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Status of KASI's Contribution to SPHEREx

  • Jeong, Woong-Seob;Yang, Yujin;Park, Sung-Joon;Pyo, Jeonghyun;Jo, Youngsoo;Kim, Il-Joong;Bang, Seungcheol;Lee, Bomee
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.2
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    • pp.53.1-53.1
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    • 2021
  • The KASI team are participating in the NASA MIDEX mission (PI Institute: Caltech), the all-sky infrared spectro-photometric surveyor SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer). The SPHEREx will provide us the first all-sky infrared spectro-photometric data set to probe the origin of our Universe, to explore the origin and evolution of galaxies, and to explore whether planets around other stars could harbor life. After the project PDR (Preliminary Design Review) was successfully passed on the last September, the fabrication of flight hardware is in progress. As an international partner, KASI deeply involved in all fields of projects, i.e., the development of calibration facility, the construction of data reduction modules and the science studies for the SPHEREx. After finishing the fabrication and test of calibration facility for the SPHEREx in this year, it will be delivered to Caltech. Here, we report the status of the SPHEREx project and the progress in the Korean participation.

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A Search for Exoplanets around Northern Circumpolar Stars. VII. Detection of Planetary Companion Orbiting the Largest Host Star HD 18438

  • Byeong-Cheol Lee;Jae-Rim Koo;Gwanghui Jeong;Myeong-Gu Park;Inwoo Han;Yeon-Ho Choi
    • Journal of The Korean Astronomical Society
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    • v.56 no.1
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    • pp.35-40
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    • 2023
  • We have been conducting a exoplanet search survey using Bohyunsan Observatory Echelle Spectrograph (BOES) for the last 18 years. We present the detection of exoplanet candidate in orbit around HD 18438 from high-precision radial velocity (RV) mesurements. The target was already reported in 2018 (Bang et al. 2018). They conclude that the RV variations with a period of 719 days are likely to be caused by the pulsations because the Lomb-Scargle periodogram of HIPPARCOS photometric and Hα EW variations for HD 18438 show peaks with periods close to that of RV variations and there were no correlations between bisectors and RV measurements. However, the data were not sufficient to reach a firm conclusion. We obtained more RV data for four years. The longer time baseline yields a more accurate determination with a revised period of 803 ± 5 days and the planetary origin of RV variations with a minimum planetary companion mass of 21 ± 1 MJup. Our current estimate of the stellar parameters for HD 18438 makes it currently the largest star with a planetary companion.

A Study on Foreigners' Experience ofWearingK Fashion -Focusing on Nepalese, Vietnamese, and Mongolian Foreigners in 20s and 30s- (K 패션 착용경험에 관한 연구 -20~30대 네팔, 베트남, 몽골 외국인을 중심으로-)

  • Shreejana Maharjan;Sujoung Cha
    • Journal of Fashion Business
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    • v.28 no.2
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    • pp.15-32
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    • 2024
  • This study aimed to investigate the perceptions and preferences of foreigners residing in Korea towards K-fashion. It sought to provide suggestions for the future development of K-fashion targeting this growing demographic. The results revealed that the longer foreigners had lived in Korea, the more positively they rated Korean fashion, shopping, and culture. The majority of foreigners purchased K-fashion items online, with popular choices including T-shirts, jackets, shirts, and jeans. Both men and women identified shoulders as a common problematic area when wearing clothing, with some issues also reported in the lumbar region. In terms of preferences, younger males (teens and twenties) were more inclined towards fads and celebrity wear compared to older males (thirties and forties). Similarly, younger females (teens and twenties) showed a higher preference for functionality and celebrity wear compared to older females (thirties and forties). These findings suggest that men tend to prioritize aesthetic factors when choosing K-fashion, while women prioritize practical considerations. To better cater to foreign consumers, suggestions for the development of K-fashion include promoting it through K-pop stars, considering dimensions related to foreigners' shoulders when designing top items, diversifying colors, sizes, and patterns, and providing English versions of online shopping platforms.

Poststroke Depression : A Review of the Latest Oriental Medicine Articles (뇌졸중 후 우울증 : 한방 치료에 대한 국내외 최신 문헌 고찰)

  • Lee, Je-Won;Lee, Bo-Mae-Na;Jang, Woo-Seok;Hwang, Ha-Yeon;Baek, Kyung-Min
    • The Journal of Internal Korean Medicine
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    • v.33 no.4
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    • pp.448-464
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    • 2012
  • Objectives : This study reviews the latest articles in Korea and other countries that studied oriental medicine treatment on poststroke depression. Methods : Korean articles were retrieved from the 9 major Korean web article search engines. Foreign articles were retrieved from PubMed. Article published date was from 2000 up to September 2012. There were no restrictions on the types of publication, but articles not available in full text were excluded. The methodological quality was assessed according to Cochrane's assessment of risk of bias and Newcastle-Ottawa quality assessment scale. Results : Twenty-two articles were included in this study. Eleven articles were published in Korea, the rest were published in China. Nine articles were randomized controlled trials (RCT), one article was a non-randomized study (NRS), four articles were case reports, three articles were cross-sectional studies, two articles were comparative studies. In RCT articles, risk of selection bias and performance bias were generally high, risk of detection bias was unclear. The NRS article took four stars in Newcastle-Ottawa quality assessment. Comparison Hamilton rating scale for depression score between oriental medicine treated group and western medicine treated group revealed that there was no remarkable difference in mean score changes after treatment on PSD. Conclusions : The results of this study suggest that oriental medicine treatment is as effective as western medicine treatment for PSD. In the future, more rigorous oriental medicine treatment studies should be conducted.

An Analysis of Types and Sources of Background Knowledges of Elementary Preservice Teachers' Questions about Astronomy Contents in Elementary Science Text Books (초등 과학교과서 천문 내용에 대한 예비교사들의 질문의 배경지식 유형과 출처 분석)

  • Lee, Myeong-Je
    • Journal of Korean Elementary Science Education
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    • v.35 no.2
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    • pp.194-204
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    • 2016
  • The purpose of this study is to find out the relationship between types and sources of background knowledges of elementary preteachers' questions about astronomy contents in the elementary science text books. Data were extracted from the preteachers' classes established in a university of education. The results are as follows. First, right background knowledges of questions were found in about 58% questions, wrong background knowledges 15%, and no background knowledges 26%. Second, it was found that 'school' as a source of background knowledges was found in 29% questions, 'friend' 21%, 'internet' 14%, 'book reading' 12%, 'others' 9%, 'TV' 7%, 'institute' 4%. In case of the type that right background knowledges have casual relation or correlation with question contents, 'book reading' and 'TV' sources rate increased, but 'internet' and 'others' decreased when compared to total questions. In the type which background knowledges are right and did not have casual relation or correlation with question contents, 'internet' source rate increased and 'friend' decreased. In case of the type that wrong background knowledges do not have casual relation or correlation with question contents, 'friend' and 'TV' sources rate increased, but 'school' and 'book reading' decreased. The type which background knowledges are right and did not have casual relation or correlation with question contents, 'internet' source rate increased and 'friend' decreased. In case of the type of no background knowledges, 'TV' and 'institute' source rate increased, but 'internet' and 'book reading' decreased. Third, the questions in 'Earth and Moon' unit have little background knowledges. The questions in 'solar system and stars' have background knowledges with no relation to the questions. Especially, in the unit 'changes of seasons', right background knowledges were found in more than half questions, but the contents of questions and background knowledges were not connected scientifically.

LARGE-SCALE [OIII] AND [CII] DISTRIBUTIONS OF THE LARGE MAGELLANIC CLOUD WITH FIS-FTS

  • Takahashi, A.;Yasuda, A.;Kaneda, H.;Kawada, M.;Kiriyama, Y.;Mouri, A.;Mori, T.;Okada, Y.;Takahashi, H.
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.219-220
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    • 2012
  • We present the results of far-infrared spectroscopic observations of the Large Magellanic Cloud (LMC) with FIS-FTS. We covered a large area across the LMC, including 30 Doradus (30 Dor) and N44 star-forming regions, by 191 pointings in total. As a result, we detect the [OIII] and [CII] line emission as well as far-infrared dust continuum emission throughout the LMC. We find that the [OIII] emission is widely distributed around 30 Dor. The observed size of the distribution is too large to be explained by massive stars in 30 Dor, which are assumed to be enshrouded by clouds with the constant gas density estimated from the [OIII] line intensities. Therefore the surrounding structure is likely to be highly clumpy. We also find a global correlation between the [OIII] and the far-infrared continuum emission, suggesting that the gas and dust are well mixed in the highly-ionized region where the dust survives in clumpy dense clouds shielded from energetic photons. Furthermore we find that the ratios of [CII]/CO are as high as 110,000 in 30 Dor, and 45,000 even on average, while they are typically 6,000 for star-forming regions in our Galaxy. The unusually high [CII]/CO is also consistent with the picture of clumpy small dense clouds.

OBSERVATIONS OF STAR FORMATION INDUCED BY GALAXY-GALAXY AND GALAXY-INTERGALACTIC MEDIUM INTERACTIONS WITH AKARI

  • Suzuki, T.;Kaneda, H.;Onaka, T.
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.243-248
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    • 2012
  • Nearby spiral galaxies M101 and M81 are considered to have undergone a galaxy-galaxy interaction. M101 has experienced HI gas infall due to the interaction. With AKARI far-infrared (IR) photometric observations, we found regions with enhanced star forming activity, which are spatially close to regions affected by the interaction. In addition, the relation between the star formation rate (SFR) and the gas content for such regions shows a significant difference from typical spiral arm regions. We discuss possible explanations for star formation processes on a kiloparsec scale and the association with interaction-triggered star formation. We also observed the compact group of galaxies Stephan's Quintet (SQ) with the AKARI Far-infrared Surveyor (FIS). The SQ shows diffuse intergalactic medium (IGM) due to multiple collisions between the member galaxies and the IGM. The intruder galaxy NGC 7318b is currently colliding with the IGM and causes a large-scale shock. The 160 micron image clearly shows the structure along the shock ridge as seen in warm molecular hydrogen line emission and X-ray emission. The far-IR emission from the shocked region comes from the luminous [CII]$158{\mu}m$ line and cold dust (~ 20 K) that coexist with molecular hydrogen gas. Survival of dust grains is indispensable to form molecular hydrogen gas within the collision age (~ 5 Myr). At the stage of the dusty IGM environment, [CII] and $H_2$ lines rather than X-ray emission are powerful cooling channels to release the collision energy.

FAR-IR GALACTIC EMISSION MAP AND COSMIC OPTICAL BACKGROUND

  • Matsuoka, Y.
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.353-356
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    • 2012
  • We present new constraints on the cosmic optical background (COB) obtained from an analysis of the Pioneer 10/11 Imaging Photopolarimeter (IPP) data. After careful examination of the data quality, the usable measurements free from the zodiacal light are integrated into sky maps at the blue (${\sim}0.44{\mu}m$) and red (${\sim}0.64{\mu}m$) bands. Accurate starlight subtraction was achieved by referring to all-sky star catalogs and a Galactic stellar population synthesis model down to 32.0 mag. We find that the residual light is separated into two components: one component shows a clear correlation with the thermal $100{\mu}m$ brightness, whilst the other shows a constant level in the lowest $100{\mu}m$ brightness region. The presence of the second component is significant after all the uncertainties and possible residual light in the Galaxy are taken into account, thus it most likely has an extragalactic origin (i.e., the COB). The derived COB brightness is ($(1.8{\pm}0.9){\times}10^{-9}$ and $(1.2{\pm}0.9){\times}10^{-9}\;erg\;s^{-1}\;cm^{-2}\;sr^{-1}\;{\AA}^{-1}$ in the blue and red spectral regions, respectively, or $7.9{\pm}4.0$ and $7.7{\pm}5.8\;nW\;m^{-2}\;sr^{-1}$. Based on a comparison with the integrated brightness of galaxies, we conclude that the bulk of the COB is comprised of normal galaxies which have already been resolved by the current deepest observations. There seems to be little room for contributions from other populations including "first stars" at these wavelengths. On the other hand, the first component of the IPP residual light represents the diffuse Galactic light (DGL)-scattered starlight by the interstellar dust. We derive the mean DGL-to-$100{\mu}m$ brightness ratios of $2.1{\times}10^{-3}$ and $4.6{\times}10^{-3}$ at the two bands, which are roughly consistent with previous observations toward denser dust regions. Extended red emission in the diffuse interstellar medium is also confirmed.

A Study on the Image of Adult Foundations (남.녀 파운데이션 이미지 연구)

  • Lee, Hyo-Jin;Yang, A-Rang
    • The Research Journal of the Costume Culture
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    • v.19 no.2
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    • pp.255-268
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    • 2011
  • This study carefully explored today's preferable beauty images, analyzed Korean adult purchasing trends of functional underwear and market analysis of the most popular items and their designs. Information and methods are based largely on reference book material as well as analysis of real domestic data. The paper's research timeline simply spans the last three years, as in accordance with project parameters. Helping improve body shape, foundation literally means 'substructur' and 'base'. The formativeness in these adult foundations typically has three main category classifications. First, natural modern image. This is where we find natural beauty including that which embodies a cool modern sense. Here, you can often see such patterns as either stripes and dots, or simply no patterns at all. Colors are green, red-brown, incarnadine, or khaki from a natural or basic human body color. Its products are marketed as both solid and durable eco-friendly materials, and lace-seethrough. Fashion's natural modern image is undoubtedly the most popular style purchase choice among both genders. Second, sweet romantic image. This mainly consists of two concepts : a sweet and romantic theme, and visual appeal. Patterns include flowers, lips, heart, stars, candies and various other appealing characters. Its main colors are pink, yellow, red, purple, and violet. Products are decorated with laces, frills and ribbons. Since only men's semi-girdles carry such designs, this fashion foundation is largely a women's world. While men show an obvious interest in foundation, they still mostly prefer the choice of natural modern images. Third, mystic sexy image. This is defined as all feminine images of mysterious and classic sexual beauty. Patterns are variously expressed as paisley, flowers, and geometric. Colors are largely purple, blue-green, royal-blue, cobalt, and black. Products are commonly decorated with beading, spangles, hot-fixes and so on. While this image can be found in all kinds of women's foundations, it typically appears only in men's corsets and girdles.

PROPERTIES OF OPEN CLUSTERS CONTAINING BLUE STRAGGLERS

  • Lee, Hyun-Uk;Chang, Heon-Young
    • Journal of The Korean Astronomical Society
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    • v.50 no.3
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    • pp.51-59
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    • 2017
  • The presence of blue stragglers pose challenges to standard stellar evolution theory, in the sense that explaining their presence demands a complex interplay between stellar evolution and cluster dynamics. In the meantime, mass transfer in binary systems and stellar collisions are widely studied as a blue straggler formation channel. We explore properties of the Galactic open clusters where blue stragglers are found, in attempting to estimate the relative importance of these two favored processes, by comparing them with those resulting from open clusters in which blue stragglers are absent as of now. Unlike previous studies which require a sophisticated process in understanding the implication of the results, this approach is straightforward and has resulted in a supplementary supporting evidence for the current view on the blue straggler formation mechanism. Our main findings are as follows: (1) Open clusters in which blue stragglers are present have a broader distribution with respect to the Z-axis pointing towards the North Galactic Pole than those in which blue stragglers are absent. The probability that two distributions with respect to the Z-axis are drawn from the same distribution is 0.2%. (2) Average values of $log_10(t)$ of the clusters with blue stragglers and those without blue stragglers are $8.58{\pm}0.232$ and $7.52{\pm}0.285$, respectively. (3) The clusters with blue stragglers tend to be relatively redder than the others, and are distributed broader in colors. (4) The clusters with blue stragglers are likely brighter than those without blue stragglers. (5) Finally, blue stragglers seem to form in condensed clusters rather than simply dense clusters. Hence, we conclude that mass transfer in binaries seems to be a relatively important physical mechanism of the generation of blue stragglers in open clusters, provided they are sufficiently old.