Digital Commons Network^™

Enhanced Light Extraction Efficiency From Gan Light Emitting Diodes Using Photonic Crystal Grating Structures, Simeon S. Trieu

Master's Theses

Gallium nitride (GaN) light emitting diodes (LED) embody a large field of research that aims to replace inefficient, conventional light sources with LEDs that have lower power, higher luminosity, and longer lifetime. This thesis presents an international collaboration effort between the State Key Laboratory for Mesoscopic Physics in Peking University (PKU) of Beijing, China and the Electrical Engineering Department of California Polytechnic State University, San Luis Obispo. Over the course of 2 years, Cal Poly’s side has simulated GaN LEDs within the pure blue wavelength spectrum (460nm), focusing specifically on the effects of reflection gratings, transmission gratings, top and bottom …

Phased Array 802.11g Antenna, Allen G. Peters

Master's Theses

This thesis involves the development of a 2.4GHz phased array antenna for consumer wireless applications. 802.11g specifications include 11 channels from 2.412 GHz to 2.472 GHz. Each channel has a 22MHz minimum bandwidth with a 5 MHz center-to-center interchannel spacing. Design goals for the phased array include an operating frequency of 2.437GHz (channel 6 center frequency). The array antenna design procedure can be integrated into a future antenna laboratory experiment.

Design considerations for the antenna array include cost, producibility, compatibility with 802.11b/g devices, and performance. Dipole antenna elements are arranged in a linear array to simplify calculations and to provide …

Taxonomy, Biogeography And Pest Status Of Marmara Sp. In Northern Mexico And California Citrus Production, Paul Semet

Master's Theses

A novel lepidopteran sex pheromone lure which was thought to be species-specific to the citrus pest Marmara gulosa (Lepidoptera: Gracillariidae) Guillén (McElfresh et al. 2009) has attracted male moths exhibiting two distinct morphologies. The morphological features examined were the sclerotized parts that make up the male genitalia; which include the valvular lobes, costal lobes, cucullar lobes, and the aedeagus. The sclerotized parts were methodically dissected and mounted on microscope slides. Digital images captured of the slide-mounted specimens proved to be inconsistent with the illustrations provided in the original Marmara gulosa species description (Guillén et al. 2001).

The morphologies of all …

High Resolution Simulation Of Synthetic Aperture Radar Imaging, Cindy G. Romero

Master's Theses

The goal of this Master’s thesis is to develop a more realistic simulation of Synthetic Aperture Radar (SAR) that has the ability to image detailed targets, and that can be used for Automatic Target Recognition (ATR). This thesis project is part of ongoing SAR ATR research at California Polytechnic State University (Cal Poly) sponsored by Raytheon Space & Airborne Systems and supervised by Dr. John Saghri.

SAR is a form of radar that takes advantage of the forward motion of an antenna mounted on a moving platform (such as an airplane or spacecraft) to synthetically produce the effect of a …

The Relationship Between Quality Of Life And Leed-Nd Certified / Certifiable Neighborhoods, Stephanie Nicole Timm

Master's Theses

The United States Green Building Council (USGBC) has developed a rating system that examines the sustainability of neighborhoods. They have specifically stated that that LEED-ND certified neighborhoods will protect and enhance residents’ overall health, the natural environment, and quality of life. This study uses relevant quality of life indicators that are commonly identified by social scientists as accurate interpreters of the various quality of life domains to determine if there is, in fact, a relationship between LEED-ND and quality of life. Four of the ten domains examined were found to be related to LEED-ND certified/certifiable neighborhoods, thus, to a certain …

Improved Rf Power Extraction From 1.55um Ge-On-Soi Pin Photodiodes With Load Impedance Optimization, Andrew L. Huard

Master's Theses

VLSI miniaturization has created the need for high-density, low-cost, monolithically-integrated optical interconnects. High output power photodetectors are needed to directly drive load circuitry, which improves the noise performance and dynamic range of optical communications links by eliminating a post amplifier stage. Elimination of the post amplifier also reduces circuit cost and complexity. A new Si-Ge PIN waveguide photodiode with 31GHz bandwidth and 93% quantum efficiency at 1550nm has been developed by Yin et al., which was fabricated using standard CMOS processes on a Silicon substrate. This thesis demonstrates a method for improving the RF power extraction from these photodiodes by …

Aperture Coupled Microstrip Antenna Design And Analysis, Michael Paul Civerolo

Master's Theses

A linearly-polarized aperture coupled patch antenna design is characterized and optimized using HFSS antenna simulation software. This thesis focuses on the aperture coupled patch antenna due to the lack of fabrication and tuning documentation for the design of this antenna and its usefulness in arrays and orthogonally polarized communications. The goal of this thesis is to explore dimension effects on aperture coupled antenna performance, to develop a design and tuning procedure, and to describe performance effects through electromagnetic principles.

Antenna parameters examined in this study include the dimensions and locations of the substrates, feed line, ground plane coupling slot, and …

Reducing Cluster Power Consumption By Dynamically Suspending Idle Nodes, Brian Michael Oppenheim

Master's Theses

Close to 1% of the world's electricity is consumed by computer servers. Given that the increased use of electricity raises costs and damages the environment, optimizing the world's computing infrastructure for power consumption is worthwhile. This thesis is one attempt at such an optimization. In particular, I began by building a cluster of 6 Intel Atom based low-power nodes to perform work analogous to data center clusters. Then, I installed a version of Hadoop modified with a novel power management system on the cluster. The power management system uses different algorithms to determine when to turn off idle nodes in …

Scale Model Shake Table Testing Of Underground Structures In Soft Clay, Victor A. Crosariol

Master's Theses

Underground structures perform an important role in transportation systems in many seismically active regions around the world, but empirical data regarding the seismic behavior of these structures is limited. This research works towards filling that empirical gap through the use of scale model shake table testing. Underground seismic soil-structure interaction (USSSI) effects were investigated for a stiff rectangular tunnel cross-section embedded within soft clay. San Francisco Young Bay Mud was used as a prototype soil for developing a scale model soil mixture consisting of kaolinite, bentonite, class C fly ash, and water. A single cell Bay Area Rapid Transit (BART) …

Frontal Plane Humeral Elevation Effects On The Pullout Strength Of Suture Anchors Used In Rotator Cuff Repair, Peter Joshua Larson

Master's Theses

The rotator cuff offers the stabilizing forces necessary for fine arm movement. The most common injury to the rotator cuff is the partial or full thickness tear of the supraspinatus tendon, which attaches the humerus to the scapula on the superior side, due to an acute or chronic injury. These injuries account for more than 4.5 million physician visits per year. Depending on the degree of tear, arthroscopic surgery may be needed to reattach the torn tendon to the humeral head. The current preferred method of surgery involves the insertion of a suture anchor into the humeral head that ties …

Applied System Identification For A Four Wheel Reaction Wheel Platform, Seth F. Silva

Master's Theses

Applied System Identification for a Four Wheel Reaction Wheel Platform

By

Seth Franklyn Silva

At the California Polytechnic State University, San Luis Obispo there is a four-wheel reaction wheel pyramidal simulator platform supported by an air-bearing. This simulator has the current capability to measure the wheel speeds and angular velocity of the platform, and with these measurements, the system identification process was used to obtain the mass properties of this simulator. A handling algorithm was developed to allow wireless data acquisition and command to the spacecraft simulator from a “ground” computer allowing the simulator to be free of induced torques …

Multiple Robot Boundary Tracking With Phase And Workload Balancing, Michael Jay Boardman

Master's Theses

This thesis discusses the use of a cooperative multiple robot system as applied to distributed tracking and sampling of a boundary edge. Within this system the boundary edge is partitioned into subsegments, each allocated to a particular robot such that workload is balanced across the robots. Also, to minimize the time between sampling local areas of the boundary edge, it is desirable to minimize the difference between each robot’s progression (i.e. phase) along its allocated sub segment of the edge. The paper introduces a new distributed controller that handles both workload and phase balancing. Simulation results are used to illustrate …

Lateral-Torsional Vibration Of A Side-Loaded Rotor With Asymmetric Shaft Stiffness, Clinton T. Judd

Master's Theses

Using energy equations a four degrees of freedom analytical model is developed for a two-disk rotor with shaft stiffness asymmetry. A radial constant force is applied to the outboard disk to emphasize the effects of gravity or aerodynamic side loading. Special emphasis is placed on characterizing the lateral and torsional vibration trends associated with shaft asymmetry which may be used to identify failing shafts in operational rotor systems. Simulation reveals distinct patterns in lateral and torsional response, with strong dependencies on the magnitude of the side load, magnitude of the asymmetry and proximity of the lateral and torsional natural frequencies. …

Systems Engineering Analysis And Digital Communication Bus Design For The Cal Poly Super Project, Matt Marcus Camack

Master's Theses

With an expected lifetime of 20 years and an expected cost of $500, the Cal Poly Sustainable Power for Electrical Resources (SuPER) project needed a strong central design. This thesis looks at the work completed by students over the previous 5 years, with an eye on the future, to create the phase 2 design. Part of this new structure focuses on a distributed communication bus for monitoring system health and status. Instead of complex and costly computer or FPGA systems, the new system will run solely with microcontrollers. This reduces costs and will hopefully still be used within 5, 10, …

Piedras Blancas Motel Feasibility Study And Redevelopment Alternatives, Gordon Douglas Anderson

Master's Theses

The Piedras Blancas Motel is a 1950’s era roadside motel comprised of 11 lodging units, plus a cafe, laundry room, manager’s apartment, and adjacent storage area. It is located seven miles north of San Simeon and nine miles south of the San Luis Obispo/Monterey County line. In 2005, the property was purchased using State, Federal, and private funds, and then transferred to the California Department of Parks and Recreation (State Parks). Although it has been closed to the public since 2005, the Site offers day-use parking and convenient beach access.

This professional project, under contract with the California Coastal Conservancy, …

Http 1.2: Distributed Http For Load Balancing Server Systems, Graham M. O'Daniel

Master's Theses

Content hosted on the Internet must appear robust and reliable to clients relying on such content. As more clients come to rely on content from a source, that source can be subjected to high levels of load. There are a number of solutions, collectively called load balancers, which try to solve the load problem through various means. All of these solutions are workarounds for dealing with problems inherent in the medium by which content is served thereby limiting their effectiveness. HTTP, or Hypertext Transport Protocol, is the dominant mechanism behind hosting content on the Internet through websites. The entirety of …

Negative Conductance Load Modulation Rf Power Amplifier, Cody R. Neslen

Master's Theses

The number of mobile wireless devices on the market has increased substantially over the last decade. The frequency spectrum has become crowded due to the number of devices demanding radio traffic and new modulation schemes have been developed to accommodate the number of users. These new modulation schemes have caused very poor efficiencies in power amplifiers for wireless transmission systems due to high peak-to-average power ratios (PAPR). This thesis first presents the issue with classical power amplifiers in modern modulation systems. A brief overview of current attempts to mitigate this issue is provided. A new RF power amplifier topology is …

Pulse Density Modulated Soft Switching Cycloconverter, Jesse Timothy Adamson

Master's Theses

Single stage cycloconverters generally incorporate hard switching at turn on and soft switching at turn off. This hard switching at turn on combined with the slow switching speeds of thyristors (the switch of choice for standard cycloconverters) limits their use to lower frequency applications.

This thesis explores the analysis and design of a pulse density modulated (PDM), soft switching cycloconverter. Unlike standard cycloconverters, the controller in this converter does not adjust thyristor firing angles. It lets only complete half cycles of the input waveform through to the output. This allows and requires a much greater frequency step down from the …

Digital Signaling Processor Resource Management For Small Office Phone Systems, John T. Gilkeson

Master's Theses

Contemporary small office phone systems are specialized computers that connect a variety of phones within the office and to the local phone company. These systems use digital signaling processors (DSPs) to convert signals from analog to digital and vice-versa. Many different types of applications run on the DSPs and different businesses have varying application needs. Given the systems have limited amounts of DSP resources and growing numbers of applications for a phone system, an administrator needs a way to configure the uses of resources based on their individual business needs.

This thesis provides an overview of a system for configuring …

Standalone Antenna Demonstration System, Alexander James Hempy

Master's Theses

Antenna systems play a significant role in today’s electronic communications. They are essential for cell phones, satellites, radio, and radar among many other important applications. This paper describes the design, assembly, and operation of an antenna demonstration system designed to instill interest in the field of antenna design among high school and undergraduate college students. The system is portable, supplied solely by DC power supplies, easily reproducible, and includes rotational axes to illustrate antenna performance limitations and requirements. It provides a visual indication of wireless signal strength and demonstrates several antenna performance characteristics including polarization, gain and directivity, radiation patterns …

Monocular Vision And Image Correlation To Accomplish Autonomous Localization, Matthew Paul Schlachtman

Master's Theses

For autonomous navigation, robots and vehicles must have accurate estimates of their current state (i.e. location and orientation) within an inertial coordinate frame. If a map is given a priori, the process of determining this state is known as localization. When operating in the outdoors, localization is often assumed to be a solved problem when GPS measurements are available. However, in urban canyons and other areas where GPS accuracy is decreased, additional techniques with other sensors and filtering are required.

This thesis aims to provide one such technique based on monocular vision. First, the system requires a map be generated, …

Textured Hierarchical Precomputed Radiance Transfer, Harrison Lee Mckenzie Chapter

Master's Theses

Computing complex lighting simulations such as global illumination is a computationally intensive task. Various real time solutions exist to approximate aspects of global illumination such as shadows, however, few of these methods offer single pass rendering solutions for soft shadows (self and other) and inter-reflections. In contrast, Precomputed Radiance Transfer (PRT) is a real-time computer graphics technique which pre-calculates an object's response to potential incident light. At run time, the actual incident light can be used to quickly illuminate the surface, rendering effects such as soft self-shadows and inter-reflections. In this thesis, we show that by calculating PRT lighting coefficients …

Development Of A Meshless Method To Solve Compressible Potential Flows, Alejandro Ramos

Master's Theses

The utility of computational fluid dynamics (CFD) for solving problems of engineering interest has experienced rapid growth due to the improvements in both memory capacity and processing speed of computers. While the capability now exists for the solution of the Navier-Stokes equations about complex and complete aircraft configurations, the bottleneck within the process is the time consuming task of properly generating a mesh that can accurately solve the governing partial differential equations (PDEs). This thesis explored two numerical techniques that attempt to circumvent the difficulty associated with the meshing process by solving a simplified form of the continuity equation within …

Numerical Examination Of Flow Field Characteristics And Fabri Choking Of 2d Supersonic Ejectors, Brett G. Morham

Master's Theses

An automated computer simulation of the two-dimensional planar Cal Poly Supersonic Ejector test rig is developed. The purpose of the simulation is to identify the operating conditions which produce the saturated, Fabri choke and Fabri block aerodynamic flow patterns. The effect of primary to secondary stagnation pressure ratio on the efficiency of the ejector operation is measured using the entrainment ratio which is the secondary to primary mass flow ratio.

The primary flow of the ejector is supersonic and the secondary (entrained) stream enters the ejector at various velocities at or below Mach 1. The primary and secondary streams are …

A Constant Conduction Angle Biased Rf Power Amplifier For Improved Linearization In Class C Operation, Greg Lacaille

Master's Theses

Class C power amplifiers offer higher efficiency than class B power amplifiers, but suffer from poor linearity. A feedback based biasing system to improve the linearity of a class C power amplifier is designed. A class B amplifier with a gain of 20 dB and 20 MHz bandwidth at 900 MHz acts as the launching point for the design. The biasing and output network of the class B power amplifier is modified to produce a class C amplifier at conduction angles of 180°, 162°, 126°, 90°, and 54°. A feedback based biasing system, which uses two matched and scaled down …

Novel Inverse Airfoil Design Utilizing Parametric Equations, Kevin A. Lane

Master's Theses

The engineering problem of airfoil design has been of great theoretical interest for almost a century and has led to hundreds of papers written and dozens of methods developed over the years. This interest stems from the practical implications of airfoil design. Airfoil selection significantly influences the application's aerodynamic performance. Tailoring an airfoil profile to its specific application can have great performance advantages. This includes considerations of the lift and drag characteristics, pitching moment, volume for fuel and structure, maximum lift coefficient, stall characteristics, as well as off-design performance.

A common way to think about airfoil design is optimization, the …

Benchmarked Hard Disk Drive Performance Characterization And Optimization Based On Design Of Experiments Techniques, Yu-Wei Lin

Master's Theses

This paper describes an experimental study offered by Designs of Experiments (DOE) within the defined factor domains to evaluate the factor effects of simultaneous characteristics on the benchmarked hard disk drive performance by proposing well-organized statistical models for optimizations. The numerical relations of the obtained models permit to predict the behaviors of benchmarked disk performances as functions of significant factors to optimize relevant criteria based on the needs.

The experimental data sets were validated to be in satisfying agreement with predicted values by analyzing the response surface plots, contour plots, model equations, and optimization plots. The adequacy of the model …

Greywater As A Method Of Water Conservation In Arroyo Grande, Danielle Castle

Master's Theses

The purpose of this professional project is to address the practical implications of decentralized greywater usage in the City of Arroyo Grande. This professional project consists of two products: a brief greywater guide for the City and a background report. The greywater guide is intended for city planners to use for general information about greywater systems. The guide addresses Arroyo Grande’s potable water shortage; what greywater is; advantages and concerns about greywater use; plants that are tolerant and intolerant of greywater irrigation; appropriate detergents to use with a greywater system; and a summary of California greywater law. The background report …

Preference Driven University Course Scheduling System, Heather A. Bellardo

Master's Theses

University course planning and scheduling is the process of determining what courses to offer, how many sections are needed, determining the best term to offer each section, assigning a faculty member to instruct each section, and scheduling each section to a timeslot to avoid conflicts. The result of this task has an impact on every student and faculty member in the department. The process is typically broken down into three major phases: course offering planning, faculty assignment to planned course sections, and course scheduling into timeslots.

This thesis looks at each of these phases for the Industrial and Manufacturing department …

Determining The Optimum Operating Parameters Of A Unipolar Pwm Inverter, Michael James Mccarty

Master's Theses

This study presents a determination of the optimum operating parameters of a unipolar PWM inverter through theoretical and experimental analysis. The inverter is investigated in its simplest form without input DC-DC conversion or output filtering. The intent of this study is to understand the core of the inverter thoroughly before adding peripheral elements such as output filtering. Variations on the input voltage level and switching frequency were investigated to determine their impacts on the operation of the inverter and harmonics produced. Theoretical modeling and calculations confirmed by experimental measurements and analysis allow determination of the inverter operating conditions which allow …