• Title/Summary/Keyword: Cluster observation

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Two Morphotypes in Korean Striped Bitterlins, Acheilognathus yarnutsutae Mori (Cvprinidae, Pisces) (줄납자루 Acheilognathus yamatsutae Mori(잉어과, 어강)의 두 type)

  • Chae, Byung-Soo;Yang, Hong-Jun
    • The Korean Journal of Zoology
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    • v.37 no.1
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    • pp.49-57
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    • 1994
  • In the course of an investigation on the morphological variation of Korean striped bittering, Acheilognathus vamatsutae Mori, two kinds of morrholoflical types were found. Some morphological characters were compared between them and multivariate analysis was conducted. Since the difference of the barbel length between them was very significant (p < 0.01,1-test), they should be designated as L-and 5-type Hshes: fishes with long barbels and those with should barbels, respectively. Lateral line scales, snout length and prepectoral length showed a tendency that the observation could be distinguished from each other (p < 0.05, Duncan's multiple range tests. There were no individuals over 70 mm BL in S-type and so S-type fishes were somewhat dwarf than L-type fishes. The two types were also clearly distinguished by multivariate analyses using cluster and discriminant analyses. According to the observation on the four populations of the Naktong River, the blue-green stripe on the body side and the white band on the margin of anal fin in males of S-type fishes were well developed through the year but those of males of L-type fishes completely disappeared or became slender during nonbreedins season as that of females. Of the seven localities surveved, there were no places that the two types cohabit. S-type fishes are limited only in the Kumho and Wichon River of the Naktong River system but L-type fishes are distributed more widely In the Hongchon, Mangvons, Somjin, Mirang and Panbyon River.

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Mycorrhizal Development and Growth Stimulation of Pinus thunbergii Seedlings Inoculated with Pisolithus tinctorius at Two Soil Mixtures Treated with Six Nitrogen Levels (배양토(培壤土) 및 질소(窒素) 시비(施肥) 수준(水準)이 모래밭 버섯균(菌) (Pisolithus tinctorius)을 접종(接種)한 해송(海松)(Pinus thunbergii) 묘(苗)의 생장(生長)과 균근(菌根) 형성(形成)에 미치는 영향(影響))

  • Oh, Kwang In;Park, Whoa Shig
    • Journal of Korean Society of Forest Science
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    • v.77 no.4
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    • pp.361-370
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    • 1988
  • This study was carried out for observation of growth, mycorrhizal formation and nutrient absorption of Pinus thunbergii seedlings treated with two soil mixtures and various nitrogen levels after inoculation with mycorrhizal fungus, Pisolithus tinctorius. 1. Seedlings grown on vermiculite applied with $50-150{\mu}g/ml$ nitrogen levels were well developed with pinnate type and cluster-like mycorrhizae. But seedlings on sandy loam had monopodial type in addition to the above-mentioned two types. 2. Optimum fertilization level for mycorrhizal formation is 50 or $150{\mu}g/ml$ N that showed best mycorrhizal formation of $86.4({\pm}3.14)%$ or $73.0({\pm}7.21)%$, respectively, but increased nitrogen levels decreased formation of mycorrhizal short roots. Seedlings applied with $450{\mu}g/ml$ nitrogen level decreased in net assimilation rate (NAR) and crop growth rate(CGR) during early growth of the seedlings, and they were increased since Aug, when nutrient application was stopped. 9. Inorganic nutrient absorption was increased more in seedlings grown on vermiculite and inoculated growth medium than those grown on sandy loam and noninoculated one, and it was gradually increased with increasing nitrogen increasing nitrogen level until $350{\mu}g/ml$. But $450{\mu}g/ml$ nitro gen level rather reduced absorption of nutrient.

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Identifying the Research Fronts in Korean Library and Information Science by Document Co-citation Analysis (문헌동시인용 분석을 통한 한국 문헌정보학의 연구 전선 파악)

  • Lee, Jae Yun
    • Journal of the Korean Society for information Management
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    • v.32 no.4
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    • pp.77-106
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    • 2015
  • By document co-citation analysis with Korean Citation Index (KCI) data, this study accurately identified the research fronts and hot topics in Korean library and information science (LIS) from 2004 to 2013. 159 core papers in LIS domain and their citations are scraped manually from Korean Citation Index web site. In the cluster analysis and network analysis, 159 core papers were grouped into 27 clusters with multiple papers and 8 singlton clusters. Among the 27 clusters which have multple papers, 'LIS education' cluster was the largest with 16 core papers, and 'citation analysis & intellectual structure analysis' cluster had the strongest citation impact according to the ehs-index. Closer observation of the citations to the core papers in each research front showed that 67.5% of the citations were made by LIS research papers and 32.5% of the citations were made by non-LIS research papers. Considering the share of citations and the citation impact growth index, 'local documentation', 'citation analysis & intellectual structure analysis', and 'research trends analysis' were identified as the most emerging research front in Korean library and information science. The analytical methods used in this study have great potential in discovering the characteristics of research fronts in Korean interdisciplinary research domains.

Spectroscopic Confirmation of Galaxy Clusters at z~0.92

  • Kim, Jae-Woo;Im, Myungshin;Lee, Seong-Kook;Hyun, Minhee
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.45.1-45.1
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    • 2015
  • Galaxy clusters have provided important information to understand the evolution of the universe, since the number density and mass of clusters are tightly related to the cosmological parameters. In addition, galaxy clusters are an excellent laboratory to investigate the galaxy evolution in dense environments. However, finding galaxy clusters at high redshift ($z{\geq}1$) still remains as a main subject in astronomy due to their rareness and difficulty in identifying such objects from optical imaging data alone. Here, we report a spectroscopic follow-up observation of distant galaxy cluster candidates identified by a deep optical-NIR dataset of Infrared Medium-deep Survey. Through the galaxy spectra taken with the IMACS instrument on the Magellan telescope, we confirm at least 3 massive clusters at z~0.92. Interestingly, the maximum spatial separation between these clusters is ~8Mpc, which implies that this system is a new supercluster in the distant universe. We also discuss properties of galaxies in these clusters based on multi-wavelength photometric data.

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An Observation on Environmental Modification Behavior: Implications for University Apartments' Design (환경조절 행태에 대한 관찰연구: 대학 아파트 설계를 위한 시사점)

  • Kim, DukSu
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.18 no.3
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    • pp.9-17
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    • 2012
  • 본 연구는 미국 소재 T 대학교의 학생아파트를 대상으로 하여 창밖으로 보이는 외부 환경의 차이와 거주자의 환경조절 행태 사이의 관계를 분석하는 관찰연구로 진행되었다. 거주자와 거주환경간에 발생하는 부조화는 환경 스트레스의 한 원인이 된다. 이러한 환경 스트레스에 대한 대응 전략으로 거주자는 그들의 환경을 조정하곤 한다. 본 연구는 실내에서 식물을 키우거나 거주자의 취향에 따라 커튼을 교체하는 등의 환경조절 행태를 분석의 대상으로 한다. 창문과 현관 영역에서 발생하는 환경조절 행태의 정도를 비교 관찰하기 위해 군집형과 일자형으로 되어 있는 두 개의 배치 유형을 연구의 대상으로 선정하였다. 군집형 유형(cluster type: type A)은 상대적으로 도로에 가깝고 거실 창문의 조망이 다른 건물에 가로막혀 있으며, 일자형 유형(parallel type: type B)은 가로막고 있는 건물이 없어 자연경관을 거실 창문을 통해 조망할 수 있는 배치상의 두드러진 차이점이 있다. 관찰연구를 통해 군집형 유형에서 일자형 유형보다 더 높은 빈도로 식물 화분과 개별 커튼 등을 이용한 개인적 환경조절이 이루어진 흔적이 발견되었다. 이러한 결과는 창문을 통해 보이는 외부 경관의 특성이 거주자의 환경조절 행태에 미치는 영향의 정도를 암시하고 있다. 결론적으로 관찰연구에서 나타난 거주자의 환경조정 행태를 반영하여 디자인 고려사항을 제안하였다.

Analysis of Wind Sector Division for Pohang Area - Part I : Coarse Division of Wind Sector for Pohang Area Using Meteorological Observation Data - (포항지역에 대한 바람권역 분석 -Part I : 기상관측자료를 토대로 분석한 성긴 바람권역 분석-)

  • Jung, Jong-Hyeon;Leem, Heon-Ho;Leem, Hwa-Woon;Chang, Hyuk-Sang;Shon, Byung-Hyun
    • Journal of Environmental Science International
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    • v.17 no.4
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    • pp.385-396
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    • 2008
  • The air quality data is important for understanding and analyzing a surrounding influence. In that light, it is positively necessary for a propriety assessment to determine a location of the air quality monitoring sites. In this study, the climate analysis about temperature and wind, using the meteorological data in the Pohang, is conducted to do that. In the next stage, we distinguished the wind by east-west or north-south component, which has less correlation than temperature, analyzed and divided the wind sector. As the result, the wind circumstance of the Pohang is divided into major 5 wind sector; that is the urban area, the northeast coastal area, the east ocean and the west mountainous area. We think that an analysis on detailed wind sector by utilizing the numerical simulation is needed.

Properties of $ Y_2O_3$ Thin Films Prepared by ICBD Method (ICBD 법에 의한 $ Y_2O_3$박막특성에 관한 연구)

  • Jeon, J. S.;Moon, J.;Lee, S. I.;Shim, T. E.;Hwang, J. N.
    • Journal of the Korean Vacuum Society
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    • v.5 no.3
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    • pp.245-250
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    • 1996
  • $Y_2O_3$ thin film on si(100) was successfully grown by ionized cluster beam(ICBD) technique at substrate temperature of around $500^{\circ}C$ and pressure of ~$10^{-5}$Torr.To prevent the oxidation of Si substrae, a very thin yttrium layer was deposited on Si before reactive depositing of oxygen and yttrium source. In asdeposited stage, b.c.c and h.c.p strucutres of $Y_2O_3$ were observed from S-ary analysis. From the observation of spots and ring patterns in selected area diffractin(SAD) patterns. crystallane formation and growth could be proceeded during the deposition. $Y_2O_3$/mixed layer/$SiO_2=170\AA/50\AA/10\AA$ structure were verified by high resolution transmition electron imcroscopy(HRTEM) image, and the formation of amorphous layer of SiO2 was discussed . Electricla charateristics of the film were also investigated . In as-deposited Pt/$Y_2O_3$/Si sturcuture, leakage current was less than $10^{-6}$A/$\textrm{cm}^2$ at 7MV/cm strength.

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$K_s$-band luminosity evolution of AGB populations based on star clusters in the Large Magellanic Cloud

  • Ko, You-Kyung;Lee, Myung-Gyoon
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.56.2-56.2
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    • 2012
  • We present a study of the asymptotic giant branch (AGB) contribution to the total Ks band luminosity of star clusters in the Large Magellanic Cloud (LMC) as a function of age. AGB stars, a representative intermediate-age population, are a strong source of NIR to MIR emission so that they are a critical component for understanding the near-to-mid infrared observation of galaxies. Current calibration of IR emission in evolutionary population synthesis (EPS) models for galaxies is mainly based on a small number of LMC star clusters. However, each LMC star cluster with intermediate age contains only a few AGB stars so that it suffers from a stochastic effect. Therefore a large number of them are needed for solid calibration of the EPS models. We study physical properties of a large number of LMC star clusters to estimate the Ks band luminosity fraction of AGB stars in star clusters as a function of age. We discuss the stochastic effect in calibrating models, and the importance of this calibration for studying the evolution of not only nearby galaxies but also of high-z galaxies.

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Verifing Formation of Area of Influence of Subway Station through Land Value Distribution Analysis - Case Study on Seoul

  • Lee, Byoungkil;Lee, Sangkyeong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.34 no.4
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    • pp.403-411
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    • 2016
  • This research has the purpose to develop a method to evaluate whether station’s area of influence has been formed, and verify formation of the area of influence through empirical analysis of all subway stations in Seoul. First, we created buffers of 100m intervals from 100m to 1000m, based on subway station exits, calculated the average land price of each buffer, and divided station areas of influence into 10 clusters using K-means clustering with the average land prices as values of observation. Subsequently, we have assumed a decreasing price curve from increasing distance from a nearby subway station, estimated a price curve and evaluated whether the area of influence actually exists using regression analysis of each cluster. The 10 area of influence clusters were largely divided into strong, weak, and no area of influence of subway station. The stations where the strong areas of influence are formed are mainly located in center, sub-centers, and local centers; stations where weak and no areas of influence are formed are mostly located in the adjacent areas of center or sub-centers or suburbs.

Regulation of the sufABCDSE Operon by Fur

  • Lee, Joon-Hee;Yeo, Won-Sik;Roe, Jung-Hye
    • Journal of Microbiology
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    • v.41 no.2
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    • pp.109-114
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    • 2003
  • A promoter that is inducible by paraquat and menadione, the superoxide generators, independently of soxRS has been found in front of the sufABCDSE operon in Escherichia coli. Based on the observation that SufA is a holomog of IscA that functions in the assembly of iron sulfur cluster and the sufA promoter (sufAp) contains a putative Fur-binding consensus, we investigated whether this gene is regulated by Fur, a ferric uptake regulator, When examined in several sufAp-lacZ chromosomal fusion strains, sufAp was induced by EDTA, an iron chelator and a well-known Fur-inducer, The basal level of sufA expression increased dramatically in fur mutant, suggesting repression of sufAp by Fur. The derepression in fur mutant and EDTA-induction of sufA expression required nucleotides up to -61, where a putative Fur box is located. Purified Fur protein bound to the DNA fragment containing the putative Fur box between -35 and -10 promoter elements. The regulation by Fur and menadione induction of sufAp acted independently. The rpoS mutation increased sufA induction by menadione, suggesting that the stationary sigma factor RpoS acts negatively on sufA induction.