• Title/Summary/Keyword: 빙하중

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Reconsideration on the Importation Pathway of Ancient Korean Rice(Oryzar sativar L.) (고대 한반도에서 재배된 벼의 전래 경로에 대한 고찰)

  • Park, Tae-Shik
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.54 no.1
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    • pp.119-123
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    • 2009
  • Importation pathway of rice cultivar into Korea was re-established with considering ancient geo-ecological characteristics of the Sororibyeo excavated from Cheongwon. It is assumed that Sororibyeo settled down in Korea by the importation pathway along the southern seashore of China through old downstream of Geumgang by a southern Korean human race when China and Korea were not yet separated each other by the Yellow Sea. This importation pathway was designated as "Old Geumgang-Sorori Rice Road", in this study. It is further inferred that Korean Peninsula was geographically isolated by ocean after the Ice Age. In consequence, Gawajibyeo, an ancient rice with little genetic variation, was evolved from Sororibyeo, which is estimated to evolve into rice cultivar in Korean Peninsula.

East Asian Monsoon History as Indicated by C/N Ratios and ${\delta}^{13}C$ Evidence from the Estuarine Tidal Flat Sediments in the West Coast of Korea (서해안 염하구 습지 퇴적물의 지화학적 분석 (C/N 및 ${\delta}^{13}C$)에 기반한 동아시아 몬순 변동 연구)

  • Park, Jung-Jae;Shin, Young-Ho
    • Journal of the Korean Geographical Society
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    • v.45 no.5
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    • pp.541-552
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    • 2010
  • Geochemical and physical investigations such as ${\delta}^{13}C$ isotope ratio, carbon/nitrogen (C/N) ratio, magnetic susceptibility (MS), and particle size analyses were carried out on the estuarine tidal flat sediments from the west coast of Korea in order to reconstruct the East Asian summer monsoon variability during the late Pleistocene and Holocene Our results indicated that the summer monsoon probably peaked around 7,700-7,800 yr BP and then started to decline about 7,400 yr BP in the Korean peninsular, and that the monsoon was relatively weak between 24,000-24,500 yr BP but relatively strong between 18,500-19,500 yr BP during the Last Glacial Maximum. Our estuarine geochemical data have proven to be valuable as a new proxy for detecting the shifts in monsoon strength. This new evidence will be helpful, especially for Korean paleoenvironmental studies with few proxy data archives.

Analysis of Properties of Rubbed Polyimide Alignment Layer and Rubbing Effect of Various Rubbing Cloths for LCD Fabrication (LCD 제조용 러빙포 물성에 따른 러빙된 폴리이미드 배향막의 특성 및 러빙효과 분석)

  • Ahn, Hong-Jun;Lee, Jang-Ju;Ahn, Jong-Soo;Park, Kyung-Chul;Noh, Jae-Gyu;Yoo, Dong-Yeon;Paek, Sang-Hyon
    • Polymer(Korea)
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    • v.35 no.5
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    • pp.385-389
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    • 2011
  • In rubbing process, process factors, the properties of alignment layer and the physical properties of rubbing cloth have acted as important variables. These factors affect the orientation properties of the alignment layer by rubbed extent that is determined by rubbing density and rubbing force. In this work, we studied the effects of rubbing cloths with different pile density and rigidity on rubbing density(length) and rubbing force. As the pile density and rigidity of rubbing cloths increased, the birefringence and the surface roughness of the rubbed alignment layers became bigger, but the characteristics of rubbing-effect had differed each other. The pile density of rubbing cloths which was related with the number of pile, affected the rubbing density(length). On the other hand, the pile rigidity of rubbing was closely related to rubbing force rather than the rubbing density(length).

Long-lived cosmogenic nuclide, Beryllium-10 and its applications (장반감기 우주선유발 동위원소, $^{10}Be$과 그 응용)

  • Kim, K.J.;Jull, A.J.T;Woo, H.J.
    • The Korean Journal of Quaternary Research
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    • v.20 no.2
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    • pp.30-50
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    • 2006
  • The long-lived radionuclide, $^{10}Be$, is produced by cosmic-ray effects in the atmosphere of the earth as well as its surface and that of other planetary surfaces and atmospheres. Accelerator mass spectrometry (AMS) was developed in late 1970s, which made $^{10}Be$ terrestrial measurements more feasible. Since then, many research applications of $^{10}Be$ for both terrestrial and extraterrestrial applications have been developed, which parallel the wide range of radiocarbon ($^{14}C$) research applications. This paper summarizes production mechanisms of $^{10}Be$ both in the atmosphere and on the surface of terrestrial and extraterrestrial environments and also provides numerous $^{10}Be$ research applications in the fields of geomorphology, oceanography, archaeology, glaciology, cosmochemistry, climatology, and planetary science. We also review some $^{10}Be$ AMS research applications.

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Distribution and Characteristics of Native Conifers in Korea (국내 자생 구과식물의 분포 및 특성)

  • Jong Cheol Yang
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2020.08a
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    • pp.3-3
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    • 2020
  • 최근 지구온난화로 인한 기후변화로 인해 지리적 분포가 한정적인 한반도 구과식물들은 점점 서식지 내 생육에 위협을 받고 있다. 이러한 구과식물의 지속이용가능한 보전을 위해서는 각 종별 형질 특성 및 분포, 생육정보 등의 기초정보 구축이 필요할 것이다. 구과식물(Pinidae, Conifers)은 전 세계적으로 나자식물(Gymnosperms)의 3/5정도인 630여분류군이 분포하는 것으로 알려져 있다(Farjon, 2008). 은행나무나 소철나무류 등 다른 나자식물과 비교하여 여러 복잡한 구조로 이루어진 구과(웅성, 자성 구과)를 형성하고, 잎은 대부분 바늘형으로 단순하며, 상록성인 특징 등으로 구분된다. 우리나라에 분포 및 식재되고 있는 나자식물 중 은행나무와 소철나무를 제외한 모든 나자식물이 구과식물에 속한다. 구과식물이 전 세계적으로 넓은 분포역을 갖지만, 종별로는 제한적인 분포를 갖는 것들이 많이 나타난다. 우리나라에 자생하는 구과식물 대부분도 동북아시아에만 분포하는 종들이 대다수이다. 한반도 구과식물은 총 5과 12속 23종 5변종 총 28분류군으로 확인되었다. 소나무과는 5속 12분류군으로 구상나무와 분비나무의 형태적 중복형질이 확인되었으며, 측백나무과는 3속 9분류군으로 눈향나무를 변종에서 종 수준으로 적용하였고, 어청도에서 해변노간주의 분포를 확인하였다. 개비자나무과는 1속 3분류군으로 수형에 따라 큰개비자나무, 눈개비자나무, 개비자나무로 구분하였다. 주목과는 비자나무속을 포함하여 2속 3분류군으로 설악눈주목에 대한 세부적인 분류학적 재검토가 필요할 것으로 판단한다. 나한송과는 1속 1분류군으로 신안군 가거도에서 나한송의 자생지를 확인하였다. 구상나무와 분비나무의 형태적 구분형질이 모호함에 따라 집단별 유전정보 분석을 통한 계통지리학적 연구를 수행하였다. 분석을 통해 구상나무는 빙하기에 북부지역의 조상종이 남하하여 분화되고, 후빙기에 중부지역까지 분포확장이 이루어진 것으로 판단된다.

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Recent Research Trends in American Geomorphology and Hydrogeography (미국에서의 지형학과 수문지리학의 최근 연구동향)

  • Chang Heejun;Kim Changhwan
    • Journal of the Korean Geographical Society
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    • v.39 no.6 s.105
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    • pp.873-887
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    • 2004
  • We examined research trends in geomorphology and hydrogeography in America based on papers presented at the annual meetings of the Association of American Geographers(AAG) and papers published in two AAG journals between 2002 and 2004. Among the 437 papers in geomorphology, $40\%$ of the papers concerned fluvial geomorphology, followed by environmental geomorphology and glacial and periglacial geomorphology concern. Among the 452 papers in hydrogeography, about $20\%$ of the papers focused on water, law and institutional aspects, followed by hydrogeomorphology and hydrologic modeling. Twenty one papers examining geomorphology and hydeogeography were published in two AAG journals, and fluvial geomorpholoy was the dominant theme. GIS was used for $29\%$ papers in geomorphology and $35\%$ of papers in hydrogeography($35\%$), suggesting that other methods, including geostatistics, field survey, and qualitative methods, are employed as well. This methodological diversification seems to be associated with solving such complex environmental problems as integrated watershed management and implies that geomorphologists and hydrogeographers are expanding their traditional territories and are making close connections with human-environment geographers and human geographers. Geomorphologists and hydrogeographers are likely to continue examining the causes of and solving environmental problems that humans are currently facing and might face in the future.

Elementary, Middle, and High School Students' Perception of Polar Region (초·중·고등학생들의 극지에 대한 인식)

  • Chung, Sueim;Choi, Haneul;Kim, Minjee;Shin, Donghee
    • Journal of the Korean earth science society
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    • v.42 no.6
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    • pp.717-733
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    • 2021
  • This study is aimed to provide basic data to set the direction of polar literacy education and to raise awareness of the importance of polar research. Elementary, middle, and high school students' perception of the polar region was examined in terms of current status of polar information, impression regarding polar regions, and awareness of related issues. The study included 975 students from nine elementary, middle, and high schools, who responded to 16 questions, including close-ended and open-ended items. The results suggest that students had more experiences regarding the polar region on audiovisual media, but relatively limited learning experiences in school education. The impression they had of the polar region was confined to the monotonous image of a polar bear in crisis, following the melting of the glacier due to global warming. The students formed powerful images by combining scenes they saw in audiovisual media with emotions. In terms of recognizing problems in the polar region, the students were generally interested in creatures, natural environment, and climate change, but their interests varied depending on their school level and their own career path. The students highly valued the scientist's status as agents to address the problems facing the region, and gave priority to global citizenship values rather than practical standards. Based on the results, we suggest the following: introducing and systematizing content focusing on the polar region in the school curriculum, providing a differentiated learning experience through cooperation between scientists and educators, establishing polar literacy based on concepts that are relevant to various subjects, earth system-centered learning approach, setting the direction for follow-up studies and the need for science education that incorporates diverse values.

Accuracy Assessment of Tide Models in Terra Nova Bay, East Antarctica, for Glaciological Studies of DDInSAR Technique (DDInSAR 기반의 빙하연구를 위한 동남극 테라노바 만의 조위모델 정밀도 평가)

  • Han, Hyangsun;Lee, Joohan;Lee, Hoonyol
    • Korean Journal of Remote Sensing
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    • v.29 no.4
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    • pp.375-387
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    • 2013
  • Accuracy assessment of tide models in polar ocean has to be performed to accurately analyze tidal response of glaciers by using Double-Differential Interferometric SAR (DDInSAR) technique. In this study, we used 120 DDInSAR images generated from 16 one-day tandem COSMO-SkyMed DInSAR pairs obtained for 2 years and in situ tide height for 11 days measured by a pressure type wave recorder to assess the accuracy of tide models such as TPXO7.1, FES2004, CATS2008a and Ross_Inv in Terra Nova Bay, East Antarctica. Firstly, we compared the double-differential tide height (${\Delta}\dot{T}$) for Campbell Glacier Tongue extracted from the DDInSAR images with that predicted by the tide models. Tide height (T) from in situ measurement was compared to that of the tide models. We also compared 24-hours difference of tide height ($\dot{T}$) from in situ tide height with that from the tide models. The root mean square error (RMSE) of ${\Delta}\dot{T}$, T and $\dot{T}$ decreased after the inverse barometer effect (IBE)-correction of the tide models, from which we confirmed that the IBE of tide models should be corrected requisitely. The RMSE of $\dot{T}$ and ${\Delta}\dot{T}$ were smaller than that of T. This was because $\dot{T}$ is the difference of tide height during temporal baseline of the DInSAR pairs (24 hours), in which the errors from mean sea level of the tide models and in situ tide, and the tide constituents of $S_2$, $K_2$, $K_1$ and $P_1$ used in the tide models were canceled. This confirmed that $\dot{T}$ and ${\Delta}\dot{T}$ predicted by the IBE-corrected tide models can be used in DDInSAR technique. It was difficult to select an optimum tide model for DDInSAR in Terra Nova Bay by using in situ tide height measured in a short period. However, we could confirm that Ross_Inv is the optimum tide model as it showed the smallest RMSE of 4.1 cm by accuracy assessment using the DDInSAR images.

Diversity Analysis for Archaeal amoA Gene in Marine Sediment of Svalbard, Arctic Circle (북극 Svalbard 지역 해양 퇴적물의 고세균 amoA 유전자의 다양성 분석)

  • Park, Soo-Je;Rhee, Sung-Keun
    • Korean Journal of Microbiology
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    • v.50 no.2
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    • pp.164-168
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    • 2014
  • The ecosystem of the Arctic region has been increasingly affected by global warming. Archaeal ammonia monooxygenase alpha subunit coding gene (amoA) which is a key enzyme for nitrification was used to investigate the effect of runoff water of ice melt on microbial community of nitrogen cycle. The archaeal amoA genes at coastal area of Svalbard, Arctic region were PCR-amplified and sequenced after clone library construction. Analysis of archaeal amoA gene clone libraries suggested that the station 188 which is in the vicinity to the area of runoff water harbor lower ammonia-oxidizing archaeal diversity than the station 176 and 184. The average amino acid sequence identity within all archaeal amoA gene clones was 94% (with 91% nucleotide sequence identity). While all the clones of the station 188 were affiliated with Nitrosoarchaeaum clade containing strains isolated from low-salinity and terrestrial environments, about 45% of total clones of the station 176 and 184 were related to marine Nitosopumilus clade. Interestingly, other typical archaeal amoA gene clones of thaumarchaeal I.1b clade frequently retrieved from terrestrial environments was identified at station 188. Microbial community of nitrogen cycle in marine sediment might be affected by input of sediments caused by runoff glacier melt waters.

Application of KOMPSAT-5 SAR Interferometry by using SNAP Software (SNAP 소프트웨어를 이용한 KOMPSAT-5 SAR 간섭기법 구현)

  • Lee, Hoonyol
    • Korean Journal of Remote Sensing
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    • v.33 no.6_3
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    • pp.1215-1221
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    • 2017
  • SeNtinel's Application Platform (SNAP) is an open source software developed by the European Space Agency and consists of several toolboxes that process data from Sentinel satellite series, including SAR (Synthetic Aperture Radar) and optical satellites. Among them, S1TBX (Sentinel-1 ToolBoX)is mainly used to process Sentinel-1A/BSAR images and interferometric techniques. It provides flowchart processing method such as Graph Builder, and has convenient functions including automatic downloading of DEM (Digital Elevation Model) and image mosaicking. Therefore, if computer memory is sufficient, InSAR (Interferometric SAR) and DInSAR (Differential InSAR) perform smoothly and are widely used recently in the world through rapid upgrades. S1TBX also includes existing SAR data processing functions, and since version 5, the processing capability of KOMPSAT-5 has been added. This paper shows an example of processing the interference technique of KOMPSAT-5 SAR image using S1TBX of SNAP. In the open mine of Tavan Tolgoi in Mongolia, the difference between DEM obtained in KOMPSAT-5 in 2015 and SRTM 1sec DEM obtained in 2000 was analyzed. It was found that the maximum depth of 130 meters was excavated and the height of the accumulated ore is over 70 meters during 15 years. Tidal and topographic InSAR signals were observed in the glacier area near Jangbogo Antarctic Research Station, but SNAP was not able to treat it due to orbit error and DEM error. In addition, several DInSAR images were made in the Iraqi desert region, but many lines appearing in systematic errors were found on coherence images. Stacking for StaMPS application was not possible due to orbit error or program bug. It is expected that SNAP can resolve the problem owing to a surge in users and a very fast upgrade of the software.