Engineering Commons^™

Fellow Eye Changes In Patients With Nonischemic Central Retinal Vein Occlusion: Assessment Of Perfused Foveal Microvascular Density And Identification Of Nonperfused Capillaries, Alexander Pinhas, Michael Dubow, Nishit Shah, Eric Cheang, Chun L. Liu, Moataz Razeen, Alexander Gan, Rishard Weitz, Yusufu N. Sulai, Toco Y.P. Chui, Alfredo Dubra, Richard B. Rosen

Biomedical Engineering Faculty Research and Publications

Purpose: Eyes fellow to nonischemic central retinal vein occlusion (CRVO) were examined for abnormalities, which might explain their increased risk for future occlusion, using adaptive optics scanning light ophthalmoscope fluorescein angiography.

Methods: Adaptive optics scanning light ophthalmoscope fluorescein angiography foveal microvascular densities were calculated. Nonperfused capillaries adjacent to the foveal avascular zone were identified. Spectral domain optical coherence tomography, ultrawide field fluorescein angiographies, and microperimetry were also performed.

Results: Ten fellow eyes of nine nonischemic CRVO and 1 nonischemic hemi-CRVO subjects and four affected eyes of three nonischemic CRVO and one nonischemic hemi-CRVO subjects were imaged. Ninety percent of fellow …

Using Eye And Head Movements As A Control Mechanism For Tele-Operating A Ground-Based Robot And Its Payload, Kathryn C. Hicks

Computational Modeling & Simulation Engineering Theses & Dissertations

To date, eye and head tracking has been used to indicate users' attention patterns while performing a task or as an aid for disabled persons, to allow hands-free interaction with a computer. The increasing accuracy and the reduced cost of eye- and head-tracking equipment make utilizing this technology feasible for explicit control tasks, especially in cases where there is confluence between the visual task and control.

The goal of this research was to investigate the use of eye-tracking as a more natural interface for the control of a camera-equipped, remotely operated robot in tasks that require the operator to simultaneously …

New Engineering Approaches To Arrhythmias And Myocardial Infarction, Frency Varghese

Biomedical Engineering Theses & Dissertations

In this thesis, we present new engineering approaches to several important cardiac diseases. Chapter 1 considers the dynamics of arrhythmias. The most dangerous arrhythmias are reentrant arrhythmias, including ventricular fibrillation and ventricular tachycardia. During these arrhythmias, there are one or several rotating excitation waves present in the heart. Because of their shape, these waves are called scroll waves; their center of rotation is a one-dimensional curve called the filament. Filaments largely constrain the configuration of a scroll wave but are much simpler, so much effort has gone into describing scroll wave dynamics in terms of the dynamics of their filaments. …

Numerical Studies And Optimization Of Magnetron With Diffraction Output (Mdo) Using Particle-In-Cell Simulations, Alireza Majzoobi

Electrical & Computer Engineering Theses & Dissertations

The first magnetron as a vacuum-tube device, capable of generating microwaves, was invented in 1913. This thesis research focuses on numerical simulation-based analysis of magnetron performance. The particle-in-cell (PIC) based MAGIC software tool has been utilized to study the A6 and the Rising-Sun magnetron structures, and to obtain the optimized geometry for optimizing the device performance. The A6 magnetron is the more traditional structure and has been studied more often. The Rising-Sun geometry, consists of two alternating groups of short and long vanes in angular orientation, and was created to achieve mode stability.

The effect of endcaps, changes in lengths …

Axisymmetric Bi-Propellant Air Augmented Rocket Testing With Annular Cavity Mixing Enhancement, Allen A. C. Capatina

Master's Theses

Performance characterization was undertaken for an air augmented rocket mixing duct with annular cavity configurations intended to produce thrust augmentation. Three mixing duct geometries and a fully annular cavity at the exit of the nozzle were tested to enable thrust comparisons. The rocket engine used liquid ethanol and gaseous oxygen, and was instrumented with sensors to output total thrust, mixing duct thrust, combustion chamber pressure, and propellant differential pressures across Venturi flow measurement tubes.

The rocket engine was tested to thrust maximum, with three different mixing ducts, three major combustion pressure sets, and a nozzle exit plane annular cavity (a …

Thrust Prediction For A Rotor Operating In A Ship Airwake, Mathew Thomas

Mechanical & Aerospace Engineering Theses & Dissertations

This report details work performed at Old Dominion University focused on developing a thrust prediction capability for a rotor operating in a ship airwake. The study has built upon previous experimental work utilizing particle image velocimetry-based velocity field measurements to quantify the degree of coupling in a simplified rotor/ship airwake experiment. Using the velocity field data of the previous study, a database was built representing the volume over the landing deck. Rotor thrust was computed using blade element methods and compared to direct load cell measurements and to a superposed velocity field. Results show that the blade element method has …

A Sliding Mode Lco Regulation Strategy For Dual-Parallel Underactuated Uav Systems Using Synthetic Jet Actuators, N. Ramos-Pedroza, W. Mackunis, M. Reyhanoglu

Publications

"A sliding mode control- (SMC-) based limit cycle oscillation (LCO) regulation method is presented, which achieves asymptotic LCO suppression for UAVs using synthetic jet actuators (SJAs). With a focus on applications involving small UAVs with limited onboard computational resources, the controller is designed with a simplistic structure, requiring no adaptive laws, function approximators, or complex calculations in the control loop. The control law is rigorously proven to achieve asymptotic regulation of both pitching and plunging displacements for a class of systems in a dual-parallel underactuated form, where a single scalar control signal simultaneously affects two states. Since dual-parallel underactuated systems …

Pattern Formation Of Elastic Waves And Energy Localization Due To Elastic Gratings, A. Berezovski, J. Engelbrecht, Mihhail Berezovski

Publications

Elastic wave propagation through diffraction gratings is studied numerically in the plane strain setting. The interaction of the waves with periodically ordered elastic inclusions leads to a self-imaging Talbot effect for the wavelength equal or close to the grating size. The energy localization is observed at the vicinity of inclusions in the case of elastic gratings. Such a localization is absent in the case of rigid gratings.

How Trust In Commercial Airline Pilots Is Affected By Their Perceived Sociability: A Mediation Analysis, Stephen Rice, Scott R. Winter, Russell Tokarski

Publications

Sociability relates to one’s preference to interact with others or remain alone. The current study sought to determine how a pilot’s perceived sociability would relate to consumers’ trust ratings in their pilot using participants from India and the United States. Consumers were presented with one of two scenarios. In the control condition, the pilot was described as sociable, while in the other, the pilot was presented as unsociable. Participants were then asked to rate their trust in the pilot based off of these cues. In general, participants indicated that the pilot who was perceived as unsociable was less trusting compared …

Techno-Economic Analysis Of Protein Concentrate Produced By Flash Hydrolysis Of Microalgae, Alexander Nana Yaw Asiedu

Civil & Environmental Engineering Theses & Dissertations

Process simulation and techno-economic analysis of 95wt.% protein concentrate from microalgae has been performed using SuperPro Designer v. 9.0. This work, first of its kind, is focused on the economic analysis of protein concentrate that includes processes such as microalgae cultivation, harvesting, protein extraction and drying steps. A baseline capacity of 160 MT/day protein concentrate production on commercial basis has been analyzed. This throughput requires 336 MT/day dry algae (54 wt.% protein). The amount of carbon dioxide required to grow this quantum of algae is estimated to be 648 MT/day, which is produced from an in situ 21 MW power …

Modeling Napl Dissolution From Pendular Rings In Idealized Porous Media, Junqi Huang, John A. Christ, Mark N. Goltz, Avery H. Demond

Faculty Publications

The dissolution rate of nonaqueous phase liquid (NAPL) often governs the remediation time frame at subsurface hazardous waste sites. Most formulations for estimating this rate are empirical and assume that the NAPL is the nonwetting fluid. However, field evidence suggests that some waste sites might be organic wet. Thus, formulations that assume the NAPL is nonwetting may be inappropriate for estimating the rates of NAPL dissolution. An exact solution to the Young‐Laplace equation, assuming NAPL resides as pendular rings around the contact points of porous media idealized as spherical particles in a hexagonal close packing arrangement, is presented in this …

Determination Of The Polymerisation Rate Of A Low-Toxicity Diacetone Acrylamide-Based Holographic Photopolymer Using Raman Spectroscopy, Dervil Cody, Emilia Mihaylova, Luke O'Neill, Izabela Naydenova

Articles

The polymerisation rate of a low-toxicity Diacetone Acrylamide (DA)-based photopolymer has been measured for the first time using Raman spectroscopy. A value for the polymerisation rate of 0.020 s⁻¹ has been obtained for the DA photopolymer by modelling the polymerisation reaction dynamics as a stretched exponential or Kohlrausch decay function. This is significantly lower than the polymerisation rate of 0.100 s⁻¹ measured for the well known Acrylamide (AA)-based photopolymer composition. The effect of the additive glycerol on the polymerisation rate of the DA-based photopolymer has also been investigated. The inclusion of glycerol is observed to increase the rate …

A Survey Of Security And Privacy Challenges In Cloud Computing: Solutions And Future Directions, Yuhong Liu, Yan Lindsay Sun, Jungwoo Ryoo, Athanasios V. Vasilakos

Computer Science and Engineering

While cloud computing is gaining popularity, diverse security and privacy issues are emerging that hinder the rapid adoption of this new computing paradigm. And the development of defensive solutions is lagging behind. To ensure a secure and trustworthy cloud environment it is essential to identify the limitations of existing solutions and envision directions for future research. In this paper, we have surveyed critical security and privacy challenges in cloud computing, categorized diverse existing solutions, compared their strengths and limitations, and envisioned future research directions.

Evaluating The Usability Of The Laboratory Information System (Lis) In Coombe Hospital And Hail Hospital, Fahad Alanazi

Dissertations

Today, with the rapid evolution of technology, there has also been a rapid development of medical software and systems in hospitals. These systems and software are now being used globally in many hospitals by users of different languages and cultures. Governments and private hospitals pay large sums of money to utilise highly efficient technology. When systems are changed or updated, employees often find it difficult to deal with the characteristics of the new systems. Also, behavioral factors, such as the fear of committing simple errors, might affect system performance and prevent the full utilization of the staff potential. In this …

Electrical & Computer Engineering News, Georgia Southern University

Electrical & Computer Engineering: News & Publications (2014-2023)

• EE Faculty, Staff, and Students participate – with great success – in the 2015 STEM Fest

An Understanding Of Student Satisfaction, Lorraine Sweeney

Dissertations

Retention is a challenge for all third level institutions and retention rates remain higher than colleges would like them to be, this has intensified in recent years as participants in higher education has increased and diversified. Third level institutions which would not only benefit from increased fees but also through low cost word of mouth promotion and an enhanced reputation. As such, an important concern for colleges is retaining students and understanding the reasons why students may choose to leave a program. While student satisfaction and retention is a well researched topic there remains questions to be answered in terms …

Semantic Models As Knowledge Repositories For Data Modellers In The Financial Industry, Gary Thompson

Dissertations

Data modellers working in the financial industry are expected to use both technical and business knowledge to transform data into the information required to meet regulatory reporting requirements. This dissertation explores the role that semantic models such as ontologies and concept maps can play in the acquisition of financial and regulatory concepts by data modellers. While there is widespread use of semantic models in the financial industry to specify how information is exchanged between IT systems, there is limited use of these models as knowledge repositories. The objective of this research is to evaluate the use of a semantic model …

An Exploration Of The Use Of Gamification In Agile Software Development, Alan Mcclean

Dissertations

Although Project Management has existed for many millennia, software project management is relatively new. As a discipline, software project management is considered difficult. The reasons for this include that software development is non-deterministic; opaque and delivered under ever-increasing time pressure in a volatile environment. Evolving from Incremental and Iterative Development (IID), Agile methodologies have attempted to address these issues by focusing on frequent delivery; working closely with the customer; being responsive to change and preferring working software to extensive documentation. This focus on delivery rather than documentation has sometimes been misrepresented as no documentation, which has led to a shortfall …

A Novel And Domain-Specific Document Clustering And Topic Aggregation Toolset For A News Organisation, Claire Mcmahon

Dissertations

Large collections of documents are becoming increasingly common in the news gathering industry. A review of the literature shows there is a growing interest in datadriven journalism and specifically that the journalism profession needs better tools to understand and develop actionable knowledge from large document sets. On a daily basis, journalists are tasked with searching a diverse range of document sets including news gathering services, emails, freedom of information requests, court records, government reports, press releases and many other types of generally unstructured documents. Document clustering techniques can help address problems of understanding the ever expanding quantities of documents available …

An Evaluation Of Selection Strategies For Active Learning With Regression, Jack O'Neill

Dissertations

While active learning for classification problems has received considerable attention in recent years, studies on problems of regression are rare. This paper provides a systematic review of the most commonly used selection strategies for active learning within the context of linear regression. The recently developed Exploration Guided Active Learning (EGAL) algorithm, previously deployed within a classification context, is explored as a selection strategy for regression problems. Active learning is demonstrated to significantly improve the learning rate of linear regression models. Experimental results show that a purely diversity-based approach to

Seismic Fragility Analysis For Highway Bridges With Consideration Of Soil-Structure Interaction And Deterioration, Xin Zong

Dissertations, Theses, and Capstone Projects

Bridges are critical elements within the highway transportation network. It is very important for the owner or designer to perform the risk assessment of the highway bridges during extreme events, such as earthquakes, due to their importance to the network, commerce, economic vitality and mobility. Recent studies show that seismic fragility curves are useful tools for the seismic risk assessment of highway bridges.

Although general seismic fragility approach has been well established in the last two decades and numerous retrofit methods have been applied to highway bridges in New York City (NYC) metropolitan area, which has been classified as moderate …

3d Scene Reconstruction With Micro-Aerial Vehicles And Mobile Devices, Ivan Dryanovski

Dissertations, Theses, and Capstone Projects

Scene reconstruction is the process of building an accurate geometric model of one's environment from sensor data. We explore the problem of real-time, large-scale 3D scene reconstruction in indoor environments using small laser range-finders and low-cost RGB-D (color plus depth) cameras. We focus on computationally-constrained platforms such as micro-aerial vehicles (MAVs) and mobile devices. These platforms present a set of fundamental challenges - estimating the state and trajectory of the device as it moves within its environment and utilizing lightweight, dynamic data structures to hold the representation of the reconstructed scene. The system needs to be computationally and memory-efficient, so …

Coupled Auto-Associative Neural Networks For Heterogeneous Face Recognition, Benjamin S. Riggan, Christopher Reale, Nasser M. Nasrabadi

Department of Electrical and Computer Engineering: Faculty Publications

Several models have been previously suggested for learning correlated representations between source and target modalities. In this paper, we propose a novel coupled autoassociative neural network for learning a target-to-source image representation for heterogenous face recognition. This coupled network is unique, because a cross-modal transformation is learned by forcing the hidden units (latent features) of two neural networks to be as similar as possible, while simultaneously preserving information from the input. The effectiveness of this model is demonstrated using multiple existing heterogeneous face recognition databases. Moreover, the empirical results show that the learned image representation—common latent features—by the coupled auto-associative …

Simulating The Energy Performance Of A Foam Roof System, Florida Solar Energy Center, Jeffrey Sonne

FSEC Energy Research Center®

Annual residential simulations were run in 13 US cities to determine the energy savings of using an insulated foam tile roof in retrofit applications where ceiling insulation was only R-11 or R-19. Variations included leaving the attic vented and sealing the attic space.

Don't Just Blindly Follow All 'Green' Trends -- Do Your Research First, Michael Bass

UCF Forum

Nowadays it is politically correct to be “green” – to say and do things that seem to minimize one’s impact on the environment and to preach to others to do the same.

Thermodynamic Analysis Of Closed Steady Or Cyclic Systems, Jim A. Mcgovern

Articles

Closed, steady or cyclic thermodynamic systems, which have temperature variations over their boundaries, can represent an extremely large range of plants, devices or natural objects, such as combined heating, cooling and power plants, computers and data centres, and planets. Energy transfer rates can occur across the boundary, which are characterized as heat or work. We focus on the finite time thermodynamics aspects, on energy-based performance parameters, on rational efficiency and on the environmental reference temperature. To do this, we examine the net work rate of a closed, steady or cyclic system bounded by thermal resistances linked to isothermal reservoirs in …

The Effect Of A Reversible Shear Transformation On Plastic Deformation Of An Amorphous Solid, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

Molecular dynamics simulations are performed to investigate the plastic response of a model glass to a local shear transformation in a quiescent system. The deformation of the material is induced by a spherical inclusion that is gradually strained into an ellipsoid of the same volume and then reverted back into the sphere. We show that the number of cage-breaking events increases with increasing strain amplitude of the shear transformation. The results of numerical simulations indicate that the density of cage jumps is larger in the cases of weak damping or slow shear transformation. Remarkably, we also found that, for a …

Conflict-Aware Real-Time Routing For Industrial Wireless Sensor-Actuator Networks, Chengjie Wu, Dolvara Gunatilaka, Mo Sha, Chenyang Lu

All Computer Science and Engineering Research

Process industries are adopting wireless sensor-actuator networks (WSANs) as the communication infrastructure. WirelessHART is an open industrial standard for WSANs that have seen world-wide deployments. Real-time scheduling and delay analysis have been studied for WSAN extensively. End-to-end delay in WSANs highly depends on routing, which is still open problem. This paper presents the first real-time routing design for WSAN. We first discuss end-to-end delays of WSANs, then present our real-time routing design. We have implemented and experimented our routing designs on a wireless testbed of 69 nodes. Both experimental results and simulations show that our routing design can improve the …

Maximizing Network Lifetime Of Wireless Sensor-Actuator Networks Under Graph Routing, Chengjie Wu, Dolvara Gunatilaka, Abusayeed Saifullah, Mo Sha, Paras Tiwari, Chenyang Lu, Yixin Chen

All Computer Science and Engineering Research

Process industries are adopting wireless sensor-actuator networks (WSANs) as the communication infrastructure. The dynamics of industrial environments and stringent reliability requirements necessitate high degrees of fault tolerance in routing. WirelessHART is an open industrial standard for WSANs that have seen world-wide deployments. WirelessHART employs graph routing schemes to achieve network reliability through multiple paths. Since many industrial devices operate on batteries in harsh environments where changing batteries are prohibitively labor-intensive, WSANs need to achieve long network lifetime. To meet industrial demand for long-term reliable communication, this paper studies the problem of maximizing network lifetime for WSANs under graph routing. We …

Runtime Detection Of A Bandwidth Denial Attack From A Rogue Network-On-Chip, Rajesh Jayashankarashridevi, Dean Michael Ancajas, Koushik Chakraborty, Sanghamitra Roy

Electrical and Computer Engineering Faculty Publications

In this paper, we propose a covert threat model for MPSoCs designed using 3rd party Network-on-Chips (NoC). We illustrate that a malicious NoC can disrupt the availability of on-chip resources, thereby causing large performance bottlenecks for the software running on the MPSoC platform. We then propose a runtime latency auditor that enables an MPSoC integrator to monitor the trustworthiness of the deployed NoC throughout the chip lifetime. For the proposed technique, our comprehensive cross-layer analysis indicates modest overheads of 12.73% in area, 9.844% in power and 5.4% in terms of network latency.