Engineering Commons^™

Securing Critical Infrastructure: A Ransomware Study, Blaine M. Jeffries

Theses and Dissertations

This thesis reviews traditional ransomware attack trends in order to present a taxonomy for ransomware targeting industrial control systems. After reviewing a critical infrastructure ransomware attack methodology, a corresponding response and recovery plan is described. The plan emphasizes security through redundancy, specifically the incorporation of standby programmable logic controllers. This thesis goes on to describe a set of experiments conducted to test the viability of defending against a specialized ransomware attack with a redundant controller network. Results support that specific redundancy schemes are effective in recovering from a successful attack. Further experimentation is conducted to test the feasibility of industrial …

Plasmonic Grating Geometrics And Wavelength-Dependent Focus Depth In Infrared Detectors, Patrick R. Kennedy

Theses and Dissertations

The objective for this research is to determine a relationship between plasmonic grating geometries and the wavelength-dependent focus depth. This research is focused on enhancing the signal collected by infrared detectors by using a metal grating as a planar lens to focus light in the detecting region of the substrate. This can be used to maintain a thinner absorbing region and possibly to create multi-color imaging in a single pixel. Simulations demonstrate that the plasmonic lens is capable of creating a wavelength dependent focus spot.

Bandwidth Analysis Of A Tightly-Packed Crossed-Dipole Array For Satellite Communications, Lawrence J. Lee

Theses and Dissertations

A bandwidth analysis of a tightly-packed crossed-dipole array antenna is presented in this thesis. A parametric study is described which varies the element spacing in the array and the resulting change in the terminal impedances is reported. The increased mutual coupling seen by the elements as a result of smaller element spacings is shown to minimize the variation in the value of the elements terminal currents across a 0.3 GHz to 3.0 GHz frequency range. This small variation in current translates into a minimal variation in the terminal impedances for a fixed excitation voltage. This is shown to be an …

Quality Of Service Impacts Of A Moving Target Defense With Software-Defined Networking, Samuel A. Mayer

Theses and Dissertations

An analysis of the impact a defensive network technique implemented with software-defined networking has upon quality of service experienced by legitimate users. The research validates previous work conducted at AFIT to verify claims of defensive efficacy and then tests network protocols in common use (FTP, HTTP, IMAP, POP, RTP, SMTP, and SSH) on a network that uses this technique. Metrics that indicate the performance of the protocols under test are reported with respect to data gathered in a control network. The conclusions of these experiments enable network engineers to determine if this defensive technique is appropriate for the quality of …

Assessment Of Structure From Motion For Reconnaissance Augmentation And Bandwidth Usage Reduction, Jonathan B. Roeber

Theses and Dissertations

Modern militaries rely upon remote image sensors for real-time intelligence. A typical remote system consists of an unmanned aerial vehicle, or UAV, with an attached camera. A video stream is sent from the UAV, through a bandwidth-constrained satellite connection, to an intelligence processing unit. In this research, an upgrade to this method of collection is proposed. A set of synthetic images of a scene captured by a UAV in a virtual environment is sent to a pipeline of computer vision algorithms, collectively known as Structure from Motion. The output of Structure from Motion, a three-dimensional model, is then assessed in …

Expected Coverage (Excov): A Proposal To Compare Fuzz Test Coverage Within An Infinite Input Space, Evan V. Swihart

Theses and Dissertations

A Fuzz test is an approach used to discover vulnerabilities by intentionally sending invalid inputs to a system for the purpose of triggering some type of fault or unintended effect that renders the system vulnerable to an exploit. Fuzz testing is an important cyber-testing technique used to find and fix vulnerabilities before they are exploited. The fuzzing of military data links presents a particular challenge because existing fuzzing tools cannot be easily applied to these systems. As a result, the tools and techniques used to fuzz these links vary widely in sophistication and effectiveness. Because of the infinite, or nearly …

Securing Data In Transit Using Two Channel Communication, Clark L. Wolfe

Theses and Dissertations

Securing data in transit is critically important to the Department of Defense in todays contested environments. While encryption is often the preferred method to provide security, there exist applications for which encryption is too resource intensive, not cost-effective or simply not available. In this thesis, a two-channel communication system is proposed in which the message being sent can be intelligently and dynamically split over two or more channels to provide a measure of data security either when encryption is not available, or perhaps in addition to encryption. This data spiting technique employs multiple wireless channels operating at the physical layer, …

Flightline Heroics And The Façade Of A Healthy Common Support Equipment Fleet, Benjamin D. Bobic

Theses and Dissertations

Access to serviceable support equipment enables aircraft maintenance crews the ability to efficiently keep assigned aircraft safe and mission capable. Current Air Force policy does not require formal management and enterprise fleet health reporting of serialized support equipment. As such, articulating funding requirements to replace equipment has been a challenge for equipment managers. To better articulate support equipment requirements, equipment managers need quantifiable support equipment data. A previous study examined the relationship between aircraft availability and support equipment availability. While finding no significant correlation, the author identifies the practices of "Frankensteining" and "Beg-Borrow-Steal" as possible reasons for the absence of …

Evaluating Contingency Construction Methods: A Delphi Study, William E. Bentley

Theses and Dissertations

The purpose of this research was to evaluate which existing RED HORSE vertical construction system was “best” suited for contingency operations and the relative pros/cons/challenges associated with each. RED HORSE units, having existed for over 50 years, currently have 4 active duty squadrons currently employed overseas in multiple military contingency environments. Based on site visits, it was established that the Ultimate Building Machine (UBM)/K-Span, Professionally Engineered Buildings (PEB), and the FrameCAD system are the three most prevalent vertical construction systems/methods in use by RED HORSE. Fourteen Subject Matter Experts (SME) from across the Air Force participated in a Delphi study …

Defining Success In Air Force Infrastructure Asset Management Through Use Of The Delphi Method, Brendan J. Maestas

Theses and Dissertations

Asset Management has a history of policy mandates within the US Government dating back to 1990’s. In order to accomplish these many directives, the Air Force Civil Engineer community has adopted a mindset and framework commonly referred to as Asset Management. Despite numerous references and guidance to establish Asset Management principles, the Air Force has not yet developed a clear and concise way to define or measure overarching success in Asset Management. This research effort focuses on closing the knowledge gap between issued policy and implementation. It examines Asset Management implementation efforts in other government agencies, private industries, and in …

Cost And Performance Difference Of High Performance Sustainable Buildings, Philip A. Ramsey

Theses and Dissertations

Varying legislation and executive orders coupled with needs for energy resiliency have led the United States Air Force to pursue sustainable construction. The limited understandings of initial costs to implement these changes have contributed to poor project cost estimating and changed implementation of legal requirements. A student t-test for populations with unequal variance was accomplished on the final normalized contract cost of 1628 Air Force Military Construction (MILCON) projects executed between 2002 and 2017. Future design considerations for net zero energy buildings were compiled from a net zero energy residential community in Fontana, California. There was no statistically significant difference …

Conceptual Systems Security Analysis Aerial Refueling Case Study, Martin Trae Span Iii

Theses and Dissertations

In today’s highly interconnected and technology reliant environment, systems security is rapidly growing in importance to complex systems such as automobiles, airplanes, and defense-oriented weapon systems. While systems security analysis approaches are critical to improving the security of these advanced cyber-physical systems-of-systems, such approaches are often poorly understood and applied in ad hoc fashion. To address these gaps, first a study of key architectural analysis concepts and definitions is provided with an assessment of their applicability towards complex cyber-physical systems. From this initial work, a definition of cybersecurity architectural analysis for cyber-physical systems is proposed. Next, the System Theory Theoretic …

A Study Of The Air Force Airworthiness Assessment Process With Recommendations For Reusable Launch Vehicles, Austin A. Troya

Theses and Dissertations

Flight safety is a critical design and engineering consideration within the United States Department of Defense (DoD) and particularly the United States Air Force (USAF). This study conducts an independent evaluation of the airworthiness assessment process used by the United States Air Force’s Engineering Directorate through modeling and simulation. The airworthiness process is examined for its ability to effectively verify sound engineering design and efficiency with respect to the implementation of new software-based assessment tools and its impact on timeliness of reviews and resource utilization. Simulation results guide recommendations for reducing non-value-added activities and strategic leveling of resource demands to …

Land Cover Influences On Airborne Noise Propagation At Usaf Installations, Ariel L. Waiters

Theses and Dissertations

Mitigation of aircraft noise and encroachment by residential areas at various U.S. military installations remains a challenge and hampers effective military operations. The Air Force has established standard practices that utilize computational noise models to generate and display noise propagation from military installations. Despite great advances in models and mitigation action plans, the current USAF Noisemap modeling tool and methods do not consider the effects of variation in land cover. Moreover, such limitations could greatly affect the accuracy of predicting aircraft noise pollution. The standard modeling method assumes a ground cover impedance of 225 ^Kpa*s/_m², which …

An Open Source Approach To Social Media Data Gathering, Anthony J. Kallhoff

Theses and Dissertations

Modern usage of social media affords the military intelligence and analytic communities novel approaches to gather information. However, the tools and resources to develop these methodologies are still maturing. Furthermore, current data acquisition tools are not available to the DoD for all social media platforms. This thesis addresses a small subset of this problem by developing an open source methodological approach to collect and manage data from a popular social media site that has previously been inaccessible to defense intelligence organizations. This approach was operationalized via the R package called instaExtract, and an exemplar analysis was performed to demonstrate its …

Market Basket Analysis With Shortened Web Link Click Data, James C. Gallagher

Theses and Dissertations

Market research is an indispensable part of an organization's ability to understand market dynamics in an area. Over the past 20 years data collection and analysis through Knowledge Discovery through Databases (KDD) has arisen to supplement the traditional methods of surveys and focus groups. Market Basket Analysis is an area of KDD that identifies associations between commonly purchased items. As social media use has grown, link shortening companies help users share links in a constrained space environment and, in exchange, collect data about each user when a link is clicked. This research applies market basket analysis techniques with graph mining …

Scheduling Tool For The Nevada Test And Training Range, Miguel J. Macias

Theses and Dissertations

Presently, the 57th Wing Scheduler at Nellis AFB schedules daily mission requests to the Nevada Test and Training Range (NTTR) airspace manually. The process is time consuming and may lead to suboptimal range resource allocations. The goal of this study is to provide the scheduler with an automated scheduling approach that will improve range scheduling efficiency. The tool developed uses range request data from units at Nellis AFB to produce daily mission schedules for a month long scheduling horizon with Microsoft VBA code and a commercial Integer Program (IP) solver. Under our current understanding of scheduler priorities, we formulate the …

Experimental Designs, Meta-Modeling, And Meta-Learning For Mixed-Factor Systems With Large Decision Spaces, Zachary C. Little

Theses and Dissertations

Many Air Force studies require a design and analysis process that can accommodate for the computational challenges associated with complex systems, simulations, and real-world decisions. For systems with large decision spaces and a mixture of continuous, discrete, and categorical factors, nearly orthogonal-and-balanced (NOAB) designs can be used as efficient, representative subsets of all possible design points for system evaluation, where meta-models are then fitted to act as surrogates to system outputs. The mixed-integer linear programming (MILP) formulations used to construct first-order NOAB designs are extended to solve for low correlation between second-order model terms (i.e., two-way interactions and quadratics). The …

Enhanced Grain Partitioning Of X-Ray Microtomography Segmented Images, Nicholas C. Skrivanos Ii

LSU Master's Theses

In the field of petroleum engineering, rock samples are often taken from wells during the drilling process. Grain partitioning of digital three-dimensional microtomography segmented images obtained from these samples provides valuable in-situ properties and statistics that allow for accurate particle and structure characterization. This information can be used directly in detailed production and reservoir analysis, and can also be used to generate realistic packing models for advanced simulation. Additionally, the partitioned image can be used as a building block for realistic hydraulic fracture modeling. This technology has applications in other fields as well, such as core analysis in soil sciences …

Influence Of Coolant Flow Rate Parameters In Scaling Gas Turbine Cooling Effectiveness On A Flat Plate, Jacob P. Fischer

Theses and Dissertations

Effective film cooling relies on the performance of the selected cooling hole shape and placement of the holes on the surface of the blade. To test each holes effectiveness, large scale, low-temperature testing has been used to reduce cost and complexity. The resulting quantity from this testing is called the adiabatic effectiveness (n). The adiabatic effectiveness can then scaled up to engine operating conditions to predict how the selected film cooling hole will perform. This process is complicated by the nonlinear variation of gas properties between coolant and freestream conditions as well as between the experimental and engine conditions. In …

Comparison Of Traditional Versus Cubesat Remote Sensing: A Model-Based Systems Engineering Approach, Daniel L. Cipera

Theses and Dissertations

This thesis compares the ability of both traditional and CubeSat remote sensing architectures to fulfill a set of mission requirements for a remote sensing scenario. Mission requirements originating from a hurricane disaster response scenario are developed to derive a set of system requirements. Using a Model-based Systems Engineering approach, these system requirements are used to develop notional traditional and CubeSat architecture models. The technical performance of these architectures is analyzed using Systems Toolkit (STK); the results are compared against Measures of Effectiveness (MOEs) derived from the disaster response scenario. Additionally, systems engineering cost estimates are obtained for each satellite architecture …

Impact Of Substrate To Inoculum Ratio On Methane Production In High Solids Anaerobic Digestion (Hs-Ad) Of Food Waste, Yard Waste, And Biosolids, Phillip James Dixon

USF Tampa Graduate Theses and Dissertations

High solids anaerobic digestion (HS-AD) is an alternative for managing the organic fraction of municipal solids waste (MSW), which produces mainly methane (CH4) and fertilizer as byproducts. HS-AD offers a potentially more economically and environmentally sustainable option compared with landfilling or incineration waste-to-energy facilities. However, HS-AD is a complex process requiring specific microbial communities working together symbiotically. Previous studies have found that the substrate to inoculum (S/I) ratio affects CH4 production and yield in HS-AD reactors by affecting substrate mass and energy transfer as well as microbial activity. In this thesis, biochemical methane potential (BMP) assays were used to investigate …

Field Testing Of Affordable Well Head Protection For Locally Manufactured, Self-Supply Pitcher Pumps On Manually Driven Tubewells In Madagascar, Michal Usowicz

USF Tampa Graduate Theses and Dissertations

Lack of water access is an issue of global importance. The WHO and UNICEF’s Joint Monitoring Program estimated that in 2015 71% of the world’s population used a safely managed drinking water source and 89% of the world’s population used an improved water source within a 30-minute round trip of home. Madagascar’s national statistics lags far behind these global statistics with 54% of the population using improved water sources, 31% using unimproved water sources, and 16% with no service at all.

This research studied water access in Madagascar with self-supply Pitcher Pumps attached on hand-driven tubewells. The term self-supply in …

Enhanced, Risk-Based Faa Oversight On Part 145 Maintenance Practices: A Qualitative Study, Bryan G. Sheehan, Timm J. Bliss, Chad L. Depperschmidt

Journal of Aviation Technology and Engineering

The purpose of this qualitative study was to examine the phenomenon of enhanced, risk-based Federal Aviation Administration (FAA) oversight of Part 145 repair stations in Oklahoma that performed aircraft maintenance for Part 121 air carriers. Specifically, this research was utilized to explore the lived (personal) experiences of Part 145 repair station managers concerning operational changes in air carrier maintenance practices. The researchers’ intent was not to examine the effectiveness of changes implemented by the FAA; instead, to explore how management has experienced the enhanced changes in their Oklahoma-based Part 145 repair stations. Forty-two percent of the participants indicated a weak …

Functional Trait Differences Between Native Bunchgrasses And The Invasive Grass Bromus Tectorum, Huiqin H.E., Thomas A. Monaco, Thomas A. Jones

Forage and Range Research Laboratory Publications

We conducted 30- and 60-d greenhouse experiments to compare functional traits of Bromus tectorum (invasive annual grass) and four perennial bunchgrasses under well-watered or drought conditions. Even under drought, B. tectorum experienced significantly less stress (i.e., higher xylem pressure potential and greater shoot water content, water use per day and water-use efficiency) and biomass production than the perennial grasses after 30 d. However, after 60 d, its superiority was reduced under infrequent watering. Differences among perennial grasses were more pronounced for physiological traits under infrequent watering and for morphological traits under frequent watering. Elymus multisetus (fastgrowing species) had a higher …

Red Hot: Researchers Develop Imaging Test For Glowing Rocket Engines | College Of Engineering, Usu College Of Engineering

College of Engineering News

Researchers at Utah State University are learning more about how extreme temperatures affect the structural integrity of rocket engines.

A Model-Based Approach For Estimation Of Changes In Lumbar Segmental Kinematics Associated With Alterations In Trunk Muscle Forces, Iman Shojaei, Navid Arjmand, Judith R. Meakin, Babak Bazrgari

Biomedical Engineering Faculty Publications

The kinematics information from imaging, if combined with optimization-based biomechanical models, may provide a unique platform for personalized assessment of trunk muscle forces (TMFs). Such a method, however, is feasible only if differences in lumbar spine kinematics due to differences in TMFs can be captured by the current imaging techniques. A finite element model of the spine within an optimization procedure was used to estimate segmental kinematics of lumbar spine associated with five different sets of TMFs. Each set of TMFs was associated with a hypothetical trunk neuromuscular strategy that optimized one aspect of lower back biomechanics. For each set …

Internet Of Things For A Smart Transportation System, Ahmed Yahya Awad

Theses and Dissertations

Today, school buses transport millions of students to and from schools. Therefore, the safety of school students is still a hot topic and the most imperative issue. The evolution of wireless location-based services has created consumer requests for the availability of global positioning systems (GPS) in urban and indoor environments. Nowadays, there is a requirement to improve a monitoring system for the school bus, that monitors its location and speed. This work investigates two different ways to track the vehicle through ordinary GPS or Assisted-GPS (A-GPS). A-GPS improves startup performance (time-to-first-fix (TTFF)), of a GPS satellite-based positioning system in the …

Embedded System Design Of Low-Power Wearable Bioelectronic Devices, Matthew S. Hopper

USF Tampa Graduate Theses and Dissertations

The miniaturization of electronics in modern times has enabled the possibility of creating a “continuity of care” using small wearable bioelectronic devices. Using wearable devices, such as the Fitbit or Garmin fitness trackers, allows for the exchange of data between devices which can be used to improve the accuracy of data analysis and thus patient health.

In this thesis work, three wearable bioelectronic devices are proposed: an EOG-based eye-gaze tracking assistive technology device for the physically disabled to control a computer cursor, a battery-operated miniaturized polysomnograph that can store and transmit data wirelessly to sleep technicians and a trauma-detecting personal …

Walking Speed Differentially Alters Spinal Loads In Persons With Traumatic Lower Limb Amputation, Brad D. Hendershot, Iman Shojaei, Julian C. Acasio, Christopher L. Dearth, Babak Bazrgari

Biomedical Engineering Faculty Publications

Persons with lower limb amputation (LLA) perceive altered motions of the trunk/pelvis during activities of daily living as contributing factors for low back pain. When walking (at a singular speed), larger trunk motions among persons with vs. without LLA are associated with larger spinal loads; however, modulating walking speed is necessary in daily life and thus understanding the influences of walking speed on spinal loads in persons with LLA is of particular interest here. Three-dimensional trunk-pelvic kinematics, collected during level-ground walking at self-selected (SSW) and two controlled speeds (~1.0 and ~1.4 m/s), were obtained for seventy-eight participants: 26 with transfemoral …