• International Journal of Highway Engineering
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• v.10 no.1
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• pp.97-104
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• 2008

Many atypical structures on the roadside are exposed to traffics unshielded posing great danger. One way to shield an atypical structure to secure the occupant safety is to stack energy absorbing material modules in front of the structure. This paper presents the analysis method of module type crash cushion made of EPS blocks using simple energy balance of the car and crash cushion and numerical examples for 0.9ton-500km/h, 0.9ton-60km/h and 0.9ton-70km/h impact are presented. This method gives simple estimation of maximum acceleration, time of crash, whether or not the vehicle stops completely before whole cushion is being crushed. However, since the acceleration and velocity data from the analysis is so crudely spaced that calculation of safety indices such is RA and OIV is not possible. Problem is overcome by using data interpolation. The spline and linear interpolation is introduce and safety analysis is made and the results are compared.

• Journal of Biomedical Engineering Research
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• v.24 no.1
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• pp.15-21
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• 2003

In this study, for a safetv assessment of light weight wheelchair occupant in frontal crash, we tested a dynamic sled impact test. we carried out total 6 times test and impact speed was 20g/48 km/h. By using Hybrid III 50%ile male dummy, head injury criteria(HIC), neck flexion moment, neck axial tension force, neck shear force. chest acceleration, head, wheelchair and knee excursion were measured, we evaluated light weight wheelchair occupant safety by motion criteria(MC) which proposed in SAE J2249 and combined injury criteria(CIC) which is a voluntary standard(GM-IARV) of General Motors Co.. when we assumed that the maximum injury value in frontal crash was 100%, the result of motion criteria(MC) of wheelchair occupant was 52%, occupant upper body injury index(CIC) was 60.1%.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.3
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• pp.149-155
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• 2010

Currently various safety tests are being performed in many countries with growing interest in vehicle safety. However the vehicles which have good safety performance in these tests could not secure the good performance in real car to car accident. So new test protocol using progressive deformable barrier (PDB) was proposed by EEVC in Europe, NHTSA in USA and some vehicle manufacturers, etc. The target of PDB test is to control partner protection in addition to self-protection on the same test. The proposal is to update current ECE R.94 frontal ODB test. So barrier, impact speed, overlap are changed to avoid bottoming-out in the test configuration. In this paper 3 different tests (R.94, EuroNCAP and PDB test) were carried out using current production vehicles with same structure. The results of these tests were compared to understand PDB test. As a result PDB test shows the highest vehicle deceleration and dummy injury because PDB offers a progressive increase in stiffness in depth and height. However vehicle intrusion was affected with rather test velocity than stiffness of deformable barrier. PDB deformation data is used for partner protection assessment using PDB software and it shows that the test vehicle is rather not aggressive.

• 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.

• Composites Research
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• v.28 no.2
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• pp.65-69
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• 2015

This study dealt with dynamic characteristics by real car crash simulation of composite support structures for road facilities. The effects of different material properties of composites for various car crash speeds are studied using the LS-DYNA finite element program for this study. In this study, the existing finite element analysis of steel support structures using the LS-DYNA program is further extended to study dynamic behaviors of the support structures made of various composite materials. Based on the passenger safety assessment, the numerical results for various parameters are verified by comparing different models with internal energy occurred in the support and car.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.2
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• pp.182-189
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• 2003

We have found that the damage of the front part for a vehicle and that of the rear part for a vehicle are the majority of frequency experienced by the traffic accidents. In conventional bumper system was designed by safety standard regulation at low speed crash. For example there are 2.5 mile and 5 mile bumper. The conventional bumper system was the crash from max 5.5 mile to 3 mile low speed occurs most frequently and results in the highest rate of repairing cost in statistically. On this study, in order to check the damageability and repairability of gas tube bumper system RCAR 15 km/h 40 % offset frontal crash test was adopted in low speed and we have a gas tube bumper parts test and vehicle test with gas tube bumper, we can find gas tube bumper system definitely can improve the damageability and repairability of the vehicles and contribute to down the repairing cost.

• Journal of Korean Society of Transportation
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• v.28 no.2
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• pp.151-159
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• 2010

This paper presents a research result that was performed to develop a more accurate freeway crash prediction model than existing models. While the existing crash models only focus on developing crash relationships associated with highway geometric conditions found on a short section of a crash site, this research applies a different approach considering the upstream highway geometric conditions as well. Theoretically, crashes occur while motorists are in motion, and particularly at freeways vehicle speed at one specific point is very sensitive to upstream geometric conditions. Therefore, this is a reasonable approach. To form the analysis data base, this research gathers the geometric conditions of the West Seaside Freeway 269.3 km and six years crash data ranging 2003-2008 for these freeway sections. As a result, it is found that crashes fit well into Negative Binomial Distribution, and, based on the developed model, total number of crashes is inversely proportional to highway curve length and radius. Contrarily, crash occurrences are proportional to tangent length. This result is different from existing crash study results, and it seems to be resulted from this research assumption that a crash is influenced greatly by upstream geometric conditions. Also, this research provides the expected effects on crash occurrences of the length of downgrade sections, speed camera placements, and the on- and off- ramp presences. It is expected that this research result is useful for doing more reasonable highway designs and safety audit analysis, and applying the same research approach to national roads and other major roads in urban areas is recommended.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.307-320
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• 2017

The objective of this study is to identify the effectiveness of ESC(Electronic Stability Control) based on a meta analysis technique. Accident Rate, Fatal Crash Rate, Loss of Control Crash Rate were set as indexes of traffic safety evaluation. Also, reviews on the effectiveness of ESC were collected using keyword, 'ESC'. As a result, the Effect size of accident rate odd ratio was 0.90. When ESC system was applied on vehicles, accident rate decreased by 10%. Also, the Effect size of fatal crash rate odd ratio was 0.64. When ESC system was applied on vehicles, fatal crash rate decreased by 36%. Lastly, the Effect size of loss of control crash rate odd ratio was 0.73. When ESC system was applied on vehicles, loss of control crash rate decreased by 27%. The outcome of this study would be effectively used for developing polices and regulations for ESC installation obligation of commercial vehicles.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.1023-1024
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• 2012

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.106-111
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• 2012

Recently the usage of bicycle has increased steeply in Korea owing to traffic culture of well- being. In a car to bicycle accident investigation, the throw distance of bicycle is very important factor for reconstructing of the accident. The variables that influence on the throw distance of bicycle can be classified into the factors of vehicle and bicycle. Simulations and collision tests in actual car to bicycle accident were executed for obtaining throw distance of bicycle. The simulations were done by PC-$CRASH^{TM}$ and for actual crash tests sand bags were used for the behavior of bicyclist instead of dummy. Factors considered were vehicle velocity and the moving angles of bicycle, also the types of bicycle and vehicle were fairy cycle and automobile, respectively. From the results, the throw distances of a head-on tire collision of $0^{\circ}$ direction was longer than that of tire crash test of $45^{\circ}$ direction, and the throw distances of a head -on frame crash test of $90^{\circ}$ direction was longer than that of frame crash test of $45^{\circ}$ direction. In addition restitution coefficient between vehicle and bicycle was estimated as about 0.1 with based on actual crash tests. Finally the increaser vehicle velocity the longer the throw distances of bicycle, and the results of simulation were relatively good agreement to the experimental results.