Electrical and Computer Engineering Commons^™

Understanding The Radiation Effects On Fiber Optic Sensors, Sohel Rana

Boise State University Theses and Dissertations

In this dissertation, the effects of radiation (gamma, neutron or mixed gamma and neutron) on optical fiber sensors are studied and new techniques for real-time measurement of radiation-induced macroscopic changes in optical fibers are presented. It is crucial among the research and development efforts in the nuclear energy field to conduct experiments in Advanced Test Reactor (ATR) to support lifetime extension, novel fuels and materials development, better fuel management, and enhanced safety of existing as well as future nuclear power plants (NPP). Due to their unparalleled and unique advantages over traditional sensors, optical fiber sensors are deemed potential candidates for …

Design And Analysis Of Beam Steering Antennas For Next-Generation Wireless Communication, Shafaq Kausar

Boise State University Theses and Dissertations

Reconfigurable antennas have gained immense interest since the last few decades. Reconfigurable antennas can steer beams dynamically in response to the signal environment, they can also support multiple simultaneous beams. This research work aims to make considerable advancements in the design and analysis of low cost and low power beam steerable antennas. It focuses on the design and demonstration of several prototypes with advanced functionalities, such as passive (broadband, multi-beam, shapable beams) and active (electronically reconfigurable) antennas. The first part of this dissertation covers the design and development of passive metamaterial based multibeam antenna at 30 GHz. Designed antenna is …

Rapid, Reliable Tissue Fractionation Algorithm For Commercial Scale Biorefineries, Rahul Reddy Kancharla

Boise State University Theses and Dissertations

Increasing demand, limited supply, and the impact on the environment raise significant concerns about the consumption of fossil fuels. Because of this, global economies are facing two significant energy challenges: i) securing the supply of reliable and affordable energy and ii) achieving the transformation to a low-carbon, high-efficiency, and sustainable energy system. Recently, there has been growing interest in developing portable transportation fuels from biomass in order to reduce the petroleum consumption in the transportation sector - a major contributor to greenhouse gas emission. A cost-effective conversion process to produce biofuels from lignocellulosic biomass material relies not just on the …

Millimeter-Wave Channel Measurements In Airport Environment, Mahfuza Khatun

Boise State University Theses and Dissertations

The wide spectrum available at millimeter-wave (mmWave) bands promises very high data rates and has been proposed as an attractive solution to provide high-speed and reliable wireless communication. Further, there are various potential usages of mmWave technology in transportation, aviation, autonomous vehicles, robotics, etc. Specifically, it is anticipated that automation through this technology will affect and improve the operations in every phase in airport environments. Consequently, the extended autonomous capabilities at airports will generate and consume more information and increase the demand for robust data transfer, which requires larger data rates than ever before. Hence, mmWave frequency, due to its …

Real-Time Measurement Of Parametric Influences On The Refractive Index And Length Changes In Silica Optical Fibers, Sohel Rana, Austin Fleming, Harish Subbaraman, Nirmala Kandadai

Electrical and Computer Engineering Faculty Publications and Presentations

In this paper, we present a simple cascaded Fabry-Perot interferometer (FPI) that can be used to measure in real-time the refractive index (RI) and length variation in silica optical fibers caused due to external physical parameters, such as temperature, strain, and radiation. As a proof-of-concept, we experimentally demonstrate real-time monitoring of temperature effects on the RI and length and measure the thermo-optic coefficient (TOC) and thermal expansion coefficient (TEC) by using the cascaded FPI within a temperature range of 21–486°C. The experimental results provide a TEC of 5.53 × 10⁻⁷ /°C and TOC of 4.28 × 10⁻⁶ /°C …

A Deep Unsupervised Feature Learning Spiking Neural Network With Binarized Classification Layers For The Emnist Classification, Ruthvik Vaila, John Chiasson, Vishal Saxena

Electrical and Computer Engineering Faculty Publications and Presentations

End user AI is trained on large server farms with data collected from the users. With ever increasing demand for IoT devices, there is a need for deep learning approaches that can be implemented at the Edge in an energy efficient manner. In this work we approach this using spiking neural networks. The unsupervised learning technique of spike timing dependent plasticity (STDP) and binary activations are used to extract features from spiking input data. Gradient descent (backpropagation) is used only on the output layer to perform training for classification. The accuracies obtained for the balanced EMNIST data set compare favorably …

Effect Of Room Air Exposure On The Field Emission Performance Of Uv Light Irradiated Si-Gated Field Emitter Arrays, Ranajoy Bhattacharya, Mason Cannon, Rushmita Bhattacharjee, Jim Browning

Electrical and Computer Engineering Faculty Publications and Presentations

Field emission cathodes are promising candidates in nanoscale vacuum channel transistors and are used in microwave vacuum electron devices. Prior research has shown that UV light exposure as well as 350 °C vacuum bake can desorb water vapor from Si field emission tips, resulting in lower work function and improved emission performance. However, after long exposure to room air (greater than 24 h), the improved performance is lost as water adsorbs on the tips. In this study, experiments were carried on two sets of 1000 × 1000 Si-gated field emitter arrays to determine the length of time that emitters can …

Handwritten English Word Recognition Using A Deep Learning Based Object Detection Architecture, Riktim Mondal, Samir Malakar, Elisa H. Barney Smith, Ram Sarkar

Electrical and Computer Engineering Faculty Publications and Presentations

Handwriting is used to distribute information among people. To access this information for further analysis the page needs to be optically scanned and converted to machine recognizable form. Due to unconstrained writing styles along with connected and overlapping characters, handwriting recognition remains a challenging task. Most of the methods in the literature use lexicon-based approaches and train their models on large datasets having near 50 K word samples to achieve good results. This results in high computational requirements. While these models use around 50 K words in their dictionary when recognizing handwritten English text, the actual number of words in …

Future Needs Of The Cybersecurity Workforce, Connie Justice, Char Sample, Sin Ming Loo, Alex Ball, Clay Hampton

Electrical and Computer Engineering Faculty Publications and Presentations

Expected growth of the job market for cyber security professionals in both the US and the UK remains strong for the foreseeable future. While there are many roles to be found in cyber security, that vary from penetration tester to chief information security officer (CISO). One job of particular interest is security architect. The rise in Zero Trust Architecture (ZTA) implementations, especially in the cloud environment, promises an increase in the demand for these security professionals. A security architect requires a set of knowledge, skills, and abilities covering the responsibility for integrating the various security components to successfully support an …

Exciton Delocalization And Scaffold Stability In Bridged Nucleotide-Substituted, Dna Duplex-Templated Cyanine Aggregates, Simon K. Roy, Olga A. Mass, Donald L. Kellis, Christopher K. Wilson, John A. Hall, Bernard Yurke, William B. Knowlton

Electrical and Computer Engineering Faculty Publications and Presentations

Molecular excitons play a foundational role in chromophore aggregates found in light-harvesting systems and offer potential applications in engineered excitonic systems. Controlled aggregation of chromophores to promote exciton delocalization has been achieved by covalently tethering chromophores to deoxyribonucleic acid (DNA) scaffolds. Although many studies have documented changes in the optical properties of chromophores upon aggregation using DNA scaffolds, more limited work has investigated how structural modifications of DNA via bridged nucleotides and chromophore covalent attachment impact scaffold stability as well as the configuration and optical behavior of attached aggregates. Here we investigated the impact of two types of bridged nucleotides, …

Active Compensation Of Radiation Effects On Optical Fibers For Sensing Applications, Sohel Rana, Austin Fleming, Nirmala Kandadai, Harish Subbaraman

Electrical and Computer Engineering Faculty Publications and Presentations

Neutron and gamma irradiation is known to compact silica, resulting in macroscopic changes in refractive index (RI) and geometric structure. The change in RI and linear compaction in a radiation environment is caused by three well-known mechanisms: (i) radiation-induced attenuation (RIA), (ii) radiation-induced compaction (RIC), and (iii) radiation-induced emission (RIE). These macroscopic changes induce errors in monitoring physical parameters such as temperature, pressure, and strain in optical fiber-based sensors, which limit their application in radiation environments. We present a cascaded Fabry–Perot interferometer (FPI) technique to measure macroscopic properties, such as radiation-induced change in RI and length compaction in real time …

A Multi-Dimensional Child-Langmuir Law For Any Diode Geometry, N. R. Sree Harsha, Marcus Pearlman, Jim Browning, Allen L. Garner

Electrical and Computer Engineering Faculty Publications and Presentations

While prior theoretical studies of multi-dimensional space-charge limited current (SCLC) assumed emission from a small patch on infinite electrodes, none have considered emission from an entire finite electrode. In this paper, we apply variational calculus (VC) and conformal mapping, which have previously been used to derive analytic solutions for SCLC density (SCLCD) for nonplanar one-dimensional geometries, to obtain mathematical relationships for any multi-dimensional macroscopic diode with finite cathode and anode. We first derive a universal mathematical relationship between space-charge limited potential and vacuum potential for any diode and apply this technique to determine SCLCD for an eccentric spherical diode. We …

Attenuation Of Several Common Building Materials: Millimeter-Wave Frequency Bands 28, 73, And 91 Ghz, Mahfuza Khatun, Changyu Guo, Hani Mehrpouyan

Electrical and Computer Engineering Faculty Publications and Presentations

Future cellular systems will make use of millimeter-wave (mm-wave) frequency bands. Many users in these bands are located indoors, i.e., inside buildings, homes, and offices. The typical building material attenuations in these high-frequency ranges are of interest for link budget calculations. In this article, we report on a collaborative measurement campaign to find the attenuation of several typical building materials in three potential mm-wave bands (28, 73, and 91 GHz). Using directional antennas, we took multiple measurements at multiple locations using narrow-band and wideband signals and averaged out residual small-scale fading effects. The materials include clear glass, drywall (plasterboard), plywood, …

Spatiotemporal Pattern Detection With Neuromorphic Circuits, Robert C. Ivans

Boise State University Theses and Dissertations

In this dissertation, neuromorphic circuits are used to implement spiking neural networks in order to detect spatiotemporal patterns. Unsupervised training and detection-by-design techniques were used to attain the appropriate connectomes and perform pattern detection.

Unsupervised training was performed by feeding random digital spikes with a repeating embedded spatiotemporal pattern to a spiking neural network composed of leaky integrate-and-fire neurons and memristor-R(t) element circuits which implement spike-timing-dependent plasticity learning rules.

Detection-by-design was achieved using neuromporphic circuits and digital logic gates. When detection-by-design was achieved using both neuromorphic circuits and digital logic gates, a network was created of spatiotemporal pattern detector circuits, …

A Wireless, Multi-Channel Printed Capacitive Strain Gauge System For Structural Health Monitoring, Kshama Lakshmi Ranganatha

Boise State University Theses and Dissertations

Structural health monitoring of soft structural textiles plays a key role within the space industry to ensure the safety and integrity of space habitats, parachutes, and decelerator systems. Strain monitoring could be an effective means to evaluate structural integrity, but conventional monitoring systems are not suitable because they are intended for large, rigid structures. To overcome the limitations of rigid sensors, we recently proposed using printed capacitive strain gauges (CSGs) on flexible substrates to monitor the structural health of soft structure materials. Here, we present a strategy and implementation of a wireless, multi-channel readout system for distributed monitoring of soft …

Long Term Field Emission Current Stability Characterization Of Planar Field Emitter Devices, Ranajoy Bhattacharya, Marco Turchetti, P. Donald Keathley, Karl K. Berggren, Jim Browning

Electrical and Computer Engineering Faculty Publications and Presentations

Lateral field emission devices have been characterized and degradation tested for >1000 h to study stability and reliability. Two types of planar device structures, diode and bowtie, were studied. These nanoscale devices have 10–20 nm tip to tip or tip to collector dimensions with the tips fabricated from Au/Ti. Typical currents of 2–6 nA at 6 V were measured. The devices were placed on lifetime tests in a vacuum of < 10⁻⁸ Torr and biased at 6 V DC for >1000 h. Seven total devices were tested with one failing at 300 h. and three of the devices showed < 5% degradation in current until 1400 h when testing was stopped, and three other devices showed a sudden drop of ≈20% ranging from 700 to 900 h. Optical microscope images of one of the devices that failed catastrophically at 350 h show physical arc damage where the bond pad narrows to the emitter trace. Scanning electron microscope images of a bowtie part that completed 1400 h of operation showed no obvious erosion or damage to the tips.

A New Feature Extraction Approach For Script Invariant Handwritten Numeral Recognition, Pawan Kumar Singh, Iman Chatterjee, Ram Sarkar, Elisa Barney Smith, Mita Nasipuri

Electrical and Computer Engineering Faculty Publications and Presentations

Handwritten numeral recognition is a challenging research problem because of the enormous varieties of styles in which human beings write the numerals. Several researchers have tried to find solutions to this problem with exceptional recognition accuracies. However, most of these solutions have been dedicated to single script numerals. Such methods are inappropriate for multi-lingual nations such as India where a large number of scripts are used. Keeping this issue in mind, a new feature descriptor named symbolization of binary images (SBI) is introduced here for the recognition of handwritten numerals of different scripts. Effectiveness of SBI is supported …

Space-Charge Limited Current In Planar And Cylindrical Crossed-Field Diodes Using Variational Calculus, Adam M. Darr, Ranajoy Bhattacharya, Jim Browning, Allen L. Garner

Electrical and Computer Engineering Faculty Publications and Presentations

No abstract provided.

Industrial Control System Data Resiliency, Daniel A. Bovard

Boise State University Theses and Dissertations

This thesis identifies and fortifies against a critical vulnerability in industrial control system (ICS) security. A properly designed ICS security framework consists of a multi-layered approach starting with heavy fortifications in information technology and ending with control information of operational technology. Currently, ICS security frameworks lack visibility and place blind trust in devices at the lowest level of the control hierarchy. Attaining control data visibility at the lowest level of the control hierarchy is critical to increasing the resiliency of an ICS security posture. This thesis demonstrates how this data can be captured at the lowest level of the control …

Phase Change Temperature Sensor For High Radiation Environment: Material, Additive Technology And Structure Development, Al Amin Ahmed Simon

Boise State University Theses and Dissertations

Performance of any sensor in a nuclear reactor involves reliable operation under a harsh environment (i.e., high temperature, neutron irradiation, and a high dose of ionizing radiation). In this environment, accurate and continuous monitoring of temperature is critical for the reactor's stability and proper functionality. Furthermore, during the development and testing stages of new materials and structural components for these systems, it is imperative to collect in-situ measurement data about the exact test conditions for real-time analysis of their performance. To meet the compelling need of such sensing devices, we propose radiation-hard temperature sensors based on the phase change phenomenon …

Study And Design Of Array And Beamsteering Antennas For Millimeter Wave Band Application, Saeideh Shad

Boise State University Theses and Dissertations

Millimeter wave (mmWave) communication systems have attracted significant interest regarding supporting high data rate of Gigabit/s communications for the new generation of wireless communication networks. MmWave communication systems have frequency ranges in between 30 and 300 GHz wherein an enormous amount of unused bandwidth is available. Although the available bandwidth of mmWave frequencies is promising for high data rate communications, the propagation characteristics of mmWave frequencies are significantly different from microwave frequency band in terms of path loss, diffraction and blockage, and atmospheric absorption. In general, the overall losses of mmWave signals are significantly larger than that of microwave signals …

Lemons Into Lemonade!, Thad B. Welch, Cameron H. G. Wright, Michael G. Morrow

Electrical and Computer Engineering Faculty Publications and Presentations

This paper discusses a trial of offering two senior/first-year graduate classes in a 7-week format, one following the other. Thus, a student could complete two courses (6-credits), dealing with two closely related topics, in one semester. In this case, the courses were Digital Communication Systems and Wireless Communications.

During the first week of the first 7-week course, all of the in-class demonstrations and hands-on experiences needed to be shifted to online/remote delivery. This was primarily accomplished using the Amazon Web Services (AWS) AppStream, cloud computing system.

The planned real-world signal capture and analysis project changed to an optional attendance …

Effects Of Memristive Synapse Radiation Interactions On Learning In Spiking Neural Networks, Sumedha Gandharava Dahl, Robert C. Ivans, Kurtis D. Cantley

Electrical and Computer Engineering Faculty Publications and Presentations

This study uses advanced modeling and simulation to explore the effects of external events such as radiation interactions on the synaptic devices in an electronic spiking neural network. Specifically, the networks are trained using the spike-timing-dependent plasticity (STDP) learning rule to recognize spatio-temporal patterns (STPs) representing 25 and 100-pixel characters. Memristive synapses based on a TiO₂ non-linear drift model designed in Verilog-A are utilized, with STDP learning behavior achieved through bi-phasic pre- and post-synaptic action potentials. The models are modified to include experimentally observed state-altering and ionizing radiation effects on the device. It is found that radiation interactions tend …

Numerical Analysis Of Radiation Effects On Fiber Optic Sensors, Sohel Rana, Harish Subbaraman, Austin Fleming, Nirmala Kandadai

Electrical and Computer Engineering Faculty Publications and Presentations

Optical fiber sensors (OFS) are a potential candidate for monitoring physical parameters in nuclear environments. However, under an irradiation field the optical response of the OFS is modified via three primary mechanisms: (i) radiation-induced attenuation (RIA), (ii) radiation-induced emission (RIE), and (iii) radiation-induced compaction (RIC). For resonance-based sensors, RIC plays a significant role in modifying their performance characteristics. In this paper, we numerically investigate independently the effects of RIC and RIA on three types of OFS widely considered for radiation environments: fiber Bragg grating (FBG), long-period grating (LPG), and Fabry-Perot (F-P) sensors. In our RIC modeling, experimentally calculated refractive index …

A Low Cost Sensor System For Monitoring And Predicting Corrosion Of Long Term Spent Nuclear Fuel Storage, Vikram M. Patel

Boise State University Theses and Dissertations

With the closing of the Yucca mountain storage facility, on-site storage of spent nuclear fuel at reactor sites has increased and will continue to increase until a permanent storage facility is prepared. Dry storage canisters are used to store spent nuclear fuel waste over long periods of time, but are susceptible to mechanical failure via corrosion. This dissertation presents a system to monitor the integrity of the storage canister. Sensor data fusion algorithms have been designed to predict the integrity of the storage system and provide feedback for preventative maintenance. The environmental conditions that lead to corrosion have been replicated …

Studying The Electron Population Effects On Magnetron Oscillation Via Particle-In-Cell Simulation, Andong Yue

Boise State University Theses and Dissertations

This research examines magnetron physics via the Particle-In-Cell simulations of two magnetron models, the 2D Rising Sun magnetron model and the 3D L3Harris CWM-75kW magnetron model, by using new data analytic schemes. Two data analytic schemes are presented, the electron population analysis and the breadth ratio analysis; these schemes reveal insights into the magnetron physics that are not readily accessible otherwise. Both magnetron models were simulated a) without priming, b) with RF priming, and c) with modulated electron injection. The research found that the 2D Rising Sun magnetron model is sensitive to RF priming; a 50 ns RF priming at …

Design And Development Of Optical Waveguide Architectures For Real-Time Temperature Monitoring In Extreme Environments, Bahareh Badamchi

Boise State University Theses and Dissertations

This dissertation prompts on the research and development of a new real-time, reusable, and reversible optical sensor for integrated temperature monitoring in harsh environments. This is achieved through integrating the photonic properties of optical waveguides/optical fiber and the phase change properties of chalcogenide glasses (ChGs). ChG materials have very specific crystallization temperatures beyond which these materials transform from being a dielectric material to a metallic material. When such ChG material is coated over a dielectric optical waveguide, in the crystalline phase, highly localized surface plasmon polariton (SPP) modes are generated at the waveguide: metallic ChG interface. In this case, the …

Millimeter-Wave Channel Measurement At 73ghz And 81ghz, Changyu Guo

Boise State University Theses and Dissertations

The abundant spectrum available at mmWave band can provide high capacity, high throughput, and low latency. In this thesis, we present experimental measurements for 73 and 81 GHz mmWave bands. Wideband propagation measurements were performed at the Boise Airport concourse C area and tarmac for both line-of-sight (LOS) and non-line-of sight (NLOS) scenarios. Power delay profiles were recorded and analyzed with close-in free space reference path loss models and floating intercept path loss models. In addition, building material attenuation at 28, 73, and 91 GHz is presented. Measurements at 73 GHz for wideband and narrowband signal are performed with directional …

Temperature Effects On Gated Silicon Field Emission Array Performance, Ranajoy Bhattacharya, Nedeljko Karaulac, Winston Chern, Akintunde Ibitayo Akinwande, Jim Browning

Electrical and Computer Engineering Faculty Publications and Presentations

Silicon field emitter arrays (Si FEAs) are being explored as an electron source for vacuum channel transistors for high temperature electronics. Arrays of 1000 × 1000 silicon tip based gated field emitters were studied by measuring their electrical characteristics up to 40 V of DC gate bias with a 1.3 mA emission current at different temperatures from 25 to 400 °C. At ∼350 °C, residual gas analyzer measurements show that water desorption and carbon dioxide partial pressures increase significantly, the gate to emitter leakage current decreases by more than ten times, and the collector current increases by more than ten …

Chalcogenide Glass-Capped Fiber-Optic Sensor For Real-Time Temperature Monitoring In Extreme Environments, Bahareh Badamchi, Al-Amin Ahmed Simon, Maria Mitkova, Harish Subbaraman

Electrical and Computer Engineering Faculty Publications and Presentations

We demonstrate a novel chalcogenide glass (ChG)-capped optical fiber temperature sensor capable of operating within harsh environment. The sensor architecture utilizes the heat-induced phase change (amorphous-to-crystalline) property of ChGs, which rapidly (80–100 ns) changes the optical properties of the material. The sensor response to temperature variation around the phase change of the ChG cap at the tip of the fiber provides abrupt changes in the reflected power intensity. This temperature is indicative of the temperature at the sensing node. We present the sensing performance of six different compositions of ChGs and a method to interpret the temperature profile between 440 …