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Creators/Authors contains: "Choi, J"

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  1. Pre-college engineering teachers bring unique backgrounds to their teaching practice. Many engineering teachers follow a non-traditional route to teaching engineering, often coming to engineering from teaching other subjects or from careers in other fields. Among the many variations influencing engineering teaching practices is pedagogical content knowledge (PCK), defined as the “the knowledge of, reasoning behind, and enactment of the teaching of particular topics in a particular way with particular students for particular reasons for enhanced student outcomes [1]”. This multiple case study explores the PCK of five middle school engineering teachers implementing the same middle school engineering curriculum, STEM-ID. The 18- week STEM-ID curriculum engages students in contextualized challenges that incorporate foundational mathematics and science practices and advanced manufacturing tools such as computer aided design (CAD) and 3D printing, while introducing engineering concepts like pneumatics, aeronautics, and robotics. Drawing on observation and interview data collected over the course of two semester-long implementations of STEM-ID, the study addresses the research question: What variations in PCK are evident among engineering teachers with different professional backgrounds and levels of experience? Five teachers were purposively selected from a larger group of teachers implementing the curriculum because they represent a range of professional backgrounds: one veteran engineering teacher, one former Math teacher, one former Science teacher, one former English/Language Arts teacher, and one novice teacher with a background in the software industry. The study utilizes the Refined Consensus Model of PCK to investigate connections between teacher backgrounds, personal PCK (pPCK), the personalized professional knowledge held by teachers, and enacted PCK (ePCK), the knowledge teachers draw on to engage in pedagogical reasoning while planning, teaching, and reflecting on their practice. Observation, interview, and survey data were triangulated to develop narrative case summaries describing each teacher’s PCK, which were then subjected to cross-case analysis to identify patterns and themes across teachers. Findings describe how teachers’ backgrounds translated into diverse forms of pPCK that informed the pedagogical moves and decisions teachers made as they implemented the curriculum (ePCK). Regardless of the previous subject taught (math, science, or ELA), teachers routinely drew upon their pPCK in other subjects as they facilitated the engineering design process. Teachers with previous experience teaching math or science tended to be more likely than others to foreground the integration of math or science within the curriculum. Comparison of ePCK observed as teachers implemented the curriculum revealed that, in spite of having a more fully developed pPCK in teaching engineering, the veteran engineering teacher did not exhibit more sophisticated ePCK than novice engineering teachers. In addition to contributing to the field’s understanding of engineering teachers’ PCK, these findings hold implications for the recruitment, retention, and professional development of engineering teachers. 
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    Free, publicly-accessible full text available June 22, 2026
  2. Gentry, E; Ju, F; Liu, X (Ed.)
    Free, publicly-accessible full text available June 1, 2026
  3. Free, publicly-accessible full text available July 1, 2026
  4. We present VoiceCraft-Dub, a novel approach for automated video dubbing that synthesizes high-quality speech from text and facial cues. This task has broad applications in filmmaking, multimedia creation, and assisting voice-impaired individuals. Building on the success of Neural Codec Language Models (NCLMs) for speech synthesis, our method extends their capabilities by incorporating video features, ensuring that synthesized speech is time-synchronized and expressively aligned with facial movements while preserving natural prosody. To inject visual cues, we design adapters to align facial features with the NCLM token space and introduce audio-visual fusion layers to merge audio-visual information within the NCLM framework. Additionally, we curate CelebV-Dub, a new dataset of expressive, real-world videos specifically designed for automated video dubbing. Extensive experiments show that our model achieves high-quality, intelligible, and natural speech synthesis with accurate lip synchronization, outperforming existing methods in human perception and performing favorably in objective evaluations. We also adapt VoiceCraft-Dub for the video-to-speech task, demonstrating its versatility for various applications. 
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    Free, publicly-accessible full text available April 3, 2026
  5. We present a quantum network that distributes entangled photons between the University of Illinois Urbana-Champaign and a public library in Urbana. The network allows members of the public to perform measurements on the photons. We describe its design and implementation and outreach based on the network. Over 400 instances of public interaction have been logged with the system since it was launched in November 2023. 
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