Electrical and Electronics Commons^™

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 …

Model Predictive Control Of Timed Continuous Petri Nets, Huaiyu Zhan

Theses

This thesis addresses the optimal control problem of timed continuous Petri nets. The theory of Model Predictive Control (MPC) is first discussed. Then continuous Petri nets (PN) are introduced as a powerful tool for modelling, simulation and analysis of discrete event/continuous systems. Their useful capabilities are studied. Finally, a macroscopic model based on PN as a tool for designing control laws that improve the behavior of traffic systems is given. The goal is to find an approach that minimizes the total delay of cars in an intersection by computing the switching sequence of the traffic lights. The simulation results show …

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 …

Detection Of Video Frame Insertion Based On Constraint Of Human Visual Perception, Lu Zheng

Theses

Recently, due to availability of inexpensive and easily-operable multimedia tools, digital multimedia technology has experienced drastic advancements. At the same time, video forgery becomes much easier and makes more difficult to validate the video content. Consequently, the origin and integrity of video can no longer be taken for granted. A methodology is developed that is capable of detecting the video frame insertion based on the constraint of human visual perception. The main idea is based on the so-called differential sensitivity. That is, that the variation of brightness of neighboring video frames has some constraint. First, the video sequence is partitioned …

Model Predictive Control For Building Temperature Regulation, Weiqiang Dong

Theses

With the rapid increase in human consumption of energy, global warming is becoming an urgent problem. According to the past research, a significant part of greenhouse gas release and electricity consumption has been connected to buildings. Heating systems are the major contributor to high energy consumption of buildings. Better methods for decreasing energy consumption of buildings should be proposed and applied.

Model predictive control is widely used in building temperature regulation. Each model predictive control has its advantage. Through the comparison of several methods, this thesis discusses their respective features. The combination of a Matlab-based modeling system CVX and model …

Research On Mppt Methods For Photovoltaic System Based On Microgrid, Jingchu Ji

Theses

This thesis introduces some basic concepts about a microgrid. Then it discusses the structure of photovoltaic system (PVS) which contains a solar panel and simplified PV models. Next, it discusses and compares different methods for Maximum Power Point Tracking (MPPT) with PVS. It presents three types of DC-DC converters -- Buck, Boost and Buck-Boost converter. This work proposes to apply a DC-DC converter of Buck-Boost type to make PVS controllable because this type of converter has the largest range for operational region so that it can get the best result on MPPT. Finally, this thesis presents a kind of new …

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 …

Gpu Implementation Of Block Transforms, Boyan Zhang

Theses

Traditionally, intensive floating-point computational ability of Graphics Processing Units (GPUs) has been mainly limited for rendering and visualization application by architecture and programming model. However, with increasing programmability and architecture progress, GPUs inherent massively parallel computational ability have become an essential part of today's mainstream general purpose (non-graphical) high performance computing system. It has been widely reported that adapted GPU-based algorithms outperform significantly their CPU counterpart.

The focus of the thesis is to utilize NVIDIA CUDA GPUs to implement orthogonal transforms such as signal dependent Karhunen-Loeve Transform and signal independent Discrete Cosine Transform. GPU architecture and programming model are examined. …

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. …

Image Statistical Frameworks For Digital Image Forensics, Patchara Sutthiwan

Dissertations

The advances of digital cameras, scanners, printers, image editing tools, smartphones, tablet personal computers as well as high-speed networks have made a digital image a conventional medium for visual information. Creation, duplication, distribution, or tampering of such a medium can be easily done, which calls for the necessity to be able to trace back the authenticity or history of the medium. Digital image forensics is an emerging research area that aims to resolve the imposed problem and has grown in popularity over the past decade. On the other hand, anti-forensics has emerged over the past few years as a relatively …

Three-Dimensional Magnetic Field Sensor In Ibm 0.18Μm Cmos Technology, Gang Wang

Theses

This work presents a compact three-dimensional Magnetic Field Sensor (MFS) designed in standard Complementary Metal-Oxide-Semiconductor (CMOS) technology. A circular Vertical Hall Device (VHD) for horizontal magnetic field detection and a split- drain Horizontal Hall Device (HHD) for the vertical magnetic field detection are integrated to implement the three-dimensional M FS. This merged design has the advantage of smaller area and lower power consumption. The sensitivity of the vertical hall device (ring-shaped magneto-resistor) and the horizontal hall device (Split-Drain Magnetic Field-Effect Transistor (SD-MAGFET)) is estimated as 0.11V/T and 2.88V/T respectively. The vertical direction of the magnetic field detection demonstrates a higher …

Moxon Based Rfid Tag Reader And Gps Antenna, Haojiong Liu

Theses

Modern communication applications at UHF frequencies require antennas with wide band, high forward gain, low backward radiation, high cross-polarization, small size and low manufacture cost. The Moxon antenna based on a two element Yagi-Uda antenna over the ground reflector is one of the most favorite antennas for HAM operators which can produce outstanding front to back ratio of radiated power, good match over the desired band and relatively low elevation height.

A sequence of topologies has been proposed from a single vertical element to two vertical elements of the Moxon arms, until the lately patented Broadband Circularly Polarized Moxon Based …

Source Localization Via Time Difference Of Arrival, Ciprian Romeo Comsa

Dissertations

Accurate localization of a signal source, based on the signals collected by a number of receiving sensors deployed in the source surrounding area is a problem of interest in various fields. This dissertation aims at exploring different techniques to improve the localization accuracy of non-cooperative sources, i.e., sources for which the specific transmitted symbols and the time of the transmitted signal are unknown to the receiving sensors. With the localization of non-cooperative sources, time difference of arrival (TDOA) of the signals received at pairs of sensors is typically employed.

A two-stage localization method in multipath environments is proposed. During the …

Target Localization In Passive And Active Systems : Performance Bonds, Vlad Mihai Chiriac

Dissertations

The main goal of this dissertation is to improve the understanding and to develop ways to predict the performance of localization techniques as a function of signal-to-noise ratio (SNR) and of system parameters. To this end, lower bounds on the maximum likelihood estimator (MLE) performance are studied. The Cramer-Rao lower bound (CRLB) for coherent passive localization of a near-field source is derived. It is shown through the Cramer-Rao bound that, the coherent localization systems can provide high accuracies in localization, to the order of carrier frequency of the observed signal. High accuracies come to a price of having a highly …

High Rate Space Time Code With Linear Decoding Complexity For Multiple Transmitting Antennas, Amir Laufer

Dissertations

The multipath nature of the wireless channel, results in a superposition of the signals of each path at the receiver. This can lead to either constructive or destructive interference. Strong destructive interference is frequently referred to as deep fade and may result in temporary failure of communication due to the severe drop in the channel's signal-to-noise ratio (SNR). To avoid this situation, signal diversity might be introduced. When having more than one antenna at the transmitter and / or receiver, forming a Multiple-Input Multiple-Output (MIMO) channel, spatial diversity can be employed to overcome the fading problem. Space time block codes …

Influence Of Defects And Impurities On Solar Cell Performance, Vinay Budhraja

Dissertations

Multicrystalline silicon (mc-Si) solar cells exhibit high impurity content and higher density of crystal defects such as grain boundaries, dislocations, stacking faults and impurity precipitates. Even though the effect of dislocations on mc-Si solar cell performance has been studied, a severe lack of understanding of the quantitative effects of dislocations on cell parameters still exists. Some correlation has been reported under the assumption of a uniform distribution of dislocation density and a negligible effect of front and back surface recombination velocity. This assumption can cause a significant error as the current mc-Si technology provides good surface passivation by SiN:H and …

Wireless Sensor Network For Health Monitoring, Jin Soo Choi

Dissertations

Wireless Sensor Network (WSN) is becoming a significant enabling technology for a wide variety of applications. Recent advances in WSN have facilitated the realization of pervasive health monitoring for both homecare and hospital environments. Current technological advances in sensors, power-efficient integrated circuits, and wireless communication have allowed the development of miniature, lightweight, low-cost, and smart physiological sensor nodes. These nodes are capable of sensing, processing, and communicating one or more vital signs. Furthermore, they can be used in wireless personal area networks (WPANs) or wireless body sensor networks (WBSNs) for health monitoring. Many studies were performed and/or are under way …

Analysis Of A Composite Dielectric-Ferrite Loaded Resonator Using The Transmission Line Model With Application To A Tunable Dual Mode Bandpass Filter, Charlotte Blair

Dissertations

A magnetically tuned filter is presented in this dissertation. Filter tuning of a dielectric ceramic resonator is accomplished using by using two oppositely biased ferrites. Specifically, a change in the applied magnetic field is used to alter the permeability of the ferrite so as to achieve maximum tuning range. Through electromagnetic (EM) simulations and laboratory experiments, tuning of the filter passband by 20 MHz is demonstrated.

This investigation focuses on the design of a bandpass resonator using a combination of dielectric-ferrite material layers. An initial simplification of the geometry of the structure is used as the basis for a program …

Trust Management Schemes For Peer-To-Peer Networks, Lin Cai

Dissertations

Peer-to-peer (P2P) networking enables users with similar interests to exchange, or obtain files. This network model has been proven popular to exchange music, pictures, or software applications. These files are saved, and most likely executed, at the downloading host. At the expense of this mechanism, worms, viruses, and malware find an open front door to the downloading host and gives them a convenient environment for successful proliferation throughout the network. Although virus detection software is currently available, this countermeasure works in a reactive fashion, and in most times, in an isolated manner. A trust management scheme is considered to contain …