Digital Commons Network^™

Sponges Of The Caribbean: Linking Sponge Morphology And Associated Bacterial Communities, Ericka Ann Poppell

Master's Theses

The ecological and evolutionary relationship between sponges and their symbiotic microflora remains poorly understood, which limits our ability to understand broad scale patterns in benthic-pelagic coupling on coral reefs. Previous research classified sponges into two different categories of sponge microbial associations: High Microbial Abundance (HMA) and Low Microbial Abundance (LMA) sponges. Choanocyte chamber morphology and density was characterized in representatives of HMA and LMA sponges using scanning electron microscopy from freeze-fractured tissue. Denaturing Gradient Gel Elextrophoresis was used to examine taxonomic differences among the bacterial communities present in a variety of tropical sponges. The results supported the hypothesis that choanocyte …

Sustainability And The Future: A Case Study On Environmental Perspectives Of The Future Generation Of Scientists, Abby Jane Davidson

Master's Theses

In the natural sciences, countless studies have sought to quantify the environmental impacts of varying anthropogenic activities and have predicted and modeled future scenarios for the natural world under the siege of human forces. Faith for the study of and action to ameliorate environmental impacts is often put in the hands of scientists. However, little research has been conducted to look at the attitudes and perceptions future scientists have towards the environment with regard to anthropogenic environmental impacts, sustainability, and the future. Therefore, the purpose of this qualitative case study was to take an intensive look at one such group …

Tri-State Boolean Satisfiability With Commit: An Efficient Partial Solution Using Hyperlogic, Kevin Michael Byrd

Master's Theses

We present two implementation enhancements for the Boolean satisfiability problem and one visualization technique. The first is an expansion to a tri-nary logic system with a commit phase. The three states are (1) true, (2) false, and (3) don't care. We abstracted the operations of AND and OR to this hyperlogic system in a novel way. The commit phase works on one variable at a time and transitions values from temporary to permanent whenever possible. We viewed tri-state logic as a hyperspace above the binary (Boolean) logic. The second improvement is algorithmic. We modified the semantics of the classic 3 …

Fraction-Free Methods For Determinants, Deanna Richelle Leggett

Master's Theses

Given a matrix of integers, we wish to compute the determinant using a method that does not introduce fractions. Fraction-Free Triangularization, Bareiss’ Algorithm (based on Sylvester’s Identity) and Dodgson’s Method (based on Jacobi’s Theorem) are three such methods. However, both Bareiss’ Algorithm and Dodgson’s Method encounter division by zero for some matrices. Although there is a well-known workaround for the Bareiss Algorithm that works for all matrices, the workarounds that have been developed for Dodgson’s method are somewhat difficult to apply and still fail to resolve the problem completely. After investigating new workarounds for Dodgson’s Method, we give a modified …

Mechanisms Of Non-Enzymatic Peptide Bond Formation: Thioester And Transamidation Routes, Danielle Amie Landry

Master's Theses

The reaction mechanisms employed during non-ribosomal peptide (amide) synthesis in the non-ribosomal modular enzyme complex and in the enzyme glutaminyl cyclase were also used for spontaneous peptide (amide) synthesis in a buffered, abiotic solution. Analytical analyses revealed that spontaneous peptide (amide) bond formation occurred under mild prebiotic conditions during both the thioester-based production of phenylalanine peptides and peptidyl thioesters, and the spontaneous cyclization of glutamine t-butyl ester (Gln-tbe) into pyroglutamic acid t-butyl ester. Internal standard-based quantitative MS determined that 4.9 x 10-5 sec-1 was the rate constant for spontaneous Gln-tbe cyclization in imidazole buffer, pH 7, at 50°C, and that …

Stationary Density Computation Of The Frobenius-Perron Operators Based On The Dirac Delta Function, Suanrong Chen

Master's Theses

The statistical study of chaotic dynamical systems has received a great deal of attention in the past several decades. As a branch of applied mathematics, its application has been found in various fields in science and engineering, while the theory and methods for the existence and computation of absolutely invariant measures have played an important role in this field. In this study, we focus on the computation of a nontrivial fixed point of Frobenius-Perron operators (F-P operators).

Let S: [0,1] → [0,1] be a piecewise monotonic mapping, and let P_S : [0,1] → [0,1] be the Frobenius-Perron operators …

Applied Bayesian Networks, Steven David Spansel

Master's Theses

A Bayesian Network is a stochastic graphical model that can be used to maintain and propagate conditional probability tables among its nodes. Here, we use a Bayesian Network to model results from a numerical riverine model. We develop an discretization optimization algorithm that improves efficiency and concurrently increases the overall accuracy of the resulting network. We measure accuracy using a new prediction accuracy criteria that includes an a posteriori soft correction. Furthermore, we show that this accuracy quickly asymptotes and begins to show diminishing returns on large data sets.

A Parametric Method Of Perspective Alignment And Color Correction For Skin Lesion Imaging, Jian Xu

Master's Theses

ABSTRACT

A Parametric Method of Perspective Alignment and Color Correction on Skin Lesion Imaging

Jian Xu

This thesis investigates the employment of a parametric and fiducial-based perspective alignment method, and a color correction method in the context of digital skin lesion imaging. Specifically, the thesis focuses on the problem of restoring geometric and color distortion caused by variable imaging conditions across multiple skin lesion images.

As the first step, an overview of the problem and relevant methods are presented. Next, the theoretical assumptions of relevant methods and practical requirements in clinical environment are compared. Based on the understanding on the …

Salt Contamination Of Ground And Surface Water In Connecticut: A Compilation And Synthesis Of Historic Data And Local Scale Testing, James P. Cassanelli

Master's Theses

No abstract provided.

Geomagnetic Compensation For Low-Cost Crash Avoidance Project, John C. Torres

Master's Theses

The goal of this work was to compensate for the effects of the Earth’s magnetic field in a vector field magnetic sensor.  The magnetic sensor is a part of a low-cost crash avoidance system by Stephane Roussel where the magnetic sensor was used to detect cars passing when it was mounted to a test vehicle.  However, the magnetic sensor’s output voltage varied when it changed orientation with respect to the Earth’s magnetic field.  This limited the previous work to only analyze detection rates when the test vehicle travelled a single heading.  Since one of the goals of this system is …

Exploring Trade-Offs In Auv Controller Design For Shark Tracking, Louis James Bertsch Iv

Master's Theses

This thesis explores the use of an Autonomous Underwater Vehicle (AUV) to track and pursue a tagged shark through the water. A controller was designed to take bearing and range to the shark tag and then control the AUV to pursue it.

First, the ability of a particle filter to provide an accurate estimation of the location of the shark relative to the AUV is explored. Second, the ability of the AUV to follow the shark's path through the water is shown. This ability allows for localized environmental sampling of the shark's preferred path. Third, various path weightings are used …

High-Resolution, Non-Contact Angular Measurement System For Psa/Rsa, Ronald D. Sloat

Master's Theses

A non-contact angular measurement system for Pitch Static Attitude (PSA) and Roll Static Attitude (RSA) of hard disk drive sliders is designed and built. Real-time sampling at over 15 KHz is achieved with accuracy of +/- 0.05 degrees over a range of approximately 2-3 degrees. Measuring the PSA and RSA is critical for hard drive manufacturers to control and improve the quality and reliability of hard drives. Although the hard drive industry is able to measure the PSA and RSA at the subassembly level at this time, there is no system available that is able to measure PSA/RSA at the …

Probabilistic Fault Displacement Hazard Analysis For Reverse Faults And Surface Rupture Scale Invariance, Zachary E. Ross

Master's Theses

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A methodology is presented for evaluating the potential surface fault displacement on reverse faults in a probabilistic manner. This methodology follows the procedures put forth for Probabilistic Fault Displacement Hazard Analysis (PFDHA). Empirical probability distributions that are central to performing a PFDHA are derived from field investigations of reverse faulting events. Statistical analyses are used to test previously assumed properties of scale invariance with respect to magnitude for normalized displacement. It is found that normalized displacement is statistically invariant with respect to magnitude and focal mechanism, allowing for the …

The State Of Software Engineering Maturity And Licensure, Travis Lawrence Dean

Master's Theses

IEEE-CS is pursuing licensing for software engineers, but ACM believes that software engineering is too immature, and regulating the profession would be premature. In 1996, Norman Gibbs and Gary Ford from Carnegie Mellon University performed a qualitative survey of the maturity of the software engineering profession. I apply this model to the present state of the art in software engineering and analyze the results for 2010. I analyze the maturity of software engineering to determine that the profession is not yet ready for licensure. This is not because the infrastructure of software engineering is too immature, but because we have …

Evaluation Of Stain Blocking Primer Coatings With Low Volatile Organic Compound (Voc) Content And Effects Of Drying Conditions On The Properties Of Water Reducible Coatings For Polypropylene, Megan Alexandra Hart

Master's Theses

The California Air Resources Board (CARB) plans to reduce the volatile organic compound (VOC) limit of specialty primers, sealers, and undercoaters (SPSU), also referred to as stain blocking primers, from 350 g/L to 100 g/L in January of 2012. These coatings are primarily used as stain blocking primers over a variety of substrates, such as wood and drywall. Currently the stain blocking primers that are considered most effective are solvent based primers that contain VOC levels much higher than 100 g/L. The goal of this study is to determine if primers on the market today with a VOC content of …

Artificial Neural Networking As A Decision Tool For Natural Gas Investment, Micah D. Denecour

Master's Theses

With the growing interest in the Marcellus Shale and its natural gas deposits, there are opportunities to purchase and hold land for investment purposes. A robust decision tool is needed to help guide investors towards the most profitable properties. Artificial neural networks have many unique benefits that make them an ideal candidate for this purpose.

The artificial neural networks created in this study had nine independent variables. Combinations of these nine variables were created to describe 300 theoretical properties available for purchase. Each of these properties were then evaluated by an expert in the field and given a score from …

Integration Of Aeroservoelastic Properties Into The Nasa Dryden F/A-18 Simulator Using Flight Data From The Active Aeroelastic Wing Program, Alexander Wong Chin

Master's Theses

Aircraft structures have varying stiffness levels making them flexible. Consequently, this elastic property becomes increasingly important at high speeds affecting the flight dynamics of the aircraft.  In high speed aircraft such as the F/A-18, elastic structural properties must be accounted for to ensure confidence in predicted flight dynamics in order to avoid adverse aeroelastic phenomena throughout flight.

Data from the F/A-18 Active Aeroelastic Wing (AAW) program was used to create aeroservoelastic (ASE) models at varying flight conditions. The discretized ASE models were integrated into the NASA Dryden F/A-18 simulator in parallel with the traditional 6-DOF (degrees-of-freedom) flight dynamics calculations to …

Dynamic Inversion And Backstepping Controller Robustness Analysis For A Reusable Launch Vehicle, Janet M. Coakley

Master's Theses

The Air Force has been working towards developing technology for operationally responsive space (ORS), which is the ability to launch military assets into space without the long set up time currently required. Part of the solution to ORS is to develop a reusable booster vehicle capable of sending any vehicle into orbit, then descending back to the atmosphere and landing unpowered so that it may take another vehicle into orbit with a 48 hour turnaround time. Currently classical gain tuning techniques are used to design a controller for a specific mission, which may hinder the vehicle’s ability to perform multiple …

Utilization Of Geographic Information System For Research, Management, And Education In The Natural Resources Management Department At California Polytechnic State University, San Luis Obispo, David In Yun

Master's Theses

Geographic Information System (GIS) is “an organized collection of computer hardware, software, geographic data, and personnel designed to efficiently capture, store, update, manipulate, analyze, and display all forms of geographically referenced information” (ESRI, 1997a). The Natural Resources Management Department at California Polytechnic State University, San Luis Obispo, California, hereafter NRM, was one of the early users of GIS technology. Although GIS was primarily used as an educational tool, it was also used for cataloging and displaying resource information for management planning and research projects. As the computing technology advanced, GIS became more powerful and easier to use. NRM faculty and …

A Microsimulation Of Traffic, Parking, And Emissions At California Polytechnic State University – San Luis Obispo, Steven Michael Kilbert

Master's Theses

Traffic and parking congestion are significant issues at many universities nationwide. The delays experienced result in wasted time, money, and fuel for students, faculty and staff, not to mention the negative contributions to the environment. This paper quantifies the amount of vehicle emissions generated during an average morning peak hour in the university environment. Using VISSIM and CMEM microsimulation packages, a model is created for California Polytechnic State University- San Luis Obispo to aggregate the collective transportation behaviors and practices of the campus and recognize the implications these behaviors pose on the transportation network as a whole. Reasonable estimates are …

The Highest Good And The Best Activity: Aristotle On The Well-Lived Life, Philip William Bauchan

Master's Theses

The question of how Aristotle characterizes eudaimonia, or living-well, in the Nicomachean Ethics has long been a contentious issue amongst Aristotelian scholars. The secondary literature has been roughly divided between inclusivist readers, who argue that Aristotle designates both theoria, or contemplation, and the practical virtues, and exclusivist readers, who argue that Aristotle singles out theoria alone. This thesis seeks to forge a middle ground between these two perspectives by focusing on the central claim of Book I that the eudaimonia is virtuous activity. Reading Book X in light of Book I's claim then allows one to show that both the …

An Advanced Controller For A Semi-Active Wheelchair Suspension, David J. Smith

Master's Theses

An Advanced Controller for a Semi-Active Wheelchair Suspension was designed, built and tested.  The suspension consisted of a Goodyear 1S3-011 air spring, IQ Valves high speed proportional solenoid valve, and a custom made accumulator.  Several controller designs specific to semi-active suspensions were designed and tested.  The controllers investigated were skyhook, acceleration driven damping, and a combined control law employing both a dual and single sensor version.  The implementation of skyhook control suffered performance degradation from the idealization due to particular elements of hardware, however acceleration driven damping showed a marked and statistically significant improvement over skyhook control, in hardware, by …

Differences In Eubacterial And Archaeal Soil Communities Along A Precipitation Transect In The Mojave Desert, Elaine Pressly Bryant

Master's Theses

Deserts occupy one third of the total land mass of Earth, yet little is known about microbial soil communities under conditions of low precipitation and humidity. The Mojave Desert of the Southwestern United States provides an opportunity to observe microbial communities along a precipitation transect. The diversity of these communities can elucidate which specific groups of Eubacteria and Archaea are best adapted to limited liquid water.

Two methods were utilized to determine patterns and trends of the microbial soil communities under varying precipitation levels. Viable plate counts allowed comparison of culturable microorganisms over a four-year period. Molecular techniques distinguished unculturable …

Teaching And Learning Of Proof In The College Curriculum, Maja Derek

Master's Theses

Mathematical proof, as an essential part of mathematics,

is as difficult to learn as it is to teach. In this thesis, we

provide a short overview of how mathematical proof is understood

by students in K-16. Furthermore, we answer questions about

mistakes students usually make in the transition period from high

school to college in understanding mathematics and mathematical

proof. Through a case study, we learned that deduction mistakes

characteristic for early mathematical education, such as arguing

from an example, can be abandoned very easily as students begin to

understand the inadequacy of one, or finitely many, examples when

arguing …

Social Support And Gender Effects On Academic Confidence In Foster Youth, Carolyn Suzanne Gillard

Master's Theses

Finding the predictors for academic success is critical for foster youth to become productive citizens as adults. The purpose of this study was to investigate the role of social support in the academic confidence of transitional foster youth. Because the literature suggests men and women benefit from social support differentially, I also examined gender as the moderating variable for social support and academic confidence. A sample of 82 foster youth (15-18 years old) from San Joaquin County's Human Service Agency volunteered to participate. Participants were given the Student Perceived Availability of Social Support Questionnaire (SPASSQ) to assess their perceptions of …

Problem Solving With Geographic Networks In The Sacramento-San Joaquin Delta, Steven Hong

Master's Theses

The Sacramento-San Joaquin Delta (Delta) serves as the crossroads for many geographic networks that crisscross California. These include a conveyance network for drinking water, a biological network for delta smelt, and a transportation network for roads. As a result, local Delta issues concerning flooding and endangered fish hold implications for the entire state. This thesis explores these underlying network structures that pass through the Delta as a means for solving subsets of these most difficult challenges.

Recognition of these larger networks enable the transformation of the Delta's convoluted maze of waterways and islands into a series of nodes and segments. …

Modeling Of The Impact Of Electrical Stressors On The Degradation Process Of Power Mosfets, Shompa Shohiny Mahiuddin

Master's Theses

This research focused on building a model based on collection of experimental data acquired with high electrical stressors at the gate of the power MOSFET under an isothermal condition to analyze certain deviations of intrinsic properties leading to degradation. The primary indicators were threshold shift, deviation in switching characteristics, and significant expansion of the Miller Plateau due to accelerated stressing of the device from the pristine condition. The intrinsic mechanism associated with the threshold shift and changes in the parasitic capacitances were observed and analyzed with mathematical precision and device parameter simulation. It was seen that, in addition to altered …

Development Of A Chemically Reacting Flow Solver On The Graphic Processing Units, Hai Le

Master's Theses

The focus of the current research is to develop a numerical framework on the Graphic Processing Units (GPU) capable of modeling chemically reacting flow. The framework incorporates a high-order finite volume method coupled with an implicit solver for the chemical kinetics. Both the fluid solver and the kinetics solver are designed to take advantage of the GPU architecture to achieve high performance. The structure of the numerical framework is shown, detailing different aspects of the optimization implemented on the solver. The mathematical formulation of the core algorithms is presented along with a series of standard test cases, including both nonreactive …

Energy And Exergy Analysis Of Data Center Economizer Systems, Michael Elery Meakins

Master's Theses

Electrical consumption for data centers is on the rise as more and more of them are being built. Data center owners and operators are looking for methods to reduce energy consumption and electrical costs. One method of reducing facility costs for a chilled water plant is by adding an economizer. Most studies concerning economizer systems are conducted largely by looking at energy alone since the primary focus is reducing electrical costs. Understanding how much exergy is destroyed, where it is destroyed, and why it is destroyed provides a more complete view on how environmental impacts can be minimized while reducing …

African American Community College Student Perceptions Of Mathematics Instructor Immediacy Behaviors And Perceived Cognitive Learning, Georgia Lynne Toland

Master's Theses

The purpose of this research is to examine what instructor immediacy behaviors are perceived to most positively affect the perceived cognitive learning of African American community college mathematics students. Data were provided via voluntary student surveys collected in various mathematics classrooms at two community colleges. The survey instrument was modeled from the works of Gorham (1988) and Sanders and Wiseman (1990) and included an experimental survey method of direct questioning. The perceptions of African American community college students regarding the behaviors of their mathematics instructors, along with their stated preferred instructor behaviors, produced a subset of effective strategies similar to …