• 대한교통학회지
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• 제29권3호
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• pp.93-101
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• 2011

우리나라의 교통사고 발생현황은 2008년 기준 215,822건으로 예년에 비하여 소폭 감소하는 추세이나 주요 선진국에 비해서는 여전히 높은 수준이다. 그 중 단속류 시설에서 발생하는 사고는 보행자들이 직접적으로 차량에 노출되어 차대사람 사고의 비율이 높아 심각한 결과를 유발하기 때문에 이를 방지하기 위한 추가적인 고려가 필요하다. 이에 교통사고의 유형별로 영향을 미치는 인자를 분석하였다. 단속류 시설에서 교통사고는 크게 차대차 사고와 차대 사람 사고로 그 성격과 특성이 구분될 수 있다. 따라서 교통사고 유형을 크게 두가지로 구분하고, 2005년부터 2007년까지 서대문구에서 발생한 교통사고 자료 분석을 통해 교통사고의 심각도와 외생적 변수들간의 관계를 추정하였다. 본 연구에서는 단속류 시설에서 교통사고 유형별 요인을 구조방정식모형(SEM : Structural Equation Modeling)을 이용하여 도출해내고, 모형을 구축하여 유형별로 사고의 주요인들을 파악하여 비교하였다. 최종 모형에서 도출된 결론은 차대차 사고에서는 도로 요인이, 차대사람 사고에서는 환경 요인이 크게 영향을 미치고 있는 것으로 분석되었다.

• 한국안전학회지
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• 제24권2호
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• pp.94-99
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• 2009

This study deals with the traffic accidents at the 3-legged signalized intersections in Cheongu. The goals are to analyze the geometric, traffic and operational conditions of intersections and to develop a various functional forms that predict the accidents. The models are developed through the correlation analysis, the multiple linear, the multiple nonlinear, Poisson and negative binomial regression analysis. In this study, two multiple linear, two multiple nonlinear and two negative binomial regression models were calibrated. These models were all analyzed to be statistically significant. All the models include 2 common variables(traffic volume and lane width) and model-specific variables. These variables are, therefore, evaluated to be critical to the accident reduction of Cheongju.

• Nuclear Engineering and Technology
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• 제48권5호
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• pp.1140-1153
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• 2016

Since the inception of nuclear power as a commercial energy source, safety has been recognized as a prime consideration in the design, construction, operation, maintenance, and decommissioning of nuclear power plants. The release of radioactivity to the environment requires the failure of multiple safety systems and the breach of three physical barriers: fuel cladding, the reactor cooling system, and containment. In this study, nuclear reactor containment pressurization has been modeled in a large break-loss of coolant accident (LB-LOCA) by programming single-cell and multicell models in MATLAB. First, containment has been considered as a control volume (single-cell model). In addition, spray operation has been added to this model. In the second step, the single-cell model has been developed into a multicell model to consider the effects of the nodalization and spatial location of cells in the containment pressurization in comparison with the single-cell model. In the third step, the accident has been simulated using the CONTAIN 2.0 code. Finally, Bushehr nuclear power plant (BNPP) containment has been considered as a case study. The results of BNPP containment pressurization due to LB-LOCA have been compared between models, final safety analysis report, and CONTAIN code's results.

• 한국직업건강간호학회지
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• 제14권1호
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• pp.56-70
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• 2005

Objectives: The purpose of this study is to develop a linking model between industrial injury insurance organs and local organizations providing social welfare health services, for the activation of medical rehabilitation services for industrial injury patients. Method: Research design for this study was a multi-step research through literature review, field research, and group interviews with persons in charge, to compare local society-oriented medical rehabilitation programs. The term of researches Sep.1 ~ Nov. 30, 2004. Results: 1. Home nurses from Workers Accident Medical Corporation have been taken to be adequate to case managers, who link industrial accident insurance institutions to local society services for the activation of medical rehabilitation services for industrial injury patients. They have been chosen for case managers because they have richer understanding and experiences of objects of industrial accidents than any other specialists, and because they have proved to be able to provide direct home services as a specialist. We have established the center for case management affairs within the workers accident general hospital, organized the committee for case management with doctors in charge, doctors in rehabilitation, rehabilitation consultants, social welfare workers, physical therapists, and nurses, determined objects of case managements from those of long-term recuperation, and constructed a course of case management containing from case management plans to evaluation. 2. We have made files of community resources, and organized the council of industrial accident administration to have it in charge of the adjustment and linking of services in case management affairs. 3. Because there are inequality of community resources between areas, differences in experiences in and bases for linking, and disparity of core organizations with active linking in the system of linking between public and civil sectors, we have taken a system of linking between parallel organs to be the core. In our linking model, workers accident general hospital, hospitals designated for industrial injury, and rehabilitation hospitals are linked in parallel, inadequate long-term recuperation managers are trusted to an workers accident medical corporations through examination by the examination committee in Korea Labor Welfare Corporation, and are dealt with by the committee for case management. Of the hospitals designated for industrial accidents, those running a home caring center provide home caring services for the handicapped at home from industrial injury. 4. Workers Accident Medical Corporation take part in medical rehabilitation, and Korea Labor Welfare Corporation in vocational/social rehabilitation. Furthermore, in the model, the latter should construct a system for job opportunities through Internet portals and provide cyber vocational consultation and introduction. Conclusion: Improvement of systems is needed to apply the linking model to practical affairs. Because this model is centered for practical affairs, it should be put under the analysis of effects, and evaluation of its adequacy to practical application, and its effects and efficiency through experimental running in the 8 workers accident general hospital in Korea.

• Nuclear Engineering and Technology
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• 제51권8호
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• pp.1939-1950
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• 2019

The MELCOR code useful for a plant-specific hydrogen risk analysis has inevitable limitations in prediction of a turbulent flow of a hydrogen mixture. To investigate the accuracy of the hydrogen risk analysis by the MELCOR code, results for the turbulent gas behavior at pipe rupture accident were compared with CFX results which were verified by the American National Standard Institute (ANSI) model. The postulated accident scenario was selected to be surge line failure induced by station blackout of an Optimized Power Reactor 1000 MWe (OPR1000). When the surge line failure occurred, the flow out of the surgeline was strongly turbulent, from which the MELCOR code predicted that a substantial amount of hydrogen could be released. Nevertheless, the results indicated nonflammable mixtures owing to the high steam concentration released before the failure. On the other hand, the CFX code solving the three-dimensional fluid dynamics by incorporating the turbulence closure model predicted that the flammable area continuously existed at the jet interface even in the rising hydrogen mixtures. In conclusion, this study confirmed that the MELCOR code, which has limitations in turbulence analysis, could underestimate the existence of local combustible gas at pipe rupture accident. This clear comparison between two codes can contribute to establishing a guideline for computational hydrogen risk analysis.

• 한국가스학회지
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• 제7권1호
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• pp.10-18
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• 2003

도시가스시설에서 사고가 발생할 때 그 영향을 평가하는 방법론에 대하여 현실을 고려한 모델을 개발하였다. 즉 사건수목분석(ETA)을 통하여 발생할 수 있는 사고의 형태를 도출하였고 가스의 누출 속도를 음속인 경우와 아음속인 경우에 대하여 계산하였다. 가스의 누출시 화재가 주로 피해를 유발하므로 화재가 발생하여 사망, 화상 및 건물에 피해를 줄 수 있는 경우 그 피해범위를 산정하는 방법을 제시하였다. 마지막으로 적절한 가정을 도입하여 사고로 인한 총 손실비용을 계산하는 방법을 제시하였다.

• 한국철도학회논문집
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• 제1권1호
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• pp.1-9
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• 1998

Described in this paper is the result of a study on collision analysis of TGV-K using 1-dimensional model for crashworthy design. Crashworthy design of the front end is very important because majority of the impact energy (more than 70%) is absorbed by the crush of the front end when the train is collided with an obstacle like a tank lorry. Guideline for the crashworthy design can be described from the collision analysis of the whole train using a 1-dimensional model. Since the headstock of TGV-K is not designed in a crashworthy point of view, a conceptual design of the headstock to improve crashworthiness is suggested and evaluated using 1-dimensional collision analysis. The suggested design, which adopts an energy absorber and a crashworthy headstock, shows a good behaviour on the accident scenario of SNCF (collision at 110 km/h against a movable rigid mass of 15 ton).

• 한국안전학회지
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• 제32권6호
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• pp.143-149
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• 2017

According to traffic accidents statistics, the number of fatalities, injuries and the rate of increase of traffic accidents have been decreasing over last 5-years. The fatality rate is 1.9 for total accidents but the fatality rate for single vehicle accidents shows a 7.9, which is 4 times greater than the average for all accidents. Single vehicle accidents, usually occur as a vehicle impacts a fixed objects on the roadside as the vehicle runs-off from the road. However, few researches have been conducted considering the accident severity of single vehicle accidents which impact to the fixed objects on the road. The single vehicle accident is directly related to the composition of road cross section, (since it is the required the minimum width of a road for all run-off-the-road vehicles to recover or come to a safe stop). Therefore, this study analyzes the influence of road cross section on traffic accidents to find out the severity of single vehicle accident. To analyze the road elements which are related to the accident severity, the Ordered Probit Model was used. As variables, the element of road cross section such as the radius(m), vertical curve(%), cross sectional grade(%), road width(m). number of climbing lane, median, and curb, were used (as was the 3-years of accidents data). This study found out that cross slope(%), road width(m), and the number of climbing lane are related to the severity of accident. The result of this study could be expected to improve the road safety and to be used as the base data for further road safety research.

• 한국도로학회논문집
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• 제16권5호
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• pp.133-142
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• 2014

PURPOSES : The objective was to develop the advanced method which could not explain each observation's specific characteristic in the present negative binomial method that results in under-estimation of the standard error(t-value inflation) and affects the confidence of whole derived results. METHODS : This study dealt with traffic accidents occurring within interchange segment on highway main line with RPNB(Random Parameter Negative Binomial) method that enables to take account of heterogeneity. RESULTS : As a result, AADT and lighting installation type on the road were revealed to have random parameter and in terms of other geometric variables, all were derived as fixed parameter(same effect on every segment). Also, marginal effects were adapted to analyze the relative effects on traffic accidents. CONCLUSIONS : This study proves that RPNB method which considers each observation's specific characteristics is better fitted to the accident data with geometrics. Thus, it is recommended that RPNB model or other methods which could consider the heterogeneity needs to be adapted in accident analysis.

• Nuclear Engineering and Technology
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• 제53권2호
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• pp.532-548
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• 2021

Nuclear power plants contain several monitoring systems that can identify the in-vessel phenomena of a severe accident (SA). Though a lot of analysis and research is carried out on SA, right from the development of the nuclear industry, not all the possible circumstances are taken into consideration. Therefore, to improve the efficacy of the safety of nuclear power plants, additional analytical studies are needed that can directly monitor severe accident phenomena. This paper presents an interacting multiple model (IMM) based fault detection and diagnosis (FDD) approach for the identification of in-vessel phenomena to provide the accident propagation information using reactor vessel (RV) out-wall temperature distribution during severe accidents in a nuclear power plant. The estimation of wall temperature is treated as a state estimation problem where the time-varying wall temperature is estimated using IMM employing three multiple models for temperature evolution. From the estimated RV out-wall temperature and rate of temperature, the in-vessel phenomena are identified such as core meltdown, corium relocation, reactor vessel damage, reflooding, etc. We tested the proposed method with five different types of SA scenarios and the results show that the proposed method has estimated the outer wall temperature with good accuracy.