Digital Commons Network^™

Hybridizing And Applying Computational Intelligence Techniques, Jeffery Scott Shelburg

Masters Theses

"As computers are increasingly relied upon to perform tasks of increasing complexity affecting many aspects of society, it is imperative that the underlying computational methods performing the tasks have high performance in terms of effectiveness and scalability. A common solution employed to perform such complex tasks are computational intelligence (CI) techniques. CI techniques use approaches influenced by nature to solve problems in which traditional modeling approaches fail due to impracticality, intractability, or mathematical ill-posedness. While CI techniques can perform considerably better than traditional modeling approaches when solving complex problems, the scalability performance of a given CI technique alone is not …

Liquid Phase Sintering Of 20bi(Zn₀.₅Ti₀.₅)O₃-80batio₃ Dielectrics With Bismuth-Zinc-Borate And Bismuth Borosilicate Glasses, David I. Shahin

Masters Theses

"Dielectrics in the Bi(Zn₀.₅Ti₀.₅O₃-BaTiO₃ system (specifically 20BZT-80BT, in mol%) are promising candidates for high energy density capacitor applications due to broad temperature-dependent dielectric constant maxima and a relatively field-independent permittivity. Bulk samples require sintering temperatures of greater than 1180ºC to reach useful densities. Due to incompatibility of Bi with low-pO₂ processing, BZT-BT-based multilayer capacitors must utilize noble metal electrodes that resist oxidation during sintering. Sintering temperatures must be reduced to allow use of less expensive electrode materials (Cu, etc.). This work studies the reduced temperature sintering behavior and dielectric properties of BZT-BT sintered with 30 Bi₂O₃-30ZnO-40B₂O₃ and 50Bi₂O₃-25B₂O₃-25SiO₂ (mol%) liquid …

Secure Design Defects Detection And Correction, Wenquan Wang

Masters Theses

"Bad design and software defects often make source codes hard to understand and lead to maintenance difficulties. In order to detect and fix such defects, researchers have systematically investigated these issues and designed different effective algorithms to tackle the problems. However, most of these methods need source codes/models for defect detection and correction. Commercial companies, like banks, may not be willing to provide their source models due to data security. Therefore, it is a huge challenge to detect software detects by a consulting company as well as to keep source models confidential. This thesis analyze security issues in existing approaches …

Lexis In Chemical Engineering Discourse: Analyzing Style In Chemical Engineering Research Articles Through A Rhetorical Lens, David Lamar Young

Masters Theses

"This study examines the style of chemical engineering research articles to discover stylistic trends that may be applicable to authors looking to publish their own research. Rhetorical stylistic analysis was used as a research method to allow for thorough analysis of all articles in the sample. Ten research articles from the two prominent chemical engineering journals were chosen using specific criteria to constitute a sample of articles that could most accurately represent the population of chemical engineering research articles. Each article was then analyzed line by line to identify markers of chemical engineering research article style, including the following: ▬Use …

New Sensorless, Efficient Optimized And Stabilized V/F Control For Pmsm Machines, Seyed Hesam Jafari

Masters Theses

"With the rapid advances in power electronics and motor drive technologies in recent decades, permanent magnet synchronous machines (PMSM) have found extensive applications in a variety of industrial systems due to its many desirable features such as high power density, high efficiency, and high torque to current ratio, low noise, and robustness. In low dynamic applications like pumps, fans and compressors where the motor speed is nearly constant, usage of a simple control algorithm that can be implemented with least number of the costly external hardware can be highly desirable for industry. In recent published works, for low power PMSMs, …

Production Of 1,3-Propanediol From Glycerol Under Haloalkaline Conditions By Halanaerobium Hydrogeniformans, Daniel William Roush

Masters Theses

"With increased demands around the world to make modern lifestyles more environmentally friendly, the chemical commodity market has rapidly shifted. Through new technologies in chemical production, certain high value products have oversaturated the market and have become high-volume, low value waste products. The expansion of biodiesel production offers a prime example; high volumes of glycerol byproduct from this process have shifted glycerol from a high priced commodity to a common waste product. A number of microorganisms are known to synthesize the polymeric precursor 1,3-propanediol from glycerol; however, crude glycerol from biodiesel production creates a harsh environment for most microbes, and …

Harmonic Compensation In A Grid Using Doubly Fed Induction Generators, Omkar Amol Ghatpande

Masters Theses

"Ideally, electric utilities are expected to deliver a sinusoidal voltage with a constant rated frequency, while customers are expected to draw a sinusoidal current with unity power factor. The recent widespread use of harmonic producing equipment in industrial applications, especially non-linear loads, has increased the distortion of electric currents and voltages in transmission and distribution systems. This thesis proposes a method of using multiple reference frame theory for measuring and mitigating harmonic currents of nonlinear loads using a doubly fed induction generator. The most significant low-order harmonics to be compensated are calculated using a multiple reference frame harmonic observer. This …

Insufficient Ct Data Reconstruction Based On Directional Total Variation (Dtv) Regularized Maximum Likelihood Expectation Maximization (Mlem) Method, Fahima Fahmida Islam

Masters Theses

"Sparse tomography is an efficient technique which saves time as well as minimizes cost. However, due to few angular data it implies the image reconstruction problem as ill-posed. In the ill posed problem, even with exact data constraints, the inversion cannot be uniquely performed. Therefore, selection of suitable method to optimize the reconstruction problems plays an important role in sparse data CT. Use of regularization function is a well-known method to control the artifacts in limited angle data acquisition. In this work, we propose directional total variation regularized ordered subset (OS) type image reconstruction method for neutron limited data CT. …

Tensile Failure During Structural Development Of Single-Layer Buckle Folds, Xiaolong Liu

Masters Theses

"Folds and fold trains of sedimentary strata are among the most common structural traps systems for hydrocarbon reservoirs. The existence of tensile fractures associated to buckle folding is associated to the distribution of extensional strain in the outer arc of the fold hinges. This study investigates the conditions under which tensile stresses develop due to buckling in a realistic in situ stress scenario. By applying a 2D finite element modeling approach, the influence of realistic mechanical stratigraphy (including strain rate, overburden depth, competence contrasts, viscosity, and permeability) on the development of single-layer buckle folds with Newtonian viscous rheology is studied. …

Role Of Nicotine In Oxidative Stress, Rakesh Kacham

Masters Theses

"Nicotine, a major alkaloid, is present in tobacco products as well as in smaller amounts in potatoes, tomatoes, and eggplants. Although it is the addictive compound in cigarettes, nicotine is believed to play a protective role in neurodegenerative disorders such as Parkinson's disease. Researchers have found that the short-term administration of nicotine may help improve the memory process by reducing oxidative stress in the brain. Our studies have shown that, by blocking Fenton's reaction, nicotine is able to inhibit free radical generation, so this research has focused on the antioxidant properties of nicotine. The cell lines of the alveoli, blood …

Automatic Detection Of Polypoid Skin Lesions: The Squash Sign, Saurabh G. Karnik

Masters Theses

“Earlier detection of malignant melanoma can save lives. Automatic in-vivo methods of melanoma detection including smart-phone applications are now available, but specificity is low, i.e. too many benign lesions are detected as possible melanomas. Polypoids, elevated and rounded lesions are one class of benign lesions. These raised lesions with piecewise circular borders, predominantly intradermal nevi and cutaneous polyps (IDNs), are always benign. Variegated coloring present in polypoid lesions can lead physicians to perform an unneeded biopsy. Contact dermatoscope plates with gel squash these lesions, leaving a “squash sign” marker of benignancy which can be automatically detected. We present a method …

Significance And Analysis Of Milia-Like Cysts In Dermoscopy Skin Lesion Images, Sneha K. Mahajan

Masters Theses

“Milia-like cysts (MLCs) are dermoscopic structures frequently observed in seborrheic keratoses(SKs), which are the most common type of skin lesions. Diverse appearances of these skin lesions make them difficult to differentiate from melanoma, a deadly type of skin cancer. Classified by size into two main groups, starry MLCs and cloudy MLCs, the presence of these structures in a skin lesion has been known to help differentiate benign lesions from melanoma. Though the presence of cloudy MLCs is not exclusively associated with SKs, they can be a useful tool to differentiate SKs from melanoma. This research study determines the statistical occurrence …

A Conforming Method For Regional Marginal Loss Surplus Allocation, Xiaolong Wang

Masters Theses

"The marginal transmission loss model is used in electricity markets across the United States to measure a resource's marginal contribution to system loss. This model prices loss into the locational marginal price as a marginal loss component. Marginal loss pricing will render a net revenue surplus within an energy balanced system. This marginal loss surplus (MLS) is typically allocated back to scheduling coordinators in proportion to the measured demand on a system-wide basis. However, when the system experiences heterogeneous loss across different regions, the system-wide allocation method fails to recognize the regional differences in actual loss costs. As a result, …

Dynamic Mechanical Analysis And Computer Simulation Of Polyurea Aerogels, Victoria Ann Prokopf

Masters Theses

"Historically, the use of aerogels has been limited due to their poor mechanical properties. However, polyurea aerogels have proven to be mechanically strong under quasi-static conditions. Polyurea aerogels can be created by filling molds of the desired shape with a liquid solution that then creates a solid gel filled with liquid. The liquid can be removed from the gel by supercritical drying. This thesis outlines dynamic testing as well as simulation for polyurea aerogels.

Testing has been conducted in dynamic tension and bending for densities of polyurea aerogels ranging from 0.12 g/cm³ to 0.31 g/cm³. In most …

Enhancement Of Vortex Induced Vibrations Using Roughness Strips, Ashwin Vinod

Masters Theses

"The current experimental work focuses on studying the effects of surface roughness on vortex induced vibration (VIV) of an elastically mounted circular cylinder which is free to vibrate in a direction transverse to the flow. Flow separation in known to occur due to viscous effects when a fluid flows over a bluff body. The separation of fluid causes shedding of alternating vortices in the downstream region, which in turn impart an alternating force on the bluff body. The vibrations incurred due to such forces are called as Vortex Induced Vibrations (VIV) and have been traditionally known to be harmful to …

Implementation Of Project Based Learning Technique To Enhance Engineering Education, Dinesh Kanigolla

Masters Theses

"This study investigated the impact of introducing a semester project into three engineering courses where practical application of theoretical knowledge is applicable. Three courses were examined in this work: an undergraduate course in quality, a graduate course in Lean, and a graduate course in Six Sigma. For this research, student teams were given hands-on-projects that included collaboration with local companies. Surveys were conducted to assess the impact of project based learning on students' knowledge. Student responses were recorded and analyzed to determine how students felt the use of the semester project affected the course and to identify the response patterns …

Development Of A Postprocessor For A Multi-Axis Cnc Milling Center, Mihir Satish Adivarekar

Masters Theses

"Most of the current college design and manufacturing curricula are primarily focused on computer aided design (CAD), while less emphasis is given to computer aided manufacturing (CAM). A great opportunity has been missed as the benefits of CAD/CAM cannot then be fully learned. Postprocessor plays a vital role in integration of CAD//CAM with computer numerically controlled (CNC) machines. Hence, postprocessor must be developed accurately. This thesis is composed of one paper. Paper I proposes a novel methodology to determine compensation vectors for the post processor of multi-axis milling center. The new approach that has been implemented in Paper I involves …

A Generalized Approach For Compliant Mechanism Design Using The Synthesis With Compliance Method, With Experimental Validation, Ashish B. Koli

Masters Theses

"Compliant mechanisms offer numerous advantages over their rigid-body counterparts. The synthesis with compliance technique synthesizes compliant mechanisms for conventional rigid-body synthesis tasks with energy/torque specifications at precision positions. In spite of its usefulness, the method suffers from some limitations/problems. The purpose of this work is to investigate these sensitivities with the synthesis with compliance technique and improve upon existing method. A new, simple but efficient, method for synthesis with compliance using an optimization approach is proposed, and its usefulness and simplicity demonstrated over the existing method. The strongly and weakly coupled system of kinematic and energy/torque equations in the existing …

Comparison Of Square Root Of Time Approach And Statistical Approach To Minimize Subjectivity In The Determination Of Minimum In-Situ Stress, Soumitra Bhaskar Nande

Masters Theses

"A formation's minimum in-situ stress is an important parameter to determine for hydraulic fracturing. While minimum in-situ stress, and its orientation, can be measured from triaxial tests on core, it is more common to measure it as closure stress, by performing pressure testing of wells in the field. Closure stress is considered equal to, or a good approximation of the minimum in-situ stress for most cases. The analytical methods applied to such pressure testing include the square root of time plot, G function plot and the G-dP/dG plot. These plots require the engineer to fit tangent lines to the data, …

Dynamic Contact Analysis Of A Piezoelectrically Driven Ultrasonic Crawler-Actuator, Dwight Santiago Maness

Masters Theses

"A standing wave ultrasonic motor (SWUM) is presented in this thesis. The actuator is piezoelectrically powered and operates in the first and second bending modes to move forwards and backwards, respectively. The kinematic stability of the crawler, backed by experimental results is shown in the first paper presented in this thesis. This study demonstrates that in the absence of a preload or kinematic constraints, the crawler shows vertical stability. A full transient analysis using the finite element method is performed characterizing the speed and contact variables is conducted in the second paper. The results show that given enough time the …

Cfd Simulation Of Void Flow In Eccs, Lifeng Wang

Masters Theses

"Emergency core cooling system (ECCS) has been studied extensively for reactor safety. Emergency core cooling system (ECCS) is designed to make sure the reactor core it is protected by providing sufficient heat removal during accident conditions. In a loss-of-coolant-accident (LOCA) scenario, the ECCS is designed to take over the reactor core cooling by drawing water from a reservoir or tank. Voids may be introduced into the ECCS through a variety of means leading to total or partial loss of suction supply, or through gas depressurization resulting from difference in gas saturation pressure and ambient pressure. The transportation of voids through …

3d Seismic Data Interpretation Of Boonsville Field, Texas, Aamer Ali Alhakeem

Masters Theses

"The Boonsville field is one of the largest gas fields in the US located in the Fort Worth Basin, north central Texas. The highest potential reservoirs reside in the Bend Conglomerate deposited during the Pennsylvanian. The Boonsville data set is prepared by the Bureau of Economic Geology at the University of Texas, Austin, as part of the secondary gas recovery program. The Boonsville field seismic data set covers an area of 5.5 mi². It includes 38 wells data. The Bend Conglomerate is deposited in fluvio-deltaic transaction. It is subdivided into many genetic sequences which include depositions of sandy conglomerate representing …

A New Method For Failure Modes And Effects Analysis And Its Application In A Hydrokinetic Turbine System, Liang Xie

Masters Theses

"The traditional failure modes and effects analysis (FMEA) is a conceptual design methodology for dealing with potential failures. FMEA uses the risk priority number (RPN), which is the product of three ranked factors to prioritize risks of different failure modes. The three factors are occurrence, severity, and detection. However, the RPN may not be able to provide consistent evaluation of risks for the following reasons: the RPN has a high degree of subjectivity, it is difficult to compare different RPNs, and possible failures may be overlooked in the traditional FMEA method. The objective of this research is to develop a …

A Structural Analysis Of The El Kasr Structure In The Western Desert Of Egypt, Trevor Charles Ellis

Masters Theses

"The El Kasr structure was studied in order to investigate the origins and evolution of the enigmatic Desert Eyes structures of the Western Desert due to its accessibility and uniqueness among the structures. The El Kasr structure, an elongate structural basin with low limb dips, is unique among the "Desert Eyes" structures in that it: 1) occurs in isolation in otherwise horizontal sedimentary rock, 2) the long dimension of the basin is oriented NNW, 3) it is closely spatially associated with the less common NNW fault zones, and 4) is composite in nature. The structure was investigated using remote sensing …

An Evaluation Of De-Embedding Techniques For Tsvs, Nicholas Garrett Erickson

Masters Theses

"One of the most important aspects of modern electronic designs is device measurement and characterization. Without device measurement and characterization, the functionality of end designs cannot be guaranteed. At the silicon level (on-wafer), extracting the electrical performance of devices and structures has grown increasingly more complex with the continual shrink of feature sizes. Compared to the overall measurement setup (VNA, cables, probes, interposers, etc.), the ultra small size of on-wafer structures leads to their electrical performance being easily overshadowed by other, larger fixtures. Thus, many scientists and engineers have worked to devise ever more accurate calibration and de-embedding techniques for …

Libration Point Orbits Near Small Bodies In The Elliptic Restricted Three-Body Problem, Bharat Mahajan

Masters Theses

"In this study, the feasibility of using libration point orbits to explore small solar system bodies, including asteroids and comets, is considered. A novel design for a small body mission is proposed that makes use of libration point orbits as "parking" orbits. In considering a human exploration mission to asteroids or comets, these "parking" orbits may provide benefits including a safe vantage point for staging/observation, reduced perturbation effects from the nonuniform gravitational field of the body, fewer communication blackouts, ease of guidance and control of a lander on the surface, etc. Because small solar system bodies have extremely low mass …

Efficient Integrity Verification Of Replicated Data In Cloud, Raghul Mukundan

Masters Theses

"The cloud computing is an emerging model in which computing infrastructure resources are provided as a service over the Internet. Data owners can outsource their data by remotely storing them in the cloud and enjoy on-demand high quality services from a shared pool of configurable computing resources. By using these data storage services, the data owners can relieve the burden of local data storage and maintenance. However, since data owners and the cloud servers are not in the same trusted domain, the outsourced data may be at risk as the cloud server may no longer be fully trusted. Therefore, data …

Predicting Solar Radiation Based On Available Weather Indicators, Frank Joseph Sauer

Masters Theses

"Solar radiation prediction models are complex and require software that is not available for the household investor. The processing power within a normal desktop or laptop computer is sufficient to calculate similar models. This barrier to entry for the average consumer can be fixed by a model simple enough to be calculated by hand if necessary.

Solar radiation modeling has been historically difficult to predict and accurate models have significant assumptions and restrictions on their use. Previous methods have been limited to linear relationships, location restrictions, or input data limits to one atmospheric condition. This research takes a novel approach …

Technical Modeling And Control System Development Of Hybrid Energy System Using Coal, Nuclear, Wind And Diesel, Uday Guntupalli

Masters Theses

"Addressing the growing energy concerns of the modern world is a challenging problem. Traditional carbon intensive fuel sources like coal, diesel which are instrumental in meeting today's grid demand are struggling to meet the stringent environmental regulations. Operations of independent renewable energy sources despite reducing costs are not comparable to existing costs of electricity. A sustainable approach to address these concerns is proposed in this work. A hypothetical hybrid system involving traditional fuel sources like coal, small modular nuclear reactor and renewable energy source wind is analyzed through dynamic modeling using various tools.

Various simulation tools were analyzed and the …

Fuzzy Logic Color Detection: Blue Areas In Dermoscopy Melanoma Images, Mounika Lingala

Masters Theses

"Malignant melanoma is one of the deadliest forms of skin cancer and is one of the most rapidly increasing cancers in the world. Image analysis techniques for the early detection of melanoma are dependent upon the detection of multiple color shades in melanoma images. Use of magnified visible-light imaging by dermoscopy allows detailed investigation of these color shades. This research explores the fuzzy logic methods for the detection and characterization of blue color shades to discriminate melanoma from benign skin lesions. Standard thresholds are placed on the RGB dermoscopy images firstly and then the restrictiveness is explored by implementing fuzzy …