Physical Sciences and Mathematics Commons^™

Mathematical Models Of Nutrient Recycling And Toxin Production In A Gradostat, Xiaoyang Dong

Mathematics Dissertations

We discuss several gradostat models in which a microbial population excretes a biochemical that can get recycled back into the system as a nutrient source. Each mathematical model consists of six ordinary differential equations and represents the dynamics of harmful algal blooms in lakes with fringing coves. We examine three different situations of biochemical production which is based on the algal growth rate, mortality, and nutrient concentration, respectively. Local and global stability analysis of the equilibria predicts that algal abundance and biochemical concentration can be both washed out or persistent under different environmental conditions. All theoretical results are supported by …

An Interpolation Based Approach For Pattern Recognition And Generation, Vishnukumar Galigekere Nagabhushana

Computer Science and Engineering Dissertations

A large number of problems in computer vision and computer graphics can essentially be reduced to a pattern recognition problem. In this thesis, we explore a novel interpolation based framework to address some of the various recognition problems in these areas. Our interpolation based framework is a supervised learning algorithm that allows for both generation (synthesis) of new patterns as well as perception (analysis) of existing patterns. The method is simple to implement and yet, expects a very straightforward and intuitive set of parameters to model the complex nature of such recognition problems.Specifically, given a set of training data along …

Hardware And Software Systems For Control Of Assistive Robotic Devices Using Point-Of-Gaze Estimation, Christopher Dale Mcmurrough

Computer Science and Engineering Dissertations

Eye gaze based interaction has many useful applications in human-machine interfaces, assistive technologies, and multimodal systems. Traditional input methods, such as the keyboard and mouse, are not practical in many situations and can be ineffective for some users with physical impairments. Knowledge of the user point of gaze (PoG) can be a powerful data modality in intelligent systems by facilitating intuitive control, perception of user intent, and enhanced interactive experiences.This research aims to advance the use of non-traditional, multimodal interfaces in assistive robotic devices for the benefit of users with severe physical disabilities. The data modalities which are of particular …

Sparse And Large-Scale Learning Models And Algorithms For Mining Heterogeneous Big Data, Xiao Cai

Computer Science and Engineering Dissertations

With the development of PC, internet as well as mobile devices, we are facing a data exploding era. On one hand, more and more features can be collected to describe the data, making the size of the data descriptor larger and larger. On the other hand, the number of data itself explodes and can be collected from multiple resources. When the data becomes large scale, the traditional data analysis method may fail, suffering the curse of dimensionality and etc. In order to explore and analyze the large-scale data more accurately and more efficiently, based on the characteristic of the data, …

Image Annotation And Feature Engineering Via Structural Sparsity And Low Rank Approximation, Deguang Kong

Computer Science and Engineering Dissertations

Nowadays, in order to sense environment and understand human behaviors, data analysis plays a more and more important role to handle heterogeneous data ranging from different domains, e.g., image categorization/annotation, customer segmentation, traffic prediction, ad optimization, recommendation systems, privacy analysis, etc. The large amount of multivariate data raises the fundamental problem of data mining: how to discover meaningful compact patterns hidden in the high-dimensional noisy observations? One approach is to do dimension reduction, which finds the low-dimensional subspace and thus encodes data in a low-dimensional structure. The other approach is to do feature selection or feature engineering, which manipulates the …

Novel Methods For Entity-Centric Information Exploration, Ning Yan

Computer Science and Engineering Dissertations

We witness an unprecedented proliferation of entity graphs that capture entities (e.g., persons, products, organizations) and their relationships. Such entity data gradually evolves into the most comprehensive knowledge graph ever built by human beings. The flourish of entity data also boosts a growing demand for entity-centric information exploration tasks. Different from traditional information retrieval tasks that are based on statistics of text terms, entity-centric information exploration tasks are usually based on metrics over entities, their relationships, or graph structures. In this work, we identified two essential tasks in entity-centric information exploration: 1) how to do faceted navigation over a set …

Effective Collaboration In Opportunitic Networks, Umair Sadiq

Computer Science and Engineering Dissertations

Opportunistic networks formed by users' mobile devices have the potential to exploit a rich set of distributed service components that can be composed to provide each user with a multitude of application level services. In opportunistic networks, tasks such as content sharing and service execution among remote devices are facilitated by intermediate devices capable of short–range wireless connectivity, also called relays that receive, move around, and forward the data.To enable effective collaboration in such an environment, we make three novel contributions: (i) an adaptive forwarding scheme, ProxiMol, to select suitable relays for data transfer; (ii) a distributed mechanism to select …

Applying Combinatorial Testing To Systems With A Complex Input Space, Mehra Nouroz Borazjany

Computer Science and Engineering Dissertations

Combinatorial testing, which has been shown very effective in fault detection, is a testing strategy that applies the theory of combinatorial design to test software programs. Given a program under test with k parameters, t-way combinatorial testing requires all combinations of values of t (out of k) parameters be covered at least once, where t is usually a small integer. Combinatorial testing can significantly reduce the cost of testing while increasing its effectiveness.Input space modeling is an important step in combinatorial testing. The input space of a subject program must be modeled before combinatorial testing can be applied to it. …

Quantitative Analysis Of Surface Enhanced Raman Spectra, Shuo Li

Computer Science and Engineering Dissertations

Quantitative analysis of Raman spectra using surface-enhanced Raman scattering (SERS) nanoparticles has shown the potential and promising trend of development in vivo molecular imaging. One of the key job is from the intensities of Raman signals to predict the quantities of analytes. Direct classical least squares (DCLS) and multivariate calibration (MC) are commonly used methods. DCLS relies on source Raman signals as the references. But the inherent Instability of Raman signals make the DCLS model not robust enough. MC model relies on a batch of training mixture Raman signals together with the ground truth mixing concentrations to build the multivariate …

Advanced Combinatorial Testing Algorithms And Applications, Linbin Yu

Computer Science and Engineering Dissertations

Combinatorial testing (CT) has been shown to be a very effective testing strategy. Given a system with n parameters, t-way combinatorial testing, where t is typically much smaller than n, requires that all t-way combinations, i.e., all combinations involving any t parameter values, be covered by at least one test. This dissertation focuses on two important problems in combinatorial testing, including constrained test generation and combinatorial sequence testing.For the first problem, we focus on constraint handling during combinatorial test generation. Constraints over input parameters are restrictions that must be satisfied in order for a test to be valid. Constraints can …

Concept Drift Datasets, Patrick Lindstrom

Doctoral

This zip file contains the datasets used in the PhD thesis:

Lindstrom, P., 2013. Handling Concept Drift in the Context of Expensive Labels. Technological University Dublin. For more information about the datasets please see the README file and the aforementioned thesis.

Solving The Optimization Control Problem For Lunar Soft Landing Using Minimization Technique, Lizeth Patricia Ocampo

Mathematics Theses

Minimizing fuel consumption in lunar missions has been a well studied and documented optimization problem. In this paper two cases of the lunar Lander are studied. The first case is the one dimensional problem where the objective is to make a vertical soft landing using the minimum amount of fuel. The second case has the same objective but an initial tangential velocity greater than zero is given making it a two dimensional problem. The first case is solved using Newton's shooting method, finite difference method (using MATLAB's embedded function bvp4c), and solving it explicitly. For the second case, a minimization …

A Non-Heme Diiron Monooxygenase From Salmonella Typhimurium: Biochemical Characterization Of Trna-Modifying Miae, Siai Zhang

Chemistry & Biochemistry Theses

MiaE is a carboxylate bridged, non-heme diiron monooxygenase which catalyzes the O2-dependent hydroxylation of a hypermodified tRNA nucleoside at position 37 (2-methylthio-N-6-isopentenyl adenosine (37)-tRNA) [designated ms²i⁶A₃₇] to produce ms²i⁶A₃₇. In Salmonella typhimurium, synthesis of ms²i⁶A₃₇ requires a multi-step enzyme-catalyzed process that includes two other enzymes, MiaA and MiaB. Therefore, to study the hydroxylation step in this reaction pathway, all the elements within this reaction pathway (tRNA substrate, MiaA, MiaB, and MiaE) are required. In this work, methods for in vitro tRNA synthesis were developed for the biosynthesis of viable MiaA/MiaB/MiaE substrates. Additionally, the enzymes MiaA and MiaB were recombinantly cloned, …

Reducing Pb Bioaccessibility In Soil Through The Addition Of Apatite Ii, Zachary Robert Tondre

Earth & Environmental Sciences Theses

This study was an investigation of the bioaccessibility of Pb in the presence of phosphate acting as an immobilizing constituent in the form of fish bone material, specifically Apatite II. Phosphate-induced Pb immobilization refers to the process by which Pb ions replace calcium ions and form insoluble Pb-phosphate. A commercially available A-horizon soil was spiked with dried Pb-bearing paint containing various Pb forms (e.g., carbonates, sulfates, and oxides). The paints were added to the soil at 2% weight for weight (w/w). The paints (in solid form) were initially ground and sieved through a <100 micron mesh to provide a <100 μm size fraction. Once a paint was mixed with a soil, typically in duplicate, replicates were either retained or further amended with Apatite II. Soil columns were created using a series of 250 mL syringes individually filled with each paint spiked soil sample, some of which were amended with Apatite II at 5% w/w. For six months the columns were eluted regularly with Milli-Q water and at six months, subsamples were removed from the top of each soil column in order to evaluate any change in potential bioaccessibility of the Pb associated with soil. Thus, this work focuses on the bioaccessibility of Pb in a group of soil column samples based on the weak acid solubility of the Pb in the soil, and on an electron microscopic analysis of the Pb in the soils. Each soil column sample was subjected to an in vitro relative bioaccessibility assessment (RBA), in which a simulated gastric fluid (SGF) was used to simulate and project the effects of digestion on the Pb contaminated soils. The SGF was intended to mimic the acidic quality of the human stomach and yields approximate results of how much Pb could potentially be released into the acid solution through human digestion. The SGF solution was essentially composed of hydrochloric acid (HCL) adjusted to a pH of 2.5. From the soil columns, 3g of soil were removed and 1g was added to 100 mL of SGF and then tumbled for 1 hour at 37°C in a modified toxicity characteristic leaching procedure system. After this time a sample of the fluid was collected an the amount of Pb in the fluid was measured. Photomicrographs of each soil column were obtained using a scanning electron microscope with a back-scattered electron detector and an energy dispersive x-ray spectrometer. These digital images were used to determine the chemical nature of various Pb-bearing constituents within each soil sample. This study concluded that the addition of Apatite II led to a reduction in the bioaccessibility of Pb in some of the test soils, determined through differences in in vitro RBA and through the recognition of Pb-phosphate particle phases in the soil samples. Previous studies have found that the addition of Apatite II as a remediation technique for Pb contaminated soil can be successful, however this is the first time that Pb contamination of the soil has been in the form of Pb-bearing paint. Furthermore, this study is notable for identifying changes in Pb bioaccessibility of Pb derived from Pb-bearing paint over the short time-span of six months.

Chemostratigraphy Of The Mississippian-Age Barnett Formation, Fort Worth Basin, Wise County, Texas Usa, Chizoba Charity Nsianya

Earth & Environmental Sciences Theses

The Mississippian- age Barnett Formation is a shale-gas system dominated by fine grained clay- to silt -size particles deposited in the Fort Worth Basin, a peripheral foreland basin that formed during the late Paleozoic as a result of continental collision between Laurasia and Gondwana. A detailed assessment of the chemostratigraphy and depositional environment of the Barnett Formation in the northern end of Fort Worth Basin, Texas will be studied using a variety of geochemical methods. One drill core located in the south-eastern part of Wise County (Texas, USA) was scanned at high resolution (~ 2 inch interval) using a hand- …

A Model Of Short Term Surface Deformation Of Soufriere Hills Volcano, Montserrat Constrained By Gps Geodesy, Erin Elizabeth Mcpherson

Earth & Environmental Sciences Theses

Geodetic surveying is a core volcano monitoring technique. Measurements of how the crust deforms can give valuable insight into the mechanisms and processes that drive an eruption, and the way in which they change (Odbert et al., 2012). Campaign and continuous GPS geodetic measurements on Soufrière Hills Volcano, Montserrat are reported here from 1995 to 2010, spanning three dome growth and repose episodes extending the results of Mattioli et al. (2010). Soufriere Hills Volcano (SHV), Montserrat, in the Lesser Antilles island arc, became active in 1995, and for nearly two decades, geodetic surveys have been conducted using both continuous and …

Examining Ruthenium Chromophores For The Photochemical Reduction Of Co₂To Methanol, David J. Boston

Chemistry & Biochemistry Dissertations

Our consumption of energy for transportation and electricity has been growing as quickly as our population. As this demand for energy increases we increase our production of carbon dioxide by the burning of fossil fuels to try and meet this increasing demand. A sustainable method to convert carbon dioxide (CO₂) to a viable liquid fuel is one potential way in which both the increasing energy demand and increasing CO₂ concentration issues can both be helped. Currently such methods being investigated include thermal, electrochemical, and photochemical processes. Because thermal conversion is not an ideal situation because of the requirement of strong …

Effect Of Oil Viscosity Change On Oil Production: Co₂ Enhanced Oil Recovery In The Permian Basin And Potential In The Gabon Basin, Christel Simon Obame Bivegue

Earth & Environmental Sciences Theses

With most oil fields around the world reaching maturation it is not uncommon for oil companies to investigate the possibility of implementing CO₂ Enhanced Oil Recovery. The injection of CO₂ in a reservoir reduces the oil viscosity within the reservoir, which can later be more easily pushed towards a producing well. Computer simulators such as BOAST NFR are key tools in order to simulate the response of a reservoir to CO₂ EOR and predict oil production. This thesis investigates an example of CO₂ EOR in the Gabon Basin where such technique has yet to be implemented. Oil production has been …

Chemostratigraphy Of The Upper Cretaceous From Central And South Texas With Focus On The Eagle Ford Group, Brett Huffman

Earth & Environmental Sciences Theses

The fine-grained organic-rich rocks of the Eagle Ford (Cenomanian-Turonian) were deposited during the Upper Cretaceous in the shallow waters of the Western Interior Seaway. Five drill cores recovered from two counties, four from Travis County, Texas and one from Frio County, Texas, have been scanned from between two foot and half foot intervals with a hand-held energy-dispersive x-ray fluorescence (HH-ED-XRF) spectrometer to acquire major (e.g. Ca, Si, Al) and trace (e.g. Mo, V, Ni) element data for quantitative analysis. Additionally, gamma ray logs have been analyzed for two of the cores. Major element geochemistry indicates the Eagle Ford deposited in …

Timing, Provenance, And Paleoclimate Implications Of The Cenozoic Eolian Deposition In The Central Rocky Mountains, Usa, Jillian Rowley

Earth & Environmental Sciences Theses

This study applies detrital zircon U-Pb geochronology and sandstone petrography to constrain the timing and provenance of Cenozoic eolian sandstone in the central Rocky Mountains. Four samples, collected at the transition to eolian deposition along a west-east transect, have maximum depositional ages of 35.9±0.7 Ma, 35.4±2.0 Ma, 33±0.9 Ma, and 30±1.0 Ma, suggesting the transition initiated during the latest Eocene-earliest Oligocene and became younger eastward. A total of 766 zircon grains consist of a 17-44 Ma population, derived from the distal ignimbrite flare-up in western and southwestern North America, and a population older than 45 Ma, recycled from local Laramide …

The Electronic Properties Of Noble Metal Doped Silicon Nanocrystals Using Hybrid Density Functional Theory, Cedric Leon Mayfield

Physics Theses

One of the most challenging issues in semiconductor physics is to engineer band structures for a particular device. Contemporary photovoltaic (PV) and photoelectrochemical (PEC) devices rely on defect energy levels and nano-scaling to customize their band structures. As the length scale of a material becomes comparable to the exciton Bohr radius the free particle behavior of charge carriers transition to bound states where energy levels are quantized. In this thesis, hybrid density functional theory has been used to study the electronic properties of silicon nanocrystals (SiNCs) having 75, 150 and 300 silicon atoms. The atomic coordinates were defined by two …

Nanoscintillators For Radiation Detection, Ryan Gregory Hall

Physics Theses

In the search for faster, more effective methods for detection of and protection against radiological weapons, advances in materials for radiation detection are a critical component of any successful strategy. This work focuses on producing inexpensive, but highly sensitive, nanoparticle alternatives to existing single-crystal installations. Attention is given to particular types of promising inorganic scintillators: LaF₃, yttrium-aluminum-garnet (YAG), and SrF₂, each one an inorganic host doped with additional elements that encourage luminescent decay and increase effective Z-value. I examine the possible routes to synthesize these compounds, and the difficulties and benefits of each method. After synthesizing these materials, testing was …

Predicting A New Quaternary Photocatalyst Suitable For Pec Process To Produce Hydrogen And Determnation Of Its Structural, Electronics, And Optical Properties Using Density Functional Theory, Pranab Sarker

Physics Theses

Our present work represents a comprehensive theoretical and computational research in quest for predicting new photocatalysts suitable for photoelectrochemical process (PEC) to produce hydrogen by splitting water. We predict a new photocatalyst, CuBiW₂O₈ that exhibits some promising photocatalytic features seemed elusive to date. It is well known that all physical properties are calculated once ground state structure is known. However, knowing crystal structure is extremely challenging and was considered unpredictable before the material is synthesized. Our density functional theory (DFT) determines the crystal structure of CuBiW₂O₈ to be monoclinic which was later found energetically equivalent to its experimental counterpart. In …

Gis Data: York County, Virginia Tidal Marsh Inventory, Marcia Berman, Karinna Nunez, Sharon Killeen, Tamia Rudnicky, Carl Hershner, Kory Angstadt, David Stanhope, David Weiss, Karen Duhring, Christine Tombleson

Data

The 2013 Tidal Marsh Inventory update for York County, Virginia was generated using on-screen digitizing techniques in the most recent version of ArcGIS® - ArcMap while viewing conditions observed in the most recent imagery from the Virginia Base Mapping Program (VBMP). Dominant plant community types were primarily determined during field surveys from shallow-draft boats moving along the shoreline. Land-based surveys were performed in some locations. One shapefile is developed that portrays tidal marsh areas represented as polygons. A metadata file accompanies the shapefile to define attribute accuracy, data development, and any use restrictions that pertain to the data.

Gis Data: Charles City County, Virginia Tidal Marsh Inventory, Marcia Berman, Karinna Nunez, Sharon Killeen, Tamia Rudnicky, Kory Angstadt, Julie Bradshaw, David Weiss, Carl H. Hershner

Data

The 2013 Tidal Marsh Inventory update for Charles City County, Virginia was generated using on-screen digitizing techniques in the most recent version of ArcGIS® - ArcMap while viewing conditions observed in the most recent imagery from the Virginia Base Mapping Program (VBMP). Dominant plant community types were primarily determined during field surveys from shallow-draft boats moving along the shoreline. Land-based surveys were performed in some locations. One shapefile is developed that portrays tidal marsh areas represented as polygons. A metadata file accompanies the shapefile to define attribute accuracy, data development, and any use restrictions that pertain to the data.

Gis Data: Charles City County, Virginia Shoreline Inventory Report, Marcia Berman, Karinna Nunez, Sharon Killeen, Tamia Rudnicky, Kory Angstadt, Julie Bradshaw, David Weiss, Carl Hershner

Data

The data inventory developed for the Shoreline Inventory is based on a three tiered shoreline assessment approach. In most cases this assessment characterizes conditions that can be observed from a small boat navigating along the shoreline. The three tiered shoreline assessment approach divides the shorezone into three regions:

1) the immediate riparian zone, evaluated for land use; 2) the bank, evaluated for height, stability, cover and natural protection; and 3) the shoreline, describing the presence of shoreline structures for shore protection and recreational purposes. GPS registered videography was used to collect data on conditions observed in the field.

Three GIS …

Gis Data: York County, Virginia Shoreline Inventory Report, Marcia Berman, Karinna Nunez, Sharon Killeen, Tamia Rudnicky, Carl Hershner, Kory Angstadt, David Stanhope, David Weiss, Karen Duhring, Christine Tombleson

Data

The data inventory developed for the Shoreline Inventory is based on a three tiered shoreline assessment approach. In most cases this assessment characterizes conditions that can be observed from a small boat navigating along the shoreline. The three tiered shoreline assessment approach divides the shorezone into three regions: 1) the immediate riparian zone, evaluated for land use; 2) the bank, evaluated for height, stability, cover and natural protection; and 3) the shoreline, describing the presence of shoreline structures for shore protection and recreational purposes.

The 2009 Inventory for York County was updated using on-screen, digitizing techniques in ArcMap v10.0 while …

New Matrix Completion Models For Social Information Retrieval Application, Jin Huang

Computer Science and Engineering Dissertations

Many popular social web sites have emerged during the past decade and completely changed many users' everyday live. Recently, social information retrieval models, where conventional information retrieval meets the social context of search and recommendation, have become the central topic in machine learning, data mining, information retrieval and many other areas.A particular application of social information retrieval is the recommendation. Such recommendation ranges from classic recommendation movie rating recommendation in user-item matrices, trust and reputation modeling between members in any social network. If we model such recommendation in the form of matrices, then such recommendation can be formulated as recovering …

Exploratory Mining Of Collaborative Social Content, Mahashweta Das

Computer Science and Engineering Dissertations

The widespread use and growing popularity of online collaborative content sites (e.g., Yelp, Amazon, IMDB) has created rich resources for consumers to consult in order to make purchasing decisions on various items such as restaurants, e-commerce products, movies, etc. It has also created new opportunities for producers of such items to improve business by designing better products, composing succinct advertisement snippets, building more effective personalized recommendation systems, etc. This motivates us to develop a framework for exploratory mining of user feedback on items in collaborative social content sites. Typically, the amount of user feedback (e.g., ratings, reviews) associated with an …

Adaptive Dialogue Systems For Assistive Living Environments, Alexandros Papangelis

Computer Science and Engineering Dissertations

Adaptive Dialogue Systems (ADS) are intelligent systems, able to interact with users via multiple modalities, such as speech, gestures, facial expressions and others. Such systems are able to make conversation with their users, usually on a specific, narrow topic. Assistive Living Environments are environments where the users are by definition not competent with technology, due to various factors, such as mental or physical disabilities, age and others. While technology that helps improve these people's quality of life exists, many times they cannot access it due to inflexible interfaces. ADS, therefore, have the potential to bridge users and technology by acting …