• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.3
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• pp.287-297
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• 2019

The recent increase in crude oil trading has led to an increase in the workings of SPM for crude oil carriers. VLCCs generally encounter difficulty entering port due to limitations in terms of sea depth and maneuverability. The SPM is a system that allows mooring to the buoy located in the outer sea for such vessels. However, the buoy is more affected by relatively external forces because of their of shore location. Therefore, the safety assessment of SPM is particularly important as it can lead to large oil pollution disasters in the event of SPM accidents. Despite this, in the implementation of the Marine Traffic Safety Audit Scheme in Korea, there exists no guidance for SPM. In this study, a SPM mooring safety assessment is performed using OPTIMOOR, a numerical analysis program, so as to understand the mooring characteristics of SPM. As a result, it is confirmed that the tension of mooring lines and hull movement in the SPM are greatly affected by the encounter angles with external forces. In addition, it is found that the maximum tension of the mooring line is elevated as the water depth becomes shallower through sensitivity analysis. According to SPM characteristics, which has a large influence on the encounter angle, this study has proposed an amendment to setting criteria in the implementation of the Maritime Traffic Safety Audit Scheme which could improve the reliability and accuracy of mooring safety assessments.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.3
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• pp.227-233
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• 2011

Korea coastal area is highly potential dangerous zone of marine accident due to frequent ship's encounters. VTS center can't identify ship's information because of beyond VHF range. It is also difficult of us to efficiently manage vessel traffic beyond VTS control area, so that it can't prevent marine accident. Presently, korean government is conducting maritime traffic safety assessment according to enlargement of harbor & development of new port but do not have the system which provide danger of information depending on maritime traffic environment with real time. So it is necessary to develop evaluation index which can assess sea risk through the evaluation of maritime traffic environment. In this paper, on the basis of vessel navigator's risk consciousness, we carried out survey & statistical analysis vessel navigator's subjective risk depending on the LOA, crossing situation($045^{\circ}$, $090^{\circ}$, $135^{\circ}$), overtaking, head-on situation, encountering vessel's side, within or outside harbor, speed with other vessel(ex. same, fast or slow), speed difference with other vessel and distance with other vessel & propose basic expression to develop maritime traffic safety evaluation model. And by using this model, we can confirm that this proposing expression is suitable for domestic maritime traffic environment.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.9-16
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• 2017

As a preliminary study of enter or leaving traffic patterns of the Korea main port, port Management Information System (Port-MIS) data was used to check the volume of vessels entering and leaving the port of Busan, and three consecutive days from each seasons were selected for study. Selected 12-day General Information Center on Maritime Safety & Security (GICOMS) data was also used to analyze the traffic pattern in the main traffic lane of Busan port for dangerous goods carrier. Also, the distance between dangerous goods carriers and Oryukdo breakwater of east breakwater in the main traffic lane was analyzed. Collision probability was estimated using the cumulative probability distribution function of the normal distribution for the maritime traffic safety audit scheme based on the assumption that a ship's trajectory has a normal distribution for a section of the route. However, in case of entry or leaving thorough the Oryukdo breakwater and entry thorough the east breakwater, ship's sailing trajectories were revealed not to follow a normal distribution via regularity testing using a KS-test and SW-test. Especially in the north port, the tendency of the right side of the ship to pass was remarkable. It is desirable to develop a traffic model suitable for the characteristics of the port rather than to apply general traffic theories, and to apply this model to a maritime traffic safety diagnosis, so further research is needed.

• Journal of Navigation and Port Research
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• v.40 no.5
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• pp.257-263
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• 2016

Mombasa is the principle port of Kenya, serving inland countries in Eastern and central Africa. Mombasa port has undergone a massive infrastructure upgrade and dredging works with an expectation that more vessels and large post Panamax ships will be able to enter Mombasa port. Therefore, it is vital to carry out a marine traffic risk assessment in order to quantify the degree of navigation safety needed in the Mombasa approach channel and also to evaluate the navigation risk imposed on transit traffic by local ferry traffic. In this paper, a marine traffic risk assessment is carried out using the IWRAP mk2, Environmental Stress (ES) model, and the PARK model. Risk assessment results show that Likoni area has an unacceptable stress/risk ranking at 20.7% by the ES model and 38.89% by the PARK model. The IWRAP mk2 model shows that the crossing area has the highest risk of crossing collision and the area at the entrance to the inner channel has a high risk of grounding. The conclusions derived from this study will provide the basis for proposing the most effective countermeasure to improve navigation safety in the Mombasa approach channel.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.81-84
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• 2016

Mombasa is the principle port of Kenya, serving hinter countries in Eastern and central Africa. Mombasa port has undergone a massive infrastructure upgrade and dredging works with an expectation that more vessels and large post Panamax ships will be able to call at Mombasa port. Therefore, it is vital to carry out a marine traffic risk assessment so as to quantify the degree of navigation safety on Mombasa approach channel and also to evaluate navigation risk imposed on transit traffic by local ferry traffic. In this paper marine traffic risk assessment is carried out using IWRAP mk2, Environmental Stress model, and PARK model. Risk assessment results show that Likoni area has unacceptable stress/ risk ranking at 20.7% on ES model and 38.89% by PARK model. IWRAP mk2 model shows that crossing area has the highest risk of crossing collision and the area at the entrance to inner channel has a high risk of grounding. The conclusions derived from this study will provide the basis for proposing the most effective countermeasure so as to improve navigation safety in Mombasa approach channel.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.52-54
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• 2012

Saigon-Vungtau fairway is the main and the most important fairway of the major economic areas: Ho Chi Minh City, Dong Nai Province and Ba Ria-Vung Tau Province in Vietnam. In last 5 years, 80% of accidents happened on the fairway were caused by collision and contact/impact. This presentation study on marine traffic investigation in the adjacent of the fairway to find out problems related to marine traffic for improving Marine Traffic Safety Management in this area.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.3
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• pp.253-258
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• 2015

The purpose of this study is to find suitable probability distribution function of complex distribution data like multimodal. Normal distribution is broadly used to assume probability distribution function. However, complex distribution data like multimodal are very hard to be estimated by using normal distribution function only, and there might be errors when other distribution functions including normal distribution function are used. In this study, we experimented to find fit probability distribution function in multimodal area, by using AIS(Automatic Identification System) observation data gathered in Mokpo port for a year of 2013. By using chi-squared statistic, gaussian mixture model(GMM) is the fittest model rather than other distribution functions, such as extreme value, generalized extreme value, logistic, and normal distribution. GMM was found to the fit model regard to multimodal data of maritime traffic flow distribution. Probability density function for collision probability and traffic flow distribution will be calculated much precisely in the future.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.47 no.4
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• pp.428-434
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• 2011

To establish a vessel safety management system for improving the safety of vessel's traffic and preventing vessel's traffic accidents, the state of marine traffic in the Busan South Port was investigated and analyzed as preliminary survey of the countermeasures. As a result of the study, there are 1,158 vessels in a day, 48 vessels in an hour, and the maximum traffic is about 118 vessels between 16:00 and 17:00 hours everyday, which requires to establish and operate a traffic control system necessarily for ensuring vessel's traffic safety. Furthermore, passages of tanker, passenger ship, cargo vessel and government vessel showed to sail along main traffic lane to be obtained enough sea depth at the survey area. However, passages of fishing vessel and launch showed to sail freely at all survey area owing to outstanding maneuverability and a shallow draft. Some vessels of launch sailed along main traffic lane, but other vessels crossed to sail it. The passages to cross main traffic lane is higher the risk of collision. Therefore, safety measures are urgently needed for the operation of the Busan South Port management system and the prevention of marine pollution.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.75-75
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• 2017

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.2
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• pp.209-214
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• 2010

This study examined environmental condition, marine accidental data, marine traffic capacity and traffic flow, and fisheries zone status near Ulsan approaching water area. A questionnaire survey of marine traffic system was conducted on experts and users, and new plan was proposed. On the basis of the responses of experts and users to questionnaire, the essential factor of navigation danger and the essential factor of collision risk as well as the improvement plans were proposed. More efficient navigational fairway was set up through this study.