Electrical and Electronics Commons^™

Vector Processor Virtualization: Distributed Memory Hierarchy And Simultaneous Multithreading, Seyedamin Rooholamin

Dissertations

Taking advantage of DLP (Data-Level Parallelism) is indispensable in most data streaming and multimedia applications. Several architectures have been proposed to improve both the performance and energy consumption for such applications. Superscalar and VLIW (Very Long Instruction Word) processors, along with SIMD (Single-Instruction Multiple-Data) and vector processor (VP) accelerators, are among the available options for designers to accomplish their desired requirements. On the other hand, these choices turn out to be large resource and energy consumers, while also not being always used efficiently due to data dependencies among instructions and limited portion of vectorizable code in single applications that deploy …

Cloud-Aided Wireless Systems: Communications And Radar Applications, Shahrouz Khalili

Dissertations

This dissertation focuses on cloud-assisted radio technologies for communication, including mobile cloud computing and Cloud Radio Access Network (C-RAN), and for radar systems.

This dissertation first concentrates on cloud-aided communications. Mobile cloud computing, which allows mobile users to run computationally heavy applications on battery limited devices, such as cell phones, is considered initially. Mobile cloud computing enables the offloading of computation-intensive applications from a mobile device to a cloud processor via a wireless interface. The interplay between offloading decisions at the application layer and physical-layer parameters, which determine the energy and latency associated with the mobile-cloud communication, motivates the inter-layer …

Instruction Fusion And Vector Processor Virtualization For Higher Throughput Simultaneous Multithreaded Processors, Yaojie Lu

Dissertations

The utilization wall, caused by the breakdown of threshold voltage scaling, hinders performance gains for new generation microprocessors. To alleviate its impact, an instruction fusion technique is first proposed for multiscalar and many-core processors. With instruction fusion, similar copies of an instruction to be run on multiple pipelines or cores are merged into a single copy for simultaneous execution. Instruction fusion applied to vector code enables the processor to idle early pipeline stages and instruction caches at various times during program implementation with minimum performance degradation, while reducing the program size and the required instruction memory bandwidth. Instruction fusion is …

On Greening Optical Access Networks, Mina Taheri Hosseinabadi

Dissertations

With the remarkable growth of fiber-based services, the number of FTTx subscribers has been dramatically increasing in recent years. Owing to the environmental concern, reducing energy consumption of optical access networks has become an important issue for network designers. In Ethernet passive optical network (EPON), the optical line terminal (OLT) located at the central office broadcasts the downstream traffic to all optical network units (ONUs), each of which checks all arrival downstream packets to obtain those destined to itself. Since traffic of ONUs changes dynamically, properly defining the sleep mode for idle ONUs can potentially save a significant amount of …

Verification Of Emotion Recognition From Facial Expression, Yanjia Sun

Dissertations

Analysis of facial expressions is an active topic of research with many potential applications, since the human face plays a significant role in conveying a person’s mental state. Due to the practical values it brings, scientists and researchers from different fields such as psychology, finance, marketing, and engineering have developed significant interest in this area. Hence, there are more of a need than ever for the intelligent tool to be employed in the emotional Human-Computer Interface (HCI) by analyzing facial expressions as a better alternative to the traditional devices such as the keyboard and mouse.

The face is a window …

Generalized Dft: Extensions In Communications, Yuewen Wang

Dissertations

Discrete Fourier Transform (DFT) is a restricted version of Generalized DFT (GDFT) which offers a very limited number of sets to be used in a multicarrier communication system. In contrast, as an extension on Discrete Fourier Transform (DFT) from the linear phase to non-linear phase, the proposed GDFT provides many possible carrier sets of various lengths with comparable or better performance than DFT. The availability of the rich library of orthogonal constant amplitude transforms with good performance allows people to design adaptive systems where user code allocations are made dynamically to exploit the current channel conditions in order to deliver …

Optimization Methods For Active And Passive Localization, Nil Garcia

Dissertations

Active and passive localization employing widely distributed sensors is a problem of interest in various fields. In active localization, such as in MIMO radar, transmitters emit signals that are reflected by the targets and collected by the receive sensors, whereas, in passive localization the sensors collect the signals emitted by the sources themselves. This dissertation studies optimization methods for high precision active and passive localization.

In the case of active localization, multiple transmit elements illuminate the targets from different directions. The signals emitted by the transmitters may differ in power and bandwidth. Such resources are often limited and distributed uniformly …

Reliability Study Of Zr And Al Incorporated Hf Based High-K Dielectric Deposited By Advanced Processing, Md Nasir Uddin Bhuyian

Dissertations

Hafnium-based high-x dielectric materials have been successfully used in the industry as a key replacement for SiO₂ based gate dielectrics in order to continue CMOS device scaling to the 22-nm technology node. Further scaling according to the device roadmap requires the development of oxides with higher x values in order to scale the equivalent oxide thickness (EOT) to 0.7 nm or below while achieving low defect densities. In addition, next generation devices need to meet challenges like improved channel mobility, reduced gate leakage current, good control on threshold voltage, lower interface state density, and good reliability. In order to …

Optical Properties Of Strain-Engineered Multilayer Si/Sige Nanostructures, Selina Akter Mala

Dissertations

The long carrier radiative lifetimes in indirect band gap semiconductors such as crystalline Si (c-Si) and Ge impede the development of efficient light-emitting devices and lasers. Multilayer Si/SiGe nanostructures are considered to be the strong candidates for efficient and high-speed optoelectronic devices integrated into CMOS platforms. Since c-Si and Ge have a considerable lattice mismatch of ~ 4.2%, Si/Si_1-xGe_x(x < 0.5) nanostructures in the form of nano-layers (NLs) or cluster multilayers (CMs) modify the band structure and create non-uniform strain distribution. Engineering of Si/Si_1-xGe_xnanostructures with the predicted composition and interface abruptness, which controls spatial separation between electrons and holes and carrier radiative recombination rate, is critical in producing the desired fast and efficient photoluminescence …

Synchrophasor Assisted Efficient Fault Location Techniques In An Active Distribution Network, Anil Khanal

Dissertations

Reliability of an electrical system can be improved by an efficient fault location identification for the fast repair and remedial actions. This scenario changes when there are large penetrations of distributed generation (DG) which makes the distribution system an active distribution system. An efficient use of synchrophasors in the distribution network is studied with bidirectional power flow, harmonics and low angle difference consideration which are not prevalent in a transmission network. A synchrophasor estimation algorithm for the P class PMU is developed and applied to identify efficient fault location. A fault location technique using two ended synchronized measurement is derived …

Global Optimization Methods For Localization In Compressive Sensing, Marco Rossi

Dissertations

The dissertation discusses compressive sensing and its applications to localization in multiple-input multiple-output (MIMO) radars. Compressive sensing is a paradigm at the intersection between signal processing and optimization. It advocates the sensing of “sparse” signals (i.e., represented using just a few terms from a basis expansion) by using a sampling rate much lower than that required by the Nyquist-Shannon sampling theorem (i.e., twice the highest frequency present in the signal of interest). Low-rate sampling reduces implementation’s constraints and translates into cost savings due to fewer measurements required. This is particularly true in localization applications when the number of measurements is …

Congestion Control, Energy Efficiency And Virtual Machine Placement For Data Centers, Yan Zhang

Dissertations

Data centers, facilities with communications network equipment and servers for data processing and/or storage, are prevalent and essential to provide a myriad of services and applications for various private, non-profit, and government systems, and they also form the foundation of cloud computing, which is transforming the technological landscape of the Internet. With rapid deployment of modern high-speed low-latency large-scale data centers, many issues have emerged in data centers, such as data center architecture design, congestion control, energy efficiency, virtual machine placement, and load balancing.

The objective of this thesis is multi-fold. First, an enhanced Quantized Congestion Notification (QCN) congestion notification …

Modeling, Control And Simulation Of Control-Affine Nonlinear Systems With State-Dependent Transfer Functions, Roger Kobla Kwadzogah

Dissertations

There has been no known research that applies nonlinear transfer function to a nonlinear control problem. The belief is that nonlinear systems have no transfer functions. The Laplace transformation required to define transfer functions is not tractable mathematically when the coefficients of the differential equation are functions of state, output and control variables. In other words, it is not defined for systems that do not obey principles of superposition. Only linear systems obey this principle. Therefore, this dissertation work represents the very first research to demonstrate how transfer functions can be used to represent and design feedback control for nonlinear …

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. …

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 …

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 …

Exploitation Of Infrared Polarimetric Imagery For Passive Remote Sensing Applications, Joao Miguel Mendes Romano

Dissertations

Polarimetric infrared imagery has emerged over the past few decades as a candidate technology to detect manmade objects by taking advantage of the fact that smooth materials emit strong polarized electromagnetic waves, which can be remotely sensed by a specialized camera using a rotating polarizer in front of the focal plate array in order to generate the so-called Stokes parameters: S₀, S₁, S₂, and DoLP. Current research in this area has shown the ability of using such variations of these parameters to detect smooth manmade structures in low contrast contrast scenarios.

This dissertation proposes …

Adaptive Data Acquisition For Communication Networks, Behzad Ahmadi

Dissertations

In an increasing number of communication systems, such as sensor networks or local area networks within medical, financial or military institutions, nodes communicate information sources (e.g., video, audio) over multiple hops. Moreover, nodes have, or can acquire, correlated information sources from the environment, e.g., from data bases or from measurements. Among the new design problems raised by the outlined scenarios, two key issues are addressed in this dissertation: 1) How to preserve the consistency of sensitive information across multiple hops; 2) How to incorporate the design of actuation in the form of data acquisition and network probing in the optimization …

Enabling Sustainable Power Distribution Networks By Using Smart Grid Communications, Chun-Hao Lo

Dissertations

Smart grid modernization enables integration of computing, information and communications capabilities into the legacy electric power grid system, especially the low voltage distribution networks where various consumers are located. The evolutionary paradigm has initiated worldwide deployment of an enormous number of smart meters as well as renewable energy sources at end-user levels. The future distribution networks as part of advanced metering infrastructure (AMI) will involve decentralized power control operations under associated smart grid communications networks. This dissertation addresses three potential problems anticipated in the future distribution networks of smart grid: 1) local power congestion due to power surpluses produced by …

High Performance Digital Signal Processing: Theory, Design, And Applications In Finance, Mustafa Ugur Torun

Dissertations

The way scientific research and business is conducted has drastically changed over the last decade. Big data and data-intensive scientific discovery are two terms that have been coined recently. They describe the tremendous amounts of noisy data, created extremely rapidly by various sensing devices and methods that need to be explored for information inference. Researchers and practitioners who can obtain meaningful information out of big data in the shortest time gain a competitive advantage. Hence, there is more need than ever for a variety of high performance computational tools for scientific and business analytics. Interest in developing efficient data processing …

End-To-End Network Measurement For Wired And Wireless Networks, Khondaker Musfakus Salehin

Dissertations

A number of Internet applications require accurate characterization of different network parameters. There is, therefore, a need to determine whether the networks that carry packets for those applications comply with the requirements. Network measurement provides the means to perform this determination. This work focuses on schemes for measuring several parameters both in wired and wireless environments.

The need of measuring packet processing time (PPT) of the end hosts (i.e., workstations) in a wired network is unveiled. PPT is defined as the time elapsed between the arrival of a packet at the data-link layer and the time when the packet is …

A Novel Approach To Intelligent Navigation Of A Mobile Robot In A Dynamic And Cluttered Indoor Environment, Daniel Opoku

Dissertations

The need and rationale for improved solutions to indoor robot navigation is increasingly driven by the influx of domestic and industrial mobile robots into the market. This research has developed and implemented a novel navigation technique for a mobile robot operating in a cluttered and dynamic indoor environment. It divides the indoor navigation problem into three distinct but interrelated parts, namely, localization, mapping and path planning. The localization part has been addressed using dead-reckoning (odometry). A least squares numerical approach has been used to calibrate the odometer parameters to minimize the effect of systematic errors on the performance, and an …

Blind Recognition Of Analog Modulation Schemes For Software Defined Radio, Haifeng Xiao

Dissertations

With the emergence of software defined radios (SDRs), an adaptive receiver is needed that can configure various parameters, such as carrier frequency, bandwidth, symbol timing, and signal to noise ratio (SNR), and automatically identify modulation schemes. In this dissertation research, several fundamental SDR tasks for analog modulations are investigated, since analog radios are often used by civil government agencies and some unconventional military forces. Hence, the detection and recognition of "old technology" analog modulations remain an important task both for civil and military electronic support systems and for notional cognitive radios.

In this dissertation, a Cyclostationarity-Based Decision Tree classifier is …

Graphene-Coated Substrates For Biochemical And Optoelectronic Applications, Amrita Banerjee

Dissertations

Graphene - monolayer or a few layers of graphite -- has proven to possess remarkable properties: large thermal conductivity, mechanical robustness, two-dimensional ultra large electronic mobility, chemical inertness and biochemical compatibility. Realization of some applications has been impeded by lack of a large area deposition method. By using a novel methodology to deposit graphene on solid and perforated substrates, various optoelectronic and biochemical elements have been demonstrated in this thesis: (1) graphene based transistors were fabricated and their characteristics were assessed. The mobility for such transistors exceeded 5000 cm2/V·s, much larger than their silicon based counterparts. Such attribute opens up …

High Aspect Ratio Electrodes For High Yield Electroporation Of Cells, Anil B. Shrirao

Dissertations

Electroporation is a widely used process in cell biology studies. It uses an electric field to create pores on the cell membrane in order to either insert exogenous molecules inside the cells or disrupt the cell membrane to kill the cells. Current micro-fluidic electroporation devices use the planar electrodes situated at the bottom of a microchannel. These planar electrodes i) require a high voltage and ii) generate a nonuniform electric field which result in low yield of the electroporation. The standard silicon microfabrication technologies are not suitable to fabricate non-planar electrodes required to increase the yield of electroporation.

In this …

Design, Modeling And Fabrication Of Shear Mode Bulk Acoustic Wave Sensor As A Potential Biosensor, Chi-Jung Cheng

Dissertations

There has been an increasing interest in development of thin film bulk acoustic wave resonator (FBAR) devices for chemical and biological sensing applications in the environmental and biomedical industries. The zinc oxide (ZnO) thin film based FBAR devices provides attractive advantages, such as high resonant frequency, small size, and rapid response. Typically, the ZnO-based FBAR devices are operated in the longitudinal wave mode where the ZnO crystallites are perpendicular to the substrate. In gaseous environments, the longitudinal mode FBAR device provides high sensitivity for mass sensing. However, the longitudinal wave mode is adversely affected when used in liquid environments because …

Driver Behavior Classification And Lateral Control For Automobile Safety Systems, Jing Yang

Dissertations

Advanced driver assistance systems (ADAS) have been developed to help drivers maintain stability, improve road safety, and avoid potential collision. The data acquisition equipment that can be used to measure the state and parameter information of the vehicle may not be available for a standard passenger car due to economical and technical limitations. This work focuses on developing three technologies (longitudinal tire force estimation, driver behavior classification and lateral control) using low-cost sensors that can be utilized in ADAS.

For the longitudinal tire force estimation, a low cost 1Hz positioning global system (GPS) and a steering angle sensor are used …

Advanced Intelligent Control And Optimization For Cardiac Pacemaker Systems, Wei Shi

Dissertations

Since cardiovascular diseases are major causes of morbidity and mortality in the developed countries and the number one cause of death in the United States, their accurate diagnosis and effective treatment via advanced cardiac pacemaker systems have become very important. Intelligent control and optimization of the pacemakers are significant research subjects. Serious but infrequently occurring arrhythmias are difficult to diagnose. The use of electrocardiogram (ECG) waveform only cannot exactly distinguish between deadly abnormalities and temporary arrhythmias. Thus, this work develops a new method based on frequency entrainment to analyze pole-zero characteristics of the phase error between abnormal ECG and entrained …

Energy Harvesting-Aware Design Of Wireless Networks, Fabio Iannello

Dissertations

Recent advances in low-power electronics and energy-harvesting (EH) technologies enable the design of self-sustained devices that collect part, or all, of the needed energy from the environment. Several systems can take advantage of EH, ranging from portable devices to wireless sensor networks (WSNs). While conventional design for battery-powered systems is mainly concerned with the battery lifetime, a key advantage of EH is that it enables potential perpetual operation of the devices, without requiring maintenance for battery substitutions. However, the inherent unpredictability regarding the amount of energy that can be collected from the environment might cause temporary energy shortages, which might …

Auger-Mediated Processes And Photoluminescence In Group Iv Semiconductor Nanostructures, Nikhil Modi

Dissertations

Group IV semiconductors (Si, Ge) are inefficient light emitting materials due to their indirect bandgap structure. Nanostructures of Si, Ge, and SiGe however, have shown relatively high photoluminescence (PL) quantum efficiency (QE) at low carrier concentrations. At higher carrier concentrations, the PL QE of these nanostructures is drastically reduced due to the onset of a fast non-radiative process attributed to Auger recombination. Moreover, this onset occurs earlier in structures with reduced physical dimensions, than in bulk material. The study of Auger-mediated processes in group IV nanostructures is therefore critical to understanding the physics of carrier recombination and photonic device limitations. …