Engineering Commons^™

Developing An Early Life Cycle Manufacturability Assessment For Conceptual Designs, Tonya Gamblin Mccall

Theses and Dissertations

Studies have shown that 70 – 80% of a product's life cycle costs are committed by the end of the product design phase (Anderson, 2014; National Research Council, 1991; Swift, 1987). This supports the general claim that decision making in the conceptual stage drives the cost throughout the life cycle. The use of concurrent engineering has been viewed as the answer to this problem, offering the Design for Excellence (DFX) as one approach for evaluating product designs across specific disciplines. This research focuses on a subset of DFX referred to as Design for Manufacturability to develop a means to assess …

Practical Requirements Elicitation In Modern Product Development: A Multi-Case Study In Discontinuous Innovation, Michael King

Theses and Dissertations

Practical modern product development, specifically rapid, lean efforts to create new disrupting or specialized products, face constraints that require modified requirements elicitation (RE) techniques. Requirements elicitation conventions have not been updated to address the challenges of these approaches, and industry practitioners lack the tools to select the most efficient techniques. This study examines the RE approaches performed by three resource-limited teams conducting discontinuous new product development through a multi-case study to identify gaps between the literature and practice, with suggestions to fill them. Our findings suggest modern RE practices and challenges closely reflect those found by studies on RE in …

Towards Structured Planning And Learning At The State Fisheries Agency Scale, Caleb A. Aldridge

Theses and Dissertations

Inland recreational fisheries has grown philosophically and scientifically to consider economic and sociopolitical aspects (non-biological) in addition to the biological. However, integrating biological and non-biological aspects of inland fisheries has been challenging. Thus, an opportunity exists to develop approaches and tools which operationalize planning and decision-making processes which include biological and non-biological aspects of a fishery. This dissertation expands the idea that a core set of goals and objectives is shared among and within inland fisheries agencies; that many routine operations of inland fisheries managers can be regimented or standardized; and the novel concept that current information and operations can …

Project Selection In Facility And Infrastructure Maintenance Organizations, Bayram M. Kurbanov

Theses and Dissertations

The current Air Force Civil Engineer Center (AFCEC) built infrastructure Facility Sustainment Restoration and Modernization (FSRM) portfolio management methodology results in an unbalanced project portfolio. The consequence of this unbalance is that majority of the funding goes towards buildings on the flightline and Facility Support Services activities do not get adequate funding which leads to further deterioration of those facilities. This research investigates whether decision support framework based on Value-Focused Thinking (VFT) process yields better project selection outcomes for facility and infrastructure maintenance organizations. To accomplish that, the investigation focuses on understanding current AFCEC decision support methodology, building an alternative …

Integrating Model-Based Systems Engineering Industry Transformations For Workforce Development, Wilma Analisa Ankobiah

Theses and Dissertations

This study explores whether MBSE industry workforce requirements are being satisfied by the academic curricula of US institutions. Using an industry survey, which is highlighted in Chapter 3, identifies the existing perception of MBSE from various industries and explores the MBSE needs of professionals, such as tools concepts and languages. It examines how industry professionals perceive MBSE, the advantages and challenges of MBSE use and the preferred MBSE tools, languages and knowledge of concepts deemed necessary to ensure project success in the respective industry sectors. Results of phase 1 industry survey will summarize the current MBSE concepts, tools and languages …

Optimal Scheduling Of Aircraft Test And Evaluation Fleets To Balance Availability For Testing And Training, Sarah E. Hoops

Theses and Dissertations

The 96th Test Wing at Eglin Air Force Base manually schedules a fleet of approximately 26 aircraft to conduct a range of missions over a one-to-two year planning period. This study automates the scheduling process, does so in a manner that optimizes multiple planning goals related to aircraft availability for training, and provides the 96th Test Wing with a software tool for the implementation that can be used by operational analysts within the command. We formulate the scheduling problem as a multiobjective, nonlinear, binary integer math program that seeks to maximize both the lowest percent of time any aircraft is …

Cooperative Wide Area Search Algorithm Analysis Using Sub-Region Techniques, Shawn Whitney

Theses and Dissertations

Recent advances in small Unmmaned Aerial Vehicle (UAV) technology reinvigorates the need for additional research into Wide Area Search (WAS) algorithms for civilian and military applications. But due to the extremely large variability in UAV environments and design, Digital Engineering (DE) is utilized to reduce the time, cost, and energy required to advance this technology. DE also allows rapid design and evaluation of autonomous systems which utilize and support WAS algorithms. Modern WAS algorithms can be broadly classified into decision-based algorithms, statistical algorithms, and Artificial Intelligence (AI)/Machine Learning (ML) algorithms. This research continues on the work by Hatzinger and Gertsman …

Operational And Cost Analysis Of A Leo Radar-Based Satellite Constellation, Kyle O. Norbert

Theses and Dissertations

This thesis presents a methodology to assess the ability of a Low-Earth Orbit (LEO) satellite constellation to successfully accomplish the GMTI mission in a cost-effective fashion. A simulation model was developed to test the coverage performance of 512 unique constellation designs. Significant factors were revealed by developing regression models that revealed the most critical constellation trade-offs on measures of performance. A Value-Focused Thinking (VFT) approach was applied to assign weights to a broad range of measures of performance from which the Pareto distribution on a cost-capability plot revealed cost-effectiveness. A novel measure of performance was developed and analyzed that accounted …

Root-Cause Analysis Of Rsaf Maintenance-Related Flight Safety Mishaps, Heaf H. Alqahtani

Theses and Dissertations

Poor maintenance is a major factor in many aviation mishaps. This is due to the fact that some maintenance activities are carried out improperly or overlooked as a result of human error. It is important to acknowledge that maintenance mistakes are a visible sign of deeper organizational issues. Therefore, adequate solutions to maintenance issues must consider organizational influences. Despite efforts to reduce the accident rate within the Royal Saudi Air Force (RSAF), the RSAF suffers from an increasing trend in mishaps attributed to maintenance. Therefore, safety data was analyzed to examine trends. Additionally, the Human Factors Analysis and Classification System …

Value Focused Thinking Analysis Of C-Band Australia Radar Operations, Samuel Ray Grothman

Theses and Dissertations

The radars used for Space Domain Awareness (SDA) are inherently all-weather, day/night sensors capable of around the clock operations. Despite this fact, some radars are operated for fewer than their maximum operating capabilities. The decision-making process for selecting the operating hours of a sensor has historically been based on only a few factors or just one. This research uses the techniques in Value Focused Thinking to develop an evaluation process to score possible alternatives and find the alternative with the most value for the decision maker. By investigating the value that is added by operating an SDA radar, it is …

Evaluating Performance Competencies In The Royal Saudi Air Force Engineering Directorate And Squadrons, Faisal A. Al Dawood

Theses and Dissertations

The effectiveness of tasks performed by the directorate of aeronautical engineering and squadrons in RSAF directly impacts flight safety, which in turn influences the organization either positively or negatively. Therefore, improving engineers' competencies will improve the overall performance of the organization. The study refined and reconstructed a model, namely a T-shape competency model, to assess the engineers' competencies which revealed some management and competency-related deficiencies and concluded with managerial recommendations.

Retention Prediction And Policy Optimization For United States Air Force Personnel Management, Joseph C. Hoecherl

Theses and Dissertations

Effective personnel management policies in the United States Air Force (USAF) require methods to predict the number of personnel who will remain in the USAF as well as to replenish personnel with different skillsets over time as they depart. To improve retention predictions, we develop and test traditional random forest models and feedforward neural networks as well as partially autoregressive forms of both, outperforming the benchmark on a test dataset by 62.8% and 34.8% for the neural network and the partially autoregressive neural network, respectively. We formulate the workforce replenishment problem as a Markov decision process for active duty enlisted …

A Methodological Framework For Parametric Combat Analysis, Dustin L. Hayhurst Sr.

Theses and Dissertations

This work presents a taxonomic structure for understanding the tension between certain factors of stability for game-theoretic outcomes such as Nash optimality, Pareto optimality, and balance optimality and then applies such game-theoretic concepts to the advancement of strategic thought on spacepower. This work successfully adapts and applies combat modeling theory to the evaluation of cislunar space conflict. This work provides evidence that the reliability characteristics of small spacecraft share similarities to the reliability characteristics of large spacecraft. Using these novel foundational concepts, this dissertation develops and presents a parametric methodological framework capable of analyzing the efficacy of heterogeneous force compositions …

A Biomechanical Approach To Prevent Falls In Ergonomic Settings, Sachini Kodithuwakku Arachchige

Theses and Dissertations

Introduction: Fall-related injuries are exceptionally prevalent in occupational settings. While endangering the workers’ health, falls cause poor productivity and increased economic burden in the workplace. Hence, identifying these threats and training workers to achieve proper postural control is crucial. Purpose: Study 1: To investigate the ankle joint kinematics in unexpected and expected trip responses during single-tasking (ST), dual-tasking (DT), and triple-tasking (TT), before and after a physically fatiguing exercise. Study 2: To investigate the impact of virtual heights, DT, and training on static postural stability and cognitive processing. Methods: Study 1: Twenty collegiate volunteers (10 males and females, one left …

Assessing Readiness For Implementation Of Prognostics And Health Management In Small And Medium Enterprises, Sara C. Fuller

Theses and Dissertations

Prognostics and Health Management (PHM) refers to using robust sensing, monitoring, and control to detect, assess, and track system health degradation and failure modes, allowing for enhanced management and operational decisions. The need for PHM within a manufacturing facility has increased due to a variety of reasons, such as the increasing complexity of manufacturing equipment.

A lack of readiness for digital implementations is linked to failure. The literature highlights certain barriers and enablers that can signal whether a technology implementation will be successful, such as management and maintenance employees’ desire to change the existing process, an understanding and willingness to …

Bayesian Network Development For Depots Location Selection With Biomass Supply System Excellence, Alaa Ashraf Abulhamail

Theses and Dissertations

The renewable energy of the wood pellet market has taken great attention over the last few periods. However, the returns from the pellet business depend largely on how well the quality of biomass. The objective is to economically harvest pellets matching pellet standards set forward by the U.S. markets. The single-mindedness of this study is to develop a Bayesian network model to ensure a high-quality flow through the supply chain of the pallet industry in the top ten counties in Mississippi state. Multiple critical decisions (harvesting, storage, transportation, and quality control) of a biomass-to-pellet supply system could potentially affect the …

Bayesian Network Development And Validation For Siting Selection, Abdullah Hassan Battawi

Theses and Dissertations

In this study, increasing electricity demand requires considerable attention to increasing the diversity of power generation. Alternative energy can produce heating and power systems and thermal storage. Our objective and every organization’s objectives are to minimize its energy consumption cost under electricity demand uncertainty. In rural areas, heat and power availability and stability are also crucial. Combined heat and power have proven their effectiveness as a subsequent to Electricity. This paper identified four criteria and eleven sub-criteria to determine the most appropriate structure location for combined heat and power in the rural community. The Bayesian Network technology has been applied …

Developing Novel Optimization And Machine Learning Frameworks To Improve And Assess The Safety Of Workplaces, Amin Aghalari

Theses and Dissertations

This study proposes several decision-making tools utilizing optimization and machine learning frameworks to assess and improve the safety of the workplaces. The first chapter of this study presents a novel mathematical model to optimally locate a set of detectors to minimize the expected number of casualties in a given threat area. The problem is formulated as a nonlinear binary integer programming model and then solved as a linearized branch-and-bound algorithm. Several sensitivity analyses illustrate the model's robustness and draw key managerial insights. One of the prevailing threats in the last decades, Active Shooting (AS) violence, poses a serious threat to …

Development Of Software Tools For Efficient And Sustainable Process Development And Improvement, Jake P. Stengel

Theses and Dissertations

Infrastructure is a key component in the well-being of our society that leads to its growth, development, and productive operations. A well-built infrastructure allows the community to be more competitive and promotes economic advancement. In 2021, the ASCE (American Society of Civil Engineers) ranked the American infrastructure as substandard, with an overall grade of C-. The overall ranking suffers when key infrastructure categories are not maintained according to the needs of the population. Therefore, there is a need to consider alternative methods to improve our infrastructure and make it more sustainable to enhance the overall grade. One of the challenges …

A Model-Based Approach To Cubesat Propulsion And Payload Analysis, Madeline H. Johnson

Theses and Dissertations

Currently, there are only limited ways to increase mission success of CubeSats in terms of component and mission compatibility. The Payload Analysis Tool (PAT), developed by Air Force Institute of Technology (AFIT) students, combines the power of multiple tools to analyze payload compatibility on a single CubeSat bus. The PAT simulates a CubeSat mission with a variety of payloads to better understand how the payloads interact with the bus in terms of power, data rate, and memory, but it lacks a propulsion system. This thesis research advances the PAT by including a propulsion system which allows for increased mission time …

Reconciliation, Restoration And Reconstruction Of A Conflict Ridden Country, Muhammad S. Riaz

Theses and Dissertations

Conflict has sadly been a constant part of history. Winning a conflict and making a lasting peace are often not the same thing. While a peace treaty ends a conflict and often dictates terms from the winners’ perspective, it may not create a lasting peace. Short of unconditional surrender, modern conflict ends with a negotiated cessation of hostilities. Such accords may have some initial reconstruction agreements, but Reconciliation, Restoration and Reconstruction (RRR) is a long term process. This study maintains that to achieve a lasting peace: 1) The culture and beliefs of the conflict nation must be continuously considered and …

Educational Data Mining For Predicting University Students' Performance, To Enhance University Admission Criteria, Youssef Amr Naga

Theses and Dissertations

This thesis aims to propose and evaluate possible predictors of success for incoming university students to the American University in Cairo (AUC) who wish to enroll in its engineering programs, by considering their overall grade point average (GPA) at graduation as the measure of their success (output variable). This study is composed of two phases. First, available university admission variables; i.e., gender, high school diploma, high school score, and proficiency level in the English language (the language of instruction at AUC) at the time of application are evaluated as a predictor of students’ performance using five different data mining techniques. …

Modeling Multi-Criteria Decision-Making Problems With Applications In Last Mile Delivery And School Safety Assessment, Ayat Alrahahleh

Theses and Dissertations

The last-mile delivery option has become a focal point of academic research and industrial development in recent years. Multiple factors such as increased demands on delivery flexibility, customer requirements, delivery urgency, and many others are enforcing to adopt this option. For fulfilling this paradigm shift in delivery and providing additional flexibility, drones can be considered as a viable option to use for last-mile delivery cases. Numerous drones are available in the market with varying capacities and functionalities, posing a significant challenge for decision-makers to select the most appropriate drone type for a specific application. For this purpose, this study proposes …

Supplier Performance Scorecard Utilization In The Medical Device Manufacturing Healthcare Supply Chain, Justin Cardisco

Theses and Dissertations

The medical device manufacturing industry has a deficiency in determining how to improve supplier performance for the components and systems they purchase. Many complex medical devices require components from superb suppliers. But how does a medical device manufacturer (MDM) impartially assess supplier performance to know which suppliers to continuing with (or even boost purchase volumes) and which suppliers they should exit? This study describes which supplier-specific metrics are most important to medical device manufacturers (MDMs) so they can utilize this supplier performance scorecard backed by real-world inputs. This research will focus on five categories to measure MDM supplier performance (Quality, …

An Optimization Modeling Framework To Evaluate Civilians Response Under Active Shooter Violence Situations, Joseph G. Kerlin

Theses and Dissertations

Workplace safety is under serious threat due to the increasing trend of active shooter violence in recent years. Therefore, it becomes essential that the safety of a workplace is rigorously and, most importantly, methodologically assessed against active shooter violence. To serve this purpose, this study proposes a machine learning-optimization framework to assess the safety of a building against possible active shooter violence. First, several state-of-the-art machine learning models are employed to predict an agent’s movement decisions (with directions) under different violence scenarios. The predictions are then utilized in a mixed-integer linear programming model to maximize the agent’s utility under a …

Development Of Simulation Framework For Impact Analysis Of Launch Delays On Lunar Base Station, Giulio Cristello

Theses and Dissertations

Humans have not ventured beyond Earth since the days of the Apollo missions. NASA astronauts were the first and last to set foot on the lunar surface, and it is again thanks to NASA that the initiative to go back to the Moon is moving forward. The Artemis missions will land men and women on the lunar surface with the purpose of establishing a long-term presence on the Moon. The current Artemis Plan includes the Artemis Base Camp, a lunar base stationed on the lunar South Pole. The maintenance of the base will require frequent missions to be performed in …

Complexity Analysis And Parallel Implementation Of The Well Optimized Linear Finder (Wolf) Atmospheric Turbulence Compensation (Atc) Algorithm On Gpu Technology With Comparative Analysis Of Traditional Phase Diverse Atc Methods, Yang Xin

Theses and Dissertations

A new high-speed, high-accuracy general transfer function estimation method for diversitybased problems, known as the Well Optimized Linear Finder Algorithm (WOLF Algorithm), has been developed [1]. Compared to the traditional phase diversity ATC methods, the WOLF Algorithm has less computational complexity and better approximation of the Optical Transfer Function (OTF) and consequently the entrance pupil phases. We compare the time complexity between the traditional Phase Diversity atmospheric turbulence compensation approach and the WOLF Algorithm. The results show that the WOLF Algorithm is dramatically faster than traditional phase diversity methods theoretically. We also implement the time complexity results of the WOLF …

Computational Speed Improvement Of The Well Optimized Linear Finder (Wolf) Transfer Function Estimation Methodology For Phase-Diverse Atmospheric Turbulence Compensation (Atc) Applications Using Pre-Calculated, Parallel Complex Exponential Phase Difference Chains, Erlin He

Theses and Dissertations

The Well-Optimized Linear Finder (WOLF) high-speed, phase-dominant, transfer function estimation method was developed by Professor William W. Arrasmith at Florida Institute of Technology. The novel, high-speed, transfer function estimation method is robust and can be applied to atmospheric turbulence compensation (ATC)/blind deconvolution optical imaging problems. The WOLF methodology uses a diversitybased approach with an adapted error metric to quickly remove effects of atmospheric turbulence and system noise effects present in an incoherent, optical imaging system. In this research, we improve performance of the WOLF algorithm by investigating the impact of applying parallel processing technology to pre-calculate an expanding set of …

Model-Based Operational Performance Evaluation Of Augmented Reality Applications In Supported Employment Training, Ruo Lun Pan

Theses and Dissertations

Supported employment is a service provided by social enterprises to help persons with disabilities (PWD) to assimilate into their work environment and maintain their jobs for as long as possible. Social enterprises that provide such services are able to receive incentives from the government but they still rely on a limited funding. Augmented reality (AR) has been tested in various fields such as remote support and training employees, including PWDs. This thesis aims to evaluate the operational performance of augmented reality in supported employment using a model-based systems engineering approach paired with a simulation model. The simulation model evaluates three …

Developing A Model-Based Approach To Forecast A Competitor's System, Christopher A. Del Vecchio

Theses and Dissertations

The purpose of this research is to develop a model-based approach to intelligence forecasting of a competitor’s system. This analysis currently uses a document-based practice to capture all knowledge of the forecast and its development. A framework of antithesis processes, or Anti-Processes, were derived from the systems engineering technical processes. This was then combined with analytical tradecraft from the field of competitive technical intelligence to build a SysML reference model, which was then applied to a small case study to enhance and refine the model. The Anti-Process framework and SysML reference model provide a rigorous, model-based approach to intelligence forecasts …