• Title/Summary/Keyword: Coast line

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A Study on the Ship Design of a new ICLL for the 21st Century (21세기 국제만재흘수선협약에 따른 선박설계의 연구)

  • Park M.K.;Kwon Y.J.
    • Journal of Korean Port Research
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    • v.7 no.1
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    • pp.89-114
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    • 1993
  • ICLL 66 is the most widely ratified instrument of the IMO and is, along with the International Convention on Safety of life at Sea (SOLAS), the primary document setting forth internationally agreed ship safety standards. ICLL 66 set freeboard requirement based on experience gained from the first Load Line Convention in 1930 and on contemporary developments in ship design. Reexamination of ICLL 66 is indicated by the proliferation of novel ship designs for which it lacks adequate regulations and by significant advancements in analytical seakeeping and deck wetness prediction techniques now available to the designer. In this paper, the Freeboard Advisory Group reviews these issues against the changing climate of the marine industry and maritime administrations, discusses the state of the art in analytical seakeeping programs, and outlines a series of recommendations for the establishment of a new international load line convention for the next century. The steps needs for an international program at IMO are discussed and a new convention is proposed.

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Change of Seawater Intrusion Range by the Difference of Longitudinal Dispersivity in Hydrodynamic Modeling (수리동역학적 모델링에서 분산지수에 따른 해수침투 범위의 변화)

  • 심병완;정상용;김희준;성익환
    • Journal of Soil and Groundwater Environment
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    • v.7 no.4
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    • pp.59-67
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    • 2002
  • As a parameter for hydrodynamic modeling to define the range of seawater intrusion, dispersivities are frequently determined from pre-experiments or theoretical studies because field experiments need a lot of time and expenses. If the dispersivities are inadequate for an aquifer, the numerical results may have some errors. We examined the validity of longitudinal dispersivities by comparing the ranges of seawater intrusion with numerical modeling, field data and apparent resistivity sections. In the numerical modeling the TDS distributions simulated by the Xu's longitudinal dispersivity are more similar to the values of TDS measured at monitoring wet]s and boreholes than those by the Neuman's longitudinal dispersivity. The ranges of seawater intrusion by numerical simulations using Xu's longitudinal dispersivity show that the contour line of 1000 ㎎/L. as TDS is located at 480 m from the coast in May, while at 390 m in July. The difference is originated from the shift of the interface between seawater and fresh water. It moved toward the coast in July because of the seasonal increase of hydraulic gradient according to rainfall. A contour line of 15 ohm-m was used to define the range of seawater intrusion in apparent resistivity sections. From this criterion on the interface between seawater and fresh water, the range of seawater intrusion is located at 450 m from the coast. This result is similar to the range of seawater intrusion simulated by the numerical modeling using Xu's dispersivity. Therefore the range of seawater intrusion shows the difference due to the dispersivities used for the hydrodynamic modeling and the dispersivity generated by the Xu's equation is considered more effective to decide the range of seawater intrusion in this study area.

Abundance Estimation of the Finless Porpoise, Neophocaena phocaenoides, Using Models of the Detection Function in a Line Transect (Line Transect에서 발견율함수 추정에 사용되는 모델에 따른 상괭이, Neophocaena phocaenoides의 자원개체수 추정)

  • Park, Kyum-Joon;Kim, Zang-Geun;Zhang, Chang-Ik
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.40 no.4
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    • pp.201-209
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    • 2007
  • Line transect sampling in a sighting survey is one of most widely used methods for assessing animal abundance. This study applied distance data, collected from three sighting surveys using line transects for finless porpoise that were conducted in 2004 and 2005 off the west coast of Korea, to four models (hazard-rate, uniform, half-normal and exponential) that can use a variety of detection functions, g (x). The hazard-rate model, a derived model for the detection function, should have a shoulder condition chosen using the AIC (Akaike Information Criterion), as the most suitable model. However, it did not describe a shoulder shape for the value of g(x) near the track tine and underestimated g (x), just as the exponential model did. The hazard-rate model showed a bias toward overestimating the densities of finless porpoises with a higher coefficient of variation (CV) than the other models did. The uniform model underestimated the densities of finless porpoise but had the lowest CV. The half-normal model described a detection function with a shape similar to that of the uniform model. The half-normal model was robust for finless porpoise data and should be able to avoid density underestimation. The estimated abundance of finless porpoise was 3,602 individuals (95% CI=1,251-10,371) inshore in 2005 and 33,045 individuals (95% CI=24,274-44,985) offshore in 2004.

Comparison of live shrimp bait catch efficiency in single line fishery

  • Koo, Myungsung;Munechika, Ishizaki;Cho, Samkwang;Bae, Bongseong;Cha, Bongjin
    • Fisheries and Aquatic Sciences
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    • v.24 no.11
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    • pp.383-389
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    • 2021
  • On the southern coast of South Korea, dark-banded rockfish, sea bass, and red seabream are caught by single-line fishing. In particular, red seabream and sea bass are caught in the Jeollanam-do region using gear with attached fishing hooks, such as longline and single-line gear, with live shrimp as bait. The objective of this study was to compare the catch efficiency of two types of live shrimp (naturally grown Shiba shrimp [Metapenaeus joyneri] and cultured whiteleg shrimp [Litopenaeus vannamei]) used as bait. The investigation included interviews, on-board surveys, and water tank experiments. Interviews were conducted with relevant parties to determine the preference for live shrimp as bait, and the results showed a greater preference for cultured whiteleg shrimp. Further, an on-board survey was conducted to compare catch efficiency between these two types of live shrimp bait for single-line fishing. The on-board investigations were conducted once or twice a month between June and October. In total, the amounts of fish caught using naturally grown Shiba shrimp and cultured whiteleg shrimp were 56 and 52, respectively. Of these, the numbers of sea bass, the primary target fish species, caught using naturally grown Shiba shrimp and cultured whiteleg shrimp were 43 and 40, respectively. Thus, the results showed that there was almost no difference in the number of fish caught based on the bait used. However, according to a water tank experiment, cultured whiteleg shrimp survived longer than naturally grown Shiba shrimp.

Strategic Considerations for Development of Gunsan(Saemangum) Port in terms of China (중국효과에 따른 새만금항만의 전략적 발전가능성 모색)

  • Yeo, Gi-Tae;Seo, Su-Wan
    • Journal of Korea Port Economic Association
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    • v.24 no.4
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    • pp.139-152
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    • 2008
  • China's rapid growth of economy and developing logistics facilities such as sea and air ports can give the good effects to increase the trade and logistics cargo volumes within Pan Yellow Sea Economic Bloc which consists of Korea, China, Japan and Russia. These phenomenon also stimulate the development of the West Coastal Integrated Belt in South Korea. In the past 20th century, South Korea's advanced and developed areas were located on the Kyeong-Bu Axis, the straight line of Seoul and Busan. However, due to the china's effect, this axis is moving into the West Coast area between Incheon (Seoul) and Mokpo, which is closely located to China. In this aspect, sea ports located in West Coast of Korea have shown the steep increase in container and non-container cargo volumes. With regard to the changing environments in sea ports, this paper's aim is to investigate the developing potential of Gunsan (Saemangum) area located on mid of West Coast. As results, targeted area have shown the potential in terms of port network, supply chain management and transferring location for container cargoes. Moreover, for implementing the suitable roles, construction of New Saemangun port, closely located in Gunsan port, is needed to overcome the limitations of Gunsan port.

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Distribution of Anchovy Eggs and Larvae off the Western and Southern Coasts of Korea (한국남해 및 서해 연안해역에서의 멸치난치어의 분포)

  • KIM Jin Yeong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.16 no.4
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    • pp.401-409
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    • 1983
  • The distribution of anchovy eggs and larvae was studied using the ichthyoplankton samples and oceanographic data collected in the western and southern waters of Korea over the period of April through June in 1981 and 1982. Three water masses, the Tsushima Warm Current, the South Korean Coatal Water and the Yellow Sea Bottom Cold Water, are found to exert extensive influences of the distribution of anchovy eggs and larvae. The Tsushima Warm Current contacts with the South Korean Coastal Water to produce a coastal front between Cheju Island and Tsushima Island in the southern waters of Korea. Off the west coast of Korea, a coastal front is also formed running parallel with the western coast-line of Korea in the area between the Yellow Sea Bottom Cold Water and the extended part of the South Korean Coastal Water. In the southern waters of Korea anchovy eggs were found chiefly in the coastal waters inside the front, and larvae appeared to both sides on the front. The distribution of anchovy eggs and larvae off the west coast of Korea, however, was limited largely to the coastal waters of more than $12^{\circ}C$ in temperature. In the southern waters of Korea prelarvae appeared in the coastal area, and postlarvae in the offshore area. While in the western waters of Korea prelarvae were found in the southern part of the waters, and postlarvae in the northern part. Anchovy eggs and larvae were distributed in the considerably limited area of the coastal waters off the south coast of Korea in 1981 when the temperature gradient of the coastal front was sharper than in 1982.

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A Study on the Improvement of Marine Pollution Response Education Program of Korea Coast Guard Academy - Focusing on Comparison between Domestic and Foreign Curriculums - (해양경비안전교육원 해양오염방제교육 프로그램 개선에 관한 연구 - 유류오염 방제 교육과정에 대한 국내외 비교를 중심으로 -)

  • Choi, Hyun Kue
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.4
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    • pp.365-375
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    • 2017
  • Approximately 250 marine pollution accidents involving oil and HNS spills are reported every year in the Republic of Korea. It is necessary that a strengthen of specialization of marine pollution response personnel on marine pollution response due to a diminution of damage when a major oil and HNS spill incident occurred, as in the case of the M/V Heibei Spirit and the M/V Maritime Maisie. In regard to this, the International Maritime Organization (IMO) has planned to revise the OPRC Model Training Course to strengthen expertise for oil spill incident responses. Through a comparison of curriculum with the Korea Coast Guard Academy (KCGA) program, a revised IMO Model Course and the OSRL training institute, this study recommends the following improvements for the education program of the KCGA in response to oil spills. This study suggests several options in line with this approach to revise the oil spill response education curriculum, exercise, discussions and making materials. Accreditation of the KCGA as an institute that provides an IMO Model training course developed according to the revised IMO Model Course material is proposed.

Wave and surface current measurement with HF radar in the central east coast of Korea (동해중부에서 HF Radar를 이용한 파랑 및 해수유동 관측)

  • Kim, Moo-Hong;Kim, Gyung-Soo;Kim, Hyeon-Seong
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.6
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    • pp.771-780
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    • 2014
  • We installed HF Radar of Array type in Site A and Site B, observing the real-time wave and current in the central East coast of Korea. WERA(WavE RAdar) in this research uses HF Radar of Array Type with frequency range of 24.525 MHz, developed by Helzel, Germany. Each site is a 8-Channel system consisting of four transmitters and eight receivers, generating wave and current data, being observed every thirty minutes at the present time. HF Radar has grid resolution of an interval of 1.5 km using bandwidth of 150 kHz; The wave data covers an observation range of about 25 km, and the current data covers the maximum observation range of about 50 km. The Wave data observed by HF Radar was compared and verified with the AWAC data observed in the research sites. MIT also compared the Current data observed by HF Radar with Monthly the East sea average surface current and current flow pattern provided by KOHA(Korea Hydrographic and oceanographic Administration). The regression line and deviation of the comparison data of Wave was calculated by Principal Component Analysis, which showed correlation coefficient 0.86 and RMSD 0.186. Besides, data analysis of long-term changes of the current in the East coast showed that, during August and September, the North Korean Cold Current flow into the southward direction and the East Korean Warm Current flow into the northward direction in the coast.

Characteristics of Surface Topography and Sediments before and after the Typhoon Kompasu in the Gochang Open-Coast Intertidal Flat, Korea (태풍 곤파스 전과 후의 고창 개방형 조간대 표층 지형과 퇴적물 특성)

  • Kang, Sol-Ip;Ryang, Woo-Hun;Chun, Seung-Soo
    • Journal of the Korean earth science society
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    • v.40 no.2
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    • pp.149-162
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    • 2019
  • In the macro-tide open coast of the Korean western coast, typhoon effects were investigated in terms of variations on topography, surface sediment, and sedimentary environment, which appeared before and after the typhoon Kompasu of 2010. The Kompasu of small size and strong intensity landed on the southwestern coast of the Korean Peninsula and passed across the inland between September 1st and 2nd in 2010. Topography and surface sediments before and after the typhoon were measured and sampled along the survey line of 22 sites in the Gochang Donghori intertidal flat. The intertidal area was divided into high tidal zone, middle tidal zone, and lower tidal zone on the basis of mean high water level, mean sea level, and mean low water level. Topographic variation before and after the typhoon represented deposition of average 0.03 m in high tidal zone, erosion of average -0.15 m in middle tidal zone, and erosion of average -0.39 m in lower tidal zone, respectively. Surface sediments of the intertidal flat consisted mainly of fine to medium sands, and the ratio of fine sand was the largest both before and after the typhoon. Surface sediments after the typhoon became finer in mean grain size showing well sorting rather than those before the typhoon.

Seasonal Variation of Surface Sediments in the Myeongsasipri Tidal Flat, Gochanggun, SW Korea (고창군 명사십리 조간대 표층 퇴적물의 계절 변화)

  • So, Kwang-Suk;Ryang, Woo-Hun;Kwon, Yi-Kyun
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.14 no.3
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    • pp.181-188
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    • 2009
  • The macro tidal flat of the Gochanggun Myongsasipri, located on the southwestern coast of Korea, is studied in terms of seasonal variations of surface sediment and sedimentary environment. Surface sediments of 45 sites in the winter (February) and the summer (August) are sampled across three survey lines (15 sites in each survey line), respectively. The tidal flat of open-coast Myongsasipri is mainly composed of fine to medium sand, the distribution of which shows a coast-parallel trend. Grain-size distribution has a bi-modal trend, and grain size in the winter is coarser than that in the summer. During the winter, the upper tidal flat is dominated by medium sand, while the lower tidal flat is dominated by find sand. Such a feature is attributed to wave-dominated sedimentation in the winter. The finer grains of the summer rather than that of the winter and relationship between texture parameters suggest that tidal energy plays an important role in tidal-flat sedimentation during the summer. This study represents an environmental change from wave-dominated conditions in the winter to tide-dominated conditions in the summer as a result of the seasonal variation in the intensity of onshore-directed winds and waves in the Myongsasipri tidal flat.