• 제목/요약/키워드: Sea states

검색결과 314건 처리시간 0.022초

A study on prediction of whipping effect of very large container ship considering multiple sea states

  • Kim, Beomil;Choung, Joonmo
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제12권1호
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    • pp.387-398
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    • 2020
  • In the design stage of the very large container ships, some methodologies for the whipping effects have been developed, but most of them are based on single sea state. We developed a methodology that considers multiple sea states. Fluid-structure Interaction (FSI) analyses with one dimensional structural model were carried out to capture slamming-induced transient whipping behaviors. Because of the nature of random phases of the applied wave spectra, the required period for entire FSI analyses was determined from the convergence study where the whipping effect became stable. Low pass filtering was applied to the transient whipping responses to obtain the hull girder bending moment processes. Peak counting method for the filtered whipping responses was used to obtain collection of the vertical bending moment peaks. The whipping effect from this new method is compared with that from based on single sea state approach. The efficiency and advantage of the new methodology are presented.

운항조건 및 해상상태가 대형 화물선의 파랑 중 굽힘모멘트에 미치는 영향 (Effects of Operational Condition and Sea States on Wave-Induced Bending Moments of Large Merchant Vessels)

  • 김동문;백점기
    • 대한조선학회논문집
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    • 제40권5호
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    • pp.60-67
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    • 2003
  • For risk or reliability assessment of ship structures against particular hazardous situations such as total loss or sinking due to hull girder collapse, the short-term based response analysis rather than the long-term response analysis is required to determine wave-induced bending moments when the ship encounters a storm of specific duration and with a specified small encounter probability. In the present study, the effects of operational condition and sea states on wave-induced bending moments of large merchant vessels are investigated. A series of the short-term response analyses for a hypothetical VLCC and a Capesize bulk carrier (CSBC) are carried out with varying operational condition and sea states which include ship speed, significant wave height and wave persistence time, using the linear-strip theory based program ABS/SHIPMOTION and the MIT sea-keeping tables. The computed results are also compared with the IACS design formula predictions. The results and insights developed from the present study are summarized.

미(美) Lassen 함(艦)의 남중국해(南中國海) 기동(機動)은 '투키디데스 함정'의 전조(前兆)? (Worsening Tension Between the United States and China in the South China Sea, A Sign of 'Thucydides Trap'?)

  • 양정승
    • Strategy21
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    • 통권38호
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    • pp.287-320
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    • 2015
  • On October 27, 2015, USS Lassen(DDG82), a 9,200 ton class Aegis destroyer of the United States Navy, began its operations within 12 nautical miles of Subi Reef, one of the seven artificial islands that China has built and claimed sovereignty over. The maneuver was joined by anti-submarine patrol airplanes such as P-8A and P-3. The White House press secretary mentioned that the President of the United States approved the operation. In response, China announced that it warned the US Navy ship about the 'illegal violation' by sending two destroyers(PLAN Lanzhou and Taizhou). This event represents a close call case where tension between the United States and China in the South China Sea might have been elevated to a conflict between the two navies. Moreover, considering that this happened only one month after Chinese president Xi's state visit to the United States, the event shows that the positions of the two countries have become starkly different to the extent that they are so hard to be reconciled. The United States' position is different from those of Vietnam and the Philippines. Countries like Vietnam and the Philippines have been directly involved in disputes with regard to sovereignty claims across the waters in the South China sea. As for the United States, being a third party in the disputes, it still cannot be a by-stander watching the whole waters in the region fall under the influence of China. Accordingly, the United States maintains that all countries bear the rights of innocent passage and military operations in the Exclusive Economic Zones(EEZ) as stipulated by the United Nations Convention on the Law of the Sea(UNCLOS). In contrast, China claims that, historically, the South China sea has been part of China's territorial waters, and that foreign countries are not allowed to conduct military operations within the waters. It strongly accuses that such military operations are illegal. Against this background, this paper tracks the different positions of the United States and China on the issues regarding the South China sea. It also carefully looks at the possibility that, in the process of dealing with the issues, the two countries may get into an armed conflict as the phrase 'Thucydides Trap' predicts.

On the effects of hull-girder vibration upon fatigue strength of a Post-Panamax container ship disaggregated by short-term sea state

  • Fukasawa, Toichi;Mukai, Keiichi
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제6권2호
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    • pp.431-441
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    • 2014
  • The effects of hull-girder vibration on the fatigue strength of a Post-Panamax container ship are discussed in the present paper. Firstly, the short-term sea states are categorized according to the occurrence probability of each sea state. Time histories of hull-girder stress in short-term sea states are calculated by means of a nonlinear simulation code of ship response assuming that the hull-girder is rigid and flexible. Then, the calculated stress peaks are processed by the rainflow counting method, where two different counting procedures are used based on the considerations of crack propagation behaviors. Finally, the fatigue damage in life time of the ship in each categorized short-term sea state is estimated by means of Miner's rule. Based on the calculated results, the effects of hull-girder vibrations on the fatigue damage are clarified by disaggregated damage from short-term sea state.

황해에 있어서의 해양오염방지를 위한 지역적 협력에 관한 연구 (A Study on the Regional Cooperation for the Prevention of Marine Pollution in the Yellow Sea)

  • 이윤철;최성규
    • 한국항해학회지
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    • 제16권2호
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    • pp.41-52
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    • 1992
  • It is, as everyone knows, very important for human beings to protect and conserve marine environment. We has believed the ocean is so wide and deep that it cannot be polluted. But it has begun to doubt the capacity of self-purification of the ocean due to pollution arising from marine casualities. It has proved that semi-enclosed sea is likely to be polluted and cannot be restored easily once pollution occurs. Therefore, first of all it is important to take preventive measures for prevention of marine pollution in the semi-enclosed sea like the Yellow Sea. Many of regional conventions for prevention of marine pollution have come into existence. this dissertation was set out for the fact that the Yellow Sea is semi-enclosed sea which is vulnerable to marine pollution. It is desirable not to deal with marine preservation of the Yellow Sea by a single exclusively but to deal with it by cooperation of all coastal states under the present circumstances. I proposed a program of regional cooperation to protect and conserve the Yellow Sea. This program must be progressed with gradual arrangements. First, they must establist a basic cooperation committee to work basic affairs on the protection of marine environment within the Yellow Sea. The Committee Mainly play parts of study and research concerned with pollution of the Yellow Sea in the non-governmental side and consist of legal and scientific experts. Second, they must establish the control Committee to prevent marine pollution of the Yellow Sea substantially. There is a reason that regional cooperation cannot be directly concluded with the regional tready. Because there is a problem of Recognition of States left. In principle, a subject of tready must be a state in the International Law. But they have not made Recognition of State which is demanded by International Law between North and South Koreas. Therefore, the Control committee must play a substantial part of prevention from pollution instead of the treaty. Finally, we concluded tentatively named $\ulcorner$Convention on Regional Cooperation for Protection of Marine Environment of the Yellow Sea from Pollution$\lrcorner$ if the matter is settled which is related to Recognition of States in the International Law.

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한국의 원양어업관련 국제분쟁 사례연구 (A Study on International Disputes with Korean Distant-Water Sea Fisheries)

  • 김민종
    • 수산경영론집
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    • 제34권1호
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    • pp.69-85
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    • 2003
  • The primary objective of this thesis is to study, case by case, the international disputes for fishing rights between fishing nations and costal states never imagined till the introduction of the UN Convention on the Law of the Sea adopted in 1982 and came into effect in November 16, 1994, which governs the high seas and EEZ in a new manner. Such a study is to provide help in the understanding on this new marine system and how to deal with. This is addressed by the perspectives of disputes (a) in the high seas between fishing nations having traditionally enjoyed the principle of the freedom of the high seas and costal states, (b) in the EEZ between fishing nations and costal states possessing the exclusive jurisdiction over living marine resources and sovereign rights for determining allowable catch and the surplus in its EEZ. The article can be divided into four main parts. First, both the general principles of the settlement of international disputes, and the nature and procedures described in the UNCLOS are introduced. Second, it gives cases of tuna long-liner, North Pacific trawler and squid jigger occurred in the coastal states EEZ, and analyses the problem in both terms of its background and final judgment. It further describes the possible issues in case it depends on the International Tribunal for the Law of the Sea for its settlement. Third, closely tied to above, important points such as the right of hot pursuit, prompt release of vessel and crew, and the limits of cooperation with costal states inspector on board fishing vessels are considered mostly based on the UNCLOS, Bilateral Agreement and UNIA. Finally, the article concludes as follows ; The need for broad analyses on the nature of international suits and legal system for the settlement, to win the case before the International Tribunal for the Law of the Sea or coastal states court, is really acknowledged. However, considering the lack of previous studies about it, it is preferably recommended that governmental efforts for making legal standards to cover the judicial costs, for helping industry out of becoming bankrupt.

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공해조업선(公海操業船)에 대한 관할권문제(管轄權問題)와 기국(旗國)의 책임(責任) (A Study on the Jurisdictional Problems for Fishing Vessels Engaging High Sea Fishery and the Responsibility of Flag States)

  • 최종화
    • 수산해양교육연구
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    • 제5권2호
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    • pp.138-146
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    • 1993
  • In accordance with the establishment of 200 nautical miles EEZ regime as a customary international law since the mid - 1980s, the area of global high seas became reduced relatively. On the other hand, the importance of high seas fishing ground became serious for the distant-water fishing states like Korea. But it can be expected that international dispute on the jurisdictional problem of the fishing vessels engaging high sea fishery will occur frequently owing to institutional inertia of the UNLOS Convention on this matter. "The Draft Agreement to Promote Compliance with International Conservation and Management Measures by Fishing Vessels on the High Seas" as an international code of conduct for responsible fishing which was adopted by FAO in 1993 is providing the more consolidating and definiting rules for jurisdictional responsibility of flag states to make completion the loophole of the UNLOS Convention. As a precondition for the effective control and enforcement of activities of the fishing vessels engaging high sea fishery, the Draft Agreement is providing some articles allowing the flag states to hold the rights of granting nationality, fishery permission, fishery supervision and control with punishment for the fishing vessels entitled to fly their own flag. Accordingly it can be evaluated that this Draft Agreement does not deviate on the whole from the traditional practice and the basic legal principle of the UNLOS Convention.

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해군력이 해양 영토분쟁의 해결에 미치는 영향 (A Study on the Influence of Naval Power upon the Resolution of Maritime Territorial Disputes)

  • 한종환
    • Strategy21
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    • 통권44호
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    • pp.103-141
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    • 2018
  • As the South China Sea maritime dispute illustrates, when considering the place where maritime claims occur, states do not have many choices to respond to maritime claims in which disputed areas are located far away from the land and are surrounded by the sea. As Mearsheimer (2014) points out, the sea stops power projection. Therefore, in order to adopt coercive as well as peaceful settlement policies to deal with maritime claims, states need to overcome obstacles (the sea) to project power. It means that if states want to conduct a specific foreign policy action, such as negotiating maritime borderlines or arguing sovereignty on islands, they need a tool (naval power) to coerce or to persuade the opponent. However, there are lack of research that studies maritime claims from the perspective of naval power. This research project fills this gap based on naval power. How do relative levels of naval power and (dis) parities of naval power influence the occurrence of MIDs over maritime claims? Naval power is a constitutive element during maritime claims. If disputants over maritime claims have required naval power to project their capability, it means that they have the capability to apply various ways, such as aggressive options including MIDs, to accomplish their goals. So, I argue that when two claimants have enough naval power to project their capabilities, the likelihood of MIDs over maritime claims increases. Given that one or both states have a certain level of naval power, how does relative naval power between two claimants influence the management of maritime claims? Based on the power transition theory, I argue that when the disparities of relative naval power between claimants becomes distinctive, militarized conflicts surrounding maritime territory are less probable. Based on the ICOW project which codes maritime claims from 1900 to 2001, the empirical results of the Poisson models show if both claimants have projectable naval power, the occurrence of MIDs over maritime claims increases. In addition, the result shows that when disputants maintain similar relative naval powers, they are more likely to initiate MIDs over maritime claims. To put it differently, if naval capabilities' gap between two claimants becomes larger, the probability of the occurrence of MIDs decreases.

일반폐기물 매립장의 침출수에 의한 하부토양의 오염과 해안점토층을 이용한 폐기물 매립장의 건설 가능성 (Pollution Characteristics of Leachate and Underground Soil of the Landsfill Site and Possibilities of Landfill Site using Clay Layer of the Sea Shore)

  • 이병호;전옥수
    • 한국환경과학회지
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    • 제7권3호
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    • pp.383-392
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    • 1998
  • Pollution characteristics of leachate and underground soul of the two landfill states were Investigated Domestic wastes were dumped In the two adjacent landfill states. Only small portion of S landifill site was filled with domestic wastes at the first stage of dumping, and most portion of the site was filled with construction wastes. However Y landfill strate was filed with mostly domestic wastes. Higher concentrations of organic pollutants including VOCs were measured In Y landfill site leachate than In S tendon site. Underground souls of the two linam states were analyzed by the two kinds of leaching methods, KEP (Korean Extraction Processl and Acid Digestion. Underground souls of the both landfill states were not polluted by leachates. Underground soils of the two were composed of firie salty material. Thus It Is fecund that fine silty soul layer of the sea shore may be used as a landfillsite.

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해수면 상승이 유엔해양법협약 적용에 미치는 영향 분석 (Analysis on the Legal Impacts of Sea-Level Rise for the Application of the UN Convention on the Law of the Sea)

  • 이용희
    • 해양환경안전학회지
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    • 제29권2호
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    • pp.147-159
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    • 2023
  • 기후변화로 인하여 해수면 상승이 발생하고 있고, 그로 인한 악영향에 대해 연안국을 비롯한 국제사회의 우려가 커지고 있다. 해수면 상승으로 해안선이 후퇴하고 섬등 해양지형물이 수몰되는 경우 그러한 해안선을 기점으로 설정된 연안국 관할해역 외측한계의 변경 가능성, 기존 해양경계획정조약의 개정 필요성, 섬 또는 암석이 암석 또는 수중암초로 변경됨에 따른 법적 지위의 변화 등 많은 국제해양법적 쟁점을 발생시키고 있다. 이 논문에서는 해수면 상승이 국제해양법에 미치는 효과에 한정하여, 쟁점별로 소도서개발도상국, 세계국제법학회, 유엔 국제법위원회의 주장을 검토하고 유엔해양법협약의 해석론적 측면에서 해결방안을 제시하였다.