• Journal of Navigation and Port Research
• /
• v.43 no.3
• /
• pp.186-196
• /
• 2019

Berthing energy is majorly influenced by the berthing velocity. It is necessary to design an appropriate berthing velocity for each pier, since excessive berthing velocity can cause berthing accident causing damage to the ship and pier. In this study, as a statistical approach for berthing velocity, the probability distributions suitable for the berthing velocities were confirmed using the K-S test, the A-D test and the Q-Q plot. As a result, the frequency distribution of the berthing velocity was found to be suitable using the Weibull distribution as well as the lognormal distribution. Additionally, the predicted values obtained through estimation of the berthing velocity using the concept of probability of exceedance in this study is proposed as a reference of design berthing velocity. It can be observed that the design berthing velocity is set to be somewhat low so that it does not practically match with the reality. This study and its results can be expected to contribute to the development of a proper design velocity calculation method.

• Journal of the Korean Institute of Navigation
• /
• v.18 no.4
• /
• pp.33-47
• /
• 1994

On developing port system, the performance tests of system in relation to ship maneuver generally consists of the three parts: the channel transit, the manoeuvring in a turning basin and the docking/undocking. The quantifications of risk of an accident has priviously been difficult due to the low occurrence of accidents relative to the number of transits. Additionally, accident statistics could not be related port system because of the large number of factors contributing to the accident. such as human error, equipment failure, visibility, light, traffic. etc. In case of the channel transit, "Relative Risk Factor(RRF)" or "Relative Risk Factor for Meeting Traffic" was proposed as the as the measures derived to quantify the relative risk of accident by M.W.Smith. This factor measure the tracking performance, the turning performance and the passing performance at meeting traffic. On the other hand, the safety of berthing maneuver is not measured with a few evaluating factors as controlled due to complex controllabilites such as steering, engine, side thrusters or tugs. This work, therefore, aims to propose the evaluating measure by the Analytic Hierarchy Process(AHP). Six experimental scenarios were establised under the various environmental conditions as independent variables. In every simulation, the difficulty of maneuver was scored by captain and compared with AHP scores. The results show almost same and from which the weights of eight evaluating factors could be fixed. Additionally, the limit value of relative factor in berthing safety to six scenarios could be estimated to 0.11.e estimated to 0.11.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.26 no.2
• /
• pp.139-148
• /
• 2020

The most important factor affecting the berthing energy generated when a ship berths is the berthing velocity. Thus, an accident may occur if the berthing velocity is extremely high. Several ship features influence the determination of the berthing velocity. However, previous studies have mostly focused on the size of the vessel. Therefore, the aim of this study is to analyze various features that influence berthing velocity and determine their respective importance. The data used in the analysis was based on the berthing velocity of a ship on a jetty in Korea. Using the collected data, machine learning classification algorithms were compared and analyzed, such as decision tree, random forest, logistic regression, and perceptron. As an algorithm evaluation method, indexes according to the confusion matrix were used. Consequently, perceptron demonstrated the best performance, and the feature importance was in the following order: DWT, jetty number, and state. Hence, when berthing a ship, the berthing velocity should be determined in consideration of various features, such as the size of the ship, position of the jetty, and loading condition of the cargo.

• Journal of Navigation and Port Research
• /
• v.45 no.3
• /
• pp.95-101
• /
• 2021

Marine Incidents based on Heinrich's law are very important in preventing accidents. However, marine Incident data are mainly qualitative and are used to prevent similar accidents through case sharing rather than statistical analysis, which can be confirmed in the marine Incident-related data posted in the Korea Maritime Safety Tribunal. Therefore, this study derived quantitative results by analyzing the causes of marine incidents during berthing using various methods of statistical analysis. To this end, data involving marine incidents from various shipping companies were collected and reclassified for easy analysis. The main keywords were derived via primary analysis using text mining. Only meaningful words were selected via verification by an expert group, and time series and cluster analysis were performed to predict marine incidents that may occur during berthing. Although the role of an expert group was still required during the analysis, it was confirmed that quantitative analysis of marine incidents was feasible, and iused to provide cause and accident prevention information.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2017.11a
• /
• pp.36-38
• /
• 2017

The advent of the era of data age and advances inartificial intelligence technology has led to innovations in various business areas. In particular, many attempts have been made to improve the stability of the marine accident, which has not previously been applied by a data-drive approach. Most of the marine accidents happen at a time when the vessel isapproaching a port and preparing for berthing. Although the cause of the accident has many factors, it is often caused by the difficulties of communication between the ship navigator and the control center. In particular, communication in English makes difficulties for navigators, not English astheir first language. To do this, proper English conversation education forsailors is very important. In order to support the issue, this study presents data and framework for the development of a chatbot for ship safety education.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.30 no.2
• /
• pp.209-216
• /
• 2024

Four accidents occurred between 2020 and 2022 after car ferries built according to a coastal passenger ship modernization plan collided with other ships or came into contact with the dock when entering Jeju Port. Accidents primarily occurred owing to careless ship handling and drift by wind during ship handled by herself using bow and stern thrusters without tugboats. Accordingly, in this study, we analyzed the collision accident focusing on car ferry H and the critical wind speed at which the ship cannot be controlled using its own power, tugboat operation plan in increasing wind speed were proposed based on the power required for the ship to berth parallel to the pier without a tugboat considering the external force and moment generated while the ship is berthing. A analysis of the critical wind speed of car ferry H by relative wind direction when using tugboats or not according to the loading status and the berthing speed, showed that one tugboat should be used at the stern when the lateral wind speed is over 10 m/s and two tugboats should be used when the lateral wind speed is over 14m/s berthing at Jeju port.

• International Journal of Ocean System Engineering
• /
• v.1 no.4
• /
• pp.211-221
• /
• 2011

Tugboats are widely used near harbors to assist with various operations such as the berthing and deberthing of very large vessels and the towing of barges. Capsizing accidents involving tugboats occasionally take place when the tugboat makes rapid turns in harsh weather conditions. When there is little evidence suggesting how the accident occurred and when the crew members are missing, it is necessary to predict the time history of the towing vessel’s attitude and trajectory from its departure point to when and where it capsized, depending on various input parameters using a numerical simulation. In this paper, the dynamics of a tugboat and a towed barge in conjunction with the external force and moment were established, and the possible input parameters and operational scenarios which might influence the large roll motion of the tugboat were identified. As a result of analyzing the simulated time history of the excessive roll motion of the tugboat, it was found that roll motion can take place when the tugboat is situated on the crest of a wave and when it is pulled by a towed barge through a towing line. The main cause of the accident would be the parameters that primarily influence such situations. These are the wave parameters, course changing scenario, and the amount of tension.

• Annual Conference of KIPS
• /
• 2021.11a
• /
• pp.1364-1367
• /
• 2021

불량 방충재 납입 사건에 따른 방충재 관리의 중요성 및 선박 접안사고가 화두가 되면서 본 논문에서는 현재 방충재 점검 시스템과 그로 인해 발생하는 선박의 접안사고 위험에 대해 문제를 제기한다. 문제를 해결하기 위해 본 논문은 "스마트 방충재 로봇"을 제안하며, 제안하는 로봇의 기능은 다음과 같다. 첫째, 부두에 부착된 방충재의 상태를 실시간으로 확인하고, 전용 애플리케이션을 통해 방충재를 관리한다. 둘째, 방충재 교체 시 부두 위치에 따른 해상조건을 수집하여 적합한 방충재를 추천한다. 셋째, 방충재 손상 또는 선박이 제한 접안속도 초과 시 스마트 방충재 로봇을 투입하여 선박의 접안사고를 방지한다.

• Journal of Navigation and Port Research
• /
• v.45 no.1
• /
• pp.9-15
• /
• 2021

According to IMO, MASS is defined as a vessel operated at various levels independent of human interference. The safety navigation support service for MASS is designed to improve the safety and efficiency of MASS by developing public services on shore for ship arrivals/departures and for cargo handling. The safety navigation support service consists of a total of six types of services: autonomous operation, berthing/unberthing/mooring, cargo handling and ship arrival/departure service, PSC inspection, condition monitoring, and accident response support services. In order to support accident response service, the relative importance of a bridge navigational equipment was assessed by stratifying the navigation system to provide safe and efficient support services by objective judgment through specific and quantitative methods using AHP, one of decision-making methods used by an expert group. The survey was conducted by dividing the bridge navigational equipment into depth, location, and speed information. As a result of applying the AHP method, the importance of depth, location, and speed information was assessed. The relative importance of each equipment for providing location information was also assessed in order of Radar, DGPS, ECDIS, Gyro compass, Autopilot, and AIS. This was similar to survey results on the utilization of each operator's preference and its impact on marine accidents.

• Journal of Korea Port Economic Association
• /
• v.23 no.2
• /
• pp.109-120
• /
• 2007

The purpose of this paper is to verify the two problems(normalization for the different inputs and outputs data, translation invariant for the negative data) which will be occurred in measuring the seaport DEA(data envelopment analysis) efficiency. The main result is as follow: Normalization and translation invariant in the BCC model for measuring the seaport efficiency by using 26 Korean seaport data in 1995 with two inputs(berthing capacity, cargo handling capacity) and three outputs(import cargo throughput, export cargo throughput, number of ship calls) was verified. The main policy implication of this paper is that the port management authority should collect the more specific data and publish these data on the inputs and outputs in the seaports with consideration of negative(ex. accident numbers in each seaport) and positive value for analyzing the efficiency by the scholars, because normalization and translation invariant in the data was verified.