Engineering Commons^™

Electric Field Analysis In Insulating Films For Complex Electrode Systems, Anusha Jambula

Electrical & Computer Engineering Theses & Dissertations

Complex electrode systems with thin insulating materials demand careful examination of field distribution near the electrodes to improve the breakdown characteristics of dielectrics and optimal utilization of the space. The present work contributes to an extended research of physical electrode systems, namely axi-symmetric and non-uniform field systems. In an attempt to optimize the dimensions of the electrode system for subsequent use in electrical measurements, such as electroluminescence, capacitance and conduction current, field values at key points (sharp edges and triple junctions) in an axi-symmetric electrode system are simulated as a function of clearances between low voltage and guard electrodes. Since …

Selective Phase-Based De-Weathering (Spdw), Christopher Morris

Electrical & Computer Engineering Theses & Dissertations

No Abstract.

Electric Field Computation Of Wet Insulating Surfaces, Bhargavi Sarang

Electrical & Computer Engineering Theses & Dissertations

High voltage outdoor insulators form the backbone of modem power systems and therefore play a pivotal role in reliable supply of power. The presence of water droplets/films due to rain, fog, etc. enhances the electric field intensity and leads to electrical breakdown subsequently affecting the longevity of the insulator. The magnitude of surface E-fields necessary for initiation of electrical breakdown is a function of water repellent characteristic of an insulator called hydrophobicity. Thus, knowledge of field distribution around water droplets/films at various hydrophobic levels is significant in designing a better insulating material.

The current research analyzed electric field distributions on …

Determining The Utility Of Technology For Education, Brian Spencer Dillon

Computational Modeling & Simulation Engineering Theses & Dissertations

There is a substantial debate concerning the place of technology in education. This debate has been going on over every technology introduced through at least three millennia although the modern version takes place in journal articles. Technology, in the general sense, is already in the educational arena 1n ways which have become so commonplace that we hardly question them today. More modern technologies, however, meet perpetual resistance in achieving their potential. This paper calls into question the most recent trend in research and suggests a new research paradigm which focuses not only on student achievement, but on a variety of …

Analysis Of Jump Linear Systems Driven By Lumped Processes, Jorge R. Chavez Fuentes

Electrical & Computer Engineering Theses & Dissertations

Safety critical control systems such as flight control systems use fault-tolerant technology to minimize the effect of faults and increase the dependability of the system. In fault-tolerant systems, the system availability process indicates the current operational mode of an interconnection of digital logic devices. It is a process that results from the transformation of the stochastic processes characterizing the availability of the devices forming the system. To assess safety critical control systems, the following measures of performance will be considered: the steady-state mean output power, the mean output energy, the mean time to failure and the mean time to repair. …

Laser Scribing Of Ito And Ito/Ag Coated Glass Substrates Comparison Of Back And Front Side Ablation, Oguzhan Balki

Electrical & Computer Engineering Theses & Dissertations

The ablation of indium tin oxide (ITOl thin films on glass for laser scribing is performed with nanosecond, 1064 nm pulses. ITO and ITO/Ag ablation from the coating side are compared to those from the glass side. The results show that complete coating removal with wide ablation profile is achieved at a lower fluence when the ablation is performed from the glass side. Laser scribing is used to fabricate an antenna structure from ITO and ITO/Ag thin films. For a wireless sensor application, it is often that thin film conductivity needs to be maximized. Fabrication of a multilayer ITO/Ag film …

Embedding Gps Data Into Speech Signal, Kagan Can

Electrical & Computer Engineering Theses & Dissertations

Communication between deployed troops is very important on a battlefield. The real time knowledge of the location of the communicating patter is also very important in many situations because if you do not know the exact position of your units you cannot give correct orders. A minor error in an order can cause fatal results or lead to defeat. In many cases the position of the units is given through the speech channel by simply speaking the coordinates of the location. This can cause misunderstandings due to misinterpretation of the speech and makes it unsafe to rely on such communications. …

How To Improve Project Management For Agile Federation Development, Priyanka Kotikalpudi

Engineering Management & Systems Engineering Theses & Dissertations

Developing a simulation federation out of a variety of heterogeneous simulation solutions is a complex task requiring very effective project management support in order to accomplish the common objectives and goals of this M&S federation. This thesis study conducts a detailed survey of available literature to identify the project management methods that can be extended to be applied to manage the development of simulation systems. The literature review led to the following two main results: (a) in general, there is insufficient literature dealing with M&S challenges for project management, (b) in particular, the two challenges of often changing requirements leading …

Combining Molecular And Imaging Biomarkers To Enhance Maldi Biomarker Analysis, Ayyappa Chowdary Vadlamudi

Electrical & Computer Engineering Theses & Dissertations

This thesis presents a three-step method to predict prostate cancer (PCa) regions on biopsy tissue samples based on high confident, low resolution PCa regions marked by a pathologist. First, a prediction model is designed to predict PCa regions using matrix-assisted laser desorption mass spectrometry (MALDI-MS) tissue imaging data from one prostate tissue slice. Second, a texture analysis technique is applied to a high magnification optical image for the same purpose from an adjacent tissue slice. Finally, those two results are fused to obtain the PCa regions that will assist MALDI imaging biomarker analysis. Experiments show that the texture analysis based …

Turbulent Flow Studies Of A Scaled Model Of A Large Mining Truck - Computations And Experiment, Wayne Randolph Sexton

Mechanical & Aerospace Engineering Theses & Dissertations

Modern mining operations are highly reliant on the amount of material that can be removed from the earth, transported to processing, and then processed. The companies that design and build mining dump trucks concentrate on improving the material payload capacity. Currently, the largest trucks are 400ton-class trucks. The design of these large mining dump trucks certainly does not stem from aerodynamics, but rather, from functionality and payload As a result, the shear size and asymmetric functional design creates interesting turbulent wakes on, around, and behind these trucks. This research focuses on the turbulent flow behind the truck. Computational Fluid Dynamic …

Estimation And Management Of Observation Time For Low Earth Orbit Satellite, Serdar Cagirdar

Mechanical & Aerospace Engineering Theses & Dissertations

In this thesis, time to observation for a generic low Earth orbit satellite after being tasked for reconnaissance of a particular surface target is investigated. A closed-form Keplerian propagation of the nominal orbit is used as the process for computing a solution to the time to observation for both scanning and staring sensors. Orbital maneuvers to reach the target sooner than the nominal trajectory are also considered. In this way time to observation is managed. Lambert's problem, which is used to determine an orbit of a satellite from two position vectors and the time of flight between them, is used …

Optimization Of The Odu Maglev System Ridership Performance, Eric Salvador M. De Leon

Mechanical & Aerospace Engineering Theses & Dissertations

The purpose of this research is to optimize the ODU People Mover project (Maglev vehicle) by providing a valid estimate of system "ridership" performance via modeling and simulation. The results considered both service parameters and cost of system operation. The system studied three stations on a line with no closed loop which was evidently unique, but the methods and approaches used for the problem can be applied to any transportation system or layout.

To achieve this objective -- design constraints and other relevant system inputs were identified that impacted the design parameters of the transportation system and permitted assessment of …

Multi-Element Airfoil Optimization Using Computational Fluid Dynamics, Mustafa Kubilay Ictuzer

Mechanical & Aerospace Engineering Theses & Dissertations

High-lift systems are frequently used on commercial transport aircrafts to obtain low speed performance, in terms of take-off and landing field lengths and approach speed. To maximize the take-off and landing performance within the critical restrictions required by the new generation transport wing designs, enhanced high-lift technologies are needed. Moreover, the economic realities faced by the airlines require a design that is mechanically simple and effective. These facts lead us to the optimization of the high lift systems.

Optimizing a high-lift system improves an aircraft's take-off and landing performance. The weight of the system, the advantages and the disadvantages all …

Modeling And Analysis Of Low Earth Orbit Satellite And Ground Station Data Exchange Topology, Ersin Kocoglu

Mechanical & Aerospace Engineering Theses & Dissertations

In order to utilize space effectively, the primary function of satellite control in orbit around the Earth must be accomplished. This controlling process includes two main segments, ground stations serving as the controller units and orbiting satellites as the units to be controlled. This thesis explores a topological data exchange model that contains one satellite and multiple ground stations. The model is implemented in digital computer software. This model has multiple purposes and can be used to simulate satellite passes over ground stations and can also be used to predict communication time and the amount of transferred data. The model …

Nuclear Electromagnetic Currents In Chiral Effective Field Theory, Saori Pastore

Physics Theses & Dissertations

A nucleon-nucleon potential and consistent nuclear electromagnetic currents are derived in chiral effective field theory retaining pions and nucleons as explicit degrees of freedom. The calculation of the potential is carried out up to next-to-next-to leading order (N²LO), while the currents include up to N³LO corrections. The potential at N² LO and currents at N³LO consist of two-pion-exchange and contact contributions. The currents are then utilized to study a number of low-energy electromagnetic observables induced by magnetic dipole transitions, such as the deuteron and trinucleon magnetic moments and the np, nd and n …

Towards A Formal Theory Of Interoperability, Saikou Y. Diallo

Computational Modeling & Simulation Engineering Theses & Dissertations

This dissertation proposes a formal theory of interoperability that explains 1) what interoperability is as opposed to how it works, 2) how to tell whether two or more systems can interoperate and 3) how to identify whether systems are interoperating or merely exchanging bits and bytes. The research provides a formal model of data in M&S that captures all possible representations of a real or imagined thing and distinguishes between existential dependencies and transformational dependencies. Existential dependencies capture the relationships within a model while transformational dependencies capture the relationships between interactions with a model. These definitions are used to formally …

A Novel Digital Audio Watermarking Approach By Embedding Coefficients In Discrete Cosine Transform Domain, Erol Duymaz

Electrical & Computer Engineering Theses & Dissertations

Watermarking is a basic secure communication method. It is used for embedding a recognizable pattern in media in such a manner that modification of the media also modifies the pattern, thus making it easy to detect the modification. This technique and its variants have many practical applications pertaining to secure communications, media verification, etc. Digital audio watermarking is a technique for embedding data within an audio signal in such a way that the original and the modified audio signals are essentially identical. The embedded data can be used for various purposes such as secure communication in military applications, owner identification …

Analysis Of Helicopter Downwash/Frigate Airwake Interaction Using Statistically Designed Experiments, Yavuz Nacakli

Mechanical & Aerospace Engineering Theses & Dissertations

A research program to investigate helicopter downwash/frigate airwake interaction has been initiated using a statistically robust experimental program featuring Design of Experiments. Engineering analysis of the helicopter/frigate interface is complicated by the fact that two flowfields become inherently coupled as separation distance decreases. The final objective of this work is to develop experimental methods to determine when computer simulations need to include the effects of a coupled flowfield versus using a simplified representation by superposing the velocity fields of the individual flowfields. The work presented was performed in the Old Dominion University Low Speed Wind Tunnel using a simplified 1/50 …

Utilizing Knowledge Transfer To Promote Management Of Countervailing Risks In Value Stream Analysis, Jeffery A. Temple

Engineering Management & Systems Engineering Theses & Dissertations

Organizations are frequently faced with the challenges of modifying and streamlining their processes by utilizing the latest process improvement techniques such as Lean Thinking. They use these techniques to allow them to better perform their organizational purposes through the elimination of waste and non-value added steps. Personnel performing these modifications need to account for potential outcomes and risks when streamlining processes. An association of knowledge transfer and experience to the identification and handling of these countervailing or alternative risks when performing Lean Thinking value stream analysis is investigated. The elements of risk management, Lean Thinking and knowledge transfer are described. …

Towards A Theory Of Understanding Within Problem Situations, Jose J. Padilla

Engineering Management & Systems Engineering Theses & Dissertations

The concept of understanding is ambiguously used across areas of study, such as philosophy and cognitive sciences. This ambiguity partly originates from understanding's generally accepted definition of 'grasping' of something. Further, the concept is confounded with concurrent processes such as learning and decision making. This dissertation provides a general theory of understanding (GTU) that explains the concept of understanding unambiguously and separated from concurrent processes.

The GTU distinguishes between the process of understanding and its outcomes. Understanding, defined as a process, is the matching of knowledge, worldview, and problem. The outcome of this process is the assignment of a truth …

An Experimental Study Of The Near Wake Field Behind A Propeller Aircraft, Hasan Ozgur Yavas

Mechanical & Aerospace Engineering Theses & Dissertations

This thesis presents an experimental study of the wake behind a generic, high wing, half model of a propeller driven aircraft. Wake surveys are performed at a free stream velocity of 9m/s in the Old Dominion University Low-Speed Wind Tunnel. The objective of the study is understanding the general characteristics of development and interaction of tip vortices, flap vortices, and propeller vortices in the wake of a two propeller aircraft. The measurements in the wake were obtained by using hot-wire anemometry. Measurements were made both using single wire and X-wire probes mounted on a traverse mechanism on three planes behind …

Expression Invariant Face Recognition Using Shifted Phase-Encoded Joint Transform Correlation Technique, Trisha Ahmed

Electrical & Computer Engineering Theses & Dissertations

A new face recognition algorithm using a synthetic discriminant function based shifted phase-encoded fringe-adjusted joint transform correlation (SDF-SPFJTC) technique is proposed. The dark region in an input image is enhanced by using a nonlinear technique named ratio enhancement in gaussian neighborhood (REIGN). Histogram equalization and Gaussian smoothing are then performed to the enhanced face images and the synthetic discriminant function (SDF) image before they are subjected to the joint transform correlation process. The two distinct correlation peaks produced on extreme ends of the SPFJTC plane signifies the recognition of a potential target. A post processing step utilizes the peak-to-clutter ratio …

The Influence Of Mechanical Circulation On Water Column Stability And Dissolved Oxygen In Stratified Lakes, Paal Engebrigtsen

Civil & Environmental Engineering Theses & Dissertations

Surface circulators have been used in wastewater and industrial lagoons for many years, but only recently have they been designed for lakes and reservoirs as a water quality management tool. Their relatively low capital investment and operational costs make them an attractive chemical free option for ameliorating the symptoms of eutrophication. Little research has been conducted on their effectiveness in impacting water quality. Today many lake managers are waiting for independent research on surface circulators' performance before installing such systems.

The Occoquan Reservoir was the primary site for a study conducted to examine the influence of surface circulation on water …

Human Osteoblast Proliferation In Culture Following A Nanosecond Pulsed Electric Field (Nspef), Leonard Joseph Carinci Jr.

Biological Sciences Theses & Dissertations

Osteoblasts are mononucleate bone forming cells responsible for the deposition of new bone. Application of mechanical stress on bone reveals its ability to produce and release electric potentials across the cell membrane called piezoelectricity. The electric potentials produced in response to mechanical stress may have a direct correlation on osseous cells and the signaling pathways that regulate proliferation. Nanosecond pulsed electric fields (nsPEFs) are high intensity, ultrashort pulses which have the ability to maintain the integrity of the cell membrane by avoiding traditional electroporation. We delivered 8 nsPEFs (0.5 Hz) of a 25 kV/cm or 35 kV/cm electric field strength …

Nato Human View Architecture And Human Networks, Holly A. H. Handley, Nancy P. Houston

Engineering Management & Systems Engineering Faculty Publications

The NATO Human View is a system architectural viewpoint that focuses on the human as part of a system. Its purpose is to capture the human requirements and to inform on how the human impacts the system design. The viewpoint contains seven static models that include different aspects of the human element, such as roles, tasks, constraints, training and metrics. It also includes a Human Dynamics component to perform simulations of the human system under design. One of the static models, termed Human Networks, focuses on the human-to-human communication patterns that occur as a result of ad hoc or deliberate …

Electrically Mediated Delivery Of Plasmid Dna To The Skin, Using A Multielectrode Array, Richard Heller, Yolmari Criz, Loree C. Heller, Richard A. Gilbert, Mark J. Jaroszeski

Bioelectrics Publications

The easy accessibility of skin makes it an excellent target for gene transfer protocols. To take full advantage of skin as a target for gene transfer, it is important to establish an efficient and reproducible delivery system. Electroporation is a strong candidate to meet this delivery criterion. Electroporation of the skin is a simple, direct, in vivo method to deliver genes for therapy. Previously, delivery to the skin was performed by means of applicators with relatively large distances between electrodes, resulting in significant muscle stimulation and pain. These applicators also had limitations in controlling the directionality of the applied field. …

Crystallization Of Community-Acquired Respiratory Distress Syndrome Toxin From Mycoplasma Pneumonia, Olga N. Pakhomova, Alexander B. Taylor, Argentina Becker, Stephen P. Holloway, T. R. Kannan, Joel B. Baseman, P. John Hart

Bioelectrics Publications

Community-acquired respiratory distress syndrome toxin (CARDS TX) is a 591-amino-acid protein with ADP-ribosyltransferase and vacuolating activities that damages the cells lining the respiratory tracts of patients infected with the bacterial pathogen Mycoplasma pneumoniae. Crystals of CARDS TX were grown in space group C2, with unit-cell parameters a = 191.4, b = 107.4, c = 222.1 A, beta = 90.6 degrees. A complete 2.2 A data set was obtained from a single CARDS TX crystal.

Using Simulation Systems For Decision Support, Andreas Tolk

Computational Modeling & Simulation Engineering Faculty Publications

This chapter describes the use of simulation systems for decision support in support of real operations, which is the most challenging application domain in the discipline of modeling and simulation. To this end, the systems must be integrated as services into the operational infrastructure. To support discovery, selection, and composition of services, they need to be annotated regarding technical, syntactic, semantic, pragmatic, dynamic, and conceptual categories. The systems themselves must be complete and validated. The data must be obtainable, preferably via common protocols shared with the operational infrastructure. Agents and automated forces must produce situation adequate behavior. If these requirements …

M&S Body Of Knowledge: Progress Report And Look Ahead, Andreas Tolk

Computational Modeling & Simulation Engineering Faculty Publications

No abstract provided.

Challenges For Human, Social, Cultural, And Behavioral Modeling, S. K. Numrich, Andreas Tolk

Computational Modeling & Simulation Engineering Faculty Publications

Today's military focus has moved away from the force-on-force battlefield of the past century and into the domain of irregular warfare and its companion security, stability, transition and reconstruction missions. With that change in focus has come a need to examine the operational environment from a wider perspective, one that includes the whole range of human experiences and circumstances. As the set of factors and list of players expands, the need for reliable modeling and simulation increases, if for no other reason than to help the human decision maker make sense of this expanded decision space. However, to do this, …