Physical Sciences and Mathematics Commons^™

Evaluating The Performance Of Estimators In Sem And Irt With Ordinal Variables, Bo Klauth

Dissertations

In conducting confirmatory factor analysis with ordered response items, the literature suggests that when the number of responses is five and item skewness (IS) is approximately normal, researchers can employ maximum likelihood with robust standard errors (MLR). However, MLR can yield biased factor loadings (FL) and FL standard errors (FLSE) when the variables are ordinal. Other estimators are available. Unweighted least squares and weighted least squares with adjusted mean and variance (ULSMV and WLSMV) are known as the estimators for CFA with ordinal variables (CFA-OV). Another estimator, marginal maximum likelihood (MML), is used in the item response theory (IRT), specifically …

Pfas In News Media: A Quantitative And Qualitative Analysis, Madison Haley

University Honors Theses

News media analysis allows for a greater understanding of mainstream public concerns throughout time. The history of US news articles covering per- and polyfluoroalkyl substances (PFAS), a class of chemicals posing increasing threats to public health and the environment, demonstrates Americans' awareness and perceptions of these chemicals over time. Based on the quantitative and qualitative analyses of PFAS-related national news articles in 2012-2022, this study discusses media representations and public perceptions of PFAS during the stated period. Results indicate an over 5700% increase in PFAS-related news articles over the 10-year timespan. Further, thematic analysis reveals that PFAS-related news articles are …

The Coupled Modified Yajima–Oikawa System: Model Derivation And Soliton Solutions, Junchao Chen, Bao-Feng Feng, Ken-Ichi Maruno

School of Mathematical & Statistical Sciences Faculty Publications

In this paper, we consider a coupled modified Yajima–Oikawa (YO) system which describes the nonlinear resonant interaction between one long wave (LW) and two short waves (SWs). It is shown that this coupled system can be derived from a three-component modified nonlinear Schrödinger equations through asymptotic reductions. Furthermore, the bright, dark multi-soliton and multi-breather solutions in terms of determinants are obtained respectively by virtue of the bilinear Kadomtsev–Petviashvili-hierarchy reduction technique. The detailed analysis of dynamical properties for one- and two-solitons and breathers is performed, which show the interesting collision properties for the bright and dark solitons. Particularly, differing from …

Stream-Evolving Bot Detection Framework Using Graph-Based And Feature-Based Approaches For Identifying Social Bots On Twitter, Eiman Alothali

Dissertations

This dissertation focuses on the problem of evolving social bots in online social networks, particularly Twitter. Such accounts spread misinformation and inflate social network content to mislead the masses. The main objective of this dissertation is to propose a stream-based evolving bot detection framework (SEBD), which was constructed using both graph- and feature-based models. It was built using Python, a real-time streaming engine (Apache Kafka version 3.2), and our pretrained model (bot multi-view graph attention network (Bot-MGAT)). The feature-based model was used to identify predictive features for bot detection and evaluate the SEBD predictions. The graph-based model was used to …

Blockchain-Enabled Ehr Sharing In Healthcare Federation: Sharding And Interblockchain Communication, Faiza Hashim

Dissertations

Electronic Health Records (EHRs) are crucial components of the healthcare system, facilitating accurate and efficient diagnosis. Blockchain technology has emerged as a promising solution to improve EHRs sharing among medical practitioners while ensuring privacy and security. By leveraging its decentralized, distributed, immutable, and secure architecture, blockchain has the potential to revolutionize the healthcare system. However, due to security concerns, blockchain networks in healthcare typically operate in private or consortium modes, resulting in isolated networks within a federation. Scalability remains a significant challenge for blockchain networks, as the number of participating nodes increases within each network of the federation. Consensus mechanisms …

Exceptional Point Based Lattice Gyroscopes, Masoumeh Izadparast, Gururaj V. Naik, Henry O. Everitt, Hamidreza Ramezani

Physics & Astronomy Faculty Publications

Ring laser gyroscopes (RLGs) based on non-Hermitian exceptional points (EPs) have garnered much recent interest due to their exceptional sensitivity. Such gyroscopes typically consist of two-ring laser resonators, one with loss and one with an equal amount of optical gain. The coupling strength between these ring resonators is a key parameter determining the sensitivity of EP-based RLGs. Here we explore how the exceptional sensitivity demonstrated in this coupled dimer may be further enhanced by adding more dimers in an array. Specifically, we propose two types of ring laser gyroscope lattice arrays, each composed of N coupled dimers arrayed serially or …

Photon Propagation In Magnetized Dense Quark Matter. A Possible Solution For The Missing Pulsar Problem., Efrain J. Ferrer

Physics & Astronomy Faculty Publications

In this paper it is reviewed the topological properties and possible astrophysical consequences of a spatially inhomogeneous phase of quark matter, known as the Magnetic Dual Chiral Density Wave (MDCDW) phase, that can exist at intermediate baryon density in the presence of a magnetic field. Going beyond mean-field approximation, it is shown how linearly polarized electromagnetic waves penetrating the MDCDW medium can mix with the phonon fluctuations to give rise to two hybridized modes of propagation called as axion polaritons because of their similarity with certain modes found in condensed matter for topological magnetic insulators. The formation of axion polaritons …

(R2031) M/M/1 Retrial Queue With Working Vacation And Interruption In Bernoulli Schedule Under N-Control Pattern, P. Manoharan, S. Pazhani Bala Murugan, A. Sobanappriya

Applications and Applied Mathematics: An International Journal (AAM)

An M/M/1 retrial queue with working vacation and interruption in Bernoulli schedule under N-control pattern is investigated in this article. To describe the system, we employ a QBD analogy. The model’s stability condition is deduced. The stationary probability distribution is generated by utilizing the matrix-analytic technique. The performance measures and special cases are designed. The model’s firmness is demonstrated numerically

(R2027) A New Class Of Pareto Distribution: Estimation And Its Applications, Anitta Susan Aniyan, Dais George

Applications and Applied Mathematics: An International Journal (AAM)

The classical Pareto distribution is a positively skewed and right heavy-tailed lifetime distribution having a lot many applications in various fields of science and social science. In this work, via logarithmic trans-formed method, a new three parameter lifetime distribution, an extension of classical Pareto distribution is generated. The different structural properties of the new distribution are studied. The model parameters are estimated by the method of maximum likelihood and Bayesian procedure. When all the three parameters of the distribution are unknown, the Bayes estimators cannot be obtained in a closed form and hence, the Lindley’s approximation under squared error loss …

The X-Ray Variation Of M81* Resolved By Chandra And Nustar, Shu Niu, Fu-Guo Xie, Q. Daniel Wang, Li Ji, Feng Yuan, Min Long

Computer Science Faculty Publications and Presentations

Despite advances in our understanding of low-luminosity active galactic nuclei (LLAGNs), the fundamental details about the mechanisms of radiation and flare/outburst in hot accretion flow are still largely missing. We have systematically analysed the archival Chandra and NuSTAR X-ray data of the nearby LLAGN M81*, whose L_bol ∼ 10⁻⁵L_Edd. Through a detailed study of X-ray light curve and spectral properties, we find that the X-ray continuum emission of the power-law shape more likely originates from inverse Compton scattering within the hot accretion flow. In contrast to Sgr A*, flares are rare in M81*. Low-amplitude variation …

A Novel Approach To Extending Music Using Latent Diffusion, Keon Roohparvar, Franz J. Kurfess

Master's Theses

Using deep learning to synthetically generate music is a research domain that has gained more attention from the public in the past few years. A subproblem of music generation is music extension, or the task of taking existing music and extending it. This work proposes the Continuer Pipeline, a novel technique that uses deep learning to take music and extend it in 5 second increments. It does this by treating the musical generation process as an image generation problem; we utilize latent diffusion models (LDMs) to generate spectrograms, which are image representations of music. The Continuer Pipeline is able to …

Strongly Invertible Knots, Equivariant Slice Genera, And An Equivariant Algebraic Concordance Group, Allison N. Miller, M. Powell

Mathematics & Statistics Faculty Works

We use the Blanchfield form to obtain a lower bound on the equivariant slice genus of a strongly invertible knot. For our main application, let K be a strongly invertible genus one slice knot with nontrivial Alexander polynomial. We show that the equivariant slice genus of an equivariant connected sum #ⁿ K is at least n/4. We also formulate an equivariant algebraic concordance group, and show that the kernel of the forgetful map to the classical algebraic concordance group is infinite rank.

Lightning: An X-Ray To Submillimeter Galaxy Sed-Fitting Code With Physically Motivated Stellar, Dust, And Agn Models, Keith Doore, Erik B. Monson, Rafael T. Eufrasio, Bret D. Lehmer, Kristen Garofali, Antara Basu-Zych

Physics Faculty Publications and Presentations

We present an updated version of Lightning, a galaxy spectral energy distribution (SED) fitting code that can model X-ray to submillimeter observations. The models in Lightning include the options to contain contributions from stellar populations, dust attenuation and emission, and active galactic nuclei (AGNs). X-ray emission, when utilized, can be modeled as originating from stellar compact binary populations with the option to include emission from AGNs. We have also included a variety of algorithms to fit the models to observations and sample parameter posteriors; these include adaptive Markov Chain Monte Carlo (MCMC), affine-invariant MCMC, and Levenberg–Marquardt gradient-descent (MPFIT) algorithms. To …

Solving The Cable Equation, A Second-Order Time Dependent Pde For Non-Ideal Cables With Action Potentials In The Mammalian Brain Using Kss Methods, Nirmohi Charbe

Master's Theses

In this thesis we shall perform the comparisons of a Krylov Subspace Spectral method with Forward Euler, Backward Euler and Crank-Nicolson to solve the Cable Equation. The Cable Equation measures action potentials in axons in a mammalian brain treated as an ideal cable in the first part of the study. We shall subject this problem to the further assumption of a non-ideal cable. Assume a non-uniform cross section area along the longitudinal axis. At the present time, the effects of torsion, curvature and material capacitance are ignored. There is particular interest to generalize the application of the PDEs including and …

Laboratory Simulations Of H2s Generation In The Bakken Petroleum System, Alexander V. Chakhmakhchev, Bethany A. Kurz, Timothy O. Nesheim, David J. Miller, Carol B. Grabanski, Saptashati Biswas, Marc D. Kurz, Nicholas A. Azzolina, James A. Sorensen

EERC Publications, Papers, & Presentations

This work focuses on quantifying the H₂S generation potential of the Madison Group and Bakken Formation source rocks during the maturation process.

Data-Driven Analysis For Causality Of Parent–Child Interactions In The Bakken, Kyoung Min, Alexander V. Chakhmakhchev, Xue Yu, Nicholas A. Azzolina, Darren D. Schmidt, Bethany A. Kurz, James A. Sorensen

EERC Publications, Papers, & Presentations

This study 1) evaluates the effect of parent–child interaction on productivity by assessing depletion effects and the impact of different completion designs and 2) investigates how refracturing strategies affect parent–child interactions.

Developing A High-Efficiency Method For Field-Scale Simulation Of A Tight And Naturally Fractured Reservoir In The Williston Basin, Xincheng Wan, Lu Jin, Tao (Todd) Jiang, James A. Sorensen, Chenyu Wu, Ahmed Merzoug

EERC Publications, Papers, & Presentations

A novel FDO (fracture and DRV optimization) workflow was proposed in this study to better reproduce the production and water injection history of a tight reservoir with natural fractures in the Williston Basin. Compared to most of the published work in this area, the FDO workflow can significantly improve the simulation efficiency for field-scale simulation models considering the presence of a complex natural fracture network.

When Brain-Inspired Ai Meets Agi, Lin Zhao, Lu Zhang, Zihao Wu, Yuzhong Chen, Haixing Dai, Xiaowei Yu, Zhengliang Liu, Tuo Zhang, Xintao Hu, Xi Jiang, Xiang Li, Dajiang Zhu, Dinggang Shen, Tianming Liu

Computer Science Faculty Research & Creative Works

Artificial General Intelligence (AGI) has been a long-standing goal of humanity, with the aim of creating machines capable of performing any intellectual task that humans can do. To achieve this, AGI researchers draw inspiration from the human brain and seek to replicate its principles in intelligent machines. Brain-inspired artificial intelligence is a field that has emerged from this endeavor, combining insights from neuroscience, psychology, and computer science to develop more efficient and powerful AI systems. In this article, we provide a comprehensive overview of brain-inspired AI from the perspective of AGI. We begin with the current progress in brain-inspired AI …

Life, Death, And Ai: Exploring Digital Necromancy In Popular Culture—Ethical Considerations, Technological Limitations, And The Pet Cemetery Conundrum, James Hutson, Jay Ratican

Faculty Scholarship

This article explores the rise of generative AI, particularly ChatGPT, and the combination of large language models (LLM) with robotics, exemplified by Ameca the Robot. It addresses the need to study the ethical considerations and potential implications of digital necromancy, which involves using AI to reanimate deceased individuals for various purposes. Reasons for desiring to engage with a disembodied or bodied replica of a person include the preservation of memories, emotional closure, cultural heritage and historical preservation, interacting with idols or influential figures, educational and research purposes, and creative expression and artistic endeavors. As such, this article examines historical examples …

(R2032) Modeling The Effect Of Sanitation Effort On The Spread Of Carrier-Dependent Infectious Diseases Due To Environmental Degradation, Ram Naresh, Sandhya Rani Verma, J. B. Shukla, Manju Agarwal

Applications and Applied Mathematics: An International Journal (AAM)

In this present study, an SIS model is proposed and analyzed to study the effect of sanitation effort in controlling the spread of carrier-dependent infectious disease in a human habitat due to environmental degradation. The dynamics of the model consist of six dependent variables, the susceptible population density, infective population density, carrier population density, cumulative density of environmental degradation and the density of sanitation effort applied on carrier population and degraded environment. In the modeling process, the carrier population density and sanitation effort are modeled logistically and the degradation of the environment is assumed to be directly proportional to the …

(R1965) Some More Properties On Generalized Double Fuzzy Z Alpha Open Sets, K. Jayapandian, A. Saivarajan, O. Uma Maheswari, J. Sathiyaraj

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, a new class of sets termed as double fuzzy generalized Z alpha closed sets and double fuzzy generalized Z alpha open sets are introduced with the help of double fuzzy Z alpha open and double fuzzy Z alpha closed sets, respectively. Using these sets double fuzzy generalized Z alpha border, double fuzzy generalized Z alpha exterior and double fuzzy generalized Z alpha frontier of a fuzzy set in double fuzzy topological spaces are introduced. Also, the topological properties and characterizations of these sets and operators are studied. Furthermore, suitable examples have been provided to illustrate the theory.

Enhanced Methods In Forensic Mass Spectrometry For Targeted And Untargeted Drug Analysis, Dina M. Swanson

USF Tampa Graduate Theses and Dissertations

Forensic science has long used mass spectrometry for the analysis of drugsand metabolites. Traditionally, screening methods consisted of color tests or immunoassay and confirmation methods used gas chromatography with mass spectrometry, which was considered the gold standard for identification. In the last several decades, advances in liquid chromatography with mass spectrometry (LCMS) have brought this technology to the forefront of forensic drug identification. Drug identification in forensic drug chemistry and forensic toxicology has become increasingly challenging due to the rapid increase in illicit drug analogs including novel opioids such as fentanyl analogs. Traditional screening methodologies are often unable to identify …

The Role Of The Armed Forces Of The Philippines (Afp) In Disaster Response And Adaptation Strategies To Climatic Disasters In Manila, Edmundo Nicolas Jr.

Geography Masters Research Papers

This study described the roles of the Armed Forces of the Philippines (AFP) in Disaster Risk Reduction Management (DRRM) in Metro Manila and how climate-induced hazards impact the role of the military. It used a qualitative approach, which involved semi- structured interviews among AFP officers and barangay leaders with expertise and experience in DRRM and an analysis of selected policy documents and military doctrine. These methods revealed that: (1) the military acts as a political first-aid, since they are the first responders – thus, the face of the local government – in climactic disasters during peacetime; (2) the military is …

Patient Engagement In A Multimodal Digital Phenotyping Study Of Opioid Use Disorder, Cynthia I. Campbell, Ching-Hua Chen, Sara R. Adams, Asma Asyyed, Ninad R. Athale, Monique B. Does, Saeed Hassanpour, Emily Hichborn, Melanie Jackson-Morris, Nicholas C. Jacobson, Heather K. Jones, David Kotz, Chantal A. Lambert-Harris, Zhiguo Li, Bethany Mcleman, Varun Mishra, Catherine Stanger, Geetha Subramaniam, Weiyi Wu, Christopher Zegers, Lisa A. Marsch

Dartmouth Scholarship

Background: Multiple digital data sources can capture moment-to-moment information to advance a robust understanding of opioid use disorder (OUD) behavior, ultimately creating a digital phenotype for each patient. This information can lead to individualized interventions to improve treatment for OUD.

Objective: The aim is to examine patient engagement with multiple digital phenotyping methods among patients receiving buprenorphine medication for OUD.

Methods: The study enrolled 65 patients receiving buprenorphine for OUD between June 2020 and January 2021 from 4 addiction medicine programs in an integrated health care delivery system in Northern California. Ecological momentary assessment (EMA), sensor data, and social media …

Flash-Rt: Using High-Dose Radiation For Clinical Radiation Therapy, Deja Stubbs

University Honors Theses

This paper is a literature review on the possible mechanisms behind the FLASH effect and why such research can advance the world of radiology treatment by modifying current clinical linear accelerators to produce ultra-high doses of radiation. Radiation Therapy, also known as external Beam Radiation Therapy, is a common type of cancer treatment. Globally, cancer is the second-leading cause of death, but has seen an increase in survival rates over the past couple of years. Cancer can develop in almost any part of the body since cancer is defined as uncontrolled cell growth. The FLASH Effect is seen when treating …

Indigenous Water Justice: Theory, Gaps, And Opportunities For Application, Ruby Howard

University Honors Theses

Indigenous people are particularly at risk of water scarcity in the U.S. and abroad, and face high rates of nonexistent or failing water infrastructure, water pollution, pipeline proposals that threaten water resources, and water-related climate change impacts. They also are often unequipped, politically and economically, to react and adapt to these impacts, resulting in devastating health impacts. Due to this widespread insecurity, many scholars are calling for the application of a theory and set of principles known as water justice. However, Indigenous people have pointed out that water justice literature does not focus enough on Indigenous issues, often neglecting the …

Covalent Adaptable Networks For Wood Coatings, Jachin Boaz Clarke

Materials Engineering

Wood swells and shrinks causing problems with seasonal humidity. Applying thick coatings of reactive finishes based on cross-linked polyurethane, epoxy, or polyesters can slow moisture-vapor exchange. However, the use of thick coatings leads to cracking and crazing sooner than thin finishes. This research proposes the addition of 3.3 mol % triazabicyclodecene, a conventionally used covalent adaptable network catalyst, in a commercially available polyester-based wood coating. The self-healing of the wood coating is tested using DMA stress relaxation and compression molding. The result from DMA renders inconclusive and compression molding indicates the novel wood coating oxidizes at elevated temperatures. The wood …

The Mobility Of Long-Lived Radioisotopes And Their Burial In The Marine Environment, Neil Redmond

Dissertations

Marine sediments record chemical signals that reflect past environmental conditions. It is important to establish how these signals are created and whether they may be altered over time so that they can be useful for reconstructing ocean history. Measurements of uranium isotopes are used as a novel proxy for sedimentary diagenetic processes (Chapter 2). Because ²³⁴U can be ejected from mineral lattice during the decay of ²³⁸U, it creates a pool of U in porewater that is potentially mobilized and then deposited elsewhere in the core. We found that alpha-recoiled ²³⁴U is sensitive to differences in sediment …

Position-Guided Text Prompt For Vision-Language Pre-Training, Alex Jinpeng Wang, Pan Zhou, Mike Zheng Shou, Yan Shuicheng

Research Collection School Of Computing and Information Systems

Vision-Language Pre-Training (VLP) has shown promising capabilities to align image and text pairs, facilitating a broad variety of cross-modal learning tasks. However, we observe that VLP models often lack the visual grounding/localization capability which is critical for many downstream tasks such as visual reasoning. In this work, we propose a novel Position-guided Text Prompt (PTP) paradigm to enhance the visual grounding ability of cross-modal models trained with VLP. Specifically, in the VLP phase, PTP divides the image into N x N blocks, and identifies the objects in each block through the widely used object detector in VLP. It then reformulates …

Improving Quantal Cognitive Hierarchy Model Through Iterative Population Learning, Yuhong Xu, Shih-Fen Cheng, Xinyu Chen

Research Collection School Of Computing and Information Systems

In this paper, we propose to enhance the state-of-the-art quantal cognitive hierarchy (QCH) model with iterative population learning (IPL) to estimate the empirical distribution of agents’ reasoning levels and fit human agents’ behavioral data. We apply our approach to a real-world dataset from the Swedish lowest unique positive integer (LUPI) game and show that our proposed approach outperforms the theoretical Poisson Nash equilibrium predictions and the QCH approach by 49.8% and 46.6% in Wasserstein distance respectively. Our approach also allows us to explicitly measure an agent’s reasoning level distribution, which is not previously possible.