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Full-Text Articles in Engineering

Wavelength Dependence Of Transverse Mode Coupling With/Without E-Block Of Gan Laser Cavity, K. Lal, G. Chavoor, Xiaomin Jin Dec 2011

Wavelength Dependence Of Transverse Mode Coupling With/Without E-Block Of Gan Laser Cavity, K. Lal, G. Chavoor, Xiaomin Jin

Electrical Engineering

Transverse mode wavelength dependence in the gallium nitride (GaN) laser cavity is a new topic. Modal analysis simulations are run to optimize the blue GaN-based laser diode with a wavelength of 400, 430, and 460 nm. It is shown that the optical confinement factor (OCF) has a strong dependence on wavelength of emission and electron-block (e-block) thickness. The OCF can be changed from 4.9% at a 460-nm wavelength to 7.6% at 400 nm, which is a 55% difference. The effect of adding an e-block layer of different widths is also investigated with results showing that an e-block layer can change …


Auto-Tuning Antenna, John Chen, Jennifer Tighe Dec 2011

Auto-Tuning Antenna, John Chen, Jennifer Tighe

Electrical Engineering

Radio transmitters and antennas have differing impedances at the output and feedpoint, depending on frequency. Modern antenna tuning methods involve manual or automatic resistance and reactance network adjustment to match transmitter and antenna impedance. This reduces power reflections to the transmitter, but introduces losses and prevents full transmitter power from being radiated at the antenna. This project utilizes a variable length antenna element to tune and match transmitter and antenna impedances, allowing efficient power transfer to the antenna. The antenna length varies from 0 to 30.5 inches. The method involves an RF signal with a maximum power of 2 watts …


Electric Vehicle Safety, Art Maccarley Nov 2011

Electric Vehicle Safety, Art Maccarley

Electrical Engineering

No abstract provided.


Wavelength Dependence Of Transverse Mode Coupling With/Without E-Block Of Gan Laser Cavity, Krishneel Lal Nov 2011

Wavelength Dependence Of Transverse Mode Coupling With/Without E-Block Of Gan Laser Cavity, Krishneel Lal

Electrical Engineering

No abstract provided.


A Parallel Energy-Sharing Control For Fuel Cell-Battery- Ultracapacitor Hybrid Vehicle, Jennhwa Wong, N.R. N. Idris, Makbul Anwari, Taufik Taufik Sep 2011

A Parallel Energy-Sharing Control For Fuel Cell-Battery- Ultracapacitor Hybrid Vehicle, Jennhwa Wong, N.R. N. Idris, Makbul Anwari, Taufik Taufik

Electrical Engineering

This paper proposes a parallel energy-sharing control for fuel cell hybrid vehicles (FCHVs) application. The hybrid source consists of fuel cells (FCs) stack, battery packs and Ultracapacitor (UC) modules. In the proposed parallel energy sharing control, each source is connected to a DC bus via power electronics converters. A total of six control loops are applied in the supervisory system in order to regulate the DC bus voltage, control of power flow and at the same time to monitor the state of charge (SOC) of each energy storage device. Simulation with experiment verifications are carried out to verify the proposed …


Light Extraction Improvement Of Gan Leds Using Nano-Scale Top Transmission Gratings, Greg Chavoor, Xiaomin Jin, Ashton Ellaboudy, Xing-Xing Fu, Xiang-Ning Kang, Bei Zhang, Guo-Yi Zhang Aug 2011

Light Extraction Improvement Of Gan Leds Using Nano-Scale Top Transmission Gratings, Greg Chavoor, Xiaomin Jin, Ashton Ellaboudy, Xing-Xing Fu, Xiang-Ning Kang, Bei Zhang, Guo-Yi Zhang

Electrical Engineering

In this paper, we use a Finite-Difference Time-Domain GaN LED model to study constant wave (CW) average power of extracted light. The structure simulated comprises of a 200nm-thick p-GaN substrate, 50nm-thick MQW, 400nm-thick n-GaN substrate, and a 200nm n-GaN two-dimensional Photonic Crystal(2PhC) grating. We focus on optimizing three design parameters: grating period (A), grating height (d), and fill factor (FF). In the primary set of simulations, we fix the fill factor at 50% and simulate ten different grating periods (100 to 1000nm in steps of 100nm) and four different grating heights (50 to 200nm in steps of 50nm), and calculate …


Improvement Of Solar Cell Efficiency Using Nano-Scale Top And Bottom Grating, Xiaomin Jin, Ashton Ellaboudy, Greg Chavoor Aug 2011

Improvement Of Solar Cell Efficiency Using Nano-Scale Top And Bottom Grating, Xiaomin Jin, Ashton Ellaboudy, Greg Chavoor

Electrical Engineering

We study solar-cell designs using nano-grating on both top (transmission) and bottom (reflection) of the solar cell. First, we perform simulations based on rigorous coupled wave analysis (RCWA) to evaluate the diffraction top gratins. In RCWA method, we calculate up to 20 harmonics, and sweep the launch angle of incident light from 0 to 90 degree. The incident light varies from100nm to 1200nm wavelength. Triangular grating can achieve higher light absorption compared to the rectangular grating. The best top grating is around 200nm grating period, 100nm grating height, and 50% filling factor, which responses to 37% improvement for triangular grating …


A New Undergraduate Laboratory Course In Magnetic Design, Taufik Taufik, Scott Mcclusky, Jonathon Paolucci, Dale S. Dolan Aug 2011

A New Undergraduate Laboratory Course In Magnetic Design, Taufik Taufik, Scott Mcclusky, Jonathon Paolucci, Dale S. Dolan

Electrical Engineering

This paper presents a set of new laboratory experiments developed in conjunction with an undergraduate course in magnetic design. The course has recently been reintroduced as a technical elective course where students learn the basics of inductor and transformer design. Five new laboratory experiments have been developed to cover magnetic concepts and to provide students with the hands-on experience in designing and building magnetic components. The paper presents an overview of the course, and highlights the new lab experiments in the course.


Development Of Wind Tunnel For Laboratory Wind Turbine Testing, Dale S. Dolan, Danny Zepeda, Taufik Taufik Aug 2011

Development Of Wind Tunnel For Laboratory Wind Turbine Testing, Dale S. Dolan, Danny Zepeda, Taufik Taufik

Electrical Engineering

This paper presents the development of a wind tunnel that will be used for wind turbine testing in a controlled environment. The prototype is designed to be able to provide wind speeds of up to 20 m/s (~43mph) depending on the cross sectional area of the tunnel chamber. A 42 inch tube axial fan is driven by a 5hp induction motor using a variable frequency drive to allow continuously variable wind speeds from near zero up to the maximum wind speed. The fan is rated to produce ~25,000 CFM and the corresponding wind speed is therefore dependent on chamber cross …


Foce Medium Voltage Load Switcher, Eric Nelson, Sean Tolibas Aug 2011

Foce Medium Voltage Load Switcher, Eric Nelson, Sean Tolibas

Electrical Engineering

No abstract provided.


Constant Conduction Angle Experimental Generation For Rf Power Amplifiers, Michael Spahn Aug 2011

Constant Conduction Angle Experimental Generation For Rf Power Amplifiers, Michael Spahn

Electrical Engineering

As the demand for more devices to become wireless increases, there is a need for linear, efficient monolithic power amplifiers to deal with the variations in modulation of signals. With partial support from Cal Poly C3RP Grant #52268, this paper explains the implementation of and analyzes a circuit that actively biases a bipolar transistor to operate as a Class C amplifier. The Class C amplifier can maintain constant conduction angle over a range of output powers by using a Class B amplifier to force a scaled DC current vs. input magnitude curve on to a Class C amplifier. The knee …


Wireless Passive Power Transfer Using Wire Antennas, Sheng Da Zhang Aug 2011

Wireless Passive Power Transfer Using Wire Antennas, Sheng Da Zhang

Electrical Engineering

This project tests and analyzes the efficiency of directional and omnidirectional antennas in wireless power transfer for charging. The project demonstrates the steps of construction and properties of dipole, monopole, and Yagi Uda antennas. A low power high frequency DC rectifier circuit converts the received RF power from the antenna and stored it as DC voltage on a capacitor. The receiver circuit also estimates the power received by the antenna. Wireless RF power transmission proves to be inefficient for short distances. The best efficiencies of the antennas were under 50% even at 0.1meter. The near field attenuation starts at around …


140 New Montgomery Power Distribution Design, Stephen Shaffer Aug 2011

140 New Montgomery Power Distribution Design, Stephen Shaffer

Electrical Engineering

The Power Distribution Design for a high-rise building requires a great deal of coordination and design from the structural, electrical, mechanical, telecommunication, and PG&E engineers. This report will cover how I was able to coordinate and design the power distribution system for 140 New Montgomery, a 28 story building located in San Francisco. Furthermore, this report will cover the steps taken in the future to ensure a smooth transition from the schematic design phase to the construction document phase.


Lip Localization Algorithm Using Gabor Filters, Robert E. Hursig, Jane Xiaozheng Zhang, Chiweng Kam Jul 2011

Lip Localization Algorithm Using Gabor Filters, Robert E. Hursig, Jane Xiaozheng Zhang, Chiweng Kam

Electrical Engineering

This paper describes a lip localization algorithm within a still image frame for subsequent tracking and audiovisual speech recognition processing. A Gabor filter-based feature space is promoted as a means to localize lips within an image based off of shape. This filtered space is shown to effectively differentiate facial features, including lips, from their backgrounds and to bound the full extent of the lips within a face-classified region of interest. Extensive training and test sets are used to justify design decisions and performance.


Aperture Coupled Patch Antenna Design Methods, Michael Civerolo, Dean Arakaki Jul 2011

Aperture Coupled Patch Antenna Design Methods, Michael Civerolo, Dean Arakaki

Electrical Engineering

Microstrip patch antennas have been used extensively in applications requiring low-profile, mounting structure conforming, and low-cost wireless communications. Feed methods (antenna-transmission line interface) are critical for optimum performance. The aperture coupled technique exhibits reduced transmission line radiation and enhanced antenna radiation and co- to cross-pol performance relative to microstrip and probe fed configurations. Researchers have focused on analytical methods and design improvements without identifying parametric tradeoffs or design methods. Hence, this paper presents theoretically and parametrically identified critical antenna dimensions and performance effects, and a design procedure to convert desired performance requirements into operational prototypes.


Teaching Sustainability Analysis In Electronics Lecture Courses, David Braun Jun 2011

Teaching Sustainability Analysis In Electronics Lecture Courses, David Braun

Electrical Engineering

Based on positive prior experiences teaching sustainability analysis in electronics laboratory courses, this work explores techniques for teaching sustainability analysis in lecture courses. As difficult as it may seem to incorporate sustainability into integrated circuit courses or other engineering courses, it may prove as easy as asking students to consider how the coursework relates to sustainability issues.

The need to educate students “to design a system, component, or process to meet desired needs within realistic constraints such as economic, environmental, social, political, ethical, health and safety, manufacturability, and sustainability” has gained sufficient value to deserve its own ABET Program Outcome, …


Modeling Of A Gyro-Stabilized Helicopter Camera System Using Artificial Neural Networks, Nicholas Layshot, Xiao-Hua Yu Jun 2011

Modeling Of A Gyro-Stabilized Helicopter Camera System Using Artificial Neural Networks, Nicholas Layshot, Xiao-Hua Yu

Electrical Engineering

On-board gimbal systems for camera stabilization in helicopters are typically based on linear models. Such models, however, are inaccurate due to system nonlinearities and complexities. As an alternative approach, artificial neural networks can provide a more accurate model of the gimbal system based on their non-linear mapping and generalization capabilities. This paper investigates the applications of artificial neural networks to model the inertial characteristics (on the azimuth axis) of the inner gimbal in a gyro-stabilized multi-gimbal system. The neural network is trained with time-domain data obtained from gyro rate sensors of an actual camera system. The network performance is evaluated …


Neural Network Based Edge Detection For Automated Medical Diagnosis, Dingran Lu, Xiao-Hua Yu, Xiaomin Jin, Bin Li, Quan Chen, Jianhua Zhu Jun 2011

Neural Network Based Edge Detection For Automated Medical Diagnosis, Dingran Lu, Xiao-Hua Yu, Xiaomin Jin, Bin Li, Quan Chen, Jianhua Zhu

Electrical Engineering

Edge detection is an important but rather difficult task in image processing and analysis. In this research, artificial neural networks are employed for edge detection based on its adaptive learning and nonlinear mapping properties. Fuzzy sets are introduced during the training phase to improve the generalization ability of neural networks. The application of the proposed neural network approach to the edge detection of medical images for automated bladder cancer diagnosis is also investigated. Successful computer simulation results are obtained.


Portable Solar Desalination System, Genaro Sanchez, Alan Galarza, Erick Del Real Jun 2011

Portable Solar Desalination System, Genaro Sanchez, Alan Galarza, Erick Del Real

Electrical Engineering

Clean water and reliable energy can be difficult to obtain in remote locations such as desert villages, secluded islands, and other places where no fresh water can be found. The primary goal for this project is address these problems by implementing a portable desalinization plant system that is to be powered by solar energy PV system as the main energy source.


Mp3 Player System Design, Eric Wu Jun 2011

Mp3 Player System Design, Eric Wu

Electrical Engineering

The purpose of this project is to design and build a portable audio player that reads music files off an SD card, decodes the music file and outputs the music through a headphone jack. A microcontroller running FreeRTOS will facilitate the data transfer between an SD card and the decoding chip. The decoded audio will then be sent to a high-end DAC chip that outputs the sound.


Terrain Classification For Autonomous Rmax Helicopter Search And Rescue, Erin West Jun 2011

Terrain Classification For Autonomous Rmax Helicopter Search And Rescue, Erin West

Electrical Engineering

No abstract provided.


Sick Laser Scanner Power Supply For Use With A Yamaha Rmax Uav, Elliot Due Jun 2011

Sick Laser Scanner Power Supply For Use With A Yamaha Rmax Uav, Elliot Due

Electrical Engineering

No abstract provided.


Formula Hybrid Primary Electrical Systems Senior Project Report, Gregg Schultz, Matthew (Matt) Tolman Jun 2011

Formula Hybrid Primary Electrical Systems Senior Project Report, Gregg Schultz, Matthew (Matt) Tolman

Electrical Engineering

This senior project involves the "Primary electrical systems" (excluding data-acquisition) for Cal Poly’s Hybrid Racecar Team: SAE Formula Hybrid. Effectively, this project involves the high-voltage and low-voltage electrical systems one would typically find in an electric car, with the addition of some circuitry for an on-board battery charger. The primary electrical systems need to follow strict rules and guidelines as given by the Formula Hybrid Competition, as well as provide reliable and high-performance operation to ensure a competition-worthy vehicle. In addition to designing, building, testing, and competing with the Primary electrical systems, we will also generate a detailed step-by-step "guide" …


Autonomous Golf Cart Vision Using Hsv Image Processing And Commercial Webcam, John D. Fulton Jun 2011

Autonomous Golf Cart Vision Using Hsv Image Processing And Commercial Webcam, John D. Fulton

Electrical Engineering

Using openCV I was able to use a store bought webcam and my laptop to build code that could detect the lane lines and the curb on the road and use them to calculate a trajectory for an autonomous vehicle to follow. The code does have some flaws, as discovered in testing, and definitely room for improvement but it still functions as a useful basis for development. Developed primarily for the Autonomous Golf Car Project at Cal Poly the principles of how it functions could be applied to other projects that want to use computer vision.


Wirelessly Operated Pa Loudspeaker System For Rmax Search-And-Rescue Uav: A Preliminary Design, Travis Luke, Nolan Uchizono Jun 2011

Wirelessly Operated Pa Loudspeaker System For Rmax Search-And-Rescue Uav: A Preliminary Design, Travis Luke, Nolan Uchizono

Electrical Engineering

This paper discusses the approach used to implement a wireless PA loudspeaker system on a search-and-rescue RMAX UAV.

The purpose of this project is to allow the continuation of communication between search-and-rescue workers as well as potential rescuees in an environment that won't always allow it. Since rugged terrain tends to cause interference between two radio communications, there needs to be a way to bypass this problem. In addition, people in need of rescue are unlikely to be using a radio on an emergency frequency, so there needs to be a way to efficiently issue orders or evacuation notices without …


60 Watt Embedded Solar Cell Umbrella, Matthew Devoss Jun 2011

60 Watt Embedded Solar Cell Umbrella, Matthew Devoss

Electrical Engineering

No abstract provided.


Laser Cursor, Michael Liman Jun 2011

Laser Cursor, Michael Liman

Electrical Engineering

A user controls a cursor on a computer screen using a laser pointer. A camera picks up the laser pointer’s position and sends the data to the computer to move the cursor in the correct position.


Air Scratch: An Innovative Touch-Free Dj Controller, Nixon Vandel Jun 2011

Air Scratch: An Innovative Touch-Free Dj Controller, Nixon Vandel

Electrical Engineering

This project explores the design and development of a touchless DJ interface. It requires fundamental knowledge of the operation of DJ software and hardware. Two theremins and two microcontrollers are integrated into the design and encompass the analog/digital aspect of the project. The design was created after researching hands free and touchless electronic controllers. The features incorporated into Air Scratch are very common and useful for DJs. The principle of a touchless DJ controller was first tested using software, and then later developed into hardware; primarily for copyright issues. The DJ software used by Air Scratch is found online for …


Cal Poly Power System Design & Analysis, Minesh D. Patel Jun 2011

Cal Poly Power System Design & Analysis, Minesh D. Patel

Electrical Engineering

The scope of this project encompasses the design and analysis of the Cal Poly Power System at the distribution level using the SKM software environment. The purpose is to accurately model the power system in software so theoretical calculations and analysis can be executed. This requires sufficient preliminary research to obtain data for the main buildings on campus, sound interpretation of one line diagrams, designing the system within the software using realistic values and then performing analysis to model real world situations. The data collected is under maximum load conditions for a specified time period using medium voltage parameters. The …


Controller Board Prototype Development For The Cal Poly Super Project, Clifford Susa Jun 2011

Controller Board Prototype Development For The Cal Poly Super Project, Clifford Susa

Electrical Engineering

Now in phase two of development, the Cal Poly Sustainable Power for Electrical Reources (SuPER) project will provide power to families for an estimated lifespan of 20 years at a cost of $500. Phase two of the SuPER project looks at implementing microcontrollers to monitor the health and status of the system. This senior project looks specifically at the performances of the SuPER Controller which communicates with the SuPER Digitizer to gather data such as voltage, current, temperature, and power. An SD memory card will store this data, and to view this data, then download to a PC.