Engineering Commons^™

Mining Dynamic Recurrences In Nonlinear And Nonstationary Systems For Feature Extraction, Process Monitoring And Fault Diagnosis, Yun Chen

USF Tampa Graduate Theses and Dissertations

Real-time sensing brings the proliferation of big data that contains rich information of complex systems. It is well known that real-world systems show high levels of nonlinear and nonstationary behaviors in the presence of extraneous noise. This brings significant challenges for human experts to visually inspect the integrity and performance of complex systems from the collected data. My research goal is to develop innovative methodologies for modeling and optimizing complex systems, and create enabling technologies for real-world applications. Specifically, my research focuses on Mining Dynamic Recurrences in Nonlinear and Nonstationary Systems for Feature Extraction, Process Monitoring and Fault Diagnosis. …

Educators’ Resistance To The Technology And Engineering Education Transition, Kenneth L. Rigler Ph.D.

Applied Technology Faculty Publications

The purpose of the qualitative grounded theory study was to explore why industrial arts educators resisted organizational change to technology and engineering education. An exploratory, grounded theory method was used to identify new theory related to educators’ resistance because the current literature did not provide a theoretical perspective about why industrial arts educators have resisted the change. The sampling frame was derived from a database of 379 secondary technology and engineering education teachers in the state of Kansas, and a sample size of 13 participants was needed to reach theoretical saturation of the phenomenon. The data for the study was …

Densification Of W-Ni-Fe Powders Using Laser Sintering, Xuan Wang, Matthew Wraith, Stephen Burke, Howard Rathbun, Kyle Devlugt

Industrial and Manufacturing Engineering

In this paper, Laser Sintering (LS) of 90%W–7%Ni–3%Fe (wt.%) powders have been investigated, with the goal to understand the influence of final density by laser power, scanning speed, laser trace width, and the number of scanning passes. The results suggest that the laser power and scanning speed are the most important factors influencing density; the influence of trace width and number of scanning passes are not significant. With the increase of laser power and decrease of scanning speed, higher density can be achieved. The microstructure analysis indicated that the porosity changed from open porosity to closed porosity with higher laser …

In The Face Of Anticipation: Decision Making Under Visible Uncertainty As Present In The Safest-With-Sight Problem, Bryan A. Knowles

Masters Theses & Specialist Projects

Pathfinding, as a process of selecting a fixed route, has long been studied in

Computer Science and Mathematics. Decision making, as a similar, but intrinsically different, process of determining a control policy, is much less studied. Here, I propose a problem that appears to be of the first class, which would suggest that it is easily solvable with a modern machine, but that would be too easy, it turns out. By allowing a pathfinding to anticipate and respond to information, without setting restrictions

on the \structure" of this anticipation, selecting the \best step" appears to be an intractable problem.

After …

Optimization Of Process Parameters In Micro Electrical Discharge Machining (Edm) Of Ti-6al-4v Alloy, Farshid Alavi

Masters Theses & Specialist Projects

Ti-6Al-4V has a wide range of applications such as in the automotive and aerospace industries. Nevertheless, titanium alloys are very difficult to machine by conventional methods. Micro-EDM is a non-conventional machining method that uses the thermal effect of precisely controlled sparks. Manufacturers are looking for the methods and optimal settings to increase the productivity of micro-EDM in terms of lessening machining time and tool wear. Moreover, surface integrity of the machined area is crucial for some products such as biomedical implants.

The objective of this study was to investigate the effects of the micro-EDM process parameters on response variables, in …

Breakdown Voltage Performances Of Aluminum And Copper Conductor Wire Under Compression Stresses, Richard Donald Suchanek Iii

Masters Theses & Specialist Projects

In the global, competitive market of energy transformation, increased operational expenses and depletion of raw materials have resulted in companies pursuing alternate materials to reduce consumer costs. In electrical applications, energy is transformed using materials with high electrical conductive properties. The conductive material used to transmit a signal is called conductor wire and is comprised of any material that has the ability to move charged particles from one point to another without propagation or delay. The conductor wire in many applications is encapsulated in epoxy resin called enamel. The enamel is the insulation system that provides necessary dielectric clearances to …

The Casualty Transportation Of Ebola Outbreak In Liberia: A Simulation Study, Hyejin Cho

Open Access Theses

In this paper, we have solved the unique problem of casualty transportation problem under Ebola by developing dynamic policies for vehicle routing in order to provide practical decision support. The objective of the proposed model is to minimize the total transmission risk. We describe the problem with real- constraints and parameters based on the empirical data of the 2014 Ebola outbreak in Liberia. The casualty transportation problem is a variant of Dynamic Pick-up and Delivery Problems (DPDP), in which a vehicle is dispatched to demand location in real time and it then transports the demands to the aimed area (destination). …

Developing Agent-Based Simulation Models Of Task Performance Of Cognitively Diverse Teams, Megan Marie Nyre

Open Access Theses

Team-oriented work dominates industry, government, and academic areas with the goal of solving increasingly complex problems. However, the scope and external validity of traditional human factors research is inherently limited by the time and resources required to conduct laboratory studies. The model described in this thesis integrates simulation with human factors by providing an operationalized model that incorporates cognitive diversity and domain expertise. Convergence and functionality of the model have been established through a series of analyses, and a clear path for future research has been identified. By integrating simulation methods into human factors subject areas, researchers may be able …

A Case Study Of Two-Echelon Multi-Depot Vehicle Routing Problem, Tianqi Yu

Open Access Theses

The Vehicle Routing Problem (VRP) is a classic combinatorial optimization problem and a topic still studied for practical applications. Current research focuses on single echelon distribution systems such as distribution centers serving customers. However, in typical distribution, goods flows among regional distribution centers, local warehouses and customers, defined as a two-echelon network. The two-echelon multiple depot VRP problem is documented and applied to two stages illustrated by a small scale computational example. In the first stage, the simulated annealing algorithm is employed to determine the routes between local warehouses and final customers. For the second stage, trial-and-error is applied to …

A Retrospective Study Of Amusement Ride Restraint And Containment Systems: Identifying Design Challenges For Statistically Rare Anthropometric Cases, Paula M. Stenzler

Engineering Management & Systems Engineering Theses & Dissertations

The intent of this project was to conduct a retrospective study of amusement ride restraint and containment systems’ failures to identify the challenges associated with existing design criteria to safely accommodate statistically rare groups that fall outside amusement industry standards. Innovations in ride technology provide an opportunity for injuries to occur if restraint and containment systems cannot properly accommodate unique patron anthropometry. It is paramount to understand how anthropometric features contribute to the patron’s ability to defeat ride restraint and containment systems. A systemic perspective was used based on industry accident data to frame the problem associated with restraint and …

Multi-Level Analytic Network Process Model To Mitigate Supply Chain Disruptions In Disaster Recovery Planning, Martina Ursula Kroener

Master's Theses

Over the past few decades, environmental changes have led to more frequent occurrences and greater intensities of natural disasters worldwide. In terms of globally connected supply chains, this has resulted in an enormous economical loss for corporations. Therefore, Business Continuity and Disaster Recovery (BC/DR) planning and management has become essential for businesses in order to protect their critical business flow. Yet there is a lack of systematic and transparent methodologies for companies to handle this problem.

Hence, this thesis introduces a novel approach to combine consecutive steps of the Disaster Recovery Planning (DRP) process within one application. The multi-criteria decision-making …

Interactive Spatiotemporal Analysis Of Oil Spills Using Comap In North Dakota, Yong Shin Park, Hamad Al-Qublan, Eunsu Lee, Gokhan Egilmez

Mechanical and Industrial Engineering Faculty Publications

The aim of the study is to analyze the oil spill pattern from various types of incidents and contaminants to determine the extent that incident data can be used as a baseline to prevent hazardous material releases and improve response activities at a state level. This study addresses the importance of collecting and sharing oil spill incidents as well as analytics using the data. Temporal, spatial and spatiotemporal analysis techniques are employed for the oil-spill related environmental incidents observed in the state of North Dakota, United States of America, from 2000 to 2014, as a result of the oil boom. …

A "Big Bang" Versus A "Small Bang" Approach: A Case Study Of The Expeditionary Combat Support System (Ecss) And The Maintenance, Repair, And Overhaul Initiative (Mroi), George B. Lafiguera

Theses and Dissertations

In 2003, the United States Air Force embarked on one of the largest and most comprehensive logistical transformation to delineate the logistics community’s strategy for supporting the warfighter. A key aspect of this campaign plan was to leverage information technology through an enterprise resource planning (ERP) solution called the Expeditionary Combat Support System (ECSS), a “big-bang” approach. In early 2012, the ECSS program was cancelled mainly due to uncontrollable increases in costs and schedule overruns. In late 2012, the Air Force Sustainment Center (AFSC) launched the Maintenance, Repair, and Overhaul initiative (MROi), a “small-bang” approach, to increase enterprise visibility and …

A Logistic Regression And Markov Chain Model For The Prediction Of Nation-State Violent Conflicts And Transitions, Nicholas Shallcross

Theses and Dissertations

Using open source data, this research formulates and constructs a suite of statistical models that predict future transitions into and out of violent conflict and forecasts the regional and global incidences of violent conflict over a ten-year time horizon. A total of thirty predictor variables are tested and evaluated for inclusion in twelve conditional logistic regression models, which calculate the probability that a nation will transition from its current conflict state, either In Conflict or Not in Conflict, to a new state in the following year. These probabilities are then used to construct a series of nation-specific Markov chain models …

Determining The Degree Of The Routinization Of Additive Manufacturing In The Air Logistics Complexes, Candis A. Woods

Theses and Dissertations

Fiscal constraints have affected the USAF’s spending and sustainment of weapons systems that are being utilized beyond their programmed life cycle; therefore, it is imperative that processes be given the critical eye for improvement, innovative approaches, and/or best practice implementation. The AFSC, part of the AFMC, has embarked on a groundbreaking effort to transform operations and leverage industry best practices, while maintaining focus on warfighter support to create “The AFSC Way.” The AFSC Way is based on a shared leadership model that emphasizes speed, safety, and quality, which gives way to innovative ideas and new technologies in order to achieve …

A Model Of Ambient Noise Caused By Wind Flow, Jovan Popovich

Theses and Dissertations

The generation of noise caused by wind owing past a human ear is an important yet vastly understudied factor in determining the ambient noise of an environment experienced by a human observer. Sound level measurements were obtained from wind tunnel tests simulating a human experiencing wind ows at various speeds and from various directions. This data set was used in this thesis. This thesis presents a collection of models for predicting wind noise levels across a broad spectrum of frequencies based on wind speed and angle inputs. Graphical approaches are included to characterize the observed data and illustrate the models' …

United States Air Force Officer Manpower Planning Problem Via Approximate Dynamic Programming, Amelia E. Bradshaw

Theses and Dissertations

The United States Air Force (USAF) is concerned with managing its officer corps to ensure sufficient personnel for mission readiness. Manpower planning for the USAF is a complex process which requires making decisions about accessions. Uncertainty about officer retention complicates such decisions. We formulate a Markov decision process model of the Air Force officer manpower planning problem (AFO-MPP) and utilize a least squares approximate policy iteration algorithm as an approximate dynamic programming (ADP) technique to attain solutions. Computational experiments are conducted on two AFO-MPP instances to compare the performance of the policy determined with the ADP algorithm to a benchmark …

Using Multiple Objective Decision Analysis To Position Federal Product And Service Codes Within The Kraljic Portfolio Matrix, Robert T. Montgomery

Theses and Dissertations

Despite the best efforts of the Federal Government to implement strategic sourcing, recent Government Accountability Office (GAO) reports highlight major procurement deficiencies and encourage the use of commercial best practices to identify and reap substantial savings. The Kraljic Portfolio Matrix (KPM) is considered the premier tool for purchasing organizations to determine which commercial best practices to utilize for different categories of spend. However, critics of the KPM point to its lack of analytical rigor and the absence of a simplistic quantitative methodology for implementation. The Air Force Installation Contracting Agency (AFICA), the centralized procurement arm for 79 USAF installations worldwide, …

Contingency Workload Demand Forecast Techniques For Cargo And Flying Hours, Calvin J. Bradshaw Iii

Theses and Dissertations

Accurate forecasting of contingency workload demand for USTRANSCOM (USTC) is a herculean effort. Transportation Working Capital Fund (TWCF) managers rely on various subject matters outside and within the combatant command to estimate future workload. Since rates are set annually, when TWCF activities use incorrect or incomplete projections of workload, this leads to erroneous price structures and misaligned customer billing rates. The USTC leadership lacks the ability to accurately forecast workload demand, which is a key driver for service provider rate-setting. As a result, some customers perceive spiked rates and seek service from other competitors, which generates lost revenue, customer dissatisfaction …

Application Of Non-Rated Line Officer Attrition Levels And Career Field Stability, Christine L. Zens

Theses and Dissertations

The Air Force monitors the strength of its active duty officer force and attempts to achieve the difficult challenge of employing a diversity of talent among career specialties and experience levels. This study completes two objectives, predicting future manning levels for 23 career fields, and providing a statistical framework to assess the stability of these fields. The first part of the study applies regression and survival analysis to subpopulations within the active duty Air Force officer corps, and then aggregates them by year to forecast future personnel levels. Four career fields are considered, including Acquisitions (ACQ), Logistics (LOG), Support (SPT), …

Modeling The Components Of An Economy As A Complex Adaptive System, Richard J. Mickelsen

Theses and Dissertations

Complex systems science is a relatively new discipline and has not been widely applied to the field of economics. Much of current economic theory relies on principles of constrained optimization and often fails to see economic variables as part of an interconnected network. While tools for forecasting economic indicators are based primarily on autoregressive techniques, these techniques are not always well-suited to predicting the future performance of highly volatile data sets such as the stock market. This research portrays the stock market as one component of a networked system of economic variables, with the federal funds rate acting as an …

Rate Setting Analysis: A Statistical Approach To Outlier Analysis In The Rate Setting Process Within The United States Transportation Command, Warren B. Mcgriff

Theses and Dissertations

The rate setting process implemented by the USTRANSCOM J8 Program Analysis & Financial Management Directorate (USTC J8 or TCJ8) is of importance, as accurate rates yield proper and equitable recoupment of costs from customers and ensure USTC can achieve an accurate Net Operating Result (NOR) in each given year. This research sought to identify areas in which the current rate setting methodology can be improved. We initially examined the use of six months of historical cost data versus a full year of data to set rates, concluding that there is not a statistically significant difference with respect to their relative …

Long-Term Impacts Of Military Drawdown On The Industrial Base, Anton H. Martyn

Theses and Dissertations

Since World War II, competition in the defense industry has fallen by over 90 percent. Over half of contracts currently executed by the United States Navy and Air Force are awarded without any competition. With the recent defense budget cuts, and an extended period of reduced defense spending ahead, more of which is going to sustainment and overhead than ever before, each year prime contractors are fighting over an even smaller piece of the procurement pie, which could have a deleterious effect on national security if these contractors go out of business or further consolidate through mergers. This study used …

A Response Surface Validation Of A Quantum Key Distribution Model, Jacob M. Ehrlich

Theses and Dissertations

The need for secure communication in the presence of an adversary introduced the field of cryptology -- the practice and study of techniques for secure communication. A common method to secure communication is to distribute a secret key among authorized parties so they can encrypt and decrypt messages between each other. By doing so, ideally, any messages intercepted by a third party are meaningless. An innovative technique to distribute a shared key is Quantum Key Distribution (QKD). QKD uses laws of quantum mechanics to generate and distribute such keys. The purpose of this thesis is to validate an existing mathematical …

Modeling And Economy’S Dynamics And External Influences Through A System Of Differential Equations, Thomas M. Dickey

Theses and Dissertations

This research proposes a methodology to develop models for the greater understanding of the application of the economic instrument of national power through a selection of factors that define the economic condition of a country. The major components of an economy are identified as GDP per capita, a treasury bond yield, and a major stock market index. The components have interconnected dynamics along with external influences from the United Stated Federal Funds Rate and foreign direct investment. These connections are considered through a metamodel in the form of a system of differential equations which is solved as an inverse problem. …

Overhaul Facility Planning And Control Tool Selection And Implementation Analysis, Santiago L. Martin

Theses and Dissertations

The Argentine Air Force Materiel General Directorate (AAFMGD) has initiated an effort to assure logistical support and to gradually increase the productivity and efficiency of related processes. Within the efforts of increased productivity and efficiency over the AAF Overhauling Facilities, the Planning and Control Departments (PCD) became targets for improvements. These departments are tasked with providing the best certainty and visibility of all assets within their facilities to feed the logistics pipeline, and better support air operations. This thesis, sponsored by the MGD, is focused on achieving improvements in the PCD processes, through an academically rigorous evaluation of confounding factors …

Heterogeneous Air Defense Battery Location: A Game Theoretic Approach, Nicholas T. Boardman

Theses and Dissertations

The Unites States and its allies confront a persistent and evolving threat from missile attacks as nations around the world continue to invest and advance their current capabilities. Within the air defense context of a missile-and-interceptor engagement, a challenge for the defender is that surface to air interceptor missile batteries often must be located to protect high-value targets dispersed over a vast area, subject to an attacker observing the disposition of batteries prior to developing and implementing an attack plan. To model this scenario, we formulate a two-player, three-stage, perfect information, sequential move, zero-sum game that accounts for, respectively, a …

Epidemiology, Cost, And Aircraft Choice For Aeromedical Evacuation In Africom, Daniel A. Griffith

Theses and Dissertations

A significant shortfall exists in the medical capability provided to US Service members deployed to the African Area of Responsibility because of unknown epidemiology, large distances, limited resources, and high patient movement cost. The first step in closing this gap is to understand the types, demographics, diagnoses, and distribution of the patients requiring aeromedical evacuation. This research examined the DoD’s aeromedical evacuation missions from Africa between 2010 and 2014. Of the 274 patients and 170 missions identified from available data, a gap is evident in aeromedical evacuation capability with over 23% of Priority patients and almost 10% of Urgent patients …

Determining Air Base Installation Capacity Through Multivariate Analysis, Perry L. Cansick

Theses and Dissertations

Per the Air Force Strategic Master Plan, the Air Force will adjust their current basing structure to provide the most effective and efficient installations to support national defense objectives. The Air Force may be required to make strategic basing decisions that close installations and relocate missions to achieve an optimal basing structure. However, before making these decisions, the Air Force needs to have a comprehensive understanding of installation capacity. This research provides an operational definition of installation capacity, which is necessary for measuring installation-level, infrastructure capacity. Using this definition, the research evaluates a set of capacity indicators using principal component …

Logistics Simulation For Long Duration Logistics Wargames, Kevin R. Cardenas

Theses and Dissertations

Wargames were originally created to test wartime strategies against opposing forces within a short time frame. Due to the short duration design of these wargames, logistics were deemed irrelevant and it was incorrectly assumed that the warfighter would be logistically supported for the entire duration of the wargame. The purpose of this thesis is to provide insight to the value of capturing logistics within a wargame and to better model the increased requirement for Agile Combat Support. This research utilizes a logistics simulation tool and its outputs to conduct statistical analyses comparing a baseline scenario created to mirror the Joint …