Engineering Commons^™

The NTh-Order Comprehensive Adjoint Sensitivity Analysis Methodology For Response-Coupled Forward/Adjoint Linear Systems (NTh-Casam-L): Ii. Illustrative Application, Dan Gabriel Cacuci

Faculty Publications

This work illustrates the application of the n^th-order comprehensive adjoint sensitivity analysis methodology for response-coupled forward/adjoint linear systems (abbreviated as “n^th-CASAM-L”) to a paradigm model that describes the transmission of particles (neutrons and/or photons) through homogenized materials, as encountered in radiation protection and shielding. The first-, second-, and third-order sensitivities of responses that depend on both the forward and adjoint particle fluxes are obtained exactly, in closed-form, underscoring the principles and methodology underlying the n^th-CASAM-L. The results presented in this work underscore the fundamentally important role of the n^th-CASAM-L in the quest …

The NTh-Order Comprehensive Adjoint Sensitivity Analysis Methodology For Response-Coupled Forward/Adjoint Linear Systems (NTh-Casam-L): I. Mathematical Framework, Dan Gabriel Cacuci

Faculty Publications

This work presents the mathematical framework of the n^th-Order Comprehensive Adjoint Sensitivity Analysis Methodology for Response-Coupled Forward/Adjoint Linear Systems (abbreviated as “n^th-CASAM-L”), which is conceived for obtaining the exact expressions of arbitrarily-high-order (n^th-order) sensitivities of a generic system response with respect to all of the parameters (including boundary and initial conditions) underlying the respective forward/adjoint systems. Since many of the most important responses for linear systems involve the solutions of both the forward and the adjoint linear models that correspond to the respective physical system, the sensitivity analysis of such responses makes it necessary …

The NTh-Order Comprehensive Adjoint Sensitivity Analysis Methodology For Response-Coupled Forward/Adjoint Linear Systems (NTh-Casam-L): I. Mathematical Framework, Dan Gabriel Cacuci

Faculty Publications

This work presents the mathematical framework of the n^th-Order Comprehensive Adjoint Sensitivity Analysis Methodology for Response-Coupled Forward/Adjoint Linear Systems (abbreviated as “n^th-CASAM-L”), which is conceived for obtaining the exact expressions of arbitrarily-high-order (n^th-order) sensitivities of a generic system response with respect to all of the parameters (including boundary and initial conditions) underlying the respective forward/adjoint systems. Since many of the most important responses for linear systems involve the solutions of both the forward and the adjoint linear models that correspond to the respective physical system, the sensitivity analysis of such responses makes it necessary …

Detecting Malware In Memory With Memory Object Relationships, Demarcus M. Thomas Sr.

Theses and Dissertations

Malware is a growing concern that not only affects large businesses but the basic consumer as well. As a result, there is a need to develop tools that can identify the malicious activities of malware authors. A useful technique to achieve this is memory forensics. Memory forensics is the study of volatile data and its structures in Random Access Memory (RAM). It can be utilized to pinpoint what actions have occurred on a computer system.

This dissertation utilizes memory forensics to extract relationships between objects and supervised machine learning as a novel method for identifying malicious processes in a system …

A Parametric Computational Fluid Dynamics (Cfd) Study Of In-Line Horizontal Axis Wind Turbines (Hawts) With Yaw, North Alyster Yates

Masters Theses

Because of the constant use of non-renewable fossil fuels, and the enormous impact they have on global warming and pollution, there has been a push to use more eco-friendly and renewable sources for power. One such form is wind power via turbines. The most common form, Horizontal Axis Wind Turbines (HAWTs), can generate massive amounts of power. However, they also have a serious flaw in their design. As the wind passes through the swept area of the blades and past the tower, it creates massive disturbances in the airflow. These disturbances are called a ‘wake’. When trying to create a …

A Longitudinal Analysis Of Pathways To Computing Careers: Defining Broadening Participation In Computing (Bpc) Success With A Rearview Lens, Mercy Jaiyeola

Theses and Dissertations

Efforts to increase the participation of groups historically underrepresented in computing studies, and in the computing workforce, are well documented. It is a national effort with funding from a variety of sources being allocated to research in broadening participation in computing (BPC). Many of the BPC efforts are funded by the National Science Foundation (NSF) but as existing literature shows, the growth in representation of traditionally underrepresented minorities and women is not commensurate to the efforts and resources that have been directed toward this aim.

Instead of attempting to tackle the barriers to increasing representation, this dissertation research tackles the …

Predictive Computational Materials Modeling With Machine Learning: Creating The Next Generation Of Atomistic Potential Using Neural Networks, Mashroor Shafat Nitol

Theses and Dissertations

Machine learning techniques using artificial neural networks (ANNs) have proven to be effective tools to rapidly mimic first principles calculations. These tools are capable of sub meV/atom accuracy while operating with linear scaling with respect to the system size. Here novel interatomic potentials are constructed based on the rapid artificial neural network (RANN) formalism. This approach generates precise force fields for various metals that have historically been difficult to describe at the atomic scale. These force fields can be utilized in molecular dynamics simulations to provide new physical insights. The RANN formalism, which is incorporated into a LAMMPS molecular dynamics …

A Study Of The Effect Of Load And Displacement Control Strategies On Joint Strength In Friction Bit Joining Of Ga Dp 1180 Steel And Aa 7085-T71, Taylor George Berg

Theses and Dissertations

Friction Bit Joining (FBJ) is a new technology that can be used to join dissimilar materials together. This ability makes it a good candidate for creating lightweight structures for the automotive industry by combining lightweight materials such as aluminum to stronger materials like advanced high-strength steels. The automotive industry is putting significant effort into interest in reducing vehicle structure weight to increase fuel efficiency and reduce greenhouse gas emissions. Joining of dissimilar materials is a challenge they face in the light weighting the body of the vehicle. The purpose of the current research is to employ FBJ in the joining …

Design Of Plastic Contaminant Eliminator In Seed Cotton, Joshua H. Tandio

Theses and Dissertations

Plastic contamination in cotton is a problem in cotton industry and researchers have worked on this problem with different approaches. This thesis documents the design of mechanical and electronic real-time systems for detecting and removing plastic contaminants. The mechanical system was designed to expose plastic embedded inside the seed cotton to the sensor and to separate plastic contaminated cotton from the process stream. The detection system consisted of an embedded computer interfaced with a USB camera and Neural Network (NN) software running in it. Two NN models were tested, a transfer learning model and a built-from-scratch original model. The original …

The Development Of An Immersive Virtual Exploratory Engine (Ivee) For Immersive Analytics, Sofia Karam

Theses and Dissertations

Due to increasing data complexity, researchers are struggling to visually explore data using traditional methods. Research has shown that a variety of analytics-related tasks can be enhanced using new emerging technologies (e.g., virtual reality [VR] and augmented reality [AR]). This paper provides a detailed design approach for developing an immersive virtual engine system for conducting exploratory and descriptive data analytics. This system is called the Immersive Virtual Exploratory Engine (IVEE), is a VR system that allows users to experience full intractability with its graphical elements and examines various datasets within the same immersive environment. Basic plots—such as histograms, line plots, …

Mixing Temperature, Binder Content, And Dust Content Effects On Stone Matrix Asphalt, Abhinash Subedi

Theses and Dissertations

This study focuses on the effects of mixing temperature, binder content, and dust content on the performance of Stone Matrix Asphalt (SMA). Mixes produced at different mixing temperatures and with or without added polymer modified binder (P_b) and/or bag house dust (BHD) were evaluated. Two different types of specimens: laboratory mixed laboratory compacted, and plant mixed laboratory compacted were evaluated by Cantabro Mass Loss (CML) testing in an unaged condition or after a laboratory conditioning protocol (CP) was applied. Additional P_b and BHD were added to plant produced mixes in the laboratory before mixing. Results showed that …

Torque Vectoring To Maximize Straight-Line Efficiency In An All-Electric Vehicle With Independent Rear Motor Control, William Blake Brown

Theses and Dissertations

BEVs are a critical pathway towards achieving energy independence and meeting greenhouse and pollutant gas reduction goals in the current and future transportation sector [1]. Automotive manufacturers are increasingly investing in the refinement of electric vehicles as they are becoming an increasingly popular response to the global need for reduced transportation emissions. Therefore, there is a desire to extract the most fuel economy from a vehicle as possible. Some areas that manufacturers spend much effort on include minimizing the vehicle’s mass, body drag coefficient, and drag within the powertrain. When these values are defined or unchangeable, interest is driven to …

Using A Systemic Skills Model To Build An Effective 21st Century Workforce: Factors That Impact The Ability To Navigate Complex Systems, Morteza Nagahi

Theses and Dissertations

The growth of technology and the proliferation of information made modern complex systems more fragile and vulnerable. As a result, competitive advantage is no longer achieved exclusively through strategic planning but by developing an influential cadre of technical people who can efficiently manage and navigate modern complex systems. The dissertation aims to provide educators, practitioners, and organizations with a model that helps to measure individuals’ systems thinking skills, complex problem solving, personality traits, and the impacting demographic factors such as managerial and work experience, current occupation type, organizational ownership structure, and education level. The intent is to study how these …

A Data-Driven Approach For The Investigation Of Microstructural Effects On The Effective Piezoelectric Responses Of Additively Manufactured Triply Periodic Bi-Continuous Piezocomposite, Wenhua Yang

Theses and Dissertations

A two-scale model consisting of ceramic grain scale and composite scale are developed to systematically evaluate the effects of microstructures (e.g., residual pores, grain size, texture) and geometry on the piezoelectric responses of the polarized triply periodic bi-continuous (TPC) piezocomposites. These TPC piezocomposites were fabricated by a recently developed additive manufacturing (AM) process named suspension-enclosing projection-stereolithography (SEPS) under different process conditions. In the model, the Fourier spectral iterative perturbation method (FSIPM) and the finite element method will be adopted for the calculation at the grain and composite scale, respectively. On the grain scale, a DL approach based on stacked generative …

The Development Of A Finite Element Model For Ballistic Impact Predictions, Richard Allen Perkins

Theses and Dissertations

Concrete is a widely used product and is an important application throughout industry due to its inexpensive cost and wide range of applications. This work focuses on understanding the behavior of high strength concrete in high strain rate ballistic impact loading scenarios. A finite element analysis was created with the implementation of the Concrete Damage and Plasticity Model 2 (CDPM2) to represent the material behavior. The model’s parameters were calibrated to existing literature and the results were analyzed by a comparison of the impact velocity to residual velocity and a qualitative assessment of the impact crater. The model captured the …

Effects Of The Inclusion Of Rice Hull Derived Bio-Oil On Wood Pellet Production, Tyler E. Lowe

Theses and Dissertations

Wood pellet production has become an advancing industry for the sake of reducing greenhouse emissions into the atmosphere especially, in European Union countries. Researchers and industry executives seek new methods and materials to improve the pelletization process. Rice hulls or husks has the potential to aid in wood pelletization as they possess high calorific values. This study focuses on using rice hull derived bio-oil from pyrolysis, which will also decrease ash content, as an additive to aid in the wood pelletization process. Using two groups of rice hull derived bio-oil as an additive in wood pelletization: Group 1 uses heavy …

Development Of A Three Degree-Of-Freedom Control Simulation For A Group 3 Large Unmanned Aircraft System, Majka Anna Wilczynski

Theses and Dissertations

Aircraft modeling and simulation has become increasingly important in the aviation world. Simulations allow for safer and more economical training prior to flight testing. In this project, a three degree-of-freedom control simulation coded in a MATLAB environment is used to assess and simulate the dynamic stability of group three unmanned aircraft system. By calculating, evaluating, and simulating the static and dynamic stability derivatives of the aircraft, this project will allow for the estimation of the handling qualities of an unmanned aircraft system. This can help mitigate risks that come along with altering the mass and aerodynamic properties of an aircraft, …

Evaluation Of Hyperspectral Band Selection Techniques For Real-Time Applications, Samantha Butler

Theses and Dissertations

Processing hyperspectral image data can be computationally expensive and difficult to employ for real-time applications due to its extensive spatial and spectral information. Further, applications in which computational resources may be limited can be hindered by the volume of data that is common with airborne hyperspectral image data. This paper proposes utilizing band selection to down-select the number of spectral bands to consider for a given classification task such that classification can be done at the edge. Specifically, we consider the following state of the art band selection techniques: Fast Volume-Gradient-based Band Selection (VGBS), Improved Sparse Subspace Clustering (ISSC), Maximum-Variance …

3d Shape Estimation Of Negative Obstacles Using Lidar Point Cloud Data, Viswadeep Lebakula

Theses and Dissertations

Obstacle detection and avoidance plays a crucial role in the autonomous navigation of unmanned ground vehicles (UGV). Information about the obstacles decreases as the distance between the UGV and obstacles increases. However, this information decreases much more rapidly for negative obstacles than for positive obstacles. UGV navigation becomes more challenging in off-road environments due to the higher probability of finding negative obstacles (e.g., potholes, ditches, trenches, etc.) compared with on-road environments. One approach to solve this problem is to avoid the candidate path with a negative obstacle, but in off-road environments avoiding negative obstacles in all situations is not possible. …

Effects Of Bonding Pressure And Lamina Thickness On Mechanical Properties Of Clt Composed Of Southern Yellow Pine, Cody S. Bates

Theses and Dissertations

This study produced cross-laminated timber panels at a range of four lamina thickness (5/8, 1, 1 1/8, and 1 1/4 inch) and three bonding pressures (50, 125, 200 psi), producing a total of 12 panels for mechanical testing. The goal of this study is to observe how the thickness and pressure trends affect the mechanical properties of CLT. Tests include flatwise bending, flatwise shear, internal-bond, and delamination. Results showed that bending MOE decreases as the panel thickness increases while bonding pressure had no significance. Bending MOR was less significant for the thickness and more significant for pressure compared to the …

Unmanned Ground Vehicle System To Collect Soil Moisture Data, Austin Edward Flynt

Theses and Dissertations

With an increased interest in precision agriculture, it is important to identify efficient ways to monitor soil moisture. Soil moisture can be monitored using handheld sensors, but this method is laborious and time consuming. Remote methods, such as radar systems can be used as well, but these methods require ground truth data to verify their accuracy. It becomes clear that to collect this data regularly and reliably, a mobile robotic device is necessary. This thesis proposes to implement mobile robot take soil moisture measurements with less human effort than existing methods while maintaining the same accuracy. This soil moisture data …

Modeling The Ballistic Limit Of Fragment Simulating Projectiles Impacting A36 Mild Steel Spaced Armor Configurations, Daniel H. Rios-Estremera

Theses and Dissertations

Terminal ballistics study multivariate behavior and aftermath of projectile and target interactions. Tests and models are often based on monolithic armors, however, layered and spaced armors are common in real world applications. Such configurations add complexities that require research to understand their effects on terminal ballistics. The ballistic limit velocity (V50) represents the speed where armor perforation probability is 50%. It is used for quantitative comparison of protection capabilities for different armors. This research studied the V50 of spaced and layered A36 steel armors against fragment simulating projectiles (FSPs). Four methods for estimating armor V50 were evaluated and compared to …

A Dual Perspective Towards Building Resilience In Manufacturing Organizations, Steven A. Fazio

Theses and Dissertations

Modern manufacturing organizations exist in the most complex and competitive environment the world has ever known. This environment consists of demanding customers, enabling, but resource intensive Industry 4.0 technology, dynamic regulations, geopolitical perturbations, and innovative, ever-expanding global competition. Successful manufacturing organizations must excel in this environment while facing emergent disruptions generated as biproducts of complex man-made and natural systems. The research presented in this thesis provides a novel two-sided approach to the creation of resilience in the modern manufacturing organization. First, the systems engineering method is demonstrated as the qualitative framework for building literature-derived organizational resilience factors into organizational structures …

Leveraging Choice Modeling Technique For Enhancing The Cyber Resilience Of The Smart Grid, Kesava Karishma Devi Dadi

Theses and Dissertations

This research focuses on the cyber-attack of the smart grid and its retrieval to a normal state by estimating the smart grid's resilience. This study developed a theoretical model to estimate the resilience of the smart grid using choice modeling. A utility function is formulated based on various factors and sub-factors of resilience to estimate the resilience of the smart grid. Choice modeling is applied to estimate the model parameters in various fields such as marketing, energy, transportation, and health and to predict the outcome.

Hydrology And Water Quality Analysis In The Big Black River Watershed, Mississippi, Moniba Shabbir

Theses and Dissertations

Evaluating hydrology and water quality for the Big Black River Watershed in Mississippi was accomplished by using the Better Assessment Science Integrating Point and Nonpoint Source (BASINS 4.5), Loading Simulation Program in C++ (LSPC), and Water Quality Analysis Simulation Program (WASP) models. The watershed model calibration was originally accomplished by using historical data collected from U.S. Geological Survey (USGS). The watershed model was calibrated using data from 2000 through 2018 in order to quantify stream flow and point source discharges under a variety of hydrologic conditions. The model predicted response of hydrology was consistent with the observed data range. The …

Field Durability Test Of Clt Wall Envelope Using Physical Barriers Against Termites And Structural Performance Of Nailed Hold-Down Brackets Connected To Fungus-Exposed Clt Walls, Kamal Neupane

Theses and Dissertations

The effectiveness of using commercial polyethylene flashing and stainless-steel mesh in CLT wall systems as the termite barriers were evaluated in a short-term field test. American Wood Protection Association (AWPA) E21's visual ratings ranged from 10 to 9 in the specimens showing little damage when no physical barriers were used. Termites were able to crawl beyond the physical barriers in few specimens showing the necessity of further research on height and installation method of physical barriers. On the second part, the effect of decay caused due to Postia placenta, a brown-rot fungus, on the structural performance of hold-down brackets connected …

Catalytic Light Alkanes Selective Conversion Through Ammonia-Assisted Reforming, Siavash Fadaeerayeni

Theses and Dissertations

The fact that hydrogen is a clean and versatile fuel offers an attractive carbon-free source of energy and leverages the U.S. economy toward long-term sustainable economic growth. At an industrial scale, hydrogen production is mostly relying on methane steam reforming producing stoichiometric amounts of carbon oxides (CO and CO2), which imposes economic and environmental concerns. To mitigate the issue, we propose NH3 assisted anaerobic reforming of natural gas liquids (ethane and propane) as an alternative approach to produce COx free hydrogen. Here, in the first chapter, through comprehensive performance evaluation, characterization, and transient kinetic studies, it is shown that the …

Uncertainty-Aware Deep Learning For Prediction Of Remaining Useful Life Of Mechanical Systems, Samuel J. Cornelius

Theses and Dissertations

Remaining useful life (RUL) prediction is a problem that researchers in the prognostics and health management (PHM) community have been studying for decades. Both physics-based and data-driven methods have been investigated, and in recent years, deep learning has gained significant attention. When sufficiently large and diverse datasets are available, deep neural networks can achieve state-of-the-art performance in RUL prediction for a variety of systems. However, for end users to trust the results of these models, especially as they are integrated into safety-critical systems, RUL prediction uncertainty must be captured. This work explores an approach for estimating both epistemic and heteroscedastic …

The Development Of Authentic Virtual Reality Scenarios To Measure Individuals’ Level Of Systems Thinking Skills And Learning Abilities, Vidanelage L. Dayarathna

Theses and Dissertations

This dissertation develops virtual reality modules to capture individuals’ learning abilities and systems thinking skills in dynamic environments. In the first chapter, an immersive queuing theory teaching module is developed using virtual reality technology. The objective of the study is to present systems engineering concepts in a more sophisticated environment and measure students learning abilities. Furthermore, the study explores the performance gaps between male and female students in manufacturing systems concepts. To investigate the gender biases toward the performance of developed VR module, three efficacy measures (simulation sickness questionnaire, systems usability scale, and presence questionnaire) and two effectiveness measures (NASA …

Development Of A Bioinspired Nugalbot For Precision Seeding Of Rice, Harsa Dhani

Theses and Dissertations

Many people around the world live in islands with mountainous lands. These people plant upland rice for their staple food. However, farming in these disadvantageous farms requires high input and gains low yield. One possible solution for improving productivity is by utilizing precision seeding. This study is focused on developing a robot for precision seeding of rice that is suitable for farming in rough terrain. A bioinspired human arm robot for picking seeds and making a hole on the ground was developed in accordance with Aalborg method for bioinspired design. Development of a mobile platform to carry the robot arm …