Engineering Commons^™

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 …

Electric Vehicle Safety, Art Maccarley

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

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

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

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

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

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 …

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

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

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

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

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.

Integrating Embedded Computing Systems Into High School And Early Undergraduate Education, Bridget Benson, Arash Arfaee, Choon Kim, Ryan Kastner, Rajesh K. Gupta

Electrical Engineering

Early exposure to embedded computing systems is crucial for students to be prepared for the embedded computing demands of today's world. However, exposure to systems knowledge often comes too late in the curriculum to stimulate students' interests and to provide a meaningful difference in how they direct their choice of electives for future education and careers. This paper describes an experience with integrating embedded computing systems education into high school and early undergraduate curricula to give students that needed early exposure. It provides assessment data that illustrates the success and limitations of the efforts described as well as the lessons …

Digital Control Of Parallel-Connected Dc-Dc Converters, Taufik, Daniel Forbes, Dale Dolan, Ratna Ika Putri

Electrical Engineering

This paper presents a digitally-controlled paralleled DC-DC converter. The main objective of the digital control is to achieve load sharing while operating at close to peak efficiency over an extremely wide load range. Results from computer simulations using Simulink show the digital control could indeed accomplish the objectives, but the improvements over a single converter depend on the original efficiency characteristics of the converters. An application for a high-power electric vehicle charger utilizing this converter setup is considered.

Top Transmission Grating Gan Led Simulations For Light Extraction Improvement, Simeon Trieu, Xiaomin Jin, Ashton Ellaboudy, Bei Zhang, Xiang-Ning Kang, Guo-Yi Zhang, Xiong Chang, Wei Wei, Sun Yong Jian, Fu Xing Xing

Electrical Engineering

We study the top transmission grating’s improvement on GaN LED light extraction efficiency. We use the finite difference time domain (FDTD) method, a computational electromagnetic solution to Maxwell’s equations, to measure light extraction efficiency improvements of the various grating structures. Also, since FDTD can freely define materials for any layer or shape, we choose three particular materials to represent our transmission grating: 1) nonlossy p-GaN, 2) lossy indium tin oxide (ITO), and 3) non-lossy ITO (α=0). We define a regular spacing between unit cells in a crystal lattice arrangement by employing the following three parameters: grating cell period (Α), grating …

A New Hardware Design Scheme Of Symbol Synchronization For An Underwater Acoustic Receiver, Li Ying, Bridget Benson, Ryan Kastner, Chen Lan

Electrical Engineering

Conventional time domain symbol synchronizer uses static predefined threshold to evaluate the level of environment noise and extract synchronization signal, but is less feasible to apply in underwater acoustic channel because of the great delay and noise variance make the threshold definition inaccurate. The paper provides a new hardware scheme using real time orthogonal sliding correlation as adaptive threshold to build a symbol synchronizer suitable for an underwater FSK acoustic receiver. The design has been implemented and evaluated on FPGA board. Both the simulation and real data experimental results show that the design provides accurate synchronization which consumes 9% of …

Pipe Flow – A Tutorial For Electrical Engineers, William Ahlgren

Electrical Engineering

Energy is transported over long distances primarily by electric power transmission lines and by pipelines carrying gas or liquid fuel. Electric power engineers need to compare these two energy transmission methods, but often lack knowledge of fluid mechanics pre‐requisite to understanding pipeline transmission. This article provides a focused tutorial to provide the necessary background in the fluid mechanics of pipe flow.

Building A Visual Front-End For Audio-Visual Automatic Speech Recognition In Vehicle Environments, Robert Hursig, Jane Zhang

Electrical Engineering

Automatic speech recognition (ASR) holds the promise of providing a natural, efficient, and safer means for communication between humans and computers and can profoundly change the way we live. Since its invention in the 1950s, ASR has witnessed considerable research activities and in recent years is finding its way into practical applications as evidenced by more and more consumer devices such as PDAs and mobile phones adding ASR features. While mainstream ASR has focused almost exclusively on the acoustic signal, the performance of these systems degrades considerably in the real-world in the presence of noise. One way to overcome this …