• Journal of the Korea Society for Simulation
• /
• v.18 no.2
• /
• pp.19-27
• /
• 2009

This paper addresses the berth allocation problem in naval ports. Navy vessels need various services such as emergency repair, missile loading, oil supply and many others while commercial vessels only unload and load container at the port. Furthermore, naval vessels have to shift frequently due to a limited capacity of the port. The objective of this paper is to minimize the total number of nesting vessels at the naval port. In other word, the objective is to maximize the total number of naval battleships engaging in the sea. A mixed integer programming(MIP) model is developed and experiments are conducted with ILOG CPLEX 11.0. We compare the computational results of the MIP model to the current scheduling approach by the ROK Navy. The results showed that MIP model performed well by minimizing the number of nesting vessels. and avoiding unnecessary shifts.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.7
• /
• pp.980-991
• /
• 2023

To prevent accidents near the quay caused by a ship, ports are generally designed and constructed through navigation and berthing safety assessment. However, unpredictable accidents such as ship collisions with the quay or personal accidents caused by ropes still occur sometimes during the ship berthing or mooring process. Automatic mooring systems, which are equipped with an attachment mechanism composed of robotic manipulators and vacuum pads, are designed for rapid and safe mooring of ships. This paper deals with a displacement and velocity measurement system for the automatic mooring device, which is essential for the position and speed control of the vacuum pads. To design a suitable system for an automatic mooring device, we first analyze the sensor's performance and outdoor environmental characteristics. Based on the analysis results, we describe the configuration and design methods of a displacement and velocity measurement system for application in outdoor environments. Additionally, several algorithms for detecting the sensor's state and estimating a ship's velocity are developed. The proposed method is verified through some experiments for displacement and speed measurement targeted at a moving object with constant speed.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.13 no.2 s.29
• /
• pp.141-146
• /
• 2007

In this study, we have investigated several input factors and output factors to maintain safety management of domestic shipping companies, and then have analyzed the efficiency of performance about each shipping companies' safety management system from 1998 year to 2004 year using DEA method. The result of analysis shows that the annual mean efficiency index of total companies tended downward every year. Analysis was that the cause was increase of the cost of repairing ship, the cost of ship's stores and idle day of ship while the number of marine accidents and sanctions of PSC, ship's insurances and P&I insurances was decreased.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 1999.06a
• /
• pp.93-98
• /
• 1999

톨루엔, o-크실렌등의 유기용제는 도료공업 등의 혼합용제와 기계부품의 세척등에 많이 사용되고 있다. 그러나 이들 물질들은 공정상의 제조, 저장, 처리과정 및 취급과 사용 중에 부주의로 인한 밀폐구역에서의 누출로 폭발과 화재사고가 자주 발생하고 있다. 97년 5월 $\Delta$$\Delta$조선소에서 건조 중이던 선박 기관실의 선체 탱크내부 도장작업 중 화재ㆍ폭발이 발생하였으며, 97년 10월 $\square$$\square$조선소에서 수리중이던 유조선의 Tank 내부와 pipe line에 체류중인 가연성 증기가 인화되어 화재ㆍ폭발사고가 98년 6월 김해시 소재 00공업(주)에서 솔벤트로 공작기계 부품을 세척하던중 가연성 증기가 인화되어 화재가 발생하였다. (중략)

• Proceedings of the Korea Information Processing Society Conference
• /
• 2014.11a
• /
• pp.613-616
• /
• 2014

오늘날 선박, 항공, 자동차산업 등의 복합화로 인하여 내장형 소프트웨어의 중요성이 크게 대두되고 있다. 중요도가 높아질수록 고장 현상 발생률이 증가하고 이에 따른 오류나 고장에 대한 영향도 급증 하기 때문에, 신뢰성이 그만큼 중요하게 되었다. 신뢰성은 ISO/IEC 9126, ISO/IEC 12119 등에서 기능성, 사용성, 효율성, 유지보수성, 이식성과 함께 언급되고 있다. 신뢰성의 부특성에는 성숙성, 오류허용성, 회복성, 준수성이 있고, 이에 따라 품질평가 항목 메트릭이 제시되어 있다. 그러나 신뢰성 평가 기준은 수리적 난해함과 데이터 수집에 관한 문제에 부딪혀 적용하는 데에 어려움이 따르는 실정이다. 이와 같은 문제점을 해결하기 위해, 각 세부 평가 항목에 대한 체크리스트를 가지고 품질평가 메트릭에 적용하였다. 또한, 기존에 제시되어 있는 대표적인 신뢰성 모델 두 가지 NHPP(Non-Homogeneous Poisson Process) Model과 Jelinski-Moranda Model을 성숙성과 오류허용성의 품질평가 메트릭과 연관시켜 효율적으로 신뢰성을 측정하는 방안에 대하여 모색하였다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2015.04a
• /
• pp.595-598
• /
• 2015

오늘날 선박, 항공, 자동차산업 등의 복합화로 인하여 내장형 소프트웨어의 중요성이 크게 대두되고 있다. 중요도가 높아질수록 고장 현상 발생률이 증가하고 이에 따른 오류나 고장에 대한 영향도 급증하기 때문에, 신뢰성이 그만큼 중요하게 되었다. 신뢰성의 부특성에는 성숙성, 오류허용성, 회복성, 준수성이 있고, 이에 따라 품질평가 항목 메트릭이 제시되어 있다. 신뢰성 평가 기준은 수리적 난해함과 데이터 수집에 관한 문제에 부딪혀 적용하는 데에 어려움이 따르는 실정이다. 이와 같은 문제점을 해결하기 위하여 품질평가 메트릭의 새로운 방안을 제시하였다. 기존에 제시되어 있는 대표적인 신뢰성 모델 두 가지 NHPP(Non-Homogeneous Poisson process) Model과 Jelinski-Moranda Model의 결과 값과 제시한 방법을 토대로 나온 결과 값을 비교하여 타당성을 입증한다. 기존의 난해한 방법을 이용하지 않고도 정확한 평가 결과를 얻을 수 있도록 하는 것이 본 연구의 목적이다.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.28 no.1
• /
• pp.44-52
• /
• 2016

Kelvin's (1887) theory that predicts position of ship wave crest can be applied only in deep water. Havelock's (1907) theory that predicts cusp locus angle can be applied in whole water depths but cannot predict the position of ship wave crest. In this study, using the linear dispersion fully, we develop the equations to predict ship wave crest in whole water depths and, using the developed equations, we predict cusp locus angle. We simulate ship wave propagation using FLOW-3D in the condition of Johnson's (1985) hydraulic experiment and find that the cusp locus angles predicted by the present theory are close to numerical results of FLOW-3D and hydraulic experimental data. We also simulate for various conditions and compare numerical results of distances between adjacent wave crests and values predicted by the present theory. For Froude number less than unity, the numerical results are close to the values predicted by the theory. For Froude number greater than unity, the constant value of $C_1$ which determines the distance between the ship and the first ship wave crest is almost equal to zero and the numerical results of distances between adjacent ship waves excluding the first ship are close to the values predicted by the theory.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.10
• /
• pp.140-148
• /
• 2019

Large cast iron structures are used in casings and pipes in shipsand chemical plants. Broken parts in the casings and pipescan result in failures even when stresses are below the yield strength of the part's materials. Fatigue failure of a large cast iron structure is inevitable due to the design constraints and low reliability of the material strength. A small structure can be repaired by welding, but a large structure cannot because it cannot be preheated slowly and uniformly. This study shows that a large structure can be repaired by a cold joint method using a crack repair screw. Large cast iron structures were manufactured by GC 300, and their design stress is below 3.5 MPa. The tensile strength on notched specimens repaired by crack repair screws was 8.2 MPa. Therefore, the safety factors of structures repaired by crack repair screws have a value above 2.3 and are considered to be high values.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.10
• /
• pp.2454-2460
• /
• 2013

So far, the port cargo handling capacity of general cargo was computed using simple formulae based on mathematical models. However, this simple calculation could not be able to reflect the reality. Thus, the simulation method was applied in this paper to overcome the limitation that the calculation method used in the past studies has. The process occurring from arrival to departure of a ship, which is reflecting the process rules of berth, was modeled to estimate the optimum level of handling capacity by using an example of the loading and unloading of an appropriated wharf at the harbor, and simulation was performed by developing the prototype. The actual processing capability of Mukho port was compared to the estimated capability calculated using the simulation method and the optimum level of capability could be computed by repeatedly simulating the input variable condition of the simulation prototype.

• Journal of Korea Port Economic Association
• /
• v.30 no.1
• /
• pp.175-194
• /
• 2014

Because the thawing of the Arctic ocean is slowly accelerating due to global warming, recently exploring resources in Arctic ocean and transporting resources by using the North Pole route have been getting spotlight. Since the original route transported by the Suez Canal from Korea to Europe could be shorten about 8,000km in distance(decreased about 38% compared to the original route), which means shortening about 10 voyage dates, it is expected to bring huge logistics cost reduction. Once the North Pole route is commercialized successfully, it would be one of the most important variables that affects future of Busan port and guides for economic development of Busan. Therefore, the purpose of this study is to analyze Busan port and the economic growth of Busan area by researching promising industry, based on the effect of freight transporting by the Northern sea route on the economy of Busan. For this study, questionnaire surveys and interviews were conducted for 64 people of experts in the shipping and port industry, relevant government, and academics. The survey finding shows that port logistics industry is a promising business in Busan in terms of its growth and competitiveness. It is necessary to develop feeder network facilities that prepare for commercialization of the Northern sea route as a short and medium term plan and provide professional manpower training in polar regions. Ship supply business would also play an important role. It is identified that revitalization of shipbuilding and ocean plant industry should be done in terms of Arctic business. With regard to the fishery industry it is found that modernization of fishery ship and development of fishery equipment used in polar areas should be carried out.