• 천문학회지
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• 제29권spc1호
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• pp.53-54
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• 1996

Based on the database of 128 disk galaxies (66 SO, 62 S and Irr) mailnly compiled from Kent and Gunn (1982) and Doi et a1.(1995) which is complete down to m < 15.6 mag within a radius of $3^{\circ}$, the orientation of spin vectors of disk galaxies of the Coma cluster has been analyzed. The results confirm the morphological dependence of the orientation of disk galaxies found from the analsis of the Virgo cluster. Common features of orientation of disk galaxies of both clusters are outlined.

• 천문학논총
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• 제30권2호
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• pp.389-392
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• 2015

We identify a strong lensing galaxy in the cluster IRC 0218 that is spectroscopically confirmed to be at z = 1.62, making it the highest-redshift strong lens galaxy known. The lens is one of the two brightest cluster galaxies and lenses a background source galaxy into an arc and a counterimage. With Hubble Space Telescope (HST) grism and Keck/LRIS spectroscopy, we measure the source redshift to be $z_S=2.26$. Using HST imaging, we model the lens mass distribution with an elliptical power-law profile and account for the effects of the cluster halo and nearby galaxies. The Einstein radius is $^{\theta}E=0.38^{+0.02{\prime}{\prime}}_{-0.01}$ ($3.2^{+0.2}_{-0.1}kpc$) and the total enclosed mass is $M_{tot}(<^{\theta}_E)=1.8^{+0.2}_{-0.1}{\times}10^{11}M_{\odot}$. We estimate that the cluster environment contributes ~ 10% of this total mass. Assuming a Chabrier IMF, the dark matter fraction within $^{\theta}E$ is $f^{Chab}_{DM}=0.3^{+0.1}_{-0.3}$, while a Salpeter IMF is marginally inconsistent with the enclosed mass ($f^{Salp}_{DM}=-0.3^{+0.2}_{-0.5}$).

• 대한수학회보
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• 제33권1호
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• pp.1-16
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• 1996

Earlier in 1935[12], M. S. Robertson introduced the class of quadrant preserving functions. More precisely, let Q be the class of all functions f(z) analytic in the unit disk $D = {z : $\mid$z$\mid$ < 1}$ such that f(0) = 0, f'(0) = 1, and the range f(z) is in the j-th quadrant whenever z is in the j-th quadrant of D, j = 1,2,3,4. This class Q contains the subclass of normalized, odd univalent functions which have real coefficients. On the other hand, this class Q is contained in the class T of odd typically real functions which was introduced by W. Rogosinski [13]. Clearly, if $f \in Q$, then f(z) is real when z is real and therefore the coefficients of f are all real. Recently, it was observed by Y. Abu-Muhanna and T. H. MacGregor [1] that any function $f \in Q$ is odd. Instead of functions "preserving quadrants", the authors [1] have introduced the notion of "preserving sectors".

• Weed & Turfgrass Science
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• 제2권1호
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• pp.55-61
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• 2013

본 연구는 한반도에 자생하는 난지형 한국잔디류의 자생지에서의 형태적 특성과 재배 포지에서의 형태적 특성 및 자생지에서의 토양특성을 조사한 것이다. 한국 남서부지역을 중심으로 바닷가 주변과 농로변, 산정 바위 틈 등에서 채집된 들잔디류 41개체, 중지류 28개체, 갯잔디류 22개체, 금잔디류 8개체로 총 4종 99개체를 채집하여 조사한 결과 대부분 자생지와 재배 포지에서 형태적 특성에 큰 차이를 보이지 않았으나, 갯잔디류에서는 잎의 각도와 금잔디류에서 화수당 종자 수에서는 차이를 보였다. 이는 갯잔디가 재배 환경에 따라 영향을 많이 받는 것으로 판단된다. 한국잔디류 수집지역의 토양 특성은 모든 조사구에서 토양산도는 약 pH 6인 약산성 토양이었으며, 치환성 양이온 중 나트륨($Mg^+$)은 0.06-0.02 $cmol{_c}^+kg^{-1}$, 마그네슘($Mg^{2+}$) 0.09-0.03 $cmol{_c}^+kg^{-1}$, 칼륨($K^+$) 0.02-0.01 $cmol{_c}^+kg^{-1}$로 나타나 척박한 토양에서 생육되고 있었다.

• 아시안잔디학회지
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• 제11권4호
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• pp.311-320
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• 1997

This study was carried out to induce and maintain callus from 59 zoysiagrass lines, to know the effective disinfestation method for zoysiagrass stolon as explant and the difference in the response of callus induction among 59 lines, and to investigate the effect of medium, growth regulators, light, temperature, stolon part and internode position on callus induction and emhryogenic callus(E.C.) formation. The treatment of 0.lmg/L $HgCl_2$for 15 min resulted in no contamination and the highest callus induction(46.6%). Callus was induced from the 59 zoysiagrass lines. The callus growth of Z. japonica and Z. sinica was generally better than Z. matrella Ten cell lines whose callus and stolon grow fast in culture and in field, respectively were selected to he used for breeding. Callus induction was the most effective at 2.0mg /L of both 2, 4-D and picloram in MS medium. MS medium was the best for callus induction and growth while LS medium was the best for embryogenic callus and shoot formation. Callus induction and growth was better at 28, 31$^{\circ}C$. than 25$^{\circ}C$. and dark condition was better than light condition in MS me-dium containing 2mg/L 2,4-D. While callus induction was better with node part as explant than with internode part, callus growth and embryogenic callus formation was better with internode part. In 'Japonica 1', the first internode was the most effective in callus induction, but third internode was the best in '$M_2$ X $S_2$'.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2005년도 동계학술연구발표회 및 2차 아시안포럼
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• pp.8-9
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• 2005

• 한국작물학회지
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• 제48권1호
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• pp.20-24
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• 2003

Proline is known as an osmotrotectant to enhance tolerance against both salt and dehydration stresses. A P5CS ($\Delta^1$-pyrroline-5-carboxylate synthetase) plays a major role in regulation of synthesis of proline. An overexpression of the mothbean P5CS gene in transgenic tobacco plant increased the levels of proline and osmotolerance. In an attempt to look for the possibility to use content of proline as well as a level of P5CS gene expression as molecular markers for salt tolerance, the amounts of proline and transcript levels of P5CS were measured as functions of either concentration of NaCl or length of treatment period among different species of zoysiagrass. Hybridzoysia showed the highest level of proline ($329\mu\textrm{g}$/g.f.w.) among five different species of zoysiagrass at 250 mM NaCl in 24 hours. The level of P5CS transcript was also the highest in the hybridzoysia at 250 mM NaCl in 24 hours. The transcriptions of P5CS gene were induced at the rates of 1.2, 1.2, 1.8, and 1.8, upon treatment of 250 mM NaCl in Z. japonica, Z. matrella, Z. sinica and hybridzoysia respectively. Based on a correlation between the level of P5CS transcript and the proline content among different species of zoysiagrass, a comparative structural analysis of the gene for P5CS from either Z. sinica or hybridzoysia may lead to an understanding of mechanism for salt tolerance shown differently among zoysiagrasses.

• 아시안잔디학회지
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• 제18권4호
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• pp.201-209
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• 2004

본 실험은 한국잔디 신품종 '세녹'(특허출원:10-2003-0072018) 개발에 관한 것으로, 한국에서 수집한 유전자원 중 갯잔디와 금잔디계통을 인공교배 방법을 이용해 F1계통을 얻었다. F1 계통을 포장상태에서 방임수분을 통해 변이확대를 하였으며, 이들 방임수분 후대에서 선발한 것으로 유전적으로 잔디의 녹색도가 진하며, 낮게 자라는 특성이 있고 품질이 우수하며 잎의 강직성이 높다 엽폭이 3.1mm로 중엽형이며, 초장이 14cm로 낮고, 잎각도가 67.3도로 넓으며, 지면으로부터 최하위 엽의 잎몸 기부까지의 길이가 2cm로 낮은 형태적 특성을 갖고 있어 낮은 잔디 깎기에 적응할 수 있는 영양번식형 잔디이다. 또한 RAPD 밴드 특성에서 한국잔디 신품종 세녹(Senock)이 특이 밴드를 갖어 식별성이 있다.

• 아시안잔디학회지
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• 제19권2호
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• pp.131-140
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• 2005

본 연구는 한국잔디류 5개 기본종, 상업종, 품종, 육종계통을 포함한 잔디류에 대하여 내한성 및 생육속도를 조사한 것이다. 실험은 총 41종의 한국잔디류를 사용하여 경기북부지역과 중부지역에서 적응실험을 수행하였다. 조사는 내한성(겨울철 생존율), 늦가을 녹색률, 이른봄 녹색률, 밀도, 생육속도 등을 가시적으로 평가하였다. 경기북부(적성면) 내한성 시험에서는 41종의 잔디 중 Z. matrella, Z. tenuifolia, USm, S4M2의 4종($9.7\%$)이 동사하였으며 나머지 37($90.3\%$)종은 생존하였다. 또한 식재 1년 후 생육이 가장 왕성한 계통으로 Anyang1, Samdeock1, Anyang2, SJ21, Pyeongdong 등을 확인할 수 있었으며, 이들은 모두 Z. sinica와 Z. macrostachya의 유전적 특성을 갖고 있는 중엽형 잔디들이었다. 중부지역(천안)에서 월동 후 생존한 잔디는 29종($70.7\%$)으로 나타났고, 고사한 잔디는 12종($29.3\%$)으로 나타났다. 경기도 적성 지역에 비해 천안에서 고사잔디가 많았던 이유는 천안 실험이 용기 조건에서 수행된 것으로 동해와 더불어 건조 피해가 심했던 것으로 생각된다. 동해와 건조 피해에도 불구하고 생존율이 높았던 잔디로는 Anyang2, AJ9-7, Samdeock1, Samdeock2, Samdeock3, 그리고 Zenith-C 등 이었다. 반면에 적성지역에서 생육이 양호했던 SJ2-19, NSm, 88Mey, 88Mey-75, 88Mey-9S SJ21-10, ASm, DBm 등은 천안실험에서 고사한 것으로 보아 한국잔디류는 동해보다는 겨울철 건조에 의한 피해가 높은 것으로 생각된다.

• 천문학논총
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• 제32권1호
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• pp.317-319
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• 2017

We propose a cosmological survey to probe star formation and nuclear activity in galaxies at redshifts of z=2-4 by polycyclic aromatic hydrocarbon (PAH) features using the SPICA mid-infrared instrument (SMI) with a spectral resolution of R=20. We will cover a wavelength range of $20-36{\mu}$ that corresponds to z=2-4 for the PAH features (11.3, 7.7, and $6.2{\mu}$). The sensitivity will be $1{\times}10^{-19}W/m^2(5{\sigma})$ in case of a reference survey that covers 4 arcmin2 field in a one-hour observation. It corresponds to $L_{IR}=2{\times}10^{11}L_{\odot}$ at z=3 and will give us more than 10000 galaxies in a 450 hour survey.