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Full-Text Articles in Engineering

Analysis Of Twitter Networks To Aid Open Source Intelligence Capabilities: A Multilayer Network Approach, Austin P. Logan Mar 2022

Analysis Of Twitter Networks To Aid Open Source Intelligence Capabilities: A Multilayer Network Approach, Austin P. Logan

Theses and Dissertations

Open Source Intelligence using social media is a practice which gives military intelligence analysts a window into the thoughts and minds of an online population. Using Social Network Analysis, user interactions on Twitter will be modeled as a weighted and directed network. Topic modeling through Latent Dirichlet Allocation uncovers the topics of discussion in Tweets and is then integrated into a multi-layer network which allows users to be connected to the conversations with which they have participated. Influential users in this network as well as highly connected groups of individuals are then discovered to paint a picture for intelligence analysts …

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Assessing The United States Foreign Assistance Activities Impact On Violent Conflicts, Daniel F. Feze Mar 2022

Assessing The United States Foreign Assistance Activities Impact On Violent Conflicts, Daniel F. Feze

Theses and Dissertations

The Global Fragility Act, H.R.2116 116th Cong. (2019), “directs the Department of State to establish the interagency Global Fragility Initiative to stabilize conflict-affected areas and prevent violence globally, and establishes funds to support such efforts”. The United States Agency for International Development (USAID) has identified deteriorating economies, weak or illegitimate political institutions, and competition over natural resources as causes of violence, extremism and instability (USAID, 2021). The agency gives priority to mitigating the causes and consequences of violent conflicts, instability and extremism and funds programs and activities to accomplish that (USAID, 2021). With this study, we aim to quantitatively assess …

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Coupled Orbit-Attitude Dynamics And Control Of A Cubesat Equipped With A Robotic Manipulator, Charles M. Carr Mar 2022

Coupled Orbit-Attitude Dynamics And Control Of A Cubesat Equipped With A Robotic Manipulator, Charles M. Carr

Theses and Dissertations

This research investigates the utility and expected performance of a robotic servicing CubeSat. The coupled orbit-attitude dynamics of a 6U CubeSat equipped with a four-link serial manipulator are derived. A proportional-integral-derivative controller is implemented to guide the robot through a series of orbital scenarios, including rendezvous and docking following ejection from a chief spacecraft, repositioning the end effector to a desired location, and tracing a desired path with the end effector. Various techniques involving path planning and inverse differential kinematics are leveraged. Simulation results are presented and performance metrics such as settling time, state errors, control use, and system robustness …

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Covariance Analysis For Multi-Source Navigation Architecture, Tristan T. Williams Mar 2022

Covariance Analysis For Multi-Source Navigation Architecture, Tristan T. Williams

Theses and Dissertations

Currently, analysis on navigation systems can be slow and computationally expensive using Monte Carlo approaches. Covariance analysis is a tool that can return trade space analysis results promptly and can be computationally reasonable. This research aims to create a covariance analysis tool in a new navigation framework architecture, PntOS. The creation of this covariance tool is explained in coordination with the tool being used in a few different navigation scenarios with the results. These scenarios include a Doppler LiDAR velocity sensor and magnetic anomaly navigation.

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Predicting Tf33-Pw-100a Engine Failures Due To Oil Issues Using Survival Analyses, Anna M. Davis Mar 2022

Predicting Tf33-Pw-100a Engine Failures Due To Oil Issues Using Survival Analyses, Anna M. Davis

Theses and Dissertations

In 2007, the Office of the Assistant Secretary of Defense for Sustainment pushed for the need to transition to a Condition Based Maintenance Plus (CBM ) initiative for weapon systems in the U.S. Department of Defense. The CBM initiative can help increase aircraft availability (AA) for the United States Air Force. There are many reasons where AA can be affected but one such issue is engine availability primarily due to oil issues. Within the CBM perspective, this study examines the risk of a jet engine failure due to an oil issue and attempts to predict an engines time until next …

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Critical Evaluation Of Construction Industry-Related Additive Manufacturing Research: A Scientometric Analysis, Tyler J. Brunjes Mar 2022

Critical Evaluation Of Construction Industry-Related Additive Manufacturing Research: A Scientometric Analysis, Tyler J. Brunjes

Theses and Dissertations

Review of construction-related AM literature is used to identify the advantages, challenges, and current trends of the research. Using a scientometric analysis of 522 bibliographic records, this research systematically analyzed construction related AM research to determine the key research areas and trends. Results showed that starting in 2015, the field has been growing at an exponential rate. Recent AM research focused on materials and reinforcement topics, which matched the most notable challenges of AM, which are material rheology, reinforcement, and lacking construction standards. This study provides an insight into AM research and identifies areas requiring more innovation before its commercial …

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The Cyber Wargame Commodity Course Of Action Automated Analysis Method, Alex Hoffendahl Mar 2022

The Cyber Wargame Commodity Course Of Action Automated Analysis Method, Alex Hoffendahl

Theses and Dissertations

In the modern operational landscape, strategic decisions are made and executed, under uncertain conditions, with many potential constraints and limited information. The end goal of these decisions is to minimize and mitigate the effect of adversarial threats, which may or may not act in line with previous assumptions. Wargaming is a powerful tool that allows for the practical implementation of theoretical knowledge into real-world scenarios, enhancing decision-makers critical thinking and problem solving skills. Furthermore, including cyber-effects in a wargame leads to a broader decision scope for an entire operation. This research aims to enhance the analytical capabilities and overall usability …

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Understanding Logistics Airmen’S Risk Information Seeking And Processing During The Covid-19 Pandemic: The Role Of Organizational Meetings In An Extended Prism Framework, Christopher T. Price Mar 2022

Understanding Logistics Airmen’S Risk Information Seeking And Processing During The Covid-19 Pandemic: The Role Of Organizational Meetings In An Extended Prism Framework, Christopher T. Price

Theses and Dissertations

The purpose of this survey-based research was to understand how organizational workplace meetings surrounding the COVID-19 pandemic impacted logistics Airmen across the United States Air Force and subsequently played a role into their risk seeking behavior on social media. Specifically, this research tested an expanded Planned Information Risk Seeking Model with organizational meetings as an antecedent to determine if current meetings influenced an Airman's perceived behavioral control, attitude toward seeking, subjective norms, knowledge sufficiency an intentions to seek information regarding COVID-19.

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Accelerating Transition To Production By Manufacturing Readiness Focus During Development, William K. Duncan Mar 2022

Accelerating Transition To Production By Manufacturing Readiness Focus During Development, William K. Duncan

Theses and Dissertations

The Department of Defense has adopted management tools, such as Manufacturing Readiness Levels (MRLs), which seek to address issues that have delayed the transition to production and delivery of deployment-ready systems. The MRL scale and assessment process institutes periodic reviews of products during the acquisition process. Specifically, MRLs provide a scale to measure, and importantly communicate, progress by evaluating and summarizing multiple aspects of product maturity. Unfortunately, issues are often identified during the periodic assessments which, if addressed earlier, would have further streamlined product delivery. The current research applies Model Based System Engineering tools to analyze and refine organizational structures …

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Airworthiness Decision Factors In The Us Air Force, Derek N. Dennis Mar 2022

Airworthiness Decision Factors In The Us Air Force, Derek N. Dennis

Theses and Dissertations

There are multiple airworthiness (AW) certification paths for aircraft platforms and their modifications. Specifically, military commercial derivative aircraft (MCDA) have a unique opportunity to pursue either FAA certification, military certification or a combination of both. Policy tells MCDA programs to pursue FAA certification to the maximum extent possible, however, the policy lacks clarity regarding where that extent ends. This concept of extent encompasses multiple factors and the choice of an AW basis is a complex decision. Under ideal conditions the decision maker, the program manager, has the experience and insight to support their decision, however, this is not always the …

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Investigating The Relationship Of Preventive And Corrective Maintenance In Chiller Assets Using Linear Regression Analysis, Jacob A. Franke Mar 2022

Investigating The Relationship Of Preventive And Corrective Maintenance In Chiller Assets Using Linear Regression Analysis, Jacob A. Franke

Theses and Dissertations

Asset managers must balance maintenance plans between preventive (PM) and corrective maintenance (CM). While PM plans have been a staple for decades, the benefits achieved have not been thoroughly examined at the asset specific level. This study focuses on the U.S. Air Force chiller portfolio to better understand the relationship between PM and CM, utilizing multiple stages of linear regression modeling and data from 14 US Air Force installations. PM and CM were found to be positively correlated, with PM accounting for relatively small portions of the variance experienced in CM. This study reveals the value of standardized data collection …

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A Critical Review Of Climate Change On Coastal Infrastructure Systems, Gregory J. Howland Jr. Mar 2022

A Critical Review Of Climate Change On Coastal Infrastructure Systems, Gregory J. Howland Jr.

Theses and Dissertations

This thesis is a response to climate threats identified by DoD report on Climate Change in 2019. A critical review of climate change literature related to coastal infrastructure was conducted to synthesize past research and to inform future research. This review intends to inform how climate change may impact infrastructure systems, how those impacts are evaluated, can the investigation be improved, and what can stakeholders learn from the outcomes. The end goal is to find climate change mitigation strategies and adaptation measures, or identify the easiest path to get to that end. The compiled information will inform civilian and military …

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A Framework For Assessing Facility-Level Vulnerability And Risk To Extreme Weather Events, Blake A. Gawlik Mar 2022

A Framework For Assessing Facility-Level Vulnerability And Risk To Extreme Weather Events, Blake A. Gawlik

Theses and Dissertations

Intensifying extreme weather events, tied to the rise in the global average temperature, put global built infrastructure at risk. This presents a daunting challenge for organizational leaders who are tasked to determine how best to adapt current infrastructure to uncertain future events. To develop adaptation plans and policies, vulnerability and risk must be downscaled to an actionable scale, such that planners, designers, and engineers can make adaptation recommendations. However, previous research has largely assessed risk at coarser scales, e.g., regional, national, or global. These assessments are informative, but do not help those tasked to lead adaptation to make detailed, actionable …

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Magnetic Navigation Using Online Calibration Filter Analysis, Jonnathan D. Bonifaz Mar 2022

Magnetic Navigation Using Online Calibration Filter Analysis, Jonnathan D. Bonifaz

Theses and Dissertations

Magnetic navigation using the Earth’s magnetic anomaly field has proven to be a promising alternative that can provide coverage for a navigation system. This research demonstrates a magnetic navigation system using an extended Kalman filter (EKF) to aid an aircraft’s inertial navigation system (INS). Traditional magnetic anomaly navigation uses a “static calibration method,” which takes post-processed data to calibrate, obtaining the Tolles-Lawson coefficients needed for magnetic anomaly navigation filter compensation. These coefficients are constant and may cause drifts in the navigation filter if not re-calibrated. The online calibration method continuously updates the Tolles-Lawson coefficients as a filter state, reducing the …

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Improving Task-Operator Analysis For Training Through The Integration Of Human Learning Taxonomies And Systems Engineering Models, James M. Earley Mar 2022

Improving Task-Operator Analysis For Training Through The Integration Of Human Learning Taxonomies And Systems Engineering Models, James M. Earley

Theses and Dissertations

Training is a critical part of force sustainment, but the life-cycle cost of recurring training can be quite high. Further, the promotion of the Multi-Capable Airman (MCA) concept leads to questions on how best to train airmen on tasks outside of their core career field. The MCA concept, coupled with continued increase of technology effectiveness, incentivize the replacement of formerly in-residence-only training with distance training that enables Just-in-Time (JIT) learning. However, effective implementation of the MCA concept may also require adaptive training which considers the knowledge, skills, and attitudes (KSAs) developed by a trainee within their core career field when …

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Quantifying Project Complexity To Resource Project Managers, Jereme R. Henrard Mar 2022

Quantifying Project Complexity To Resource Project Managers, Jereme R. Henrard

Theses and Dissertations

This research develops a multi-criteria decision analysis model to quantify project complexity and inform decision-makers in resource-constrained organizations with the Tyndall Program Management Office (PMO) as a case study. The complexity score is used as a risk metric to determine the appropriate number of skilled or novice project managers to effectively manage the PMO portfolio to mitigate cost and schedule overruns. The research provides an innovative approach to consider manning levels at the PMO and other project management-focused organizations/sections.

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Ground Vehicle Navigation With Depth Camera And Tracking Camera, Hongseok Kim Mar 2022

Ground Vehicle Navigation With Depth Camera And Tracking Camera, Hongseok Kim

Theses and Dissertations

The aim of this research is to provide autonomous navigation of a 4 wheel vehicle using commercial, off-the-shelf depth and tracking cameras. Some sensitive operations need accuracy within a few inches of navigation ability for indoor or outdoor scenarios where GPS signals are not available. Combination of the Visual Odometry (VO), Distance-Depth (D-D), and Object Detection data from the cameras can be used for accurate navigation and object avoidance. The Intel RealSense D435i, a depth camera, generates depth measurements and the relative position vector of an object. The Intel RealSense T265, a tracking camera, generates its own coordinate system and …

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Climate Change Risk To Coastal Airfield Stormwater Systems, Jedidiah R. Langlois Mar 2022

Climate Change Risk To Coastal Airfield Stormwater Systems, Jedidiah R. Langlois

Theses and Dissertations

Climate change is resulting in rising sea levels and increased rainfall, posing new challenges to stormwater management, particularly along coastlines. The airfield stormwater systems of Tyndall Air Force Base discharge directly into an interior bay of the Gulf of Mexico through tidal canals and ditches, creating a risk of system inundation from high tidewater conditions from sea-level rise (SLR). This study explores the performance and consequences of an inundated stormwater system from SLR during rainfall events using the EPA’s Stormwater Management Model (SWMM). One hundred and fifty-three combinations of SLR and return year storms were applied to a model of …

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System Phasing And Schedule Growth Analysis, Daniel A. Long Mar 2022

System Phasing And Schedule Growth Analysis, Daniel A. Long

Theses and Dissertations

Software development research, once a priority for the DoD, has received less focus in recent years. What research that has occurred has focused on size and cost prediction of software. Generally lacking in these studies is analysis on phase distributions and schedule. Putnam (1978) showed that there were measurable effects between early program management and final schedule growth, but these relationships have not been explored using the 2001-2021 DoD Software Resources Data Report (SRDR) database. Additionally, industry software development guidance provides rules of thumb for effort allocation, but a comparison of the rules to DoD software projects is nonexistent. This …

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Characterizing Complex-Valued Neural Network Model Approximations Of 4-Input 4-Output Complex-Valued Reference Block Models, Larry C. Llewellyn Ii Mar 2022

Characterizing Complex-Valued Neural Network Model Approximations Of 4-Input 4-Output Complex-Valued Reference Block Models, Larry C. Llewellyn Ii

Theses and Dissertations

System simulation models are often decomposed and abstracted as a collection of interconnected subsystem block models to facilitate system understanding, design, and analysis. Each subsystem block model contains mathematical functions that receive, process, and transmit signals that are modeled as real numbers, complex numbers, and/or logic values. This dissertation evaluates the use of a single two-layer complex-valued neural network model to approximate 4-input, 4-output subsystem reference block models in terms of accuracy, performance, and error. The research is novel in that it uses a neural network for continuous function approximation instead of data categorization; it uses a neural network designed …

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Developing An Adaptable Best Value Contractor Selection Tool For Federal Construction Projects, Robert B. Kitson Mar 2022

Developing An Adaptable Best Value Contractor Selection Tool For Federal Construction Projects, Robert B. Kitson

Theses and Dissertations

Currently, there is no Air Force-wide best practice or standard for using an other-than lowest price source selection process for construction projects. Installations often award contracts using Lowest Price Technically Acceptable (LPTA) because of perceived cost and time savings. However, a heavy reliance on LPTA often leads to long-term decreases in quality and value. To allow the Air Force to receive the best value for its construction funding, a simple and adaptable tool was developed that allows installations to pursue contractor selection for construction projects by other-than lowest price methods. This research conducted a systematic literature review to obtain a …

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Development And Assessment Of A Model-Based Framework On User Toolkits, Brandon J. Koury Mar 2022

Development And Assessment Of A Model-Based Framework On User Toolkits, Brandon J. Koury

Theses and Dissertations

The Department of Defense (DoD) has a limited number of resources to accomplish a variety of missions which involve deploying personnel to support and maintain aircraft operating throughout the world. The DoDs maintenance structure codes maintainers to perform maintenance on specific airframes. This structure limits the flexibility of maintainers and leads to deploying resources in a reactionary manner to address capability gaps in deployed environments. The Just-In-Time Multi-Mission Airman (JIT MMA) concept aims to resolve these issues. Currently, the necessary technologies are unknown, but user toolkits are a concept to consider. A user toolkit is a concept that allows users …

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A Scientometric Analysis Of Smart Sensors In Facility Management And Applications In Air Force Operations, Joseph-Thomas H. Lehotsky Mar 2022

A Scientometric Analysis Of Smart Sensors In Facility Management And Applications In Air Force Operations, Joseph-Thomas H. Lehotsky

Theses and Dissertations

To investigate the areas which smart sensors can be implemented to assist facility managers to optimize limited resources, this research consists of a scientometric analysis to identify the areas of research quantitatively and qualitatively. Existing literature related to smart sensors in facility management operations were compiled and trends were analyzed to determine the ways in which researchers have been applying this technology. The title, abstracts, and keyword were used to perform frequency, networking, and clustering analysis. This research effort serves to provide ways in which Air Force installations can implement smart sensors in a way which fulfills the initiatives posed …

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Investigation Into Engineering Change Order Costs And Appropriate Rules-Of-Thumb, Kaiana M. Miller Mar 2022

Investigation Into Engineering Change Order Costs And Appropriate Rules-Of-Thumb, Kaiana M. Miller

Theses and Dissertations

Engineering Change Orders (ECO) are technical requirements changes to existing contracts. To account for the potential increase in contract costs stemming from ECOs, current acquisition practice is to estimate a dollar value to hold in management reserve (MR) in case of ECO occurrence. Estimators often rely on rules-of-thumb when developing these estimates. Specifically, estimators use a 10% rule-of-thumb for estimating MR contract costs in the Development life cycle phase and a 5% rule-of-thumb for contracts in the Production or O&S life cycle phase. However, no empirical data supports or validates these 10% and 5% figures. Using a new data source, …

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A Post-Disaster Construction Portfolio Optimization Framework For Tyndall Afb Rebuild Post Hurricane Michael, Andre J. May Mar 2022

A Post-Disaster Construction Portfolio Optimization Framework For Tyndall Afb Rebuild Post Hurricane Michael, Andre J. May

Theses and Dissertations

Natural disasters such as hurricanes, earthquakes, tsunamis, and extreme flooding cause severe social and economic disruptions. Restoration of social and revenue-generating services often requires extensive reconstruction, from the facility to the campus scale. For multi-facility portfolios, decision-makers must prioritize post-disaster reconstruction activities appropriately to ensure facilities and infrastructure are restored. In addition, any expansion or new construction initiatives are ideally completed in order of decision-maker and community preference. Most post-disaster optimization and decision framework research consider a single stakeholder as guiding decisions related to a project portfolio. However, these portfolio prioritization frameworks ignore the effect of multiple stakeholders and competing …

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Efficiency Mapping And Determination Of Reliability, Resiliency And Vulnerability Of Atmospheric Water Generators In The United States, Erica F. Sadowski Mar 2022

Efficiency Mapping And Determination Of Reliability, Resiliency And Vulnerability Of Atmospheric Water Generators In The United States, Erica F. Sadowski

Theses and Dissertations

Atmospheric Water Generators (AWG) extract water from the air using one of three available technologies: refrigeration, sorption, and fog harvesting. A refrigeration device works like a dehumidifier and works best in conditions above 60% relative humidity. A sorption device utilizes a desiccant to extract the water vapor from the air and works in very low humidity levels. A fog harvesting device utilizes a mesh to capture the water vapor from the air and requires 100% relative humidity. In this research, I analyze two refrigeration-based devices and one sorption-based device and their efficacy in providing supplemental water supply. Due to climatological …

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Persistence And Mitigation Of Pfas Within Concrete Stormwater Drainage Infrastructure, Jason R. Mcdonald Mar 2022

Persistence And Mitigation Of Pfas Within Concrete Stormwater Drainage Infrastructure, Jason R. Mcdonald

Theses and Dissertations

The persistence, fate, and transport of per- and poly-fluoroalkyl substances, which have been shown to have adverse effects on human health, have been previously studied in environmental media such as soils and groundwater. This study investigates concrete, a medium that is rarely studied but frequently present in instances where PFAS originating from AFFF releases and spills have occurred. Used heavily throughout aviation firefighting, AFFF poses environmental hazards due to the length of PFAS degradation and toxicological implications, thus its classification as a forever chemical. From the very limited reports to date, studies have suggested very slow release from concrete, potentially …

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A Decadal Analysis Of Shifts In Engineering Manufacturing Development Factors For Dod Assets, Michael J. Smith Mar 2022

A Decadal Analysis Of Shifts In Engineering Manufacturing Development Factors For Dod Assets, Michael J. Smith

Theses and Dissertations

This research involves the analysis of standard parametric factors by decade within the development stage of acquisitions. Analysts use factors to develop budgets, create a baseline for measuring project progress, or as a crosscheck to the other estimating techniques. This research analyzed data from 408 1921s across seven decades and eight work breakdown structure (WBS) elements. It further analyzed these decades by commodity type, contract and contractor type, and service branch. The statistical tests used in this research determined which decades within our categories were dissimilar and drew conclusions about the impact of those differences. These tests determined that factors …

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Application Of Machine Learning Models With Numerical Simulations Of An Experimental Microwave Induced Plasma Gasification Reactor, Owen D. Sedej Mar 2022

Application Of Machine Learning Models With Numerical Simulations Of An Experimental Microwave Induced Plasma Gasification Reactor, Owen D. Sedej

Theses and Dissertations

This thesis aims to contribute to the future development of this technology by providing an in-depth literature review of how this technology physically operates and can be numerically modeled. Additionally, this thesis reviews literature of machine learning models that have been applied to gasification to make accurate predictions regarding the system. Finally, this thesis provides a framework of how to numerically model an experimental plasma gasification reactor in order to inform a variety of machine learning models.

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Natural Infrastructure Alternatives Mitigate Hurricane-Driven Flood Vulnerability: Application To Tyndall Air Force Base, Kiara L. Vance Mar 2022

Natural Infrastructure Alternatives Mitigate Hurricane-Driven Flood Vulnerability: Application To Tyndall Air Force Base, Kiara L. Vance

Theses and Dissertations

Hurricane frequency and magnitude intensification are expected over the remainder of the twenty-first century. Uncertainty in future projections requires that coastal communities approach adaptation decisions with caution. Traditional approaches are costly and inflexible. Soft policy adaptations are largely unenforceable. Hard, natural adaptations have emerged as an opportunity to partially mitigate the growing risk of extreme flooding, without the large investments required for traditional approaches, where natural infrastructure already exists. Existing literature for natural adaptations has not leveraged intensification expectations for hurricane events. This research uses multihazard damage evaluation software and spatial analysis to investigate placement of dredged sediment as a …

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