• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.1
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• pp.42-60
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• 2024

This study analyzed the characteristics of mixed traffic flows with autonomous vehicles on highway weaving sections and assessed the safety of vehicle-following pairs based on surrogate safety indicators. The intelligent driver model (IDM) was utilized to emulate the driving behavior of autonomous vehicles, and the weaving sections were divided into lengths of 300 and 600 meters for analysis within a micro-traffic simulation (VISSIM). Although significant differences were found in the average speed, density, and headway between the two sections through t-test results, no significant differences were observed when comparing the number of conflicts per indicator and the vehicle-following pair. Four safety indicators were selected for the mixed traffic evaluation based on their ability to represent risk levels similar to those perceived by drivers. The safety analysis, based on the selected four indicators, determined that autonomous vehicles following other autonomous vehicles were the safest pairing. Future research should focus on integrating these indicators into a single comprehensive index for analysis.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.81-83
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• 2015

본 연구에서는 항만 전 항로의 위험도를 평가할 수 있는 새로운 해상교통안전평가모델을 제안하였다. 이를 위하여, 항만을 일정간격으로 나누어, 통항 선박의 분포를 바탕으로 구간별 위험도를 계산할 수 있는 알고리즘을 개발하였다. 본 모델의 효용성을 검증하기 위하여, 오사카항만 전 항로 위험도 평가를 실시하였다. 계산 결과에 따라, 오사카 항만 전 항로에 해당하는 위험도를 표시하고, 이를 이용하여 위험지도를 제시하였다. 위험 지도를 실시간 표시함으로써, 항만 내 항로 및 특정 구역의 위험도를 파악할 수 있었다. 이는 VTS 관제 센터와 같은 항만 관리 측면에서 중요한 자료로 활용될 뿐만 아니라, 새롭게 설계될 항로의 위험도 계산 등에 활용될 것으로 예상된다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.3
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• pp.11-18
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• 2013

Since 1996, Korean National Police Agency has been promoting a project for installation of Automated Speed Enforcement (ASE) system aiming at reduction of accidents. The number has increased to 5,348 stations throughout country as of December 2012. Recently, the Section Speed Enforcement Systems have been installed at many sites to produce a general effect well beyond the localised effect at overt fixed camera sites. In this study aims, we have analyzed the effects of the Section Speed Enforcement System at the Misiryeong tunnel section. We have found that there were a statistically significant 21.4%~31.% reduction of the average speed and 45.9% reduction in a number of traffic accidents per month. Accordingly, the study indicates that the Section Speed Enforcement Systems at Misiryeong tunnel section has effective to produce road safety.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.280-280
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• 2015

최근 봄철을 맞아 산을 찾는 등산객의 수가 증가하고 있으며 그에 따른 안전사고 발생 위험도 높아지고 있다. 산지재해 중 가장 많이 발생하고 있는 산사태나 토석류는 산을 찾는 등산객에게도 많은 안전사고를 발생시키고 있으나 아직까지 탐방로의 위험성과 안전에 대한 연구는 미흡한 실정이다. 본 연구에서는 설악산 국립공원 탐방로를 중심으로 재해발생 이력조사 및 현장조사를 실시하고 분석에 필요한 공간 데이터를 구축하였으며 설악산 전체 탐방로를 유역단위로 분할하여 위험성 분석을 실시하였다. 전체 탐방로를 대상으로 GIS기반의 확률론적 분석과 SINMAP을 이용하여 위험성 평가를 수행하였으며 그 결과 일부 탐방로 구간에서 위험성이 높게 나타났다. 탐방로 위험구간을 유역별로 나누어 분석함으로써 탐방로 전체에서 유역단위로 위험요소를 판단하는 자료로 활용될 수 있을 것으로 판단된다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.3
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• pp.73-84
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• 2010

This study presents a novel method to identify hazardous segments of freeway using global positioning system(GPS) based probe vehicle data. A variety of candidate contributing factors leading to higher potential of accident occurrence were extracted from the probe vehicle dataset. The research problem was defined as a classification problem, then a well-known classifier, bayesian neural network was adopted to solve the problem. A binary logistic regression technique was also used for selecting salient input variables. Test results showed that the proposed method is promising in extracting hazardous freeway sections. The outcome of this study will be effectively used for evaluating the safety of freeway sections and deriving countermeasures to prevent accidents.

• The Korean Journal of Applied Statistics
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• v.20 no.1
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• pp.39-52
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• 2007

Crossover trials of new drugs in the treatment of angina pectoris, which frequently use treadmill exercise test for the assessment of its efficacy, produce censored survival times. In this paper we consider analysis approaches for censored survival times from crossover trials. Previously, a stratified Cox model for paired observation and nonparametric methods have been presented as possible analysis methods. On the other hand, the differences of two survival times would produce interval-censored survival times and we propose a Cox model for interval-censored data as n alternative analysis method. Example data is analyzed in order to compare these different methods.

• Journal of Navigation and Port Research
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• v.27 no.2
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• pp.103-109
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• 2003

Evaluating the risk of collision quantitatively plays a key role in developing the expert system of navigation and collision avoidance. This study analysed the existing methods of appraising the collision risk, examined the problem that are intrinsic to them, and developed a new approach to its evaluation by using the sech function as an alternative to them. This paper applied the new method in appraising the collision risk and suggested how to decide the safe range of ownship's action.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.6
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• pp.43-53
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• 2010

The increasing interest in the use of automated photographic equipment in Korea enables to detect speed violation and enforce traffic laws. Since 1996, Korean National Police Agency has been promoting a project for installation of Automated Speed Enforcement (ASE) system aiming at reduction of accidents. Recently, point to point speed cameras operate to measure a driver's average speed across length of road and/or the spot speed at individual camera sites along the road length. In this study, we were analyzed to driver's operating characteristics in point to point speed cameras. The point to point speed camera system has link-long influence on drivers and their speeds despite enforcement being visible only at the start and end of enforced road length. Then, mean and 85th percentile speeds were below speed limit along enforced road length by the two camers. Also, Female drivers were driving at low speed than male drivers along the road length.

• Journal of the Korea Safety Management & Science
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• v.2 no.1
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• pp.59-75
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• 2000

최근의 추세를 볼 때 위험관리에 관한 중요성이 점점 증대하고 있다. 그럼에도 불구하고 우리나라 은행들의 위험관리 실태는 아직 미흡한 실정이다. 그리고 대부분의 은행들이 현재 위험관리에 대응하기 위하여 ALM의 갭관리, 듀레이션관리 등을 행하고 있지만 BIS에서 중요시하고 있는 VaR의 개발과 운용은 아직 초보단계에 있다. 한국 주식포트폴리오에서 몬테카를로 시뮬레이션과 Full Variance Covariance Model의 VaR값은 비슷한 수준으로 Diagonal Model 의 VaR값 보다 작음을 알 수 있다. 이는 좀 더 정교한 계산이 요구되는 Full Variance Covariance Model의 VaR값이 보다 단순한 Diagonal Model의 VaR값 보다 정확성면에서 우수하다는 것을 보여주고 있다. 한편 이자율포트폴리오 의 경우에는 델타-감마 분석법과 몬테카를로 시뮬레이션의 경우 95% 신뢰구간의 VaR는 델타-감마 분석법이 작지만 99% 신뢰구간에서의 VaR는 몬테카를로 시뮬레이션방법이 작다는 것을 알 수 있다. 그래서 어느 한 가지 방법에 의한 VaR추정치가 가장 좋은 것이라고 단정하기 어려움을 알 수 있었다.

• Journal of Korea Water Resources Association
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• v.50 no.4
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• pp.277-288
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• 2017

A probabilistic risk analysis of levee system estimates the overall level of flood risk associated with the levee system, according to a series of possible flood scenarios. It requires the uncertainty analysis of all the risk components, including hydrological, hydraulic and geotechnical parts computed by employing MCMC (Markov Chain Monte Carlo), MCS (Monte Carlo Simulation) and FOSM (First-Order Second Moment), presents a joint probability combined each probability. The methodology was applied to a 12.5 km reach from upstream to downstream of the Gangjeong-Goryeong weir, including 6 levee reaches, in Nakdong river. Overtopping risks were estimated by computing flood stage corresponding to 100/200 year high quantile (97.5%) design flood causing levee overflow. Geotechnical risks were evaluated by considering seepage, slope stability, and rapid drawdown along the levee reach without overflow. A probability-based compound risk will contribute to rising effect of safety and economic aspects for levee design, then expect to use the index for riverside structure design in the future.