Physical Sciences and Mathematics Commons^™

Quantifying Risks Of Climate Change And Sea Level Rise To Naval Station Norfolk (Serdp Rc-1701), Kelly Burks-Copes

October 2, 2013: Quantifying Risks and Moving Forward

No abstract provided.

Use Of Immersive Visualization For The Control Of Dental Anxiety During Dental Hygiene Treatment, Carmelo Padrino-Barrios

Dental Hygiene Theses & Dissertations

Purpose: The purpose of this study was to determine the effectiveness of immersive visualization (IV) therapy, a technique that provides visual and stereoscopic display through the use of eyewear, in anxious patients during an oral prophylaxis. Methods: A convenience sample of thirty adults was enrolled. A split mouth design was utilized. Subjects were randomly divided into two groups: group A (use of IV for the right side of the mouth), and group B (use of IV for the left side of the mouth). Subjects received a full mouth oral prophylaxis (removal of supra and subgingival calculus and selective polishing), always …

Using Real Property Layouts To Study The Foreclosure Contagion Effect In Real Estate With Agent-Based Modeling And Simulation, Daniele Vernon-Bido

Computational Modeling & Simulation Engineering Theses & Dissertations

Foreclosures in the United States increased sharply from 2007 to 2009. These foreclosures had a spillover effect on neighboring property values causing additional foreclosures. This is known as the foreclosure contagion effect.

Recent studies have quantified the discount attributed to foreclosure contagion using equation-based techniques. However, the discount varied between studies and markets. Further studies using agent-based modeling and simulation have demonstrated the relationship between the discounts, the time a foreclosure remains on the market, the prevailing interest rates and the average property values.

This study uses agent-based modeling and simulation (ABMS) to explore the differences that varying neighborhood densities …

Http Mailbox - Asynchronous Restful Communication, Sawood Alam

Computer Science Theses & Dissertations

Traditionally, general web services used only the GET and POST methods of HTTP while several other HTTP methods like PUT, PATCH, and DELETE were rarely utilized. Additionally, the Web was mainly navigated by humans using web browsers and clicking on hyperlinks or submitting HTML forms. Clicking on a link is always a GET request while HTML forms only allow GET and POST methods. Recently, several web frameworks/libraries have started supporting RESTful web services through APIs. To support HTTP methods other than GET and POST in browsers, these frameworks have used hidden HTML form fields as a workaround to convey the …

Field Emission Studies Toward Improving The Performance Of Dc High Voltage Photoelectron Guns, Mahzad Bastaninejad

Mechanical & Aerospace Engineering Theses & Dissertations

Field emission is the main mechanism that prevents DC high voltage photoemission electron guns from operating at the very high bias voltages required to produce low emittance beams. Gas conditioning is shown to eliminate field emission from cathode electrodes used inside DC high voltage photoelectron guns. Measurements and simulation results indicate that gas conditioning eliminates field emission from cathode electrodes via two mechanisms: sputtering and implantation, with the benefits of implantation reversed by heating the electrode. The field emission characteristics of 5 stainless steel electrodes varied significantly upon the initial application of voltage but improved to nearly the same level …

Protein Loop Length Estimation From Medium Resolution Cryoem Images, Andrew R. Mcknight

Computer Science Theses & Dissertations

In the post-genomic era, proteomics research presents a new frontier in life science. Proteins play roles in virtually every biological process, and understanding their atomic structures is the key to unraveling how they carry out their work. Compared to the over half million protein sequences in UniProt, only around 25,000 unique sequences have been atomically modeled and deposited to PDB (Protein Databank). Cryoelectron Microscopy (cryoEM) is an important biophysical technique that produces 3D subnanometer resolution images of molecules not amenable to past approaches like x-ray crystallography or nuclear magnetic resonance. De novo modeling is becoming a promising approach to derive …

Improving The Stability Of High And Low Bandgap Polymers Organic Photovoltaic Devices Using A Solution Based Titanium Sub-Oxide Interfacial Layer, Kurniawan Foe

Electrical & Computer Engineering Theses & Dissertations

The improvement in device efficiency has brought organic photovoltaic (OPV) devices closer to commercial viability, highlighting the importance of studying the lifetime and stability of OPV devices. At present, the lifetime and stability of OPV devices is much shorter and poor mainly caused by oxygen, moisture, and light resulting in the oxidation on low work function electrodes and the degradation of the morphology of the photoactive layer. To improve the lifetime and stability of the OPV devices, we used newly developed low bandgap polymer, PCDTBT, as the electron acceptor material and a solution based titanium sub-oxide (TiOx) interfacial layer inserted …

A Multi-Configuration Display Methodology Incorporating Reflection For Real-Time Haptic-Interactive Virtual Environments, Mohammad F. Obeid

Computational Modeling & Simulation Engineering Theses & Dissertations

There is a natural need for real-time min-or reflection in many interactive virtual reality applications to achieve visuo-haptic collocation through optical reflection. Its use, however, calls for adjustments to the original model since a mirror reverses image characteristics. This thesis introduces a design and implementation of a generic configuration component for virtual environments that adjusts image characteristics and haptic interfaces to accommodate various display setups while preserving the correct orientation and properties of the original models in the graphical scene. Four different but related approaches were developed for image connection and are compared and contrasted against primary criteria. The haptic …

Atmospheric Pressure He-Air Plasma Jet: Breakdown Process And Propagation Phenomenon, Asma Begum, Mounir Laroussi, Mohammad Rasel Pervez

Electrical & Computer Engineering Faculty Publications

In this paper He-discharge (plasma jet/bullet) in atmospheric pressure air and its progression phenomenon has been studied experimentally using ICCD camera, optical emission spectroscopy (OES) and calibrated dielectric probe measurements. The repetitive nanosecond pulse has applied to a plasma pencil to generate discharge in the helium gas channel. The discharge propagation speed was measured from the ICCD images. The axial electric field distribution in the plasma jet is inferred from the optical emission spectroscopic data and from the probe measurement. The correlation between the jet velocities, jet length with the pulse duration is established. It shows that the plasma jet …

Tdma Slot Reservation In Cluster-Based Vanets, Mohammad Salem Almalag

Computer Science Theses & Dissertations

Vehicular Ad Hoc Networks (VANETs) are a form of Mobile Ad Hoc Networks (MANETs) in which vehicles on the road form the nodes of the network. VANETs provide several services to enhance the safety and comfort of drivers and passengers. These services can be obtained by the wireless exchange of information among the vehicles driving on the road. In particular, the transmission of two different types of messages, safety/update and non-safety messages.

The transmission of safety/update message aims to inform the nearby vehicles about the sender's current status and/or a detected dangerous situation. This type of transmission is designed to …

Computational Dynamics For The Flexible Multi-Body System, Yu Liu

Mechanical & Aerospace Engineering Theses & Dissertations

Research in computational dynamics has tremendously developed in the recent years because of the demand for analysis and simulation of various multi-body systems in the growing bio-medical, mechanical and aerospace industries. These multi-body systems are made of individual bodies that are interconnected via mechanical joints. Mathematically, these joints that connect the bodies can be described as constraint equations imposed upon the motions of the involved free bodies. This process will result in an equation of motion expressed in the form of a differential-algebraic equation (DAE). This is one of the main difficulties when dealing with the multi-body system because these …

Evaluating Alternatives For Augmented Water Quality Improvement Utilizing Oyster Restoration As Best Management Practice (Bmp), Stephanie Roberts Long

Civil & Environmental Engineering Theses & Dissertations

Due to several anthropogenic influences, the Chesapeake Bay has experienced a marked decrease in water quality since the colonists arrived at the Jamestown settlement in Virginia during the 1600s. Higher concentrations of nitrogen and phosphorus have enriched the estuaries and coastal waters via point sources (sewage treatment plants and industrial wastes), nonpoint sources (agricultural run-off and septic tank discharges) and the atmosphere (Newell et al., 2005). Restoring oyster beds is considered a Best Management Practice (BMP) to improve water quality as well as provide physical habitat for aquatic species and a healthier estuarine system (USACE Native Oyster Restoration Master …

Asbpa Sea Level Rise Findings, Maura Boswell

March 13, 2013: Regional Sea Level Rise Assessment, Adaptation and Flood Mitigation Projects

No abstract provided.

City Of Norfolk Coastal Flood Mitigation Program, Brian Joyner

March 13, 2013: Regional Sea Level Rise Assessment, Adaptation and Flood Mitigation Projects

No abstract provided.

Willoughby Spit Shoreline Improvement Project Of Ocean View Beach, Maura Boswell

March 13, 2013: Regional Sea Level Rise Assessment, Adaptation and Flood Mitigation Projects

No abstract provided.

Fema Region Iii Coastal Storm Surge Study, Mike Forte, Jeff Hanson, Michelle Hamor

March 13, 2013: Regional Sea Level Rise Assessment, Adaptation and Flood Mitigation Projects

No abstract provided.

Usace Flood Risk Management Partners In Shared Responsibility, Michelle Hamor

March 13, 2013: Regional Sea Level Rise Assessment, Adaptation and Flood Mitigation Projects

No abstract provided.

Recurrent Coastal Flooding: How Should Virginia Respond?, Molly Mitchell Rogerro

March 13, 2013: Regional Sea Level Rise Assessment, Adaptation and Flood Mitigation Projects

No abstract provided.

The Root Cause Of Failure In Complex It Projects: Complexity Itself, Kaitlynn M. Whitney, Charles B. Daniels

Engineering Management & Systems Engineering Faculty Publications

Increased demand for better technology and perpetual global expansion continue to provide developers with many project opportunities for success, as well as failure. While no industry is immune from project failure, the Information Technology (IT) industry is shown to be more susceptible to risk and failure than those of other industries. Agile project management, which facilitates adaptation to changing circumstances and alleviates rigid formal controls, has become more popular in the software development industry though is not entirely compatible with traditional project management approaches.In this paper we will examine the primary causes of IT project management failure stated in modern …

Brust-Schiffrin Synthesis Of Catalytic Bipodal Pdpt Nanoparticles With Some Mechanistic Insights, Sangbum Han, Vara P. Sheela, Wei Cao, Balasubramanian Ramjee

Applied Research Center Publications

Brust–Schiffrin reduction of Pd and Pt precursors in the presence of resorcinarene amine surfactant led to the formation of substantially Pt rich, PdPt bimetallic nanoparticles of a V-shape or variants on the V-shape. New insights into this reaction are provided on the basis of reversed Brust–Schiffrin syntheses, DLS, UV-vis, and NMR analysis. Based on our experiments we conclude that the resorcinarene amine surfactant is part of the inverse micelle formed from TOABr and it also selectively complexes with the Pd salts prior to their reduction. Remarkably, the composition of the bipodal nanoparticles could be varied substantially by varying the reaction …

Special Issue On Medical Simulation, Michel Audette, Hanif M. Ladak

Computational Modeling & Simulation Engineering Faculty Publications

We would like to welcome you to this Special Issue on Medical Simulation, the first of its kind not only for SIMULATION: Transactions of The Society for Modeling and Simulation International, but for any technical journal. Our respective backgrounds are an indication of the technical and clinical breadth of medical simulation, as we approach the subject as primarily medical image analysis and biomechanics experts respectively, each with a variety of clinical interests spanning virtual reality (VR)–based neuro-, orthopedic and ear-nose-and-throat surgery. Moreover, we believe that the breadth of the papers that comprise this issue reflects an even broader perspective. After …

Gpu-Optimized Code For Long-Term Simulations Of Beam-Beam Effects In Colliders, Y. Roblin, V. Morozov, B. Terzić, M. Aturban, D. Ranjan, M. Zubair

Computer Science Faculty Publications

We report on the development of the new code for long-term simulation of beam-beam effects in particle colliders. The underlying physical model relies on a matrix-based arbitrary-order symplectic particle tracking for beam transport and the Bassetti-Erskine approximation for beam-beam interaction. The computations are accelerated through a parallel implementation on a hybrid GPU/CPU platform. With the new code, a previously computationally prohibitive long-term simulations become tractable. We use the new code to model the proposed medium-energy electron-ion collider (MEIC) at Jefferson Lab.

A Method For Identifying Personalized Representations In Web Archives, Mat Kelly, Justin F. Brunelle, Michele C. Weigle, Michael L. Nelson

Computer Science Faculty Publications

Web resources are becoming increasingly personalized — two different users clicking on the same link at the same time can see content customized for each individual user. These changes result in multiple representations of a resource that cannot be canonicalized in Web archives. We identify characteristics of this problem by presenting a potential solution to generalize personalized representations in archives. We also present our proof-of-concept prototype that analyzes WARC (Web ARChive) format files, inserts metadata establishing relationships, and provides archive users the ability to navigate on the additional dimension of environment variables in a modified Wayback Machine.

Orientation Invariant Ecg-Based Stethoscope Tracking For Heart Auscultation Training On Augmented Standardized Patients, Nahom Kidane, Salim Chemlal, Jiang Li, Frederic D. Mckenzie, Tom Hubbard

Computational Modeling & Simulation Engineering Faculty Publications

Auscultation, the act of listening to the heart and lung sounds, can reveal substantial information about patients’ health and other cardiac-related problems; therefore, competent training can be a key for accurate and reliable diagnosis. Standardized patients (SPs), who are healthy individuals trained to portray real patients, have been extensively used for such training and other medical teaching techniques; however, the range of symptoms and conditions they can simulate remains limited since they are only patient actors. In this work, we describe a novel tracking method for placing virtual symptoms in correct auscultation areas based on recorded ECG signals with various …

Review Of Us And Eu Initiatives Toward Development, Demonstration, And Commercialization Of Lignocellulosic Biofuels, Venkatesh Balan, David Chiaramonti, Sandeep Kumar

Civil & Environmental Engineering Faculty Publications

Advanced biofuels produced from lignocellulosic biomass offer an exciting opportunity to produce renewable liquid transportation fuels, biochemicals, and electricity from locally available agriculture and forest residues. The growing interest in biofuels from lignocellulosic feedstock in the United States (US) and the European Union (EU) can provide a path forward toward replacing petroleum-based fuels with sustainable biofuels which have the potential to lower greenhouse gas (GHG) emissions. The selection of biomass conversion technologies along with feedstock development plays a crucial role in the commercialization of next-generation biofuels. There has been synergy and, even with similar basic process routes, diversity in the …

Non-Equilibrium Pressure Control Of The Height Of A Large-Scale, Ground-Coupled, Rotating Fluid Column, R. L. Ash, I. R. Zardadhkan

Mechanical & Aerospace Engineering Faculty Publications

When a ground-coupled, rotating fluid column is modeled incorporating non-equilibrium pressure forces in the Navier-Stokes equations, a new exact solution results. The solution has been obtained in a similar manner to the classical equilibrium solution. Unlike the infinite-height, classical solution, the non-equilibrium pressure solution yields a ground-coupled rotating fluid column of finite height. A viscous, non-equilibrium Rankine vortex velocity distribution, developed previously, was used to demonstrate how the viscous and non-equilibrium pressure gradient forces, arising in the vicinity of the velocity gradient discontinuity that is present in the classical Rankine vortex model, effectively isolate the rotating central fluid column from …

Distal Placement Of An End-To-Side Bypass Graft Anastomosis: A 3d Computational Study, John Di Cicco, Ayodeji Demuren

Mechanical & Aerospace Engineering Faculty Publications

A three-dimensional (3D) computational fluid dynamics study of shear rates around distal end-to-side anastomoses has been conducted. Three 51% and three 75% cross-sectional area-reduced 6 mm cylinders were modeled each with a bypass cylinder attached at a 30-degree angle at different placements distal to the constriction. Steady, incompressible, Newtonian blood flow was assumed, and the full Reynolds-averaged Navier-Stokes equations, turbulent kinetic energy, and specific dissipation rate equations were solved on a locally structured multiblock mesh with hexahedral elements. Consequently, distal placement of an end-to-side bypass graft anastomosis was found to have an influence on the shear rate magnitudes. For the …

Investigation Of Nbnx Thin Films And Nanoparticles Grown By Pulsed Laser Deposition And Thermal Diffusion, Ashraf Hassan Farha

Electrical & Computer Engineering Theses & Dissertations

Niobium nitride films (NbNx) were grown on Nb and Si (100) substrates using pulsed laser deposition (PLD), laser heating, and thermal diffusion methods. Niobium nitride films were deposited on Nb substrates using PLD with a Q-switched Nd: YAG laser (λ = 1064 nm, 40 ns pulse width, and 10 Hz repetition rate) at different laser fluences, different nitrogen background pressures and deposition temperatures. The effect of changing PLD parameters for films done by PLD was studied. The seen observations establish guidelines for adjusting the laser parameters to achieve the desired morphology and phase of the grown NbNx films.

When the …

Watershed-Scale Hybrid Stochastic-Deterministic Modeling Framework And Diffused Sources Superpositioning, Ruby Juvah Damalie

Civil & Environmental Engineering Theses & Dissertations

Predicting hydrologic system behavior is imperative to planning and management of water resources. The study developed an integrated hybrid stochastic and deterministic framework to improve prediction accuracy for overland flow and diffused sources in a watershed. The methodology includes sampling input parameters at system level and contribution of nonpoint source from hydrologically disconnected areas (heretofore referred to as system-level approach and superpositioning respectively). System-level approach includes the integration of a topography-based sampling grid generalized linear model developed by the study and Monte Carlo methods. The superpositioning method adopts in-stream water quality equation for overland flow pollution estimation.

The system-level approach …

Hyperspectral Image Classification Using A Spectral-Spatial Sparse Coding Model, Ender Oguslu, Guoqing Zhou, Jiang Li, Lorenzo Bruzzone (Ed.)

Electrical & Computer Engineering Faculty Publications

We present a sparse coding based spectral-spatial classification model for hyperspectral image (HSI) datasets. The proposed method consists of an efficient sparse coding method in which the l₁/l_q regularized multi-class logistic regression technique was utilized to achieve a compact representation of hyperspectral image pixels for land cover classification. We applied the proposed algorithm to a HSI dataset collected at the Kennedy Space Center and compared our algorithm to a recently proposed method, Gaussian process maximum likelihood (GP-ML) classifier. Experimental results show that the proposed method can achieve significantly better performances than the GP-ML classifier when training data …