Electrical and Computer Engineering Commons^™

Computing With Spintronics: Circuits And Architectures, Rangharajan Venkatesan

Open Access Dissertations

This thesis makes the following contributions towards the design of computing platforms with spintronic devices. 1) It explores the use of spintronic memories in the design of a domain-specific processor for an emerging class of data-intensive applications, namely recognition, mining and synthesis (RMS). Two different spintronic memory technologies — Domain Wall Memory (DWM) and STT-MRAM — are utilized to realize the different levels in the memory hierarchy of the domain-specific processor, based on their respective access characteristics. Architectural tradeoffs created by the use of spintronic memories are analyzed. The proposed design achieves 1.5X-4X improvements in energy-delay product compared to a …

Design And Analysis Of Solar Cells By Coupled Electrical - Optical Simulation, Xufeng Wang

Open Access Dissertations

Careful electrical design and optical design are both crucial for achieving high-efficiency solar cells. It is common to link these two aspects serially; the optical design is first done to minimize reflection and maximize light trapping, and then the resulting optical generation rate is input to the electrical simulation. For very high efficiency solar cells that approach the Shockley-Queisser limit, however, electrical and optical transports are tightly coupled in both directions. Photons generated by radiative recombination can be reabsorbed to create additional electron-hole pairs (so-called photon recycling), which decreases losses. A variety of novel photon management schemes are currently being …

Estimating Toner Usage With Laser Electrophotographic Printers, And Object Map Generation From Raster Input Image, Lu Wang

Open Access Dissertations

Accurate estimation of toner usage is an area of on-going importance for laser, electrophotographic (EP) printers. In Part 1, we propose a new two-stage approach in which we first predict on a pixel-by-pixel basis, the absorptance from printed and scanned pages. We then form a weighted sum of these pixel values to predict overall toner usage on the printed page. The weights are chosen by least-squares regression to toner usage measured with a set of printed test pages. Our two-stage predictor significantly outperforms existing methods that are based on a simple pixel counting strategy in terms of both accuracy and …

Image Analysis Using Visual Saliency With Applications In Hazmat Sign Detection And Recognition, Bin Zhao

Open Access Dissertations

Visual saliency is the perceptual process that makes attractive objects "stand out" from their surroundings in the low-level human visual system. Visual saliency has been modeled as a preprocessing step of the human visual system for selecting the important visual information from a scene. We investigate bottom-up visual saliency using spectral analysis approaches. We present separate and composite model families that generalize existing frequency domain visual saliency models. We propose several frequency domain visual saliency models to generate saliency maps using new spectrum processing methods and an entropy-based saliency map selection approach. A group of saliency map candidates are then …

Nuclear Magnetic Resonance Studies On Lithium And Sodium Electrode Materials For Rechargeable Batteries, Tetiana Nosach

Dissertations, Theses, and Capstone Projects

In this thesis, Nuclear Magnetic Resonance (NMR) spectroscopic techniques are used to study lithium and sodium electrode materials for advanced rechargeable batteries. Three projects are described in this thesis. The first two projects involve 6Li, 7Li and 31P NMR studies of two cathode materials for advanced rechargeable batteries. The third project is a study of sodium titanate cathode materials for Na-ion batteries, where 1H, 7Li, and 23Na static and magic angle spinning NMR were used in order to obtain detailed information on the chemical environments.

Cited2-Mediated Mechanotransduction And Its Use For Chondroprotection, Daniel J. Leong

Dissertations, Theses, and Capstone Projects

Novel prevention and therapeutic treatment for cartilage degradation is urgently called for, as cartilage degradation is a hallmark for arthritic diseases including osteoarthritis (OA) and rheumatoid arthritis (RA), and there is a high incidence of arthritis-related disability and high medical costs. While both underuse (e.g. physically inactive lifestyle) and overuse (e.g. high impact or intense repetitive joint use as seen in certain sports) are risk factors for cartilage degradation, recent studies highlight that dynamic moderate loading is associated with reduced incidence of developing OA. Exercise is prescribed in most cases at moderate levels for both OA and RA patients, and …

Synthesis, Fabrication And Characterization Of Magnetic And Dielectric Nanoparticles And Nanocomposite Films, Xiaohua Liu

Dissertations, Theses, and Capstone Projects

Materials science is an interdisciplinary field investigating the structure-property relationship in solid-state materials scientifically and technologically. Nanoscience is concerned with the distinctive properties that matter exhibits when confined to physical dimensions on the order of 10^-9 meters. At these length scales, behaviors of particles or elaborate structures are often governed by the rules of quantum mechanics in addition to the physical properties associated with the bulk material.

The work reported here seeks to employ nanocystals, binary nanocomposites and thin films of materials, to build versatile, functional systems and devices. With a focus on dielectric, ferroelectric, and magnetoelectric performance, a …

Novel On-Chip Applications Using Silicon Photonics, Rania Gamal

Theses and Dissertations

The emerging field of silicon photonics offers solutions to designing CMOScompatible optical devices. By taking advantage of the immense fabrication infrastructure offered by the silicon industry, it would be possible to design optical structures that are smaller, faster, less-power consuming and cheaper than traditional, non-silicon-based optical devices. In this dissertation, the design and performance testing of two novel silicon photonic structures are presented: 1) Silicon nanowire ridge waveguide for sensing applications at the optical transmission frequency. 2) Doped silicon plasmonic structures for negative-index, epsilon-near-zero and sensing applications at the mid-infrared. For the first design, silicon nanowires are arranged in a …

Speaker Independent Acoustic-To-Articulatory Inversion, An Ji

Dissertations (1934 -)

Acoustic-to-articulatory inversion, the determination of articulatory parameters from acoustic signals, is a difficult but important problem for many speech processing applications, such as automatic speech recognition (ASR) and computer aided pronunciation training (CAPT). In recent years, several approaches have been successfully implemented for speaker dependent models with parallel acoustic and kinematic training data. However, in many practical applications inversion is needed for new speakers for whom no articulatory data is available. In order to address this problem, this dissertation introduces a novel speaker adaptation approach called Parallel Reference Speaker Weighting (PRSW), based on parallel acoustic and articulatory Hidden Markov Models …

An Innovative Ran Architecture For Emerging Heterogeneous Networks: "The Road To The 5g Era", Shahab Hussain

Dissertations, Theses, and Capstone Projects

The global demand for mobile-broadband data services has experienced phenomenal growth over the last few years, driven by the rapid proliferation of smart devices such as smartphones and tablets. This growth is expected to continue unabated as mobile data traffic is predicted to grow anywhere from 20 to 50 times over the next 5 years. Exacerbating the problem is that such unprecedented surge in smartphones usage, which is characterized by frequent short on/off connections and mobility, generates heavy signaling traffic load in the network "signaling storms". This consumes a disproportion amount of network resources, compromising network throughput and efficiency, and …

Timing Mark Detection On Nuclear Detonation Video, Daniel T. Schmitt, Gilbert L. Peterson

Faculty Publications

During the 1950s and 1960s the United States conducted and filmed over 200 atmospheric nuclear tests establishing the foundations of atmospheric nuclear detonation behavior. Each explosion was documented with about 20 videos from three or four points of view. Synthesizing the videos into a 3D video will improve yield estimates and reduce error factors. The videos were captured at a nominal 2500 frames per second, but range from 2300-3100 frames per second during operation. In order to combine them into one 3D video, individual video frames need to be correlated in time with each other. When the videos were captured …

Machine Learning Nuclear Detonation Features, Daniel T. Schmitt, Gilbert L. Peterson

Faculty Publications

Nuclear explosion yield estimation equations based on a 3D model of the explosion volume will have a lower uncertainty than radius based estimation. To accurately collect data for a volume model of atmospheric explosions requires building a 3D representation from 2D images. The majority of 3D reconstruction algorithms use the SIFT (scale-invariant feature transform) feature detection algorithm which works best on feature-rich objects with continuous angular collections. These assumptions are different from the archive of nuclear explosions that have only 3 points of view. This paper reduces 300 dimensions derived from an image based on Fourier analysis and five edge …

Camera Viewpoint Invariant Vehicular Traffic Segmentation And Classification, Jeffrey B. Flora

Electrical & Computer Engineering Theses & Dissertations

The goal of this intelligent transportation systems work is to develop a computer vision method that is view angle independent for segmenting and classifying vehicular traffic on highway systems. In order to achieve this goal, this work implements an algorithm for vehicle segmentation, feature extraction, and classification using the existing Virginia Department of Transportation (VDOT) infrastructure on networked traffic cameras. The VDOT traffic video is analyzed for vehicle detection and segmentation using an adaptive Gaussian mixture model algorithm. Speed estimation is performed using a single camera calibration. Size and shape features from morphological properties and texture features from histogram of …

A Microsoft Vba Application For Generating Heat Maps, Mark Polczynski, Michael Polczynski

Electrical and Computer Engineering Faculty Research and Publications

A choropleth map is a form of thematic map used to portray the structural characteristics of some particular geographical distribution not apparent in data presented in tabular form. Preparation of a choropleth map starts with the assignment of map features to classes based on the value of a specific feature attribute followed by the association of classes of features with appropriate map colors or symbols. Map features are often geographical regions with naturally or artificially defined boundaries, but choropleth maps can also be prepared by segmenting the area to be mapped into a regular grid of regions. Maps prepared with …

Emergency Diesel-Electric Generator Set Maintenance And Test Periodicity, Stephen John Fehr

Engineering Management & Systems Engineering Theses & Dissertations

Manufacturer and industry recommendations vary considerably for maintenance and tests of emergency diesel-electric generator sets supporting critical operations power systems facilities. There is little consistency among sets of similar technology, and manufacturers and their representatives often provide contradictory guidance. As a result, periodicity of emergency diesel-electric generator set maintenance and tests varies considerably in practice. This work proposes and tests a research and analysis framework to develop parametric regression survival models of modern diesel-electric generator sets in emergency standby duty as a function of maintenance periodicity, test periodicity, and other predictors. Within this framework, predictors are developed from common maintenance …

Towards A Dynamic View Of Genetic Networks: A Kalman Filtering Framework For Recovering Temporally-Rewiring Stable Networks From Undersampled Data, Jehandad Khan

Theses and Dissertations

It is widely accepted that cellular requirements and environmental conditions dictate the architecture of genetic regulatory networks. Nonetheless, the status quo in regulatory network modeling and analysis assumes an invariant network topology over time. We refocus on a dynamic perspective of genetic networks, one that can uncover substantial topological changes in network structure during biological processes such as developmental growth and cancer progression. We propose a novel outlook on the inference of time-varying genetic networks, from a limited number of noisy observations, by formulating the networks estimation as a target tracking problem. Assuming linear dynamics, we formulate a constrained Kalman …

Optimal Pmu Placement For Identification Of Multiple Power Line Outages In Smart Grids, Jie Wu, Jinjun Xiong, Prasenjit Shil, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

Placing appropriate numbers of PMUs is critical to collect phase angle data for best identifying multiple line outages in wide-area transmission system, because of high deployment costs. This work focuses on exploring the global optimal strategy of PMU deployment for maximizing the average identification capability of multiple line outages. Inspired by Kullback-Leibler (KL) distance, this paper proposes the closed-form mathematical model to describe the average identification capability of multiple simultaneous line outages. Using IEEE 14-bus system, the optimal trade-off between the average identification capability and the number of PMUs is characterized. The proposed model successfully portrays the statistical identification performance …

Development Of An Integrated Network Visualization And Graph Analysis Tool For Biological Networks, David Carbonetta

Theses and Dissertations

There has been steady increase in the amount of molecular data generated by experiments and computational methods performed on biological networks. There is a growing need to obtain an insight into the organization and structure of the massive and complex biological networks formed by the interacting molecules. To that end, this work presents the development of an integrated network visualization and graph analysis plugin within the Cytoscape framework. The plugin is capable of computing and visualizing a comprehensive set of dyad, node, and graph level statistics. The evaluation of the plugin on a range of biological networks and its memory …

Breast Cancer Detection Using Interferometric Music: Experimental And Numerical Assessment, Giuseppe Ruvio, Raffaele Solimene, Antonio Cuccaro, Domenico Gaetano, Jacinta Browne, Max Ammann

Articles

Purpose: In microwave breast cancer detection, it is often beneficial to arrange sensors in close proximity to the breast. The resultant coupling generally changes the antenna response. As an a priori characterization of the radio frequency system becomes difficult, this can lead to severe degradation of the detection efficacy. The purpose of this paper is to demonstrate the advantages of adopting an interferometric multiple signal classification (I-MUSIC) approach due to its limited dependence from a priori information on the antenna. The performance of I-MUSIC detection was measured in terms of signal-to-clutter ratio (SCR), signal-to-mean ratio (SMR), and spatial displacement (SD) …

Near-Infrared Optical Absorption Enhanced In Black Silicon Via Ag Nanoparticle-Induced Localized Surface Plasmon, Peng Zhang, Shibin Li, Chunhua Liu, Xiongbang Wei, Zhiming Wu, Yadong Jiang, Zhi Chen

Electrical and Computer Engineering Faculty Publications

Due to the localized surface plasmon (LSP) effect induced by Ag nanoparticles inside black silicon, the optical absorption of black silicon is enhanced dramatically in near-infrared range (1,100 to 2,500 nm). The black silicon with Ag nanoparticles shows much higher absorption than black silicon fabricated by chemical etching or reactive ion etching over ultraviolet to near-infrared (UV-VIS-NIR, 250 to 2,500 nm). The maximum absorption even increased up to 93.6% in the NIR range (820 to 2,500 nm). The high absorption in NIR range makes LSP-enhanced black silicon a potential material used for NIR-sensitive optoelectronic device.

PACS

78.67.Bf; 78.30.Fs; 78.40.-q; 42.70.Gi

Improved Field Projection In Equivalence Principle Algorithm With Rotated Cwbc Basis, Zu Hui Ma, Sheng Sun, Lijun Jiang, Weng Cho Chew, Mao Kun Li

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a dual-basis testing method is utilized to enhance the field projection in the equivalence principle algorithm (EPA). Due to the presence of identity operators in the EPA formulation, the near-field calculation is less accurate with field projection errors. This issue can be effectively remedied by using the recently proposed dual-basis function of Rao-Wilton-Glisson basis function, named as rotated Chen-Wilton-Buffa-Christiansen basis function. Numerical result shows the validity of the proposed method.

A Discontinuous Galerkin Time Domain-Boundary Integral Method For Analyzing Transient Electromagnetic Scattering, Ping Li, Li (Lijun) Jun Jiang, Yifei Shi, Hakan Bagci

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents an algorithm hybridizing discontinuous Galerkin time domain (DGTD) method and time domain boundary integral (BI) algorithm for 3-D open region electromagnetic scattering analysis. The computational domain of DGTD is rigorously truncated by analytically evaluating the incoming numerical flux from the outside of the truncation boundary through BI method based on the Huygens' principle. The advantages of the proposed method are that it allows the truncation boundary to be conformal to arbitrary (convex/ concave) scattering objects, well-separated scatters can be truncated by their local meshes without losing the physics (such as coupling/multiple scattering) of the problem, thus reducing …

Second-Harmonic Generation In Metal Nanoparticles Modeling By Surface Integral Equation, Xiaoyan Y.Z. Xiong, Li (Lijun) Jun Jiang, Yat Hei Lo, Weng Cho Chew

Electrical and Computer Engineering Faculty Research & Creative Works

Metals are centrosymmetric materials which only posse local surface second-harmonic (SH) nonlinearities due to the symmetry broken at the surface. In this work the surface integral equation (SIE) is used for evaluating SH radiation generated from metal nanoparticles with arbitrary shapes. The whole SIE system is solved by employing the Galerkin testing procedure and Rao-Wilton-Gillson (RWG) basis functions. The mutual coupling between fundamental and second harmonic field is captured. The method is validated by comparisons with the analytic SH-Mie solution. This method paves the way for accurate and efficient design of general SH nonlinear nanoplasmonic structures.

Applying Cem Techniques To Solve Nano-Scale Quantum Transport Problems, Jun Z. Huang, Weng Cho Chew, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Two widely used algorithms in computational electromagnetics (CEM) society, namely the asymptotic waveform evaluation (AWE) technique and the model order reduction (MOR) mode matching method, are employed to calculate electron wave propagation in novel nanoelectronic devices.

Linearly Polarized Near Field Focused Slot-Array Waveguide, Meng Lin Chen, Shulabh Gupta, Zi Long Ma, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

A 2-D slot array structure to achieve near-field beam focusing, with a linear polarization, is proposed and demonstrated using full-wave simulations. The proposed structure has a negligible cross-polarization and its far-field gain is lower by 10 dB compared to the non-focus case, indicating a good focusing in the near-field of the structure.

An Ibc Enhanced Dgtd Scheme For Transient Analysis Of Em Interactions With Graphene, Ping Li, Li (Lijun) Jun Jiang, Hakan Baʇci

Electrical and Computer Engineering Faculty Research & Creative Works

A discontinuous Galerkin time-domain (DGTD) method is proposed for analyzing electromagnetic field interactions on graphene from microwave to terahertz frequencies. An impedance boundary condition (IBC) is utilized to model the graphene within the DGTD framework. The numerical flux is reformulated to take into account the IBC. Highly dispersive surface conductivity of graphene present in the resulting flux expression is approximated in terms of rational functions using the fast-relaxation vector-fitting technique. Via inverse Laplace transform, this facilitates the time domain matrix equations into an integral form for time variable t, finite integral technique (FIT) with recursive convolution method is employed to …

Reduced-Permittivity Meandered Single-Beam Full-Space Scanning Phase-Reversal Leaky-Wave Antenna, Shulabh Gupta, Li (Lijun) Jun Jiang, Christophe Caloz

Electrical and Computer Engineering Faculty Research & Creative Works

A meandered version of the phase-reversal leaky-wave antenna is introduced to reduce the permittivity requirement εeff > 4 for single-beam full-space scanning.

"Green" On-Chip Inductors In Three-Dimensional Integrated Circuits, Umamaheswara Rao Tida, Varun Mittapalli, Cheng Zhuo, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

Through-silicon-vias (TSVs) are the enabling technique for three-dimensional integrated circuits (3D ICs). However, their large area significantly reduces the benefits that can be obtained by 3D ICs. On the other hand, a major limiting factor for the implementation of many on-chip circuits such as DC-DC converters and resonant clocking is the large area overhead induced by spiral inductors. Several works have been proposed in the literature to make inductors out of idle TSVs. In this paper, we will demonstrate the effectiveness of such TSV inductors in addressing both challenges. Experimental results show that by replacing conventional spiral inductors with TSV …

Advances In Sca And Rf-Dna Fingerprinting Through Enhanced Linear Regression Attacks And Application Of Random Forest Classifiers, Hiren J. Patel

Theses and Dissertations

Radio Frequency (RF) emissions from electronic devices expose security vulnerabilities that can be used by an attacker to extract otherwise unobtainable information. Two realms of study were investigated here, including the exploitation of 1) unintentional RF emissions in the field of Side Channel Analysis (SCA), and 2) intentional RF emissions from physical devices in the field of RF-Distinct Native Attribute (RF-DNA) fingerprinting. Statistical analysis on the linear model fit to measured SCA data in Linear Regression Attacks (LRA) improved performance, achieving 98% success rate for AES key-byte identification from unintentional emissions. However, the presence of non-Gaussian noise required the use …

Hyperfine Interactions In The Electron Paramagnetic Resonance Spectra Of Point Defects In Wide-Band-Gap Semiconductors, Eric M. Golden

Theses and Dissertations

The focus of this research was to acquire definitive experimental data on predominant point defects in three important wide-band-gap semiconductors. Hyperfine interactions in electron paramagnetic resonance spectra were used to characterize the neutral nitrogen acceptor in zinc oxide, to identify a silicon interstitial impurity in titanium dioxide, and to determine the electronic structure of the singly ionized sulfur vacancy in stannous hexathiohypodiphosphate (SPS). Research on the basic properties of these technologically important materials plays a crucial role in the development of advanced optical and electronic systems. Zinc oxide is an electro-optic material with the potential to produce high performance electronics …