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Creators/Authors contains: "Koh, D"

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  1. This convergent mixed method study investigates learner engagement during a blended, transmedia curriculum called CryptoComics which is designed to teach 3rd-5th graders about cryptology and cybersecurity. Curriculum design is presented through the lens of four engagement facilitators: (1) anchoring the curriculum with a comic book, (2) blending digital and unplugged media, (3) supporting situational interest via a transmedia narrative and (4) designing for social-cultural relevance. Latent profile analysis is used to develop profiles of learner engagement using quantitative indicators of cognitive and emotional engagement collected across 204 students at 13 implementation sites in the Eastern U.S. Qualitative indicators of engagement include teacher weekly check-ins submitted by 17 teachers working at the 13 implementation sites, student interviews, and classroom observations of 26 students participating in the curriculum at two local sites. Quantitative and qualitative results converge to suggest the majority of the students participating in the curriculum were highly engaged cognitively and emotionally. Qualitative data (1) suggest some third graders may be less cognitively engaged due to challenging content, (2) provide evidence for how design of the blended, transmedia curriculum supported, and some cases hindered, engagement, (3) highlight the importance of transitions between blended learning components in facilitating engagement and (4) uncover questions regarding one of the quantitative measures selected as an indicator of cognitive engagement. 
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  2. K-12 teachers and students are vulnerable to cybersecurity attacks and mostly ill-prepared to deal with them. The CO- VID-19 pandemic has only increased these risks because of the reliance on digital technology in education and increased free time young children and adolescents spend online. Simultaneously, the U.S. is facing an extreme shortage of cybersecurity professionals. Given the rise of cyberattacks and the need for cybersecurity professionals, a concerted effort to prepare preservice teachers to integrate cybersecurity education across the K-12 curriculum is needed. In our vision for 2025, all preservice teachers across the country are prepared to integrate age-appropriate cybersecurity concepts, skills and career awareness in the curriculum regardless of their content area or grade level specialization. We propose a repository of stand-alone activities and full curricula developed through collaboration among K-12 educators, teacher educators, and cybersecurity experts that could be adopted across teacher education programs. We use the elementary grades as a con- text for providing examples of some activities that might be included in the repository. We also provide recommendations for developing such a repository and for individual teacher educators who want integrate cybersecurity education in pre-service teacher education right now. 
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  3. We present a search for long-lived particles (LLPs), produced in kaon decays, that decay to two muons inside the ICARUS neutrino detector. This channel would be a signal of hidden sector models that can address outstanding issues in particle physics such as the strong CP problem and the microphysical origin of dark matter. The search is performed with data collected in the Neutrinos at the Main Injector (NuMI) beam at Fermilab corresponding to 2.41 × 10 20 protons-on-target. No new physics signal is observed, and we set world leading limits on heavy QCD axions, as well as for the Higgs portal scalar among dedicated searches. Limits are also presented in a model-independent way applicable to any new physics model predicting the process K π + S ( μ μ ) , for a LLP S . This result is the first search for new physics performed with the ICARUS detector at Fermilab. It paves the way for the future program of LLP searches at ICARUS. Published by the American Physical Society2025 
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    Free, publicly-accessible full text available April 1, 2026
  4. Abstract This paper reports on a measurement of electron-ion recombination in liquid argon in the ICARUS liquid argon time projection chamber (LArTPC). A clear dependence of recombination on the angle of the ionizing particle track relative to the drift electric field is observed. An ellipsoid modified box (EMB) model of recombination describes the data across all measured angles. These measurements are used for the calorimetric energy scale calibration of the ICARUS TPC, which is also presented. The impact of the EMB model is studied on calorimetric particle identification, as well as muon and proton energy measurements. Accounting for the angular dependence in EMB recombination improves the accuracy and precision of these measurements. 
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  5. Abstract The ICARUS liquid argon time projection chamber (LArTPC) neutrino detector has been taking physics data since 2022 as part of the Short-Baseline Neutrino (SBN) Program. This paper details the equalization of the response to charge in the ICARUS time projection chamber (TPC), as well as data-driven tuning of the simulation of ionization charge signals and electronics noise. The equalization procedure removes non-uniformities in the ICARUS TPC response to charge in space and time. This work leverages the copious number of cosmic ray muons available to ICARUS at the surface. The ionization signal shape simulation applies a novel procedure that tunes the simulation to match what is measured in data. The end result of the equalization procedure and simulation tuning allows for a comparison of charge measurements in ICARUS between Monte Carlo simulation and data, showing good performance with minimal residual bias between the two. 
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  6. Abstract The Pandora Software Development Kit and algorithm libraries perform reconstruction of neutrino interactions in liquid argon time projection chamber detectors. Pandora is the primary event reconstruction software used at the Deep Underground Neutrino Experiment, which will operate four large-scale liquid argon time projection chambers at the far detector site in South Dakota, producing high-resolution images of charged particles emerging from neutrino interactions. While these high-resolution images provide excellent opportunities for physics, the complex topologies require sophisticated pattern recognition capabilities to interpret signals from the detectors as physically meaningful objects that form the inputs to physics analyses. A critical component is the identification of the neutrino interaction vertex. Subsequent reconstruction algorithms use this location to identify the individual primary particles and ensure they each result in a separate reconstructed particle. A new vertex-finding procedure described in this article integrates a U-ResNet neural network performing hit-level classification into the multi-algorithm approach used by Pandora to identify the neutrino interaction vertex. The machine learning solution is seamlessly integrated into a chain of pattern-recognition algorithms. The technique substantially outperforms the previous BDT-based solution, with a more than 20% increase in the efficiency of sub-1 cm vertex reconstruction across all neutrino flavours. 
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    Free, publicly-accessible full text available June 1, 2026
  7. The determination of the direction of a stellar core collapse via its neutrino emission is crucial for the identification of the progenitor for a multimessenger follow-up. A highly effective method of reconstructing supernova directions within the Deep Underground Neutrino Experiment (DUNE) is introduced. The supernova neutrino pointing resolution is studied by simulating and reconstructing electron-neutrino charged-current absorption on Ar 40 and elastic scattering of neutrinos on electrons. Procedures to reconstruct individual interactions, including a newly developed technique called “brems flipping,” as well as the burst direction from an ensemble of interactions are described. Performance of the burst direction reconstruction is evaluated for supernovae happening at a distance of 10 kpc for a specific supernova burst flux model. The pointing resolution is found to be 3.4 degrees at 68% coverage for a perfect interaction-channel classification and a fiducial mass of 40 kton, and 6.6 degrees for a 10 kton fiducial mass respectively. Assuming a 4% rate of charged-current interactions being misidentified as elastic scattering, DUNE’s burst pointing resolution is found to be 4.3 degrees (8.7 degrees) at 68% coverage. Published by the American Physical Society2025 
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    Free, publicly-accessible full text available May 1, 2026
  8. ProtoDUNE Single-Phase (ProtoDUNE-SP) is a 770-ton liquid argon time projection chamber that operated in a hadron test beam at the CERN Neutrino Platform in 2018. We present a measurement of the total inelastic cross section of charged kaons on argon as a function of kaon energy using 6 and 7 GeV / c beam momentum settings. The flux-weighted average of the extracted inelastic cross section at each beam momentum setting was measured to be 380 ± 26 mbarns for the 6 GeV / c setting and 379 ± 35 mbarns for the 7 GeV / c setting. Published by the American Physical Society2024 
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  9. The Module-0 Demonstrator is a single-phase 600 kg liquid argon time projection chamber operated as a prototype for the DUNE liquid argon near detector. Based on the ArgonCube design concept, Module-0 features a novel 80k-channel pixelated charge readout and advanced high-coverage photon detection system. In this paper, we present an analysis of an eight-day data set consisting of 25 million cosmic ray events collected in the spring of 2021. We use this sample to demonstrate the imaging performance of the charge and light readout systems as well as the signal correlations between the two. We also report argon purity and detector uniformity measurements and provide comparisons to detector simulations. 
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