Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Electrical and Computer Engineering (45)
- Mechanical Engineering (43)
- Civil and Environmental Engineering (37)
- Physical Sciences and Mathematics (26)
- Civil Engineering (25)
-
- Electromagnetics and Photonics (19)
- Optics (19)
- Physics (19)
- Computer Engineering (15)
- Environmental Engineering (11)
- Industrial Engineering (11)
- Operations Research, Systems Engineering and Industrial Engineering (11)
- Transportation Engineering (11)
- Energy Systems (9)
- Aerospace Engineering (8)
- Engineering Science and Materials (8)
- Electrical and Electronics (6)
- Environmental Sciences (6)
- Water Resource Management (5)
- Aerodynamics and Fluid Mechanics (4)
- Biomechanics and Biotransport (4)
- Biomedical Engineering and Bioengineering (4)
- Biomechanical Engineering (3)
- Nanoscience and Nanotechnology (3)
- Power and Energy (3)
- Computer and Systems Architecture (2)
- Electro-Mechanical Systems (2)
- Hydraulic Engineering (2)
- Other Computer Engineering (2)
- Keyword
-
- Energy Analysis (5)
- Buildings (4)
- Energy Efficiency (4)
- Simulation (3)
- Heat Pumps (2)
-
- Moisture (2)
- Ventilation (2)
- Action Research (1)
- Additive manufacturing (1)
- Air Conditioning (1)
- Anisotropy (1)
- Attics (1)
- Automation (1)
- Baldrige Performance Excellence Framework (1)
- Bending (1)
- Biomaterials (1)
- Breast cancer (1)
- CNC machine tending (1)
- Catalytic properties (1)
- Commercial (1)
- Cycles (1)
- Data Analysis (1)
- Dehumidification (1)
- Device (1)
- Ducts (1)
- Electric vehicles (1)
- Energy (1)
- Energy Consumption (1)
- Engineering (1)
- Experiment (1)
- Publication
- Publication Type
Articles 151 - 176 of 176
Full-Text Articles in Engineering
Computational Imaging With Limited Photon Budget, Zheyuan Zhu
Computational Imaging With Limited Photon Budget, Zheyuan Zhu
Electronic Theses and Dissertations
The capability of retrieving the image/signal of interest from extremely low photon flux is attractive in scientific, industrial, and medical imaging applications. Conventional imaging modalities and reconstruction algorithms rely on hundreds to thousands of photons per pixel (or per measurement) to ensure enough signal-to-noise (SNR) ratio for extracting the image/signal of interest. Unfortunately, the potential of radiation or photon damage prohibits high SNR measurements in dose-sensitive diagnosis scenarios. In addition, imaging systems utilizing inherently weak signals as contrast mechanism, such as X-ray scattering-based tomography, or attosecond pulse retrieval from the streaking trace, entail prolonged integration time to acquire hundreds of …
Investigation Of Computer Vision Concepts And Methods For Structural Health Monitoring And Identification Applications, Chuanzhi Dong
Investigation Of Computer Vision Concepts And Methods For Structural Health Monitoring And Identification Applications, Chuanzhi Dong
Electronic Theses and Dissertations
This study presents a comprehensive investigation of methods and technologies for developing a computer vision-based framework for Structural Health Monitoring (SHM) and Structural Identification (St-Id) for civil infrastructure systems, with particular emphasis on various types of bridges. SHM is implemented on various structures over the last two decades, yet, there are some issues such as considerable cost, field implementation time and excessive labor needs for the instrumentation of sensors, cable wiring work and possible interruptions during implementation. These issues make it only viable when major investments for SHM are warranted for decision making. For other cases, there needs to be …
Optical Sensing Of Structural Dynamics In Complex Media, Jose Rafael Guzman Sepulveda
Optical Sensing Of Structural Dynamics In Complex Media, Jose Rafael Guzman Sepulveda
Electronic Theses and Dissertations
Quantifying the structural dynamics of complex media is challenging because of the multiple temporal and spatial scales involved. Thanks to the ability to retrieve collective dynamics noninvasively, light scattering-based approaches are often the methods of choice. This dissertation discusses specific features of dynamic light scattering that utilizes spatio-temporal coherence gating. It is demonstrated that this optical fiber-based approach can operate over a large range of optical regimes and it has a number of unique capabilities such as an effective isolation of single scattering, a large sensitivity, and a high collection efficiency. Moreover, the approach also provides means for proper ensemble …
Characterization Of Rare-Earth Doped Thermal Barrier Coatings For Phosphor Thermometry, Quentin Fouliard
Characterization Of Rare-Earth Doped Thermal Barrier Coatings For Phosphor Thermometry, Quentin Fouliard
Electronic Theses and Dissertations
Thermal Barrier Coatings have been extensively used to protect and insulate the metallic components in turbine engines from extreme environments to achieve higher turbine inlet temperatures, resulting in an increase in combined engine cycle efficiency, lowering NOx emissions and fuel consumption. Additionally, as the major failure mechanisms determining lifetime are thermally activated during engine operation, uncertainty in temperature measurements affects lifetime prediction. Early detection of Thermal Barrier Coatings spallation symptoms, associated with local delamination induced temperature changes, can reduce forced engine outages. Further improvements are envisioned with the development of more reliable measurement techniques. For this purpose, Phosphor Thermometry has …
Enhanced Concrete Bridge Assessment Using Artificial Intelligence And Mixed Reality, Enes Karaaslan
Enhanced Concrete Bridge Assessment Using Artificial Intelligence And Mixed Reality, Enes Karaaslan
Electronic Theses and Dissertations
Conventional methods for visual assessment of civil infrastructures have certain limitations, such as subjectivity of the collected data, long inspection time, and high cost of labor. Although some new technologies (i.e. robotic techniques) that are currently in practice can collect objective, quantified data, the inspector's own expertise is still critical in many instances since these technologies are not designed to work interactively with human inspector. This study aims to create a smart, human-centered method that offers significant contributions to infrastructure inspection, maintenance, management practice, and safety for the bridge owners. By developing a smart Mixed Reality (MR) framework, which can …
Probabilistic Spatio-Magnitude Sinkhole Hazard Analysis For East Central Flrodia, Yong Je Kim
Probabilistic Spatio-Magnitude Sinkhole Hazard Analysis For East Central Flrodia, Yong Je Kim
Electronic Theses and Dissertations
In Karst areas, sinkholes are a major geohazard that creates damage and economic loss to building and civil infrastructure. The main goal of the proposed study is to develop a probabilistic spatio-magnitude sinkhole susceptibility model that predicts the potential of sinkhole occurrence on a regional scale. The dissertation presents statistical techniques such as frequency ratio (FR) and logistic regression (LR), and a machine learning technique such as artificial neural network (ANN) to develop the sinkhole hazard models. The study area was limited to the East Central Floria (ECF) region. Seven hydrogeological factors were identified as key contributing factors to sinkhole …
Integration Of Computational Fluid Dynamics And Machine Learning For Modeling Scaffold Pore Structure For Tissue Engineering, Amir Rouhollahi
Integration Of Computational Fluid Dynamics And Machine Learning For Modeling Scaffold Pore Structure For Tissue Engineering, Amir Rouhollahi
Electronic Theses and Dissertations
Freeze-casting is a popular method to produce biomaterial scaffolds with highly porous structures. Three approaches are developed to predict the scaffold pore structure as function of experimental conditions including mold geometry, material and thermal boundary conditions. First, a mathematical model integrating Computational Fluid Dynamics (CFD) with Population Balance Model is developed to predict average pore size (APS) of 3D porous chitosan alginate scaffolds and to assess the influence of the geometrical parameters of mold on scaffold pore structure. The model predicted the crystallization pattern and APS for scaffolds cast in different diameter molds and filled to different heights. The predicted …
Multi-Scale Modeling Of Viscoelastic Thin-Ply Composites, Milinda Madhusanka Yapa Yapa Hamillage
Multi-Scale Modeling Of Viscoelastic Thin-Ply Composites, Milinda Madhusanka Yapa Yapa Hamillage
Electronic Theses and Dissertations
Thin ply composites have been under the microscope of researchers for around two decades since Kawabe introduced the thin ply technology, in the Industrial Technology Center in Fukui, Japan. With the advancement of the technological aspects of manufacturing carbon fiber composites the tow spreading has improved so much as to reduce the thickness of a conventional ply up to even six-fold. Over the years carbon fiber composites have gained interest in space structures for reinforcement purposes in antennas, as structural elements that store strain energy and support the deployment of deployable structures, and in reflector concepts. Now thin-ply composites are …
Implications Of Groundwater Plume Transport And Analysis Of Karst Aquifer Characteristics In Central Florida, Daljit Sandhu
Implications Of Groundwater Plume Transport And Analysis Of Karst Aquifer Characteristics In Central Florida, Daljit Sandhu
Electronic Theses and Dissertations
Groundwater aquifers make up the primary source of drinking water in Florida. It is imperative to protect and maintain water quality to ensure optimal drinking water conditions. Florida is known for being prone to sinkholes due to karst features. One sinkhole event occurred beneath a phosphogypsum stack, and leaked a large amount of radioactive waste in the Floridan aquifer, raising water quality concerns. To study the behavior of contaminant transport, the radioactive waste plume was modeled by coupling hydraulic and chemistry concepts. Adsorption was studied to see if it can serve as a potential remediation solution to the contaminant waste, …
Nanoscale Spectroscopy In Energy And Catalytic Applications, Yi Ding
Nanoscale Spectroscopy In Energy And Catalytic Applications, Yi Ding
Electronic Theses and Dissertations
Emerging societal challenges such as the need for more sustainable energy and catalysis are requiring more sensitive and versatile measurements at the nanoscale. This is the case in the design and optimization of new materials for energy harvesting (solar cells) and energy storage devices (batteries and capacitors), or for the development of new catalysts for carbon sequestration or other reactions of interest. Hence, the ability to advance spectroscopy with nanoscale spatial resolution and high sensitivity holds great promises to meet the demands of deeper fundamental understanding to boost the development and deployment of nano-based devices for real applications. In this …
Shape Recovery Behavior Of Carbon Nanopaper Shape Memory Polymer Composite, Veli Bugra Ozdemir
Shape Recovery Behavior Of Carbon Nanopaper Shape Memory Polymer Composite, Veli Bugra Ozdemir
Electronic Theses and Dissertations
This thesis presents analytical, experimental and modeling studies of the shape recovery behavior of electrically activated Carbon Nanopaper (CNP) Shape Memory Polymer (SMP)composite. The composite structure studied consists of a CNP layer sandwiched by two SMP layers where the CNP layer acts as a flexible electrical heater when a voltage difference is applied. The behavior of CNP/SMP composite presents a coupled electrical - thermal - structural problem. The governing equations for the multiphysics behavior are derived. Derived parameters as a result of multiphysics analysis and effects of these parameters on the shape recovery behavior are investigated. The mechanical properties of …
Stochasticity In An Artificial Neuron Using Ag/2d-Mos2/Au Threshold Switching Memristor, Madison Manley
Stochasticity In An Artificial Neuron Using Ag/2d-Mos2/Au Threshold Switching Memristor, Madison Manley
Honors Undergraduate Theses
Neuromorphic computing comprises of systems that are based on the human brain or artificial neural networks, with the promise of creating a brain inspired ability to learn and adapt, but technical challenges, such as developing an accurate neuroscience model of the functionality of the brain to building devices to support these models, are significantly hindering the progress of neuromorphic systems. This has paved the way for artificial neural networks (ANN) to meet these criteria. The memristor has become an emerging candidate to realize ANN through emulation synapse and neuron behavior. In this work, we are fabricating an Ag/MoS2/Au …
Mechanical Characterization Of Anisotropic Fused Deposition Modeled Polylactic Acid Under Combined Monotonic Bending And Torsion Conditions, Aaron T. Santomauro
Mechanical Characterization Of Anisotropic Fused Deposition Modeled Polylactic Acid Under Combined Monotonic Bending And Torsion Conditions, Aaron T. Santomauro
Honors Undergraduate Theses
Mechanical strength of polylactic acid (PLA) is increasingly relevant with time because of its attractive mechanical properties and 3D printability. Additive manufacturing (AM) methods, such as fused deposition modeling (FDM), stereolithography (SLA), and selective laser sintering (SLS), serve a vital role in assisting designers with cheap and efficient generation of the desired components. This document presents research to investigate the anisotropic response of multi-oriented PLA subjected to multiple monotonic loading conditions. Although empirical data has previously been captured for multi-oriented PLA under tensile and compressive loading conditions, the data has yet to be applied with regard to a representative component …
Modeling Of Wrong Way Driving Entries And Developing Innovative Approaches For Evaluating The Effectiveness Of Advanced Wrong Way Driving Countermeasures, Md Imrul Kayes
Electronic Theses and Dissertations
Wrong-way driving (WWD) is a hazardous behavior on interstates, toll roads, and other high-speed limited access facilities. Since WWD crashes are rare, recent researchers have studied WWD events such as WWD 911 calls and WWD citations to understand the overall nature and trend of WWD. It is very difficult to build credible statistical models based solely on crashes due to the small sample size since these are only 3% of all crashes. Modeling of WWD non-crash events can result in more accurate models. A model was developed for Florida limited access facilities to identify roadway factors and traffic characteristics of …
Broadband Mid-Infrared Frequency Combs Generated Via Frequency Division, Qitian Ru
Broadband Mid-Infrared Frequency Combs Generated Via Frequency Division, Qitian Ru
Electronic Theses and Dissertations
Frequency combs have revolutionized metrology and demonstrated numerous applications in science and technology. Combs operating in the mid-infrared region could be beneficial for molecular spectroscopy for several reasons. First, numerous molecules have their spectroscopic signatures in this region. Furthermore, the atmospheric window (3-5μm and 8-14μm) is located here. Additionally, a mid-infrared frequency comb could be employed as a diagnostic tool for the many components of human breath, as well as for detection of harmful gases and contaminants in the atmosphere. In this thesis, I used synchronously pumped subharmonic optical parametric oscillators (OPOs) operating at degeneracy to produce ultra-broadband outputs near …
Theoretical And Experimental Study For Tailoring The Electromagnetic Properties Of Conductive Materials, Jeffrey Jennings
Theoretical And Experimental Study For Tailoring The Electromagnetic Properties Of Conductive Materials, Jeffrey Jennings
Electronic Theses and Dissertations
Induction in leaded, implanted medical devices exposed to radio frequency (RF) magnetic fields during magnetic resonance imaging (MRI) produce Joule heating in adjacent tissues causing various issues, including death. Given the importance of MRI as a diagnostic tool and the growth in leaded device-related treatments, identification of a solution ensuring their compatibility is of great interest. Electromagnetic (EM) surface property tailoring in lead materials to change their inductive response by adding functionally-graded, heterogeneous surface layers is a possible solution. However, non-uniform EM properties introduce two challenges: the added complexity of analyses and characterization of the graded region. This dissertation addresses …
Controlled Bubble Dynamics Inside Micropillar Arrays, Faraz Khalil Arya
Controlled Bubble Dynamics Inside Micropillar Arrays, Faraz Khalil Arya
Electronic Theses and Dissertations
Bubble dynamics inside micro domains was manipulated and used to pump liquid. Micropillars were formed inside two 1.5 mm wide and 220 µm high microchannels with a length of 23 mm. One microchannel had three arrays of micropillars with diameters of 40 µm and the other had a single array of micropillars with diameters of 30 µm. An array of five 200 µm by 200 µm heaters was deposited inside these micropillar arrays and was used to control bubble size and trajectory. A sequential power switching of the heaters was used to pump liquid in a desired direction with a …
Hybrid Multi-Objective Optimization Of Left Ventricular Assist Device Outflow Graft Anastomosis Orientation To Minimize Stroke Rate, Blake Lozinski
Hybrid Multi-Objective Optimization Of Left Ventricular Assist Device Outflow Graft Anastomosis Orientation To Minimize Stroke Rate, Blake Lozinski
Electronic Theses and Dissertations
A Left Ventricular Assist Device (LVAD) is a mechanical pump that is utilized as a bridge to transplantation for patients with a Heart Failure (HF) condition. More recently, LVADs have been also used as destination therapy and have provided an increase in the quality of life for patients with HF. However, despite improvements in VAD design and anticoagulation treatment, there remains a significant problem with VAD therapy, namely drive line infection and thromboembolic events leading to stroke. This thesis focuses on a surgical maneuver to address the second of these issues, guided by previous steady flow hemodynamic studies that have …
Investigation Of Coastal Vegetation Dynamics And Persistence In Response To Hydrologic And Climatic Events Using Remote Sensing, Subrina Tahsin
Investigation Of Coastal Vegetation Dynamics And Persistence In Response To Hydrologic And Climatic Events Using Remote Sensing, Subrina Tahsin
Electronic Theses and Dissertations
Coastal Wetlands (CW) provide numerous imperative functions and provide an economic base for human societies. Therefore, it is imperative to track and quantify both short and long-term changes in these systems. In this dissertation, CW dynamics related to hydro-meteorological signals were investigated using a series of LANDSAT-derived normalized difference vegetation index (NDVI) data and hydro-meteorological time-series data in Apalachicola Bay, Florida, from 1984 to 2015. NDVI in forested wetlands exhibited more persistence compared to that for scrub and emergent wetlands. NDVI fluctuations generally lagged temperature by approximately three months, and water level by approximately two months. This analysis provided insight …
A Framework To Develop Anomaly Detection/Fault Isolation Architecture Using System Engineering Principles, Thomas Clark
A Framework To Develop Anomaly Detection/Fault Isolation Architecture Using System Engineering Principles, Thomas Clark
Electronic Theses and Dissertations
For critical systems, timely recognition of an anomalous condition immediately starts the evaluation process. For complex systems, isolating the fault to a component or subsystem results in corrective action sooner so that undesired consequences may be minimized. There are many unique anomaly detection and fault isolation capabilities available with innovative techniques to quickly discover an issue and identify the underlying problems. This research develops a framework to aid in the selection of appropriate anomaly detection and fault isolation technology to augment a given system. To optimize this process, the framework employs a model based systems engineering approach. Specifically, a SysML …
Stragglers-Robust First-Order Distributed Optimization Algorithms Over Networks Utilizing Gradient Coding, Elie Atallah
Stragglers-Robust First-Order Distributed Optimization Algorithms Over Networks Utilizing Gradient Coding, Elie Atallah
Electronic Theses and Dissertations
This dissertation considers distributed algorithms for centralized and decentralized networks that solve general convex optimization problems. First, a centralized algorithm is explored for parameter server networks robust to the straggler problem. It is proved that the server nodes' estimates converge to the minimizer of the global objective function with connections vulnerable to an allowed number of stragglers. We then show that convergence is also attained in other different cases: Either by using only the received local gradients scenario or the scenario of using delayed local gradients for the non received gradients. Concurrently, the convergence rates for the above aforementioned scenarios …
Dynamics Of A Perfectly Premixed Jet Flame Exhibiting Self-Excited High-Frequency, Transverse Thermoacoustic Instabilities, Lucky Tran
Electronic Theses and Dissertations
This work is an investigation of the behavior of a premixed turbulent jet flame in a cylindrical dump combustor. The degeneracy of the simple configuration in this study lends itself for a detailed study of inherent mechanisms of a self-excited thermoacoustic instability in isolation from system coupling effects, enabling detailed numerical simulations to be carried out to supplement experimental findings. Tests were done at a nominal pressure of 8 bar and inlet temperature around 450 ˚C. Self-excited large eddy simulations were also carried out in OpenFOAM, using a b-Ξ flame-wrinkling model to model the combustion process. Eigenfrequency analysis in COMSOL …
Compressible Turbulent Reactions For Hypersonic Propulsion Applications, Jonathan Sosa
Compressible Turbulent Reactions For Hypersonic Propulsion Applications, Jonathan Sosa
Electronic Theses and Dissertations
This work presents the first measurement of turbulent burning velocities of a highly-turbulent compressible standing flame induced by shock-driven turbulence in a Turbulent Shock Tube. High-speed schlieren, chemiluminescence, PIV, and dynamic pressure measurements are made to quantify flame-turbulence interaction for high levels of turbulence at elevated temperatures and pressure. Distributions of turbulent velocities, vorticity and turbulent strain are provided for regions ahead and behind the standing flame. The turbulent flame speed is directly measured for the high-Mach standing turbulent flame. From measurements of the flame turbulent speed and turbulent Mach number, transition into a non-linear compressibility regime at turbulent Mach …
Frequency-Reconfigurable Microstrip Patch And Cavity-Backed Slot Espars, Wei Ouyang
Frequency-Reconfigurable Microstrip Patch And Cavity-Backed Slot Espars, Wei Ouyang
Electronic Theses and Dissertations
Wireless communication systems have rapidly evolved over the past decade which has led to an explosion of mobile data traffic. Since more and more wireless devices and sensors are being connected, the transition from the current 4G/LTE mobile network to 5G is expected to happen within the next decade. In order to improve signal-to-noise ratio (SNR), system capacity, and link budget, beam steerable antenna arrays are desirable due to their advantage in spatial selectivity and high directivity. Electronically steerable parasitic array radiator (ESPAR) that can achieve low-cost continuously beamsteering using varactor diodes have attracted a lot of attention. This dissertation …
A Smart Uav Platform For Railroad Inspection, Ryan Debevec
A Smart Uav Platform For Railroad Inspection, Ryan Debevec
Electronic Theses and Dissertations
Using quadcopters for analysis of an environment has been an intriguing subject of study recently. The purpose of this work is to develop a fully autonomous UAV platform for Railroad inspection The dynamics of the quadrotor is derived using Euler's and Newton's laws and then linearized around the hover position. A PID controller is designed to control the states of the quadrotor in a manner to effectively follow a vision-based path, using the down facing camera on a Parrot Mambo quadrotor. Using computer vision the distance from the position of the quadrotor to the position of the center of the …
Cavitation And Heat Transfer Over Micro Pin Fins, Arash Nayebzadeh
Cavitation And Heat Transfer Over Micro Pin Fins, Arash Nayebzadeh
Electronic Theses and Dissertations
With the dramatic increase in the usage of compact yet more powerful electronic devices, advanced cooling technologies are required to maintain delicate electronic components below their maximum allowable temperatures and prevent them from failure. One solution is to use innovative pin finned heat sinks. This research is centered on the evaluation of hydrodynamic cavitation properties downstream pin fins and extended toward single-phase heat transfer enhancement of array of pin fins in microchannel. In this work, transparent micro-devices capable of local wall temperature measurements were micro fabricated and tested. Various experimental methods, numerical modeling and advanced data processing techniques are presented. …