Electrical and Electronics Commons^™

Rss Based Localization In A Rayleigh Fading Environment, Rojina Adhikary

Electronic Theses and Dissertations

The objective of this thesis is to quantify the improvement that can be obtained in sensor agent localization accuracy as a function of the number of multipath components that can be resolved. We assume that a known number sensor agents are located at unknown coordinates within a rectangular grid having anchors at the corner locations, whose locations are known. Further, we assume fading is Rayleigh and that the propagation constant is constant but unknown. Also, we assume that modulation is spread spectrum and that either the sensors or agents are capable of resolving multipath components down to the chip level …

Adaptive Relay-Selection In Decode-And-Forward Cooperative Systems, Adham Ahmed Hagag

Electronic Theses and Dissertations

In the past few years adaptive decode-and-forward cooperative diversity systems have been studied intensively in literature. Many schemes and protocols have been proposed to enhance the performance of the cooperative systems while trying to alleviate its drawbacks. One of the recent schemes that had been shown to give high improvements in performance is the best-relay selection scheme. In the best-relay selection scheme only one relaying nodes among the relays available in the system is selected to forward the source's message to the destination. The best relay is selected as the relay node that can achieve the highest end-to-end signal-to-noise ratio …

Design And Implementation Of An X-Band Passive Rfid Tag, Praharshin Melaka Senadeera

Dissertations

This research presents a novel fully integrated energy harvester, matching network, multi-stage RF-DC rectifier, mode selector, RC oscillator, LC oscillator, and X-band power amplifier implemented in IBM 0.18-µm RF CMOS technology. We investigated different matching schemes, antennas, and rectifiers with focus on the interaction between building blocks. Currently the power amplifier gives the maximum output power of 5.23 dBm at 9.1GHz. The entire RFID tag circuit was designed to operate in low power consumption. Voltage sensor circuit which generates the enable signal was designed to operate in very low current. All the test blocks of the RFID tag were tested. …

Investigation Of Hfox/Cu Resistive Memory For Advanced Encryption Applications, Benjamin David Briggs

Legacy Theses & Dissertations (2009 - 2024)

The Advanced Encryption Standard (AES) is a widely used encryption algorithm to protect data and communications in today's digital age. Modern AES CMOS implementations require large amounts of dedicated logic and must be tuned for either performance or power consumption. A high throughput, low power, and low die area AES implementation is required in the growing mobile sector. An emerging non-volatile memory device known as resistive memory (ReRAM) is a simple metal-insulator-metal capacitor device structure with the ability to switch between two stable resistance states. Currently, ReRAM is targeted as a non-volatile memory replacement technology to eventually replace flash. Its …

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, 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/HfO_x/Ti stack: …

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, 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, 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, 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 …

3d Printed Electromagnetic Transmission And Electronic Structures Fabricated On A Single Platform Using Advanced Process Integration Techniques, Paul I. Deffenbaugh

Open Access Theses & Dissertations

3D printing has garnered immense attention from many fields including in-office rapid prototyping of mechanical parts, outer-space satellite replication, garage functional firearm manufacture, and NASA rocket engine component fabrication. 3D printing allows increased design flexibility in the fabrication of electronics, microwave circuits and wireless antennas and has reached a level of maturity which allows functional parts to be printed. Much more work is necessary in order to perfect the processes of 3D printed electronics especially in the area of automation. Chapter 1 shows several finished prototypes of 3D printed electronics as well as newly developed techniques in fabrication. Little is …

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, 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, 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, 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, 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 …

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 …

Service And Communication Management In Cooperative Vehicular Networks, Olivia Brickley

Theses

The concept of Intelligent Transportation Systems (ITS) presents new R&D challenges for the transportation and ICT sectors and is currently receiving considerable interest from the research community. The primary objective of ITS is the creation of advanced road traffic systems for improved traffic safety, efficiency, and travelling comfort. Basic vehicle and roadside infrastructure collaboration allows for an increase in efficiency and safety and acts as the foundation for an extensive service set to achieve these ITS goals. Applications such as journey planning, automatic tolling and emergency warnings, among others, are envisaged in a system which can potentially reform modern transportation. …

A Novel Waveform For Emergency Services Mobile Ad-Hoc Networks : The Link Layer Perspective, Sebastian Helmle

Theses

Existing wireless communication systems of emergency services mainly enable ordinary unicast or broadcast voice communications. The increasing demand for data services such as messaging, file transfer, maps, etc requires those long-range communication systems to provide higher data rates while maintaining robustness against link failures. In this thesis, various aspects of a link layer design specifically for narrowband mobile ad-hoc networks (MANETs) that are targeted at emergency services are investigated.

The major aspect of this thesis is the optimisation of a time division multiple access (TDMA) design considering both efficient and reliable multicast resource reservation. An approach to mathematically describe a …

Wind Energy In Ireland - An Analysis Of Percentage Error In Forecasting, Michael Mcdonald

Dissertations

This research aimed to examine the percentage error in forecasting of wind energy using datasets from a small wind farm in Ireland. Furthermore, the study aimed to compare this calculated data to the national forecasting percentage errors. Internationally, the electrical sector and society are undergoing a revolution in terms of 'green economy'. This paradigm shift towards renewable energy technologies is recognised as a priority, with diminution of finite fossil fuels at its core. Renewable energy as a sector has provided significant financial stimulation to global economies in recent years. Moreover, wind energy has provided significant amounts of clean electricity throughout …