Engineering Commons^™

A Multi-Agent Systems Approach For Analysis Of Stepping Stone Attacks, Marco Antonio Gamarra

Electrical & Computer Engineering Theses & Dissertations

Stepping stone attacks are one of the most sophisticated cyber-attacks, in which attackers make a chain of compromised hosts to reach a victim target. In this Dissertation, an analytic model with Multi-Agent systems approach has been proposed to analyze the propagation of stepping stones attacks in dynamic vulnerability graphs. Because the vulnerability configuration in a network is inherently dynamic, in this Dissertation a biased min-consensus technique for dynamic graphs with fixed and switching topology is proposed as a distributed technique to calculate the most vulnerable path for stepping stones attacks in dynamic vulnerability graphs. We use min-plus algebra to analyze …

A Cfd Study Of Steady Fully Developed Laminar Flow Through A 90-Degree Bend Pipe With A Square Cross-Sectional Area, Subodh Sushant Toraskar

Mechanical & Aerospace Engineering Theses & Dissertations

Fluid flow through a closed curved conduit has always been a topic of extensive research, as it has many practical and industrial applications. The flow is generally characterized by a presence of secondary flow, vortical motions and pressure losses for different flow regimes. These observed irregularities may positively or negatively impact the flow. They are beneficial for cases where mixing of fluids is required, usually observed for multiphase flow regimes or detrimental for cases involving particles in the fluid. There are also instances where a particle-laden fluid transported through the curved pipe was directly related to corrosion- erosion related problems. …

Computational Analysis Of Antipode Algorithms For The Output Feedback Hopf Algebra, Lance Berlin

Electrical & Computer Engineering Theses & Dissertations

The feedback interconnection of two systems written in terms of Chen-Fliess series can be described explicitly in terms of the antipode of the output feedback Hopf algebra. At present, there are three known computational approaches to calculating this antipode: the left coproduct method, the right coproduct method, and the derivation method. Each of these algorithms is defined recursively, and thus becomes computationally expensive quite quickly. This motivates the need for a more complete understanding of the algorithmic complexity of these methods, as well as the development of new approaches for determining the Hopf algebra antipode. The main goals of this …

Extension Of A Penalty Method For Numerically Solving Constrained Multibody Dynamic Problems, Troy Newhart

Mechanical & Aerospace Engineering Theses & Dissertations

Numerical analysis of constrained static and multibody dynamic systems has become an integral part of engineering analysis with the continued improvements in technology and software availability. Many methods currently exist for numerically solving constrained static and dynamic systems. The applicability of a penalty method for constrained static solutions is observed in many academic texts and papers. The appeal for using a penalty method in statics pertains to its ease of implementation, computational suitability, and accuracy. This thesis extends a static penalty method for use with constrained multibody dynamics to observe if the penalty method’s benefits are similar for a dynamics …

Enhanced Sensing Performance Of Novel Nanostructured Zno Gas Sensors In Ethanol Vapor Concentration Detection Applications, Pengtao Lin

Electrical & Computer Engineering Theses & Dissertations

Sensors are devices which have been commonly used to measure the functional dependence and the variability of physical parameters like temperature, pressure, pH, voltage, current, concentration, and others. Among the numerous kinds of sensors in different areas, gas sensors have been widely used and investigated for gas monitoring. Gas sensors are of crucial importance for the detection of hazardous atmospheres, because toxic gases are frequently odorless, colorless, invisible, rapidly evaporating, and flammable, and would otherwise go unnoticed. Gas sensors have been used in a variety of applications among others for the detection of specific gas species and the detection of …

Communication Capability For A Simulation-Based Test And Evaluation Framework For Autonomous Systems, Ntiana Sakioti

Computational Modeling & Simulation Engineering Theses & Dissertations

The design and testing process for collaborative autonomous systems can be extremely complex and time-consuming, so it is advantageous to begin testing early in the design. A Test & Evaluation (T&E) Framework was previously developed to enable the testing of autonomous software at various levels of mixed reality. The Framework assumes a modular approach to autonomous software development, which introduces the possibility that components are not in the same stage of development. The T&E Framework allows testing to begin early in a simulated environment, with the autonomous software methodically migrating from virtual to augmented to physical environments as component development …

Gesture Based Control Of Semi-Autonomous Vehicles, Brian Sanders

Computational Modeling & Simulation Engineering Theses & Dissertations

The objective of this investigation is to explore the use of hand gestures to control semi-autonomous vehicles, such as quadcopters, using realistic, physics based simulations. This involves identifying natural gestures to control basic functions of a vehicle, such as maneuvering and onboard equipment operation, and building simulations using the Unity game engine to investigate preferred use of those gestures. In addition to creating a realistic operating experience, human factors associated with limitations on physical hand motion and information management are also considered in the simulation development process. Testing with external participants using a recreational quadcopter simulation built in Unity was …

Adaptive Control Of Base Isolation Systems Using The Transmissibility-Based Semi-Active Controller, Ramin Rabiee

Civil & Environmental Engineering Theses & Dissertations

Base isolation system is one of the most effective seismic protection systems which is widely used to protect buildings of high importance against seismic hazards. However, the performance of these systems might be impaired under long-period earthquake ground motions due to the resonance effect. The main focus of this dissertation is the development of an adaptive semi-active control algorithm to improve the performance of conventional base isolation systems. The proposed control law works based on the transmissibility theory, called the transmissibility-based semi-active (TSA) controller, which can adaptively change the damping of the base-isolation system based on the response of the …

The Jump Seat Experience, Luke Moriarty

Student Works

It was a Tuesday afternoon as I sat in the conference room of Aegean Airlines, an airline based in the country of Greece. My fellow peers, professors and I were here on a study abroad program, currently participating in a week long workshop with the airline company. It was lunch time, all gathered around at rectangle tables when we found out the answer to our long-anticipated question. The Chief Pilot stood up stating he had an announcement to make. All of the students including myself had a look confusion and anticipation on our faces, we wondered could this be what …

Air Force Space Programs: Comparing Estimates To Final Development Budgets, Christopher Elworth, Edward D. White, Jonathan D. Ritschel, Gregory E. Brown

Faculty Publications

This article analyzes how development budget estimates, as reported in the Selected Acquisition Reports, change over time for primarily Air Force space programs. Government acquisition policy emphasizes the importance of developing an accurate point estimate for programs to ensure program budget efficiency; however, statistics imply space programs tend to underspend at the beginning of the program and to overspend at the end of Initial Operational Capability. This suggests new phasing methods that reflect the unique needs of space and perhaps other developmental-type programs by allocating more of the budget in later years rather than at the beginning of the program, …

Modeling And Testing Powerplant Subsystems Of A Solar Uas, Luke J. Bughman

Master's Theses

In order to accurately conduct the preliminary and detailed design of solar powered Unmanned Aerial Systems (UAS), it is necessary to have a thorough understanding of the systems involved. In particular, it is desirable to have mathematical models and analysis tools describing the energy income and expenditure of the vehicle. Solar energy income models may include available solar irradiance, photovoltaic array power output, and maximum power point tracker efficiency. Energy expenditure models include battery charging and discharging characteristics, propulsion system efficiency, and aerodynamic efficiency. In this thesis, a series of mathematical models were developed that characterize the performance of these …

Effect Of The Physical Micro-Environment On Cell Adhesion And Force Exertion, Mohamad Eftekharjoo

Mechanical & Aerospace Engineering Theses & Dissertations

Physical characteristics of the microenvironment, such as geometry and stiffness, influence cell adhesion and contractile forces. Here, we determined how these physical factors influenced cell force exertion and adhesion in two specific contexts that have broad relevance.

Fibroblasts are cells in connective tissues that interact with a fibrous extracellular matrix (ECM) that have a predominantly one-dimensional (1D) (fibrillar) geometry. However, it has been unclear as to how the 1D nature of the fibrillar ECM influences the forces exerted by fibroblasts. Here, we used fibroblast cells adherent on fibronectin lines on polyacrylamide (PAA) gels of stiffness 13 and 45 kPa to …

Los Efectos De La Minería En La Salud: El Movimiento Social Aymara En Torno Al Cerro Márquez, Maya Hajny Fernandez

Independent Study Project (ISP) Collection

With the political and social state of Chile’s history, mining has been present for hundreds of years, affecting the land and the indigenous populations in the country. This study asked how mining in the town of Ticnamar would affect the community, what positive and negative results mining activity has, what the most important elements of the social movement against mining are and how all of these elements influence health. The study sought to learn and study the impact of and the motivations that mining could have in the community of Ticnamar, and how it is perceived by the community. More …

Designing An Accessible Wave Energy Conversion Device For Powering Ocean Sensors, Sophie Coppieters ‘T Wallant

Independent Study Project (ISP) Collection

Currently, less than 5% of our oceans are comprehensively monitored and much more ocean data is needed to facilitate understanding of ocean physics, carbon cycling, and ocean ecosystems. Today, most autonomous ocean sensors are powered by primary battery, which have both limited capacity and lifetime. The goal of this research is to design a small, accessible renewable wave energy device to power autonomous free-floating ocean sensors. By designing a cheap, accessible, and simple wave energy converter, this work hopes to make ocean sensor deployment easier and cheaper for researchers, increase the lifetime of autonomous ocean sensors, and reduce the reliance …

Assessing The Implications Of A Tidal Barrage Power Plant In Hvalfjörður, Iceland, Olive M. Colangelo

Independent Study Project (ISP) Collection

As climate change continues to threaten the future state of our world, we are searching for measures to take for mitigation. Among these measures, the most talked about method is the development of renewable energies. Great amounts of attention is paid to solar and wind power, but relatively little effort is given to researching the possibilities of ocean energy, particularly tidal barrage energy. This study assesses the possibility of a tidal barrage plant in Hvalfjörður, Iceland. This hypothetical power plant in Hvalfjörður would have an installed capacity of 840MWh and could produce 613GWh per year. This is less than 0.01% …

Medical Dental Device: Biogeneric Implant Prototype, Ibeth Erazo, Aneeza Hussain, Renata Budny, Gaffar Gailani

Publications and Research

Teeth are lost due to tooth decay, injury, disease, or other causes. Today, dental implants extend the range of care to a variety of patients undergoing necessary prosthodontic rehabilitation. If the benefits of such treatments are to be maximized, then implants must be selected on logical basis and placed within the context of the full range of treatment modalities. However, modern dental implant systems are based on multiple components often leading to micro-movements which cause stress on the bone or bacterial infections, both of which compromise the success of osseointegration and consequently jeopardize the whole implant adaptation. Thus, a new …

Modeling The Uranium-Silicon Phase Equilibria Based On Computational And Experimental Analysis, Tashiema Lixona Ulrich

Theses and Dissertations

As part of Accident tolerant fuel initiative, the uranium-silicide compound, U3Si2, is under consideration as a potential replacement for conventional uranium dioxide fuel. It is of interest as its higher uranium density of 11.3 g(U)/cm3 compared to 9.7 g(U)/cm3 for UO2 may allow use of more robust, but less neutronically economical fuel cladding. The improved uranium content would not only accommodate the neutronic penalty inherent to certain accident tolerant cladding concepts but also facilitate improved reactor performance with the potential for longer fuel cycles.

The U-Si system has been the subject of various studies that mainly focused on thermophysical properties, …

Bison Simulation-Based Identification Of Important Design Criteria For U3si2 Fuels With Composite-Monolithic Duplex Sic Cladding, Jacob A. Yingling

Theses and Dissertations

Accident Tolerant Fuels (ATF) require a combination of fuel and cladding which have comparable longevity characteristics to UO2 while improving resistance to radiological release during and after accidents. U3Si2 has been proposed for use in ATF concepts for its high uranium density and high thermal conductivity which provide improved fuel performance. However, some of U3Si2’s material properties are not well understood. One such property, thermal creep of U3Si2, is an important contributing factor to U3Si2’s viability as an ATF. No experimentally derived thermal creep model is published for U3Si2, and previous analyses of compressive thermal creep experimental data lack statistical …

Quantifying And Elucidating The Effect Of Co2 On The Thermodynamics, Kinetics And Charge Transport Of Aemfcs, Yiwei Zheng

Theses and Dissertations

Anion exchange membrane fuel cells (AEMFCs) have shown significant promise to provide clean, sustainable energy for grid and transportation applications – and at a lower theoretical cost than more established proton exchange membrane fuel cells (PEMFCs). Adding to the excitement around AEMFCs is the extremely high peak power that can now be obtained (> 3 W cm-2) and continuously improving durability (1000+ h), which has made the future deployment of AEMFCs in real-world applications a serious consideration. For some applications (e.g. automotive), the most critical remaining practical issue with AEMFCs is understanding and mitigating the effects of atmospheric CO2 (in …

Adipose Tissue Engineering: A Therapeutic Strategy For The Treatment Of Obesity And Glucose Intolerance, Michael A. Hendley

Theses and Dissertations

Despite available treatment options, the number of people afflicted by type 2 diabetes has steadily risen for decades. Nearly 90% of the diabetic population also suffers from obesity and the link between the two diseases is undeniable. Characterized by rapid expansion of the adipose tissue and improper lipid storage, the mishandling of lipids by adipose tissue promotes the diabetic state. Excess lipids, unable to be properly stored, build up in peripheral tissues promoting insulin resistance and type 2 diabetes. Therapeutic strategies designed to address adipose tissue lipid handling could represent a promising treatment strategy for obesity associated type 2 diabetes. …

Enhanced Heat Transfer In Spray Cooling Through Surface Modifications: An Experimental And Computational Study, Azzam Saadi Salman

Theses and Dissertations

Today, dissipating high heat flux safely is one of the greatest challenges for thermal engineers in thermal management systems, and it becomes a critical barrier to technological developments for many engineering applications. Due to technological advances and aggressive micro-miniaturization of electronic components, the surface area of most devices has shrunk while the computational power increased exponentially. Therefore, the amount of heat dissipated from surfaces has increased significantly. Numerous cooling techniques have been introduced to replace the traditional air cooling systems and to maintain the efficiency and reliability of electronic components. Microelectronics work efficiently and safely at surface temperatures of < 100 ℃ and 125 ℃ for general and defense applications, respectively. One of the proposed alternative schemes is spray cooling, which is considered one of the most advanced cooling methods. It is used for high and ultra-high heat flux dissipation, as it can dissipate 150-200 W/cm2 while maintaining the surface temperature within this range. Also, spray cooling removes a large amount of energy at a lower liquid flow rate compared to other cooling techniques, such as jet impingement and microchannel heat sink. The thermal performance of spray cooling systems can be enhanced either actively or passively. Active enhancement is a very efficient technique; however, it adds more pumping power. The present work focuses on three main objectives: evaluating and analyzing spray cooling performance, developing a three-dimensional numerical multi-phase model for heat transfer process in spray cooling and enhancing the thermal performance of spray cooling passively.

First, …

Computational Wave Field Modeling In Anisotropic Media, Sajan Shrestha

Theses and Dissertations

In this thesis, a meshless semi-analytical computational method is presented to compute the ultrasonic wave field in generalized anisotropic material while understanding the physics of wave propagation in detail. To understand the wave-damage interaction in an anisotropic material, it is neither feasible nor cost-effective to perform multiple experiments in the laboratory. Hence, recently the computational nondestructive evaluation (CNDE) received much attention to performing the NDE experiments in a virtual environment. In this thesis, a fundamental framework is constructed to perform the CNDE experiment of a thick composite specimen in a Pulse-Echo (PE) and through-transmission mode. To achieve the target, the …

Molecular Modeling Of Tethered Polyelectrolytes For Novel Biomedical Applications, Merina Jahan

Theses and Dissertations

Current research trends throughout the world focus on designing intelligent materi- als and systems for diverse applications in all courses of life. Biomaterials research encompasses a major part in this revolution due to the increased effort in fulfilling unmet medical needs to treat complex physiological and neurodegenerative disorders. Polymers play inevitable roles in these research endeavors for their ubiquitous pres- ence in biological systems. Therefore, it is crucial to understand how the polymeric molecules interact within diverse biological environments, to efficiently engineer them for various drug delivery and biosensing systems. The use of experimental design and selection of different polymers …

Using A Nondispersive Wave Propagation For Measuring Dynamic Fracture Initiation Toughness Of Materials: Experimental And Numerical Based Study, Ali Fahad Fahem

Theses and Dissertations

Fracture mechanics has been a subject of great interest in the engineering community for decades. During this period, fracture parameters such as Stress Intensity Factor (SIF), J-integral, and Crack-Tip Opening Displacement (CTOD) have been developed and used to characterize the fracture properties of most engineering materials under quasi-static loading condition. Usually, these properties are obtained experimentally by using standard methods such as ASTM E399, E1820 or E1920 to evaluate the stress intensity factor ������ ������������, elastic-plastic toughness ������ ������������ and crack tip opening displacement (CTOD) respectively. Conversely, most critical engineering applications are subjected to a sudden or high strain rate …

A Novel And Inexpensive Solution To Build Autonomous Surface Vehicles Capable Of Negotiating Highly Disturbed Environments, Jason Moulton

Theses and Dissertations

This dissertation has four main contributions. The first contribution is the design and build of a fleet of long-range, medium-duration deployable autonomous surface vehicles (ASV). The second is the development, implementation, and testing of inex-pensive sensors to accurately measure wind, current, and depth environmental vari- ables. The third leverages the first two contributions, and is modeling the effects of environmental variables on an ASV, finally leading to the development of a dynamic controller enabling deployment in more uncertain conditions.

The motivation for designing and building a new ASV comes from the lack of availability of a flexible and modular platform …

Cybersecurity Issues In The Context Of Cryptographic Shuffling Algorithms And Concept Drift: Challenges And Solutions, Hatim Alsuwat

Theses and Dissertations

In this dissertation, we investigate and address two kinds of data integrity threats. We first study the limitations of secure cryptographic shuffling algorithms regarding preservation of data dependencies. We then study the limitations of machine learning models regarding concept drift detection. We propose solutions to address these threats.

Shuffling Algorithms have been used to protect the confidentiality of sensitive data. However, these algorithms may not preserve data dependencies, such as functional de- pendencies and data-driven associations. We present two solutions for addressing these shortcomings: (1) Functional dependencies preserving shuffle, and (2) Data-driven asso- ciations preserving shuffle. For preserving functional dependencies, …

Challenges In Large-Scale Machine Learning Systems: Security And Correctness, Emad Alsuwat

Theses and Dissertations

In this research, we address the impact of data integrity on machine learning algorithms. We study how an adversary could corrupt Bayesian network structure learning algorithms by inserting contaminated data items. We investigate the resilience of two commonly used Bayesian network structure learning algorithms, namely the PC and LCD algorithms, against data poisoning attacks that aim to corrupt the learned Bayesian network model.

Data poisoning attacks are one of the most important emerging security threats against machine learning systems. These attacks aim to corrupt machine learning models by con- taminating datasets in the training phase. The lack of resilience of …

Wireless Rf Induced Energy Absorption And Heating Of Lanthanum-Nickel Alloy In The Near-Field, Michael Dillon Lindsay

Theses and Dissertations

This thesis will investigate whether and how a synthetic metal-magnetic alloy absorbs enough near-field electromagnetic (EM) radiation for heating. Although resistive elements could be used for indirect heating, a wireless radio frequency (RF) method is explored because of its advantages in its non-intrusive nature and its ability to direct or focus energy within a specific area. For our case, the RF heating process relies on the materials ability to absorb sufficient RF energy due to the induced currents. We expect there to be significant surface resistance due to the conductivity and magnetic permeability of the material and thus heat. This …

Experimental Investigations Of Levee Breach Flows, Ibrahim Adil Ibrahim

Theses and Dissertations

Two individual but related problems involving levee breach flow are studied. The first one involves experimental and dynamic modeling of steady flow through a levee breach, and the second one involves experimental investigation of flood management by an engineered levee breach. Both studies are conducted in the Hydraulics Laboratory, the University of South Carolina.

In the first problem, an idealized levee breach on a trapezoidal embankment was studied. Flow data including water depths, surface velocities, and flow discharges were collected from 28 experiments considering different cases of breach width and downstream water depth. Ultrasonic sensors were used to record the …

Exercises Integrating High School Mathematics With Robot Motion Planning, Ronald I. Greenberg, George K. Thiruvathukal

Computer Science: Faculty Publications and Other Works

This paper presents progress in developing exercises for high school students incorporating level-appropriate mathematics into robotics activities. We assume mathematical foundations ranging from algebra to precalculus, whereas most prior work on integrating mathematics into robotics uses only very elementary mathematical reasoning or, at the other extreme, is comprised of technical papers or books using calculus and other advanced mathematics. The exercises suggested are relevant to any differerential-drive robot, which is an appropriate model for many different varieties of educational robots. They guide students towards comparing a variety of natural navigational strategies making use of typical movement primitives. The exercises align …