Computer Engineering Commons^™

Characterization Of Metal-Insulator-Transition (Mit) Phase Change Materials (Pcm) For Reconfigurable Components, Circuits, And Systems, Brent L. Danner

Theses and Dissertations

Many microelectromechanical systems (MEMS) use metal contact micro-switches as part of their reconfigurable device design. These devices utilize a mechanical component that can wear down and fail over time. Metal insulator transition (MIT) materials, also known as phase change materials (PCMs), exhibit a reversible transition that can be used to replace the mechanical component in reconfigurable devices. In the presence of a thermal or electric field stimuli, the PCMs will transition back and forth between a crystalline and amorphous state. During this transformation, the resistivity, reflectivity, and Young's modulus of the material drastically change. This research effort focuses on characterizing …

Learning Enterprise Malware Triage From Automatic Dynamic Analysis, Jonathan S. Bristow

Theses and Dissertations

Adversaries employ malware against victims of cyber espionage with the intent of gaining unauthorized access to information. To that end, malware authors intentionally attempt to evade defensive countermeasures based on static methods. This thesis analyzes a dynamic analysis methodology for malware triage that applies at the enterprise scale. This study captures behavior reports from 64,987 samples of malware randomly selected from a large collection and 25,591 clean executable files from operating system install media. Function call information in sequences of behavior generate feature vectors from behavior reports from the les. The results of 64 experiment combinations indicate that using more …

Emulation Of Industrial Control Field Device Protocols, Robert M. Jaromin

Theses and Dissertations

It has been shown that thousands of industrial control devices are exposed to the Internet, however, the extent and nature of attacks on such devices remains unknown. The first step to understanding security problems that face modern supervisory control and data acquisition (SCADA) and industrial controls networks is to understand the various attacks launched on Internet-connected field devices. This thesis describes the design and implementation of an industrial control emulator on a Gumstix single-board computer as a solution. This emulator acts as a decoy field device, or honeypot, intended to be probed and attacked via an Internet connection. Evaluation techniques …

Design And Analysis Of A Small Form Factor Desktop Computer Enclosure, Curt Adkins

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science and Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Masters of Science Engineering Technology by Curt Adkins on March 13, 2013.

Distributed Fiber-Optic Laser-Ultrasound Generation Based On Ghost-Mode Of Tilted Fiber Bragg Gratings, Jiajun Tian, Qi Zhang, Ming Han

Department of Electrical and Computer Engineering: Faculty Publications

Active ultrasonic testing is widely used for medical diagnosis, material characterization and structural health monitoring. Ultrasonic transducer is a key component in active ultrasonic testing. Due to their many advantages such as small size, light weight, and immunity to electromagnetic interference, fiber-optic ultrasonic transducers are particularly attractive for permanent, embedded applications in active ultrasonic testing for structural health monitoring. However, current fiberoptic transducers only allow effective ultrasound generation at a single location of the fiber end. Here we demonstrate a fiber-optic device that can effectively generate ultrasound at multiple, selected locations along a fiber in a controllable manner based on …

Microfluidic Refractive Index Sensor Based On An All-Silica In-Line Fabry–Perot Interferometer Fabricated With Microstructured Fibers, Jiajun Tian, Yujie Lu, Qi Zhang, Ming Han

Department of Electrical and Computer Engineering: Faculty Publications

We report a microfluidic fiber-optic refractive index (RI) sensor based on an in-line Fabry-Perot (FP) interferometer, which is formed by a silica tube sandwiched by two microstructured fibers (MFs). The sensor reported here can be fabricated at low cost, possess a robust structure, and has microfluidic capability. The micro-sized holes in the MFs naturally function as microfluidic channels through which liquid samples can be efficiently and conveniently delivered into and out of the FP cavity by a pressure/vacuum pump system for high-performance RI measurement. Due to the microfluidic capability enabled by the MFs, only sub microliter sample is required. We …

Segmented Nanowires Displaying Locally Controllable Properties, Eli Anguelova Sutter, Peter Werner Sutter

Department of Electrical and Computer Engineering: Faculty Publications

Vapor-liquid-solid growth of nanowires is tailored to achieve complex one-dimensional material geometries using phase diagrams determined for nanoscale materials. Segmented one-dimensional nanowires having constant composition dis play locally variable electronic band structures that are deter mined by the diameter of the nanowires. The unique electrical and optical properties of the segmented nanowires are exploited to form electronic and optoelectronic devices. Using gold-germanium as a model system, in situ transmis sion electron microscopy establishes, for nanometer-sized Au Ge alloy drops at the tips of Ge nanowires (NWs), the parts of the phase diagram that determine their temperature dependent equilibrium composition. The …

Caddy: A 2005 Roborodentia Entry With Vision And Path Planning Abilities, Taylor Braun-Jones

Computer Engineering

Roborodentia is an autonomous robotics competition held each year during Cal Poly’s Open House. For the 2005 competition, robot entries needed to navigate a maze searching for three randomly placed golf balls, collect them, and then deposit the balls in the “nest” at the end of the maze. A newly added aspect for the 2005 competition included two bonus balls that were placed on a platform behind the wall in two predetermined corners of the maze.

Caddy is a robot that was entered into the 2005 Roborodentia competition. Caddy included a vision system that allowed searching for balls down untraveled …

Discrimination Of Individual Tigers (Panthera Tigris) From Long Distance Roars, An Ji, Michael T. Johnson, Edward J. Walsh, Joann Mcgee, Douglas L. Armstrong

Electrical and Computer Engineering Faculty Research and Publications

This paper investigates the extent of tiger (Panthera tigris) vocal individuality through both qualitative and quantitative approaches using long distance roars from six individual tigers at Omaha's Henry Doorly Zoo in Omaha, NE. The framework for comparison across individuals includes statistical and discriminant function analysis across whole vocalization measures and statistical pattern classification using a hidden Markov model (HMM) with frame-based spectral features comprised of Greenwood frequency cepstral coefficients. Individual discrimination accuracy is evaluated as a function of spectral model complexity, represented by the number of mixtures in the underlying Gaussian mixture model (GMM), and temporal model complexity, …

A Quantitative Analysis Of Memory Controller Page Policies, Matthew Blackmore

Dissertations and Theses

Two common goals in computing system design are increasing performance and decreasing power consumption. DRAM-based memory subsystems are a major component of both system performance and power consumption. Memory controllers employ strategies to efficiently schedule DRAM operations to reduce latency and to utilize DRAM low power modes when possible. One of the most important of these is the page policy, which determines when to close pages in DRAM. An effective DRAM memory controller page policy is important to minimizing power consumption and increasing system performance. This thesis explores the impact memory controller page policy has on performance as measured by …

Multi-Gain-Stage Ingaas Avalanche Photodiode With Enhanced Gain And Reduced Excess Noise, George M. Williams, Madison Compton, David A. Ramirez, Majeed M. Hayat, Andrew S. Huntington

Electrical and Computer Engineering Faculty Research and Publications

We report the design, fabrication, and test of an InGaAs avalanche photodiode (APD) for 950-1650 nm wavelength sensing applications. The APD is grown by molecular beam epitaxy on InP substrates from lattice-matched InGaAs and InAlAs alloys. Avalanche multiplication inside the APD occurs in a series of asymmetric gain stages whose layer ordering acts to enhance the rate of electron-initiated impact ionization and to suppress the rate of hole-initiated ionization when operated at low gain. The multiplication stages are cascaded in series, interposed with carrier relaxation layers in which the electric field is low, preventing avalanche feedback between stages. These measures …

A New Look At Azimuthal Wave Propagation Constants Of An N-Layered Dielectric Coated Pec Cylinder, Jason V. Paul, Peter J. Collins, Ronald A. Coutu Jr.

Electrical and Computer Engineering Faculty Research and Publications

A method for determining the azimuthal wave propagation constants supported by an n-layered dielectric coated PEC cylinder is presented. The method, based on a Green's function described in , is designed to optimally handle layered cylinders where the number of layers is extremely large as might be encountered in structures designed using transformational optics. The method is also tractable for any stratification profile without the need for individual layer analysis. We implement a recently developed numerical method to calculate Bessel functions of complex order and argument. Our method is verified by comparison with previously published results. We also present new …

Comparison Of Post-Detonation Combustion In Explosives Incorporating Aluminum Nanoparticles: Influence Of The Passivation Layer, William K. Lewis, C. G. Rumchik, M. J. Smith, K. A. Shiral Fernando, Christopher A. Crouse, Jonathan E. Spowart, Elena A. Guliants, Christopher E. Bunker

Electrical and Computer Engineering Faculty Publications

Aluminum nanoparticles and explosive formulations that incorporate them have been a subject of ongoing interest due to the potential of aluminum particles to dramatically increase energy content relative to conventional organic explosives. We have used time-resolved atomic and molecular emission spectroscopy to monitor the combustion of aluminum nanoparticles within the overall chemical dynamicsof post-detonation fireballs. We have studied the energy release dynamics of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) charges incorporating three types of aluminum nanoparticles: commercial oxide-passivated nanoparticles, oleic acid-capped aluminum nanoparticles (AlOA), and nanoparticles in which the oxide shell of the particle has been functionalized with an acrylic monomer and copolymerized into …

Xing-Zone Bridge Construction For Multi-Hop Cognitive Radio Networks With Channel Bonding, Feng Ye, Yi Qian, Yaoqing Lamar Yang, Hamid Sharif

Department of Electrical and Computer Engineering: Faculty Publications

Cognitive radio is an efficient technique to relieve the tense of wireless spectrum scarcity by allowing unlicensed secondary users (SUs) to access the licensed band opportunistically without causing interference to primary users (PUs). Although Federal Communications Commission (FCC) recently ruled that the data of PU activity schedule is accessible to SUs 24 hours ahead, which relieves SUs from heavy sensing or interruption by sudden PU activity, however, multi-hop wireless cognitive radio networks (MWCRN) suffers a unique problem caused by the fact that the spectrum resources are not unified in different areas affected by different PUs. In other words, an SU …

A Hierarchical Power Management Strategy For Multiple Single-Phase Roadway Microgrids, Yanping Jiao, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a centralized hierarchical power management strategy for multiple single-phase wind/solar generation-based roadway microgrids integrated into a threephase utility distribution grid. The proposed power management strategy consists of a Central Power Management Controller (CPMC) operating at the distribution grid level to regulate the power flow between the distribution grid and the microgrids, a Supervisory Power Management Controller (SPMC) operating at the microgrid level for voltage and frequency control of each microgrid under the coordination of the CPMC, and a Local Power Management Controller operating at the unit level for power management of each individual unit under the coordination …

Sizing Router Buffer For The Internet With Heterogeneous Tcp, Peng Yang, Ertong Zhang, Lisong Xu

Department of Electrical and Computer Engineering: Faculty Publications

The router buffer sizing problem is a vital problem to the performance of the Internet. The traditional rule-of-thumb is that the router buffer size should be equal to the bandwidthdelay product (BDP) of a link. Recent studies show that the router buffer size can be significantly smaller than the BDP without causing negative impact on the TCP performance in the Internet. But a fundamental assumption of all those studies is that all the TCP traffic in the Internet is generated by the traditional RENO protocol, which, however, is no longer true as the current Internet is dominated by multiple different …

Stability And Dynamic Performance Improvement Of A Sensorless Ipmsm Drive Via Adaptive Estimated-Speed- Assisted Position Prediction And Current Quality Evaluation, Yue Zhao, Wei Qiao, Long Wu

Department of Electrical and Computer Engineering: Faculty Publications

This paper studies stability issues of sensorless torque control of high power interior permanent magnet synchronous machines (IPMSMs) under large load transients, e.g., complete torque reversals with the highest slew rate allowed. To perform a sensorless vector control, a current model-based sliding-mode observer is utilized to estimate the rotor position. The correlation between current regulation quality and position estimation accuracy is theoretically studied and experimentally verified. Based on the correlation, the accuracy of position estimation can be evaluated online indirectly. Moreover, an adaptive estimated-speed-assisted position prediction (ESAPP) scheme is proposed to improve the stability and performance of the sensorless control …

On Physical Layer Security For Cognitive Radio Networks, Zhihui Shu, Yi Qian, Song Ci

Department of Electrical and Computer Engineering: Faculty Publications

In this article we explore the security issues on physical layer for cognitive radio networks. First we give an overview on several existing security attacks to the physical layer in cognitive radio networks. We then discuss the related countermeasures on how to defend against these attacks. We further investigate one of the most important physical layer security parameters, the secrecy capacity of a cognitive radio network, and study the outage probability of secrecy capacity of a primary user from a theoretical point of view. Furthermore, we present performance results for secrecy capacity and outage probability between a node and its …

Wind Turbine Fault Detection And Isolation Using Support Vector Machine And A Residual-Based Method, Jianwu Zeng, Dingguo Lu, Yue Zhao, Zhe Zhang, Wei Qiao, Xiang Gong

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a novel scheme combining support vector machines (SVM) and a residual-based method for wind turbine fault detection and isolation (FDI). SVMs with radius basis function kernels are used for detecting and identifying sensor stuck and offset faults, where binary codes of fault types are used as the outputs of the SVMs to minimize the number of SVMs being used. The same output of a SVM may correspond to different types of faults and the final decision is made by all SVMs instead of one SVM. Moreover, a residual-based fault detection method using a time-variant threshold is developed …

Multilayered Plasmonic Covers For Comblike Scattering Response And Optical Tagging, Francesco Monticone, Christos Argyropoulos, Andrea Alu

Department of Electrical and Computer Engineering: Faculty Publications

We discuss the potential of multilayered plasmonic particles to tailor the optical scattering response. The interplay of plasmons localized in thin stacked shells realizes peculiar degenerate cloaking and resonant states occurring at arbitrarily close frequencies. These concepts are applied to realize ultrasharp comblike scattering responses and synthesize staggered, ideally strong superscattering states closely coupled to invisible states. We demonstrate robustness to material losses and to variations in the background medium, properties that make these structures ideal for optical tagging.

Broadband Absorbers And Selective Emitters Based On Plasmonic Brewster Metasurfaces, Christos Argyropoulos, Khai Q. Le, Nadia Mattiucci, Giuseppe D'Aguanno, Andrea Alu

Department of Electrical and Computer Engineering: Faculty Publications

We discuss the possibility of realizing utlrabroadband omnidirectional absorbers and angularly selective coherent thermal emitters based on properly patterned plasmonic metastructures. Instead of relying on resonant concentration effects that inherently limit the bandwidth, we base our design on the combination of two inherently nonresonant effects: plasmonic Brewster funneling and adiabatic plasmonic focusing. Using this approach, we propose compact, broadband absorption and emission spanning terahertz, infrared, and optical frequencies, ideal for various energy and defense applications.

Plasmonic Nanoparticles And Metasurfaces To Realize Fano Spectra At Ultraviolet Wavelengths, Christos Argyropoulos, Francesco Monticone, Giuseppe D'Aguanno, Andrea Alu

Department of Electrical and Computer Engineering: Faculty Publications

We discuss the possibility to realize sharp Fano scattering signatures in the ultraviolet (UV) range, based on dipolar scattering of nanoparticles. At these frequencies, material losses usually do not allow sharp resonant effects, hindering plasmonic applications based on higher-order multipolar modes, like conventional Fano resonances. We propose to excite degenerate scattering states supported by core-shell nanoparticles made of a sapphire core and an aluminum shell. We predict enhanced, highly confined fields, supporting sharp far-field scattering signatures from single nanoparticles and planar arrays of them. These results may lead to the design of UV filters, photodetectors, sensors, and energy-harvesting devices.

Prediction Of Peptides Binding To Mhc Class I And Ii Alleles By Temporal Motif Mining, Cem Meydan, Hasan H. Otu, Osman Ugur Sezerman

Department of Electrical and Computer Engineering: Faculty Publications

Background: MHC (Major Histocompatibility Complex) is a key player in the immune response of most vertebrates. The computational prediction of whether a given antigenic peptide will bind to a specific MHC allele is important in the development of vaccines for emerging pathogens, the creation of possibilities for controlling immune response, and for the applications of immunotherapy. One of the problems that make this computational prediction difficult is the detection of the binding core region in peptides, coupled with the presence of bulges and loops causing variations in the total sequence length. Most machine learning methods require the sequences to be …

Exploring The Microsoft .Net Micro Framework For Prototyping Applied Wireless Sensor Networks, Jay D. Carlson, Mateusz Mittek, Lance C. Pérez

Department of Electrical and Computer Engineering: Faculty Publications

Most Wireless Sensor Network platforms – such as the Mica, Iris, and Telos B families of motes – use lowpower 8-bit microprocessors which have limited memory and processing capabilities, thus requiring researchers to implement communication protocols and data processing routines using lowlevel programming practices that are tedious and cumbersome. Rich features available in modern desktop operating systems – such as threads, memory management, and exception-handling – are largely absent. The Microsoft .NET Micro Framework implements a scaled-back .NET framework suitable for development on low-cost, low-power wireless sensors, while providing developers a rapid software development environment for prototyping embedded applications. Here, …

Bearing Fault Diagnosis For Direct-Drive Wind Turbines Via Current-Demodulated Signals, Xiang Gong, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

Bearing faults account for a large portion of all faults in wind turbine generators (WTGs). Current-based bearing fault diagnosis techniques have great economic benefits and are potential to be adopted by the wind energy industry. This paper models the modulation effects of bearing faults on the stator currents of a direct-drive wind turbine equipped with a permanent-magnet synchronous generator (PMSG) operating with a variable shaft rotating frequency. Based on the analysis, a method consisting of appropriate current frequency and amplitude demodulation algorithms and a 1P-invariant power spectrum density algorithm is proposed for bearing fault diagnosis of variable-speed direct-drive wind turbines …

Inactivation Of E. Coli Affected By Medium Conductivity In Pulsed Electric Field Processing, Tanya Kirilova Gachovska, Jeyamkondan Subbiah, Harshavardhan Thippareddi, David Marx, Frazer Williams

Department of Electrical and Computer Engineering: Faculty Publications

No abstract provided.

Vibration Energy Harvesting For Wireless Underground Sensor Networks, Salman Kahrobaee, Mehmet C. Vuran

Department of Electrical and Computer Engineering: Faculty Publications

Recent developments in wireless underground communication have enabled the realization of underground sensor network applications. To this end, it is desirable to provide a sustainable operation for wireless underground sensor networks (WUSNs) with extended lifetimes as maintenance is significantly costly. One promising method towards sustainable operation is to harvest energy underground based on the vibration sources in the environment. However, to the best of our knowledge, underground vibration energy harvesting has not been investigated before. In this paper, the feasibility of vibration energy harvesting for WUSNs is investigated. First, an analytical framework is developed to model the maximum harvestable power …

A Multiagent Modeling And Investigation Of Smart Homes With Power Generation, Storage, And Trading Features, Salman Kahrobaee, Rasheed A. Rajabzadeh, Leen-Kiat Soh, Sohrab Asgarpoor

Department of Electrical and Computer Engineering: Faculty Publications

Smart homes, as active participants in a smart grid, may no longer be modeled by passive load curves; because their interactive communication and bidirectional power flow within the smart grid affects demand, generation, and electricity rates. To consider such dynamic environmental properties, we use a multiagent-system-based approach in which individual homes are autonomous agents making rational decisions to buy, sell, or store electricity based on their present and expected future amount of load, generation, and storage, accounting for the benefits each decision can offer. In the proposed scheme, home agents prioritize their decisions based on the expected utilities they provide. …

Optimum Sizing Of Distributed Generation And Storage Capacity In Smart Households, Salman Kahrobaee, Sohrab Asgarpoor, Wei Qiao

Department of Electrical and Computer Engineering: Faculty Publications

In the near future, a smart grid will accommodate customers who are prepared to invest in generation-battery systems and employ energymanagement systems in order to cut down on their electricity bills. The main objective of this paper is to determine the optimum capacity of a customer’s distributed-generation system (such as a wind turbine) and battery within the framework of a smart grid. The proposed approach involves developing an electricity management system based on stochastic variables, such as wind speed, electricity rates, and load. Then, a hybrid stochastic method based on Monte Carlo simulation and particle swarm optimization is proposed to …

Real-Time Stereo Matching On Cuda Using An Iterative Refinement Method For Adaptive Support-Weight Correspondences, Jedrzej Kowalczuk, Eric T. Psota, Lance C. Pérez

Department of Electrical and Computer Engineering: Faculty Publications

High-quality real-time stereo matching has the potential to enable various computer vision applications including semi-automated robotic surgery, teleimmersion, and 3-D video surveillance. A novel real-time stereo matching method is presented that uses a two-pass approximation of adaptive supportweight aggregation, and a low-complexity iterative disparity refinement technique. Through an evaluation of computationally efficient approaches to adaptive support-weight cost aggregation, it is shown that the two-pass method produces an accurate approximation of the support weights while greatly reducing the complexity of aggregation. The refinement technique, constructed using a probabilistic framework, incorporates an additive term into matching cost minimization and facilitates iterative processing …