• 제목/요약/키워드: small vessels

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4.99톤급 표준어선형 어선의 초기 복원성 평가에 관한 연구 (A Study on the Initial Stability Evaluation of 4.99-Tons-Class Standard Fishing Vessels)

  • 김혜우;김상현;이선우;윤형석;이효근
    • 해양환경안전학회지
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    • 제30권2호
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    • pp.176-183
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    • 2024
  • 주로 소형어선에서 발생하고 있는 연근해에서의 전복사고를 예방하기 위해 소형어선의 복원성 평가는 중요하다. 하지만 국내 「어선법」에서는 24m 미만의 소형어선에 대한 복원성 평가 규정이 미비한 실정이다. 2022년 해양수산부에서 안전복지를 강화하여 고시한 표준어선형에 관한 안전성 기준에 따르면, 표준어선형을 따르는 선박은 길이와 무관하게 안전성 기준에 따른 복원성을 가져야 한다. 이에 본 연구에서는 상기 기준을 활용하여 24m 미만에 해당하는 4.99톤급 어선에 대한 복원성 평가를 수행하고 해당 기준으로 복원성을 평가하는 것이 적합한지 검토하는 것을 목표로 한다. 또한 다양한 상부구조물을 가지는 4.99톤급 소형어선에 대해서도 해당 기준이 유효한지 검토를 수행한다. 이를 위해 어선의 초기횡메타센타높이(GM)를 이용한 초기복원성과 한계경사각에서의 복원정(GZα)을 평가하였다. 그리고 현재 표준어선형의 소형어선에서 주로 활용되는 상부구조물의 형태를 활용하여 대상선과 동일한 하부 선형과 제원을 가지는 소형어선 6종을 추가로 선정하여 상부구조물 변화에 따른 복원성 변화도 검토하였다. 4.99톤급의 표준어선형을 대상으로 한 연구 결과, 안전복지를 강화한 표준어선형에 대한 안전성 기준은 4.99톤급 표준어선형의 어선에도 적용 가능하며, 상부구조물에 변화에 따른 복원성 변화는 크지 않은 것으로 확인되었다.

Form Parameter 기법을 활용한 딥러닝 기반의 소형선박 초기복원성 계산에 관한 연구 (A Study on the Initial Stability Calculation of Small Vessels Using Deep Learning Based on the Form Parameter Method)

  • 이동근;오상진;임채옥;김진욱;신성철
    • 한국산업융합학회 논문집
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    • 제27권1호
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    • pp.161-172
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    • 2024
  • Approximately 89% of all capsizing accidents involve small vessels, and despite their relatively high accident rates, small vessels are not subject to ship stability regulations. Small vessels, where the provision of essential basic design documents for stability calculations is omitted, face challenges in directly calculating their stability. In this study, considering that the majority of domestic coastal small vessels are of the Chine-type design, the goal is to establish the major hull form characteristic data of vessels, which can be identified from design documents such as the general arrangement drawing, as input data. Through the application of a deep learning approach, specifically a multilayer neural network structure, we aim to infer hydrostatic curves, operational draft ranges, and more. The ultimate goal is to confirm the possibility of directly calculating the initial stability of small vessels.

Estimation of drafts and metacentric heights of small fishing vessels according to loading conditions

  • Kim, Dong Jin;Yeo, Dong Jin
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제12권1호
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    • pp.199-212
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    • 2020
  • A large percentage of maritime accidents in coastal seas are related to small fishing vessels. In order to investigate causes of maritime accidents, it is often necessary to carry out dynamic simulations for the estimation of trajectories and motions of vessels. Initial conditions of vessels such as main dimensions, loading conditions and hydrostatic properties are required for the accurate simulations. Small fishing vessels usually have few records of hydrostatic properties during their fishing operations. Therefore, in this study, estimation procedures for hydrostatic properties of small fishing vessels are proposed. At first, hull form characteristics of Korean small fishing vessels are investigated. Most of vessels have hard-chines and centerline skegs, they have similar hull forms. Bonjean curves of several small fishing vessels whose gross tonnages are below 10 tons are normalized with vessel breadths and depths. Representative bonjean curves are derived from normalized bonjean curves, and a representative hull plan is obtained as well. If the vessel loading conditions such as total weights and centers of gravity are given, fore and aft drafts can be calculated by using the representative bonjean curves with the constraint that weights and buoyancies are in equilibrium. Metacentric heights are also estimated by using the representative hull plan. Drafts and metacentric heights estimated by proposed iterative estimation procedures are compared with actual vessel data, estimated values are in good agreements with actual values. In addition, normalized fore and aft drafts, metacentric heights of vessels can be formulated as the linear functions of normalized total weights and centers of gravity. Empirical formulas of drafts and metacentric heights are proposed, and it is confirmed that the empirical formulas also provide reasonable results, which are similar to the results by iterative estimation procedures with representative bonjean curves and hull plan.

소형어선 검사제도 현실과 개선방안 (Improvement Policy about Inspection systems of Small fishing Vessels)

  • 이광남
    • 해양환경안전학회지
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    • 제11권2호
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    • pp.51-63
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    • 2005
  • 소형어선 검사제도와 관련하여 최근에 정부에서는 선박검사대상에 제외되었던 선외기등 총톤수 2톤 미만의 선박(이하 소형어선)에 대하여 선박안전법 적용대상으로 확대하여 어민들의 안정적인 조업활동을 지원하여야 한다는 근거하에 선박안전법 개정(제3조)에 관한 입법이 추진중에 있다. 소형어선의 검사여부 문제에 대해 어선의 안전확보 차원에서 검사를 해야 된다는 측면과 영세민과 노년층으로 현행 검사비 및 검사수수료의 비용 부담 및 어선검사를 받는데 소요되는 많은 시간 등의 문제로 종전과 같이 검사대상에서 제외되어야 한다고 주장하고 있다. 이러한 상반된 의견에 대한 대안으로 영세어민의 생업에 사용하거나 소형어선에 대한 검사는 원칙적으로 선박의 소유 또는 사용자가 자발적으로 수행하여야 하며 행정적인 규제는 이러한 목적 달성을 위한 최소한의 정책수단으로 제한되는 것이 바람직한 것으로 나타났다. 또한, 주요 수산국들 처럼 우리나라도 소형어선 검사를 위한 다양한 프로그램개발이 필요하다. 특히, 소형어선에 대한 검사를 실시하는 경우, 어선검사료 정부 지원, 최소한의 안전확보 검사, 어선건조시 검사, 검사기간을 연장하는 방안을 고려하여 정책을 추진할 필요가 있는 것으로 파악되었다.

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Superoxide Dismutase Activity in Small Mesenteric Arteries Is Downregulated by Angiotensin II but Not by Hypertension

  • Kang, Kyu-Tae;Sullivan, Jennifer C.;Pollock, Jennifer S.
    • Toxicological Research
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    • 제34권4호
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    • pp.363-370
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    • 2018
  • Many studies reported reduced antioxidant capacity in the vasculature under hypertensive conditions. However, little is known about the effects of antihypertensive treatments on the regulation of vascular antioxidant enzymes. Thus, we hypothesized that antihypertensive treatments prevent the reduction of antioxidant enzyme activity and expression in the small vessels of angiotensin II-induced hypertensive rats (ANG). We observed the small mesenteric arteries and small renal vessels of normotensive rats (NORM), ANG, and ANG treated with a triple antihypertensive therapy of reserpine, hydrochlorothiazide, and hydralazine (ANG + TTx). Systolic blood pressure was increased in ANG, which was attenuated by 2 weeks of triple therapy (127, 191, and 143 mmHg for NORM, ANG, and ANG + TTx, respectively; p < 0.05). Total superoxide dismutase (SOD) activity in the small mesenteric arteries of ANG was lower than that of NORM. The protein expression of SOD1 was lower in ANG than in NORM, whereas SOD2 and SOD3 expression was not different between the groups. Reduced SOD activity and SOD1 expression in ANG was not restored in ANG + TTx. Both SOD activity and SOD isoform expression in the small renal vessels of ANG were not different from those of NORM. Interestingly, SOD activity in the small renal vessels was reduced by TTx. Between groups, there was no difference in catalase activity or expression in both the small mesenteric arteries and small renal vessels. In conclusion, SOD activity in the small mesenteric arteries decreased by angiotensin II administration, but not by hypertension, which is caused by decreased SOD1 expression.

A Study on Application of Electric Propulsion System using AFE Rectifier for Small Coastal Vessels

  • Jeon, Hyeonmin;Kim, Seongwan;Kim, Jongsu
    • 해양환경안전학회지
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    • 제24권3호
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    • pp.373-380
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    • 2018
  • The small coastal vessel registered in Korea, small coastal vessels with a gross tonnage of 10 tons or less account for 94.6 % and among them, aged vessels over 16 years age indicate 40.6 %. In order to reduce GHG emissions from small coast vessels, discussions are underway to replace aging ships' propulsion units with eco - friendly propulsion facilities, and the electric propulsion ship is emerging as one of the measures. The electric propulsion system using the DFE rectifier, which was applied in the conventional large commercial vessel, was effective in reducing the harmonics and improving the DC output voltage of the DC link stage, but it occupied a large volume and caused an increase in the overall system price. Therefore, in this paper, we propose an electric propulsion system using AFE rectifier with a small volume of system that can be applied to a small coastal vessel. In order to analyze the effectiveness of the overall system, the load profile was applied to obtain accurate and rapid speed tracking performance of the propulsion motor affected by the speed load. In addition, the power factor and total harmonic distortion factor of the voltage and current on the improved power output side are derived through simulation.

소형 어선 및 화물선의 복원성기준 연구 (Study on the Stability Criteria for Small Fishing Vessels and Cargo Ships)

  • 권수연;이희준
    • 선박안전
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    • 통권22호
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    • pp.19-33
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    • 2007
  • According to amendments of ship safety act which comes into force from 4 Nov. 2007, the amended stability criteria should be applied to the small vessels of 12m or more in length. In this paper, the dimensions of domestic small vessels and the casualty reports of capsizing accidents are analyzed. And 58 ships are sampled, modeled for the investigation of the stability performance. Based on the regression analysis of the model ship's allowable metacentric-heights under several stability requirements, stability criteria for small fishing vessels and cargo ships are proposed.

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소형선박의 복원성기준 연구 (A Study on the Stability Criteria of Small Vessels)

  • 권수연;이희준
    • 대한조선학회논문집
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    • 제44권3호
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    • pp.285-295
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    • 2007
  • In order to ensure safety of small vessels, the amended Ship Safety Act will come into force on 4th. Nov. 2007. This study is performed to suggest the stability criteria of fishing vessels and cargo ships of 12m in length and over but less than 24m in length which will be new object of amended Ship Safety Act. We have analyze the dimensions of domestic small vessels and the casualty reports of capsizing accidents. According to the analyzed result, 58 ships that are in the range of the dimension are modeled and the stability calculation has been carried out. The Stability for the 58 ships has been analyzed by comparing the result that applied the selected standard in the national standard to the stability calculation. Based on the regression analysis of the model ship's allowable transverse metacentric-heights under several stability requirements, stability criteria for small fishing vessels and cargo ships are proposed.

국제 소형어선 안전기준 개발 (Development on IMO Standard of Safety for Small Fishing Vessels)

  • 연효흠;최경신;하일홍
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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    • pp.125-126
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    • 2006
  • This document summarizes the work completed during the interessional period by the IMO SLF correspondence group on the drafting of Safety standards for small fishing vessels, which was established at IMO SLF 48.

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해양안전 확보를 위한 소형어선 법제도 개선에 관한 연구 (A Study on the Advancement of the Legal System for Small Fishing Vessels to Ensure Marine Safety)

  • 송병화;이경훈;최운규
    • 해양환경안전학회지
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    • 제24권7호
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    • pp.875-888
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    • 2018
  • 대한민국 정부는 해양사고 예방 및 해양안전 확보를 위해 지속적으로 법제도를 개선하고 있다. 그럼에도 불구하고 최근 해양사고는 계속적으로 증가하고 있어, 그동안 정부의 해양안전관련 법제도 개선방안 실효성은 미흡했음을 시사하고 있다. 최근 해양사고의 발생현황을 살펴보면, 전체 해양사고 건수 중 총톤수 10톤 미만의 소형어선이 차지하는 비중은 5년('13~'17년)평균의 44.9 %를 차지하고 있다. 이에 따라 본 연구에서는 해양사고 비중이 높은 소형어선의 해양안전 확보방안을 모색하기 위해, 관련 국내외 법제도의 현황과 특징을 조사 및 분석하였다. 그 결과, 국내 소형어선 관련 법제도는 어선과 비어선의 관련법이 통합('97)되고 분법('09)된 이력에 따라 접목교잡(接木交雜)의 현상을 보이고 있으며, 제도의 개선방안은 안전설비의 비치강화라는 단편적인 개선만 이루어 졌다는 문제점이 식별되었다. 또한, 해외 관련 법제도에서는 어선 소유자 및 운항자의 책임강화 및 자율검사제도 도입 등의 특징이 확인되었다. 본 연구에서는 이를 바탕으로 국내 해양안전 확보를 위해 실효성 있는 소형어선 법제도 개선방안을 제시하였다.