• Title/Summary/Keyword: sea transport

Search Result 630, Processing Time 0.028 seconds

Far-field Transport of Effluent Plumes Discharged from Masan Sea Outfalls

  • Kim, Young-Do;Kang, See-Whan;Seo, Il-Won;Oh, Byung-Cheol
    • Ocean and Polar Research
    • /
    • v.22 no.2
    • /
    • pp.69-80
    • /
    • 2000
  • A 3-D particle tracking model with normalized characteristic equations has been developed to predict the variation of near-field mixing characteristics and the far-field transport of the effluent plumes discharged from sea outfalls. The model was applied to the case study on the Masan sea outfall plumes discharged through a submerged multiport-diffuser. Numerical simulations of the effluent transport for 15 days which cover neap and spring tidal cycles in Masan Bay were conducted using fall velocities of the solid wastes and the initial plume characteristics obtained from normalized near-field characteristic equations. The results showed that time variations in near-field minimum dilutions with tidal ambient flow conditions are about $45{\sim}49$. Most of the heavy particles in the effluent plumes were settled and deposited in the vicinity of the outfalls immediately, and the finer particles were transported eastwards 3 km away from the outfalls for 15 days. A similar depositional trend of contaminated sediment was also found during a recent field survey.

  • PDF

A Study on the Risk Management of Container Transport at Sea (컨테이너의 해상운송(海上運送)과 위험관리(危險管理)에 관한 연구(硏究))

  • Nam, Young-Eun;Park, Sang-Gap
    • Journal of the Korean Institute of Navigation
    • /
    • v.25 no.2
    • /
    • pp.137-148
    • /
    • 2001
  • This paper aims to select the appropriate risk management techniques on the risks of container transport at sea based on risk and risk management theory. Risk management can be defined as a systematic process for the identification and evaluation of pure loss exposure faced by an organization or individual, and for the selection and administration of the most appropriate techniques for treating such exposures. Risks of container at sea transport are widely divided into three categories, such as risk of container itself, risk of container cargo and liability to third party. This paper places emphasis on the risks of container transport at sea as well as limits its scope from container terminal to container terminal.

  • PDF

Estimation of Sea Water Transport by Water-depth Variation at Pier-bridge between Busan New-port and the Nakdong River Estuary (부산 신항-낙동강 하구역 연결잔교부의 물질수송 해석(II) - 잔교주변 해저수심변화에 따른 해수소통량 예측 -)

  • Lee, Young-Bok;Ryu, Seung-Woo;Yoon, Han-Sam
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.14 no.3
    • /
    • pp.197-203
    • /
    • 2008
  • This study analyzed the characteristics of sea water transport between Busan New-port and the Nakdong River estuary. Numerical modeling was used to evaluate the characteristics of the tidal current. Numerical simulations of three different topographies were conducted. The results are summarized as follows: 1) The volume of sea water transport was reduced by $0.7{\sim}18.4%$ when water depth was decreased at Busan New-port (10 m); 2) The volume of sea water transport was increased by $3.5{\sim}21.9%$ when a channel (depth 5 m) was constructed in the direction of the Nakdong River estuary.

  • PDF

The Records of Origin and Transport of Sediments From the Past to the Present in the Yellow Sea

  • Yi, Hi-Il;Chun, Jong-Hwa;Shin, Im-C.;Shin, Dong-Hyeok;Jou, Hyeong-Tae
    • Journal of the korean society of oceanography
    • /
    • v.39 no.1
    • /
    • pp.96-106
    • /
    • 2004
  • A total of 116 surface sediment samples were obtained on the Yellow Sea and analyzed for grain size and geochemical elements in order to interpret the present sediment transportation. Thirty-nine cores and 3,070 line-km shallow seismic profiles are analyzed for sedimentary records of Yellow Sea in the past. Results show that the boundary of sediment transport between Korean side and Chinese side is about between $123^{\circ}E$ and $124^{\circ}E$. The similar result is produced from Shi et al. (in this publication). Two cyclonic patterns of surface sediments are recognized in the northeastern and southwestern Yellow Sea, while the strong front zone of the mud patch and sandy sediments are found in the southeastern Yellow Sea (the southwestern part of Korean coasts). The formation of fine-particle sediment packages, called for Northwest Mudbelt Deposit (NWMD), Hucksan Mudbelt Deposit (HSMD) and Jeju Mudbelt Deposit (JJMD), are resulted from eddies (gyres) of water circulations in the Yellow Sea. NWMD has been formed by cyclonic (anticlockwise) eddy. NWMD is composed of thick, homogeneous, relatively semi-consolidated gray clay-dominated deposit. On the other hand, HSMD and JJMD are formed by anticyclonic (clockwise) eddies. They are thick, homogeneous, organic-rich gray, silt-dominated deposit. Both core and surface sediments show that the middle zone across Chinese and Korean side contains bimodal frequency of grain-size distribution, indicating that two different transport mechanisms exist. These mud packages are surrounded by sand deposits from both Korea and China seas, indicating that Yellow Sea, which is the shallow sea and epicontinental shelf, is formed mostly by sand deposits including relict sands. The seismic profiles show such as small erosional/non-depositional channels, sand-ridges and sand-waves, Pleistocene-channelfilled deposits, a series of channels in the N-S major channel system, and thick Holocene sediment package, indicating that more complex sedimentary history exists in the Yellow Sea.

A Study on the Transport of Anchovy Engraulis japornicus Egg-larvae in the South Sea of Korea (한국 남해안의 멸치(Engraulis japornicus) 난자치어 수송에 관한 연구)

  • Kim, Dong-Sun;Bae, Sang-Wan
    • Journal of Environmental Science International
    • /
    • v.20 no.11
    • /
    • pp.1403-1415
    • /
    • 2011
  • To understand the transport of anchovy egg-larvae, an integrated model consisting of a hydrodynamic model and a three-dimensional Lagrangian diffusion model was used for the anchovy Engraulis japornicus egg-larvae trace. Fist, in order to determine the circulation characteristics of the South Sea of Korea, residual flow according to tide, density and wind effect was investigated. In offshore regions, tide-induced residual current tends to flow eastward during the spring tide and westward during the neap tide. Residual flow is irregular due to the bottom topography in the coastal area. No special tendency was apparent in the open sea. Especially, the flow in the offshore regions showed results similar to that of the Tsushima Warm Current. The transport of anchovy egg-larvae is decided the physical properties of sea water. It is estimated that anchovy eggs spawned near the Jeju Island travels offshore, rather than to coastal areas, and grow in the front area between the coastal sea and offshore regions.

Optimizing Total Transport Cost Incurred under Specific Port System: With a Case of Managing POSCO-owned Berths (특수항만구조하에서의 물류비용 최적화에 관한 연구 - 포항제철의 원료부두 사례를 중심으로 -)

  • Kim, Weon-Jae
    • Journal of Korea Port Economic Association
    • /
    • v.26 no.3
    • /
    • pp.42-55
    • /
    • 2010
  • This paper primarily deals with a decision-making for determining the number of voyages in each ship size under a specific port structure in order to minimize the total transport cost consisting of transport cost at sea, queuing cost in port, and inventory cost in yard. As a result of computer simulation using queuing model characterized by inter-arrival time distribution, we were able to find out some combination of voyage numbers of 3 ship-size(50,000-ton, 100,000-ton, and 200,000-ton), where the total transport cost can be minimized under a specific port structure. The simulation model also allows us to figure out any trade-off relationship among sea transport cost, queuing cost in port, and inventory cost in yard. Put it differently, an attempt to reduce the sea transport cost by increasing the number of voyages of the largest ship size, the transport cost incurred in both port and yard is hypothesized to be increased and vice versa. Consequently, Port managers are required to adjust the number of annual number of voyages allocated in each ship size, put into the sea lines for importing raw materials, in order to optimize the transport costs incurred under the specific port system. We may consider a net present value(NPV) model for performing an economic feasibility analysis on port investment project. If a total discounted net benefit, including cost savings, exceeds the initial investment for an additional berth construction, then we accept the port investment project. Otherwise, we reject the proposed port investment plan.

Transport Process and Directly Entrainment Possibility into the Yellow Sea of Todarodes Pacificus Winter Cohort (살오징어(Todaroes pacificus) 겨울발생군의 이동패턴 및 직접적 황해 유입 가능성)

  • Song, Ji-Young;Lee, Joon-Soo;Kim, Jung-Jin;Lee, Ho-Jin;Park, Myung-Hee;Han, In-Seong
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.50 no.2
    • /
    • pp.183-194
    • /
    • 2017
  • The catch of Todarodes pacificus in the Yellow Sea is commonly known as the winter cohort. So, to understand the transport process of winter cohort of T. pacificus, and to identify whether the simulated individuals which are transported directly into the Yellow Sea (YS) influence these resources immediately, we conducted a Lagrangian-particle-tracking numerical experiments of T. pacificus from 2005 to 2010 using LTRANS and ROMS. The results show that: (1) Most of the released individuals spread out to the open sea by the Kuroshio and the Tsushima Warm Current around 30 days after release. (2) Unlike the hypothesis proposed by Rosa et al. (2011), Around $30-33N^{\circ}$ near Jeju Island simulated the initial position (3) About 0.01% of individuals released in December were transported solely into the YS around 15 days after release. However there were no surviving individuals due to the low temperature less than $12^{\circ}C$. Also the variation of individuals entered into the YS was not significantly correlated with it in YS catches during the experimental period. Therefore, the most of resources in the YS is assumed to be more influenced by diverse factors of the Pacific Ocean and East Sea than the direct transport in the YS of winter cohort.

A review study on the Yug Bu Ha Hap Hyul (육부하합혈(六腑下合穴)의 도입(導入) 배경(背景)에 관(關)한 연구(硏究))

  • Lee, Bong-Hyo;Lim, Sung-Chul;Lee, Kyung-Min;Kim, Jae-Su;Jung, Tae-Young
    • Korean Journal of Acupuncture
    • /
    • v.26 no.3
    • /
    • pp.77-85
    • /
    • 2009
  • Objectives : The lower sea points of the six bowels is one of the most useful acupuncture prescription in the treatment for diseases related with six organs. There have been many studies on the effects of each acupoint, but it is difficult to find a systemic review about the whole of it. The purpose of this study is to review the lower sea points of the six bowels and investigate the background of the induction of that. Materials and Methods : 1. The authors performed systemic review about the lower sea points of the six bowels using related-literatures such as Neijing and Nanjing. 2. We investigated the background of the induction and the necessity through the meaning of the character Hop (合). We thought the clinical usefulness of that. Results and Conclusions : The lower sea points of the six bowels had been made for the supplement of the sea point of the five transport points and it might be possible to substitute the sea point of the five transport points with the lower sea points of the six bowels owing to the clinical usefulness of the lower sea points of the six bowels.

  • PDF

Influences of the Sea Surface Wind on Current and Thermal Structures in the Southwestern Part of the East Sea of Korea (동해 남서해역의 해류 및 열구조에 미치는 해상풍의 영향)

  • NA Jung-Yul;PAENG Dong-Guk
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.25 no.1
    • /
    • pp.15-28
    • /
    • 1992
  • Temporal variations of the path of the East Korea Warm Current(EKWC) which flows northward along the east coast of Korea were analysed to investigate whether the EKWC directly influences the existence of the so-called Warm Core in the Ulreung basin. From the 13 years(1975-1987) data of the Fisheries Research and Development Agency(FRDA), the $10^{\circ}C$ isotherm at the 100m depth and the depth of $2^{\circ}C$ isotherm and the temperature field at the 200m depth were used for identification of the path and the central position of the Warm Core. Sea surface winds computed from the surface pressure charts gave the monthly-averaged wind stress curl over the East Sea which was used for determination of the Sverdrup transport. And the mass transport stream functions were computed by use of the Sverdrup balance. The variations of the path show that the EKWC does not always have a fixed path and fluctuates with time. And the existence of the Warm Core is independent upon the presence of the EKWC even when the EKWC doesn't flow northward along the east coast of Korea. In view of the mass transport stream functions, the influences of the sea surface winds on the branching of the Tsushima Warm Currents and the presence of the EKWC were investigated. The presence of the EKWC may be hindered by the southward flow driven by the sea surface winds when the Tsushima currents are rather weak. A very weak correlation exists between the north-south component of the Sverdrup transport and the position of the Warm Core. However, a small but significant part of the southward transport across the latitudinal line of $38^{\circ}N$ indicates that cold water from the northern part of the East Sea may be driven and be forced to flow beneath the permanent thermocline in such a way that the thermal structure of the Warm Core and its position might be changed.

  • PDF