Open Access. Powered by Scholars. Published by Universities.®
Electrical and Computer Engineering Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Electrical and Electronics (359)
- Electromagnetics and Photonics (307)
- Physical Sciences and Mathematics (302)
- Physics (294)
- Optics (293)
-
- Systems and Communications (36)
- Power and Energy (24)
- Computer Engineering (9)
- Materials Science and Engineering (8)
- Biomedical (7)
- Robotics (7)
- Communication (6)
- Other Communication (6)
- Social and Behavioral Sciences (6)
- Biomedical Engineering and Bioengineering (5)
- Communication Technology and New Media (5)
- Computer Sciences (5)
- Health Communication (5)
- Mechanical Engineering (5)
- Other Computer Engineering (5)
- Electronic Devices and Semiconductor Manufacturing (4)
- Medicine and Health Sciences (4)
- Operations Research, Systems Engineering and Industrial Engineering (4)
- Aerospace Engineering (3)
- Artificial Intelligence and Robotics (3)
- Bioelectrical and Neuroengineering (3)
- Civil and Environmental Engineering (3)
- Other Electrical and Computer Engineering (3)
- Keyword
-
- Nonlinear optics (16)
- Optics (16)
- Laser (11)
- Liquid crystal (11)
- Remote sensing (8)
-
- Semiconductor lasers (8)
- Antenna (7)
- Modeling (7)
- Photonics (7)
- Reliability (7)
- UWB (7)
- Femtosecond (6)
- Infrared (6)
- Machine learning (6)
- Power electronics (6)
- Radio frequency (6)
- Radiometer (6)
- Simulation (6)
- Algorithms (5)
- Coherence (5)
- Control (5)
- Diffraction (5)
- Digital control (5)
- LDMOS (5)
- Lasers (5)
- Liquid crystal display (5)
- Photovoltaics (5)
- Power amplifiers (5)
- Radar (5)
- Semiconductors (5)
- Publication Year
- Publication
- Publication Type
Articles 91 - 120 of 919
Full-Text Articles in Electrical and Computer Engineering
Mechanically Reconfigurable Materials And Devices Based On Two-Dimensional Transition Metal Dichalcogenide Layers, Emmanuel Okogbue
Mechanically Reconfigurable Materials And Devices Based On Two-Dimensional Transition Metal Dichalcogenide Layers, Emmanuel Okogbue
Electronic Theses and Dissertations, 2020-2023
The recent advances in electronic technologies are geared towards a combination of continued miniaturization in device components and their integration onto unconventional platforms. These efforts are aimed towards achieving electronic devices with various form factors and novel functionalities which are unattainable from traditional devices. Among these envisioned 'futuristic' technologies, electronic devices which are mechanically reconfigurable and operable under harsh operational conditions in the form of stretching, twisting and folding offer tremendous amount of unparalleled opportunities. This dissertation studies two-dimensional (2D) transition metal dichalcogenide (TMDs), a distinct class of materials with peculiar optical, electrical and mechanical properties for mechanically reconfigurable electronics. …
Secure And Trustworthy Hardware And Machine Learning Systems For Internet Of Things, Shayan Taheri
Secure And Trustworthy Hardware And Machine Learning Systems For Internet Of Things, Shayan Taheri
Electronic Theses and Dissertations, 2020-2023
The advancements on the Internet have enabled connecting more devices into this technology every day. This great connectivity has led to the introduction of the internet of things (IoTs) that is a great bed for engagement of all new technologies for computing devices and systems. Nowadays, the IoT devices and systems have applications in many sensitive areas including military systems. These challenges target hardware and software elements of IoT devices and systems. Integration of hardware and software elements leads to hardware systems and software systems in the IoT platforms, respectively. A recent trend for the hardware systems is making them …
Low-Profile Wireless Passive Temperature Sensors, Ectis Velazquez
Low-Profile Wireless Passive Temperature Sensors, Ectis Velazquez
Electronic Theses and Dissertations, 2020-2023
This thesis explores design challenges and promising solutions for temperature sensors for high temperature environments such as combustion turbines. To survive this high temperature environment of over 1000 °C the sensors are required to be robust in their electrical and mechanical properties. Wire connections for these high temperature environments are a complex problem due to the physical limitations of most materials at those high temperatures. In this thesis, robust ceramic sensors based on microwave resonators are demonstrated for high temperature environments, with some studies into optimizing the techniques used to measure them, as well as the distance at which their …
Periodicity Estimation Using Representations In Nested Periodic Dictionaries With Applications In Neural Engineering, Pouria Saidi
Periodicity Estimation Using Representations In Nested Periodic Dictionaries With Applications In Neural Engineering, Pouria Saidi
Electronic Theses and Dissertations, 2020-2023
In this dissertation, we investigate periodicity estimation with nested periodic dictionaries (NPDs), a newly introduced family of matrices that can capture periodicity in the data. We address two main problems. First, we study the detection of periodic signals using their representations in NPDs. To this end, the detection problem is posed as a composite hypothesis testing problem, where the signals are assumed to admit sparse representations in a Ramanujan Periodicity Transform (RPT) dictionary as an instance of NPDs. For the binary case, we develop a generalized likelihood ratio detector and obtain exact distributions of the test statistics in terms of …
The Effect Of Annealing Temperatures And Inert/Reactive Gasses On Optical Properties Of Cu2o And Cuo Thin Films, Radu Bunea
Electronic Theses and Dissertations, 2020-2023
The Cu2O and CuO thin films were synthesized by using RF sputtering technique. Comparisons were made with films created by deposition at room temperature followed by thermal annealing between 1000C and 4000C and using different gases, oxygen (O2) (oxidizing and reactive gas) and nitrogen (N2) (inert gas), besides air. The thickness of the thin films were kept constant, around 2000 Å (Angstrom). In addition, the RF power and pressure deposition were kept constant, as well. The thin films were evaluated for a range of wavelengths between 200 nm and 400 nm (Ultra Violet spectrum), …
Switchable Slot-Ring Antennas For Customizable Phased Array Applications, Junyi Huang
Switchable Slot-Ring Antennas For Customizable Phased Array Applications, Junyi Huang
Electronic Theses and Dissertations, 2020-2023
Switchable-band shared-aperture slot-ring antennas with wide bandwidth and polarization agility are explored in this article for phased array applications. A common antenna aperture can be reconfigured between S-band and C-band arrays using PIN diode switches. A new arraying technique is implemented herein to achieve reconfigurable polarization states. Within each array element, only one port is needed to realize reconfigurable polarization states by providing appropriate phases to each port. Compared with the state of the art, this arrangement can reduce the number of ports of a large phased array by half, therefore significantly reduce the cost and complexity, eliminate the isolation …
High-Density Neurochemical Microelectrode Array To Monitor Neurotransmitter Secretion, Kevin White
High-Density Neurochemical Microelectrode Array To Monitor Neurotransmitter Secretion, Kevin White
Electronic Theses and Dissertations, 2020-2023
Neuronal exocytosis facilitates the propagation of information through the nervous system pertaining to bodily function, memory, and emotions. Using amperometry, an electrochemical technique that directly detects electroactive molecules, the sub-millisecond dynamics of exocytosis are revealed and the modulation of neurotransmitter secretion due to neurodegenerative diseases or pharmacological treatments can be studied. The method of detection using amperometry is the exchange of electrons due to a redox reaction at an electrochemically sensitive electrode. As electroactive molecules, such as dopamine, undergo oxidation, electrons are released from the molecule to the electrode and an oxidation current is generated and recorded. Despite the significance …
Reliability And Failure Analysis Of Gan-On-Si Power Devices, Wen Yang
Reliability And Failure Analysis Of Gan-On-Si Power Devices, Wen Yang
Electronic Theses and Dissertations, 2020-2023
Wide bandgap power semiconductor devices, especially Gallium Nitride (GaN) high electron mobility transistors (HEMTs), have gained a lot of attention for high power applications due to their low on-resistance and high switching speed compared to their silicon counterparts. However, the reliability and failure issues related to dynamic performance, gate reliability, and electrostatic discharge have limited the wide applications of GaN power devices. This dissertation presents a systematic study of reliability and failure analysis of GaN-on-Si power devices. Firstly, the correlation between the physical trap mechanisms and the dynamic on-resistance (Ron) degradation has been investigated using a multi-frequency C-V measurement during …
Reliable And Efficient Cognitive Radio Communications Using Directional Antennas, Hassan Yazdani
Reliable And Efficient Cognitive Radio Communications Using Directional Antennas, Hassan Yazdani
Electronic Theses and Dissertations, 2020-2023
Cognitive Radio (CR) is a promising solution that enhances spectrum utilization by allowing an unlicensed or Secondary User (SU) to access licensed bands in a such way that its imposed interference on a license holder Primary User (PU) is limited, and hence fills the spectrum holes in time and/or frequency domains. Resource allocation, which involves scheduling of available time and transmit power, represents a crucial problem for the performance evaluation of CR systems. In this dissertation, we study the spectral efficiency maximization problem in an opportunistic CR system. Specifically, in the first part of the dissertation, we consider an opportunistic …
Performance Enhancement Of Rf/Microwave Devices Using Filter Synthesis Techniques, Ricardo Lovato
Performance Enhancement Of Rf/Microwave Devices Using Filter Synthesis Techniques, Ricardo Lovato
Electronic Theses and Dissertations, 2020-2023
This dissertation shows that filter synthesis techniques can be used to design and enhance the performance of several discrete components of the RF front-end. Throughout this work, a block diagram of a typical receiver is used to illustrate each component separately. Four main areas are covered: (1) filter/antenna integration, (2) frequency-tunable filter/antenna integration with control of the bandwidth characteristics, (3) antenna arrays designed based on integrated cavity resonators, and (4) novel low-loss phase shifters using band-pass and band-stop filters. The filter/antenna designed using two cavity resonators with a slot antenna in the second cavity. The slot antenna excites two modes …
Distributed Service Restoration In Active Distribution Networks, Nejad Reza Roofegari
Distributed Service Restoration In Active Distribution Networks, Nejad Reza Roofegari
Electronic Theses and Dissertations, 2020-2023
Despite tremendous efforts on increasing power system reliability, outages and blackouts are inevitable. These losses can be greatly reduced by fast and reliable restoration mechanisms. Largescale distribution networks and increasing penetration of distributed energy resources (DERs) make restoration one of the most challenging problems in power systems. The prevailing centralized restoration scheme is costly, limited by information privacy of entities, unreliable due to dependence on central units, and might suffer from single-point failures. In this dissertation, a fully distributed restoration framework based on the alternating direction method of multipliers (ADMM) is proposed to address these challenges. Accordingly, the restoration problem …
Ultra-Low Power Circuits And Architectures For Neuromorphic Computing Accelerators With Emerging Tfets And Rerams, Jie Lin
Electronic Theses and Dissertations, 2020-2023
Neuromorphic computing using post-CMOS technologies is gaining increasing popularity due to its promising potential to resolve the power constraints in Von-Neumann machine and its similarity to the operation of the real human brain. To design the ultra-low voltage and ultra-low power analog-to-digital converters (ADCs) for the neuromorphic computing systems, we explore advantages of tunnel field effect transistor (TFET) analog-to-digital converters (ADCs) on energy efficiency and temperature stability. A fully-differential SAR ADC is designed using 20 nm TFET technology with doubled input swing and controlled comparator input common-mode voltage. To further increase the resolution of the ADC, we design an energy …
Characterization Of Left Ventricular Volumes And Ejection Fraction In Patients With A Left Ventricular Assist Device, Viswajith Siruvallur Vasudevan
Characterization Of Left Ventricular Volumes And Ejection Fraction In Patients With A Left Ventricular Assist Device, Viswajith Siruvallur Vasudevan
Electronic Theses and Dissertations, 2020-2023
In the treatment of heart patients, as a bridge to recovery, the challenge currently in using a continuous-flow left ventricular assist device (LVAD), is to provide a method to monitor the recovery of the heart. This dissertation addresses the hypothesis that continuous monitoring of the ejection fraction of a patient implanted with an LVAD should be to examine the progress of the patient without the need for excessive in vivo measurements. Also, the ejection fraction can be used to provide a control mechanism for the pump depending on the requirements of each patient. In this dissertation, the left ventricle, in …
Thermodynamic Theory Of Heavily Multimoded Nonlinear Optical Systems, Fan Wu
Thermodynamic Theory Of Heavily Multimoded Nonlinear Optical Systems, Fan Wu
Electronic Theses and Dissertations, 2020-2023
The quest for ever higher information capacities has brought about a renaissance in multimode optical waveguide systems. This resurgence of interest has recently initiated a flurry of activities in nonlinear multimode fiber optics. The sheer complexity emerging from the presence of a multitude of nonlinearly interacting modes has led not only to new opportunities in observing a host of novel optical effects that are otherwise impossible in single-mode settings, but also to new theoretical challenges in understanding their collective dynamics. In this dissertation, we present a consistent thermodynamical framework capable of describing in a universal fashion the exceedingly intricate behavior …
High Performance Micro-Scale Light Emitting Diode Display, Fangwang Gou
High Performance Micro-Scale Light Emitting Diode Display, Fangwang Gou
Electronic Theses and Dissertations, 2020-2023
Micro-scale light emitting diode (micro-LED) is a potentially disruptive display technology because of its outstanding features such as high dynamic range, good sunlight readability, long lifetime, low power consumption, and wide color gamut. To achieve full-color displays, three approaches are commonly used: 1) to assemble individual RGB micro-LED pixels from semiconductor wafers to the same driving backplane through pick-and-place approach, which is referred to as mass transfer process; 2) to utilize monochromatic blue micro-LED with a color conversion film to obtain a white source first, and then employ color filters to form RGB pixels, and 3) to use blue or …
Novel Fibers And Components For Space Division Multiplexing Technologies, Juan Carlos Alvarado Zacarias
Novel Fibers And Components For Space Division Multiplexing Technologies, Juan Carlos Alvarado Zacarias
Electronic Theses and Dissertations, 2020-2023
Passive devices and amplifiers for space division multiplexing are key components for future deployment of this technology and for the development of new applications exploring the spatial diversity of light. Some important devices include photonic lantern (PL) mode multiplexers supporting several modes, fan-in/fan-out (FIFO) devices for multicore fibers (MCFs), and multimode amplifiers capable of amplifying several modes with low differential modal gain penalty. All these components are required to overcome the capacity limit of single mode fiber (SMF) communication systems, driven by the growing data capacity demand. In this dissertation I propose and develop different passive components and amplifiers for …
Monolithic Thin-Film Lithium Niobate Scanning Micromirror: Design And Simulation, Abimanyu Veerappan
Monolithic Thin-Film Lithium Niobate Scanning Micromirror: Design And Simulation, Abimanyu Veerappan
Electronic Theses and Dissertations, 2020-2023
In this thesis, a novel scanning micromirror is introduced in which a thin layer of lithium niobate (few micrometer thick) is utilized as both as the structural material and the actuating piezoelectric medium. In this novel monolithic design, the conventional composite torsional hinges are avoided. The finite element simulations performed and reported in here indicate that the proposed design offers a superior performance in terms of higher scan angle and linear angle control compared to the existing solutions for the same dimensions. The simulation results predict an optical scan angle of 125.6° at a resonant frequency of 550 Hz using …
Thin-Film Lithium Niobate Integrated Photonics On Silicon For Electro- And Nonlinear-Optic Applications, Amirmahdi Honardoost
Thin-Film Lithium Niobate Integrated Photonics On Silicon For Electro- And Nonlinear-Optic Applications, Amirmahdi Honardoost
Electronic Theses and Dissertations, 2020-2023
In order to overcome the drawbacks associated with conventional bulk lithium niobate photonic, thin-film lithium-niobate-on-silicon has been pursued recently. This work presents contributions made to electro-, and nonlinear-optic applications of this technology. For electrooptic applications, detailed modeling and design guidelines of optical and radio-frequency parameters of ultracompact modulators are developed and their accuracy in predicting the high-speed performance of such devices have been verified by comparison with experimental results. Novel design techniques and pathways for ultrahigh-speed (sub-terahertz) operation of such modulators, achieving up to 400 GHz modulation bandwidth, are also presented. For optical interconnect applications, novel structures for ultralow-power consumption …
In Pursuit Of Low-Dimensional Manifold Structures In High-Dimensional Data, Mahlagha Sedghi
In Pursuit Of Low-Dimensional Manifold Structures In High-Dimensional Data, Mahlagha Sedghi
Electronic Theses and Dissertations, 2020-2023
The ever-increasing availability of large-scale and high-dimensional data offers unprecedented opportunities for data-driven studies across widely differing domains ranging from marketing and web mining, to bioinformatics and space exploration. Yet, it also poses formidable challenges in face of storing, organizing and analyzing such data. Often though, high-dimensional data tend to lie close to some low-dimensional structures. Aside from substantial computational and storage conservations, discovering such structures also contributes to improved learning and inference performance. A majority of existing work assume linear data models which fail to effectively capture the complex patterns of real-world problems. Non-linear models on the other hand …
Transient Mid-Ir Nonlinear Refraction In Air And Nonlinear Optical Properties Of Organometallic Complexes, Salimeh Tofighi
Transient Mid-Ir Nonlinear Refraction In Air And Nonlinear Optical Properties Of Organometallic Complexes, Salimeh Tofighi
Electronic Theses and Dissertations, 2020-2023
This dissertation explores two main topics: Transient nonlinear refraction of air in Mid-IR spectral range and nonlinear optical properties of organometallic complexes. For seeing a vibrational and rotational Raman response the molecule should be Raman active. The first requirement for being a Raman active molecule is that the polarizability of molecule must be anisotropic. Linear symmetric molecules do have rotational Raman spectra. Not all the vibrational mode can be excited by a femtosecond pulse. The pulsewidth of our excitation beam should be less than the half of the vibration period. In this dissertation my excitation pulsewidth is not short enough …
Development Of High-Power Single-Mode Yb-Doped Fiber Amplifiers And Beam Analysis, Steffen Wittek
Development Of High-Power Single-Mode Yb-Doped Fiber Amplifiers And Beam Analysis, Steffen Wittek
Electronic Theses and Dissertations, 2020-2023
High-power fiber laser systems enjoy a widespread use in manufacturing, medical, and defense applications as well as scientific research, due to their remarkable power scalability, high electrical to optical efficiency, compactness and ruggedness. However, single-mode fiber power scaling has stagnated in the past years, primarily due to the onset of nonlinear effects such as stimulated Brillouin/Raman scattering and transverse modal instabilities. This thesis addresses the analysis and mitigation of transverse modal instabilities in high-power fiber amplifiers. I describe the high-power fiber amplifier testbed that I set up to test fibers fabricated in house. I will show our results of a …
Novel Computational Approaches For Multidimensional Brain Image Analysis, Harish Raviprakash
Novel Computational Approaches For Multidimensional Brain Image Analysis, Harish Raviprakash
Electronic Theses and Dissertations, 2020-2023
The overall goal of this dissertation is focused on addressing challenging problems in 1D, 2D/3D and 4D neuroimaging by developing novel algorithms that combine signal processing and machine learning techniques. One of these challenging tasks is the accurate localization of the eloquent language cortex in brain resection pre-surgery patients. This is especially important since inaccurate localization can lead to diminshed functionalities and thus, a poor quality of life for the patient. The first part of this dissertation addresses this problem in the case of drug-resistant epileptic patients. We propose a novel machine learning based algorithm to establish an alternate electrical …
Factors Affecting The Performance Of Photo-Voltaic Solar Energy Storage, Vasanth Bhat
Factors Affecting The Performance Of Photo-Voltaic Solar Energy Storage, Vasanth Bhat
Electronic Theses and Dissertations, 2020-2023
One of the most important factors in a nation's development is energy availability. All the aspects of its economy are directly proportional to the energy resources. Oil is one of the most sought energy resources currently. Solar energy is one of the most important renewable sources of energy available to us. With oil deposits depleting and current global warming, there is an emphasis on using more and more renewable sources or clean energy. This has led to immense research on solar cells and how it could better be used to get maximum output. Storage of energy is another aspect that …
Attosecond Transient Absorption Spectroscopy In The Water Window, Andrew Chew
Attosecond Transient Absorption Spectroscopy In The Water Window, Andrew Chew
Electronic Theses and Dissertations, 2020-2023
The push to study the atomic and molecular dynamics at ever smaller time scales has been the main driving force for developing laser systems with ever shorter pulse durations. Thus far, picosecond lasers and femtosecond lasers have been used with great success in femtochemistry to study molecular dynamics such as molecular rotation and vibration, which all occur in the tens to hundreds of femtosecond. To study electron dynamics however, which are on the order of attoseconds, one needs attosecond laser sources to be able to have the time resolution required to probe ultrafast electron dynamics such as AC Stark shifts, …
High-Fidelity Mini-Led And Micro-Led Displays, Yuge Huang
High-Fidelity Mini-Led And Micro-Led Displays, Yuge Huang
Electronic Theses and Dissertations, 2020-2023
Mini-LED and micro-LED are emerging disruptive display technologies, because they can work as local dimmable backlight to significantly enhance the dynamic range of conventional LCDs, or as sunlight readable emissive displays. However, there are still unresolved issues impairing their display fidelity: 1) motion blur on high-resolution, large-size and high-luminance devices, 2) limited contrast ratio on mini-LED backlit LCD (mLED-LCD), 3) relatively high power consumption, and 4) compromised ambient contrast ratio. This dissertation tackles with each of these issues for achieving high display fidelity. Motion blur is caused by slow liquid crystal response time and image update delays. Low-duty ratio operation …
Multi-Parameter Optical Metrology: Quantum And Classical, Walker Larson
Multi-Parameter Optical Metrology: Quantum And Classical, Walker Larson
Electronic Theses and Dissertations, 2020-2023
The insights offered by quantum mechanics to the field of optical metrology are many-fold, with non-classical states of light themselves used to make sensors that surpass the sensitivity of sensors using classical states of light. Unfortunately, this advantage, referred to often as "super-sensitivity" is notoriously fragile, and even the slightest experimental imperfections may greatly reduce the efficacy of the non-classical sensors, sometimes completely obviating their advantage. In my thesis I have shown that the performance of an otherwise ideal two-photon interferometer, which exploits entanglement between photons to make super-sensitive measurements of phase, is crippled by the slightest introduction of decoherence …
Midwave Vs Longwave Infrared Search And Track And Aerosol Scattering Target Acquisition Performance, Steven Butrimas
Midwave Vs Longwave Infrared Search And Track And Aerosol Scattering Target Acquisition Performance, Steven Butrimas
Electronic Theses and Dissertations, 2020-2023
The decision on whether to use a mid wave infrared (MWIR) or long wave infrared (LWIR) sensor for a given task can be a formidable verdict. The scope entails facts about the observable source, the atmospheric interactions, and the sensor parameters within the hardware device. Even when all the individual metrics are known, the combination ultimately determines whether a MWIR or LWIR sensor is more appropriate. Despite the vast number of variables at play, the reduction of inputs through focused studies can provide essential insight into MWIR and LWIR comparisons. This dissertation focuses on the roles of point source target …
Heterogeneous Integrated Photonics For Nonlinear Frequency Conversion And Polarization Diversity, Tracy Sjaardema
Heterogeneous Integrated Photonics For Nonlinear Frequency Conversion And Polarization Diversity, Tracy Sjaardema
Electronic Theses and Dissertations, 2020-2023
Silicon has proven to be one of the materials of choice for many integrated photonic applications. However, silicon photonics is limited by certain material shortcomings. Two shortcomings addressed in this work are zero second-order optical nonlinearity, and the lack of methods available to achieve broadband polarization diversity. Heterogeneous integrated solutions for these shortcomings of silicon photonics are presented in this work. First, nonlinear frequency conversion is demonstrated with thin-film lithium niobate on silicon substrates. The method for reaching the highest-achieved second-harmonic generation conversion efficiency, using active monitoring during periodic poling, is discussed. Additionally, a cascaded approach for generating higher-order harmonics …
Characterization Of Contact Resistance Properties Of Different Tlm Structure Designs, Nicole A. Karam Pannaci
Characterization Of Contact Resistance Properties Of Different Tlm Structure Designs, Nicole A. Karam Pannaci
Digital Repository: Showcase of Undergraduate Research Excellence
No abstract provided.
Design, Construction, And Characterization Of A Combined Mini-Co₂/Voc Sensor And Gas Chromatograph For Field Research, Rishi Basdeo, Michael Hampton
Design, Construction, And Characterization Of A Combined Mini-Co₂/Voc Sensor And Gas Chromatograph For Field Research, Rishi Basdeo, Michael Hampton
Digital Repository: Showcase of Undergraduate Research Excellence
No abstract provided.