Digital Commons Network^™

Seu-Induced Persistent Error Propagation In Fpgas, Keith S. Morgan

Theses and Dissertations

This thesis introduces a new way to characterize the dynamic SEU cross section of an FPGA design in terms of its persistent and non-persistent components. An SEU in the persistent cross section results in a permanent interruption of service until reset. An SEU in the non-persistent cross section causes a temporary interruption of service, but in some cases this interruption may be tolerated. Techniques for measuring these cross sections are introduced. These cross sections can be measured and characterized for an arbitrary FPGA design. Furthermore, circuit components in the non-persistent and persistent cross section can statically be determined. Functional error …

Design And Development Of Triangular, Spiral, And Fractal Antennas For Radio Frequency Identification Tags, Jeevan K. Vemagiri

Doctoral Dissertations

This dissertation reports on the design and development of three compact, non-meandered microstrip patch antennas for ultra high frequency (UHF) radio frequency identification (RFID) applications. The monopole antennas considered in this work are an inset-fed triangular antenna, one arm Archimedes spiral antenna and a Half-Sierpinski fractal antenna. These antennas with small length to width ratios (< 2/1), can be the preferred choice, in the tagging of small size consumer end products, over the ubiquitous meandered dipole antenna (length/width > 5/1), which is often the antenna of choice, due to its high gain for UHF RFID applications. The lengths and widths of all three antennas are less than 5.5 cm. Earlier reports of planar antennas for RFID applications in the UHF range have lengths …

A Genetic Algorithms Approach To Non-Coding Rna Gene Searches, Jennifer A. Smith

Electrical and Computer Engineering Faculty Publications and Presentations

A genetic algorithm is proposed as an alternative to the traditional linear programming method for scoring covariance models in non-coding RNA (ncRNA) gene searches. The standard method is guaranteed to find the best score, but it is too slow for general use. The observation that most of the search space investigated by the linear programming method does not even remotely resemble any observed sequence in real sequence data can be used to motivate the use of genetic algorithms (GAs) to quickly reject regions of the search space. A search space with many local minima makes gradient decent an unattractive alternative. …

An Adaptive Algorithm To Identify Ambiguous Prostate Capsule Boundary Lines For Three-Dimensional Reconstruction And Quantitation, Rania Yousry Hussein

Electrical & Computer Engineering Theses & Dissertations

Currently there are few parameters that are used to compare the efficiency of different methods of cancerous prostate surgical removal. An accurate assessment of the percentage and depth of extra-capsular soft tissue removed with the prostate by the various surgical techniques can help surgeons determine the appropriateness of surgical approaches. Additionally, an objective assessment can allow a particular surgeon to compare individual performance against a standard. In order to facilitate 3D reconstruction and objective analysis and thus provide more accurate quantitation results when analyzing specimens, it is essential to automatically identify the capsule line that separates the prostate gland tissue …

Soft-Started Induction Motor Modeling And Heating Issues For Different Starting Profiles Using A Flux Linkage Abc Frame Of Reference, M. G. Solveson, Behrooz Mirafzal, Nabeel Demerdash

Electrical and Computer Engineering Faculty Research and Publications

In order to mitigate the adverse effects of starting torque transients and high inrush currents in induction motors, a popular method is to use electronically controlled soft-starting voltages utilizing series-connected silicon-controlled rectifiers (SCRs). Investigation of semioptimum soft-starting voltage profiles was implemented using a flux linkage ABC frame of reference model of a soft-started three-phase induction motor. A state-space model of the soft-starter thyristor switching sequence for the motor and load was developed and implemented in a time-domain simulation to examine winding heating and shaft stress issues for different starting profiles. Simulation results of line starts and soft starts were compared …

Sub-Banded Reconstructed Phase Spaces For Speech Recognition, Kevin M Indrebo, Richard J. Povinelli, Michael T. Johnson

Electrical and Computer Engineering Faculty Research and Publications

A novel method combining filter banks and reconstructed phase spaces is proposed for the modeling and classification of speech. Reconstructed phase spaces, which are based on dynamical systems theory, have advantages over spectral-based analysis methods in that they can capture nonlinear or higher-order statistics. Recent work has shown that the natural measure of a reconstructed phase space can be used for modeling and classification of phonemes. In this work, sub-banding of speech, which has been examined for recognition of noise-corrupted speech, is studied in combination with phase space reconstruction. This sub-banding, which is motivated by empirical psychoacoustical studies, is shown …

Gaussian Mixture Models And Neural Networks For Automatic Speaker Identification, Usha Gayatri Chalkapally

Electrical & Computer Engineering Theses & Dissertations

Automatic Speaker Recognition is the process of automatically recognizing who is speaking on the basis of individual information contained in speech signals. This technique of Automatic Speaker Recognition makes it possible to use the speaker's voice to verify their identity and control access to services such as voice dialing, banking by telephone, telephone shopping, database access services, information services, voice mail, security control for confidential information areas, and remote access to computers.

In this thesis, the techniques of Gaussian Mixture Models and Neural Networks for Automatic Speaker Identification are presented. Algorithms for Speaker Identification using Gaussian Mixture Models were developed, …

Learning As A Nonlinear Line Of Attraction For Pattern Association, Classification And Recognition, Ming-Jung Seow

Electrical & Computer Engineering Theses & Dissertations

Development of a mathematical model for learning a nonlinear line of attraction is presented in this dissertation, in contrast to the conventional recurrent neural network model in which the memory is stored in an attractive fixed point at discrete location in state space. A nonlinear line of attraction is the encapsulation of attractive fixed points scattered in state space as an attractive nonlinear line, describing patterns with similar characteristics as a family of patterns.

It is usually of prime imperative to guarantee the convergence of the dynamics of the recurrent network for associative learning and recall. We propose to alter …

Performance Analysis Of Recoverable Flight Control Systems Subject To Neutron-Induced Upsets Using Hybrid Dynamical Models, Hong Zhang

Electrical & Computer Engineering Theses & Dissertations

It has been observed that atmospheric neutrons can produce single-event upsets in digital flight control hardware. Potentially, they can reduce system performance and introduce a safety hazard. One experimental system-level approach investigated to help mitigate the effects of these upsets is NASA Langley's Recoverable Computer System. It employs rollback error recovery using dual-lock-step processors together with new fault tolerant architectures and communication subsystems.

In this dissertation, a class of stochastic hybrid dynamical models, which consists of a jump-linear system and a stochastic finite-state automaton, is used to describe the performance of a Boeing 737 aircraft system in closed-loop with a …

Decentralized Cooperative Aerial Surveillance Using Fixed-Wing Miniature Uavs, Randal Beard, Derek Kingston, Timothy W. Mclain, Derek Nelson

Faculty Publications

Numerous applications require aerial surveillance. Civilian applications include monitoring forest fires, oil fields and pipelines, and tracking wildlife. Applications to homeland security include border patrol and monitoring the perimeter of nuclear power plants. Military applications are numerous. The current approach to these applications is to use a single manned vehicle for surveillance. However, manned vehicles are typically large and expensive. In addition, hazardous environments and operator fatigue can potentially threaten the life of the pilot. Therefore, there is a critical need for automating aerial surveillance using unmanned air vehicles (UAVs). This paper gives an overview of a cooperative control strategy …

Development Of A Cost Effective Mini Autonomous Underwater Vehicle, Chiu-Feng Lin, Chyuan-Yow Tseng

Journal of Marine Science and Technology–Taiwan

This paper describes the development of a cost effective mini autonomous underwater vehicle. The mini size of the vehicle is achieved by extracting the control module hardware out from the vehicle vessel and by reducing the on-board sensors. The control of the vehicle is conducted by a base station wirelessly telecommunicating with the vehicle. Furthermore, the reduction of the sensors also reduces the cost of the vehicle. For the purpose, in the vehicle, a single sensor featuring a CCD camera is mounted at the front of the vehicle. The images taken by this CCD camera are used both for obstacle …

Managing Bandwidth And Traffic Via Bundling And Filtration In Large-Scale Distributed Simulations, Roberto C. Sánchez

Theses and Dissertations

Research has shown that bandwidth can be a limiting factor in the performance of distributed simulations. The Air Force's Distributed Mission Operations Center (DMOC) periodically hosts one of the largest distributed simulation events in the world. The engineers at the DMOC have dealt with the difficult problem of limited bandwidth by implementing application level filters that process all DIS PDUs between the various networks connected to the exercise. This thesis examines their implemented filter and proposes: adaptive range-based filtering and bundling together of PDUs. The goals are to reduce the number of PDUs passed by the adaptive filter and to …

Gauging Voip Call Quality From 802.11 Wlan Resource Usage, Miroslaw Narbutt, Mark Davis

Conference papers

In this paper we experimentally study the relationship between resource utilization in the wireless LAN and the quality of VoIP calls transmitted over the wireless medium. Specifically we evaluate how its overall capacity is shared between three basic MAC bandwidth components (load, access and free) as the number of VoIP calls increases and how it influences transmission impairments (delay, loss and jitter) and thus call quality. Resource utilization (under the MAC bandwidth components framework) is calculated by a WLAN probe application that passively “sniffs” packets at the L2/MAC layer of the wireless medium and analyses their headers and temporal characteristics. …

Statistical Models Of Reconstructed Phase Spaces For Signal Classification, Richard J. Povinelli, Michael T. Johnson, Andrew C. Lindgren, Felice M. Roberts, Jinjin Ye

Electrical and Computer Engineering Faculty Research and Publications

This paper introduces a novel approach to the analysis and classification of time series signals using statistical models of reconstructed phase spaces. With sufficient dimension, such reconstructed phase spaces are, with probability one, guaranteed to be topologically equivalent to the state dynamics of the generating system, and, therefore, may contain information that is absent in analysis and classification methods rooted in linear assumptions. Parametric and nonparametric distributions are introduced as statistical representations over the multidimensional reconstructed phase space, with classification accomplished through methods such as Bayes maximum likelihood and artificial neural networks (ANNs). The technique is demonstrated on heart arrhythmia …

Fast Video Stabilization Algorithms, Mohammed A. Alharbi

Theses and Dissertations

A fast and robust electronic video stabilization algorithm is presented in this thesis. It is based on a two-dimensional feature-based motion estimation technique. The method tracks a small set of features and estimates the movement of the camera between consecutive frames. It is used to characterize the motions accurately including camera rotations between two imaging instants. An affine motion model is utilized to determine the parameters of translation and rotation between images. The determined affine transformation is then exploited to compensate for the abrupt temporal discontinuities of input image sequences. Also, a frequency domain approach is developed to estimate translations …

Active Fpga Security Through Decoy Circuits, Bradley D. Christiansen

Theses and Dissertations

Field Programmable Gate Arrays (FPGAs) based on Static Random Access Memory (SRAM) are vulnerable to tampering attacks such as readback and cloning attacks. Such attacks enable the reverse engineering of the design programmed into an FPGA. To counter such attacks, measures that protect the design with low performance penalties should be employed. This research proposes a method which employs the addition of active decoy circuits to protect SRAM FPGAs from reverse engineering. The effects of the protection method on security, execution time, power consumption, and FPGA resource usage are quantified. The method significantly increases the security of the design with …

Low-Cost Wavelength Measurement Based On A Macrobending Single-Mode Fiber, Qian Wang, Gerald Farrell, Thomas Freir, Ginu Rajan, Pengfei Wang

Articles

A low-cost all-fiber wavelength measurement technique is proposed and demonstrated. A macrobending standard single-mode fiber is developed as an edge filter with an optimal design and simple surface processing. A ratiometric wavelength measurement system employing the developed macrobending fiber filter demonstrates a resolution of ∼10 pm in a wavelength range from 1500 to 1560 nm with ease of assembly and calibration.

A Simple Project Paradigm For Teaching Computer Architecture, Yul Chu

Electrical and Computer Engineering Faculty Publications

This paper presents a teaching method for a possible computer architect by using a simple DCT project for an undergraduate-level computer architecture course. The goal of the project is to let students (two or three students per team) understand the concept of computer hardware and how to design a simple RISC-type 32-bit Instruction Set Architecture (ISA). The project consists of three different tasks: 1) D (Design) - Designing a processor at the abstract level; 2) C (Code) - Writing a simulation program for the ISA; and 3) T (Test) - Running a test program to verify each function of computer …

Advanced Methods In Automatic Modulation Classification For Emerging Technologies, Hong Li

Dissertations

Modulation classification (MC) is of large importance in both military and commercial communication applications. It is a challenging problem, especially in non-cooperative wireless environments, where channel fading and no prior knowledge on the incoming signal are major factors that deteriorate the reception performance. Although the average likelihood ratio test method can provide an optimal solution to the MC problem with unknown parameters, it suffers from high computational complexity and in some cases mathematical intractability. Instead, in this research, an array-based quasi-hybrid likelihood ratio test (qHLRT) algorithm is proposed, which depicts two major advantages. First, it is simple yet accurate enough …

Dynamic Bandwidth Management With Service Differentiation Over Ethernet Passive Optical Networks, Yuanqiu Luo

Dissertations

Ethernet passive optical networks (EPONs) address the first mile of the communication infrastructure between the service provider central offices and the customer sites. As a low-cost, high speed technology, EPONs are deemed as the solution to the bottleneck problem of the broadband access network.

A major feature of EPONs is the utility of a shared upstream channel among the end users. Only a single optical network unit (GNU) may transmit during a timeslot to avoid data collisions. In order to provide diverse quality of service (QoS), the bandwidth management of the upstream channel is essential for the successful implementation of …

Cross-Layer Design For Wireless Sensor Relay Networks, Lichuan Liu

Dissertations

In recent years, the idea of wireless sensor networks has gathered a great deal of attention. A distributed wireless sensor network may have hundreds of small sensor nodes. Each individual sensor contains both processing and communication elements and is designed in some degree to monitor the environmental events specified by the end user of the network. Information about the environment is gathered by sensors and delivered to a remote collector.

This research conducts an investigation with respect to the energy efficiency and the cross-layer design in wireless sensor networks. Motivated by the multipath utilization and transmit diversity capability of space-time …

Medium Access Control Design For All-Ip And Ad Hoc Wireless Network, Zaihan Jiang

Dissertations

Medium Access Control (MAC) protocol in a wireless network controls the access of wireless medium by mobile terminals, in order to achieve its fair and efficient sharing. It plays an important role in resource management and QoS support for applications. All-IP wireless WAN is fully IP protocol-based and it is a strong candidate beyond 3G (Third Generation Wireless Network). Ad hoc wireless network has recently been the topic of extensive research due to its ability to work properly without fixed infrastructure.

This dissertation is composed of two main parts. The first part pursues a Prioritized Parallel Transmission MAC (PPTM) design …

Performance Analysis Of Collaborative Hybrid-Arq Protocols Over Fading Channels, Igor Stanojev

Theses

Impairments due to multipath signal propagation on the performance of wireless communications systems can be efficiently mitigated with time, frequency or spatial diversity. To exploit spatial diversity, multiple-antenna technology has been thoroughly investigated and emerged as one of the most mature communications areas. However, the need for smaller user terminals, which results in insufficient spacing for antenna collocation, tends to limit the practical implementation of this technology. Without compromising terminal dimensions, future wireless networks will therefore have to exploit their broadcast nature and rely on collaboration between single-antenna terminals for exploiting spatial diversity.

Among cooperative schemes, Collaborative ARQ transmission protocols, …

Desulfovibrio Desulfuricans G20 Tetraheme Cytochrome Structure At 1.5 A˚ And Cytochrome Interaction With Metal Complexes, Mrunalini Pattarkine, J J. Tanner, C A. Bottoms, Y H. Lee, Judy D. Wall

Faculty Works

The structure of the type I tetraheme cytochrome c3 from Desulfovibrio desulfuricans G20 was determined to 1.5 A˚ by X-ray crystallography. In addition to the oxidized form, the structure of the molybdate-bound form of the protein was determined from oxidized crystals soaked in sodium molybdate. Only small structural shifts were obtained with metal binding, consistent with the remarkable structural stability of this protein. In vitro experiments with pure cytochrome showed that molybdate could oxidize the reduced cytochrome, although not as rapidly as U(VI) present as uranyl acetate. Alterations in the overall conformation and thermostability of the metal-oxidized protein were investigated …

Intelligent Routing Protocol For Ad Hoc Wireless Network, Chaorong Peng, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

A novel routing scheme for mobile ad hoc networks (MANETs), which combines hybrid and multi-inter-routing path properties with a distributed topology discovery route mechanism using control agents is proposed in this paper. In recent years, a variety of hybrid routing protocols for Mobile Ad hoc wireless networks (MANETs) have been developed. Which is proactively maintains routing information for a local neighborhood, while reactively acquiring routes to destinations beyond the global. The hybrid protocol reduces routing discovery latency and the end-to-end delay by providing high connectivity without requiring much of the scarce network capacity. On the other side the hybrid routing …

An Adaptive Distributed Data Aggregation Based On Rcpc For Wireless Sensor Networks, Guogang Hua, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

One of the most important design issues in wireless sensor networks is energy efficiency. Data aggregation has significant impact on the energy efficiency of the wireless sensor networks. With massive deployment of sensor nodes and limited energy supply, data aggregation has been considered as an essential paradigm for data collection in sensor networks. Recently, distributed source coding has been demonstrated to possess several advantages in data aggregation for wireless sensor networks. Distributed source coding is able to encode sensor data with lower bit rate without direct communication among sensor nodes. To ensure reliable and high throughput transmission with the aggregated …

Robust Image Transmission Over Mimo Space-Time Coded Wireless Systems, Daewon Song, Chang Wen Chen

Electrical Engineering and Computer Science Faculty Publications

We present in this paper an integrated robust image transmission scheme using space-time block codes (STBC) over multi-input multi-output (MIMO) wireless systems. First, in order to achieve an excellent error resilient capability, multiple bitstreams are generated based on wavelet trees along the spatial orientations. The spatial-orientation trees in the wavelet domain are individually encoded using SPIHT. Error propagation is thus limited within each bitstreams. Then, Reed-Solomon (R-S) codes as forward error correction (FEC) are adopted to combat transmission errors over error-prone wireless channels and to detect residual errors so as to avoid error propagation in each bitstream. FEC can reduce …

Unconventional Optical Imaging Using A High Speed, Neural Network Based Smart Sensor, William W. Arrasmith

Electrical Engineering and Computer Science Faculty Publications

The advancement of neural network methods and technologies is finding applications in many fields and disciplines of interest to the defense, intelligence, and homeland security communities. Rapidly reconfigurable sensors for real or near-real time signal or image processing can be used for multi-functional purposes such as image compression, target tracking, image fusion, edge detection, thresholding, pattern recognition, and atmospheric turbulence compensation to name a few. A neural network based smart sensor is described that can accomplish these tasks individually or in combination, in real-time or near real-time. As a computationally intensive example, the case of optical imaging through volume turbulence …

A New Eccentric Geomagnetic Dipole To Give The Correct Dip Pole Locations, Annraoi De Paor, Ted Burke

Articles

In this paper, we describe a new eccentric dipole model of the Earth’s magnetic field. The constraints under which the conventional eccentric dipole model is defined result in predicted dip pole locations that differ significantly from the measured locations. Here, we give a preliminary exposition of a new dipole model which, because it is constrained by the observed dip pole locations, overcomes this problem.

Design And Fabrication Of Optically-Pumped Guided-Mode Resonance Surface-Emitting Lasers, Preston Phillip Young

Electrical Engineering Dissertations - Archive

This dissertation describes the design and fabrication of guided-mode resonance (GMR) structures and their applications to laser devices. These include tunable Ti:Sapphire lasers as well as semiconductor lasers with integrated light emitting layers. The resonance characteristics of GMR structures are determined by the designed and fabricated waveguide-grating parameters. The primary tool for the design and simulation analysis of GMR devices is rigorous coupled-wave analysis (RCWA). This numerical method is used to provide diffraction efficiency calculations as well as simulations of the electric fields within GMR structures. RCWA-based field analysis is used to design an optically pumped GMR surface-emitting laser (GMR-SEL) …