• Title/Summary/Keyword: 기학(氣學)

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Grain-Size Distribution of Source Areas of Asian Dust (Yellow Sand) in China

  • Yi, Hi-Il;Shin, Im-Chul
    • The Korean Journal of Quaternary Research
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    • v.21 no.2
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    • pp.77-79
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    • 2007
  • The source regions of Asian Dusts (Yellow Sands) in the western part of China are investigated, and the soil samples are collected samples for approximately 15 days during the spring of 2005. Particle sizes of sediments are analyzed and compared with each other. These grain-size analyses from the source areas can be compared Particle sizes between loess deposits and desert sands in western part of China and desert areas show distinctive differences. Loess deposits are predominantly composed of fine sands and silts. The distinction between the final characteristics of Asian Dust particles arrived in Korea and characteristics during transportation can be recognized comparison with the Asian Dust particles collected where the dust particles settled down. The characteristics of Asian Dust particle sizes can provide the basic information regarding the transportation history from the source region.

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Monsoonal Precipitation Variation in the East Asia: Tree-Ring Evidences from Korea and Inner Mongolia

  • Park, Won-Kyu;Liu Yu
    • The Korean Journal of Quaternary Research
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    • v.17 no.2
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    • pp.63-69
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    • 2003
  • Three tree-ring monsoon rainfall reconstructions from China and Korea have been used in this paper to investigate the variation of the East Asian summer monsoon over the past 160 years. Statistically, there is no linear correlation on a year-by-year basis between Chinese and Korean monsoon rainfall, but region-wide synchronous variation on decadal-scale was observed. Strong monsoon intervals (more rainfall) were 1860-1890, 1910-1925,1940-1960, and weak monsoon periods (dry or even drought) were 1890-1910, 1925-1940, 1960- present. Reconstructions also display that the East Asian summer monsoon suddenly changed from strong into weak around mid-1920, and the East Asian summer monsoon keeps going weak after 1960.

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Sedimentology of the intertidal flat sediments in the Seosan Bay, west coast of Korea and its implication on the Holocene sea level changes (韓國 西海岸 서산만에 發達한 一部 潮間帶 堆積層에 대한 堆積學的 硏究와 第四紀 海洋地質學的 考察)

  • Park Yong-Ahn;Lee Il-Sang
    • The Korean Journal of Quaternary Research
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    • v.1 no.1
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    • pp.21-34
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    • 1987
  • In the present study area, a part of intertidal flat in the Seosan Bay, west coast of Korea, characteristic three dominant tidal sedimentary facies and their related several typical sedimentary structures are described, Furthermore, a possible interpretation about the time stratigraphic developments of these intertidal deposits is suggested by introducing very late Quaternary (Holocene) sea-level rise in Korean Seas.

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A preliminary study of prehistoric tunnel-dwelling sites and rock-shelters in Che-Ju Island, Korea (제주도지방의 선사문화와 동굴${\cdot}$바위 그늘 주거지)

  • Lee, Chung-Kyu;Kang, Chang-Wha
    • The Korean Journal of Quaternary Research
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    • v.1 no.1
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    • pp.47-67
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    • 1987
  • Geologically speaking, many lava tunnels and caves are characteristic geomorphic features in Che-Ju Island. Especially, cave-ins are found along cliffs of shoreline and streams. The prehistoric early inhabitants in the island used the tunnels and cave-ins as their major shelters from palaeolithic period to the iron period (AD300-600). These tunnel-dwelling sites and rock-shelters are unsidered to be long-term shelters from the palaeolithic period to the neolithic period. However, these shelters and sites might be changed as temporary camping sites from the bronze to the iron period.

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Copper and manganese in the Anoxic Sediments banweol Tidal Flat West Coast of Korea (서해 경기만 반월 조간대 퇴적물의 망간과 구리의 함량 특성)

  • 박용안
    • The Korean Journal of Quaternary Research
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    • v.8 no.1
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    • pp.1-8
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    • 1994
  • 한국서해 경기만 남부 반월조간대 퇴적층에서 망간과구리의 함량특성을 밝히기 위 하여 총 3개의 주상시료를 채취하여 퇴적물의 입자와 유기탄소(organic carbon)함량을 일차 적으로 분석하였고 이에 따른 중요 시료에 대하여 망간과 구리의 함량을 분석하였다. 이러 한 분석결과는 연구지역의 망간함량이 연근해역 퇴적물의 망간함량에 비해 낮고 구리함량은 상대적으로 높다. 연구지역 내에서도 환원환경인 중부와 하부조간대에서 망간함량이 낮고 구리의 함량이 높게 나타났다. 이와같이 반월조간대 퇴적물의 망간 함량이 낮은 이유는 환 원환경에 공급괸 망간 산화물이 수 mm 깊이의 퇴적층에서 용해되고 그결과 생성된 용존 망간이 퇴적층과 해수와의 경계면(interface)으로 이동 제거 되었기 때문이다. 그러나 구리- 유기물 결합체는 퇴적물내에서 분해되고 그결과 생성된 용존구리는 황화물로 재 침전 되기 때문에 높은 함량을 나타내는 것으로 해석된다, 이와같은 결과는 반월 조간대 퇴적층의 초 기속작용의 영향을 받는 것으로 사료된다.

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The Paleoenvironment of the Northern Part of the Nagdong River Delta (낙동강 삼각주 북부의 고환경)

  • 오건환
    • The Korean Journal of Quaternary Research
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    • v.8 no.1
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    • pp.33-42
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    • 1994
  • The study area is filled up by alluvium which can be classified into lower and upper beds by the facies of deposits and their degree of weathering. The lower bed is not of marine but of fluvial. The upper bed is mainly composed of clay and silt or fine sand beds col-ored dark or dark gray which are of neritic or brackish yielding mollusca fossils. The oyster(Crassostrea ariakensis) obstained from the depth of 3m below the present sea level in the upper bed was dated at 4,100 110Y.B.P. and the veneridae(Meretrix lamarck) 1m height above the present delta plain in the old sand bar was dated at 1,700 85Y,B,P. It is therfore concluded that the study area a small kern col of terrestri-al basin prior to postglacial age had experienced the Holocene transgression. Consequently the study area is considered to have been progressively formed under neritic or brackish circumstance before 1,700Y.B.P.

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The Environmental Change of Korea based on the Isopollen Map during the Holocene

  • Yoon, Soon-Ock
    • The Korean Journal of Quaternary Research
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    • v.22 no.2
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    • pp.6-11
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    • 2008
  • Vegetation change reconstructed by pollen analysis is effective to clarify natural conditions such as climate and soil as well as intensity of human activity. Pollen analysis in Korea is difficult to obtain peaty soil sedimented by low relief geomorphollogically and formation age is usually confined to obtain information during young Holocene as well as little absolute age data. Isopollen map was constructed in order to analyze the change of vegetation environment time-spatially during Holocene based on the 30 data with age dated from 78 results from pollen analysis in Korea. The indicatives for vegetation environment were the main trees in Korea such as Alnus, Pinus, Quercus and AP/NAP during the periods of 6,000 y.BP, 4,000 y.BP, 3,000 y.BP, 2,000 y.BP, 1,000 y.BP. As a result, the regional time-spatial patterns of vegetation distribution appeared clearly on the isopollen map. The dominant vegetation stage was repeated in the different pattern e.g. the dominance between Alnus and Quercus at West Coast and between Pinus and Quercus at East Coast competitively.

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Let s Sing the Songs of Electrical Engineering (A method of Teaching Learning Electrical Engineering by Song) (전기공학을 노래로 부르자 (부절: 노래를 통한 새로운 전기공학 교수-학습방법 시도))

  • Kim, Il-Dong
    • Proceedings of the KIEE Conference
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    • 2005.07d
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    • pp.2974-2976
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    • 2005
  • 본 논문에서는 전기공학의 핵심내용들을 시문으로 작성하여 젊은 학생들이 즐겨 부르는 가요나 새로운 곡 등에 붙여 부르게 함으로서 학습효과를 증진시키는 방법을 제시하였다. 이해하기 어렵고 잃어버리기 쉬운 전기 이론을 노래로 부르면서 춤을 추거나 율동을 하면 더욱 효과적임을 보였다. 대표적으로 작사되고 노래에 붙여진 것으로는 "전기공학개론가", "전기회로이론가", "전기계량단위가" 및 "전자기학을 노래해" 등이 예시되었다. 강의 도중에 알맞은 대목이 나오면 즉흥 적으로 부르기도 하고 노래를 MP3파일로 제작해서 홈페이지에 올려놓아 학생들이 평소에 임의로 다운받아 따라 부를 수 있게 하였으며 실제로 수업에 활용하여 실증한 바도 있다.

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AN INTEGRATED SYSTEM FOR COMPUTATIONAL AERODYNAMIC, STRUCTURAL AND RF STEALTH ANALYSIS (공력-구조-RF 스텔스 통합 전산해석 시스템 연구)

  • Park, G.R.;Yang, Y.R.;Jung, S.K.;Myong, R.S.;Cho, T.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.78-82
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    • 2010
  • An integrated multi-disciplinary design system plays a critical role in the preliminary design of an aircraft. In this paper such system is developed for the multi-disciplinary computation and design; aerodynamics elasticity, and radio frequency stealth. Common data base of geometry and structured grids is generated and used for aerodynamic, structural and eletromagnetics analysis. The Navier-Stokes CFD, FEM, and CEM technique are used for aerodynamic, structural, and RF stealth computations respectively.

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