Digital Commons Network^™

An Incentive Based Approach To Detect Selfish Nodes In Mobile P2p Network, Hemanth Meka

Masters Theses

"The growth of mobile devices led to the wide use of Mobile P2P networks. These networks are used in a wide variety of areas and hence there is lot of research in the field of mobile networks. Detecting selfish nodes is one of the research topics triggered due to the popularity of mobile P2P networks. It is necessary to detect selfish nodes in such networks to improve the efficiency of the network. In this thesis, an incentive based approach to detect selfish nodes is designed and evaluated. This approach differs from the existing work as it (i) can be used …

Simulation Of The Field Electron Emission Characteristics Of A Flat Panel X-Ray Source, Chrystian Mauricio Posada ArbeláEz

Masters Theses

"A distributed flat panel x-ray source is designed as an alternative for medical and industrial imaging fields. The distributed x-ray source corresponds to a two dimensional array of micro (~100μm) x-ray cells similar in format to a field emission display. In this paper the electron field emission characteristics of a single of the proposed micro-sized x-ray cells are simulated. The field electron emission from the CNTs-based cathode is simulated using the Particle-In-Cell code OOPIC Pro. The electron source is simulated as a triode structure, composed of an emitting cathode, extracting grid and anode. The possibility of using focusing lenses to …

Towards On-Line Voltage Stability Assessment Using Synchrophasors, Himanshu Subandhu Hirlekar

Masters Theses

"Voltage instability has become a growing concern in the operation of power systems in recent years. The reason is that power systems all over are being operated with reduced margins because of increased demand exacerbated by a general reluctance to invest in improvement of the electric grid infrastructure. Until recently it was difficult to predict voltage instability in the on-line environment. However, advances in technology has made possible the on-line monitoring and assessment of voltage stability. Synchrophasors is a relatively new technology in the field of power systems which allows system operators to monitor the system conditions at specific measurement …

Uncertainty Quantification Integrated To Computational Fluid Dynamic Modeling Of Synthetic Jet Actuators, Srikanth Adya

Masters Theses

"The Point Collocation Non-Intrusive Polynomial Chaos (NIPC) method was applied to a stochastic synthetic jet actuator problem to demonstrate the integration of computationally efficient uncertainty quantification to the high-fidelity CFD modeling of Synthetic Jet Actuators. The uncertainty quantification approach was first implemented in two stochastic model problem cases for the prediction of peak exit plane velocity using a Fluid Dynamic Based analytical model of the Synthetic Jet Actuator, which is computationally less expensive than CFD simulations. The NIPC results were compared with direct Monte Carlo sampling results. To demonstrate the efficient uncertainty quantification in CFD modeling of synthetic jet actuators, …

Characterization Of Shielding Effectiveness For Metallic Enclosures, Nicholas Bennett Mentesana

Masters Theses

"This topic discusses and verifies an equation for estimating the shielding effectiveness of metallic enclosures through the use of numerical simulations. Using ideas from Bethe's "Theory of Diffraction by Small Holes", a previous student from the Missouri S&T Electromagnetic Compatibility Laboratory developed an equation that would yield an envelope prediction for the worst-case EMI from an aperture array backed by an over-moded cavity. Min Li (PhDEE '99) used results from measurements, simulations, and physics-based equations to formulate a simple equation that would predict these EMI levels. The main purpose of this thesis is to revisit this work and determine when …

Mutual Attraction Guided Search: A Novel Solution Method To The Traveling Salesman Problem With Vehicle Dynamics, Jared Adam Nisbett

Masters Theses

"Traveling Salesman Problem (TSP) solution techniques are often used for route planning for automated vehicles. Most TSP solution methods focus on path length as the fitness reference, however in many cases, traversal time is of more practical importance. Mutual Attraction Guided Search (MAGS) is a novel solution method that uses an iterative process to simultaneously optimize both angle of travel through each target as well as the ordering of the targets in order to optimize path traversal time. MAGS deterministically locates a locally optimum solution quickly and can optimize for the acceleration limits of a specific vehicle rather than requiring …

Managing A Solar Sensor Array Project: Analyzing Insolation & Motivation, Beth A. Yount

Masters Theses

"The renewable power industry is rapidly growing today and is in need of much data to augment the advancement of the field. Photovoltaic technology, while making substantial improvement over the last 60 years, still has some significant hurdles to overcome. When shading, dust, or damaged cells reduce the power output of one panel, the traditional series-parallel configurations make it so every panel in series with that lower current panel, will also have its current lowered; this lowers the overall power output of the array significantly. Advancements in configurations and converters could change this phenomenon and dramatically increase a solar array's …

3-Dimensional Computational Fluid Dynamics Modeling Of Solid Oxide Fuel Cell Using Different Fuels, Sachin Laxman Puthran

Masters Theses

"Solid oxide fuel cell (SOFC) technology has been of great interest over many years due to its flexibility in using different fuels for operation; including the fundamental fuel i.e. Hydrogen. Various computational and numerical models have been developed along with experimental work to evaluate the performance as well as to identify and overcome the problems faced in the development of SOFC's. In an attempt to achieve efficient operation with respect to design and combined thermal and electrochemical perspective, the main objective of the proposed study is to present a three-dimensional computational model, which will serve as a framework for the …

Quantifying Model Uncertainty Using Measurement Uncertainty Standards, Harsheel Rajesh Shah

Masters Theses

"Model uncertainty quantification is mainly concerned with the problem of determining whether the observed data is consistent with the model prediction. In real world, there is always a disagreement between a simulation model prediction and the reality that the model intends to represent. Our increased dependence on computer models emphasizes on model uncertainty which is present due to uncertainties in model parameters, lack of appropriate knowledge, assumptions and simplification of processes. In addition, when models predict multi-variate data, the experimental observation and model predictions are highly correlated. Thus, quantifying the uncertainty has a basic requirement of comparison between observation and …

Adaptive Rule-Based Malware Detection Employing Learning Classifier Systems, Jonathan Joseph Blount

Masters Theses

"Efficient and accurate malware detection is increasingly becoming a necessity for society to operate. Existing malware detection systems have excellent performance in identifying known malware for which signatures are available, but poor performance in anomaly detection for zero day exploits for which signatures have not yet been made available or targeted attacks against a specific entity. The primary goal of this thesis is to provide evidence for the potential of learning classier systems to improve the accuracy of malware detection.

A customized system based on a state-of-the-art learning classier system is presented for adaptive rule-based malware detection, which combines a …

Rapid Simulation Of The Statistical Variation Of Crosstalk In Cable Harness Bundles, Xiang Li

Masters Theses

"Accurate assessment of crosstalk problems in cable harnesses requires simulation methods that account for the statistical variation of harness parameters. Methods are proposed to determine the influence of the statistical variation in wire positions, the rate that wires change position (i.e. "twist"), harness height, harness density (i.e. how closely wires are packed) and circuit loads. Methods use a combination of simulation and probability theory. Simulations use the T-parameter method, a rapid simulation technique for harness bundles. Simulation time is further improved by using the mean and variance of crosstalk estimated for fixed harness parameter values to estimate the mean and …

Mutation Of The Hof1 Pest Domain Affects Cytokinesis In Budding Yeast, Katherine E. Stockstill

Masters Theses

"Cytokinesis is the division of a cell into two daughter cells. Cytokinesis failure results in polyploidy, which may contribute to tumorigenesis or cause cell death. The Saccharomyces cerevisiae protein Hof1, which is required for efficient cytokinesis, is phosphorylated during mitosis. The hypothesis that MEN (mitotic exit network) dependent phosphorylation regulates Hof1 degradation, triggering completion of cytokinesis was tested. Hof1 contains a PEST sequence, which is rich in proline, glutamic acid, serine, and threonine, and is believed to be involved in protein degradation. To test the hypothesis, we created two non-phosphorylatable mutants of the Hof1 PEST domain tagged with GFP. The …

Visual Inspection And Ground Penetrating Radar Investigation Of The Historical Pulaski County Poor Farm Cemetery, Ibrahim E. Ahmed

Masters Theses

"This thesis is a comprehensive summary of the geotechnical investigation of the Historical Pulaski County Poor Farm Cemetery, southeast Waynesville, Missouri. This research demonstrates that unmarked graves in an abandoned historical cemetery can be located using visual site inspection and ground penetrating radar techniques.

During the course of these investigations, multiple visual site inspections of Pulaski County Poor Farm Cemetery were conducted and ground penetrating radar data were acquired. Based on the visual site inspections and the interpretation of ground penetrating radar data, a total of one-hundred and fifty-one (151) graves were identified; eighty-seven (87) of the graves were mapped …

Location Privacy Policy Management System, Arej Awodha Muhammed

Masters Theses

"The advance in wireless communication and positioning systems has permitted development of a large variety of location-based services that, for example, can help people easily locate family members or find nearest gas station or restaurant. As location-based services become more and more popular, concerns are growing about the misuse of location information by malicious parties. In order to preserve location privacy, many efforts have been devoted to preventing service providers from determining users' exact locations. Few works have sought to help users manage their privacy preferences; however management of privacy is an important issue in real applications. This work developed …

Heat Transfer Augmentation In Rectangular Ducts Due To Passive Flow Destabilization, James Jackson Tinsley

Masters Theses

"The following thesis documents the comparison of surface enhancements in rectangular ducts for heat transfer enhancement of the air-side of off-road heat exchangers. Two sets of experiments were completed, one utilizing air as the working fluid, and the other utilizing water. Five air geometries and four water geometries were studied, including those with crosswise bumps, longitudinal vortex generators, and a unique rifling geometry. A smooth test section was also tested in the water experiments to verify the experimental setup. Such verification had been performed previously for the air experiments by Rucker [2007]. The experiment involved an applied constant heat flux …

Density Determination Of Tristructural-Isotropic Nuclear Fuel Using Multiple Projection X-Ray Radiography, Frank Angelo Strantz

Masters Theses

"Effective methods of enhancing the safety and efficiency of the nuclear power industry embolden its perception and economic viability. Fuel reliability is an essential component of the prosperity of next generation high temperature reactors; as such, an equally dependable quality control method is mandatory. Tristructural-isotropic (TRISO) fuel, the fuel developed for use in these reactors, utilizes density measurement of coating layers as a standard for quality control. Common methods of measuring density, such as sink-float and ceramography are destructive, and as such generate radioactive waste, take a relatively long time to prepare samples, rely on a low sampling rate to …

Numerical Simulation Of Relative Permeability Modifier Effect On Oil And Water Production, Murad Mohammedahmed Abdulfarraj

Masters Theses

"Excess water production is one of the most prevalent operational problems that oil companies are facing. Polymers and polymer gels have been used widely to control excess water production for mature oilfields. It is well known that polymers/gels can reduce the permeability to water (Krw) much more than that to oil (Kro). This phenomenon is called disproportionate permeability reduction (DPR) and the polymers or gels that exhibit this behavior are called relative permeability modifier (RPM). When RPMs are placed in reservoir, reduced permeability to water can lead to decreased water production, and sometimes increased hydrocarbon production, therefore prolonging the useful …

Introduction To The Bible, Michael L. Dusing

Syllabus Repository

No abstract provided.

Advance (Spring 2011), Georgia Southern Division Of Continuing And Professional Education

Division of Continuing & Professional Education

No abstract provided.

Crustal Structure And Evolution Beneath The Colorado Plateau And The Southern Basin And Range Province, Lamuail Bashir

Doctoral Dissertations

"Stacking of about 15,500 P-to-S receiver functions recorded at 72 USArray and other broadband seismic stations placed on the Colorado Plateau and the SBRP in Arizona revealed systematic spatial variations in crustal Vp/Vs, crustal thickness and amplitude of P-to-S converted phases. Our results reveal that the BRP is characterized by a thin crust (28.2 ± 0.5 km), a mean Vp/Vs of 1.761 ± 0.014 and a mean amplitude (R) of P - to - S converted wave (relative to that of the direct P wave) of 0.181 ± 0.014 that are similar to a typical continental crust, consistent with the …

First-Principles Studies Of Complex Hydrides For Li-Ion Battery And Hydrogen Storage Applications, Timothy Hudson Mason

Doctoral Dissertations

"We employ density functional theory in a computational study of two energy storage systems.

In the first, we explore the thermodynamic viability of light metal hydrides as a high capacity Li-ion battery negative electrode. Given a set of solid-state and gas-phase reactants, we have determined the phase diagram in the Li-Mg-B-N-H system in the grand canonical ensemble as a function of lithium electrochemical potential. We present computational results for several new conversion reactions with predicted capacities between 2400 and 4000 mAhg⁻¹ that are thermodynamically favorable and that do not involve gas evolution. We provide experimental evidence for the reaction pathway …

Two New Spline-Based Methods And Real Data Applications: High-Resolution Receiver Function Calculations From Teleseismic Broadband Waveforms And High-Accuracy Practical Potential-Field Integral Transformations, Bingzhu Wang

Doctoral Dissertations

"While receiver function (RF) calculation is fundamentally important and widely used, it is not well solved due to unstable deconvolution. A spline-based RF calculation method was proposed and it is demonstrated that both individual RFs and the stacked RF calculated with the spline method have sharper peaks than those with the water-level spectral division method and the iterative deconvolution method. At the common peaks on the stacked RFs, there are close similarities for all three RF calculation methods. The better calculated RFs with the spline method lead to improved H - K analysis and improved determination of the optimal Moho …

Femtosecond Laser Micromachining Of Microstructures For Sensing And Detection, Yukun Han

Doctoral Dissertations

"This thesis focuses on the fabrication and analysis of miniature functional devices that can be used for different sensing and detection applications. As the first step, the surface characteristics and morphology of the micro/nano structures on substrates (fused silica and silicon) fabricated in water and in air by femtosecond laser were investigated. Based on this study, three micro devices have been designed and fabricated by femtosecond laser, and they were analyzed for optical and chemical sensing and detections. The three micro devices are: 1) an optical Fabry-Perot interferometer in optical fiber (made from fused silica) with smooth cavity surfaces. The …

Agent-Based Analysis And Mitigation Of Failure For Cyber-Physical Systems, Jing Lin

Doctoral Dissertations

"Techniques exist for assessment, modeling, and simulation of physical and cyber infrastructures, respectively; but such isolated analysis is incapable of fully capturing the interdependencies that occur when they intertwine to create a cyber-physical system (CPS). The first contribution of this doctoral research includes qualitative representation of the operation of a CPS in a single multi-agent model. Dependable operation of a CPS is contingent upon correct interpretation of data describing the state of the system. To this end, we propose agent-based semantic interpretation services that extract useful information from raw sensor data. We utilize the summary schemas model to reconcile differences …

Impact Of Stochastic Loads And Generations On Power System Transient Stability, Theresa Odun-Ayo

Doctoral Dissertations

"Randomness in physical systems is usually ultimately attributed to external noise. Dynamic systems are driven not only by our own control inputs, but also disturbances which cannot be modeled deterministically. A linear system model is justifiable for a number of reasons, often such a model is adequate for the purpose at hand, and when non-linearities do exist, the typical engineering approach is to linearize about some nominal point or trajectory to achieve a perturbation or error model. However, in order for the resulting model to fit data generated by the real world, these disturbances need to be modeled stochastically. The …

Hardware Emulation Of Wireless Communication Fading Channels, Fei Ren

Doctoral Dissertations

"This dissertation investigates several main challenges to implementing hardware-based wireless fading channel emulators with emphasis on incorporating accurate correlation properties. Multiple-input multiple-output (MIMO) fading channels are usually triply-selective with three types of correlation: temporal correlation, inter-tap correlation, and spatial correlation. The proposed emulators implement the triply-selective fading Channel Impulse Response (CIR) by incorporating the three types of correlation into multiple uncorrelated frequency-flat Rayleigh fading waveforms while meeting real-time requirements for high data-rate, large-sized MIMO, and/or long CIR channels. Specifically, mixed parallel-serial computational structures are implemented for Kronecker products of the correlation matrices, which makes the best tradeoff between computational speed …

Stress Measurement And Development Of Zirconium Diboride-Silicon Carbide Ceramics, Jeremy Lee Watts

Doctoral Dissertations

"Research presented in this dissertation focused on the production of ZrB₂-SiC composites and their characterization; in particular their mechanical properties and thermally generated residual stresses. Thermally generated stresses were measured using Raman spectroscopy as well as both neutron and x-ray diffraction. For 70 vol% ZrB₂ - 30 vol% SiC composites neutron diffraction revealed that the SiC phase was under ~880 MPa compressive stress and the ZrB₂ phase was under ~450 MPa tension at room temperature. It was also discovered that stresses began to accumulate at ~1400 ⁰C upon cooling from the processing temperature (1900 ⁰C -2000 ⁰C). Raman spectroscopy and …

Ceeme: Compensating Events Based Execution Monitoring Enforcement For Cyber-Physical Systems, Thoshitha T. Gamage

Doctoral Dissertations

"Fundamentally, inherently observable events in Cyber-Physical Systems with tight coupling between cyber and physical components can result in a confidentiality violation. By observing how the physical elements react to cyber commands, adversaries can identify critical links in the system and force the cyber control algorithm to make erroneous decisions. Thus, there is a propensity for a breach in confidentiality leading to further attacks on availability or integrity. Due to the highly integrated nature of Cyber-Physical Systems, it is also extremely difficult to map the system semantics into a security framework under existing security models. The far-reaching objective of this research …

Diesel Particulate Matter Dispersion Analysis In Underground Metal/Nonmetal Mines Using Computational Fluid Dynamics, Yi Zheng

Doctoral Dissertations

"Diesel Particulate Matter (DPM) is a natural by-product from operating diesel engines. Since diesel power is a major source of energy for mining operations today, the adverse health effects of DPM are of a great concern. To thoroughly resolve DPM problems, it is critical that DPM propagation characteristics be understood to arrive at a sensible and practical method for addressing DPM-related issues. To achieve this, a computational fluid dynamics (CFD) method is used to simulate DPM dispersion and to predict its concentration distribution. Industrial field studies were reconstructed to evaluate the possibility of different CFD models. Experiments were also carried …

Effect Of Hydrophobicity And Surface Roughness On Two-Phase Flow In Rectangular Microchannels, Gautham C. Unni

Doctoral Dissertations

"Two-phase flows in microchannels have received significant attention recently, and have become the cornerstone of numerous microfluidic devices. Microscale devices used for bioengineering applications, oil recovery, and chemical and catalytic microreactor applications involve the transport of bubbles in confined fluidic networks in channels of micrometer length scale. These types of two-phase flows result in pressure variations, leading to an overall increase in pressure drop. Among various flow parameters, pressure drop is extensively used in design of microfluidic devices. There are several parameters that affect the pressure drop across two-phase flow in microchannels. In the present study, the goal is to …