• Journal of Navigation and Port Research
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• v.42 no.4
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• pp.277-282
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• 2018

Recently, the Vessel Traffic Service (VTS) coverage has expanded to include coastal areas following the increased attention on vessel traffic safety. However, it has increased the workload on the VTS operators. In some cases, when the traffic volume increases sharply during the rush hour, the VTS operator may not be aware of the risks. Therefore, in this paper, we proposed a new method to recognize ship movement anomalies automatically to support the VTS operator's decision-making. The proposed method generated traffic pattern model without any category information using the unsupervised learning algorithm.. The anomaly score can be calculated by classification and comparison of the trained model. Finally, we reviewed the experimental results using a ship-handling simulator and the actual trajectory data to verify the feasibility of the proposed method.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.402-409
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• 2016

Vessel traffic servies (VTS) control movements in ports and coastal areas 24 hours a day using VHF. Thus, we were able to check ship movements and the patterns followed by VTS officers in VTS areas using VHF communication analysis. This study is intended to identify control intervals for dangerous situations and provide VTS officers with basic data and guidelines to prevent these occurrences in advance. We listened to Busan port's VHF communication for seven days and obtained risk values using the Park model with reference to controlled ships. The probability of a dangerous situation arising under a controller's watch per unit of time was confirmed to follow a Poisson distribution. As a result, for each 3.50 hours that VTS directly controls an area, (and in daytime for each 2.85 hours) a ship communicates in a VTS area every 3.84 hours, and some of there communications exceed certain risk values in VTS areas.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.1
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• pp.70-77
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• 2005

This paper studied the feasibility for utilization of the automatic fishing information recording system, which stores and manages navigational information and fish catch results of a fishing vessel in a portable storing device, in order to help promote the systematic management of fishing information by offshore and coastal fishing vessels. Position accuracy was within 10 meters on the position accuracy experiment using GPS module. Characteristics of navigation according to the navigation, anchoring and fishing operation showed the difference of navigation track information for GPS, and fishing possibility of fishing boat could be estimated through the analysis as the utilization result of system for the large pair trawl and large purse seiners. In particular, it is impossible to provide false positional information by arbitrarily operating the system, and it may be possible to present the factual results of fish catch by date, fishing ground, and fish species by comparing the fishing information with fish catch. Such contents are considered to be useful as basic data for the management of fisheries resources.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.2
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• pp.69-74
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• 2017

These days as there are a growing vessel volume in the costal area, the marine accidents has being increased. IMO recommend that all vessels have to be equipped with the safety equipments mandatorily for the safety navigation. Almost medium and large size vessels are equipped with the safety navigational equipments, But many small size vessels are not equipped with those ones because of its owner's financial hardship or indifference. So for the safety of small size vessels in the coastal area, the marine accidents such as stranding, sinking, collision, and so on, have to be protected in advance or the occurred accidents has to be treated quickly. In this paper, the safety equipment for small size vessels having these functions has been developed. This equipment can guarantee the safety of small size vessels in defenseless state considerably by displaying these states in seamen's Smart phone or the cheap dedicated terminal and also informing the control center and nearby other vessels of these states.

• International Journal of Naval Architecture and Ocean Engineering
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• v.5 no.1
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• pp.116-131
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• 2013

The resistance performance of an icebreaking cargo vessel in pack ice conditions was investigated numerically and experimentally using a recently developed finite element (FE) model and model tests. A comparison between numerical analysis and experimental results with synthetic ice in a standard towing tank was carried out. The comparison extended to results with refrigerated ice to examine the feasibility of using synthetic ice. Two experiments using two different ice materials gave a reasonable agreement. Ship-ice interaction loads are numerically calculated based on the fluid structure interaction (FSI) method using the commercial FE package LS-DYNA. Test results from model testing with synthetic ice at the Pusan National University towing tank, and with refrigerated ice at the National Research Council's (NRC) ice tank, are used to validate and benchmark the numerical simulations. The designed ice-going cargo vessel is used as a target ship for three concentrations (90%, 80%, and 60%) of pack ice conditions. Ice was modeled as a rigid body but the ice density was the same as that in the experiments. The numerical challenge is to evaluate hydrodynamic loads on the ship's hull; this is difficult because LS-DYNA is an explicit FE solver and the FSI value is calculated using a penalty method. Comparisons between numerical and experimental results are shown, and our main conclusions are given.

• Journal of Navigation and Port Research
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• v.47 no.4
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• pp.212-219
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• 2023

Vessel Traffic Service (VTS) area presents a complex traffic pattern due to ships entering or leaving the port to utilize port facilities, as well as ships passing through the coastal area. To ensure safe and efficient management of maritime traffic, VTS operators continuously monitor and control vessels in real time. However, during periods of high traffic congestion, the workload of VTS operators increases, which can result in delayed or inadequate VTS services. Therefore, it would be beneficial to predict traffic congestion and congested areas to enable more efficient traffic control. Currently, such prediction relies on the experience of VTS operators. In this paper, we defined vessel traffic congestion from the perspective of a VTS operator. We proposed a method to generate traffic networks using historical navigational data and predict traffic congestion and congested areas. Experiments were performed to compare prediction results with real maritime data (Daesan port VTS) and examine whether the proposed method could support VTS operators.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.2
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• pp.185-192
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• 2022

Fisheries is known as a high-risk industry in Korea, and various efforts have been made to reduce occupational accidents. Trap fisheries represent crustacean production, accounting for 4.7% of total fisheries production and 10.7% of its production value, which is classified as a relatively high-risk industry. With the disaster insurance payment data of the National Federation of Fisheries Cooperatives (NFFC) from 2016 to 2020, the accident rate of the entire fishery, the accident rate of trap fisheries, and the type of disasters in the past five years were analyzed. As a result, the average fishery accident rate for the past five years was 5.31%, but it was high at 6.15% for coastal trap fisheries and 5.59% for offshore trap fisheries. Slips and trips, struck by objects and contact with machinery were the most common types of the accident according to the characteristics of the work, and hand injuries were analyzed the most. Additional efforts, including education for accident prevention, development of personal protective equipment and improvement of the working environment, are needed to prevent accidents caused by repeated types of disasters.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.267-268
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• 2022

Jeju coastal waters are limited to high-risk areas due to the passage of international cruise ships, passenger ships, with a large number of people and fishing boats, or to the jeju port and the jeju civilian-military combined port and near by seas, so a VTS system will be established along jeju and seogwipo coast. There is no accurate standard for determining the number of people required by the maritime traffic control center. Therefore, this study calculated the required operating personnel for control seats on the coast of jeju and seogwipo by using VTS big data to efficiently calculate the workload of maritime traffic control. It is judged that this study can be used basic data for research that sets the standard for calculating the control workload.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.242-243
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• 2023

Different incident angles concerning ocean conditions and weather greatly influence small vessel navigation. Particularly for small vessels, different incident angles result in distinct motion characteristics closely related to stability. Based on actual coastal wave data, this study conducted simulations and experiments to analyze the motion characteristics of small vessels navigating in irregular waves. The analysis revealed that significant motions primarily occurred at lower speeds from the bow sea. In contrast, as the speed increased, the roll motions due to the bow sea decreased, but those due to the stern seas increased. Consequently, adjusting the incident wave angles according to vessel speed can enhance stability and navigational efficiency for small vessels.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.1
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• pp.47-52
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• 2011

On the high seas, under international law, a ship is subject to the jurisdiction of the state whose flag she flies. Vessels of any flag are free to navigate the high seas without interference from other states. Thus, there are certain limits of coastal state's exercising law enforcement jurisdiction over a foreign flag vessel on the high seas. However, there are exceptions to exclusive flag state jurisdiction. One of them is the theory of constructive presence. The other is theory of partial execution. Korea Coast Guard's law enforcement authority should be exercised more actively based on those theories supported by the international cases.