Engineering Commons^™

Production And Inventory Control In Complex Production Systems Using Approximate Dynamic Programming., Han Wu

Electronic Theses and Dissertations

Production systems focus not only on providing enough product to supply the market, but also on delivering the right product at the right price, while lowering the cost during the production process. The dynamics and uncertainties of modern production systems and the requirements of fast response often make its design and operation very complex. Thus, analytical models, such as those involving the use of dynamic programming, may fail to generate an optimal control policy for modern production systems. Modern production systems are often in possession of the features that allow them to produce various types of product through multiple working …

An Adaptable Fuzzy-Based Model For Predicting Link Quality In Robot Networks., Christopher J. Lowrance

Electronic Theses and Dissertations

It is often essential for robots to maintain wireless connectivity with other systems so that commands, sensor data, and other situational information can be exchanged. Unfortunately, maintaining sufficient connection quality between these systems can be problematic. Robot mobility, combined with the attenuation and rapid dynamics associated with radio wave propagation, can cause frequent link quality (LQ) issues such as degraded throughput, temporary disconnects, or even link failure. In order to proactively mitigate such problems, robots must possess the capability, at the application layer, to gauge the quality of their wireless connections. However, many of the existing approaches lack adaptability or …

Mixing And Mean Age In Multiphase Systems., David Chandler Russ

Electronic Theses and Dissertations

Mean age theory is a useful tool for analyzing mixing by providing spatial distributions of time based data for material inside a system using a steady-state CFD approach, but has been limited to single phase systems. Mean age theory was extended here to multiphase systems by defining the scalar tracer concentration independently for individual phases, which allows mean age to be solved at steady-state for each phase independently within a multiphase system. The theory was validated by comparing multiphase mean age (MMA) distributions extracted from spatial distributions determined computationally at two locations where RTDs were experimentally measured in a water-oil …

Green Logistic Network Design : Intermodal Transportation Planning And Vehicle Routing Problems., Xiaoren Duan

Electronic Theses and Dissertations

Due to earth's climate change and global warming, environmental consideration in the design of logistic systems is accelerating in recent years. In this research we aim to design an efficient and environmentally friendly logistical system to satisfy both government and carriers. In particular, we considered three problems in this dissertation: intermodal network design, deterministic green vehicle routing problem and stochastic green vehicle routing problem. The first problem aims to design an economic and efficient intermodal network including three transportation modes: railway, highway and inland waterway. The intent of this problem is to increase the utilization percentage of waterway system in …

The Influence Of Superabsorbent Polymer (Cassava Startch) On The Rheological Behavior Of Cement Pastes., James Wong

Electronic Theses and Dissertations

Rheological properties are the properties typically reference flow properties of concrete and are related to processing, construction, and setting. The purpose of this research was to investigate the influence of superabsorbent polymers (SAP) and superplasticizer (SP) on rheological properties, specifically of cement pastes with 0.35, 0.45 and 0.55 water-to-cement ratios (w/c), SAP water replacement dosages of 0%, 5%, 10%, 15%, 20% and 25% were tested. Tests included rheological measurements of yield stress, viscosity using the Bingham equation and the flow behavior index using Herschel-Bulkley equation. Slump diameter tests were used to measure flow of the cement pastes. Comparisons of slump …

A Comparative Usability Study Of Web-Based Personal Health Records., Alexandra Doggett

Electronic Theses and Dissertations

Previous research on Personal Health Records (PHRs) has focused on applications that are “tethered” to a specific Electronic Health Record (EHR). However, this is a gap in research on the usability of unaffiliated, independent PHRs, as well as a gap in research on college-aged PHR users. Based on this gap in the literature, a single factor, within-subject experiment was conducted using 18 participants from the University of Louisville to determine if one PHR had superior usability and design. The testing included the completion of six tasks in three different PHRs. Dependent variables included task time, mouse movement, mouse clicks, keystrokes, …

Efficacy Of Subcutaneous Electrocardiogram Leads For Synchronous Timing And Aortic Root Cannulation For Chronic Counterpulsation Therapy., Stephen R. Carnahan

Electronic Theses and Dissertations

Background: Counterpulsation devices (CPD) require electrocardiogram (ECG) lead implantation for timing device filling and ejection with the native heart. Non- implantable leads limit the scope of CPD treatment to short-term therapy. Standard transvenous/epicardial ECG leads increase the invasiveness of therapy.

Methods: To overcome these limitations, subcutaneous ECG leads were tested in chronic (n=6) and acute (n=5) bovine models. ECG waveforms from clinical- grade epicardial (control) leads and subcutaneous (test) leads were simultaneously recorded resulting in 830 data epochs (30-s each) for a total of 44,614 heart beats. Device triggering using R-wave detection was calculated for each lead type and compared. …

Mental Workload Measurement For Competitive Video Games., Jamal Mcfarland

Electronic Theses and Dissertations

The purpose of this study was to explore different ways to measure mental workload for competitive video games using two different techniques: heart rate variability (HRV) and the NASA Task Load Index (TLX). eSports is a rising form of a competitive sport as well as a source of entertainment for people all over the world. I write this in hopes to find efficient and verified ways to estimate mental workload. I also hope this work can pioneer the expansion of literature for the competitive gaming scene.

The study design is a single factor, within-subject design. The single factor was Game …

Automated Analysis Of Cancerous Histological Samples., Thomas Allen Tennill

Electronic Theses and Dissertations

The use of immunohistochemistry has become commonplace in the field of cancer diagnosis. A major limitation to the ability to use this tool effectively is the time consuming tasks required for the analysis of data due to the fact that it is largely done by hand. Additionally, because of this, there is an inherent level of subjectivity in the results obtained from this process that may depend on who it is conducting the analysis. Therefore, there exists a need for a method that is able to quantify results from immunohistochemical techniques in a way that it is both time-effective and …

The Electropolishing Of Electron Beam Melting, Additively Manufactured Ti6al4v Titanium : Relevance, Process Parameters And Surface Finish., Austin Lassell

Electronic Theses and Dissertations

Additive Manufacturing (AM) is the next frontier in manufacturing technology, but with this new frontier comes new challenges in post processing techniques. In an attempt to gain further knowledge of the post processing of metal AM components, the Electropolishing (EP) of Electron Beam Melting (EBM), Additively Manufactured Ti- 6Al-4V alloy parts is investigated in the following work. Additive Manufacturing (AM) is predominant in a number of industries, with electronics and consumer goods, aerospace, automotive and medical constituting the majority of AM sales. For most of these, Powder Bed Fusion (PBF) AM technology is of great interest given the ability of …

A Radial Basis Function Method For Solving Optimal Control Problems., Hossein Mirinejad

Electronic Theses and Dissertations

This work presents two direct methods based on the radial basis function (RBF) interpolation and arbitrary discretization for solving continuous-time optimal control problems: RBF Collocation Method and RBF-Galerkin Method. Both methods take advantage of choosing any global RBF as the interpolant function and any arbitrary points (meshless or on a mesh) as the discretization points. The first approach is called the RBF collocation method, in which states and controls are parameterized using a global RBF, and constraints are satisfied at arbitrary discrete nodes (collocation points) to convert the continuous-time optimal control problem to a nonlinear programming (NLP) problem. The …

Mechanical Properties And Microstructure Evolution Of 17-4 Ph Stainless Steel Processed By Laser-Powered Bed Fusion., Harish Irrinki

Electronic Theses and Dissertations

Laser powder bed fusion (L-PBF) is a potential manufacturing route for the production of tooling using different steel materials. However, there is a limited understanding of how the mechanical properties and microstructures of the L-PBF produced parts vary with change in powder type and process conditions. The current research studied the influence of L-PBF process parameters on mechanical properties and microstructures of 17-4PH stainless steel using gas and water-atomized powders. The results demonstrate the feasibility of using water-atomized powders as starting raw materials instead of typically used gas-atomized powders to fabricate parts in the L-PBF process at high energy densities.

Statistical Behavior Of Distributed Microgrids With Cascading Model Predictive Control, Yasser Yasaei

Electrical and Computer Engineering ETDs

The problem of integration of distributed energy resources into the grid is addressed in this study. The main objective is to deploy such resources as an alternative for conventional resources in a power system, and to increase renewable resources share in the generationmix. Distributed energy resources in general come with small capacities, and may have an intermittent nature. The former characteristic limits their impact on large scale grid applications, while the latter characteristic can induce serious stability problems in the system. As the first step, an appropriate model is developed to mathematically describe the behavior of such resources and to …

Acoustic Firearm Discharge Detection And Classification In An Enclosed Environment, Lorenzo Luzi, Eric Gonzalez, Paul Bruillard, Matthew Prowant, James Skorpik, Michael Hughes, Scott Child, Duane Kist, John E. Mccarthy

Mathematics Faculty Research

Two different signal processing algorithms are described for detection and classification of acoustic signals generated by firearm discharges in small enclosed spaces. The first is based on the logarithm of the signal energy. The second is a joint entropy. The current study indicates that a system using both signal energy and joint entropy would be able to both detect weapon discharges and classify weapon type, in small spaces, with high statistical certainty.

Bs News May/June

Building Services Engineering

No abstract provided.

Using Portable Transducers To Measure Tremor Severity, Rodger J. Elble, James Mcnames

Electrical and Computer Engineering Faculty Publications and Presentations

Background: Portable motion transducers, suitable for measuring tremor, are now available at a reasonable cost. The use of these transducers requires knowledge of their limitations and data analysis. The purpose of this review is to provide a practical overview and example software for using portable motion transducers in the quantification of tremor.

Methods: Medline was searched via PubMed.gov in December 2015 using the Boolean expression “tremor AND (accelerometer OR accelerometry OR gyroscope OR inertial measurement unit OR digitizing tablet OR transducer).” Abstracts of 419 papers dating back to 1964 were reviewed for relevant portable transducers and methods of tremor analysis, …

A Study On The Synthesis And Properties Of Gold Nanoparticles And Their Applications To Surface Enhanced Raman Spectroscopy, Daniel Robert Soden

Graduate Theses/Dissertations

Surface enhanced Raman substrates represent a critical step in the sensitivity augmentation of Raman spectroscopy, but due to the time and expertise currently required in the synthesis process, they have not been fully realized within an industrial setting. This thesis aims to investigate a new technique in surface enhanced Raman spectroscopy (SERS) substrate fabrication designed to decrease synthesis time and map the most effective growth parameters for a successful Raman intensity boost. Sputter physical vapor deposition was utilized to deposit a gold (Au) layer on an insulating substrate, and annealing treatments were applied to agglomerate the Au atoms into the …

Hardware Trojan Detection Via Golden Reference Library Matching, Lucas Weaver

Graduate Theses and Dissertations

Due to the proliferation of hardware Trojans in third party Intellectual Property (IP) designs, the issue of hardware security has risen to the forefront of computer engineering. Because of the miniscule size yet devastating effects of hardware Trojans, few detection methods have been presented that adequately address this problem facing the hardware industry. One such method with the ability to detect hardware Trojans is Structural Checking. This methodology analyzes a soft IP at the register-transfer level to discover malicious inclusions. An extension of this methodology is presented that expands the list of signal functionalities, termed assets, in addition to introducing …

High Step-Up/Down Transformerless Multilevel Converter For Renewable Energy Applications, Haider Ghazi Mhiesan

Graduate Theses and Dissertations

This thesis focuses on a high step-up/down transformerless dc-dc modular multilevel converter (MMC) that would be applicable to dc power systems. The design achieves high voltage ratios for interfacing renewable energy sources such as photovoltaic and line interactive Uninterruptible Power System (UPS) systems. The circuit topology provides for high step-up/down dc-dc conversion ratios using an MMC approach operating in resonant mode in order to improve overall efficiency. This topology operates to step-up the input voltage with 1:10 or larger conversion ratio. As a bidirectional converter, it also provides step-down capability at the same voltage ratio (10:1 or greater). The MMC …

Investigation Of Optical Properties Of Zinc Oxide Photodetector, Tyler Chism

Graduate Theses and Dissertations

UV photodetection devices have many important applications for uses in biological detection, gas sensing, weaponry detection, fire detection, chemical analysis, and many others. Today’s photodetectors often utilize semiconductors such as GaAs to achieve high responsivity and sensitivity. Zinc oxide, unlike many other semiconductors, is cheap, abundant, non-toxic, and easy to grow different morphologies at the micro and nano scale. With the proliferation of these devices also comes the impending need to further study optics and photonics in relation to phononics and plasmonics, and the general principles underlying the interaction of photons with solid state matter and, specifically, semiconductors. For this …

Experimental And Computational Studies Of Cortical Neural Network Properties Through Signal Processing, Wesley Patrick Clawson

Graduate Theses and Dissertations

Previous studies, both theoretical and experimental, of network level dynamics in the cerebral cortex show evidence for a statistical phenomenon called criticality; a phenomenon originally studied in the context of phase transitions in physical systems and that is associated with favorable information processing in the context of the brain. The focus of this thesis is to expand upon past results with new experimentation and modeling to show a relationship between criticality and the ability to detect and discriminate sensory input. A line of theoretical work predicts maximal sensory discrimination as a functional benefit of criticality, which can then be characterized …

Correcting Current Imbalances In Three-Phase Four-Wire Distribution Systems, Vinson Joseph Jones

Graduate Theses and Dissertations

The objective of this thesis is to present the theory, design, construction, and testing of a proposed solution to unbalanced current loading on three-phase four-wire systems. The Unbalanced Current Static Compensator is the name of the prototype; herein referred to as the UCSC. The purpose of this prototype is to redistribute current between the three phases of a distribution system. Through this redistribution, negative- and zero-sequence currents are eliminated and a balanced system is seen upstream from the point of installation.

The UCSC consists of three separate single-phase H-bridge inverters that all share the same dc-link capacitor. Each of these …

Achieving A Better Balance Between Productivity And Performance On Fpgas Through Heterogeneous Extensible Multiprocessor Systems, Abazar Sadeghian

Graduate Theses and Dissertations

Field Programmable Gate Arrays (FPGAs) were first introduced circa 1980, and they held the promise of delivering performance levels associated with customized circuits, but with productivity levels more closely associated with software development. Achieving both performance and productivity objectives has been a long standing challenge problem for the reconfigurable computing community and remains unsolved today. On one hand, Vendor supplied design flows have tended towards achieving the high levels of performance through gate level customization, but at the cost of very low productivity. On the other hand, FPGA densities are following Moore's law and and can now support complete multiprocessor …

Assessment Of An Industrial Type Radiant Heating System For Drying Rough Rice, Anne Adhiambo Okeyo

Graduate Theses and Dissertations

Rough rice is normally harvested at moisture contents (MCs) higher than that for safe storage. The objective for this study was to investigate the effectiveness of scaled-up infrared (IR) heating followed by tempering steps to dry freshly-harvested rough rice. An industrial type, pilot scale, IR drying equipment, designed to convey rough rice on a vibrating conveyor belt was used in this study. The heating zone of the equipment had catalytic IR emitters powered by natural gas. Freshly-harvested rough rice of long-grain pureline (cv. Cheniere), long-grain hybrid (cv. 6XP 756) and medium-grain (cv. CL 271) cultivars at initial moisture contents (IMCs) …

Growth, Characterization And Simulation Of Tungsten Selenide Thin Films For Photovoltaic Applications, Qinglei Ma

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

An excellent candidate for an earth abundant absorber material is tungsten selenide (WSe₂) which can be directly grown as a p-type semiconductor with a band gap value that matches well the solar spectrum. Although several fabrication methods were reported, further improvement is highly needed to make high quality WSe₂ films. In addition, the numerical modelling of WSe₂ solar devices is highly desired to assess the overall utility of the material. In this work, the growth and characterization of tungsten selenide thin films are investigated, as well simulations of homo- and hetero-junction devices. In the first part, …

Stabilization Of Vegetable Oil-Based Quenchants To Thermal-Oxidative Degradation: Experimental Strategy And Effect Of Oxidation On Quenching Performance, Éder Cícero Adão Simêncio, Rosa Lúcia Simêncio Otero, Lauralice De Campos Franceschini Canale, George E. Totten

Mechanical and Materials Engineering Faculty Publications and Presentations

Although petroleum oils continue to be the dominant type of basestock for the formulation of vaporizable quenchants, there is increasing pressure to identify an alternative basestock to address the limitations to their continued use because they are not a renewable basestock and they possess generally poor toxicity and biodegradability properties. Currently the most often cited alternative basestocks are those based on seed oils since they are renewable and usually non-toxic but especially because they are typically readily biodegradable. However, they suffer a critically important deficiency in that they are also typically much less stable to thermal-oxidative degradation than petroleum oils. …

An Example Of Atomic Requirements - Login Screen, William L. Honig

Computer Science: Faculty Publications and Other Works

A simple example of what an atomic or individual or singular requirement statement should be. Using the example of the familiar login screen, shows the evolution from a low quality initial attempt at requirements to a complete atomic requirement statement. Introduces the idea of a system glossary to support the atomic requirement.

Atomic Requirements Quick Notes, William L. Honig, Shingo Takada

Computer Science: Faculty Publications and Other Works

Working paper on atomic requirements for systems development and the importance of singular, cohesive, individual requirements statements. Covers possible definitions of atomic requirements, and their characteristics. Atomic requirements improve many parts of the development process from requirements to testing and contracting.

Investigation Of 186Re Via Radiative Thermal-Neutron Capture On 185Re, David A. Matters, Andrew G. Lerch, A. M. Hurst, L. Szentmiklosi, J. J. Carroll, B. Detwiler, Zs. Revay, John W. Mcclory, Stephen R. Mchale, R. B. Firestone, B. W. Sleaford, M. Krticka, T. Belgya

Faculty Publications

Partial ��-ray production cross sections and the total radiative thermal-neutron capture cross section for the ¹⁸⁵Re(n,��)¹⁸⁶Re reaction were measured using the Prompt Gamma Activation Analysis facility at the Budapest Research Reactor with an enriched ¹⁸⁵Re target. The ¹⁸⁶Re cross sections were standardized using well-known ³⁵Cl(n,��)³⁶Cl cross sections from irradiation of a stoichiometric ^natReCl₃ target. The resulting cross sections for transitions feeding the ¹⁸⁶Re ground state from low-lying levels below a cutoff energy of E_c=746keV were combined with a modeled probability of ground-state feeding from levels above E …

Conceptual Design Of Sleeve Rotor Synchronous Reluctance Motor For Traction Applications, Patel B. Reddy, Kevin Grace, Ayman M. El-Refaie

Electrical and Computer Engineering Faculty Research and Publications

Synchronous reluctance machines are very appealing for high speed traction motor design due to their robustness, simple structure, absence of magnets, and simple control. The absence of magnets means that synchronous reluctance (SynRel) machines are not susceptible to price variability and sustainability of rare-earth materials. Moreover, there are no concerns about demagnetisation or uncontrolled generation mode. However, the challenge of achieving a good constant power to speed ratio is dependent on the mechanical aspects of the design. Conventional SynRel designs perform poorly compared with the permanent magnet machines due to the presence of bridges and/or centre posts in absence of …