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The Formative Processes and Ages of Paleo-coastal Sediments in Dangjeong-ri, Seocheon-gun in the Western Coast, South Korea (II): Complementation of Chronological Data and a Developmental Model of Coastal Geomorphology over the Past 200,000 Years (서해안 서천군 당정리 일대에 분포하는 육상 고해안 퇴적물의 형성 과정과 형성 시기(II): 추가 연대 자료 및 제4기 후기 연안 지형 발달 모델)

  • Shin, Jae-Ryul;Hong, Yeong-Min;Ryu, Hui-Gyeong;Hong, Seongchan
    • Journal of The Geomorphological Association of Korea
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    • v.28 no.3
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    • pp.51-61
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    • 2021
  • Following the previous study, we report a complementary dating data on the silty layers deposited in paleo-tidal conditions of the study area, Dangjeong-ri, Seocheon-gun and suggest coastal terrain development processes over the past 200,000 years. Based on the dating results, the silty layers distributed up to 25 m above mean sea level were deposited between 171 and 183 ka, and the gravel layer deposited in a fluvial environment of a paleo-Dangjeong stream was found to have formed between 78 and 83 ka. Considering relative altitudes of distribution, an uplift rate of the study area in the western coast is judged to be relatively 0.5~0.7 low to that of Pohang area in the eastern coast. Compared to Busan and Sacheon areas in the southern coast, it is assumed that an uplift rate of the study area shows a similar level with those during the late Quaternary.

The Formative Processes and Ages of Paleo-coastal Sediments in Dangjeong-ri, Seocheon-gun in the Western Coast, South Korea: Evaluation of the Mode and Strain Rate of the Late Quaternary Tectonism (III) (서해안 서천군 당정리 일대에 분포하는 육상 고해안 퇴적물의 형성 과정과 형성 시기: 한반도 제4기 후기 지각운동의 양식과 변형률 산출을 위한 연구(III))

  • Shin, Jae-Ryul;Hong, Yeong-Min;Hong, Seongchan
    • Journal of The Geomorphological Association of Korea
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    • v.27 no.1
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    • pp.33-45
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    • 2020
  • A number of unconsolidated deposits, consisting of a layer of gravels and silt, are found in Dangjeong-ri, Seocheon-gun in the western coast. From below in the stratigraphic sequence, the gravel layer ranging up to a maximum thickness of about 2 meters is interpreted as being formed by fluvial processes of an old channel (Dangjeong S.), and the overlying silt or sandy silt layer of 2 to 3 thickness meters is assumed to be emerged paleo-tidal sediments which was deposited in low tidal-energy environments. As the results of rock surface IRSL datings, the depositional ages of gravels are confirmed as ca. 78,000 ~ 83,000 years BP, indicating that the layer was formed in response to a high-stand sea level of MIS 5a along the Dangjeongcheon estuary. It is presumed that the relative height of 4.5 meter between the altitude of the stream bed (9.5 m) and the altitude of the bedrock boundary in the gravel layer (14 m) indicates the uplift amount since deposition. Paleo-sedimentary environments and an altitude of paleo-shoreline in the study area will be discussed with additional age dating focused on the silt layer.

Aquatic and Riparian Flora of the Nakdonggang River Tributary (Sangju: Byeongseong-cheon, Buk-cheon, Oeseo-cheon) (낙동강 지류의 수생 및 수변 식물상(상주: 병성천, 북천, 외서천))

  • Hwang, Yong;Hong, Jeong-Ki
    • Korean Journal of Plant Resources
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    • v.33 no.5
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    • pp.516-535
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    • 2020
  • This study was conducted to provide information on local resource plants by identifying aquatic and Riparian flora. We investigated the aquatic and riparian floras in 3 streams(Byeongseong-cheon, Buk-cheon, Oeseo-cheon) from February to October 2019. 321 taxa (i.e. 300 species, 5 subspecies, 15 varieties 1 Cultivars from 203 genera of 78 families) of the vascular plants were found in the survey area. Byeongseong-cheon is 133 taxa, Buk-cheon is 233 taxa and Oeseo-cheon is 132 taxa. Among 321 taxa, we found 5 endemic species, 3 red list plants, and However, endangered plants were not found in 3 streams. Aquatic and Riparian plant 138 taxa(i.e. Aquatic plant 20 taxa, Riparian plant 118 taxa). Life forms is annual plant 43 taxa, biennial plant 24 taxa, perennial plant 71 taxa. Aquatic plant growth forms emergent hydrophyte 13 taxa, floating leaved hydrophyte 1 taxa, submerged hydrophyte 6 taxa. The number of floristic regional indicator plants was 15 (i.e. 1 species of IV degree, 3 taxa of III degree, 5 taxa of II degree, and 6 taxa of I degree). Approved foreign export plants 31 taxa. In addition, 52 naturalized plants were identified, and the percentage of Naturalized Index (NI) and Urbanization Index (UI) were 16.1%, and 16.2%, respectively. Vascular plant usability and reclassification result is Edible 213 species (66%), Medicinal 244 species (76%), Flavor 10 species (3%), Industrial 136 species (42%), Ornamental 137 species (36%), Restoration 117 species (36%), Compost 155 species (48%), Unknown 7 species (5%). We hope that our results provide reference data to set up strategy of resources plants, conservation of biodiversity in the 3 streams and Sangju-si areas.

Studies on Ecological Characteristics of Some Soybean(Glycine max (L.) Merr.) Cultivars l. Effects of Planting Dates on Yields and Other Agronomic Characteristics (주요 대두품종의 생태적 특성에 관한 연구 제1보 파종기가 수량 및 제 특성에 미치는 영향)

  • 최경구;김진기;권용주;이성춘;전병기
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.25 no.3
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    • pp.41-49
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    • 1980
  • This study was carried out to find the most suitable soybean cultivars and optimum planting dates by checking yields and other agronomic characteristics in the Jeonbug area. It was observed that seed yields and other characteristics tended to increase for early planting dates, and the correlation between yields and other characteristics seemed to vary with planting dates. Tousan 73 and Williams among the 20 varieties used, appeared to have high yields no matter what the planting date, thus these are the most promising varieties in the Jeonbug area. However, further studies are needed on these varieties of soybeans.

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Studies on the major nutritional components of commercial dried lavers (Porphyra yezoensis) cultivated in Korea (시판 건조김의 주요 영양성분)

  • Kim, Ki-Woong;Hwang, Jae-Ho;Oh, Myung-Joo;Kim, Min-Yong;Choi, Myeong-Rak;Park, Wook-Min
    • Food Science and Preservation
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    • v.21 no.5
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    • pp.702-709
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    • 2014
  • This study was conducted to provide basic date on the proximate composition and amino acid, fatty acid, sugar, and mineral contents of commercial dried lavers cultivated in Korea (in Seocheon, Wando, Goheung and Busan). The moisture, crude ash, crude fat, crude protein, and carbohydrate content ranges of the dried lavers were 5.67~7.43%, 8.01~8.95%, 1.54~2.25%, 37.77~39.98%, and 43.83~46.24%, respectively. The total amino acid, free amino acid, and essential amino acid concentrations were highest (25,982.15 mg/100 g, 4,545.44 mg/100 g, and 9,048.28 mg/100 g) in the dried lavers cultivated from Wando. The compositions of the fatty acids in four dried lavers were 16.30~22.15% saturated fatty acids, 6.04~7.73% monounsaturated fatty acids, and 70.33~76.03% polyunsaturated fatty acids. The sugar contents per 100 g of dried lavers were 3,678.84~4,052.52 mg of galactose, 2,112.30~2,473.86 mg of fructose, 1,103.74~1,648.39 mg of mannose, 361.67~590.21 mg of glucose, 8.63~10.38 mg of ribose, and 21.43~48.32 mg of xylose. The mineral concentrations in the dried lavers cultivated from Wando and Busan were low (Cu < Mn < Zn < Fe < Ca < Mg < Na < K), as were those in the dried lavers cultivated from Seocheon and Goheung (Cu < Mn < Zn < Fe < Mg < Ca < Na < K).

Development of Geometry Design S/W using Analysis on Machining Characterization considering EndMill Geometry (엔드밀 형상에 따른 가공특성 분석을 이용한 형상설계 S/W 개발)

  • 한창규;고성림;유중학;서천석;김경배
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.04a
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    • pp.111-117
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    • 2004
  • The tool geometry parameters and cutting process have complex relationships. Until now, various cutting test were needed to acquire optimal design of end mill for the purpose of high speed machining, due to the insufficient knowledge about cutting process. In high speed machining. Using various tools with different geometry, relationships between tool geometry parameter (rake angle, clearance angle, length of cutter) and cutting process (cutting force, surface accuracy, surface roughness) have been studied. Acquired data can be used to design optimal tool for high speed machining and developed tool geometry design S/W.

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Development of Reliability Prediction Program for Tool Life (공구 수명의 신뢰성 예측 프로그램 개발)

  • 이수훈;김봉석;강태한;송준엽;강재훈;서천석
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.04a
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    • pp.317-322
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    • 2004
  • This paper deals with a prediction method of tool life in view of the reliability assessment. In this study, the flank wear was studied among multi-factors deciding the tool wear state. Firstly, tool lift was predicted by correlation between flank wear and cutting time, based on the extended Taylor tool life equation of turning data, including parameters of cutting speed, feed rate, and cutting depth. Secondly, each of cutting conditions of endmilling was equivalently converted to apply ball endmill data to the extended Taylor equation. The web-based reliability prediction program for tool lift is being developed as one of reliability assessment programs to for the machine tools.

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An Analysis of the Discovering and Survey Techniques for Rural Amenity Resources - A Case Study of Seochen County - (농촌어메니티자원 발굴 및 조사기법의 특성분석 - 서천군을 사례로 -)

  • Heo, Jun
    • Journal of Korean Society of Rural Planning
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    • v.13 no.2
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    • pp.75-84
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    • 2007
  • Rural amenity resources show a particular rural community's identity. They also provide recreational, aesthetic and economic value. This research aimed at systematizing finding surveying techniques of rural amenity resources for planning rural community. For conducting the study, existing finding and surveying techniques of rural amenity resources in the case of comprehensive Amenity Planning of Seochen County in Choongcheongnam Province. The research findings are as followings; (1) 190 amenity resources were found in Seochen County, (2) archival research and interview methods were used for finding resources, (3) the present status and maintenance conditions were examined through on-the-spot survey, (4) resources were photographed and recorded by making descriptive notes verbally and diagrammatically.

Gap Between Rural Village Planning and Implementation - Focused on Unique Experience Village, Seochon - (농촌마을계획과 실행의 차이 분석 - 충남 서천군 이색체험마을 사례를 중심으로 -)

  • Jung, Hui;Kim, Hye-Min
    • Journal of Korean Society of Rural Planning
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    • v.13 no.3
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    • pp.91-101
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    • 2007
  • Recently the number of rural development plans are increased and projects supported by government are various. These makes rural plans important. But there are many gaps between proposed plan and implementation. These gaps were wasteful in terms of resource management. This study examines differences between plan and implementation and the reasons why they are occurred. For this purpose, we did a case study which is focused on the four-year implementation of 2004-2006 "Unique Experience Village Master Plan" of Seochon, Chungbuk. As a result, we verified facts of gaps and causes, and two major causes were detected : one is the absence of operating and managing body(such as promoter of project, village leader, residences), and the other is inadequate master plan.

Study on the Design of End Mill Geometry for the High Speed Machining (고속 가공용 엔드밀의 형상설계에 관한 연구)

  • 이상규;배승민;고성림;김경배;서천석
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.67-70
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    • 2001
  • The tool geometry parameters and cutting process have complex relationships. Until now, numerous cutting tests were needed to acquire optimal design of end mill for the purpose of high speed machining, due to the insufficient knowledge about cutting process in high speed machining. Using various tools with different geometry, relationships between tool geometry parameter(rake angle, clearance angle, length of cutter) and cutting process(cutting force, surface accuracy, surface roughness) have been studied. Acquired data can be used to design optimal tool for high speed machining

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