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Full-Text Articles in Engineering

Design Of Engineered Biomaterial Architectures Through Natural Silk Proteins, Nicholas Kurland Nov 2013

Design Of Engineered Biomaterial Architectures Through Natural Silk Proteins, Nicholas Kurland

Theses and Dissertations

Silk proteins have provided a source of unique and versatile building blocks in the fabrication of biomedical devices for addressing a range of applications. Critical to advancing this field is the ability to establish an understanding of these proteins in their native and engineered states as well as in developing scalable processing strategies, which can fully exploit or enhance the stability, structure, and functionality of the two constituent proteins, silk fibroin and sericin. The research outlined in this dissertation focuses on the evolution in architecture and capability of silks, to effectively position a functionally-diverse, renewable class of silk materials within …

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Hot Spot Identification And Analysis Methodology, Jacob S. Farnsworth Nov 2013

Hot Spot Identification And Analysis Methodology, Jacob S. Farnsworth

Theses and Dissertations

The Utah Department of Transportation (UDOT) Traffic and Safety Division continues to advance the safety of roadway sections throughout the state. To aid UDOT in meeting their goal the Department of Civil and Environmental Engineering at Brigham Young University (BYU) has worked with the Statistics Department in developing analysis tools for safety. The most recent of these tools has been the development of a hierarchical Bayesian Poisson Mixture Model (PMM) statistical model of traffic crashes and safety on UDOT roadways statewide and the integration of the results of this model in a Geographic Information System (GIS) framework. This research focuses …

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Novel Liposomes For Targeted Delivery Of Drugs And Plasmids, Marjan Javadi Nov 2013

Novel Liposomes For Targeted Delivery Of Drugs And Plasmids, Marjan Javadi

Theses and Dissertations

People receiving chemotherapy not only suffer from side effects of therapeutics but also must buy expensive drugs. Targeted drug and gene delivery directed to specific tumor-cells is one way to reduce the side effect of drugs and use less amount of therapeutics. In this research, two novel liposomal nanocarriers were developed. This nanocarrier, called an eLiposome, is basically one or more emulsion droplets inside a liposome. Emulsion droplets are made of perfluorocarbons which usually have a high vapor pressure. Calcein (as a model drug) and Paclitaxel were used to demonstrate drug delivery, and plasmids and siRNA were used to exemplify …

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Developing An Architecture Framework For Cloud-Based, Multi-User, Finite Element Pre-Processing, Jared Calvin Briggs Nov 2013

Developing An Architecture Framework For Cloud-Based, Multi-User, Finite Element Pre-Processing, Jared Calvin Briggs

Theses and Dissertations

This research proposes an architecture for a cloud-based, multi-user FEA pre-processing system, where multiple engineers can access and operate on the same model in a parallel environment. A prototype is discussed and tested, the results of which show that a multi-user preprocessor, where all computing is done on a central server that is hosted on a high performance system, provides significant benefits to the analysis team. These benefits include a shortened preprocessing time, and potentially higher-quality models.

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An Investigation Into The Mechanisms Of Formation Of The Hard Zone In Fsw X65, Jacob D. Allred Nov 2013

An Investigation Into The Mechanisms Of Formation Of The Hard Zone In Fsw X65, Jacob D. Allred

Theses and Dissertations

Friction stir welding (FSW) of HSLA steel commonly produces a hard zone (HZ) on the advancing side (AS) of the weld. Despite its detrimental effects on weld toughness, the mechanisms of its formation have not been thoroughly investigated and are not well understood. This paper investigates the various mechanisms in FSW believed to affect the weld HZ, namely: strain, strain-rate, peak temperature and cooling rate. Gleeble tests indicate that strain and strain rate have negligible effects on weld HZ with cooling rate and peak temperature as dominant effects. Jominy tests resulted in cooling rate having 270% greater influence than peak …

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Enhancing Ground Based Telescope Performance With Image Processing, John C. Zingarelli Nov 2013

Enhancing Ground Based Telescope Performance With Image Processing, John C. Zingarelli

Theses and Dissertations

The Space Surveillance Telescope (SST) is a Defense Advanced Research Projects Agency (DARPA) program designed to detect objects in space like Near Earth Asteroids (NEAs) and space debris in the Geosynchronous Earth Orbit (GEO) belt. Binary hypothesis tests (BHTs) have historically been used to facilitate the detection of new objects in space. In this dissertation, a multi-hypothesis test (MHT) detection strategy is introduced to improve the detection performance of the SST. In this context, the MHT determines if an unresolvable point source is in the center, corner or side of a pixel in contrast to a BHT, which only tests …

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Trajectory Generation And Optimization For Experimental Investigation Of Flapping Flight, Michael Schnebly Wilcox Nov 2013

Trajectory Generation And Optimization For Experimental Investigation Of Flapping Flight, Michael Schnebly Wilcox

Theses and Dissertations

Though still in relative infancy, the field of flapping flight has potential to have a far-reaching impact on human life. Nature presents a myriad of examples of successful uses of this locomotion. Human efforts in flapping flight have seen substantial improvement in recent times. Wing kinematics are a key aspect of this study. This study summarizes previous wing trajectory generators and presents a new trajectory generation method built upon previous methods. This includes a novel means of commanding unequal half-stroke durations subject to robotic trajectory continuity requirements. Additionally, previous optimization methods are improved upon. Experimental optimization is performed using the …

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An Incremental Trace-Based Debug System For Field-Programmable Gate-Arrays, Jared Matthew Keeley Nov 2013

An Incremental Trace-Based Debug System For Field-Programmable Gate-Arrays, Jared Matthew Keeley

Theses and Dissertations

Modern society increasingly relies upon integrated circuits (ICs). It can be very costly if ICs do not function properly, and large portions of designer effort are spent on their verification. The use of field-programmable gate arrays (FPGAs) for verification and debug of ICs is increasing. FPGAs are faster than simulation and cost less than fabricating an ASIC prototype. However, the major challenge of using FPGAs for verification and debug is observability. Designers must use special techniques to observe the values of FPGA's internal signals. This thesis proposes a new method for increasing the observability of FPGAs and demonstrates its feasibility. …

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Simulating The Performance Of Tracking A Spinning Missile At C-Band, Darren Robert Kartchner Nov 2013

Simulating The Performance Of Tracking A Spinning Missile At C-Band, Darren Robert Kartchner

Theses and Dissertations

The amplitude fluctuation induced by a spinning missile acts as a disturbance on tracking schemes that use sequential lobing (e.g., conscan). In addition, if a tracking system converts from S-band to C-band, the beamwidth is narrower and the wrap-around antenna on the missile requires more patches, and so the margin of error for tracking decreases. Tracking performance is simulated with a spinning missile with ballistic and fly-by trajectories while running at C-band. The spinning missile causes a periodic component in the pointing error, and when the scan frequency is an integer multiple of the roll rate, several tracking schemes lose …

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Dynamic Nanochannels For Biosensing Applications, Joseph B. Oxborrow Nov 2013

Dynamic Nanochannels For Biosensing Applications, Joseph B. Oxborrow

Theses and Dissertations

Inexpensive label-free detection of biomarker panels in serum could revolutionize earlycancer diagnosis and treatment. Such detection capabilities may be possible with dynamicnanochannels in conjunction with electrical impedance measurement. In Dr. Greg Nordin's lab I designed, fabricated and tested several iterations of these sensors with polydimethyl-siloxane microfluidics. The final design yielded a dynamic nanochannel array sensor thatshowed a 140% impedance change when exposed to 14µM bovine serum albumin in phos-phate buffered saline. For the geometry and noise limits of the tested device, simulationsindicated that a minimum detectable concentration of 20pM with specifically bound strep-tavidin should be possible. However, the polydimethylsiloxane approach …

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Design And Analysis Of Digital True Random Number Generator, Avantika Yadav Oct 2013

Design And Analysis Of Digital True Random Number Generator, Avantika Yadav

Theses and Dissertations

Random number generator is a key component for strengthening and securing the confidentiality of electronic communications. Random number generators can be divided as either pseudo random number generators or true random number generators. A pseudo random number generator produces a stream of numbers that appears to be random but actually follow predefined sequence. A true random number generator produces a stream of unpredictable numbers that have no defined pattern. There has been growing interest to design true random number generator in past few years. Several Field Programmable Gate Array (FPGA) and Application Specific Integrated Circuit (ASIC) based approaches have been …

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Signal Processing Of Electroencephalogram For The Detection Of Attentiveness Towards Short Training Videos, Paul Nussbaum Oct 2013

Signal Processing Of Electroencephalogram For The Detection Of Attentiveness Towards Short Training Videos, Paul Nussbaum

Theses and Dissertations

This research has developed a novel method which uses an easy to deploy single dry electrode wireless electroencephalogram (EEG) collection device as an input to an automated system that measures indicators of a participant’s attentiveness while they are watching a short training video. The results are promising, including 85% or better accuracy in identifying whether a participant is watching a segment of video from a boring scene or lecture, versus a segment of video from an attentiveness inducing active lesson or memory quiz. In addition, the final system produces an ensemble average of attentiveness across many participants, pinpointing areas in …

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Experimental And Computational Assessment Of Mechanical Circulatory Assistance Of A Patient-Specific Fontan Vessel Configuration, Steven Chopski Oct 2013

Experimental And Computational Assessment Of Mechanical Circulatory Assistance Of A Patient-Specific Fontan Vessel Configuration, Steven Chopski

Theses and Dissertations

The treatment of single ventricle anomalies is a formidable challenge for clinical teams caring for patients with congenital heart disease. Those patients fortunate to survive surgical palliation contend with lifelong physical limitations and late stage pathophysiology. A mechanical blood pump specifically designed to increase pressure in the great veins would augment flow through the lungs and provide hemodynamic stability until a donor heart is located. To support the development of such medical devices, this research characterized the fluid dynamics of mechanical assistance in the Fontan circulation by performing numerical analyses and particle image velocimetry (PIV) studies in a patient-specific in …

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The Development Of Updated And Improved Slw Model Parameters And Its Application To Comprehensive Combustion Predictions, John T. Pearson Oct 2013

The Development Of Updated And Improved Slw Model Parameters And Its Application To Comprehensive Combustion Predictions, John T. Pearson

Theses and Dissertations

Accurate modeling of radiative heat transfer through combustion gases has received considerable attention in recent years. The spectral line weighted-sum-of-gray-gases (SLW) model was developed based on detailed line-by-line spectral data of gases. A critical element of the SLW model is the absorption line blackbody distribution function (ALBDF). This function was designed to utilize the spectral properties of gases in an efficient and compact manner. However, there are several limitations of the ALBDF in its original form. First, the valid ranges of temperature and pressure are not large enough to include important applications, such as oxy-combustion, where temperatures can exceed 2500 …

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Real-Time Color Treebasis Feature Matching On A Limited-Resource Hardware System, Garrett Sean Hartman Oct 2013

Real-Time Color Treebasis Feature Matching On A Limited-Resource Hardware System, Garrett Sean Hartman

Theses and Dissertations

This research has been conducted in order to create a robust, lightweight feature detecting and matching algorithm that builds upon the foundation set by the TreeBASIS algorithm. The goal is to create a color-based version of the TreeBASIS algorithm that uses less hardware resources than the original, is more accurate in its matching capabilities, can successfully be deployed on a resource-limited FPGA platform, and can process in real time. This thesis first presents the newly designed hardware tri-channel FAST Feature Detector that finds features in color. Next the TreeBASIS algorithm is analyzed to discover what improvements can be made in …

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Application Of Machine Learning And Parametric Nurbs Geometry To Mode Shape Identification, Robert Mceuen Porter Oct 2013

Application Of Machine Learning And Parametric Nurbs Geometry To Mode Shape Identification, Robert Mceuen Porter

Theses and Dissertations

In any design, the dynamic characteristics of a part are dependent on its geometric and material properties. Identifying vibrational mode shapes within an iterative design process becomes difficult and time consuming due to frequently changing part definition. Although research has been done to improve the process, visual inspection of analysis results is still the current means of identifying each vibrational mode determined by a modal analysis. This research investigates the automation of the mode shape identification process through the use of parametric geometry and machine learning.In the developed method, displacement results from finite element modal analysis are used to create …

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Design Exploration And Analysis Of Carbon-Infiltrated Carbon Nanotube Vascular Stents, Darrell John Skousen Sep 2013

Design Exploration And Analysis Of Carbon-Infiltrated Carbon Nanotube Vascular Stents, Darrell John Skousen

Theses and Dissertations

The purpose of this research was to design, develop, and test coronary stent designs composed of carbon-infiltrated carbon nanotubes (CI-CNTs). Coronary stents currently have two major complications: restenosis and thrombosis. CI-CNT stents have potential to address both of these issues, and therefore may provide improved clinical outcomes. CI-CNT stent geometry is patterned using high-resolution photolithography that provide advantages in design possibilities.To develop a coronary stent, a standard design process was followed including: background, design specifications, concept generation, development, analysis, and testing. Background research was first completed and general design specifications for coronary stent performance were compiled. Multiple design concepts were …

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Modeling Effect Of Microstructure On The Performance Of Fibrous Heat Insulation, Raghu Arambakam Sep 2013

Modeling Effect Of Microstructure On The Performance Of Fibrous Heat Insulation, Raghu Arambakam

Theses and Dissertations

Heat insulation is the process of blocking the transfer of thermal energy between objects at different temperatures. Heat transfer occurs due to conduction, convection, or radiation, as well as any combination of these three mechanisms. Fibrous insulations can completely suppress the convective mode of heat transfer for most applications, and also help to reduce the conductive and radiative modes to some extent. In this study, an attempt has been made to computationally predict the effects of microstructural parameters (e.g., fiber diameter, fiber orientation and porosity) on the insulation performance of fibrous materials. The flexible simulation method developed in this work …

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Dc, Microwave, And Noise Properties Of Gan Based Heterojunction Field Effect Transistors And Their Reliability Issues, Congyong Zhu Sep 2013

Dc, Microwave, And Noise Properties Of Gan Based Heterojunction Field Effect Transistors And Their Reliability Issues, Congyong Zhu

Theses and Dissertations

AlGaN/GaN and InAlN/GaN-based heterojunction field effect transistors (HFETs) have demonstrated great high power and high frequency performance. Although AlGaN/GaN HFETs are commercially available, there still remain issues regarding long-term reliability, particularly degradation and ultimately device failure due to the gate-drain region where the electric field peaks. One of the proposed degradation mechanisms is the inverse-piezoelectric effect that results from the vertical electric field and increases the tensile strain. Other proposed mechanisms include hot-electron-induced trap generation, impurity diffusion, surface oxidation, and hot-electron/phonon effects. To investigate the degradation mechanism and its impact on DC, microwave, and noise performance, comprehensive stress experiments were …

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Origami-Based Design For Engineering Applications, Kevin Campbell Francis Sep 2013

Origami-Based Design For Engineering Applications, Kevin Campbell Francis

Theses and Dissertations

Origami can be a powerful source of design inspiration in the creation of reconfigurable systems with unparalleled performance. This thesis provides fundamental tools for designers to employ as origami-based designs are pursued in their respective fields of expertise. The first chapter introduces origami and makes connections between origami and engineering design through a survey of engineered applications and characterizing the relationship between origami and compliant mechanisms. The second chapter evaluates the creasing of non-paper sheet materials, such as plastics and metals, to facilitate origami-based compliant mechanism design. Although it is anticipated that most origami-based design will result from surrogate folds …

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Scattering, Adsorption, And Langmuir-Hinshelwood Desorption Models For Physisorptive And Chemisorptive Gas-Surface Systems, Brook I. Bentley Sep 2013

Scattering, Adsorption, And Langmuir-Hinshelwood Desorption Models For Physisorptive And Chemisorptive Gas-Surface Systems, Brook I. Bentley

Theses and Dissertations

Surface effects limit the performance of hypersonic vehicles, micro-electro-mechanical devices, and directed energy systems. This research develops methods to predict adsorption, scattering, and thermal desorption of molecules on a surface. These methods apply to physisorptive (adsorption and scattering) and chemisorptive (thermal desorption) gas-surface systems, and are developed under the Direct Simulation Monte Carlo construct. The novel adsorption and scattering contribution, the Modified Kisliuk with Scattering method, predicts angular and energy distributions, and adsorption probabilities. These results agree more closely with experiment than the state-of-the-art Cercignani-Lampis-Lord scattering kernel. Super-elastic scattering is predicted. Gas-adlayer interactions are included for the first time. The …

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Trajectory Optimization For Spacecraft Collision Avoidance, James W. Sales Jr. Sep 2013

Trajectory Optimization For Spacecraft Collision Avoidance, James W. Sales Jr.

Theses and Dissertations

The last several decades have resulted in an unfortunate byproduct of space exploration and development: orbital debris. Satellites in Low Earth Orbit have been required to make an ever increasing number of course corrections in order to avoid collisions. Despite efforts to the contrary, collisions continue to occur, each time creating additional debris and increasing the requirement for the remaining satellites to maneuver. Every required maneuver decreases a satellite's service life. The purpose of this study is to develop a minimum thrust profile to maneuver an orbiting satellite out of its projected error ellipse before a collision occurs. For comparison, …

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Passive Mimo Radar Detection, Daniel E. Hack Sep 2013

Passive Mimo Radar Detection, Daniel E. Hack

Theses and Dissertations

Passive multiple-input multiple-output (MIMO) radar is a sensor network comprised of multiple distributed receivers that detects and localizes targets using the emissions from multiple non-cooperative radio frequency transmitters. This dissertation advances the theory of centralized passive MIMO radar (PMR) detection by proposing two novel generalized likelihood ratio test (GLRT) detectors. The first addresses detection in PMR networks without direct-path signals. The second addresses detection in PMR networks with direct-path signals. The probability distributions of both test statistics are investigated using recent results from random matrix theory. Equivalence is established between PMR networks without direct-path signals and passive source localization (PSL) …

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Enhancing Electromagnetic Side-Channel Analysis In An Operational Environment, David P. Montminy Sep 2013

Enhancing Electromagnetic Side-Channel Analysis In An Operational Environment, David P. Montminy

Theses and Dissertations

Side-channel attacks exploit the unintentional emissions from cryptographic devices to determine the secret encryption key. This research identifies methods to make attacks demonstrated in an academic environment more operationally relevant. Algebraic cryptanalysis is used to reconcile redundant information extracted from side-channel attacks on the AES key schedule. A novel thresholding technique is used to select key byte guesses for a satisfiability solver resulting in a 97.5% success rate despite failing for 100% of attacks using standard methods. Two techniques are developed to compensate for differences in emissions from training and test devices dramatically improving the effectiveness of cross device template …

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Metrics For Emitter Selection For Multistatic Synthetic Aperture Radar, Sean R. Stevens Sep 2013

Metrics For Emitter Selection For Multistatic Synthetic Aperture Radar, Sean R. Stevens

Theses and Dissertations

A bistatic implementation of synthetic aperture radar (SAR) to form images of the ground from an aircraft makes use of separate emitters and receivers. When not using cooperative emitters, ground based communications systems can provide illumination. One way to improve performance of these waveforms, which are not designed for SAR, is a multistatic implementation, formed from multiple bistatic systems. This leads to the problem of selecting a subset from a potentially large set of emitters to use for image formation. A framework for this selection between sets of emitters is proposed using multiple objective optimization. This approach requires use of …

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Development Of Availability And Sustainability Spares Optimization Models For Aircraft Reparables, Edmund K. W. Pek Sep 2013

Development Of Availability And Sustainability Spares Optimization Models For Aircraft Reparables, Edmund K. W. Pek

Theses and Dissertations

The Republic of Singapore Air Force (RSAF) conducts Logistics Support Analysis (LSA) studies in various engineering and logistics efforts on the myriad of weapon systems. In these studies, inventory spares provisioning, availability and sustainability analyses are key focus areas to ensure asset sustenance. In particular, OPUS10, a commercial-off-the-shelf software, is extensively used to conduct reparable spares optimization in acquisition programs. However, it is limited in its ability to conduct availability and sustainability analyses of time-varying operational demands, crucial in Operations & Support (O&S) and contingency planning. As the RSAF seeks force structure expansion to include more sophisticated weapon systems, the …

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Architecting Integrated System Health Management For Airworthiness, Kerwin C. Teong Sep 2013

Architecting Integrated System Health Management For Airworthiness, Kerwin C. Teong

Theses and Dissertations

Integrated System Health Management (ISHM) for Unmanned Aerial Systems (UAS) has been a new area of research - seeking to provide situational awareness to mission and maintenance operations, and for improved decision-making with increased self-autonomy. This research effort developed an analytic architecture and an associated discrete-event simulation using Arena® to investigate the potential benefits of ISHM implementation onboard an UAS. The objective of this research is two-fold: firstly, to achieve continued airworthiness by investigating the potential extension of UAS expected lifetime through ISHM implementation, and secondly, to reduce life cycle costs by implementing a Condition-Based Maintenance (CBM) policy with better …

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Characterizing G-Loading, Swirl Direction And Rayleigh Losses In An Ultra Compact Combustor, Jacob D. Wilson Sep 2013

Characterizing G-Loading, Swirl Direction And Rayleigh Losses In An Ultra Compact Combustor, Jacob D. Wilson

Theses and Dissertations

Previous research has been conducted showing significant benefits on combustion efficiency and stability by creating high centripetally accelerated, also known as g-loaded, combustion environments. Ultra Compact Combustor systems decrease size and weight of the overall engine by burning in a circumferential direction around a hybrid vane row where the high equivalence ratio cavity flow is quick quenched to lean by the core flow. The hybrid vane row integrates the compressor, combustor, and turbine for further length reduction and weight savings. Fuel and air are brought into the cavity and combusted in a high g-loaded environment driven by air injection at …

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Image Annotation And Topic Extraction Using Super-Word Latent Dirichlet, George E. Noel Iii Sep 2013

Image Annotation And Topic Extraction Using Super-Word Latent Dirichlet, George E. Noel Iii

Theses and Dissertations

This research presents a multi-domain solution that uses text and images to iteratively improve automated information extraction. Stage I uses local text surrounding an embedded image to provide clues that help rank-order possible image annotations. These annotations are forwarded to Stage II, where the image annotations from Stage I are used as highly-relevant super-words to improve extraction of topics. The model probabilities from the super-words in Stage II are forwarded to Stage III where they are used to refine the automated image annotation developed in Stage I. All stages demonstrate improvement over existing equivalent algorithms in the literature.

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Radio Frequency Based Programmable Logic Controller Anomaly Detection, Samuel J. Stone Sep 2013

Radio Frequency Based Programmable Logic Controller Anomaly Detection, Samuel J. Stone

Theses and Dissertations

The research goal involved developing improved methods for securing Programmable Logic Controller (PLC) devices against unauthorized entry and mitigating the risk of Supervisory Control and Data Acquisition (SCADA) attack by detecting malicious software and/or trojan hardware. A Correlation Based Anomaly Detection (CBAD) process was developed to enable 1) software anomaly detection discriminating between various operating conditions to detect malfunctioning or malicious software, firmware, etc., and 2) hardware component discrimination discriminating between various hardware components to detect malfunctioning or counterfeit, trojan, etc., components.

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