• Title/Summary/Keyword: 선박안정성

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기계학습을 이용한 수출 컨테이너의 무게그룹 분류

  • Gang, Jae-Ho;Gang, Byeong-Ho;Ryu, Gwang-Ryeol;Kim, Gap-Hwan
    • Proceedings of the Korea Inteligent Information System Society Conference
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    • 2005.05a
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    • pp.77-86
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    • 2005
  • 컨테이너 터미널에서는 장치장으로 반입되는 수출 컨테이너의 무게를 몇 단계 그룹으로 나누고 각 무게그룹 별로 모아서 장치한다. 이는 수출 컨테이너를 선박에 싣는 적하 작업 시 선박의 안정성을 위하여 무거운 무게그룹의 컨테이너들을 장치장에서 먼저 반출하여 선박의 바닥 쪽에 놓기 위함이다. 하지만 반입되는 컨테이너의 무게그룹을 결정할 때 사용하는 운송사로부터 받은 무게정보는 부정확한 경우가 많아 하나의 스택(stack)에 서로 다른 무게그룹에 속하는 컨테이너들이 섞이게 된다. 이로 인하여 무거운 무게그룹의 컨테이너를 반출할 때 해당 컨테이너의 상단에 놓여진 보다 가벼운 무게그룹의 컨테이너들을 임시로 옮겨야 하는 재취급(rehandling, reshuffling)이 발생하게 된다. 적하작업 시 장치장에서 재취급이 빈번히 발생하면 작업이 지연되므로 터미널 생산성 향상을 위해서는 재취급 발생을 가급적 줄여야 한다. 본 논문에서는 기계학습 기법을 적용하여 반입 컨테이너의 무게그룹을 보다 정확히 추정하는 방안을 제안한다. 또한 탐색을 통하여 분류기 생성에 관여하는 비용행렬(cost matrix)을 조정함으로써 재취급 발생을 줄일 수 있는 분류기(classifier)를 생성하는 방안을 함께 소개한다. 실험 결과 본 논문에서 제안하는 방안 적용 시 재취급 발생을 $5{\sim}7%$ 정도 줄일 수 있음을 예상할 수 있었다.

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Activation of Korean Ship Finance through Study on Chinese Ship Finance Market (중국 선박금융 시장 연구를 통한 국내 선박금융 활성화)

  • Kim, Dae-Jin;Kim, Ju-Hyeoun
    • Journal of Korea Port Economic Association
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    • v.35 no.2
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    • pp.1-20
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    • 2019
  • This study aims to establish a method for activating Korean ship finance through an analysis on the development of Chinese ship finance market, which has grown rapidly in recent years. It focuses on its main institutions, laws and policies, strengths and weaknesses, market share, and development status. Because 80.7% of South Korea's economy depends upon foreign trade and 99.7% of the South Korea's traded volume is transported by ships, shipping has assumed an important role in Korean economy. However, since the global financial crisis, Korean shipping and shipbuilding industry has been facing difficulties and Hanjin, the biggest Korean shipping company, went bankrupt in 2017. One of the key aspects of the competitiveness of the shipping and shipbuilding industry is acquiring competitive shipping assets; therefore, stable and smooth supply of ship finance is crucial for the development of the shipping and shipbuilding industry. Given this background, the study analyzed how the Chinese ship finance market has grown rapidly in the past 30 years and identified the problems, strengths, and weaknesses of the Chinese ship finance. The analysis on the status of the Chinese ship finance market is expected to suggest a direction for establishing methods for activating the Korean ship finance market, which is facing scarcity of finance, even as the global ship finance market has remained depressed since the global financial crisis. Although this study focused exclusively on the Chinese market, future research can draw conclusions from a comparative analysis that includes the Japanese ship finance market; the conclusions obtained would contribute to the establishment of long-term policies and plans for Korean ship finance.

Evaluation of Stability of Small Modular Reactor (SMR) Power Ship in Waves (소형 모듈 원자력(SMR) 발전 선박의 파랑 중 안정성 평가)

  • Kyoungwan Lee;Sundon Choi;Byungyoung Moon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.30 no.5
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    • pp.499-505
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    • 2024
  • To address the issue of global warming, various regulations and policies for reducing greenhouse gas emissions are being implemented. In this context, the number of countries targeting carbon neutrality, the latter of which entails reducing net carbon emissions to zero, is increasing, and small modular reactors (SMRs) are investigated extensively as a new model for power plants. SMRs, although measuring only 5%-10% of the size of conventional large nuclear power plants, are highly efficient systems that can generate hundreds of megawatts of power. Compared with fossil fuel-based power plants, SMRs generate less carbon emissions and can complement the unstable energy supply from renewable sources. However, the use of SMRs is opposed by local residents owing to the risk of significant radioactive-material leakage when a nuclear-power-plant accident occurs. Hence, floating, small nuclear-power vessels are being investigated and installed in the ocean, thus simplifying the process of securing land, compensating nearby residents, and increasing safety against natural disasters. In this study, the towing stability of SMR power ships is analyzed, and the result shows no significant risk of towing to the destination in sea states 3, 4, and 5.

Strategies of Car-Ferry Shipping Companies According to the Korea-China Free Trade Agreement (한·중 FTA 체결에 따른 수도권항만 카페리선사의 발전방안)

  • Park, Sung-Eun;Ahn, Seung-Bum
    • Journal of Korea Port Economic Association
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    • v.34 no.1
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    • pp.111-132
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    • 2018
  • As China continues to evolve as a major economic power and the Free Trade Agreement (FTA) between the Republic of Korea and China was ratified on June 1, 2015, market volume between the two countries is expected to grow more rapidly. This study aims on improving the efficiency of car-ferry lines. We conducted two surveys- for shippers and forwarders of car-ferry companies, and container liners. The study analyzes the decision factors for delivery companies and their importance for shippers and forwarders of car-ferry companies and container liners. Based on analysis of prior studies on the competition for car-ferry companies and liners, three primary variables are selected-promptness, economics, and safety. The promptness variable consists of shipping time, loading/unloading time, and customs clearing time. The economic variable consists of marine transportation cost from a domestic harbor to China, loading/unloading cost in the harbor, and overland transport cost from the harbor to shippers inland. Finally, the safety variable consists of cargo damage rates, safety facilities, such as lashing and shoring, and punctuality of transportation time. The survey and AHP results show that the promptness, safety, and economics factors are 0.549, 0.309, and 0.142 in the shipper groups of car-ferry companies' category, respectively. It indicates that there is considerable difference in the importance of each factor. In contrast, the factors are 0.350, 0.348, and 0.302 in the forwarders category, which suggests that there is little difference in each factor's importance. As for shippers and forwarders of liners, the importance of each factor is found to be in the following order: economics, safety, and promptness.

A Study on the Analysis of Reasons for Job Change and Countermeasures among Professionals in the Ship Management Industry (선박관리산업 전문인력 이직 원인 분석 및 대책 연구)

  • Tae-Ryong Park;Do-Yeon Ha;Yul-Seong Kim
    • Journal of Navigation and Port Research
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    • v.48 no.3
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    • pp.146-154
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    • 2024
  • The ship management industry in South Korea has been growing steadily, leading the government to implement policies to support its development in response to changing environmental conditions. These policies aim to improve the competitiveness of South Korea's ship management industry by recognizing the importance of skilled professionals in determining its success. Plans and policies have been put in place to cultivate these professionals, but ship management companies are currently facing a serious shortage of manpower. To enhance the industry's competitiveness, it is essential to attract and retain competent ship management professionals. Therefore, this study investigates the reasons for turnover among these professionals. The research results identified four factors contributing to turnover: Work Environment, Economic Compensation and Welfare Benefits, Self-Development, and Promotion and Career Advancement. Subsequent multiple regression analysis based on these factors revealed the need to strengthen economic rewards and benefits in order to reduce turnover rates among ship management professionals. This study provides foundational data for the development of stable human resource management policies for the future of the ship management industry.

롤포밍을 위한 박판 미세구조물 기초 연구

  • 김형종;최두선;제태진;박재현;정동원
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.05a
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    • pp.257-257
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    • 2004
  • 자동차, 항공. 선박, 가전, 건축 및 방위 산업 등 현대 사회의 핵심 기간산업은 제품의 대부분을 금속 판재를 이용하여 제품을 생산한다 따라서 향상된 물성 특성을 갖춘 금속 판재를 이용함으로써 기존 제품의 성능을 더욱 향상시킬 수 있다 이러한 관점에서, 현대 사회는 에너지 자원이 점차 고갈되어 가고 있고 소비자의 기호 수준이 향상되어 고성능의 제품을 요구하고 있으므로, 높은 에너지 효율성과 구조의 안정성 및 신뢰성을 동시에 만족시킬 수 있는 초경량 고강도 재료 개발이 활발히 진행되고 있다.(중략)

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무인등대 탈·부착형 소형 풍력발전시스템 연구

  • O, Myeong-Gong;Gang, Chil-Se
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2014.10a
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    • pp.362-363
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    • 2014
  • 항로표지는 선박의 안전한 항해를 도와주는 해상 교통에 매우 중요한 시설이다. 등대(무인등대, 등표)는 야간에 등화로 항로의 안전 수역과 암초 등 장애물의 위치를 표시하기 위하여 무인 섬이나 간출암 등에 설치하는 구조물이며, 해상이라는 특수적인 운용환경으로 인하여 높은 수준의 신뢰성과 안정성이 요구된다. 무인등대용 풍력발전기는 강한 바람에도 발전기가 파손 되지 않고 운영 될 수 있도록 내구성이 있어야 하나 설치운영 결과 해상의 기상악화, 돌풍, 해풍 등에 의한 잦은 파손 및 고장 발생으로 이에 대응할 수 있는 제품 개발이 필요하다.

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A study on a ballast optimization algorithm for onboard decision support system (선내탑재 의사결정지원 시스템을 위한 발라스트 최적화 알고리즘에 관한 연구)

  • Shin Sung-Chul
    • Journal of Navigation and Port Research
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    • v.29 no.10 s.106
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    • pp.865-870
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    • 2005
  • Because there are only a limited number of means of action that are available for the master to pursue in the event of flooding, onboard decision support system has been required. The majority of systems activated during a flooding emergency (such as watertight and semi-watertight doors, bulkhead valves, dewatering pumps etc.) almost exclusively aim to restore a sufficiently high level of subdivision to prevent flooding from spreading through the ship. Even though assuming the flooding scenario is not catastrophic, the use of ballast tanks can be an additional and very effective tool to ensure both prevention of flooding spreading and also improve ship stability. This paper describes an optimization algorithm devised to choose the set of ballast tanks that should be filled in order to achieve an optimal response to a flooding accident.

New Practical and Eco-friendly Recycling method of FRP Boats (FRP선박의 재처리시스템과 활용성 연구)

  • Yoon, Koo-Young
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.10 no.3
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    • pp.181-186
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    • 2007
  • Despite of environmental problems(safety hazards), mechanical recycling of FRP boats, which involves shredding and grinding of the scrap FRP in a new product. is one of the simpler and more technically proven methods than incineration or reclamation ones. Because FRP is made up of reinforced fiber glass, it is very difficult to break into pieces. It also occurs secondary problem such as air pollution and unacceptable shredding noise level. The another urgent problem which is a serious barrier to FRP recycling is very limited reusable applications. This study is to propose a new method which is efficient and environment friendly waste FRP regenerating system. And it also have shown the polymer cement and fiber-reinforced concrete applications with the waste FRP.

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Design and Measured Data Analysis of a Shipboard Indoor Signal Propagation Characteristics Based on Three Way Signature Sequence Packet Mode (세방향 서명 수열 패킷 방식 기반 선내 전파 전달특성 측정시스템 설계 및 분석)

  • Kim, Jeong-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.1
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    • pp.193-197
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    • 2015
  • Recently, the new issues for the safety and the information delivery system in the ship are raised. The deployment and the efficient algorithms of deploying the wireless sensor networks instead of using the built-in wired networks or the setup of the new wired networks is more desirable than the deployment of the wired networks in a ship after its final production since it can reduce the cost and the time of the brand new wired networks by reshaping some of the internal structure of the ship. In this paper, the shipboard signal propagation measurement system based on the signature sequence-three way slave mode are designed and its measureed data are analysed after measuring the signal propagation characteristics. Consequently, it is expected that the reliable and cost-effective signal measurement system with the three way algorithm for the deployment of the shipboard wireless networks can be achieved.