Digital Commons Network^™

Process Development For Compression Molding Of Hybrid Continuous And Chopped Carbon Fiber Prepreg For Production Of Functionally Graded Composite Structures, Corinne Marie Warnock

Master's Theses

Composite materials offer a high strength-to-weight ratio and directional load bearing capabilities. Compression molding of composite materials yields a superior surface finish and good dimensional stability between component lots with faster processing compared to traditional manufacturing methods. This experimental compression molding capability was developed for the ME composites lab using unidirectional carbon fiber prepreg composites. A direct comparison was drawn between autoclave and compression molding methods to validate compression molding as an alternative manufacturing method in that lab. A method of manufacturing chopped fiber from existing unidirectional prepreg materials was developed and evaluated using destructive testing methods. The results from …

Examining The Association Between Psychotropic Medication And Suicidal Desire And Risk, Brittney L. Assavedo

Master's Theses

The primary aim of this study was to examine the relationship between components of suicidal desire and psychotropic medication. Specifically, the usage of psychotropic medication, the usage of specific classes of psychotropic medications and the amount of psychotropic medication utilized and differences in feelings of perceived burdensomeness, thwarted belongingness and overall suicide risk were examined. The present study utilized pre-collected data consisting of 225 patients with substance use disorder undergoing residential treatment for substance dependence. It was posited that individuals utilizing psychotropic medications would exhibit higher mean levels of thwarted belongingness, perceived burdensomeness, and suicide risk relative to individuals not …

Effects Of Failure On Subsequent Performance In The Bottlenose Dolphin (Tursiops Truncatus), Lisa Kay Lauderdale

Master's Theses

The current study examined the immediate effects of two types of failure during operant-conditioning based training sessions in 11 bottlenose dolphins (Tursiops truncatus) at the U.S. Navy Marine Mammal Program in San Diego, CA. While learning a multi-faceted behavior not commonly found in nature, such as beaching, animals are likely to perform approximations of the behavior that are not successful and do not result in reinforcement. The effects of failure on beaching trials were systematically investigated over a three-month period by determining the mean failure rate and the probability of success after initial success, initial attempts, and initial …

A Cultural Consideration: Eliminating The Barriers In Order To Effectively Communicate Crises, Morgan H. Dunaway

Master's Theses

This study aimed at gaining a better understanding of the Hispanic American culture in an effort to evaluate how they view and receive messages sent from the government. The purpose of this study was to further the conversation that messages should be designed with careful thought in order to resonate with the target audience involved in the communication process. A previous study found that the majority of the Hispanic American population felt as if they are overlooked and would not be warned properly in a time of crisis (Heath, Lee, & Ni, 2009). Therefore, the present study focused on variables …

Child Routines And Self-Regulation As Mediators Of Parenting Practices And Externalizing Problems In Preschoolers, Lovina R. Bater

Master's Theses

Studies clearly indicate that parenting practices relate to child externalizing behaviors, although the mechanisms underlying this relation are less well understood. Researchers suggest that daily routines are one way through which parenting practices relate to externalizing behaviors, allowing children to regulate their thoughts, emotions, and behaviors accordingly, potentially promoting development of appropriate self-regulatory behaviors. Self-regulation is also a possible route through which child routines inversely relate to externalizing behaviors. These relationships have been tested in school-age and older children, yet self-regulatory abilities are known to develop during the preschool period. This study examined child routines and self-regulation as serial mediators …

Movements, Habitat Use, And Demography Of Western Pond Turtles In An Intermittent Central California Stream, Joseph Paul Belli

Master's Theses

By Joseph P. Belli

Western Pond Turtles, Emys (Actinemys) marmorata, were captured (n=173) in 2011 (wet year) and 2012-2013 (successively drier drought years) along upper Coyote Creek, an intermittent stream in central California. Males outnumbered females 2.8:1, juveniles less than 120 mm long made up 26% of captures, growth rates varied among individuals, and little growth occurred in turtles older than 10 years. I radio-tracked turtles from May 2011 through August 2013 to ascertain movements and seasonal habitat use. Males had much larger home ranges than females (means of 2281 m for males and 501 m for females in 2012), …

Face Recognition: An Engineering Approach, Farshad Ghahramani

Master's Theses

In computer vision, face recognition is the process of labeling a face as recognized or unrecognized. The process is based on a pipeline that goes through collection, detection, pre-processing, and recognition stages. The focus of this study is on the last stage of the pipeline with the assumption that images have already been collected and pre-processed. Conventional solutions to face recognition use the entire facial image as the input to their algorithms. We present a different approach where the input to the recognition algorithm is the individual segment of the face such as the left eye, the right eye, the …

Consumer Complaints And Protection: Stable Analysis And Design Patterns, Vishnu Sai Reddy Gangireddy

Master's Theses

The concept of consumer complaints and protection has numerous applications across various domains. Using traditional methods of modeling design patterns is a tedious and costly task. The Software Stability Mode (SSM) is a more efficient and effective modeling method. In this thesis, the differences between the traditional method and the SSM is addressed. Then, several patterns are developed using the SSM to deal with consumer complaints. Each area, Advice, Appraisal, Commitment, Complaint, Compliance, Deed, Guideline, Gratification, Judgment, Model, Need, Ownership, Promotion, Rate, Review, Selling, Support, View, and Violation, is explored and the core knowledge of the concept of consumer complaints …

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 …

Digestibility Of Two Complete Pelleted Diets By The Horse (Equus Caballus) As A Model Animal For Nondomestic Hindgut Fermenters, Emily M. Schwartz

Master's Theses

Estimating nutrient and energy requirements of exotic animals is a necessary component of nutrition management in zoos and other wildlife facilities. In the absence of species-specific data, domestic animal models are often referenced. Herbivorous hindgut fermenters, such as horses, zebra, and rhinoceros, rely on microbial fermentation in the cecum and colon to utilize dietary structural carbohydrates. The study objective was to measure the digestible energy of two (LOW, HIGH) complete pelleted diets by the horse as a model for nondomestic hindgut fermenters. Seven, individually housed, adult Quarter Horse (Equus caballus) geldings were assigned to one of two diets as 100% …

Automated Multi-Modal Search And Rescue Using Boosted Histogram Of Oriented Gradients, Matthew A. Lienemann

Master's Theses

Unmanned Aerial Vehicles (UAVs) provides a platform for many automated tasks and with an ever increasing advances in computing, these tasks can be more complex. The use of UAVs is expanded in this thesis with the goal of Search and Rescue (SAR), where a UAV can assist fast responders to search for a lost person and relay possible search areas back to SAR teams. To identify a person from an aerial perspective, low-level Histogram of Oriented Gradients (HOG) feature descriptors are used over a segmented region, provided from thermal data, to increase classification speed. This thesis also introduces a dataset …

Sparse Aperture Speckle Interferometry Telescope Active Optics Control System, Matthew Clause

Master's Theses

A conventional large aperture telescope required for binary star research is typically cost prohibitive. A prototype active optics system was created and fitted to a telescope frame using relatively low cost components. The active optics system was capable of tipping, tilting, and elevating the mirrors to align reflected star light. The low cost mirror position actuators have a resolution of 31 nm, repeatable to within 16 nm. This is accurate enough to perform speckle analysis for the visible light spectrum. The mirrors used in testing were not supported with a whiffletree and produced trefoil-like aberrations which made phasing two mirrors …

Identifying And Predicting Rat Behavior Using Neural Networks, Jonathan A. Gettner

Master's Theses

The hippocampus is known to play a critical role in episodic memory function. Understanding the relation between electrophysiological activity in a rat hippocampus and rat behavior may be helpful in studying pathological diseases that corrupt electrical signaling in the hippocampus, such as Parkinson’s and Alzheimer’s. Additionally, having a method to interpret rat behaviors from neural activity may help in understanding the dynamics of rat neural activity that are associated with certain identified behaviors.

In this thesis, neural networks are used as a black-box model to map electrophysiological data, representative of an ensemble of neurons in the hippocampus, to a T-maze, …

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 …

Divergent Plume Reduction Of A High-Efficiency Multistage Plasma Thruster, Christopher M. Barlog

Master's Theses

High Efficiency Multistage Plasma Thrusters (HEMPTs) are a relatively new form of electric propulsion that show promise for use on a variety of missions and have several advantages over their older EP competitors. One such advantage is their long predicted lifetime and minimal wall erosion due to a unique periodic permanent magnet system. A laboratory HEMPT was built and donated by JPL for testing at Cal Poly. Previous work was done to characterize the performance of this thruster and it was found to exhibit a large plume divergence, resulting in decreased thrust and specific impulse. This thesis explores the design …

Gut Microbiota Of Migratory Passerines At Stopover, William Bagley Lewis

Master's Theses

Although the gut microbiota provides many beneficial functions to animal hosts, relatively little is known about the gut microbiota of passerines. It is likely that gut microbes are especially important during the migratory phase; however gut atrophy experienced during prolonged migratory flight may cause disruptions of the stable microbiota. Fecal samples were collected from several species of passerine after crossing the Gulf of Mexico during spring migration and before crossing during fall, and microbiota communities were analyzed using next-generation sequencing. Despite showing large inter-individual variation, a core microbiota composed largely of Firmicutes and Proteobacteria was identified in all birds. Microbiota …

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, …

Are Large Dogs Smarter Than Small Dogs? Investigating Within Species Differences In Large And Small Dogs: Spatial Memory, Megan S. Broadway

Master's Theses

The study of canine cognition can be useful in understanding the ontology and selective pressures that affect the development of cognitive abilities. Dogs have undergone intensive artificial selection yielding distinctive breeds which differ both phenotypically and behaviorally. Breed based cognitive differences have not been found but some studies suggest there may be differences in broader categories such as working disposition and sex. The influence of size on canine cognition has not been thoroughly addressed despite the fact that large dogs are often perceived to be ‘smarter’ than small dogs. This preconception has only recently been addressed and supported in one …

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 …

High Resolution Melt Analysis Of Samples With Differential Dna Methylation To Identify Tissue Source Of Origin, Stephanie M. Ledgerwood

Master's Theses

In Forensic Science casework, identifying the source of a tissue can assist in crime scene reconstruction. Currently, presumptive testing methods to identify tissue type are utilized in crime scene laboratories, but there is a need for a more reliable confirmatory test for tissue type identification. High Resolution Melt (HRM) analysis is an innovative technology that has the potential to determine tissue types through variations in DNA methylation patterns. Recently, DNA methylation patterns have been found to correspond with specific tissue types in particular regions of DNA. Two markers, B_SPTB_03 and DDX4 have been effective in differentiating sperm from other tissue …

Burial Chronological Sequencing Of The Colonial Maya Cemetery At Tipu, Belize Using Fluoride Ion Analysis, Nicole Musselwhite

Master's Theses

This thesis ascertains the sequence of burials using fluoride ion electrode analysis at the colonial cemetery at Tipu, Belize in order to explore demographic and other cultural effects associated with European contact. The cemetery at Tipu in west central Belize, dating from within the first century of Spanish contact, has provided one of the largest and best preserved Maya skeletal series, with over 500 burials recovered. While this series has undergone vast amounts of analysis, there has yet been an analysis conducted to view how patterns changed over time. This is of interest given the rapid culture change associated with …

The Effects Of Foliar Nutrient Applications On Split, Yield, And Internal Fruit Quality Of 'Wonderful' Pomegranate (Punica Granatum L.), John Matthew Chater

Master's Theses

Fruit split is the most important physiological disorder in pomegranate production, causing devastating crop losses worldwide. Foliar nutrient applications have been used experimentally to mitigate pomegranate fruit split but none have been conducted using the industry standard cultivar, Wonderful, and little is known about the effects of foliar nutrient applications on pomegranate. Additionally, investigations into putative health benefits of pomegranate fruit have increased interest in its production but limited evidence exists regarding effects of agricultural practices such as foliar fertilizer applications on internal fruit quality. ‘Wonderful’ pomegranate trees at 2 commercial orchards were treated with foliar applications of ZnSO_{4 …}

Quantifying Variability In Oculomotor And Manual Choice Response Times, Angelica Godinez

Master's Theses

Response times (RTs) of various motor systems have traditionally been used to characterize aspects of human performance (e.g., fatigue, disease states). However, the properties and sensitivity of different motor systems to detect changes in neural states across multiple timescales remain an open question. In this thesis, we attempt to characterize the difference in sensitivity of the pursuit, saccadic, and manual systems to detect changes in stimulus strength. In Experiment 1, we used a modified Yes-No task to test the effects of contrast (5, 10, 20, 40, 80, 100%) on three pursuit, saccadic, and manual RT’s for three observers. In Experiment …

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 …

A Study Of Laser Ablation Propulsion Using Polyoxymethelyne And A High Power Diode Laser, Michael David Kolesar

Master's Theses

With an increased interest by universities, government and commercial groups in using constellations of pico and and nano satellites, the need for micro-thrusters to aid in the station-keeping capabilities has become strong. This report examines using polymers and a laser to ablate material as a potential propulsion option for station-keeping. Homopolymer polyoxymethelyne (POM), commonly known as Delrin™, was tested as a fuel for a high powered (20 Watt 980 nm) solid state diode laser ablation thruster to be used for station-keeping on pico and nano sized satellites. The experiments required a partial vacuum to reduce the effects of air decomposition …

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 …

Geographic Variation In The Life History And Morphology Of The Pacific Geoduck, Panopea Generosa, Gabriela Navas

Master's Theses

The Pacific geoduck, Panopea generosa, is an ideal candidate to investigate patterns of life history variation and morphological plasticity in shell shape, as it occurs over a large geographic range, inhabits different marine environments, and experiences intense fishing pressure in some locations (i.e., Mexico and Washington). Six populations were sampled from Washington to Mexico to evaluate evidence for geographic variation in demography, life history, and morphology. Results provided evidence for a latitudinal cline with larger clams occurring in locations characterized by colder water temperature. Age structure and longevity analyses indicated that life expectancy was significantly lowered at intertidal sites compared …