Digital Commons Network^™

Advancing Vapor Intrusion Science Using Systematic Frameworks To Foster Informed Decision Making, Hong Cheng Tay

Theses and Dissertations--Civil Engineering

Vapor intrusion, the migration of subsurface vapors into indoor air spaces, is an important source of indoor air contamination to consider at hazardous waste sites contaminated by volatile organic compounds (VOCs). There is considerable uncertainty and variability in the factors that influence vapor intrusion processes, which poses a significant challenge for decision making, despite advancements in vapor intrusion science. This dissertation consolidates knowledge from existing scientific advances and investigates scientific gaps associated with the vapor intrusion preferential pathway conceptual model (i.e. conduit vapor intrusion), associated with the vapor entry pathway into buildings via sewer systems. The overall goal of this …

Acoustic Characterization Of A Quadcopter Using A Test Stand, Jared Schmal

Theses and Dissertations--Mechanical and Aerospace Engineering

Unmanned Aerial Vehicles (UAVs) with multirotor propulsion and control, commonly called drones or multicopters, generate a complex acoustic field that is not entirely understood. Many components and their interactions contribute to the overall noise level and behavior of the acoustic field. However, performing acoustic measurements on a multicopter in a confined space, such as a small anechoic chamber, can be an extremely difficult and time-consuming process. A test stand was developed to allow for rapid and safe acoustic measurements in a controlled environment. The design, development, and initial measurements are discussed. The performance and acoustic response are assessed to examine …

Optimal Subspace Estimation For Linear Nested Arrays: Applications And Performance Metrics, Brendan Dunn

Open Access Master's Theses

OSE (Optimal Subspace Estimation) is an algorithm that obtains an estimated subspace from structured data observed in noise. While OSE is able to obtain an accurate subspace estimate with a small number of snapshots, it has not been demonstrated how this affects the performance of many applications that leverage OSE. One such application is beamforming; Using an OSE-based beamformer, this thesis will apply common performance metrics to measure how much of an advantage an accurate subspace estimate provides. This algorithm will be compared against other widely used beamformers such as MPDR and DMR to benchmark its efficacy. Mismatch is then …

A Governance-Centric Framework For Strengthening Healthcare Cybersecurity: A Systems Perspective, Sujatha Alla, Sai Gireesh Komaragiri, Teresa Duvall, Satluk Karahan, Nagesh Bheesetty, Vijay Kumar Chattu

Engineering Management & Systems Engineering Faculty Publications

Healthcare systems face unprecedented security and privacy challenges due to increasing digitization and interconnectedness. This paper provides a comprehensive analysis of these challenges by examining various cyberattacks, defensive mechanisms, and governance frameworks within modern healthcare infrastructure. The research systematically categorizes prevalent security threats, such as ransomware, insider threats, and data breaches, identifying vulnerabilities specific to healthcare systems. Furthermore, the study evaluates current defensive strategies, including encryption techniques, access control systems, and intrusion detection tools, assessing their effectiveness against complex cyber threats. A key focus is placed on governance structures and their role in cybersecurity resilience. The research explores how regulatory …

Secured Communication And Coexistence For Efficient Spectrum Utilization, Xue Wei

Electronic Theses & Dissertations (2024 - present)

Over the years, the demand for wireless communications has grown exponentially, resulting in a scarcity of available spectrum. This scarcity leads to the need for efficient spectrum utilization, a key factor in ensuring reliable and uninterrupted communications. One of the key challenges in achieving reliable communication is ensuring secure transmissions to protect the privacy and integrity of data for active users. Wireless communications are vulnerable to eavesdropping, interception, and unauthorized access, which can compromise the confidentiality and integrity of transmitted data. The coexistence of multiple wireless communication systems is another challenge to be addressed for passiver users. In many cases, …

Kinetic Takedown Methods For Unmanned Aerial Systems (Uas), Boston John

Space Dynamics Laboratory Publications

Drone Swarms

• Difficult to detect

• Can overwhelm defense systems

• Low cost makes them ideal for tactical warfare

Visible Modulation Of Epsilon Near Zero Materials, Jonathan M. Weber

Theses and Dissertations

While Epsilon-Near-Zero materials have offered many benefits from their introduction to the field of nonlinear optics, those materials have also narrowed the range of wavelengths often studied. With reliable and proven enhancements to light-matter interaction in the ENZ region, many researchers have had little reason to extend the spectrum measured in experiments. The purpose of this work is to measure the intensity dependent refractive index of Indium Tin Oxide across a broad spectral range, from ultraviolet to near infrared, to improve the understanding of semiconductor nonlinearities far from Lorentz and Drude resonances. Furthermore, the visible region is naturally low-loss in …

Reverse Geometric Dispersion In The Beaufort Sea: Dissecting Sound Propagation At Long Ranges In Ducted Profiles, Jessica Desrochers

Open Access Dissertations

Acoustic propagation in the Arctic is evolving as surface temperatures increase and ice melts, resulting in a changing sound propagation environment. This study investigates the acoustic arrival structure in the Canada Basin and its connection to the underlying sound speed profiles. Two Seagliders were deployed in the summer of 2016 and 2017, diving in a sawtooth pattern collecting conductivity, temperature, and depth (CTD) data as part of the Canada Basin Acoustic Glider Experiment (CABAGE). These data are used to calculate sound speed profiles used to predict and understand acoustic arrival structures.

The warming of the Pacific Summer Water and surface …

Afit Generative Ai Teaching Guidebook, Afit Faculty Learning Community, Mark G. Bateman, Brett J. Borghetti, Allen W. Dukes, Nicholas C. Francis, Mike Frick, Bobbie Oh, Kevin Patterson, Hiren J. Patel, Mark G. Reith, Erick S. Tyndall, Teresa M. Walton, Torrey J. Wagner, Timothy S. Wolfe, Jonathan Zemmer

AFIT Documents

AFIT is proud to highlight the Generative AI Teaching Guidebook, a resource designed to provide military educators with practical insights, strategies, and use cases for integrating Generative AI (Gen AI) into their teaching practices. Developed through a collaborative effort involving AFIT faculty across various departments within the Graduate School of Engineering and Management and the School of Systems and Logistics, this digital resource serves as a starting point for educators exploring how to leverage Gen AI in their classrooms. It offers accessible examples and best practices, ensuring utility for instructors of all technical backgrounds. The guidebook provides a comprehensive overview …

Efficient Oxidation Of Methylene Blue Via Catalytic Activation Of Peroxymonosulfate Via An Engineered Δ-Feooh/Pili Nutshell Biochar Composite, Lorenz Borromeo

Applied Environmental Research

This study introduces a novel composite catalyst formed by anchoring delta iron oxyhydroxide (δ-FeOOH) onto pyrolyzed Pili nutshell biochar via a room-temperature coprecipitation technique, marking the first application of Pili nutshell waste in advanced oxidation processes for wastewater treatment. This innovative methodology enhances catalyst dispersion and stability, facilitating the activation of peroxymonosulfate (PMS) to generate reactive sulfate radicals (SO4•–) for the degradation of methylene blue (MB), a thiazine dye commonly used in the medical field and the dye industry. Different techniques have been used to characterize synthesized composites in terms of their morphology, elemental composition, surface functional groups, and crystalline …

The Space Rescue Professional: Operationalizing Guardians For The Future, Benjamin Johnis, Robert Bettinger, James Dean

Faculty Publications

The escalating competition in space exploration demands a dedicated space rescue capability. This article argues for the establishment of a space rescue professional (SRP) career field within the Department of Defense and the US Space Force. By harnessing existing US Air Force combat rescue expertise and partnering with the National Aeronautics and Space Administration, the Space Force can rapidly develop a robust SRP program with the warrant officer corps as its backbone. This article addresses a critical gap in national space policy to outline a cost-effective dual-service training pipeline and SRP operational roles. Such an investment safeguards astronauts, bolsters US …

Microwave Absorption Properties Of Porous Activated Carbon/Nickel Oxide Composites Derived From Coconut Husks, Mohamad Zul Aqiman Shukeri, Nor Zakiah Yahaya, Ezzan Afifah Zainuddin, Nazri Mahmud, Liyana Zahid, Hasliza A. Rahim

Journal of Metals, Materials and Minerals

Porous Activated Carbon (AC) is a promising material for microwave absorbing materials, showing potential in communication and modern warfare. The study explores the process of creating porous AC from coconut husks using hydrochloric acid and carbonization at varying temperatures, followed by doping AC with nickel oxide to create an AC/NiO polymer composite with varying thicknesses. These composites are compared to AC composites loaded in a paraffin matrix. The dielectric and microwave (MW) properties of the AC/NiO and AC polymer composites at various thicknesses were analyzed using a Performance (PNA)-X Network Analyzer. The study also examines the carbon content and porosity …

Decomposition Of Diisopropyl Methylphosphonate (Dimp) Exposed To Elevated Temperatures And Combustion Products Of Reactive Materials, Elif Irem Senyurt

Dissertations

The safe and efficient destruction of chemical weapon agents (CWAs) stockpiles remains a critical global challenge. Understanding the thermophysical properties, decomposition mechanisms, and interactions of CWAs with their environment is crucial for developing effective strategies to mitigate their threats. Diisopropyl methylphosphonate (DIMP) and Dimethyl methylphosphonate are commonly used nerve agent surrogates. This dissertation focuses on DIMP and DMMP, investigates their properties and behavior under conditions relevant to prompt defeat scenarios.

The thermophysical properties of DIMP and DMMP were experimentally characterized, including vapor-liquid surface tension (3-60 °C) and viscosities of neat and aqueous solutions. Results revealed significant non-ideal behavior in aqueous …

End-To-End Autonomous Quadcopter Using Reinforcement Learning, Mohamed Marwan Chawa

Theses and Dissertations

This thesis investigates the potential of Reinforcement Learning (RL) for achieving robust and adaptable quadcopter control, focusing on trajectory and attitude stabilization. We compare state-of-the-art RL algorithms, specifically Proximal Policy Optimization (PPO), against traditional Proportional-Integral-Derivative (PID) controllers across three tasks: hovering, slow trajectory following, and fast trajectory following. To enhance realism, we employ a modified PyFlyt simulation environment with a high-fidelity Crazyflie 2.x model, accounting for motor dynamics, noise, wind disturbances, and aerodynamic drag.

The challenge of operating a quadcopter can be divided into two distinct parts: planning a flight path and actually following that path. Our focus is on …

The Coalition Development Of Allied Close Air Support Doctrine During World War Ii, David S. Stieghan

Doctoral Dissertations and Projects

This research aims to discover how the American and British air forces worked collaboratively to provide ground support to their armies in Europe during World War II. While the official histories and scholars of the two countries concentrate on their unique national efforts, they analyze little of their cooperative efforts. By examining primary and secondary research sources to discover the experiments, doctrine development, and combat experience of both air forces, an understanding emerges that both nations combined their efforts in World War II in separate directions until beginning to work together on planning for the D-Day invasion.

By discovering the …

Predicting Chaotic Systems With Quantum Echo-State Networks, Erik Connerty, Ethan N. Evans, Gerasimos Angelatos, Vignesh Narayanan

Publications

Recent advancements in artificial neural networks have enabled impressive tasks on classical computers, but they demand significant computational resources. While quantum computing offers potential beyond classical systems, the advantages of quantum neural networks (QNNs) remain largely unexplored. In this work, we present and examine a quantum circuit (QC) that implements and aims to improve upon the classical echo-state network (ESN), a type of reservoir-based recurrent neural networks (RNNs), using quantum computers. Typically, ESNs consist of an extremely large reservoir that learns high-dimensional embeddings, enabling prediction of complex system trajectories. Quantum echo-state networks (QESNs) aim to reduce this need for prohibitively …

Air Supremacy, The Enabler Of Close Air Support Operations – An Evaluation Of Past, Present, And Future Air Campaigns., Owen Topolnicki

Senior Honors Theses

The achievement of gaining aerial supremacy, or lack thereof, is the hinge upon which Close Air Support (CAS) swings. The attainment of it enables CAS specialist aircraft, not unlike the Ju-87 Stuka or A-10 Thunderbolt II, to be exceptionally effective in their operating environment. While the lack of it, forces aircrews to pioneer new solutions either in the form of multi-role aircraft (capable of self-defense), or other innovative solutions similar to unmanned aerial systems (UAS’s), as aptly seen in the ongoing Russo-Ukrainian conflict. Thus, the ability of an air force to gain air supremacy and to do so quickly, …

Ai, American Politics, And Modern Warfare, Madisen Campbell

Space and Defense

As artificial intelligence (AI) transforms modern warfare, it will pose profound ethical challenges for America’s constitutional democracy.

Technological advancements in the world today, particularly the field of artificial intelligence (AI), impact the current political system in the United States. The importance of understanding and addressing the complex challenges and opportunities of incorporating AI into American politics is key to developing a profound understanding of AI in modern warfare and the implications it has for policy making in America. The need for policy makers and military leaders to receive insight on the development of AI and to develop strategic approaches for …

Earth To Orbit: Three Models For Strengthening Space Deterrence, Anton Dahm

Space and Defense

Nuclear, cyber, and integrated deterrence models hold lessons for space deterrence strategy, including declared thresholds, resilient space architecture, and the embrace of international competition in technological innovation.

The United States depends heavily on space capabilities, significantly more than any other country. Not only does space enable navigation, communications, environmental monitoring, and other vital capabilities, but space has also been described as the most essential warfighting domain. However, the U.S. space architecture mirrors its early days: relying on important, expensive payloads on a limited number of satellites. While providing important capabilities to U.S. decision-makers, kinetic and non-kinetic weapons can easily target …

Strategic Space Cooperation: U.S. Space Command And The National Guard’S State Partnership Program, David Moore, Jesse Morehouse, Patrick Mitchell

Space and Defense

In 2022, the U.S. Space Command (USSPACECOM) and the National Guard's State Partnership Program (SPP) began pursuing security cooperation objectives while integrating the space domain into greater deterrence efforts. As the newest combatant command (CCMD) with space as its Area of Responsibility (AOR), USSPACECOM has global strategic partnership interests and recognizes the value of the enduring relationships inherent in SPP. This cooperation allows the National Guard to offer its strong relationships, space expertise, and industry knowledge to USSPACECOM. This provides a foundation for USSPACECOM's security cooperation efforts. This article discusses the SPP's role in supporting USSPACECOM's engagement strategy and the …

A Premature Obituary For Conventional Deterrence, Jeffery S. Lehmkuhl

Space and Defense

As the United States (US) continues to shift its weight of effort towards great power competition, some scholars and practitioners have questioned the relevance of conventional forces and their ability to deter. Chief among them is Sean McFate, who asserts that “conventional war is unicorn hunting” and that “no one fights that way anymore.”1 Jim Sciutto echoes McFate’s claims in his book The Shadow War and states that the US is losing to Russia and China in a new way of warfare that is conducted below the threshold of conventional warfare.2 Leading Russian General Valery Gerasimov furthered this claim when …

Nuclear Regimes In The 21st Century, Stephen J. Cimbala, Adam Lowther

Space and Defense

The modern nuclear operations practitioner is facing a more complex future than at any point since the height of the Cold War. Understanding the past, present, and possible future of nuclear force structure and doctrine offers the policy maker a useful way to make sense of unfolding events and place them within a broader context. With China, Russia, and North Korea all posing a growing nuclear risk to the United States, a strong grasp on the available options for countering these threats is certainly important.

Table Of Contents Vol. 15 No. 2

Space and Defense

No abstract provided.

Space And Defense Vol. 15 No. 2 Fall 2024 (Whole Issue)

Space and Defense

No abstract provided.

Unveiling The Shadows: The Influence Of Anonymity And Fake Accounts On Cyberbully Intention In Social Media, Muzdalini Malik, Hapini Awang, Nur Suhaili Mansor, Mohamad Fadli Zolkipli, Khuzairi Mohd Zaini, Abdulrazak F. Shahatha Al-Mashhadani

Iraqi Journal for Computer Science and Mathematics

Cyberbullying has arisen as a prevalent and worrying issue in the digital age, substantially influencing the well-being and mental health of social media users. Previous studies have identified several factors and theories of cyberbullying. Still more in-depth research is required to understand the key factors influencing cyberbullying intention in social media. This study aims to identify the factors influencing cyberbullying intention in social media and examine the moderating effect of fake accounts on cyberbullying intention. An extensive literature review has been conducted to examine the gaps in existing studies on cyberbullying intention. As a result, this study uses the Theory …

Space Operations Education Research: Studying Undergraduate Experiences As Predictors Of Early Career Performance For Military Space Operations Officers, Keith Balts

All Dissertations

Undergraduate students who go on to operate space systems, e.g., satellites, launch systems, and ground-based systems, come from a diverse set of demographics and undergraduate experiences. The United States Space Force (USSF), and United States Air Force (USAF) before them, like many professions, have a demonstrated interest in who enters their ranks, but have had limited research available to them to inform their recruiting, selection, training, and early career development policies and processes.

This Profession-Based Education Research study, a term introduced here in contrast to Discipline-Based Education Research, focused on the military space operations profession. This study analyzed newly commissioned …

Clusteredlog: Optimizing Log Structures For Efficient Data Recovery And Integrity Management In Database Systems, Mariha Siddika Ahmad, Brajendra Panda

Electrical Engineering and Computer Science Faculty Publications and Presentations

In modern database systems, efficient log management is crucial for ensuring data integrity and facilitating swift recovery from potential data corruption or system failures. Traditional log structures, which store operations sequentially as they occur, often lead to significant delays in accessing and recovering specific data objects due to their scattered nature across the log. ClusteredLog addresses the limitations of traditional logging methods by implementing a novel logical organization of log entries. Instead of simply storing operations sequentially, it groups related operations for each data item into clusters. As a result, ClusteredLog enables faster identification and recovery of damaged data items …

Hydraulic Boundary Conditions Determine Biofilm Growth Patterns And Permeability In Groundwater, Jason Tyler Mick

Boise State University Theses and Dissertations

Biofilms are naturally occurring consortia of bacteria that colonize porous media such as streambed sediments, soils, and aquifers. Biofilm growth leads to clogging (i.e., bioclogging), which reduces the porosity and permeability of the porous medium and directly influences how nutrients and contaminants are transported and transformed in groundwater. To improve our understanding of how bioclogging regulates nutrient and contaminant fluxes, we must better characterize how flow conditions influence the spatial and temporal progression of biofilm growth within natural porous media geometries, as well as understand how this progression alters fluid flow.

In this study, I conducted microfluidic experiments to test …

Strategies To Alleviate Flickering: Bayesian And Smoothing Methods For Deep Learning Classification In Video, Noah Miller, Glen Ryan Drumm, Lance Champagne, Bruce A. Cox, Trevor Bihl

Faculty Publications

Excerpt: Increasing reliance on autonomous systems requires confidence in the accuracies produced from computer vision classification algorithms. Computer vision (CV) for video classification provides phenomenal abilities, but it often suffers from “flickering” of results. Flickering occurs when the CV algorithm switches between declared classes over successive frames. Such behavior causes a loss of trust and confidence in their operations.

Integrating Humanities Into Cybersecurity Education: Enhancing Ethical, Historical, And Sociopolitical Understanding In Technical Training, Joseph Frusci

Journal of Cybersecurity Education, Research and Practice

The increasing complexity of cybersecurity challenges necessitates a holistic educational approach that integrates both technical skills and humanistic perspectives. This article examines the importance of infusing humanities disciplines such as history, ethics, political science, sociology, law, and anthropology—into cybersecurity education. Through a pilot course developed for Staten Island Technical High School, aligned with the New York State K-12 Computer Science and Digital Fluency Standards, students were introduced to an interdisciplinary curriculum that combined technical cybersecurity training with historical analysis, ethical reasoning, and sociopolitical context. The results of pre- and post-course assessments demonstrated significant improvements in critical thinking, ethical decision-making, and …