Digital Commons Network^™

Mechanical Simulation Of Articular Cartilage Based On Experimental Results, Kevin Matthew Stewart

Master's Theses

Recently, a constituent based cartilage growth finite element model (CGFEM) was developed in order to predict articular cartilage (AC) biomechanical properties before and after growth. Previous research has noted limitations in the CGFEM such as model convergence with growth periods greater than 12 days. The main aims of this work were to address these limitations through (1) implementation of an exact material Jacobian matrix definition using the Jaumann-Kirchhoff (J-K) method and (2) quantification of elastic material parameters based upon research findings of the Cal Poly Cartilage Biomechanics Group (CPGBG). The J-K method was successfully implemented into the CGFEM and exceeded …

Internet-Scale Reactive Routing And Mobility, Daniel B. Nelson

Master's Theses

Since its commercialization, the Internet has grown exponentially. A large variety of devices can communicate creating advanced services for a diverse ecosystem of applications. However, as the number of Internet hosts has grown, the size of routing tables required to correctly route data between them has also increased exponentially. This growth rate necessitates increasingly frequent upgrades to routing device hardware, providing them with additional memory for fast-access storage of route information. These upgrades are both physically and fiscally untenable, and a new Internet routing solution is necessary for future growth.

This research focuses around an incrementally deployable, reactive routing system …

An Approach Based On Wavelet Decomposition And Neural Network For Ecg Noise Reduction, Suranai Poungponsri

Master's Theses

Electrocardiogram (ECG) signal processing has been the subject of intense research in the past years, due to its strategic place in the detection of several cardiac pathologies. However, ECG signal is frequently corrupted with different types of noises such as 60Hz power line interference, baseline drift, electrode movement and motion artifact, etc. In this thesis, a hybrid two-stage model based on the combination of wavelet decomposition and artificial neural network is proposed for ECG noise reduction based on excellent localization features: wavelet transform and the adaptive learning ability of neural network. Results from the simulations validate the effectiveness of this …

Analysis & Design Of Improved Multiphase Interleaving Dc-Dc Converter With Input-Output Bypass Capacitor, Rudi Rudianto

Master's Theses

As the transistor count per chip in computer microprocessors surpasses one billion, the semiconductor industry has become more and more concerned with meeting processor’s power requirements. This poses a design challenge for the power supply module, especially when the processor operates at low voltage range. For example, the electrical requirement for the newest Intel microprocessors has exceeded 100A with an input voltage of approximately 1V. To overcome this problem, multiphase DC-to-DC converters encased in a voltage regulator module (VRM) have become the standard means of supplying power to computer microprocessor.

This study proposes a new topology for the multiphase DC-to-DC …

The Relationship Between Plasma Steroid Hormone Concentrations And The Reproductive Cycle Of The Northern Pacific Rattlesnake, Crotalus Oreganus, Craig Michael Lind

Master's Theses

To gain a better understanding of the role of steroid hormones in vertebrate reproduction, we quantified steroid hormone concentrations in a free ranging population of the Northern Pacific rattlesnake, Crotalus oreganus. Plasma steroid hormone concentrations were quantified for both male and female snakes throughout the active season (Mar-Oct). We measured testosterone (T), 5α-dihydrotestosterone (DHT), and corticosterone (B) concentrations in male and female snakes. 17β-estradiol (E2) and progesterone (P) were measured in females only. We also observed breeding behaviors (e.g. consortship, courtship, and copulation) in the field and measured testis and follicle size in male and female snakes from museum collections. …

Energetic Path Finding Across Massive Terrain Data, Andrew N. Tsui

Master's Theses

Before there were airplanes, cars, trains, boats, or bicycles, the primary means of transportation was on foot. Unfortunately, many of the trails used by ancient travelers have long since been abandoned. We present a software tool which can help visualize and predict where these forgotten trails might lie through the use of a human-centered cost metric. By comparing the paths generated by our software with known historical trails, we demonstrate how the tool can indicate likely trails used by ancient travelers. In addition, this new tool provides novel visualizations to better help the user understand alternate paths, effect of terrain, …

Novel Current-Fed Boundary-Mode Parallel-Resonant Push-Pull Converter, Jonathan David Paolucci

Master's Theses

The inherent difficulty in designing high voltage power supplies is often compounded by demands of high reliability, high performance, and safe functionality. A proposed high step-up ratio DC-DC converter meets the exacting requirements of applications such as uninterruptible power systems, radar, and pulsed power systems. The proposed DC-DC converter topology combines a multi-phase buck input stage with a novel self-tracking zero-voltage-switching (ZVS) resonant output stage. Traditionally, the inclusion of multiple power processing stages within a power supply topology severely degrades the overall converter efficiency. Due to the inherent high efficiency per stage, however, this effect is minimized. The self-tracking switching …

A Graphical Approach To Testing Real-Time Embedded Devices, Steven M. Day

Master's Theses

Software Testing is both a vital and expensive part of the software development lifecycle. Improving the testing process has the potential for large returns. Current testing methodologies used to test real-time embedded devices are examined and the weaknesses in them are exposed. This leads to the introduction of a new graphical testing methodology based on flowcharts. The new approach is both a visual test creation program and an automated execution engine that together frame a new way of testing. The new methodology incorporates flow-based diagrams, visual layouts, and simple execution rules to improve upon traditional testing approaches. The new methodology …

Computers For The Masses: The American Socio-Technological Change Of The 1970'S And 1980'S, Robert Bryan Goodman

Master's Theses

This thesis developed out of my personal curiosity on the subject of high-technological development. Specifically, high-technology’s shift from primarily a military tool to a consumer product raised several questions to answer since first taking an interest in the subject. My lifestyle, like many other Americans in my generation, incorporates computers, cell-phones, and video game consoles as not only an innovative tool, but a standard and necessary mode of production. In our contemporary society, technology is obtainable everywhere. As an entertaining tool in the form of video games to a productivity tool in our workplaces, most individuals have assimilated consumer electronics. …

Prestressing Concrete With Shape Memory Alloy Fibers, Skye M. Orvis

Master's Theses

Concrete is considerably stronger in compression than it is in tension. When cracks form in concrete members, the flexural stiffness of the member decreases and the deflection increases which increases the overall size of the member. Prestressing concrete remedies this problem by inducing a compressive stress in the concrete thereby reducing the net tension in the member and increasing the load required to crack the member. Traditional prestressing is generally limited to large, straight members. During the last decade, shape memory alloys (SMA) have become more prevalent in engineering and civil engineering applications. The shape memory effect refers to the …

The Influence Of Incentives Offered By Local Governments To Private Developers Or Land Owners On The Rate Of Brownfield Redevelopment, Erik Benjamin Simon

Master's Theses

Redevelopment of brownfield sites has become increasingly popular since the inception of voluntary cleanup programs in the early to mid 1990’s. Local governments have begun to offer incentives to private developers or land owners to offset costs associated with contamination and encourage the redevelopment of properties that are typically underutilized. Incentives may take several forms including, but not limited to, fast-tracked project approval, risk based cleanup standards, liability relief, tax breaks, and direct funding assistance.

This study investigates how incentives that are offered by local governments to private developers or land owners influence the rate of redevelopment in their sphere …

Assessing Near-Field Outdoor Concentration Variability From Residential Wood Smoke Combustion Sources, Courtney E. Ward

Master's Theses

ABSTRACT Assessing Near-Field Outdoor Concentration Variability from Residential Wood Smoke Combustion Sources Courtney Ward The primary goal of this research was to determine whether near field effects from residential wood smoke emissions have a significant impact on acute and/or average PM2.5 concentrations, and therefore health risks. To this end, three primary research objectives were addressed: (1) measurement of the variability of wood smoke concentrations within a residential neighborhood with wood smoke sources, (2) establishment of whether the magnitude of near-source contributions to exposures can be estimated using typically available data, and (3) prediction of wood smoke concentrations using linear regression …

The Impact Of Lipid Percentage On Fibrous Cap Stability In Atherosclerotic Lesions, Anita Lorraine Crompton

Master's Theses

Coronary artery disease (CAD) is a common cause of sudden cardiac death. Much of the disease is not completely understood, which makes treatment and prevention difficult. Many researchers are using technology, such as advanced imaging techniques and finite element analysis, to better understand the disease. While there is much progress being made to look at the analysis of actual excised diseased arteries, there is still not a standardized model to predict the future of any one lesion. The purpose of this study is to explore the possibility of creating a standardized model to predict the mechanical stability of the fibrous …

Viability Of Alternative Genetic Improvement Strategies Using Whole Genome Selection On Commercial Dairy Operations, Levi W.M. Gassaway

Master's Theses

The objective of this thesis was to determine the viability of alternative genetic improvement strategies (GIS). Each alternative GIS combined the use of whole genome selection (WGS) with common reproductive methods (non-sexed semen artificial insemination (AI), sexed semen AI, embryo transfer utilizing non-sexed semen AI) that can be found on a commercial dairy operation. The viability of each GIS was determined using a discounted gene flow model, designed with parameters of a typical western dairy operation, to evaluate the following variables: reproductive method, selection intensity, accuracy of prediction and female age-class. Of the GIS investigated, a heifer-based strategy that used …

A Highly Abstracted Method Of Fpga-Based Development For Secondary Surveillance Radar Transpond Detection, James Penn Watt

Master's Theses

Traditional FPGA-based digital design is based on writing hardware definition language (HDL) code from scratch. Time to market, cost of development, and the level of training required for designers all can be reduced with a simplified and abstracted design strategy. This project intends to demonstrate a graphical user interface (GUI) layer of abstraction on top of existing commercially produced design aids including MATLAB, Simulink, and Xilinx System Generator. This project performs and demonstrates a specific implementation example of a Secondary Surveillance Radar (SSR) message decoder as proof-of-concept for the abstracted design method. The abstracted digital design methods shown in this …

Preparation And Characterization Of Electrospun Poly(D, L-Lactide-Co-Glycolide) Scaffolds For Vascular Tissue Engineering And The Advancement Of An In Vitro Blood Vessel Mimic, Tiffany Richelle Pena

Master's Theses

PREPARATION AND CHARACTERIZATION OF ELECTROSPUN POLY(D,L-LACTIDE-CO-GLYCOLIDE) SCAFFFOLDS FOR VASCULAR TISSUE ENGINEERING AND THE ADVANCEMENT OF AN IN VITRO BLOOD VESSEL MIMIC

Tiffany Richelle Peña

Currently, an estimated 1 in every 3 adult Americans are affected by one or more cardiovascular complications. The most common complication is coronary artery disease, specifically atherosclerosis. Outcomes of balloon angioplasty treatments have been significantly improved with the addition of drug eluting stents to the process. Although both bare metal and drug eluting stents have greatly increased the effectiveness of angioplasty and decreased the occurrence of restenosis, several complications still exist. For this reason, the stent …

Designing A Microbial Prolyl Peptidase Delivery System For The Treatment Of Celiac Disease, Matthew J. Shurtleff

Master's Theses

Celiac disease is an autoimmune enteropathy resulting from the ingestion of gluten and gluten-like proteins from wheat, barley and rye in afflicted individuals. Indigestible gluten-derived peptides rich in proline residues are known to be responsible for eliciting the inappropriate immune response characteristic of the disease. In this investigation, surface level expression of prolyl peptidase activity by genetically engineered probiotic lactobacilli was postulated to be a possible treatment for this disease. Plasmid-based reporter vectors were constructed utilizing a novel, homology-based cloning technique to assess the expression and localization signals from the S-layer protein gene of Lactobacillus acidophilus. These plasmids were mutated …

Simulation Of An Oxidizer-Cooled Hybrid Rocket Throat: Methodology Validation For Design Of A Cooled Aerospike Nozzle, Peter Alexander Brennen

Master's Theses

A study was undertaken to create a finite element model of a cooled throat converging/diverging rocket nozzle to be used as a tool in designing a cooled aerospike nozzle. Using ABAQUS, a simplified 2D axisymmetric model was created featuring only the copper throat and stainless steel support ring, which were brazed together for the experimental test firings. This analysis was a sequentially coupled thermal/mechanical model. The steady state thermal data matched closely to experimental data. The subsequent mechanical model predicted a life of over 300 cycles using the Manson-Halford fatigue life criteria. A mesh convergence study was performed to establish …

Advanced Thermosonic Wire Bonding Using High Frequency Ultrasonic Power: Optimization, Bondability, And Reliability, Minh-Nhat Ba Le

Master's Theses

Gold wire bonding typically uses 60 KHz ultrasonic frequency. Studies have been reported that increasing ultrasonic frequency from 60KHz to 120KHz can decrease bonding time, lower bonding temperature, and/or improve the bondability of Au metalized organic substrates. This thesis presents a systematic study of the effects of 120 KHz ultrasonic frequency on the reliability of fine pitch gold wire bonding. Two wire sizes, 25.4 and 17.8 μm in diameter (1.0 and 0.7 mil, respectively) were used. The gold wires were bonded to metalized pads over organic substrates with five different metallization. The studies were carried out using a thermosonic ball …

Design, Fabrication, And Implementation Of A Single-Cell Capture Chamber For A Microfluidic Impedance Sensor, Joshua-Jed Doria Fadriquela

Master's Theses

A microfluidic device was created for single-cell capture and analysis using polydimethylsiloxane (PDMS) channels and a glass substrate to develop a microfluidic single-cell impedance sensor for cell diagnostics. The device was fabricated using photolithography to create a master mold which in turn will use soft lithography to create the PDMS components for constant device production. The commercial software, COMSOLTM Multiphysics, was used to quantify the fluid dynamics in shallow micro-channels.

The device will be able to capture a cell and sequester it long enough to enable measurement of the impedance spectra that can characterize cell. The proposed device will be …

Effects Of Experience On Maternal Behavior In Belding’S Ground Squirrels (Spermophilus Beldingi): Older And Wiser?, Mikael Langner

Master's Theses

Maternal behavior is an important behavior because it influences whether or not raising one’s offspring is successful. Maternal experience is positively correlated with successful maternal behavior. This association is evident when comparing first-time mothers with mothers who have prior experience raising young. Life experience not related to raising young can also positively influence maternal behavior. In this work, the hypothesis that is tested is whether or not maternal experience enhances the ability of a female to assess the threat level of a situation. The model species used to conduct the study is the Belding ground squirrel (Spermophilus beldingi), …

A Flight Simulation Study Of The Simultaneous Non-Interfering Aircraft Approach, Brian H. Reel

Master's Theses

Using a new implementation of a NASA flight simulation of the Quiet Short-Haul Research Aircraft, autopilots were designed to be capable of flying both straight in (ILS) approaches, and circling (SNI) approaches. A standard glideslope coupler was sufficient for most conditions, but a standard Proportional-Integral-Derivative (PID) based localizer tracker was not sufficient for maintaining a lateral track on the SNI course. To track the SNI course, a feed-forward system, using GPS steering provided much better results.

NASA and the FAA embrace the concept of a Simultaneous, Non-Interfering (SNI) approach as a way to increase airport throughput while reducing the noise …

Target Tracking Using Various Filters In Synthetic Aperture Radar Data And Imagery, Jessica L. Kiefer

Master's Theses

This thesis explores the use and accuracy of several discrete-time image filters for the purpose of target tracking in Synthetic Aperture Radar imagery. Both extended targets and point targets are used for tracking, showing the need for different types of filters for each target type.

Monte Carlo analysis is performed on the results of the extended target filter results to determine the absolute mean-squared error between the filter prediction of the target centroid and the actual location of the target centroid. Two different filters were chosen for the extended target: Kalman and H Infinity.

Both the Kalman and H Infinity …

City Of South Lake Tahoe Subdivision Ordinance: An Opportunity For Smart Growth, Sustainability, And Application Streamlining, Hilary Kay Hodges

Master's Theses

The City of South Lake Tahoe currently does not have an adopted subdivision ordinance. This has caused confusion about the approval process and regulatory requirements as well as delays in application processing. This Professional Project will explore the opportunity for the City to adopt a subdivision ordinance that would provide direction for subdivision design and approval and further the City’s smart growth and sustainability policies. However, there would need to be careful consideration for the potential increase in costs that are associated with additional fees or off-site improvement requirements. The Subdivision Ordinance would be written with the goals of achieving …

An Experiment On Integrated Thermal Management Using Metallic Foam, Derek M. Geiger

Master's Theses

This report details an approach to using metal foam heat exchangers inside an integrated thermal management system on a variable cycle engine. The propulsion system of interest is a variable cycle engine with an auxiliary, variable flow rate fan. The feasibility of utilizing an open-celled metallic foam heat exchanger in the ducting between the constant and variable-fans on this variable cycle engine to cool the avionics was explored using an experimental approach. Two heat exchangers, 6.3 inch width by 6.3 inch length by 0.5 inch thickness, were constructed from 20 and 40 pores per inch (PPI) metal foam and tested. …

Validation Of Linearized Flight Models Using Automated System-Identification, Keith Eric Rothman

Master's Theses

Optimization based flight control design tools depend on automatic linearization tools, such as Simulink®’s LINMOD, to extract linear models. In order to ensure the usefulness and correctness of the generated linear model, this linearization must be accurate. So a method of independently verifying the linearized model is needed. This thesis covers the automation of a system identification tool, CIFER®, for use as a verification tool integrated with CONDUIT®, an optimization based design tool. Several test cases are built up to demonstrate the accuracy of the verification tool with respect to analytical results and matches with LINMOD. Several common nonlinearities are …

Incremental Validation Of Formal Specifications, Paul S. Corwin

Master's Theses

This thesis presents a tool for the mechanical validation of formal software specifications. The tool is based on a novel approach to incremental validation. In this approach, small-scale aspects of a specification are validated, as part of the stepwise refinement of a formal model.

The incremental validation technique can be considered a form of "lightweight" model checking. This is in contrast to a "heavyweight" approach, wherein an entire large-scale model is validated en masse.

The validation tool is part of a formal modeling and specification language (FMSL), used in software engineering instruction. A lightweight, incremental approach to validation is beneficial …

Evaluation Of Herbicide Efficacy As Influenced By Adjuvant And Nozzle Type, Catherine L. (Grissom) Ansolabehere

Master's Theses

White clover (Trifolium repens) is a common and difficult weed to control in turfgrass as it is a highly visible and unsightly weed that disrupts the uniformity of the turfgrass surface. This weed is a serious problem in the turfgrass industry in California and there is a need for better methods of control. With more regulations on pesticides and less information about efficient application techniques, controlling white clover with available herbicides can be difficult.

Compatibility trials were conducted during the summer of 2005 to determine the compatibility of the herbicides and adjuvants planned for use in subsequent greenhouse and field …

Harmonic Analysis Of A Static Var Compensated Mixed Load System, James David Ruckdaschel

Master's Theses

As power electronic based controllers and loads become more prevalent in power systems, there is a growing concern about how the harmonics generated by these controllers and loads affect the power quality of the system. One widely used power electronic based load is the Variable Frequency Drive (VFDs) used to vary the speed of an induction motor; whereas a common example of a power electronic based controller used in power systems is the Static VAR Compensator (SVC) for improving a system’s power factor. In this thesis, the harmonic content and overall performance of a system including both a VFD and …

Design And Control Considerations For A Skid-To-Turn Unmanned Aerial Vehicle, Tanner Austin Sims

Master's Theses

The use of Unmanned Aerial Vehicles (UAVs) are rapidly expanding and taking on new roles in the military. In the area of training and targeting vehicles, control systems are expanding the functionality of UAVs beyond their initially designed purpose. Aeromech Engineering’s NXT UAV is a high speed target drone that is intended to simulate a small aircraft threat. However, in the interest of increasing functionality, enabling NXT to accomplish wings level skidding turns provides the basis for a UAV that can simulate a threat from a missile. Research was conducted to investigate the aerodynamic and performance characteristics of a winged …