Electrical and Computer Engineering Commons^™

Resilient And Real-Time Control For The Optimum Management Of Hybrid Energy Storage Systems With Distributed Dynamic Demands, Christopher R. Lashway

FIU Electronic Theses and Dissertations

A continuous increase in demands from the utility grid and traction applications have steered public attention toward the integration of energy storage (ES) and hybrid ES (HESS) solutions. Modern technologies are no longer limited to batteries, but can include supercapacitors (SC) and flywheel electromechanical ES well. However, insufficient control and algorithms to monitor these devices can result in a wide range of operational issues. A modern day control platform must have a deep understanding of the source. In this dissertation, specialized modular Energy Storage Management Controllers (ESMC) were developed to interface with a variety of ES devices. The EMSC provides …

Electrical Characterization Of Irradiated Semiconducting Amorphous Hydrogenated Boron Carbide, George Glen Peterson

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Semiconducting amorphous partially dehydrogenated boron carbide has been explored as a neutron voltaic for operation in radiation harsh environments, such as on deep space satellites/probes. A neutron voltaic device could also be used as a solid state neutron radiation detector to provide immediate alerts for radiation workers/students, as opposed to the passive dosimetry badges utilized today. Understanding how the irradiation environment effects the electrical properties of semiconducting amorphous partially dehydrogenated boron carbide is important to predicting the stability of these devices in operation. p-n heterojunction diodes were formed from the synthesis of semiconducting amorphous partially dehydrogenated boron carbide on silicon …

Nanostructure Evolution Of Magnetron Sputtered Hydrogenated Silicon Thin Films, Dipendra Adhikari, Maxwell M. Junda, Sylvain X. Marsillac, Robert W. Collins, Nikolas J. Podraza

Electrical & Computer Engineering Faculty Publications

Hydrogenated silicon (Si:H) thin films have been prepared by radio frequency (RF) magnetron sputtering. The effect of hydrogen gas concentration during sputtering on the resultant film structural and optical properties has been investigated by real time spectroscopic ellipsometry (RTSE) and grazing incidence x-ray diffraction (GIXRD). The analysis of in-situ RTSE data collected during sputter deposition tracks the evolution of surface roughness and film bulk layer thickness with time. Growth evolution diagrams depicting amorphous, nanocrystalline and mixed-phase regions for low and high deposition rate Si:H are constructed and the effects of process parameter (hydrogen gas concentration, total pressure and RF power) …

Laser-Assisted Metal Organic Chemical Vapor Deposition Of Gallium Nitride, Hossein Rabiee Golgir

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

Due to its unique properties, gallium nitride is of great interest in industry applications including optoelectronics (LEDs, diode laser, detector), high power electronics, and RF and wirelss communication devices. The inherent shortcomings of current conventional deposition methods and the ever-increasing demand for gallium nitride urge extended efforts for further enhancement of gallium nitride deposition. The processes of conventional methods for gallium nitride deposition, which rely on thermal heating, are inefficient energy coupling routes to drive gas reactions. A high deposition temperature (1000-1100 °C) is generally required to overcome the energy barriers to precursor adsorption and surface adatom migration. However, there …

Ionic Thermoelectric Paper, Fei Jiao, Ali Naderi, Dan Zhao, Joshua Schlueter, Maryam Shahi, Jonas Sundström, Hjalmar Granberg, Jesper Edberg, Ujwala Ail, Joseph W. Brill, Tom Lindström, Magnus Berggren, Xavier Crispin

Physics and Astronomy Faculty Publications

Ionic thermoelectric materials, for example, polyelectrolytes such as polystyrene sulfonate sodium (PSSNa), constitute a new class of materials which are attracting interest because of their large Seebeck coefficient and the possibility that they could be used in ionic thermoelectric SCs (ITESCs) and field effect transistors. However, pure polyelectrolyte membranes are not robust or flexible. In this paper, the preparation of ionic thermoelectric paper using a simple, scalable and cost-effective method is described. After a composite was fabricated with nanofibrillated cellulose (NFC), the resulting NFC–PSSNa paper is flexible and mechanically robust, which is desirable if it is to be used in …

A Hardware One-Time Pad Prototype Generator For Localising Cloud Security, Paul Tobin, Lee Tobin, Michael Mckeever, Jonathan Blackledge

Conference papers

In this paper, we examine a system for encrypting data before storing in the Cloud. Adopting this system gives excellent security to stored data and complete control for accessing data by the client at different locations. The motivation for developing this personal encryption came about because of poor Cloud security and doubts over the safety of public encryption algorithms which might contain backdoors. However, side-channel attacks and other unwanted third-party interventions in Cloud security, probably contribute more to the poor security record history. These factors led to the development of a prototype for personalising security locally which defeats cryptanalysis. The …

Electronic And Magnetic Properties Of Two-Dimensional Nanomaterials Beyond Graphene And Their Gas Sensing Applications: Silicene, Germanene, And Boron Carbide, Sadegh Mehdi Aghaei

FIU Electronic Theses and Dissertations

The popularity of graphene owing to its unique properties has triggered huge interest in other two-dimensional (2D) nanomaterials. Among them, silicene shows considerable promise for electronic devices due to the expected compatibility with silicon electronics. However, the high-end potential application of silicene in electronic devices is limited owing to the lack of an energy band gap. Hence, the principal objective of this research is to tune the electronic and magnetic properties of silicene related nanomaterials through first-principles models.

I first explored the impact of edge functionalization and doping on the stabilities, electronic, and magnetic properties of silicene nanoribbons (SiNRs) and …

Chaos-Based Cryptography For Cloud Computing, Paul Tobin, Lee Tobin, Michael Mckeever, Jonathan Blackledge

Conference papers

Cloud computing and poor security issues have quadrupled over the last six years and with the alleged presence of backdoors in common encryption ciphers, has created a need for personalising the encryption process by the client. In 2007, two Microsoft employees gave a presentation ``On the Possibility of a backdoor in the NIST SP800-90 Dual Elliptic Curve Pseudo Random Number Generators'' and was linked in 2013 by the New York Times with notes leaked by Edward Snowden. This confirmed backdoors were placed, allegedly, in a number of encryption systems by the National Security Agency, which if true creates an urgent …

Toward Improving Electrocardiogram (Ecg) Biometric Verification Using Mobile Sensors: A Two-Stage Classifier Approach, Robin Tan, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

Electrocardiogram (ECG) signals sensed from mobile devices pertain the potential for biometric identity recognition applicable in remote access control systems where enhanced data security is demanding. In this study, we propose a new algorithm that consists of a two-stage classifier combining random forest and wavelet distance measure through a probabilistic threshold schema, to improve the effectiveness and robustness of a biometric recognition system using ECG data acquired from a biosensor integrated into mobile devices. The proposed algorithm is evaluated using a mixed dataset from 184 subjects under different health conditions. The proposed two-stage classifier achieves a total of 99.52% subject …

Real-Time Internal Temperature Estimation And Health Monitoring For Igbt Modules, Ze Wang

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

Field experiences have demonstrated that power semiconductor devices, such as insulated-gate bipolar transistors (IGBTs), are among the most fragile components of power electronic converters. Thermomechanical stresses produced by temperature variations during operational and environmental loads are the major causes of IGBT degradation. As the devices are often operated under complex working conditions, temperature variations and the associated damage are difficult to predict during the converter design stage. A promising approach—online health monitoring and prognosis for power semiconductor devices—that can avoid device failure and effectively schedule maintenance has attracted much interest.

This dissertation research focused on real-time accurate internal temperature estimation …

Marine Mammal Tracks From Two-Hydrophone Acoustic Recordings Made With A Glider, Elizabeth T. Küsel, Tessa Munoz, Martin Siderius, David K. Mellinger, Sara L. Heimlich

Electrical and Computer Engineering Faculty Publications and Presentations

A multinational oceanographic and acoustic sea experiment was carried out in the summer of 2014 off the western coast of the island of Sardinia, Mediterranean Sea. During this experiment, an underwater glider fitted with two hydrophones was evaluated as a potential tool for marine mammal population density estimation studies. An acoustic recording system was also tested, comprising an inexpensive, off-the-shelf digital recorder installed inside the glider. Detection and classification of sounds produced by whales and dolphins, and sometimes tracking and localization, are inherent components of population density estimation from passive acoustics recordings. In this work we discuss the equipment used …

Quantitative Analysis Of X-Ray Fluorescence Absorption And Emission For Thickness Determination Of Ald-Grown Metal And Oxide Nanoscaled Films, Tarek M. Abdel-Fattah, Alex Wixtrom, Larry Arias, Kai Zhang, Helmut Baumgart

Electrical & Computer Engineering Faculty Publications

This study describes the use of X-ray fluorescence spectroscopy (XRF) to determine the thickness of nanoscaled thin films of insulating oxides such as Al₂O₃, HfO₂, and ZrO₂, semiconducting oxides such as TiO₂, ZnO, and metals like Pt, on silicon substrates synthesized by atomic layer deposition (ALD) technology. XRF thickness measurements were compared with the predicted layer thickness based on calculations from known ALD growth rates for each metal or metal oxide films. The ALD growth rates have been calibrated with TEM cross-sectional measurements of the resulting film thickness. The results …