Engineering Commons^™

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), …

Numerical Modeling Of Shockwave Initiated Combustion Of A Hydrogen-Oxygen Mixture Within A Shock Tube, Reed Forehand

Electronic Theses and Dissertations, 2020-2023

Shock tubes are as close to an ideal reactor as most modern experiments can attain to examine chemical kinetics. As reaction temperatures drop, homogeneous combustion within a shock tube begins to exhibit inhomogeneous modes, which in a typical Hydrogen-Oxygen system are ex- pressed as deflagration to detonation transition. Experimental results of such a system in the Uni- versity of Central Florida's low-pressure shock tube have been collected through end and side-wall imaging to analyze flame structure and chemical kinetics. The purpose of this work is to con- duct a baselining of these results using both chemical and computational fluid dynamics …

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 …

On The Strategic Relationship Between Leadership And Innovation In Us Firms, Shabeer Kirmani

Electronic Theses and Dissertations, 2020-2023

Leadership is one of the most important factors in organizational success. Innovation is another of most important factors in organizational success. Leaders play a pivotal role in the innovation capabilities of organizations. One of the most important areas in Leadership Studies (LS) is the association between leadership style and the firm's innovation performance, but a lack of understanding and consensus still remains as a major issue. This research aims to address the research gap by reviewing the empirical literature and determining how the ambidextrous leadership (transactional and transformational) styles in top level U.S. management (CEOs) are related with firm ambidextrous …

The Effect Of Dynamic Span Wise Bending On The Forces Of A Pitching Flat Plate, Manoj Prabakar Sargunaraj

Electronic Theses and Dissertations, 2020-2023

A novel experiment has been conducted to investigate the effect of dynamic spanwise bending on the formation of a dynamic stall vortex on a rapidly pitching flat plate. Experiments have been performed in a towing tank at different nondimensional pitch rates (Kp) in the range of 0.4112 < Kp < 0.8225, and four maximum pitch angles (30° , 45°, 60°, and 90°) at a Reynolds number of 12,000. Synchronized direct force measurements and particle image velocimetry (PIV) are used to characterize the effect of bending on the unsteady forces and the flow field. An unsteady analytical model based on the bending and pitching kinematics is used to model the lift force histories. It is found that a spanwise bending of a pitching wing alleviated the unsteady lift forces. However, the main contribution was found to come from the non-circulatory forces. The circulation and pressure analysis of the pitching wing revealed little or no sensitivity to the wing bending motions examined.

Energy-Efficient In-Memory Architectures Leveraging Intrinsic Behaviors Of Embedded Mram Devices, Shadi Sheikhfaal

Electronic Theses and Dissertations, 2020-2023

For decades, innovations to surmount the processor versus memory gap and move beyond conventional von Neumann architectures continue to be sought and explored. Recent machine learning models still expend orders of magnitude more time and energy to access data in memory in addition to merely performing the computation itself. This phenomenon referred to as a memory-wall bottleneck, is addressed herein via a completely fresh perspective on logic and memory technology design. The specific solutions developed in this dissertation focus on utilizing intrinsic switching behaviors of embedded MRAM devices to design cross-layer and energy-efficient Compute-in-Memory (CiM) architectures, accelerate the computationally-intensive operations …

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 …

Incinerator Ash Characterization - Implications For Elevated Temperature Landfills, Angel Villarruel-Moore

Electronic Theses and Dissertations, 2020-2023

The occurrence of temperatures in municipal solid waste (MSW) landfill gas (LFG) extraction systems in excess of 55°C is a problem that has gained much attention in the solid waste industry, both domestically and globally. Facilities which frequently experience such temperatures are termed Elevated Temperature Landfills (ETLFs), and recent research conducted at the University of Central Florida (UCF) has provided strong evidence that ash, both MSW incinerator ash (MSWIA) and coal combustion ash (CCA), when co-disposed with unburned MSW, provides materials which are able to participate in abiotic exothermic reactions that may lead to the development or sustainment of ETLFs. …

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 …

A Holistic Approach For Power Systems Using Machine Learning And System Dynamics, Bibi Ibrahim

Electronic Theses and Dissertations, 2020-2023

The growing digital economy has imposed greater demand on the electricity supply's reliability in the past decades, with more consumers and electric vehicles (EV) becoming connected to the electric grid. While the uncertainty of the outcomes is unavoidable, there is a need for more accurate forecasts, modeling tools, and detailed roadmaps that can support the reliable transitioning of power systems. Predicting the electricity demand growth will allow energy managers to understand consumer demand in the near future better. However, there are challenges for forecasting the peak demand growth since it is very difficult to model the various complex features that …

Applying Machine Learning Techniques To Improve Safety And Mobility Of Urban Transportation Systems Using Infrastructure- And Vehicle-Based Sensors, Zubayer Islam

Electronic Theses and Dissertations, 2020-2023

The importance of sensing technologies in the field of transportation is ever increasing. Rapid improvements of cloud computing, Internet of Vehicles (IoV), and intelligent transport system (ITS) enables fast acquisition of sensor data with immediate processing. Machine learning algorithms provide a way to classify or predict outcomes in a selective and timely fashion. High accuracy and increased volatility are the main features of various learning algorithms. In this dissertation, we aim to use infrastructure- and vehicle-based sensors to improve safety and mobility of urban transportation systems. Smartphone sensors were used in the first study to estimate vehicle trajectory using lane …

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 …

Experimental Characterization And Crystal Plasticity Modeling Of Mechanical Properties And Microstructure Evolution Of Additively Manufactured Inconel 718 Superalloy, Saeede Ghorbanpour

Doctoral Dissertations

In this thesis, the mechanical behavior of the additively manufactured (AM) IN718 nickel-based superalloy and their correlations with the evolution of microstructure are studied comprehensively. The effects of manufacturing parameters, build orientations, and post processing procedures, i.e. standard heat treatment and hot isostatic pressing (HIP), on various mechanical properties including monotonic compression and tension strength, low cyclic fatigue performance, high cyclic fatigue behaviour, and fatigue crack growth behavior are investigated. Due to the high temperature applications of the IN718 alloy, elevated temperature properties are examined as well. Electron Backscattered Diffraction (EBSD) technique is employed to measure the initial and deformed …

Eece 7216/8216: Computer Vision (Syllabus), Madhusudhanan Balasubramanian

Electrical and Computer Engineering Syllabi Archive

Course Description: Principles and applications of computer vision, advanced image processing techniques as applied to computer vision, shape analysis, and object recognition.

Biom 2720: Experimental Design And Analysis For Biomedical Engineering (Syllabus), Stephen Strain

Biomedical Engineering Syllabi Archive

Course Description: Application of probability, statistics, error analysis, uncertainty in design and performance of biomedical engineering experimentation; discussion and evaluation of common experimental designs for medical device development.

Subsumption Reduces Dataset Dimensionality Without Decreasing Performance Of A Machine Learning Classifier, Donald C. Wunsch, Daniel B. Hier

Chemistry Faculty Research & Creative Works

When Features in a High Dimension Dataset Are Organized Hierarchically, There is an Inherent Opportunity to Reduce Dimensionality. Since More Specific Concepts Are Subsumed by More General Concepts, Subsumption Can Be Applied Successively to Reduce Dimensionality. We Tested Whether Sub-Sumption Could Reduce the Dimensionality of a Disease Dataset Without Impairing Classification Accuracy. We Started with a Dataset that Had 168 Neurological Patients, 14 Diagnoses, and 293 Unique Features. We Applied Subsumption Repeatedly to Create Eight Successively Smaller Datasets, Ranging from 293 Dimensions in the Largest Dataset to 11 Dimensions in the Smallest Dataset. We Tested a MLP Classifier on All …

Data-Driven Identification Of Governing Partial Differential Equations For The Transmission Line Systems, Yanming Zhang, Lijun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Discovering governing equations for transmission line is essential for the study on its properties, especially when the nonlinearity is introduced in a transmission line system. In this paper, we propose a novel data-driven approach for deriving the governing partial differential equations based on the spatial-temporal samples of current and voltage in the transmission line system. The proposed method is based on the ridge regression algorithm to determine the active spatial differential terms from the candidate library that includes nonlinear functions, in which the time and spatial derivatives are estimated by using polynomial interpolation. Three examples, including uniform and nonuniform transmission …

Decoupling Of Antennas With Adjacent Frequency Bands, Min Li, Lijun Jiang, Lawrence Kwan Yeung

Electrical and Computer Engineering Faculty Research & Creative Works

A decoupling device called cascaded power dividing decoupling network (C-PDDN) is presented for two antennas operating in adjacent frequency bands. Design formulas are derived to determine parametrical variables for high isolation. A prototype of a testing array consisting of two base-station dipole antennas is realized on a Rogers PCB for demonstration purposes. Simulated and experimental results show that good impedance matching, and high isolation are achieved simultaneously after adopting the C-PDDN.

Treatment Of Cutting Oil Via Fe0/Air And Al0/Air Using Waste From Auto Parts Manufacturing, Warangkana Srimoke

Chulalongkorn University Theses and Dissertations (Chula ETD)

Used shot blast and aluminium dross wastes generated from auto part manufacturing were applied as catalysts under the modified-air Fenton (MAF) system to treat synthetic cutting oil wastewater. Experimental designs were applied to find optimum conditions in terms of size and amount of catalyst, initial pH, initial cutting oil concentration, air flow rate, and mixing speed. Fe0 and Al0 forms were found in used shot blast and aluminum dross, respectively, according to XRD and XRF results, and the element contents of Fe and Al were found to be 96.37 % and 37.13 %, respectively. For used shot blast under the …

Seismic Performance Of Mechanically Spliced Precast Bridge Columns With New Couplers, Evan Greeneway

Electronic Theses and Dissertations

Lap splicing is not always the most economical or practical approach to achieve reinforcement bar continuity. Mechanical bar splices, or bar couplers, are one alternative that may be far more practical. Currently, the US codes do not allow for the use of bar couplers in the plastic hinge region for RC members in areas of high seismic activity. There has not been enough research into the couplers behavior when subjected to significant inelastic lateral deformations. The Lohr Structures Laboratory was used to conduct an experimental study on campus of South Dakota State University to evaluate the seismic performance of mechanically …

Best Used-Car Selling Service In Us, Sirisha Pola, Jennifer Wagner, Fenny Jin, Pallavi Gusain, Alfonso Herrero

Engineering and Technology Management Student Projects

During the Covid-19 pandemic, a shift in the way people do things has been seen across many different industries, the automobile industry is not the exception, new car production and distribution has decreased based on the restrictions placed by many countries to ensure the safety of its citizens, this has made it quite difficult on the new car dealerships, in addition, people are seeing that the need for a car has gone down significantly since working from home has become a more and more common. However, there is a sector of the automotive industry that is having a boom, used …

Network Function Virtualization Technology Adoption Strategies, Abdlrazaq Ayodeji Adeyi Shittu

Walden Dissertations and Doctoral Studies

Network function virtualization (NFV) is a novel system adopted by service providers and organizations, which has become a critical organizational success factor. Chief information officers (CIOs) aim to adopt NFV to consolidate and optimize network processes unavailable in conventional methods. Grounded in the diffusion of innovation theory (DOI), the purpose of this multiple case research study was to explore strategies chief information officers utilized to adopt NFV technology. Participants include two CIOs, one chief security information officer (CSIO), one chief technical officer (CTO), and two senior information technology (IT) executives. Data were collected through semi-structured telephone interviews and eight organizational …

Model And Data, Equilibrium Of Self-Formed, Single-Thread, Sand-Bed Rivers, Enrica Viparelli, Esther C. Eke

Faculty Publications

This submission contains the following files, also uploaded as Supplementary Information for the manuscript Equilibrium of self-formed, single-thread, sand-bed rivers submitted after major revisions to the AGU journal Geophysical Research Letters.

Excel file with embedded macro Equilibrium_calculator.xlxm, contains the solver of the analytical model presented in the manuscript.

Excel file Equilibrium_results.xlxs contains model data used to generate the plots.

Novel Tools For Analysis Of Disordered Sleep And Motor Behavior In Preclinical Models Of Disease, Dillon M. Huffman

Theses and Dissertations--Biomedical Engineering

Subtle changes in sleep architecture can accompany and be symptomatic of various diseases or disorders. Understanding the complex interactions between sleep and health requires the ability to characterize sleep, probe its underlying mechanisms through perturbation, and quantify dependent physiological outcomes. Rodent models have come to be accepted as a valuable tool for preclinical investigations. However, experimental tools to accomplish such research typically rely on laborious methods that limit throughput and flexibility. Thus, research tools that minimize workload could be of great value to the research community and expedite investigation of the underlying mechanisms of sleep and further the development of …

Changes In Cardiovascular, Respiratory, And Neural Activity By Music: Effects Of Breathing Pathway On Feeling Emotions, Mohammad Javad Mollakazemi

Theses and Dissertations--Biomedical Engineering

Listening to music can induce emotional and physiological changes. Increasing recognition of the palliative effects of music has led to its use as an adjuvant therapeutic tool in the treatment of various diseases. It is also well known that autonomic nervous activities and some cardiorespiratory rhythms change in correspondence with music. However, less is known about how these effects triggered by music come about. Listening to music affects synchronization between electroencephalograms (EEGs) and cardiac rhythmic activity. This interaction between cardiac and electrical responses led us to investigate whether EEG segments synchronized to different portions of the cardiac cycle can better …

Facilitating Analysis Of Toxoplasma Gondii Bradyzoite Metabolic Activity Via Image Processing And Multivariate Logistic Regression For High Throughput Classification Of Mitochondrial Morphologies, Brooke Place

Theses and Dissertations--Biomedical Engineering

Approximately a third of the population worldwide is chronically infected by the parasite Toxoplasma gondii. During chronic infection the parasite resides within tissue cysts as the poorly understood bradyzoite form. Observation of these bradyzoites via microscopic imaging within tissue cyst purified from infected mouse brains has shown metabolic activity with heterogeneous replication potential. With fluorescence microscopy imaging targeting the parasite’s actively respiring mitochondria, the parasite’s metabolic state can be further investigated as the morphology of mitochondria can be associated with specific physiologic states. However, manually classifying mitochondrial morphologies from these images can be tedious and prone to error as …

Risk-Based Construction Inspection, Shannon Rush

Theses and Dissertations--Civil Engineering

State Transportation Agencies have been experiencing staffing difficulties in the last couple of decades due to the deterioration of infrastructure and a large number of employees retiring or transitioning to the private sector. Therefore, the STA demographic has become much younger and a loss of critical knowledge has resulted from this changeover. Construction Inspection in particular has been severely impacted. Inspired by the NCHRP Synthesis 450, the Kentucky Transportation Cabinet has initiated the Risk-Based Construction Inspection project which focuses on prioritizing construction activities based on the risk associated with failure of that work item. The purpose of which is to …

Life Cycle Assessment Of Polylactic Acid Biopolymer Industrial Waste Management Techniques In Belize, Dennis J. Newby

Theses and Dissertations--Civil Engineering

In January 2020, the Government of Belize enacted an Implementation Strategy and Action Plan to phase-out single-use plastics and to transition to products like bioplastics. This work investigated the environmental effects of using alternative waste management techniques to manage polylactic acid biopolymer (PLA) waste by using life cycle assessment (LCA). The following treatment options were compared: landfill, landfill expansion, cogeneration, and anaerobic digestion. The landfill and landfill expansion processes both had a global warming potential of 0.01 kg of CO₂ eq. per kg of PLA waste managed compared to the cogeneration and anaerobic digestion processes -0.03 and -0.06 kg …

Assessing Freeway Crash Risk Using Crowdsourced Waze Incident Alerts, Eugene Boasiako Antwi

Theses and Dissertations--Civil Engineering

Traffic data obtained through crowdsourcing are becoming more accessible to traffic agencies due to advancements in smartphone technology. Traffic managers aim to use this data to complement their conventional sources of data and provide additional context in their analysis. In this study, Waze incident alerts are integrated with GPS-Probe speed data and Kentucky State Police (KSP) crashes to assess their impact on traffic flow and safety on freeways in Kentucky. The analysis showed that the presence of a vehicle on the shoulder is associated with about 36.7% of freeway crashes in Kentucky. The presence of a vehicle on the shoulder …