• 한국자동차공학회논문집
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• 제21권6호
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• pp.100-107
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• 2013

Although automotive safety technologies have been developed steadily, the efforts for pedestrian protection still seems to be insufficient. In a car-pedestrian accident, the structures such as the engine under a hood, the lower part of a windshield and the A-pillar are the major causes of fatal pedestrian injuries. Recently, there have been several studies on the active safety system to reduce the pedestrian injuries. The safety system consists of an active hood lift system and a pedestrian airbag. In this research, the safety performance of the active hood lift system and the pedestrian airbag is investigated by using the finite element method. The finite element model of the system is set up based on the head impact test, and the impact analyses are performed. The necessity and the usefulness of the safety system are verified.

• 한국항공운항학회지
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• 제23권2호
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• pp.1-6
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• 2015

The RSA is intended to prevent the following five types of events from becoming an accident: landing overruns, landing undershoots, landing veer-offs, takeoff overruns and takeoff veer-offs. The improved models are based on evidence from worldwide accidents and incidents that occurred during the past 27 years. The analysis utilizes historical data from the specific airport and allows the user to take into consideration specific operational conditions to which movements are subject, as well as the actual or planned RSA conditions in terms of dimensions, configuration, type of terrain, and boundaries defined by existing obstacles. This paper shows how to apply the improved models for Risk Assessment of Runway Safety Areas (Airport cooperative research program(ACRP) Report 50) into an airport and the outcome differences between the old models based on ACRP report 3-Analysis of aircraft overrun and undershoots for runway safety areas and the new models from ACRP report 50 in the specific airport.

• 한국생산제조학회지
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• 제18권4호
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• pp.410-416
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• 2009

In recent years, the rollover accident of large class of vehicles has become important safety issue. Even though the rollover form a small percentage of all traffic accidents, they have a fatal effect upon the driver and passenger. Among the traffic accidents occurred in driving, the rollover is the major cause of traffic fatalities. Therefore, it is required to develop the analytical and experimental techniques for predicting rollover propensity of vehicles and also to improve the vehicle suspension design in the viewpoint of rollover resistance. In this study, the parameter sensitivities for the roll angle of SUV suspension are analyzed, and then the determined design parameters are optimized by using the regression model function of the response surface methods. The analysis results show that the roll angle of the optimized vehicle is decreased as compared with the initial vehicle and also the rollover possibility is decreased when the roll rate of the front suspension is larger than the roll rate of the rear suspension.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 춘계학술대회 논문집
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• pp.71-76
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• 2004

선박의 충돌 또는 좌초 사고에 대응하기 위하여 위험 화물을 운반하는 선박의 경우 이중 선체를 채용하고 있으나 이중선체의 충돌 에너지 흡수 정도와 내판의 파단 여부를 효과적으로 판단하는 기준은 아직 연구 대상으로 남아 있다. 본 연구에서는 실제선박의 충돌강도 해석을 하기 위해서 상용해석코드인 LS-DYNA3D를 사용하고 다양한 시나리오에 따라 동적 해석을 수행하였다. 본 연구를 위하여 46K의 Chemical／Product Carrier를 해석 대상 선박으로 정하여 하중 조건과 충돌 속도를 달리하여도 Energy-Indentation, Force-Indentation에 관한 연구를 수행하였다. 본 연구를 통해 얻어진 결과 및 정의는 충돌 사고에서의 매커니즘과 충돌 강도 평가에 유익한 정보를 제공하게 될 것이라 판단된다.

• Structural Engineering and Mechanics
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• 제60권2호
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• pp.337-350
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• 2016

Even though extensive researches have been performed for steam explosion due to their complex mechanisms and inherent uncertainties, establishment of severe accident management guidelines and strategies is one of state-of-the arts in nuclear industry. The goal of this research is primarily to examine effects of vessel failure modes and locations on nuclear facilities under typical steam explosion conditions. Both discrete and integrated models were employed from the viewpoint of structural integrity assessment of steel components and evaluation of the cracking and crushing in reinforced concrete structures. Thereafter, comparison of systematic analysis results was performed; despite the vessel failure modes were dominant, resulting maximum stresses at the all steel components were sufficiently lower than the corresponding yield strengths. Two failure criteria for the reinforced concrete structures such as the limiting failure ratio of concrete and the limiting strains for rebar and liner plate were satisfied under steam explosion conditions. Moreover, stresses of steel components and reinforced concrete structures were reduced with maximum difference of 12% when the integrated model was adopted comparing to those of discrete models.

• International Journal of Aerospace System Engineering
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• 제3권2호
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• pp.22-25
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• 2016

This dissertation tried to analyze passenger behaviors after an accident with the possibilities of a variety of accidents open reflecting the phases of the times of increasing interests in safety of passengers as the use of means of transportation such as cars and airplanes is increasing. Because a lot of data on head-on collisions, broadside collisions and reverse side collisions have been gathered through lots of experiments and interpretations, I chose to study a relatively unfamiliar subject, dropping collision. For example, I tried to study passenger behaviors in seating position after a dropping collision in preparation for falling accidents due to recent frequently-occurring sinkholes, driver's carelessness or mechanical problems. I used MADYMO, passenger behavior interpretation program, and experimented with 2 meters high Drop Test device which I made in person to increase the reliability of the results. On the basis of these, I compared the real experiments with interpretations.

• 한국안전학회지
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• 제31권3호
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• pp.156-161
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• 2016

An accident of an ammonia tank pipeline at a storage plant resulted in one death and three injuries in 2014. Many accidents including toxic gas releases and explosions occur in the freezing and refrigerating systems using ammonia. Especially, the consequence can be substantial due to that the large amount of ammonia is usually being used in the refrigeration systems. In this study, offsite consequence analysis has been investigated when ammonia leaks outdoors from large storages. Both flammable and toxic effects are under consideration to calculate the affected area using simulation programs for consequence analysis. ERPG-2 concentration (150 ppm) has been selected to calculate the evacuation distance out of various release scenarios for their dispersions in day or night. For offsite residential, the impact area by flammability is much smaller than that by toxicity. The methodology consists of two steps as followings; 1. Calculation for discharge rates of accidental release scenarios. 2. Dispersion simulation using the discharge rate for different conditions. This proactive prediction for accidental releases of ammonia would help emergency teams act as quick as they can.

• 한국융합학회논문지
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• 제10권7호
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• pp.175-182
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• 2019

본 연구는 기계학습 기법 중 토픽 모델링을 활용하여 건설현장에서 발생하는 추락재해에 대한 토픽을 분류하고 각 토픽에 따른 재해요인을 분석하였다. 잠재 디리클레 할당 기반의 토픽 모델링을 적용하기 위해 텍스트 데이터의 전처리를 하였고 Perplexity 점수로 평가하여 모형의 신뢰성을 높였다. 각 토픽에서 공통으로 도출된 추락재해의 대부분은 소규모 사업장에 속한 일용직 작업자들에게 발생하였다. 추락재해의 대부분의 원인은 안전장비 미착용, 현장 정리 정돈 미흡, 안전장비의 성능 및 착용 상태로 인해 제대로 작동하지 않은 것으로 판단되었다. 추락재해를 예방하고 절감하기 위해서는 소규모 사업장에 맞는 안전교육과 작업장의 정리 정돈과 개인 안전장비의 적절한 착용 상태 및 성능을 확인하는 것이 중요한 것으로 도출되었다.

• 한국의료질향상학회지
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• 제27권1호
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• pp.2-9
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• 2021

Patient safety remains one of the most important health care issues in Korea. To improve patient safety, we have introduced concepts from the field of safety science such as the Swiss cheese model, and adopted several methodologies previously used in other industries, including incident reporting systems, root cause analysis, and failure mode and effects analysis. This approach has enabled substantial progress in patient safety to be made through undertaking patient safety improvement activities in hospitals that are systems-based, rather than individual-based. However, these methods have the shared limitation of focusing on negative consequences of patient safety. Therefore, the paradigm shift from Safety I to Safety-II in safety science becomes the focus of our discussion. We believe that Safety-II will complement, rather than replace, Safety-I in the discipline of patient safety. In order to continuously advance patient safety practices in Korea, it is necessary that Korea keeps abreast of the recent global trends and development in safety science. In addition, more focus should be placed on testing the feasibility of new patient safety approaches in real-world situations.

• Structural Engineering and Mechanics
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• 제82권2호
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• pp.233-244
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• 2022

Following a loss of control, the impact against a road barrier in a turn predominates among the most severe motorcyclist accidents. These road restraint devices can be equipped with a motorcycle screen, the function of which is to restrain the rider and minimize the consequences of the impact in terms of the severity of injuries. The performance of these screens is evaluated by the European normative procedure EN1317-8, which specifies the test conditions, based on one or two configurations. In practice, however, these impact conditions are very diverse, difficult to extrapolate from accident analysis and therefore poorly investigated. This study is interested in improving knowledge of these impact conditions in terms of impact speed, impact angle and particularly position of the rider. A finite element model has been developed to simulate the dynamic behavior of the rider from loss of control to impact on the screen. Statistical analysis of the results shows a high variability of the impact conditions, in particular with regard to the direction of turn (to the right or to the left). Some improvements are suggested in order to overcome the limitations inherent in standard procedures.