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.

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.

사진 초증감 처리장치의 제작

김강민,이종웅,심경진,Kim, Gang-Min,Lee, Jong-Ung,Sim, Gyeong-Jin 한국천문학회 1991 天文學論叢 Vol.6 No.1

여러가지 초증감 처리법 중에서 굽기(baking), 쐬기(soaking)과 진공처리(evacuation)를 할 수 있는 초증감처리장치를 설계 제작하고 초증감 처리 결과 시험에 이용되는 표준감광기 (sensitometer)와 농도쐐기 (step wedge)를 제작하였다. 이를 천체사진용 건판인 103a-O와 IIIa-J에 시험적으로 사용하여 감도와 신호대 잡음비의 증가를 확인하였다.

실시간 송수펌프 최적운영 시스템 개발

김강민,최정욱,강두선,강민구,김병섭,Kim, Gang-Min,Choe, Jeong-Uk,Gang, Du-Seon,Gang, Min-Gu,Kim, Byeong-Seop 한국수자원학회 2015 물과 미래(한국수자원학회지) Vol.48 No.12

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.

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 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.

송수펌프용량 및 배수지규모에 따른 송·배수시스템의 운영비용 및 체류시간 분석

김강민,최정욱,정동휘,강두선,Kim, Kangmin,Choi, Jeongwook,Jung, Donghwi,Kang, Doosun 한국수자원학회 2017 한국수자원학회논문집 Vol.50 No.12

Recently, various studies have been conducted to optimize the pump operation scheduling and/or the pump/tank size minimizing the system cost of water distribution network. Prior to that, it is important to understand the sensitivity of pump/tank size on the system cost and overall water quality. Here, we have performed the sensitivity analysis to investigate the effect of pump/tank size on the economic cost (construction and operation) and water quality (water age). The analysis was applied on a real, large-scale water transmission network currently operating in South Korea. The results revealed that the pump/tank size has a strong influence on system construction/operation costs. Especially, the tank size has a significant effect on the system-wide water quality. In the case of applied networks, the operating cost decreases as the capacity of the facility increases, but the design cost increases. Using a sensitivity analysis, a suitable range of pump/tank size could be suggested to minimize costs and stabilize the water quality at the same time prior to a system design. 최근 송 배수시스템의 최적 펌프운영과 펌프 및 배수지의 적정용량 산정을 위한 다양한 연구가 진행되고 있다. 시설물의 적정 용량을 선정하기에 앞서 송수펌프 용량 및 배수지규모에 따른 시스템 비용(건설 및 운영비용) 과 시스템 내 수질 변화를 분석하는 과정이 필요하다. 본 연구에서는 민감도 분석을 통해 송수펌프 용량과 배수지의 크기가 실제 시스템의 건설 및 운영비용, 그리고 시스템 전반의 수질에 미치는 영향을 분석하였다. 국내 대규모 지방상수도 시스템을 대상으로 분석을 실시하여 시설물 규모가 비용 및 수질에 미치는 영향을 명확히 파악하였다. 적용 네트워크의 경우, 시설물의 용량이 증가할수록 운영비용은 감소하지만, 설계비용은 증가하는 것으로 나타났으며, 이를 통해 비용최소화와 수질안정화를 동시에 만족하는 시설물의 적정용량 범위를 파악할 수 있을 것으로 판단된다.

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.