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Full-Text Articles in Physical Sciences and Mathematics

Concordance Of 2-Knots, Nathan Sunukjian Apr 2021

Concordance Of 2-Knots, Nathan Sunukjian

University Faculty Publications and Creative Works

In this paper we investigate the 0-concordance classes of 2-knots in S4, an equivalence relation that is related to understanding smooth structures on 4-manifolds. Using Rochlin’s invariant, and invariants arising from Heegaard–Floer homology, we will prove that there are infinitely many 0-concordance classes of 2-knots.


Meeting Potential New U.S. Climate Goals, Mei Yuan, Alexander R. Barron, Noelle Selin, Paul Picciano, Lucy E. Metz, John Reilly, Henry Jacoby Apr 2021

Meeting Potential New U.S. Climate Goals, Mei Yuan, Alexander R. Barron, Noelle Selin, Paul Picciano, Lucy E. Metz, John Reilly, Henry Jacoby

Environmental Science and Policy: Faculty Publications

We explore the performance of a potential addition to U.S. climate policy using authority under Section 115 of the Clean Air Act, with special attention to distributional effects among the states. This portion of the Act concerns trans-boundary air pollution, and under its provisions a national greenhouse target could be allocated among the states, with the details of state implementation optionally guided by a model rule as under other provisions of the Act. With trading allowed among the states, such a measure could lead to a national price on the covered gases. While we adopt features of a possible Section …


Revisiting Hudson County Water Co. V. Mccarter: Realism, The Public Trust Doctrine, And Environmental Conservation In The Lochner Era, Steven Huffman Apr 2021

Revisiting Hudson County Water Co. V. Mccarter: Realism, The Public Trust Doctrine, And Environmental Conservation In The Lochner Era, Steven Huffman

Masters Theses & Specialist Projects

Legal histories of the Gilded Age and Progressive Era tend to focus inordinately on economic regulation within a doctrinal framework in which private rights, equal protection, and “substantive” due process guided judicial decision-making. Consequently, the overarching economic context in prevailing legal historiography obscures an important yet oft-overlooked development in the linkage between public rights, natural resource trusteeship, and the early-twentieth-century environmental conservation movement. This development is inextricably tied to the evolution of water law in the late nineteenth century and the expansion of the American commercial republic. A normative understanding of public water rights during this period is confined to …


The Effect Of Environmental Context Upon Visual Distance Perception, Jessica M. Dukes Apr 2021

The Effect Of Environmental Context Upon Visual Distance Perception, Jessica M. Dukes

Masters Theses & Specialist Projects

The ability of 16 younger adults to visually perceive distances in depth was evaluated within three environmental contexts (indoors in the dark, indoors in the light, and outdoors). The observers' task was to bisect an 8m distance interval in all contexts using both monocular and binocular vision. In the outdoor environment (a natural grassy field), the observers' judgments indicated perceptual compression of farther distances similar to that obtained in many previous studies. In the indoor lighted environment (a 10.2 x 9.6m laboratory room), the observers' judgments were consistent with perceptual expansion of farther distances. Finally, there was a beneficial effect …


Statistical Study Of The Effect Of Implementing An Airveyor System On The Warpage Of Injection Molded Closures, Charles Wesley Bozarth Apr 2021

Statistical Study Of The Effect Of Implementing An Airveyor System On The Warpage Of Injection Molded Closures, Charles Wesley Bozarth

Masters Theses & Specialist Projects

Berry Global in Bowling Green, Kentucky produces predominantly polypropylene container closures. One variant, the 83mm lined jar closure, is produced by first being injection molded, placed in work-in-progress (WIP) hold for 24 hours to cool, and then finished through the auxiliary liner operation into a final product. While this process is an effective method to produce a quality large-diameter closure and allows the polypropylene adequate time to cool without warping out of shape, the 24-hour WIP time and the manpower needed to accomplish this can negatively impact several business metrics as well as employee safety.

The purpose of this thesis …


Synthesis And Catalytic Oxidation Of Organic Substrates By Light-Harvesting Metalloporphyrins, Christian Alcantar Apr 2021

Synthesis And Catalytic Oxidation Of Organic Substrates By Light-Harvesting Metalloporphyrins, Christian Alcantar

Masters Theses & Specialist Projects

note: Some notation in this abstract may not appear exactly as formatted in the thesis.

In this work, ruthenium, iron, and manganese light-harvesting metalloporphyrins have been successfully synthesized to serve as biomimetic models of the active site of Cytochrome P450 for the development of a green and efficient oxidation catalyst. The covalent introduction of light-harvesting boron-dipyrrin (BODIPY) fluorophores on the porphyrin macrocycle allows for the absorption of a broader range of visible light in addition to that captured by the porphyrin aromatic system alone. It is expected that this core-antenna system will increase the absorbed light energy and transfer it …


Buffer Overflow And Sql Injection In C++, Noah Warren Kapley Apr 2021

Buffer Overflow And Sql Injection In C++, Noah Warren Kapley

Masters Theses & Specialist Projects

Buffer overflows and SQL Injection have plagued programmers for many years. A successful buffer overflow, innocuous or not, damages a computer’s permanent memory. Safer buffer overflow programs are presented in this thesis for the C programs characterizing string concatenation, string copy, and format get string, a C program which takes input and output from a keyboard, in most cases. Safer string concatenation and string copy programs presented in this thesis require the programmer to specify the amount of storage space necessary for the program’s execution. This safety mechanism is designed to help programmers avoid over specifying the amount of storage …


Reimagining The Duck Stamp, Hunting Licensure And Public Land Preservation, Alec Wayne Boyd-Devine Apr 2021

Reimagining The Duck Stamp, Hunting Licensure And Public Land Preservation, Alec Wayne Boyd-Devine

Masters Theses & Specialist Projects

The American Migratory Bird Hunting and Conservation Stamp, or Duck Stamp, is a form of licensure issued by the Federal Government for waterfowl hunters. Why do physical stamps act as licensure to hunt waterfowl on both public and private land in the United States? How did the stamp become the key that grants access to resources that supposedly should be owned by the public? The duck stamp has been well-documented in conservation communities as a resource which has made significant positive impacts on the environment. The increase of anti-hunting sentiments in our society combined with fewer hunters per capita may …


Variable Autoencoders For Biosensor Data Augmentation, Solomon Kim Apr 2021

Variable Autoencoders For Biosensor Data Augmentation, Solomon Kim

Honors Theses

Over the past decade machine learning and artificial intelligence's resurgence spawned the desire to mimic human creative ability. Initially attempts to create images, music, and text flooded the community, though little has been learned regarding constrained, one-dimensional data generation. This paper demonstrates a variational autoencoder approach to this problem. By modeling biosensor current and concentration data we aim to augment the existing dataset. In training a multi-layer neural network based encoder and decoder we were able to generate realistic, original samples., These results demonstrate the ability to realistically augment datasets, improving training of machine learning models designed to predict concentration …


Spectator Proton Detection And Reconstruction In Deep Inelastic D(E,EpS) Scattering, David Payette Apr 2021

Spectator Proton Detection And Reconstruction In Deep Inelastic D(E,EpS) Scattering, David Payette

Physics Theses & Dissertations

A Radial Time Projection Chamber (RTPC) was designed and installed in Jefferson Lab's Hall B as part of the BONuS12 (Barely Off-shell Nucleon Structure) experiment. The goal of BONuS12 is to accurately measure the structure function of the neutron by scattering 11 GeV electrons and detecting them with the CLAS12 spectrometer. Deuterium gas was used as an effective neutron target, and the new RTPC was used to detect low- momentum spectator protons. Protons follow a curved path in the 5 Tesla solenoid that is part of CLAS12, ionizing the He-CO2 gas in an annular drift region surrounding the target. These …


Exploring Qcd Factorization At Moderate Energy Scales, Eric Alan Moffat Apr 2021

Exploring Qcd Factorization At Moderate Energy Scales, Eric Alan Moffat

Physics Theses & Dissertations

Asymptotic freedom in QCD facilitates the use of partonic degrees of freedom over short distances, but physical processes are sensitive to a wide range of scales. Thus, it is necessary in QCD calculations to utilize a factorization scheme to separate a process into perturbative and non-perturbative factors. This separation relies on an assumption that one energy scale is infinitely larger than the other scales involved in the process. However, much experimental research in areas such as nucleon structure and quark-hadron duality occur at more moderate energy scales where that basic assumption may not be true but perturbative calculations should still …


The Role Of Privacy Within The Realm Of Healthcare Wearables' Acceptance And Use, Thomas Jernejcic Apr 2021

The Role Of Privacy Within The Realm Of Healthcare Wearables' Acceptance And Use, Thomas Jernejcic

Masters Theses & Doctoral Dissertations

The flexibility and vitality of the Internet along with technological innovation have fueled an industry focused on the design of portable devices capable of supporting personal activities and wellbeing. These compute devices, known as wearables, are unique from other computers in that they are portable, specific in function, and worn or carried by the user. While there are definite benefits attributable to wearables, there are also notable risks, especially in the realm of security where personal information and/or activities are often accessible to third parties. In addition, protecting one’s private information is regularly an afterthought and thus lacking in maturity. …


The Fundamental Limit Theorem Of Countable Markov Chains, Nathanael Gentry Apr 2021

The Fundamental Limit Theorem Of Countable Markov Chains, Nathanael Gentry

Senior Honors Theses

In 1906, the Russian probabilist A.A. Markov proved that the independence of a sequence of random variables is not a necessary condition for a law of large numbers to exist on that sequence. Markov's sequences -- today known as Markov chains -- touch several deep results in dynamical systems theory and have found wide application in bibliometrics, linguistics, artificial intelligence, and statistical mechanics. After developing the appropriate background, we prove a modern formulation of the law of large numbers (fundamental theorem) for simple countable Markov chains and develop an elementary notion of ergodicity. Then, we apply these chain convergence results …


The Effectiveness Of Professional Punters, Arthur N. Tanyel Apr 2021

The Effectiveness Of Professional Punters, Arthur N. Tanyel

Senior Honors Theses

Sports analytics have become a major part of how many sports fans enjoy the games they love. The trend has touched sports from football to cricket. One aspect of football that has been less discussed is punting. The current standard metrics, gross yardage and net yardage, give an idea of how a punter performed in a given season, but they also may be skewed by a number of factors, such as the skill of the offense or the punt coverage team. In this paper, we will look at some previous attempts to measure punting prowess, and then further develop a …


Electrostatic Design And Characterization Of A 200 Kev Photogun And Wien Spin Rotator, Gabriel G. Palacios Serrano Apr 2021

Electrostatic Design And Characterization Of A 200 Kev Photogun And Wien Spin Rotator, Gabriel G. Palacios Serrano

Electrical & Computer Engineering Theses & Dissertations

High-energy nuclear physics experiments at the Jefferson Lab Continuous Electron Beam Accelerator Facility (CEBAF) require high spin-polarization electron beams produced from strained super-lattice GaAs photocathodes activated to negative electron affinity in a high voltage photogun operating at 130 kV dc. A pair of Wien filter spin rotators in the injector provides precise control of the electron beam polarization at the end station target. An upgrade of the CEBAF injector to better support the upcoming Moller experiment requires increasing the electron beam energy to 200 keV, resulting in better transmission through injector apertures and improved photocathode lifetime. In addition, the energy …


Commissioning & Characterization Of Magnetized Gridded Thermionic Electron Source, Mark Stefani Apr 2021

Commissioning & Characterization Of Magnetized Gridded Thermionic Electron Source, Mark Stefani

Electrical & Computer Engineering Theses & Dissertations

Collaborative efforts to design and fabricate a magnetized gridded thermionic electron source have been conducted between Xelera and Jefferson Lab. Commissioning and characterization of an electron gun fabricated by Xelera was performed to benchmark the viability of future electron source designs and capabilities. The work involved simulation, installation, trouble-shooting, modifications of the design, commissioning, characterization, and magnetization of the electron beam produced. A specially designed cavity as well as novel diagnostic tools and methods were developed, implemented, and experimentally tested. Finally, the gun was used to demonstrate a previously unachieved current of magnetized electron beam from a gridded thermionic source …


Weakly Supervised Segmentation Via Instance-Aware Propagation, Huang Xin, Qianshu Zhu, Yongtuo Liu, Shengfeng He Apr 2021

Weakly Supervised Segmentation Via Instance-Aware Propagation, Huang Xin, Qianshu Zhu, Yongtuo Liu, Shengfeng He

Research Collection School Of Computing and Information Systems

Peak Response Map (PRM) highlighting the discriminative regions can be extracted from a pre-trained classification network. We can accurately localize instances of each class with the help of these response maps. However, these maps cannot provide reliable information for segmentation even with off-the-shelf object proposals. This is because neither PRM nor the proposals know which regions can be regarded as a complete instance. In this paper, we tackle this problem by proposing an Instance-aware Cue propagation Network (ICN) with a new proposal-matching strategy. In particular, the ICN aims to filter out background distractions and cover the complete instance, while our …


Privacyprimer: Towards Privacy-Preserving Episodic Memory Support For Older Adults, Thivya Kandappu, Vigneshwaran Subbaraju, Qianli Xu Apr 2021

Privacyprimer: Towards Privacy-Preserving Episodic Memory Support For Older Adults, Thivya Kandappu, Vigneshwaran Subbaraju, Qianli Xu

Research Collection School Of Computing and Information Systems

Built-in pervasive cameras have become an integral part of mobile/wearable devices and enabled a wide range of ubiquitous applications with their ability to be "always-on". In particular, life-logging has been identified as a means to enhance the quality of life of older adults by allowing them to reminisce about their own life experiences. However, the sensitive images captured by the cameras threaten individuals' right to have private social lives and raise concerns about privacy and security in the physical world. This threat gets worse when image recognition technologies can link images to people, scenes, and objects, hence, implicitly and unexpectedly …


Enconter: Entity Constrained Progressive Sequence Generation Via Insertion-Based Transformer, Lee Hsun Hsieh, Yang Yin Lee, Ee-Peng Lim Apr 2021

Enconter: Entity Constrained Progressive Sequence Generation Via Insertion-Based Transformer, Lee Hsun Hsieh, Yang Yin Lee, Ee-Peng Lim

Research Collection School Of Computing and Information Systems

Pretrained using large amount of data, autoregressive language models are able to generate high quality sequences. However, these models do not perform well under hard lexical constraints as they lack fine control of content generation process. Progressive insertion-based transformers can overcome the above limitation and efficiently generate a sequence in parallel given some input tokens as constraint. These transformers however may fail to support hard lexical constraints as their generation process is more likely to terminate prematurely. The paper analyses such early termination problems and proposes the ENtity-CONstrained insertion TransformER (ENCONTER), a new insertion transformer that addresses the above pitfall …


Practical Server-Side Wifi-Based Indoor Localization: Addressing Cardinality & Outlier Challenges For Improved Occupancy Estimation, Anuradha Ravi, Archan Misra Apr 2021

Practical Server-Side Wifi-Based Indoor Localization: Addressing Cardinality & Outlier Challenges For Improved Occupancy Estimation, Anuradha Ravi, Archan Misra

Research Collection School Of Computing and Information Systems

Server-side WiFi-based indoor localization offers a compelling approach for passive occupancy estimation (i.e., without requiring active participation by client devices, such as smartphones carried by visitors), but is known to suffer from median error of 6–8 meters. By analyzing the characteristics of an operationally-deployed, WiFi-based passive indoor location system, based on the classical RADAR algorithm, we identify and tackle 2 practical challenges for accurate individual device localization. The first challenge is the low-cardinality issue, whereby only the associated AP generates sufficiently frequent RSSI reports, causing a client to experience large localization error due to the absence of sufficient measurements from …


Efficient Retrieval Of Matrix Factorization-Based Top-K Recommendations: A Survey Of Recent Approaches, Duy Dung Le, Hady W. Lauw Apr 2021

Efficient Retrieval Of Matrix Factorization-Based Top-K Recommendations: A Survey Of Recent Approaches, Duy Dung Le, Hady W. Lauw

Research Collection School Of Computing and Information Systems

Top-k recommendation seeks to deliver a personalized list of k items to each individual user. An established methodology in the literature based on matrix factorization (MF), which usually represents users and items as vectors in low-dimensional space, is an effective approach to recommender systems, thanks to its superior performance in terms of recommendation quality and scalability. A typical matrix factorization recommender system has two main phases: preference elicitation and recommendation retrieval. The former analyzes user-generated data to learn user preferences and item characteristics in the form of latent feature vectors, whereas the latter ranks the candidate items based on the …


Dismastd: An Efficient Distributed Multi-Aspect Streaming Tensor Decomposition, Keyu Yang, Yunjun Gao, Yifeng Shen, Baihua Zheng, Lu Chen Apr 2021

Dismastd: An Efficient Distributed Multi-Aspect Streaming Tensor Decomposition, Keyu Yang, Yunjun Gao, Yifeng Shen, Baihua Zheng, Lu Chen

Research Collection School Of Computing and Information Systems

Tensor decomposition is a fundamental multidimensional data analysis tool for many data-driven applications, such as social computing, computer vision, and bioinformatics, to name but a few. However, the rapidly increasing streaming data nowadays introduces new challenges to traditional static tensor decomposition. It requires an efficient distributed dynamic tensor decomposition without re-computing the whole tensor from scratch. In this paper, we propose DisMASTD, an efficient distributed multi-aspect streaming tensor decomposition. First, we prove the optimal tensor partitioning problem is NP-hard. Second, we present two heuristic tensor partitioning approaches to ensure the load balancing. Third, we develop a distributed multi-aspect streaming tensor …


Newslink: Empowering Intuitive News Search With Knowledge Graphs, Yueji Yang, Yuchen Li, Anthony Tung Apr 2021

Newslink: Empowering Intuitive News Search With Knowledge Graphs, Yueji Yang, Yuchen Li, Anthony Tung

Research Collection School Of Computing and Information Systems

News search tools help end users to identify relevant news stories. However, existing search approaches often carry out in a "black-box" process. There is little intuition that helps users understand how the results are related to the query. In this paper, we propose a novel news search framework, called NEWSLINK, to empower intuitive news search by using relationship paths discovered from open Knowledge Graphs (KGs). Specifically, NEWSLINK embeds both a query and news documents to subgraphs, called subgraph embeddings, in the KG. Their embeddings' overlap induces relationship paths between the involving entities. Two major advantages are obtained by incorporating subgraph …


Digital Sustainability And Its Implications For Finance And Climate Change, Gerard George, Simon J.D. Schillebeeckx Apr 2021

Digital Sustainability And Its Implications For Finance And Climate Change, Gerard George, Simon J.D. Schillebeeckx

Research Collection Lee Kong Chian School Of Business

As the pandemic forced the entire world to a virtual standstill, nature revived a little. The US emitted 10.3% less CO2 in 2020 than in 2019 and other regions similarly experienced emission declines. Depending on the source, global carbon emissions were down between 4 and 8% in 2020.2 Consumers globally have expressed more concern about sustainability, an observation confirmed by large survey research by Accenture, Kantar, Boston Consulting Group (BCG), and Ipsos.3 In its latest Emissions Gap Report4 , the UN Environment Programme (UNEP) explicitly connected the pandemic to climate change, nature loss, and pollution. Besides the acceleration of business …


Tackling Regional Climate Change And Food Security Issues: An Introduction, Md. Saidul Islam, Edson Kieu Apr 2021

Tackling Regional Climate Change And Food Security Issues: An Introduction, Md. Saidul Islam, Edson Kieu

Research Collection Lee Kong Chian School Of Business

Regional organizations are central to effectively addressing the current and future impacts of climate change and food security issues. Climate change and food security issues can only be dealt with through extensive policies that adopt a multi-sector, multi-stakeholder approach. An examination of three regional organizations (the Association of Southeast Asian Nations, the Pacific Islands Forum, and the South Asian Association for Regional Cooperation) can provide new insights into current climate change mitigation policies that will ensure food security for future generations. This opening chapter thus begins with the premise that regional organizations are optimally positioned to address climate change and …


Expanding The Use Of Natural And Nature-Based Infrastructure To Enhance Coastal Resiliency, Marcia Berman, Pamela Mason, Jessica Hendricks, Tamia Rudnicky Apr 2021

Expanding The Use Of Natural And Nature-Based Infrastructure To Enhance Coastal Resiliency, Marcia Berman, Pamela Mason, Jessica Hendricks, Tamia Rudnicky

Reports

The vulnerability of coastal communities and the growing risks of coastal infrastructure continue largely due to past and ongoing patterns of development in high risk areas. This project is focused on increasing the use of natural and nature-based features (NNBFs) to increase resilience of coastal communities to flooding caused by extreme weather events.


Cybersecurity Risk Assessment Using Graph Theoretical Anomaly Detection And Machine Learning, Goksel Kucukkaya Apr 2021

Cybersecurity Risk Assessment Using Graph Theoretical Anomaly Detection And Machine Learning, Goksel Kucukkaya

Engineering Management & Systems Engineering Theses & Dissertations

The cyber domain is a great business enabler providing many types of enterprises new opportunities such as scaling up services, obtaining customer insights, identifying end-user profiles, sharing data, and expanding to new communities. However, the cyber domain also comes with its own set of risks. Cybersecurity risk assessment helps enterprises explore these new opportunities and, at the same time, proportionately manage the risks by establishing cyber situational awareness and identifying potential consequences. Anomaly detection is a mechanism to enable situational awareness in the cyber domain. However, anomaly detection also requires one of the most extensive sets of data and features …


A New Method For Estimating The Physical Characteristics Of Martian Dust Devils, Shelly Cahoon Mann Apr 2021

A New Method For Estimating The Physical Characteristics Of Martian Dust Devils, Shelly Cahoon Mann

Mechanical & Aerospace Engineering Theses & Dissertations

Critical to the future exploration of Mars is having a detailed understanding of the atmospheric environment and its potential dangers. The dust devil is one of these potential dangers. The transport of dust through saltation is believed to be the driving mechanism responsible for Martian weather patterns. The two primary mechanisms for dust transport are dust storms and dust devils. Dust devils on Mars are a frequent occurrence with one in five so called giant dust devils being large enough to leave scars on the surface that are visible from space. Due to the thin atmosphere, winds of 60 mph …


Evaluating The Role Of The Stringent Response Mechanism In Clostridioides Difficile Survival And Pathogenesis, Astha Pokhrel Apr 2021

Evaluating The Role Of The Stringent Response Mechanism In Clostridioides Difficile Survival And Pathogenesis, Astha Pokhrel

Chemistry & Biochemistry Theses & Dissertations

The human pathogen Clostridioides difficile is increasingly tolerant of multiple antibiotics and causes infections with a high rate of recurrence, creating an urgent need for new preventive and therapeutic strategies. The stringent response, a universal bacterial response to extracellular stresses, governs antibiotic survival and pathogenesis in diverse organisms but has not previously been characterized in C. difficile. This dissertation explores the ability of C. difficile to mount the stringent response. The bacteria encode a full-length, canonical bifunctional Rel/Spo Homolog or RSH enzyme. C. difficile RSH is incapable of utilizing GTP as a substrate but readily synthesizes putative 5’-pGpp-3’ alarmones. …


Biophysical And Structural Studies On Telomeric G-Quadruplexes From Tetrahymena Thermophila, Dana Beseiso , '21 Apr 2021

Biophysical And Structural Studies On Telomeric G-Quadruplexes From Tetrahymena Thermophila, Dana Beseiso , '21

Senior Theses, Projects, and Awards

G-quadruplexes (GQs) are non-canonical DNA structures composed of stacks of stabilized guanine tetrads (G-tetrads). GQs are highly diverse structures that can be categorized by their strand directionality, number of G-tetrads, and loop types among other parameters. Due to their high guanine content, GQs are expected to fold in regions such as telomers or oncogene promoters. They are thus firmly established as biologically viable targets for the development of anticancer therapeutics. In order to harvest GQs’ therapeutic potential, extensive structural studies are required to elucidate the structures’ diverse topologies alone and in complex with selective ligands. Towards this goal, this thesis …