• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.4
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• pp.167-189
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• 2022

In the case of SAE autonomous driving levels 2 and 3, since complete autonomous driving is impossible, the take-over process is essential, and take-over time(TOT) is the most important factor in determining the safety of the autonomous driving system. Accordingly, research on TOT is being actively conducted, but each research is independently conducted and general conclusions that integrate various research results are required. Therefore, in this study, the factors affecting TOT were analyzed using meta-analysis, which integrates the results of individual studies and presents an integrated opinion. As a result of meta-analysis, a total of 10 influencing factors were selected, and most of them were related to the non-driving related task(NDRT) type. In addition, implications for the future research direction of take-over and NDRT were presented.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.311.2-311
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• 2002

Even through the problem of misalignment is of great importance, not much work has been reported in the literature on the effect of misalignment on the vibrations of the gear-bearing systems. Therefore, the nonlinear dynamic characteristics of the gear driving system due to misalignment are investigated in this work. Transmission error for helical gear and bearing nonlinear stiffness is calculated. (omitted)

• Korean Journal of Culture and Social Issue
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• v.12 no.3
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• pp.23-47
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• 2006

The purpose of this research is to study the relation between the change of driver's driving confidence level in the age categories and driving behavior. To survey the driving confidence level, we used the 'Driving Confidence Scale' questionnaire and surveyed the drive career, mileage, driving days, violation of traffic regulation (drunk driving, overspeed), traffic accident experience (assaulter, sufferer) together. The subjects of investigation were from 19-year-old to 80-year-old and 1,055 persons were participated in the research totally. To examinethe structure of driving confidence level, we executed the factor analysis. We compared the driving confidence level in the age categories (under 29-year-old, 30~39, 40~49, 50~64, over 65-year-old) and studied the relation between driving confidence level and driving behavior. Driving confidence level was composed of 4 factors such as 'insensibility to situation', 'unsafe driving', 'careless concentration' and 'self-efficacy of driving', and there was decreasing tendency for driving confidence level and overall driving behavior according to increasing age. Driving confidence level had the interrelation with age range, assaulting accident, suffered accident, driving period, drunk driving, overspeed, driving career and so on. We examined the difference of driving confidence level and driving behavior by dividing the participated drivers' groups into the traffic accident experienced group, drunk driving group and overspeed driving group, and there was a significant difference on driving confidence level and driving behavior between the group who had not experienced the violation of traffic regulation or traffic accident and another group who had experienced the violation of traffic regulation or traffic accident.

• Journal of Ocean Engineering and Technology
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• v.24 no.3
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• pp.72-78
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• 2010

This paper presents a design approach of driving system for tidal flat vehicle. Firstly, topographic and geological survey of tidal flat zone was accomplished. 'Anac' located in the west-south coast of South Korea was chosen for the survey area. From the survey, the basic design data such as distribution of gullies size and bearing pressure was obtained. To figure out the shape of driving system, numerical simulations were carried out. Through the numerical dynamic simulations using $Recurdyn^{TM}$, the performance of various concepts of driving system was analyzed. From the results, we propose the conceptual design with the functions: a) low contact pressure, b) powerful driving force transmission, c) adaptation to the ground undulation. To satisfy these functional requirements, the driving system adopts rubber tracks, sprockets, tires and suspensions. The static structural analysis of the frame structure was executed as well, from which the detailed design was drawn out. To validate the performance of the designed driving system, the test vehicle which has gasoline engine of 27HP and mechanical transmission was constructed. The driving tests of the vehicle were performed twice at the "Anac" area, and unveiled its capability.

• Journal of Auto-vehicle Safety Association
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• v.14 no.3
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• pp.35-40
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• 2022

In this study, the driving performances of elderly who's age is over 65 were evaluated. The driving simulation was conducted using a compact driving simulation (CDS) and the simulation scenarios were developed from actual roads by replicating geometry of skewed intersection and traffic control devices located in Jungnang-gu, Seoul, Korea. 27 elderly drivers and 10 non-elderly drivers were recruited and participated on the virtual turning right and going straight driving experiment of CDS. Virtual driving data of driving time, speed, distance, acceleration and deceleration speeds, brake power, and steering wheel rotation angle were recorded and analyzed. Generally, elderly driver took more times to pass through the skewed intersection road and showed lower approaching speed as much as 40% and 25% in case of turning right and going straight scenarios respectively. The speed deviation at skewed intersection road between elderly and non-elderly driver is expected to cause frequent lane changes and overtaking.

• Tribology and Lubricants
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• v.14 no.4
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• pp.51-57
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• 1998

Recently, bent-axis-type axial piston pumps driven by rods being in extensively used in the world, because of simple design, lightweight, effective cost. So, to guarantee the quality of bent-axis-type axial piston pumps driven by rods, it is necessary to know characteristics of the driving mechanism of rods. But, as they perform both reciprocating and spinning motions, it is difficult to understand driving mechanism. In this paper, I studied the theoretical driving mechanisms of cylinder block driven by rods through geometric method. I found that the cylinder block was driven by one rod in limited area and the driving area was changed by rod's tilting angle and cylinder block's swivel angle.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.6
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• pp.222-230
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• 1999

A fixed type driving simulator is constructed with a car body, beam projector, operation software , driving scenario, and audio equipments. With the simulator, the cognitive effects of fatigue due to two hour continuous driving of a straight road is investigated . The effects of alcohol on driving performance is also studied. The braking operation and lane keeping performance due to fatigue and alcohol are investigated. Changes of vehicle motion due to these effects are verified by computer simulation.

• Journal of the Ergonomics Society of Korea
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• v.29 no.1
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• pp.55-59
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• 2010

Driver distraction is a major cause of traffic accidents in Korea. Various measures are being introduced to detect and warn driver distraction. The objective of this research is to investigate changes in driver's physiological signals due to distraction during driving. Driving simulator experiments have been carried out to investigate discrepancy in EEG signals among normal driving, DMB watching during driving, and cellular phone use during driving. Based on the discrepancy, combination of EEG signals have been identfied as candidate variables for detecting driver distraction. Statistical analysis has been carried out to verify their statistical significance.

• Journal of Power System Engineering
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• v.6 no.2
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• pp.73-81
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• 2002

In this study, electronically controlled automatic transmission adopted on a subcompact model in the market was modelled, and the driving performances of the transmission were simulated with the models. Kinetic and dynamic models of working components are established. The driving simulation program is developed with those models, and the various driving conditions are analyzed. With the results, the dynamic behaviour of the engine and the automatic transmission is easily understood. Especially, the transient performances of torque converter and clutches are deeply analyzed. Skipping the vehicle road test by using this analyzing tool, we can expect the cost down and the reduction of the development period of automatic transmission.

• Journal of Korean Society of Transportation
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• v.35 no.2
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• pp.160-168
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• 2017

In the past 10 years, the accidents caused by drowsy driving have occupied about 23% of all traffic accidents in Korea expressway network and this rate is the highest one among all accident causes. Unlike other types of accidents caused by speeding and distraction to the road, the accidents by drowsy driving should be managed differently because the drowsiness might not be controlled by human's will. To reduce the number of accidents caused by drowsy driving, researchers previously focused on the spot based analysis. However, what we actually need is a segment (link) and occurring time based analysis, rather than spot based analysis. Hence, this research performs initial effort by adapting link concept in terms of drowsy driving on highway. First of all, we analyze the accidents caused by drowsy in historical accident data along with their road environments. Then, links associate with driving time are analyzed using digital tachograph (DTG) data. To carry this out, negative binomial regression models, which are broadly used in the field, including highway safety manual, are used to define the relationship between the number of traffic accidents on expressway and drivers' behavior derived from DTG. From the results, empirical Bayes (EB) and potential for safety improvement (PSI) analysis are performed for potential risk segments of accident caused by drowsy driving on the future. As the result of traffic accidents caused by drowsy driving, the number of the traffic accidents increases with increase in annual average daily traffic (AADT), the proportion of trucks, the amount of DTG data, the average proportion of speeding over 20km/h, the average proportion of deceleration, and the average proportion of sudden lane-changing.