Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Optics (5)
- Optimization (4)
- Simulation (4)
- Algorithms (3)
- Education (3)
-
- Fatigue (3)
- Frequency combs (3)
- Machine learning (3)
- Modeling (3)
- Photonics (3)
- Raman spectroscopy (3)
- System dynamics (3)
- Action recognition (2)
- Activity recognition (2)
- Adverse events (2)
- Aluminum (2)
- Cerium oxide nanoparticles (2)
- Cognitive (2)
- Complex event recognition (2)
- Composites (2)
- Computer vision (2)
- Cooperative control (2)
- Copper (2)
- Cubesat (2)
- Data envelopment analysis (2)
- Decision support system (2)
- Degradation (2)
- Diffusion (2)
- Droplet (2)
- Fiber amplifier (2)
Articles 1 - 30 of 172
Full-Text Articles in Entire DC Network
Understanding The Capabilities And Limitations Of Advanced Interactive M&S: A Cricothyroidotomy Simulation Case Study, Lillian Campbell-Wynn
Understanding The Capabilities And Limitations Of Advanced Interactive M&S: A Cricothyroidotomy Simulation Case Study, Lillian Campbell-Wynn
Electronic Theses and Dissertations
Simulation for surgical education and training is increasingly perceived as a valuable contribution to traditional teaching methods providing a structured learning experience. Surgical simulations allow surgeons to practice tactics, techniques and procedures numerous times without the cost, limitations and ethical problems of using cadaver-based models. The goal of this research is to advance the use of modeling and simulation in support of emergency medical training. This research explores questions identified through a case study of two different modeling and simulation techniques – virtual reality and mannequins - in the support of combat emergency medical education and training. To reduce the …
Design Optimization Of Llc Topology And Phase Skipping Control Of Three Phase Inverter For Pv Applications, Utsav Somani
Design Optimization Of Llc Topology And Phase Skipping Control Of Three Phase Inverter For Pv Applications, Utsav Somani
Electronic Theses and Dissertations
The world is heading towards an energy crisis and desperate efforts are being made to find an alternative, reliable and clean source of energy. Solar Energy is one of the most clean and reliable source of renewable energy on earth. Conventionally, extraction of solar power for electricity generation was limited to PV farms, however lately Distributed Generation form of Solar Power has emerged in the form of residential and commercial Grid Tied Micro-Inverters. Grid Tied Micro-Inverters are costly when compared to their string type counterparts because one inverter module is required for every single or every two PV panels whereas …
First Principle Studies Of Cu-Carbon Nanotube Hybrid Structures With Emphasis On The Electronic Structures And The Transport Properties, Chengyu Yang
Electronic Theses and Dissertations
Carbon nanotubes have been regarded as ideal building blocks for nanoelectronics and multifunctional nanocomposites due to their exceptional strength, stiffness, flexibility, as well as their excellent electrical properties. However, carbon nanotube itself has limitations to fulfill the practical application needs: 1) an individual carbon nanotube has a low density of states at the Fermi level, and thus its conductivity is only comparable to moderate metals but lower than that of copper. 2) Metallic and semiconducting nanotubes are inherently mixed together from the synthesis, and the selection/separation is very difficult with very low efficiency. 3) Carbon nanotubes alone cannot be used …
Routing, Localization And Positioning Protocols For Wireless Sensor And Actor Networks, Mustafa Akbas
Routing, Localization And Positioning Protocols For Wireless Sensor And Actor Networks, Mustafa Akbas
Electronic Theses and Dissertations
Wireless sensor and actor networks (WSANs) are distributed systems of sensor nodes and actors that are interconnected over the wireless medium. Sensor nodes collect information about the physical world and transmit the data to actors by using one-hop or multi-hop communications. Actors collect information from the sensor nodes, process the information, take decisions and react to the events. This dissertation presents contributions to the methods of routing, localization and positioning in WSANs for practical applications. We first propose a routing protocol with service differentiation for WSANs with stationary nodes. In this setting, we also adapt a sports ranking algorithm to …
Nano-Particles In Multi-Scale Composites And Ballistic Applications, Jason Gibson
Nano-Particles In Multi-Scale Composites And Ballistic Applications, Jason Gibson
Electronic Theses and Dissertations
Carbon nanotubes, graphene and nano sized core shell rubber particles have all been extensively researched for their capability to improve mechanical properties of thermoset resins. However, there has been a lack of research on their evaluation for energy absorption in high velocity impact scenarios, and the fundamental mechanics of their failure mechanisms during highly dynamic stress transfer through the matrix. This fundamental research is essential for laying the foundation for improvement in ballistic performance in composite armor. In hard armor applications, energy absorption is largely accomplished through delamination between plies of the composite laminate. This energy absorption is accomplished through …
Heat And Fluid Flow Characterization Of A Single-Hole-Per-Row Impingement Channel At Multiple Impingement Heights, Roberto Claretti
Heat And Fluid Flow Characterization Of A Single-Hole-Per-Row Impingement Channel At Multiple Impingement Heights, Roberto Claretti
Electronic Theses and Dissertations
The present work studies the relationship between target and sidewall surfaces of a multirow, narrow impingement channel at various jet heights with one impingement hole per row. Temperature sensitive paint and constant flux heaters are used to gather heat transfer data on the target and side walls. Jet-to-target distance is set to 1, 2, 3, 5, 7 and 9 jet diameters. The channel width is 4 jet diameters and the jet stream wise spacing is 5 jet diameters. All cases were run at Reynolds numbers ranging from 5,000 to 30,000. Pressure data is also gathered and used to calculate the …
Integrated Data Fusion And Mining (Idfm) Technique For Monitoring Water Quality In Large And Small Lakes, Benjamin Vannah
Integrated Data Fusion And Mining (Idfm) Technique For Monitoring Water Quality In Large And Small Lakes, Benjamin Vannah
Electronic Theses and Dissertations
Monitoring water quality on a near-real-time basis to address water resources management and public health concerns in coupled natural systems and the built environment is by no means an easy task. Furthermore, this emerging societal challenge will continue to grow, due to the ever-increasing anthropogenic impacts upon surface waters. For example, urban growth and agricultural operations have led to an influx of nutrients into surface waters stimulating harmful algal bloom formation, and stormwater runoff from urban areas contributes to the accumulation of total organic carbon (TOC) in surface waters. TOC in surface waters is a known precursor of disinfection byproducts …
Self-Assembled Two-Component Organic Tubes: Structures And Applications, Wenlang Liang
Self-Assembled Two-Component Organic Tubes: Structures And Applications, Wenlang Liang
Electronic Theses and Dissertations
Bile acids are physiologically important metabolites, which are synthesized in liver as the end products of cholesterol metabolism and then secreted into the intestines. They play a critical role in the digestion and absorption of fats and fat-soluble vitamins through emulsifications. The amphipathic and chiral nature of bile acids makes their unique building blocks for assembling supramolecular structures including vesicles, fibers, ribbons and hollow tubes. Lithocholic acid (LCA) is a secondary bile acid. Our studies show LCA can selfassemble into helical tubes in aqueous solution by the linear aggregation and fusion of vesicles. The objective of this dissertation is to …
Vision-Based Sensing And Optimal Control For Low-Cost And Small Satellite Platforms, Bradley Sease
Vision-Based Sensing And Optimal Control For Low-Cost And Small Satellite Platforms, Bradley Sease
Electronic Theses and Dissertations
Current trends in spacecraft are leading to smaller, more inexpensive options whenever possible. This shift has been primarily pursued for the opportunity to open a new frontier for technologies with a small financial obligation. Limited power, processing, pointing, and communication capabilities are all common issues which must be considered when miniaturizing systems and implementing low-cost components. This thesis addresses some of these concerns by applying two methods, in attitude estimation and control. Additionally, these methods are not restricted to only small, inexpensive satellites, but offer a benefit to large-scale spacecraft as well. First, star cameras are examined for the tendency …
Pulsed Tm-Fiber Laser For Mid-Ir Generation, Pankaj Kadwani
Pulsed Tm-Fiber Laser For Mid-Ir Generation, Pankaj Kadwani
Electronic Theses and Dissertations
The thulium fiber laser has gained interest due to its long emission wavelength, large bandwidth (~1.8 – 2.1 µm), high efficiencies (~60 %), and high output power levels both in cw as well as pulsed regimes. Applications like remote sensing, machining, medical tissue ablation, and mid-infrared generation benefit from high peak power thulium laser sources. Pulsed thulium fiber laser systems are advancing rapidly towards higher peak power levels and are becoming the preferred sources for these applications. This dissertation work describes the development of novel nanosecond pulsed thulium fiber laser systems with record high peak power levels targeting mid-infrared generation. …
Load Estimation For Electric Power Distribution Networks, Chiebuka Eyisi
Load Estimation For Electric Power Distribution Networks, Chiebuka Eyisi
Electronic Theses and Dissertations
In electric power distribution systems, the major determinant in electricity supply strategy is the quantity of demand. Customers need to be accurately represented using updated nodal load information as a requirement for efficient control and operation of the distribution network. In Distribution Load Estimation (DLE), two major categories of data are utilized: historical data and direct real-time measured data. In this thesis, a comprehensive survey on the state-of-the-art methods for estimating loads in distribution networks is presented. Then, a novel method for representing historical data in the form of Representative Load Curves (RLCs) for use in realtime DLE is also …
Fast-Response Liquid Crystals For Photonic And Display Applications, Jie Sun
Fast-Response Liquid Crystals For Photonic And Display Applications, Jie Sun
Electronic Theses and Dissertations
Liquid crystal devices are attractive for many applications such as information displays, spatial light modulators and adaptive optics, because their optical properties are electrically tunable. However, response time of liquid crystal devices is a serious concern for many applications especially for those who require large phase modulation (≥2π). This is because a thick LC layer is usually needed to achieve a large phase shift while the response time of a nematic LC is highly determined by the cell gap.
An Exploration Of Unmanned Aerial Vehicle Direct Manipulation Through 3d Spatial Interaction, Kevin Pfeil
An Exploration Of Unmanned Aerial Vehicle Direct Manipulation Through 3d Spatial Interaction, Kevin Pfeil
Electronic Theses and Dissertations
We present an exploration that surveys the strengths and weaknesses of various 3D spatial interaction techniques, in the context of directly manipulating an Unmanned Aerial Vehicle (UAV). Particularly, a study of touch- and device- free interfaces in this domain is provided. 3D spatial interaction can be achieved using hand-held motion control devices such as the Nintendo Wiimote, but computer vision systems offer a different and perhaps more natural method. In general, 3D user interfaces (3DUI) enable a user to interact with a system on a more robust and potentially more meaningful scale. We discuss the design and development of various …
Investigation On Electrical Properties Of Rf Sputtered Deposited Bcn Thin Films, Adithya Prakash
Investigation On Electrical Properties Of Rf Sputtered Deposited Bcn Thin Films, Adithya Prakash
Electronic Theses and Dissertations
The ever increasing advancements in semiconductor technology and continuous scaling of CMOS devices mandate the need for new dielectric materials with low-k values. The interconnect delay can be reduced not only by the resistance of the conductor but also by decreasing the capacitance of dielectric layer. Also cross-talk is a major issue faced by semiconductor industry due to high value of k of the inter-dielectric layer (IDL) in a multilevel wiring scheme in Si ultra large scale integrated circuit (ULSI) devices. In order to reduce the time delay, it is necessary to introduce a wiring metal with low resistivity and …
Life Long Learning In Sparse Learning Environments, John Reeder
Life Long Learning In Sparse Learning Environments, John Reeder
Electronic Theses and Dissertations
Life long learning is a machine learning technique that deals with learning sequential tasks over time. It seeks to transfer knowledge from previous learning tasks to new learning tasks in order to increase generalization performance and learning speed. Real-time learning environments in which many agents are participating may provide learning opportunities but they are spread out in time and space outside of the geographical scope of a single learning agent. This research seeks to provide an algorithm and framework for life long learning among a network of agents in a sparse real-time learning environment. This work will utilize the robust …
Simulation-Based Cognitive Workload Modeling And Evaluation Of Adaptive Automation Invoking And Revoking Strategies, Christina Rusnock
Simulation-Based Cognitive Workload Modeling And Evaluation Of Adaptive Automation Invoking And Revoking Strategies, Christina Rusnock
Electronic Theses and Dissertations
In human-computer systems, such as supervisory control systems, large volumes of incoming and complex information can degrade overall system performance. Strategically integrating automation to offload tasks from the operator has been shown to increase not only human performance but also operator efficiency and safety. However, increased automation allows for increased task complexity, which can lead to high cognitive workload and degradation of situational awareness. Adaptive automation is one potential solution to resolve these issues, while maintaining the benefits of traditional automation. Adaptive automation occurs dynamically, with the quantity of automated tasks changing in real-time to meet performance or workload goals. …
Active Learning With Unreliable Annotations, Liyue Zhao
Active Learning With Unreliable Annotations, Liyue Zhao
Electronic Theses and Dissertations
With the proliferation of social media, gathering data has became cheaper and easier than before. However, this data can not be used for supervised machine learning without labels. Asking experts to annotate sufficient data for training is both expensive and time-consuming. Current techniques provide two solutions to reducing the cost and providing sufficient labels: crowdsourcing and active learning. Crowdsourcing, which outsources tasks to a distributed group of people, can be used to provide a large quantity of labels but controlling the quality of labels is hard. Active learning, which requires experts to annotate a subset of the most informative or …
Distributed Extremum Seeking And Cooperative Control For Mobile Cooperative Communication Systems, Said Alabri
Distributed Extremum Seeking And Cooperative Control For Mobile Cooperative Communication Systems, Said Alabri
Electronic Theses and Dissertations
In this thesis, a distributed extremum seeking and cooperative control algorithm is designed for mobile agents to disperse themselves optimally in maintaining communication quality and maximizing their coverage. The networked mobile agents locally form a virtual multiple-input multipleoutput (MIMO) communication system, and they cooperatively communicate among them by using the decode and forward cooperative communication technique. The outage probability is used as the measure of communication quality, and it can be estimated real-time. A general performance index balancing outage probability and spatial dispersion is chosen for the overall system. The extremum seeking control approach is used to estimate and optimize …
Generation And Printing Of Strictly Monodisperse Droplets, Hongxu Duan
Generation And Printing Of Strictly Monodisperse Droplets, Hongxu Duan
Electronic Theses and Dissertations
Highly monodisperse droplets are attracting great attention both in many research areas, such as aerosol science, combustion, and Nano-manufacturing. This thesis invents a novel aerosol generator: “Periodic Electro Hydro-dynamic Chopper” termed as “PEHD chopper”, and develops a new method to directly print micro-patterns with monodisperse droplets. The principle of the PEHD chopper is to use the fringe electric field of a capacitor to introduce controlled perturbation on a liquid jet. We first derived the governing equations for a circular inviscid liquid jet under transverse electric fields. The electric fields were obtained through numerical simulation. Then we used a high speed …
A Linear Multiplexed Electrospray Thin Film Deposition System, Brandon Lojewski
A Linear Multiplexed Electrospray Thin Film Deposition System, Brandon Lojewski
Electronic Theses and Dissertations
Liquid spray is essential to industries requiring processes such as spray coating, spray drying, spray pyrolysis, or spray cooling. This thesis reports the design, fabrication, and characterization of a thin film deposition system which utilizes a linear multiplexed electrospray (LINES) atomizer. First, a thorough review of the advantages and limitations of prior multiplexed electrospray systems leads to discussion of the design rationale for this work. Next, the line of charge model was extended to prescribe the operating conditions for the experiments and to estimate the spray profile. The spray profile was then simulated using a Lagrangian model and solved using …
Experimental And Numerical Investigations On Bond Durability Of Cfrp Strengthened Concrete Members Subjected To Environmental Exposure, Haider Al-Jelawy
Experimental And Numerical Investigations On Bond Durability Of Cfrp Strengthened Concrete Members Subjected To Environmental Exposure, Haider Al-Jelawy
Electronic Theses and Dissertations
Fiber reinforced polymer (FRP) composites have become an attractive alternative to conventional methods for external-strengthening of civil infrastructure, particularly as applied to flexural strengthening of reinforced concrete (RC) members. However, durability of the bond between FRP composite and concrete has shown degradation under some aggressive environments. Although numerous studies have been conducted on concrete members strengthened with FRP composites, most of those studies have focused on the degradation of FRP material itself, relatively few on bond behavior under repeated mechanical and environmental loading. This thesis investigates bond durability under accelerated environmental conditioning of two FRP systems commonly employed in civil …
A Framework For Measuring The Value-Added Of Knowledge Processes With Analysis Of Process Interactions And Dynamics, Jose Cintron
A Framework For Measuring The Value-Added Of Knowledge Processes With Analysis Of Process Interactions And Dynamics, Jose Cintron
Electronic Theses and Dissertations
The most known and widely used methods use cash flows and tangible assets to measure the impact of investments in the organization’s outputs. But in the last decade many newer organizations whose outputs are heavily dependent on information technology utilize knowledge as their main asset. These organizations’ market values lie on the knowledge of its employees and their technological capabilities. In the current technology-based business landscape the value added by assets utilized for generation of outputs cannot be appropriately measured and managed without considering the role that intangible assets and knowledge play in executing processes. The analysis of processes for …
Strategic Improvement: A Systems Approach Using The Balanced Scorecard Methodology To Increase Federally Financed Research At The University Of Central Florida, Joseph Walters
Electronic Theses and Dissertations
The University of Central Florida has many successful measures to reflect on as it celebrates its 50th year in 2013. It is the university with the 2nd largest student population in the U. S. and its overall ranking in the U.S. News & World Report has improved 4 years in a row. However, with respect to research, the federally funded research and development for the University of Central Florida (UCF) has remained flat. In addition, when compared to other schools, its portion of those federal research dollars is small. This thesis lays the groundwork for developing a model for improving …
A Real-Time Crane Service Scheduling Decision Support System (Css-Dss) For Construction Tower Cranes, Amir Tork
A Real-Time Crane Service Scheduling Decision Support System (Css-Dss) For Construction Tower Cranes, Amir Tork
Electronic Theses and Dissertations
The success of construction projects depends on proper use of construction equipment and machinery to a great extent. Thus, appropriate planning and control of the activities that rely on construction equipment could have significant effects on improving the efficiency of project operations. Cranes are the largest and most conspicuous construction equipment, widely used in typical construction sites. They play a major role in relocation of materials in horizontal and vertical directions on construction sites. Given the nature of activities relying on construction cranes in various stages of a project, cranes normally have control over the critical path of the project …
Barium Based Halide Scintillator Ceramics For Gamma Ray Detection, William Shoulders
Barium Based Halide Scintillator Ceramics For Gamma Ray Detection, William Shoulders
Electronic Theses and Dissertations
As our understanding of ceramic processing methods for the purpose of fabricating polycrystalline optical materials has increased over the past few decades, the race is on to bring ceramic technology to markets where single crystalline materials have traditionally been used. One such market is scintillators. This Master’s thesis focuses specifically on a class of materials attractive for use as gamma-ray scintillators. These barium based halides can potentially be utilized in applications ranging from ionizing radiation detection in the field to high-energy physics experimentation. Barium bromide iodide and barium chloride single crystals have already showed high light yield, fast scintillation decay, …
Growth And Characterization Of Zno Based Semiconductor Materials And Devices, Ming Wei
Growth And Characterization Of Zno Based Semiconductor Materials And Devices, Ming Wei
Electronic Theses and Dissertations
Wide band gap semiconductors such as MgxZn1-xO represent an excellent choice for making optical photodetectors and emitters operating in the UV spectral region. High crystal and optical quality MgxZn1-xO thin films were grown epitaxially on c-plane sapphire substrates by plasma-assisted Molecular Beam Epitaxy. ZnO thin films with high crystalline quality, low defect and dislocation densities, and sub-nanometer surface roughness were achieved by applying a low temperature nucleation layer. The critical growth conditions were discussed to obtain a high quality film: the sequence of Zn and O sources for initial growth of nucleation layer, growth temperatures for both ZnO nucleation and …
Optically Isotropic Liquid Crystals For Display And Photonic Applications, Jin Yan
Optically Isotropic Liquid Crystals For Display And Photonic Applications, Jin Yan
Electronic Theses and Dissertations
For the past few decades, tremendous progress has been made on liquid crystal display (LCD) technologies in terms of stability, resolution, contrast ratio, and viewing angle. The remaining challenge is response time. The state-of-the-art response time of a nematic liquid crystal is a few milliseconds. Faster response time is desirable in order to reduce motion blur and to realize color sequential display using RGB LEDs, which triples the optical efficiency and resolution density. Polymer-stabilized blue phase liquid crystal (PS-BPLC) is a strong candidate for achieving fast response time because its self-assembled cubic structure greatly reduces the coherence length. The response …
Optimization And Design Of Photovoltaic Micro-Inverter, Qian Zhang
Optimization And Design Of Photovoltaic Micro-Inverter, Qian Zhang
Electronic Theses and Dissertations
To relieve energy shortage and environmental pollution issues, renewable energy, especially PV energy has developed rapidly in the last decade. The micro-inverter systems, with advantages in dedicated PV power harvest, flexible system size, simple installation, and enhanced safety characteristics are the future development trend of the PV power generation systems. The double-stage structure which can realize high efficiency with nice regulated sinusoidal waveforms is the mainstream for the micro-inverter. This thesis studied a double stage micro-inverter system. Considering the intermittent nature of PV power, a PFC was analyzed to provide additional electrical power to the system. When the solar power …
Inverse Problems In Multiple Light Scattering, John Broky
Inverse Problems In Multiple Light Scattering, John Broky
Electronic Theses and Dissertations
The interaction between coherent waves and material systems with complex optical properties is a complicated, deterministic process. Light that scatters from such media gives rise to random fields with intricate properties. It is common perception that the randomness of these complex fields is undesired and therefore is to be removed, usually through a process of ensemble averaging. However, random fields emerging from light matter interaction contain information about the properties of the medium and a thorough analysis of the scattered light allows solving specific inverse problems. Traditional attempts to solve these kinds of inverse problems tend to rely on statistical …
Evaluation Of The Biodegradability And Toxicity Of Pca And Mpca, Juan Rueda
Evaluation Of The Biodegradability And Toxicity Of Pca And Mpca, Juan Rueda
Electronic Theses and Dissertations
The main types of hypergolic propellants used at Kennedy Space Center (KSC) are hydrazine (HZ) and monomethylhydrazine (MMH). HZ and MMH are classified as hazardous materials and they are also known to be potentially carcinogenic to humans; therefore, handling these substances and their waste is strictly regulated. The wastes streams from HZ and MMH have been estimated to be the main hazardous wastes streams at KSC. Currently at KSC these wastes are first neutralized using citric acid and then they are transported on public roads for incineration as hazardous materials. A new method using alpha ketoglutaric acid (AKGA) was proposed …