Stellar Magnetic Activity Measure Based on IUE Mg II h+k Emission Lines of Main-Sequence G Stars

김도운,최화진,이유 한국천문학회 2022 Journal of The Korean Astronomical Society Vol.55 No.2

Stellar magnetic activity is important for formulating the evolution of the star. To represent the stellar magnetic activity, the S index is defined using the Ca II H+K flux measure from the Mount Wilson Observatory. Mg II lines are generated in a manner similar to the formation of Ca II lines, which are more sensitive to weak chromospheric activity. Mg II flux data are available from the International Ultraviolet Explorer (IUE). Thus, the main purpose of this study was to analyze the magnetic activity of stars. We used 343 high-resolution IUE spectra of 14 main-sequence G stars to obtain the Mg II continuum surface flux and Mg II line-core flux around 2,800 ˚A. We calculated S index using the IUE spectra and compared it with the conventional Mount Wilson S index. We found a color (B − V) dependent association between the S index and the Mg II emission line-core flux. Furthermore, we attempted to obtain the magnetic activity cycles of these stars based on the new S index. Unfortunately, this was not successful because the IUE observation interval of approximately 17 years is too short to estimate the magnetic activity cycles of G-type stars, whose cycles may be longer than the 11 year mean activity cycle of the sun.

The variability of magnetic activity in solar‐type stars

Fabbian, D.,Simoniello, R.,Collet, R.,Criscuoli, S.,Korhonen, H.,Krivova, N. A.,Olá,h, K.,Jouve, L.,Solanki, S. K.,Alvarado‐,Gó,mez, J. D.,Booth, R.,Garcí,a, R. A.,Lehtinen, J. WILEY‐VCH Verlag GmbH Co. KGaA 2017 Astronomische Nachrichten Vol.338 No.7

<P>This article reviews the current knowledge and status of investigations on the variable magnetic activity of cool stars. We discuss the Sun in the context of solar‐type stars, highlighting peculiarities and common features in terms of its magnetic activity and variability over different time scales. We examine how both theory and observations are providing new clues about the main physical processes that generate magnetic fields in the interior of cool stars, as well as about those that lead to evolving stellar surface magnetism and varying chromospheric and coronal phenomena. We then proceed to discuss the relations between stellar age, rotation, and activity throughout the evolution of cool stars. Finally, we touch upon the importance of understanding stellar magnetism also in view of its effect on planetary environments.</P>

채층 활동이 강한 별들의 분광선

강영운,김호일,이우백,오규동,KANG YOUNG WOON,KIM HOIL,LEE WOO BAIK,OH KYU DONG 한국천문학회 2000 天文學論叢 Vol.15 No.suppl1

We have reviewed the magnetic activity in close binaries. Solar like magnetic activity indicators such as photometric spots, chromo spheric emission, coronal X-ray and radio emission, and flare activity are commonplace in many cool stars with convective envelopes. Using the UV spectra we confirmed the strength of stellar activity increases with more rapid rotation and later spectral types which corresponds to the increasing depth of the star's convective envelope. Apart from very young stellar objects such as T Tauri stars, the stars with the highest levels of activity are close binary systems composed of cool stars, i.e., the chromospherically active binaries such as RS CVn, BY Dra, W UMa and related systems. The IUE low and high dispersion spectra of V711 Tau, VW Cep and SW Lac are used for ultraviolet photometry and for a variation study of chromospheric activity. Evidence of chromospherically activity is indicated by the intensity variation of the Mg II emission line with orbital phase.

스포츠스타의 사회공헌활동과 선수 이미지, 선수 일체감, 기부인식 형성의 구조적 관계

김용래(Kim, Yong-Rae) 한국체육과학회 2016 한국체육과학회지 Vol.25 No.4

The purpose of this study was to identify the causal relationship between sports stars" social contribution activity, and player image, sense of unity and donation awareness formation. For this purpose, this study employed the convenient sampling method, one of nonprobability sampling, and sampled 281 persons out of the college students and graduate students specializing in sports-related majors in "S" College located in Seoul and in "H" College located in Gwangju who had the experience of watching the K League soccer game in the soccer stadium more than once and listening to the sports broadcasting of soccer games more than ten times. Data were statistically analyzed with the use of SPSS 18.0 and AMOS 18.0. Frequency analysis, correlation analysis and reliability analysis were conducted with the use of SPSS 18.0. Confirmatory factor analysis and structural equation model analysis were conducted with the use of AMOS 18.0. As a result, the following conclusion was drawn: First, it was found that soccer stars" social contribution activity had a significant effect on their player image. Second, it was found that soccer stars" social contribution activity had a significant effect on their sense of unity. Third, it was found that soccer stars" player image did not have an effect on their donation awareness formation. Fourth, it was found that soccer stars" sense of unity did not have an effect on their donation awareness formation. Fifth, it was found that soccer stars" social contribution activity had a significant effect on their donation awareness formation.

K-pop 스타의 크로스오버 활동과 팬 충성도 사이의 상관관계 연구

윤여광(Yeo-Kwang Yoon),조인희(In-Hee Cho) 한국엔터테인먼트산업학회 2016 한국엔터테인먼트산업학회논문지 Vol.10 No.6

K-pop 스타들의 ‘장르파괴’ 현상이 가속화되고 있다. 단순히 노래와 춤만으로 전 세계 수용자들의 마음을 사로잡는 것이 아니라 음악을 기반으로 연기와 CF까지 영역을 확장시키며 크로스오버(Cross over) 활동을 하고 있다. 가수와 배우, 그리고 CF모델의 경계를 넘나드는 탈(脫) 아이돌화가 이루어지고 있는 것이다. 이렇게 음악과 연기, 음악과 CF를 넘나들며 다양한 활동을 펼치는 아이돌을 ‘연기돌’‘CF돌’등으로 부르고 있다. 그렇다면 K-pop스타들의 크로스오버 활동을 팬들은 어떻게 평가하고 있을까? 아쉽게도 K-pop 스타의 크로스오버 활동에 대한 선행연구가 많지 않고 아이돌 가수들의 ‘장르파괴’ 연예활동이 수용자 충성도에 어떠한 영향을 끼치고 있는지에 대한 연구도 미진하다. 따라서 본 연구는 K-pop의 최대 수요층이라고 할 수 있는 대학생들을 대상으로 K-pop 스타의 크로스오버 활동이 그들의 팬 충성도에 어떠한 영향을 주는지를 파악함으로써 한류 마케팅 등에 시사점을 제공하고자 한다. 선행연구를 통해 도출한 변수들의 구성요소는 다음과 같다. K-pop 스타의 크로스오버활동은 연기, 음악, CF 등 3개로 설정하였으며, 수용자의 팬 충성도는 스타 충성도와 팬 커뮤니티 충성도로 구분하였다. 또한 선행연구를 바탕으로 가설을 설정하고 이에 따른 영향관계를 규명하기 위해 서울과 수도권 대학생들을 대상으로 설문조사를 실시하였다. 본 연구의 실증분석 결과는 다음과 같다. 첫째, K-pop 스타 크로스오버 활동은 대학생 수용자의‘스타 충성도’에 영향을 미치는 것으로 분석되었다. 즉, K-pop 스타에 대한 수용자들의 충성도는 음악 활동 뿐 만 아니라 다양한 연예활동(연기활동, CF활동 등)의 복합적인 결과물로 나타나는 것이다. 둘째, 커뮤니티에 대한 충성도에는 음악활동만이 영향을 미치는 것으로 나타났고, 연기활동과 CF활동은 커뮤니티 충성도에 큰 영향은 미치지 않았다. 커뮤니티 활동은 팬들의 적극적인 참여와 행동으로 완성된다. 가장 적극적인 충성도의 표현 방법이라고 할 수 있다. 따라서 수용자들은 K-pop 스타가 장르파괴를 통해 다양한 연예활동을 하는 것은 좋지만 음악을 통해 아이돌로서의 정체성을 강화하길 바라고 있었다. The "genre destruction" of K-pop stars is continuing to accelerate. Rather than captivating consumers around the world simply with singing and dancing, they are engaged in crossover activities expanding to the fields of acting and commercial films based on their music. They are de-idolizing by going beyond the boundaries of singing, acting as commercial models. These idols in various activities such music and acting or music and advertisements are called "actor-dols" and "CF-dols". So how do fans evaluate these crossover activities of K-pop stars? Unfortunately, there are few preceding studies on the crossover activities of K-pop stars and there are insufficient studies on the effects of "genre destroying" activities of idol singers on consumer loyalty. Therefore, this study identifies the impact of crossover activities by K-pop stars on fan loyalty among college students, who are the biggest consumer groups of K-pop to provide implications on Hallyu marketing, etc. The components of variables deduced from preceding studies are as follows. The crossover activities of K-pop stars were set in the three fields of acting, music and CF (commercial films, advertisements) and the fan loyalty of consumers were categorized as star loyalty and fan community loyalty. Furthermore, the hypothesis was set based on preceding studies, and in order to examine the influencing relationships, surveys were held for college students in Seoul and surrounding areas. The empirical analysis results of this study are as follows. First, it was found that the crossover activities of K-pop stars affected the "star loyalty" of college consumers. In other words, the loyalty of consumers for K-pop stars were found to be a compound outcome of not only music activities, but various celebrity activities (acting, CF, etc.). Second, it was found that loyalty in communities was only affected by music activities, while acting and CF activities did not have significant impact on community loyalty. Community activities are completed with the assertive participation and actions of fans. It can be said that it is the most assertive method of expressing loyalty. Therefore, while it is good for K-pop stars to engage in various celebrity activities through genre destruction, they are also expected to strengthen their identity as idols through music.

Evaluation of the Biological Activity of Extracts from Star-Anise (Illicium verum)

정해정 한국식품영양과학회 2009 Preventive Nutrition and Food Science Vol.14 No.3

This study was carried out to investigate the biological activities of star anise extracts obtained from four different solvents (water, methanol, ethanol and chloroform) by measuring total polyphenol and flavonoid contents, DPPH radical scavenging, hydroxyl radical scavenging, nitrite scavenging activity and antimicrobial activity. The methanol extract showed the highest extraction yield, followed by ethanol, water and chloroform. The properties of the extracting solvents significantly affected the total polyphenol content. Methanol extracts contained more total polyphenols than any other extracts. The highest DPPH radical scavenging activity was found in methanol extract. The hydroxyl radical and nitrite scavenging activity were highest in methanol and ethanol extracts. In antimicrobial activity, water extract showed stronger activities than methanol and ethanol extract against Micrococcus luteus and Bacillus subtilis, and no inhibitory effects on Gram negative bacteria were found in all extracts at the concentration used.

Active Star를 이용한 FlexRay 네트워크 구현

장인걸(In-Gul Jang),전창하(Chang-Ha Jeon),이재경(Jae-Kyung Lee),정진균(Jin-Gyun Chung) 대한전자공학회 2009 電子工學會論文誌-SC (System and control) Vol.46 No.4

FlexRay는 차량의 성능향상과 많은 전자제어 유닛으로 인해 발생하는 배선 및 성능저하를 개선하기 위한 고성능 통신 시스템 네트워크의 표준이다. 최대 10Mbps의 데이터 전송 속도를 가지며 2개의 채널을 통해 동시에 전송할 수 있다. FlexRay 시스템을 하드웨어로 구현하기 위해 SDL로 설계된 결과를 토대로 Verilog HDL을 이용하여 설계하였고, Magna/Hynix 0.18 um 공정을 이용해 Synopsys Design Compiler를 사용해 합성하였다. FlexRay 시스템에서 여러 노드 사이의 통신 제어를 위해 active star와 passive star가 사용되는데 active star는 최대 10Mbps의 빠른 데이터 전송에 주로 쓰인다. 본 논문에서는 active star를 이용한 FlexRay 네트워크를 구현하기 위해 설계한 FlexRay 시스템 외에 active star를 제어하기 위한 별도의 controller를 구현하였고 하나의 송신노드에 두 개의 수신노드를 연결하여 각각의 수신노드에 다른 프레임 메시지를 전송하는 실험을 통하여 올바른 동작이 이뤄짐을 확인하였다. FlexRay is a new standard of network communication system which provides solutions to the degradation problems generated by many ECU (Electronic Control Unit) connections in automobiles and automation systems. The upper bound of the data rate is 10Mbps and it provides two channels for redundancy. In this paper, FlexRay system is first designed using SDL. For hardware implementation, FlexRay system is designed using Verilog HDL based on the SDL design result. The designed system is synthesized using Synopsys Design Compiler with the Magna/Hynix 0.18 um cell library. In this paper, to construct a FlexRay network, active star is used since active star systems can provide high speed data transmission up to 10Mbps. The performance of the star network is tested using one transmitter node and two receiver nodes.

채층 활동이 강한 별들의 분광선

강영운,김호일,이우백,오규동 한국천문학회 2000 天文學論叢 Vol.15 No.2

We have reviewed the magnetic activity in close binaries. Solar like magnetic activity indicators such as photometric spots, chromo spheric emission, coronal X-ray and radio emission, and flare activity are commonplace in many cool stars with convective envelopes. Using the UV spectra we confirmed the strength of stellar activity increases with more rapid rotation and later spectral types which corresponds to the increasing depth of the star's convective envelope. Apart from very young stellar objects such as T Tauri stars, the stars with the highest levels of activity are close binary systems composed of cool stars, i.e., the chromospherically active binaries such as RS CVn, BY Dra, W UMa and related systems. The IUE low and high dispersion spectra of V711 Tau, VW Cep and SW Lac are used for ultraviolet photometry and for a variation study of chromospheric activity. Evidence of chromospherically activity is indicated by the intensity variation of the Mg II emission line with orbital phase.

Evaluation of the Biological Activity of Extracts from Star-Anise (Illicium verum)

Chung, Hai-Jung The Korean Society of Food Science and Nutrition 2009 Preventive Nutrition and Food Science Vol.14 No.3

This study was carried out to investigate the biological activities of star anise extracts obtained from four different solvents (water, methanol, ethanol and chloroform) by measuring total polyphenol and flavonoid contents, DPPH radical scavenging, hydroxyl radical scavenging, nitrite scavenging activity and antimicrobial activity. The methanol extract showed the highest extraction yield, followed by ethanol, water and chloroform. The properties of the extracting solvents significantly affected the total polyphenol content. Methanol extracts contained more total polyphenols than any other extracts. The highest DPPH radical scavenging activity was found in methanol extract. The hydroxyl radical and nitrite scavenging activity were highest in methanol and ethanol extracts. In antimicrobial activity, water extract showed stronger activities than methanol and ethanol extract against Micrococcus luteus and Bacillus subtilis, and no inhibitory effects on Gram negative bacteria were found in all extracts at the concentration used.

Evaluation of the Biological Activity of Extracts from Star-Anise (Illicium verum)

Hai-Jung Chung 한국식품영양과학회 2009 Preventive Nutrition and Food Science Vol.14 No.3

This study was carried out to investigate the biological activities of star anise extracts obtained from four different solvents (water, methanol, ethanol and chloroform) by measuring total polyphenol and flavonoid contents, DPPH radical scavenging, hydroxyl radical scavenging, nitrite scavenging activity and antimicrobial activity. The methanol extract showed the highest extraction yield, followed by ethanol, water and chloroform. The properties of the extracting solvents significantly affected the total polyphenol content. Methanol extracts contained more total polyphenols than any other extracts. The highest DPPH radical scavenging activity was found in methanol extract. The hydroxyl radical and nitrite scavenging activity were highest in methanol and ethanol extracts. In antimicrobial activity, water extract showed stronger activities than methanol and ethanol extract against Micrococcus luteus and Bacillus subtilis, and no inhibitory effects on Gram negative bacteria were found in all extracts at the concentration used.