Digital Commons Network^™

Multi-Objective Optimal Dispatch Of Distributed Energy Resources, Ayomide Longe

Masters Theses

"This thesis is composed of two papers which investigate the optimal dispatch for distributed energy resources. In the first paper, an economic dispatch problem for a community microgrid is studied. In this microgrid, each agent pursues an economic dispatch for its personal resources. In addition, each agent is capable of trading electricity with other agents through a local energy market. In this paper, a simple market structure is introduced as a framework for energy trades in a small community microgrid such as the Solar Village. It was found that both sellers and buyers benefited by participating in this market. In …

A Sentence-Based Image Search Engine, Weizhi Meng

Masters Theses

"Nowadays people are more interested in searching the relevant images directly through search engines like Google, Yahoo or Bing, these image search engines have dedicated extensive research effort to the problem of keyword-based image retrieval. However, the most widely used keyword-based image search engine Google is reported to have a precision of only 39%. And all of these systems have limitation in creating sentence-based queries for images.

This thesis studies a practical image search scenario, where many people feel annoyed by using only keywords to find images for their ideas of speech or presentation through trial and error. This thesis …

Detection And Cancellation Of Sinusoidal Fading Power Variation In Wireless Communication Systems, Sushruth Sastry

Masters Theses

"Fading channel estimation in wireless communication systems depends on an expected model for fading and any assumptions made about the channel itself. The bit error rate (BER) performance of the communication system is affected by how closely these assumptions made in designing the estimation technique match the deployment environment. Any unforeseen disturbances or hindrances in the environment deteriorate the BER performance of the system when the estimation system is not designed to combat such disturbances. To deal with such unforeseen obstacles, additional mathematical models can be proposed to model such disturbances and then the estimation techniques can either be reinforced …

Development Of Two Color Imaging Pyrometer For Studying Thermal History Of Laser Metal Deposition, Niroop Matta

Masters Theses

"The laser aided manufacturing process is a process in which parts are built by adding material into the melt pool created by a laser. This process involves a complex thermal history which is important in determining the quality of the parts built. The objective of this study is to develop a high resolution two color imaging pyrometer which can measure the temperature of an object without the dependence of spectral emissivity of the material at an economical price. An 8.8 MP CMOS sensor is used as an imaging sensor. The visible spectrum of light is used for temperature measurement. The …

Small Sample Saddlepoint Confidence Intervals In Epidemiology, Pasan Manuranga Edirisinghe

Doctoral Dissertations

"In section 1, we develop a novel method of confidence interval construction for directly standardized rates. These intervals involve saddlepoint approximations to the intractable distribution of a weighted sum of Poisson random variables and the determination of hypothetical Poisson mean values for each of the age groups. Simulation studies show that, in terms of coverage probability and length, the saddlepoint confidence interval (SP) outperforms four competing confidence intervals obtained from the moment matching (M8), gamma-based (G1,G4) and ABC bootstrap (ABC) methods.

In section 2, we first consider Brillinger's classical model for a vital rate estimate with a random denominator. We …

Electrical Resistivity Imaging For Long-Term Autonomous Monitoring Of Hydrocarbon Degradation: Lessons From The Deepwater Horizon Oil Spill, Jeffrey W. Heenan, Lee D. Slater, Dimitrios Ntarlagiannis, Estella A. Atekwana, Babu Z. Fathepure, Sonal Dalvi, Cameron Ross, D. Dale Werkema, Eliot A. Atekwana

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Conceptual models for the geophysical responses associated with hydrocarbon degradation suggest that the long-term evolution of an oil plume will result in a more conductive anomaly than the initial contamination. In response to the Deepwater Horizon (DH) oil spill into the Gulf of Mexico in 2010, an autonomous resistivity monitoring system was deployed on Grand Terre, Louisiana, in an attempt to monitor natural degradation processes in hydrocarbon-impacted beach sediments of this island. A 48-electrode surface array with a 0.5-m spacing was installed to obtain twice-daily images of the resistivity structure of the shallow subsurface impacted by oil. Over the course …

Quantitative Modeling Of The Equilibration Of Two-Phase Solid-Liquid Fe By Atomistic Simulations On Diffusive Time Scales, Ebrahim Asadi, Mohsen Asle Zaeem, Sasan Nouranian, Michael I. Baskes

Materials Science and Engineering Faculty Research & Creative Works

In this paper, molecular dynamics (MD) simulations based on the modified-embedded atom method (MEAM) and a phase-field crystal (PFC) model are utilized to quantitatively investigate the solid-liquid properties of Fe. A set of second nearest-neighbor MEAM parameters for higherature applications are developed for Fe, and the solid-liquid coexisting approach is utilized in MD simulations to accurately calculate the melting point, expansion in melting, latent heat, and solid-liquid interface free energy, and surface anisotropy. The required input properties to determine the PFC model parameters, such as liquid structure factor and fluctuations of atoms in the solid, are also calculated from MD …

Narrow-Band Search Of Continuous Gravitational-Wave Signals From Crab And Vela Pulsars In Virgo Vsr4 Data, J. Aasi, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

In this paper we present the results of a coherent narrow-band search for continuous gravitational-wave signals from the Crab and Vela pulsars conducted on Virgo VSR4 data. In order to take into account a possible small mismatch between the gravitational-wave frequency and two times the star rotation frequency, inferred from measurement of the electromagnetic pulse rate, a range of 0.02 Hz around two times the star rotational frequency has been searched for both the pulsars. No evidence for a signal has been found and 95% confidence level upper limits have been computed assuming both that polarization parameters are completely unknown …

The Role Of Multiple Electron Capture In The X-Ray Emission Process Following Charge Exchange Collisions With Neutral Targets, Sebastian Otranto, N. D. Cariatore, Ronald E. Olson

Physics Faculty Research & Creative Works

In this work we theoretically study photonic spectra that follow charge exchange processes between highly charged ions and neutral argon and CO targets. The range of collision energies studied is 5 eV/amu-10 keV/amu, covering typical EBIT-traps and Solar Wind energies. Our studies are based on multiple electrons schemes within the classical trajectory Monte Carlo method. Electrons are sorted with the sequential binding energies for the target under consideration. The role played by the multiple electron capture process for the different collision systems under consideration is explicitly analyzed and its contribution separated as arising from double radiative decay and autoionizing multiple …

One-Loop Dominance In The Imaginary Part Of The Polarizability: Application To Blackbody And Noncontact Van Der Waals Friction, Ulrich D. Jentschura, Grzegorz Lach, Maarten Dekieviet, Krzysztof Pachucki

Physics Faculty Research & Creative Works

Phenomenologically important quantum dissipative processes include blackbody friction (an atom absorbs counterpropagating blueshifted photons and spontaneously emits them in all directions, losing kinetic energy) and noncontact van der Waals friction (in the vicinity of a dielectric surface, the mirror charges of the constituent particles inside the surface experience drag, slowing the atom). The theoretical predictions for these processes are modified upon a rigorous quantum electrodynamic treatment, which shows that the one-loop "correction" yields the dominant contribution to the off-resonant, gauge-invariant, imaginary part of the atom's polarizability at room temperature, for typical atom-surface interactions. The tree-level contribution to the polarizability dominates …

Long-Range Atom-Wall Interactions And Mixing Terms: Metastable Hydrogen, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

We investigate the interaction of metastable 2S hydrogen atoms with a perfectly conducting wall, including parity-breaking S-P mixing terms (with full account of retardation). The neighboring 2P_1/2 and 2P_3/2 levels are found to have a profound effect on the transition from the short-range, nonrelativistic regime, to the retarded form of the Casimir-Polder interaction. The corresponding P state admixtures to the metastable 2S state are calculated. We find the long-range asymptotics of the retarded Casimir-Polder potentials and mixing amplitudes for general excited states, including a fully quantum electrodynamic treatment of the dipole-quadrupole mixing term. The decay width of the …

Electron- And Photon-Impact Ionization Of Furfural, D. B. Jones, E. Ali, K. L. Nixon, P. Limão-Vieira, M.-J. Hubin-Franskin, J. Delwiche, C. G. Ning, J. Colgan, Andrew J. Murray, Don H. Madison, M .J. Brunger

Physics Faculty Research & Creative Works

The He(i) photoelectron spectrum of furfural has been investigated, with its vibrational structure assigned for the first time. The ground and excited ionized states are assigned through ab initio calculations performed at the outer-valence Green's function level. Triple differential cross sections (TDCSs) for electron-impact ionization of the unresolved combination of the 4a" + 21a' highest and next-highest occupied molecular orbitals have also been obtained. Experimental TDCSs are recorded in a combination of asymmetric coplanar and doubly symmetric coplanar kinematics. The experimental TDCSs are compared to theoretical calculations, obtained within a molecular 3-body distorted wave framework that employed either an orientation …

Developing, Using, And Interacting In The Flipped Learning Movement: Gaps Among Subject Areas, Hsin-Liang Chen, Kevin L. Summers

University Libraries Faculty Research & Creative Works

The purpose of this paper is to investigate the current video collection of an open-access video website (TED-Ed). The research questions focus on its content as evidence of development, its viewership as evidence of use, and flipping as evidence of interaction in informal learning. In late September 2013, 686 video lessons were posted on the TED-Ed website that spanned 12 academic subject categories and 60 academic subject subcategories, as labeled and sorted on the TED-Ed website itself. The findings of the analysis of the TED-Ed video collection indicate several gaps in the humanities, social science, and natural science academic areas …

Comparisons Of Horizontal-Axis Wind Turbine Wake Interaction Models, Jordan M. Wilson, Cole J. Davis, Subhas K. Venayagamoorthy, Paul R. Heyliger

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, Reynolds-averaged Navier-Stokes (RANS) simulations are performed using the k-ϵ and k-ω shear stress transport (SST) turbulence closure schemes to investigate the interactions of horizontal-axis wind turbine (HAWT) models in the neutrally stratified atmospheric boundary layer (ABL). A comparative study of actuator disk, actuator line, and full rotor models of the National Renewable Energy Laboratory (NREL) 5 MW reference turbine is presented. The open-source computational fluid dynamics (CFD) code open foam 2.1.0 and the commercial software ANSYS fluent 13.0 are used for simulations. Single turbine models are analyzed for turbulent structures and wake resolution in the downstream region. …

Comparison Of Single- And Dual-Polarization-Based Rainfall Estimates Using Nexrad Data For The Nasa Iowa Flood Studies Project, Bong Chul Seo, Brenda Dolan, Witold F. Krajewski, Steven A. Rutledge, Walter Petersen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This study compares and evaluates single-polarization (SP)- and dual-polarization (DP)-based radar rainfall (RR) estimates using NEXRAD data acquired during Iowa Flood Studies (IFloodS), a NASA GPM ground validation field campaign carried out in May-June 2013. The objective of this study is to understand the potential benefit of the DP quantitative precipitation estimation, which selects different rain-rate estimators according to radar-identified precipitation types, and to evaluate RR estimates generated by the recent research SP and DP algorithms. The Iowa Flood Center SP (IFC-SP) and Colorado State University DP(CSU-DP) products are analyzed and assessed using two high-density, high-quality rain gauge networks as …

Data-Enabled Field Experiment Planning, Management, And Research Using Cyberinfrastructure, Ibrahim Demir, Helen Conover, Witold F. Krajewski, Bong Chul Seo, Radosław Goska, Yubin He, Michael F. Mceniry, Sara J. Graves, Walter Petersen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In the spring of 2013, NASA conducted a field campaign known as Iowa Flood Studies (IFloodS) as part of the Ground Validation (GV) program for the Global Precipitation Measurement (GPM) mission. The purpose of IFloodS was to enhance the understanding of flood-related, space-based observations of precipitation processes in events that transpire worldwide. NASA used a number of scientific instruments such as ground based weather radars, rain and soil moisture gauges, stream gauges, and disdrometers to monitor rainfall events in Iowa. This article presents the cyberinfrastructure tools and systems that supported the planning, reporting, and management of the field campaign and …

Nexrad Nws Polarimetric Precipitation Product Evaluation For Ifloods, Luciana K. Cunha, James A. Smith, Witold F. Krajewski, Mary Lynn Baeck, Bong Chul Seo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The NEXRAD program has recently upgraded the WSR-88D network observational capability with dual polarization (DP). In this study, DP quantitative precipitation estimates (QPEs) provided by the current version of the NWS system are evaluated using a dense rain gauge network and two other single-polarization (SP) rainfall products. The analyses are performed for the period and spatial domain of the Iowa Flood Studies (IFloodS) campaign. It is demonstrated that the current version (2014) of QPE from DP is not superior to that from SP mainly because DP QPE equations introduce larger bias than the conventional rainfall- reflectivity [i.e., R(Z)] relationship for …

The Formation And Fate Of Internal Waves In The South China Sea, Matthew H. Alford, Thomas Peacock, Jennifer A. Mackinnon, Jonathan D. Nash, Maarten C. Buijsman, Luca A. Centurioni, Shenn-Yu Chao, Ming-Huei Chang, David M. Farmer, Oliver B. Fringer, Ke-Hsien Fu, Patrick C. Gallacher, Hans C. Graber, Karl R. Helfrich, Steven M. Jachec, Christopher R. Jackson, Jody M. Klymak, Dong S. Ko, Sen Jan, T. M. Shaun Johnson, Sonya Legg, I-Huan Lee, Ren-Chih Lien, Matthew J. Mercier, James N. Mourn, Ruth Musgrave, Jae-Hun Park, Andrew I. Pickering, Robert Pinkel, Luc Rainville, Steven R. Ramp, Daniel L. Rudnick, Sutanu Sarkar, Alberto Scotti, Harper L. Simmons, Louis C. St. Laurent, Subhas Karan Venayagamoorthy, Yu-Huai Wang, Joe Wang, Ying J. Yang, Theresa Paluszkiewicz, Tswen-Yung David Tang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Internal gravity waves, the subsurface analogue of the familiar surface gravity waves that break on beaches, are ubiquitous in the ocean. Because of their strong vertical and horizontal currents, and the turbulent mixing caused by their breaking, they affect a panoply of ocean processes, such as the supply of nutrients for photosynthesis¹, sediment and pollutant transport² and acoustic transmission³; they also pose hazards for man-made structures in the ocean⁴. Generated primarily by the wind and the tides, internal waves can travel thousands of kilometers from their sources before breaking⁵, making it …

Efficient Calculation Of Large Finite Periodic Structures Based On Surface Wave Analysis, Xiaoyan Y.Z. Xiong, Ling Ling Meng, Li (Lijun) Jun Jiang, Wei E.I. Sha, Fan Yang

Electrical and Computer Engineering Faculty Research & Creative Works

The electromagnetic modeling of practical finite periodic structures is a topic of growing interest. Due to the truncation of infinite periodic structures, surface waves will be excited and localized near discontinuous interfaces leading to the edge effect. In this work, surface waves are numerically extracted and their magnitudes and decay rates are analyzed for different materials and geometries. Based on the exponential decay of the surface wave, a novel method is developed by connecting the solution to the large finite array problem with that to a relatively small one to achieve low complexity and memory consumption. The method numerically reconstructs …

Electrospray Of An Energetic Ionic Liquid Monopropellant For Multi-Mode Micropropulsion Applications, Steven P. Berg, Joshua L. Rovey, Benjamin D. Prince, Shawn W. Miller, Raymond J. Bemish

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The multi-mode chemical-electric propulsion capable energetic ionic liquid propellant [Emim][EtSO4]-HAN is electro sprayed in a 100 µm capillary emitter to test the electric-mode performance of the propellant. The ionic liquid exhibits stable electrospray emission in both cation and anion extraction modes at a nominal extraction voltage of 3400 V. Near field measurements of current and mass flow rate distribution are taken at flow rates from 0.19 nL/s to 3.06 nL/s. Total emission current, as measured by Faraday cup and integrated, increases from 754 nA to 3195 nA for cation emission and from 552 nA to 2012 nA for anion emission. …

Model For Consolidation Analysis Of Layered Soils Under Depth-Dependent Loading, Hefu Pu, Patrick J. Fox

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A numerical model is presented for one-dimensional large strain consolidation of a layered soil stratum. The algorithm accounts for vertical strain, soil self-weight, conventional constitutive relationships, changing material properties during consolidation, unload/reload, time-dependent loading and boundary conditions, an externally applied hydraulic gradient, and multiple soil layers with different material properties. The model can also accommodate depth-dependent loading and variable preconsolidation stress profiles. Verification checks of the model show excellent agreement with available analytical and numerical solutions for consolidation of soils with multiple layers and depth-dependent loading. An overview of this model is presented, and a parametric study is performed to …

Development, Testing, And Analytical Modeling Of Fiber-Reinforced Polymer Bridge Deck Panels, Hesham R. Tuwair

Doctoral Dissertations

A fiber-reinforced, polyurethane foam core was developed, tested, and evaluated as a possible replacement for the costly honeycomb core that is currently used to manufacture fiber-reinforced polymer (FRP) bridge deck panels. Replacing these panels would reduce both initial production costs and construction times while also enhancing structural performance. Experimental, numerical, and analytical investigations were each conducted. Three different polyurethane foam (PU) configurations were used for the inner core during the study’s first phase. These configurations consisted of a high-density PU foam (Type 1), a gridwork of thin, interconnecting, glass fiber/resin webs that formed a bidirectional gridwork in-filled with a low-density …

Evolutionary Dynamics Of Speciation And Extinction, Dawn Michelle King

Doctoral Dissertations

Presented here is an interdisciplinary study that draws connections between the fields of physics, mathematics, and evolutionary biology. Importantly, as we move through the Anthropocene Epoch, where human-driven climate change threatens biodiversity, understanding how an evolving population responds to extinction stress could be key to saving endangered ecosystems. With a neutral, agent-based model that incorporates the main principles of Darwinian evolution, such as heritability, variability, and competition, the dynamics of speciation and extinction is investigated. The simulated organisms evolve according to the reaction-diffusion rules of the 2D directed percolation universality class. Offspring are generated according to one of three reproduction …

Privacy-Preserving Power Usage Control In Smart Grids, Huchun

Doctoral Dissertations

"The smart grid (SG) has been emerging as the next-generation intelligent power grid system because of its ability to efficiently monitor, predicate, and control energy generation, transmission, and consumption by analyzing users' real-time electricity information. Consider a situation in which the utility company would like to smartly protect against a power outage. To do so, the company can determine a threshold for a neighborhood. Whenever the total power usage from the neighborhood exceeds the threshold, some or all of the households need to reduce their energy consumption to avoid the possibility of a power outage. This problem is referred to …

High-Performance Extreme Learning Machines: A Complete Toolbox For Big Data Applications, Anton Akusok, Kaj Mikael Bjork, Yoan Miche, Amaury Lendasse

Engineering Management and Systems Engineering Faculty Research & Creative Works

This Paper Presents a Complete Approach to a Successful Utilization of a High-Performance Extreme Learning Machines (Elms) Toolbox for Big Data. It Summarizes Recent Advantages in Algorithmic Performance; Gives a Fresh View on the Elm Solution in Relation to the Traditional Linear Algebraic Performance; and Reaps the Latest Software and Hardware Performance Achievements. the Results Are Applicable to a Wide Range of Machine Learning Problems and Thus Provide a Solid Ground for Tackling Numerous Big Data Challenges. the Included Toolbox is Targeted at Enabling the Full Potential of Elms to the Widest Range of Users.

Particle Swarm Optimization Based Selective Ensemble Of Online Sequential Extreme Learning Machine, Yang Liu, Bo He, Diya Dong, Yue Shen, Tianhong Yan, Rui Nian, Amaury Lendasse

Engineering Management and Systems Engineering Faculty Research & Creative Works

A Novel Particle Swarm Optimization based Selective Ensemble (PSOSEN) of Online Sequential Extreme Learning Machine (OS-ELM) is Proposed. It is based on the Original OS-ELM with an Adaptive Selective Ensemble Framework. Two Novel Insights Are Proposed in This Paper. First, a Novel Selective Ensemble Algorithm Referred to as Particle Swarm Optimization Selective Ensemble is Proposed, noting that PSOSEN is a General Selective Ensemble Method Which is Applicable to Any Learning Algorithms, Including Batch Learning and Online Learning. Second, an Adaptive Selective Ensemble Framework for Online Learning is Designed to Balance the Accuracy and Speed of the Algorithm. Experiments for Both …

Dynamic Behavior Of Operational Wind Turbines Considering Aerodynamic And Seismic Load Interaction, Mohammad-Amin Asareh

Doctoral Dissertations

"With the advancements in the wind energy production industry, the demand for a cost effective and safe design of wind turbine structures is growing rapidly. The wide deployment of wind turbines in locations with high seismic hazard has lead engineers to take into account a more comprehensive seismic design of such structures. In response to the need for a computational tool that can perform coupled simulations of wind and seismic loads, a seismic module has been developed for the publicly available National Renewable Energy Laboratory (NREL) code, FAST, at the first step of this research. This achievement allows engineers working …

Synthesis, Characterization And Application Of Acrylic Colloidal Unimolecular Polymer (Cup), Ameya Manohar Natu

Doctoral Dissertations

"Colloidal Unimolecular Polymer (CUP) particles were prepared by the process of water reduction on amphiphilic acrylic copolymers prepared via free radical polymerization technique. The formation of CUP particles was driven by the polymer-polymer interaction being greater than the polymer-solvent interaction and entropically favored by release of the water. It was demonstrated by Dynamic Light Scattering technique that CUP particles based on copolymers below 13,000 MW were unstable and the particles aggregated to a higher particle size. For the polymers with molecular weight (MW) above 13,000, a good correlation between the theoretical and experimental CUP particle size was observed. The rheology …

Advancements In Uncertainty Quantification With Stochastic Expansions Applied To Supersonic And Hypersonic Flows, Thomas Kelsey West Iv

Doctoral Dissertations

"The primary objective of this study was to develop improved methodologies for efficient and accurate uncertainty quantification with stochastic expansions and apply them to problems in supersonic and hypersonic flows. Methods introduced included approaches for efficient dimension reduction, sensitivity analysis, and sparse approximations. These methods and procedures were demonstrated on multiple stochastic models of hypersonic, planetary entry flows, which included high-fidelity, computational fluid dynamics models of radiative heating on the surface of hypersonic inflatable aerodynamic decelerators during Mars and Titan entry. For these stochastic problems, construction of an accurate surrogate model was achieved with as few as 10% of the …

Stability Design Criteria And Volt Var Control For Distribution System With Single Phase Solid State Transformers, Darshit Girishchandra Shah

Doctoral Dissertations

Due to recent advancements in semiconductor technology, power electronic converters for high voltage, high power, and high frequency applications will soon be commercially available. Conventional single phase distribution transformers are replaced by solid state transformers (SST) in a distribution test system to investigate their interactive dynamics. Under certain circumstances, instabilities due to harmonic resonance are observed. A design criterion for solid state transformer during no load conditions has been proposed in order to avoid instability using an impedance-based analysis. Stability assessment is also extended to include the impact of distribution system voltages and system wide impedance analysis. It is shown …