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Articles 19801 - 19830 of 196429

Full-Text Articles in Engineering

Usmepcom Prescreens: A Value-Focused Thinking Approach, Phillip M. Koenig Mar 2024

Usmepcom Prescreens: A Value-Focused Thinking Approach, Phillip M. Koenig

Theses and Dissertations

As the recruiting crisis continues to impact the United States Armed Forces, the United States Military Entrance Processing Command (USMEPCOM) continues to search for ways to increase its capability to efficiently determine which applicants are suited for military service. Unfortunately, USMEPCOM does not have a way to evaluate newly suggested alternatives. By leveraging Value-Focused Thinking (VFT), this research describes 28 fundamental objectives that can be applied to a variety of current and future decision problems. Further, this research applies these fundamental objectives to analyze a current decision problem: reengineering the prescreen process to decrease the time from prescreen submission to …

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The Use Of Deep Learning And Transfer Learning In Complex Problems, Jacob S. Lang Mar 2024

The Use Of Deep Learning And Transfer Learning In Complex Problems, Jacob S. Lang

Theses and Dissertations

Deep neural networks and transfer learning show potential in addressing complex problems such as the Tower of Hanoi and knapsack problems. The primary aim is to examine how the use of deep neural networks and transfer learning can enhance the ability of artificial learning systems to generalize. Transfer learning plays a crucial role in machine learning, particularly in the domain of artificial neural networks, as it helps overcome the challenges associated with limited data, computational efficiency, and generalization. The methodology used in this research involves the creation of data sets for the Tower of Hanoi and knapsack problems. To predict …

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Knowledge Management Modeling And Decision Analysis For Usmepcom, Luke G. Wunderlich Mar 2024

Knowledge Management Modeling And Decision Analysis For Usmepcom, Luke G. Wunderlich

Theses and Dissertations

This thesis explores the adoption of Value-Focused Thinking (VFT) in enhancing the Knowledge Management (KM) program at USMEPCOM, aiming to align decision-making with the organization’s values and goals. Through evaluating the current knowledge flow and policy drafts, it proposes categorizing command messages, establishing a centralized information repository, and scheduling a daily order release to improve information accessibility and operational readiness. Although no alternative offers a perfect solution, implementing Command Message Categorization is expected to significantly enhance operational efficiency and prepare USMEPCOM for future challenges.

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Discerning Satellite Subsystem Costs To Improve Cost Estimation, Ryan A. Candella Mar 2024

Discerning Satellite Subsystem Costs To Improve Cost Estimation, Ryan A. Candella

Theses and Dissertations

The race for supremacy in the space environment is accelerating, with the United States taking a significant step by establishing its dedicated military branch for space operations. Achieving dominance in this realm relies on efficiently managing costs and securing rapid funding to initiate new programs. One step towards accomplishing this goal is to comprehend the cost distribution across the primary components of a Space Vehicle Bus and to delve into lower-level Work Breakdown Structure (WBS) elements for more precise and expeditious cost estimations. To achieve this, descriptive statistics for a variety of Bus subsystem WBS elements are provided in this …

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Characterization Of Per- And Polyflouroalkyl Substances In Aqueous Filmforming Foam Wash Waters, John M. Diskin Mar 2024

Characterization Of Per- And Polyflouroalkyl Substances In Aqueous Filmforming Foam Wash Waters, John M. Diskin

Theses and Dissertations

The fiscal year 2020 National Defense Authorization Act mandated the publication of a military specification for a fluorine-free firefighting foam available for use no later than October 1, 2023. Replacing AFFF with a fluorine-free alternative creates the issue of decontaminating current firefighting infrastructure of residual PFAS without replacing these systems. To eliminate outstanding PFAS, the proposed solution is to drain the AFFF from current fire suppression systems and flush the plumbing three times with uncontaminated water. This study tested the efficacy of the triple rinse method by conducting scaled down experiments on a variety of plumbing components from a retired …

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Machine Learning Predictions Of Electricity Transfers Between Balancing Authorities In The Carolinas, Victoria Groleau Mar 2024

Machine Learning Predictions Of Electricity Transfers Between Balancing Authorities In The Carolinas, Victoria Groleau

Theses and Dissertations

Climate change through reduced streamflow, increased temperatures, and other factors impacts the efficiency of energy generation systems. The United States electric grid is comprised of a large network of balancing authorities engaged in trading electricity to maintain balance between supply and demand. The generation of electricity, a pivotal component of this balance, is impacted by climate change and weather variability as well as the growing demand for energy. Several hydro climatological factors such as streamflow, air temperature, and wind speed significantly influence the efficiency of power plant electricity generation. Due to the exchange of electricity between balancing authorities, impacts to …

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Long-Term Deterioration And Investment Modeling Of Water Distribution Infrastructure, Bethany M. Dorian Mar 2024

Long-Term Deterioration And Investment Modeling Of Water Distribution Infrastructure, Bethany M. Dorian

Theses and Dissertations

The United States Air Force (USAF) and municipal utilities rely on asset management processes to maximize utility of infrastructure assets while decreasing maintenance and repair costs. One of the core tenants of asset management is assessing the condition of the asset, which for water distribution pipes is challenging and costly to obtain. As a result, asset managers often rely upon pipe deterioration modeling using existing data, filling in the gaps when assessments are not available. This thesis uses USAF water distribution network data to develop a series of time-homogenous Markov chain probability models based on two sampling methods and four …

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Integrating Eod And Readiness Competencies Into The Ce Cgo Competency Framework, Kristina L. Johnson Mar 2024

Integrating Eod And Readiness Competencies Into The Ce Cgo Competency Framework, Kristina L. Johnson

Theses and Dissertations

In the last few years, the strategic focus of the United States defense posturing has shifted from legacy conflict in the Middle East to focusing on the Pacific with increased emphasis that Airmen must be educated and trained to deter or prevail in any conflict. To achieve this goal, the Department of Air Force (DAF) has evolved to utilizing a competency-based education framework with the Civil Engineer career field adopting this strategy and releasing the first version of their occupational competencies in 2020. However, DAF force posturing has evolved since 2020. With the new deployment system, Agile Combat Employment scheme …

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A Statistical Analysis Of Phased Construction Projects, Timothy M. Dejong Mar 2024

A Statistical Analysis Of Phased Construction Projects, Timothy M. Dejong

Theses and Dissertations

The construction industry is known for exceeding target budgets and schedules, and Department of Defense projects are no exception. The Air Force Installation & Mission Support Center (AFIMSC) manages a budget of $3.14 billion to repair, alter, demolish, and maintain Air Force facilities. However, an ever-increasing backlog of maintenance and repair work and a consistently underfunded repair program pose an increased financial risk to the sustainability of the construction and repair program. Phasing large construction efforts is a potential strategy that has recently been used to yield efficiencies by AFIMSC program managers. This study presents a statistical analysis of phased …

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Modeling Recovery Of The Florida Electric Transmission Grid After Severe Weather Event, Wei B. Guan Mar 2024

Modeling Recovery Of The Florida Electric Transmission Grid After Severe Weather Event, Wei B. Guan

Theses and Dissertations

Predicted changes to the climate are expected to increase the frequency and severity of extreme weather events. The Florida electric grid is a critical infrastructure system susceptible to severe weather events, especially hurricanes, causing widespread damage and outages. A foundational concept of the electric grid’s resilience is its ability to recover after extreme weather events, such as hurricanes and flooding. The recovery of the electrical grid after an extreme event is predicated upon the electrical asset's remoteness and the component's level of damage. Using fragility analysis, previous models have assessed the mean time to recover for transmission towers and substations …

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Predictive Analytics For Military Construction Overruns: A Machine Learning Approach, William D. Hunter Mar 2024

Predictive Analytics For Military Construction Overruns: A Machine Learning Approach, William D. Hunter

Theses and Dissertations

This research focused on analyzing cost and schedule overruns in a specific set of Air Force MILCON projects. Using data from the Built Infrastructure Common Operating Picture (BICOP), several advanced machine learning techniques, including LASSO regression and Random Forest, were applied to uncover patterns and build predictive models. The work sought to enhance the decision-making capabilities and efficiency of project managers within the Air Force through data-driven insights. A key finding from the models indicated that location was the most important factor in influencing a project’s tendency toward cost and schedule overrun. The best model for predicting schedule overrun achieved …

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Advanced Oxidation Of Tert-Butanol With Ultraviolet Light Emitting Diodes And Hydrogen Peroxide, Lauren R. Mainolfi Mar 2024

Advanced Oxidation Of Tert-Butanol With Ultraviolet Light Emitting Diodes And Hydrogen Peroxide, Lauren R. Mainolfi

Theses and Dissertations

Tert-butanol (TBA), a versatile chemical widely used in industrial processes, poses exposure risks through inhalation, ingestion, and skin contact. Environmental contamination, often from industrial activities, emphasizes the importance of robust waste management and monitoring to protect water supplies from potential TBA migration and ensure drinking water safety. This study employed hydrogen peroxide (H2O2): TBA molar ratios of 100, 200, 400, and 500:1 in a Continuous Flow Stirred-Tank Reactor (CSTR) with UV-LED as the TBA degradation mechanism in an Advanced Oxidation Process (AOP). The UV-LEDs and H2O2 were synergistically employed to generate hydroxyl radicals in an advanced oxidation process. Gas chromatography–mass …

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Quantifying Resilience And Redundancy For Air Force Linear Infrastructure, Ryan C. Jakovich Mar 2024

Quantifying Resilience And Redundancy For Air Force Linear Infrastructure, Ryan C. Jakovich

Theses and Dissertations

The historical underfunding of USAF infrastructure necessitates a strategic approach to reduce excess infrastructure while preserving resilience in the face of potential first-strike scenarios. This thesis formulates an infrastructure resilience metric that assesses network performance under varying degrees of damage. Furthermore, the study calculates the impact of redundant infrastructure by introducing added structural elements and measuring the resultant reduction in performance loss during damage scenarios. Utilizing USAF geospatial infrastructure data, adjacency matrices representing graph theory networks were constructed in Arc GIS Pro and evaluated using coding languages from the IGraph library and algorithms developed in RStudio. The newly proposed performance …

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Optimizing Hub And Spoke Selections For Adaptive Basing In Agile Combat Employment, Alan Heng Mar 2024

Optimizing Hub And Spoke Selections For Adaptive Basing In Agile Combat Employment, Alan Heng

Theses and Dissertations

Advancing technologies and emerging competitors within the Indo-Pacific region have rendered the use of fixed installations for United States Air Force (USAF) operations less than optimal for generating airpower. The adoption of Agile Combat Employment (ACE) is imperative and emphasizes a hub-and-spoke model. However, the methodology for selection of contingency locations remains undecided. Current selection of optimal sites hinges on an optimization framework, employing either rank-based or mathematical approaches that consider various criteria to assess and quantify each location. These criteria are then addressed through objectives and constraints, forming the basis for an effective decision-making process. This paper introduces two …

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Artificial Intelligence And Perception: An Empirical Study, Anthony J. Neil Mar 2024

Artificial Intelligence And Perception: An Empirical Study, Anthony J. Neil

Theses and Dissertations

This thesis investigates the impact of adjusting artificial intelligence explainability levels’ outputs on user perception. The overarching study extends within the Explainable Artificial Intelligence (XAI) domain. It examines a spectrum of variables, including performance, cognizance, familiarity, transparency, system bias, and the overall impact of AI, to understand their collective and individual effects that enable effective professional use in an organization. The study aims to illuminate the relationship between the degree of explainability provided by large language models such as ChatGPT, Bard, and Bing AI and the performance of these models when tasked with XAI adjustments.

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Analyzing Cost Risk In Department Of Defense Program Office Estimates, Todd L. Millard Mar 2024

Analyzing Cost Risk In Department Of Defense Program Office Estimates, Todd L. Millard

Theses and Dissertations

This research studies cost risk for Department of Defense (DoD) acquisition programs during development and has three overarching objectives: 1) analyze the degree of change in cost risk (quantified as risk dollars) as programs mature, 2) analyze the accuracy of cost risk estimates (quantified as risk error) as programs progress, and 3) adopt risk analysis techniques common in the commercial banking industry to analyze cost risk in DoD programs. For the first objective, some evidence of significant positive trends in relative risk dollars is found for ACAT 1, 2, and 3 programs. For the second objective, there is no strong …

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An Analysis Of Military Construction Cost Escalation And How It Is Accounted For In Cost Estimating Practices, Benjamin D. Rieben Mar 2024

An Analysis Of Military Construction Cost Escalation And How It Is Accounted For In Cost Estimating Practices, Benjamin D. Rieben

Theses and Dissertations

Construction escalation is a significant economic phenomenon that plays an important role in the construction industry. It refers to the steady increase in the costs associated with facility and infrastructure projects over time. Accurately capturing escalation is a key component in the development of construction cost estimates, and failure to adequately account for escalation can have far-reaching consequences. This is especially true for Military Construction (MILCON) projects, which account for billions of dollars of defense spending annually. The Department of Defense (DoD) utilizes a unit cost approach to develop rough order of magnitude (ROM) estimates for MILCON projects. The DoD …

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Estimating Stimulated Raman Scattering Noise In Cwdm O-Band Channels Induced By Two Classical Dwdm Sources In A Quantum Network Fiber Segment, Kurt T. Spranger Ii Mar 2024

Estimating Stimulated Raman Scattering Noise In Cwdm O-Band Channels Induced By Two Classical Dwdm Sources In A Quantum Network Fiber Segment, Kurt T. Spranger Ii

Theses and Dissertations

The purpose of this research is to estimate the stimulated Raman scattering noise induced in CWDM O-band channels by two DWDM classical sources in a terrestrial quantum optical network containing classical and quantum optical signal coexistence in the same fiber segment. A use case is defined and analyzed which extracts a single fiber segment from a notional Bell state measurement found in a notional terrestrial quantum network. A stimulated Raman scattering noise model is employed in a Python simulation to estimate and rank-order the five O-band channels with the least amount of relative induced stimulated Raman scattering noise when given …

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Root Cause Analysis For Troop Construction Schedule Delays And Cost Overruns, Richard H. Wilkens Mar 2024

Root Cause Analysis For Troop Construction Schedule Delays And Cost Overruns, Richard H. Wilkens

Theses and Dissertations

Troop construction can be an effective tool when a project is simple enough to execute projects in a timely and cost effective manner. However, underlying variables plague these projects causing them to miss anticipated deadlines which in return could make them more costly. Significant variables that convey impact to cost and schedule are Equipment Operating Issues, Edits During Construction, Design Flaws, Lack of Communication, Poor User Coordination, Improper Documentation, Inaccurate Submittals, Low Quality Control, and Lack of Experience. Project engineers and project managers must provide effective continuity as well as improve their own competence and situational awareness to effectively mitigate …

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Development Of A Metric To Quantify Facility Hardening, Jesse C. Solorzano Mar 2024

Development Of A Metric To Quantify Facility Hardening, Jesse C. Solorzano

Theses and Dissertations

This research investigates the intricate aspect of infrastructure resilience, focusing on the distinction between hardening and resilience. Hardening, often used interchangeably, with enhancing resilience, involves strategies to strengthen facilities, networks, or systems against various threats. Despite its recognized importance in mitigating physical disruptions and enhancing facility functionality amid different threats, a significant vagueness persists in quantitatively defining hardening. This thesis addresses this gap by developing a quantifiable metric for facility hardening, separate from general resilience measures. The study begins by exploring the historical context of facility hardening, linked to catastrophic events and the need for resilient infrastructure. It explores various …

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Analyzing The Effects Of Atmospheric Turbulence On Polarization-Entangled Photon Pairs Using Quantum State Tomography, Noah S. Everett Mar 2024

Analyzing The Effects Of Atmospheric Turbulence On Polarization-Entangled Photon Pairs Using Quantum State Tomography, Noah S. Everett

Theses and Dissertations

To help in building a quantum-based communication link, we experimentally designed a system to simulate atmospheric turbulence and characterize its effects on a polarization-entangled photon-pair source. The simulated turbulence is constructed using two afocal optical systems with a phase plate inserted in each to mimic both weak and strong atmospheric turbulence respectively. After propagation, quantum state tomography (QST) is performed on each pair to reconstruct the density matrix of the pair’s overall polarization state. In characterization of the simulated turbulence, we were able to reach strengths up to a D/r0 of 18.2, which begins to approach the strong turbulent regime. …

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Training Schedule For The 56th Maintenance Group, Samantha K. O'Rourke Mar 2024

Training Schedule For The 56th Maintenance Group, Samantha K. O'Rourke

Theses and Dissertations

The 56th Equipment Maintenance Squadron (56 EMS) provides equipment maintenance and back shop maintenance for the F-35 Joint Strike Fighter. The squadron executes thousands of sorties and flight hours annually. This operations tempo requires maintenance to prevent equipment failures, minimization of aircraft downtime, insurance of safety and compliance, and training of maintenance personnel. The squadron incorporates periodic training sessions to train maintenance personnel skills needed by airmen. This research investigates the optimization of these training sessions employing mixed integer programming (MIP). A multi-objective MIP model is developed to address the complex needs of various training activities, such as: training regiments, …

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Standardization Of Risk Classifications For Unmanned Space Vehicle Missions, Collin A. Gwaltney Mar 2024

Standardization Of Risk Classifications For Unmanned Space Vehicle Missions, Collin A. Gwaltney

Theses and Dissertations

This paper seeks to model risk classification levels (A-D) for 122 Space Vehicle programs. Models include multinomial logistic regression as well as random forest, a machine learning technique based on decision trees. We use independent variables (IVs) which are theoretically correlated to risk class for the regression and one random forest model. We then include all IVs and allow the random forest technique to use those which provide the most information on risk class before paring down the number of IVs to only 7. We show that the accuracy of predictions increases from 62% to 87% by using random forest …

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Investigation Of The Effect Of Internal Reynolds Number And Advective Capacity Ratio On Gas Turbine Film Cooling Parameters, John P. Di Lella Mar 2024

Investigation Of The Effect Of Internal Reynolds Number And Advective Capacity Ratio On Gas Turbine Film Cooling Parameters, John P. Di Lella

Theses and Dissertations

The desire for more powerful engines drives higher turbine inlet temperatures and a greater need to cool them. Experimentalists attempt to match cooling effectiveness between two conditions by matching several non-dimensional parameters, one of which is the coolant warming factor. The first investigation of this study examines the effect of the internal Reynolds number and the advective capacity ratio on the coolant warming factor by making use of a computational model and four different gases. It indicates the non-negligible and opposing effects of external convection and solid conduction on the coolant warming factor at matched internal Reynolds number and advective …

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Performance Of Humans And Agents In A Systems Modeling Language V2 Task: A User-Centered Evaluation Approach, Allen W. Dukes Mar 2024

Performance Of Humans And Agents In A Systems Modeling Language V2 Task: A User-Centered Evaluation Approach, Allen W. Dukes

Theses and Dissertations

The Department of Defense is adopting Digital Engineering practices for its workforce. Simultaneously, the larger Systems Engineering community strives to modernize and define those Digital Engineering practices. These efforts to move from traditionally document-based approaches to pure digital implementations will require enhanced capabilities to manage and digitally track the lifecycle of a program or product. However, this growth must address tool design through an iterative process focusing on usability for many user types. Many tools and technologies exist but often lack an assessment of usability when engineers design tools for other engineers. Including usability when developing solutions for Digital Engineering …

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Influence Of Environmental Barrier Coatings On The Overall Effectiveness Of A Film Cooled Ceramic Matrix Composite Plate, Shane P. Lindsay Mar 2024

Influence Of Environmental Barrier Coatings On The Overall Effectiveness Of A Film Cooled Ceramic Matrix Composite Plate, Shane P. Lindsay

Theses and Dissertations

Silicon carbide ceramic matrix composites, a promising new potential upgrade over the conventional metals currently used for jet engine turbine blades, have a propensity to oxidize in a combustion environment. Engine manufacturers often apply environmental barrier coatings to prevent the composites from oxidizing. What is unclear, however, is how environmental barrier coatings effect underlying composite temperatures. This research examined the coatings’ effects by first characterizing the influence of environmental barrier coatings on the underlying temperature of a protected ceramic, then evaluating the significance of lateral conduction for cooling a coated ceramic, and finally comparing cooling results for coated and uncoated …

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Rapid Passive Safety Determination Using Backward Reachability For Spacecraft Rendezvous And Proximity Operations, Kealy A. Murphy Mar 2024

Rapid Passive Safety Determination Using Backward Reachability For Spacecraft Rendezvous And Proximity Operations, Kealy A. Murphy

Theses and Dissertations

As the prevalence of autonomous space systems rise, there is an urgent demand for robust and precise safety analysis. The future of RPO necessitates coordination of satellites in a dynamic and congested space environment while avoiding collisions. Passive safety in RPO refers to the implementation of strategies that minimize the collision risk in the event of orbital or control deviations. This multifaceted problem includes maintaining KOZ, utilizing predictive modeling to anticipate collision scenarios, and designing spacecraft with robust GNC systems allowing for timely course corrections. The current literature’s focus has been on the separation distance between spacecraft as a primary …

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Preliminary Assessment Of Cislunar Disposal Orbits, Ryan M. Sargent Mar 2024

Preliminary Assessment Of Cislunar Disposal Orbits, Ryan M. Sargent

Theses and Dissertations

This thesis investigates the disposal of end-of-life spacecraft from key orbits with a focus on minimizing delta-v expenditure and preventing debris propagation. Simulated Lyapunov and halo orbits around the L2 Lagrange point are analyzed for disposal feasibility. Both impulsive and continuous thrust methods are explored to achieve disposal trajectories. Continuous thrust will be modeled after a Hall thruster utilizing electric propulsion. Leveraging the Circular Restricted Three Body Problem framework, low delta-v cost trajectories are computed, with a multi-level correction algorithm optimizing total delta-v via heteroclinic connections. The study assesses various delta-v amounts for Earth-Moon system escape and evaluates the potential …

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Human Performance Modeling Architecture With Hc-130j Mission Application, Stephanie G. Slimp Mar 2024

Human Performance Modeling Architecture With Hc-130j Mission Application, Stephanie G. Slimp

Theses and Dissertations

The DOD emphasizes digital engineering using Model-Based Systems Engineering (MBSE), where MBSE includes SysML-based models of systems. Analysis of system impacts on the human operators and their performance typically occurs through non-MBSE approaches, if at all. One current process, considered the As-Is process for this research, evaluates human performance and workload using IMPRINT, a discrete event simulation (DES) tool. IMPRINT primarily exists as a standalone tool with limited built-in functionality to integrate with an MBSE tool. Using the HC-130J and its crew during a CSAR mission as the system, this research develops a generalizable and updateable human performance modeling architecture …

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Rotorcraft Assisted Aircraft Inspection System: Creation And Component Assessment, Adam J. Warren Mar 2024

Rotorcraft Assisted Aircraft Inspection System: Creation And Component Assessment, Adam J. Warren

Theses and Dissertations

Aircraft require frequent inspections to perform their missions safely. Current visual inspection methods are time-consuming and dangerous for inspection personnel, but they are necessary to spot flaws that could endanger the aircraft during flight. This research explores a set of methods for transforming a set of target inspection criteria into camera specifications that will allow a UAS aircraft inspection system to perform inspections on the top skin of an aircraft. Given the minimum distance for the UAS to fly above the aircraft, minimum flaw size to search for on the aircraft, minimum number of pixels to display that flaw size, …

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