powerful strategy for optimizing network infrastructure. It allows multiple virtual servers to run on a single physical server, maximizing resource utilization and improving efficiency. Deploying server virtualization using Docker technology offers a lightweight and flexible approach to optimizing network infrastructure. Docker contains package applications and their dependencies, enabling consistent and efficient deployment across various environments. Specifically, optimizing virtual server infrastructure using Docker Technology in the automotive sector focuses on improving the efficiency and management of the company's virtual server resources. By implementing Docker technology, a container platform that allows the packaging and running of applications in …

Timbre Style Transfer For Musical Instruments Acoustic Guitar And Piano Using The Generator-Discriminator Model, Widean Nagari, Joan Santoso, Esther Irawati Setiawan

Knowledge Engineering and Data Science

Music style transfer is a technique for creating new music by combining the input song's content and the target song's style to have a sound that humans can enjoy. This research is related to timbre style transfer, a branch of music style transfer that focuses on using the generator-discriminator model. This exciting method has been used in various studies in the music style transfer domain to train a machine learning model to change the sound of instruments in a song with the sound of instruments from other songs. This work focuses on finding the best layer configuration in the generator- …

The Elements Of Governance And Their Association With Aviation Safety Oversight Effectiveness, João Souza Dias Garcia

Doctoral Dissertations and Master's Theses

States and their respective national civil aviation authorities promote the improvement of the global civil aviation system by developing and enforcing safety regulations for aircraft design, operations, personnel training, infrastructure, and air traffic management, among other topics. For many years, the International Civil Aviation Organization (ICAO) has driven the continuous improvement of states’ safety oversight functions, supporting them in evaluating the effectiveness of these functions by conducting audits under the Organization’s Universal Safety Oversight Audit Program (USOAP). While the benefits of these assessments have been broadly recognized, scholarly literature on the factors commonly associated with safety oversight effectiveness across states …

Damage Control Measures In Composites: Focus On Damage Tolerance Of Aerospace Structures, Kais Jribi

Doctoral Dissertations and Master's Theses

Barely Visible Impact Damage (BVID) in composite materials presents a stealthy yet significant risk to structural integrity, particularly challenging due to its elusive nature. The approach adopted here diverges from traditional methodologies, focusing on the novel application of Digital Image Correlation (DIC) to map surface area changes during in-situ Compression After Impact (CAI) tests. This technique allows for an in-depth analysis of planar strains along the x and y axes, shedding light on the material's behavior under stress.

A pivotal advancement lies in developing a method for precisely identifying when BVID-induced delamination recommences. By meticulously analyzing strain pattern deviations along …

Optimization Of Human Interactions In The College Campus Model Via Simio Integration, Benjamin E. Chaback

Doctoral Dissertations and Master's Theses

College campuses are a significant part of life in some cities. Many students each year attend university, pursuing additional knowledge from faculty members. Both staff and faculty members rely on these students to have successful jobs and to ensure the university functions. Yet recently, more and more students are attending, leading to overcrowding, lower admission rates, and difficulty getting into good programs. Previous work exists on qualitative student affairs and quantitative retention data, yet little on using simulations to model this problem. This work aimed to (a) Determine the ability to successfully model human interactions/people flow on a college campus, …

Impacts Of Space Launch Operations On Florida East Coast Airspace Users, Sakurako Kuba

Doctoral Dissertations and Master's Theses

With an increasing number of space flight operations in the United States, space flight integration into the National Airspace System (NAS) is a pertinent area of research so safe and efficient operations in NextGen airspace can be achieved. The currently implemented procedure for Florida east coast launches temporarily closes the airspace to keep all air traffic operations out of the launch trajectory and potential hazard areas to maintain the safety of air traffic and space vehicles. This results in the flight deviation from the shortest flight route, leading to extended flight distance, prolonged flight time, and extra fuel burn. This …

Development Of Eagle3d Solver For Wall Modeled Les Of Transonic Flows, Spencer Moore

Doctoral Dissertations and Master's Theses

Wall modeled Large Eddy Simulation (LES) is an area of interest due to its ability to lower computational costs of LES simulation. Even with the application of wall models, LES still proves to have practicality issues when it comes to use in industry, due to the expertise, time, and computational resources required to get results. A case described by an axisymmetric transonic bump is explored utilizing the Embry-Riddle Aeronautical Universities in house unstructured finite volume multi-element CFD code, Eagle3D. Eagle3D, has been brought to the state of the art and validated against current research using this transonic bump case as …

Low Cost Magnetometer Calibration And Distributed Simultaneous Multipoint Ionospheric Measurements From A Sounding Rocket Platform, Joshua W. Milford

Doctoral Dissertations and Master's Theses

Low-cost and low-size-weight-and-power (SWaP) magnetometers can provide greater accessibility for distributed simultaneous measurements in the ionosphere, either onboard sounding rockets or on CubeSats. The Space and Atmospheric Instrumentation Laboratory (SAIL) at Embry-Riddle Aeronautical University has launched a multitude of sounding rockets in recent history: one night-time mid-latitude rocket from Wallops Flight Facility in August 2022 and three mid-latitude rockets from White Sands Missile Range during the October 2023 annular solar eclipse. All rockets had a comprehensive suite of instruments for electrodynamics and neutral dynamics measurements. Among this suite was one science-grade three-axis fluxgate magnetometer (Billingsley TFM65VQS / TFM100G2) and up …

Development Of On-The-Fly Quasi-Steady State Approximation For Chemical Kinetics In Cfd, Abhinav Balamurugan

Doctoral Dissertations and Master's Theses

This study analyzes the feasibility of On-The-Fly Quasi-Steady-State Approximation (OTF-QSSA) application for solving chemical kinetics within Computational Fluid Dynamics (CFD) simulations, aiming to reduce the computational demand of detailed mechanisms. An algorithm that dynamically identifies and designates Quasi-Steady-State (QSS) species at specific grid locations and instances during the simulation was developed. With this information, our method pseudo-delays the advancement of concentrations for these QSS species—effectively setting their rate of concentration change to zero for a set number iteration before updating using the detailed mechanism and thereby omitting the computationally intensive processes typically required for their calculation during those skipped iteration. …

Distributed Adaptive Control Methods For Uncertain Multiagent Systems With Coupled Dynamics, Islam Aly

Doctoral Dissertations and Master's Theses

For a multiagent system, a major challenge is achieving overall system stability and performance in the presence of not only uncertainties but also coupled dynamics. Another challenge for these systems is designing distributed adaptive controllers with user-assigned positions in this case and defining the convergence rate of the reference model for each agent using only local (i.e., agent-based) information. Discrete-time architectures have an advantage over their continuous counterparts as they can be directly executed on embedded hardware without the need for discretization. Yet, because of the difficulty of ensuring Lyapunov difference expressions, their designs, which are based on quadratic Lyapunov-based …

Ti Nano Powder Speckle Pattern Creation And Use In Dic Of Zno Modified Single Carbon Fibers, James Matthew Harris

Doctoral Dissertations and Master's Theses

As the use of composites continues to grow across aerospace, naval, automotive, construction, 3D printing, and other countless industries, so does the desire to continuously improve their mechanical properties. Improving the adherence of the fiber-matrix interface is one important step for amplifying the capabilities of composites. Work has been performed in modifying carbon fibers by growing zinc oxide (ZnO) nanorods in the fiber surface using a hydrothermal approach, increasing interfacial area and fiber-matrix friction. Macroscale evaluation has shown that the interfacial modification decreases the inter-ply movement and reduces the processing strains and residual stresses. To fully understand the mechanism taking …

Evaluating Flight Crew Decision-Making Through Part 121 Taxi Operations, Grant Marsh

Doctoral Dissertations and Master's Theses

With the mandate of Automatic Dependent Surveillance-Broadcast (ADS-B) going into effect at the start of 2020, commercial companies have been able to log and store information on aircraft identification, airspeed, heading, and altitude all in one database.to Now, anyone can access previously hard-to-obtain flight data for analysis using a commercially available database. While ADS-B provides information on “what is happening,” information on “why” flight crews operate aircraft in a certain way is not incorporated into ADS-B.

The National Aeronautics and Space Administration’s (NASA) Aviation Safety Reporting System (ASRS) collects reports written by flight crews, Air Traffic Control Specialists, and other …

Numerical Study In Wind Energy Extraction From Controlled Limit-Cycle Oscillations In Modified Glauert Airfoil, Ethan L. Deweese

Doctoral Dissertations and Master's Theses

Typically, wind energy harvesting technology employs wind turbines. Towards the goal of meeting increasing energy needs with renewable energy sources a novel wind energy harvesting scheme is considered, utilizing a modified Glauert (MG) airfoil experiencing aeroelastic limit cycle oscillation (LCO) from which energy may be extracted. Synthetic jet actuators (SJA)s are used along with the unique geometry of the MG airfoil to control flow separation and amplify the LCO and energy generation potential of the system. The discussed wind energy harvesting scheme could provide flexibility in allowing installations previously unsuitable to wind turbines due to geometric or low wind velocity …

Emergent Themes Of Operational Safety At Urban Air Mobility At Vertiports: The Stakeholder Perspective, Tracy Leigh Lamb

Doctoral Dissertations and Master's Theses

The emerging urban air mobility (UAM) industry is dynamic, complex, and still highly conceptual, as vertiports are not currently an operational reality in the United States. The UAM vertiport is at the epicenter of the emerging advanced aviation ecosystem, representing significant operating costs of approximately $130 million per year and more than that to design, develop, and implement. In addition to setting up and operating capital, there are considerable challenges relating to the safe design, development location, and operation of UAM vertiports, representing the confluence of human and autonomous systems, whose interdependence is not yet fully understood. UAM vertiport stakeholders …

Passenger Traits That Predict The Bystander Intervention Model Steps During An Inflight Assault On A Flight Attendant, Michael Pettit

Doctoral Dissertations and Master's Theses

Every major U.S. airline has experienced a violent inflight assault on one of their flight attendants. The problem is becoming more widespread, but industry leaders have few coping strategies. The first step toward addressing the issue is understanding the various aspects of the event, including the actions of other passengers (bystanders) who may witness the assault. There is ample literature on bystander reactions to similar events such as bullying, medical emergencies, injuries, and violent attacks, but none dedicated to a flight attendant assault or passenger reactions to it.

At the core of bystander action is the bystander effect, which postulates …

Implementation Of Path Planning Methods To Detect And Avoid Gps Signal Degradation In Urban Environments, Ayush Raminedi

Doctoral Dissertations and Master's Theses

In the modern world, various missions are being carried out under the assistance of autonomous flight vehicles due to their ability to operate in a wide range of flight conditions. Regardless, these autonomous vehicles are prone to GPS signal loss in urban environments due to obstructions that cause scintillation, multi-path, and shadowing. These effects that decrease the GPS functionality can deteriorate the accuracy of GPS positioning causing losses in signal tracking leading to a decrease in navigation performance. These effects are modeled into the simulation environment and are used as part of the path planning algorithm to provide better navigation …

Indentation Protection Of Lithium-Ion Batteries Using Woven Fiber Metal Laminates, Sida Xu

Doctoral Dissertations and Master's Theses

Lithium-ion batteries are widely used as electric power sources for smartphones, tablets, laptops, e-scooters, unmanned aerial vehicles, aircraft, electric vehicles, airport equipment, and numerous other transportable electronic devices. When these types of batteries get excessively loaded, damage can occur. To study the effects of excessive damage, lithium-ion battery modules with prismatic cells were subjected to destructive quasi-static indentation using a V-shaped stainless steel wedge indenter at different loading orientations, directions, and rates. The modules were discharged to a very low state of charge prior to testing. Force and voltage were measured as a function of displacement to monitor the damaging …

Prediction Of Handling Qualities Deficiencies For Advanced Air Mobility Aircraft, Louis Spier

Doctoral Dissertations and Master's Theses

To date, there are hundreds of Advanced Air Mobility (AAM) vehicles under development. Most of these vehicles differ significantly from traditional airplanes and rotorcraft when it comes to configuration and handling qualities. Handling qualities for traditional airplanes and rotorcraft are often very predictable. All AAM concepts currently under development feature some sort of fly-by-wire flight control system. Regulatory agencies already have decades of experience with certifying fly-by-wire airplanes. Fly-by-wire rotorcraft have proven to be significantly more difficult to certify and several flight test accidents have occurred as a result of handling qualities deficiencies, or “cliffs”. To ensure the safe and …

Mitigating Engine Unstart In Scramjets With Porous Bleeders, Ryan Lindley

Doctoral Dissertations and Master's Theses

The effectiveness of porous bleeders in mitigating unstart phenomena and enhancing isolator effectiveness in a hypersonic scramjet was investigated. Through computational fluid dynamics simulations, the impact of porous bleeder design parameters such as pressure jump coefficient and bleeder size on isolator effectiveness and unstart prevention was evaluated. Results indicated that porous bleeders delayed flow separation and reduced adverse pressure gradients, thereby enhancing isolator performance. Additionally, porous bleeders demonstrated promising capabilities in preventing full unstart events and mitigating oscillatory unstart phenomena.

Benchmarking Of A Sco2 Heat Exchanger Flow Loop, David Velasco

Doctoral Dissertations and Master's Theses

Heat transfer of supercritical carbon dioxide (sCO2) was studied experimentally by commissioning a sCO2 flow loop featuring a horizontal tube-in-tube counterflow heat exchanger with a circular cross section. The main objective was to establish experimental heat transfer research capabilities for sCO2 at Embry-Riddle Aeronautical University’s (ERAU) Thermal Science Lab. sCO2 experiences a drastic change in thermophysical properties near its critical point that results in unique heat transfer characteristics. The high pressures at which sCO2 exists make the large gradients in thermophysical and transport properties difficult to study, experimentally and numerically. However, understanding the heat transfer characteristics and thermophysical behavior of …