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The Relevance Of Time-To-Digital Converters To Small Platform Direction Finding Systems, Paul Jeffrey Nelson
The Relevance Of Time-To-Digital Converters To Small Platform Direction Finding Systems, Paul Jeffrey Nelson
Electronic Theses and Dissertations
This thesis explores a Time-Difference-of-Arrival (TDOA) approach to radio direction finding, utilizing picosecond-resolution Time-to-Digital Converters (TDCs). By measuring the relative time of arrival of a pulsed RF signal impinging on an antenna array, direction of arrival (DOA) can be ascertained. This technology enables versatile DOA calculation on platforms only several meters in length, and offers various size, weight, power, and cost advantages when compared to present DF technologies. A short baseline S-band TDOA DF system utilizing TDCs is designed, fabricated, and tested in a laboratory environment. This research suggests that such a DF system based on TDCs provides sufficient accuracy …
Characterization Of Aluminum Doped Zinc Oxide Thin Films For Photovoltaic Applications, Bojanna P. Shantheyanda
Characterization Of Aluminum Doped Zinc Oxide Thin Films For Photovoltaic Applications, Bojanna P. Shantheyanda
Electronic Theses and Dissertations
Growing demand for clean source of energy in the recent years has increased the manufacture of solar cells for converting sun energy directly into electricity. Research has been carried out around the world to make a cheaper and more efficient solar cell technology by employing new architectural designs and developing new materials to serve as light absorbers and charge carriers. Aluminum doped Zinc Oxide thin film, a Transparent conductive Oxides (TCO) is used as a window material in the solar cell these days. Its increased stability in the reduced ambient, less expensive and more abundance make it popular among the …
Bit-Rate Aware Reconfigurable Architecture For H.264/Avc Deblocking Filter, Rakan Khraisha
Bit-Rate Aware Reconfigurable Architecture For H.264/Avc Deblocking Filter, Rakan Khraisha
Electronic Theses and Dissertations
In H.264/AVC, DeBlocking Filter (DBF) achieves bit rate savings and it is used to improve visual quality by reducing the presence of blocking artifacts. However, these advantages come at the expense of increasing computational complexity of the DBF due to highly adaptive mode decision and small 4x4 block size. The DBF easily accounts for one third of the computational complexity of the decoder. The computational complexity required for various target applications from mobile to high definition video applications varies significantly. Therefore, it becomes apparent to design efficient architecture to adapt to different requirements. In this work, we exploit the scalability …
Reconfigurable Architecture For H.264/Avc Variable Block Size Motion Estimation Based On Motion Activity And Adaptive Search Range, Sumedha Kodipyaka
Reconfigurable Architecture For H.264/Avc Variable Block Size Motion Estimation Based On Motion Activity And Adaptive Search Range, Sumedha Kodipyaka
Electronic Theses and Dissertations
Motion Estimation (ME) technique plays a key role in the video coding systems to achieve high compression ratios by removing temporal redundancies among video frames. Especially in the newest H.264/AVC video coding standard, ME engine demands large amount of computational capabilities due to its support for wide range of different block sizes for a given macroblock in order to increase accuracy in finding best matching block in the previous frames. We propose scalable architecture for H.264/AVC Variable Block Size (VBS) Motion Estimation with adaptive computing capability to support various search ranges, input video resolutions, and frame rates. Hardware architecture of …
Concentric Layout, A New Scientific Data Layout For Matrix Data Set In Hadoop File System, Lu Cheng
Concentric Layout, A New Scientific Data Layout For Matrix Data Set In Hadoop File System, Lu Cheng
Electronic Theses and Dissertations
The data generated by scientific simulation, sensor, monitor or optical telescope has increased with dramatic speed. In order to analyze the raw data speed and space efficiently, data preprocess operation is needed to achieve better performance in data analysis phase. Current research shows an increasing tread of adopting MapReduce framework for large scale data processing. However, the data access patterns which generally applied to scientific data set are not supported by current MapReduce framework directly. The gap between the requirement from analytics application and the property of MapReduce framework motivates us to provide support for these data access patterns in …
Reactive Control Of Autonomous Dynamical Systems, Jiangmin Chunyu
Reactive Control Of Autonomous Dynamical Systems, Jiangmin Chunyu
Electronic Theses and Dissertations
This thesis mainly consists of five independent papers concerning the reactive control design of autonomous mobile robots in the context of target tracking and cooperative formation keeping with obstacle avoidance in the static/dynamic environment. Technical contents of this thesis are divided into three parts. The first part consists of the first two papers, which consider the target-tracking and obstacle avoidance in the static environment. Especially, in the static environment, a fundamental issue of reactive control design is the local minima problem(LMP) inherent in the potential field methods(PFMs). Through introducing a state-dependent planned goal, the first paper proposes a switching control …
Validation Of Wideband Ocean Emissivity Radiative Transfer Model, Sonya Crofton
Validation Of Wideband Ocean Emissivity Radiative Transfer Model, Sonya Crofton
Electronic Theses and Dissertations
Radiative Transfer Models (RTM) have many applications in the satellite microwave remote sensing field, such as the retrieval of oceanic and atmospheric environmental parameters, including surface wind vectors and sea surface temperatures, integrated water vapor, cloud liquid, and precipitation. A key component of the ocean RTM is the emissivity model used to determine the brightness temperature (Tb) at the ocean’s surface. A new wideband ocean emissivity RTM developed by the Central Florida Remote Sensing Laboratory (CFRSL) calculates ocean emissivity over a wide range of frequencies, incidence angles, sea surface temperatures (SST), and wind speed. This thesis presents the validation of …
Learning From Geometry In Learning For Tactical And Strategic Decision Domains, Jason Gauci
Learning From Geometry In Learning For Tactical And Strategic Decision Domains, Jason Gauci
Electronic Theses and Dissertations
Artificial neural networks (ANNs) are an abstraction of the low-level architecture of biological brains that are often applied in general problem solving and function approximation. Neuroevolution (NE), i.e. the evolution of ANNs, has proven effective at solving problems in a variety of domains. Information from the domain is input to the ANN, which outputs its desired actions. This dissertation presents a new NE algorithm called Hypercube-based NeuroEvolution of Augmenting Topologies (HyperNEAT), based on a novel indirect encoding of ANNs. The key insight in HyperNEAT is to make the algorithm aware of the geometry in which the ANNs are embedded and …
Phoneme-Based Video Indexing Using Phonetic Disparity Search, Carlos Leon Barth
Phoneme-Based Video Indexing Using Phonetic Disparity Search, Carlos Leon Barth
Electronic Theses and Dissertations
This dissertation presents and evaluates a method to the video indexing problem by investigating a categorization method that transcribes audio content through Automatic Speech Recognition (ASR) combined with Dynamic Contextualization (DC), Phonetic Disparity Search (PDS) and Metaphone indexation. The suggested approach applies genome pattern matching algorithms with computational summarization to build a database infrastructure that provides an indexed summary of the original audio content. PDS complements the contextual phoneme indexing approach by optimizing topic seek performance and accuracy in large video content structures. A prototype was established to translate news broadcast video into text and phonemes automatically by using ASR …
Modeling And Simulation Of Soft Bodies, Jaruwan Mesit
Modeling And Simulation Of Soft Bodies, Jaruwan Mesit
Electronic Theses and Dissertations
As graphics and simulations become more realistic, techniques for approximating soft body objects, that is, non-solid objects such as liquids, gases, and cloth, are becoming increasingly common. The proposed generalized soft body method encompasses some specific cases of other existing models enabling simulation of a variety of soft body materials by parameter adjustment. This research presents a general method of soft body model and simulation in which parameters for body control, surface deformation, volume control, and gravitation, can be adjusted to simulate different types of soft bodies. In this method, the soft body mesh structure maintains configuration among surface points …
Optimization Of Process Parameters For Reduced Thickness Cigses Thin Film Solar Cells, Shirish A. Pethe
Optimization Of Process Parameters For Reduced Thickness Cigses Thin Film Solar Cells, Shirish A. Pethe
Electronic Theses and Dissertations
With the advent of the 21st century, one of the serious problems facing mankind is harmful effects of global warming. Add to that the ever increasing cost of fuel and the importance of development of clean energy resources as alternative to fossil fuel has becomes one of the prime and pressing challenges for modern science and technology in the 21st century. Recent studies have shown that energy related sources account for 50% of the total emission of carbon dioxide in the atmosphere. All research activities are focused on developing various technologies that are capable of converting sunlight into electricity with …
Extreme Ultraviolet Spectral Streak Camera, John Michael Szilagyi
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 …
The Next Generation Botnet Attacks And Defenses, Ping Wang
The Next Generation Botnet Attacks And Defenses, Ping Wang
Electronic Theses and Dissertations
A "botnet" is a network of compromised computers (bots) that are controlled by an attacker (botmasters). Botnets are one of the most serious threats to today’s Internet; they are the root cause of many current Internet attacks, such as email spam, distributed denial of service (DDoS) attacks , click fraud, etc. There have been many researches on how to detect, monitor, and defend against botnets that have appeared and their attack techniques. However, it is equally important for us to investigate possible attack techniques that could be used by the next generation botnets, and develop effective defense techniques accordingly in …
Researches On Reverse Lookup Problem In Distributed File System, Junyao Zhang
Researches On Reverse Lookup Problem In Distributed File System, Junyao Zhang
Electronic Theses and Dissertations
Recent years have witnessed an increasing demand for super data clusters. The super data clusters have reached the petabyte-scale can consist of thousands or tens of thousands storage nodes at a single site. For this architecture, reliability is becoming a great concern. In order to achieve a high reliability, data recovery and node reconstruction is a must. Although extensive research works have investigated how to sustain high performance and high reliability in case of node failures at large scale, a reverse lookup problem, namely finding the objects list for the failed node remains open. This is especially true for storage …
Establishing Degradation Rates And Service Lifetime Of Photovoltaic Systems, Albert Leyte-Vidal
Establishing Degradation Rates And Service Lifetime Of Photovoltaic Systems, Albert Leyte-Vidal
Electronic Theses and Dissertations
As fossil fuel sources continue to diminish, oil prices continue to increase, and global warming and CO2 emissions keep impacting the environment, it has been necessary to shift energy consumption and generation to a different path. Solar energy has proven to be one of the most promising sources of renewable energy because it is environmentally friendly, available anywhere in the world, and cost competitive. For photovoltaic (PV) system engineers, designing a PV system is not an easy task. Research demonstrates that different PV technologies behave differently under certain conditions; therefore energy production varies not only with capacity of the system …
Class-E Cascode Power Amplifier Analysis And Design For Long Term Reliability, Karan Kutty
Class-E Cascode Power Amplifier Analysis And Design For Long Term Reliability, Karan Kutty
Electronic Theses and Dissertations
This study investigated the Class-E power amplifier operating at 5.2 GHz. Since the operation of this amplifier applies a lot of stress on the switching transistor, a cascode topology was applied in order to reduce the drain-source voltage stress. Such an amplifier was designed and optimized in order to improve stability, power added efficiency, and matching. A layout for the said design was then created to be fabrication-ready using the TSMC 0.18 um technology. Post-layout simulations were performed in order to realize a more realistic circuit performance with the layout design in mind. Long-term stress effects, such as oxide breakdown, …
Highly Integrated Dc-Dc Converters, Hongwei Jia
Highly Integrated Dc-Dc Converters, Hongwei Jia
Electronic Theses and Dissertations
A monolithically integrated smart rectifier has been presented first in this work. The smart rectifier, which integrates a power MOSFET, gate driver and control circuitry, operates in a self-synchronized fashion based on its drain-source voltage, and does not need external control input. The analysis, simulation, and design considerations are described in detail. A 5V, 5-µm CMOS process was used to fabricate the prototype. Experimental results show that the proposed rectifier functions as expected in the design. Since no dead-time control needs to be used to switch the sync-FET and ctrl-FET, it is expected that the body diode losses can be …
Design And Simulation For Encoded Pn-Ofc Saw Sensor Systems, John Pavlina
Design And Simulation For Encoded Pn-Ofc Saw Sensor Systems, John Pavlina
Electronic Theses and Dissertations
Surface acoustic wave (SAW) sensors provide versatility in that they can offer wireless, passive operation in numerous environments. Various SAW device embodiments may also be employed for retrieval of the sensed data. Single sensor systems typically use a single carrier frequency and a simple device embodiment since tagging is not required. However, it is necessary in a multi-sensor environment to both identify the sensor and retrieve the information. Overlapping sensor data signals in time and frequency present problems when attempting to collect the sensed data at the receiver. This dissertation defines a system simulation environment exclusive to SAW sensors. The …
An Optimal Control Approach For Determiniation Of The Heat Loss Coefficient In An Ics Solar Domestic Water Heating System, Camilo Gil
Electronic Theses and Dissertations
Water heating in a typical home in the U.S. accounts for a significant portion (between 14% and 25%) of the total home's annual energy consumption. The objective of considerably reducing the home's energy consumption from the utilities calls for the use of onsite renewable energy systems. Integral Collector Storage (ICS) solar domestic water heating systems are an alternative to help meet the hot water energy demands in a household. In order to evaluate the potential benefits and contributions from the ICS system, it is important that the parameter values included in the model used to estimate the system's performance are …
Reconfigurable Computing For Video Coding, Jian Huang
Reconfigurable Computing For Video Coding, Jian Huang
Electronic Theses and Dissertations
Video coding is widely used in our daily life. Due to its high computational complexity, hardware implementation is usually preferred. In this research, we investigate both ASIC hardware design approach and reconfigurable hardware design approach for video coding applications. First, we present a unified architecture that can perform Discrete Cosine Transform (DCT), Inverse Discrete Cosine Transform (IDCT), DCT domain motion estimation and compensation (DCT-ME/MC). Our proposed architecture is a Wavefront Array-based Processor with a highly modular structure consisting of 8*8 Processing Elements (PEs). By utilizing statistical properties and arithmetic operations, it can be used as a high performance hardware accelerator …
Biosignal Processing Challenges In Emotion Recognitionfor Adaptive Learning, Aniket Vartak
Biosignal Processing Challenges In Emotion Recognitionfor Adaptive Learning, Aniket Vartak
Electronic Theses and Dissertations
User-centered computer based learning is an emerging field of interdisciplinary research. Research in diverse areas such as psychology, computer science, neuroscience and signal processing is making contributions the promise to take this field to the next level. Learning systems built using contributions from these fields could be used in actual training and education instead of just laboratory proof-of-concept. One of the important advances in this research is the detection and assessment of the cognitive and emotional state of the learner using such systems. This capability moves development beyond the use of traditional user performance metrics to include system intelligence measures …
The Pdf Of Irradiance For A Free-Space Optical Communications Channel: A Physics Based Model, David Wayne
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 …
Digital Pulse Width Modulator Techniques For Dc - Dc Converters, Majd Batarseh
Digital Pulse Width Modulator Techniques For Dc - Dc Converters, Majd Batarseh
Electronic Theses and Dissertations
Recent research activities focused on improving the steady-state as well as the dynamic behavior of DC-DC converters for proper system performance, by proposing different design methods and control approaches with growing tendency to using digital implementation over analog practices. Because of the rapid advancement in semiconductors and microprocessor industry, digital control grew in popularity among PWM converters and is taking over analog techniques due to availability of fast speed microprocessors, flexibility and immunity to noise and environmental variations. Furthermore, increased interest in Field Programmable Gate Arrays (FPGA) makes it a convenient design platform for digitally controlled converters. The objective of …
Evaluating The Benefits Of 3d Stereo In Modern Video Games, Tad Litwiller
Evaluating The Benefits Of 3d Stereo In Modern Video Games, Tad Litwiller
Electronic Theses and Dissertations
We present a study that investigates user performance benefits of 3D stereo in modern video games. Based on an analysis of several video games that are best suited for use with commercial 3D stereo drivers and vision systems, we chose five modern titles focusing on racing, first person shooter, third person shooter, and sports game genres. For each game, quantitative and qualitative measures were taken to determine if users performed better and learned faster in the experimental group (3D stereo display) than in the control group (2D display). A game experience pre-questionnaire was used to classify participants into beginner, intermediate, …
Query Processing In Location-Based Services, Fuyu Liu
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 …
Three-Port Micro-Inverter With Power Decoupling Capability For Photovoltaic (Pv) Systems Applications, Souhib Harb
Three-Port Micro-Inverter With Power Decoupling Capability For Photovoltaic (Pv) Systems Applications, Souhib Harb
Electronic Theses and Dissertations
The Photovoltaic (PV) systems have been realized using different architectures, starting with the string and centralized PV system to the modular PV system. Presently, decentralized inverters are being developed at the PV panel power level (known as AC – PV Modules). Such new PV systems are becoming more attractive and many expect this will be the trend of the future. The AC-Module PV system consists of an inverter attached to one PV panel. This integration requires that both devices have the same life-span. Although, the available commercial inverters have a relatively short life-span (10 years) compared to the 25 –year …
Design Of Silicon Controlled Rectifers Sic] For Robust Electrostatic Discharge Protection Applications, Zhiwei Liu
Design Of Silicon Controlled Rectifers Sic] For Robust Electrostatic Discharge Protection Applications, Zhiwei Liu
Electronic Theses and Dissertations
Electrostatic Discharge (ESD) phenomenon happens everywhere in our daily life. And it can occurs through the whole lifespan of an Integrated Circuit (IC), from the early wafer fabrication process, extending to assembly operation, and finally ending at the user‟s site. It has been reported that up to 35% of total IC field failures are ESD-induced, with estimated annual costs to the IC industry running to several billion dollars. The most straightforward way to avoid the ICs suffering from the threatening of ESD damages is to develop on-chip ESD protection circuits which can afford a robust, low-impedance bypassing path to divert …
Control Strategy For Maximizing Power Conversion Efficiency And Effectiveness Of Three Port Solar Charging Station For Electric Vehicles, Christopher Hamilton
Control Strategy For Maximizing Power Conversion Efficiency And Effectiveness Of Three Port Solar Charging Station For Electric Vehicles, Christopher Hamilton
Electronic Theses and Dissertations
Recent trends in the energy sector have provided opportunities in the research of alternative energy sources and optimization of systems that harness these energy sources. With the rising cost of fossil fuel and rising concern about detrimental effects that fossil fuel consumption has on the environment, electric vehicles are becoming more prevalent. A study put out in 2009 gives a prediction that in the year 2025, 20% of new vehicles will be PHEVs.[1] As energy providers become more concerned about a growing population and diminishing energy source, they are looking into alternative energy sources such as wind and solar power. …
Conventional And Zvt Synchronous Buck Converter Design, Analysis, And Measurement, Mark Cory
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 …
Design Of A Wideband Dual-Polarized Cavity Backed Slot Antenna, Rajesh Paryani
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 …