• Journal of the Korean Institute of Intelligent Systems
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• v.27 no.2
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• pp.113-118
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• 2017

Various studies on the method of ship collision risk assessment for alarm have been reported constantly, and the result of the studies is applied to navigation devices. However, it is known that navigators ignore or turn off frequent alarms from the devices of predicting collision risk, because they may avoid collisions in the most of situations. In oder to make the prediction of ship collision risk more useful, it is necessary to consider the customary actions of ship collision avoidance. This paper proposes a system of analyzing collision avoidance measures of ships according to the types of encounter and managing the avoidance history of each ship. The core module of the system is designed as a neuro-fuzzy based inference system, and the test of the module validates the proposed system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.1033-1036
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• 2013

A study about collision resolution is needed because huge file, video and multimedia information are transmitted to wireless LAN. CSMA/CR protocol guarantees fairness, but doesn't consider QoS. To practicalize CSMA/CR protocol in saturation fully-connected single hop network environments, this paper proposes method of collision compensation. previous CSMA/CR protocol chooses CR Slot only considering fairness, but this paper chooses front CR Slot for compensation of collision to station experiencing collisions. The station transmits jam signal and has channel priority of transmission. So transmitting efficiency and successful transmission probability rise. This proposed simple method can offer benefit to station experiencing collisions without additional hardware cost.

• Journal of Navigation and Port Research
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• v.33 no.1
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• pp.43-50
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• 2009

Recently, many maritime accidents have been increased and the collisions due to human error are given a great deal of proportions out of them We develop the Real-time Collision Risk Monitoring System (CRMS) for the navigational officers to cope with the emergency situation promptly and thus to reduce the probability of casualty. In this study, the risk of collision and grounding is evaluated by two kinds of method. The first method is based on Fuzzy algorithm, which evaluates the risk of collision between traffic ships. The second method is based on Environmental Stress (ES) Model, where the total risk of collision and grounding is evaluated by the environmental stress felt by human. The developed real-time CRMS has been installed to the ship handling simulator system and its capabilities have been tested through simulator experiments.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.1023-1030
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• 2021

Korea Maritime Safety Tribunal (KMST) statistics released in of 2019 indicated that most collision accidents involving small-size vessels with less than 20 gross-tonnage occur mainly due to operational carelessness, such as forward-looking negligence and unskilled vessel control. As an effective remedy, training and education for vessel operators are being strengthened to prevent accidents. However, collision accidents are increasing, and technical measures are continuously developed to reduce accidents caused by human factors. In this study, an avoidance algorithm and prototype of terminal-controller against collision between two nearby vessels was developed for implementation on relative navigation control by adopting WAVE telecommunication technology. Moreover, several sea trial tests were performed to verify the collision avoidance algorithm and control system using two fishing vessels for dif erent scenarios.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2020.11a
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• pp.179-180
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• 2020

해상교통을 모의하기 위해서는 주요 요소인 선박운항자의 인적요인에 대한 모델링 필요하며, 현실감 있는 해상교통 상황의 재현 및 예측을 위해 선박운항자 행동양식, 항해전문성, 항해오류 등을 모델링하여 반영하는 것이 필요하다. 본 발표에서는 에이전트 기반의 해상교통 시뮬레이션을 위해서 선박운항자의 충동회피를 위한 행동 분석를 수행했으며, 기초 데이터의 확보를 위해 설문조사를 실시하였다. 설문조사를 통해 분석된 정보를 이용하여 선박 충돌상황에서 선박운항자의 행동과 유사한 에이전트 기반의 항해행동 모델 개발현황을 소개하고자 한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.176-178
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• 2019

2019년 2월 28일 용호부두에서 러시아 화물선이 예선을 사용하지 않고 출항하면서 계류 요트와 1차 충돌하고 이어 2차로 광안대교와 충돌하였다. 선박의 진행에 따라 전심의 위치가 변하며, 특히 예선을 사용할 때는 전심의 위치가 달라지게 된다. 조선자가 예선의 도움을 받는 상황에서 의도하는 조종을 하기 위해서는 예선의 예항력의 크기와 전심의 위치 그리고 속력을 고려하여야 한다. 본 고에서는 예선지원여부와 접이안 자세에 따른 선박조종법을 소개하고, 안전조선 대책을 제시하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.6
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• pp.202-210
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• 2019

This paper evaluated the performance of passenger vehicles with an AEB(Autonomous Emergency Braking) for various pedestrian-vehicle collision situations. The experiment was conducted at a speed of 30-60km/h on a 2017 3,000cc vehicle using a range of collision scenarios. The results showed that the test vehicle stopped before crashing a pedestrian dummy under all scenarios at 30km/h. The test vehicle reduced the speed but crashed the pedestrian dummy in all scenarios at 40-60km/h. From the paired t-test, there was a speed difference from the AEB system at a significant level of 0.05. In addition, the percentage of speed reduction was quite different for each scenario tested. It was concluded that the current AEB system can prevent pedestrian collisions at speed of 30km/h, but cannot prevent collisions with pedestrians at speed of 40-60 km/h.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.1
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• pp.1-8
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• 2019

In December 2017, many collision accidents of small vessels, such as those between oil refineries and fishing boats, occurred near Yeonghung-do in Incheon. In order to prevent marine casualties from small vessels, the government is striving to improve the safety capabilities of ship operators by strengthening education and improving the working environment. They are providing education and refining training regulations for fishermen operating vessels under 5 tons. However, the situation includes certain vulnerabilities. In this study, we propose a collision prevention algorithm for small vessels using the Wireless Access in Vehicular Environments (WAVE) communication system, which is a new communication technique to prevent collisions with small ships. The collision avoidance algorithm used is based on DCPA/TCPA. Research analyses, simulation experiments and questionnaires have been conducted to define the criteria of DCPA/TCPA. As a result, the standard for DCPA was $8(L_a+L_b)$ and for TCPA was 2.5 min. Three different accident cases were selected, and this algorithm was applied to confirm alarm responses at certain times. This algorithm can provide information to the operators of small ships in advance to help them recognize potential collision situations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.3
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• pp.373-378
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• 2006

One of the biggest problems that should be solved in present RFID systems is a reduction of identification efficiency by the collision of singals between different tags. As the number of tags, which should be identified, increases over the size of allocated round, more slots experiences the collision between them. It can causes generation of tag collision assigning the fixed round size and so, allocated round size should be regulated properly. This paper proposes the algorithm which can reduce collision between tags, and allocate specific round size dynamically for efficient tag identification. After each round is finished, the reader allocates the round size dynamically using the collision information of the slot. All collision informations of the slot consists of the number of slots which came into conflict, tags which were realized properly without any conflictions and empty slots. We used slotted aloha algorithm as the collision detection algorithm and finally, checked that this could be used very usefully when this algorithm which was proposed effectively could not know how many number of tags were exisisted through the simulation in advance.

• Journal of Navigation and Port Research
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• v.45 no.6
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• pp.298-305
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• 2021

Identifying the effect of turning characteristics on collision avoidance for Maritime Autonomous Surface Ships (MASS) can provide a key to avoid the collision of MASS. The purpose of this study was to derive a method to identify the effect of turning characteristics, which can be changed by various rudder angles and the ship's speed, on collision avoidance. The turning circle was observed using a mathematical model of a 161-meter-long ship, and it was analyzed that the turning circle had an effect on collision avoidance through numerical simulations of collision avoidance for four collision situations of two ships. The evaluation results using the two variables, the minimum relative distance between two ships and the minimum time at the minimum relative distance, demonstrated that the rudder angle has a major influence on the change of the minimum relative distance, and the ship's speed has a major influence on the change of the minimum time. The evaluation method proposed in this study was expected to be applicable to collision avoidance as a measures in remote control of MASS.