• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.8
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• pp.935-943
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• 2012

In accidents involving the collision of railway vehicles, there is a risk that structural members might penetrate the cab frame of the railway vehicle in the space in which the driver or passengers are seated. To reduce this risk, worldwide, studies on the collision of railway vehicles are underway. In North America, the Code of Federal Regulations (CFR) was revised in 2010 to include crush criteria for a collision and the corner post in an end frame. In this study, a crush analysis and crush test for a collision post and a crash analysis for a rigid cylinder were performed according to the CFR. The analysis and test results were compared and reviewed. This study aims to determine the usefulness of crush analysis for developing various end frames, and to understand the crush and crash characteristics and review the accuracy of the analysis.

• Journal of Space Technology and Applications
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• v.2 no.1
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• pp.13-29
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• 2022

Recently, the number of space objects around the Earth has increased rapidly, necessitating systematic space risk management. This paper proposes a dual-mode framework for assessing the risk of collision between space objects. The proposed framework consists of microscopic and macroscopic modes. The former focuses on one-to-one collision events, and the latter assesses the overall collision risk inside a cell located in space. Two risk assessment case studies using the proposed two modes demonstrate the effectiveness of the proposed framework.

• 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 Navigation and Port Research Conference
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• 2018.11a
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• pp.231-233
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• 2018

부산항은 "한진 해운 파산"과 같은 불확실한 해운 상황에도 불구하고 2017년도 2,000만 TEU 이상 물동량을 처리하였다. 선박 생산성 또한 높은 수준으로 세계에서 가장 바쁜 터미널 6위를 달성하였다. 우리는 이러한 높은 수준을 유지하기 위하여 고객에게 생산성뿐만 아니라 고품질의 안전성 또한 제공하여야한다. 부산항 'A' 터미널에서 발생한 지난 3년간의 사고 데이터를 분석하여 어떤 장비가 가장 많이 사고를 발생하였고 어떤 위험점이 가장 높은지를 위험성 평가기법으로 알아보고, 이러한 사고를 미연에 방지하기 위한 방안을 보우타이 기법을 활용하여 제시하고자 한다. 실증자료를 분석한 결과 터미널 내의 이동장비 중 야드 트랙터의 충돌사고가 가장 높은 것으로 나타났다. 안전한 부산항을 만들기 위하여 우리는 가장 먼저 야드 트랙터의 충돌사고 예방법 (Control measure)과 사고 발생 시 대처방안 (Recovery measure)을 철저히 준비하여 사고를 미연에 방지하여야 할 것이다. 본 연구의 결과는 관련 실무에 다양한 시사점을 제공하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.07a
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• pp.18-20
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• 2015

In ports of Korea, the marine traffic flow is congested due to a large number of vessels coming in and going out. In order to improve the safety and efficiency of these vessels, South Korea is operating with a Vessel Traffic System, which is monitoring its waters 24-7. However despite these efforts of the VTS (Vessel Traffic System) officers, marine accidents are occurring in their assigned districts and it is made a danger situation every 20minute. On this paper, we listened to Busan VHF channel for 3days and applied to collision risk model. With collision risk model, We deducted a moment which advise or recommend to vessel. We suggested a collision risk model as VTSO support system.

• 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.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.06a
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• pp.120-122
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• 2014

선박의 조타기 작동 신호를 AIS를 통하여 전달함으로써 상대선박의 변침의도를 신속히 파악하여 충돌위험을 피할 수 있는 선회조기감지시스템을 구현하고 실선실험을 통하여 그 실효성을 검증하였다. 또한, 실선실험을 통해 선박의 타각정보가 AIS를 통해 송 수신이 가능하다는 것을 확인하였으며, ECDIS에 표시된 타각정보는 주변선박의 충돌회피에 크게 기여할 것으로 판단된다. 선회조기감지시스템은 선박의 안전운항을 위한 정보 제공의 필요성, 선박 통항량 증가 및 고속화 등으로 인한 위험성 증대로 VTS관제의 역할이 더욱 중요시 되고 있는 상황에서 선박의 조타각이 표시된 해당 시스템을 활용할 경우 변침상황을 보다 신속히 파악할 수 있으므로 관제가 보다 쉬워질 것으로 예상된다. 또한, 선박의 침몰이나 VDR의 소실로 인한 해양사고 분석의 어려움도 AIS를 통한 조타신호가 저장된 해양안전종합정보시스템(GICOMS)의 분석을 통해 다소 해소될 것으로 판단된다.

• Journal of Navigation and Port Research
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• v.41 no.3
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• pp.93-102
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• 2017

When VTSOs (Vessel Traffic Service Operator) determine the degree of collision risk for two vessels, they consider comprehensive information about each vessel's course, speed, DCPA, TCPA, and encountering situation. In this study, we proposed a utility function based on the risk attitudes of VTSOs toward the Risk Index (RI). The RI was calculated using the risk of encounter, the risk of approach, and the risk of time for two vessels in order to predict each ship's collision risk from the VTS viewpoint. We obtained each coefficient of the RI and the risk attitude through a survey of collision risks among VTSOs of Korea. In order to verify whether the proposed utility is reasonable, we validated by applying the degree of collision risk to some historical cases of accidents in Busan port along with the Ship of ES value($ES_S$) of ES(Environmental Stress) model.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.22 no.4
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• pp.224-229
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• 2010

Collision fragility analysis of offshore bridge by ship was performed. Collision velocity and angle were chosen as random variables then collision of 18,000DWT and 30,000DWT ships with bridge was analyzed. Displacement response surface of bridge by ship collision was estimated by varying ship velocity from 2 m/s to 7 m/s. Using the result of reliability analysis, fragility curves of collision was established and risk of offshore bridge to collision velocity as median and log-standard deviation was presented.

• Journal of Navigation and Port Research
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• v.39 no.3
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• pp.199-207
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• 2015

In ports of Korea, the marine traffic flow is congested due to a large number of vessels coming in and going out. In order to improve the safety and efficiency of these vessels, South Korea is operating with a Vessel Traffic Service System, which is monitoring its waters for 24 hours. However despite these efforts of the VTS (Vessel Traffic Service) officers, collisions are occurring continuously, the risk situation is analyzed that occurs once in about 20 minutes, the risk may be greater. It investigated to reduce these accidents by providing a safety standard for collision danger in a timely manner. Thus, this study has developed a risk prediction module to predict risk in advance. This module can avoid collision risk to adjust the speed and course of ship using a risk evaluation model based on ship operator's risk perspective. Using this module, the ship operators and VTS officers can easily be identified risks in complex traffic situations, so they can take an appropriate action against danger in near future including course and speed change. To verify the effectiveness of this module, this paper predicted the risk of each encounter situation and confirmed to be capable of identifying a risk changes in specific course and speed changes at Busan coastal water.