Physical Sciences and Mathematics Commons^™

Generation Of Multi-Charged Aluminum Ions From Femtosecond Laser Induced Plasma, Frederick Guy Wilson

Electrical & Computer Engineering Theses & Dissertations

Laser-induced plasma multi-charged ion (MCI) sources have gained in popularity over the last thirty years with the advent of reliable, high peak power, short temporal pulse laser systems. Utilization of laser-induced plasma MCI sources allows for production of a wide array of ion species from a variety of source target materials. In this thesis an investigation of the generation of MCis from an aluminum (Al) target source through laser-induced plasma from a femtosecond (fs) pulsed laser system is outlined and the results presented and analyzed. In order to characterize the production of the Al MCis resulting from the fs laser …

Toward A Theory Of Multi-Method Modeling And Simulation Approach, Mariusz A. Balaban

Computational Modeling & Simulation Engineering Theses & Dissertations

The representation via simulation models can easily lead to simulation models too simple for their intended purpose, or with too much detail, making them hard to understand. This problem is related to limitations of the modeling and simulation methods. A multi-method Modeling and Simulation (M&S) approach has the potential for improved representation by taking advantage of methods' strengths and mitigating their weaknesses. Despite a high appeal for using multiple M&S methods, several related problems should be addressed first. The current level of theoretical, methodological, and pragmatic knowledge related to a multi-method M&S approach is limited. It is problematic that there …

Physio@Home: Exploring Visual Guidance And Feedback Techniques For Physiotherapy Exercises, Richard Tang, Xing-Dong Yang, Scott Bateman, Joaquim Jorge, Anthony Tang

Research Collection School Of Computing and Information Systems

Physiotherapy patients exercising at home alone are at risk of re-injury since they do not have corrective guidance from a therapist. To explore solutions to this problem, we designed Physio@Home, a prototype that guides people through pre-recorded physiotherapy exercises using realtime visual guides and multi-camera views. Our design addresses several aspects of corrective guidance, including: plane and range of movement, joint positions and angles, and extent of movement. We evaluated our design, comparing how closely people could follow exercise movements under various feedback conditions. Participants were most accurate when using our visual guide and multi-views. We provide suggestions for exercise …

Mining Business Competitiveness From User Visitation Data, Doan Thanh Nam, Freddy Chong Tat Chua, Ee-Peng Lim

Research Collection School Of Computing and Information Systems

Ranking businesses by competitiveness is useful in many applications including business (e.g., restaurant) recommendation, and estimation of intrinsic value of businesses for mergers and acquisitions. Our literature reveals that previous methods of business ranking have ignored the competing relationship among businesses within their geographical areas. To account for competition, we propose the use of PageRank model and its variant to derive the Competitive Rankof businesses. We use the check-ins of users from Foursquare, a location-based social network, to model the winners of competitions among stores. The results of our experiments show that Competitive Rank works well when evaluated against ground …

Exploring Discriminative Features For Anomaly Detection In Public Spaces, Shriguru Nayak, Archan Misra, Kasthuri Jeyarajah, Philips Kokoh Prasetyo, Ee-Peng Lim

Research Collection School Of Computing and Information Systems

Context data, collected either from mobile devices or from user-generated social media content, can help identify abnormal behavioural patterns in public spaces (e.g., shopping malls, college campuses or downtown city areas). Spatiotemporal analysis of such data streams provides a compelling new approach towards automatically creating real-time urban situational awareness, especially about events that are unanticipated or that evolve very rapidly. In this work, we use real-life datasets collected via SMU's LiveLabs testbed or via SMU's Palanteer software, to explore various discriminative features (both spatial and temporal - e.g., occupancy volumes, rate of change in topic{specific tweets or probabilistic distribution of …

Maximizing Lifetime In Clustered Wsns With Energy Harvesting Relay: Profiling And Modeling, Pengfei Zhang, Hwee-Pink Tan, Gaoxi Xiao, Yi Yu

Research Collection School Of Computing and Information Systems

Inspired by clustering and energy harvesting techniques, we study multiple-cluster wireless sensor networks with energy harvesting (EH) sensors serving as relay for cluster heads. In this paper, we derive the model for realistic energy harvesting rate. Then we propose distributed matching algorithm for EHs to serve as relay for CHs. The proposed algorithm could find optimal/near-optimal CH-EH matching in short time and still achieve good performance. We evaluate the performance of our method through theoretical analysis as well as simulation.

Best Upgrade Plans For Single And Multiple Source-Destination Pairs, Yimin Lin, Kyriakos Mouratidis

Research Collection School Of Computing and Information Systems

In this paper, we study Resource Constrained Best Upgrade Plan (BUP) computation in road network databases. Consider a transportation network (weighted graph) G where a subset of the edges are upgradable, i.e., for each such edge there is a cost, which if spent, the weight of the edge can be reduced to a specific new value. In the single-pair version of BUP, the input includes a source and a destination in G, and a budget B (resource constraint). The goal is to identify which upgradable edges should be upgraded so that the shortest path distance between source and …

Measuring User Influence, Susceptibility And Cynicalness In Sentiment Diffusion, Roy Ka-Wei Lee, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Diffusion in social networks is an important research topic lately due to massive amount of information shared on social media and Web. As information diffuses, users express sentiments which can affect the sentiments of others. In this paper, we analyze how users reinforce or modify sentiment of one another based on a set of inter-dependent latent user factors as they are engaged in diffusion of event information. We introduce these sentiment-based latent user factors, namely influence, susceptibility and cynicalness. We also propose the ISC model to relate the three factors together and develop an iterative computation approach to …

Spectropathology For The Next Generation: Quo Vadis?, Hugh Byrne, Malgorzata Baranska, Gerwin J. Pupples, Nick Stone, Bayden Wood, Kathleen M. Gough, Peter Lasch, Phil Heraud, Josep Sulé-Suso, Ganesh Sockalingum

Articles

Although the potential of vibrational spectroscopy for biomedical applications has been well demonstrated, translation into clinical practice has been relatively slow. This Editorial assesses the challenges facing the field and the potential way forward. While many technological challenges have been addressed to date, considerable effort is still required to gain acceptance of the techniques among the medical community, standardise protocols, extend to a clinically relevant scale, and ultimately assess the health economics underlying clinical deployment. National and international research networks can contribute much to technology development and standardisation. Ultimately, large-scale funding is required to engage in clinical trials and instrument …

Development Of Superconducting Spoke Cavities For High-Velocity Applications, Christopher Shawn Hopper

Physics Theses & Dissertations

To date, superconducting spoke cavities have been designed, developed, and tested for particle velocities up to β0 ~ 0.6, but there is a growing interest in possible applications of spoke cavities for high-velocity applications. The first task is to explore the design parameter space for low-frequency, high-velocity, single- and double-spoke superconducting cavities in order to determine how each design parameter affects the electromagnetic properties, in particular the surface electromagnetic fields and the shunt impedance. Once an electromagnetically optimized, high-velocity spoke cavity is designed, there are several other characteristics that need to be investigated. These include multipacting scenarios, higher-order mode excitation …

Catalysis Of Stark-Tuned Interactions Between Ultracold Rydberg Atoms, Aye Lu Win

Physics Theses & Dissertations

We present the study of the catalysis effect in the resonant energy transfer between ultracold ⁸⁵Rb Rydberg atoms. We have investigated the energy transfer process of 34p + 34p → 34s + 35s, and observed Stark-tuned Forster resonances. When additional Rydberg atoms of 34d state are included in the interaction, an increase in the population of 34s states atoms is observed. Although the 34d state atoms do not directly participate in the resonant energy transfer that produces 34s state atoms, they add an additional interaction channel 34p + 34 …

Meson Photo-Couplings From Lattice Quantum Chromodynamics, Christian J. P. Shultz

Physics Theses & Dissertations

We explore the calculation of three-point functions featuring a vector current insertion in lattice Quantum Chromodynamics. These three-point functions, in general, contain information about many radiative transition matrix elements simultaneously. We develop and implement the technology necessary to isolate a single matrix element via the use of optimized operators, operators designed to interpolate a single meson eigenstate, which are constructed as variationally optimized linear combination of meson interpolating fields within a large basis. In order to frame the results we also explore some well known phenomenology arising within the context of the constituent quark model before transitioning to a lattice …

Avoiding Spoilers On Mediawiki Fan Sites Using Memento, Shawn M. Jones

Computer Science Theses & Dissertations

A variety of fan-based wikis about episodic fiction (e.g., television shows, novels, movies) exist on the World Wide Web. These wikis provide a wealth of information about complex stories, but if readers are behind in their viewing they run the risk of encountering spoilers" -- information that gives away key plot points before the intended time of the show's writers. Enterprising readers might browse the wiki in a web archive so as to view the page prior to a specific episode date and thereby avoid spoilers. Unfortunately, due to how web archives choose the "best" page, it is still possible …

Computational Development For Secondary Structure Detection From Three-Dimensional Images Of Cryo-Electron Microscopy, Dong Si

Computer Science Theses & Dissertations

Electron cryo-microscopy (cryo-EM) as a cutting edge technology has carved a niche for itself in the study of large-scale protein complex. Although the protein backbone of complexes cannot be derived directly from the medium resolution (5-10 Å) of amino acids from three-dimensional (3D) density images, secondary structure elements (SSEs) such as alpha-helices and beta-sheets can still be detected. The accuracy of SSE detection from the volumetric protein density images is critical for ab initio backbone structure derivation in cryo-EM. So far it is challenging to detect the SSEs automatically and accurately from the density images at these resolutions. This dissertation …

Proclivity Or Popularity? Exploring Agent Heterogeneity In Network Formation, Xiaotian Wang

Computational Modeling & Simulation Engineering Theses & Dissertations

The Barabasi-Albert model (BA model) is the standard algorithm used to describe the emergent mechanism of a scale-free network. This dissertation argues that the BA model, and its variants, rarely take agent heterogeneity into account in the analysis of network formation. In social networks, however, people's decisions to connect are strongly affected by the extent of similarity. In this dissertation, the author applies an agent-based modeling (ABM) approach to reassess the Barabasi-Albert model. This study proposes that, in forming social networks, agents are constantly balancing between instrumental and intrinsic preferences. After systematic simulation and subsequent analysis, this study finds that …

A Survey Of Aquatic Organisms For The Cyanotoxin Beta-Methylamino-L-Alanine (Bmaa), Ian M. Sammler

OES Theses and Dissertations

Cyanobacteria blooms are increasing globally as a result of eutrophication. Many cyanobacteria are potentially harmful, not only because of the oxygen depleted zones created when they decay, but also because of the toxins they produce. β- Methylamino-L-alanine (BMAA), reportedly produced by many species of cyanobacteria, is a non-proteinogenic amino acid that has been linked to the development of neurodegenerative diseases (amyotrophic lateral sclerosis (ALS) and Alzheimer's) in humans. This study presents results from an assessment of BMAA in cyanobacteria and their grazers from the lower Chesapeake Bay and Lake Erie regions. BMAA was analyzed in samples prepared with the EZ:Faast™ …

Potential For Biocontrol Of Environmental Vibrio Spp. By Predatory Bacteria Bacteriovorax, Patrick Tennis

OES Theses and Dissertations

The scale of predator-prey interactions varies from the iconic (e.g., lions and gazelles) to the microscopic (e.g., protists and bacteria). Bdellovibrio-and-like-organisms (BALOs) are bacteria that prey upon other Gram-negative bacteria, including pathogens. In particular, the halophilic genus Vibrio, many species of which are disease agents, has been shown to be susceptible to attack by BALOs. One motivation of the present research is to assess the potential for biocontrol of Vibrio by Bacteriovorax. This investigation is the first to test the susceptibility of Vibrio strains (n = 26) originating from a variety of geographic locations to predation by …

Doppler Shifted Internal Waves In A Shallow Water Region, William D. Boll

OES Theses and Dissertations

Measurements of velocity fields from a high frequency ( 1.2 MHz) vertical acoustic doppler current profiler (V ADCP) along with density and temperature profiles were taken in coastal waters on the New Jersey shelf. Time series span six consecutive months from May through October 2003, capturing the transition of the water column from a highly stratified summer into a fully mixed winter season. Barotropic tides interact with variations in local bathymetry causing disturbances within the fluid medium which govern internal wave characteristics. During the months of June, July, and August, a high number of internal wave signals were observed. Spectra …

Blue Carbon In Freshwater / Brackish Marshes On The Barrier Islands Of Virginia Aboveground Net Primary Productivity And Carbon Pools, Emily Caitlin Adams

Biological Sciences Theses & Dissertations

"Blue carbon" is a relatively new concept describing carbon distributed tidally and sequestered via net production within coastal ecosystems, including seagrass beds, mangrove forests, and salt-water marshes. These systems sequester carbon at least 10 times faster than terrestrial systems. Fresh to brackish wetlands that receive irregular tidal influence due to overwash and storm events have not been typically studied as blue carbon systems. My objective was to quantify carbon pools within four interdunal fresh to brackish marshes on Hog Island, Virginia to determine their blue carbon potential. Marshes 1 and 2 were farthest from the ocean, below and above a …

Blue Carbon In Coastal Freshwater/Brackish Marshes On The Barrier Islands Of Virginia: Belowground Carbon Dynamics, Nathan M. Sedghi

Biological Sciences Theses & Dissertations

Some coastal ecosystems sequester substantially more carbon (blue carbon) than land locked systems due to high net primary production and deposition associated with oceanic influences. Most blue carbon research has focused on mangroves, seagrass beds, and salt marshes. Studies on blue carbon potential of coastal freshwater marshes are less common. Barrier islands frequently flood, with seawater reaching interior ecosystems. I examined brackish/freshwater marshes on Virginia barrier islands for possible roles as blue carbon systems. I studied four interior marshes on Hog Island, which varied in proximity to a direct overwash path and protection by a trail berm that divides northern …

In Vivo Near Ir Fluorescent Imaging Of Hollow Polymeric Nanocapsules, Venkata Suresh Patthipati

Biological Sciences Theses & Dissertations

Medical Imaging has been an integral component in medical diagnosis and therapeutics. It is frequently used in conjunction with other treatment modalities and has been used for developing applications that range from cancer management to clinical practice. Nanotechnology and its applications are foreseen to have a profound impact on life sciences. Nanomaterial based imaging has a significant potential in addressing medical challenges such as tumor localization, targeted delivery of drugs and real time diagnosis and management of circulation pathology. In particular, polymer based nanoparticles are increasingly being developed as they can be customized according to the diagnostic and/or therapeutic requirements. …

Zero-Inflated Models To Identify Transcription Factor Binding Sites In Chip-Seq Experiments, Sameera Dhananjaya Viswakula

Mathematics & Statistics Theses & Dissertations

It is essential to determine the protein-DNA binding sites to understand many biological processes. A transcription factor is a particular type of protein that binds to DNA and controls gene regulation in living organisms. Chromatin immunoprecipitation followed by highthroughput sequencing (ChIP-seq) is considered the gold standard in locating these binding sites and programs use to identify DNA-transcription factor binding sites are known as peak-callers. ChIP-seq data are known to exhibit considerable background noise and other biases. In this study, we propose a negative binomial model (NB), a zero-inflated Poisson model (ZIP) and a zero-inflated negative binomial model (ZINB) for peak-calling. …

Exploring The Effect Of Climate Change On Biological Systems, Nardos Sori

Chemistry & Biochemistry Theses & Dissertations

The present and potential future effect of global warming on the ecosystem has brought climate change to the forefront of scientific inquiry and discussion. For our investigation, we selected two organisms, one from cyanobacteria and one from a cereal plant to determine how climate change may impact these biological systems. The study involved understanding the physiological and adaptive responses at both the genetic and protein function levels to counteract environmental stresses. An increase in atmospheric carbon dioxide is a key factor in global climate change and can lead to alterations in ocean chemistry. Cyanobacteria are important, ancient and ubiquitous organisms …

Investigation Of The Potential For Algaenan To Produce Hydrocarbon Based Fuels From Algae By Hydrous Pyrolysis, Wassim Adel Obeid

Chemistry & Biochemistry Theses & Dissertations

The use of algae as a feedstock for hydrous pyrolysis has a high potential for producing biofuels. The non-food nature of algae in addition to the various advantages associated with the hydrous pyrolysis process makes this combination for the production of biofuels of high interest. However, current results from algae processing have alluded to some challenges: byproducts arising from the thermal transformation of carbohydrates and proteins, which become incorporated in the oil fraction, result in high oxygen and nitrogen contents of the oil. Accordingly, this produces an oil of low quality for refineries. This dissertation investigates use of a pretreatment …

Java Animated Software For Teaching The Frank-Wolfe Algorithm For Static Traffic Network Equilibrium, Zhi Li

Computational Modeling & Simulation Engineering Theses & Dissertations

The popular Frank-Wolfe (FW) algorithm for solving the network equilibrium problems plays an important role in transportation simulation. Not only has the basic Frank Wolfe algorithm been studied, but also other variations of the FW algorithm (such as Conjugate Frank Wolfe and Bi-Conjugate Frank Wolfe algorithms) have been extensively studied by the research communities.

In this work, the basic Frank Wolfe algorithm is re-visited for the purpose of developing a useful, user-friendly, and appealing Java computer animation for enhancing the teaching effectiveness of this fundamental transportation static network equilibrium algorithm. Since the shortest path (SP) algorithms (such as the well-known …

The Large Intracellular Loop Of Hzip4 Is An Intrinsically Disordered Zinc Binding Domain, Robert Dempski, Elizabeth Bafaro, Sagar Antala, Tuong-Vi Nguyen, Stephen Dzul, Brian Doyon, Timothy Stemmler

Robert E. Dempski

The human (h) ZIP4 transporter is a plasma membrane protein which functions to increase the cytosolic concentration of zinc. hZIP4 transports zinc into intestinal cells and therefore has a central role in the absorption of dietary zinc. hZIP4 has eight transmembrane domains and encodes a large intracellular loop between transmembrane domains III and IV, M3M4. Previously, it has been postulated that this domain regulates hZIP4 levels in the plasma membrane in a zinc-dependent manner. The objective of this research was to examine the zinc binding properties of the large intracellular loop of hZIP4. Therefore, we have recombinantly expressed and purified …

Crowdsourced Earthquake Early Warning, Sarah Minson, Benjamin Brooks, Craig Glennie, Jessica Murray, John Langbein, Susan Owen, Thomas Heaton, Robert Iannucci, Darren Hauser

Robert A Iannucci

Earthquake early warning (EEW) can reduce harm to people and infrastructure from earthquakes and tsunamis, but it has not been implemented in most high earthquake-risk regions because of prohibitive cost. Common consumer devices such as smartphones contain low-cost versions of the sensors used in EEW. Although less accurate than scientific-grade instruments, these sensors are globally ubiquitous. Through controlled tests of consumer devices, simulation of an Mw (moment magnitude) 7 earthquake on California’s Hayward fault, and real data from the Mw 9 Tohoku-oki earthquake, we demonstrate that EEW could be achieved via crowdsourcing.

Total Positivity For A Class Of Non-Exchangeable Copulas, Roy Cerqueti, Claudio Lupi

Claudio Lupi

A Comparison Of Student Perceptions To Actual Performance In Chemistry, Ross Hudson

Dr Ross Hudson

This research was part of a larger study into student performance in senior chemistry with regard to question type and content. This paper examines student perceptions about question type and context and compares these perceptions to actual performance. How students perceive different types of questions and how it influences their self-belief and motivation were the focus of this study. Student responses to different styles or types of questions have been well researched over time. In this study Year 11 chemistry students were quizzed about their preferences to Multiple-Choice questions and Open Response question types and how the presence of each …

Electron Penetration Range For Diverse Materials, Anne C. Starley, Lisa M. Phillipps, J. R. Dennison

Anne Starley