• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2000.06a
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• pp.270-275
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• 2000

본 연구는 다변량 통계분석을 이용하여 자동차사고성향에 대한 공통적인 특성을 찾아내고 그것이 심리적 성격특성과 관련이 있는가를 분석하고자 수행되었다. 이를 위하여 학생집단, 일반인집단 그리고 운전기사집단의 성격적 특성과 자동차사고경험 혹은 그 가능성을 비교 검토하였다. KG식 일반생활질문지에 의한 설문분석결과에 따르면 사고친화성향에 따라 2개의 집단으로 분류하는 것이 타당하다고 판단되었고, 수량화분석에 의해서도 집단을 구분할수 있었지만 일반인과 운전자 집단간에는 차이가 있었다.

• Journal of Educational Research in Mathematics
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• v.19 no.4
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• pp.565-584
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• 2009

This study is aimed at providing the theoretical framework of characteristics of mathematical thinking processes and structuring the thinking process patterns of the mathematical gifted students through the analysis of their cognitive thinking processes. For this purpose, this study is trying to analyze characteristics of mathematical thinking processes of the mathematical gifted students in an objective and a systematic way, by using think-aloud method. For comparative study, the analysis framework with the use of the thinking characteristic code as a content-oriented method and the problem-solving processes code as a process-oriented method was developed, and the differences of thinking characteristics between the two groups chosen by the coding system which represented the subjects' thinking processes in the form of the language protocol through thinking-aloud method were compared and analyzed.

• Journal of Korean Society of Transportation
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• v.29 no.4
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• pp.43-51
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• 2011

Since a variety of factors are associated with crash occurrence, the analysis of causes of crash is a hard task for traffic researchers and engineers. Among contributing factors leading to crash, the characteristics of driver is of keen interest. This study attempted to identify factors affecting the severity of pedestrian in the collision between pedestrian and vehicle. In particular, our analyses were focused on the novice driver. A binary logistic regression technique was adopted for the analyses. The results showed that driver's age, crash location, and the frequency of violations were dominant factors for the severity. Findings are expected to be useful information for deffective policy- and education-based countermeasures.

• Journal of Korean Society of Transportation
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• v.35 no.2
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• pp.105-115
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• 2017

Each year, a number of tourists visit Jeju Island, a popular tourist destination in the Republic of Korea. A large portion of the tourists (about 61%) use a rental car as a means of transportation. With this reason, the number of rental cars registered in Jeju was 15,517 in 2011, while the total number of the rental car has rapidly increased to 26,338 in 2015. For the same period, the number of rental car involved traffic accidents has been doubled. Thus, this study aims to analyze the rental car accidents' characteristics, clarifying primary factors related to rental car accidents in Jeju Island. To do this, 918 rental car accidents and 4,201 non-commercial passenger car accidents that occurred in Jeju island over the two years (2014-2015) were compared, using statistical methods such as chi-square test and z-test. The results show that the characteristics of rental car involved accidents are different from those caused by the passenger cars. Most of the rental car accidents in Jeju were caused by young drivers and drivers who had just obtained their driver's licenses. This study finds that driver immaturity, unfamiliar geography, and driving an unfamiliar vehicle are the main causes of the rental car accidents. Statistical analysis confirms that the characteristics of these accidents appeared significantly different from the passenger cars in terms of human and environmental factors. On the other hand, there is no clear evidence that vehicle-related characteristics are different between rental car and non-commercial passenger car accidents. The implications on transportation safety analysis and effective solutions to prevent rental car traffic accidents are discussed.

• Journal of Korean Society of Transportation
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• v.31 no.6
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• pp.53-66
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• 2013

The major purpose of this study is to evaluate methodologies to predict the injury severity of pedestrian-vehicle collisions. Methodologies to be evaluated and compared in this study include Binary Logistic Regression(BLR), Ordered Probit Model(OPM), Support Vector Machine(SVM) and Decision Tree(DT) method. Valuable insights into applying methodologies to analyze the characteristics of pedestrian injury severity are derived. For the purpose of identifying causal factors affecting the injury severity, statistical approaches such as BLR and OPM are recommended. On the other hand, to achieve better prediction performance, heuristic approaches such as SVM and DT are recommended. It is expected that the outcome of this study would be useful in developing various countermeasures for enhancing pedestrian safety.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.80-82
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• 2019

태양광발전과 풍력발전으로 대표되는 분산형 전원이 계통에 연계됨에 따라 계통 사고 발생 시에 계통연계형 인버터에 대한 각국의 계통 규정(Grid code)이 더욱 엄격해 지고 있다. 최근 국외 계통 규정에서는 저 전압 사고뿐만 아니라 영 전압 사고 시에 인버터가 일정 시간 계통 연계를 유지하며 무효전류 출력 기법을 통해 계통 복구를 지원할 것을 요구하고 있다. 계통 사고 시, 사고 전압 잔존량에 따라 무효전류를 정확하게 출력하기 위해 인버터의 PLL(Phase Locked Loop) 제어는 중요하다. 그러나 이러한 PLL 제어의 동적 특성은 계통 사고 순간의 전압 강하 및 사고 위상에 따라 영향을 받게 되고 영 전압 사고에서는 위상 추종이 불가능하기 때문에 복합적인 문제가 나타난다. 본 논문에서는 영 전압 사고에서 사고 위상에 따라 각각 다르게 나타나는 PLL 동적 특성을 시뮬레이션을 통해 분석하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.74-76
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• 2011

다기능 선박조종시뮬레이터(Full-mission Shiphandling Simulator)를 이용한 사고분석 방법은 먼저 사고관련 정보기록을 수집하여 이에 맞는 항만/해역의 데이터베이스를 만들고 이를 바탕으로 사고 선박의 제원, 사진 및 기타정보를 토대로 일반적인 변수 값 기관 특성정보, Hydrodynamic 특성 변경과 선박의 외형에 따라 선박의 데이터베이스를 만들고, 시험운항을 통한 수치를 보정한다. 그리고 이 데이터베이스를 기초로 하여 시뮬레이션 시나리오를 만들어서 사고 당시를 재연하면서 그때, 그때의 상황의 자료를 수집하여 분석하게 된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.181-189
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• 2008

The purpose of this study is to comparatively analyze the characteristics and models of traffic accidents by day and nighttime. In pursuing the above, this study gives particular attentions to testing the differences and developing the models (multiple linear and non-linear and Poisson and negative binomial regression) using the data of Cheongju 4-legged signalized intersections. The main results analyzed are as follows. First, the differences between day and nighttime accidents were defined. Second, 12 accident models which are all statistically significant were developed. Finally, the differences between day and nighttime models were comparatively analyzed using the common and specific variables.

• International Journal of Highway Engineering
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• v.13 no.2
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• pp.49-56
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• 2011

Understanding various casual factors affecting the occurrence of freeway traffic crash is a backbone of deriving effective countermeasures. The first step toward understanding such factors is to identify crash risks on freeways. Unlike existing studies, this study focused on the unsafe vehicle maneuvering that can be detected by in-vehicle sensors. The recent advancement of sensor technologies allows us to gather and analyze detailed microscopic events leading to crash occurrence such as the abrupt change in acceleration. This study used an accelerometer to capture the unsafe events. A set of candidate variables representing unsafe events were derived from analyzing acceleration data obtained by the accelerometer. Then, the crash risk was modeled by the binary logistic regression technique. The probabilistic outcome of crash risk can be provided by the proposed model. An application of the methodology assessing crash risk was presented, and further research items for the successful field implementation were also discussed.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.5
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• pp.827-835
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• 2017

With the rapid progress of ageing several issues concurrently occur, and one important social issue that must be resolved is accidents involving Elderly drivers. Efforts to reduce the frequency of such accidents is a must in order to be prepared to face a superaged society. Currently people aged 65 or older are prescribed as an "Elderly person." Therefore, various studies concerning accidents involving Elderly drivers apply this age criteria to separate regular drivers and Elderly drivers. However, there is no criteria to practically discern Elderly drivers with certain physical features as vulnerable road users based on a level of acceptable accuracy. Therefore, this studies intends to compare the possibility of accidents by age group of Elderly drivers by correlation analysis to analyze the accident characteristics by age group. Results showed that for drivers aged 75 and older, their influence on major accident characteristics by vehicle type increased with higher age groups. In particular, passenger cars had a relatively low accident frequency rate for drivers aged between 70 and 80, but for drivers aged 75 to 84, they had higher influence on accidents for the same vehicle type. This demonstrates that as ageing progresses and the average life expectancy increases, the age span of elders continues to increase, meaning that characteristics differ by age group among the aged. This study confirmed that the influence on the possibility of accidents differs by age group among the aged.