Digital Commons Network^™

Scaled Synthetic Aperture Radar System Development, Ryan K. Green

Master's Theses

Synthetic Aperture Radar (SAR) systems generate two dimensional images of a target area using RF energy as opposed to light waves used by cameras. When cloud cover or other optical obstructions prevent camera imaging over a target area, SAR can be substituted to generate high resolution images. Linear frequency modulated signals are transmitted and received while a moving imaging platform traverses a target area to develop high resolution images through modern digital signal processing (DSP) techniques. The motivation for this joint thesis project is to design and construct a scaled SAR system to support Cal Poly radar projects. Objectives include …

Structural Damage Assessment Using Artificial Neural Networks And Artificial Immune Systems, Arthur Q.X. Shi

Master's Theses

Structural health monitoring (SHM) systems have been technologically advancing over the past few years. Improvements in fabrication and microelectronics allow the development of highly sophisticated sensor arrays, capable of detecting and transmitting an unprecedented amount of data. As the complexity of the hardware increases, research has been performed in developing the means to best utilize and effectively process the data. Algorithms from other computational fields are being introduced for the first time into SHM systems. Among them, the artificial neural network (ANN) and artificial immune systems (AIS) show great potential. In this thesis, features are extracted out of the acceleration …

Spacecraft Trajectory Optimization Suite (Stops): Optimization Of Multiple Gravity Assist Spacecraft Trajectories Using Modern Optimization Techniques, Timothy J. Fitzgerald

Master's Theses

In trajectory optimization, a common objective is to minimize propellant mass via multiple gravity assist maneuvers (MGAs). Some computer programs have been developed to analyze MGA trajectories. One of these programs, Parallel Global Multiobjective Optimization (PaGMO), uses an interesting technique known as the Island Model Paradigm. This work provides the community with a MATLAB optimizer, STOpS, that utilizes this same Island Model Paradigm with five different optimization algorithms. STOpS allows optimization of a weighted combination of many parameters. This work contains a study on optimization algorithm performance and how each algorithm is affected by its available settings.

STOpS successfully found …

Cost-Based Decision Making Model For Regional In-House Versus Outsourcing Logistics, Henrik Darren Lee

Master's Theses

This thesis proposes a model for selecting between insourcing logistics for local distribution and outsourcing these functions to a third-party logistics (3PL) company. Supply chain optimization, as well as global supply chain management, are topics that are now well-covered; local distribution, despite its integral function in an organization, is much less researched. Models exist for network design and optimization, but the practical application of these network models may call for decisions and considerations that are not covered in these optimization models.

A breakeven analysis selection model between using in-house logistic system and 3PL is derived, considering various regional parameters. The …

Predicting Invasive Range Of Eucalyptus Globulus In California, Anthony J. Lopez

Master's Theses

Eucalyptus globulus is the subject of intense debate in California. Its invasive potential, aggressive growth, reproductive biology, and association with fire make the prediction of spread important in California. Two modeling simulations, Climex and Maxent, will illustrate the distribution and potential growth range of E. globulus in California based on climate and presence. Modeling the potential range of growth will predict invasive spread. The anticipated result is the continued spread of E. globulus in coastal regions with adequate moisture and suitable climate. Predicting the range of E. globulus in California dictates management strategy and is key for preventing further introduction, …

A Lidar Based Semi-Autonomous Collision Avoidance System And The Development Of A Hardware-In-The-Loop Simulator To Aid In Algorithm Development And Human Studies, Thomas F. Stevens

Master's Theses

In this paper, the architecture and implementation of an embedded controller for a steering based semi-autonomous collision avoidance system on a 1/10^th scale model is presented. In addition, the development of a 2D hardware-in-the-loop simulator with vehicle dynamics based on the bicycle model is described. The semi-autonomous collision avoidance software is fully contained onboard a single-board computer running embedded GNU/Linux. To eliminate any wired tethers that limit the system’s abilities, the driver operates the vehicle at a user-control-station through a wireless Bluetooth interface. The user-control-station is outfitted with a game-controller that provides standard steering wheel and pedal controls along …

Open Source Toolkit For Reentry Object Modeling, Christopher Lloyd Ostrom Ii

Master's Theses

Predicting the mass, position, and velocity of an object during its reentry are critical to satisfy NASA and ESA requirements. This thesis outlines a 3-D orbit and mass determination system for use on low earth orbit as applicable to general objects, of various material and size. The solution uses analytical models to calculate heat flux and aerodynamic drag, with some basic numerical models for simple orbit propagation and mass flow rate due to ablation. The system outlined in this thesis currently provides a framework for rough estimates of demise altitude and final mass, but also allows for many potential accuracy …

Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts

Master's Theses

Microalgae can be grown on municipal wastewater media to both treat the wastewater and produce feedstock for algae biofuel production. However the reliability of treatment must be demonstrated, as well as high areal algae productivity on recycled wastewater media and efficient sedimentation harvesting. This processes was studied at pilot scale in the present research.

A pilot facility was operated with nine CO₂-supplemented raceway ponds, each with a 33-m² surface area and a 0.3-m depth, continuously from March 6, 2013 through September 24, 2014. The ponds were operated as three sets of triplicates with two sets continuously fed …

"Living In The Confluence Of Two Eternities": The Impact Of Politicized Religion In Richmond, Virginia, 1845-1914, Timothy Allen Case

Master's Theses

This thesis analyzes the political nature of religion before, during, and after the Civil War in Richmond, Virginia, the capitol city of the Confederacy. I contend that the relationship between the state and the church, politics and faith, public space and sacred space was forever changed by the war and its origins. Sacred space and sacred actors became political space and political actors before the war in the debates over slavery, during the war in defense of the Confederacy, and continued in this role in its aftermath. Their faith in God and his providence for the South aided Southerners as …

Screening Bioactive Molecules In Tetrahymena Thermophila Using Phagocytosis Determined By Flow Cytometry, Santosh Gummidipundi

Master's Theses

The evaluation of molecules that have potentially bioactive significance is an expanding field, but current screening assays are expensive and time consuming. Mammalian cell-based assays require aseptic techniques, complex media and long generation times. This thesis reports on an assay that incorporates Tetrahymena phagocytic ingestion and flow cytometry to evaluate several potentially bioactive molecules. Several factors that influenced optimal and reproducible results were analyzed. Seven potentially bioactive molecules (serotonin, norepinephrine, dopamine, morphine, colchicine, mexiletine and procainamide) were evaluated to determine their effect on phagocytosis by Tetrahymena. Assay results indicated that the phagocytic rate was unaffected by serotonin, norepinephrine, dopamine, and …

Mitochondrial Dysfunction And Lipid Metabolism Play A Major Role In The Lethality Caused By Developmental Alcohol Exposure, Payam Khodabakhshi

Master's Theses

Exposure to ethanol during development causes a variety of physical, developmental, and cognitive abnormalities. In humans, these symptoms are referred to as fetal alcohol syndrome (FAS) or fetal alcohol spectrum disorder (FASD). Previously, we established a Drosophila melanogaster model of FASD and showed that developmental ethanol exposure causes oxidative stress, and that this is a primary cause of the developmental lethality and delay associated with ethanol exposure. In this study, we investigate the role of fatty acid metabolism and lipid accumulation in connection to FASD. Here, we show that developmental ethanol exposure leads to dysregulation of fatty acid metabolism and …

Burrowing Owl (Athene Cunicularia) Diet And Abundance At A Stopover And Wintering Ground On Southeast Farallon Island, California, Sara Lee Chandler

Master's Theses

On the Farallon Islands the burrowing owl (Athene cunicularia) is a native migrant and predator of the non-native house mouse (Mus musculus) and the native ashy storm-petrel (Oceanodroma homochroa). Burrowing owl predation on the ashy storm-petrel is unnaturally exacerbated by the abundance of house mouse prey in the fall, which may encourage more owls to overwinter. When the cyclic mouse population crashes in winter, the owls prey upon storm-petrels, a species of conservation concern. In 2009, the U.S. Fish and Wildlife Service proposed eradication of the house mouse from the Farallon Islands in order to reduce owl predation on and …

The Relationship Between Organizational Justice And Various Dimensions Of Pay Satisfaction, Xinyi Li

Master's Theses

Pay satisfaction has been linked to important organizational outcomes such as work performance and turnover intentions. One way to predict employees’ pay satisfaction is through organizational justice. The purpose of this study was to examine the role of organizational justice perceptions in predicting various pay satisfaction dimensions. A sample of 107 employees participated in an online survey. Consistent with the hypotheses, results showed that pay-related distributive justice perceptions were a stronger predictor of pay level satisfaction than pay-related procedural justice perceptions, and that benefits-related procedural justice perceptions were a stronger predictor of benefits determination satisfaction and benefits administration satisfaction than …

Looking Backward, Moving Forward: The Experiences Of Indo-Fijian Immigrant Women In California, Ambrita Nand

Master's Theses

This study helps address gaps in knowledge concerning the lives of Indo-Fijian immigrant women in California and offers a space for their voices to be heard. The subsequent chapters investigate the lives of five Indo-Fijian immigrant women and their experiences upon migrating to Modesto, California. Using a qualitative research approach, data were collected through participant observations, semi-structured in-depth interviews and informal conversations. The data are presented as anthropological silhouettes, a form of life-writing (the recording of events and experiences of a life), which explores each individual woman’s experience with life in Fiji to her eventual migration and transition to life …

Factors Affecting Western Snowy Plover Winter Foraging Habitat Selection In San Francisco Bay Ponds, Benjamin Gabriel Pearl

Master's Theses

Within the San Francisco Bay Area, Western Snowy Plovers (Alexandrinus

nivosus nivosus) nest and winter in former salt ponds. They face a number of threats

including human-altered habitats and high levels of predation by mesopredators and

raptors. The South Bay Salt Pond Restoration Project (the Project) is a large wetland

restoration project that will change and potentially eliminate snowy plover habitat in the

region. As the Project returns salt ponds to tidal wetland, there will be less of the dry,

flat, and sparsely vegetated habitat that plovers need for breeding and wintering habitat.

A greater understanding of the specific microhabitat …

Ritual And Religion In The Ohlone Cultural Area Of Central California, Doug Jones

Master's Theses

This thesis is an analysis of aspects of ritual and religion based upon reports from archaeological sites throughout the historical territory of the Native American peoples grouped by ethnographers under the term Ohlone, as well as other relevant sources of ethnographic, historical, and biographical information. Through research and review of recorded site documentation, as well as consultation with local archaeologists, three sites which clearly and extensively represent aspects of Ohlone religious life were identified and described in detail. This included type sites for mortuary practices, rock art, and cosmology/archaeoastronomy. The compilation and analysis of this material generated important information regarding …

Complex Effects Of Nitrogen Pollution And Grazing On Nectar Resources Of The Adult Bay Checkerspot Butterfly (Euphydryas Editha Bayensis), Nidhi Jain

Master's Theses

Recent anthropogenic increases in atmospheric nitrogen due to urbanization and combustion have had many adverse effects on natural systems, including loss of biodiversity, especially in sensitive habitats. One such region is the serpentine ecosystem of Coyote Ridge in San Jose, CA, the last refuge for recurring populations of the federally threatened Bay Checkerspot Butterfly (BCB) (Euphydryas editha bayensis). Increases in non-native grass cover and decreases in native forb cover (including cover of the BCB’s native larval host plants) have been attributed to the fertilizing effects of increased atmospheric nitrogen deposition. To counteract this effect, grazing has been implemented as a …

Chloroflexi: The Tale Of A Bacterium Present In Human And Environmental Habitats, Jayashree Sanjeeviraman

Master's Theses

The phylum Chloroflexi is relatively unexplored, with the majority of its representatives being uncultivable. As a result, these microorganisms have not been characterized beyond their morphology and simple staining reactions, making the study of this phylum extremely challenging. Chloroflexi has been detected in the human oral cavity of patients suffering from peri-implantitis and in the vagina of patients suffering from bacterial vaginosis. Interestingly, Chloroflexi is also present in various environments such as freshwater lakes, soil, deep-sea sponges, hot springs and activated wastewater. Isolation of an environmental Chloroflexi with high 16S rRNA gene homology to a human-associated counterpart could be used …

The Role Of Nitric Oxide In Skeletal Simulated Microgravity Response, Luan Tran

Master's Theses

Prolonged exposure to the space environment leads to bone loss. Using a ground-based model for microgravity (hind-limb unloading), it has been shown in rodents that proliferation and differentiation activity of osteoprogenitors are decreased with exposure to simulated microgravity (Kostenuik et al., 1997). Osteoblast mineralization activity has been shown to increase with nitric oxide supplementation (Afzal et al., 2004; Koyama et al., 2000). I hypothesized that the degenerative effects of microgravity exposure result from chronic changes in nitric oxide regulation in osteoprogenitors, and that supplementation with exogenous nitric oxide following exposure would ameliorate these changes. In 20 C57Bl/6 mice, hind-limb unloading …

Design Of An Attitude Control System For Spin-Axis Control Of A 3u Cubesat, Alexander Joseph Westfall

Master's Theses

This paper describes the design process of developing a spin-axis control system for a 3U CubeSat, a relatively small satellite. Design requires the CubeSat to de-spin after deployment and direct its antenna to track Earth nadir position. The one degree of freedom controller is developed for the TechEdSat, which is a CubeSat with a payload that allows for the assumption that rotation pitch and yaw rates are sufficiently close to zero. Satellite torqueing disturbances are modeled with reaction wheel noise for a more complete system analysis. Sensor noise is unmodeled. Frequency domain and time domain analyses are presented; the entire …

Burnout Versus Personality: Predicting Volunteer Retention, Conor Thomas Tuohy

Master's Theses

Employee turnover is an important issue for any organization, but it is of critical importance for volunteer organizations. Research shows that a strong predictor of volunteer turnover is a volunteer’s intention to remain in that organization. This study measured volunteers’ intention to remain and compared the known predictor of burnout to the potential predictor of personality (through personality traits) in order to find a better predictor of a volunteer’s intention to remain in an organization. Using survey data obtained from 65 participants from a single volunteer organization, this study showed that burnout and personality traits failed to predict a volunteer’s …

Lithologic Controls On Knickpoint Formation In Sierra Nevada Bedrock Channels, Brittany Danielle Johnson

Master's Theses

In the Sierra Nevada Mountains, the distribution of knickpoints in bedrock channels is often used as evidence to argue that the mountain range has been recently uplifted. The assumption that bedrock channel knickpoints are transient features responding to a recent pulse of uplift contributes to the ongoing debate about the range’s geomorphic and tectonic evolution. Determining how knickpoints form in heterogeneous granitic landscapes remains fundamental in understanding the lithologic, tectonic, and climatic controls on bedrock incision. Defining the controls on knickpoint formation may limit how knickpoints are used to infer the tectonic history of the Sierra Nevada. In this study, …

Postcolonialism And The Marshallese Diaspora: Structural Violence And Health In The Marshallese Community In Springdale, Arkansas, Alexander J. Hirata

Master's Theses

Despite moving to the United States for better healthcare, among other benefits, Marshallese Compact of Free Association (COFA) migrants residing in Springdale, Arkansas continue to face similar acute health problems as Marshallese living in the Republic of the Marshall Islands (RMI), and often without access to health services. These problems include high rates of noncommunicable diseases, such as type 2 diabetes and thyroid cancer, as well as rare conditions such as Hansen’s Disease.

To research this, I studied the limited texts surrounding the Marshallese diaspora, as well as relevant bodies of literature: postcolonialism, Pacific migration theory, and global health and …

A Comparison Of Two Function-Based Interventions: Ncr Vs. Dro In A Preschool Classroom, Zachary C. Labrot

Master's Theses

The purpose of this study was to determine the relative efficacy of non-contingent reinforcement (NCR) and differential reinforcement of other behavior (DRO) after behavioral functions have been identified through indirect, descriptive, and experimental assessment. Participants included three preschool-age children in center-based classrooms (Head Start) in a southeastern school district. Functional assessment data were used to inform treatment procedures, which were examined with an alternating treatments design. This study examined (1) relative differences in the efficacy of NCR and DRO in decreasing problem behaviors in preschool children, (2) relative differences in the efficacy of NCR and DRO in increasing appropriate behavior, …

Development And Validation Of A Survey Of Knowledge Of Autism Spectrum Disorder, Laura Katherine Hansen

Master's Theses

As autism spectrum disorder (ASD) is more commonly diagnosed, having knowledge of the disorder becomes increasingly important for educators, parents, and the general public. Previous research regarding knowledge of ASD, focused mainly on knowledge possessed by those in the educational field, has found that individuals may perceive themselves as possessing average knowledge regarding ASD but have low actual knowledge (as defined by the researchers) regarding specific aspects of the disorder (Williams et al., 2011). Studies support the notion that there is a general lack of knowledge of different aspects of ASD among teachers; however, there has been little research regarding …

An Integrated Drought Index (Idi) Incorporating Physical And Social Aspects, Rebecca L. Lanier

Master's Theses

The purpose of this research was to determine significant bio-physical (physical and environmental) and social variables that can be integrated into a drought index to predict areas susceptible to drought. Severe drought events are capable of causing millions of dollars in damage. The 1988 drought caused the United States approximately $40 billion in damage. Drought forecasting, modeling, and detection have, therefore, become imperative to understand the social, economic and environmental impacts of droughts, and also to explore how these impacts play a role in the occurrence of a drought. A number of drought indices widely used in the U.S. rely …

Achieving Relationships, Frederick C. Melancon

Master's Theses

These stories attempt to follow John Gardner’s instruction to create a dream that will engage the reader. Mirroring the goal that an author has to create a relationship with his audience, each story in turn focuses on emotional details that convey the characters’ feelings of isolation or, alternatively, inclusion in their communities. In the first story, a young man tries to recreate his father’s king cake. In the next, a middle school girl fixates on her relationship with her sister. Trying to recapture the memory of a lost daughter, a man searches for the perfect nectar snowball. A mom, then, …

Staging Sex Or Fighting Foreignness? Marlowe's Edward Ii As Xenophobic Drama, James D. Baker

Master's Theses

Christopher Marlowe’s drama Edward II has long been known for its representation of a close male, arguably homosexual, friendship between King Edward II and his favorite, the French Piers Gaveston, as well as their union’s negative effects on the court. Indeed much criticism exists on the common belief that the characters’ relationship is problematic in early modern England both because the two characters are male and because there is an obvious class divide. However, critics have seemed to overlook Gaveston’s being French, even in light of the massive immigration to England during the late sixteenth and early seventeenth centuries. This …

The Moderating Role Of Chronological Age On The Relationship Between Psychological Age And Facets Of Health: A Longitudinal Analysis, Gretchen A. Petery

Master's Theses

Past research has consistently found a negative relationship between psychological age and health. Nearly all of that research, however, has been cross-sectional, and the few panel studies that exist include only a single aspect of health and measured with older adults. The present study sought to replicate and expand on a recent 2-wave cross-lagged panel investigation that explored the causal interplay between several dimensions of health and psychological age in middle age and older adults. In the current study employees (N = 409), ranging in age from 22 to 70, from six manufacturing organizations participated in three surveys approximately …

Maternal History Of Childhood Sexual Abuse And Adolescent Sexual Risk Behaviors: Potential Mechanisms Of Intergenerational Effects, Sanne N. Wortel

Master's Theses

Almost a quarter of women experience some kind of childhood sexual abuse (CSA). Although CSA is associated with subsequent difficulties in women’s sexual well-being and parenting, few studies have examined whether maternal CSA history impacts how parents navigate the sexual development of their children. Using a cross-sectional sample of 194 low-income adolescents girls (Mean age = 15.4), the goal of this study was to: 1) test whether maternal CSA is predictive of adolescent sexual risk behaviors (SRBs), and 2) identify parenting/family characteristics (sexual communication, sexual beliefs, parental monitoring and autonomy granting, and mother-daughter relationship quality) that may mediate this relationship. …