Electrical and Computer Engineering Commons^™

Employing A User-Centered Design Process For Cybersecurity Awareness In The Power Grid, Jean C. Scholtz, Lyndsey Franklin, Aditya Ashok, Katya Leblanc, Christopher Bonebrake, Eric Andersen, Michael Cassiadoro

Journal of Human Performance in Extreme Environments

In this paper, we discuss the process we are using in the design and implementation of a tool to improve the situation awareness of cyberattacks in the power grid. We provide details of the steps we have taken to date and describe the steps that still need to be accomplished. The focus of this work is to provide situation awareness of the power grid to staff from different, non-overlapping roles in an electrical transmission organization in order to facilitate an understanding of a possible occurrence of a cyberattack. Our approach follows a user-centered design process and includes determining the types …

Deep Gaze Velocity Analysis During Mammographic Reading For Biometric Identification Of Radiologists, Hong-Jun Yoon, Folami Alamudun, Kathy Hudson, Garnetta Morin-Ducote, Georgia Tourassi

Journal of Human Performance in Extreme Environments

Several studies have confirmed that the gaze velocity of the human eye can be utilized as a behavioral biometric or personalized biomarker. In this study, we leverage the local feature representation capacity of convolutional neural networks (CNNs) for eye gaze velocity analysis as the basis for biometric identification of radiologists performing breast cancer screening. Using gaze data collected from 10 radiologists reading 100 mammograms of various diagnoses, we compared the performance of a CNN-based classification algorithm with two deep learning classifiers, deep neural network and deep belief network, and a previously presented hidden Markov model classifier. The study showed that …

Universality Of Fast Quenches From The Conformal Perturbation Theory, Anatoly Dymarsky, Michael Smolkin

Physics and Astronomy Faculty Publications

We consider global quantum quenches, a protocol when a continuous field theoretic system in the ground state is driven by a homogeneous time-dependent external interaction. When the typical inverse time scale of the interaction is much larger than all relevant scales except for the UV-cutoff the system’s response exhibits universal scaling behavior. We provide both qualitative and quantitative explanations of this universality and argue that physics of the response during and shortly after the quench is governed by the conformal perturbation theory around the UV fixed point. We proceed to calculate the response of one and two-point correlation functions confirming …

Metastable Ar(1s5) Density Dependence On Pressure And Argon-Helium Mixture In A High Pressure Radio Frequency Dielectric Barrier Discharge, Daniel J. Emmons, David E. Weeks, Ben Eshel, Glen P. Perram

Faculty Publications

Simulations of an α-mode radio frequency dielectric barrier discharge are performed for varying mixtures of argon and helium at pressures ranging from 200 to 500 Torr using both zero and one-dimensional models. Metastable densities are analyzed as a function of argon-helium mixture and pressure to determine the optimal conditions, maximizing metastable density for use in an optically pumped rare gas laser. Argon fractions corresponding to the peak metastable densities are found to be pressure dependent, shifting from approximately 15% Ar in He at 200 Torr to 10% at 500 Torr. A decrease in metastable density is observed as pressure …

Novel Approaches For Mutual Coupling Reduction Among Vertical And Planar Monopole Elements, Ayman Abbosh Isaac

Theses and Dissertations

Modern wireless systems such as 4G LTE-A, RFID, Wi-Fi, WiMAX, and GPS utilize miniaturized antenna array elements to improve performance and reliability through diversity and increase throughput using spatial multiplexing schemes of MIMO systems. One original contribution in this thesis is to significantly reduce the complexity of traditional design approaches targeting mutual coupling reductions such as metamaterials, defected ground plane structures, soft electromagnetic surfaces using novel design alternatives. A decoupling network is proposed, which consists of a rectangular metallic ring along with two tuning strips printed on a dielectric substrate, surrounding a two-element monopole antenna array fed by a coplanar …

Accurate Location Of Evolving Faults On Transmission Lines Using Sparse Wide Area Measurements, Xiangqing Jiao, Yuan Liao

Electrical and Computer Engineering Faculty Publications

In electric power systems, not all fault conditions remain unchanged during faults. An evolving fault has one characteristic initially and changes to a different condition subsequently. Locating evolving faults is challenging due to the change in fault type shortly after the fault initiation. This paper presents a new approach for estimating the locations of evolving faults on transmission lines. By using sparse wide area voltage measurements, this method is able to accurately locate evolving faults without requiring measurements from either end of the faulted line. There is no need to detect whether a fault is an evolving fault or not. …

A Phase Change Material For Reconfigurable Circuit Applications, Dushyant Tomer, Ronald A. Coutu Jr.

Electrical and Computer Engineering Faculty Research and Publications

The large resistance contrast between amorphous and crystalline states of phase change materials (PCM) makes them a promising candidate for data-storage applications. Germanium telluride (GeTe), an early member of the PCM family, shows ~6 orders of magnitude difference in resistivity upon phase transition. In this paper, two different heating methods, direct (Joule) and indirect thermal heating, were applied to induce a phase transition in vertical and horizontal GeTe resistors. In the electrical measurements, it was observed that thermal heating produces a two orders of magnitude larger difference in GeTe resistivity that the Joule heating, irrespective of the resistor’s geometry and …

Mechanical And Electrical Characterization Of Carbon Fiber/Bucky Paper/Zinc Oxide Hybrid Composites, Suma Ayyagari, Marwan Al-Haik, Virginie Rollin

Publications

The quest for multifunctional carbon fiber reinforced composites (CFRPs) expedited the use of several nano reinforcements such as zinc oxide nanorods (ZnO) and carbon nanotubes (CNTs). Zinc oxide is a semi-conductor with good piezoelectric and pyroelectric properties. These properties could be transmitted to CFRPs when a nanophase of ZnO is embedded within CFRPs. In lieu of ZnO nanorods, Bucky paper comprising mat of CNTs could be sandwiched in-between composite laminae to construct a functionally graded composite with enhanced electrical conductivities. In this study, different configurations of hybrid composites based on carbon fibers with different combinations of ZnO nanorods and Bucky …

Silicon Compilation And Test For Dataflow Implementations In Gasp And Click, Swetha Mettala Gilla

Dissertations and Theses

Many modern computer systems are distributed over space. Well-known examples are the Internet of Things and IBM's TrueNorth for deep learning applications. At the Asynchronous Research Center (ARC) at Portland State University we build distributed hardware systems using self-timed computation and delay-insensitive communication. Where appropriate, self-timed hardware operations can reduce average and peak power, energy, latency, and electromagnetic interference. Alternatively, self-timed operations can increase throughput, tolerance to delay variations, scalability, and manufacturability.

The design of complex hardware systems requires design automation and support for test, debug, and product characterization.

This thesis focuses on design compilation and test support for dataflow …

A Fast And Robust Extrinsic Calibration For Rgb-D Camera Networks, Po-Chang Su, Ju Shen, Wanxin Xu, Sen-Ching S. Cheung, Ying Luo

Electrical and Computer Engineering Faculty Publications

From object tracking to 3D reconstruction, RGB-Depth (RGB-D) camera networks play an increasingly important role in many vision and graphics applications. Practical applications often use sparsely-placed cameras to maximize visibility, while using as few cameras as possible to minimize cost. In general, it is challenging to calibrate sparse camera networks due to the lack of shared scene features across different camera views. In this paper, we propose a novel algorithm that can accurately and rapidly calibrate the geometric relationships across an arbitrary number of RGB-D cameras on a network. Our work has a number of novel features. First, to cope …

Conductive Contact Area Estimation For Carbon Nanotube Via Interconnects Using Secondary-Electron Imaging, Yusuke Abe, Makoto Suzuki, Anshul Vyas, Cary Y. Yang

Electrical and Computer Engineering

A major challenge for carbon nanotube (CNT) to become a viable replacement of copper and tungsten in the next-generation on-chip via interconnects is the high contact resistance between CNT and metal electrodes. A first step in meeting this challenge is an accurate characterization of via contact resistance. In this paper, the scanning electron microscope (SEM) image contrast at low landing energy is employed to estimate the conductive CNT area inside vias. The total conductive CNT area inside each via is deduced using SEM image with 0.1 keV landing energy and a specified threshold brightness, yielding via resistance versus CNT area …

Communication Based Control For Dc Microgrids, Mahmoud S. Saleh, Yusef Esa, Ahmed Mohamed

Publications and Research

Centralized communication-based control is one of the main methods that can be implemented to achieve autonomous advanced energy management capabilities in DC microgrids. However, its major limitation is the fact that communication bandwidth and computation resources are limited in practical applications. This can be often improved by avoiding redundant communications and complex computations. In this paper, an autonomous communication-based hybrid state/event driven control scheme is proposed. This control scheme is hierarchical and heuristic, such that on the primary control level, it encompasses state-driven local controllers, and on the secondary control level, an event-driven MG centralized controller (MGCC) is used. This …

Effects Of Edge Inclination Angles On Whispering-Gallery Modes In Printable Wedge Microdisk Lasers, Cong Chen, Lei Wan, Hengky Chandrahalim

Faculty Publications

The ink-jet technique was developed to print the wedge polymer microdisk lasers. The characterization of these lasers was implemented using a free-space optics measurement setup. It was found that disks of larger edge inclination angles have a larger free spectral range (FSR) and a lower resonance wavelength difference between the fundamental transverse electric (TE) and transverse magnetic (TM) whispering-gallery modes (WGMs). This behavior was also confirmed with simulations based on the modified Oxborrow’s model with perfectly matched layers (PMLs), which was adopted to accurately calculate the eigenfrequencies, electric field distributions, and quality parameters of modes in the axisymmetric microdisk resonators. …

An Overview Of The Usage Of Default Passwords, Brandon Knierem, Xiaolu Zhang, Philip Levine, Frank Breitinger, Ibrahim Baggili

Electrical & Computer Engineering and Computer Science Faculty Publications

The recent Mirai botnet attack demonstrated the danger of using default passwords and showed it is still a major problem. In this study we investigated several common applications and their password policies. Specifically, we analyzed if these applications: (1) have default passwords or (2) allow the user to set a weak password (i.e., they do not properly enforce a password policy). Our study shows that default passwords are still a significant problem: 61% of applications inspected initially used a default or blank password. When changing the password, 58% allowed a blank password, 35% allowed a weak password of 1 character.

Electron Effective Mass In Sn-Doped Monoclinic Single Crystal B-Gallium Oxide Determined By Mid-Infrared Optical Hall Effect, Sean Knight, Alyssa Mock, Rafal Korlacki, Vanya Darakchieva, Bo Monemar, Yoshinao Kumagai, Ken Goto, Masataka Higashiwaki, Mathias Schubert

Department of Electrical and Computer Engineering: Faculty Publications

The isotropic average conduction band minimum electron effective mass in Sn-doped monoclinic single crystal B-Ga₂O₃ is experimentally determined by the mid-infrared optical Hall effect to be (0.28460.013)m₀ combining investigations on (010) and (_201) surface cuts. This result falls within the broad range of values predicted by theoretical calculations for undoped B-Ga₂O₃. The result is also comparable to recent density functional calculations using the Gaussian-attenuation- Perdew-Burke-Ernzerhof hybrid density functional, which predict an average effective mass of 0.267m₀. Within our uncertainty limits, we detect no anisotropy for the electron effective mass, which …

A Survey Of Digital Systems Curriculum And Pedagogy In Electrical And Computer Engineering Programs, Hector A. Ochoa, Mukul V. Shirvaikar

Faculty Publications

Digital Systems is one of the basic foundational courses in Electrical and Computer Engineering. One of the challenges in designing and modifying the curriculum for the course is the fast pace of technology change in the area. TTL chips that were in vogue with students building physical circuits, have given way to new paradigms like FPGA based synthesis with hardware description languages such as VHDL. However, updating a course is not as simple as just changing the book, and changing the syllabus. A large amount of work needs to be done in terms of selecting the book that will accommodate …

Evolutionary Optimization For Safe Navigation Of An Autonomous Robot In Cluttered Dynamic Unknown Environments, Arash Roshanineshat

ETD Archive

We present a path planning approach based on probabilistic methods for a robot to navigate in a cluttered, dynamic, unknown environment. There are dynamic obstacles moving around and static obstacles located in the map. The robot does not have any prior information about them but should be able to navigate through the map beginning from a known starting point and safely ending at a known target point. The only information the robot has is the location of the starting point and the target point and it uses sensory information to collect information about its surroundings. Our method is compared to …

An Yb3+-Ho3+ Codoped Glass Microsphere Laser In The 2.0Μm Wavelength Regions, Angzhen Li, Jibo Yu, Meng Zhang, Xiaosong Lu, Jiquan Zhang, Elfed Lewis, Gerald Farrell, Pengfei Wang

Articles

In this letter, an Yb 3+ -Ho 3+ codoped sol-gel silica microsphere lasing at around 2.0 μm is reported. The gain microsphere is fabricated by overlaying the 1.0 mol% Yb 3+ -0.2 mol% Ho 3+ codoped sol-gel solution on the surface of a pure silica microsphere and is then heated using a CO 2 laser. Using a traditional fiber taper-microsphere coupling method, we observe the single- and multi-mode microsphere laser outputs around 2.0 μm using a 980 nm laser diode as a pump source, with a low threshold pumping power of 14.7 mW. The ability to fabricate sol-gel codoped silica …

A High-Temperature Humidity Sensor Based On A Singlemode-Side Polished Multimode-Singlemode Fiber Structure, Xianfan Wang, Ke Tian, Libo Yuan, Elfed Lewis, Gerald Farrell, Pengfei Wang

Articles

A relative humidity (RH) sensor based on a simple singlemode-side polished multimode-singlemode (SSPMS) fiber hybrid structure is investigated, which is capable of working over a relatively high-temperature range, at which many RH sensors based on moisture sensitive material coatings cannot operate. The beam propagation method is used to analyze the light transmission characteristics within the side polished multimode fiber (SPMMF) structure. Experimental results show that the SPMMF surface roughness has a significant influence on the sensor's humidity sensing performance, as a result of the adsorption and desorption of water molecules along the side polished surface. A higher surface roughness results …

Validation Of Low-Cost Wireless Eeg System For Measuring Event-Related Potentials, Yongxiang Wang, Zhengwei Wang, William Clifford, Charles Markham, Tomas Ward, Catherine Deegan

Conference Papers

This study used the traditional P300 speller paradigm to compare a medical grade Electroencephalography (EEG) system, the G.Tec, with a consumer grade EEG system, the Emotiv, in the detection of P300 components within Event Related Potential (ERP) signals. The experiment focused on four electrodes known to produce optically induced visual evoked potential. A successful comparison of the two approaches was made. It was shown that both systems could measure an ERP. The paper concludes with discussion comparing the low-cost wireless EEG system with the medical grade EEG system.

Carbon Nanotube Ultracapacitor Characteristics And Cell Design, Antonis A. Orphanou

Engineering Ph.D. Theses

A model of carbon nanotube (CNT) ultracapacitor (CNU) as a high-performance energy storage device is developed based on simulations of electrolyte ion motions between cathode and anode. Using a molecular dynamics (MD) approach, the equilibrium positions of electrode charges interacting through Coulomb potential are determined, which in turn yield the equipotential surface and electric field associated with the capacitor. With an applied AC voltage, the current is computed from the nanotube and electrolyte particle distribution and interaction, resulting in a frequency-dependent CNU impedance. From the current and impedance profiles, the Nyquist and Cyclic Voltammetry plots are then extracted. Results of …

Approaches To Denoise The Diffuse Optical Signals For Tissue Blood Flow Measurement, Peng Zhang, Zhiguo Gui, Yu Shang

Faculty & Staff Scholarship

Various diseases are relevant to the abnormal blood flow in tissue. Diffuse correlation spectroscopy (DCS) is an emerging technology to extract the blood flow index (BFI) from light electric field temporal autocorrelation data. To account for tissue heterogeneity and irregular geometry, we developed an innovative DCS algorithm (i.e., the Nth order linear algorithm, or simply the NL algorithm) previously, in which the DCS signals are fully utilized through iterative linear regressions. Under the framework of NL algorithm, the BFI to be extracted is significantly influenced by the linear regression approach adopted. In this study, three approaches were proposed and evaluated …

Ssaw: A New Sequence Similarity Analysis Method Based On The Stationary Discrete Wavelet Transform, Jie Lin, Donald Adjeroh, Bing-Hua Jiang, Yue Jiang

Faculty & Staff Scholarship

Background: Alignment-free sequence similarity analysis methods often lead to significant savings in computational time over alignment-based counterparts.

Results: Anewalignment-freesequencesimilarityanalysismethod,calledSSAWisproposed.SSAWstandsfor Sequence Similarity Analysis using the Stationary Discrete Wavelet Transform (SDWT). It extracts k-mers from a sequence, then maps each k-mer to a complex number field. Then, the series of complex numbers formed are transformed into feature vectors using the stationary discrete wavelet transform. After these steps, the original sequence is turned into a feature vector with numeric values, which can then be used for clustering and/or classification.

Conclusions: Usingtwodifferenttypesofapplications,namely,clusteringandclassification,wecomparedSSAW against the the-state-of-the-art alignment free sequence analysis methods. SSAW demonstrates competitive or …

Ez-Ag: Structure-Free Data Aggregation In Manets Using Push-Assisted Self-Repelling Random Walks, V Kulathumani, M Nakagawa, A Arona

Faculty & Staff Scholarship

This paper describes EZ-AG, a structure-free protocol for duplicate insensitive data aggregation in MANETs. The key idea in EZ-AG is to introduce a token that performs a self-repelling random walk in the network and aggregates information from nodes when they are visited for the first time. A self-repelling random walk of a token on a graph is one in which at each step, the token moves to a neighbor that has been visited least often. While self-repelling random walks visit all nodes in the network much faster than plain random walks, they tend to slow down when most of the …

Parametric Investigation Of Combustion And Heat Transfer Characteristics Of Oscillating Linear Engine Alternator, Mehar Bade, Nigel N. Clark, Matthew C. Robinson, Parviz Famouri

Faculty & Staff Scholarship

An Oscillating Linear Engine Alternator (OLEA) has the potential to overcome the thermal, mechanical, and combustion inadequacies encountered by the conventional slider-crank engines. The linear engines convert the reciprocating piston motion into electricity, thereby eliminating needless crankshaft linkages and rotational motion. As the dead center positions are not explicitly identified unlike crankshaft engines, the linear engine exhibits different stroke and compression ratio every cycle and should manage the unfavorable events like misfire, rapid load changes, and overfueling without the energy storage of a flywheel. Further, the apparatus control and management strategy is difficult for OLEA when compared to conventional engines …

Feature-Based And String-Based Models For Predicting Rna-Protein Interaction, Donald Adjeroh, Maen Allaga, Jun Tan, Jie Lin, Yue Jiang, Ahmed Abbasi, Xiaobo Zhou

Faculty & Staff Scholarship

In this work, we study two approaches for the problem of RNA-Protein Interaction (RPI). In the first approach, we use a feature-based technique by combining extracted features from both sequences and secondary structures. The feature-based approach enhanced the prediction accuracy as it included much more available information about the RNA-protein pairs. In the second approach, we apply search algorithms and data structures to extract effective string patterns for prediction of RPI, using both sequence information (protein and RNA sequences), and structure information (protein and RNA secondary structures). This led to different string-based models for predicting interacting RNA-protein pairs. We show …

Hyperspectral Imaging And K-Means Classification For Histologic Evaluation Of Ductal Carcinoma In Situ, Yasser Khouj, Jeremy Dawson, James Coad, Linda Vona-Davis

Faculty & Staff Scholarship

Hyperspectral imaging (HSI) is a non-invasive optical imaging modality that shows the potential to aid pathologists in breast cancer diagnoses cases. In this study, breast cancer tissues from different patients were imaged by a hyperspectral system to detect spectral differences between normal and breast cancer tissues. Tissue samples mounted on slides were identified from 10 different patients. Samples from each patient included both normal and ductal carcinoma tissue, both stained with hematoxylin and eosin stain and unstained. Slides were imaged using a snapshot HSI system, and the spec- tral reflectance differences were evaluated. Analysis of the spectral reflectance values indicated …

Simulation Of A Mos Or Mis Structured Spatial Light Modulator For Terahertz (Thz) Imaging, Md Shahanur Alam

Browse all Theses and Dissertations

A large area, square-gate Metal-Oxide/Insulator-Semiconductor (MOS or MIS) structured `Spatial Light Modulator' has been proposed for the Terahertz (THz) imaging at room temperature. This theoretical study has been done entirely by using the MATLAB platform. The 1D Poisson's equation has been solved iteratively by Euler's method with the exact Fermi-Dirac integral for n-doped Si-MOS and GaAs- MIS capacitors in deep accumulation mode. Free carrier density and the potential profile have been found for the degenerate case. The results have been compared with the analytical method, which is approximated by Boltzmann statistics, and clearly, show the difference between the degenerate case …

Real-Time Path Planning And Obstacle Avoidance For Mobile Robots With Actuator Faults, Ravindra Vibha Bellur

Browse all Theses and Dissertations

In this research, a fault-tolerant path planning and obstacle avoidance algorithm is implemented for mobile ground robots. The fault-tolerant system architecture consists of the following three components: (1) an online fault diagnosis module for detecting and estimating actuator faults in the mobile robot; (2) a localization and mapping module for dynamic terrain mapping and obstacle detection; (3) a path planning and obstacle avoidance module for generating way points from a given point to the desired destination, avoiding the detected obstacles and moving along these way points. The online fault diagnostic information is used to compensate for the effect of faults, …

Simultaneous Measurement Of Displacement And Temperature Based On Baloon - Shaped Bent Smf Structure Incorporating An Lpg, Ke Tian, Wenlei Yang, Gerald Farrell, Elfed Lewis, Xianfan Wang, Pengfei Wang

Articles

Abstract—A novel optical fibre sensor based on a balloon-shaped bent single-mode (BSBS) fibre structure incorporating a long-period grating (LPG) for simultaneous measurement of displacement and temperature is described and experimentally demonstrated. The sensor is fabricated by splicing a BSBS fibre structure formed Mach-Zehnder interferometer (MZI) with an LPG. Due to the interference dip which is formed by the BSBS fibre structure is sensitive to external displacement and temperature variation, while that formed by LPG only depends on temperature, displacement and temperature therefore can be unambiguously and simultaneously measured by this sensor. Experimental results show that this sensor offers a high …