Physical Sciences and Mathematics Commons^™

Unrestricted Factor Analysis: A Powerful Alternative To Confirmatory Factor Analysis, Jan-Benedict E.M. Steenkamp, Alberto Maydeu-Olivares

Faculty Publications

The gold standard for modeling multiple indicator measurement data is confirmatory factor analysis (CFA), which has many statistical advantages over traditional exploratory factor analysis (EFA). In most CFA applications, items are assumed to be pure indicators of the construct they intend to measure. However, despite our best efforts, this is often not the case. Cross-loadings incorrectly set to zero can only be expressed through the correlations between the factors, leading to biased factor correlations and to biased structural (regression) parameter estimates. This article introduces a third approach, which has emerged in the psychometric literature, viz., unrestricted factor analysis (UFA). UFA …

Symmetries, Zero Modes And Light Transport In Non-Hermitian Photonics, Jose David Hernandez Rivero

Dissertations, Theses, and Capstone Projects

We approach some fundamental aspects of photonic dissipative systems treated by a non-Hermitian theory. Inspired by the possibilities provided by some major non-Hermitian symmetries, we study systematically the properties of the novel pseudochirality, pseudo-anti-Hermiticity, and supersymmetry. We analyze other aspect of photonics, the zero mode, which has a profound connection to non-Hermitian physics. We propose a scheme to realize a zero mode that exists even in the absence of symmetries. Finally, we approach light transport in non-Hermitian photonic systems, where the introduction of gain and loss can modify drastically the propagation speed of wavepackets.

The Application Of Electron Backscatter Diffraction To The Forensic Analysis Of Minerals, Tiffany J. Millett

Dissertations, Theses, and Capstone Projects

Electron Backscatter Diffraction has been largely used in the metallurgic and material sciences and until now, has found few applications in the forensic sciences. One of the few utilizations of this technique in forensic science is in firearm serial number restoration as a complementary technique to the time-consuming and tedious chemical etching methods. This research aims to expand the uses of Electron Backscatter Diffraction in the forensic sciences as it applies to other types of samples, specifically as it pertains to forensic mineral analysis.

Electron Backscatter Diffraction offers the analyst information regarding crystal structure of a material, so long as …

Development Of Optical Nanomaterial For Enhanced Cerenkov Imaging, Qize Zhang

Dissertations, Theses, and Capstone Projects

Cancer is a significant public health problem worldwide and is the second leading cause of death in the United States. Imaging has increasingly been used over the last two decades to improve the diagnosis and guidance of tumor tissue removal surgery. Among the most widely used techniques for in vivo imaging are planar and tomographic fluorescence imaging and bioluminescence imaging. Despite their utility, these techniques are primarily restricted to preclinical use. Factors that have prevented translation from the bench to the bedside include depth-penetration considerations, regulatory issues, and toxicity. A recent development in nuclear imaging has been the ability to …

External Validation Of A Laboratory Prediction Algorithm For The Reduction Of Unnecessary Labs In The Critical Care Setting

Faculty, Staff and Student Publications

BACKGROUND: Unnecessary laboratory tests contribute to iatrogenic harm and are a major source of waste in the health care system. We previously developed a machine learning algorithm to help clinicians identify unnecessary laboratory tests, but it has not been externally validated. In this study, we externally validate our machine learning algorithm.

METHODS: To externally validate the machine learning algorithm that was originally trained on the Medical Information Mart for Intensive Care (MIMIC) III database, we tested the algorithm in a separate institution. We identified and abstracted data for all patients older than 18 years admitted to the intensive care unit …

Fluid Pathways In Magmatic Fluid-Dominated Hydrothermal System: Upper Resurgent Cone, Brothers Volcano, New Zealand, Esther G. Goita

Honors Theses

The Tonga-Kermadec Arc is an active volcanic arc located between New Zealand and Fiji. The arc expands over an approximate distance of 2530 km. The Kermadec Arc is currently host to over 30 volcanoes, the majority of which are submarine. The magmatic activity along the arc is characterized by the convergence between the Pacific and Australian plates. Brothers volcano is the most active hydrothermal system along the Kermadec arc and hosts two distinct hydrothermal systems, one magmatic fluid dominated, and the other seawater dominated, making the site perfect for studying nascent volcanogenic massive sulfide formation and fluid pathways. The International …

Joint Control Of Manufacturing And Onsite Microgrid System Via Novel Neural-Network Integrated Reinforcement Learning Algorithms, Jiaojiao Yang, Zeyi Sun, Wenqing Hu, Louis Steinmeister

Mathematics and Statistics Faculty Research & Creative Works

Microgrid is a promising technology of distributed energy supply system, which consists of storage devices, generation capacities including renewable sources, and controllable loads. It has been widely investigated and applied for residential and commercial end-use customers as well as critical facilities. In this paper, we propose a joint state-based dynamic control model on microgrids and manufacturing systems where optimal controls for both sides are implemented to coordinate the energy demand and supply so that the overall production cost can be minimized considering the constraint of production target. Markov Decision Process (MDP) is used to formulate the decision-making procedure. The main …

Stability Of Polyethylene Glycol-Coated Copper Nanoparticles And Their Optical Properties, Deborah Okyere, Ryan H. Manso, Xiao Tong, Jingyi Chen

Chemistry & Biochemistry Faculty Publications and Presentations

Oxidation is a corrosion reaction where the corroded metal forms an oxide. Prevention of oxidation at the nanoscale is critically important to retain the physicochemical properties of metal nanoparticles. In this work, we studied the stability of polyethylene glycol (PEG) coated copper nanoparticles (PEGylated CuNPs) against oxidation. The freshly-prepared PEGylated CuNPs mainly consist of metallic Cu which are quite stable in air although their surfaces are typically covered with a few monolayers of cuprous oxide. However, they are quickly oxidized in water due to the presence of protons that facilitate oxidation of the cuprous oxide to cupric oxide. PEG with …

Editorial: Engineering Nucleic Acids-Based Functional Nanomaterials, Nanodrugs, And Biosensors, Jabrane Jouha, Fengli Li, Wen-Ta Su, Chenguang Fan, Dayong Yang, Hai Xiong

Chemistry & Biochemistry Faculty Publications and Presentations

Editorial on the Research Topic: Engineering Nucleic Acids-Based Functional Nanomaterials, Nanodrugs, and Biosensors

Artificial Atoms From Cold Bosons In One Dimension, Fabian Brauneis, Timothy G. Backert, Simeon I. Mistakidis, Mikhail Lemeshko, Hans Werner Hammer, Artem G. Volosniev

Physics Faculty Research & Creative Works

We Investigate The Ground-State Properties Of Weakly Repulsive One-Dimensional Bosons In The Presence Of An Attractive Zero-Range Impurity Potential. First, We Derive Mean-Field Solutions To The Problem On A Finite Ring For The Two Asymptotic Cases: (I) All Bosons Are Bound To The Impurity And (Ii) All Bosons Are In A Scattering State. Moreover, We Derive The Critical Line That Separates These Regimes In The Parameter Space. In The Thermodynamic Limit, This Critical Line Determines The Maximum Number Of Bosons That Can Be Bound By The Impurity Potential, Forming An Artificial Atom. Second, We Validate The Mean-Field Results Using The …

Silverrush. Xii. Intensity Mapping For Ly Α Emission Extending Over 100-1000 Comoving Kpc Around Z ∼2-7 Laes With Subaru Hsc-Ssp And Chorus Data, Shotaro Kikuchihara, Yuichi Harikane, Masami Ouchi, Yoshiaki Ono, Takatoshi Shibuya, Ryohei Itoh, Ryota Kakuma, Akio K. Inoue, Haruka Kusakabe, Kazuhiro Shimasaku, Rieko Momose, Yuma Sugahara, Satoshi Kikuta, Shun Saito

Physics Faculty Research & Creative Works

We conduct intensity mapping to probe for extended diffuse Lyα emission around Lyα emitters (LAEs) at z ∼2-7, exploiting very deep (∼26 mag at 5σ) and large-area (∼4.5 deg2) Subaru/Hyper Suprime-Cam narrowband (NB) images and large LAE catalogs consisting of a total of 1540 LAEs at z = 2.2, 3.3, 5.7, and 6.6 obtained by the HSC-SSP and CHORUS projects. We calculate the spatial correlations of these LAEs with ∼1-2-billion-pixel flux values of the NB images, deriving the average Lyα surface brightness (SBLyα ) radial profiles around the LAEs. By carefully estimating systematics such as fluctuations of sky background and …

Blocklens: Visual Analytics Of Student Coding Behaviors In Block-Based Programming Environments., Sean Tung, Huan Wei, Haotian Li, Yong Wang, Meng Xia, Huamin. Qu

Research Collection School Of Computing and Information Systems

Block-based programming environments have been widely used to introduce K-12 students to coding. To guide students effectively, instructors and platform owners often need to understand behaviors like how students solve certain questions or where they get stuck and why. However, it is challenging for them to effectively analyze students’ coding data. To this end, we propose BlockLens, a novel visual analytics system to assist instructors and platform owners in analyzing students’ block-based coding behaviors, mistakes, and problem-solving patterns. BlockLens enables the grouping of students by question progress and performance, identification of common problem-solving strategies and pitfalls, and presentation of insights …

2022 - Draft Final - Butte Reduction Works (Brw) Smelter Area Mine Waste Remediation And Contaminated Groundwater Hydraulic Control Site Phase Iii Quality Assurance Project Plan (Qapp), Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

Iowa Waste Reduction Center Newsletter, June 2022, University Of Northern Iowa. Iowa Waste Reduction Center.

Iowa Waste Reduction Center Newsletter

Contents:

--- Your Guide to Small Business Assistance: Air Permit Applications& Emissions Reporting
--- Mapping of Rural Iowa Food Deserts
--- NoCoast Beer Co. Achieves Iowa Green Brewery Platinum Certification
--- IWRC’s Jennifer Trent to serve on the Des Moines Climate Action & Adaptation Plan Technical Advisory Group (TAG)
--- IWRC Welcomes New Environmental Intern: Sam Lueders
--- Industry News

Diagnostics Of Dementia From Structural And Functional Markers Of Brain Atrophy With Machine Learning, Tetiana Habuza

Dissertations

Dementia is a condition in which higher mental functions are disrupted. It currently affects an estimated 57 million people throughout the world. A dementia diagnosis is difficult since neither anatomical indicators nor functional testing is currently sufficiently sensitive or specific. There remains a long list of outstanding issues that must be addressed. First, multimodal diagnosis has yet to be introduced into the early stages of dementia screening. Second, there is no accurate instrument for predicting the progression of pre-dementia. Third, non-invasive testing cannot be used to provide differential diagnoses. By creating ML models of normal and accelerated brain aging, we …

The Reasonableness Standard Of Compliance In The Singapore Personal Data Protection Act, Warren B. Chik

Research Collection Yong Pung How School Of Law

The “reasonableness test” establishes the threshold of compliance and accountability under the Singapore Personal Data Protection Act. This “open-ended” test is flexible enough to take into account and react to changes in the scope and uses of personal data to maintain an equilibrium between the interest of individuals in the protection of their personal information on the one hand and the needs of organisations for access to, and the use of, such data on the other. This article seeks to provide a better understanding of how the test works by comparing it to the objective and function of the fair …

Optical Studies Of Wide Bandgap Photonic Materials, Nikesh Maharjan

Dissertations, Theses, and Capstone Projects

In this dissertation work, optical properties of wide bandgap materials such as hexagonal Boron Nitride (h-BN) and Zinc Oxide (ZnO) have been studied. Deep UV photoluminescence spectroscopy was employed to study the optical properties of bulk h-BN and powder crystals using a laser of wavelength 200 nm, which is the fourth harmonic of Ti:Sapphire laser as excitation source. The properties and chemical compositions of annealed and unannealed bulk h-BN were investigated. The PL spectra from h-BN samples annealed at 900 ºC in ambient air, had strong phonon assisted band edge emissions along with a sharp atomic-like emission line at 4.09 …

Understanding Coastal And Inland Hydrometeorological Hazards Produced By Extratropical And Tropical Cyclones Along The East Coast Of The United States, Katherine Towey

Dissertations, Theses, and Capstone Projects

As global temperatures continue to rise, the effects of anthropogenic climate change will impact the magnitude and frequency of pluvial, fluvial, and coastal flooding events. If we want to accurately predict changes in these flooding events, we need to fully understand them in the current climate. As such, this research examines the relationship between hydrometeorological hazards and the characteristics of the storm types, such as extratropical cyclones (ETCs) and tropical cyclones (TCs), that produce such hazards. Through the use of observational and reanalysis data, the work herein utilizes a cyclone-hazard association algorithm and extreme value analysis to assess the extent, …

A Comparison Of Exotic And Pyraf In Analyzing Exoplanet Transits, Kailei A. Gallup

Physics

In this paper we discuss the data analysis processes using PyRaf, a Python-based version of IRAF, which is one of the most commonly used coding softwares in the astronomy community, as well as the analysis process using EXOTIC. Additionally, we will compare the outcomes from each process to determine if either has significant benefits over the other.

Two-Current Transition Amplitudes With Two-Body Final States, Keegan H. Sherman, Feliipe G. Ortega-Gama, Raúl A. Briceño, Andrew W. Jackura

Physics Faculty Publications

We derive the on-shell form of amplitudes containing two external currents with a single hadron in the initial state and two hadrons in the final state, denoted as 1 + J → 2 + J . This class of amplitude is relevant in precision tests of the Standard Model as well as for exploring the structure of excited states in the QCD spectrum. We present a model-independent description of the amplitudes where we sum to all orders in the strong interaction. From this analytic form we are able to extract transition and elastic resonance form factors consistent with previous work …

Evaluating Loblolly Pine Bioenergy Development Potential Using Ahp Integrated Weighted Overlay And Network Optimization In Virginia, Usa, Huynh Truong Gia Nguyen, Erik Lyttek, Pankaj Lal, Taylor Wieczerak, Trang Luong

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Bioenergy is an essential piece of the United States’ (US) energy portfolio. However, questions surrounding bioenergy sourcing and adoption at the producer level remain persistent challenges, hampering proliferation in areas not already available. To establish new industries, individual regions must be evaluated for various bioenergy feedstocks and incorporate elements for environmental, societal, and economic growth. This study assessed the overall potential for loblolly pine (Pinus taeda) in Virginia, US, for domestic bioenergy by utilizing stakeholder preferences for site selection and biomass potential from a regional growth and yield model. Our results show that bioenergy in the state requires widespread planting …

Air Pollutant Levels And Asthma Emergency Room Visits In A Highly Populous Us Urban County During 2018-19, Osaremhen Ikhile, Jingjing Yin, Atin Adhikari

Biostatistics, Epidemiology & Environmental Health Sciences: Faculty Publications

Objective: Air pollutants are linked to asthma exacerbation. The study purpose was to demonstrate an association between air pollutants levels and asthma emergency room (ER) visit trends in a highly populated US urban county in Georgia during 2018-2019.

Methods: Time series analyses were conducted for the variations in daily numbers of children and adult asthma emergency room visits and changes in daily mean PM_2.5, daily mean PM₁₀ concentrations, daily max 1-hour SO₂ concentrations, daily max 1-hour NO₂ concentrations, daily max 8-hour ozone concentrations, and airborne pollen loads for 2018 to 2019 and potential trends were …

Magnetism Of Novel Rare-Earth-Free Intermetallic Compounds, Haohan Wang

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Rare-earth-free magnets have drawn lots of interest because of their low cost, and the production is not limited by the shortage of rare-earth elements. This dissertation focuses on three rare-earth-free materials, Fe-Co-Ti alloys, Fe-Ni-B alloys, and Co-Si. All of them are synthesized by arc melting followed by melt-spinning. Fe_3+xCo_3−xTi₂ (x = 0, 2, 3) alloys exhibit hexagonal crystal structures and show non-collinear spin structures according to neutron diffraction. The magnetic moments have projections on both the c-axis and basal plane, and the corresponding misalignment angle exhibits a nonlinear decrease with …

Speciation With Gene Flow In A Narrow Endemic West Virginia Cave Salamander (Gyrinophilus Subterraneus), Evan H. Campbell Grant, Kevin P. Mulder, Adrianne B. Brand, Douglas B. Chambers, Addison H. Wynn, Grace Capshaw, Matthew L. Niemiller, John G. Phillips, Jeremy F. Jacobs, Shawn R. Kuchta, Rayna C. Bell

United States Geological Survey: Staff Publications

Due to their limited geographic distributions and specialized ecologies, cave species are often highly endemic and can be especially vulnerable to habitat degradation within and surrounding the cave systems they inhabit. We investigated the evolutionary history of the West Virginia Spring Salamander (Gyrinophilus subterraneus), estimated the population trend from historic and current survey data, and assessed the current potential for water quality threats to the cave habitat. Our genomic data (mtDNA sequence and ddRADseq-derived SNPs) reveal two, distinct evolutionary lineages within General Davis Cave corresponding to G. subterraneus and its widely distributed sister species, Gyrinophilus porphyriticus, that …

Single-Pass Inline Pipeline 3d Reconstruction Using Depth Camera Array, Zhexiong Shang, Zhigang Shen

Department of Construction Engineering and Management: Faculty Publications

A novel inline inspection (ILI) approach using depth cameras array (DCA) is introduced to create high-fidelity, dense 3D pipeline models. A new camera calibration method is introduced to register the color and the depth information of the cameras into a unified pipe model. By incorporating the calibration outcomes into a robust camera motion estimation approach, dense and complete 3D pipe surface reconstruction is achieved by using only the inline image data collected by a self-powered ILI rover in a single pass through a straight pipeline. The outcomes of the laboratory experiments demonstrate one-millimeter geometrical accuracy and 0.1-pixel photometric accuracy. …

Communicative Strategies For Building Public Confidence In Data Governance: Analyzing Singapore's Covid-19 Contact-Tracing Initiatives, Gordon Kuo Siong Tan, Sun Sun Lim

Research Collection College of Integrative Studies

Effective social data governance rests on a bedrock of social support. Without securing trust from the populace whose information is being collected, analyzed, and deployed, policies on which such data are based will be undermined by a lack of public confidence. The COVID-19 pandemic has accelerated digitalization and datafication by governments for the purposes of contact tracing and epidemiological investigation. However, concerns about surveillance and data privacy have stunted the adoption of such contact-tracing initiatives. This commentary analyzes Singapore's contact-tracing initiative to uncover the reasons for public resistance and efforts by the state to address them. The government's contact-tracing program …

Information Sources, Perceived Personal Experience, And Climate Change Beliefs, Sonny Rosenthal

Research Collection College of Integrative Studies

This study proposes and tests a model of serial mediation based on the norm activation model and value-belief-norm theory. It argues that beliefs about climate change are related to perceived personal experience, which is related to the use of different information sources. Structural equation modeling of survey data from 1084 adult residents of Singapore found mixed support for three hypotheses. Results showed that perceived personal experience of climate change was related to the use of traditional media (β = 0.20), social media (β = 0.16), and interpersonal sources (β = 0.13), but not institutional sources. Perceived personal experience of climate …

Fisheries Science Update - Australian Herring - June 2022, Department Of Primary Industries And Regional Development, Western Australia

Fisheries Science Updates

The latest weight of evidence stock assessment for Australian herring indicates that management arrangements introduced in 2015, combined with suitable environmental conditions, have led to the recovery of the resource.

The Department of Primary Industries and Regional Development (DPIRD) tracks our aquatic resources by undertaking weight of evidence stock assessments every three to five years.

DPIRD has undertaken four contemporary weight of evidence stock assessments of Australian herring since 2000.

The 2000 assessment (22 years ago) indicated the catch was sustainable. However, by 2013 the Australian herring stock status had become high risk and ‘unacceptable’, and new measures were introduced. …

Fractional Bernstein Operational Matrices For Solving Integro-Differential Equations Involved By Caputo Fractional Derivative, M.H.T. Alshbool, Mutaz Mohammad, Osman Isik, Ishak Hashim

All Works

The present work is devoted to developing two numerical techniques based on fractional Bernstein polynomials, namely fractional Bernstein operational matrix method, to numerically solving a class of fractional integro-differential equations (FIDEs). The first scheme is introduced based on the idea of operational matrices generated using integration, whereas the second one is based on operational matrices of differentiation using the collocation technique. We apply the Riemann–Liouville and fractional derivative in Caputo’s sense on Bernstein polynomials, to obtain the approximate solutions of the proposed FIDEs. We also provide the residual correction procedure for both methods to estimate the absolute errors. Some results …

New Mexico Acequias In Valencia: A Documentary Report, José A. Rivera Ph.D.

Researchers

In 2014 and 2019 the New Mexico Acequia Association attended events organized by the Water Tribunal of Valencia in Spain commemorating the fifth and tenth anniversaries when the acequias of Valencia and Murcia were listed by UNESCO as examples of the Intangible Cultural Heritage of Humanity. The documentary report provides the context for and significance of the two visits along with a series of photographs that tell the story for the benefit of the citizens of New Mexico.