Development Of Novel Technologies To Enhance Performance And Reliability Of Iii-Nitride Avalanche Photodiodes,
2014
University at Albany, State University of New York
Development Of Novel Technologies To Enhance Performance And Reliability Of Iii-Nitride Avalanche Photodiodes, Puneet Harischandra Suvarna
Legacy Theses & Dissertations (2009 - 2024)
Solar-blind ultraviolet avalanche photodiodes are an enabling technology for applications in the fields of astronomy, communication, missile warning systems, biological agent detection and particle physics research. Avalanche photodiodes (APDs) are capable of detecting low-intensity light with high quantum efficiency and signal-to-noise ratio without the need for external amplification. The properties of III-N materials (GaN and AlGaN) are promising for UV photodetectors that are highly efficient, radiation-hard and capable of visible-blind or solar-blind operation without the need for external filters. However, the realization of reliable and high performance III-N APDs and imaging arrays has several technological challenges. The high price and …
Oxide Defect Engineering Methods For Valence Change (Vcm) Resistive Random Access Memories,
2014
University at Albany, State University of New York
Oxide Defect Engineering Methods For Valence Change (Vcm) Resistive Random Access Memories, Jihan Ocampo Capulong
Legacy Theses & Dissertations (2009 - 2024)
Electrical switching requirements for resistive random access memory (ReRAM) devices are multifaceted, based on device application. Thus, it is important to obtain an understanding of these switching properties and how they relate to the oxygen vacancy concentration and oxygen vacancy defects. Oxygen vacancy defects in the switching oxide of valence-change-based ReRAM (VCM ReRAM) play a significant role in device switching properties. Oxygen vacancies facilitate resistive switching as they form the conductive filament that changes the resistance state of the device. This dissertation will present two methods of modulating the defect concentration in VCM ReRAM composed of Pt/HfOx/Ti stack: …
Development Of A One-Dimensional Position Sensitive Detector For Tracking Applications,
2014
University at Albany, State University of New York
Development Of A One-Dimensional Position Sensitive Detector For Tracking Applications, Leigh Kent Lydecker
Legacy Theses & Dissertations (2009 - 2024)
Optical Position Sensitive Detectors (PSDs) are a non-contact method of tracking the location of a light spot. Silicon-based versions of such sensors are fabricated with standard CMOS processing, are inexpensive and provide a real-time, analog signal output corresponding to the position of the light spot. Because they are non-contact, they do not degrade over time from surface friction due to repetitive sliding motion associated with standard full contact sliding potentiometers. This results in long, reliable device lifetimes. In this work, an innovative PSD was developed to replace the linear hard contact potentiometer currently being used in a human-computer interface architecture.
Cross-Layer Capacity Optimization In Ofdma Systems: Wimax And Lte,
2014
University of Mississippi
Cross-Layer Capacity Optimization In Ofdma Systems: Wimax And Lte, Bimal Paudel
Electronic Theses and Dissertations
Given the broad range of applications supported, high data rate required and low latency promised; dynamic radio resource management is becoming vital for newly emerging air interface technologies such as wireless interoperability for microwave access (Wimax) and long term evolution (lte) adopted by international standards. This thesis considers orthogonal frequency division multiple access (ofdma) system, which has been implemented in both Wimax and lte technologies as their air interface multiple access mechanism. A framework for optimized resource allocation with quality of service (qos) support that aims to balance between service provider's revenue and subscriber's satisfaction is proposed. A cross-layer optimization …
Optimized Image Compressed Sensing And Transmission Through Wireless Channels,
2014
University of Mississippi
Optimized Image Compressed Sensing And Transmission Through Wireless Channels, Saheed Olanigan
Electronic Theses and Dissertations
This thesis examines the robust behavior of quantized compressed sensing measurements during transmission through an additive white gaussian noise wireless channel. The poor rate-distortion performance that accompanies compressed sensing after applying quantization has led to several works in quantized compressed sensing. However, most of these works have less consideration of the effect of transmission channel on the resulting bit stream of the quantized compressed sensing measurements. For an additive white gaussian noise wireless channel model, the quantizer and bit energy signal-to-noise ratio determines the degree of the channel effect. This thesis explores the effect of quantization and channel noise during …
Energy Optimization Of A Free-Piston Enhanced Hybrid Vehicle,
2014
North Carolina Agricultural and Technical State University
Energy Optimization Of A Free-Piston Enhanced Hybrid Vehicle, Kenneth Jarod Jones
Dissertations
The world’s heavy dependence on vehicles which utilize hydrocarbon fuels as a primary power source has renewed the interest in electric and hybrid vehicles for industrial, commercial, and public use. The primary objective of this movement is centered on increased efficiency in energy usage for transportation. Hybrid vehicles which utilize an internal combustion engine as a linear generator, converting energy stored in hydrocarbon fuels into electrical power, could serve as a transitioning technology. The free-piston enhanced hybrid vehicle (FPHV) could potentially fill this role. The present work contains a theoretical and numerical approach to analyzing and optimizing the usage of …
A New Algorithm For Piecewise Affine System Identification And Its Application To A Mems Switch,
2014
Department of Electrical and Electronic Engineering, Cork Institute of Technology, Cork, Ireland.
A New Algorithm For Piecewise Affine System Identification And Its Application To A Mems Switch, Niel Canty
Theses
Over the past ten years, hybrid systems, and piecewise affine (PWA) systems in particular have been viewed as viable option for modelling nonlinear systems. Many methods have been developed to cater for the identification of a PWA model from input/output data. This thesis focuses on the clustering based identification approach. This method uses a Least Squares (LS) identification algorithm which, in this thesis, is shown to perform poorly in practice. The clustering based algorithm is also limited by the number of initialisation parameters that need to be chosen. These parameters have a significant influence on the resulting PWA model accuracy, …
Design And Analysis Of Reconfigurable Sensing Antennas For Wireless Sensing Applications,
2014
University of Mississippi
Design And Analysis Of Reconfigurable Sensing Antennas For Wireless Sensing Applications, Qian Qiao
Electronic Theses and Dissertations
Reconfiguration sensing antenna (rsa) is a novel antenna concept, which not only can transmit or receive radio waves but also can sense the surrounding environment. The environment sensing is realized by reconfiguring the antenna's characteristics, such as resonant frequency, and radar cross section (rcs). The rsas possess the advantages of passive and low cost, which make them suitable for the large-scale wireless sensing networks (wsns) deployment. In this dissertation, the rsas concept is demonstrated, and two sensing mechanisms performed in the rsas are investigated. In order to verify these sensing mechanisms, four rsas are designed, analyzed, and measured. All the …
Treatment-Specific Approaches For Analysis And Control Of Left Ventricular Assist Devices,
2014
University of Central Florida
Treatment-Specific Approaches For Analysis And Control Of Left Ventricular Assist Devices, George Faragallah
Electronic Theses and Dissertations
A Left Ventricular Assist Device (LVAD) is a mechanical pump that helps patients with heart failure conditions. This rotary pump works in parallel to the ailing heart and provides an alternative path for blood flow from the weak left ventricle to the aorta. The LVAD is controlled by the power supplied to the pump motor. An increase in the pump motor power increases the pump speed and the pump flow. The LVAD is typically controlled at a fixed setting of pump power. This basically means that the controller does not react to any change in the activity level of the …
Control Based Soft Switching Three-Phase Micro-Inverter: Efficiency And Power Density Optimization,
2014
University of Central Florida
Control Based Soft Switching Three-Phase Micro-Inverter: Efficiency And Power Density Optimization, Ahmadreza Amirahmadi
Electronic Theses and Dissertations
In the field of renewable energy, solar photovoltaic is growing exponentially. Grid-tied PV micro-inverters have become the trend for future PV system development because of their remarkable advantages such as enhanced energy production due to MPPT implementation for each PV panel, high reliability due to redundant and distributed system architecture, and simple design, installation, and management due to its plug-and-play feature. Conventional approaches for the PV micro-inverters are mainly in the form of single-phase grid connected and they aim at the residential and commercial rooftop applications. It would be advantageous to extend the micro-inverter concept to large size PV installations …
Learning Collective Behavior In Multi-Relational Networks,
2014
University of Central Florida
Learning Collective Behavior In Multi-Relational Networks, Xi Wang
Electronic Theses and Dissertations
With the rapid expansion of the Internet and WWW, the problem of analyzing social media data has received an increasing amount of attention in the past decade. The boom in social media platforms offers many possibilities to study human collective behavior and interactions on an unprecedented scale. In the past, much work has been done on the problem of learning from networked data with homogeneous topologies, where instances are explicitly or implicitly inter-connected by a single type of relationship. In contrast to traditional content-only classification methods, relational learning succeeds in improving classification performance by leveraging the correlation of the labels …
Practical Issues In Gpram Development,
2014
University of Central Florida
Practical Issues In Gpram Development, Yin Li
Electronic Theses and Dissertations
In this thesis, two parts of practical issues in the GPRAM system design are included. The first part is the coding part. The sum-product decoding algorithm of LDPC codes has been refined to fit for the GPRAM hardware implementation. As we all know, communication channel has noise. The noise in telecom system is different from that in GPRAM systems. So the noise should be handled well in the GPRAM design. A noise look-up table was created for FPGA and those noises in the table are quantized. The second part of the thesis is to convert perfect images in video stream …
Learning To Grasp Unknown Objects Using Weighted Random Forest Algorithm From Selective Image And Point Cloud Feature,
2014
University of Central Florida
Learning To Grasp Unknown Objects Using Weighted Random Forest Algorithm From Selective Image And Point Cloud Feature, Md Shahriar Iqbal
Electronic Theses and Dissertations
This method demonstrates an approach to determine the best grasping location on an unknown object using Weighted Random Forest Algorithm. It used RGB-D value of an object as input to find a suitable rectangular grasping region as the output. To accomplish this task, it uses a subspace of most important features from a very high dimensional extensive feature space that contains both image and point cloud features. Usage of most important features in the grasping algorithm has enabled the system to be computationally very fast while preserving maximum information gain. In this approach, the Random Forest operates using optimum parameters …
Investigation Of Different Dielectric Materials As Gate Insulator For Mosfets,
2014
University of Central Florida
Investigation Of Different Dielectric Materials As Gate Insulator For Mosfets, Ritika Oswal
Electronic Theses and Dissertations
The scaling of semiconductor transistors has led to a decrease in thickness of the silicon dioxide layer used as gate dielectric. The thickness of the silicon dioxide layer is reduced to increase the gate capacitance, thus increasing the drain current. If the thickness of the gate dielectric decreases below 2nm, the leakage current due to the tunneling increases drastically. Hence it is necessary to replace the gate dielectric, silicon dioxide, with a physically thicker oxide layer of high-k materials like Hafnium oxide and Titanium oxide. High-k dielectric materials allow the capacitance to increase without a huge leakage current. Hafnium oxide …
Translation Of 'Seasons Of Life: A Panoramic Selection Of Songs By Rabindranath Tagore',
2014
University of Dayton
Translation Of 'Seasons Of Life: A Panoramic Selection Of Songs By Rabindranath Tagore', Monish Ranjan Chatterjee
Electrical and Computer Engineering Faculty Publications
No abstract provided.
Constant-Stress Accelerated Life Test Of White Organic Light-Emitting Diode Based On Least Square Method Under Weibull Distribution,
2014
Edith Cowan University
Constant-Stress Accelerated Life Test Of White Organic Light-Emitting Diode Based On Least Square Method Under Weibull Distribution, J Zhang, C Liu, G Cheng, X Chen, J Wu, Q Zhu, Laichang Zhang
Research outputs 2014 to 2021
It is currently hard to estimate the reliability parameters of organic light-emitting diodes (OLEDs) when conducting a life test at normal stress, due to the remarkably improved life of OLEDs to thousands hours. This work adopted three constant-stress accelerated life tests (CSALTs) to predict the life of white OLEDs in a short time. The Weibull function was applied to describe the life distribution, and the shape and scale parameters were estimated using the least square method. The experimental test data were statistically analyzed using a self-developed software. The life of white OLEDs predicted via this software is in good agreement …
Critical Analysis Of Transmitarray Antenna Design,
2014
University of Mississippi
Critical Analysis Of Transmitarray Antenna Design, Ahmed H. Abdelrahman
Electronic Theses and Dissertations
In recent years, transmitarray antenna concept attracts growing interests of many scientists in the antenna area. It combines the favorable features of the lens antenna that are based on optical theory and the microstrip arrays that are based on array theory, leading to a low profile design with high gain, high radiation efficiency, and flexible radiation performance. Transmitarrays are now emerging as a new generation of high-gain antennas for long-distance communications. In this dissertation, comprehensive analysis, new methodologies, and novel designs of transmitarray antennas are presented. * detailed analysis of the design of planar space fed array antennas is presented. …
Model Analysis And Predictive Control Of Double Electrode Submerged Arc Welding Process For Fillet Joints With Root Opening,
2014
University of Kentucky
Model Analysis And Predictive Control Of Double Electrode Submerged Arc Welding Process For Fillet Joints With Root Opening, Yi Lu
Theses and Dissertations--Electrical and Computer Engineering
Submerged Arc Welding (SAW) for fillet joints is one of the major applications in the shipbuilding industry. Due to the requirement for the weld size, a sufficient amount of metal must be deposited. In conventional SAW process, the heat input is proportional to the amount of metal melted and is thus determined by the required weld size. To meet this requirement, an excessive amount of heat is applied causing large distortions on the welded structures whose follow-up straightening is highly costly. In order to reduce the needed heat input, Double-Electrode (DE) technology has been practiced creating the Double-Electrode SAW (DE-SAW) …
Machine-Human Cooperative Control Of Welding Process,
2014
University of Kentucky
Machine-Human Cooperative Control Of Welding Process, Weijie Zhang
Theses and Dissertations--Electrical and Computer Engineering
An innovative auxiliary control system is developed to cooperate with an unskilled welder in a manual GTAW in order to obtain a consistent welding performance. In the proposed system, a novel mobile sensing system is developed to non-intrusively monitor a manual GTAW by measuring three-dimensional (3D) weld pool surface. Specifically, a miniature structured-light laser amounted on torch projects a dot matrix pattern on weld pool surface during the process; Reflected by the weld pool surface, the laser pattern is intercepted by and imaged on the helmet glass, and recorded by a compact camera on it. Deformed reflection pattern contains the …
Development Of Northrop-Grumman Mark Viie Training Unit And Wireless Video System For Use In Immersive Environments,
2014
University of Kentucky
Development Of Northrop-Grumman Mark Viie Training Unit And Wireless Video System For Use In Immersive Environments, Randall Lee Lewis
Theses and Dissertations--Electrical and Computer Engineering
A training unit has been developed that allows NVESD researchers to develop training simulations within virtual environments to enhance infantry skill and awareness. A ground station was developed to house a computer, power system, and video transmission system. This station will allow for a remote operator to wirelessly send a video/audio stream to the handset. The ground station also allows the use of external video and audio inputs to be sent using onboard converters. Different wireless frequencies were evaluated to determine the best for long-range transmission of content. A handset was developed from a carbon fiber prototype shell. The handset …
