• Korean Journal of Plant Taxonomy
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• v.52 no.1
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• pp.45-53
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• 2022

Halenia coreana is an endangered, endemic species that is distributed in only a few locations in Korea, such as Mts. Hwaaksan and Daeamsan. It has been recently segregated from H. corniculata, broadly distributed in cold temperate regions that include northern Japan, the Russian Far East, northeastern China, Mongolia, and eastern Europe, where population sizes are usually large. To examine the genetic diversity of H. coreana and evaluate the level of genetic differentiation of the species compared with that of H. corniculata, we surveyed 183 candidate simple sequence repeats (SSR) motif markers for H. coreana and H. corniculata from sequence data of amplified fragments of a specific length in the genome. A total of 17 genomic-SSR markers were selected to examine the levels of genetic diversity and differentiation using 17 samples of H. coreana and 60 samples of three populations of H. corniculata. The results here suggest that the genetic diversity of H. coreana is very low with a high frequency of inbreeding within its population. We found that H. coreana is genetically differentiated from H. corniculata, supporting the recognition of the geographically isolated H. coreana as a distinct species.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.72.3-72.3
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• 2019

OB associations are young stellar systems on a few tens to a hundred parsec scale, and many of them are composed of multiple substructures. It is suggested that some hints about their formation process are probably imprinted on structural features and internal kinematics. In this context, we study the massive star forming region W4 in the Cassiopeia OB6 association using the Gaia proper motion data and high-resolution optical spectra taken from Hectochelle on MMT. We probe the structure and internal kinematics of W4 to trance its formation process. Several nonmembers with different kinematic properties are excluded in our sample. Some of them may be young stellar population spread over a large area of the Perseus spiral arm given their wide spatial distribution over 50 parsecs. W4 is composed of an central open cluster (IC 1805) and an extended stellar component. Their global expansion patterns are detected in stellar proper motion. In this presentation, we will further discuss the formation process of W4, based on the velocity dispersions of stars comprising these substructure.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.350-350
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• 2021

한국건설기술연구원의 돌발홍수연구센터는 돌발홍수예측 시스템을 구축하여 2019년부터 전국에서의 돌발홍수정보를 제공하고 있다. 2019년에는 초단기 예측 모델인 Macgill Algorithm for Precipitation-nowcast by Lagrangian Extrapolation(MAPLE) 알고리즘으로부터 생산된 초단기 예측 강우를 활용하여 동(읍/면) 단위로 1시간 선행 예보를 제공하였다. 2020년에는 추가로 초단기 예측 강우와 수치예보 자료를 병합한 예측 병합 강우 자료를 생산하여 예측 선행시간을 1시간에서 3시간까지 확장하였다. 돌발홍수예측 시스템의 목표는 도시 및 산지소하천에서의 돌발홍수에 대응하기 위한 정보를 실시간으로 사용자에게 제공하여 수재해에 빠르게 대응하는 것이다. 이에 돌발홍수예측 시스템은 2019년부터 실시간으로 운영하여 홍수기에 보다 빠른 돌발홍수정보를 제공해왔다. 본 연구에서는 2020년 우기에 운영된 돌발홍수시스템에 대한 평가를 수행하였다. 이를 위해 부산(07.23), 대전(07.29), 서울(08.01), 경기-충북(08.02)에서 발생한 수재해 사례를 분석하였다.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.51.1-51.1
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• 2020

The Rosette Nebula is the most actively star-forming region in the Monoceros OB2 association. This region hosts more than three stellar groups, including the most populous group NGC 2244 at the center of the region and the smaller stellar groups around the border of the H II bubble. To trace their formation process, we investigate the kinematic properties of these groups using the Gaia astrometric data and high-resolution spectra taken from observation with Hectochelle on MMT. The proper motions of stars in NGC 2244 show a pattern of radial expansion. The signature of cluster rotation is also detected from their radial velocities. On the other hand, the small groups appear to be physically associated with some clouds at the ridge of the H II region. Among them, the group near the eastern pillar-like gas structure shows the signature of feedback-driven star formation. In this presentation, we will further discuss the formation process and dynamical evolution of the stellar groups in the Rosette Nebula, based on the observation and results of N-body simulations.

• Publications of The Korean Astronomical Society
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• v.38 no.3
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• pp.147-160
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• 2023

In this study, we explore and catalog Korean astronomical heritages that are known to be preserved in foreign countries. We exclude old astronomical books from the catalog because they have been well studied and exist in numbers far too large for the scope of this study. From various documents and online collections, we find a total of 38 Korean astronomical heritages in six countries: 10, 11, and 14 items from the UK, France, and Japan, respectively, and 1 item from Germany, the US, and China each. These include items that are suspected to be of Chinese heritage and items of unconfirmed possession status. We divide the astronomical heritages primarily into two groups: time-keeping instruments (18 items) and astronomical charts (20 items). In this paper, we briefly review them according to country. We believe that this study provides a foundation for further detailed studies on each item, such as the Gujang-Cheonsang-Yeolcha-Bunya-Jido (舊藏天象列次分野之圖) preserved in the Library of Congress, United States.

• Food Science and Preservation
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• v.30 no.4
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• pp.562-572
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• 2023

In this study, we aimed to evaluate the quality of Aralia elata shoots according to different packaging methods during storage at 2℃. The highest level of dehydration and wilting incidences were observed in polypropylene containers with polyvinyl chloride wrap (PP+PVC), and these levels continually increased during the entire storage period, compared to other packaging methods. The overall marketability of A. elata shoot packaged in polyethylene terephthalate container (PET) and PP with the mineral-coted functional warp (PP+F) constantly declined during storage with a similar level of 38.6 and 36.0% at 15 days in storage, respectively. PP with PET cover packaging (PP+PET) showed the lowest decay and wilting rates during the entire storage, and the wilting score at 10th day was 51.9, 58.0, 51.8% suppressed, as compared to PET, PP+PVC, and PP+F, respectively. Consequently PP+PET packaging effectively decreased the deterioration of A. elata and maintained marketability for 10 days of storage at 2℃.

• Nutrition Research and Practice
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• v.18 no.2
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• pp.165-179
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• 2024

BACKGROUND/OBJECTIVES: Mushroom consumption, rich in diverse nutrients and bioactive compounds, is suggested as a potential significant contributor to preventing cardiometabolic diseases (CMDs). This systematic review aimed to explore the association between mushrooms and cardiometabolic health outcomes, utilizing data from prospective cohort studies and clinical trials focusing on the general population, with mushrooms themselves as a major exposure. SUBJECTS/METHODS: All original articles, published in English until July 2023, were identified through searches on PubMed, Ovid-Embase, and google scholar. Of 1,328 studies, we finally selected 5 prospective cohort studies and 4 clinical trials. RESULTS: Existing research is limited, typically consisting of 1 to 2 studies for each CMD and cardiometabolic condition. Examination of articles revealed suggestive associations in some cardiometabolic conditions including blood glucose (both fasting and postprandial), high-density lipoprotein cholesterol related indices, high-sensitivity C-reactive protein, and obesity indices (body weight, body mass index, and waist circumference). However, mushroom consumption showed no association with the mortality and morbidity of cardiovascular diseases, stroke, and type 2 diabetes, although there was a potentially beneficial connection with all cause-mortality, hyperuricemia, and metabolic syndrome. CONCLUSION: Due to the scarcity of available studies, drawing definitive conclusions is premature. Further comprehensive investigations are needed to clarify the precise nature and extent of this relationship before making conclusive recommendations for the general population.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.47.1-47.1
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• 2015

We present an optical spectroscopic study of 28 supernova remnant (SNR) candidates in M81 and two SNR candidates in M82. The optical spectra of these SNR candidates were obtained using the MMT/Hectospec as a part of the K-GMT Science Program. Based on the [S II]/$H{\alpha}$ ratio and the radial velocity, we find that twenty six out of the M81 candidates are genuine SNRs. Two SNR candidates in M82 are thought to be shocked condensations in the galactic outflow or SNRs. In the spectral line ratio diagrams, M81 SNRs are divided into two groups: an [O III]-strong group and an [O III]-weak group. The [O III]-weak SNRs have larger sizes, and may have faster shock velocity. We estimate the nitrogen and oxygen abundance of the SNRs from the comparison with shock-ionization models. We find a radial gradient in nitrogen abundance, $dLog(N/H)/dlogR=-0.023{\pm}0.009\;dex\;kpc^{-1}$ little evidence for the gradient in oxygen abundance. The nitrogen abundance shows shallower gradient than those of the planetary nebulae and H II regions of M81. We find five X-ray emitting SNRs. Their X-ray hardness colors are consistent with thermal SNRs.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.68.2-69
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• 2015

We present [Fe II] $1.644{\mu}m$ features around ultracompact H II regions (UCHIIs) found on a quest for the "footprint" outflow features of UCHIIs -the features produced by outflowing materials ejected during an earlier, active accretion phase of massive young stellar objects (MYSOs). We surveyed 237 UCHIIs in the first Galactic quadrant, employing the CORNISH UCHII catalog and UWIFE data, which is an imaging survey in [Fe II] $1.644{\mu}m$ performed with UKIRT-WFCAM under ~0.''8 seeing conditions. The [Fe II] features were found around five UCHIIs. We interpret the [Fe II] features to be shock-excited by outflows from YSOs and estimate the outflow mass-loss rates from the [Fe II] flux which are ${\sim}1{\times}10^{-6}-4{\times}10^{-5}M{\odot}yr^{-1}$. We propose that the [Fe II] features might be the "footprint" outflow features, but more studies are required to clarify whether or not this is the case. This is based on the morphological relation between the [Fe II] and 5 GHz radio features, the outflow mass-loss rate, the travel time of the [Fe II] features, and the existence of several YSO candidates near the UCHIIs.

• Journal of The Korean Astronomical Society
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• v.50 no.3
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• pp.61-70
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• 2017

We study the angular correlation function of bright ($K_s{\leq}19.5$) Extremely Red Objects (EROs) selected in the Subaru GTO 2$deg^2$ field. By applying the color selection criteria of $R-K_s$ > 5.0, 5.5, and 6.0, we identify 9055, 4270, and 1777 EROs, respectively. The number density is consistent with similar studies on the optical - NIR color selected red galaxies. The angular correlation functions are derived for EROs with different limiting magnitude and different $R-K_s$ color cut. When we assume that the angular correlation function $w({\theta})$ follows a form of a power-law (i.e., $w({\theta})=A{\theta}^{-{\delta}}$), the value of the amplitude A was larger for brighter EROs compared to the fainter EROs. The result suggests that the brighter, thus more massive high-redshift galaxies, are clustered more strongly compared to the less massive galaxies. Assuming that EROs have redshift distribution centered at ~ 1.1 with ${\sigma}_z=0.15$, the spatial correlation length $r_0$ of the EROs estimated from the observed angular correlation function ranges ${\sim}6-10h^{-1}Mpc$. A comparison with the clustering of dark matter halos in numerical simulation suggests that the EROs are located in most massive dark matter halos and could be progenitors of $L_{\ast}$ elliptical galaxies.