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2018

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Articles 901 - 930 of 13646

Full-Text Articles in Physical Sciences and Mathematics

Changes To Subaqueous Delta Bathymetry Following A High River Flow Event, Wax Lake Delta, Usa, Amanda Rose Whaling Dec 2018

Changes To Subaqueous Delta Bathymetry Following A High River Flow Event, Wax Lake Delta, Usa, Amanda Rose Whaling

Graduate Theses and Dissertations

I report changes to the subaqueous bathymetry of the Wax Lake Delta (WLD) located in coastal Louisiana with the purpose of quantifying the two- and three-dimensional evolution of the entire delta front. The spatial distribution and volume of erosion and deposition were determined by differencing two Digital Elevation Models (DEMs) collected 16 months apart, including the 2nd largest high flow event (flood) in the WLD’s recorded history. The difference map showed 6.41×10^6 m^3 ± 3.70% of sediment were deposited and 1.19×10^7 m^3 ± 2.71% were eroded yielding 5.46×10^6 m^3 ± 7.32% of net erosion in the survey area (~75.9 km^2). …


Holocene Formation And Evolution Of Horn Island, Mississippi, Usa, Nina Gal Dec 2018

Holocene Formation And Evolution Of Horn Island, Mississippi, Usa, Nina Gal

Master's Theses

Horn Island, one of the most stable barriers along the Mississippi-Alabama chain, provides critical habitat, helps regulate estuarine conditions in the Mississippi Sound, and reduces wave energy and storm surge for the mainland. This study integrates 2,200 km of high-resolution geophysics, 35 sediment cores, and 15 radiocarbon ages to better understand the formation and evolution of the island in response to sea-level rise, storms, and antecedent geology. The Biloxi and Pascagoula incised valleys converge at Horn Island and have played a profound role in the evolution of the system. Within the incised valleys, numerous shallow paleochannels between 4 and 9 …


Hydrogeologic Framework Studies Of Portions Of The Niobrara River, Douglas R. Hallum, Steven S. Sibray, Leslie M. Howard Dec 2018

Hydrogeologic Framework Studies Of Portions Of The Niobrara River, Douglas R. Hallum, Steven S. Sibray, Leslie M. Howard

Conservation and Survey Division

The Nebraska Department of Natural Resources (NeDNR) and Upper Niobrara-White Natural Resources District (UNWNRD) expressed interest in improving understanding and their ability to effectively manage water resources in and around a particular reach of the Niobrara River. Aquifer-thickness contours mapped by the Conservation and Survey Division (CSD) indicate that the principle aquifer has zero thickness in this area. Additionally, the statewide geologic bedrock map produced by CSD shows non-aquifer strata of the White River Group along the same reach, and this setting is consistent with the designation of an “aquifer absent area,” as in the present document. Water-management policy development …


Improved Gas Sensing Performance Of Ald Azo 3-D Coated Zno Nanorods, P. Lin, X. Chen, K. Zhang, H. Baumgart Dec 2018

Improved Gas Sensing Performance Of Ald Azo 3-D Coated Zno Nanorods, P. Lin, X. Chen, K. Zhang, H. Baumgart

Electrical & Computer Engineering Faculty Publications

This paper reports an enhancement on the sensing performance of ZnO nanorod ethanol sensors with a new approach by utilizing nested coatings of Aluminum doped ZnO (AZO) thin films by Atomic Layer Deposition (ALD) technology. ZnO nanorods were grown by the hydrothermal method with the ZnO seed layer synthesized on Silicon wafers by ALD. To enhance the sensing performance of ZnO nanorod ethanol sensors, multiple coated AZO thin film 3-D coatings were deposited on the surface of the intrinsic ZnO nanorods by ALD.To investigate the sensing performance of the ZnO nanorods sensor for the detection of ethanol vapor, a gas …


A Plausible Resolution To Hilbert’S Failed Attempt To Unify Gravitation & Electromagnetism, Florentin Smarandache, Victor Christianto, Robert Neil Boyd Dec 2018

A Plausible Resolution To Hilbert’S Failed Attempt To Unify Gravitation & Electromagnetism, Florentin Smarandache, Victor Christianto, Robert Neil Boyd

Branch Mathematics and Statistics Faculty and Staff Publications

In this paper, we explore the reasons why Hilbert’s axiomatic program to unify gravitation theory and electromagnetism failed and outline a plausible resolution of this problem. The latter is based on Gödel’s incompleteness theorem and Newton’s aether stream model.


Substellar And Low-Mass Dwarf Identification With Near-Infrared Imaging Space Observatories, Benne W. Holwerda, J. S. Bridge, R. Ryan, M. A. Kenworthy, N. Pirzkal, M. Andersen, S. Wilkins, R. Smit, S. R. Bernard, T. Meshkat, R. Steele, R. C. Bouwens Dec 2018

Substellar And Low-Mass Dwarf Identification With Near-Infrared Imaging Space Observatories, Benne W. Holwerda, J. S. Bridge, R. Ryan, M. A. Kenworthy, N. Pirzkal, M. Andersen, S. Wilkins, R. Smit, S. R. Bernard, T. Meshkat, R. Steele, R. C. Bouwens

Faculty and Staff Scholarship

Aims. We aim to evaluate the near-infrared colors of brown dwarfs as observed with four major infrared imaging space observatories: the Hubble Space Telescope (HST), the James Webb Space Telescope (JWST), the Euclid mission, and the WFIRST telescope. Methods. We used the SPLAT SPEX/ISPEX spectroscopic library to map out the colors of the M-, L-, and T-type dwarfs. We have identified which color-color combination is optimal for identifying broad type and which single color is optimal to then identify the subtype (e.g., T0-9). We evaluated each observatory separately as well as the narrow-field (HST and JWST) and wide-field (Euclid and …


Flow Adaptive Video Object Segmentation, Fanqing Lin Dec 2018

Flow Adaptive Video Object Segmentation, Fanqing Lin

Theses and Dissertations

We tackle the task of semi-supervised video object segmentation, i.e, pixel-level object classification of the images in video sequences using very limited ground truth training data of its corresponding video. Recently introduced online adaptation of convolutional neural networks for video object segmentation (OnAVOS) has achieved good results by pretraining the network, fine-tuning on the first frame and training the network at test time using its approximate prediction as newly obtained ground truth. We propose Flow Adaptive Video Object Segmentation (FAVOS) that refines the generated adaptive ground truth for online updates and utilizes temporal consistency between video frames with the help …


Discovery Of Paleotsunami Deposits Along Eastern Sunda Arc: Potential For Megathrust Earthquakes In Bali, Hanif Ibadurrahman Sulaeman Dec 2018

Discovery Of Paleotsunami Deposits Along Eastern Sunda Arc: Potential For Megathrust Earthquakes In Bali, Hanif Ibadurrahman Sulaeman

Theses and Dissertations

Several laterally extensive candidate tsunami deposits are preserved along coastlines facing the eastern Java Trench, indicating it has experienced mega-thrust earthquakes in the past. We investigated 37 coastal sites in Bali, Lombok, Sumba and Timor islands, many of which preserve course sand and pebble layers that overlie sharp basal contacts with scour marks into the mud, fine upward in grain size, and have bimodal grain size distributions. Other unique features are the common occurrence of marine fossils and concentrations of heavy minerals. The occurrence of these high-energy deposits interlayered with clay-rich units indicates the coarse clastics are anomalous because they …


Cake Cam: Take Your Photo And Be In It Too, Candice Lynn Davis Dec 2018

Cake Cam: Take Your Photo And Be In It Too, Candice Lynn Davis

Theses and Dissertations

In this thesis we explore a different kind of computer-mediated collaboration (CMC) in which two people collaborate to perform a single task in a time-sensitive asymmetric situation wherein one person is more invested in the outcome than the other is. Our conjecture is that interactive computing can quickly communicate intent, which may help mediate time-sensitive asymmetric tasks between two people. We explore this idea specifically in the context of asking a stranger to take one's picture at a tourist site. Consider a tourist handing a cell phone to a complete stranger and asking the stranger to take the tourist's picture …


Normally Supportive Sublattices Of Crystallographic Space Groups, Miles A. Clemens Dec 2018

Normally Supportive Sublattices Of Crystallographic Space Groups, Miles A. Clemens

Theses and Dissertations

Normal subgroups can be thought of as the primary building blocks for decomposing mathematicalgroups into quotient groups. The properties of the resulting quotient groups are oftenused to determine properties of the group itself. This thesis considers normal subgroups of threedimensionalcrystallographic space groups that are themselves three-dimensional crystallographicspace groups; for convenience, we refer to such a subgroup as a csg-normal subgroup. We identifypractical restrictions on csg-normal subgroups that facilitate their tabulation. First, the point groupof an csg-normal subgroup must be a normal subgroup of the crystallographic point group of thespace group, which we refer to for convenience as a cpg-normal subgroup. …


The Use Of Tissue And Serum ”˜Omics' Methods To Characterize Disease, Ying Ding Dec 2018

The Use Of Tissue And Serum ”˜Omics' Methods To Characterize Disease, Ying Ding

Theses and Dissertations

Preeclampsia (PE) is a multisystem disorder that contributes to maternal and fetal mortality and morbidity worldwide. It is characterized by de-novo hypertension and proteinuria or other maternal organ damage after 20 weeks of gestation. Evidence suggested that endogenous digitalis-like factor (EDLF) contributes to the pathogenesis of PE, and that the potential source of EDLF is the placenta. EDLF can inhibit the sodium pump (SP) specifically and may lead to hypertension, it has also been associated with hypoxia, oxidative stress and other abnormalitites present in PE.We studied whether normal human placenta responded to SP inhibition casued by EDLF with a change …


The Bird And The Fish: Motion Field-Based Frame Interpolation In The Context Of A Story, Thomas Sterling Ellsworth Dec 2018

The Bird And The Fish: Motion Field-Based Frame Interpolation In The Context Of A Story, Thomas Sterling Ellsworth

Theses and Dissertations

Animating by hand can be a long and challenging process in part because of the necessity of drawing every frame by hand. 3D animation media minimize this problem with the use of automatically interpolated frames, but despite significant research no universally acceptable techniques have been demonstrated for 2 dimensional interpolation. In this paper we explore computer-assisted optimizations to the animation pipeline. Specifically, we utilize 3D motion fields to create more realistic in-between frames for sets of 2D ``key frames.'' We demonstrate our method by using it to create 2D special effects for a 30-second clip of an animated short film.


Influence Of Natural And Anthropogenic Environmental Variability On Larval Fish Diet, Growth, And Condition In The Northcentral Gulf Of Mexico, Angie Hoover Dec 2018

Influence Of Natural And Anthropogenic Environmental Variability On Larval Fish Diet, Growth, And Condition In The Northcentral Gulf Of Mexico, Angie Hoover

Master's Theses

The northern Gulf of Mexico experiences high levels of freshwater runoff annually from various sources including the Mississippi River and Mobile Bay, among other sources. Early life history stages of fishes are especially vulnerable to environmental variability created by freshwater discharge. The objectives of this study were to describe the available prey field, diet, growth and condition of larval fishes with respect to various effects of freshwater discharge in the northern Gulf. The first chapter compared these parameters in larval Gulf Menhaden (Brevoortia patronus) collected from three different water masses characterized by physical and biological parameters after the …


Cleaver: Classification Of Everyday Activities Via Ensemble Recognizers, Samantha Hsu Dec 2018

Cleaver: Classification Of Everyday Activities Via Ensemble Recognizers, Samantha Hsu

Master's Theses

Physical activity can have immediate and long-term benefits on health and reduce the risk for chronic diseases. Valid measures of physical activity are needed in order to improve our understanding of the exact relationship between physical activity and health. Activity monitors have become a standard for measuring physical activity; accelerometers in particular are widely used in research and consumer products because they are objective, inexpensive, and practical. Previous studies have experimented with different monitor placements and classification methods. However, the majority of these methods were developed using data collected in controlled, laboratory-based settings, which is not reliably representative of real …


Improving Ultra-Wideband Localization By Detecting Radio Misclassification, Cory A. Mayer Dec 2018

Improving Ultra-Wideband Localization By Detecting Radio Misclassification, Cory A. Mayer

Master's Theses

The Global Positioning System (GPS) and other satellite-based positioning systems are often a key component in applications requiring localization. However, accurate positioning in areas with poor GPS coverage, such as inside buildings and in dense cities, is in increasing demand for many modern applications. Fortunately, recent developments in ultra-wideband (UWB) radio technology have enabled precise positioning in places where it was not previously possible by utilizing multipath-resistant wide band pulses.

Although ultra-wideband signals are less prone to multipath interference, it is still a bottleneck as increasingly ambitious projects continue to demand higher precision. Some UWB radios include on-board detection of …


Influence Of High Aspect Ratio Nanoparticle Filler Addition On Piezoelectric Nanocomposites, Jeremy A. Armas Dec 2018

Influence Of High Aspect Ratio Nanoparticle Filler Addition On Piezoelectric Nanocomposites, Jeremy A. Armas

Master's Theses

Piezoelectric nanogenerators (PNGs) are a new class of energy harvesting materials that show potential as a direct energy source for low powered electronics. Recently, piezoelectric polymers have been utilized for PNG technology due to low toxicity, high flexibility, and facile solution processing which provide manufacturing opportunities such as screen printing. Throughout the last decade, countless projects have focused on how to enhance the energy harvesting capabilities of these PNGs through the incorporation of nanoparticle fillers, which have been reported to enhance the piezoelectric properties of the film either directly through their intrinsic piezoelectric properties or through acting as surfaces for …


3d Scintillator Detector Quenching Characterization For Scanning Proton Beams, Fahed Alsanea Dec 2018

3d Scintillator Detector Quenching Characterization For Scanning Proton Beams, Fahed Alsanea

Dissertations & Theses (Open Access)

Proton pencil beam scanning is becoming the standard treatment delivery technique for proton therapy centers. Scanned proton pencil beams provide a highly conformal dose distribution. The complex dose distribution poses challenges for quality assurance measurements leading to sophisticated detector setups and time consuming measurements. Fast 3D measurements are therefore desirable to verify the complex dose distribution and to enable the utilization of the full potential of proton therapy. The overall objective of this project is to improve volumetric scintillators detectors to provide 3D measurements for applications for beam commissioning, quality assurance program, and patient-specific treatment delivery verification.

Detectors based on …


Measurement Of The Cross Section Of Top Quark Pairs In Association With A Photon In Lepton+Jets Events At √S =13 Tev, Titas Roy Dec 2018

Measurement Of The Cross Section Of Top Quark Pairs In Association With A Photon In Lepton+Jets Events At √S =13 Tev, Titas Roy

Theses and Dissertations

The Large Hadron Collider (LHC) at CERN is the world’s biggest and most powerful accelerator. Colliding protons at the highest centre of mass energy yet, data are being collected by the detectors at an unprecendented rate, making it possible to search for new particles as well as make precise measurements. With the increase in statistics and energy of the data collected, it is now possible to make precise measurements with events that have a relatively low probability of occuring. In this thesis, the production cross section of a top quark pair plus a radiated photon, tt¯+γ, is measured in proton-proton …


Automatic Anuran Species Recognition Via Vocalization, Katrina Smart Dec 2018

Automatic Anuran Species Recognition Via Vocalization, Katrina Smart

Theses and Dissertations

Species recognition of Anuran vocalization is an important problem in ecology, which is costly and time consuming. Recently, biologists have turned to machine learning techniques to automate the process. An automated process can be made even more helpful if available to use on a smart phone, which can be used in the field by scientists and citizen scientists alike. The problem of automatic frog call recognition is challenging because features need to be chosen that can properly separate different species’ very similar sounding vocalizations. This thesis offers the following contributions: 1. Three novel feature extraction methods, which do not require …


Development Of Portable Embedded Face Recognition Prototype, Prasad S. Garapati Dec 2018

Development Of Portable Embedded Face Recognition Prototype, Prasad S. Garapati

Theses and Dissertations

In this thesis, we focus on developing a prototype for collecting multispectral images for face recognition. With such application, the quality of the image is an important factor that affects the accuracy of the recognition. However, the sensory data either provided in RGB channel or in NIR channel. The images acquired in RGB and NIR were never aligned in previous developments during my literature study. Thus, I propose an embedded system prototype capable of acquiring NIR and RGB images providing multispectral information which is computation efficient for real time face recognition applications.


Infrastructure-Based Access Policy Enforcement Using Software-Defined Networks, Tyler Carden Culp Dec 2018

Infrastructure-Based Access Policy Enforcement Using Software-Defined Networks, Tyler Carden Culp

Theses and Dissertations

This thesis describes a method to enhance network security using software defined networks. Standard networks use perimeter-based defenses to block attackers from gaining access to internal systems. A key problem with standard networks is that once a malicious entity has gained access to the network, they are often able to freely move throughout the network and to attack internal systems with impunity. This problem can be mitigated by placing defenses such as firewalls between machines on the network, but this approach requires significant resources and constant maintenance. If the network infrastructure itself is leveraged as a defense by individualizing the …


Mitigating Memory Randomization Weaknesses Via Moving Target Defense, Sultan M. Aldossary Dec 2018

Mitigating Memory Randomization Weaknesses Via Moving Target Defense, Sultan M. Aldossary

Theses and Dissertations

In this dissertation, we address the problem of weakness of address space layout randomization. The address space randomization technique was proposed to make determining the address of a shared library more difficult since each instance of the program is loaded into a random base address. However, when address space randomization layout (ASLR) is implemented on a 32-bit system, an attacker can use a brute force attack to guess the address of the shared library.The main goal of the research described in this dissertation is to study the use of a dispatching algorithm and multiple back-end servers as a moving target …


Lighting A Path To Biofouling Prevention: Investigating The Effect Of Ultraviolet Light On Biofouling, Cierra Rose Braga Dec 2018

Lighting A Path To Biofouling Prevention: Investigating The Effect Of Ultraviolet Light On Biofouling, Cierra Rose Braga

Theses and Dissertations

Ultraviolet light (UV) is considered an environmentally friendly antifouling method because it disrupts biological growth without the release of harmful toxins. The application of UV for the marine shipping industry is a relatively new concept, and there still remains many unknowns before it can be fully implemented. This research investigated several aspects of applying UVC for the control of fouling. A novel method of using embedded UV LEDs within a silicone coating for fouling control proved to be very effective at preventing fouling. The research also investigated the effect of using an external UVC light treatment to control fouling on …


Wind-Driven Setup, Roughness, And Drag Over A Depth- And Fetch-Limited Coastal Estuary, Jeffrey Allen Colvin Dec 2018

Wind-Driven Setup, Roughness, And Drag Over A Depth- And Fetch-Limited Coastal Estuary, Jeffrey Allen Colvin

Theses and Dissertations

The understanding of the momentum exchange across the air-sea interface is critical to accurately model and forecast wind speed, wave properties, setup, and circulation. This is particularly true for a restricted estuary, such as the Indian River Lagoon (IRL), where wind is the driving force behind water movement due to the limited number of direct ocean connections. Current atmospheric and hydrodynamic models use formulations of the drag coefficient and/or roughness length based on open ocean studies in which wave properties are not considered. This dissertation develops two parameterizations – one for wind setup and one for the drag coefficient – …


Late Quaternary Evolution And Stratigraphic Framework Influence On Coastal Systems Along The North-Central Gulf Of Mexico, Usa, Robert Hollis Dec 2018

Late Quaternary Evolution And Stratigraphic Framework Influence On Coastal Systems Along The North-Central Gulf Of Mexico, Usa, Robert Hollis

Master's Theses

Coastal systems in the Gulf of Mexico are threatened to reduced sediment supply, storm impacts and relative sea level rise (RSLR). The geologic record can provide insights of geomorphic threshold crossings (formation, progradation, transgression, destruction) to these forcing mechanisms to predict future barrier evolution to climate change. The stratigraphic framework and antecedent topography directly influence coastal evolution over geologic timescales. This study synthesizes ~2100km of geophysical data, 700+ sediment cores, and 63 radiocarbon dates to regionally map two sequence boundaries, multiple ravinement surfaces and fourteen depositional facies. One marine isotope stage (MIS) 6 valley’s fill provided up to 300 x10 …


Towards Automated Domain-Oriented Lexicon Construction And Dimension Reduction For Arabic Sentiment Analysis, Hasan A. Alshahrani Dec 2018

Towards Automated Domain-Oriented Lexicon Construction And Dimension Reduction For Arabic Sentiment Analysis, Hasan A. Alshahrani

Dissertations

Sentiment analysis is a type of text mining that uses Natural Language Processing (NLP) tools to identify and label opinionated text. There are two main approaches of sentiment analysis: lexicon-based, and statistical approach. In our research, we use the lexicon-based approach because the lexicon contains sentiment words and phrases which are the main linguistic units to express sentiments. More specifically, we work with domain-oriented lexicons as they are more efficient than general ones because the polarity is heavily driven by domains.

Arabic language has a degree of uniqueness that makes it hard to be processed with the available cross-language tools …


Retinex-Based Visibility Enhancement System For Inclement Weather With Tracking And Distance Estimation Capabilities, Marwan S. Alluhaidan Dec 2018

Retinex-Based Visibility Enhancement System For Inclement Weather With Tracking And Distance Estimation Capabilities, Marwan S. Alluhaidan

Dissertations

Road conditions affected by weather are well known to have an impact on the number of vehicle accidents and fatalities, due to low- to no-visibility conditions. According to the U.S. Department of Transportation, there are more than 1,259,000 crashes each year. On average, 6,000 people are killed and more than 445,000 people are injured annually due to severe weather conditions. These accidents could be significantly reduced if real-time visibility enhancement systems were made available. However, eliminating the impact of weather conditions on visibility is still lacking and beyond our control. The time has come to develop technology that is capable …


An Architectural Design And Evaluation Of An Affective Tutoring System For Novice Programmers, Hua Leong Fwa Dec 2018

An Architectural Design And Evaluation Of An Affective Tutoring System For Novice Programmers, Hua Leong Fwa

Research Collection School Of Computing and Information Systems

Affect is prevalent in learning and it influences students’ learning achievement. This paper details the design and evaluation of an Affective Tutoring System (ATS) that tutors student in computer programming. Although most ATSs are purpose built for a specific domain, making adaptation to another domain difficult, this ATS is architected for adaptability and extensibility. This study also addresses a lack of research exploring the theories and methods of integrating affect and learning within the learning process by proposing methods of regulating the negative affect of students. Both quantitative and qualitative techniques were used for evaluation of the effectiveness of the …


Authorized Function Homomorphic Signature, Qingwen Guo, Qiong Huang, Guomin Yang Dec 2018

Authorized Function Homomorphic Signature, Qingwen Guo, Qiong Huang, Guomin Yang

Research Collection School Of Computing and Information Systems

Homomorphic signature (HS) is a novel primitive that allows an agency to carry out arbitrary (polynomial time) computation f on the signed data (m) over right arrow and accordingly gain a signature sigma(h) for the computation result f ((m) over right arrow) with respect to f on behalf of the data owner (DO). However, since DO lacks control of the agency's behavior, receivers would believe that DO did authenticate the computation result even if the agency misbehaves and applies a function that the DO does not want. To address the problem above, in this paper we introduce a new primitive …


Exploration Of Students’ Conceptual Understanding Of Trigonometric Functions, Stedius Salivatory Bernado Dec 2018

Exploration Of Students’ Conceptual Understanding Of Trigonometric Functions, Stedius Salivatory Bernado

Theses & Dissertations

This study was an exploration of students’ conceptual understanding of trigonometric functions as this is the basis of their trigonometric skills. Trigonometric skills are very important skills needed in fields such as architecture and engineering. The link between facts, skills and conceptual understanding is therefore very important for students who wish to pursue such careers. A qualitative design was used in the study. Twenty five students studying in a public secondary school, were selected from among those taking PCM (Physics, Chemistry and Mathematics) in form six. The data was collected using a questionnaire in form of a test and interviews. …