Engineering Commons^™

Sub-Circuit Selection And Replacement Algorithms Modeled As Term Rewriting Systems, Eric D. Simonaire

Theses and Dissertations

Intent protection is a model of software obfuscation which, among other criteria, prevents an adversary from understanding the program’s function for use with contextual information. Relating this framework for obfuscation to malware detection, if a malware detector can perfectly normalize a program P and any obfuscation (variant) of the program O(P), the program is not intent protected. The problem of intent protection on programs can also be modeled as intent protection on combinational logic circuits. If a malware detector can perfectly normalize a circuit C and any obfuscation (variant) O(C) of the circuit, the circuit is not intent protected. In …

Limitations Of A True Random Number Generator In A Field Programmable Gate Array, Jennifer L. Brady

Theses and Dissertations

Random number generators are used in many areas of engineering, computer science, most notably in simulations and cryptographic applications. There are true random number generators (TRNG) and pseudo random number generators (PRNG). Only a true random number generator is secure because the output bits are non-repeating and nonreproducible. As society has become more dependent on electronic technology the need for true random number generators has increased due to processes that require encryption in everyday use. A fast true random number generator on a field programmable gate array presents digital designers with the ability to have the generator on chip. Since …

Experiments In Distributed Multi-Robot Coordination, Larry Dale Ballard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Consensus control algorithms for multi-agent systems are an area of much research. Several consensus control laws are experimentally validated on a multi-robot testbed in this thesis. A graphical user interface (GUI) is developed that simplies use of the testbed, as well as allows the execution of the testbed programs to be divided across multiple computers. This not only provides a more powerful computing environment, but a more realistic communication environment for the testbed. A method for a time varying or dynamic formation is both proposed and experimentally validated on the testbed. This research also explores a method for dynamic group …

Design Of Tunable Edge-Coupled Microstrip Bandpass Filters, Srinidhi V. Kaveri

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis is a study of tunability of edge-coupled filters. Microstrip edge-coupled bandpass filters are planar structures and have advantages such as easy design procedures and simple integration into circuits.

Three tuning techniques were implemented. The first technique involved the loading of one open end of each coupled into tunable capacitors. The second technique used a tunable resonator in series with the edge-coupled blocks. The final design made use of tunable feedback sections.

A detailed mathematical analysis of each design was performed. MATLAB code based on the analyses was written. The MATLAB simulations were compared to Agilent Advanced Design System …

A C To Register Transfer Level Algorithm Using Structured Circuit Templates: A Case Study With Simulated Annealing, Jonathan D. Phillips

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A tool flow is presented for deriving simulated annealing accelerator circuits on a field programmable gate array (FPGA) from C source code by exploring architecture solutions that conform to a preset template through scheduling and mapping algorithms. A case study carried out on simulated annealing-based Autonomous Mission Planning and Scheduling (AMPS) software used for autonomous spacecraft systems is explained. The goal of the research is an automated method for the derivation of a hardware design that maximizes performance while minimizing the FPGA footprint. Results obtained are compared with a peer C to register transfer level (RTL) logic tool, a state-of-the-art …

Student Achievement And Affective Traits In Electrical Engineering Laboratories Using Traditional And Computer-Based Instrumentation, Matthew D. Lammi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Distance education has the ability to transcend distance and time, reaching students anywhere at any time, particularly those underrepresented in engineering. Engineering is a practice-oriented profession requiring an interweaving of scientific theory and applied hands-on activities. Despite the need for distance education in engineering, few studies have systematically investigated the impact of student achievement and attitude in distance engineering laboratories. This quasi-experimental research addressed that need by studying the cognitive and affective domains of achievement in engineering laboratories while employing computer-based and traditional oscilloscopes. The students from two courses, electrical engineering for nonmajors and electronic fundamentals, were randomly assigned into …

Analysis And Design Of Interleaving Multiphase Dc-To-Dc Converter With Input Lc Filter, Kevin Thomas Delrosso

Master's Theses

The future of microprocessors is unknown. Over the past 40 years, their historical trend has been for adopting smaller and more powerful designs that drive the world that we live in today. The state of the microprocessor business today faces a crossroad, wishing to continue on the historical trend of doubling the number of transistors on a chip every 18 months (Moore’s Law) but also facing the realistic task of needing to power these sophisticated devices. With the low voltages and high currents that are required for these microprocessors to operate, it poses a difficult task for the future designers …

Range Precision Of Ladar Systems, Steven E. Johnson

Theses and Dissertations

A key application of Laser Detection and Ranging (LADAR) systems is measurement of range to a target. Many modern LADAR systems are capable of transmitting laser pulses that are less than a few nanoseconds in duration. These short-duration pulses provide excellent range precision. However, randomness in the detected laser signals places limits on the precision. The goal of this dissertation is to quantify the range precision limits of LADAR systems. The randomness in the time between photon arrivals, which is called shot noise, is discussed in depth. System-dependent noise sources such as dark current and detector gain variation are considered. …

Investigation Into The Acupuncture And Meridian System, Jingong Pan

Dissertations

The Meridian system conceived by the ancient Chinese has been described and referenced for more than a thousand years. The Meridians meaning paths are the main trunks that run longitudinally within the body. The Meridian system consists of about 400 acupuncture nodes and 20 Meridian channels connecting most of these points. It deals with the routing and distribution of certain signals that may affect physiological functions. It integrates meridians, tissues and organs into a complex system.

Initially, modeling of the acupuncture system is investigated. The physical effect of injecting an acupuncture needle at a node is suggested by an equivalent …

A Two Dimensional Model Of Magnetic Field Assisted Assembly, Gaurev Devrani

Theses

A simplified model to simulate the magnetic field distribution for applications in magnetic field assisted assembly of semiconductor device structures, using commercial software (Vizimag), has been implemented. Solenoids have been utilized to serve as electromagnets that are responsible for the assembly process. Magnetic shielding techniques have been deployed to isolate the influence of one solenoid over another. These solenoids are used to move the devices that need to be placed in recesses within the substrate. The bottom of the devices and the recesses are coated with magnetic materials to facilitate the movement and placement of devices within the recesses in …

Statistical Methods For Polarimetric Imagery, Daniel A. Lemaster

Theses and Dissertations

Estimation theory is applied to a physical model of incoherent polarized light to address problems in polarimetric image registration, restoration, and analysis for electro-optical imaging systems. In the image registration case, the Cramer-Rao lower bound on unbiased joint estimates of the registration parameters and the underlying scene is derived, simplified using matrix methods, and used to explain the behavior of multi-channel linear polarimetric imagers. In the image restoration case, a polarimetric maximum likelihood blind deconvolution algorithm is derived and tested using laboratory and simulated imagery. Finally, a principal components analysis is derived for polarization imaging systems. This analysis expands upon …

Material Perturbations To Enhance Performance Of The Theile Half-Width Leaky Mode Antenna, Jason A. Girard

Theses and Dissertations

Microstrip traveling-wave antennas, often referred to as leaky-wave antennas, have been shown to radiate when the dominant or fundamental mode is suppressed and the first higher-order mode is excited. One such microstrip variation is the Thiele Half-Width (THW) antenna, which operates from 5.9 - 8.2 GHz for this research. Increasing the bandwidth over which the THW antenna radiates is desired, as is a fundamental understanding of the propagation characteristics over this region. This dissertation seeks to vary or perturb the material and physical properties of the THW antenna, including strip-width variations and modifications of the substrate layer, to achieve these …

Performance Analysis Of Effective Range And Orientation Of Uhf Passive Rfid, Paul N. Roque

Theses and Dissertations

The purpose of this research is to characterize the performance of UHF passive RFID tags. Factors of importance are the impact of tag orientation and distance from the RFID reader. Within this study, a comprehensive literature review of RFID technology is presented as well as the methodology used for the research. Furthermore, an analysis of RFID tag experiments is discussed and the results reviewed. To accomplish this task, two main objectives have been established as goals for the study. The first objective is to determine an optimum tag orientation within the RFID reader’s normal read range. Once the optimum tag …

Optical Properties And Carrier Transport In Si/ Si1-Xgex Nanostructures, Eun Kyu Lee

Dissertations

Defect-free epitaxial growth of Ge on a ~4 % lattice-mismatched single-crystal Si substrate is achieved using reduced dimension nanoscale heterostructures, where efficient structural relaxation might occur due to an enhanced adatom migrations and high surface-to-volume ratio. For development of novel electronic or optical devices based on these novel structures, understanding of their electrical and optical properties is crucial. This study explores the optical properties and carrier transport in two different types of Si/Si _1-xGe _xnanostructures: Ge nanowires (NWs) forming nanoscale heterojunctions with Si substrates and multilayers of SiGe clusters embedded into a Si matrix.

Micron-long Ge nanowires grown …

Vector Support For Multicore Processors With Major Emphasis On Configurable Multiprocessors, Hongyan Yang

Dissertations

It recently became increasingly difficult to build higher speed uniprocessor chips because of performance degradation and high power consumption. The quadratically increasing circuit complexity forbade the exploration of more instruction-level parallelism (JLP). To continue raising the performance, processor designers then focused on thread-level parallelism (TLP) to realize a new architecture design paradigm. Multicore processor design is the result of this trend. It has proven quite capable in performance increase and provides new opportunities in power management and system scalability. But current multicore processors do not provide powerful vector architecture support which could yield significant speedups for array operations while maintaining …

Raman Scattering In Free Standing Porous Si Films, Thenappan Chidambaram

Theses

In this thesis, Raman Scattering of free standing porous silicon on sapphire samples of controllably varying porosity is studied. The free standing, fully crystalline porous silicon films were prepared by electrochemical etching and the porous structure were lifted-off by a procedure based on electro-polishing. During Raman scattering measurements, the samples are exposed to relatively high intensity laser radiation. Free-standing porous Si sample temperature and thermal conductivity are calculated by comparing intensities of Stokes and anti-Stokes Raman peaks. Compared to crystalline Si, we find strong decrease in thermal conductivity accompanied by a change in the phonon spectra. Also, comparing Stokes and …

Synthesis And Analysis Of Carbon Nanowalls And Their Raman Spectroscopy, Amit Mahajan

Theses

Growth of Carbon Nanowalls has been carried out by Radio Frequency Chemical Vapor Deposition (RF-PECVD) on various substrates. Hydrogen was used as an active gas for the growth where as Ethanol bubbled with Argon was used as carbon source for formation of Carbon Nanowalls (CNW). The growth was then confinned by Raman Spectroscopy and Scanning Electron Microscope (SEM) images. Also the need of using catalyst in CNW has been analyzed. The intensities of D and G bands obtained from Raman spectrum have been related to the length of Graphene walls, to study the CNW's length on different substrates.

The growth …

A Timer Module For An 8051 Microcontroller, Troy England

Electrical Engineering Undergraduate Honors Theses

A timer module for an 8051 Microcontroller is designed from the ground up. It could potentially be integrated into a larger 8051 for use in lunar and Martian missions. It follows through a synchronous digital design flow from HDL code through layout verification. The timer shows functionality at 100MHz with some minor glitches.

Measurement Of Absolute Argon Excited State Populations And Electron Energy Distribution Functions In An Ar-A-Si Plasma, Katherine Herring

Electrical Engineering Undergraduate Honors Theses

Deposition systems utilizing plasma are used for a variety of tasks, including tool coatings and creating thin-film materials. In order to have repeatable results, the internal conditions of a plasma chamber need to be known. This project centered on the use of data from optical emissions and a Langmuir probe from an argon plasma amorphous silicon depositing system. An electron energy distribution function (EEDF) was obtained from manipulation of the Langmuir probe data. This EEDF was then input to an argon collisional-radiative model (CRM) to obtain the electron population of the 4p level of the argon plasma. Through an absolute …

Algorithm Development For Column Water Vapor Retrieval Using The Sun And Aureole Measurement (Sam) Sensor, Joshua Bruce Williams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To understand and model the energetics of the Sun-Earth connection, measurements of specific atmospheric molecules are beneficial. The objective is to formulate an algorithm to derive temporally varying atmospheric water vapor concentrations as functions of altitude, latitude, and longitude from solar irradiance absorption measurements. The Visidyne SAM (Sun and Aureole Measurement) instrument, which studies the size and distribution of cloud particles, was used to obtain the experimental data. By introducing a spectrometer to the SAM instrument, column water vapor is produced as part of the data product. A new model optimized algorithm is developed and tested versus existing algorithms. Through …

A Ladar-Based Pose Estimation Algorithm For Determining Relative Motion Of A Spacecraft For Autonomous Rendezvous And Dock, Ronald Christopher Fenton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Future autonomous space missions will require autonomous rendezvous and docking operations. The servicing spacecraft must be able to determine the relative 6 degree-of-freedom (6 DOF) motion between the vehicle and the target spacecraft. One method to determine the relative 6 DOF position and attitude is with 3D ladar imaging. Ladar sensor systems can capture close-proximity range images of the target spacecraft, producing 3D point cloud data sets. These sequentially collected point-cloud data sets were then registered with one another using a point correspondence-less variant of the Iterative Closest Points (ICP) algorithm to determine the relative 6 DOF displacements. Simulation experiments …

A Field Programmable Gate Array Based Finite-Domain Constraint Solver, Prasad Subramanian

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Constraint satisfaction and optimization techniques are commonly employed in scheduling, industrial manufacturing, and automation processes where concepts from Operations Research (OR) and Artificial Intelligence (AI) are applied. In embedded systems, Constraint Satisfaction Problem (CSP) finds use in design, synthesis, and optimization. However, most application areas of CSP employ offline solving techniques where design requirements and constraints are captured before the system is deployed online. There is a significant amount of pre-planning and human intervention required.

In embedded systems, online constraint solving techniques are primarily used as onboard control software in order to enable a system that can dynamically adapt to …

Algorithm Development Of The Aglite-Lidar Instrument, Christian Marchant

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Particulate emissions from agricultural operations are increasingly receiving attention from regulatory bodies as a potential source of air pollution. The Space Dynamics Laboratory (SDL) has developed the Aglite system, a suite of instruments including a lidar that is capable of measuring particulate emission levels from agricultural facilities. This system provides a novel method of measuring particulate mass (PM) pollution, allowing measurements to be taken of diverse types of facilities with high temporal and spatial resolution. This high resolution allows for the measurement of emission levels generated by specific activities, fostering the development and determination of best management practices.

The Aglite …

A Review Of Variable Valve Timing Devices, Paul Shelton

Mechanical Engineering Undergraduate Honors Theses

Variable valve timing (VVT) has evolved from simple, manual controlled engine management to automatic, electronic works of engineering. Starting from the need for more power and extending into fuel efficiency and low emissions, VVT has evolved from the constant changing of needs. This paper summarizes various devices used to control the timing of valves from the early 1920s up until 2007.

Applying Frequency-Domain Equalization To Code-Division Multiple Access And Transform-Domain Communications Systems, Alfred A. Tamayo Iii

Theses and Dissertations

This research examined the theory and application of using orthogonal frequency division multiplexing (OFDM), or discrete multi-tone (DMT), frequency domain equalization (FEQ) with two communications systems that inherently possess unused carrier frequencies, or null-tones, in their respective transmission frequencies. The fundamental DMT-FEQ property relies on null-tones to equalize a non-ideal channel and mitigate the effects of interchannel interference (ICI), intersymbol interference (ISI), and noise. The two communications systems investigated were a Hadamard encoded code division multiple access (CDMA) communications system with up to 32 synchronous users and a transform domain communications system (TDCS) with only one user. Both communications systems …

Increasing Combat Aircraft Survivability Through Coherent Self-Protection Jammers, Soner Ozer

Theses and Dissertations

When the battlefields were within the visual range, the objective of deception tactics in warfare was to deceive the human senses. In the battlefield of electromagnetic spectrum, the objective of deception is to deceive the sensors of the enemy weapon systems. The survivability of the aircraft operating in hostile environment is of prime importance to the mission planner. If the aircraft can deny its location information to the tracking radar of the radar guided threat missile system, this, in return, may increase its survivability. The deception, a tactic which stems from the wisdom of ancient battles, incarnated in the form …

Anti-Tamper Method For Field Programmable Gate Arrays Through Dynamic Reconfiguration And Decoy Circuits, Samuel J. Stone

Theses and Dissertations

As Field Programmable Gate Arrays (FPGAs) become more widely used, security concerns have been raised regarding FPGA use for cryptographic, sensitive, or proprietary data. Storing or implementing proprietary code and designs on FPGAs could result in the compromise of sensitive information if the FPGA device was physically relinquished or remotely accessible to adversaries seeking to obtain the information. Although multiple defensive measures have been implemented (and overcome), the possibility exists to create a secure design through the implementation of polymorphic Dynamically Reconfigurable FPGA (DRFPGA) circuits. Using polymorphic DRFPGAs removes the static attributes from their design; thus, substantially increasing the difficulty …

Improvement Of Ecm Techniques Through Implementation Of A Genetic Algorithm, James D. Townsend

Theses and Dissertations

This research effective effort develops the necessary interfaces between the radar signal processing components and an optimization routine, such as genetic algorithms, to develop Electronic Countermeasure (ECM) waveforms under a Hardware-in-the-Loop (HILS) architecture. The various ECM waveforms are stored in an ECM library, where an operator selects the desired function to use against a particular system. This optimization works with modular components, compared to previous research that embedded a genetic algorithm into the Range Gate Pull-off (RGPO) waveform optimization loop, which can be interchanged based upon the operator's desired hardware/ software testing setup. The ECM library's first entries contain the …

Digital Fingerprinting Of Field Programmable Gate Arrays, James W. Crouch

Theses and Dissertations

Commercial off-the-shelf (COTS) component usage is becoming more prevalent in military applications due to current Department of Defense (DoD) policies. The easy accessibility of COTS will give reverse engineers a higher probability of successfully tampering, coping, or reverse engineering circuits that contain critical capabilities. To prevent this and verify the trustworthiness of hardware, circuit identification tags or serials numbers can be used. However, these values can be easily obtained and forged. To protect critical DoD technologies from possible exploitation, there is an urgent need for a reliable method to confirm a circuit’s identity using a set of unique unforgettable metrics. …

Design And Optimization Of Broadband High Impedance Ground Planes (Higp) For Surface Mount Antennas, Murat Dogrul

Theses and Dissertations

Gain and bandwidth metrics of broad-band low-profile antennas severely deteriorate when they are placed conformally onto the conductive skins of air, sea, and ground platforms. This detrimental effect is primarily due to out-of-phase reflections from the conductive body interfering with the antenna’s self radiation. Furthermore, lateral waves launched by the antenna couple into the thin substrate placed between the antenna and the platform, giving rise to surface waves resulting in significant diffraction from the edges of the substrate. To remedy these two major mechanisms degrading antenna performance, high impedance ground planes (HIGP) were designed. HIGPs made of a 2-dimensional periodic …