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Water-Tree Modelling And Detection For Underground Cables, Qi Chen Aug 2017

Water-Tree Modelling And Detection For Underground Cables, Qi Chen

All Dissertations

In recent years, aging infrastructure has become a major concern for the power industry. Since its inception in early 20th century, the electrical system has been the cornerstone of an industrial society. Stable and uninterrupted delivery of electrical power is now a base necessity for the modern world. As the times march-on, however, the electrical infrastructure ages and there is the inevitable need to renew and replace the existing system. Unfortunately, due to time and financial constraints, many electrical systems today are forced to operate beyond their original design and power utilities must find ways to prolong the lifespan of …

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Parsimonious Space-Time Temperature Series Modeling, Yanbo Xia Aug 2017

Parsimonious Space-Time Temperature Series Modeling, Yanbo Xia

All Dissertations

Climatological time series are often periodically and spatially correlated. High dimensionality issues arise when modeling periodically and spatially correlated time series data "“ often, even simple multivariate models have more parameters than data points. This dissertation develops parsimonious methods for fitting periodically and spatially correlated multivariate time series data. Parsimonious VAR (vector autoregressive) and PVAR (periodic VAR) models are pursued here. The layered procedure introduced by Lund et al. (1995) is adopted as a basic scheme, which removes periodic correlation from the data in the first layer, and fits a stationary VAR model in the second layer. The method is …

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3d Tornado Wind Field Model And Risk Assessment Of Tornado Damage, Jin Wang Aug 2017

3d Tornado Wind Field Model And Risk Assessment Of Tornado Damage, Jin Wang

All Dissertations

Tornado is one of the most severe weather events that affect the United States and other countries every year. However, the research on tornado and its effects on structures is relatively scant compared with conventional boundary-layer wind events (e.g. hurricanes). With the increasing frequency of intensive tornadoes and high profile tornado disasters (e.g. 2011 Joplin Tornado and 2013 Moore, Oklahoma Tornado), the study on tornadoes has been one of the most pressing research needs in the wind engineering community in recent years. In this research, experimental studies on characteristics of tornado wind field and tornado-structure interactions were conducted using a …

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Latent Data Modeling With Biostatistical Applications, Yan Liu Aug 2017

Latent Data Modeling With Biostatistical Applications, Yan Liu

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This dissertation consists of three projects that make use of latent variable modeling techniques. One of the focuses of this dissertation research has been in the area of spatial and spatio-temporal modeling. The specific topics and motivating problems in this study have been fully supported and motivated by the Companion Animal Parasite Council (CAPC). In particular, the CAPC has developed a rather extensive database, which houses several common dog disease data sets collected throughout the conterminous United States. This data exists at a county level and was collected monthly over a span of 5 consecutive years, and exhibits strong spatial …

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External Economic Costs Of Intelligent Urban Transportation Systems: A Method To Evaluate The Externalities Of Comparative Technology Adoption Pathways In The Urban Mobility Service Sector, Jianan Sun Aug 2017

External Economic Costs Of Intelligent Urban Transportation Systems: A Method To Evaluate The Externalities Of Comparative Technology Adoption Pathways In The Urban Mobility Service Sector, Jianan Sun

All Dissertations

By 2050, urban mobility demands will increase to 2.6 times the current level, even faster than the urban population growth. Current urban transportation plans fail to address these rapidly increasing urban mobility demands. Inefficient urban transportation generates great economic losses in traffic congestion, air pollution and climate change. The current urban transportation pressure and emerging technology-driven trends have revolutionized how industry players respond to changing consumer behavior, develop partnerships, and drive transformational changes. A transition (P2S) from current product-based competition to a marketplace focused on mobility services is expected. Electric vehicles, automated driving systems and mobility-sharing platforms are introduced to …

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Using Botnet Technologies To Counteract Network Traffic Analysis, Yu Fu Aug 2017

Using Botnet Technologies To Counteract Network Traffic Analysis, Yu Fu

All Dissertations

Botnets have been problematic for over a decade. They are used to launch malicious activities including DDoS (Distributed-Denial-of-Service), spamming, identity theft, unauthorized bitcoin mining and malware distribution. A recent nation-wide DDoS attacks caused by the Mirai botnet on 10/21/2016 involving 10s of millions of IP addresses took down Twitter, Spotify, Reddit, The New York Times, Pinterest, PayPal and other major websites. In response to take-down campaigns by security personnel, botmasters have developed technologies to evade detection. The most widely used evasion technique is DNS fast-flux, where the botmaster frequently changes the mapping between domain names and IP addresses of the …

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Correlated And Interacting Predictor Omission For Linear And Logistic Regression Models, Emily Nystrom Aug 2017

Correlated And Interacting Predictor Omission For Linear And Logistic Regression Models, Emily Nystrom

All Dissertations

In this paper, we discuss the impact of predictor omission in light of the omitted predictor's relationship with other predictors that were included in the model. Predictor omission in linear regression models (LMs) has been discussed by various sources in the literature. Our approach involves studying the impact of predictor omission for a wider range of omitted predictors than previously studied and extends the existing literature by considering the interaction status of an omitted predictor in addition to its correlation status. Results from models with uncentered predictors and models with centered predictors are considered. The mathematical implications of predictor omission …

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Efficient Numerical Methods For Magnetohydrodynamic Flow, Muhammad Mohebujjaman Aug 2017

Efficient Numerical Methods For Magnetohydrodynamic Flow, Muhammad Mohebujjaman

All Dissertations

This dissertation studies efficient numerical methods for approximating solu-tions to viscous, incompressible, time-dependent magnetohydrodynamic (MHD) flows and computing MHD flows ensembles. Chapter 3 presents and analyzes a fully discrete, decoupled efficient algorithm for MHD flow that is based on the Els¨asser variable formulation, proves its uncondi-tional stability with respect to the timestep size, and proves its unconditional con-vergence. Numerical experiments are given which verify all predicted convergence rates of our analysis, show the results of the scheme on a set of channel flow problems match well the results found when the computation is done with MHD in primitive variables, and …

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A Convenient Miniature Test Platform For Polyelectrolyte Membrane Fuel-Cell Research, Jamie A. Shetzline, Saheed Bukola, Stephen E. Creager Jul 2017

A Convenient Miniature Test Platform For Polyelectrolyte Membrane Fuel-Cell Research, Jamie A. Shetzline, Saheed Bukola, Stephen E. Creager

Publications

A simple and convenient small-scale fuel-cell test platform was created from a commercial compression fitting and graphite rod current collectors and used to conduct diagnostic tests on disk-shaped membrane-electrode assemblies (MEAs) fabricated from Nafion membranes and Nafion-impregnated platinum-on-carbon-cloth anodes and cathodes. A key advantage of this test platform is that it requires very little material, perhaps just a few milligrams, to conduct a fuel-cell test on a supported catalyst. Electrochemically-active surface area (ECSA) values for supported platinum on carbon-cloth electrodes were obtained by in-situ(in the fuel cell) and ex-situ (in liquid electrolyte) cyclic voltammetry on similarly-prepared electrodes, and values …

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A Revision Of Prespelea Park (Staphylinidae, Pselaphinae), Michael S. Caterino, Laura M. Vásquez-Vélez Jul 2017

A Revision Of Prespelea Park (Staphylinidae, Pselaphinae), Michael S. Caterino, Laura M. Vásquez-Vélez

Publications

We revise the genus Prespelea Park, redefining and redescribing the two previously known species, P.copelandi Park and P. quirsfeldi Park, and adding ten new species: P. parki Caterino & Vásquez-Vélez, sp. n., P.minima Caterino & Vásquez-Vélez, sp. n., P. morsei Caterino & Vásquez-Vélez, sp. n., P. divergens Caterino & Vásquez-Vélez, sp. n., P. carltoni Caterino & Vásquez-Vélez, sp. n., P. myersae Caterino & Vásquez-Vélez, sp. n., P. georgiensis Caterino & Vásquez-Vélez, sp. n., P. enigma Caterino & Vásquez-Vélez, sp. n., P. wagneriCaterino & Vásquez-Vélez, sp. n., and P. basalis Caterino …

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Investigation Of Chip Thickness And Force Modelling Of Trochoidal Milling, Abram Pleta, Farbod Akhavan Niaki, Laine Mears Jul 2017

Investigation Of Chip Thickness And Force Modelling Of Trochoidal Milling, Abram Pleta, Farbod Akhavan Niaki, Laine Mears

Publications

With the ever increasing pressure to reduce processing time and cost, researchers in machining have begun to develop a body of work centered around increasing the throughput of machining operations. While standard toolpaths exist, such as raster and zig-zag, alternative toolpaths have been developed to achieve beneficial kinematics and dynamics for the cutting tool to better achieve high-speed machining conditions. One such toolpath, trochoidal milling, has been identified to decrease machining process time and increase overall tool life. Understanding the undeformed chip thickness produced utilizing trochoidal milling is critical to developing advances in the field. This paper presents a novel …

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Real-Time Traffic State Estimation With Connected Vehicles, Sakib Mahmud Khan, Kaken Dey, Mashrur Chowdhury Jul 2017

Real-Time Traffic State Estimation With Connected Vehicles, Sakib Mahmud Khan, Kaken Dey, Mashrur Chowdhury

Publications

A novel framework is developed in this paper, to increase the real-time roadway traffic condition assessment accuracy, which integrates connected vehicle technology (CVT) with artificial intelligence (AI) paradigm forming a CVT-AI method. Traffic density is a major indicator of traffic conditions. In this paper, the traffic operational condition is assessed based on traffic density. A simulated network of Interstate 26 in South Carolina is developed to investigate the effectiveness of the method. The assumption is that the vehicle onboard units will forward the CV generated data to the edge devices (e.g., roadside units) for further processing. CV generated distance headway …

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Investigation Of Chip Thickness And Force Modelling Of Trochoidal Milling, Abram Pleta, Farbod Akhavan Niaki, Laine Mears Jul 2017

Investigation Of Chip Thickness And Force Modelling Of Trochoidal Milling, Abram Pleta, Farbod Akhavan Niaki, Laine Mears

Publications

With the ever increasing pressure to reduce processing time and cost, researchers in machining have begun to develop a body of work centered around increasing the throughput of machining operations. While standard toolpaths exist, such as raster and zig-zag, alternative toolpaths have been developed to achieve beneficial kinematics and dynamics for the cutting tool to better achieve high-speed machining conditions. One such toolpath, trochoidal milling, has been identified to decrease machining process time and increase overall tool life. Understanding the undeformed chip thickness produced utilizing trochoidal milling is critical to developing advances in the field. This paper presents a novel …

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Is It Engineering Or Not?, Brooke A. Whitworth, Lindsay B. Wheeler Jul 2017

Is It Engineering Or Not?, Brooke A. Whitworth, Lindsay B. Wheeler

Publications

With the widespread adoption of the Next Generation Science Standards (NGSS Lead States 2013), science teachers now aspire to integrate engineering into science instruction, as the standards suggest, yet many don’t know how. The first steps are to define engineering and identify tasks that incorporate engineering, which can be difficult and confusing. This article presents a simple explanation of engineering and offers a framework to help teachers determine whether a task is based on engineering. We also offer examples of how to integrate engineering in Earth science, chemistry, biology, and physics.

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Close Reading: The Theory Which Is Not One, Jessica Mccall Jun 2017

Close Reading: The Theory Which Is Not One, Jessica Mccall

Early Modern Culture

No abstract provided.

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A Grounded Qualitative Analysis Of The Effect Of A Focus Group On Design Process In A Virtual Internship, Matthew R. Markovetz, Sean Sullivan, Renee M. Clark, Zachari Swiecki, Golnaz Arastoopour Irgens, David W. Shaffer, Naomi C. Chesler, Cheryl A. Bodnar Jun 2017

A Grounded Qualitative Analysis Of The Effect Of A Focus Group On Design Process In A Virtual Internship, Matthew R. Markovetz, Sean Sullivan, Renee M. Clark, Zachari Swiecki, Golnaz Arastoopour Irgens, David W. Shaffer, Naomi C. Chesler, Cheryl A. Bodnar

Publications

A key component associated with the development of an entrepreneurial mindset is the ability to understand customerneeds and consider this when developing a product. This study sought to understand whether the inclusion of a customerfocus group as part of a virtual internship created any differences in the design processes of sophomore engineeringstudents (114 students). The Nephrotex virtual internship requires that students design a dialysis membrane by optimizinga selection of four components: membrane polymer, polymerization process, processing surfactant, and carbon nanotubepercentage. We found that sophomores who engaged in a focus group during the virtual internship Nephrotex showed(statistically) equal focus on cost …

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Data‐Enabled Cognitive Modeling: Validating Student Engineers’ Fuzzy Design‐Based Decision‐Making In A Virtual Design Problem, Golnaz Arastoopour Irgens, Naomi C. Chesler, Jeffrey Linderoth, David Williamson Shaffer Jun 2017

Data‐Enabled Cognitive Modeling: Validating Student Engineers’ Fuzzy Design‐Based Decision‐Making In A Virtual Design Problem, Golnaz Arastoopour Irgens, Naomi C. Chesler, Jeffrey Linderoth, David Williamson Shaffer

Publications

The ability of future engineering professionals to solve complex real‐world problems depends on their design education and training. Because engineers engage with open‐ended problems in which there are unknown parameters and multiple competing objectives, they engage in fuzzy decision‐making, a method of making decisions that takes into account inherent imprecisions and uncertainties in the real world. In the design‐based decision‐making field, few studies have applied fuzzy decision‐making models to actual decision‐making process data. Thus, in this study, we use datasets on student decision‐making processes to validate approximate fuzzy models of student decision‐making, which we call data‐enabled cognitive modeling. The results …

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Electromagnetic Radio Frequency Heating In The Pulsed Electric Current Sintering (Pecs) Process, Yufei Liu, D. H. Liebenberg Jun 2017

Electromagnetic Radio Frequency Heating In The Pulsed Electric Current Sintering (Pecs) Process, Yufei Liu, D. H. Liebenberg

Publications

Pulsed electric current sintering offers rapid sintering of many materials compared with hot press sintering. Earlier studies had demonstrated that neither sparks nor plasma formation occur in a typical apparatus such as Dr. Sinter™. Hitchcock et al. showed that electromagnetic radio frequency (rf) emission occurred during the pulsing current and suggested this emission was a relevant augmentation to the hot press sintering in addition to the current flow in the specimen. In this report the importance of rf emission in the sintering process is demonstrated and opportunities to further exploit this approach to improve the sintering process are suggested.

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The Soil Moisture Velocity Equation, Fred L. Ogden, Myron B. Allen, Wencong Lai, Jianting Zhu, Mookwon Seo, Craig C. Douglas, Cary A. Talbot Jun 2017

The Soil Moisture Velocity Equation, Fred L. Ogden, Myron B. Allen, Wencong Lai, Jianting Zhu, Mookwon Seo, Craig C. Douglas, Cary A. Talbot

Publications

Numerical solution of the one-dimensional Richards' equation is the recommended method for coupling groundwater to the atmosphere through the vadose zone in hyperresolution Earth system models, but requires fine spatial discretization, is computationally expensive, and may not converge due to mathematical degeneracy or when sharp wetting fronts occur. We transformed the one-dimensional Richards' equation into a new equation that describes the velocity of moisture content values in an unsaturated soil under the actions of capillarity and gravity. We call this new equation the Soil Moisture Velocity Equation (SMVE). The SMVE consists of two terms: an advection-like term that accounts for …

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The Influence Of Exurban Landscapes And Local Site Characteristics On Riparian Vegetation, Nathan Weaver, Kyle Barrett, Don L. Hagan Jun 2017

The Influence Of Exurban Landscapes And Local Site Characteristics On Riparian Vegetation, Nathan Weaver, Kyle Barrett, Don L. Hagan

Publications

The southern Appalachian Mountains have experienced large population growth and a change in land use in the past 30 years. The majority of development has been low density, suburban land, known as exurban development. The long-term effects of exurbanization on riparian vegetative communities in the southeastern Appalachian Mountains are not well known. We sought to determine if vegetative community composition and structure change as a function of watershed–level variables such as time since neighborhood development or percent impervious surface within the watershed. We also assessed local–scale measures of disturbance such as canopy cover and basal area. Over two years we …

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Exchange Of Polar Lipids From Adults To Neonates In Daphnia Magna: Perturbations In Sphingomyelin Allocation By Dietary Lipids And Environmental Toxicants, Namrata Sengupta, Delaney C. Reardon, Patrick D. Gerard, William S. Baldwin May 2017

Exchange Of Polar Lipids From Adults To Neonates In Daphnia Magna: Perturbations In Sphingomyelin Allocation By Dietary Lipids And Environmental Toxicants, Namrata Sengupta, Delaney C. Reardon, Patrick D. Gerard, William S. Baldwin

Publications

Because xenosensing nuclear receptors are also lipid sensors that regulate lipid allocation, we hypothesized that toxicant-induced modulation of HR96 activity would alter lipid profiles and the balance between adult survival and neonate production following exposure in Daphnia magna. Adult daphnids were exposed to unsaturated fatty acid- and toxicant- activators or inhibitors of HR96 and later starved to test whether chemical exposure altered allocation toward survival or reproduction. The HR96 activators, linoleic acid and atrazine, decreased reproduction as expected with concomitant changes in the expression of HR96 regulated genes such as magro. The HR96 inhibitors, docosahexaenoic acid (DHA) and triclosan, …

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Moliere: Automatic Biomedical Hypothesis Generation System, Justin Sybrandt, Michael Shtutman, Ilya Safro May 2017

Moliere: Automatic Biomedical Hypothesis Generation System, Justin Sybrandt, Michael Shtutman, Ilya Safro

Publications

Hypothesis generation is becoming a crucial time-saving technique which allows biomedical researchers to quickly discover implicit connections between important concepts. Typically, these systems operate on domain-specific fractions of public medical data. MOLIERE, in contrast, utilizes information from over 24.5 million documents. At the heart of our approach lies a multi-modal and multi-relational network of biomedical objects extracted from several heterogeneous datasets from the National Center for Biotechnology Information (NCBI). These objects include but are not limited to scientific papers, keywords, genes, proteins, diseases, and diagnoses. We model hypotheses using Latent Dirichlet Allocation applied on abstracts found near shortest paths discovered …

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Random Access In Nondelimited Variable-Length Record Collections For Parallel Reading With Hadoop, Jason Anderson, Christopher Gropp, Linh Ngo, Amy W. Apon May 2017

Random Access In Nondelimited Variable-Length Record Collections For Parallel Reading With Hadoop, Jason Anderson, Christopher Gropp, Linh Ngo, Amy W. Apon

Publications

The industry standard Packet CAPture (PCAP) format for storing network packet traces is normally only readable in serial due to its lack of delimiters, indexing, or blocking. This presents a challenge for parallel analysis of large networks, where packet traces can be many gigabytes in size. In this work we present RAPCAP, a novel method for random access into variable-length record collections like PCAP by identifying a record boundary within a small number of bytes of the access point. Unlike related heuristic methods that can limit scalability with a nonzero probability of error, the new method offers a correctness guarantee …

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A New Approach To Battery Management System Control Design For Increasing Battery Longevity, Ryan Alexander Bell May 2017

A New Approach To Battery Management System Control Design For Increasing Battery Longevity, Ryan Alexander Bell

All Theses

This thesis presents a new approach to battery management system control. Previous control methods did not include state of health in the decision-making process. With accurate state of health estimators available, more information should be provided to the battery management system so that a more informed decision in regards to increasing battery longevity may be made. This thesis details the development of a Simscape model for a proven state of health estimator. The Simscape model was then used to provide state of health estimations to a proposed battery management control system that prioritizes battery longevity over traditional voltage equalization battery …

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Quantitative Measures Of Regret And Trust In Human-Robot Collaboration Systems, Zhanrui Liao May 2017

Quantitative Measures Of Regret And Trust In Human-Robot Collaboration Systems, Zhanrui Liao

All Theses

Human-robot collaboration (HRC) systems integrate the strengths of both humans and robots to improve the joint system performance. In this thesis, we focus on social human-robot interaction (sHRI) factors and in particular regret and trust. Humans experience regret during decision-making under uncertainty when they feel that a better result could be obtained if chosen differently. A framework to quantitatively measure regret is proposed in this thesis. We embed quantitative regret analysis into Bayesian sequential decision-making (BSD) algorithms for HRC shared vision tasks in both domain search and assembly tasks. The BSD method has been used for robot decision-making tasks, which …

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Trunk Robot For Extended Environments, Siddharth R. Verma May 2017

Trunk Robot For Extended Environments, Siddharth R. Verma

All Theses

We describe the design and physical realization of a novel type of large-scale continuum robot. The design, based on a hybrid concentric-tube/tendon actuated structure, is realized at a significantly larger scale than previous concentric tube continuum robots, with an extended length well over one meter. While operation at this scale opens up new types of potential applications, realization at this scale presents interesting challenges. We detail and discuss the associated issues via the prototyping and testing of the physical system with the help of experiments.

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A Theoretical Foundation For The Development Of Process Capability Indices And Process Parameters Optimization Under Truncated And Censoring Schemes, Anintaya Khamkanya May 2017

A Theoretical Foundation For The Development Of Process Capability Indices And Process Parameters Optimization Under Truncated And Censoring Schemes, Anintaya Khamkanya

All Dissertations

Process capability indices (PCIs) provide a measure of the output of an in-control process that conforms to a set of specification limits. These measures, which assume that process output is approximately normally distributed, are intended for measuring process capability for manufacturing systems. After implementing inspections, however, non-conforming products are typically scrapped when units fail to meet the specification limits; hence, after inspections, the actual resulting distribution of shipped products that customers perceive is truncated. In this research, a set of customer-perceived PCIs is developed focused on the truncated normal distribution, as an extension of traditional manufacturer-based indices. Comparative studies and …

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Assessing Non-Atomicity In Groups Of Divisibility, Brandon G. Goodell May 2017

Assessing Non-Atomicity In Groups Of Divisibility, Brandon G. Goodell

All Dissertations

An integral domain D is atomic if every non-zero non-unit is a product of irreducibles. More generally, D is quasi-atomic if every non-zero non-unit divides some product of atoms. Arbitrary integral domains, however, cannot be assumed to be quasi-atomic in general; factorization in a non-atomic D can be subtle. We outline a novel method of qualifying the quasi-atomicity of D by studying ascending filtrations of localizations of D and the associated groups of divisibility. This approach yields structure theorems, cochain complexes, and cohomological results. We take care to present examples of integral domains exhibiting the spectrum of factorization behavior and …

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Procedural Spanish Moss Renderman Shader, Summer O'Neal Benton May 2017

Procedural Spanish Moss Renderman Shader, Summer O'Neal Benton

All Theses

This thesis discusses the creation of computer generated photorealistic Spanish moss, a plant that grows in trees in the American Southeast. In order to replicate the plant, a Renderman procedural shader was used that included hair-like qualities in order to replicate the surface properties of Spanish moss. The necessary attributes, how they are used in the code, and final results of the shader applied to a moss model are included in this paper.

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Detection And Classification Of Eeg Epileptiform Transients With Rbf Networks Using Hilbert Huang Transform-Derived Features, Raghu Jagadeesha May 2017

Detection And Classification Of Eeg Epileptiform Transients With Rbf Networks Using Hilbert Huang Transform-Derived Features, Raghu Jagadeesha

All Theses

Diagnosis of epilepsy or epileptic transients AEP (Abnormal Epileptiform Paroxysmal) is tedious, but important, and an expensive process. The process involves trained neurologists going over the patient's EEG records looking for epileptiform discharge like events and classifying it as AEP (Abnormal Epileptiform Paroxysmal) or non-AEP. The objective of this research is to automate the process of detecting such events and classifying them into AEP(definitely an Epileptiform Transient) and non-AEPs (unlikely an epileptiform transient). The problem is approached in two separate steps and cascaded to validate and analyze the performance of the overall system. The first step is a detection problem …

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