Digital Commons Network^™

Development Of Light Actuated Chemical Delivery Platform On A 2-D Array Of Micropore Structure, Hojjat Rostami Azmand, Hojjat Rostami Azmand

Dissertations and Theses

Localized chemical delivery plays an essential role in the fundamental information transfers within biological systems. Thus, the ability to mimic the natural chemical signal modulation would provide significant contributions to understand the functional signaling pathway of biological cells and develop new prosthetic devices for neurological disorders. In this paper, we demonstrate a light-controlled hydrogel platform that can be used for localized chemical delivery in a high spatial resolution. By utilizing the photothermal behavior of graphene-hydrogel composites confined within micron-sized fluidic channels, patterned light illumination creates the parallel and independent actuation of chemical release in a group of fluidic ports. The …

Emi Characterization For Power Supplies And Machine Learning Based Modeling In Emc/Si, Jiayi He

Doctoral Dissertations

"Signal integrity (SI) and electromagnetic interference (EMI) are essential for consumer electronics and high-speed server applications. It is necessary to do EMI and SI modeling at the design stage. In this research, several modeling approaches for EMI and SI problems are proposed. By using measurement-based modeling method, the mechanism of conducted emissions (CE) on ac to dc power supplies in an LED TV is analyzed. A system-level transient simulation model is built to predict the conducted emission (CE). To characterize the equivalent dipole moment sources in RFI and EMI problems, a dipole source reconstruction method based on machine learning techniques …

Seed Modeling Of An Esd Gun Discharge To A Usb Cable, Yang Xu

Masters Theses

“An IC protected by a transient voltage suppression (TVS) diode may fail if the TVS device does not turn on or does not turn on quickly enough, causing the IC to take the full brunt of the electrostatic discharge (ESD) event. Transient simulation models have been developed for ESD protection devices for the purpose of system-efficient ESD design (SEED). The TVS modeling methodology has been improved to better represent the physics that occurs during the TVS response and more accurately predict the interactions between off-chip and on-chip protection devices. Moreover, a complicated test scenario -- an ESD gun discharge through …

Source Reconstruction In Near Field Scanning For Rfi Application, Hosseien Rezaei

Doctoral Dissertations

"This research is divided into three major topics. The first topic, mechanical magnetic field generator for communication in the ULF range, is discussed in the first paper. The second topic, source reconstruction in near field scanning for RFI application, is discussed over the course of two papers. The third topic, analysis of imbalanced 2 or 3 Wire VHF LISN, is discussed in the last two papers.

In the first topic, the possibility to use a mechanical system (a rotating magnet) as a source (generator or antenna combined) of the ULF magnetic field is investigated. Ultralow frequency (ULF) communication systems have …

Morphology-Dependent Resonances In Two Concentric Spheres With Variable Refractive Index In The Outer Layer: Analytic Solutions, Umaporn Nuntaplook, John A. Adam

Mathematics & Statistics Faculty Publications

In many applications constant or piecewise constant refractive index profiles are used to study the scattering of plane electromagnetic waves by a spherical object. When the structured media has variable refractive indices, this is more of a challenge. In this paper, we investigate the morphology dependent resonances for the scattering of electromagnetic waves from two concentric spheres when the outer shell has a variable refractive index. The resonance analysis is applied to the general solutions of the radial Debye potential for both transverse magnetic and transverse electric modes. Finally, the analytic conditions to determine the resonance locations for this system …

A Physics-Based Pi Pre-Layout Tool For Pcb Pdn Design, Shuang Liang

Masters Theses

"With increasingly stringent requirements for lower voltage supply, and higher density in PCB PDN design, now integrity (PI) is an increasingly important aspect that must be considered. A pre-layout tool based on the Cavity Model and Boundary Element Method is built to automatically achieve a specified target impedance for a multi-layered Printed Circuit Board (PCB) Power Distribution Network (PDN) design with a minimal number of decoupling capacitors.

The pre-work about the post-layout design and analysis is proposed and the guidelines for creating a decoupling capacitors network with better performance has been built. With limit inputs, physical limitations for the minimal …

Design And Evaluation Of The 3d Printed Electromagnetic Absorber Built With Conductive Carbon-Filled Filament, Rui Mi

Masters Theses

"This research presents an application of the resistive frequency selective surface (FSS) fabricated with a 3D printed conductive material as an electromagnetic absorber for the EMI-reducing door. This solution allows to reduce radiated emissions of a router system. The resistive frequency selective surface has a three-layer structure. The top layer is a 3D printed FSS pattern, the middle layer is an air gap, and the bottom layer is a metal plane.

The first paper presents the methodology for manufacturing a frequency selective surface using the 3D printing technology, including the material characterization, design, fabrication, and evaluation.

The unpublished content presents …

Tunable Optical Filter Using Phase Change Materials For Smart Ir Night Vision Applications, Remona Heenkenda, Keigo Hirakawa, Andrew Sarangan

Electro-Optics and Photonics Faculty Publications

In this paper we present a tunable filter using Ge2Sb2Se4Te1 (GSST) phase change material. The design principle of the filter is based on a metal-insulator-metal (MIM) cavity operating in the reflection mode. This is intended for night vision applications that utilize 850nm as the illumination source. The filter allows us to selectively reject the 850nm band in one state. This is illustrated through several daytime and nighttime imaging applications.

Dales Objects: A Large Scale Benchmark Dataset For Instance Segmentation In Aerial Lidar, Nina M. Singer, Vijayan K. Asari

Electrical and Computer Engineering Faculty Publications

We present DALES Objects, a large-scale instance segmentation benchmark dataset for aerial lidar. DALES Objects contains close to half a billion hand-labeled points, including semantic and instance segmentation labels. DALES Objects is an extension of the DALES (Varney et al., 2020) dataset, adding additional intensity and instance segmentation annotation. This paper provides an overview of the data collection, preprocessing, hand-labeling strategy, and final data format. We propose relevant evaluation metrics and provide insights into potential challenges when evaluating this benchmark dataset. Finally, we provide information about how researchers can access the dataset for their use at go.udayton.edu/dales3d.

Ultrafast Thermal Modification Of Strong Coupling In An Organic Microcavity, Bin Liu, Vinod M. Menon, Matthew Y. Sfeir

Publications and Research

There is growing interest in using strongly coupled organic microcavities to tune molecular dynamics, including the electronic and vibrational properties of molecules. However, very little attention has been paid to the utility of cavity polaritons as sensors for out-of-equilibrium phenomena, including thermal excitations. Here, we demonstrate that non-resonant infrared excitation of an organic microcavity system induces a transient response in the visible spectral range near the cavity polariton resonances. We show how these optical responses can be understood in terms of ultrafast heating of electrons in the metal cavity mirror, which modifies the effective refractive index and subsequently the strong …

Wavefront-Selective Fano Resonant Metasurface, Adam C. Overvig, Andrea Alù

Publications and Research

Fano resonances are conventionally understood as sharp spectral features with selectivity in the momentum-frequency domain, implying that they can be excited only by plane waves with specific frequencies and incident angles. We demonstrate that Fano resonances can be made generally selective in the space-frequency domain. They can be tailored to resonate only when excited by a frequency, polarization, and wavefront of choice. This generalization reveals that Fano systems are characterized by eigenwaves that scatter to their time-reversed image upon reflection. Although in conventional Fano systems this trivially occurs for normally incident plane waves, we show that, in general, the selected …

Transform Based Approaches For The Detection Of Astrophysical Signals, Marwan Mahfud Alkhweldi

Graduate Theses, Dissertations, and Problem Reports

Development of new algorithms for the detection of isolated astrophysical pulses is of interest to radio astronomers. Both Fast Radio Bursts (FRBs) and several Rotating Radio Transients (RRATs) were detected through the application of a single pulse search algorithm. The conventional approach to detect astronomical pulses requires an exhaustive search for the correct dispersion measure. Its accelerated versions involve signal processing in Fourier transform space.

In this dissertation, we present several new transform-based approaches for the detection and analysis of astrophysical signals with the latest being the most effective and advanced of all. It is implemented in several steps. First, …

Mimo Antenna For Fifth Generation Mm-Wave Applications: A Bibliometric Survey, Rajeshwari R. Malekar, Laxmikant K. Shevada, Hema D. Raut, Amruta S. Dixit, Sumit Kumar

Library Philosophy and Practice (e-journal)

Nowadays most discussed technology is mm-wave and 5G communication. The requirement of 5G technology is high bandwidth, high data rate, and low latency. To fulfil these requirements for the current growth in mobile communication multiple input multiple output antenna is used. This bibliometric paper throws light on the various methods used to improve mutual coupling between multiple antennas. Various mutual coupling reduction techniques that are used in MIMO antennas like Dielectric resonator antenna, Electromagnetic Bandgap Structure, Neutralization lines, Defected Ground Structures, Metamaterial, etc. are explained. Scopus database is used for this bibliometric review on mm-wave MIMO 5G technology from the …

A Bibliometric Survey On Ultra Wideband Multiple Input Multiple Output Antenna With Improved Isolation, Laxmikant K. Shevada, Hema D. Raut, Rajeshwari R. Malekar, Amruta S. Dixit, Sumit Kumar

Library Philosophy and Practice (e-journal)

Ultra wideband (UWB) technology remains a viable choice for very high speed data communication in future applications involving large bandwidth. For boosting the data communication efficiency and to mitigate the multipath fading issue faced by UWB system with existing narrowband systems, Multiple Input Multiple Output (MIMO) antenna system is used along with UWB. Mutual coupling which must be smaller in value plays a vital role in deciding the efficiency of MIMO antenna and hence it becomes as important aspect. The mutual coupling reduction techniques of various UWB MIMO antennas are surveyed in this bibliometric paper. The bibliometric survey aims to …

Radiometric Correction Of Multispectral Cameras Using Photosensor Irradiance For Agronomy Applications, Nicholas S. Mitchell

Electronic Thesis and Dissertation Repository

Cloud coverage has a significant impact on the reflectance maps generated by multispectral cameras mounted on UAV's in small farm settings. The current approach is to calibrate the camera once before every flight and use the radiometric calibration map for the entire flight. In this work we have designed and built a downwelling and upwelling photosensor to work in sync with our custom multispectral camera. A dual reflectance panel implementation for the time dependent radiometric calibration of the multispectral camera is completed. The solar spectral irradiance curve is approximated using the current measurements from the downwelling photosensor and the ground …

Conditional Generative Adversarial Network Demosaicing Strategy For Division Of Focal Plane Polarimeters, Garrett Sargent, Bradley M. Ratliff, Vijayan K. Asari

Electrical and Computer Engineering Faculty Publications

Division of focal plane (DoFP), or integrated microgrid polarimeters, typically consist of a 2 × 2 mosaic of linear polarization filters overlaid upon a focal plane array sensor and obtain temporally synchronized polarized intensity measurements across a scene, similar in concept to a Bayer color filter array camera. However, the resulting estimated polarimetric images suffer a loss in resolution and can be plagued by aliasing due to the spatially-modulated microgrid measurement strategy. Demosaicing strategies have been proposed that attempt to minimize these effects, but result in some level of residual artifacts. In this work we propose a conditional generative adversarial …

Novel High Isolation Antennas For Simultaneous Transmit And Receive (Star) Applications, Alexander Hovsepian

FIU Electronic Theses and Dissertations

Radio frequency (RF) spectrum congestion is a major challenge for the growing need of wireless bandwidth. Notably, in 2015, the Federal Communications Commission (FCC) auctioned just 65 MHz (a bandwidth smaller than that used for WiFi) for more than $40 billion, indicating the high value of the microwave spectrum. Current radios use one-half of their bandwidth resource for transmission, and the other half for reception. Therefore, by enabling radios to transmit and receive across their entire bandwidth allocation, spectral efficiency is doubled. Concurrently, data rates for wireless links also double. This technology leads to a new class of radios and …

Improve The Prototype Of Low-Cost Near-Infrared Diffuse Optical Imaging System, Chen Xu, Mohammed Z. Shakil

Publications and Research

Diffuse Optical Tomography (DOT) and Optical Spectroscopy using near-infrared (NIR) diffused light has demonstrated great potential for the initial diagnosis of tumors and in the assessment of tumor vasculature response to neoadjuvant chemotherapy. The aims of this project are 1) to test the different types of LEDs in the near-infrared range, and design the driving circuit, and test the modulation of LEDs at different frequencies; 2) to test the APDs as a detector, and build the receiver system and compare efficiency with pre-built systems. In this project, we are focusing on creating a low-cost infrared transmission system for tumor and …

Antenna Radiation Element Designs For 5g Applications, Zhijun Gui

Electrical Engineering Undergraduate Honors Theses

This thesis introduced the advantage of the fifth-generation network and gave examples to the three major classes of applications categorized by International Telecommunication Union-Radiocommunication Sector. In this work, a patch antenna and a board-band bow-tie antenna with microelectromechanical switch design were modified to meet 5G communication purposes. The revised patch antenna produced a minimum S11 of -57.92dB, a resonant frequency at the 28GHz, and bandwidth of 4.55GHz. The modified design meets the requirements for wireless communication purposes. During the duplication process of the board-band bow-tie antenna design, multiple discrepancies were found, and the proposed results were not able to achieve. …

Digital Fabrication Of A Small Diameter Polymer Optical Waveguide, Venkat Rama Bhethanabotla, Thomas M. Weller, Roger Brandon Tipton, John Townsend Bentley, Eduardo Antonio Rojas

Publications

A novel polymer optical waveguide and method of manu­facturing is presented herein. A digitally manufactured pro­cess is described which utilizes a micro-dispensed UV optical adhesive as the contour guiding cladding, a fused deposition modeling technology for creating a core, addi­tional optical adhesive to complete the cladding and a subtractive laser process to finish the two ends of the optical interconnect.

Polarization-Selective Modulation Of Supercavity Resonances Originating From Bound States In The Continuum, Chan Kyaw, Riad Yahiaoui, Joshua A. Burrow, Viet Tran, Kyron Keelen, Wesley Sims, Eddie C. Red, Willie S. Rockward, Mikkel A. Thomas, Andrew M. Sarangan, Imad Agha, Thomas A. Searles

Electro-Optics and Photonics Faculty Publications

Bound states in the continuum (BICs) are widely studied for their ability to confine light, produce sharp resonances for sensing applications and serve as avenues for lasing action with topological characteristics. Primarily, the formation of BICs in periodic photonic band gap structures are driven by symmetry incompatibility; structural manipulation or variation of incidence angle from incoming light. In this work, we report two modalities for driving the formation of BICs in terahertz metasurfaces. At normal incidence, we experimentally confirm polarization driven symmetry-protected BICs by the variation of the linear polarization state of light. In addition, we demonstrate through strong coupling …

3-D Fabry–Pérot Cavities Sculpted On Fiber Tips Using A Multiphoton Polymerization Process, Jonathan W. Smith, Jeremiah C. Williams, Joseph S. Suelzer, Nicholas G. Usechak, Hengky Chandrahalim

Faculty Publications

This paper presents 3-D Fabry–Pérot (FP) cavities fabricated directly onto cleaved ends of low-loss optical fibers by a two-photon polymerization (2PP) process. This fabrication technique is quick, simple, and inexpensive compared to planar microfabrication processes, which enables rapid prototyping and the ability to adapt to new requirements. These devices also utilize true 3-D design freedom, facilitating the realization of microscale optical elements with challenging geometries. Three different device types were fabricated and evaluated: an unreleased single-cavity device, a released dual-cavity device, and a released hemispherical mirror dual-cavity device. Each iteration improved the quality of the FP cavity's reflection spectrum. The …

Sparse Bases And Bayesian Inference Of Electromagnetic Scattering, John Lee

Theses and Dissertations

Many approaches in CEM rely on the decomposition of complex radiation and scattering behavior with a set of basis vectors. Accurate estimation of the quantities of interest can be synthesized through a weighted sum of these vectors. In addition to basis decompositions, sparse signal processing techniques developed in the CS community can be leveraged when only a small subset of the basis vectors are required to sufficiently represent the quantity of interest. We investigate several concepts in which novel bases are applied to common electromagnetic problems and leverage the sparsity property to improve performance and/or reduce computational burden. The first …

Electromagnetic Interference Estimation Via Conditional Neural Processing, Edgar E. Gomez

Theses and Dissertations

The goal of this thesis is to determine the efficacy of employing Machine Learning (ML) to solve Joint Urgent Operational Need (JUON) CC-0575, which aims to develop a Common Operating Picture (COP) of the Global Positioning System (GPS) Electromagnetic Interference (EMI) environment. With the growing popularity of Artificial Neural Networks (ANNs), ML solutions are quickly gaining traction in businesses, academia and government. This in turn allows for problem solutions that were previously inconceivable using the classical programming paradigm. This thesis proposes a method to develop a COP of the battlefield via ANN ingestion of multiple-source signals and sensors. We conduct …

Development And Characterization Of Metal Contacts For Graded Composition Ingan Solar Cells, Reem E. Alhelais

Graduate Theses and Dissertations

There is an increasing demand for high-power electronic components and optoelectronic devices with low-loss and high efficiency. III-nitride semiconductor materials have demonstrated great potential for high-power, high-frequency, and high-temperature applications because of their remarkable and wide-ranging electronic and physical properties. These material systems, including alloys of AlN, GaN, and InN, are currently being explored for their potential to develop efficient photovoltaic cells. They can potentially achieve higher efficiency because of their very high direct wide band edge, absorption coefficients, and resistance to defects. The compositionally graded Group III-nitride alloy allows access to a large range of energies by varying the …

Fourier Transform Infrared Spectroscopy For The Measurement Of Gesn/(Si)Gesn, Solomon Opeyemi Ojo

Graduate Theses and Dissertations

Photoluminescence (PL) and Electroluminescence (EL) characterization techniques are important tools for studying the optical and electrical properties of (Si)GeSn. Light emission from these PL and EL measurements provides relevant information on material quality, bandgap energy, current density, and device efficiency. Prior to this work, the in-house PL set-up of this lab which involves the use of a commercially-obtained dispersive spectrometer was used for characterizing both GeSn thin film and fabricated devices, but these measurements were limited by issues bordering on low spectral resolution, spectral artifacts, and poor signal-to-noise ratio (SNR) thereby resulting in the possible loss of vital information and …

Multiphoton Microscopy And Deep Learning Neural Networks For The Automated Quantification Of In Vivo, Label-Free Optical Biomarkers Of Skin Wound Healing, Jake D. Jones

Graduate Theses and Dissertations

Non-healing ulcerative wounds that occur frequently in diseases such as diabetes are challenging to diagnose and treat due to numerous possible etiologies and the variable efficacy of wound care products. With advanced age, skin wound healing is often delayed, leaving elderly patients at high risk for developing these chronic injuries. As it is challenging to discriminate age-related delays from disease-related chronicity, there is a critical need to develop new quantitative biomarkers that are sensitive to wound status. Multiphoton microscopy (MPM) techniques are well-suited for 3D imaging of epithelia and are capable of non-invasively detecting metabolic cofactors (NADH and FAD) without …

Detailed Modeling Of The Flash Hydrolysis Of Algae For Biofuel-Production In Comsol Multiphysics, Noah Joseph Legrand

Mechanical & Aerospace Engineering Theses & Dissertations

Algae-derived biofuels are being commercialized as an important renewable energy source. Like any new technology, conversion improvements are desired, including reductions in process complexity and better utilization of the entire microalgae feedstock. The Old Dominion Biomass Laboratory has focused on flash hydrolysis for algae biofuel production. That process involves rapidly heating algae and water mixed as a slurry to a subcritical state. Results from small-scale bench tests are promising, but process scale up is a challenge. Currently there exists a pilot laboratory scale system utilizing induction heating in order to reach controlled reaction temperatures with a reaction duration of 10 …

Transfer-To-Transfer Learning Approach For Computer Aided Detection Of Covid-19 In Chest Radiographs, Barath Narayanan Narayanan, Russell C. Hardie, Vignesh Krishnaraja, Christina Karam, Venkata Salini Priyamvada Davuluru

Electrical and Computer Engineering Faculty Publications

The coronavirus disease 2019 (COVID-19) global pandemic has severely impacted lives across the globe. Respiratory disorders in COVID-19 patients are caused by lung opacities similar to viral pneumonia. A Computer-Aided Detection (CAD) system for the detection of COVID-19 using chest radiographs would provide a second opinion for radiologists. For this research, we utilize publicly available datasets that have been marked by radiologists into two-classes (COVID-19 and non-COVID-19). We address the class imbalance problem associated with the training dataset by proposing a novel transfer-to-transfer learning approach, where we break a highly imbalanced training dataset into a group of balanced mini-sets and …

Simulation Of An Sp8t 18 Ghz Rf Switch Using Smt Pin Diodes, Andre De Souza Vigano

Master's Theses

Radio frequency (RF) and microwave switches are widely used in several different applications including radar, measurement systems, telecommunications, and other areas. An RF switch can control a radar’s transmit vs. receive mode, select the operating band, or direct an RF signal to different paths. In this study, a single pole eight throw (SP8T) switch using only Surface Mount (SMT) components is designed and simulated in Keysight’s Advanced Design System (ADS). Single pole eight throw is defined as one input and eight possible outputs. A star network configuration with series-shunt PIN diode switches is used to create the 8-way RF switch. …