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  1. Free, publicly-accessible full text available June 30, 2024
  2. Research has highlighted that actively involving students during instruction can lead to positive outcomes for students. However, college mathematics instructors may need support to develop the knowledge and skills necessary to effectively implement this type of instruction. This study looks at how college algebra instructors in a grant-supported professional learning community (PLC) focus on different aspects of their own and others’ teaching. We leverage the instructional triangle as an analytical framework to characterize the foci of participants’ observations. We analyzed PLC meetings where participants reported on specific aspects of each other’s observed classes. Our analysis revealed that instructors each had a primary focus that drove their observations. We anticipate these different foci will inform future PLC meetings and lead to new questions about instructor thinking, and to continued development of the instructional triangle.
    Free, publicly-accessible full text available January 1, 2024

    The Vera C. Rubin Observatory Wide-Fast Deep sky survey will reach unprecedented surface brightness depths over tens of thousands of square degrees. Surface brightness photometry has traditionally been a challenge. Current algorithms which combine object detection with sky estimation systematically oversubtract the sky, biasing surface brightness measurements at the faint end and destroying or severely compromising low surface brightness light. While it has recently been shown that properly accounting for undetected faint galaxies and the wings of brighter objects can in principle recover a more accurate sky estimate, this has not yet been demonstrated in practice. Obtaining a consistent spatially smooth underlying sky estimate is particularly challenging in the presence of representative distributions of bright and faint objects. In this paper, we use simulations of crowded and uncrowded fields designed to mimic Hyper Suprime-Cam data to perform a series of tests on the accuracy of the recovered sky. Dependence on field density, galaxy type, and limiting flux for detection are all considered. Several photometry packages are utilized: source extractor, gnuastro, and the LSST science pipelines. Each is configured in various modes, and their performance at extreme low surface brightness analysed. We find that the combination of the source extractormore »software package with novel source model masking techniques consistently produce extremely faint output sky estimates, by up to an order of magnitude, as well as returning high fidelity output science catalogues.

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  4. Graphene layers placed on SrTiO3 single-crystal substrates, i.e., templates for remote epitaxy of functional oxide membranes, were investigated using temperature-dependent confocal Raman spectroscopy. This approach successfully resolved distinct Raman modes of graphene that are often untraceable in conventional measurements with non-confocal optics due to the strong Raman scattering background of SrTiO3. Information on defects and strain states was obtained for a few graphene/SrTiO3 samples that were synthesized by different techniques. This confocal Raman spectroscopic approach can shed light on the investigation of not only this graphene/SrTiO3 system but also various two-dimensional layered materials whose Raman modes interfere with their substrates.

    Free, publicly-accessible full text available March 8, 2024
  5. Free, publicly-accessible full text available November 1, 2023
  6. The Merian survey is mapping 850 degrees2 of the Hyper Suprime-Cam Strategic Survey Program (HSC-SSP) wide layer with two medium-band filters on the 4-meter Victor M. Blanco telescope at Cerro Tololo Inter-American Observatory, with the goal of carrying the first high signal-to-noise (S/N) measurements of weak gravitational lensing around dwarf galaxies. This paper presents the design of the Merian filter set: N708 and N540. The central wavelengths and filter widths of N708 and N540 were designed to detect the Ha and [OIII] emission lines of galaxies in the mass range 8 to 9 by comparing Merian fluxes with HSC broad-band fluxes. Our filter design takes into account the weak lensing S/N and photometric redshift performance. Our simulations predict that Merian will yield a sample of 85,000 star-forming dwarf galaxies with a photometric redshift accuracy of $Delta z/(1+z)= 0.01 and an outlier fraction of eta=2.8% over the redshift range 0.058more »the interplay between dark matter and stellar feedback and their roles in the evolution of dwarf galaxies.« less
    Free, publicly-accessible full text available May 30, 2024
  7. Free, publicly-accessible full text available June 1, 2024
  8. A formal pedagogical push emerged and later blossomed in designing integrated curriculum between STEM and non-STEM areas in secondary and higher education. A growing cadre of research identifies positive learning outcomes for students participating in an integrated curriculum who apply basic STEM knowledge to investigate social problems and justice issues within social contexts. Research indicates STEM students demonstrate fewer concerns with social issues, often placing a greater interest in the value of individualism. This article outlines a new integrative course, Science, Society and Self, which was supported by a National Science Foundation grant to Iona College in the Scholarships in Science, Technology, Engineering, and Mathematics (S-STEM) program. The Development of Excellence in Science through Intervention, Resilience, and Enrichment (DESIRE) program seeks to increase retention and graduation rates for economically disadvantaged and high-aptitude STEM majors. Skills important for success in STEM courses are reviewed, as are service-learning and policy applications. We also explore the intersections between nature of science (NOS) and sociological concepts. This culminates in distinguishing public science issues by connecting the intersections of human biographies, history, and societal structures through the sociological imagination, as conceived by C. Wright Mills.
  9. Abstract Recent rapid thinning of West Antarctic ice shelves are believed to be caused by intrusions of warm deep water that induce basal melting and seaward meltwater export. This study uses data from three bottom-mounted mooring arrays to show seasonal variability and local forcing for the currents moving into and out of the Dotson ice shelf cavity. A southward flow of warm, salty water had maximum current velocities along the eastern channel slope, while northward outflows of freshened ice shelf meltwater spread at intermediate depth above the western slope. The inflow correlated with the local ocean surface stress curl. At the western slope, meltwater outflows followed the warm influx along the eastern slope with a ~2–3 month delay. Ocean circulation near Dotson Ice Shelf, affected by sea ice distribution and wind, appears to significantly control the inflow of warm water and subsequent ice shelf melting on seasonal time-scales.
    Free, publicly-accessible full text available December 1, 2023