• Journal of Fisheries and Marine Sciences Education
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• v.28 no.2
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• pp.539-549
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• 2016

This study analyzed ship's passing characteristics in relation with incoming and outgoing routes in Yeosu Gwangyang Port, and examined the risk factors and measures for safety management of marine traffic. The number of passing ships in Yeosu Gwangyang Port was about 60,000 ships annually based on 2014, and the tonnage rose 73% from 447,000 thousand tons in 2005 to 770,000 thousand tons in 2014. Actually, the number of large passing ships was revealed to enormously increase. As a result of marine traffic survey in Yeosu Gwangyang Port for three days in August 2015, daily average passing ships were 408 ships, and 77% of the total passing ships passed between 04:00 and 20:00. The chemical ships and general cargo ships took up the most at 58% of the total incoming and outgoing ships, followed by other work ships at 21%, tankers at 8%, fishing vessels at 7.5% and container ships at 5.5%. Concerning the size of passing ships, ships less than 1,000 tons accounted for 58.6% of the total passing ships. Ships of 1,000-5,000 tons were 20.1%, and those of 5,000-10,000 tons were 6.8%, and more than 10,000 tons were 14.4%. Especially, ships of 500 tons and less using mainly coastal passing routes took up 49% of the total passing ships. As for ship's passage ratio by route, Nakpo sea area where many routes meet accounted for 27.2%, specified area 49%, costal route 8%, specified area's incoming and outgoing sea area around Daedo 4.5%, and Dolsan coastal ara and Kumhodo sea area 8.5%. The number of ships standing by for anchoring in the six designated anchorages was 230 for three days. The standby rate for anchoring was 25% based on the specified area passing ships. In Nakpo sea area, where many routes meet, parallel passing and cross passing between ships occurred the most frequently. In the specified area, many cases, in which incoming and outgoing cargo ships at the starting and ending parts and incoming and outgoing work ships and fishing vessels at the coastal routes cross, took place. Consequently, the following measures are urgently needed: active passing management in the Nakpo sea area, where passing routes are complex, specified areas and costal traffic routes, the elimination of rocks in the route close to Myodo, an effort to improve routes including shallow depth area dredging, and rational safety management for small work ships frequently incoming and outgoing the passing routes of large ships, and fishing vessels operated in the sea areas around those passing routes.

• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.413-419
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• 2019

Traffic routes typically have heavy traffic. Especially, the entrance of the route has a high risk of accidents occurring because of ships entering and exiting the port. However, almost of studies have focused on the distribution of traffic on the route. Thus, studies on the distribution between ships for passing through the route are insufficient. The purpose of this study was to analysis the traffic in the Busan north port No.1 route for one week. Based on present traffic conditions, one gate line was settled on the route with an analysis of traffic conditions. Based on the analysis data, each optimal time probability distribution between ships was divided into inbound/outbound and traffic volume. An analysis of the optimal probability distribution, was applied to 31 probability distributions divided into bounded, unbounded, non-negative, and advanced probability distribution. The KS test was applied for identifying three major optimal time probability distributions. According to the KS test results, the Wakeby distribution is the best optimal time probability distribution on the designated route. Although the optimal time probability distribution for other transportation studies such as on vehicles on highways is a non-negative probability distribution, this distribution is an advanced probability distribution. Thus, the application of major probability distribution for using other transportation studies is not applicable to this study Additionally, the distance between ships in actual traffic surveys and the distance estimated by the optimal probability distribution were compared. As a result of the comparison, those distances were fairly similar. However, this study was conducted in only one major port. Thus, it is necessary to investigate the time between ships and calculate a traffic volume on varying routes in future studies.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.2
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• pp.186-192
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• 2014

In this paper, we analysed vessel traffic volume and patterns of traffic flow for ships using areas where included wind farm site and adjacent waters of Daejeong Offshore Wind Farm, and estimated traffic volume by classified navigational routes according to suggestion of rational routeing measures on the basis of classified patterns after installation of offshore wind facilities. Also, we assessed vessel traffic safety for each designed routeing measures on the basis of estimated traffic volume and proposed requisite countermeasures for the safe navigation of ships. With a result of analysing patterns of traffic flow, the current traffic flow was classified by 8 patterns and the annual traffic volume was predicted to 8,975 ships. On the basis of these, expected the vessel traffic volume according to designed four routeing mesaures after installation of wind farm. As result of assessing vessel traffic safety by using powered-vessel collision model of SSPA on the basis of the estimated traffic volume, the value of collision probability was less than safe criteria $10^{-4}$. Thereby we made sure usability of the designed routeing measures for the safe navigation of ships.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.992-1001
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• 2022

The maritime traffic analysis has been conducted in various ways to solve problems arising from the complex marine environment. However, recent trends in the maritime industry, such as the development of the maritime autonomous surface ships (MASS), suggest that maritime traf ic analysis needs change. Accordingly, based on the studies conducted over the past decade for improvements, automatic identification system (AIS) data is mainly used for maritime traffic analysis. Moreover, the use of geographic information that directly af ects ship operation is relatively insufficient. Therefore, this study presented a method of using a combination of shape format data and AIS data to enhance maritime traffic analysis in preparation for the commercialization of autonomous ships. Consequently, extractable marine traffic characteristics were presented when shape format data were used for marine traffic analysis. This is expected to be used for marine traffic analysis for the introduction of autonomous ships in the future.

• 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 Navigation and Port Research
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• v.28 no.5
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• pp.413-420
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• 2004

The Busan New harbor will be opened by 2011, after which it is expected that the marine traffic volume around this area would Increase significantly and that very large ships such as 12,000 TEU container ships would come into the port. Therefore, it is necessary to build a new ships' routeing by considering these factors. In this paper, environmental circumstances, marine traffics, and the preceding studies have been reviewed and ships' routeing is proposed through experts' opinions and Delphi technique. For the purpose of validation, the proposed ships' routeings are reviewed by several guidelines on the ships' routeing and through simulation studies.

• Journal of Navigation and Port Research
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• v.42 no.2
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• pp.97-106
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• 2018

Despite the development of safety measures and improvements in preventive systems technologies, maritime traffic accidents that involve ships carrying hazardous and noxious substances (HNS) continuously occur owing to increased amount of HNS goods transported and the growing number of HNS fleet. To prevent maritime traffic accidents involving ships carrying HNS, this study proposes an intuitive route risk assessment technique using risk contours that can be visually and quantitatively analyzed. The proposed technique offers continuous information based on quantified values. It determines and structures route risk factors classified as absolute danger, absolute factors, and influential factors within the assessment area. The route risk is assessed in accordance with the proposed algorithmic procedures by means of contour maps overlaid on electronic charts for visualization. To verify the effectiveness of the proposed route risk assessment technique, experimental case studies under various conditions were conducted to compare results obtained by the proposed technique to actual route plans used by five representative companies operating the model ship carrying HNS. This technique is beneficial not only for assessing the route risk of ships carrying HNS, but also for identifying better route options such as recommended routes and enhancing navigation safety. Furthermore, this technique can be used to develop optimized route plans for current maritime conditions in addition to future autonomous navigation application.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.14 no.4
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• pp.288-294
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• 2014

Understanding a ship's present position has been one of the most important tasks during a ship's voyage, in both ancient and modern times. Particularly, a ship's dead reckoning (DR) has been used for predicting traffic situations and collision avoidance actions. However, the current system that uses the traditional method of calculating DR employs the received position and speed data only. Therefore, it is not applicable for predicting navigation within the harbor limits, owing to the frequent changes in the ship's course and speed in this region. In this study, planned routes were applied for improving the reliability of the proposed system and predicting the traffic patterns in advance. The proposed method of determining the dead reckoning position (DRP) uses not only the ships' received data but also the navigational patterns and tracking data in harbor limits. The Mercator sailing formulas were used for calculating the ships' DRPs and planned routes. The data on the traffic patterns were collected from the automatic identification system and analyzed using MATLAB. Two randomly chosen ships were analyzed for simulating their tracks and comparing the DR method during the timeframes of the ships' movement. The proposed method of calculating DR, combined with the information on planned routes and DRPs, is expected to contribute towards improving the decision-making abilities of operators.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.6
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• pp.473-481
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• 2023

In this study, a simulation system was developed to verify autonomous navigation algorithm in complex maritime traffic areas. In particular, real-world maritime traffic scenario was applied by considering near real-time maritime traffic information provided by Korean e-Navigation service. For this, a navigation simulation system of Unmanned Surface Vehicle (USV) was integrated with an e-Navigation equipment, called Electronic Chart System (ECS). To verify autonomous navigation algorithm in the simulation system, initial conditions including initial position of an own ship and a set of paths for the ship to follow are assigned by an operator. Then, considering real-world maritime traffic information obtained from the service, the simulation is implemented in which the ship repeatedly travels by avoiding surrounding obstacles (e.g., approaching ships). In this paper, the developed simulation system and its application on verification of the autonomous navigation algorithm in complex maritime traffic areas are introduced.

• Journal of Navigation and Port Research
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• v.27 no.6
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• pp.645-652
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• 2003

A virtual vessel traffic control system is introduced to contribute to prevent a marine accident such as collision and stranding from happening. Existing VTS has its limit. The virtual vessel traffic control system consists of both data acquisition by satellite remote sensing and a simulation of traffic environment stress based on the satellite data, remotely sensed data And it could be used to provide timely and detailed information about the marine safety, including the location, speed and direction of ships, and help us operate vessels safely and efficiently. If environmental stress values are simulated for the ship information derived from satellite data, proper actions can be taken to prevent accidents. Since optical sensor has a high spatial resolution, JERS satellite data are used to track ships and extract their information. We present an algorithm of automatic identification of ship size and velocity. It lastly is shown that based on ship information extracted from JERS data, a qualitative evaluation method of environmental stress is introduced.