보현산천문대 고분산 편광 분광기 개념 설계

김강민,한인우,유계화,Kim, Kang-Min,Han, In-Woo,Plachinda, S.,Valyavin, G.,Yoo, Kye-Hwa 한국천문학회 2005 天文學論叢 Vol.20 No.1

We plan to install the polarimetric optics in the AGU(acqusition and guiding unit) of the 1.8 m telescope at the BOAO(Bohyunsan Optical Astronomy Observatory). With this, the spectropolarimetric observations with the resolution of 45,000 and 60,000 in 4,000 to $8,000{\AA}$ ange could be done by the BOES(BOao Echelle Spectrograph). If we use the precision radial velocity measurement capability of the BOES, the accuracy of the magnetic field intensity measurements with this new BOES stokesmeter will be much increased. We present here the design concept of the BOES stokesmeter. Some details on the optics, mechanical parts, fiber parts and the lab test procedures of this stokesmeter are explained.

보현산천문대 중분산분광기의 성능 분석

김강민,김여정,윤태석,KIM KANG-MIN,KIM YEOJEONG,YOON TAE SEOG 한국천문학회 2001 Journal of The Korean Astronomical Society Vol.34 No.1

We tested the characteristics of the BOAO Medium Dispersion Spectrograph (MDS) such as the CCD capabilities, wavelength shift by gravity direction variation, slit illumination function and efficiency. Then we calculated the appropriate exposure time to obtain the given S/N ratio for several given magnitudes. Also the remaining problems to be improved were discussed.

빈도비와 Cosine Amplitude Method를 이용한 진부지역의 퍼지기반 산사태 취약성 예측기법 비교 연구

김강민,박혁진,Kim, Kang Min,Park, Hyuck Jin 대한자원환경지질학회 2017 자원환경지질 Vol.50 No.3

산사태 위험도 분석에서 범용적으로 활용되고 있는 통계적 취약성 분석 기법은 과거에 발생한 산사태의 위치 정보와 산사태 영향 인자들 사이의 상관관계를 통계적으로 분석하여 산사태 발생 가능성이 있는 지역을 예측하는 기법이다. 이러한 취약성 분석 기법에는 다양한 불확실성이 개입되는데 이러한 불확실성을 고려하기 위한 방법의 하나로 퍼지 기법이 활용되고 있다. 퍼지 기법은 퍼지 집합 이론이라는 수학적인 개념을 통해 불확실성을 표현하는 방법으로 특정 인자가 나타날 수 있는 정도를 소속 함수로 표현한다. 퍼지 기법은 영향 인자들의 소속 함수를 결정하는 방법과 각 영향 인자들의 소속 함수를 결합하는 연산 과정에 다양한 접근 방식이 존재하며, 기존의 연구들은 다양한 접근 방식을 활용하여 분석을 수행하여 왔다. 그러나 이렇게 다양한 접근 방식이 어떠한 결과의 차이를 초래하는지를 비교하는 연구는 수행된 사례가 적은 편이다. 따라서 본 연구에서는 진부 지역을 대상으로 빈도비를 활용하여 소속 함수를 산정하는 기법과 코사인 진폭법을 활용하여 소속 함수를 산정하는 기법을 비교하여 보았다. 또한 다양한 퍼지 연산 기법을 활용하여 산사태 취약성을 산정하고 이들 결과를 비교해 보았으며 ROC 그래프 기법을 활용하여 결과의 정확도를 산정하고 분석 기법의 적절성을 분석하였다. Statistical landslide susceptibility analysis, which is widely used among various landslide susceptibility analysis approaches, predicts the unstable area by analyzing statistical relationship between landslide occurrence locations and landslide controlling factors. However, uncertainties are involved in the procedures of the susceptibility analysis and therefore, fuzzy approach has been used to deal properly with uncertainties. The fuzzy approach used fuzzy set theory and fuzzy membership function to quantify uncertainties involved in landslide controlling factors. Various fuzzy approaches were suggested in the procedure of the membership value determination and fuzzy operation in the previous researches. However, few studies were carried out to compare the analysis results obtained from various approaches for membership function determination and fuzzy operation. Therefore, in this study, the authors selected Jinbu area, which a large number of landslides were occurred at in 2006, to apply two most commonly used methods, the frequency ratio and the cosine amplitude method to derive membership values for each controlling factor. In addition, the integration of different thematic layers to produce landslide susceptibility map was performed by several fuzzy operators such as AND, OR, algebraic product, algebraic sum and Gamma operator. The results of the landslide susceptibility analysis using two different methods for the determination of fuzzy membership values and various fuzzy operators were compared on the basis of ROC graph to check the feasibility of the fuzzy based landslide susceptibility analysis.

보현산 천문대의 대기 소광계수

김강민,손동훈,형식,윤태석,Kim, Kang-Min,Son, Dong-Hoon,Hyung, Siek,Yoon, Tae-Seog 한국천문학회 1997 天文學論叢 Vol.12 No.1

Detailed low spectral resolution observations of the spectrum have been made for three early spectral type standard stars, HR718, HR1544, HR3454, respectively, for the wavelength region 4,300 A to 7,500 A, using the Bohyunsan Optical Astronomy Observatory (BOAO) Middle- Dispersion Spectrograph. These standard stars were chosen from well-known bright northern standard stars. All of the observed long slit spectral data has been reduced and analyzed using the IRAF reduction procedure. The derived extinction coefficients are compared with the other observatory result. The derived value can be used in the determination of flux calibration of BOAO spectroscopic observation. However, until the high quality data are secured from a new series of observation in the blue region and are re-analyzed together, the extinction coefficients below the 4,000 A wavelength remains unknown.

보현산천문대 긴슬릿 분광기의 성능 분석

김강민,이병철,한인우,윤태석,Kim, Kang-Min,Lee, Byeong-Chul,Han, In-Woo,Yoon, Tae-Seog 한국천문학회 2003 天文學論叢 Vol.18 No.1

We tested the characteristics of the newly made Long Slit Spectrograph (LSS) of the BOAO which replaced the Medium Dispersion Spectrograph (MDS) in the year of 2003. Performance test results on the spectrogram shift by gravity direction variation, slit illumination function, efficiency and the precision of the radial velocity measurements show the capabilities of the LSS are much improved in every respect comparing with those of the MDS.

용액환원법에 의한 MLCC용 단분산 니켈 미분말의 합성

김강민,이종흔,윤선미,이용균,이현철,최재영,Kim, Kang-Min,Lee, Jong-Heun,Yoon, Seon-Mi,Lee, Yong-Kyun,Lee, Hyun-Chul,Choi, Jae-Young 한국세라믹학회 2005 한국세라믹학회지 Vol.42 No.10

A mono-disperse Ni powders for multilayer ceramic capacitors were prepared in a large scale by solution reduction method using $NiSO_{4}$ $N_{2}$$H_{4}$and NaOH. The exothermic reactions such as Ni-complex formation between highly concentrated $NiSO_{4}$ and $N_{2}$$H_{4}$ and the reduction of $Ni^{2+}$ into Ni provided thermal energy sufficient for spontaneous solution-reduction reaction. Because well-defined Ni particles could be prepared without external heating, the present method was named as 'auto-thermal method'. The formation of Ni­complex, the precipitation of $Ni(OH)_{2}$ gel triggered by NaOH addition, and its reduction into Ni by dissolution-recrystallization route were the reaction mechanism. The preparation of mono-disperse and spherical Ni powder was attributed to uniform distribution of reducing agent $N_{2}$$H_{2}$ within $Ni(OH)_{2}$ gel due to the decomposition of$NiSO_{4}$-$N_{2}$ $H_{4}$ complex.

보현산천문대 고분산 에셀분광기(BOES) 제작

김강민,장정균,천무영,박병곤,형식,한인우,윤태석,KIM KANG-MIN,JANG JEONG GYUN,CHUN MOO-YOUNG,PARK BYEONG-GON,HYUNG SIEK,HAN INWOO,YOON TAE SEOG,VOGT STEVEN S. 한국천문학회 2000 天文學論叢 Vol.15 No.suppl1

The BOES (BOAO Echelle Spectrograph), a fiber-fed echelle spectrograph of the BOAO 1.8 m telescope, has been designed and now is being manufactured. The BOES follows a white pupil design collimated with two off-axis parabolic mirrors. The 136mm collimating beam leaving the 41.59 grooves/mm R4 echelle grating is refocused near the narrow folding mirror. Through the two cross-disperser prisms and $\phi250 mm(f/1.5)$ transmission camera, the beam images on EEV $2k\times4k$ CCD. The BOES can take the wavelength range of 3700 to $10100{\AA}$ at a single spot with spectral resolution R = 20000 to 40000 depending on the fiber set employed. We describe the key sciences and performance, current status of construction, and future plan of the BOES.

보현산천문대 고분산 에셀 분광기(BOES)의 광섬유 부분 제작과 설치

김강민,장비호,윤태석,KIM KANG-MIN,JANG BEE-HO,GALAZUTDINOV G.,YOON TAE SEOG 한국천문학회 2004 天文學論叢 Vol.19 No.1

We present the detailed description on the fiber techniques adopted in the BOES: the design concepts and manufacturing of the v grooves, the procedures of the fiber polishing, adhering of the fibers to the v grooves, and the axis alignment of the fiber input and exit. The high efficiency and throughput of the BOES imply that the adopted fiber arts and the other optical components were well designed and properly treated. We learned that the relatively low efficiency of the 80 micron fiber comparing with the 200 and 300 micron fibers comes from the seeing and the guiding effects not from the poor fiber handling.

개질 석탄회 적용 콘크리트의 단위수량 저감 및 초기강도 개선 성능 평가

김강민(Kim, Kang Min),임두섭(Lim, Doo Sub),송용순(Song, Yong Soon),허홍기(Hur, Hong Ki) 한국콘크리트학회 2016 한국콘크리트학회 학술대회 논문집 Vol.28 No.1

Soybeans Fermented with Bacillus polyfermenticus KJS-2 Protects Oplegnathus fasciatus from Iridovirus and Pathogenic Bacterial Infection

Kang Min Kim(김강민),Hae Choon Na(나해춘),Jung Hee Park(박정희),Jae Seon Kang(강재선) 한국생명과학회 2009 생명과학회지 Vol.19 No.6

Bacillus polyfermenticus KJS-2 (B. polyfermenticus KJS-2)를 이용하여 발효된 콩(BP2FS)은 8가지의 병원성균에 대해 항균활성을 가졌다. BP2FS는 돌돔의 배양에 있어 사료첨가제로 사용되었다. 돌돔의 배양 시 BP2FS를 투여한 군(6×10⁴ cfu g?¹ 사료)과 투여하지 않은 군으로 나누었으며, 투여한 군은 120일 동안 하루에 두 번씩 투여 하였다. 120일 후에 투여한 군의 돌돔의 몸무게는 67.29±12.62 g이었으며 그렇지 않은 군의 몸무게는 56.56±8.21 g으로 나타났다. 생존율은 투여한 군(80%)과 투여하지 않은 군(40%)이었다. 폐사한 돌돔의 축적된 양은 투여한 군(18.95%)과 투여하지 않은 군(60.98%)이었다. BP2FS를 투여한 군에서 B. polyfermenticus KJS-2를 돌돔의 장내에서 검출한 결과 1.04×10⁴ cfu g?¹으로 나타났다. BP2FS를 투여 하지 않은 군의 돌돔에서는 iridovirus에 감염되었을 경우 나타나는 전형적인 증상인 비장과 간에서 비대세포가 관찰 되었다. 이 결과들은 BP2FS는 돌돔의 이리도바이러스에 대한 감염 시 예방효과를 가져온다 할 수 있다. Lyophilized powder (BP2FS) of soybeans fermented with Bacillus polyfermenticus KJS-2 (B. polyfermenticus KJS-2) exhibited in vitro antibacterial activities against eight pathogenic bacteria. BP2FS was used as a fodder additive for Oplegnathus fasciatus (O. fasciatus) culture. One group (UFD) of O. fasciatus was fed a commercial fodder, while another group (FD) was fed the same fodder, but including BP2FS (6×10⁴ cfu g?¹ fodder), two times daily for 120 days. The mean body weight of the FD group (67.29±12.62 g) was higher than that of the UFD group (56.56±8.21 g) after 120 days. The survival rate of FD was 80% compared to 40% for the UFD group. Cumulative mortalities in the FD and UFD groups were 18.95% and 60.98% respectively. B. polyfermenticus KJS-2 was isolated from the intestines of the FD group and the number of viable colonies was estimated to be 1.04×10⁴ cfu g?¹. Iridovirus and Vibrio vulnificus was detected in the organs of the UFD group but not in the FD group. All of the infected fish showed typical clinical symptoms of hemorrhage in their tail fins. Dissection of the infected internal organs revealed liver congestion and spleen enlargement - typical symptoms caused by iridovirus infection. These results clearly show that BP2FS is highly beneficial in preventing O. fasciatus from iridovirus infection.