Electrical and Computer Engineering Commons^™

Tri-Level Hierarchical Coordinated Control Of A Largescale Electric Vehicle Charging In The Smart Grid, Tawfiq M. Aljohani

FIU Electronic Theses and Dissertations

Electric Vehicles (EVs) are considered one of humanity's greatest hopes to combat the climate change crises in light of their great potentials to reduce Greenhouse Gases (GHG) emissions from two main sources: the electric power industry and the fossil-based transportation sector. To help expedite the large-scale adoption of EVs on the roads, optimal solutions are needed to overcome the technical and operational barriers that face the electrical network. This is due to the introduction of significant load levels from EVs; a substantial number is expected during peak demand hours. This dissertation addresses the various interaction between different parts of the …

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, …

Nondestructive Detection Of Codling Moth Infestation In Apples Using Pixel-Based Nir Hyperspectral Imaging With Machine Learning And Feature Selection, Nader Ekramirad, Alfadhl Y. Khaled, Lauren E. Doyle, Julia R. Loeb, Kevin D. Donohue, Raul T. Villanueva, Akinbode A. Adedeji

Electrical and Computer Engineering Faculty Publications

Codling moth (CM) (Cydia pomonella L.), a devastating pest, creates a serious issue for apple production and marketing in apple-producing countries. Therefore, effective nondestructive early detection of external and internal defects in CM-infested apples could remarkably prevent postharvest losses and improve the quality of the final product. In this study, near-infrared (NIR) hyperspectral reflectance imaging in the wavelength range of 900–1700 nm was applied to detect CM infestation at the pixel level for three organic apple cultivars, namely Gala, Fuji and Granny Smith. An effective region of interest (ROI) acquisition procedure along with different machine learning and data processing …

Temperature-Immune Self-Referencing Fabry–Pérot Cavity Sensors, Hengky Chandrahalim, Jonathan W. Smith

AFIT Patents

A passive microscopic Fabry-Pérot Interferometer (FPI) sensor an optical fiber a three-dimensional microscopic optical structure formed on a cleaved tip of an optical fighter that reflects a light signal back through the optical fiber. The reflected light is altered by refractive index changes in the three-dimensional structure that is subject to at least one of: (i) thermal radiation; and (ii) volatile organic compounds.

On The Synthesis Of Optimal Control Laws, Meir Pachter, Isaac E. Weintraub

Faculty Publications

In this paper we advocate for Isaacs' method for the solution of differential games to be applied to the solution of optimal control problems. To make the argument, the vehicle employed is Pontryagin's canonical optimal control example, which entails a double integrator plant. However, rather than controlling the state to the origin, we correctly require the end state to reach a terminal set that contains the origin in its interior. Indeed, in practice, it is required to control to a prescribed tolerance rather than reach a desired end state; achieving tight tolerances is expensive, and from a theoretical point of …

Single-Rail Adiabatic Logic For Energy-Efficient And Cpa-Resistant Cryptographic Circuit In Low-Frequency Medical Devices, Amit Degada, Himanshu Thapliyal

Electrical and Computer Engineering Graduate Research

Designing energy-efficient and secure cryptographic circuits in low-frequency medical devices are challenging due to low-energy requirements. Also, the conventional CMOS logic-based cryptographic circuits solutions in medical devices can be vulnerable to side-channel attacks (e.g. correlation power analysis (CPA)). In this article, we explored single-rail Clocked CMOS Adiabatic Logic (CCAL) to design an energy-efficient and secure cryptographic circuit for low-frequency medical devices. The performance of the CCAL logic-based circuits was checked with a power clock generator (2N2P-PCG) integrated into the design for the frequency range of 50 kHz to 250 kHz. The CCAL logic gates show an average of approximately 48% …

Defining And Detecting Toxicity On Social Media: Context And Knowledge Are Key, Amit Sheth, Valerie Shalin, Ugur Kursuncu

Publications

As the role of online platforms has become increasingly prominent for communication, toxic behaviors, such as cyberbullying and harassment, have been rampant in the last decade. On the other hand, online toxicity is multi-dimensional and sensitive in nature, which makes its detection challenging. As the impact of exposure to online toxicity can lead to serious implications for individuals and communities, reliable models and algorithms are required for detecting and understanding such communications. In this paper We define toxicity to provide a foundation drawing social theories. Then, we provide an approach that identifies multiple dimensions of toxicity and incorporates explicit knowledge …

Net-Zero Energy Districts And The Grid: An Energy-Economic Feasibility Case-Study Of The National Western Center In Denver, Co, Usa, Ben Saarloos, Jason C. Quinn

Faculty Work Comprehensive List

Given the enormous impact of buildings on energy consumption, it is important to continue the development of net-zero energy districts. Opportunities exist for energy efficiency and renewable energy on a district level that may not be feasible in individual buildings. Due to the intermittent nature of many renewable energy sources, net-zero energy districts are dependent on the energy grid. The novelty of this work is to quantify and optimize the economic cost and grid independence of a net-zero energy district using the National Western Center (NWC) in Denver, CO, USA as a case study. The NWC is a 100+ ha …

Anglo-American Nursing: A Historical Timeline Of The Field From The Renaissance To World War Ii, Carlyn Homann

Honors Projects

This timeline stands as an extensive- although not comprehensive- review of the evolution of Anglo-American nursing as a profession, but it will also explore the contributions of other nations where it is appropriate. It seeks to summarize the field and its limitations from the early 15th century to World War II, as well as the capability for upward movement within an existing hierarchy while also considering the education required of a nurse during the selected time period in order to provide context for current nursing students.

Optimum Implementation Of Compound Compression Of A Computer Screen For Real-Time Transmission In Low Network Bandwidth Environments, Conor Paxton

Masters

Remote working is becoming increasingly more prevalent in recent times. A large part of remote working involves sharing computer screens between servers and clients. The image content that is presented when sharing computer screens consists of both natural camera captured image data as well as computer generated graphics and text. The attributes of natural camera captured image data differ greatly to the attributes of computer generated image data. An image containing a mixture of both natural camera captured image and computer generated image data is known as a compound image. The research presented in this thesis focuses on the challenge …

System, Method And Apparatus For Recovering Polarization Radar Data, Julie A. Jackson, Forest Lee-Elkin

AFIT Patents

A method and apparatus that measure M coupled channels of radar polarization data (ỹ), that is a subset, which is less than the full set of received coupled channels. Sparse recovery operations are performed on the measured M coupled channels of radar polarization data (ỹ) and a representation of a set of more than M channels of radar polarization data is generated from the sparse recovery performed on the subset of coupled channels.

Artificial Intelligence-Based Power System Stabilizers For Frequency Stability Enhancement In Multi-Machine Power Systems, Aliyu Sabo, Noor Izzri Abdul Wahab, Mohammad Lutfi Othman, Mai Zurwatul Ahlam Mohd Jaffar, Hakan Acikgoz, Hamed Nafisi, Hossein Shahinzadeh

Articles

Low frequency oscillations (LFOs) occur in a system of interconnected generators connected by weak interconnection. A power system stabilizer (PSS) is commonly used to improve the capacity of the power system dampening. Under a variety of operating conditions, traditional PSSs fail to deliver superior damping. To address this issue, a Farmland Fertility Algorithm (FFA-PSSs controller) was used to solve an optimization problem for optimal design of PSSs system parameters, and its performance efficiency was compared to GA and PSO-based PSSs controllers. In addition to PSS, flexible current transmission (FACTS) devices are widely used. PSSs controllers and FACTS devices are frequently …

Machine Learning For Stock Prediction Based On Fundamental Analysis, Yuxuan Huang, Luiz Fernando Capretz, Danny Ho

Electrical and Computer Engineering Publications

Application of machine learning for stock prediction is attracting a lot of attention in recent years. A large amount of research has been conducted in this area and multiple existing results have shown that machine learning methods could be successfully used toward stock predicting using stocks’ historical data. Most of these existing approaches have focused on short term prediction using stocks’ historical price and technical indicators. In this paper, we prepared 22 years’ worth of stock quarterly financial data and investigated three machine learning algorithms: Feed-forward Neural Network (FNN), Random Forest (RF) and Adaptive Neural Fuzzy Inference System (ANFIS) for …

Hiv/Aids After The Crisis: The Evolution Of An Epidemic, Emma Paras

Honors Projects

HIV and AIDS has affected the world for over four decades. In the past, a positive HIV diagnosis could very well be a death sentence, as well as signal that an individual was a social outcast. In the past ten years, however, treatments for HIV/AIDS allow a person to live a long and relatively healthy life. In addition to examining current and future trends in HIV treatment, this paper will also discuss how the virus affects different regions of the world. Particularly in certain parts of Africa, HIV/AIDS remains deadly for many who don’t have proper access to health care …

Uptpu: Improving Energy Efficiency Of A Tensor Processing Unit Through Underutilization Based Power-Gating, Pramesh Pandey, Noel Daniel Gundi, Koushik Chakraborty, Sanghamitra Roy

Electrical and Computer Engineering Faculty Publications

The AI boom is bringing a plethora of domain-specific architectures for Neural Network computations. Google's Tensor Processing Unit (TPU), a Deep Neural Network (DNN) accelerator, has replaced the CPUs/GPUs in its data centers, claiming more than 15 × rate of inference. However, the unprecedented growth in DNN workloads with the widespread use of AI services projects an increasing energy consumption of TPU based data centers. In this work, we parametrize the extreme hardware underutilization in TPU systolic array and propose UPTPU: an intelligent, dataflow adaptive power-gating paradigm to provide a staggering 3.5 ×-6.5× energy efficiency to TPU for different input …

Impact-Based Analytics Of Cascaded False Data Injection Attacks On Smart Grids, Mohamadsaleh Jafari

FIU Electronic Theses and Dissertations

The composition of communication lines and bidirectional smart devices in smart grids makes them greatly vulnerable to cyber-attacks. False data injection attacks (FDIAs) are of the most widespread cyber-attacks severely affecting the performance of smart grids that need to be analyzed. In this context, we analyze the feasibility of launching FDIAs in power systems with high renewables leading to false relay operations (FRO). By modeling the frequency dynamics of power systems, formalizing the FRO attack as a constraint satisfaction problem, our case studies show that power grids with renewables are more susceptible to FRO attacks. Moreover, the results suggest that …

Low-Noise, Low-Power Analog Front End For Dual Detector, Event-Driven Radioactive Isotope Identification, Joseph Medinger

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

An analog front end (AFE) design for a low-noise, low-power, event-driven radioactive spectroscopy system is implemented in a 65 nm CMOS technology. The AFE is optimized for use with two scintillation based detectors, CsI(Na) and LaBr3(Ce), that utilize photo-multiplier tubes for charge amplification. The amplification within the AFE is accomplished through charge sensitive amplifier designs that are tailored to each detector type. The AFE includes adjustable bias generation circuits to allow amplifier tuning for process, voltage, and temperature variations. The presented AFE is implemented along with analog to digital acquisition circuits and a microcontroller to provide a single-chip radioactive spectroscopy …

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, …

Using The Inelastic Background In Hard X-Ray Photoelectron Spectroscopy For A Depth-Resolved Analysis Of The Cds / Cu(In,Ga)Se < Inf > 2 < / Inf > Interface, Dirk Hauschild, Ralph Steininger, Dimitrios Hariskos, Wolfram Witte, Sven Tougaard, Clemens Heske, Lothar Weinhardt

Chemistry and Biochemistry Faculty Research

The inelastic background of hard x-ray photoelectron spectroscopy data is analyzed to paint a depth-resolved picture of the CdS/Cu(In,Ga)Se2 (CdS/CIGSe) layer structure. The CdS/CIGSe interface is the central component in next-generation chalcopyrite thin-film photovoltaic devices. By analyzing both, the (unscattered) core-level peaks and the inelastic background, and by varying the excitation photon energy from 2.1 up to 14 keV, we can derive photoemission information over a broad range of electron kinetic energies and, hence, sampling depths. With this complementary information, the CdS film thickness of a CdS/CIGSe interface can be accurately determined as a function of the CdS deposition 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 …

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 …

Numerical Green's Function-Based Method For Modeling Radiated Emission From Pcbs In Shielding Enclosures, Zi An Wang, Li (Lijun) Jun Jiang, Jun Fa Mao, Ping Li

Electrical and Computer Engineering Faculty Research & Creative Works

Due to stringent electromagnetic compatibility (EMC) regulations, all electronic devices need to go through rigorous radiated emission tests before launching to market. Thus, efficient, accurate, and cheap characterization approaches are quite of interest. Instead of utilizing the time-consuming and expensive direct far-field measurement, in this work, a novel methodology on the basis of numerical Green's function (NGF) is proposed to acquire the parasitic EM emissions from PCBs placed in a shielding enclosure with ventilation slots. Referring to Schelkunoff's equivalence principle, the whole modeling procedure can be decomposed into two steps in order to obtain the emissions in the entire space. …

Approaching The Fundamental Limit Of Orbital-Angular-Momentum Multiplexing Through A Hologram Metasurface, Shuai S.A. Yuan, Jie Wu, Menglin L.N. Chen, Zhihao Lan, Liang Zhang, Sheng Sun, Zhixiang Huang, Xiaoming Chen, Shilie Zheng, Li (Lijun) Jun Jiang, Xianmin Zhang, Wei E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

Establishing and approaching the fundamental limit of orbital-angular-momentum (OAM) multiplexing are necessary and increasingly urgent for current multiple-input multiple-output research. In this work, we elaborate the fundamental limit in terms of independent scattering channels (or the degrees of freedom of scattered fields) through angular-spectral analysis, in conjunction with a rigorous Green's function method. The scattering-channel limit is universal for arbitrary spatial-mode multiplexing, which is launched by a planar electromagnetic device, such as antenna, metasurface, etc., with a predefined physical size. As a proof of concept, we demonstrate both theoretically and experimentally the limit by a phase-only metasurface hologram that transforms …

Temperature And Strain Sensing With Hybrid Interferometer, Lashari Ghulam Abbas, Zhou Ai, Farhan Mumtaz, Atta Muhammad, Yutang Dai, Rashda Parveen

Electrical and Computer Engineering Faculty Research & Creative Works

A hybrid interferometer for simultaneous measurement of strain and temperature is proposed and investigated experimentally. This hybrid design is composed of Fabry-Perot interferometer (FPI) and Michelson Interferometer (MI) cascaded with each other. It is developed by fusion splicing a single mode fiber (SMF), a multimode fiber (MMF), a dual side hole fiber (DSHF), a hollow core fiber (HCF) and a tapered-SMF. The tapered SMF was inserted into the HCF to form a reflection mirror for the FPI. The maximum temperature and strain sensitivity of the hybrid interferometer achieved through experiments is 11.6 pm/°C and 6.8 pm/mu varepsilon , respectively. The …

Evaluating Deep-Learning Models For Debris-Covered Glacier Mapping, Zhiyuan Xie, Vijayan K. Asari, Umesh K. Haritashya

Electrical and Computer Engineering Faculty Publications

In recent decades, mountain glaciers have experienced the impact of climate change in the form of accelerated glacier retreat and other glacier-related hazards such as mass wasting and glacier lake outburst floods. Since there are wide-ranging societal consequences of glacier retreat and hazards, monitoring these glaciers as accurately and repeatedly as possible is important. However, the accurate glacier boundary, especially the debriscovered glacier (DCG) boundary, which is one of the primary inputs in many glacier analyses, remains a challenge even after many years of research using conventional remote sensing methods or machine-learning methods. The GlacierNet, a deep-learning-based approach, utilized the …

Fabricating Nanophotonic Devices Using Nanofabrication Techniques, Scott Cummings

Student Scholar Symposium Abstracts and Posters

Nanofabrication processes are widely used to make the integrated circuits and computer chips that are ubiquitous in today’s technology. These fabrication processes can also be applied to the creation of nanophotonic devices. The ways in which we apply these fabrication techniques in the field of photonics is often constrained by the technologies used for electronics manufacturing which presents an interesting engineering challenge. These limitations include availability and cost of certain fabrication equipment and techniques required to create state-of-the-art nanophotonic devices. Through work with the University of California Irvine nano-fabrication cleanroom, we designed and fabricated various integrated photonic components including grating …

Genome Annotation Using Average Mutual Information, Garin P. Newcomb

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Advancements in high-throughput DNA sequencing technologies and ambitious goals for their use are resulting in the generation of a deluge of unannotated sequenced genomes. This makes computational tools that can aid in annotation increasingly valuable.

Here, we provide a detailed exploration of the utility as well as the limitations of average mutual information (AMI) in several steps of genome annotation. For a genomic sequence, AMI is a measure of the information a base contains about the base separated by a fixed lag. A profile is constructed by calculating AMI at multiple lags. In addition to traditional AMI, we employ two …

Risk-Based Machine Learning Approaches For Probabilistic Transient Stability, Umair Shahzad

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Power systems are getting more complex than ever and are consequently operating close to their limit of stability. Moreover, with the increasing demand of renewable wind generation, and the requirement to maintain a secure power system, the importance of transient stability cannot be overestimated. Considering its significance in power system security, it is important to propose a different approach for enhancing the transient stability, considering uncertainties. Current deterministic industry practices of transient stability assessment ignore the probabilistic nature of variables (fault type, fault location, fault clearing time, etc.). These approaches typically provide a conservative criterion and can result in expensive …

Dual Multivector Model Predictive Control For The Power Converters Of A Floating Owc Wec, Marcos Blanco, Dionisio Ramirez, Mohammad Ebrahim Zarei, Mahima Gupta

Electrical and Computer Engineering Faculty Publications and Presentations

Oscillating Water Column (OWC) is one of the most well-known wave energy converter (WEC). Typically, OWCs are installed in rocky shores or in custom-built breakwaters. However, since the wave profile is more favorable in an open sea, it can also be installed in a point absorber in order to increase the energy extraction.

This paper presents the development of a new dual Multivector Model Predictive Control (MMPC) for the power converters of a floating OWC WEC. The fast dynamic response featured by the proposed MMPC has proven to be very suitable to deal with the highly variable torque and velocity …

Polarization-Resolved Extreme-Ultraviolet Second-Harmonic Generation From Linbo3, Can B. Uzundal, Sasawat Jamnuch, Emma Berger, Clarisse Woodahl, Paul Manset, Yasuyuki Hirata, Toshihide Sumi, Angelique Amado, Hisazumi Akai, Yuya Kubota, Shigeki Owada, Kensuke Tono, Makina Yabashi, John W. Freeland, Craig P. Schwartz, Walter S. Drisdell

Nevada Extreme Conditions Laboratory Faculty Research

Second harmonic generation (SHG) spectroscopy ubiquitously enables the investigation of surface chemistry, interfacial chemistry, as well as symmetry properties in solids. Polarization-resolved SHG spectroscopy in the visible to infrared regime is regularly used to investigate electronic and magnetic order through their angular anisotropies within the crystal structure. However, the increasing complexity of novel materials and emerging phenomena hampers the interpretation of experiments solely based on the investigation of hybridized valence states. Here, polarization-resolved SHG in the extreme ultraviolet (XUV-SHG) is demonstrated for the first time, enabling element-resolved angular anisotropy investigations. In noncentrosymmetric LiNbO3, elemental contributions by lithium and niobium are …