• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.4
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• pp.1-12
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• 2021

Emergence of the COVID 19 pandemic has resulted in a sharp increase in the number of two-wheeler vehicular traffic accidents, prompting the introduction of numerous efforts for their prevention. This study applied XGBoost to determine the factors that affect severity of two-wheeled vehicular traffic accidents, by examining data collected over the past 10 years and analyzing the influence of each factor. Among the total factors assessed, variables affecting the severity of traffic accidents were overwhelmingly high in cases of signal violations, followed by the age group of drivers (60s or older), factors pertaining only to the car, and cases of centerline infringement. Based on the research results, a reasonable legal reform plan was proposed to prevent serious traffic accidents and strengthen safety management of two-wheeled vehicles. Based on the research results, we propose a reasonable legal reform plan to prevent serious traffic accidents and strengthen safety management of two-wheeled vehicles.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.399-399
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• 2021

최근 전세계적으로 발생하고 있는 기후변화로 인해 가뭄, 홍수, 태풍 등 자연재해의 빈도가 증가하고 있다. 특히, 강수량의 변동성이 커지면서 가뭄과 홍수가 단기간에 번갈아 가며 발생하는 경우가 자주 발생하고 있다. 가뭄과 홍수가 짧은 기간 동안에 교차해서 발생하는 급변사상은 예측하기 어려우며, 갑작스럽게 중첩되는 재난으로 인명과 재산피해 뿐 아니라 생태계에까지 심각한 영향을 미칠 것이다. 본 연구에서는 일 강수량 자료를 바탕으로 표준가중평균강수지수(Standard Weighted Average Precipitation, SWAP)를 산정하고 한강 유역의 가뭄-홍수 급변사상에 대한 특성을 분석하였다. 1966년부터 2018년까지의 한강유역 중권역별 면적평균강수량과 가중치, 이전 강수량의 영향을 받는 일수를 바탕으로 SWAP를 산정하였다. SWAP 지수가 10일 연속 -1 미만일 때를 가뭄이라 정의하고, 이후 SWAP 지수가 7일 연속 0.5 이상이면 가뭄사상이 종료된다고 판정하였다. 또한 SWAP 지수가 10일 연속 +1 초과일 때를 홍수라고 정의하고, SWAP 지수가 7일 연속 -0.5 이하가 되면 홍수사상이 종료된다고 판정하였다. 가뭄-홍수 급변사상이란 가뭄의 종료시점과 홍수의 시작시점의 차이가 5일 이내일 경우에 해당한다. 급변사상의 전·후로 강수량이 얼마나 급격하게 차이 나는지를 판단하기 위하여 급변 시점 전·후 5일의 누적 SWAP 지수인 심각도 K(Severity)를 분석지표로 활용하였다. K를 통해 한강유역 가뭄-홍수 급변사상의 시·공간적 분포를 분석하고 미래의 급변사상의 발생가능성을 예측할 수 있다. 본 연구 결과, 한강 유역의 24개 중권역 중에서 18개의 중권역이 가뭄-홍수 급변사상의 심각도가 점점 상승하는 추세이고, 가장 심각도 상승폭이 높은 중권역은 홍천강(1014)으로 첫 사상인 1967년부터부터 2015년의 마지막 사상까지 약 55% 정도 상승하였다.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.12 no.1
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• pp.115-124
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• 2001

Objective：The purpose of this study was to compare the clinical features of children with three subdiagnoses of tic disorder(transient tic disorder(TTD), chronic tic disorder(CTD) and Tourette’s disorder (TD)) and to exam the factors related with illness severity of them. Method：Subjects were 69 children who met DSM-IV criteria for tic disorder and 43 control children. All subjects were investigated demographic and clinical factors related to tic. The severity of tic was assessed with the Yale Global Tic Severity Scale(YGTSS) in tic disorder children. The Child Behavior Checklist(CBCL) was accomplished by parents of all subjects. Results：Children with TTD had not only shorter duration of tic symtoms but also milder tic severity and impairment than those with CTD and TD. They also had significantly lower scores on most CBCL subscales than children with CTD and TD, while they were similar with controls in all the CBCL subcale scores except aggressive behavior. Children with CTD and those with TD were similar to each other in clinical variables except number of tic symptom and scores on CBCL social problem subscale. The interference and intensity of motor tic symptoms and duration of tic symptoms were significant predictors of global impairment score on YGTSS, while the presence of comorbid ADHD was a preictor of the total behavior problem score of CBCL. Conclusion：These findings indicate that duration of tic symptoms and the presence of comorbid ADHD as well as the severity of tic symptoms strongly associated with the illness severity of children with tic disorder. These results also suggest that those clinical factors may be more important for assessing the severity of illness and determining the treatment strategy than the sub-diagnosis itself in children with tic disorder.

• Journal of Korean Society of Transportation
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• v.22 no.3 s.74
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• pp.59-67
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• 2004

On January 1, 2003, the motor vehicle management system in Korea was transformed from government's vehicle type approval to manufacturer's self-certification. The motor vehicle recall system with self-certification is an essential mechanism to place the liability of the vehicle defects on manufacturers and hence protect consumers from automobile accidents. This study provides a methodology to measure the benefits of motor vehicle recall system in two categories: benefits of reduction in traffic accidents and benefits of severity reduction in traffic accident. Applying the proposed methodology, the benefits of implementing motor vehicle recall system in Korea were estimated. It was estimated that 745 traffic accidents, 12 fatal accidents, and 1473 injury accidents were respectively reduced in 2002 due to implementation of motor vehicle recall system.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.46-46
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• 2017

지역가뭄빈도분석의 분위산정에 대한 신뢰성은 수문학적으로 균일한 지역으로 구분하기 위해 사용된 장기간의 과거 자료와 분석절차에 의해 결정된다. 그러나 극심한 가뭄은 매우 드물게 발생하며 신뢰 할 수 있는 지역빈도분석을 위한 지속기간이 충분치 않는 경우가 많이 발생한다. 이 외에도 우리나라의 복잡한 지형적 및 기후적 특징은 동질한 지역으로 구분하기 위한 통계적인 처리방법이 필요하였다. 본 연구에서 적용한 지역빈도분석은 여러 지역의 다양한 변수인 수문기상 특성을 분석하여 동질한 지역을 확인하고, 주요 가뭄변수(지속 시간 및 심각도)를 통합 적용하여 각각의 동질한 지역 분위를 추정함으로써 동질한 지역을 구분하는 해결책을 제시하였다. 본 연구에서는 가우시안 혼합 모형(Gaussian Mixture Model)을 기반으로 기반 군집분석 방법을 적용하여 최적의 동질한 지역을 구분하고 그 결과를 우도비검정 및 다른 유효성 검사 지수를 이용해서 확인하였다. 가우시안 혼합 모델에서 산정했던 매개변수를 방향저감 공간으로 표현하기 위해서 가우시안 혼합 모델방향 저감(GMMDR)방법을 적용하였다. 이 변수는 가뭄빈도분석을 위해 다양한 분포와 코풀라(copula) 적합도를 이용하여 추정 비교하였다. 그 결과 우리나라를 4개의 동질한 지역으로 나누게 되었다. 가우시안과 Frank copula를 이용한 Pearson type III(PE3) 분포는 우리나라의 가뭄 기간과 심각도의 공동 분포를 추정하는데 적합한 것으로 나타났다.

• Journal of Korean Society of Transportation
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• v.26 no.2
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• pp.17-24
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• 2008

Traffic accident forecasting model has been developed steadily to understand factors affecting traffic accidents and to reduce them. In Korea, the length of highways is over 3,000km, and it is within the top ten in the world. However, the number of accidents-per-one kilometer highway is higher than any other countries. The rapid increase of travel demand and transportation infrastructures since 1980's may influence on the high rates of traffic accident. Accident severity is one of the important indices as well as the rate of accident and factors such as road geometric conditions, driver characteristics and type of vehicles may be related to traffic accident severity. However, since all these factors are interacted complicatedly, the interactions are not easily identified. A structural equations model is adopted to capture the complex relationships among variables. In the model estimation, we use 2,880 accident data on highways in Korea. The SEM with several factors mentioned above as endogenous and exogenous variables shows that they have complex and strong relationships.

• Korean Journal of Psychosomatic Medicine
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• v.22 no.1
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• pp.3-12
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• 2014

Objectives : We aimed to explore the relationship among fatigue and perceived stress, depressive mood in the working population. We also examined associations with demographic and life style factors and investigated the effect of individual coping skills on these associations. Methods : Fatigue Severity Scale(FSS), Perceived Stress Scale(PSS), Brief Encounter Psychosocial Instrument - Korean version(BEPSI-K), Beck Depression Inventory(BDI), Stress Coping Skill Questionnaire were administered to 621 civil servants. All of above and other demographic factors are self-administered questionnaire survey and this study is cross sectional. Results : Mean FSS score was 3.04 which was lower than 3.22, the severity cut off score. FSS, PSS, BEPSI-K, BDI were all higher in female. Subjects with active coping skills showed relatively low fatigue, perceived stress, depressive mood than those with passive coping skills. Logistic regression analyses indicated that the PSS, BDI, BEPSI-K in working population increase the risk of fatigue and regular exercise lowers the risk. Conclusions : Adults who were afflicted by stress, experienced depressive mood or were physically inactive were at much higher risk of feeling fatigue. Since no other large data sets are available for fatigue, the results from this study could serve a very useful purpose, to furnish a basis for comparison with future research results based on more complete data.

• Proceedings of the Korean Reliability Society Conference
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• 2000.11a
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• pp.343-350
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• 2000

제조물 책임법(PL： Product Liability) 시행을 앞두고, 최근 고객 및 기업에 주목을 받고 있는 제도가 리콜제도이다. 본 연구에서는 고객 보호측면에서 국내에서 시행중인 리콜제도에 대한 고객반응을 연구하여 장차 시행될 PL에 대한 대응방향을 제시하고자 한다. 기존의 연구에서는 리콜에 대한 고객의 반응을 알아보기 위한 방법으로 경쟁을 고려하자 않은 리콜 시나리오를 구성하여 기존과 잠재고객의 반응을 파악하였다. 본 연구에서는 리콜 관련 신문보도 이후 고객의 반응을 알아보고자 경쟁관계에 있는 국내 2개 자동차사의 브랜드에 대한 상대적인지도, 리콜 정보에 대한 상대적 심각도, 그리고 각 기업의 리콜대응에 대한 고객 만족도 등이 향후 신규구매 및 재구매에 미치는 영향을 분석하고자 로지스틱 모형을 이용하였다. 그 결과, 향후 재구매시는 기업의 상대적 사회적인지도, 리콜정보에 대한 상대적 심각도 등이 유의한 영향을 미치는 것으로 나타났다. 이에 반해 신규 구매시는 향후 구매하고자 하는 제조기업과 구매시 고려하는 상품정보가 관련성이 있는 것으로 파악되었다.

• The Journal of the Korea Contents Association
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• v.13 no.4
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• pp.198-207
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• 2013

This study was to examine the effects of risk characteristic and risk perception on risk severity of natural disaster. The findings showed that the risk severity of natural disaster were classified into geographical disaster, storm and flood damage, drought damage. Typhoon among storm and flood damage showed high scores on risk severity of natural disaster. Moreover participants showed high scores on unfamiliar, undiscoverable, and unknown by scientific knowledge among risk characteristic of natural disaster. Second, risk characteristic was significantly correlated to risk perception. Third, risk characteristic influenced positively on risk severity of natural disaster. Especially, risk characteristic had great effect on storm and flood damage among natural disaster. Fourth, risk perception influenced positively on risk severity of natural disaster. Especially, risk perception had great effect on storm and flood damage among natural disaster.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.4
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• pp.1-12
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• 2017

Traffic accidents are caused by a combination of human factors, vehicle factors, and environmental factors. In the case of traffic accidents where rental cars are involved, the possibility and the severity of traffic accidents are expected to be different from those of other traffic accidents due to the unfamiliar environment of the driver. In this study, we developed a model to forecast the severity of rental car accidents by using Naive Bayes classifier for Busan, Gangneung, and Jeju city. In addition, we compared the prediction accuracy performance of two models where one model uses the variables of which statistical significance were verified in a prior study and another model uses the entire available variables. As a result of the comparison, it is shown that the prediction accuracy is higher when using the variables with statistical significance.