Digital Commons Network^™

A Heuristic Method For The Determination Of Assembly Network And Line Design For Discrete Manufacturing Processes, Ismael Hernan Naranjo Velez

Theses and Dissertations

This paper presents with a proposed alternative precedence algorithm which is determined by the Solid surfaces of the product design. The representation address in this paper address the manufacturing planning from all manufacturing levels of the product. Sequence is introduce to this paper in order to proof the propose precedence network alternatives. Both manufacturing level solutions are heuristic. This thesis explores the connection of the precedence and the sequence, as it introduces physical manufacturing constraints and its relationships to the station process planning. Precedence network are usually determine by the designer principal point and assembled connections. The proposed algorithm avoids …

Model Based Systems Engineering High Level Design Of A Sustainable Electric Vehicle Charging And Swapping Station Using Discrete Event Simulation, Obinna Henry Ginigeme

Theses and Dissertations

In line with the spate of technological advances, the transportation industry has also witnessed an increase in the adoption of Electric Vehicles (E.Vs). However, there has been and are still some underlying negating factors to the wide spread acceptance of these electric vehicles; one of note is the unavailability and inaccessibility of adequate charging infrastructure, long charging times, limited driving ranges, costs of the vehicles etc. These and many more characteristics lead to a trend popularly known as “range anxiety”. One of the major strengths of electric vehicles are their ability to be powered by electric energy via stored chemical …

An Analysis Of The Size And Impact Of Digital Footprints, Whitney Nielsen Maxwell

Theses and Dissertations

Personal information available online is known as a digital footprint. While many have a digital footprint, few if any, know what it encapsulates or how to control it. Technology and personal information are becoming more intertwined as technology becomes more integrated with everyday activities. Personal information can be defined as details that apply to a person such as race or shopping habits. Shopping habits are considered personal information by many corporations who spend money to track, or even predict purchases of individuals, whereas more traditional forms of personal information are details like gender, birthdate, and home town. With a wide …

Strain Path Effect On Austenite Transformation And Ductility In Q&P 1180 Steel, Jeffrey Grant Cramer

Theses and Dissertations

The ductility of Q&P 1180 steel was studied with regard to retained austenite transformation under different strain paths. Specimens were tested in uniaxial tension in a standard test frame as well as in situ in the scanning electron microscope (SEM). Then digital image correlation (DIC) was used to compute the effective strain at the level of the individual phases in the microstructure. Stretching experiments were also performed using limiting dome height (LDH) tooling, where specimens were strained in both biaxial and plane strain tension. The experiments were done incrementally, for each strain path, and the retained austenite at each level …

Evaluating Process Improvement Courses Of Action Through Modeling And Simulation, Joseph R. Owens

Theses and Dissertations

Quantifying an expected improvement when considering moderate-complexity changes to a process is time consuming and has potential to overlook stochastic effects. By modeling a process as a Numerical Design Structure Matrix (NDSM), simulating the proposed changes, and evaluating performance, quantification can be rapidly accomplished to understand stochastic effects. This thesis explores a method to evaluate complex process changes within Six Sigma DMAIC process improvement to identify the most desirable outcome amongst several improvement options. A tool to perform the modeling and evaluation is developed. This process evaluation tool is verified for functionality, then is demonstrated against generic processes, a case …

Effect Of Fused Filament Fabrication Process Parameters On The Mechanical Properties Of Carbon Fiber Reinforced Polymers, Abdulrahman S. Alwabel

Theses and Dissertations

Carbon fiber reinforced polymer manufactured using additive manufacturing process is relatively a new process. The ability to predict the mechanical properties of these parts with high confidence will spread the use of these high-strength materials in more applications. The purpose of this research was to determine the effect of the build time between successive layers, arrangement of fiber and nylon layers, fiber start location, and the use of support material on the mechanical properties CFRP produced by additive manufacturing process using the MarkForged (MarkOne) 3D printer. A design of experiment (DOE) we preformed to develop a mathematical model describing the …

Introduction Of Similarity Coefficient-Based Clustering Algorithms To Global Petrochemical Facility Location, Ali Saeed Alarjani

Theses and Dissertations

This research introduces a similarity coefficient-based clustering algorithm to determine the best location for a petrochemical manufacturing facility. The most global petrochemical critical attributes have been selected from relevant literature about manufacturing activities. These critical attributes have been quantified by real world numbers from the World Bank database and have been employed in the proposed model of the research. The model of the research uses the selected critical attributes data and clusters a hundred countries in similar groups according to their attractiveness level to the petrochemical facility location.

The outcomes of the developed model are classifications that show the potential …

Strategic Nurse Allocation Policies Under Dynamic Patient Demand, Osman Tuncay Aydas

Theses and Dissertations

ABSTRACT

STRATEGIC NURSE ALLOCATION POLICIES UNDER DYNAMIC PATIENT DEMAND

by Osman T. Aydas

The University of Wisconsin-Milwaukee, 2017

Under the Supervision of Professor Anthony D. Ross

Several studies have shown a strong association between nurse staffing and patient outcomes. When a nursing unit is chronically short-staffed, nurses must maintain an intense pace to ensure that patients receive timely care. Over time this can result in nurse burnout, as well as dissatisfied patients and even medical errors. Improved accuracy in the allocation of nursing staff can mitigate these operational risks and improve patient outcomes. Nursing care is identified as the single …

Optimal Warranty Period For Free-Replacement Policy Of Agm Batteries, Jennifer Paola Garantiva Poveda

Theses and Dissertations

The objective of this study is to analyze the suitability of the age-based warranty model and a millage based warranty model for absorbent glass mat batteries (AGM) for the automobile industry. The battery life expectancy can be assessed and described by a combination of different terms such as: state of health (SOH), deep of discharge (DOD), state of energy (SOE) and state of charge (SOC). However, using actual data from the field, the implementation of reliability engineering and statistical modeling we aim to calculate optimal limits for warranty policies that minimize warranty costs. The outcomes of this research will enable …

Geometry Driven Probabilistic Models For Shape Matching, Classification And Retrieval, Mark Matthew Moyou

Theses and Dissertations

Emulating human vision in a computational framework—known as computer vision—is one of the next major research areas being pursued; this emulation of vision can be viewed from a Systems Engineering perspective. The goal would be to design and develop an Intelligent Vision System built on a framework that could be tailored for specific vision applications. One of the fundamental components of vision is shape, so to design effective vision systems one needs to incorporate shape based algorithms as a core component. This dissertation progresses three facets of shape analysis algorithms: classification, retrieval and registration. Through the use of probabilistic models …

Concept Of Operations And High Level Requirements Framework For The Development Of A Computational Tool For Bridge Deterioration Analysis, Gabrielle Sue Leesman

Theses and Dissertations

In developing the lifecycles of a system, maintenance and support must be considered. Associated with this portion of the life cycle are periods between needs of maintenance and the cost of each type of maintenance. Previously a few state deterioration models have been created separately to better predict these maintenance cycles for varying ages, materials, traffic flow, and environmental conditions in the deck, substructure, and superstructure of bridges. A particular analysis tool from previous studies involves the development of Markov Chain (MC) models. This paper presents a systematic process to develop MC bridge deterioration models for state/federal transportation agencies. A …

Continuous Permeability Measurement During Unidirectional Vacuum Infusion Processing, David Wayne Hoagland

Theses and Dissertations

Composite materials have traditionally been used in high-end aerospace parts and low-end consumer parts. The reason for this separation in markets is the wide gap in technology between pre-preg materials processed in an autoclave and chop strand fiberglass blown into an open mold. Liquid composite molding has emerged as a bridge between inexpensive tooling and large, technical parts. Processes such as vacuum infusion have made it possible to utilize complex layups of reinforcement materials in an open mold style set-up, creating optimal conditions for composites to penetrate many new markets with rapid innovation. Flow simulation for liquid composite molding is …

Data Analysis And Processing Techniques For Remaining Useful Life Estimations, John Scott Bucknam

Theses and Dissertations

In the field of engineering, it is important to understand different engineering systems and components, not only in how they currently perform, but also how their performance degrades over time. This extends to the field of prognostics, which attempts to predict the future of a system or component based on its past and present states. A common problem in this field is the estimation of remaining useful life, or how long a system or component functionality will last. The well-known datasets for this problem are the PHM and C-MAPSS datasets. These datasets contain simulated sensor data for different turbofan engines …

The Application Of Artificial Neural Networks For Prioritization Of Independent Variables Of A Discrete Event Simulation Model In A Manufacturing Environment, Rebecca Pires Dos Santos

Theses and Dissertations

The high complexity existent in businesses has required managers to rely on accurate and up to date information. Over the years, many tools have been created to give support to decision makers, such as discrete event simulation and artificial neural networks. Both tools have been applied to improve business performance; however, most of the time they are used separately. This research aims to interpret artificial neural network models that are applied to the data generated by a simulation model and determine which inputs have the most impact on the output of a business. This would allow prioritization of the variables …

Measuring The Robustness Of Forensic Tools' Ability To Detect Data Hiding Techniques, Samuel Isaiah Moses

Theses and Dissertations

The goal of this research is to create a methodology that measures the robustness and effectiveness of forensic tools' ability to detect data hiding. First, an extensive search for any existing guidelines testing against data hiding was performed. After finding none, existing guidelines and frameworks in cybersecurity and cyber forensics were reviewed. Next, I created the methodology in this thesis. This methodology includes a set of steps that a user should take to evaluate a forensic tool. The methodology has been designed to be flexible and scalable so as new anti-forensic data hiding methods are discovered and developed, they can …

In Situ Characterization Of Voids During Liquid Composite Molding, Brock Don Zobell

Theses and Dissertations

Global competition is pushing the composites industry to advance and become more cost effective. Liquid Composite Molding or LCM is a family of processes that has shown significant promise in its potential to reduce process times and cost while maintaining high levels of part quality. However, the majority of research and information on composite processes have been related to prepreg-autoclave processing which is significantly different than LCM. In order for LCM processes to gain large scale implementation, significant research is required in order to model and simulate the unique nature of the resin infusion process. The purpose of this research …

Application-Driven Traffic Sensor System Acceptance Tests For Intelligent Transportation Systems, Thiago Goncalves Pereira Mendonca

Theses and Dissertations

Transportation agencies strive to keep people and goods moving. Operation and maintenance of transportation infrastructure is key to accomplish their objectives. Intelligent Transportation Systems (ITS) applications rely on massive detection grids that collectively demand significant maintenance resources. Resource constraints force transportation agencies to look for innovative ways to optimize their operational and maintenance costs while serving their users at intended performance levels. This paper presents a Systems Engineering (SE) view to derive traffic detection sensor requirements for components and subsystems based on application-specific needs. The goal of the approach is to obtain stakeholders view of an acceptable performance based on …

Facility Location Decision For Global Entrepreneurial Small-To-Medium Enterprises Using Similarity Coefficient-Based Clustering Algorithms, Suhail H. Serbaya

Theses and Dissertations

Decisions on location selection are critical for the survival of small-to-medium entrepreneurial organizations from the time they are established until later stages of operation and expansion. The selection of location for small and medium entrepreneurial businesses requires a selection strategy that incorporates relevant factors, quantifies these factors and develops a methodology that analyzes data for better decision-making. In the era of globalization where borders have become easier to transcend, many small ventures tend to choose more attractive international markets as a potential location for their operations where they can obtain higher returns on their investment. Thus, significant changes in the …

Forecasting Of Core Returns For Remanufacture: A Time Series Analysis, Priyanka Pillai

Theses and Dissertations

Over centuries, consumption of natural resources has been on a steady increase in re-sponse to the increasing global population. Increased and unsustainable use of natural re-sources in addition to increased manufacturing is a ecting the environment adversely. Hence, governments and environmental protection agencies are implementing rm regulations for industries to reduce their footprint on environmental pollution, for instance by ensuring that their waste products are not only disposed sustainably but also reduced. In response to these regulations, industries have embraced product end-of-life management strategies. These include reverse logistic, material and product recovery, reusing, recyling and remanufacturing.

This Thesis addresses one …

A Scenario-Based Parametric Analysis Of Stable Marriage Approaches To The Army Officer Assignment Problem, Matthew D. Ferguson

Theses and Dissertations

This paper compares linear programming and stable marriage approaches to the assignment problem under conditions of uncertainty. Robust solutions should exhibit reduced variability in the presence of one or more additional constraints. Several variations of each approach are compared with respect to solution quality, as measured by the overall social welfare among Officers and Assignments, and robustness as measured by the number of changes after a number of randomized perturbations. We examine the contrasts between these methods in the context of assigning Army Officers among a set of identified assignments. Additional constraints are modeled after realistic scenarios faced by Army …

Survival Analysis Of Us Air Force Officer Retention Rate, Courtney N. Franzen

Theses and Dissertations

Personnel retention is a matter of great interest in the private and public sectors. In the public sector--specifically the US Air Force--maintaining appropriate retention levels of rated officers is paramount as these officers are the backbone of the Air Force’s mission. As part of the effort to ensure proper retention rates for rated officers, retention models are created by the Air Force Personnel division that assist in predicting future retention patterns and accession needs. The techniques for creating these models, known as the "sustainment line," involve utilizing average retention percentages obtained from historical data. In this study, more statistical-based methods …

Using Markov Decision Processes With Heterogeneous Queueing Systems To Examine Military Medevac Dispatching Policies, Phillip R. Jenkins

Theses and Dissertations

major focus of the Military Health System is to provide efficient and timely medical evacuation (MEDEVAC) to battlefield casualties. Medical planners are responsible for developing dispatching policies that dictate how aerial military MEDEVAC units are utilized during major combat operations. The objective of this research is to determine how to optimally dispatch MEDEVAC units in response to 9-line MEDEVAC requests to maximize MEDEVAC system performance. A discounted, infinite horizon Markov decision process (MDP) model is developed to examine the MEDEVAC dispatching problem. The MDP model allows the dispatching authority to accept, reject, or queue incoming requests based on the request's …

2018 Military Retirement Options: An Expected Net Present Value Decision Analysis Model, Bret N. Witham

Theses and Dissertations

The 2016 NDAA authorized changes to the military retirement system transitioning from the legacy High-3 defined benefit annuity to the new Blended Retirement System (BRS). In exchange for a reduced defined benefit annuity, the BRS incorporates automatic and matching contributions to the member’s Thrift Savings Plan and a continuation payment offered at 12 years of service. In 2018,service members with less than 12 years of service will make an irrevocable decision between the two retirement systems. This research effort addresses the problem by developing a decision analysis model incorporating up to 27 different input variables. Service members can use the …

A Framework For Analyzing And Discussing Level Of Human Control Abstraction, Clifford D. Johnson

Theses and Dissertations

It is often useful to understand the impact of an artificial teammate upon human workload in human-machine teams. Levels of Autonomy (LoA) differentiate systems based on control authority. Unfortunately, human workload is not necessarily correlated with LoA. An alternate classification framework, designated the Level of Human Control Abstraction (LHCA), is proposed. LHCA differentiates system states based on the control and monitoring tasks performed and the level of decisions made by humans. The framework defines five levels, designed to differentiate between system states based upon anticipated levels of human attention. This presentation will summarize the framework and demonstrate its application.

Learning Curves: An Alternative Analysis, Sharif F. Harris

Theses and Dissertations

Learning curves are used to describe and estimate the cost performance of a serial production process. There are numerous different models and methods, however, it is not definitively known which is preferred. The research objective is to performance compare the more common learning curve models. The research goal is improved understanding of the systemic cost drivers of a production process, their relationship to cost, and present modeling methods. The research method is qualitative analysis combined with statistical regression modeling. The research identified that preference for one function or another depended upon the shape of the data and how well a …

Alternate Stimuli For The Elicitation Of Event-Related Potentials, Bryan V. Jackson

Theses and Dissertations

Brain-Computer Interfaces (BCIs) are systems that leverage user-brain activity to identify and perform specific functions. In applications requiring overt visual attention, focusing on visual stimuli with known temporal variation can elicit measurable changes in brain activity. However, elements of BCI applications can be intrusive. This research was designed to determine if Event-Related Potentials (ERPs), to include Steady-State Visually-Evoked Potentials (SSVEPs), could be elicited and interpreted from less obtrusive stimuli. Specifically, this research explores the use of variable frequency and long-wavelength (infrared) stimuli for SSVEP interpretation to explore the application of less obtrusive stimuli for application in BCIs. It was determined …

Refugees In Urban Environments: Social, Economic, And Infrastructure Impacts, Garrett L. Jameson

Theses and Dissertations

The United Nations High Commissioner for Refugees has estimated that in 2015 there were 21.3 million refugees worldwide; it is estimated that 1.8 million of these persons were newly displaced during 2015. As refugees leave their country to seek the protection of another nation's government, they generally flow into urban areas. The impact of this flow on cities and on the refugees, themselves, is not fully understood. This study is focused on the impact of government policy decisions on the social, legal, and economic integration of refugees within an urban environment. Investigation into this topic resulted in the development of …

Simulation Modeling And Analysis Of Deployed F-16 Operations And Logistics Support, Gregory D. Potts Ii

Theses and Dissertations

The purpose of this thesis is to reinforce and build upon past efforts identifying and demonstrating the need to better represent logistic capabilities and constraints within the realm of wargaming, war planning, and other analyses requiring the modeling of Air Force combat operations. We develop a framework for the porting of relevant logistic information and requirements from a reliable data source (LCOM- ATK) into a discrete event simulation environment (SIMIO), providing a simulation model for enhanced and robust analyses. The simulation we create explicitly reflects (for a selected subset of Work Unit Codes) the maintenance manpower, resources, and parts required …

An Approximate Dynamic Programming Approach For Comparing Firing Solutions In A Networked Air Defense Environment, Daniel S. Summers

Theses and Dissertations

The United States Army currently employs a shoot-shoot-look firing policy for air defense. As the Army moves to a networked defense-in-depth strategy, this policy will not provide optimal results for managing interceptor inventories in a conflict to minimize the damage to defended assets. The objective for air and missile defense is to identify the firing policy for interceptor allocation that minimizes expected total cost of damage to defended assets. This dynamic weapon target assignment problem is formulated first as a Markov decision process (MDP) and then approximate dynamic programming (ADP) is used to solve problem instances based on a representative …

Real-Time Heuristic Algorithms For The Static Weapon-Target Assignment Problem, Alexander G. Kline

Theses and Dissertations

The problem of targeting and engaging individual missiles (targets) with an arsenal of interceptors (weapons) is known as the weapon target assignment problem. As many solution techniques are based upon a transformation of the objective function, their final solutions rarely produce optimal solutions. We propose a nonlinear branch and bound algorithm to provide the first optimization approach to the untransformed problem found in the literature. Further, we propose a new heuristic based upon the branch and bound algorithm which dominates other heuristics explored in optimality gap. We also propose a heuristic based upon the optimal solution to the quiz problem …