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Structuring Emperical Methods For Reuse And Efficiency In Product Development Processes, Marshall Edwin Bare
Structuring Emperical Methods For Reuse And Efficiency In Product Development Processes, Marshall Edwin Bare
Theses and Dissertations
Product development requires that engineers have the ability to predict product performance. When product performance involves complex physics and natural phenomena, mathematical models are often insufficient to provide accurate predictions. Engineering companies compensate for this deficiency by testing prototypes to obtain empirical data that can be used in place of predictive models. The purpose of this work is to provide techniques and methods for efficient use of empirical methods in product development processes. Empirical methods involve the design and creation of prototype hardware and the testing of that hardware in controlled environments. Empirical methods represent a complete product development sub-cycle …
The Piezoresistive Effect In Microflexures, Gary K. Johns
The Piezoresistive Effect In Microflexures, Gary K. Johns
Theses and Dissertations
The objective of this research is to present a new model for predicting the piezoresistive effect in microflexures experiencing bending stresses. A linear model describing piezoresistivity exists for members in pure tension and compression. Extensions of this model to more complex loading conditions do not match experimental results. An accurate model of piezoresistivity in complex loading conditions would expand the design possibilities of piezoresistive devices. A new model to predict piezoresistive effects in tension, compression, and more complex loading conditions is proposed. The focus of this research is to verify a unidirectional form of this proposed model for microflexures in …
Statistical Methods For Kinetic Modeling Of Fischer Tropsch Synthesis On A Supported Iron Catalyst, Brian L. Critchfield
Statistical Methods For Kinetic Modeling Of Fischer Tropsch Synthesis On A Supported Iron Catalyst, Brian L. Critchfield
Theses and Dissertations
Fischer-Tropsch Synthesis (FTS) is a promising technology for the production of ultra-clean fuels and chemical feedstocks from biomass, coal, or natural gas. Iron catalysts are ideal for conversion of coal and biomass. However, precipitated iron catalysts used in slurry-bubble column reactors suffer from high attrition resulting in difficulty separating catalysts from product and increased slurry viscosity. Thus, development of an active and selective-supported iron catalyst to manage attrition is needed. This thesis focuses on the development of a supported iron catalyst and kinetic models of FTS on the catalyst using advanced statistical methods for experimental design and analysis. A high …
Observation And Tracking Of Tropical Cyclones Using Resolution Enhanced Scatterometry, Richard Ryan Halterman
Observation And Tracking Of Tropical Cyclones Using Resolution Enhanced Scatterometry, Richard Ryan Halterman
Theses and Dissertations
The QuikSCAT scatterometer provides global daily coverage of oceanic near-surface vector winds. Recently, algorithms have been developed to enhance the spatial resolution of QuikSCAT winds from 25~km to 2.5~km posting. These ultra-high resolution winds are used, in comparison with standard L2B data product winds, to observe and track tropical cyclones. Resolution enhanced winds are found to provide additional storm structure such as inner core size and structure and the presence of multiple eyewalls compared with standard resolution winds. The 2.5~km winds are also able to observe storms nearer to the shore than 25~km winds. An analysis of circulation center locatability …
A Dynamic Workflow Framework For Mass Customization Using Web Service And Autonomous Agent Technologies, Daniel J. Karpowitz
A Dynamic Workflow Framework For Mass Customization Using Web Service And Autonomous Agent Technologies, Daniel J. Karpowitz
Theses and Dissertations
Custom software development and maintenance is one of the key expenses associated with developing automated systems for mass customization. This paper presents a method for reducing the risk associated with this expense by developing a flexible environment for determining and executing dynamic workflow paths. Strategies for developing an autonomous agent-based framework and for identifying and creating web services for specific process tasks are presented. The proposed methods are outlined in two different case studies to illustrate the approach for both a generic process with complex workflow paths and a more specific sequential engineering process.
A Torque Based Power Input Model For Friction Stir Welding, Jefferson W. Pew
A Torque Based Power Input Model For Friction Stir Welding, Jefferson W. Pew
Theses and Dissertations
For decades models have been developed for predicting the size of the weld nugget and heat affected zones in fusion welded structures. The basis for these models is the welding heat input, which is fairly well understood for most arc welding processes. However, this traditional approach is not as straightforward for Friction Stir Welding (FSW). To date, there is no definitive relationship to quantify the heat input for FSW. An important step to establish a heat input model is to identify how FSW process parameters affect weld power. This study details the relationship between FSW process parameters and torque for …
An Analysis Of The Accounting Methods Used By Builders Producing Twenty-Five Or Fewer Homes Per Year, David Andrus
An Analysis Of The Accounting Methods Used By Builders Producing Twenty-Five Or Fewer Homes Per Year, David Andrus
Theses and Dissertations
Accounting plays a crucial role in the success of any business, but it is particularly vital in the construction industry, a complex field that typically requires the coordination of multiple subcontractors and multiple jobs in any given year. Although small-volume home builders make up 70 percent of the membership of the National Association of Home Builders (NAHB), a trade association of the home building industry, little is known about the accounting practices of these builders. This thesis undertook to study the accounting practices of small-volume home builders. Small-volume home builders were defined as those producing 25 homes or fewer in …
Design And Construction Of Pavements In Cold Regions: State Of The Practice, Brad Steven Smith
Design And Construction Of Pavements In Cold Regions: State Of The Practice, Brad Steven Smith
Theses and Dissertations
The effects of frost action introduce many challenges in the design and construction of roadways in cold regions throughout the United States. The penetration of frost into pavement structures can lead to differential frost heave during winter and thaw weakening during spring. Both of these damage mechanisms lead to premature pavement distress, structural deterioration, and poor ride quality. Because the availability of naturally occurring non-frost-susceptible pavement base materials is rapidly diminishing in many areas while project budgets remain largely inadequate, pavement engineers are utilizing alternative materials and techniques to minimize such damage. The purpose of this research was to investigate …
Shape Matching, Relevance Feedback, And Indexing With Application To Spine X-Ray Image Retrieval, Xiaoqian Xu
Shape Matching, Relevance Feedback, And Indexing With Application To Spine X-Ray Image Retrieval, Xiaoqian Xu
Theses and Dissertations
The National Library of Medicine (NLM), an institute in the National Institutes of Health (NIH), maintains a collection of 17,000 digitized spine X-ray images obtained from the second National Health and Nutrition Examination Survey (NHANES II). Research effort has been devoted to develop a web-accessible retrieval system that allows retrieval of images from the NHANES II database on relevant and frequently found pathologies. A comprehensive and successful image retrieval system requires effective image representation and matching methods, relevance feedback algorithms to incorporate user opinions, and efficient indexing schemes for fast access to image databases. This dissertation studies and develops approaches …
Large 3-D Deflection And Force Analysis Of Lateral Torsional Buckled Beams, Robert Parley Chase
Large 3-D Deflection And Force Analysis Of Lateral Torsional Buckled Beams, Robert Parley Chase
Theses and Dissertations
This thesis presents research on the force and deflection behavior of beams with rectangular cross-sections undergoing lateral torsional buckling. The large 3-D deflection path of buckling beam tips was closely approximated by circular arcs in two planes. A new chain algorithm element was created from pseudo-rigid-body segments and used in a chain calculation that accurately predicted the force deflection relationship of beams with large 3-D deflections.
Using Duplication With Compare For On-Line Error Detection In Fpga-Based Designs, Daniel L. Mcmurtrey
Using Duplication With Compare For On-Line Error Detection In Fpga-Based Designs, Daniel L. Mcmurtrey
Theses and Dissertations
Space destined FPGA-based systems must employ redundancy techniques to account for the effects of upsets caused by radiated environments. Error detection techniques can be used to alert external systems to the presence of these upsets. Readback with compare is an error detection technique commonly employed in FPGA-based designs. This work introduces duplication with compare (DWC) as an automated on-line error detection technique that can be used as an alternative to readback with compare. This work also introduces a set of metrics that is used to quantify the effectiveness and coverage of this error detection technique. A tool is presented that …
A Bayesian Perspective On Estimating Mean, Variance, And Standard-Deviation From Data, Travis E. Oliphant
A Bayesian Perspective On Estimating Mean, Variance, And Standard-Deviation From Data, Travis E. Oliphant
Faculty Publications
This article shows how to compute confidence intervals for mean, standard-deviation, and variance using Bayesian methods. The method is implemented in SciPy as scipy.stats.bayes_mvs After reviewing some classical estimators for mean, variance, and standard-deviation and showing that un-biased estimates are not usually desirable, a Bayesian perspective is employed to determine what is known about mean, variance, and standard deviation given only that a data set in-fact has a common mean and variance. Maximum-entropy is used to argue that the likelihood function in this situation should be the same as if the data were independent and identically distributed Gaussian. A non-informative …
Vision-Based Target Geo-Location Using A Fixed-Wing Miniature Air Vehicle, D. Blake Barber, Joshua D. Redding, Timothy W. Mclain, Randal W. Beard, Clark N. Taylor
Vision-Based Target Geo-Location Using A Fixed-Wing Miniature Air Vehicle, D. Blake Barber, Joshua D. Redding, Timothy W. Mclain, Randal W. Beard, Clark N. Taylor
Faculty Publications
This paper presents a method for determining the GPS location of a ground-based object when imaged from a fixed-wing miniature air vehicle (MAV). Using the pixel location of the target in an image, with measurements of MAV position and attitude, and camera pose angles, the target is localized in world coordinates. The main contribution of this paper is to present four techniques for reducing the localization error. In particular, we discuss RLS filtering, bias estimation, flight path selection, and wind estimation. The localization method has been implemented and flight tested on BYU’s MAV testbed and experimental results are presented demonstrating …
Information Infrastructure For Integrated Ecohydraulic And Water Resources Modeling And Assessment, R. Wallace, K. Pathak, M. Fife, Norman L. Jones, J. P. Holland, D. Stuart, J. Harris, C. Butler, D. R. Richards
Information Infrastructure For Integrated Ecohydraulic And Water Resources Modeling And Assessment, R. Wallace, K. Pathak, M. Fife, Norman L. Jones, J. P. Holland, D. Stuart, J. Harris, C. Butler, D. R. Richards
Faculty Publications
Watershed management increasingly requires ecohydraulic modeling and assessment within a regional context, rather than on a project-by-project basis. Such holistic modeling and assessment require evaluation capabilities across multiple temporal and spatial scales. Thus, modeling and assessment tools must be integrated in a scientifically and computationally effective infrastructure. The US Army Engineer Research and Development Center, in concert with the Hydrologic Engineering Center and its academic partners, including Brigham Young University, is establishing a comprehensive set of hydroinformatics modeling and assessment tools for ecohydraulic and water resources management applications, all linked based on a common data and information infrastructure. This paper …
Defining A Model For Tool Consumption Rate On Asphalt Reclamation Machines, Matthew H. Taylor
Defining A Model For Tool Consumption Rate On Asphalt Reclamation Machines, Matthew H. Taylor
Theses and Dissertations
Asphalt and concrete reclamation machines are used to cut roadways when a repair is required. The performance of these machines can affect the quality of road repairs, and cost/profitability for both contractors and governments. We believe that several performance characteristics in reclamation machines are governed by the placement and pattern of cutting picks on the cutter head. Previous studies, focused on mining and excavation applications, have shown strong correlation between placement and wear. The following study employs a screening experiment (observational study) to find significant contributors to tool wear, in applications of asphalt milling or reclamation. We have found that …
Utah Commercial Motor Vehicle Weigh-In-Motion Data Analysis And Calibration Methodology, Luke W. Seegmiller
Utah Commercial Motor Vehicle Weigh-In-Motion Data Analysis And Calibration Methodology, Luke W. Seegmiller
Theses and Dissertations
In preparation for changes in pavement design methodologies and to begin to assess the effectiveness of the weigh-in-motion (WIM) system in Utah, the Utah Department of Transportation (UDOT) contracted with a Brigham Young University (BYU) research team to conduct an evaluation of their commercial motor vehicle (CMV) data collection system statewide. The objective of this research was to evaluate the CMV data collection program in the state of Utah and to make limited recommendations for potential improvements and changes that will aid in more detailed and accurate CMV data collection across the state. To accomplish the research objectives, several tasks …
Consolidation And Interweaving Of Composite Members By A Continuous Manufacturing Process, Sarita L. Kesler
Consolidation And Interweaving Of Composite Members By A Continuous Manufacturing Process, Sarita L. Kesler
Theses and Dissertations
Recent research and development has resulted in a working prototype of an automated process for manufacturing IsoTruss® and other innovative open lattice composite structures which yields faster, and more predictable and consistent parts, while automatically consolidating individual members. This machine is sufficiently versatile to manufacture any type of open lattice structure fabricated from filamentary composite materials. The objectives of the research in this thesis were two-fold: (1) to validate this new process for making IsoTruss structures; and (2) to measure the compression strength and stiffness of specimens produced on the machine. In order to accomplish the first purpose, various parts …
A New Spectroscopic Method For The Non-Destructive Characterization Of Weathering Damage In Plastics, Andrew Robert George
A New Spectroscopic Method For The Non-Destructive Characterization Of Weathering Damage In Plastics, Andrew Robert George
Theses and Dissertations
The weathering of plastics and composites is a problem because of the loss of both physical and mechanical properties that it causes in these materials. But this weathering effect has been difficult, and in some cases, impossible to characterize without the destruction of the plastic or composite part. Clearly a rapid, reliable, and non-destructive test for the extent of the weathering damage is critically needed. A recent problem that arose at Superyacht Solutions, a boat repair company in Australia, required a solution to just this problem. Such a test was developed for Superyacht Solutions, and is being applied across a …
Predicting On-Orbit Static Single Event Upset Rates In Xilinx Virtex Fpgas, Joshua Engel, Keith S. Morgan, Michael J. Wirthlin, Paul S. Graham
Predicting On-Orbit Static Single Event Upset Rates In Xilinx Virtex Fpgas, Joshua Engel, Keith S. Morgan, Michael J. Wirthlin, Paul S. Graham
Faculty Publications
Sponsorship: Department of Energy, Los Alamos National Laboratory. This document describes the methodology used to predict single-event upset rates for Xilinx Virtex FPGAs based on the CREME96 orbit modeling tool. Using this methodology, SEU upset rates are obtained for several Xilinx Virtex FPGAs including Virtex, Virtex-II, and Virtex-4. Further, SEU upset rates are obtained for a variety of orbits for each of these FPGAs.
Mimo Communication Capacity: Antenna Coupling And Precoding For Incoherent Detection, Nicolas W. Bikhazi
Mimo Communication Capacity: Antenna Coupling And Precoding For Incoherent Detection, Nicolas W. Bikhazi
Theses and Dissertations
While the capacity of multiple-input multiple-output (MIMO) systems has been explored in considerable detail, virtually all literature on this topic ignores electromagnetic considerations. This dissertation explores electromagnetic effects on the capacity performance of these multi-antenna architectures. Specifically, it examines the impact of superdirectivity for compact antenna arrays, the effect of antenna mutual coupling, and MIMO performance of multi-mode optical fiber with non-linear detection. Superdirectivity can lead to abnormally large capacity bounds in a MIMO communication system, especially when the antennas are placed close together. Because superdirective behavior is difficult to achieve in practice, this work formulates an approach for limiting …
Simulation Of A Carbon Nanotube-Based Compliant Parallel-Guiding Mechanism: A Nanomechanical Building Block, Martin L. Culpepper, Christopher M. Dibiasio, Robert M. Panas, Spencer P. Magleby, Larry L. Howell
Simulation Of A Carbon Nanotube-Based Compliant Parallel-Guiding Mechanism: A Nanomechanical Building Block, Martin L. Culpepper, Christopher M. Dibiasio, Robert M. Panas, Spencer P. Magleby, Larry L. Howell
Faculty Publications
The authors report the behavior of a nanoscale parallel-guiding mechanism wherein the compliant components are single-walled carbon nanotubes. Parallel-guiding mechanisms are often the building blocks of macro- and microscale mechanical systems. The authors present results that provide insight into the performance of a parallel-guiding mechanism for nanoscale devices. The device exhibits a range over 75% of the device size, i.e., 5.5 nm, when actuated with 6.4 nN. Below 3.6 nN, displacements are due to bulk elastic bending of the nanotubes. Above 5.2 nN, displacements are governed by the hingelike bending of kinks in the nanotubes. van der Waals forces are …
Methods And Metrics For Human Control Of Multi-Robot Teams, Jeffrey D. Anderson
Methods And Metrics For Human Control Of Multi-Robot Teams, Jeffrey D. Anderson
Theses and Dissertations
Human-controlled robots are utilized in many situations and such use is becoming widespread. This thesis details research that allows a single human to interact with a team of robots performing tasks that require cooperation. The research provides insight into effective interaction design methods and appropriate interface techniques. The use of team-level autonomy is shown to decrease human workload while simultaneously improving individual robot efficiency and robot-team cooperation. An indoor human-robot interaction testbed was developed at the BYU MAGICC Lab to facilitate experimentation. The testbed consists of eight robots equipped with wireless modems, a field on which the robots move, an …
Active Minimization Of Acoustic Energy Density To Attenuate Radiated Noise From A Diesel Generator, Andrew J. Boone
Active Minimization Of Acoustic Energy Density To Attenuate Radiated Noise From A Diesel Generator, Andrew J. Boone
Theses and Dissertations
The focus of this thesis was to use active noise control (ANC) to globally minimize the tonal and broadband noise radiating from a diesel generator enclosure. The major goal of this research was to show that minimizing the noise within the enclosure can lead to an overall sound pressure level (SPL) reduction of radiated noise. The target levels for overall SPL reduction were at least 2 dBA. The control algorithms used in this research were based on a filtered-x LMS adaptive algorithm, which minimizes energy density (ED). Both feedforward and feedback control approaches were investigated. The noise spectrum produced by …
Characterization Of Black Liquor Sprays For Application To Entrained-Flow Processes, Andrew John Mackrory
Characterization Of Black Liquor Sprays For Application To Entrained-Flow Processes, Andrew John Mackrory
Theses and Dissertations
In this work the differences between and characteristics of water and high solids, heated black liquor sprays from air-assist atomizers are examined. Sprays were imaged with a high speed camera and the images analyzed with computer code to produce droplet size data and macroscopic spray characteristics such as mass distribution. Fluid flow rates were measured to allow relevant dimensionless groups for the spray to be calculated. A 1000 degree C tubular furnace was placed around the spray to determine the effect of industrially relevant temperatures on the droplet formation process, relative to room-temperature conditions. It was found that high solids …
Anisotropic High Aspect Ratio Etch Development For Fluorinated Polymers With Stress Relief Technique, S. Kim, Gregory P. Nordin, N. Rahmanian
Anisotropic High Aspect Ratio Etch Development For Fluorinated Polymers With Stress Relief Technique, S. Kim, Gregory P. Nordin, N. Rahmanian
Faculty Publications
The authors have developed an anisotropic, high aspect ratio (18:1) etch for perfluorocyclobutyl (PFCB) polymers with trenches as narrow as 800 nm using a CO/O2 etch chemistry in an inductively coupled plasma reactive ion etcher. Anisotropy is achieved by carbon sidewall passivation. The motivation for this etch development is to use the air trenches as very compact waveguide splitters [S. Kim et al., Opt. Eng. 45, 054602 (2006)] The authors report a new trench widening mechanism due to tensile stress of the PFCB films and a method of avoiding this widening through the use of additional stress relief trenches on …
Time-Varying Mimo Channels: Measurement, Analysis, And Modeling, Michael A. Jensen, Jon W. Wallace
Time-Varying Mimo Channels: Measurement, Analysis, And Modeling, Michael A. Jensen, Jon W. Wallace
Faculty Publications
communication nodes is analyzed. A wide-band 8 times 8 sounder is employed to measure the response of indoor and outdoor channels at 2.55 and 5.2 GHz. The rate of channel temporal variation is then quantified in terms of information theoretic metrics that indicate the loss in channel quality as transmit and receive channel state information becomes increasingly outdated. Finally, these metrics are used to investigate the ability of two different modeling strategies-a random matrix model and a physical time-varying cluster model-to capture the channel temporal variation.
An Evaluation Of Attributes And Competencies For Manufacturing Engineering Technology Graduates, Loni S. Williamson
An Evaluation Of Attributes And Competencies For Manufacturing Engineering Technology Graduates, Loni S. Williamson
Theses and Dissertations
The purpose of this study is to determine the required attributes and competencies required for a graduate from a manufacturing engineering technology baccalaureate program. A document called “Competencies of Manufacturing Engineering Technology Graduates” was compiled in October 2004. This document lists twelve attributes thought to be important for MET graduates: Leadership, Professionalism, Creativity and Problem Solving, Management, Materials, Processes, Quality, Systems, Design, Communication, Safety and Environmental Issues, and Global Awareness. Under each attribute is a list of five to seven competencies creating a total of seventy-three competencies for graduates of an MET baccalaureate program. This list of attributes and competencies …
Modeling And Data Analysis Of Conductive Polymer Composite Sensors, Hua Lei
Modeling And Data Analysis Of Conductive Polymer Composite Sensors, Hua Lei
Theses and Dissertations
Conductive polymer composite sensors have shown great potential in identifying gaseous analytes. To more thoroughly understand the physical and chemical mechanism of this type of sensors, a model was developed by combining two sub-models: a conductivity model and a thermodynamic model, which gives a relationship between the vapor concentration of analyte(s) and the change of the sensor signals. In this work, 64 chemiresistors representing eight different carbon concentrations (8–60 vol.% carbon) were constructed by depositing thin films of a carbon black–polyisobutylene composite onto concentric spiral platinum electrodes on a silicon chip. The responses of the sensors were measured in dry …
Assessment Of The Tube Suction Test For Identifying Non-Frost-Susceptible Soils Stabilized With Cement, Amy Lyn Crook
Assessment Of The Tube Suction Test For Identifying Non-Frost-Susceptible Soils Stabilized With Cement, Amy Lyn Crook
Theses and Dissertations
Frost heave is a primary mechanism of pavement distress in cold regions. The distress exhibited is dependent on the frost susceptibility of the soil within the depth of frost penetration, the availability of subsurface water, and the duration of freezing surface temperatures. Cement stabilization is one technique used to mitigate the effects of frost heave. The tube suction test (TST) is one possible method for determining the frost susceptibility of soils in the laboratory. The purpose of this research was to assess the utility of the TST for identifying non-frost-susceptible (NFS) materials stabilized with cement. This research investigated two aggregate …
A Prototype Platform For Array Feed Development, James Richard Nagel
A Prototype Platform For Array Feed Development, James Richard Nagel
Theses and Dissertations
Radio frequency interference (RFI) is a growing problem for radio astronomers. One potential solution utilizes spatial filtering by placing an array of electrically small antennas at the focal plane of a parabolic reflector. This thesis documents the design and characterization of a prototype array feed and RF receiver that were used to demonstrate the spatial filtering principle. The array consists of a 7-element hexagonal arrangement of thickened dipole antennas tuned to a center frequency of 1600 MHz. The receiver is a two-stage, low-noise frequency mixer that is tunable over the entire L-band. This thesis also documents a new receiver design …