Engineering Commons^™

Space-Based Maneuver Detection And Characterization Using Multiple Model Adaptive Estimation, Justin D. Katzovitz

Theses and Dissertations

An increasingly congested space environment requires real-time and dynamic space situational awareness (SSA) on both domestic and foreign space objects in Earth orbits. Current statistical orbit determination (SOD) techniques are able to estimate and track trajectories for cooperative spacecraft. However, a non-cooperative spacecraft performing unknown maneuvers at unknown times can lead to unexpected changes in the underlying dynamics of classical filtering techniques. Adaptive estimation techniques can be utilized to build a bank of recursive estimators with different hypotheses on a system's dynamics. The current study assesses the use of a multiple model adaptive estimation (MMAE) technique for detecting and characterizing …

Quasi-Static Nonlinear Analysis Of A Celestial Icosahedron Shaped Vacuum Lighter Than Air Vehicle, Kyle D. Moore

Theses and Dissertations

Due to the many drawbacks associated with a traditional lighter than air vehicle (LTAV), there is a desire for a LTAV which generates lift from an internal vacuum. To date, two feasible designs (the icosahedron and the hexakis icosahedron) for this so called vacuum lighter than air vehicle (VLTAV) have been studied at the Air Force Institute of Technology (AFIT). This research looks to show the feasibility of a new design for a VLTAV, the celestial icosahedron. This research includes a boundary condition study which proves the symmetric nature of the celestial icosahedron's frame with laterally constrained and unconstrained vertices. …

Navigation Using Vector And Tensor Measurements Of The Earth's Magnetic Anomaly Field, Lauren A. Mount

Theses and Dissertations

This research explores the viability of using a navigation system that relies on measurements of the magnetic anomaly field as an alternative to GPS navigation. Previous research has been conducted on developing a navigation system using the intensity of the Earth's magnetic anomaly field as an alternative signal. This research focuses on using vector and tensor measurements, as opposed to scalar measurements of the anomaly field, as a means of obtaining accurate position and orientation solutions. This paper presents two navigation systems. The first uses an Extended Kalman Filter (EKF) with vector measurements of the magnetic anomaly field to aid …

Effects Of Position Uncertainty On Passive Multistatic Sar Resolution Measures, Duy K. Nguyen

Theses and Dissertations

Given numerous exciting potentials including substantial cost savings, passive multistatic synthetic aperture radar (PMSAR) has been gaining more attention in the radar community. However, PMSAR research efforts such as emitters of opportunity selection thus far have not considered radar position uncertainty. Seeking to fill this knowledge gap, we run Monte Carlo trials to simulate transmitter position uncertainty and examine the effects on the multistatic resolution of radar sets of different geometries, center frequencies and bandwidths. By monitoring the 3dB contour of the multistatic point spread function, we find that the multistatic resolution worsens on average and the data spread grows …

They're Only Nuclear Weapons: An Exploratory Analysis Of Safety Climate Within The Nuclear Enterprise, Brandon M. Clements

Theses and Dissertations

By possessing nuclear weapons, the United States Air Force is inherently exposed to extreme safety concerns. With multiple setbacks in recent years (e.g., unauthorized transport of nuclear weapons, cheating scandals, and career dissatisfaction), some have begun to wonder how safe the nuclear enterprise truly is. Building upon the concept of safety climate, this study explores safety climate constructs and trends associated with current nuclear maintenance safety climate survey data.

Sentiment Analysis Of Twitter Data, Evan L. Munson

Theses and Dissertations

The rapid expansion and acceptance of social media has opened doors into users’ opinions and perceptions that were never as accessible as they are with today's prevalence of mobile technology. Harvested data, analyzed for opinions and sentiment can provide powerful insight into a population. This research utilizes Twitter data due to its widespread global use, in order to examine the sentiment associated with tweets. An approach utilizing Twitter #hashtags and Latent Dirichlet Allocation topic modeling were utilized to differentiate between tweet topics. A lexicographical dictionary was then utilized to classify sentiment. This method provides a framework for an analyst to …

The Developmental Test Scheduling Problem, Joseph E. Schoenbeck

Theses and Dissertations

Developmental testing of aircraft systems in the United States Air Force requires a complex set of resources for each test. The optimal scheduling of those resources is the job of the 412th Test Wing at Edwards Air Force Base. With more than 20 different Combined Task Forces requesting resources for roughly 300 flying missions each week, manual scheduling is a difficult task. The current process takes a team of schedulers several days to get a workable result from which they can start tailoring the final schedule. While concepts and techniques can be taken from industry scheduling problems, the body of …

Aerial Port Of The Future: Developing Paperless Operations, Peter J. Williams

Theses and Dissertations

Air Mobility Command (AMC) is combatting manning mismatches with antiquated processes and equipment in Aerial Port operations, and has chosen to address these issues through an initiative called “Aerial Port of the Future.” This initiative is designed to understand challenges in Aerial Ports and implement technological tools, where appropriate, to aid AMC Airmen in their duties of transporting goods and personnel through military channels. Oftentimes, personnel are forced to utilize technology that may not meet their needs, and in turn may resist implementation of the imposed technology. Therefore, first, this research identifies potential technologies designed to improve Aerial Port efficiency …

Assessing The Reliability Of The B-1b Lancer Using Survival Analysis, Francisco J. Rodriguez

Theses and Dissertations

During the 2017 posture statement to the US Senate Armed Services Committee, the Secretary of the Air Force and Chief of Staff of the Air Force stated the Air Force suffers from shrinking aircraft inventory, aging aircraft fleets, and flying beyond the expected service life. These trends are not an exception to the B-1B Lancer, which has been in service since 1986. Recently, the B-1B Lancer has maintained the lowest mission capable (MC) rates of 47.7 percent. The purpose of this research is to explore the failure rates of the B-1B Lancer using survival analysis that investigates the failure behavior …

Utilizing Supercomputing To Analyze Risks Of An Emergent Large-Scale Debris Field In Low Earth Orbit, David J. Buehler

Theses and Dissertations

The likelihood of on-orbit breakups, whether spontaneous or the result of collision, will likely continue to grow as the barriers of entry to and use of space are reduced. In all orbital regimes, especially low Earth orbit (LEO), preparation to respond quickly when the next breakup occurs is critical. This research utilizes high-performance parallel computation along with python-driven Systems Tool Kit (STK) to model a large-scale on-orbit breakup in LEO, with the goal of returning data in less than 90 minutes. The breakup is characterized by the National Aeronautics and Space Administration (NASA) EVOLVE 4.0 breakup model and is both …

An Analysis Of Aircraft Operating And Support Cost Element Structures, Garrett B. O'Hanlon

Theses and Dissertations

As the cost of DoD Weapon Systems continue to increase, the ability to more accurately predict the Operating and Support (O&S) costs for the various weapon systems has become more vital for long run affordability. The investigation into the O&S arena has been overshadowed by the research and development (R&D) and acquisition fields. This research focuses on the O&S portion of the total life cycle costs, specifically the OSD-CAPE Cost Element Structure (CES) elements and sub-elements. The research investigates seven categories of 52 aircrafts and their cost expenditures within the CES from the years 1996-2016. The first portion of the …

The Effect Of Ms2 Bacteriophage On The Activity And Performance Of Activated Sludge, Sean M. Stuntz

Theses and Dissertations

As a medical waste product, the MS2 bacteriophage has been discharged into wastewater distribution and treatment networks. To categorize its impact to suspended growth treatment methods, this research investigated the effect of the MS2 bacteriophage on activated sludge through a series of respirometry tests. The effects of MS2 bacteriophage at a concentration of 3.2x10⁸ PFU/mL were assessed by determining peak O₂ consumption, cumulative O₂ consumption, molar CO₂/O₂ ratios, and shape factors. None of the MS2 samples caused statistically significant effects on the peak or cumulative O₂ consumption. The molar CO₂/O_{2 …}

Development Of Product Recyclability Index Utilizing Design For Assembly And Disassembly Principles, Darshan P. Yadav, Deep N. Patel, Beshoy W. Morkos

Mechanical and Civil Engineering Faculty Publications

Designing products for recyclability is driven by environmental and economic goals. Several design for assembly (DFA) rules and parameters can be used to gauge the recyclability index of product designs. These indices can be used for comparative analysis of the recyclability of different products. This assists the designer in making design choices related to the product's end of life. However, many of the existing recyclability indices are only available after design and manufacturing decisions are made. If such design decisions could be made earlier in the design process, when the design space is less bound, recyclability could be considered earlier. …

Comparative Analysis Of Designing Solar And Geothermal Power Plants: A Case Study, Roberto Venegas, Sarada Kuravi, Krishna Kota, Mary Helen Mccay

Mechanical and Civil Engineering Faculty Publications

Geothermal and solar thermal are renewable, clean energy sources with immense potential for electricity generation. Concentrating Solar Power can achieve very high temperatures and high efficiencies compared to geothermal power plants. However, it is intermittent and must be coupled with thermal storage or another source for continuous power generation. Geothermal resources exist in varying temperatures but are too small for economic power production; however, it is not intermittent. This paper briefly summarizes the location-specific design considerations for geothermal and solar thermal plants. The performance of both these types of power plants is analysed in terms of capacity factor, thermal energy …

Mechanical Behavior Of Three-Dimensional Braided Nickel-Based Superalloys Synthesized Via Pack Cementation, Nicolas Lippitz, Dinc Erdeniz, Keith W. Sharp, David C. Dunand

Mechanical Engineering Faculty Research and Publications

Braided tubes of Ni-based superalloys are fabricated via three-dimensional (3-D) braiding of ductile Ni-20Cr (wt pct) wires followed by post-textile gas-phase alloying with Al and Ti to create, after homogenization and aging, γ/γ′ strengthened lightweight, porous structures. Tensile tests reveal an increase in strength by 100 MPa compared to as-braided Ni-20Cr (wt pct). An interrupted tensile test, combined with X-ray tomographic scans between each step, sheds light on the failure behavior of the braided superalloy tubes.

Overview Of Performance Based Practical Design, Christopher W. Van Dyke, Jeff Jasper, Adam J. Kirk

Kentucky Transportation Center Research Report

State transportation agencies (STAs) have increasingly turned to practical design and performance based practical design (PBPD) to inform project development and implementation — and to reduce project costs while optimizing systemwide benefits. PBPD is a design-up philosophy that encourages agencies to formulate projects to meet the purpose and need rather than adhering to ostensibly immutable design standards. This paper reviews practical design and PBPD concepts and initiatives and their application in a variety of contexts. It also summarizes best practices STAs can use to develop a PBPD program. As a holistic approach to project design, PBPD underscores context sensitive solutions …

Cal Poly Rose Float Overheight Mechanism, Ali A. Harake, Breanna H. Tran, Morgan K. Montalvo, Sergio B. Gutierrez

Mechanical Engineering

The Cal Poly Universities jointly build and enter a floral entry, commonly known as a float, into the Pasadena Tournament of Roses Rose Parade. At the end of this parade route, there is a 16’6” bridge all floats must drive under. The scope of our project is to design and build a mechanism roughly described as an “overheight” mechanism, as its function is to raise and lower large heavy structures so the float is able to pass under the bridge. This hydraulic mechanism is powered via the float animation system.

Nanostructural Origin Of Semiconductivity And Large Magnetoresistance In Epitaxial Nico2O4/Al2O3 Thin Films, Congmian Zhen, Xiaozhe Zhang, Wengang Wei, Wenzhe Guo, Ankit Pant, Xiaoshan Xu, Jian Shen, Li Ma, Denglu Hou

Xiaoshan Xu Papers

Despite low resistivity (~1 mΩ cm), metallic electrical transport has not been commonly observed in inverse spinel NiCo₂O₄, except in certain epitaxial thin films. Previous studies have stressed the effect of valence mixing and the degree of spinel inversion on the electrical conduction of NiCo₂O₄ films. In this work, we studied the effect of nanostructural disorder by comparing the NiCo₂O₄ epitaxial films grown on MgAl₂O₄ (1 1 1) and on Al₂O₃ (0 0 1) substrates. Although the optimal growth conditions are similar for the …

Review: Electric Field Driven Pumping In Microfluidic Device, Mohammad R. Hossan, Diganta Dutta, Nazmul Islam, Prashanta Dutta

Electrical and Computer Engineering Faculty Publications

Pumping of fluids with precise control is one of the key components in a microfluidic device. The electric field has been used as one of the most popular and efficient nonmechanical pumping mechanism to transport fluids in microchannels from the very early stage of microfluidic technology development. This review presents fundamental physics and theories of the different microscale phenomena that arise due to the application of an electric field in fluids, which can be applied for pumping of fluids in microdevices. Specific mechanisms considered in this report are electroosmosis, AC electroosmosis, AC electrothermal, induced charge electroosmosis, traveling wave dielectrophoresis, and …

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

• Students Ace Certified SOLIDWORKS Associate Exam

Numerical Study Of Lateral Migration Of Elliptical Magnetic Microparticles In Microchannels In Uniform Magnetic Fields, Jie Zhang, Cheng Wang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This work reports numerical investigation of lateral migration of a paramagnetic microparticle of an elliptic shape in a plane Poiseuille flow of a Newtonian fluid under a uniform magnetic field by direct numerical simulation (DNS). A finite element method (FEM) based on the arbitrary Lagrangian–Eulerian (ALE) approach is used to study the effects of strength and direction of the magnetic field, particle–wall separation distance and particle shape on the lateral migration. The particle is shown to exhibit negligible lateral migration in the absence of a magnetic field. When the magnetic field is applied, the particle migrates laterally. The migration direction …

The "Double Standard" Of Nonproliferation: Regime Type And The U.S. Response To Nuclear Weapons Program, Alina Shymanska

International Journal of Nuclear Security

There is no doubt that the NPT regime is far from being equal for all states involved. As the predominant hegemonic power since WWII, the United States plays a major role in deciding the fates of non-great power proliferators. This article tries to find the logical explanation of the phenomenon whereby some nuclear proliferators are absolved regardless of their active accumulation of nuclear arsenals while others are labeled as “rogue states” and ordered to disarm. The article suggests that a particular proliferator’s political regime could affect the way in which its state is approached by the U.S., known for its …

A Continuum Model Of Mucosa With Glycan-Ion Pairing, James D. Sterling, Shenda M. Baker

Business and Information Technology Faculty Research & Creative Works

Advances in the study of glycosoaminoglycan biohydrogels, label-free electrokinetic analysis of soft-diffuse layers in contact with saline solutions, and elucidation of ion-specific behavior in many biochemical systems offer the opportunity to marry these principal features in a new mathematical model of the mucosal glycocalyx. The model is based on the electroquasistatic subset of Maxwell's equations in the form of the steady-state continuum Poisson–Boltzmann equation for electrostatics with explicit incorporation of pairwise binding of ions to fixed charged-groups in the hydrogel. The pairwise association is modeled using reversible bimolecular reactions via stoichiometric dissociation constants that represent the rule of matching water …

Drafting In Self-Timed Circuits, Christopher Cowan

Electrical and Computer Engineering PhD Day

Intervals between data items propagating in self-timed circuits are controlled by handshake signals rather than by a clock. The sequence of handshakes can be abstracted as the movement of “tokens”. In many self-timed designs, a trailing token will catch up with a leading token, even when it trails by thousands of gate delays. Simulations in SPICE of a simple GasP circular FIFO reveal this effect. Contrary to earlier work, we find the cause of drafting to be charge stored on an isolated node between two series transistors. This mechanism occurs in many decision gates that implement a logical AND. The …

Skylux Smartphone Controlled Skylight, James A. Green Vi

Computer Engineering

There are numerous electric skylight openers available for purchase for home-use, but the majority of them are remote based, or operated by a wall-unit. Furthermore, these devices are in hard to reach places, so if one were to lose the remote on a remote operated system, the only option is to contact the manufacturer for a new device. As such, my senior project, in collaboration with Colton Sundstrom’s senior project, build upon our existing capstone project in order to allow operation of the Internet of Things (IoT) device over the internet. Our client, Richard Murray, was unsatisfied with the current …

Human Factors Contributing To Unstabilized Approaches And Landings In Commercial Aviation Incidents: An Analysis Of Asrs Reports, Garrin E. Ross

Doctoral Dissertations and Master's Theses

The purpose of this study was to investigate the human factors reported as contributing to operational incidents of unstabilized approaches and landings in United States-based commercial aviation. While previous aviation safety studies have analyzed aviation incident data when investigating the human factor influences during commercial aviation operations and incidents, unstabilized approaches and landings have not been explicitly examined using similar methods. Informed by the findings and recommendations of the Flight Safety Foundation’s Approach and Landing Accident Reduction Task Force, this study examined and analyzed the Aviation Safety Reporting System (ASRS) incident report data from unstabilized approach and landing events. The …

Manufacturing Of A Carbon Fiber Part With Complex Geometry, Caitlyn Pellemeier, Eric Rodan, Alex King, Nicolas Carlucci

Mechanical Engineering

The purpose of this study is to determine the best method for manufacturing a part with precision tolerances and a small deflection requirement. The desired tolerances include a flatness of 0.002in, parallelism of 0.005in, heat tolerance of 60℃, and a max deflection at the loaded end of the part of 0.28mm. To accomplish this, our team uses carbon fiber as the part material because compared to traditional metals it is stiffer and lighter. Carbon fiber molding processes are explored and narrowed down to Liquid Composite Molding (LCM) and Resin Transfer Molding (RTM). These processes use dry fiber combined with epoxy …

Powder Bed Surface Quality And Particle Size Distribution For Metal Additive Manufacturing And Comparison With Discrete Element Model, Irene Yee

Master's Theses

Metal additive manufacturing (AM) can produce complex parts that were once considered impossible or too costly to fabricate using conventional machining techniques, making AM machines an exceptional tool for rapid prototyping, one-off parts, and labor-intensive geometries. Due to the growing popularity of this technology, especially in the defense and medical industries, more researchers are looking into the physics and mechanics behind the AM process. Many factors and parameters contribute to the overall quality of a part, one of them being the powder bed itself. So far, little investigation has been dedicated to the behavior of the powder in the powder …

Modular Utility Rack And Accessory Line, Ian Philip Thomas

Construction Management

There is a large gap in the market for heavy duty work racks for fleet vehicles. Modular racks have recently been introduced to the industry allowing contractors the ability to customize them to their needs. However, all customizable racks are limited to lightweight applications. The high strength steel rack I have designed is both modular, and sturdy enough to handle up to an estimated one thousand pounds. On our website, contractors will be able to scroll through the available attachments for his make and model rack and view them built on to his vehicle in 3D computer generated graphics.

Corrosion Behavior Of Plasma Nitrided And Nitrocarburised Supermartensitic Stainless Steel, Frederico Augusto Pires Fernandes, Carlos Alberto Picone, George Totten, Luiz Carlos Casteletti

Mechanical and Materials Engineering Faculty Publications and Presentations

Supermartensitic stainles steels (SMSS's) are a new generation of martensitic steels that have been increasingly used in oil and gas applications due to their adequate corrosion resistance and mechanical properties. In the present study, SMSS specimens (UNS S41425) were solution heat treated and air cooled followed by plasma nitriding and nitrocarburising at 400, 450 and 500°C for 5h. The produced layers were characterized by optical microscopy, microhardness testing, X-ray diffraction and corrosion testing in NaCl 3.5% solution. Surface alloying with nitrogen or both nitrogen and carbon results in increased surface hardness and homogeneous layers in which layer thickness increases with …