• Journal of The Korean Society For Urban Railway
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• v.6 no.4
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• pp.401-410
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• 2018

Human error of the engineer are constantly occurring by insufficiency of scientific analysis considering the behavior of railway engagements and actual working conditions and lack of research for accidents. This study investigated how to improve the system through AHP and FGI analysis of interviews and questionnaires for electric vehicles driving licenses, which cultivates the most train drivers.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.2
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• pp.161-168
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• 2015

Recently, due to various environmental problems such as global warming, increases of international oil prices, exhaustion of resource, a paradigm of world automobile market is rapidly changing from conventional vehicles using internal combustion engine to eco-friendly vehicles using electric power such as EV, HEV, PHEV and FCEV. Generally, in order to measure fuel consumption and pollutant emissions of cars, chassis dynamometer tests are performed on various driving cycles before actual driving test. There are many driving cycles for performance evaluation of conventional vehicles. However, there is a lack of researches on driving cycle for EV. In this study, the urban driving cycle for performance evaluation of electric vehicles was developed. This study is composed of two parts. In the part 1, the urban driving cycle 'GUDC-EV(Gwacheon-city Urban Driving Cycle for Electric Vehicles)' was developed by using driving data, which were obtained through actual driving experiment, and statistic analysis with chronological table. In this paper part 2, in order to verify the developed driving cycle GUDC-EV, virtual EV platforms were configured and simulations were performed with actual driving data using In addition, simulation results were compared with existing driving cycles such as FTP-72, NEDC and Japan 10-15.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.2
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• pp.98-112
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• 2018

Intentional aggressive driving (IAD) is a very dangerous driving behavior that threatens to attack the adjacent vehicles. Most existing studies have focused on the independent driving characteristics of attack drivers. However, the identification of interactions between the offender and the victim is necessary for the traffic safety analysis. This study established multi-agent driving simulation environments to systematically analyze vehicle interactions in terms of traffic safety. Time-to-collision (TTC) was adopted to quantify vehicle interactions in terms of traffic safety. In addition, a exponential decay function was further applied to compare the overall pattern of change in crash potentials when IAD events occurred. The outcome of this study would be useful in developing policy-making activities to enhance traffic safety by reducing dangerous driving events including intentional aggressive driving.

• Journal of Korean Society of Transportation
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• v.25 no.2 s.95
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• pp.95-105
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• 2007

Speeding and drunken driving make drivers fail to detect hazards and cope with various driving situations. These behaviors also raise the possibility of being involved in traffic accidents and tend to increase the number of fatalities. The authors compared the driving behavior determinants of a rockless drivers group, consisting of individuals who have committed traffic accidents or offended regulations through drunken driving, with a normal drivers group. In the results, the reckless drivers group showed high scores of 'speeding' and 'drunken driving', and they also stated that they had more experiences of speeding, drunken driving and traffic accidents. In the path analysis study, it was found that the impacts of the rockless drivers group's 'risk sensitivity' and 'situational adaptability' on traffic accidents were stronger than those of normal drivers. This means 'risk sensitivity' and 'situational adaptability' can explain the origins of traffic accidents better in the reckless drivers group than accidents of the normal drivers group.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.121-129
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• 2013

To find a healthy driving posture, in this study, survey and empirical analysis given onto measurement of car-seat angle has been performed. Among 153 male respondents, those drivers who has minimum 5 year experience and 2 hours daily driving has been selected by a multiple screening process. They were further confirmed to have no discomfort history in any body region caused by the driving task. Final 44 people verified that their actual driving posture is not significantly different (p = 0.692) from healthy one they think. And their data, accordingly, the healthy driving postures are clustered based on the same seat-cushion angle, seat-back angle and trunk-thigh angle. Consequently, three seat-angles of the 44 subjects showed a significant difference only with their height information which is the most effecting factor on driving posture among the physical characteristics. That is a first result categorized healthy driving posture classified physical, if it were departmentalized into additional study, could be able to reflected a factor of "healthy" on car seat design.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.146-159
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• 2021

vehicle simulator as part of an empirical analysis the driving characteristics of elderly drivers. To this end, the driving characteristics of the elderly driver from previous study review. he driving characteristics of the elderly the driving elderly driver and general driverIn summarizing these experimental results, the -test showed different driving characteristics from general drivers in all items except for one side of the lane, such as driving speed and driving operation (brake, throttle, steering operation) at a significance level of 95%. Second, when changing lanes, it was difficult for elderly driver to maintain speed and secure an appropriate distance between carslderly driver changed lanes even in inappropriate situations (short distances between cars). Third, in unexpected situation, elderly drivers needed more distance and time.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.2
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• pp.243-247
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• 2016

Driving Event Data such as the rapid acceleration, the rapid deceleration, the sudden braking, and the sudden departure, and over speeding provide important information to predict or analyze the driving habits and accident risk of a driver. Most of the data that represent the driver's driving habits generally fit to the parametric distribution, whereas extreme parts of the data to estimate the accident risk of a driver may not. This paper presents an empirical distribution that is divided into two regions, one is from the normal distribution, and the other is from the general pareto distribution for the driving habits of a driver.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.6
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• pp.668-676
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• 2016

The accelerated convergence of automobiles and ICT has led to an increase in in-vehicle electronic devices designed to enhance the safety and convenience of drivers. Consequently, the information presentation on in-vehicle display systems for drivers and passengers need to be taken into account in order to guarantee driving stability while satisfying the needs of UX-based design users. This study compared and evaluated requirements for information items shown on in-vehicle displays regarding driving safety and convenience by groups according to driving career. A total of 38 information items related to safety and convenience that can be displayed while driving and pulling over were collected. Their level of necessity was tested and evaluated by 234 drivers. Using the results, we conducted a comparative analysis on the requirements for information presentation on in-vehicle display systems by groups according to driving career.

• Progress in Superconductivity and Cryogenics
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• v.14 no.3
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• pp.43-47
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• 2012

A linear compressor generates pulsating pressure and oscillating flow in a cryocooler such as Stirling cryocooler and pulse tube refrigerator. It is driven by AC power source and designed to operate at resonance of piston motion. The driving voltage level is determined by electric parameters of resistance, inductance and thrust constant of linear motor. From voltage equation on linear motor, the power factor of driving power is inherently less than 1. The phase difference between voltage and current of supplied power can be zero using capacitor and this can minimize a supply voltage level. Especially, the linear compressor of kW class requires high voltage and thus can cause a difficulty in selecting power supply unit due to limitation of voltage level. The capacitor in driving electric circuit is useful to settle this problem. In this study, the electric circuit of linear compressor is analytically investigated with assumption of mechanical resonance. The electric parameters of commercial linear motor are used in the analysis. The effects of capacitor on driving voltage level and power factor are investigated. From analytic results, it is shown that the voltage level can be mimized with using capacitor in driving electric circuit.

• Psychiatry investigation
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• v.15 no.12
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• pp.1162-1167
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• 2018

Objective Motor, perceptual, and cognitive functions are known to affect driving competence. Subcortical ischemic changes on brain magnetic resonance imaging (MRI) can reflect reduction in cognitive and motor performance. However, few studies have reported the relationship between subcortical ischemic changes and driving competence of the elderly. Thus, the objective of this study was to investigate the association between subcortical ischemic changes on MRI and driving abilities of the elderly. Methods Participants (n=540) were drawn from a nationwide, multicenter, hospital-based, longitudinal cohort. Each participant underwent MRI scan and interview for driving capacity categorized into 'now driving' and 'driving cessation (driven before, not driving now)'. Participants were divided into three groups (mild, n=389; moderate, n=116; and severe, n=35) depending on the degree of white matter hyperintensity (WMH) on MRI at baseline. Driving status was evaluated at follow-up. Statistical analyses were conducted using ${\chi}^2$ test, analysis of variance (ANOVA), structured equation model (SEM), and generalized estimating equation (GEE). Results In SEM, greater baseline degree of WMH was directly associated with driving cessation regardless of cognitive or motor dysfunction (${\beta}=-0.110$, p<0.001). In GEE models after controlling for age, sex, education, cognitive, and motor dysfunction, more severe change in the degree of WMH was associated with faster change from 'now driving' state to 'driving cessation' state over time in the elderly (${\beta}=-0.508$, p<0.001). Conclusion In both cross-sectional and longitudinal results, the degree of subcortical ischemic change on MRI might predict driving cessation in the elderly.