Engineering Commons^™

Optimum Distribution System Architectures For Efficient Operation Of Hybrid Ac/Dc Power Systems Involving Energy Storage And Pulsed Loads, Ahmed T. Elsayed

FIU Electronic Theses and Dissertations

After more than a century of the ultimate dominance of AC in distribution systems, DC distribution is being re-considered. However, the advantages of AC systems cannot be omitted. This is mainly due to the cheap and efficient means of generation provided by the synchronous AC machines and voltage stepping up/down allowed by the AC transformers. As an intermediate solution, hybrid AC/DC distribution systems or microgrids are proposed. This hybridization of distribution systems, incorporation of heterogeneous mix of energy sources, and introducing Pulsed Power Loads (PPL) together add more complications and challenges to the design problem of distribution systems. In this …

Design And Development Of Smart Brain-Machine-Brain Interface (Sbmibi) For Deep Brain Stimulation And Other Biomedical Applications, Muhammad S. Khan

FIU Electronic Theses and Dissertations

Machine collaboration with the biological body/brain by sending electrical information back and forth is one of the leading research areas in neuro-engineering during the twenty-first century. Hence, Brain-Machine-Brain Interface (BMBI) is a powerful tool for achieving such machine-brain/body collaboration. BMBI generally is a smart device (usually invasive) that can record, store, and analyze neural activities, and generate corresponding responses in the form of electrical pulses to stimulate specific brain regions. The Smart Brain-Machine-Brain-Interface (SBMBI) is a step forward with compared to the traditional BMBI by including smart functions, such as in-electrode local computing capabilities, and availability of cloud connectivity in …

Channel And Noise Variance Estimation For Future 5g Cellular Networks, Jorge Iscar Vergara

FIU Electronic Theses and Dissertations

Future fifth generation (5G) cellular networks have to cope with the expected ten-fold increase in mobile data traffic between 2015 and 2021. To achieve this goal, new technologies are being considered, including massive multiple-input multiple-output (MIMO) systems and millimeter-wave (mmWave) communications. Massive MIMO involves the use of large antenna array sizes at the base station, while mmWave communications employ frequencies between 30 and 300 GHz. In this thesis we study the impact of these technologies on the performance of channel estimators.

Our results show that the characteristics of the propagation channel at mmWave frequencies improve the channel estimation performance in …

Wide-Area Time-Synchronized Closed-Loop Control Of Power Systems And Decentralized Active Distribution Networks, Mehmet Hazar Cintuglu

FIU Electronic Theses and Dissertations

The rapidly expanding power system grid infrastructure and the need to reduce the occurrence of major blackouts and prevention or hardening of systems against cyber-attacks, have led to increased interest in the improved resilience of the electrical grid. Distributed and decentralized control have been widely applied to computer science research. However, for power system applications, the real-time application of decentralized and distributed control algorithms introduce several challenges. In this dissertation, new algorithms and methods for decentralized control, protection and energy management of Wide Area Monitoring, Protection and Control (WAMPAC) and the Active Distribution Network (ADN) are developed to improve the …

Magnetoelectric Nanoparticles: Paradigm Shift In Biomolecular Diagnostics, Chooda Mani Khanal

FIU Electronic Theses and Dissertations

Recently discovered multiferroic nanoparticles (MFNs) known as magnetoelectric nanoparticles (MENs) promise to revolutionize next-generation biomedical diagnostic techniques and enable rapid and cost-effective screening of lethal diseases. Due to the quantum-mechanically caused intrinsic magnetoelectric (ME) effect, these nanoparticles display strongly coupled magnetic and electric moments and thus provide a unique pathway to monitor and optionally control intrinsic characteristics of bio organisms via application of external magnetic fields. Due to the ME effect, when placed in the microenvironment of a biomolecular sample, MENs’ magnetic properties change to reflect the molecular nature of the sample. Such an unprecedented intrinsic connection to cells and …

A Biologically Plausible Supervised Learning Method For Spiking Neurons With Real-World Applications, Lilin Guo

FIU Electronic Theses and Dissertations

Learning is central to infusing intelligence to any biologically inspired system. This study introduces a novel Cross-Correlated Delay Shift (CCDS) learning method for spiking neurons with the ability to learn and reproduce arbitrary spike patterns in a supervised fashion with applicability tospatiotemporalinformation encoded at the precise timing of spikes. By integrating the cross-correlated term,axonaland synapse delays, the CCDS rule is proven to be both biologically plausible and computationally efficient. The proposed learning algorithm is evaluated in terms of reliability, adaptive learning performance, generality to different neuron models, learning in the presence of noise, effects of its learning parameters and classification …

Optimal And Miniaturized Strongly Coupled Magnetic Resonant Systems, Hao Hu

FIU Electronic Theses and Dissertations

Wireless power transfer (WPT) technologies for communication and recharging devices have recently attracted significant research attention. Conventional WPT systems based either on far-field or near-field coupling cannot provide simultaneously high efficiency and long transfer range. The Strongly Coupled Magnetic Resonance (SCMR) method was introduced recently, and it offers the possibility of transferring power with high efficiency over longer distances. Previous SCMR research has only focused on how to improve its efficiency and range through different methods. However, the study of optimal and miniaturized designs has been limited. In addition, no multiband and broadband SCMR WPT systems have been developed and …

Improving Current-Asymmetry Of Metal-Insulator-Metal Tunnel Junctions, Aparajita Singh

FIU Electronic Theses and Dissertations

In this research, Ni–NiOx–Cr and Ni–NiOx–ZnO–Cr metal-insulator-metal (MIM) junction based tunnel diodes have been investigated for the purpose of a wide-band detector. An MIM diode has a multitude of applications such as harmonic mixers, rectifiers, millimeter wave and infrared detectors. Femtosecond-fast electron transport in MIM tunnel diodes also makes them attractive for energy-harvesting devices. These applications require the tunnel diodes to have high current-asymmetry and non-linear current-voltage behavior at low applied voltages and high frequencies. Asymmetric and non-linear characteristics of Ni–NiOx-Cr MIM tunnel diodes were enhanced in this research by the addition of ZnO as a second insulator layer in …

Cbrs Spectrum Sharing Between Lte-U And Wifi: A Multiarmed Bandit Approach, Imtiaz Parvez, M.G.S. Sriyananda, Ismail Guvenc, Mehdi Bennis, Arif I. Sarwat

Electrical and Computer Engineering Faculty Publications

The surge of mobile devices such as smartphone and tablets requires additional capacity. To achieve ubiquitous and high data rate Internet connectivity, effective spectrum sharing and utilization of the wireless spectrum carry critical importance. In this paper, we consider the use of unlicensed LTE (LTE-U) technology in the 3.5 GHz Citizens Broadband Radio Service (CBRS) band and develop a multiarmed bandit (MAB) based spectrum sharing technique for a smooth coexistence with WiFi. In particular, we consider LTE-U to operate as a General Authorized Access (GAA) user; hereby MAB is used to adaptively optimize the transmission duty cycle of LTE-U transmissions. …

Securing Metering Infrastructure Of Smart Grid: A Machine Learning And Localization Based Key Management Approach, Imtiaz Parvez, Arif I. Sarwat, Longfei Wei, Aditya Sundararajan

Electrical and Computer Engineering Faculty Publications

In smart cities, advanced metering infrastructure (AMI) of the smart grid facilitates automated metering, control and monitoring of power distribution by employing a wireless network. Due to this wireless nature of communication, there exist potential threats to the data privacy in AMI. Decoding the energy consumption reading, injecting false data/command signals and jamming the networks are some hazardous measures against this technology. Since a smart meter possesses limited memory and computational capability, AMI demands a light, but robust security scheme. In this paper, we propose a localization-based key management system for meter data encryption. Data are encrypted by the key …

Structural Stability Of Functionalized Silicene Nanoribbons With Normal, Reconstructed, And Hybrid Edges, Sadegh Mehdi Aghaei, Ingrid Torres, Irene Calizo

Electrical and Computer Engineering Faculty Publications

Silicene, a novel graphene-like material, has attracted a significant attention because of its potential applications for nanoelectronics. In this paper, we have theoretically investigated the structural stability of edge-hydrogenated and edge-fluorinated silicene nanoribbons (SiNRs) via first-principles calculations. Various edge forms of SiNRs including armchair edge, zigzag edge, Klein edge, reconstructed Klein edge, reconstructed pentagon-heptagon edge, and hybrid edges have been considered. It has been found that fully fluorinated Klein edge SiNRs, in which each edge Si atom is terminated by three fluorine atoms, are the most stable structure. We also discovered that a hybrid edge structure of trihydrogenated Klein edge …

Cbrs Spectrum Sharing Between Lte-U And Wifi: A Multiarmed Bandit Approach, Imtiaz Parvez, M. G. S. Sriyananda, Ismail Guvenc, Mehdi Bennis, Arif I. Sarwat

Electrical and Computer Engineering Faculty Publications

The surge of mobile devices such as smartphone and tablets requires additional capacity. To achieve ubiquitous and high data rate Internet connectivity, effective spectrum sharing and utilization of the wireless spectrum carry critical importance. In this paper, we consider the use of unlicensed LTE (LTE-U) technology in the 3.5 GHz Citizens Broadband Radio Service (CBRS) band and develop a multiarmed bandit (MAB) based spectrum sharing technique for a smooth coexistence with WiFi. In particular, we consider LTE-U to operate as a General Authorized Access (GAA) user; hereby MAB is used to adaptively optimize the transmission duty cycle of LTE-U transmissions. …

Nanofabrication And Spectroscopy Of Magnetic Nanostructures Using A Focused Ion Beam, Ali Hadjikhani

FIU Electronic Theses and Dissertations

This research used a focused ion beam in order to fabricate record small nano-magnetic structures, investigate the properties of magnetic materials in the rarely studied range of nanometer size, and exploit their extraordinary characteristics in medicine and nano-electronics. This study consists of two parts: (i) Fabrication and study of record small magnetic tunnel junctions (ii) Introduction of a novel method for detection of magnetoelectric nanoparticles (MENs) in the tissue.

A key challenge in further scaling of CMOS devices is being able to perform non-volatile logic with near zero power consumption. Sub-10-nm nanomagnetic spin transfer torque (STT) magnetic tunneling junctions (MTJs) …

Sonochemical Synthesis Of Zinc Oxide Nanostructures For Sensing And Energy Harvesting, Phani Kiran Vabbina

FIU Electronic Theses and Dissertations

Semiconductor nanostructures have attracted considerable research interest due to their unique physical and chemical properties at nanoscale which open new frontiers for applications in electronics and sensing. Zinc oxide nanostructures with a wide range of applications, especially in optoelectronic devices and bio sensing, have been the focus of research over the past few decades. However ZnO nanostructures have failed to penetrate the market as they were expected to, a few years ago. The two main reasons widely recognized as bottleneck for ZnO nanostructures are (1) Synthesis technique which is fast, economical, and environmentally benign which would allow the growth on …

Performance Optimization Of Network Protocols For Ieee 802.11s-Based Smart Grid Communications, Nico Saputro

FIU Electronic Theses and Dissertations

The transformation of the legacy electric grid to Smart Grid (SG) poses numerous challenges in the design and development of an efficient SG communications network. While there has been an increasing interest in identifying the SG communications network and possible SG applications, specific research challenges at the network protocol have not been elaborated yet. This dissertation revisited each layer of a TCP/IP protocol stack which basically was designed for a wired network and optimized their performance in IEEE 802.11s-based Advanced Metering Infrastructure (AMI) communications network against the following challenges: security and privacy, AMI data explosion, periodic simultaneous data reporting scheduling, …

Resonance Coupling In Plasmonic Nanomatryoshka Homo- And Heterodimers, Arash Ahmadivand, Raju Sinha, Nezih Pala

Electrical and Computer Engineering Faculty Publications

Here, we examine the electromagnetic (EM) energy coupling and hybridization of plasmon resonances between closely spaced concentric nanoshells known as “nanomatryoshka” (NM) units in symmetric and antisymmetric compositions using the Finite Difference Time Domain (FDTD) analysis. Utilizing plasmon hybridization model, we calculated the energy level diagrams and verified that, in the symmetric dimer (in-phase mode in a homodimer), plasmonic bonding modes are dominant and tunable within the considered bandwidth. In contrast, in the antisymmetric dimer (out-of-phase mode in a heterodimer), due to the lack of the geometrical symmetry, new antibonding modes appear in the extinction profile, and this condition gives …

Smart Grid Security: Threats, Challenges, And Solutions, Anibal Sanjab, Walid Saad, Ismail Guvenc, Arif I. Sarwat, Saroj Biswas

Electrical and Computer Engineering Faculty Publications

The cyber-physical nature of the smart grid has rendered it vulnerable to a multitude of attacks that can occur at its communication, networking, and physical entry points. Such cyber-physical attacks can have detrimental effects on the operation of the grid as exemplified by the recent attack which caused a blackout of the Ukranian power grid. Thus, to properly secure the smart grid, it is of utmost importance to: a) understand its underlying vulnerabilities and associated threats, b) quantify their effects, and c) devise appropriate security solutions. In this paper, the key threats targeting the smart grid are first exposed while …

Graphene Fets With Low-Resistance Hybrid Contacts For Improved High Frequency Performance, Chowdhury Al-Amin, Mustafa Karabiyik, Phani Kiran Vabbina, Raju Sinha, Nezih Pala

Electrical and Computer Engineering Faculty Publications

This work proposes a novel geometry field effect transistor with graphene as a channel—graphene field-effect transistor (GFET), having a hybrid contact that consists of an ohmic source/drain and its extended part towards the gate, which is capacitively coupled to the channel. The ohmic contacts are used for direct current (DC) biasing, whereas their capacitive extension reduces access region length and provides the radio frequency (RF) signal a low impedance path. Minimization of the access region length, along with the paralleling of ohmic contact’s resistance and resistive part of capacitively coupled contact’s impedance, lower the overall source/drain resistance, which results in …

Embedded Graphical User Control Interface For An Advanced Battery Management System, Nicole C. Bugay

Honors College Research Collection

Energy storage systems have many applications including making the power grid more efficient, reliable, and economical and assisting in efficiently integrating renewable energy. Wind and solar energy are intermittent and therefore provide varying unpredictable power to the grid. Energy storage systems can be used to store energy while it is available for later use, thereby playing a significant role in the increased implementation of renewable energy. A battery management system is necessary to monitor and maintain safe, optimal operation of each battery stack in the energy storage system. The purpose of this research is to create and implement an advanced …

Optimal Operation Of Combined Photovoltaic Electrolyzer Systems, Arash Khalilnejad, Aditya Sundararajan, Alireza Abbaspour, Arif I. Sarwat

Electrical and Computer Engineering Faculty Publications

In this study, the design and simulation of a combination of a photovoltaic (PV) array with an alkaline electrolyzer is performed to maximize the production of hydrogen as a reliable power resource. Detailed electrical model of PV system, as long as thermal and electrochemical model of electrolyzer is used. Since an electrolyzer is a non-linear load, its coupling with PV systems to get the best power transfer is very important. Solar irradiation calculations were done for the region of Miami (FL, USA), giving an optimal surface slope of 25.7° for the PV array. The size of the PV array is …

Advanced Graphene Microelectronic Devices, Chowdhury G. Al-Amin

FIU Electronic Theses and Dissertations

The outstanding electrical and material properties of Graphene have made it a promising material for several fields of analog applications, though its zero bandgap precludes its application in digital and logic devices. With its remarkably high electron mobility at room temperature, Graphene also has strong potential for terahertz (THz) plasmonic devices. However there still are challenges to be solved to realize Graphene’s full potential for practical applications.

In this dissertation, we investigate solutions for some of these challenges. First, to reduce the access resistances which significantly reduces the radio frequency (RF) performance of Graphene field effect transistors (GFETs), a novel …

Mens Doped Adhesive And Influence On Fracture Toughness, Kao Z. Yang

FIU Electronic Theses and Dissertations

Composites are in high demand; however, fasteners are often required for joining process and can reduce their advantages. One solution is adhesive bonding, but uncertainty exists regarding long term durability and the ability to interrogate bonds noninvasively. One potential solution to qualify bond integrity over its service life is to dope an adhesive with magneto-electric nanoparticles (MENs). MENs can yield output magnetic signatures that are influenced by bond quality and damage state. In this study, adhesives have been doped with MENs prior to bonding at 1% volume concentration. For optimum implementation, this health monitoring system should be evaluated for effects …

Stochastic Geometry Based Analysis Of Capacity, Mobility And Energy Efficiency For Dense Heterogeneous Networks, Arvind Merwaday

FIU Electronic Theses and Dissertations

In recent years, the increase in the population of mobile users and the advances in computational capabilities of mobile devices have led to an exponentially increasing traffic load on the wireless networks. This trend is foreseen to continue in the future due to the emerging applications such as cellular Internet of things (IoT) and machine type communications (MTC). Since the spectrum resources are limited, the only promising way to keep pace with the future demand is through aggressive spatial reuse of the available spectrum which can be realized in the networks through dense deployment of small cells. There are many …

Analysis And Modeling Of Advanced Power Control And Protection Requirements For Integrating Renewable Energy Sources In Smart Grid,, Amirhasan Moghadasiriseh

FIU Electronic Theses and Dissertations

Attempts to reduce greenhouse gas emissions are promising with the recent dramatic increase of installed renewable energy sources (RES) capacity. Integration of large intermittent renewable resources affects smart grid systems in several significant ways, such as transient and voltage stability, existing protection scheme, and power leveling and energy balancing. To protect the grid from threats related to these issues, utilities impose rigorous technical requirements, more importantly, focusing on fault ride through requirements and active/reactive power responses following disturbances. This dissertation is aimed at developing and verifying the advanced and algorithmic methods for specification of protection schemes, reactive power capability and …

A High Performance Advanced Encryption Standard (Aes) Encrypted On-Chip Bus Architecture For Internet-Of-Things (Iot) System-On-Chips (Soc), Xiaokun Yang

FIU Electronic Theses and Dissertations

With industry expectations of billions of Internet-connected things, commonly referred to as the IoT, we see a growing demand for high-performance on-chip bus architectures with the following attributes: small scale, low energy, high security, and highly configurable structures for integration, verification, and performance estimation.

Our research thus mainly focuses on addressing these key problems and finding the balance among all these requirements that often work against each other. First of all, we proposed a low-cost and low-power System-on-Chips (SoCs) architecture (IBUS) that can frame data transfers differently. The IBUS protocol provides two novel transfer modes – the block and state …

An Optical Design Configuration For Wireless Data Transmission, Seyed Mohammad Amin Motahari Bidgoli

FIU Electronic Theses and Dissertations

The concept of 2D barcodes is of great relevance for use in wireless data transmission between handheld electronic devices. In a typical setup, any file on a cell phone for example can be transferred to a second cell phone through a series of images on the LCD which are then captured and decoded through the camera of the second cell phone. In this research, a new approach for data modulation in 2D barcodes is introduced, and its performance is evaluated in comparison to other standard methods of barcode modulation. In the proposed method, Orthogonal Frequency Division Multiplexing (OFDM) modulation is …

Fully Decentralized Multi-Agent System For Optimal Microgrid Control, Ricardo De Azevedo

FIU Electronic Theses and Dissertations

In preparation for the influx of renewable energy sources that will be added to the electrical system, flexible and adaptable control schemes are necessary to accommodate the changing infrastructure. Microgrids have been gaining much attention as the main solution to the challenges of distributed and intermittent generation, but due to their low inertia, they need fast-acting control systems in order to maintain stability. Multi-Agent Systems have been proposed as dynamic control and communication frameworks. Decentralized arrangements of agents can provide resiliency and the much-desired “plug and play” behavior. This thesis describes a control system that implements droop control and the …

Hybrid Energy Storage Implementation In Dc And Ac Power System For Efficiency, Power Quality And Reliability Improvements, Mustafa Farhadi

FIU Electronic Theses and Dissertations

Battery storage devices have been widely utilized for different applications. However, for high power applications, battery storage systems come with several challenges, such as the thermal issue, low power density, low life span and high cost. Compared with batteries, supercapacitors have a lower energy density but their power density is very high, and they offer higher cyclic life and efficiency even during fast charge and discharge processes. In this dissertation, new techniques for the control and energy management of the hybrid battery-supercapacitor storage system are developed to improve the performance of the system in terms of efficiency, power quality and …

Data Distribution Service-Based Interoperability Framework For Smart Grid Testbed Infrastructure, Tarek A. Youssef, Ahmed T. Elsayed, Osama A. Mohammed

Electrical and Computer Engineering Faculty Publications

This paper presents the design and implementation of a communication and control infrastructure for smart grid operation. The proposed infrastructure enhances the reliability of the measurements and control network. The advantages of utilizing the data-centric over message-centric communication approach are discussed in the context of smart grid applications. The data distribution service (DDS) is used to implement a data-centric common data bus for the smart grid. This common data bus improves the communication reliability, enabling distributed control and smart load management. These enhancements are achieved by avoiding a single point of failure while enabling peer-to-peer communication and an automatic discovery …

18f-Flt Positron Emission Tomography/Computed Tomography Imaging In Pancreatic Cancer: Determination Of Tumor Proliferative Activity And Comparison With Glycolytic Activity As Measured By 18f-Fdg Positron Emission Tomography/Computed Tomography Imaging, Senait Aknaw Debebe, Mohammed Goryawala, Malek Adjouadi, Anthony J. Mcgoron, Seza Gulec

Department of Biomedical Engineering Faculty Publications

No abstract provided.