Digital Commons Network^™

Characterization Of Flexible Hybrid Electronics Using Stretchable Silver Ink And Ultra-Thin Silicon Die, Joshua A. Ledgerwood

Master's Theses

Flexible Hybrid Electronics (FHEs) offer many advantages to the future of wearable technology. By combining the dynamic performance of conductive inks, and the functionality of ultra-thinned, traditional IC technology, new FHE devices allow for development of applications previously excluded by relying on a specific type of electronics technology.

The characterization and reliability analysis of stretchable conductive inks paired with ultra-thin silicon die in theµm range was conducted. A silver based ink designed to be stretchable was screen printed on a TPU substrate and cured using box oven, conveyor convection oven, and photonic curing processes. Reliability tests were conducted including a …

A Collaborative Web Application Framework For Least Cost Caloric Paths With Constraints On High Resolution Data, Audrey Waschura

Master's Theses

Historically, humans traveling on foot do not travel as the crow flies in a constant direction; rather, they follow the path of least resistance. The path of least resistance could mean avoiding mountain ranges, or following a stretch of terrain or avoiding large bodies of water. These paths are taken because they are easier to traverse and allow the traveler to expend the least amount of energy, or calories. Least cost caloric paths are a more realistic model of how humans travel on foot across terrain. Previous work has been done in computing and visualizing least cost caloric paths. This …

A Live Programming Environment For Python, Noah Negrey

Master's Theses

Learning how to program can be quite difficult. Beginners face two obstacles to learning to program: developing a mental model of the steps of computation and learning the syntax of a programming language. Because programmers are prone to make mistakes that introduce errors into their code, it is important that they understand what each line of code is doing in their program. I propose that a system be built in which writing code and running code happen simultaneously. This system shows the results of code to the user immediately after it is typed; this type of system is called a …

Wing Deflection Analysis Of 3d Printed Wind Tunnel Models, Matthew G. Paul

Master's Theses

This work investigates the feasibility of producing small scale, low aerodynamic loading wind tunnel models, using FDM 3D printing methods, that are both structurally and aerodynamically representative in the wind tunnel. To verify the applicability of this approach, a 2.07% scale model of the NASA CRM was produced, whose wings were manufacturing using a Finite Deposition Modeling 3D printer. Experimental data was compared to numerical simulations to determine percent difference in wake distribution and wingtip deflection for multiple configurations.

Numerical simulation data taken in the form of CFD and FEA was used to validate data taken in the wind tunnel …

Create: Clinical Record Analysis Technology Ensemble, Skylar Eglowski

Master's Theses

In this thesis, we describe an approach that won a psychiatric symptom severity prediction challenge. The challenge was to correctly predict the severity of psychiatric symptoms on a 4-point scale. Our winning submission uses a novel stacked machine learning architecture in which (i) a base data ingestion/cleaning step was followed by the (ii) derivation of a base set of features defined using text analytics, after which (iii) association rule learning was used in a novel way to generate new features, followed by a (iv) feature selection step to eliminate irrelevant features, followed by a (v) classifier training algorithm in which …

Eulerian On Lagrangian Cloth Simulation, Kyle C. Piddington

Master's Theses

This thesis introduces a novel Eulerian-on-Lagrangian (EoL) approach for simulating cloth. This approach allows for the simulation of traditionally difficult cloth scenarios, such as draping and sliding cloth over sharp features like the edge of a table. A traditional Lagrangian approach models a cloth as a series of connected nodes. These nodes are free to move in 3d space, but have difficulty with sliding over hard edges. The cloth cannot always bend smoothly around these edges, as motion can only occur at existing nodes. An EoL approach adds additional flexibility to a Lagrangian approach by constructing special Eulerian on Lagrangian …

The Design, Manufacture, And Testing Of A Novel Adhesion System For A Climbing Vehicle, Michael William Schier

Master's Theses

We present the design and fabrication of a prototype wall-climbing vehicle employing a unique combined locomotion and adhesion system in which the adhesive vacuum is transmitted through moving, perforated treads. Implementing the adhesion/drive system involved a broad range of design challenges, including: developing reliable sealing of sliding and static interfaces, understanding the frictional interactions between the drive treads and various vehicle components and surfaces on which they ride, as well as designing for lightness, manufacturability, and adjustability. The clean sheet design presented in this thesis was taken from concept to functioning prototype in less than 6 months, requiring a considered …

Optimum Design Of Composite Wing Spar Subjected To Fatigue Loadings, Juan Reuben Lazarin

Master's Theses

Composites are now being incorporated into aircraft designs because of their high strength to weight ratio compared to traditional metal materials. Due to the complexity of the material, composite parts are presently being over designed to satisfy static and fatigue requirements. A greater understanding of composite fatigue behavior will allow for even greater weight savings leading to increased fuel economy. A critical part of an aircraft that is subjected to fatigue bending loads are its wings. The forces acting on the wings include its lift distribution, powerplant, and fuel which can be carried in the wing body. When in flight …

"Ye Sons Of Mars": British Representations Of The Sudan Campaign In Print Culture, 1884–1899, Crystal E. Smith

Master's Theses

From 1884 to 1885 the British were first engaged with the Mahdist forces of Sudan in an effort to first rescue the inhabitants of Khartuom, and later to rescue the rescuer Charles “Chinese” Gordon. The affair played out both in Parliament and the newspapers as journalists became the cheerleaders for Empire. My thesis focuses on Britain’s 1884-1890 Sudan Campaign through print culture using political debates, journalism, literature, memoirs, and art. I show how the activism of the press and the romanticism of the larger media reinforced ideas about imperialism and the British role within the Empire at large.

Pscad Modeling And Stability Analysis Of A Microgrid, Kyle R. Hasan

Master's Theses

As power systems are evolving, engineers are facing, and will continue to face, new challenges with respect to maintaining the system in terms of stable operation. Many different forms of generation are becoming prevalent, including; small synchronous generators, photovoltaic generation, and energy storage techniques in the form of battery and ultracapacitor systems. One of the evolutions occurring in the power system is the emergence of microgrids, small power systems capable of isolating from the major power grid in the form of islands. Microgrids use distributed generation to provide power to small communities, and they come with several advantages and disadvantages. …

Ecosystem-Based Management In The Morro Bay Watershed And Estuary, Lucas Earle Crandall

Master's Theses

The following thesis discusses the implementation of ecosystem-based management, an emerging concept in the field of environmental planning and management, in the Morro Bay watershed and estuary. Ecosystem-based management offers solutions to problems associated with human interaction within the natural environment; former President Barack Obama advised by the National Ocean Council, Pew Oceans Commission Report and the US Commission on Ocean Policy, has mandated implementation of this concept in coastal and marine systems (National Ocean Council, 2016). The theory behind ecosystem-based management challenges many tenets of existing natural resource management. This thesis finds the concept of ecosystem-based management as favorable …

An Investigation Of Avian Wing Tip Vortex Generation Using A Biomimetic Approach, David Stewart Martin

Master's Theses

An experimental study has been conducted to develop a process allowing the creation of biologically accurate aerodynamic test models mimicking the slotted primary feather geometry of the Brown Pelican (Pelecanus occidentalis). Preserved examples of both a full Brown Pelican wing and a single primary feather were 3D scanned and digitally reconstructed using a combination of MATLAB and CAD software. The final model was then 3D printed as a collection of smaller components using a LulzBot TAZ 6 printer and Taulman3D T-Glase PET filament. After using various surface finishing techniques to improve the finish of all 3D printed parts, …

Development Of A Humidity-Resistant Coating To Impart High Oxygen Barrier Performance To Food Packaging Films, Ryan Yinghua Cox

Master's Theses

Oxygen barrier coatings have the potential to greatly extend the lifetime of certain food products by incorporating them into existing food packaging. Present technologies face definite challenges of maintaining high performance, while attaining simple and inexpensive preparation methods. The oxygen barrier effect obtained with these coatings is also susceptible to a plasticization effect when exposed to high humidity, since water vapor molecules are readily soluble in typically hydrophilic resins. In this work, we demonstrate a 1 – 2 micron thick oxygen barrier coating, prepared on a 12 micron poly(ethylene terephthalate) substrate, that has oxygen transmission rates as low as 1.44 …

Design Of An Active Harmonic Rejection N-Path Filter For Highly Tunable Rf Channel Selection, Craig J. Fischer

Master's Theses

As the number of wireless devices in the world increases, so does the demand for flexible radio receiver architectures capable of operating over a wide range of frequencies and communication protocols. The resonance-based channel-select filters used in traditional radio architectures have a fixed frequency response, making them poorly suited for such a receiver. The N-path filter is based on 1960s technology that has received renewed interest in recent years for its application as a linear high Q filter at radio frequencies. N-path filters use passive mixers to apply a frequency transformation to a baseband low-pass filter in order to achieve …

Preliminary Investigations Into Selective Laser Melting, David Takeo Otsu

Master's Theses

Selective laser melting is a promising metallic additive manufacturing process with many potential applications in a variety of industries. Through a gracious donation made by Lawrence Livermore National Laboratory, California Polytechnic State University received and installed an SLM 125 HL selective laser melting machine in February 2017. As part of the initial setup effort, a preliminary machine verification study was conducted to evaluate the general print quality of the machine with default parameter settings. Coincidentally, the as-printed microstructure of SLM components was evaluated through nil strength fracture surface examination, an alternative to conventional polish-and-etch metallography. A diverse set of components …

A Data-Driven Approach To Cubesat Health Monitoring, Serbinder Singh

Master's Theses

Spacecraft health monitoring is essential to ensure that a spacecraft is operating properly and has no anomalies that could jeopardize its mission. Many of the current methods of monitoring system health are difficult to use as the complexity of spacecraft increase, and are in many cases impractical on CubeSat satellites which have strict size and resource limitations. To overcome these problems, new data-driven techniques such as Inductive Monitoring System (IMS), use data mining and machine learning on archived system telemetry to create models that characterize nominal system behavior. The models that IMS creates are in the form of clusters that …

Anaerobic Fermentation Of Food Waste And Glycerol To Hydrogen, Eric Robert Krikorian

Master's Theses

ABSTRACT

Anaerobic Fermentation of Food Waste and Glycerol to Hydrogen

Eric Krikorian

Hydrogen has several well-known advantages as a fuel and chemical feedstock, but current methods of hydrogen production are costly and energy intensive. A potentially advantageous source of hydrogen is fermentation of organic wastes, especially any abundant, low-cost wastes with a high content of simple sugars. Molar hydrogen yields from fermenters (aka digesters) are affected by pH, organic loading rate (OLR), hydraulic residence time (HRT), and substrate type. A less studied process to increase yield is sparging with low-H₂ content gas to strip H₂ from the digester …

Development And Characterization Of Tissue Engineered Blood Vessel Mimics Under "Diabetic" Conditions, Shelby Gabrielle Kunz

Master's Theses

The development of tissue engineered blood vessel mimics for the testing of intravascular devices in vitro has been established in the Cal Poly tissue engineering lab. Due to the prevalence of cardiovascular disease in diabetic patients and minimal accessible studies regarding the interactions between diabetes and intravascular devices used to treat vascular disease, there is a need for the development of diabetic models that more accurately represents diabetic processes occurring in the blood vessels, primarily endothelial dysfunction. This thesis aimed to create a diabetic blood vessel mimic by implementing a high glucose environment for culturing human endothelial cells from healthy …

Using Computer Vision To Build A Predictive Model Of Fruit Shelf-Life, Nandan G. Thor

Master's Theses

Computer vision is becoming a ubiquitous technology in many industries on account of its speed, accuracy, and long-term cost efficacy. The ability of a computer vision system to quickly and efficiently make quality decisions has made computer vision a popular technology on inspection lines. However, few companies in the agriculture industry use computer vision because of the non-uniformity of sellable produce. The small number of agriculture companies that do utilize computer vision use it to extract features for size sorting or for a binary grading system: if the piece of fruit has a certain color, certain shape, and certain size, …

Verification Of Receiver Equalization By Integrating Dataflow Simulation And Physical Channels, David M. Ritter, Tina Smilkstein

Master's Theses

This thesis combines Keysight’s SystemVue software with a Vector Signal Analyzer (VSA) and Vector Signal Generator (VSG) to test receiver equalization schemes over physical channels. The testing setup, “Equalization Verification,” is intended to be able to evaluate any equalization scheme over any physical channel, and a decision-directed feed-forward LMS equalizer is used as an example. The decision-directed feed-forward LMS equalizer is shown to decrease the BER from 10^-2 to 10^-3 (average of all trials) over a CAT7 and CAT6A cable, both simulated and physical, for 1GHz and 2GHz carrier, and 80MHz data rate. A wireless channel, 2.4GHz Dipole …

Complex Filters As Cascade Of Buffered Gingell Structures: Design From Band-Pass Constraints, Nicole M. Hay

Master's Theses

Complex filters are multi-input, multi-output networks designed to discriminate based upon the relative phase difference between input signals. Complex filters find application in modern wireless systems for single sideband transmission and image-reject reception. This thesis presents one active complex filter implementation using two operational amplifiers per stage, termed “type-II” topology. The “type-II” originates from the passive RC-CR polyphase topology presented by Gingell in his 1973 paper, “Single sideband modulation using sequence asymmetric polyphase networks.” This new topology gains several advantages over existing complex filter implementations, namely “cascadability” (multiple sections placed in series to create a higher-order response) without altering the …

Modeling And Simulation Of A Sounding Rocket Active Stabilization System, Steven M. Maclean

Master's Theses

The Horizon Simulation Framework is a modeling and simulation framework developed to verify system level requirements. In this thesis, the framework is extended to include the Dynamic position type that existed in the early development phase of the framework. The Dynamic position type is tested through the modeling and simulation of a sounding rocket. An active control system based on linear-quadratic regulator (LQR) control theory is implemented and tested in the simulation to determine the overall effect on altitude. A first order aerodynamics and aeroprediction model are created within the framework to allow for rapid changes early in the design …

Design And Construction Of 1800w Modular Multiple Input Single Output Non-Isolated Dc-Dc Converters, Angelo Miguel Asuncion Gallardo

Master's Theses

This thesis report details the design and construction of non-isolated DC-DC converters to create a Multiple Input Single Output (MISO) converter for combining multiple renewable energy sources into one single output. This MISO uses the four-switch buck-boost topology to output a single 48V from multiple nominal 24V inputs. The MISO converter implements a modular approach to deliver 1800W output power. Each module in the MISO is rated at 600W and they share the output power equally. Hardware results show that the converter produces 1800W of output power from three sources with 96.4% efficiency. Each module also demonstrates equal sharing feature …

A Modified Boost Converter With Reduced Input Current Ripple, Nathan H. Lentz

Master's Theses

Battery-powered trends in consumer electronics, transportation, and renewable energy sectors increase demands on DC/DC converter technology. Higher switching frequency and efficiency reduces solution size and cost, while increasing power capabilities. Still, switching noise remains the primary drawback associated with any DC/DC converter. Reducing a converter’s input ripple helps prevent switching noise from spreading to other systems on a shared DC power bus. This thesis covers the analysis, simulation, and implementation of a recently-proposed boost converter topology, alongside an equivalent standard boost converter, operating in steady-state, continuous conduction mode. A Matlab-based simulation predicts each converter’s input ripple performance using a state-space …

Complementary Companion Behavior In Video Games, Gavin Scott

Master's Theses

Companion characters in are present in many video games across genres, serving the role of the player's partner. Their goal is to support the player's strategy and to immerse the player by providing a believable companion. These companions often only perform rigidly scripted actions and fail to adapt to an individual player's play-style, detracting from their usefulness. Behavior like this can also become frustrating to the player if the companions become more of a hindrance than they are a benefit. Other work, including this project's precursor, focused on building companions that mimic the player. These strategies customize the companion's actions …

Quantifying The Impact Of Truck Only Lanes On Vehicular Emissions On A Limited-Access Highway, Edward Chee Tang

Master's Theses

This thesis seeks to estimate CO₂ emissions on a portion of the U.S. 101 highway in San Luis Obispo County before and after construction of a truck only lane on the Cuesta Grade. Towards that aim, the microsimulation software, VISSIM, was used in conjunction with the Environmental Protection Agency’s emissions model, MOVES. The microsimulation model was calibrated and validated against historical and present traffic volumes obtained from Caltrans with good results using several validation measures. It was found that CO₂ emissions did decrease between 1998 and 2012 (pre and post lane addition), but this effect was shown to …

Modeling And Charging Control Of A Lithium Ion Battery System For Solar Panels, Garrett David Heinen

Master's Theses

The advancement in solar panel and battery technology makes them useful for energy supply and storage. This thesis involves the modeling and charging control of a lithium ion battery system for solar panels. The proposed model is based on the parameters and characteristics of a realistic battery and solar panel system; and the hybrid control approach combines the advantages of the adaptive incremental conductance method and the perturb and observe method to track the maximum power point of the solar panel for charging the battery unit. Computer simulation results demonstrate that this proposed approach offers a faster convergence rate than …

Evaluation Of Pc-Based Virtual Reality As A Tool To Analyze Pedestrian Behavior At Midblock Crossings, Kristina Lynn Mai

Master's Theses

The aim of this research was to analyze if current generation PC-driven virtual reality simulations can be used to accurately mimic and therefore, observe behavior at a crosswalk. Toward that goal, the following research tasks were carried out: a) Designing a 3D virtual crosswalk and recruiting volunteers to wear the HTC Vive headset and to walk across the street, b) Setting up cameras near the midblock crosswalk on University Drive at California Polytechnic State University, San Luis Obispo to observe pedestrians, and c) Comparing pedestrian behavior data from both the virtual and real midblock crosswalk. The comparison was based on …

Dc-Dc Converter Control System For The Energy Harvesting From Exercise Machines System, Alexander Sireci

Master's Theses

Current exercise machines create resistance to motion and dissipate energy as heat. Some companies create ways to harness this energy, but not cost-effectively. The Energy Harvesting from Exercise Machines (EHFEM) project reduces the cost of harnessing the renewable energy. The system architecture includes the elliptical exercise machines outputting power to DC-DC converters, which then connects to the microinverters. All microinverter outputs tie together and then connect to the grid. The control system, placed around the DC-DC converters, quickly detects changes in current, and limits the current to prevent the DC-DC converters and microinverters from entering failure states.

An artificial neural …

Application Of Statistical Predictive Models For Field Failure And Cisco Testing Data (Big Data Source: Cisco), Alyssa M. Carter

Master's Theses

Cisco was interested in how field failure categories relate to manufacturing test failures to better predict the tests that should be performed on a product after a return by a customer and what tests will be failed by a product before and after a return by a customer based on what type of failure occurred in the field. A study was conducted on one product type and 5 years of field data and the associated test data were captured. For each combination of field failure, shipping status, test area result, and test area a statistical model of the population proportion …