High-Density And High-Efficiency Soft Switching Modular Bi-Directional Dc-Dc Converter For Hybrid Electric Vehicles,
2010
University of Central Florida
High-Density And High-Efficiency Soft Switching Modular Bi-Directional Dc-Dc Converter For Hybrid Electric Vehicles, John Elmes
Electronic Theses and Dissertations
This dissertation1 presents the design of a high-density and high-efficiency soft-switching bi-directional DC-DC converter for hybrid-electric vehicles. The converter operates in a new bidirectional interleaved variable-frequency quasi-square-wave (QSW) mode, which enables high efficiency, high switching frequency, and high power-density. The converter presented utilizes a new variable frequency interleaving approach which allows for each module to operate in an interleaved position while allowing for tolerance in inductance and snubber capacitor values. The variable frequency interleaved soft-switching operation paired with a high-density nanocrystalline inductor and high-density system structure results in a very high performance converter, well exceeding that of the current technology. …
Robust Dialog Management Through A Context-Centric Architecture,
2010
University of Central Florida
Robust Dialog Management Through A Context-Centric Architecture, Victor C. Hung
Electronic Theses and Dissertations
This dissertation presents and evaluates a method of managing spoken dialog interactions with a robust attention to fulfilling the human user’s goals in the presence of speech recognition limitations. Assistive speech-based embodied conversation agents are computer-based entities that interact with humans to help accomplish a certain task or communicate information via spoken input and output. A challenging aspect of this task involves open dialog, where the user is free to converse in an unstructured manner. With this style of input, the machine’s ability to communicate may be hindered by poor reception of utterances, caused by a user’s inadequate command of …
Query Processing In Location-Based Services,
2010
University of Central Florida
Query Processing In Location-Based Services, Fuyu Liu
Electronic Theses and Dissertations
With the advances in wireless communication technology and advanced positioning systems, a variety of Location-Based Services (LBS) become available to the public. Mobile users can issue location-based queries to probe their surrounding environments. One important type of query in LBS is moving monitoring queries over mobile objects. Due to the high frequency in location updates and the expensive cost of continuous query processing, server computation capacity and wireless communication bandwidth are the two limiting factors for large-scale deployment of moving object database systems. To address both of the scalability factors, distributed computing has been considered. These schemes enable moving objects …
Extreme Ultraviolet Spectral Streak Camera,
2010
University of Central Florida
Extreme Ultraviolet Spectral Streak Camera, John Michael Szilagyi
Electronic Theses and Dissertations
The recent development of extreme ultraviolet (EUV) sources has increased the need for diagnostic tools, and has opened up a previously limited portion of the spectrum. With ultrafast laser systems and spectroscopy moving into shorter timescales and wavelengths, the need for nanosecond scale imaging of EUV is increasing. EUV’s high absorption has limited the number of imaging options due to the many atomic resonances in this spectrum. Currently EUV is imaged with photodiodes and X-ray CCDs. However photodiodes are limited in that they can only resolve intensity with respect to time and X-ray CCDs are limited to temporal resolution in …
Design Of A Wideband Dual-Polarized Cavity Backed Slot Antenna,
2010
University of Central Florida
Design Of A Wideband Dual-Polarized Cavity Backed Slot Antenna, Rajesh Paryani
Electronic Theses and Dissertations
A new technique for designing wideband dual-polarized cavity-backed slot antennas is presented. The structure is in the form of a double-resonant, dual-polarized slot antenna backed by a shallow substrate integrated cavity with a depth of approximately one tenth the free space wavelength. The presence of the cavity behind the slot enhances the antenna's directivity and reduces the possibility of surface wave propagation in the antenna substrate when the element is used in an array environment. Moreover, the dual-polarized nature of this radiating element may be exploited to synthesize any desired polarization (vertical, horizontal, RHCP, or LHCP). The double-resonant behavior observed …
The Pdf Of Irradiance For A Free-Space Optical Communications Channel: A Physics Based Model,
2010
University of Central Florida
The Pdf Of Irradiance For A Free-Space Optical Communications Channel: A Physics Based Model, David Wayne
Electronic Theses and Dissertations
An accurate PDF of irradiance for a FSO channel is important when designing a laser radar, active laser imaging, or a communications system to operate over the channel. Parameters such as detector threshold level, probability of detection, mean fade time, number of fades, BER, and SNR are derived from the PDF and determine the design constraints of the receiver, transmitter, and corresponding electronics. Current PDF models of irradiance, such as the Gamma-Gamma, do not fully capture the effect of aperture averaging; a reduction in scintillation as the diameter of the collecting optic is increased. The Gamma-Gamma PDF of irradiance is …
Hurricane Wind Speed And Rain Rate Measurements Using The Airborne Hurricane Imaging Radiometer (Hirad),
2010
University of Central Florida
Hurricane Wind Speed And Rain Rate Measurements Using The Airborne Hurricane Imaging Radiometer (Hirad), Ruba Amarin
Electronic Theses and Dissertations
This dissertation presents results for an end-to-end computer simulation of a new airborne microwave remote sensor, the Hurricane Imaging Radiometer, HIRAD, which will provide improved hurricane surveillance. The emphasis of this research is the retrieval of hurricane-force wind speeds in the presence of intense rain and over long atmospheric slant path lengths that are encountered across its wide swath. Brightness temperature (Tb) simulations are performed using a forward microwave radiative transfer model (RTM) that includes an ocean surface emissivity model at high wind speeds developed especially for HIRAD high incidence angle measurements and a rain model for the hurricane environment. …
Conventional And Zvt Synchronous Buck Converter Design, Analysis, And Measurement,
2010
University of Central Florida
Conventional And Zvt Synchronous Buck Converter Design, Analysis, And Measurement, Mark Cory
Electronic Theses and Dissertations
The role played by power converting circuits is extremely important to almost any electronic system built today. Circuits that use converters of any type depend on power that is consistent in form and reliable in order to properly function. In addition, today's demands require more efficient use of energy, from large stationary systems such as power plants all the way down to small mobile devices such as laptops and cell phones. This places a need to reduce any losses to a minimum. The power conversion circuitry in a system is a very good place to reduce a large amount of …
Blind Single Channel Sound Source Separation,
2010
Technological University Dublin
Blind Single Channel Sound Source Separation, Mark Leddy
Masters
In recent years source separation has become an increasingly popular area of research in the signal processing community. The subject has found applications in a variety of fields such as medical imaging, sound and audio, econometrics and geophysics. This document will discuss the application of source separation techniques to the area of audio. Sound source separation is the process of observing a mixture signal made up of a number of sources, and from this mixture estimating the individual source signals. Audio source separation techniques may be crudely split into the following areas; techniques that utilise attributes of the sources, and …
Long Cavity Quantum Dot Laser Diode And Monolithic Passively Mode-Locked Operation,
2010
University of Central Florida
Long Cavity Quantum Dot Laser Diode And Monolithic Passively Mode-Locked Operation, K Shavitranuruk
Electronic Theses and Dissertations
Advantage of the single QD active layer is its potential for very low threshold current density, which in turn can produce low internal optical loss. The low threshold current density and low internal loss thus enable a significant increase in laser diode cavity length. Because of the importance of the threshold current density in heatsinking, future technology of broad-area monolithic laser diodes can be implemented. The dissertation describes the development and the unique characteristics of single QD active layer laser with long cavity. The data are presented on single layer QD laser diodes that reach threshold current densities values of …
Theory Of ‘Selectivity’ Of Label-Free Nanobiosensors – A Geometro-Physical Perspective,
2010
Purdue University - Main Campus
Theory Of ‘Selectivity’ Of Label-Free Nanobiosensors – A Geometro-Physical Perspective, Pradeep R. Nair, Muhammad A. Alam
Birck and NCN Publications
Modern label-free biosensors are generally far more sensitive and require orders of magnitude less incubation time compared to their classical counterparts. However, a more important characteristic regarding the viability of this technology for applications in Genomics/Proteomics is defined by the ‘Selectivity’, i.e., the ability to concurrently and uniquely detect multiple target biomolecules in the presence of interfering species. Currently, there is no theory of Selectivity that allows optimization of competing factors and there are few experiments to probe this problem systematically. In this article, we use the elementary considerations of surface exclusion, diffusion limited transport, and void distribution function to …
Higate (High Grade Anti-Tamper Equipment) Prototype And Application To E-Discovery,
2010
Tokyo Denki University
Higate (High Grade Anti-Tamper Equipment) Prototype And Application To E-Discovery, Yui Sakurai, Yuki Ashino, Tetsutaro Uehara, Hiroshi Yoshiura, Ryoichi Sasaki
Journal of Digital Forensics, Security and Law
These days, most data is digitized and processed in various ways by computers. In the past, computer owners were free to process data as desired and to observe the inputted data as well as the interim results. However, the unrestricted processing of data and accessing of interim results even by computer users is associated with an increasing number of adverse events. These adverse events often occur when sensitive data such as personal or confidential business information must be handled by two or more parties, such as in the case of e-Discovery, used in legal proceedings, or epidemiologic studies. To solve …
Complexity Reduction For Vp6 To H.264 Transcoder Using Motion Vector Reuse,
2010
University of Texas at Arlington
Complexity Reduction For Vp6 To H.264 Transcoder Using Motion Vector Reuse, Jay R. Padia
Electrical Engineering Theses - Archive
VP6 is a video coding standard developed by On2 Technologies, Inc. It is the preferred codec for Macromedia Flash 8 video. VP6 gained importance with Macromedia Flash emerging as a widely adopted video streaming technology over the internet. H.264 is currently one of the most widely accepted video coding standards in the industry. It enables high quality video at low bitrates. Adobe adopted H.264 for its Flash video in August 2007. Adobe looks at adoption of H.264 as a major step towards enabling high quality video on the web. Hence there is increasing importance of techniques which can convert video …
Implementation And Performance Analysis Of 2-D Order 16 Integer Transforms In H.264/Avc And Avs-Video For High Definition Video Coding,
2010
University of Texas at Arlington
Implementation And Performance Analysis Of 2-D Order 16 Integer Transforms In H.264/Avc And Avs-Video For High Definition Video Coding, Madhu Peringassery Krishnan
Electrical Engineering Theses - Archive
H.264/AVC and AVS-video are two video coding standards that have a wide range of applications ranging from high-end professional camera and editing systems to low-end mobile applications. They strive to achieve maximum compression efficiency without compromising the quality of video. To this end many coding tools are defined in them. Transform coding is one among them. Transform coding represents the signal/image (that is currently in time/spatial domain) in another domain (transform domain), where most of the energy in signal/image is concentrated in a fewer number of coefficients. Thus the insignificant coefficients can be discarded after transform coding to achieve compression. …
Physics Behind Rfid Smart Card Security In Context Of Privacy,
2010
University of Texas at Arlington
Physics Behind Rfid Smart Card Security In Context Of Privacy, Kirti Chopra
Electrical Engineering Theses - Archive
In this thesis I prove that existing HF protocol is not secure. Lack of security in turn leads to violation of privacy.The unique ID on the HF RFID smart card can be sniffed by any eavesdropper. Not only eavesdropping, but cloning of the card is another significant problem that poses a privacy threat. An attacker can skim the information on a proximity card and clone it to use for his malicious purposes.RFID smart cards are now widely being used in credit cards,access system, transit system and many more such application. Tampering or malicious usage of data on aforementioned cards raises …
Position Sensorless Control Of A Magnetically Levitated (Maglev) System,
2010
University of Texas at Arlington
Position Sensorless Control Of A Magnetically Levitated (Maglev) System, Esteban Ricardo Noboa
Electrical Engineering Dissertations - Archive
The main focus of this investigation is the development and implementation of a sensorless position estimation method and hysteresis position controller for a laboratory-based Maglev system. The proposed estimation method and controller are first validated through modeling and simulation. This sensorless scheme makes use of the maglev system's magnetic signature, namely, its inductance and requires only active phase current measurements. These measurements are then used along with the phase voltage equation to estimate position information that is in a one-to-one correspondence with the system's inductance. The theoretical aspects of the sensorless scheme are described. Finite element analysis (FEA) as well …
Fault Detection And Optimal Treatment Of The Permanent Magnet Synchronous Machine Using Field Reconstruction Method,
2010
University of Texas at Arlington
Fault Detection And Optimal Treatment Of The Permanent Magnet Synchronous Machine Using Field Reconstruction Method, Amir Khoobroo
Electrical Engineering Dissertations - Archive
Permanent magnet synchronous machines (PMSM) are used extensively in industrial applications due to their relatively high power density, high efficiency, negligible rotor losses, maintenance free operation, and ease of control. Fault tolerance has become a design criterion for adjustable speed motor drives (ASMD) which are used in high impact applications. In simple terms, a fault tolerant ASMD is expected to continue its intended function in the event of a failure compliment to its remaining components. A wide variety of the research has been done on the techniques of fault detection. Most of these researches focus solely on the fault detection …
Development Of Su-8 And Pdms Miniatured Boats And Flotillas,
2010
University of Texas at Arlington
Development Of Su-8 And Pdms Miniatured Boats And Flotillas, Hao Li
Electrical Engineering Dissertations - Archive
In this work, we developed miniaturized SU-8 and PDMS miniaturized boats and flotillas, and explored their designs, fabrication, actuation, motions and driving mechanisms. Like large-scale boats and flotillas, these miniaturized boat and flotillas can be potentially applied to transport designed targets to desired locations in small fluidic systems. They may also be employed as mixers, rotators and so on. We first develop a SU-8 boat, and studied its design, fabrication, actuation and motions. In three types of tests conducted on water free surfaces of different heights in a 30-cm-long channel, the microboat had a speed in the order of 0.1 …
Light Trapping And Absorption Enhancement For High Performance Solar Cells And Infrared Photodetectors,
2010
University of Texas at Arlington
Light Trapping And Absorption Enhancement For High Performance Solar Cells And Infrared Photodetectors, Li Chen
Electrical Engineering Dissertations - Archive
This dissertation presents the work on light trapping and absorption enhancement in solar cells and infrared photodetectors. Hemispherical microstructure based omni-directional anti reflection (Omni-AR) coating has been designed and developed for solar cells, based on rigorous coupled-wave analysis (RCWA) and convective coating process. Omni-AR coating enhances light absorption in solar cells, due to the reduced reflection on the structured solar cell surfaces, and the increased optical path length (OPL) inside the solar cells. Omni-AR coating has been demonstrated as a cost-effective light trapping approach for different material systems, with very low reflection and high transmission over a large range of …
Real Time Condition Monitoring Of Chemical Batteries,
2010
University of Texas at Arlington
Real Time Condition Monitoring Of Chemical Batteries, Anahita Banaei
Electrical Engineering Dissertations - Archive
Li-Ion batteries are suitable rechargeable choices for electric and hybrid electric vehicle (EV/HEV) applications due to their relatively high level of energy and power density. One of the important issues in automotive batteries is to monitor their online state-of-charge (SOC) and state-of-health (SOH).Hence, development of an efficient method for monitoring their online state-of-charge (SOC) and state-of-health (SOH) is of high importance for vehicular applications. Open circuit voltage, as one parameter used for predicting the SOC of the battery, is not readily available during charge and discharge cycles. A wide variety of research has been done on SOC and SOH estimation …
