• 한국해양공학회지
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• 제29권6호
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• pp.418-426
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• 2015

Recently, shipping operators have been making efforts to reduce the fuel cost in various ways, such as trim optimization and bulb re-design. Furthermore, IMO restricts the hydro-dioxide emissions to the environment based on the EEDI (Energy Efficiency Design Index), EEOI (Energy Efficiency Operational Indicator), and SEEMP (Ship Energy Efficiency Management Plan). In particular, ship speed is one of the most important factors for calculating the EEDI, which is based on methods suggested by ITTC (International Towing Tank Conference) or ISO (International Standardization Organization). Many shipbuilding companies in Korea have carried out speed trials around the Korea Straits. However, the conditions for these speed trials have not been exactly the same as those for model tests. Therefore, a ship’s speed is corrected by measured environmental data such as the seawater temperature, density, wind, waves, swell, drift, and rudder angle to match the conditions of the model tests. In this study, fundamental research was performed to evaluate the ship resistance performance due to changes in the water temperature and salinity, comparing the ISO method and numerical simulation. A numerical simulation of a KCS (KRISO Container ship) with a free-surface was performed using the commercial software Star-CCM+ under three conditions that were assumed based on the water temperature and salinity data in the Korea Straits. In the simulation results, the resistance increased under low water temperature & high salinity conditions, and it decreased under high water temperature & low salinity conditions. In addition, the ISO method showed the same result as the simulation.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2013년도 춘계학술대회
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• pp.198-200
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• 2013

최근 국제해사기구(IMO)의 해양환경보호위원회에서(MEPC)는 선박에서 대기로 방출되는 CO2의 양을 최소로 하기 위해서 신조선 설계 건조시 에너지효율지수(EEDI : Energy Efficiency Design Index for new ships), 에너지 효율지표(EEOI : Energy Efficiency Operational Indicator), 그리고 에너지 효율관리 계획(SEEMP : Ship Energy Efficiency Management Plan) 지수들을 이용하여 전 세계 이산화탄소 배출 규제 방침을 운영하고 있다. 이러한 환경규제 강화와 발맞추어 세계 각국은 지속적인 Green-ship의 개발과 저탄소 고효율 선박의 운항을 위해 연구와 노력한다. 본 연구에서는 선박이 움직이는데 있어 동력이 시작되는 부분과 그 힘이 전달되어 운항자의 의식이 반영되어 선체의 이동으로 이어지기까지 흐름에 대해 도식 및 수식으로 정리하였다. 그리하여 해상의 상태와 이에 따른 운항결정이 어떤 결과를 초래할 수 있는지 살펴보고 이 부분에서 운항효율을 증대시킬 수 있는 부분에 대해 모색해 보았다. 또한 엔진의 상태에 따른 연료 절감율에 대해 살펴보고 보다 경제적 운항을 위한 적정 RPM과 속도 등에 대해서 고찰해 보았다. 이 같은 정리를 통해 앞으로의 Echo-ship, Green-ship의 연구방향에 대한 초석으로 삼고자 한다.

• 대한조선학회논문집
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• 제61권1호
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• pp.19-28
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• 2024

Environmental regulations are becoming more stringent in response to climate change, especially concerning marine pollution caused by ship emissions. Large ships are adjusting by integrating technologies to reduce pollutant emissions and transitioning to eco-friendly fuels such as low-sulfur oil and LNG. However, small ships face space constraints for installing LNG propulsion systems and the risk of power depletion with pure electric propulsion. Consequently, there's growing interest in researching hybrid propulsion methods that combine electricity and diesel for smaller vessels. Hybrid propulsion systems utilize diverse energy sources, requiring an effective method for evaluating their efficiency. This study proposes employing Bond graph modeling to comprehensively analyze energy dynamics within hybrid propulsion systems, facilitating better understanding and optimization of their efficiency. Modeling of the ship's energy system using Bond graphs will be able to provide a framework for integrating various energy sources and evaluating their effects.

• 해양환경안전학회지
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• 제23권6호
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• pp.646-651
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• 2017

본 연구는 연안여객선사의 안전관리 운영 효율성을 분석하기 위한 기초연구로 적절한 안전경영지표 평가항목을 설계하고 연안여객선사를 대상으로 평가항목의 유효성을 검증하는데 목적이 있다. 이를 위해 먼저 연안여객운송사업자의 안전관리책임자, 공무원(선박검사관), 여객선 운항관리자 등으로 구성된 전문가 그룹을 통해 연안여객선사의 자발적 안전관리 활동을 평가하기 위한 5개의 평가항목과 14개의 세부 평가요인을 선정하고 사전검증 및 테스트를 통해 객관성을 제고하였다. 이 안전경영지표 평가항목을 이용하여 44개 연안여객선사에 대한 자발적 안전관리 수준을 평가하였다. 그리고 평가항목의 유효성을 검증하기 위하여 안전경영지표 평가항목 결과와 중대해양사고 비율을 비교분석하여 평가항목의 타당성을 확인하였다. 이를 통해 자발적 안전경영 수준이 높은 업체일수록 중대해양사고가 발생하지 않고 자발적 안전관리에 무관심하거나 소홀한 업체는 상대적으로 높은 중대해양사고가 발생하고 있는 것을 알 수 있었다. 이처럼 안전경영지표 평가항목 선정을 통해 연안여객선사의 안전관리 운영 효율성을 분석하는데 중요한 항목을 객관적인 관점에서 도출하였다. 따라서 향후 안전관리 효율성 분석을 위한 기초자료로 활용될 수 있을 것이다.

• 한국항만경제학회지
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• 제28권4호
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• pp.79-98
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• 2012

해운업의 효율성과 관련된 연구접근은 해상운송과 컨테이너 항만에 치우쳐 있어 선박관리업과 관련된 연구는 찾아보기 힘든 실정이다. 이러한 측면에서 본 연구에서는 국내주요 선박관리업 회사의 효율성을 비교 분석하여 효율성방안을 제시하는 것을 연구목적으로 하였다. 이를 위해 DEA를 통해 효율성 분석을 실시했다. 분석대상은 2011년 외국적선, 국적선으로 분류한 뒤 상위 매출액 10개 기업을 선정했다. 효율성 분석을 위해 관리선박 척수를 투입변수로 선정했으며, 선원 수, 매출액을 산출변수로 선정했다. 분석 결과, 외국적선의 해영선박 국적선의 범진상운, 대한해운, 에스티엑스마린서비스, 우림선박이 효율성 1.00으로 높게 분석되었으며 또한 BDI지수와 How Robinson Container Index의 3년간 연평균(2009~2011년)과 동기간 효율성과 매출액의 상관관계를 분석한 결과, 효율성 보다는 매출액이 해상운임지수에 탄력적인 것으로 나타났다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 추계학술대회
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• pp.253-260
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• 2004

해상 구간에서의 선박 운항과 관련된 단위 비용이 선박 대형화에 비례하여 감소한다는 규모의 경제에 근거하여 최근 8,000 TED급 선박이 운항을 개시하였고, 10,000 TED급 이상 초대형선(mega ship)이 설계 단계에 있다. 본 연구에서는 운항비, 항만비용, 피더 비용 등에 대한 실증분석을 통하여 대형선의 기항지 축소에 따른 경제성을 분석한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.296-300
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• 2003

The autopilot system targets decreasing labor, working environment improvement, service safety security and elevation of service efficiency. Ultimate purpose is minimizing number of crew for guarantee economical efficiency of shipping service. Recently, being achieving research about Course Keeping Control, Track Keeping Control, Roll-Rudder Stabilization. Dynamic Ship Positioning and Automatic Mooring Control etc. which compensate nonlinear characteristic using optimizing control technique. And application research is progressing using real ship on actual field. Relation of Rudder angle which adjusted by Steering Machine and ship-heading angle are non-linear. And Load Condition of ship as non-linear element that influence to Parameter of ship. Also, because the speed of a current and direction of waves, velocity and quantity of wind etc. that is disturbance act in non-linear from, become factor who make serv ice of shipping painfully. Therefore, service system of shipping requires robust control algorithm that can overcome nonlinearity. In this paper, Using fuzzy algorithm ,Design autopilot system of ship that could overcome the non-linear factor of ship and disturbance and examined result through simulation.

• 한국소음진동공학회논문집
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• 제21권8호
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• pp.761-767
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• 2011

Free and forced vibration analysis of the global ship structure using the 3-dimensional finite element(FE) method requires not only the specialized knowledge such as ship structure interacted with fluid, damping and various excitations due to propulsion system but also time-consuming manual tasks in FE modeling, analysis and response evaluation. As a result, the quality of the vibration analysis highly depends on engineer's expertise and experience. In this study, a framework system to improve the efficiency of global ship vibration analysis is introduced. The system promising the utilization of MSC/Patran and MSC/Nastran consists of various modules to support data management, FE modeling of ship structure and loading, input deck generation for free and forced vibration analysis, data extraction and evaluation of analysis results, and databases for FE models of marine diesel engines and vibration criteria. The system may be useful for pursuing standardization of uncertain analysis factors as well as reducing time, cost and human dependency in ship vibration analysis.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.779-784
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• 2011

Free and forced vibration analysis of the global ship structure using the 3-dimensional finite element(FE) method requires not only the specialized knowledge such as ship structure interacted with fluid, damping and various excitations due to propulsion system but also time-consuming manual tasks in FE modeling, analysis and response evaluation. As a result, the quality of the vibration analysis highly depends on engineer's expertise and experience. In this study, a framework system to improve the efficiency of global ship vibration analysis is introduced. The system promising the utilization of MSC/Patran and MSC/Nastran consists of various modules to support data management, FE modeling of ship structure and loading, input deck generation for free and forced vibration analysis, data extraction and evaluation of analysis results, and databases for FE models of marine diesel engines and vibration criteria. The system may be useful for pursuing standardization of uncertain analysis factors as well as reducing time, cost and human dependency in ship vibration analysis.

• International Journal of Naval Architecture and Ocean Engineering
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• 제9권5호
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• pp.537-551
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• 2017

In this paper, a two-phase flow solver $HiFoam^{(R)}$ has been developed based on the $OpenFOAM^{(R)}$ to predict resistance of a ship in calm water. The VOF method of $OpenFOAM^{(R)}$ was reviewed and a simple flux limiter was introduced to enhance the robustness of the solver. The procedure for predicting ship motion was modified by introducing Quasi-Steady Fluid-Body Interaction (QS-FBI) with least square regression to improve the efficiency. Other minor factors were considered as well in terms of the efficiency and robustness. The HiFoam was applied to KCS and JBC simulations to validate its efficiency and accuracy by comparing the results to experimental data and STAR-CCM+. The $HiFoam^{(R)}$ was also applied to various ships and it showed good agreements to the experimental data.