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Articles 26161 - 26190 of 302581

Full-Text Articles in Physical Sciences and Mathematics

Analytic Case Study Using Unsupervised Event Detection In Multivariate Time Series Data, Jeremy M. Wightman Sep 2022

Analytic Case Study Using Unsupervised Event Detection In Multivariate Time Series Data, Jeremy M. Wightman

Theses and Dissertations

Analysis of cyber-physical systems (CPS) has emerged as a critical domain for providing US Air Force and Space Force leadership decision advantage in air, space, and cyberspace. Legacy methods have been outpaced by evolving battlespaces and global peer-level challengers. Automation provides one way to decrease the time that analysis currently takes. This thesis presents an event detection automation system (EDAS) which utilizes deep learning models, distance metrics, and static thresholding to detect events. The EDAS automation is evaluated with case study of CPS domain experts in two parts. Part 1 uses the current methods for CPS analysis with a qualitative …


Ecological Homogenization Of Oil Properties In The American Residential Macrosystem, Christopher D. Ryan, Peter M. Groffman, J. Morgan Grove, Sharon J. Hall, James B. Heffernan, Sarah E. Hobbie, Dexter H. Locke, Jennifer L. Morse, Rinku Roy Chowdhury, Tara Trammell, Multiple Additional Authors Sep 2022

Ecological Homogenization Of Oil Properties In The American Residential Macrosystem, Christopher D. Ryan, Peter M. Groffman, J. Morgan Grove, Sharon J. Hall, James B. Heffernan, Sarah E. Hobbie, Dexter H. Locke, Jennifer L. Morse, Rinku Roy Chowdhury, Tara Trammell, Multiple Additional Authors

Environmental Science and Management Faculty Publications and Presentations

The conversion of native ecosystems to residential ecosystems dominated by lawns has been a prevailing land-use change in the United States over the past 70 years. Similar development patterns and management of residential ecosystems cause many characteristics of residential ecosystems to be more similar to each other across broad continental gradients than that of former native ecosystems. For instance, similar lawn management by irrigation and fertilizer applications has the potential to influence soil carbon (C) and nitrogen (N) pools and processes. We evaluated the mean and variability of total soil C and N stocks, potential net N mineralization and nitrification, …


Jammed Solids With Pins: Thresholds, Force Networks, And Elasticity, Andy L. Zhang , '22, S. A. Ridout, Celia Parts , '22, Aarushi Sachdeva , '24, Cacey Stevens Bester, K. Vollmayr-Lee, B. C. Utter, T. Brzinski, Amy Lisa Graves Sep 2022

Jammed Solids With Pins: Thresholds, Force Networks, And Elasticity, Andy L. Zhang , '22, S. A. Ridout, Celia Parts , '22, Aarushi Sachdeva , '24, Cacey Stevens Bester, K. Vollmayr-Lee, B. C. Utter, T. Brzinski, Amy Lisa Graves

Physics & Astronomy Faculty Works

The role of fixed degrees of freedom in soft or granular matter systems has broad applicability and theoretical interest. Here we address questions of the geometrical role that a scaffolding of fixed particles plays in tuning the threshold volume fraction and force network in the vicinity of jamming. Our two-dimensional simulated system consists of soft particles and fixed “pins,” both of which harmonically repel overlaps. On the one hand, we find that many of the critical scalings associated with jamming in the absence of pins continue to hold in the presence of even dense pin latices. On the other hand, …


Gj 3090 B: One Of The Most Favourable Mini-Neptune For Atmospheric Characterisation, J. M. Almenara, X. Bonfils, J. F. Otegi, O. Attia, M. Turbet, N. Astudillo-Defru, K. A. Collins, A. S. Polanski, V. Bourrier, C. Hellier, C. Ziegler, F. Bouchy, C. Briceno, D. Charbonneau, M. Cointepas, K. I. Collins, I. Crossfield, X. Delfosse, R. F. Diaz, C. Dorn, J. P. Doty, T. Forveille, G. Gaisné, T. Gan, R. Helled, K. Hesse, J. M. Jenkins, Eric L.N. Jensen, D. W. Latham, N. Law, A. W. Mann, S. Mao, B. Mclean, F. Murgas, G. Myers, S. Seager, A. Shporer, T. G. Tan, J. D. Twicken, J. Winn Sep 2022

Gj 3090 B: One Of The Most Favourable Mini-Neptune For Atmospheric Characterisation, J. M. Almenara, X. Bonfils, J. F. Otegi, O. Attia, M. Turbet, N. Astudillo-Defru, K. A. Collins, A. S. Polanski, V. Bourrier, C. Hellier, C. Ziegler, F. Bouchy, C. Briceno, D. Charbonneau, M. Cointepas, K. I. Collins, I. Crossfield, X. Delfosse, R. F. Diaz, C. Dorn, J. P. Doty, T. Forveille, G. Gaisné, T. Gan, R. Helled, K. Hesse, J. M. Jenkins, Eric L.N. Jensen, D. W. Latham, N. Law, A. W. Mann, S. Mao, B. Mclean, F. Murgas, G. Myers, S. Seager, A. Shporer, T. G. Tan, J. D. Twicken, J. Winn

Physics & Astronomy Faculty Works

We report the detection of GJ 3090 b (TOI-177.01), a mini-Neptune on a 2.9-day orbit transiting a bright (K = 7.3 mag) M2 dwarf located at 22 pc. The planet was identified by the Transiting Exoplanet Survey Satellite and was confirmed with the High Accuracy Radial velocity Planet Searcher radial velocities. Seeing-limited photometry and speckle imaging rule out nearby eclipsing binaries. Additional transits were observed with the LCOGT, Spitzer, and ExTrA telescopes. We characterise the star to have a mass of 0.519 ± 0.013 M and a radius of 0.516 ± 0.016 R. We modelled …


Fundamental Neutron Physics At Spallation Sources, Nadia Fomin, Jason Fry, Robert W. Pattie Jr., Geoffrey L. Greene Sep 2022

Fundamental Neutron Physics At Spallation Sources, Nadia Fomin, Jason Fry, Robert W. Pattie Jr., Geoffrey L. Greene

EKU Faculty and Staff Scholarship

Low-energy neutrons have been a useful probe in fundamental physics studies for more than 70 years. With advances in accelerator technology, many new sources are spallation based. These new, high-flux facilities are becoming the sites for many next-generation fundamental neutron physics experiments. In this review, we present an overview of the sources and the current and upcoming fundamental neutron physics programs.


Finite Gaussian Neurons: Defending Against Adversarial Attacks By Making Neural Networks Say "I Don’T Know", Felix Grezes Sep 2022

Finite Gaussian Neurons: Defending Against Adversarial Attacks By Making Neural Networks Say "I Don’T Know", Felix Grezes

Dissertations, Theses, and Capstone Projects

In this work, I introduce the Finite Gaussian Neuron (FGN), a novel neuron architecture for artificial neural networks aimed at protecting against adversarial attacks.
Since 2014, artificial neural networks have been known to be vulnerable to adversarial attacks, which can fool the network into producing wrong or nonsensical outputs by making humanly imperceptible alterations to inputs. While defenses against adversarial attacks have been proposed, they usually involve retraining a new neural network from scratch, a costly task.

My works aims to:
- easily convert existing models to Finite Gaussian Neuron architecture,
- while preserving the existing model's behavior on real …


Pulsed Electroacoustic Measurements Of Polymers Irradiated With Low Energy Monoenergetic Electrons, Zachary Gibson, Jr Dennison Sep 2022

Pulsed Electroacoustic Measurements Of Polymers Irradiated With Low Energy Monoenergetic Electrons, Zachary Gibson, Jr Dennison

Physics Student Research

Understanding the dynamics and accumulation of embedded charge in dielectric materials is paramount for many applications from HVDC power transmission to spacecraft charging. The pulsed electroacoustic (PEA) method allows for nondestructive measurements of embedded charge distributions in dielectrics. The spatial resolution of PEA measurements are typically ~10 μm. However, some of the most deleterious spacecraft charging events result from electron fluxes with 10 keV to 50 keV energies, resulting in electron ranges of 1's to 10's of μm. Due to the resolution of the PEA method and the superposition of the interfacial charge with the deposited charge distribution, it is …


How Many Mutex Bugs Can A Simple Analysis Find In Go Programs?, Fumi Takeuchi, Hidehiko Masuhara, Raffi T. Khatchadourian, Youyou Cong, Keisuke Ishibashi Sep 2022

How Many Mutex Bugs Can A Simple Analysis Find In Go Programs?, Fumi Takeuchi, Hidehiko Masuhara, Raffi T. Khatchadourian, Youyou Cong, Keisuke Ishibashi

Publications and Research

In open-source software, it is known that there are many concurrency bugs. A previous study in Go revealed that a considerable number of such bugs are simple (for example, 9% of the bugs are the ones that forget to unlock a mutex,) through a manual program investigation. This paper tries to detect such bugs by applying a simple analysis to see how far such a tool can match the manual analysis. We built a simple intraprocedural control flow analysis in Go, and evaluated its performance concerning the open source programs with concurrency bugs reported in the previous study. Consequently, as …


Advanced Glycation End Products In Health And Disease, V. Prakash Reddy, Puspa Aryal, Emmanuel K. Darkwah Sep 2022

Advanced Glycation End Products In Health And Disease, V. Prakash Reddy, Puspa Aryal, Emmanuel K. Darkwah

Chemistry Faculty Research & Creative Works

Advanced glycation end products (AGEs), formed through the nonenzymatic reaction of reducing sugars with the side-chain amino groups of lysine or arginine of proteins, followed by further glycoxidation reactions under oxidative stress conditions, are involved in the onset and exacerbation of a variety of diseases, including diabetes, atherosclerosis, and Alzheimer's disease (AD) as well as in the secondary stages of traumatic brain injury (TBI). AGEs, in the form of intra- and interprotein crosslinks, deactivate various enzymes, exacerbating disease progression. The interactions of AGEs with the receptors for the AGEs (RAGE) also result in further downstream inflammatory cascade events. The overexpression …


Statistical Inference On Desirability Function Optimal Points To Evaluate Multi-Objective Response Surfaces, Peter A. Calhoun Sep 2022

Statistical Inference On Desirability Function Optimal Points To Evaluate Multi-Objective Response Surfaces, Peter A. Calhoun

Theses and Dissertations

A shortfall of the Derringer and Suich (1980) desirability function is lack of inferential methods to quantify uncertainty. Most articles for addressing uncertainty usually involve robust methods, providing a point estimate that is less affected by variation. Few articles address confidence intervals or bands but not specifically for the Derringer and Suich method. This research provides two valuable contributions to the field of response surface methodology. The first contribution is evaluating the effect of correlation and plane angles on Derringer and Suich optimal solutions. The second contribution proposes and compares 8 inferential methods--both univariate and multivariate--for creating confidence intervals on …


Using Deep Learning To Detect Social Media ‘Trolls’, Áine Macdermott, Michal Motylinski, Farkhund Iqbal, Kellyann Stamp, Mohammed Hussain, Andrew Marrington Sep 2022

Using Deep Learning To Detect Social Media ‘Trolls’, Áine Macdermott, Michal Motylinski, Farkhund Iqbal, Kellyann Stamp, Mohammed Hussain, Andrew Marrington

All Works

Detecting criminal activity online is not a new concept but how it can occur is changing. Technology and the influx of social media applications and platforms has a vital part to play in this changing landscape. As such, we observe an increasing problem with cyber abuse and ‘trolling’/toxicity amongst social media platforms sharing stories, posts, memes sharing content. In this paper we present our work into the application of deep learning techniques for the detection of ‘trolls’ and toxic content shared on social media platforms. We propose a machine learning solution for the detection of toxic images based on embedded …


Forensic Investigation Of Google Meet For Memory And Browser Artifacts, Farkhund Iqbal, Zainab Khalid, Andrew Marrington, Babar Shah, Patrick C.K. Hung Sep 2022

Forensic Investigation Of Google Meet For Memory And Browser Artifacts, Farkhund Iqbal, Zainab Khalid, Andrew Marrington, Babar Shah, Patrick C.K. Hung

All Works

Web applications have experienced a widespread adaptation owing to the agile Service Oriented Architecture (SOA) reflecting the ever-changing software needs of users. Google Meet is one of the top video conferencing applications, especially in the post-COVID19 era. Security and privacy concerns are therefore critical. This paper presents an extensive digital forensic analysis of Google Meet running on multiple browsers and software platforms including Google Chrome, Mozilla Firefox, and Microsoft Edge browsers in Windows 10 and Linux. Artifacts, traces of potential evidence, are extracted from different locations on a client's desktop, including the memory and browser. These include meeting records, communication …


Generalization Of Bi-Canonical Degrees, Joseph Brennan, Laura Ghezzi, Jooyoun Hong, Wolmer Vasconcelos Sep 2022

Generalization Of Bi-Canonical Degrees, Joseph Brennan, Laura Ghezzi, Jooyoun Hong, Wolmer Vasconcelos

Publications and Research

We discuss invariants of Cohen-Macaulay local rings that admit a canonical module ω. Attached to each such ring R, when ω is an ideal, there are integers–the type of R, the reduction number of ω–that provide valuable metrics to express the deviation of R from being a Gorenstein ring. In (Ghezzi et al. in JMS 589:506–528, 2017) and (Ghezzi et al. in JMS 571:55–74, 2021) we enlarged this list with the canonical degree and the bi-canonical degree. In this work we extend the bi-canonical degree to rings where ω is not necessarily an ideal. We also discuss generalizations to rings …


Improving Country Conflict And Peace Modeling: Datasets, Imputations, And Hierarchical Clustering, Benjamin D. Leiby Sep 2022

Improving Country Conflict And Peace Modeling: Datasets, Imputations, And Hierarchical Clustering, Benjamin D. Leiby

Theses and Dissertations

Many disparate datasets exist that provide country attributes covering political, economic, and social aspects. Unfortunately, this data often does not include all countries nor is the data complete for those countries included, as measured by the dataset’s missingness. This research addresses these dataset shortfalls in predicting country instability by considering country attributes in all aspects as well as in greater thresholds of missingness. First, a structured summary of past research is presented framed by a developed casual taxonomy and functional ontology. Additionally, a novel imputation technique for very large datasets is presented to account for moderate missingness in the expanded …


Acid Mine Drainage In The Shamokin Creek Watershed: A Spatial Analysis Of Economic And Environmental Consequences Of Coal Mining, Ben Shimer Sep 2022

Acid Mine Drainage In The Shamokin Creek Watershed: A Spatial Analysis Of Economic And Environmental Consequences Of Coal Mining, Ben Shimer

Student Project Reports

No abstract provided.


Towards Explaining Variation In Entrainment, Andreas Weise Sep 2022

Towards Explaining Variation In Entrainment, Andreas Weise

Dissertations, Theses, and Capstone Projects

Entrainment refers to the tendency of human speakers to adapt to their interlocutors to become more similar to them. This affects various dimensions and occurs in many contexts, allowing for rich applications in human-computer interaction. However, it is not exhibited by every speaker in every conversation but varies widely across features, speakers, and contexts, hindering broad application. This variation, whose guiding principles are poorly understood even after decades of entrainment research, is the subject of this thesis. We begin with a comprehensive literature review that serves as the foundation of our own work and provides a reference to guide future …


Asymptotic Classes, Pseudofinite Cardinality And Dimension, Alexander Van Abel Sep 2022

Asymptotic Classes, Pseudofinite Cardinality And Dimension, Alexander Van Abel

Dissertations, Theses, and Capstone Projects

We explore the consequences of various model-theoretic tameness conditions upon the behavior of pseudofinite cardinality and dimension. We show that for pseudofinite theories which are either Morley Rank 1 or uncountably categorical, pseudofinite cardinality in ultraproducts satisfying such theories is highly well-behaved. On the other hand, it has been shown that pseudofinite dimension is not necessarily well-behaved in all ultraproducts of theories which are simple or supersimple; we extend such an observation by constructing simple and supersimple theories in which pseudofinite dimension is necessarily ill-behaved in all such ultraproducts. Additionally, we have novel results connecting various forms of asymptotic classes …


2022-2023 Impact Series - Environmental Awareness Resource Guide, Amy An Sep 2022

2022-2023 Impact Series - Environmental Awareness Resource Guide, Amy An

Impact Series Study Guides

Environmental Awareness Impact Series Resource Guide: A guide to Impact Series events and the topic of environmental awareness.


Invariance Explains Empirical Success Of Many Intelligent Techniques, Olga Kosheleva, Vladik Kreinovich Sep 2022

Invariance Explains Empirical Success Of Many Intelligent Techniques, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

In many applications of intelligent computing, we need to choose an appropriate function -- e.g., an appropriate re-scaling function, or an appropriate aggregation function. In applications of intelligent techniques, the problem of selecting an optimal function is usually too complex or too imprecise to be solved analytically, so the best functions are found empirically, by trying a large number of alternatives. In this paper, we show that in many such cases, the resulting empirical choice can be explained by natural invariance ideas. Example range from applications to building blocks of intelligent techniques -- such as aggregation (including hierarchical aggregation) and …


Monarch Science Observer, Volume 15, College Of Sciences, Old Dominion University Sep 2022

Monarch Science Observer, Volume 15, College Of Sciences, Old Dominion University

College of Sciences Newsletter

Fall 2022, issue of Monarch Science Observer, ODU Colleges of Sciences Newsletter.


A Gpu-Based Machine Learning Approach For Detection Of Botnet Attacks, Michal Motylinski, Áine Macdermott, Farkhund Iqbal, Babar Shah Sep 2022

A Gpu-Based Machine Learning Approach For Detection Of Botnet Attacks, Michal Motylinski, Áine Macdermott, Farkhund Iqbal, Babar Shah

All Works

Rapid development and adaptation of the Internet of Things (IoT) has created new problems for securing these interconnected devices and networks. There are hundreds of thousands of IoT devices with underlying security vulnerabilities, such as insufficient device authentication/authorisation making them vulnerable to malware infection. IoT botnets are designed to grow and compete with one another over unsecure devices and networks. Once infected, the device will monitor a Command-and-Control (C&C) server indicating the target of an attack via Distributed Denial of Service (DDoS) attack. These security issues, coupled with the continued growth of IoT, presents a much larger attack surface for …


A Conical-Beam Dual-Band Double Aperture-Coupled Stacked Elliptical Patch Antenna Design For 5g, Feza Turgay Çeli̇k, Kami̇l Karaçuha Sep 2022

A Conical-Beam Dual-Band Double Aperture-Coupled Stacked Elliptical Patch Antenna Design For 5g, Feza Turgay Çeli̇k, Kami̇l Karaçuha

Turkish Journal of Electrical Engineering and Computer Sciences

This study investigates a dual-band, aperture coupled and stacked elliptical patch antenna with conical radiation. To obtain such characteristics, the TM21 mode of the radiating elliptical patches is excited by utilizing two special apertures and shorting planes. The proposed antenna operates both at 2.45 GHz and 3.5 GHz. The design aims to be used indoor applications of 5G operating in both free and planned 5G bands, respectively. Therefore, the low-profile antenna element that has a monopole-like radiation pattern is a good candidate for two-dimensional arraying. The design steps and the evolution of the proposed antenna are presented in detail. The …


Largeea: Aligning Entities For Large-Scale Knowledge Graphs, Congcong Ge, Xiaoze Liu, Lu Chen, Yunjun Gao, Baihua Zheng Sep 2022

Largeea: Aligning Entities For Large-Scale Knowledge Graphs, Congcong Ge, Xiaoze Liu, Lu Chen, Yunjun Gao, Baihua Zheng

Research Collection School Of Computing and Information Systems

Entity alignment (EA) aims to find equivalent entities in different knowledge graphs (KGs). Current EA approaches suffer from scalability issues, limiting their usage in real-world EA scenarios. To tackle this challenge, we propose LargeEA to align entities between large-scale KGs. LargeEA consists of two channels, i.e., structure channel and name channel. For the structure channel, we present METIS-CPS, a memory-saving mini-batch generation strategy, to partition large KGs into smaller mini-batches. LargeEA, designed as a general tool, can adopt any existing EA approach to learn entities’ structural features within each mini-batch independently. For the name channel, we first introduce NFF, a …


Robustness And Cross-Lingual Transfer: An Exploration Of Out-Of-Distribution Scenario In Natural Language Processing, Yu, Sicheng Sep 2022

Robustness And Cross-Lingual Transfer: An Exploration Of Out-Of-Distribution Scenario In Natural Language Processing, Yu, Sicheng

Dissertations and Theses Collection (Open Access)

Most traditional machine learning or deep learning methods are based on the premise that training data and test data are independent and identical distributed, i.e., IID. However, it is just an ideal situation. In real-world applications, test set and training data often follow different distributions, which we refer to as the out of distribution, i.e., OOD, setting. As a result, models trained with traditional methods always suffer from an undesirable performance drop on the OOD test set. It's necessary to develop techniques to solve this problem for real applications. In this dissertation, we present four pieces of work in the …


User Guided Abductive Proof Generation For Answer Set Programming Queries, Avishkar Mahajan, Martin Strecker, Meng Weng (Huang Mingrong) Wong Sep 2022

User Guided Abductive Proof Generation For Answer Set Programming Queries, Avishkar Mahajan, Martin Strecker, Meng Weng (Huang Mingrong) Wong

Research Collection Yong Pung How School Of Law

We present a method for generating possible proofs of a query with respect to a given Answer Set Programming (ASP) rule set using an abductive process where the space of abducibles is automatically constructed just from the input rules alone. Given a (possibly empty) set of user provided facts, our method infers any additional facts that may be needed for the entailment of a query and then outputs these extra facts, without the user needing to explicitly specify the space of all abducibles. We also present a method to generate a set of directed edges corresponding to the justification graph …


Evidence Of Likely Autochthonous Chagas Disease In The Southwestern United States: A Case Series Of Trypanosoma Cruzi Seropositive Blood Donors, Mary K. Lynn, Kyndall C. Dye-Braumuller, Norman L. Beatty, Patricia L. Dorn, Stephen A. Klotz, Susan L. Stramer, Rebecca L. Townsend, Hany Kamel, Jacquelyn M. Vannoy, Patrick Sadler, Susan P. Montgomery, Hilda N. Rivera, Melissa Nolan Ph.D., Mph Sep 2022

Evidence Of Likely Autochthonous Chagas Disease In The Southwestern United States: A Case Series Of Trypanosoma Cruzi Seropositive Blood Donors, Mary K. Lynn, Kyndall C. Dye-Braumuller, Norman L. Beatty, Patricia L. Dorn, Stephen A. Klotz, Susan L. Stramer, Rebecca L. Townsend, Hany Kamel, Jacquelyn M. Vannoy, Patrick Sadler, Susan P. Montgomery, Hilda N. Rivera, Melissa Nolan Ph.D., Mph

Faculty Publications

Background Chagas disease is a parasitic infection that can insidiously cause non-ischemic cardiomyopathy. Given the largely silent nature of this progressive disease, asymptomatic blood donors pose potential blood transfusion risk. Blood donation screening has become an unintentional form of Chagas disease surveillance, with thousands of new cases identified since national surveillance was initiated in 2007.

Study Design and Methods We recruited T. cruzi-positive blood donors identified from California and Arizona blood centers for confirmatory blood screening and assessment of lifetime infection risk.

Results Among eight suspected cases, we identified four confirmed US autochthonous infections. The current manuscript details the …


The Jwst Early Release Science Program For The Direct Imaging And Spectroscopy Of Exoplanetary Systems, Sasha Hinkley, Aarynn L. Carter, Shrishmoy Ray, Andrew Skemer, Beth Biller, Elodie Choquet, Maxwell A. Millar-Blanchaer, Stephanie Sallum, Brittany Miles, Niall Whiteford, Polychronis Patapis, Marshall Perrin, Laurent Pueyo, Glenn Schneider, Karl Stapelfeldt, Jason Wang, Kimberly Ward-Duong, Brendan P. Bowler, Anthony Boccaletti, Julien H. Girard, Dean Hines, Paul Kalas, Jens Kammerer, Pierre Kervella, Jarron Leisenring, Eric Pantin, Yifan Zhou, Michael Meyer, Michael C. Liu, Mickael Bonnefoy, Thayne Currie, Michael Mcelwain Sep 2022

The Jwst Early Release Science Program For The Direct Imaging And Spectroscopy Of Exoplanetary Systems, Sasha Hinkley, Aarynn L. Carter, Shrishmoy Ray, Andrew Skemer, Beth Biller, Elodie Choquet, Maxwell A. Millar-Blanchaer, Stephanie Sallum, Brittany Miles, Niall Whiteford, Polychronis Patapis, Marshall Perrin, Laurent Pueyo, Glenn Schneider, Karl Stapelfeldt, Jason Wang, Kimberly Ward-Duong, Brendan P. Bowler, Anthony Boccaletti, Julien H. Girard, Dean Hines, Paul Kalas, Jens Kammerer, Pierre Kervella, Jarron Leisenring, Eric Pantin, Yifan Zhou, Michael Meyer, Michael C. Liu, Mickael Bonnefoy, Thayne Currie, Michael Mcelwain

Astronomy: Faculty Publications

The direct characterization of exoplanetary systems with high-contrast imaging is among the highest priorities for the broader exoplanet community. As large space missions will be necessary for detecting and characterizing exo-Earth twins, developing the techniques and technology for direct imaging of exoplanets is a driving focus for the community. For the first time, JWST will directly observe extrasolar planets at mid-infrared wavelengths beyond 5 μm, deliver detailed spectroscopy revealing much more precise chemical abundances and atmospheric conditions, and provide sensitivity to analogs of our solar system ice-giant planets at wide orbital separations, an entirely new class of exoplanet. However, in …


Lingering Effects Associated With The Consumer Use Of Virtual Reality, John Porter Iii, Andrew Robb Sep 2022

Lingering Effects Associated With The Consumer Use Of Virtual Reality, John Porter Iii, Andrew Robb

Open Access Publishing Fund

Since the release of the Oculus Rift CV1 in 2016, millions of VR headsets have made their way into consumers’ homes. Since then, users have created large quantities of data about their experiences in VR through posts made to online discussion forums. We examine this data to gain insights on what sorts of “lingering effects” users report having experienced after VR, and on the progression of these effects over time. We found three major categories of lingering effects (besides simulator sickness) during our qualitative analysis: perceptual effects, behavioral effects, and changes in dreams. The perceptual and behavioral categories were further …


Enabling Rapid Chemical Analysis Of Plutonium Alloys Via Machine Learning-Enhanced Atomic Spectroscopy Techniques, Ashwin P. Rao Sep 2022

Enabling Rapid Chemical Analysis Of Plutonium Alloys Via Machine Learning-Enhanced Atomic Spectroscopy Techniques, Ashwin P. Rao

Theses and Dissertations

Analytical atomic spectroscopy methods have the potential to provide solutions for rapid, high fidelity chemical analysis of plutonium alloys. Implementing these methods with advanced analytical techniques can help reduce the chemical analysis time needed for plutonium pit production, directly enabling the 80 pit-per-year by 2030 manufacturing goal outlined in the 2018 Nuclear Posture Review. Two commercial, handheld elemental analyzers were validated for potential in situ analysis of Pu. A handheld XRF device was able to detect gallium in a Pu surrogate matrix with a detection limit of 0.002 wt% and a mean error of 8%. A handheld LIBS device was …


Orthogonal Arrays And Legendre Pairs, Kristopher N. Kilpatrick Sep 2022

Orthogonal Arrays And Legendre Pairs, Kristopher N. Kilpatrick

Theses and Dissertations

Well-designed experiments greatly improve test and evaluation. Efficient experiments reduce the cost and time of running tests while improving the quality of the information obtained. Orthogonal Arrays (OAs) and Hadamard matrices are used as designed experiments to glean as much information as possible about a process with limited resources. However, constructing OAs and Hadamard matrices in general is a very difficult problem. Finding Legendre pairs (LPs) results in the construction of Hadamard matrices. This research studies the classification problem of OAs and the existence problem of LPs. In doing so, it makes two contributions to the discipline. First, it improves …