• Korean Journal of Construction Engineering and Management
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• v.20 no.4
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• pp.69-76
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• 2019

This paper presents a method that identifies the unsafe behaviors at the level of near-misses using image analysis. The method establishes potential collision hazardous area in earthmoving operation. It is implemented using a game engine to reproduce the dangerous events that have been accepted as major difficulty in utilizing computer vision technology to support construction safety management. The method keeps realistically track of the ever-changing hazardous area by reflecting the volatile field conditions. The method opens a way to distinguish unsafe conditions and unsafe behaviors that have been overlooked in previous studies, and reflects the causal relationship which causes an accident. The case study demonstrate how to identify the unsafe behavior of a worker exposed to an unsafe area created by dump trucks at the level of near-misses and to determine the hazardous areas.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.1033-1036
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• 2008

In this paper, the analysis of impact damage behavior of a reinforced concrete structure that undergoes both a shock impulsive loading and an impact loading due to the air blast induced from an explosion is performed. Firstly, a pair of multiple loadings are selected from the scenario that an imaginary explosion accident is assumed. The RC structures strengthened with glass fiber reinforced polymer (GFRP) composites are considered as a scheme for retrofitting RC wall structures subjected to multiple explosive loadings and then the evaluation of the resistant performance against them is presented in comparison with the result of the evaluation of a RC structure without a retrofit. Also, in order to derive the result of the analysis similar to that of real explosion experiments, which require the vast investment and expense for facilities, the constitutive equation and the equation of state (EOS) which can describe the real impact and shock phenomena accurately are included with them. In addition, the numerical simulations of two concrete structures are achieved using AUTODYN-3D, an explicit analysis program, in order to prove the retrofit performance of a GFRP-strengthened RC wall structure.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.5
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• pp.85-97
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• 2009

Continuous increase of traffic demand has caused confirmed congestion, fuel consumption, emission, safety, etc. as serious social problems at the present time. The Smart Highway Project has been conducted by the supervision of Ministry of Land, Transport and Maritime Affaire to solve such problems since 2007. The Smart Highway Project includes LDWS (Lane Departure Warning System), a system to prevent broadside collisions and accidents, as a sub-technology of road-vehicle associating technologies. This system warns drivers when their vehicle deviates from the lane where they are traveling at high-speed on the highway. In this paper, the LDWS was evaluated using CBA to analyze the socio-economic consequences. Estimated benefits include reduction of accidents and convenience of drivers. In addition, the economics according to the distribution rate is various when it comes to Lane Departure Warning Technology, the economics of both cases - positive scenario and negative scenario, which was analyzed. As a result, the Benefit-Cost ratio(B/C) of negative scenario showed 0.97 in 2020 and 1.36 in 2030 while B/C ratio of the positive scenario showed 1.04 in 2020 and 1.59 in 2030, which indicated that the higher distribution rate is, the higher the economics generates. Therefore, it is judged that the introduction of Lane Departure Warning Technology will result in high economics.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.661-670
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• 2007

In this study, collision accident scenarios are derived for crashworthy design of rolling stocks because the detailed guidelines to complement domestic safety regulations with respect to collision accidents of rolling stocks are under preparation. Through this study, several collision accident scenarios are broadly investigated for those of advanced countries like USA, UK and EU. Next, the basic engineering considerations which are necessary to derive the collision accident scenarios are reviewed and analysed in some details. Finally, two collision accident scenarios are derived considering the circumstances of domestic railroads.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.4
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• pp.305-310
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• 2016

This study identified necessary navigational support services to prevent accidents through an examination and a survey on the navigation and communication systems of non-SOLAS ships. The functional and operational requirements for the identified navigational support services were discussed accordingly. Among the navigational support services proposed are an Electronic Navigational Chart (ENC) service, a route planning service, an operation monitoring service, and collision prevention support services for ships in coastal areas. To facilitate the identified navigational support services, ship navigation system, shore supporting centre and maritime communication network were discussed as a digital infrastructure. The operational methode for the digital infrastructure were discussed in the service scenarios for ships carrying dangerous cargo, large ships over 200 meters in length and high speed passenger ships over 15 knots in speed. This study will facilitate the development of policies for the improvement of ship operation management in Korean coastal waters and will contribute to improving the navigational safety of non-SOLAS ships.

• Journal of the Korea Concrete Institute
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• v.26 no.4
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• pp.429-440
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• 2014

Since the World Trade Center and Pentagon attacks in 2001, terror, military attack, or man-made disaster caused impact, explosion, and fire accident have frequently occured on civil infrastructures. However, structural behavior researches on major Prestressed Concrete (PSC) infrastructures such as bridges, tunnels, Prestressed Concrete Containment Vessel (PCCVs), and LNG tanks under extreme loading are significantly lacking. Especially, researches on possible secondary fire scenarios after terror, bombing, collision of vehicles and vessels on concrete structures have not been performed domestically where most of the past researches related to extreme loadings on structures focused on an independent isolated extreme loading scenario. Due to the outcry of public concerns and anxiety of potential terrorist attacks on major infrastructures and structures, a study is urgently needed at this time. Therefore, in this study, the bi-directional prestressed concrete $1400{\times}1000{\times}300mm$ panels applied with 430 kN prestressing force using unbonded prestressing thread bars were experimentally evaluated under impact, fire, and impact-fire combined loadings. Due to test site restrictions, impact tests were performed with 14 kN impactor with drop heights of 10m and 3.5 m to evaluate impact resistance capacity. Also, fire and impact-fire combined loading were tested using RABT fire loading curve. The measured residual strength capacities of PSC and RC specimens applied with impact, fire, impact-fire combined loadings were compared with the residual strength capacity of undamaged PSC and RC specimens for evaluation. The study results can be used as basic research data for related research areas such as protective design and numerical simulation under extreme loading scenarios.

• Journal of Korean Society of Transportation
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• v.24 no.4 s.90
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• pp.93-101
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• 2006

The signalized intersections near highway-railroad grade crossing are operated without signal preemption in Korea when trains are approaching the crossing. This signal operation is very dangerous because queues from the intersection can extend back over the track, thereby creating the Potential for a serious vehicle-train accident. And the queues from the crossing can extend to the intersection with the normal signal operation while trains Pass the crossing. In this case the intersection is disrupted, and delay and the Potential for vehicle accident increase highly In order to improve the intersection performance and Protect the accident the crossings and intersections. signal Preemption designed to provide a special control mode should be implemented. In this study it was shown that intersection Performance near highway-railroad grade crossing improved using signal preemption. When signal Preemption is implemented at the test site, the delay was reduced by about 9sec/veh. Even though there were vehicle-train accidents at the crossing in all 30 simulations without signal preemption. there was no vehicle-train accidents at all when signal preemption is used.

• Journal of the Korea Concrete Institute
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• v.29 no.3
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• pp.237-248
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• 2017

Frequent terror or military attack by explosion, impact, fire accidents have occurred recently. These attacks and incidents raised public concerns and anxiety of potential terrorist attacks on important infrastructures. However, structural behavioral researches on prestressed concrete (PSC) infrastructures such as Prestressed Concrete Containment Vessel (PCCV) and Liquefied Natural Gas (LNG) storage tanks under extreme loading are significantly lacking at this time. Also, researches on possible secondary fire scenarios after terror and bomb explosion has not been performed yet. Therefore, a study on PSC structural behavior from an blast-induced fire scenario was undertaken. To evaluate the blast-fire combined resistance capacity and its protective performance of bi-directional unbonded PSC member, blast-fire tests were carried out on $1,400mm{\times}1,000mm{\times}300mm$ PSC specimens. Blast loading tests were performed by the detonation of 25 kg ANFO explosive charge at 1.0 m standoff distance. Also, fire and blast-fire combined loading were tested using RABT fire loading curve. The test results are discussed in detail in the paper. The results can be used as basic research references for related research areas, which include protective design simulation under blast-fire combined loading.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.2
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• pp.55-72
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• 2017

Autonomous Vehicles(AV) are considered as an alternative to solve various social problems. Many researches which are related to developing technologies and AV operations have been conducted vastly and on-going. However, there seem to be little studies on various influences of AI algorithm on driving installed in AV. This study aims to examine the impacts of the ethical decisions made by Utilitarianism-based AI in AV when the oncoming car crossed over the central line. It establishes scenarios about situation of encroaching a central line and analyzes traffic impacts of ethical decision made by AV. According to the results of the analyses, as th accident occurs, overall speed of traffic decrease. There is a negative impact on the traffic flow when AV made an Utilitarian-based ethical decision by changing the lane. However, when AV choose to collide head-on, there is a positive effect to relieve traffic flow with an assistance of CACC, equipped.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.10
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• pp.1860-1866
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• 2016

Helicopter-related collision accidents with structures mostly occur at landing, especially in a limited visibility environment, which necessitates some secondary equipment like a radar that can generate stationary clutter image. In this paper, we propose an algorithm that makes an image of stationary ground clutter in two dimensional range and azimuth angle domain. We present a mathematical model for the received signals from each clutter patch in the iso range ring and analyze their clutter and Doppler characteristics, assuming that a helicopter-borne radar has a rotational antenna. We propose a filter structure, which suppresses side lobe signal components while extracting a main lobe signal component, and suggest a solution for a problem stemmed from the filtering process. Finally, by conducting a simulation we show the performance of the suggested imaging algorithm on a two dimensional virtual scenario of the topographic clutter.