• Journal of Digital Contents Society
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• v.18 no.2
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• pp.393-401
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• 2017

As the importance of software in various industry areas has been increased, the number of accidents related to software safety are growing up. The key industries such as railroads, aviation and medicine, recommend IEC 61508 and international safety standards for their own to achieve functional safety and reduce the issues caused by that. For equipment of ship navigation, there are not any particular standards or guidance which Korean users can introduce as considering software functional safety. This article defines the procedure and outcomes of the risk analysis in order to secure software functional safety in marine navigational equipment and applies them to an echo sounder as a case study.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.4
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• pp.105-115
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• 1999

To develope the best optimized hull form, it has been generalized to evaluate the preliminary hull forms with the CFD tools in the initial stage of development and for this process it is needed to prepare various competent hull forms with high degree of fairness. In this paper, a modified shape variation method was developed to maintain the shape and fairness of parent hull form and the automatic update procedure was implemented on the basis of the association concept. It was shown that the hull form of the high quality in fairness and shape inherited from the parent hull form can be archived.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.1 s.24
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• pp.33-38
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• 2006

In marine salvage, extreme tide heights and tidal currents are necessary to anchor an accidental ship. In order to meet this requirement, a simple scheme was developed which yields the spatial informations on the extreme tide from the distribution of approximate highest astronomical tide heights using a relationship between extreme and highest astronomical tides at the standard port. This method is the inference method based on horizontally homogeneity of tide. This scheme was applied to estimate extreme tide heights and tidal currents in the Namhae (southern sea of Korea). The highest astronomical tide heights are computed by amplitude of four major constituents (M2, S2, K1, O1 tide). The estimated extreme tide heights are ranged from 70 to 260 cm for return period 50 years and from 80 to 270cm for return period 100 years, respectively. For return period 100 years, extreme tidal currents show value of 1.55 times as strong as those of normal state.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.2
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• pp.228-233
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• 2014

In this paper, the motion performance in waves for the training ship Kaya of Pukyong National University is obtained by using a computer program based on Strip method. To guarantee the pleasant seafaring in ocean, the vertical acceleration of ship motion is calculated according to the location of the ship. The results of calculation by changes of ship speed are compared with the guideline of MSI(Motion Sickness Incidence). The degree of motion sickness is shown and discussed through the comparison between calculated vertical acceleration spectrum and MSI guideline. The computational results of MSI were as follow; when ship speed increased in the order of 5 knots, 10 knots, 12 knots and encounter angle became the bow quartering sea of $120^{\circ}$ compared to $180^{\circ}$ and $150^{\circ}$, the vertical acceleration values grew higher.

• Journal of the Korea Society for Simulation
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• v.20 no.3
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• pp.119-127
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• 2011

Overhaul and repair service means the sequential processes of disassembly, repair and reassembly for a product which has been used for a long time. Overhaul is required for the companies producing airplanes, ships, trains, military weapons and heavy industrial equipments which are very expensive and have a long life cycle. The most important performance measure of the overhaul repair shop is usually the lead time. Thus, how to design the manufacturing system to meet the delivery date is a major concern in overhaul repair shop. This paper introduces the case study of an overhaul repair shop producing military weapon systems with the 3D simulation tool, $QUEST^{TM}$. At first, the characteristics of overhaul shop and what should be considered for simulation modeling are explained. Then, various simulation scenarios including two types of disassembly systems, one is flow line system and the other is cell system, are discussed with the results of simulation experiments.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.4
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• pp.98-105
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• 2011

수리가능 제품은 가격 비싸고 중요성이 크면서 새 제품을 구매하기 어려운 부품을 의미하며, 항공기 또는 선박의 엔진 등을 들 수 있다. 수리가능 제품에 대하여 고장이 발생할 경우 가용성을 유지하기 위하여 즉지 교체하여야 하고, 교체된 부품은 수리에 들어가야 한다. 이러한 문제에 대한 통제 시스템은 시스템의 효율성을 결정하는 중요한 요소이기 때문에, 다양한 시스템 구성에 대하여 많은 연구가 이루어져 왔다. 본 연구에서는 우선 중앙 수리기지와 여러 지역 수리기지를 대상으로 하고 있으며, 물류량의 변화에 따라 중앙 수리기지와 지역 수리기지 간의 효과적인 운영 방안을 고려하고 있다. 각 지역 수리기지는 수리 운영 능력이 제한되어 있는 것으로 가정하고 있으며, 한정된 수의 여분의 제품을 유지하고 있다. 중앙 수리기지는 여분을 제품을 보유하거나 유지하지 않고 오직 수리 작업만을 수행하고 있다. 유한 가동에 대한 효율적인 알고리즘은 이러한 상황에 대하여 운영 능력의 한계를 고려하면서 효율성을 최대화하기 위하여 개발되었다. 지역 수리기지에서는 제품의 고장이 발생하는 속도와 현재 보유한 제품 수량에 따라 효율성이 바뀌고, 시스템이 보유할 수 있는 재고량과 수리할 수 있는 능력의 한계가 제한되어 있다. 대기행렬이론에 기반하여 고장율과 수리율에 의한 비용 함수를 정의하고, 최적해를 구할 수 있는 IMES(지능형 다단물류 시스템)을 개발하였다. 총 예상 재고량에 의한 재고 비용과 품절 비용을 최소화함으로써 최적의 보유 재고수량을 찾아내고 실제로 사용자가 활용할 수 있는 시간 내에 해를 구할 수 있는 효율성을 갖춘 알고리듬을 개발하였다. 본 연구의 목적은 전체 시스템의 총비용을 최소화하는 것이며, 예제를 통하여 알고리듬을 묘사하고 수치예제를 통한 실험을 실시하여 제안 알고리듬이 정확하고 효율적임을 보였다. 제안된 알고리즘에 의하여 매우 정확하고 효율적인 계산 결과를 얻을 수 있었으며, 이 방법을 통해 신속하고 정확하게 많은 문제를 해결할 수 있을 것으로 생각된다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.858-866
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• 2019

In line with the transformation of the shipping industry, the number of mixed-manning ships is on the rise - bringing foreign sailors aboard with their local sailors. During on-board work, a culture is formed according to mixed-manning, which leads to changes in on-board living environment. This causes various problems such as communication problems, and lack of education and training. In order to identify and solve problems caused by mixed-manning, this study presented a plan for systematic education of foreign seafarers. The officials in charge of the affairs of foreign sailors conducted questionnaire surveys at various shipping lines. The questionnaire survey results were analyzed using the IBM SPSS Statistic 26 program. Three improvement measures were proposed to solve the problems after identification of the types of education, education methods, and problems of foreign employees. This study revealed that it is imperative to systematize related education of foreign seafarers based on the results of the survey.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.447-455
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• 2005

Intra-block remarshalling is the task of rearranging into some target bays those containers which are scattered within around the block. If multiple transfer cranes installed in the block are all used together we may be able to complete the remarshalling task as early as possible. However, when multiple cranes are used simultaneously, there may occur significant delays if we do not carefully consider interferences between the cranes at the time of scheduling. Especially, delays caused by interferences occur more frequently in case of using non-crossing cranes. This paper presents an efficient heuristic method for assigning moves of containers to each crane and for determining an appropriate container moving order in a manner sensitive to the interferences. Simulation experiments have shown that the proposed method can effectively reduce delays in various environments.

• Journal of Navigation and Port Research
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• v.40 no.3
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• pp.89-95
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• 2016

S-Mode is a concept involving a standardized navigation display with accompanying standardized functionality and interfaces for navigational equipment. It was proposed by the International Federation of Shipmasters' Associations at IMO NAV $54^{th}$ session in 2008. The IMO e-Navigation Strategy Implementation Plan(SIP) addresses, S-Mode and the IMO MSC at its $95^{th}$ session in 2015 approved an output 1 to develop S-Mode guidance. In this study, it has been carried out survey of user needs for adopting S-Mode guideline on ECDIS which is core navigational equipment. It is conducted with a questionnaire survey, targeting deck officers and masters who will be the primary users of the equipment related to the e-Navigation system. In this research, users' opinion survey regarding the necessity of development, the scope of standardization, and priorities was conducted. This survey result could be contributed to development S-Mode guideline and specify the concept of S-Mode. It would be derived from standardizing component through providing elements to be considered for its development.

• Journal of Navigation and Port Research
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• v.35 no.5
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• pp.351-358
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• 2011

Recently, tugs and barges have become larger in size and increased in number. Also, most of tugs and barges are more than ten-years old. Total number of marine accident has been decreased, whereas that of accidental happening in tug-barge transportation has not been decreased. The statistics of marine accidents in 2010 shows that tug-barge accidents increased rapidly compared with those of 2009. The cause of accidental happening in tug-barge transportation is a quality of tug-barge operator the labour serious shortage of crew. This study is to give or suggest the various educational contents considering old age of crew and navigational environment for safe navigation in tug-barge transportation.