• Title/Summary/Keyword: ridge part

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Analysis of Geomorphological Changes using RS and GIS techniques in Shinduri coastal dunefield (원격탐사와 GIS 기법을 이용한 신두리 해안사구지대의 지형변화 분석)

  • Seo, Jong-Cheol
    • Journal of the Korean association of regional geographers
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    • v.8 no.1
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    • pp.98-109
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    • 2002
  • The long term land-cover changes and the pattern of morphological changes in foredune ridges and unvegetated dunes were investigated for about 30 years through analysing aerial photographs in Shinduri coastal dunefield, Korea. As a result, forested dune area increased while unvegetated dune area decreased continuously since 1967. Foredune ridges retreated landward about 80m away from the former coast-line in the middle part while they advanced seaward after construction of dike in the northern part during last 3 decades. Unvegetated dunes in the middle part of the dunefield were eroded at seaward side and moved landward away. These facts mean not only coastal dune area has been affected by man-made effects such as afforestation and coastal developments but also shinduri coastal dune area has been stabilized by plants and has been negative sediment budget.

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A Study on the Chimi of Hwangnyongsa Temple and the Building Condition of Chimi Installed (황룡사 치미와 사용처의 건축조건 연구)

  • Kim, Sookyung
    • Journal of architectural history
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    • v.31 no.6
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    • pp.59-68
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    • 2022
  • This paper is an architectural historical study on Chimi of Hwangnyongsa Temple. In this research, the shape and cross-section of the chimi are reviewed. The results of the study are as follows. The chimi is a form in which the head part facing the maru is omitted, and the upper and lower body are separated. The upper and lower bonds are assembled into a two types of joint throughout the side of the torso, and then bound with an iron strap. Because of the absence of ridge line in the front, and the narrow curved surface which makes the side plate close to the plane, the entire cross-section is triangular, and the rear plate maintains the shape of the chimi. The naerimmaru connected to the side of the chimi has a slope, so it is clear that the chimi was used on the woojingak-jibung(hipped-roof), and the wing part and back of the chimi are erected on the side roof. The height of the yongmaru and chunyeomaru is about the same and the roofing tiles of those are in contact. The roofing tiles of chunyemaru should be cut to fit the angle of the contacting part. The maru is 30 stories high of roofing tiles as a result of the on-board survey. Based on reference on the shape and timing of the production of chimi, the height of chimi, and the maru is believed to have been built before the Unified Silla Period and used in buildings with at least seven-kan frontage. Buildings corresponding to these construction conditions can be seen as Central hall and East hall in Hwangnyongsa temple.

Late Quaternary Sedimentation in the Yellow Sea off Baegryeong Island, Korea (한국 황해 백령도 주변해역 후 제4기 퇴적작용)

  • Cho, MinHee;Lee, Eunil;You, HakYoel;Kang, Nyen-Gun;Yoo, Dong-Geun
    • Geophysics and Geophysical Exploration
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    • v.16 no.3
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    • pp.145-153
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    • 2013
  • High-resolution chirp profiles were analyzed to investigate the echo types of near-surface sediments in the Yellow Sea off the Baegryeong Island. On the basis of seafloor morphology and subbottom echo characters, 7 echo types were identified. Flat seafloor with no internal reflectors or moderately to well-developed subbottom reflectors (echo type 1-1 and 1-2) is mainly distributed in the southern part of the study area. Flat seafloor with superposed wavy bedforms (echo type 1-3) is also distributed in the middle part. Mounded seafloor with either smooth surface or superposed bedforms (echo type 2-1, 2-2, and 2-3) occurs in the middle part of the study area. Irregular and eroded seafloor with no subbottom reflectors (echo type 3-1) is present in the northern part of the study area off the Baegryeong Island. According to the distribution pattern and sedimentary facies of echo types, depositional environments can be divided into three distinctive areas: (1) active erosional zone due to strong tidal currents in the northern part; (2) formation of tidal sand ridges in response to tidal currents associated with sea-level rise distributed in the middle part; and (3) transgressive sand sheets in the southern part. Such a depositional pattern, including 7 echo types, in this area reflects depositional process related to the sea-level rise and strong tidal currents during the Holocene transgression.

Mapping of the Damaged Forest by Oak Wilt Disease in Bukhansan National Park (북한산국립공원 참나무시들음병 피해지 맵핑 연구)

  • Yeum, Jung-Hun;Han, Bong-Ho;Choi, Jin-Woo;Jeong, Hee-Un
    • Korean Journal of Environment and Ecology
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    • v.27 no.6
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    • pp.704-717
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    • 2013
  • This study aims to provide basic data for management and prevention of infection damage by Oak wilt disease through mapping method of status with infected level in damaged area of Bukhansan National Park. Survey was carried out in the distributed area of oak trees with mapping unit of polygon of actual vegetation and mapped of infection ratio and infection index applying weight according to infected level. Infection ratio of oak trees in Bukhansan National Park was 58.5%, and lightly damaged ratio was 29.6%, half of the damaged ratio was 16.1%, seriously damaged ratio was 8.8% and withered ratio was 4.1%. It was serious to be infected from Beomgol ridge in Wondobong district to Hyeongjaebong in Jeongrung district. Although the infected ratio of the western part of Songchu district, Sanseong district and Gugi district centering main ridge of Bukhansan National Park was low, it of ridge and main valley was high. Infection index of hardly damaged area was 39.1% of whole area, and slightly damaged area was 41.0%, half of the damaged area was 16.1%, seriously damaged area was 3.3% and alarmed withering area was 0.4%. Infection index was high around Musugol valley in Dobong district and Jaunbong, and it of Bohyunbong of Jeongrung district and the part of Hyojari valley of Sanseong district was serious. Predicted numbers of the trees affected Oak wilt disease compared to the distributed area of oak trees was 1,585,937 trees among 2,709,147 trees of Quercus spp. 352,931 trees among the 306,161 trees of oak were infected in Woi district, the most seriously infected area and 53,141 trees among the 145,747 trees of oak was infected in Gugi district, the most slightly infected area.

Cholesterol Granuloma of Frontal Bone - A Case Report - (전두골에 발생한 콜레스테롤 육아종 1례 - 증례보고 -)

  • Lee, Sang Weon;Cha, Seung Heon;Park, Dong June;Song, Geun Sung;Choi, Chang Hwa;Lee, Young Woo
    • Journal of Korean Neurosurgical Society
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    • v.30 no.6
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    • pp.777-780
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    • 2001
  • Cholesterol granuloma of frontal bone is a rare disease which usually occurs at the lateral part of the supraorbital ridge. This expanding lesion grows slowly and extends into the orbit and anterior cranial fossa. The most common symptom is proptosis. This granuloma is composed of a granulomatous reaction surrounding cholesterol crystals. Surgical treatment involves aspiration of contents and stripping or curettage of the lining which is highly successful. We experienced a case of cholesterol granuloma of frontal bone with huge intracranial extension, which was cured by surgical removal. The clinical features, radiologic, and pathologic finding were discussed and the pertinent literatures were reviewed.

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Improved Arctic Ocean Oxygen Isotope Stratigraphy Results from the Yermak Plateau (ODP Leg 151 : Site 910A)

  • ;Jochen, Knies;dreas , Mackensen;Jens, Matthiessen;Christoph, Vogt
    • Proceedings of the Korean Quaternary Association Conference
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    • 2004.06a
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    • pp.51-51
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    • 2004
  • As an important contribution to the planed drilling (IODP) in the central part of the Arctic Ocean, we are currently working on a refined chronostratigraphy for Marine Isotope Stage (MIS) 16 to MIS 2 on the exciting material from ODP Site 910A (Leg 151) which has been recovered from the marginal Eastern Arctic Ocean (the Yermak Plateau - the Atlantic/Arctic Ocean Gateway). Several stratigraphic age fix-points support the interpretation of the stable oxygen. isotope record of planktonic foraminifer N, pachyderma sin. that is punctuated by several short-term meltwater events. We believe that our new record will serve as 'the important correlating tool for establishing a basic stratigraphy for the Quaternary Arctic Ocean as well as for generating high-resolution paleoenvironmental reconstructions in the central Arctic Ocean. Furthermore, our study will provide reference stratigraphic data sets for interpreting the micropaleontological, sedimentological and organic / inorganic - geochemical proxies of the new boreholes that will be drilled on the Lomonosov Ridge(Central Arctic Ocean) in the frame of the "Arctic Coring Expedition' (ACEX, IODP) in summer 2004.

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Population Dynamics of Pinus densiflora for. erecta at Sokwang-Ri, Uljin-Gun in Southeastern Korea

  • Yun, Chung-Weon;Bae, Kwan-Ho;Hong, Sung-Cheon
    • The Korean Journal of Ecology
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    • v.24 no.6
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    • pp.341-348
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    • 2001
  • Population dynamics of the oldest relic stand of Pinus densiflora for. erecta which remains as a status of patch in Sokwang-Ri area, Uljin-Gun, was studied to provide the basic data for conservation of the oldest pine stand in Korea. The upper slope site and ridge site including total 12 plots mainly represented Pinus densiflora for. erecta and Quercus mongolica. These two tree species showed reverse J-shaped distribution. From this information, it was concluded that intensive interspecific competition between two species could be occurring. Age distribution of P. densiflora for. erecta on the sites above middle slope area was indicated bi-modal type or tri-modal type which was known as an age structure of climax forest. Therefore, it was estimated that Pinus densiflora for. erecta population could be continuously maintained in the each patch above middle slope area. In the valley sites, hardwood species such as Q. mongolica, Q. variabilis, Styrax obassia and Acer pseudosieboldianum occupied most part of the under crown-cover area and their seedlings and saplings were developing into the closed upper layer crown because the height of upper layer crown reached about 35 meters and such a high crown height was more suitable for light utilization by plants of under layer. The growth patterns were mainly fluctuated for the entire life time of the oldest tree caused by frequent disturbance. And the initial growth curves of the mature trees and suppressed juvenile trees showed different tendencies along the sites.

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Interpretation of Gravity, Magnetic and High-resolution (3.5 kHz) Seismic Data in the Powell Basin, Antarctica (남극 파월분지 지역의 중,자력 및 고해상 (3.5 KHZ) 탄성파 자료 해석)

  • Jin, YoungKeun;Kim, KyuJung;Nam, SangHeon;Kim, YeaDong;Lee, JooHan
    • Journal of the Korean Geophysical Society
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    • v.7 no.1
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    • pp.1-10
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    • 2004
  • Gravity, magnetic and high-resolution seismic surveys were carried out in the Powell Basin to examine tectonic structure and recent sedimentation on Dec. 2002. The trend of negative gravity anomalies along the spreading axis of the Powell Basin changes from northwest to east-west toward south. Both boundaries of the basin with the Antarctic Peninsula and the South Orkey micro-continent show negative magnetic anomalies, which indicates that the boundaries were continental rift areas in the initial stage of spreading. Magnitude of the magnetic anomalies corresponding to the axis of the basin is rather small compared to those of normal spreading axises in other regions. Such small anomalies would be caused by reduction of magnetic strength of oceanic crust below thick sediments due to thermal alternation. High-resolution (3.5 kHz) seismic profiles reveal that top of the South Scotia Ridge is a flat terrain coverd with thin coarse sediments by glacial erosion. Thick oceanic sediments are deposited in the central part of the basin. Little deformation in the oceanic sediments indicates that the Powell Basin has been in stable tectonic environment after spreading of the basin stopped.

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Modeling of Sediment Transport and Sand Bank Formation in a Macrotidal

  • Park, Moon-Jin
    • Journal of the korean society of oceanography
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    • v.35 no.1
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    • pp.1-10
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    • 2000
  • A two-dimensional numerical model was applied to investigate the sediment transport and sand bank formation in a macrotidal sea, the Kyunggi and Asan Bays. The tidal residual currents show quite complex pattern including counter-rotating eddies off the northwestern corner of the Dugjeok Island that reflect the promontory effect. Complex residual eddies are also present off the coast of the Taeanbando and in the Asan Bay. Net sediment transport pattern shows that sandy sediments in the Kyunggi and Asan Bays are generally transported landward from the outer sea suggesting sediment trapping inside the bays. This phenomenon may be related to the formation and maintenance of numerous sand banks in this macrotidal sea. Alternate occurrences of deposition and erosion predicted from the numerical model along the coast of the Taeanbando with strong deposition on the southwestern part of the 'Jangansatoe'(JSB), a large sand ridge off the coast of the Taeanbando appear to reflect the loose connection of JSB, The 'Joongangcheontoe', a central sand bank (CSB) with the main axis in the NW-SE direction in the Asan Bay may undergo a modification with strong deposition along the northeastern flank. These results indicate that the sand banks are actively modified and maintained by the strong tidal currents in this shallow macrotidal sea.

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A Study on the Development of Twist Wheel Type Waste Vinyl Remover (II) - Development of Tractor Attached Vinyl Remover - (Twist Wheel 방식 폐비닐수거기 개발에 관한 연구(II) - 트랙터 부착형 수거기의 개발 -)

  • Ha, Yu-Shin;Park, Kyu-Sik;Kim, Jin-Hyun;Choe, Jung-Seob;Son, Chul-Min;Nam, Sang-Heon;Kim, Tae-Wook
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.2
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    • pp.79-84
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    • 2012
  • This study consist of two parts. One is development of a self-propelling vinyl remover which was already reported at the previous paper. This is the second part of the study. For the study, an attached vinyl remover was developed. It was consisted of connecting tractor to bucket, removing bucket from tractor, and the process was the tractor's assistance hydraulics. In the case of an attached vinyl remover, the vinyl was twisted 0.5times per 30~85cm length. The bobbin's diameter was 190mm and it's stable travelling speed was 1m/s. The revolution of the remover wheel was 90rpm to maintain the wheel's linear velocity. As seen at performance test at the field which had 950mm ridge intervals and 10 a area, the average working speed was 1m/s and the turning time was 20seconds. Therefore, the working performance was 24.5min/10a. The efficiency of used vinyl remover was 97% and working conditions were good.