• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.9
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• pp.885-892
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• 2015

In this study, we simulate the railway crash accident that occurred at the Sangwangsimni station on the Seoul Metro Line #2, and we propose a solution to minimize the damage. We use LS-DYNA, which is the commercial software employed for collision analysis to perform 1-D and 3-D simulations for the recurrence of accidents. By performing 1-D simulations, we analyze the load, displacement, absorbed energy of the couplers, and acceleration of vehicles, and we evaluate the safety in accidental collisions. By performing 3-D simulations, we analyze the deformation of the car and over-ridding. We propose methods to improve the safety in collisions involving railway vehicles, and we perform collision accident simulations to determine improvements when applying a high-performance energy absorber to the front car.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.5
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• pp.445-454
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• 2020

Non-breakaway crashworthy sliding posts move rigidly with a vehicle in the early stage of vehicle impact. During this stage, a vehicle imparts its linear momentum to the post, experiencing first-stage speed loss followed by second-stage loss from the crush of the energy-absorbing pipe (EAP) installed under the guide rail. An EAP is the key element of a crashworthy sliding post and should be confined to the post foundation. This paper covers the development of an EAP for a sliding post of 507 kg, which is a sliding post type frequently used in Korea for cantilever signs. Detailed explanations of the designs for an EAP structure using LS-DYNA impact simulation are given, and the crashworthiness of the systems are confirmed through crash tests. The EAP presented in this paper can accommodate impacts from 0.9 ton-60 km/h to 1.3 ton-80 km/h, and is applicable to foundations up to 2.7 m in length.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.3
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• pp.123-134
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• 2006

In this study ship collision risk analysis is performed to determine the design vessel for collision impact analysis of the maritime bridge. Method II which is a probability based analysis procedure is used to select the design vessel for collision impact from the risk analysis results. The analysis procedure, an iterative process in which a computed annual frequency of collapse(AF) is compared to the acceptance criterion, includes allocation method of acceptance criterion of annual frequency of bridge component collapse. The AF allocation by weights seems to be more reasonable than the pylon concentration allocation method because this AF allocation takes the design parameter characteristics quantitatively into consideration although the pylon concentration allocation method brings more economical results when the overestimated design collision strength of piers compared to the strength of pylon is moderately modified. From the assessment of ship collision risk for each bridge pier exposed to ship collision, a representative design vessel for all bridge components is selected. The design vessel size varies much from each other in the same bridge structure depending upon the vessel traffic characteristics.

• 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.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.06a
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• pp.51-53
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• 2014

항해사가 타선과의 충돌위험 인지 및 피항을 위한 Radar/ARPA 교육훈련은 오래전부터 STCW협약에 의하여 각 해양계열 및 수산계열 교육기관에서 실시되는 교과목명, 교육시간, 교육내용이 상이한 것으로 조사되었다. 하지만 각 교육기관에서 발행한 이 교육훈련과 관련한 증서는 동일한 효력을 가지고 있다. 이에 Radar/ARPA 교육훈련 내용의 세부사항이 표준화될 필요가 있으며, 최저 평가에 대한 표준도 필요할 것으로 판단된다. 본 연구는 Radar/ARPA 교육환경 개선 및 시나리오 개발, 실습노트, 평가 툴(Tool)에 대하여 개선하고자 하여 이들을 개발 제안하여 이 교육훈련의 효율적인 교육방안을 위한 기본적인 표준모델을 개발하고자 한다.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.30-32
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• 1999

본 논문에서는 자원제약을 목적함수로 하여 파이프라인 실행이 가능하게 하는 데이터패스 합성을 위해 개발되어진 스케쥴링 알고리즘들의 실행시간과 실행결과를 도표를 기준으로 정렬한다. 평가의 대상이 되는 알고리즘들은 스케쥴을 위해 제안되는 함수의 계산시점, 함수의 역할과 적용방법에 의해 구분되어지는 논문 [1],[2],[3]에 대하여 수행되어지며, 충돌을 발생시키는 파티션 내에 위치하는 모빌리티를 가지는 각각의 연산에 대해 다음 파티션으로의 지연시 충돌수 변이와 각 연산의 모빌리티를 요소로 계산되는 우선 순위 함수를 정의하여 스케쥴 순열을 정렬하는 결정하는 논문[1]과 자원 할당 가능성 판단함수를 제안하고 이를 기준으로 배정가능 범위를 축소해 나가며 연산을 스케쥴하는 논문[2]와, 논문[2]의 자원할당 가능성 판단시 부과되는 시간감소를 위해 현재의 스케쥴 상황 값들을 정량화 하여 연산이 선택되도록하여 결과적 실행 시간을 감소시키는 논문[3]에 대하여 벤치마크 성능평가와 알고리즘 실행시간 결과 비교를 수행하고 향후 연구 진행 방향을 제시한다.

• 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.

• Journal of the Society of Naval Architects of Korea
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• v.32 no.1
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• pp.103-117
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• 1995

A design-oriented method for analysis of the structural damage due to ship collisions is developed by using the idealized structural unit method(ISUM). The method takes into account yielding, crushing, rupture, the coupling effects between local and global failure of the structure, the influence of strain-rate sensitivity and the gap/contact conditions. The method is verified by a comparison of experimetal and numerical results obtained from test models of double-skin plated structures in collision/grounding situations with the present solutions. As an illustrative example, the method has been used for analyses of a side collision of a double-hull tanker. Several factors affecting ship collision response. namely the collision speed and the scantlings/arrangements of strength members, are discussed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.4A
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• pp.311-321
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• 2011

To analysis the effect of reinforcement ratio and impact velocity on local damage, a series of impact analyses are performed to predict local effects. According to these results, the reinforcement ratio has no effect on the penetration depth and perforation thickness, but notable change to the scabbing area were observed. The higher the missile velocity becomes, the greater the degree of local damage to the reinforced concrete slabs is. Analysis results will be useful in the impact-resistance design of containment buildings and structures.

• Journal of the Korea Convergence Society
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• v.9 no.10
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• pp.249-255
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• 2018

This paper presents a human-centered control algorithm for personalized autonomous driving based on the integration of inverse time-to-collision and time headway. In order to minimize the sense of difference between driver and autonomous driving, the human-centered control technology is required. Driving characteristics in case that vehicle drives with the preceding vehicle have been analyzed and reflected to the longitudinal control algorithm. The driving characteristics such as acceleration, inverse time-to-collision, time headway have been analyzed for longitudinal control. The control algorithm proposed in this study has been constructed on Matlab/Simulink environment and the performance evaluation has been conducted by using actual driving data.