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Review on the Relative Sea-level Changes in the Yellow Sea during the Late Holocene (한반도 서해안의 후기 홀로세 해수면 변동 곡선에 대한 검토)

  • Choi, Sung-Ja
    • Economic and Environmental Geology
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    • v.51 no.5
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    • pp.463-471
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    • 2018
  • In this paper, we review previous studies on the relative sea-level changes in the Yellow Sea during the Holocene to comprehensive understand the various research results. Currently, it is reported two theories : 1) the Holocene sea-level has never been higher than the present-day level; and 2) sea-level have reached highstand during mid-Holocene, followed by slow lowering to that of the present. The first theory yields a curve that is similar to a climate-change-related eustatic sea-level curve. However, in reality, most of the relative sea-level fluctuation resulted from land uplift or subsidence. The second theory yields a curve that is fairly coincident with a relative sea-level curve indicative of continental margins being located away from the ice sheets(i.e., far-field), and is considered as an effect of GIA(Glacio Isostatic Adjustment) and gravitational attraction. Based on detailed review of previous researches, we realized that they sourced the same papers, but obtained different results because they selectively chose and added the data. The data used to derive the second theory pertain to the northern Gunsan region, which is located within the western area of the Chugaryeong fault. Thus, we believe that the sea-level curve for the second theory is only representative of the area north of Gunsan, which is subject to GIA and tectonic deformation. Although the relative sea-level curve for the west coastal area is comparable to that for the far-field continental margin region, it is necessary to evaluate local tectonic activities as suggested by active seismicity in the west coastal area and the more than 400 faults currently existing in on the Korean Peninsula.

Recycling of Suspended Particulates by Atmospheric Boundary Depth and Coastal Circulation (대기경계층과 연안순환에 의한 부유입자의 재순환)

  • Choe, Hyo
    • Journal of Environmental Science International
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    • v.13 no.8
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    • pp.721-731
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    • 2004
  • The dispersion of suspended particulates in the coastal complex terrain of mountain-inland basin (city)-sea, considering their recycling was investigated using three-dimensional non-hydrostatic numerical model and lagrangian particle model (or random walk model). Convective boundary layer under synoptic scale westerly wind is developed with a thickness of about I km over the ground in the west of the mountain, while a thickness of thermal internal boundary layer (TIBL) is only confined to less than 200m along the eastern slope of the mountain, below an easterly sea breeze circulation. At the mid of the eastern slop of the mountain, westerly wind confronts easterly sea breeze, which goes to the height of 1700 m above sea level and is finally eastward return flow toward the sea. At this time, particulates floated from the ground surface of the city to the top of TIBL go along the eastern slope of the mountain in the passage of sea breeze, being away the TIBL and reach near the top of the mountain. Then those particulates disperse eastward below the height of sea-breeze circulation and widely spread out over the coastal sea. Total suspended particulate concentration near the ground surface of the city is very low. On the other hand, nighttime radiative cooling produces a shallow nocturnal surface inversion layer (NSIL) of 200 m thickness over the inland surface, but relatively thin thickness less than 100m is found near the mountain surface. As synoptic scale westerly wind should be intensified under the association of mountain wind along the eastern slope of mountain to inland plain and further combine with land-breeze from inland plain toward sea, resulting in strong wind as internal gravity waves with a hydraulic jump motion bounding up to about 1km upper level in the atmosphere in the west of the city and becoming a eastward return flow. Simultaneously, wind near the eastern coastal side of the city was moderate. Since the downward strong wind penetrated into the city, the particulate matters floated near the top of the mountain in the day also moved down along the eastern slope of the mountain, reaching the. downtown and merging in the ground surface inside the NSIL with a maximum ground level concentration of total suspended particulates (TSP) at 0300 LST. Some of them were bounded up from the ground surface to the 1km upper level and the others were forward to the coastal sea surface, showing their dispersions from the coastal NSIL toward the propagation area of internal gravity waves. On the next day at 0600 LST and 0900 LST, the dispersed particulates into the coastal sea could return to the coastal inland area under the influence of sea breeze and the recycled particulates combine with emitted ones from the ground surface, resulting in relatively high TSP concentration. Later, they float again up to the thermal internal boundary layer, following sea breeze circulation.

Temporal and spatial Analysis of Sea Surface Temperature and Thermal Fronts in the Korean Seas by Satellite data

  • Yoon Hong-Joo;Byun Hye-Kyung
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.696-700
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    • 2004
  • In the Korean seas, Sea Surface Temperature (SST) and Thermal Fronts (TF) were analyzed temporally and spatially during 8 years from 1993 to 2000 using NOAA/AVHRR MCSST. As the result of harmonic analysis, distributions of the mean SST were $10~25^{\circ}C,$ and generally SST decreased as latitude increased. SST increased in the order as following; the South Sea $(20\~23^{\circ}C),$ the East Sea $(17\~19^{\circ}C)$, and the West $Sea(13\~16^{\circ}C).$ Annual amplitudes and phases were $4\~11^{\circ}C,\;210\~240^{\circ}$ and high values were shown as following; the West Sea $(A1,\;9\~11^{\circ}C),$ the Northern East Sea $(A5,\;8\~9^{\circ}C),$ the Southern East Sea $(A4,\;6\~8^{\circ}C),$ the South Sea $(A3,\;6\~7^{\circ}C),$ the East China Sea $(A2,\;4\~7^{\circ}C)$ and phases; $A3\;(238\~242^{\circ}),\;A4\;(235\~240^{\circ}),\;A5\;(225\~235^{\circ}),\;Al\;(220\~230^{\circ}),\;A2\;(210\~235^{\circ}),$ respectively, Both of them were related inversely except the area A2, therefore the rest areas were affected by seasonal variations. TF were detected by Soble Edge Detection Method using gradient of SST. Consequently, TF were divided into 4 fronts; the Subpolar Front (SPF) based on the Cold Water Mass (low SST and salinity Subartic Water), resulting from the North Korea Cold Current (NKCC) and the East Sea Proper Cold Water in the middle and low layer, and the Warm Water Mass (high SST and salinity Subtropical Water), resulting from the Tsushima Warm Current (TWC) in area A4 and 5, the Kuroshio Front (KF) based on the Kuroshio Current (KC) and shelf waters in the East China Sea (ESC) in A2, and the South Sea Coastal Front (SSCF) based on the South Sea Coastal Water (SSCW) and TWC in A3. Also, the Tidal Front was weakly appeared in AI. TF located in steep slope of submarine topography. Annual amplitudes and phases were bounded in the same place, and these results should be considered to influence of seasonal variations.

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A Safety Study of the Fish Farm in Cheonsuman after Constructing the H Condominium (H 콘도의 건설에 따른 천수만 양식장 안전성 검토)

  • Han, Doo Hee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.8
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    • pp.4093-4099
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    • 2013
  • We studied sea water pollution by waste water of H condominium near the Bunam Lake in Seosan City. We simulated COD of discharged waste water, and other factors can be expected by proportional. The direction of sea flow is almost west, and there is no fish cultivation in the west area, so it is safe for fish cultivation. We assumed that there is no flow in the sea water, and simulated the divergence of water pollution. We concluded that, the fish cultivation will be free from danger of water pollution.

Nutrient Front Relating to the Hydrography in the Outflow Region of the Keum River (금강 하구 연안역의 해황과 관련한 영양염 전선)

  • Choi Yong Kyu;Yang Won Seok;Jeong Ju Young
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.35 no.3
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    • pp.289-296
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    • 2002
  • Using results obtained from field surveys in the outflow region of the Keum River in winter (February 22), spring (May 9), summer (July 31) and autumn (October 17) in 2000, it was described the nutrient front relating to the hydrography. It showed that the horizontal gradients was sharp in the distributions not only in salinity but also in nutrients in the region of the mouth of estuary far away about 20 km from the dyke of the Keum River during the year. The two layer structure was a ubiquitous feature in the inner estuarine side of the region showing the maximum horizontal gradients in salinity and nutrients. Although the absolute values in salinity and nutrient concentrations were distinguished by season, the nutrient front seperates the saltier and nutrients poor water in the open sea from the brackish and nutrients rich water of the plume. These results suggest that the nutrient front coincides with the esturine front in the region of freshwater influence (ROFI) of the Keum River.

A Study on Development Strategies for Kunsan Port : Focused on trade with China (군산항만의 발전전략에 관한 연구-대 중국교역을 중심으로-)

  • 백대영
    • Journal of Korea Port Economic Association
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    • v.17 no.2
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    • pp.111-137
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    • 2001
  • The establishment of the WTO system means that the global age of trade has officially arrived. Since the integration of the world economy brings about the free movement of goods and services between nations, it is inevitable that sea-bound freight will continue to increase. A recent World Bank report says that China and Korea will be the first and seventh largest economic Powers, respectively, by the year 2020. In particular, the Korea peninsula has a geo-political advantage in being developed as a major Northeast Asian container center. Moreover China's swift uprising needs new order of trade for economy belt in Northeast Asia. Therefore, it can be said that Kunsan Port. which has already been designated as a free trade zone, has greater potential to rise as a regional beach-head port and main region for foreign investment. As such. Kunsan Port will play a major role in accelerating the emergence of the West Sea in international trade. There are several strategies for developing Kunsan Port into a central container port: 1) develop Kunsan port Into an import/export front base f3r multinational corporations, 2) develop Kunsan container port into the core composite container-linked central port, 3) attract foreign investment to the Kunsan Free Trade Area so as to promote balanced development among the regions of Korea, 4) support the central government and local governments to accelerate the coming of the "West Sea Era." These recommendations call for urgent implementation.

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Development for auto lightening buoy system using solenoid (솔레노이드 장치를 이용한 양식용 부자 LED 전원공급 시스템 개발)

  • CHA, Bong-Jin;BAE, Bong-Sung;KIM, Hyun-Young;CHO, Sam-Kwang;LEE, Gun-Ho
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.52 no.1
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    • pp.17-23
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    • 2016
  • This study investigates the development of an automatic lightening buoy that can indicate an aquaculture cage at night or in rough weather. The energy for the light is generated by the linear motion of a magnet along with a coil inside the buoy as the waves cause the buoy to oscillate up and down. The principle of the magnet motion is different between the magnet and body of the buoy because the movement of the latter is dependent on the surface wave, while the former is affected by the damper. To obtain a quantitative performance of the buoy, the voltage as well as up and down motion produced by several waves were measured in the wave tank. A shorter wave period, i.e., faster motion, of the magnet produced a brighter light. It is expected that this study can aid in deciding the optimum design of a buoy capable of producing a bright light at any aquaculture site affected by sea or fresh water waves.

Study on Freight Transportation with Train Ferry between Korea and China (한.중간 열차페리를 이용한 화물수송방안연구)

  • 이용상;노학래;정병현
    • Proceedings of the KSR Conference
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    • 1999.05a
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    • pp.41-51
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    • 1999
  • Trade between Korea and China was 372million dollars accounting for 1.56% of total in 1988 and has been increased to 23,689 million dollars occupying 7% in 1997, which implies 32.2% increase on average per year. This trend will continue dramatically and consistently as China's open policy toward the world accelerates and korean companies advance into chinese market. The main trade routes are with marine transportation between korean west sea area and chinese San-Dong peninsula around east sea. However, due to the increasing traffic congestion on main roads connecting harbors and main consumer cities and capacity problem in west sea harbor areas, the logistics cost have been increased resulting in losing competitiveness of freight trade. Therefore, these road-oriented inland transportation means need to be changed to rail transport system to reduce congestion and to conserve natural environment. To achieve this scheme, efficient intermodal transportation system connecting road and rail should be constructed. These combined system will ensure timely delivery of goods and consequently the customers would make proper transportation schedule for the import/export goods in advance. Especially, combined transportation of Railroad and train ferry would cope with the logistics problem and this system would be efficient means for trade with not only China but further with many adjacent countries in central asia such as Kazakhstan and Uzbekistan

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