• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.54-62
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• 2010

The scientific analysis of car-pedestrian accidents is not an easy task because of the characteristic of the accidents itself. Since the analysis involved human being, there were few experimental data that could be used for the analysis. The coefficient of friction of human body was the one of crucial data for accident analysis, but no field experiment report was available for various roadway conditions. This study intends to measure the coefficient of friction of human body through field studies. Results showed that the coefficient of friction of human body for dry asphalt pavement conditions was 0.59~0.62, and for dry concrete pavement conditions was 0.59~0.61. In addition, the coefficients for wet asphalt pavement and for wet concrete pavement conditions were 0.56~0.59 and 0.51~0.54 respectively, indicating 5.0% and 8.3% reduction compared to the dry conditions. The deduced coefficients were validated using the simulation program. It has been confirmed that the experiment values were close to the simulation results.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.65-67
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• 2007

기존 선박사고 자료를 이용하여 향후 발생 가능한 선박사고의 확률을 계산하기 위한 이론과 프로그램 및 실험결과를 나타낸다. 기본적으로 베이지안 기법을 적용하여 다양한 사고의 원인과 결과 사이에 발생하는 인과관계를 통계적 기법으로 다양한 사고들이 발생할 수 있는 사고 확률을 계산하였다. 계산을 위하여 프로그램을 개발하고, 이 프로그램을 이용하여 제안한 방법의 유용성을 검증하였다.

• Archives of design research
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• v.15 no.4
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• pp.307-316
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• 2002

Metaphor thinking is a kind of intuitive thinking and plays a central role in design process. But there are not many researches on this topic because it happens in designer's mind during design problem solving. In this paper, we considered cognitive aspects of metaphorical thinking as they cropped up in the process of design concepts development. As a method of cognitive experiment we used a protocol analysis of the design review reports. At the end of this research we concluded that metaphorical thinking is engaged in restructuring of new frames and reconciliation of conflicting frames for the development of new design ideas and concepts. This role of metaphorical thinking makes the design thinking divergent and the design process creative.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.6
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• pp.63-68
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• 2006

Recent statistical data regarding electric shock accidents have been analyzed to examine the electric shock accidents occurred at the voltage of 22,900[V], In order to demonstrate the mechanism of the 22,900[V] electric shock accident, a number of experiments to simulate electric shock accidents have been performed based on the analysis results. In the experiment, the current flowing through a human body model was measured to quantitatively analyze the hazards of the simulated electric shock accidents in various situations. As a result of the experiment, it was shown that once an electric shock accident occurred the accident proved fatal to the human body, regardless of electric shock situation.

• Journal of The Korean Association For Science Education
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• v.31 no.4
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• pp.528-538
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• 2011

In this study, we investigated the thinking processes of 7th grade science-gifted students in designing application experiments and analyzed their performance levels in the categorized processes. The analyses of the results revealed that they considered 'setting a problem situation,' 'deciding a strategy,' 'identifying the assumptions,' 'defining the measurements,' and 'validating the assumptions' in the processes of designing experiments. However, their performance levels of the categorized processes were found to be rather low. It was especially insufficient in setting the situations concretely appropriated to solve the problems and checking their own thinking critically by proper criteria. Therefore, we suggested a potential learning strategy for designing experiments such as replacing difficult and abstract situations to concrete and familiar situations. These results may offer some implications in developing an education program for science-gifted students to foster creativity by emphasizing scientific thinking skills such as experiment design ability.

• Journal of the Korean Chemical Society
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• v.57 no.6
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• pp.813-820
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• 2013

The purpose of this study was to examine the impact of the reading framework on college students' reflective thinking in argumentation-based general chemistry laboratory. A total of 17 first grade college students taking general chemistry laboratory participated in this study, with 7 in the treatment group and the other 10 in the comparative group. For two semesters, a total of 10 argumentation-based general chemistry laboratory programs were applied. The result was shown that the lessons using the reading framework were effective in enhancing the students' reflective thinking. As the study progressed, the treatment group showed more changes toward the high level of reflective thinking than those of the comparative group.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.194-194
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• 2012

본 연구에서는 자연하천에서 Rhodamine-WT를 이용하여 추적자 실험을 수행하고 이를 바탕으로 오염사고대응예측모델에 대한 검증을 실시하고자 하였다. 최근 국내에서는 다양한 형태와 규모의 수질오염사고가 매년 수십건 이상 발생하고 있으며, 따라서 수치모형 기반의 수질오염 사고 대응 예측시스템에 대한 높은 신뢰성이 요구되고 있다. 수질사고에 노출되어 있는 지표수를 각종 용수로서 안전하게 공급하기 위해서는 정확한 수질예측이 필수적이며, 이를 위해서 수십 년간 연구되어 온 수질모델을 오염사고 대응예측시스템에 적합하도록 정확성과 신뢰성을 갖추기 위한 연구가 진행되어야 한다. 수치 모형을 이용한 물질의 이송 및 확산 모의에서는 오염물질 도달시간과 확산 농도를 결정하는 것이 가장 중요한 요소이므로 이송 및 확산 모의에 대한 검증 기법 개발 및 적용이 필요하다. 본 연구에서는 낙동강수계 지류하천인 감천에서 추적자 실험을 4회 실시하여 측정한 수리량과 농도 실측치를 이용하여 분산계수를 종 횡분산계수 산정이 가능한 2차원 유관추적법을 적용하여 산정하였다. 각 단면에 유속은 ADV-3차원 유속계인 Flow-Tracker를 사용하여 도섭으로 측정하였으며 하천의 흐름 방향의 직각으로 측선을 설치하고 펌프를 이용하여 채수를 한 다음 Rhodamie WT의 농도를 측정하였으며 측선의 위치 보정은 GPS를 통하여 보정하였다. 측정 자료를 이용하여 2차원 유관추적법으로 분산계수를 산정한 결과 각각의 측선에 따라서 다소 차이가 발생하였으며, 일부 구간에서는 이론식으로 계산한 분산계수와 근사한 값이 나타났다. 이는 사주가 매우 발달하고 만곡이 많은 실험구간의 특성상 Elder와 Fischer 식으로 계산한 값과 차이가 발생할 가능성이 높은 구간이기 때문인 것으로 판단된다. 또한 하폭에 대한 수심비가 커질수록 분산계수도 증가하고 평균유속에 대한 전단유속에 비에 비례하는 것으로 나타났다.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05b
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• pp.48-54
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• 1996

가압경수로의 부분충수 운전중 RHR 계통의 기능상실시 사고완화를 위해 가압기 manway와 증기 발생기 출구공동 manway를 동시에 개방한 경우에 대한 실험결과를 CATHAHR2 코드를 이용하여 해석하였다. 해석을 통해 이 경우에 발생하는 물리적 현상을 이해하고 이와 같은 과도기에 대해 코드 예측능력을 평가하므로 써, 실제 원전에서 사고시 적절한 사고대응 방안을 강구하는데 참고가 될 수 있도록 해석적 근거를 제시하고자 한다. 연구결과 CATHARE2 코드는 실험을 통해 관측된 주요 물리적 현상들을 타당하게 예측하였으나, 가압기와 밀림관의 DP를 과대 예측하여 원자로 상부공동의 최대압력을 실험보다 약 7kPa 높게 예측하였다. 노심 노출시간도 노심에서 기포율 분포를 비현실적으로 예측하여 실험보다 약 500초 지연되었다. 실험과 코드의 모의결과를 통하여 노심 노출은 중력주입에 의한 냉각수 보충만으로 충분히 회복될 수 있음을 확인하였다. CATHARE2 코드는 비록 상세한 현상들에 대해 다소 불확실성을 내포하였으나, 전반적인 거동분석에는 타당한 것으로 판단된다. CATHARE 코드는 노심에서 계면 마찰력을 줄임으로써 노심의 차압을 개선할 수 있었고, guide 튜브의 위치를 고온관 중심선과 일치시켜 guide 튜브내 액체의 hold-up 기간을 개선할 수 있었으며, 가압기의 계면 마찰력을 증가시켜서 밀림관에서 "plug and clearing" 현상을 모의할 수 있었다.모의할 수 있었다.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.8
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• pp.301-310
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• 2021

The TATI model is a Traffic Accident Text to RGB Image model, which is a methodology proposed in this paper for predicting the severity of traffic accidents. Traffic fatalities are decreasing every year, but they are among the low in the OECD members. Many studies have been conducted to reduce the death rate of traffic accidents, and among them, studies have been steadily conducted to reduce the incidence and mortality rate by predicting the severity of traffic accidents. In this regard, research has recently been active to predict the severity of traffic accidents by utilizing statistical models and deep learning models. In this paper, traffic accident dataset is converted to color images to predict the severity of traffic accidents, and this is done via CNN models. For performance comparison, we experiment that train the same data and compare the prediction results with the proposed model and other models. Through 10 experiments, we compare the accuracy and error range of four deep learning models. Experimental results show that the accuracy of the proposed model was the highest at 0.85, and the second lowest error range at 0.03 was shown to confirm the superiority of the performance.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.6
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• pp.31-42
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• 2019

Among the driving information recorded in the event data recorder (EDR), the speed information of the vehicle before the traffic accident is a very important factor that determines the punishment of the driver of the accident vehicle, the identification of the offender and the victim, and the possibility of avoiding the accident. Also, by analyzing the EDR data, the deceleration of the accident vehicle can be analyzed. In this study, the results of the braking test of the previous study and the analysis of the EDR data of the traffic accident vehicle were compared to suggest an appropriate deceleration value applicable to the calculation of the stopping distance. As a result of the braking test of the vehicle equipped with ABS of the previous study, the average deceleration of the vehicle was 0.79g ~ 0.94g. In addition, the deceleration value was calculated from 0.92g to 0.94g in the recent automobile safety evaluation braking test conducted by the Korea Automobile Testing & Research Institute. In addition, the deceleration value of 0.55g ~ 0.71g was calculated through the analysis of EDR data performed in this study, and the value was smaller than the deceleration value measured in the braking experiment of the previous study.