• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2020.11a
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• pp.39-41
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• 2020

충돌 회피를 위한 위험도 평가에서 CPA 계산은 핵심 요소이며, AIS의 도입 이후 AIS 정보를 이용한 CPA 계산이 필수적으로 활용되고 있다. 본 논문에서는 CPA 계산에 이용되는 AIS 정보와 실제 특성을 확인하고, 선박 위치 추정에 관련된 선행 연구들을 분석하며, 이를 가상 디지털 항로 표지 서비스에 적용할 방안을 강구한다, P. Last 등의 연구는 ROT의 중요성을 강조하고 있으나, 대부분의 선박이 필요로 하는 정확한 ROT 값을 전송하지 못하고 있는 상황을 확인했고, Ling-Zhi Sang 등의 연구는 4가지 요소를 반영한 간단한 식으로 구현하여 전 해역의 데이터로 비교한 결과 2가지 요소만을 적용한 방법에 대한 정확도의 향상을 확인할 수 없었다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.8
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• pp.688-695
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• 2014

In a small wireless environment, such as your home or office, a various network using WiMedia PHY can be mixed. Because these networks operate independently for each application, data conflict can occur between adjacent networks. To avoid data conflict, the resource in a different time zone can be utilized. However, if devices in a network increase, available resources in the network decrease, and then the lack of resources necessary to provide service can occur. To solve this problem, we propose collision avoidacne scheme for coexistence of various UWB systems. In this paper, we evaluate the performance of the proposed scheme through simulation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.10a
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• pp.261-262
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• 2012

In this research, intelligent protection system for laser boat is introduced. The function of system is to measure the distance and velocity of object from our boat and generate control signals to avoid collision with moving targets. A novel approach to estimate object's position from our ship is tackled on this paper. To do this laser sensors are used to measure distance from ship to targets. The ship position and velocity is estimated by th Kalman filter algorithm. In the real phase, the filtering method will be applied to process signal gathered by laser sensors. Simulation to estimate ship's position and velocity under noise are executed and the results are introduced to show the effectiveness of the algorithm.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.477-479
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• 2012

최근 선박의 사고가 증가하고 해양 환경오염 문제가 대두되면서 운항 중인 선박을 대상으로 하는 다양한 안전운항 솔루션에 대한 필요성이 요구되고 있다. 안전운항 솔루션은 일반적으로 육상과 선박을 연결하는 광대역 무선 데이터 통신기술, 해상 데이터를 처리할 수 있는 메타데이터 기술, 안전운항을 지원하는 서비스의 요소 기술로 구성된다. 본 논문에서는 광대역 애드혹 통신망을 기반으로 하는 선박의 안전 입출항 지원 서비스의 항목을 정의하고, 이를 구현하기 위한 서버 및 클라이언트 시스템에 대하여 기술한다. 본 연구의 안전 입출항 지원 서비스는 교통정보, 환경정보, 충돌회피지원정보로 구성되며, 선박에 탑재된 클라이언트에서 육상에 설치된 서버 시스템으로 서비스를 요청하고 정보를 제공 받도록 설계하였다. 이렇게 설계된 시스템은 테스트 플랫폼을 통해 서비스의 구현 가능성을 검토하며, 실해역(여수항)에서의 시험을 통해 그 실효성을 검증할 예정이다.

• Journal of the Korean Institute of Navigation
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• v.24 no.4
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• pp.235-246
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• 2000

인공 지능 분야에서 특히 퍼지와 같은 기술은 전반적인 산업 자동화에 많이 사용되어 왔다. 퍼지 제어는 인간의 추론 과정을 모델링한 기술로서 인간에 유사한 결정 능력과 복잡하고 다양한 환경에 매우 효과적이다. 본 논문은 이러한 퍼지 제어의 장점을 연근해의 선박 자동 항해에 적용시켜 보았다. 심해에서는 공간상의 제약이 없기 때문에 선박의 자동항해는 원하는 목표지점까지 안전하게 운항할 수 있지만, 연근해안에는 심해와 달리 각종 장애물들(작고 큰 섬들과 해안, 연근해에 작업중인 선박들)이 있으며 이것들로 인한 충돌사고가 종종 발생하고 있는 실정이다. 그러므로 연근해안에서 보다 안전하고 자율적인 항해를 위해 인공 지능 기술인 퍼지 기술을 선박에 적용시켰다. 본 논문에서 제안된 다변수 퍼지 시스템을 2개의 서로 다른 동적 환경을 가지는 지형에 적용시켜 보았고, 그에 따른 실험들을 수행했을 때, 만족할만한 결과를 얻을 수 있었다. 따라서, 본 논문에서 제안된 다변수 퍼지 제어시스템을 이용한 선박이 동적인 환경에서도 스스로 장애물을 인식하고 회피함으로 안전하게 연근해를 운항할 수 있음을 보였다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.918-927
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• 2022

The purpose of this study was to investigate the causes of collisions by examining 668 cases of merchant ship collision accidents that occurred during the past 12 years (2010-2021) and analyzed them statistically. Further, the analysis results were applied to propose a human error prevention collision avoidance (HEPCA) model. The statistical annual report of the Korea Maritime Safety Tribunal (KMST) and the collision investigation report were investigated to collect data on the causes of collisions of merchant ships, and frequency analysis was performed using the statistical analysis tool, SPSS Statistics. In the first-stage analysis, the causes of collisions were analyzed targeting 668 merchant ship collision accidents, and in the second-stage analysis, the identified maximum frequency cause factors were analyzed in detail. The analysis results identified that 98 % of the cause of the collision was the human error of the navigator, and the highest frequency was in the order of neglect of look-out > violation of navigation regulations > improper maneuvering. The cause of the neglect of look-out was mainly neglecting continuous monitoring after the first recognition of the target ship. The HEPCA model for human error prevention was proposed by applying the analysis results to the collision case of the investigation report. The results of this study are expected to be used as educational materials at marine navigator educational institutions and in practice for avoiding collisions caused by human errors of navigators.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.6
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• pp.644-655
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• 2020

This study focuses on the margin of human error when a navigator is embarrassed by the psychological fear of collision in a close-quarter situation (CQS) and is unable to perform as per the prescribed collision avoidance measures. The purpose of the study is to identify the effects of the navigator's personal characteristics or factors in relation to on-board career (OC), license rating (LR), and age on the perceived collision risk (PCR) in CQSs. In order to obtain quantified data regarding the collision risk perceived by the navigator in four typical CQSs between their own ship and a target ship, this study measured and collated the heart rate variability of 30 navigators on their own ship when two ships approached each other at a speed of 10 knots from 2.5 nautical miles to a collision situation. According to a multiple regression analysis of the measured values, the navigators' OC and LR factors had negative effects on the PCR, while the age factor had no significant effect on PCR. The t-test results showed that the PCR value was significantly higher for navigators with an OC ≤ 4 years than for those with an OC ≥ 5 years, and the LR factor was significantly higher for a class 4~6 group than for a class 2~3. This finding may be applied to the development of collision risk warning systems, particularly for navigators.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.1
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• pp.36-42
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• 2018

This paper considers the Marine Traffic Risk Assessment for fixed and moving targets, which threaten officers during a voyage. The Collision Risk Assessment Formula was calculated based on a dynamic ship domain considering the length, speed and maneuvering capability of a vessel. In particular, the Navigation Risk Assessment Model that is used to quantitatively index the effect of a ship's size, speed, etc. has been reviewed and improved using a hybrid combination of a vessel's dynamic area and the Collision Risk Assessment Formula. Accordingly, a new type of Marine Traffic Risk Assessment Model has been suggested giving consideration to the Speed Length Ratio, which was not sufficiently reflected in the existing Risk Assessment Model. The larger the Speed Length Ratio (dimensionless speed), the higher the CJ value. That is, the CJ value is presented well by the Speed Length Ratio. When the Speed Length Ratio is large, states ranging from [Caution], [Warning], [Dangerous] or [Very Dangerous] are presented from a greater distance than when the Speed Length Ratio is small. The results of this study, can be used for route and port development, including dangerous route avoidance, optimum route planning, breakwater width, bridge span, etc. as well as the development of costal navigation safety charts. This research is also applicable for the selection of optimum ship routing and the prevention of collisions for smart ships such as autonomous vessels.

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.1
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• pp.52-58
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• 2009

With the increase of marine traffic capacity, marine accidents have also been increased for recent several years. Especially watch officer must maneuver not entering into the safety minimum approaching distances when two power-driven vessels are crossing. The author calculated the safety minimum approaching distances to provide a navigator with them based on zig-zag motion by experimental ship. The obtained results are summarized as follows : 1. The greatest distance is to be kept by the give way vessel to avoid collision when the crossing course angle is $90^{\circ}$. In this case the safety minimum approaching distance must be more than from 5 times to 11 times of her own length according to her size. 2. The watch officer of the give way vessel must always take an action to avoid collisions outside of the safety minimum approaching distance. 3. When the navigator used rudder to small angle than to large angle to avoid other vessel he must take action outside the sufficient safety minimum outside distances in advance. 4. Risk of collision in crossing situation is more greater in obtuse situation than in acute one.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.2
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• pp.202-209
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• 2014

In this paper, a developed device for detecting target's location and avoiding collision is proposed. Velocity and acceleration model of target are derived to estimate target's information, i.e. position, velocity and acceleration considering process and measurement noise. Kalman filtering method applied to the estimation process and its results was confirmed by simulation. The distance measurements system using laser sensor for moving target system is also developed to confirm the effectiveness of the proposed scheme. Experiments to get information of moving target with velocity and acceleration model was executed. The data with filtering and without filtering was compared by experiments. Discontinuous measured data was changed to smooth and continuous data by Kalman filtering. It is confirmed that desired data was obtained by applying proposed scheme. UI for measuring and monitoring the target data is developed and visual and auditory alarm function is attached on the system Finally, position estimation system of moving target with good performance is achieved by low price equipments.