Digital Commons Network^™

Impact Of Configuration Variations On Small Modular Reactor Core Performance, William Kirby Compton

Masters Theses

"One of the most promising new reactor designs is the Small Modular Reactor (SMR). These reactors, which operate under 300 MWe, will help bring cheap and safe nuclear energy to remote and centralized locations alike. Their ease of construction, advanced passive safety features, and cost effectiveness make these reactors an intriguing option for the near future.

In the work presented here, a neutronics analysis of the Westinghouse SMR was performed. Westinghouse's SMR design is a scaled down version of their AP1000 plant and will produce about 225 MWe of power. Though the parameters of the reactor core will be modeled …

Evaluation Of Preformed Particle Gel Treatment Using Homogeneous And Heterogeneous Models, Hilary Ogochukwu Elue

Masters Theses

"This research investigates the effects of preformed particle gel (PPG) in remedying the problems of excess water production and low oil recovery of heterogeneous reservoirs by placing the PPG in the high-permeability layer, thus diverting displacing brine to the unswept low permeability layer. This investigation was completed with three tasks.

The first task was to evaluate the PPG swelling kinetics and strength as a function of concentration of brine. The result of this task indicate that PPG prepared with low concentration of brine swells more, becomes weaker, more deformable than PPG prepared with high concentration of brine.

The second task …

Computer Aided Detection Of Oral Lesions On Ct Images, Shaikat Mahmood Galib

Masters Theses

"Oral lesions are important findings on computed tomography images. They are difficult to detect on CT images because of low contrast, arbitrary orientation of objects, complicated topology and lack of clear lines indicating lesions. In this thesis, a fully automatic method to detect oral lesions from dental CT images is proposed to identify (1) Closed boundary lesions and (2) Bone deformation lesions. Two algorithms were developed to recognize these two types of lesions, which cover most of the lesion types that can be found on CT images. The results were validated using a dataset of 52 patients. Using non training …

Seismological Investigation Of The Okavango Rift, Botswana, Youqiang Yu

Doctoral Dissertations

The mechanisms of rifting have been intensively investigated using geological and geophysical techniques beneath mature rift zones. However, current understanding on the earliest stages of rifting is seriously limited. Here we employ recently archived data from 17 broadband seismic stations traversing northern Botswana to conduct the first shear wave splitting and mantle transition zone (MTZ) studies within the Okavango Rift Zone (ORZ). The ORZ is an incipient continental rift situated at the terminal of the southwestern branch of the East African Rift System. The resulting normal MTZ thickness and consistently rift-parallel fast polarizations imply an absence of significant thermal anomalies …

Flow Mechanisms And Numerical Simulation Of Gas Production From Shale Reservoirs, Chaohua Guo

Doctoral Dissertations

"Shale gas is one kind of the unconventional resources which is becoming an ever increasing component to secure the natural gas supply in U.S. Different from conventional hydrocarbon formations, shale gas reservoirs (SGRs) present numerous challenges to modeling and understanding due to complex pore structure, ultra-low permeability, and multiple transport mechanisms.

In this study, the deviation against conventional gas flow have been detected in the lab experiments for gas flow through nano membranes. Based on the experimental results, a new apparent permeability expression is proposed with considering viscous flow, Knudsen diffusion, and slip flow. The gas flow mechanisms of gas …

Mr4rf: Mem-Device With Impedance And Their Usage With Impedance Matching Networks For Passive Rfid Tags In The Uhf, George H. Harris

Masters Theses

"The passive RFID tag in the UHF has been employed in several different applications including, tracking, logistics, and as a sensing platform for the Internet of things (IoT). The tag is ideal for this industry due to its unique design. It harvests all of its energy from the environment, and is small, cheap, and requires little to no maintenance. However, there are two major issues limiting the potential of the passive RFID systems: the limited power harvested by the tag, and the high susceptibility to interference and coupling. In particular, dynamic environments render the traditionally fixed, RF impedance matching network …

Discrete-Time Neural Network Based State Observer With Neural Network Based Control Formulation For A Class Of Systems With Unmatched Uncertainties, Jason Michael Stumfoll

Masters Theses

"An observer is a dynamic system that estimates the state variables of another system using noisy measurements, either to estimate unmeasurable states, or to improve the accuracy of the state measurements. The Modified State Observer (MSO) is a technique that uses a standard observer structure modified to include a neural network to estimate system states as well as system uncertainty. It has been used in orbit uncertainty estimation and atmospheric reentry uncertainty estimation problems to correctly estimate unmodeled system dynamics. A form of the MSO has been used to control a nonlinear electrohydraulic system with parameter uncertainty using a simplified …

Hybrid Manufacturing Process Of SicF/Sic Composite Using Preceramic Polymer, Robert Raymond Meinders

Masters Theses

"Continuous fiber-reinforced silicon carbide (SiC_f/SiC) ceramic composites have been increasingly used due to their high temperature strength and graceful failure mechanisms. A disadvantage is the high cost and lengthy production processes that are required to develop these materials. Polymer infiltration and pyrolysis (PIP) is one of the most attractive fabrication processes for composites due to shape flexibility, mass production and relatively low cost; however, the quality of material obtained by this method has been considered insufficient due to the microstructure defects of the material obtained. This study investigated a hybrid of multiple polymer manufacturing processes to maximize quality …

American Sign Language Alphabet Recognition Using Microsoft Kinect, Cao Dong

Masters Theses

"American Sign Language (ASL) fingerspelling recognition using marker-less vision sensors is a challenging task due to the complexity of ASL signs, self-occlusion of the hand, and limited resolution of the sensors. This thesis describes a new method for ASL fingerspelling recognition using a low-cost vision camera, which is Microsoft's Kinect. A segmented hand configuration is first obtained by using a depth contrast feature based per-pixel classification algorithm. Then, a hierarchical mode-finding method is developed and implemented to localize hand joint positions under kinematic constraints. Finally, a Random Decision Forest (RDF) classifier is built to recognize ASL signs according to the …

Esd Event Locator, Syed Abrar Ul Huq

Masters Theses

"Electrostatic Discharge (ESD) presents one of the most common threats to electronic systems especially in the cases of high-speed digital systems. ESD event locator systems have been designed to determine the location of the source of the ESD event using different techniques. One such method of determining the origin of the ESD event, is the use of four antennas and a high-speed Analog to Digital Converter (ADC) system to capture the ESD events.

This thesis presents such an implementation which deals with the design of an analog front-end to a fast TI LM97600 ADC and a Virtex-5 Field-Programmable Gated Array …

Design And Implementation Of A 20 Ghz Ultra-Wide Bandwidth Channel Emulator For Differential High Speed Serial Data Links, Wei Qian

Masters Theses

"High speed serial link is now the dominant signal propagation design in various communication, computing and embedded applications. Emulation of such channels is important in signal integrity design and product testing, where full channel simulation is restricted due to the need for protection of intellectual property and frequent channel reconfiguration. This thesis introduces robust lossy material and FIR filter design methods that can be used for channel emulation to provide a solution under these restrictions. Based on the channel characterizations normally obtained in the frequency domain by vector network analysis, different emulation strategies and optimization techniques are utilized to emulate …

A Study Into Improving Transformer Loading Capability Beyond Nameplate Rating, Aakanksha Pasricha

Masters Theses

"Utilities are becoming increasingly interested in the prospect of overloading the transformers beyond the nameplate rating to meet the increased demand for power as it may be more economically viable than installing a new transformer. The safety of the transformer has to be ensured while overloading it and hence there is a maximum loading beyond which the transformer should not be overloaded. A study has been performed on 38 transformer units and the factors that limit their overloading capability have been analyzed. Ancillary equipment ratings were found to be the most prominent limiting factor. Several case studies and evaluation results …

Model Predictive Current Control Of Switched Reluctance Motor With Inductance Auto-Calibration, Xin Li

Masters Theses

"The thesis is composed of three papers, which investigate the application of Model Predictive Controller (MPC) for current control of Switched Reluctance Motor (SRM). Since the conventional hysteresis current control method is not suitable for high power SRM drive system with low inductance and limited switching frequency, MPC is a promising alternative approach for this application. The proposed MPC can cope with the measurement noise as well as uncertainties within the machine inductance profile. In the first paper, a MPC current control method for Double-Stator Switched Reluctance Motor (DSSRM) drives is presented. A direct adaptive estimator is incorporated to follow …

A New Technique For Modeling The Geomorphology Of A Slow Moving, Soft-Slope Landslide Using Terrestrial Lidar, Nathan Bradley Rohrbaugh

Masters Theses

"Soft slope movement is a big problem whether it involves an engineered slope, one that is near infrastructure, or both. Active landslides that fail slowly sometimes allow ample time to affect remedial works. In order to plan effective remedial works, there needs to be a model of the entire geometry of the slide. This thesis describes a new approach to evaluate the morphology of slope geometry using Light Detection and Ranging (LiDAR) data obtained from simple targets strategically positioned on a slide body. The data was gathered in three-month intervals over a period of one year to allow enough time …

Fuzzy Adaptive Resonance Theory: Applications And Extensions, Clayton Parker Smith

Masters Theses

"Adaptive Resonance Theory, ART, is a powerful clustering tool for learning arbitrary patterns in a self-organizing manner. In this research, two papers are presented that examine the extensibility and applications of ART. The first paper examines a means to boost ART performance by assigning each cluster a vigilance value, instead of a single value for the whole ART module. A Particle Swarm Optimization technique is used to search for desirable vigilance values. In the second paper, it is shown how ART, and clustering in general, can be a useful tool in preprocessing time series data. Clustering quantization attempts to meaningfully …

Signal Integrity Analysis Of A Low Cost Pcb To Pcb System, Kancy Robison

Masters Theses

"This report presents the analysis of a low cost PCB to PCB cable and connector system focusing on its data rate limitations and optimizing transmitter and receiver operations. Economic factors have an ineluctable presence in digital hardware engineering and, as data rates are continually pushed to new bounds, finding cheaper alternatives in hardware while maintaining performance standards becomes more relevant. This study will show the measurement and simulation of a low cost digital system which includes a PCB board, connector, and a multi-pin flex cable (ribbon cable). These S-parameter and TDR measurements/simulations are used to gain an intuition for the …

Rote-Lcs Learning Classifier System For Classification And Prediction, Benjamin Daniels

Masters Theses

"Machine Learning (ML) involves the use of computer algorithms to solve for approximate solutions to problems with large, complex search spaces. Such problems have no known solution method, and search spaces too large to allow brute force search to be feasible. Evolutionary algorithms (EA) are a subset of machine learning algorithms which simulate fundamental concepts of evolution. EAs do not guarantee a perfect solution, but rather facilitate convergence to a solution of which the accuracy depends on a given EA's learning architecture and the dynamics of the problem.

Learning classifier systems (LCS) are algorithms comprising a subset of EAs. The …

Adjoint-Based Airfoil Shape Optimization In Transonic Flow, Joe-Ray Gramanzini

Masters Theses

"The primary focus of this work is efficient aerodynamic shape optimization in transonic flow. Adjoint-based optimization techniques are employed on airfoil sections and evaluated in terms of computational accuracy as well as efficiency. This study examines two test cases proposed by the AIAA Aerodynamic Design Optimization Discussion Group. The first is a two-dimensional, transonic, inviscid, non-lifting optimization of a Modified-NACA 0012 airfoil. The second is a two-dimensional, transonic, viscous optimization problem using a RAE 2822 airfoil. The FUN3D CFD code of NASA Langley Research Center is used as the ow solver for the gradient-based optimization cases. Two shape parameterization techniques …

A Novel Entropy Production Based Full-Chip Tsv Fatigue Analysis, Tianchen Wang

Masters Theses

"Through-silicon vias (TSVs) are subject to thermal fatigue due to stress over time, no matter how small the stress is. Existing works on TSV fatigue all rely on measurement-based parameters to estimate the lifetime, and cannot consider detailed thermal profiles. In this paper, we propose a new method for TSV fatigue prediction using entropy production during thermal cycles. By combining thermodynamics and mechanics laws, the fatigue process can be quantitatively evaluated with detailed thermal profiles. Experimental results show that interestingly, the landing pad possesses the most easy-to-fail region, which generates up to 50% more entropy compared with the TSV body. …

Compressed Sensing Techniques For Radial Ultra-Short Echo Time (Ute) Magnetic Resonance Imaging, Xiahan Yang

Masters Theses

"This thesis proposes two techniques, namely Compressed Sensing (CS) and self-gating, for pre-clinical (CMRI) to reduce scan time and RF exposure to mouse heart, simply experimental procedures, and improve imaging quality. The proposed CS technique reduces the number of radial trajectories in Ultra-short Echo Time (UTE) CMRI scans on a 7 Tesla MRI machine to acquire 13% to 38% of the fully sampled k-space data. To reconstruct the image, the Non-Uniform Fast Fourier Transform (NUFFT) is utilized in each iteration of the l1-norm optimization algorithm of the CS to reduce error and aliasing. Experimental results with a phantom and a …

Thermodynamic And Chemical Kinetic Coupled Modeling For The Determination Of Cyclic Combustion Phasing In Hcci Engines, Krishawn Michele Goodwin

Masters Theses

"Homogeneous charge compression ignition (HCCI) is a low temperature combustion mode that contains great potential for decreasing emissions while increasing efficiency in internal combustion engines. The limitation is in that it is inherently difficult to control based on the lack of an external combustion trigger. This thesis outlines the potential of using the combustion residual species of carbon monoxide as a method of controlling the location of combustion by using data from a computer model. The model is a nonlinear five-state thermodynamic model that is coupled with a skeletal chemical kinetic model for PRF96. The model computes the amount of …

Design And Implementation Of Low Complexity Wake-Up Receiver For Underwater Acoustic Sensor Networks, Ming Yue

Masters Theses

"This thesis designs a low-complexity dual Pseudorandom Noise (PN) scheme for identity (ID) detection and coarse frame synchronization. The two PN sequences for a node are identical and are separated by a specified length of gap which serves as the ID of different sensor nodes. The dual PN sequences are short in length but are capable of combating severe underwater acoustic (UWA) multipath fading channels that exhibit time varying impulse responses up to 100 taps. The receiver ID detection is implemented on a microcontroller MSP430F5529 by calculating the correlation between the two segments of the PN sequence with the specified …

1-D Coordination Polymer Of Transition Metal As A Precursor To Generate Surface Active Transition Metal Catalyst, Siddharth Gopalakrishnan

Masters Theses

"The work describes the synthesis, characterization and properties of Ni, Co and Cu based 1-D coordination polymer with 1, 4-benzenedicarboxylic acid as linker and 1-methylimidazole as co-ligand. The structure of the coordination polymers were investigated employing SCXRD and showed the formation of supramolecular 3-D architecture of the 1-D coordination polymer through non covalent CH..π, π.. π, and H-bonding interaction. These 1-D coordination polymers were further characterized by IR spectroscopy and thermogravimetric analysis. Thermal decomposition of these polymeric metal complexes gave rise to carbon coated metal and metal carbides nanoparticles, for the 1-D structures of Co and …

The Effects Of Short Delay Times On Rock Fragmentation In Bench Blasts, Margaret Ruth Hettinger

Masters Theses

"Optimized rock fragmentation is essential for minimizing downstream costs to mining operations. Photographic fragmentation analysis, vibration monitoring, and high-speed video all provide measurements of blast effectiveness and supply data that allows operations to modify blasts to achieve downstream goals.

This study evaluates the effects of short hole-to-hole delay times on rock fragmentation. Photographic fragmentation analysis and various delay times were used on the same bench blast, the effects of timing on fragmentation were determined. This analysis provides a representative understanding of timing effects on fragmentation in the field, different from previous blast models which either negate the effects of timing …

An Improved Planar Cavity Model For Dielectric Characterization, Benjamin Jay Conley

Masters Theses

"Accurate characterization of the dielectric properties of the laminate materials used in printed circuit board fabrication is critical for maximizing the performance of modern high speed circuitry. While many techniques exist for characterizing dielectric materials, most existing techniques are either limited in accuracy or highly impractical for use with planar, copper-clad laminate sheets. A common method involves forming a cavity from the printed circuit board material and calculating the permittivity and dissipation factor from the measured resonant frequencies and quality factor of the cavity. This resonance technique makes the assumption of an ideal cavity, which leads to errors in both …

Fault Interpretation And Reservoir Characterization Of The Farewell Formation Within Kerry Field, Taranaki Basin, New Zealand, Waleed Deefallah M Alotaby

Masters Theses

"The Kerry Field, located in the southern offshore Taranaki Basin, is a large liquid-rich gas accumulation with a thin (20 m) oil rim. The field was discovered by the New Zealand Oil & Gas in 1986 (well Kupe South-1). The gas and oil are trapped within a 9.2 km² fault-dependent three-way dip closure in the Paleocene Farewell Formation reservoir. Pressure, volume, and temperature (PVT) data indicate that the gas and oil columns in the field are in equilibrium with one another and are saturated at current reservoir conditions.

The Farewell Formation is the uppermost formation of the Kapuni Group …

Cyber Security Research Frameworks For Coevolutionary Network Defense, George Daniel Rush

Masters Theses

"Cyber security is increasingly a challenge for organizations everywhere. Defense systems that require less expert knowledge and can adapt quickly to threats are strongly needed to combat the rise of cyber attacks. Computational intelligence techniques can be used to rapidly explore potential solutions while searching in a way that is unaffected by human bias.

Several architectures have been created for developing and testing systems used in network security, but most are meant to provide a platform for running cyber security experiments as opposed to automating experiment processes. In the first paper, we propose a framework termed Distributed Cyber Security Automation …

A New Equivalent Dipole-Moment Source Reconstruction Method For Ic Radiated Emissions Based On Near-Field Scanning, Xiao Ren

Masters Theses

"In this paper, a new dipole-moment model based on near-field scanning for representing equivalent IC radiation emissions on a PCB (Print Circuit Board) is presented. One set of dipoles (both electric dipoles and magnetic dipoles) are used to characterize near-field and far-field radiation from the source. In order to build the model, tangential electric field and magnetic field on a Huygens's box enclosing the radiation source are needed. Both the phase and magnitude of these tangential fields are obtained either in simulation or in measurement by near-field scanning method. Two steps are established to reconstruct the dipole moment. Firstly, a …

Steam Flooding Screening And Eor Prediction By Using Clustering Algorithm And Data Visualization, Na Zhang

Masters Theses

"Enhanced Oil Recovery (EOR) techniques are vitally important in the oil industry because these techniques could not only extend the life of wells, but also produce 10% to 30% additional oil from the reservoir. However, selecting the most suitable EOR techniques for unknown reservoirs is not easy for decision making. Based on literature, EOR screening criteria could help to find the best candidates for unknown projects, which is classified into two categories: conventional EOR screening and advanced EOR screening. In this research, an artificial intelligent (AI) method, hierarchical clustering algorithm, is adapted to analyze both steam flooding projects and worldwide …

Investigation Of Decoupling Capacitor Connection Methods Using Peec And Study Of Alien Crosstalk From A Broadr-Reach® Protocol Based System, Tamar Makharashvili

Masters Theses

"Power Distribution Network (PDN) for Printed Circuit Board (PCB) design requires proper power integrity analysis. In order to deliver a low-ripple DC voltage from a Voltage Regulator Module (VRM) to an Integrated Circuit (IC), a certain target input impedance should be achieved. Developing simple physics-based equivalent circuit models are essential for understanding how a system works and making crucial design decisions. In this work, the input impedance of a decoupling capacitor due to traces, pads and via discontinuities are investigated using the Physics-based Model Size Reduction (PMSR) method. Various decoupling capacitor connection methods are compared and design guidelines are provided …