Engineering Commons^™

Comparison Of Empirical And Analytical Eigenfunctions As Bases For Reduced Order Methods In Heat Transfer, Jakob G. Bates, Matthew R. Jones, Christopher R. Dillon, John Tencer

Student Works

Reduced order methods using spectral representations show promise in facilitating and accelerating heat transfer analyses. This paper proposes a taxonomy for reduced order methods, classifying a method as reduced order compression, modelling, or analysis. The performance of bases formed with analytical and empirical eigenfunctions are compared for representative reduced order tasks. The Akaike Information Criterion is applied in a novel way to compare the performance of these bases. The present study finds that both bases are parsimonious for reduced order compression tasks. Empirical eigenfunctions are more robust to for reduced order modelling with variations in modelling parameters such as thermal …

Iprec And Isoblaze: Fuzzy Subcircuit Isomorphism For Ip Detection In Physical Netlists, Dallin Dahl, Corey Simpson, Keenan Faulkner, Brent Nelson, Jeffrey Goeders

Student Works

Netlist reverse engineering has many uses, from detecting hardware trojans to recovering missing design source files. However, the basic problem of finding IP in a netlist has not been widely discussed. The problem boils down to subgraph isomorphism on graphs constructed from netlists. We present two approaches to identifying IP in larger circuits. IPRec focuses on exploiting hierarchy in the IP design and is a rather conservative approach, while Isoblaze focuses on local properties and connectivity and is more liberal in matching.

Dynamic Skin Strain Fields In The Lumbar Region During Functional Movement, Andrew Gibbons, Anton Bowden, Ulrike H. Mitchell, David T. Fullwood

Student Works

Increasing efforts to leverage skin mounted wearables has exposed a gap in our understanding of skin strain in the lumbar region. Lumbar skin is known to be both inhomogenous and anisotropic, and experiences dramatic material strain during activities of daily living (ADLs). Previous efforts to quantify strain fields during ADLs has been limited to a few activities (primarily flexion) and have neglected inhomogeneity or anisotropy. The purpose of the present work was to address this gap by measuring large-deformation skin strain tensors in healthy volunteers during a cadre of functional movements.

36 tightly packed retro-reflective markers were mounted to the …

Experimentally Measured Lumbar Skin Strains During Activities Of Daily Living, Andrew Gibbons, Paul Mcmullin, Darian Emmett, Ulrike H. Mitchell, David T. Fullwood, Anton E. Bowden

Student Works

Introduction: When mechanical stimulation of the skin, post-surgery, is kept at a minimum, the risk for hypertrophic scarring is reduced. Therefore, surgeons have utilized different tools for optimal scar outcomes such as cutting along or perpendicular to the Langers lines or collagen fiber orientation^1,2. However, biomechanical strains induced in the skin during activities of daily living (ADL) are the primary mechanism for suture opening, and increased awareness of these strains may provide informative insights to both pre-operative incision planning, as well as post-operative counseling with the patient regarding specific activities that may lead to wound re-opening.

Methods: Data …

Precision Maritime Localization And Landing With Real-Time Kinematic Gnss, Alexander Jordan, Matthew Kent Rydalch, Tim Mclain, Michael Williamson Tabango

Student Works

This paper presents a highly effective method for UAV precision shipboard localization and landing using Real-time Kinematic Global Navigation Satellite System (RTK GNSS). To assess the feasibility of RTK GNSS for this use case we explicitly exclude vision-based localization techniques which are most often presented in the literature. Instead, the methods presented in this paper use only RTK GNSS with an inertial measurement unit aboard the landing pad to estimate the state of the boat and the relative position of the UAV with respect to the boat. We use a continuous-discrete extended Kalman filter combined with a complementary filter for …

Correlation Of Segmental Lumbar Kinematics With A Wearable Skin Strain Sensor Array, Andrew Gibbons, Paul Mcmullin, Joseph Peterson, Spencer Baker, Kelly Clingo, Ulrike H. Mitchell, David T. Fullwood, Anton E. Bowden

Student Works

Introduction: Joint kinematics have been shown to be strongly diagnostic of underlying pathology in the knee, hip, shoulder, and ankle. However, the anatomical complexity of the spine has made obtaining accurate, segmental kinematics extremely challenging. Current approaches required specialized hardware (e.g., a dual x-ray system), or are highly invasive (e.g., bone pins implanted into the vertebrae). Recently, our lab has developed a wearable array of skin-mounted strain sensors that hopes to address this challenge. The purpose of the present work study was to quantify the utility of this array through comparison with real-time lumbar vertebral kinematics.

Materials and Methods: A …

A Derivation Of Scattered Intensity (Radiance) For Use In Optical Particle Counters, Brady S. Hales, Matthew R. Jones, Randy S. Lewis

Student Works

Mie scattering theory is often used to calculate the flux of light scattered off of small particles whose diameter is approximately the same order of magnitude as the wavelength of incident light. In many equations for the calculation of this flux, it is assumed that the area of interest is perpendicular to the ray of scattered light. This assumption does not apply to all cases such as low-cost (

An Iterative Five-Point Algorithm With Application To Multi-Target Tracking, Jacob H. White, Randal W. Beard

Student Works

We present ReSORtSAC: Recursively-seeded optimization, refinement, sample, and consensus. ReSORtSAC is a novel algorithm that can be used to estimate the relative pose between consecutive frames of a video sequence. Relative pose estimation algorithms typically generate a large number of hypotheses from minimum subsets and score them in order to be robust to noise and outliers. The relative pose is often represented using the essential matrix. Previous methods calculate essential matrix hypotheses directly without utilizing prior information. These equations are complex to evaluate and can return up to ten essential matrix solutions for each minimum subset, all of which must …

The Homography As A State Transformation Between Frames In Visual Multi-Target Tracking, Jacob H. White, Randal W. Beard

Student Works

No abstract provided.

Deep Rc: Enabling Remote Control Through Deep Learning, Jaron Ellingson, Gary Ellingson, Tim Mclain

Student Works

Human remote-control (RC) pilots have the ability to perceive the position and orientation of an aircraft using only third-person-perspective visual sensing. While novice pilots often struggle when learning to control RC aircraft, they can sense the orientation of the aircraft with relative ease. In this paper, we hypothesize and demonstrate that deep learning methods can be used to mimic the human ability to perceive the orientation of an aircraft from monocular imagery.

This work uses a neural network to directly sense the aircraft attitude. The network is combined with more conventional image processing methods for visual tracking of the aircraft. …

Developable Compliant-Aided Rolling-Contact Mechanisms, Todd G. Nelson, Just L. Herder

Student Works

Rolling-contact mechanisms can provide low-friction motion with unique kinematic paths. We show that developable surfaces can be used as a design tool for rolling-contact mechanisms joined with compliant bands. These mechanisms can exhibit 3D motion paths, couple rotational and translational motions into a single degree of freedom, and can be designed to exhibit various tailored kinetic responses. We set forth developable surface parametrizations well suited to the creation of rolling contacts. We highlight how the geodesic and principal curvatures of the non-ruling principal curves of a developable surface are meaningful design quantities for rolling contacts. We provide kinematic and kinetic …

Extending Motion Detection To Track Stopped Objects In Visual Multi-Target Tracking, Jacob H. White, Karl T. Salva, Randal W. Beard

Student Works

Various solutions to visual multi-target tracking have been proposed, but many of them are not capable of running in real time from a moving camera on an unmanned aerial vehicle (UAV). We present a tracker that runs in real time and tracks multiple objects while accounting for camera motion on a UAV. Our algorithm is capable of processing over 10 frames per second on a 1280x720 video sequence.

We utilize Recursive-RANSAC, an efficient algorithm for tracking multiple objects in clutter. Our work combines motion detection with optical flow and feature matching to allow stationary objects to be tracked. We use …

Visual Multiple Target Tracking From A Descending Aerial Platform, Parker C. Lusk, Randal Beard

Student Works

A real-time visual multiple target tracker is demonstrated onboard a descending multirotor. Measurements of moving ground targets are generated using the Kanade-Lucas-Tomasi (KLT) tracking method. Homography-based image registration is used to align the measurements into the same coordinate frame, allowing for the detection of independently moving objects. The recently developed Recursive-RANSAC algorithm uses the visual measurements to estimate targets in clutter. Altitude-dependent tuning increases track continuity and coverage during the descent of the vehicle. The algorithm requires no operator interaction and increases the situation awareness of the unmanned aerial system. Real-time tracking efficiency is analyzed on GPUs and CPUs. Tracking …

Relative Target Estimation Using A Cascade Of Extended Kalman Filters, Jerel Nielsen, Randal Beard

Student Works

This paper presents a method of tracking multiple ground targets from an unmanned aerial vehicle (UAV) in a 3D reference frame. The tracking method uses a monocular camera and makes no assumptions on the shape of the terrain or the target motion. The UAV runs two cascaded estimators. The first is an Extended Kalman Filter (EKF), which is responsible for tracking the UAV’s state, such as position and velocity relative to a fixed frame. The second estimator is an EKF that is responsible for estimating a fixed number of landmarks within the camera’s field of view. Landmarks are parameterized by …

Quantum Dot Band Gap Investigations, John Ryan Peterson

Student Works

Improving solar panel efficiency has become increasingly important as the world searches for cheap renewable energy. Recent developments in the industry have focused on multi-layer cells, some of which use semiconducting dyes to absorb light in place of crystalline solids. In this paper, I characterize various dyes recently synthesized for use in solar panels. These dyes contain semiconducting nanoparticles enclosed primarily by the protein ferritin to limit particle size. The band gaps were measured using either optical absorption spectroscopy or measuring the photoluminescence spectrum, depending on the type of semiconductor. The results indicate that both manganese oxide and lead sulfide …

Modeling And Control Of A Tailsitter With A Ducted Fan, Matthew Elliott Argyle

Student Works

There are two traditional aircraft categories: fixed-wing which have a long endurance and a high cruise airspeed and rotorcraft which can take-off and land vertically. The tailsitter is a type of aircraft that has the strengths of both platforms, with no additional mechanical complexity, because it takes off and lands vertically on its tail and can transition the entire aircraft horizontally into high-speed flight. In this dissertation, we develop the entire control system for a tailsitter with a ducted fan. The standard method to compute the quaternion-based attitude error does not generate ideal trajectories for a hovering tailsitter for some …

An Investigation Of The Impact A Rov Competition Curriculum Has On Student Interest In Stem, Specifically Technology And Engineering, Daniel Gordon Bates

Student Works

This research investigates the impact a Remotely Operated Vehicle (ROV) program has on student interest in, and perception of, technology and engineering (sTEm). ROV programs embed areas of science, technology, engineering and math (STEM) into their curriculum; however, emphasis for this study is placed on interest and perception of the "T" and "E" of STEM. Although there are many articles detailing the benefits of ROV programs, there is little empirical data documenting the impact on student interest and perception of sTEm. This study outlines the background of a few major ROV programs in the U.S.; specifically Utah Underwater Robotics (UUR), …

Jezik: A Cognitive Translation System Employing A Single, Visible Spectrum Tracking Detector, Davor Bzik

Student Works

A link between eye movement mechanics and the mental processing associated with text reading has been established in the past. The pausing of an eye gaze on a specific word within a sentence reflects correctness or fluency of a translated text. A cognitive translation system has been built employing a single, inexpensive web camera without the use of infrared illumination. It was shown that the system translates the text, detects rarely occurring and out-of-context words from eye gaze information, and provides solutions in real time while the user is still reading. The solutions are in form of a translation, definition …

Microspine Gripping Mechanism For Asteroid Capture, Ezekiel G. Merriam, Andrew B. Berg, Andrew Willig, Aaron Parness, Tim Frey, Larry L. Howell

Student Works

This paper details the development and early testing of a compliant suspension for a microspine gripper device for asteroid capture or micro-gravity percussive drilling. The microspine gripper architecture is reviewed, and a proposed microspine suspension design is presented and discussed. Prototyping methods are discussed, as well as testing methods and results. A path forward is identified from the results of the testing completed thus far. Key findings include: the microspine concept has been established as a valid architecture and the compliant suspension exhibits the desired stiffness characteristics for good gripping behavior. These developments will aid in developing the capability to …

The Bambow: A Bamboo-Cored Carbon-Fiber Composite Bow, Ezekiel G. Merriam

Student Works

Archery is a sport that has benefited from thousands of years of development. Starting with primitive stick-bows, ancient people found they could propel projectiles larger distances and with more effectiveness than by hand or with other mechanical aids. Over the centuries different cultures adopted and advanced different aspects of the technology, including materials, geometry, and manufacturing methods. In the Mechanical Engineering Department at BYU, Nephi's Steel Bow Competition is held annually to challenge engineering students to test their knowledge of mechanics and materials. As a past participant in this competition, I felt building an advanced composite bow would be an …

Lateral Resistance Of Pipe Piles Near 20-Ft Tall Mse Abutment Wall With Strip Reinforcements, Jason James Besendorfer

Student Works

Full scale lateral load testing was performed on four 12.75x0.375 pipe piles spaced at 3.9, 2.9, 2.8, and 1.7 pile diameters behind an MSE wall which was constructed for this research to determine appropriate reduction factors for lateral pile resistance based on pile spacing behind the back face of the wall. The load induced on eight soil reinforcements located at various transverse distances from the pile and at different depths was monitored to determine the relationship between lateral load on the pile and load induced in the reinforcement. Each pile was loaded towards the wall in 0.25 in. increments to …

Technical Note On Manipulating Multivariate Gaussian Distributions, John C. Macdonald

Student Works

In this technical note we present some derivations treating conditional, marginal, and joint distributions for Gaussian random vectors.

Cobalt Fischer-Tropsch Catalyst Preparation: Overview Of Preparation Techniques On Alumina Pellets, Brad M. Hancock, Kari M. Cook, William C. Hecker

Student Works

Fischer-Tropsch (FT) synthesis is a reaction used to convert carbon monoxide and hydrogen into high-quality liquid fuels. The FT process has been considered a promising alternative route for producing diesel fuel to meet an increasing demand for oil around the world and more strict limits to regulate auto tailpipe emissions. The U.S. Environmental Protection Agency has demanded a reduction in diesel fuel sulfur content to 15 ppm. While crude oil contains finite amounts of sulfur that needs further removal or treatment before it could be used as a commercial fuel, FT synthesis produces sulfur-free diesel fuel. The reaction takes place …