• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.2
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• pp.451-462
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• 1995

Single overload tests performed to examine the crack retardation behavior for the specimen thickness and overload ratios. Delayed crack length was tend to increase in small thickness and big overload ratio but was difference between delayed crack length and plastic zone size that expected in specimen thickness. So retardation behavior that estimated in plastic zone size, was not sufficient. Crack tip branching and striation distribution, secondary mechanisms that effected in retardation behavior, was examined by experiment and finite element analysis. Crack tip branching was affected by micro structure, and appeared the more complicatedly according to increasing damage by overload and decreasing crack driving force in base line stress level. And crack tip branching the branching angle decreased crack driving force in the crack tip. And a characteristic of the fractography on retardation zone was that striation distribution did not appear due to decreased crack driving force.

• International Journal of Computer Science & Network Security
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• v.24 no.3
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• pp.142-150
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• 2024

A conceptual model represents an understanding of a system that is going to be developed, which in this research, a driving simulation software to study driver behavior at signalised intersections. Therefore, video observation was conducted to study driver compliance behaviour within the dilemma zone at signalised intersection, with regards to driver's distance from the stop line during yellow light interval. The video was analysed using Thematic Analysis and the data extracted from it was analysed using Chi-Square Independent Test. The Thematic Analysis revealed two major themes which were traffic situation and driver compliance behaviour. Traffic situation is defined as traffic surrounding the driver, such as no car in front and behind, car in front, and car behind. Meanwhile, the Chi-Square Test result indicates that within the dilemma zone, there was a significant relationship between driver compliance behaviour and driver's distance from the stop line during yellow light interval. The closer the drivers were to the stop line, the more likely they were going to comply. In contrast, drivers showed higher non-compliant behavior when further away from stop line. This finding could help in the development of conceptual model of driving simulation with purpose in studying driver behavior.

• Journal of the Korean Society of Safety
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• v.22 no.1 s.79
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• pp.61-66
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• 2007

Car crashes are the leading cause of death for persons of every age. Specially, human-related factor has been known to be the primary causal factor of such crashes than vehicle-and environmental-related factors. There are various studies to analyze driver's behavior and characteristics in driving for reducing the car crashes in many areas of car engineering, psychology, human factor, etc. However, there are almost no studies which analyze mainly the human errors in driving and estimate their probabilities in terms of human reliability analysis. This study estimates the probability of human error in driving, i.e. driver error probability. First, fifty driver errors are investigated through DBQ (Driver Behavior Questionnaire) revision and the error likelihoods in driving are collected which are judged by skillful drivers using revised DBQ. Next, these likelihoods are converted into driver error probabilities using the results that verbal probabilistic expressions are changed into quantitative probabilities. Using these probabilities we can improve the warning effects on drivers by indicating their driving error likelihoods quantitatively. We can also expect the reduction effects of car accident through controlling especially dangerous error groups which have higher probabilities. Like these, the results of this study can be used as the primary materials of safety education on drivers.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.5
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• pp.18-34
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• 2021

Pedestrian deaths in Korea due to traffic accidents are 40 percent of the fatalities in traffic accidents, which is about twice the average of OECD member countries. To reduce severe pedestrian accidents, it is necessary to apply the accident reduction measures to high-risk drivers (novice, elderly, and commercial vehicle drivers) who are more likely to cause traffic accidents than general drivers. Therefore, this study analyzed the effect of safe driving education on high-risk drivers' behavior. Here, the safe driving education is chosen as the measure to reduce traffic accidents. As part of the study, sudden pedestrian crossing situations were implemented in the driving simulator, and the vehicle trajectory data were collected to compare the driving behavior before and after the education. Most surrogate safety measures showed no improvement in the driving behavior of novice and elderly drivers, and the effect of safe driving education was found to be significant only in the group of commercial vehicle drivers. The results implied that additional measures such as pedestrian safety infrastructure and driver assistance systems, apart from the safe driving education, may be needed for novice and elderly drivers to reduce pedestrian accidents caused by them. With the findings mentioned above, this study is expected to provide a foundation to establish a plan to reduce pedestrian accidents caused by high-risk drivers.

• IEMEK Journal of Embedded Systems and Applications
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• v.19 no.2
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• pp.101-106
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• 2024

For the commercialization of automated vehicles, it is necessary to create various scenarios that can evaluate driving safety and establish a data system that can verify them. Depending on the vehicle's ODD (Operational Design Domain), there are numerous scenarios with various parameters indicating vehicle driving conditions, but no systematic methodology has been proposed to create and combine scenarios to test them. Therefore, projects are actively underway abroad to establish a scenario library for real-world testing or simulation of autonomous vehicles. However, since it is difficult to obtain data, research is being conducted based on simulations that simulate real road. Therefore, in this study, parameters calculated through individual vehicle trajectory data extracted based on roadside CCTV image-based driving environment DB was proposed through the extracted data. This study can be used as basic data for safety standards for scenarios representing various driving behaviors.

• International Journal of Highway Engineering
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• v.7 no.4 s.26
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• pp.185-202
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• 2005

In this research, to get over restrictions of a field expreiment, we modeled a planning road through the 3D Virtual Reality and achieved data about dynamic response related to sector fluctuation and about driver's visual behavior on testers' driving the Driving Simulator Car with Eye Camera. We made constant efforts to reduce the non-reality and side effect of Driving Simulator on maximizing the accord between motion reproduction and virtual reality based on data Driving Simulator's graphic module achieved by dynamic analysis module. Moreover, we achieved data of driver's natural visual behavior using Eye Camera(FaceLAB) that is able to make an expriment without such attaching equipments such as a helmet and lense. In this paper, to evaluate the level of road's safety, we grasp the meaning of the fluctuation of safety that drivers feel according to change of road geometric structure with methods of Driving Simulator and Eye Camera and investigate the relationship between road geometric structure and safety level. Through this process, we suggest the method to evaluate the road making drivers comfortable and pleasant from planning schemes.

• International Journal of Highway Engineering
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• v.14 no.1
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• pp.103-109
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• 2012

Digital speedometer which is supposed to provide the basic data for analyzing human factors of drivers has a limitation for human behavior studies of drivers, because it records limited driving information including GPS velocities. Besides, Black Box, which is currently being actively commercialized in the market, records mostly vehicles' risky patterns rather than drivers' behaviors. As a result, it also shows a limit to analyze dangerous driving patterns. This study performed a risky driving study for human factor analysis. This study conducted before and after comparisons for real time warning study using a risky driving judgment device. The analysis was conducted based on Longitudinal acceleration, Lateral acceleration, and Yaw rate of vehicles.

• Journal of the Ergonomics Society of Korea
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• v.28 no.2
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• pp.9-16
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• 2009

The aim of this study was to evaluate the effects of the driving performance and workload according to changing driving environment and types of steering wheel. Twelve drivers who participated in this study consisted of two groups; six Japanese as the left-lane drivers who was accustomed to driving on left-hand side of the road, and six Europeans, Americans, and Korean as the right-lane drivers who was accustomed to driving on right-hand side of the road. They were asked to operate a driving simulator while using two different types of steering wheel (for the left-hand side driving and the right-hand side driving). During the experiment, a range of data were measured including driving performance, mental workload, and eye movements which were recorded in order to identify the amount of time looking towards the in-vehicle route guidance. Results indicated that the use of the steering wheel by parallel moving led to increase high attentional demand and worse glance behavior to traffic signs for the left-lane drivers. In the case of the right-lane drivers, the effects by changing driving direction were more effective than the types of steering wheel due to their habit or traits.

• International Journal of Highway Engineering
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• v.17 no.5
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• pp.83-92
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• 2015

PURPOSES : Traffic accidents and damage due to speeding should be recognized as a problem which harms society and the economy as well as the parties to the accidents. It is time to seek more detailed and concrete customized alternatives than the existing policies for the prevention of traffic accidents. METHODS: In this study, we identified the characteristics driver behavior and psychological factors that lead to speeding, and a study was carried out to verify the causality models developed from the factors we identified. RESULTS : Driving behavior variables have a significant effect on speeding behaviors in order of Lapse, Violation, and Mistake. And the violation which is defined as intentional violation showed the result which supports the research hypothesis as it has the significant effect on speeding intention and behaviors. CONCLUSIONS: The result of this study can be utilized to develop educational problems concerning speeding and previous response with the main objective of eliminating speeding driver behavior.

• Korean Journal of Culture and Social Issue
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• v.14 no.2
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• pp.1-19
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• 2008

This research investigated the influences of excessively careful driving as well as chronic disease and medications on dangerousness of traffic accident in elderly drivers. Ninety-one drivers aged 65 years and older participated in the research. To evaluate the driving behavior, we used the self-rating on driving ability questionnaire asking driving speed, the amount of driving and driving situation adaptability' and surveyed the drive career, the number of violations and accidents experience(crash, crashed) for last three years. A review of the driving patterns of elderly drivers showed that the speed and amount of driving were decreased by increasing age. 'Driving- Situational Adaptability (DSA)' consisted of 2 factors such as 'Social Environment(SE)' and 'Physical Environment(PE)'. Elderly drivers reported that their confidence level was lower in PE than in SE. Moreover they had higher difficulty and stress in PE than in SE. DSA of elderly drivers had significant correlations with 'crash' and 'crashed'. This implies that excessively careful driving of elderly drivers directly associated with accidents. Elderly drivers who have nervous system disease or gastritis had more crash accidents. The majority of elderly drivers which take medicine by chronic disease don't think that medications give don't difficulty or inconvenience in driving and constantly drives during a term of taking medicine.