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Data Supporting Research On Personalized Learning Paths, Sean Mochocki, Mark Reith Mar 2024

Data Supporting Research On Personalized Learning Paths, Sean Mochocki, Mark Reith

Faculty Publications

Personalized Learning Paths (PLPs) are a key application of Artificial Intelligence in E-Learning. In contrast to regular Learning Paths, they return a unique sequence of learning materials identified as meeting the individual needs of the students. In the literature, PLPs are often created from knowledge graphs, which assist with ordering topics and their associated learning materials. Knowledge graphs are typically directed and acyclic, to capture prerequisite relationships between topics, though they can also have bidirectional edges when these prerequisite relationships are not necessary. This data package provides a primarily un-directed knowledge graph, with associated repository of open-source learning materials that …


The Impact Of Data Preparation And Model Complexity On The Natural Language Classification Of Chinese News Headlines, Torrey J. Wagner, Dennis Guhl, Brent T. Langhals Mar 2024

The Impact Of Data Preparation And Model Complexity On The Natural Language Classification Of Chinese News Headlines, Torrey J. Wagner, Dennis Guhl, Brent T. Langhals

Faculty Publications

Given the emergence of China as a political and economic power in the 21st century, there is increased interest in analyzing Chinese news articles to better understand developing trends in China. Because of the volume of the material, automating the categorization of Chinese-language news articles by headline text or titles can be an effective way to sort the articles into categories for efficient review. A 383,000-headline dataset labeled with 15 categories from the Toutiao website was evaluated via natural language processing to predict topic categories. The influence of six data preparation variations on the predictive accuracy of four algorithms was …


The Gyrokinetic Dispersion Relation Of Microtearing Modes In Collisionless Toroidal Plasmas, Benjamin D G Chandran, A A. Schekochihin Mar 2024

The Gyrokinetic Dispersion Relation Of Microtearing Modes In Collisionless Toroidal Plasmas, Benjamin D G Chandran, A A. Schekochihin

Faculty Publications

We solve the linearized gyrokinetic equation, quasineutrality condition and Ampere's law to obtain the dispersion relation of microtearing modes (MTMs) in collisionless low- $\beta$ toroidal plasmas. Consistent with past studies, we find that MTMs are driven unstable by the electron temperature gradient and that this instability drive is mediated by magnetic drifts. The dispersion relation that we derive can be evaluated numerically very quickly and may prove useful for devising strategies to mitigate MTM instability in fusion devices.


Doubly Charged Dimers And Trimers Of Heavy Noble Gases, Gabriel Schöpfer, Stefan Bergmeister, Milan Ončák, Ianessa Stromberg, Masoomeh Mahmoodi-Darian, Paul Scheier, Olof Echt, Elisabeth Gruber Mar 2024

Doubly Charged Dimers And Trimers Of Heavy Noble Gases, Gabriel Schöpfer, Stefan Bergmeister, Milan Ončák, Ianessa Stromberg, Masoomeh Mahmoodi-Darian, Paul Scheier, Olof Echt, Elisabeth Gruber

Faculty Publications

Many doubly charged heteronuclear dimers are metastable or even thermodynamically stable with respect to charge separation. Homonuclear dicationic dimers, however, are more difficult to form. He22+ was the first noble gas dimer predicted to be metastable and, decades later, observed. Ne22+ is the only other dicationic noble gas dimer that has been detected so far. Here, we present a novel approach to form fragile dicationic species, by post-ionization of singly charged ions that are embedded in helium nanodroplets (HNDs). Bare ions are then extracted by colliding the HNDs with helium gas. We detect homonuclear doubly charged …


The Gyrokinetic Dispersion Relation Of Microtearing Modes In Collisionless Toroidal Plasmas, Benjamin D G Chandran, A A. Schekochihin Mar 2024

The Gyrokinetic Dispersion Relation Of Microtearing Modes In Collisionless Toroidal Plasmas, Benjamin D G Chandran, A A. Schekochihin

Faculty Publications

We solve the linearized gyrokinetic equation, quasineutrality condition and Ampere's law to obtain the dispersion relation of microtearing modes (MTMs) in collisionless low- $\beta$ toroidal plasmas. Consistent with past studies, we find that MTMs are driven unstable by the electron temperature gradient and that this instability drive is mediated by magnetic drifts. The dispersion relation that we derive can be evaluated numerically very quickly and may prove useful for devising strategies to mitigate MTM instability in fusion devices.


Teaching Statistics: A Technology-Enhanced Supportive Instruction (Tsi) Model During The Covid-19 Pandemic And Beyond, Serina Al-Haddad, Nancy Chick, Farshid Safi Mar 2024

Teaching Statistics: A Technology-Enhanced Supportive Instruction (Tsi) Model During The Covid-19 Pandemic And Beyond, Serina Al-Haddad, Nancy Chick, Farshid Safi

Faculty Publications

Many approaches exist in teaching statistics, however, learning statistics is frequently perceived by students as challenging. While evidence-based teaching approaches like case discussions and flipped-classroom models have been successfully incorporated into multiple disciplines, these methods can have inadequate success when students are affectively detached or sometimes paralyzed by the subject. The sudden need to switch to virtual teaching in Spring 2020 created unprecedented challenges that were overwhelming for instructors and students. This article explores the challenges of teaching a statistics course, and the importance of purposeful use of technology and supportive feedback to effectively engage students and promote learning. Furthermore, …


Coherent States Of The Laguerre–Gauss Modes, M. P. Morales Rodríguez, O. S. Magaña-Loaiza, B. Perez-Garcia, L. M. Nieto Calzada, F. Marroquín Gutiérrrez, B. M. Rodríguez-Lara Mar 2024

Coherent States Of The Laguerre–Gauss Modes, M. P. Morales Rodríguez, O. S. Magaña-Loaiza, B. Perez-Garcia, L. M. Nieto Calzada, F. Marroquín Gutiérrrez, B. M. Rodríguez-Lara

Faculty Publications

Large quantum photonic systems hold promise for surpassing classical computational limits, yet their state preparation remains a challenge. We propose an alternative approach to study multiparticle dynamics by mapping the excitation mode of these systems to physical properties of the Laguerre–Gauss modes. We construct coherent states establishing a direct link between excitation number dynamics and the evolution of the Laguerre–Gauss modes. This highlights the photon transverse spatial degree of freedom as a versatile platform for testing the fundamental aspects of quantum multiparticle systems.


Reconsidering The Reliability Of Chemical Process Simulators I: Implementation Of The Murphree And Vaporization Efficiencies, Zachary Braswell, Brian F. Hanley, Holt Ragsdale Mar 2024

Reconsidering The Reliability Of Chemical Process Simulators I: Implementation Of The Murphree And Vaporization Efficiencies, Zachary Braswell, Brian F. Hanley, Holt Ragsdale

Faculty Publications

Most chemical process simulators in widespread use today allow users to apply some type of efficiency correction to individual equilibrium stages or to equilibrium stage sections in order to align the stage or section separation performance more closely to actual tray performance in the field. Some simulators even allow for the use of component efficiencies on individual stages or in stage sections. It is our contention, however, that two of the more commonly available efficiency models, the vaporization efficiency and Murphree vapor phase efficiency, have generally been implemented incorrectly. The three major conceptual inconsistencies are (1) the assumption that the …


The Myth Of Tightening Credit Rating Standards In The Market For Corporate Debt, Karolina Krystyniak, Viktoriya Staneva Mar 2024

The Myth Of Tightening Credit Rating Standards In The Market For Corporate Debt, Karolina Krystyniak, Viktoriya Staneva

Faculty Publications

This study revisits the existing evidence of a downward trend in credit rating standards indicating that CRAs have become more conservative over time. We find that the time-series variation in the proxy for rating standards is mostly driven by the market-based variables in the model, specifically market capitalization and idiosyncratic volatility. We examine an alternative specification of the model, incorporating risk characteristics of rated firms relative to those of the average firm in the economy, and find it to have a higher explanatory power. Most importantly, we find little evidence of increased conservatism over time, in contrast to prior studies.


The Myth Of Tightening Credit Rating Standards In The Market For Corporate Debt, Karolina Krystyniak, Viktoriya Staneva Mar 2024

The Myth Of Tightening Credit Rating Standards In The Market For Corporate Debt, Karolina Krystyniak, Viktoriya Staneva

Faculty Publications

This study revisits the existing evidence of a downward trend in credit rating standards indicating that CRAs have become more conservative over time. We find that the time-series variation in the proxy for rating standards is mostly driven by the market-based variables in the model, specifically market capitalization and idiosyncratic volatility. We examine an alternative specification of the model, incorporating risk characteristics of rated firms relative to those of the average firm in the economy, and find it to have a higher explanatory power. Most importantly, we find little evidence of increased conservatism over time, in contrast to prior studies.


Detecting Anomalies In Time Series Using Kernel Density Approaches, Robin Frehner, Kesheng Wu, Alexander Sim, Jinoh Kim Mar 2024

Detecting Anomalies In Time Series Using Kernel Density Approaches, Robin Frehner, Kesheng Wu, Alexander Sim, Jinoh Kim

Faculty Publications

This paper introduces a novel anomaly detection approach tailored for time series data with exclusive reliance on normal events during training. Our key innovation lies in the application of kernel-density estimation (KDE) to scrutinize reconstruction errors, providing an empirically derived probability distribution for normal events post-reconstruction. This non-parametric density estimation technique offers a nuanced understanding of anomaly detection, differentiating it from prevalent threshold-based mechanisms in existing methodologies. In post-training, events are encoded, decoded, and evaluated against the estimated density, providing a comprehensive notion of normality. In addition, we propose a data augmentation strategy involving variational autoencoder-generated events and a smoothing …


Enriched Regions Of 228Ra Along The U.S. Geotraces Pacific Meridional Transect (Gp15), Willard S. Moore, Matt Charette, Paul Henderson, Doug Hammond, Nathaniel Kemnitz, Emilie Leroy, Eun Young Kwon, Mikael Hult Mar 2024

Enriched Regions Of 228Ra Along The U.S. Geotraces Pacific Meridional Transect (Gp15), Willard S. Moore, Matt Charette, Paul Henderson, Doug Hammond, Nathaniel Kemnitz, Emilie Leroy, Eun Young Kwon, Mikael Hult

Faculty Publications

The half‐life of 228Ra (5.7 years) aligns well with near‐surface and near‐bottom ocean mixing timescales. Because 228Ra is sourced from sediments, regions of enhanced activity represent water that has recently interacted with sediments on the continental margin or seabed. The GP15 meridional transect from Alaska to Tahiti along152°W encountered several regions in the upper ocean where 228Ra was enriched. These enrichments follow surface and subsurface ocean current patterns and pair with earlier measurements of 228Ra and transient radionuclides to reveal the origins of these enriched regions. An enriched region at Alaska margin stations 1–3 was sourced locally but did not …


Graph Theory And Graph Neural Network Assisted High-Throughput Crystal Structure Prediction And Screening For Energy Conversion And Storage, Joshua Ojih, Mohammed Al-Fahdi, Yagang Yao, Jianjun Hu, Ming Hu Mar 2024

Graph Theory And Graph Neural Network Assisted High-Throughput Crystal Structure Prediction And Screening For Energy Conversion And Storage, Joshua Ojih, Mohammed Al-Fahdi, Yagang Yao, Jianjun Hu, Ming Hu

Faculty Publications

Prediction of crystal structures with desirable material properties is a grand challenge in materials research, due to the enormous search space of possible combinations of elements and their countless arrangements in 3D space. Despite the recent progress of a few crystal structure prediction algorithms, most of those methods only target a few specific material families or are restricted to simple systems with limited element diversity. Moreover, these algorithms are usually coupled with first principles calculations and thus are computationally expensive and very time consuming. Therefore, establishing a workflow that can generate a large number of hypothetical structures with diverse elements …


Laboratory Exercise For The Radiometry Student, Michael A. Marciniak Mar 2024

Laboratory Exercise For The Radiometry Student, Michael A. Marciniak

Faculty Publications

The U.S. Air and Space Forces require optical expertise among their personnel. The Air Force Institute of Technology offers a graduate optics curriculum, which includes a three-course sequence to educate students in the optical concepts of radiometry and radiometric instrumentation. We find radiometry is often a deceptively difficult concept for students to master. To address this, we have developed an experiment in our optics-laboratory coursework to help them gain this mastery. A Fourier-transform infrared spectrometer (FTS) is used to collect spectral data from an unknown sample. FTS calibration and data collection are discussed here, as are the two specific samples …


Relative Vectoring Using Dual Object Detection For Autonomous Aerial Refueling, Derek B. Worth, Jeffrey L. Choate, James Lynch, Scott L. Nykl, Clark N. Taylor Mar 2024

Relative Vectoring Using Dual Object Detection For Autonomous Aerial Refueling, Derek B. Worth, Jeffrey L. Choate, James Lynch, Scott L. Nykl, Clark N. Taylor

Faculty Publications

Once realized, autonomous aerial refueling will revolutionize unmanned aviation by removing current range and endurance limitations. Previous attempts at establishing vision-based solutions have come close but rely heavily on near perfect extrinsic camera calibrations that often change midflight. In this paper, we propose dual object detection, a technique that overcomes such requirement by transforming aerial refueling imagery directly into receiver aircraft reference frame probe-to-drogue vectors regardless of camera position and orientation. These vectors are precisely what autonomous agents need to successfully maneuver the tanker and receiver aircraft in synchronous flight during refueling operations. Our method follows a common 4-stage process …


Speculating About Genocide: The Queensland Frontier 1859–1897, Mark Finnane, Jonathan Richards Mar 2024

Speculating About Genocide: The Queensland Frontier 1859–1897, Mark Finnane, Jonathan Richards

Faculty Publications

In the colonisation of Queensland, Australia it is commonly accepted that large numbers of Indigenous people were killed in the second half of the nineteenth century. Calculations of violent mortality have recently been revised radically upwards. We suggest that the methodology deployed in these new studies is unreliable, reflecting errors in counting and calculation, as well as underestimating the selection bias of the samples. We caution against projecting aggregate violent mortality where the underlying data are so imperfect and emphasise the value of more detailed local and regional studies to inform better understanding of colonisation's impact on First Peoples.


Worldwide Forest Surveys Reveal Forty-Three New Species In Phytophthora Major Clade 2 With Fundamental Implications For The Evolution And Biogeography Of The Genus And Global Plant Biosecurity, T. Jung, I. Milenković, Y. Balci, J. Janoušek, T. Kudláček, Z. Nagy, B. Baharuddin, J. Bakonyi, K. D. Broders, S. O. Cacciola, T. T. Chang, N. M. Chi, T. Corcobado, A. Cravador, B. Dordević, A. Durán, M. Ferreira, C. H. Fu, L. Garcia, A. Hieno, H. H. Ho, C. Hong, M. Junaid, K. Kageyama, T. Kuswinanti, C. Maia, T. Májek, H. Masuya, G. Magnano Di San Lio, B. Mendieta-Araica, N. Nasri, L. S.S. Oliveira, A. Pane Mar 2024

Worldwide Forest Surveys Reveal Forty-Three New Species In Phytophthora Major Clade 2 With Fundamental Implications For The Evolution And Biogeography Of The Genus And Global Plant Biosecurity, T. Jung, I. Milenković, Y. Balci, J. Janoušek, T. Kudláček, Z. Nagy, B. Baharuddin, J. Bakonyi, K. D. Broders, S. O. Cacciola, T. T. Chang, N. M. Chi, T. Corcobado, A. Cravador, B. Dordević, A. Durán, M. Ferreira, C. H. Fu, L. Garcia, A. Hieno, H. H. Ho, C. Hong, M. Junaid, K. Kageyama, T. Kuswinanti, C. Maia, T. Májek, H. Masuya, G. Magnano Di San Lio, B. Mendieta-Araica, N. Nasri, L. S.S. Oliveira, A. Pane

Faculty Publications

During 25 surveys of global Phytophthora diversity, conducted between 1998 and 2020, 43 new species were detected in natural ecosystems and, occasionally, in nurseries and outplantings in Europe, Southeast and East Asia and the Americas. Based on a multigene phylogeny of nine nuclear and four mitochondrial gene regions they were assigned to five of the six known subclades, 2a-c, e and f, of Phytophthora major Clade 2 and the new subclade 2g. The evolutionary history of the Clade appears to have involved the pre-Gondwanan divergence of three extant subclades, 2c, 2e and 2f, all having disjunct natural distributions on separate …


Transformative Insights: Break Up With Salt (Buws) Program’S Short-Term Influence On Hypertension Risk Factors, Jean Pierre Enriquez, Helena Salgado, Christopher Kuetsinya, Li Hsiang Lin, Elizabeth Gollub Mar 2024

Transformative Insights: Break Up With Salt (Buws) Program’S Short-Term Influence On Hypertension Risk Factors, Jean Pierre Enriquez, Helena Salgado, Christopher Kuetsinya, Li Hsiang Lin, Elizabeth Gollub

Faculty Publications

Break Up with Salt (BUWS) is a four-session community-based nutrition education program aimed at reducing key controllable hypertension risk factors. This pilot study utilized a pre-post survey design to assess short-term outcomes on food behaviors (including DASH diet eating patterns), physical activity, and overall well-being, in two groups of participants. The first “pilot” group (n = 25) completed a comprehensive, 16-item survey; the second “abbreviated” group (n = 27) completed a 5-item survey. The pilot group experienced improvements in whole grain (p = 0.04), sweetened beverage consumption, watching/reducing sodium (p = 0.04) and fat (p = 0.05) consumption, and time …


The Expected Behaviors Of Posterior Predictive Tests And Their Unexpected Interpretation, Luiza Guimarães Fabreti, Lyndon M. Coghill, Robert C. Thomson, Sebastian Höhna, Jeremy M. Brown Mar 2024

The Expected Behaviors Of Posterior Predictive Tests And Their Unexpected Interpretation, Luiza Guimarães Fabreti, Lyndon M. Coghill, Robert C. Thomson, Sebastian Höhna, Jeremy M. Brown

Faculty Publications

Poor fit between models of sequence or trait evolution and empirical data is known to cause biases and lead to spurious conclusions about evolutionary patterns and processes. Bayesian posterior prediction is a flexible and intuitive approach for detecting such cases of poor fit. However, the expected behavior of posterior predictive tests has never been characterized for evolutionary models, which is critical for their proper interpretation. Here, we show that the expected distribution of posterior predictive P-values is generally not uniform, in contrast to frequentist P-values used for hypothesis testing, and extreme posterior predictive P-values often provide more evidence of poor …


Searches For Baryon Number Violation In Neutrino Experiments: A White Paper, P. S.B. Dev, L. W. Koerner, S. Saad, S. Antusch, M. Askins, K. S. Babu, J. L. Barrow, J. Chakrabortty, A. De Gouvêa, Z. Djurcic, S. Girmohanta, I. Gogoladze, M. C. Goodman, A. Higuera, D. Kalra, G. Karagiorgi, E. Kearns, V. A. Kudryavtsev, T. Kutter, M. Malinský, D. A. Martinez Caicedo, R. N. Mohapatra, P. Nath, S. Nussinov, J. P. Ochoa-Ricoux, V. Pec, A. Rafique, J. Rodriguez Rondon, R. Shrock, H. W. Sobel, T. Stokes, M. Strait, R. Svoboda Mar 2024

Searches For Baryon Number Violation In Neutrino Experiments: A White Paper, P. S.B. Dev, L. W. Koerner, S. Saad, S. Antusch, M. Askins, K. S. Babu, J. L. Barrow, J. Chakrabortty, A. De Gouvêa, Z. Djurcic, S. Girmohanta, I. Gogoladze, M. C. Goodman, A. Higuera, D. Kalra, G. Karagiorgi, E. Kearns, V. A. Kudryavtsev, T. Kutter, M. Malinský, D. A. Martinez Caicedo, R. N. Mohapatra, P. Nath, S. Nussinov, J. P. Ochoa-Ricoux, V. Pec, A. Rafique, J. Rodriguez Rondon, R. Shrock, H. W. Sobel, T. Stokes, M. Strait, R. Svoboda

Faculty Publications

Baryon number conservation is not guaranteed by any fundamental symmetry within the standard model, and therefore has been a subject of experimental and theoretical scrutiny for decades. So far, no evidence for baryon number violation has been observed. Large underground detectors have long been used for both neutrino detection and searches for baryon number violating processes. The next generation of large neutrino detectors will seek to improve upon the limits set by past and current experiments and will cover a range of lifetimes predicted by several Grand Unified Theories. In this White Paper, we summarize theoretical motivations and experimental aspects …


Euhforia Modelling Of The Sun-Earth Chain Of The Magnetic Cloud Of 28 June 2013, G Prete, A Niemela, B Schmieder, Nada Al-Haddad, Bin Zhuang, F Lepreti, V Carbone, S Poedts Mar 2024

Euhforia Modelling Of The Sun-Earth Chain Of The Magnetic Cloud Of 28 June 2013, G Prete, A Niemela, B Schmieder, Nada Al-Haddad, Bin Zhuang, F Lepreti, V Carbone, S Poedts

Faculty Publications

Context. Predicting geomagnetic events starts with an understanding of the Sun-Earth chain phenomena in which (interplanetary) coronal mass ejections (CMEs) play an important role in bringing about intense geomagnetic storms. It is not always straightforward to determine the solar source of an interplanetary coronal mass ejection (ICME) detected at 1 au. Aims. The aim of this study is to test by a magnetohydrodynamic (MHD) simulation the chain of a series of CME events detected from L1 back to the Sun in order to determine the relationship between remote and in situ CMEs. Methods. We analysed both remote-sensing observations and in …


X-Ray Polarization Of The Black Hole X-Ray Binary 4u 1630–47 Challenges The Standard Thin Accretion Disk Scenario, Ajay Ratheesh, Michal Dovčiak, Henric Krawczynski, Jakub Podgorný, Lorenzo Marra, Alexandra Veledina, Valery F. Suleimanov, Nicole Rodriguez Cavero, James F. Steiner, Jiří Svoboda, Andrea Marinucci, Stefano Bianchi, Michela Negro, Giorgio Matt, Francesco Tombesi, Juri Poutanen, Adam Ingram, Roberto Taverna, Andrew West, Vladimir Karas, Francesco Ursini, Paolo Soffitta, Fiamma Capitanio, Domenico Viscolo, Alberto Manfreda Mar 2024

X-Ray Polarization Of The Black Hole X-Ray Binary 4u 1630–47 Challenges The Standard Thin Accretion Disk Scenario, Ajay Ratheesh, Michal Dovčiak, Henric Krawczynski, Jakub Podgorný, Lorenzo Marra, Alexandra Veledina, Valery F. Suleimanov, Nicole Rodriguez Cavero, James F. Steiner, Jiří Svoboda, Andrea Marinucci, Stefano Bianchi, Michela Negro, Giorgio Matt, Francesco Tombesi, Juri Poutanen, Adam Ingram, Roberto Taverna, Andrew West, Vladimir Karas, Francesco Ursini, Paolo Soffitta, Fiamma Capitanio, Domenico Viscolo, Alberto Manfreda

Faculty Publications

A large energy-dependent X-ray polarization degree is detected by the Imaging X-ray Polarimetry Explorer (IXPE) in the high-soft emission state of the black hole X-ray binary 4U 1630–47. The highly significant detection (at ≈50σ confidence level) of an unexpectedly high polarization, rising from ∼6% at 2 keV to ∼10% at 8 keV, cannot be easily reconciled with standard models of thin accretion disks. In this work, we compare the predictions of different theoretical models with the IXPE data and conclude that the observed polarization properties are compatible with a scenario in which matter accretes onto the black hole through a …


A Simplified Model For The Study Of Film-Boiling Droplet Motion On Microscale Ratchets, Sheldon Wang, Jeong Tae Ok, Sunggook Park, Mahmoud Elsharafi, Yu Guo Mar 2024

A Simplified Model For The Study Of Film-Boiling Droplet Motion On Microscale Ratchets, Sheldon Wang, Jeong Tae Ok, Sunggook Park, Mahmoud Elsharafi, Yu Guo

Faculty Publications

In this work, we explore a simplified model based on both analytical and computational methods for the study of film-boiling droplet motion on microscale ratchets. We consider a specific ratchet design with the length periods and depth of ratchets much smaller than the size of the droplet. We conclude based on our modeling that for the ratchet configuration considered in this paper, the conduction within the vapor film is the dominant means of heat transfer in comparison with convection and radiation. Furthermore, we demonstrate a more manageable two-dimensional model in which analytical approaches coupled with computational approaches yield reasonably accurate …


Association Between Short Birth Spacing And Child Malnutrition In Bangladesh: A Propensity Score Matching Approach, Foyez Ahmmed, Nahid Hasan, Faruk Hossain, Tareq Ferdous Khan Mar 2024

Association Between Short Birth Spacing And Child Malnutrition In Bangladesh: A Propensity Score Matching Approach, Foyez Ahmmed, Nahid Hasan, Faruk Hossain, Tareq Ferdous Khan

Faculty Publications

Objectives: This study aimed to explore the effects of short birth spacing (SBS), which is defined as a period of less than 33 months between two successive births, on multiple concurrent forms of child malnutrition (MCFCM) and at least one form of child malnutrition (ALOFCM) using propensity score matching (PSM). Methods: This study used data extracted from the 2017- 18 Bangladesh Demographic and Health Survey. PSM with four different distance functions, including logistic regression, classification and regression tree, single hidden layer neural network and random forest, were performed to evaluate the effects of SBS on MCFCM and ALOFCM. We also …


Euhforia Modelling Of The Sun-Earth Chain Of The Magnetic Cloud Of 28 June 2013, G Prete, A Niemela, B Schmieder, Nada Al-Haddad, Bin Zhuang, F Lepreti, V Carbone, S Poedts Mar 2024

Euhforia Modelling Of The Sun-Earth Chain Of The Magnetic Cloud Of 28 June 2013, G Prete, A Niemela, B Schmieder, Nada Al-Haddad, Bin Zhuang, F Lepreti, V Carbone, S Poedts

Faculty Publications

Context. Predicting geomagnetic events starts with an understanding of the Sun-Earth chain phenomena in which (interplanetary) coronal mass ejections (CMEs) play an important role in bringing about intense geomagnetic storms. It is not always straightforward to determine the solar source of an interplanetary coronal mass ejection (ICME) detected at 1 au. Aims. The aim of this study is to test by a magnetohydrodynamic (MHD) simulation the chain of a series of CME events detected from L1 back to the Sun in order to determine the relationship between remote and in situ CMEs. Methods. We analysed both remote-sensing observations and in …


X-Ray Polarization Of The Black Hole X-Ray Binary 4u 1630–47 Challenges The Standard Thin Accretion Disk Scenario, Ajay Ratheesh, Michal Dovčiak, Henric Krawczynski, Jakub Podgorný, Lorenzo Marra, Alexandra Veledina, Valery F. Suleimanov, Nicole Rodriguez Cavero, James F. Steiner, Jiří Svoboda, Andrea Marinucci, Stefano Bianchi, Michela Negro, Giorgio Matt, Francesco Tombesi, Juri Poutanen, Adam Ingram, Roberto Taverna, Andrew West, Vladimir Karas, Francesco Ursini, Paolo Soffitta, Fiamma Capitanio, Domenico Viscolo, Alberto Manfreda, Fabio Muleri, Maxime Parra, Banafsheh Beheshtipour, Sohee Chun, Nicolò Cibrario, Niccolò Di Lalla, Sergio Fabiani, Kun Hu, Philip Kaaret, Vladislav Loktev, Romana Mikušincová, Tsunefumi Mizuno, Nicola Omodei, Pierre-Olivier Petrucci, Simonetta Puccetti, John Rankin, Silvia Zane, Sixuan Zhang, Iván Agudo, Lucio A. Antonelli, Matteo Bachetti, Luca Baldini, Wayne H. Baumgartner, Ronaldo Bellazzini, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Niccolò Bucciantini, Simone Castellano, Elisabetta Cavazzuti, Chien-Ting Chen, Stefano Ciprini, Enrico Costa, Alessandra De Rosa, Ettore Del Monte, Laura Di Gesu, Alessandro Di Marco, Immacolata Donnarumma, Victor Doroshenko, Steven R. Ehlert, Teruaki Enoto, Yuri Evangelista, Riccardo Ferrazzoli, Javier A. Garcia, Shuichi Gunji, Kiyoshi Hayashida, Jeremy Heyl, Wataru Iwakiri, Svetlana G. Jorstad, Fabian Kislat, Takao Kitaguchi, Jeffery J. Kolodziejczak, Fabio La Monaca, Luca Latronico, Ioannis Liodakis, Simone Maldera, Frédéric Marin, Alan P. Marscher, Herman L. Marshall, Francesco Massaro, Ikuyuki Mitsuishi, Stephen C.-Y. Ng, Stephen L. O'Dell, Chiara Oppedisano, Alessandro Papitto, George G. Pavlov, Abel L. Peirson, Matteo Perri, Melissa Pesce-Rollins, Maura Pilia, Andrea Possenti, Brian D. Ramsey, Oliver J. Roberts, Roger W. Romani, Carmelo Sgrò, Patrick Slane, Gloria Spandre, Douglas A. Swartz, Toru Tamagawa, Fabrizio Tavecchio, Yuzuru Tawara, Allyn F. Tennant, Nicholas E. Thomas, Alessio Trois, Sergey S. Tsygankov, Roberto Turolla, Jacco Vink, Martin C. Weisskopf, Kinwah Wu, Fei Xie Mar 2024

X-Ray Polarization Of The Black Hole X-Ray Binary 4u 1630–47 Challenges The Standard Thin Accretion Disk Scenario, Ajay Ratheesh, Michal Dovčiak, Henric Krawczynski, Jakub Podgorný, Lorenzo Marra, Alexandra Veledina, Valery F. Suleimanov, Nicole Rodriguez Cavero, James F. Steiner, Jiří Svoboda, Andrea Marinucci, Stefano Bianchi, Michela Negro, Giorgio Matt, Francesco Tombesi, Juri Poutanen, Adam Ingram, Roberto Taverna, Andrew West, Vladimir Karas, Francesco Ursini, Paolo Soffitta, Fiamma Capitanio, Domenico Viscolo, Alberto Manfreda, Fabio Muleri, Maxime Parra, Banafsheh Beheshtipour, Sohee Chun, Nicolò Cibrario, Niccolò Di Lalla, Sergio Fabiani, Kun Hu, Philip Kaaret, Vladislav Loktev, Romana Mikušincová, Tsunefumi Mizuno, Nicola Omodei, Pierre-Olivier Petrucci, Simonetta Puccetti, John Rankin, Silvia Zane, Sixuan Zhang, Iván Agudo, Lucio A. Antonelli, Matteo Bachetti, Luca Baldini, Wayne H. Baumgartner, Ronaldo Bellazzini, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Niccolò Bucciantini, Simone Castellano, Elisabetta Cavazzuti, Chien-Ting Chen, Stefano Ciprini, Enrico Costa, Alessandra De Rosa, Ettore Del Monte, Laura Di Gesu, Alessandro Di Marco, Immacolata Donnarumma, Victor Doroshenko, Steven R. Ehlert, Teruaki Enoto, Yuri Evangelista, Riccardo Ferrazzoli, Javier A. Garcia, Shuichi Gunji, Kiyoshi Hayashida, Jeremy Heyl, Wataru Iwakiri, Svetlana G. Jorstad, Fabian Kislat, Takao Kitaguchi, Jeffery J. Kolodziejczak, Fabio La Monaca, Luca Latronico, Ioannis Liodakis, Simone Maldera, Frédéric Marin, Alan P. Marscher, Herman L. Marshall, Francesco Massaro, Ikuyuki Mitsuishi, Stephen C.-Y. Ng, Stephen L. O'Dell, Chiara Oppedisano, Alessandro Papitto, George G. Pavlov, Abel L. Peirson, Matteo Perri, Melissa Pesce-Rollins, Maura Pilia, Andrea Possenti, Brian D. Ramsey, Oliver J. Roberts, Roger W. Romani, Carmelo Sgrò, Patrick Slane, Gloria Spandre, Douglas A. Swartz, Toru Tamagawa, Fabrizio Tavecchio, Yuzuru Tawara, Allyn F. Tennant, Nicholas E. Thomas, Alessio Trois, Sergey S. Tsygankov, Roberto Turolla, Jacco Vink, Martin C. Weisskopf, Kinwah Wu, Fei Xie

Faculty Publications

A large energy-dependent X-ray polarization degree is detected by the Imaging X-ray Polarimetry Explorer (IXPE) in the high-soft emission state of the black hole X-ray binary 4U 1630–47. The highly significant detection (at ≈50σ confidence level) of an unexpectedly high polarization, rising from ∼6% at 2 keV to ∼10% at 8 keV, cannot be easily reconciled with standard models of thin accretion disks. In this work, we compare the predictions of different theoretical models with the IXPE data and conclude that the observed polarization properties are compatible with a scenario in which matter accretes onto the black hole through a …


Random Forests For Detecting Weak Signals And Extracting Physical Information: A Case Study Of Magnetic Navigation, Mohammadamin Moradi, Zheng-Meng Zhai, Aaron Nielsen, Ying-Cheng Lai, Aaron P. Nielsen Mar 2024

Random Forests For Detecting Weak Signals And Extracting Physical Information: A Case Study Of Magnetic Navigation, Mohammadamin Moradi, Zheng-Meng Zhai, Aaron Nielsen, Ying-Cheng Lai, Aaron P. Nielsen

Faculty Publications

It has been recently demonstrated that two machine-learning architectures, reservoir computing and time-delayed feed-forward neural networks, can be exploited for detecting the Earth’s anomaly magnetic field immersed in overwhelming complex signals for magnetic navigation in a GPS-denied environment. The accuracy of the detected anomaly field corresponds to a positioning accuracy in the range of 10–40 m. To increase the accuracy and reduce the uncertainty of weak signal detection as well as to directly obtain the position information, we exploit the machine-learning model of random forests that combines the output of multiple decision trees to give optimal values of the physical …


Seasonal Variability And Predictability Of Monsoon Precipitation In Southern Africa, Matthew F. Horan, Fred Kucharski, Moetasim Ashfaq Mar 2024

Seasonal Variability And Predictability Of Monsoon Precipitation In Southern Africa, Matthew F. Horan, Fred Kucharski, Moetasim Ashfaq

Faculty Publications

Rainfed agriculture is the mainstay of economies across Southern Africa (SA), where most precipitation is received during the austral summer monsoon. This study aims to further our understanding of monsoon precipitation predictability over SA. We use three natural climate forcings, El Niño–Southern Oscillation, Indian Ocean Dipole (IOD), and the Indian Ocean Precipitation Dipole (IOPD)—the dominant precipitation variability mode—to construct an empirical model that exhibits significant skill over SA during monsoon in explaining precipitation variability and in forecasting it with a five-month lead. While most explained precipitation variance (50%–75%) comes from contemporaneous IOD and IOPD, preconditioning all three forcings is key …


The Behavior Of ½⟨111⟩ Screw Dislocations In W–Mo Alloys Analyzed Through Atomistic Simulations, Lucas A. Heaton, Kevin Chu, Adib J. Samin Feb 2024

The Behavior Of ½⟨111⟩ Screw Dislocations In W–Mo Alloys Analyzed Through Atomistic Simulations, Lucas A. Heaton, Kevin Chu, Adib J. Samin

Faculty Publications

Analyzing plastic flow in refractory alloys is relevant to many different commercial and technological applications. In this study, screw dislocation statics and dynamics were studied for various compositions of the body-centered cubic binary alloy tungsten–molybdenum (W–Mo). The core structure did not appear to change for different alloy compositions, consistent with the literature. The pure tungsten and pure molybdenum samples had the lowest plastic flow, while the highest dislocation velocities were observed for equiatomic, W0.5Mo0.5 alloys. In general, dislocation velocities were found to largely align with a well-established dislocation mobility phenomenological model supporting two discrete dislocation mobility regimes, …


New Features Of Laboratory-Generated Epfrs From 1,2-Dichlorobenzene (Dcb) And 2-Monochlorophenol (Mcp), Lavrent Khachatryan, Marwan Y. Rezk, Divine Nde, Farhana Hasan, Slawomir Lomnicki, Dorin Boldor, Robert Cook, Phillip Sprunger, Randall Hall, Stephania Cormier Feb 2024

New Features Of Laboratory-Generated Epfrs From 1,2-Dichlorobenzene (Dcb) And 2-Monochlorophenol (Mcp), Lavrent Khachatryan, Marwan Y. Rezk, Divine Nde, Farhana Hasan, Slawomir Lomnicki, Dorin Boldor, Robert Cook, Phillip Sprunger, Randall Hall, Stephania Cormier

Faculty Publications

The present research is primarily focused on investigating the characteristics of environmentally persistent free radicals (EPFRs) generated from commonly recognized aromatic precursors, namely, 1,2-dichlorobenzene (DCB) and 2-monochlorophenol (MCP), within controlled laboratory conditions at a temperature of 230 °C, termed as DCB230 and MCP230 EPFRs, respectively. An intriguing observation has emerged during the creation of EPFRs from MCP and DCB utilizing a catalyst 5% CuO/SiO2, which was prepared through various methods. A previously proposed mechanism, advanced by Dellinger and colleagues (a conventional model), postulated a positive correlation between the degree of hydroxylation on the catalyst’s surface (higher hydroxylated, HH and less …