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Creators/Authors contains: "Feng, Song"

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  1. Abstract The solar corona is two to three orders of magnitude hotter than the underlying photosphere, and the energy loss of coronal plasma is extremely strong, requiring a heating flux of over 1,000 W m − 2 to maintain its high temperature. Using the 1.6 m Goode Solar Telescope, we report a detection of ubiquitous and persistent transverse waves in umbral fibrils in the chromosphere of a strongly magnetized sunspot. The energy flux carried by these waves was estimated to be 7.52 × 10 6  W m −2 , three to four orders of magnitude stronger than the energy loss rate of plasma in active regions. Two-fluid magnetohydrodynamic simulations reproduced the high-resolution observations and showed that these waves dissipate significant energy, which is vital for coronal heating. Such transverse oscillations and the associated strong energy flux may exist in a variety of magnetized regions on the Sun, and could be the observational target of next-generation solar telescopes. 
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  2. Abstract Solar images observed in different channels with different instruments are crucial to the study of solar activity. However, the images have different fields of view, causing them to be misaligned. It is essential to accurately register the images for studying solar activity from multiple perspectives. Image registration is described as an optimizing problem from an image to be registered to a reference image. In this paper, we proposed a novel coarse-to-fine solar image registration method to register the multichannel solar images. In the coarse registration step, we used the regular step gradient descent algorithm as an optimizer to maximize the normalized cross correlation metric. The fine registration step uses the Powell–Brent algorithms as an optimizer and brings the Mattes mutual information similarity metric to the minimum. We selected five pairs of images with different resolutions, rotation angles, and shifts to compare and evaluate our results to those obtained by scale-invariant feature transform and phase correlation. The images are observed by the 1.6 m Goode Solar Telescope at Big Bear Solar Observatory and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. Furthermore, we used the mutual information and registration time criteria to quantify the registration results. The results prove that the proposed method not only reaches better registration precision but also has better robustness. Meanwhile, we want to highlight that the method can also work well for the time-series solar image registration. 
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  3. null (Ed.)
    Management education holds promise for addressing deficiencies in interuniversity science, technology, engineering, and mathematics (STEM), as well as sustainability curricula. Accordingly, we designed, developed, implemented, and longitudinally evaluated interdisciplinary STEM-based curricula in the United States. Students in five sections of business management courses and two sections of STEM courses received a STEM-based sustainability intervention (i.e., an interdisciplinary STEM and sustainability module). To assess student outcomes following the intervention and examine the feasibility of cognitive mapping as a student learning assessment tool, we implemented a pre- and post-course modified cognitive mapping assessment in treatment and comparison courses. To interpret the results, we ran descriptives, correlations, paired sample t tests, and principal component analysis. The t tests suggest that when all coding categories are considered, those participating in curricular interventions listed significantly more sustainability terms. The principal component analysis results demonstrate that treatment courses improved variability explained by 7.23% between pre- and post-tests but declined by 8.22% for comparison courses. Overall, linkages became stronger between parent code categories for treatment courses and weaker for comparison courses. These findings add to existing research related to cognitive mapping and demonstrate the ability of the method to capture changes in student outcomes after exposure to STEM-based sustainability curriculum. 
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  4. Abstract Multiwavelength bright points (BPs) are taken to be cross sections of magnetic flux tubes extending from the surface of the photosphere upward to the higher photosphere. We aim to study the characteristics of isolated multiwavelength BPs using the cotemporal and cospatial TiO band and H α line wings from the Goode Solar Telescope at Big Bear Solar Observatory. A deep-learning method, based on Track Region-based Convolutional Neural Networks, is proposed to detect, segment, and match the BPs across multiple wavelength observations, including the TiO, H α + 1 Å, H α − 1 Å, H α + 0.8 Å, and H α − 0.8 Å line wings. Based on the efficient detection and matching result with a precision of 0.98, 1283 groups of BPs matched in all five wavelengths are selected for statistics analysis. The characteristic values of the BPs observed at the same red and blue line wings are averaged. For the BPs of the TiO, averaged H α ± 1 Å, and averaged H α ± 0.8 Å line wings, the mean equivalent diameters are 162 ± 32, 254 ± 33, and 284 ± 28 km, respectively. The maximum intensity contrasts are 1.11 ± 0.09, 1.05 ± 0.03, and 1.05 ± 0.02 , respectively. The mean eccentricities are 0.65 ± 0.14, 0.63 ± 0.11, and 0.65 ± 0.11, respectively. Moreover, the characteristic ratios of each H α ± 1 Å and H α ± 0.8 Å BP to its corresponding TiO BP are derived. H α ± 1 Å and H α ± 0.8 Å line wings BPs show 60% and 80% increases compared to TiO BPs, respectively. With increasing height, most BPs almost keep their shapes. This work is helpful for modeling the three-dimensional structure of flux tubes. 
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  5. To address deficiencies in STEM and sustainability in business management and intra-university curricula, we developed and implemented an interdisciplinary STEM-based sustainability curriculum at a university in the Western United States. Six classes participated in curricular efforts including in-person and online sections of a business management course, in-person and online sections of a general elective STEM course, and a matched control course for each ( n = 214). We systematically designed, developed, and implemented curricular interventions—multi-week STEM-based business sustainability modules—using the case teaching method. A comprehensive evaluation with pre- and post-tests was conducted to assess student sustainability cognition and affect. Significant results emerged for sustainability cognition including the environmental, social, and economic dimensions of sustainability. Counterintuitively, student sustainability affect did not improve. However, sustainability cognition and affect were significantly correlated on the post-test for treatment students, an indication that cognitive and affective changes share the same directionality. Discussion, implications, limitations, and future research directions are provided. 
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  6. Spicules are rapidly evolving fine-scale jets of magnetized plasma in the solar chromosphere. It remains unclear how these prevalent jets originate from the solar surface and what role they play in heating the solar atmosphere. Using the Goode Solar Telescope at the Big Bear Solar Observatory, we observed spicules emerging within minutes of the appearance of opposite-polarity magnetic flux around dominant-polarity magnetic field concentrations. Data from the Solar Dynamics Observatory showed subsequent heating of the adjacent corona. The dynamic interaction of magnetic fields (likely due to magnetic reconnection) in the partially ionized lower solar atmosphere appears to generate these spicules and heat the upper solar atmosphere. 
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  7. Climatic variability and shifting weather patterns, resulting in extreme weather events and natural disasters, pose risks to small businesses in the United States. This is particularly true in coastal regions of the southeast United States where extreme events such as hurricanes, flooding, and thunderstorms are projected to increase in frequency and intensity. Yet, the vast majority of small business owners do not have a disaster plan in place and an estimated 40% to 60% of small businesses that have experienced a natural disaster never reopen. This teaching case explores the impact of climatic trends and weather on one location of an outdoor tourism industry business in the coastal community of Virginia Beach, Virginia. The case draws from observed weather and sales data for the local small business. Students will draw from descriptive statistics, statistical analysis, and graphs to explore (a) long-term climatic trends for the business; (b) relationships between small business sales and local weather; and (c) strengths, weaknesses, opportunities, and threats relative to weather conditions and climate change. Instructors can give the body of this document to students. They can also make use of the supplemental teaching notes to assist them with teaching this case. 
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  8. Businesses are increasingly facing economic, social, and environmental sustainability challenges. Science, technology, engineering, and math (STEM) are needed to address business sustainability needs, yet such competencies are noticeably absent from academic literature and business curricula. To mend the curricular gap, we make the case for developing cross-disciplinary STEM-based business sustainability curricula that enhance students’ sustainability literacy and cognitive abilities related to STEM and sustainability. A literature review is provided that documents curricular gaps specific to STEM and sustainability in the academic literature and in business sustainability program offerings. We then present a framework that can be used to integrate STEM and sustainability across the curricula and to evaluate curricular implementation. This review provides timely and relevant information that can help business management educators, instructors, and administrators justify, design, develop, implement, and evaluate STEM-based business sustainability curricula. 
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  9. Abstract Instrumental observations indicate that Amazon precipitation and streamflow extremes have increased during the last 40 years, possibly due to anthropogenic changes and natural variability. How unprecedented these changes might be is difficult to determine because some paleoclimatic, instrumental, and climate model simulations suggest that Amazonian precipitation and streamflow may be subject to multidecadal variability with return intervals longer than most direct observations. A new 258‐yearlong tree‐ring chronology ofCedrela odoratahas been developed in the eastern Amazon and has been used to reconstruct wet season precipitation totals from 1759–2016. Reconstructed drought extremes are associated with significant sea surface temperature anomalies over the tropical Pacific and Atlantic Oceans. Strong multidecadal variance is identified in the reconstruction that may reflect a component of natural rainfall variability relevant to forest ecosystem dynamics and suggesting that recent hydroclimate changes over the eastern Amazon may not be unprecedented over the past 258 years. 
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