Digital Commons Network^™

Methodology To Quantify Vertical Accelerations Of Planing Craft In Irregular Waves, Jennifer Suzanne Grimsley

Mechanical & Aerospace Engineering Theses & Dissertations

Planing craft operating in waves at high speeds can experience high, repetitive vertical accelerations that are random and nonlinear in relation to the sea condition. A proper understanding of vertical accelerations is critical to meet statistically based criteria for structural design, habitability, and equipment selection. Historically, it was assumed that planing craft vertical accelerations fit the Exponential distribution, and design methods adopted this conclusion. However, several published papers have raised doubts regarding the accuracy and validity of this Exponential distribution assumption.

The statistical behavior of planing craft vertical accelerations are examined for the Parent and Peak data sets from twenty-eight …

Dispersion Of Cytotoxic Properties Of Multi-Walled Carbon Nanotubes Suspended In Biological Solutions With Tween 80: Their Role In Enhancing Killing Effects Of Nanosecond Pulse Electric Fields On Tumor Cell Lines, Bhargava S. Kalluri

Biological Sciences Theses & Dissertations

The objective of this study was to determine whether multi-walled carbon nanotubes (MWCNTs) suspended in the surfactant Tween 80 give an additive killing effect on tumor cells when exposed to nsPEFs. In this study, MWCNTs were suspended in DMEM and RPMI with or without T80 (surfactant). The size distribution of MWCNTs suspended in these solutions was evaluated with a Delsa™ Nano Zeta potential and sub micro particle Size Analyzer and confirmed with microscopy. The cytotoxicity of MWCNTs dispersed in different concentrations of T80 was evaluated in PANC1 (Human pancreatic cancer cell line) and Jurkat cell lines (Human T-cell lymphoblast cell …

Emotional Intelligence And Its Potential In Engineering Management, Jesse Ray Toepfer

Engineering Management & Systems Engineering Theses & Dissertations

Assuming that the modern connotation of Emotional Intelligence (El) took shape with Wayne Leon Payne's 1986 dissertation, A Study of Emotion: Developing Emotional Intelligence, Self-Integration, Relating to Fear, Pain, and Desire, EI is nearing its thirtieth birthday. Relatively speaking, EI is still very young, and there are a handful of researchers who are still trying to explore and define El. Significant efforts have been made to develop the concept of EI, and the ramifications of EI on an individual's professional performance.

Often more technical and exacting in nature, the field of engineering management exhibits many aspects that are unique relative …

Application Of The Coastal Storm Impulse (Cosi) Parameter To Predict Coastal Erosion, Robert Aaron Walker

Civil & Environmental Engineering Theses & Dissertations

A new coastal storm-strength parameter, the Coastal Storm Impulse (COSI) parameter, was introduced at the 2006 International Conference of Coastal Engineering (ICCE) in San Diego and further discussed at the ICCE 2008 in Hamburg. COSI is based on the conservation of linear, horizontal momentum to combine storm surge, wave dynamics, and currents over the storm duration. Both tropical storms (hurricanes) and extra-tropical storms (northeasters) can produce similar COSI parameters. Potential implications of such a storm classification system include the evaluation of potential coastal erosion and coastal infrastructure, as well as providing a universal storm strength indicator that is directly tied …

Experimental Investigation Of A Non-Thermal Atmospheric Pressure Plasma Jet, Asma Begum

Electrical & Computer Engineering Theses & Dissertations

The main objective of this dissertation is to understand the formation of the plasma jet from the plasma pencil, and the propagation of the plasma jet in the ambient atmosphere where the effect of the external electric field is almost zero. Before investigating the formation and propagation phenomenon of the plasma jet, common physical properties of plasma jets are determined by using the imaging technique and optical emission spectroscopy. The first goal of this dissertation is to establish the laminar helium gas flow channel through a plasma pencil.

The formation position, formation time, and the criterion of the plasma jet …

A Predictive Game Theoretic Model To Assess Us - Russian Response To An Islamic Safe-Haven In The Caucasus Region, Christopher Wayne Hartline

Computational Modeling & Simulation Engineering Theses & Dissertations

The thesis examines possible US and Russian policy decisions following the establishment of an Islamist safe-haven in Chechnya. Conflicting national policies affect the possibility of a negotiated settlement. Domestic and international political considerations constrain the decision-making of the two nations. The author applies game theory to examine the sequential decision-making of the two nations. The extensive form model draws outcome payoff values from a bounded uniform distribution. This approach naturally models uncertainty; and, it allows repeated probabilistic instantiations of the model. These instantiations produce a range of solutions. The most likely outcome was a negotiated settlement, generally following a tit-for-tat …

Multi-Scale Edge Detection Algorithms And Their Information-Theoretic Analysis In The Context Of Visual Communication, Bo Jiang

Electrical & Computer Engineering Theses & Dissertations

The unrealistic assumption that noise can be modeled as independent, additive and uniform can lead to problems when edge detection methods are applied to low signal-to-noise ratio (SNR) images. The main reason for this is because the filter scale and the threshold for the gradient are difficult to determine at a regional or local scale when the noise estimate is on a global scale. Therefore, in this dissertation, we attempt to solve these problems by using more than one filter to detect the edges and discarding the global thresholding method in the edge discrimination. The proposed multi-scale edge detection algorithms …

Analytic Construction Of Periodic Orbits In The Restricted Three-Body Problem, Mohammed A. Ghazy

Mechanical & Aerospace Engineering Theses & Dissertations

This dissertation explores the analytical solution properties surrounding a nominal periodic orbit in two different planes, the plane of motion of the two primaries and a plane perpendicular to the line joining the two primaries, in the circular restricted three-body problem. Assuming motion can be maintained in the plane and motion of the third body is circular, Jacobi's integral equation can be analytically integrated, yielding a closed-form expression for the period and path expressed with elliptic integral and elliptic function theory. In this case, the third body traverses a circular path with nonuniform speed. In a strict sense, the in-plane …

Wavelet-Based Enhancement Technique For Visibility Improvement Of Digital Images, Numan ÜNaldı

Electrical & Computer Engineering Theses & Dissertations

Image enhancement techniques for visibility improvement of color digital images based on wavelet transform domain are investigated in this dissertation research.

In this research, a novel, fast and robust wavelet-based dynamic range compression and local contrast enhancement (WDRC) algorithm to improve the visibility of digital images captured under non-uniform lighting conditions has been developed. A wavelet transform is mainly used for dimensionality reduction such that a dynamic range compression with local contrast enhancement algorithm is applied only to the approximation coefficients which are obtained by low-pass filtering and down-sampling the original intensity image. The normalized approximation coefficients are transformed using …

Post-Project Risk Perception And Systems Management Reaction, Baqer Alali

Engineering Management & Systems Engineering Theses & Dissertations

The objective of this research is to identify whether risk management in projects has any role in risk management in systems. Projects, systems, and risk management are three integral concepts in the management of various enterprises and agencies. Risk management is a common concept in systems and project processes. To avoid failures or crisis during their life cycles, projects and systems managers practice risk management. Projects and systems have well defined life cycles during which the risk is defined, controlled, and managed. Risk management is conducted in each phase of projects and systems. Projects are initiated to close certain operational …

The Influence Of Network Factors On Network Centric Operations, Mehmet Fidanci

Engineering Management & Systems Engineering Theses & Dissertations

As Information Age changes the lifestyle of all humankinds, it also changes the way how to defense and secure the borders are secured and defended. The Information Age is about information superiority. It evolves the command and control concept, proactively, to optimize the size of the units and their connections within a combat force for effective mission accomplishment. The biggest issue is how big a unit will be and how they will arrange and connect it to the command and control structure in order for the unit to be effective on the battlefield. While some arrangements connect to each other …

Simultaneous Higher Harmonic Detection And Extraction Of Information From Oxygen Spectra, Karan Dineshchandra Mohan

Electrical & Computer Engineering Theses & Dissertations

Wavelength Modulation Spectroscopy (WMS) is a highly sensitive technique that utilizes synchronous detection at the N-th harmonics of a modulating frequency, by modulating the laser beam used to probe a gaseous species. The advantage of this technique lies in the greater effective signal-to-noise ratio one obtains as a direct consequence of the larger amount of structure present in the higher harmonics, and thus a greater amount of information that can be obtained from that structure. We present the development of a novel technique where data at multiple harmonics is obtained simultaneously, rather than sequentially. This removes the susceptibility of the …

Simulation Studies Of Pulsed Voltage Effects On Cells, Jiahui Song

Electrical & Computer Engineering Theses & Dissertations

This dissertation research focuses on the new field of pulsed electric field interactions with biological cells. In particular, "Intracellular Electromanipulation" which has important biomedical applications, is probed. Among the various aspects studied, nanosecond, high-intensity pulse induced electroporation is one phenomena. It is simulated based on a coupled scheme involving the current continuity and Smoluchowski equations. A dynamic pore model can be achieved by including a dependence on the pore population density and a variable membrane tension. These changes make the pore formation energy E(r) self-adjusting and dynamic in response to pore formation. Additionally, molecular dynamics (MD) simulations are also discussed …

The Effect Of Systematic Error In Forced Oscillation Wind Tunnel Test Apparatuses On Determining Nonlinear Unsteady Aerodynamic Stability Derivatives, Brianne Y. Williams

Mechanical & Aerospace Engineering Theses & Dissertations

One of the basic problems of flight dynamics is the formulation of aerodynamic forces and moments acting on an aircraft in arbitrary motion. Classically conventional stability derivatives are used for the representation of aerodynamic loads in the aircraft equations of motion. However, for modern aircraft with highly nonlinear and unsteady aerodynamic characteristics undergoing maneuvers at high angle of attack and/or angular rates the conventional stability derivative model is no longer valid. Attempts to formulate aerodynamic model equations with unsteady terms are based on several different wind tunnel techniques: for example, captive, wind tunnel single degree-of-freedom, and wind tunnel free-flying techniques. …

Using Micro-Simulation To Evaluate Transit Signal Priority For Lrt Operations In A Downtown Environment, Faisal Mahmud

Civil & Environmental Engineering Theses & Dissertations

Transit Signal Priority or TSP is an operational strategy that facilitates the movement of transit vehicles such as buses, light rail or streetcars, through traffic-signal controlled intersections. The benefits of TSP operations include improved schedule adherence and improved transit travel times with minimal impact to normal traffic operations. New advances in Global Positioning Systems, detection and communication, and control strategies have helped overcome many problems with early systems and increased interest in implementing TSP for Light Rail Transit (LRT) and other transit operations. The increased capabilities of these advanced systems have led to a dramatic increase in operational and planned …

Analysis And Optimization Of Dynamic Spectrum Sharing For Cognitive Radio Networks, Manish Wadhwa

Electrical & Computer Engineering Theses & Dissertations

The goal of this dissertation is to present the analysis and optimization of dynamic spectrum sharing for cognitive radio networks (CRNs). Spectrum scarcity is a well known problem at present. In order to deal with this problem, dynamic spectrum sharing (DSS) was proposed. DSS is a technique where cognitive radio networks dynamically and opportunistically share the channels with primary users. The major contribution of this dissertation is in analyzing the problem of dynamic spectrum sharing under different scenarios and developing optimal solutions for these scenarios. In the first scenario, a contention based dynamic spectrum sharing model is considered and its …

A Study Of Passive Earth Pressure In Anisotropic Sand With Various Wall Movement Modes, Achmad Bakri Muhiddin

Civil & Environmental Engineering Theses & Dissertations

This study investigated the effect of anisotropy on passive pressure in sands by developing computer simulation utilizing FLAC code for plane strain condition. A series of wall movement modes was applied namely translation, rotation about a point below the wall, RBT, and rotation about a point above the wall, RTT.

From comparisons with other FLAC model in translation mode with isotropic material, the coefficients of passive pressure K_p were similar to each other except for some combinations of zero dilation, low wall friction, and high angle of internal friction ϕ. Dilation angle has less effect on K_p than …

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 …

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. …

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 …

Hybrid Intelligent Optimization Methods For Engineering Problems, Yasin Volkan Pehlivanoglu

Mechanical & Aerospace Engineering Theses & Dissertations

The purpose of optimization is to obtain the best solution under certain conditions. There are numerous optimization methods because different problems need different solution methodologies; therefore, it is difficult to construct patterns. Also mathematical modeling of a natural phenomenon is almost based on differentials. Differential equations are constructed with relative increments among the factors related to yield. Therefore, the gradients of these increments are essential to search the yield space. However, the landscape of yield is not a simple one and mostly multi-modal. Another issue is differentiability. Engineering design problems are usually nonlinear and they sometimes exhibit discontinuous derivatives for …

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 …

Providing Location Security In Vehicular Ad Hoc Networks, Gongjun Yan

Computer Science Theses & Dissertations

Location is fundamental information in Vehicular Ad-hoc Networks (VANETs). Almost all VANET applications rely on location information. Therefore it is of importance to ensure location information integrity, meaning that location information is original (from the generator), correct (not bogus or fabricated) and unmodified (value not changed). We present validation mechanisms to provide location integrity for VANETs. In the initial mechanism, we assume that all vehicles are equipped with a radar, a GPS receiver, and a transceiver. Since radar has a limited radar range and transceiver has a limited transmission range, we build network cells as a security unit as well …

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 …

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 …

A Decision Making Construct For Complex Situations, Van Edward Brewer

Engineering Management & Systems Engineering Theses & Dissertations

The uncertainty inherently associated with complexity challenges decision-making processes, indicating a need for a construct for decision making in complex situations. A review of the literature on systems, complexity, and paradigms indicates that such a construct must be internally consistent with well-defined philosophical foundations and further that systems and complexity (as used in complex situations) are not necessarily internally consistent with traditional philosophical foundations. Therefore, a decision making construct for complex situations requires research into different foundations. This research addresses these gaps, deriving axiological and methodological components based on a set of principles consistent with the ontology and epistemology of …

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. …

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 …

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 …