• Journal of Auto-vehicle Safety Association
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• v.6 no.2
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• pp.23-28
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• 2014

Commercial vehicle ESC assessment for curvature road was conducted. The previous study of ESC activation condition for losing controllability utilizing the test protocols of double lane change and sine with dwell method was conducted without considering the geometric complexity of roadway design. Since critical rollover accidents were frequently observed in the exit ramp zone, variety of curve, slope and bank have been added for analysis conditions. Detailed feature of the ramp including location, dimension and design characteristics have been analyzed from the typical trumpet type ramp design. Analyzing accident data from 2008, two specific ramps have been selected due to their complexity in design and severity in steering operation.

• Journal of Auto-vehicle Safety Association
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• v.11 no.4
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• pp.63-68
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• 2019

The Korean traffic systems for transportation vulnerable are still under development and their social life are limited even if the traffic environment systems are developed consistently. To secure his/her mobility right, it has been required to set up the particular system for the traffic welfare, for example the express and intercity bus operations for wheelchair users. The express and intercity bus development for wheelchair users based on the original bus model has been performed. This study has investigated the safety tolerance for the bus stiffness, rollover and side impact characteristics to ensure occupant safety using the finite element models. The wheelchair bus model showed the improved crashworthiness according to the partially reinforced structure and better safety tolerance for the wheelchair users.

• Journal of Auto-vehicle Safety Association
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• v.13 no.3
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• pp.47-53
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• 2021

This study is a study to estimate the VSL (Value of a Statistical Life) and CBA (Cost-benefit analysis) of the rollover safety standard for hydrogen buses, VSL is an economic value concept used to quantify the benefits of avoiding death. CBA shows the effect of cost-benefit, and if B/C is greater than 1, there is a social effect. In order to estimate the VSL and CBA, the hydrogen bus introduction scenario was assumed to be optimistic (20,000 vehicles in 2030), neutral (15,000 vehicles in 2030), and pessimistic (10,000 vehicles in 2030), and the effect of reducing human casualties was estimated. As a result, except for the pessimistic market situation of introducing hydrogen buses (10,000 vehicles in 2030) and the VSL reduction ratio of 10%, all policies were judged to have high cost-benefit effects. These results indicate that the introduction of the rollover safety standard for hydrogen buses is a socially effective policy.

• Journal of the Ergonomics Society of Korea
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• v.13 no.1
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• pp.15-25
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• 1994

Based on Fatal Accident Reporting System (FARS) data, safety belt effect- tiveness in preventing fatalities is investigated for the following five types of crashes: frontal, left, rear, right, and rollover. Passenger cars containing two occupants, a driver and a right front passenger, are included in this analysis. For each crash type, these cars containing the two occupants are classified into four categories according to the safety belt usage categories for the two front seat occupants, namely, both belted, both unbelted, and either one was belted but not both. Relative risks of driver and right front passenger fatalities are compared among these four cases. For each crash type, two independent estimates of safety belt effectiveness are obtained for drivers and for right front passengers. The weighted average of the two estimates is calculated for drivers and for right front passengers for the five crash types. Using FARS data starting 1978 throught 1983, safety belts are more effective in rollover accidents than in frontal collisions. In rollover accidents, safety belt effectiveness estimate for drivers is $68%{\pm} 6% $ and that for right front passengers is $71%{\pm}6% $ , in which the error limits indicate one standard error. Sfety belt effectiveness estimates for drivers and right front passengers involved in frontal collisions are $41%{\pm} 9% $ and $37%{\pm} 10% $ , respectively. For left and right sided collisions and for both drivers and right-front-passengers, none of the four estimates are significantly different from 0%, statistically : however, when left and right sided collisions are combined with far sided occupants(drivers involved in right sided collisions and right front passengers involved in left sided collisions) safety belt effectiveness is significant, $38%{\pm} 12% $ . For rear collisions, the estimate for drivers shows statistically significant positive effect, $60%{\pm}23% $ . while for right-front-passengers the estimate is not significantly different from 0%. These results show that a safety belt is an effective restraint system not only in frontal crashes but also in a variety of crashes.

• Journal of the Korea Society for Simulation
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• v.32 no.4
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• pp.77-84
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• 2023

In the agricultural sector, power sources are being developed that use alternative energy sources such as electric tractors and hydrogen tractors, away from internal combustion engine tractors. As parts such as engines and transmissions used in conventional internal combustion engine tractors are replaced with motors and batteries, the center of gravity changes, and thus the risk of rollover should be considered. The purpose of this study is to analyze the overturn angle of the main parts of the electric tractor through dynamic simulation to minimize the overturn accident and to derive the optimal arrangement of parts to improve stability. A total of nine dynamics simulations were conducted by designing three components of the PTO motor, drive motor and the battery pack, and three factors of the arrangement method. As a result of the experiment, it was confirmed that Type3 Level3, in which the drive motor and the PTO motor are located at the front and rear of the tractor, and two battery packs are located in the middle of the tractor, has a high rollover angle. As a result of this study, the stability increased as the center of gravity was placed backward and located below. Future research needs to be done to find the optimal location of parts considering their performance and placement efficiency.

• Journal of Auto-vehicle Safety Association
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• v.12 no.3
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• pp.52-60
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• 2020

Usage of EDR(Event Data Recorder) report for traffic accident analysis is currently increasing due to government regulation of EDR data release. Nevertheless, a lot of investigators simply adopt by comparing the number of ignition cycles(crash) at event to the number of ignition cycles(download) without an exact judgment whether event data occurred by this accident or not. In the EDR report, besides ignition cycles, there are many factors such as event record type, algorithm active(rear/rollover/side/frontal), time between events, event severity status(rollover/rear/right side/reft side/frontal), belt switch circuit status, driver/passenger pretensioner/air-bag deployment, PDOF(Principal Direction of Force) by ΔV to be able to decide whether or not to adopt. also the event data is considered enough to vehicle damaged state, accident situation at the scene of the accident. and there is described in "all data should be examined in conjunction with other available physical evidence from the vehicle and scene" in the CDR(Crash Data Retrieval) report. Therefore many investigators have to decide whether or not to adopt after they consider sufficiently to above factors when they are the traffic accident analysis and investigate the causes of a accident on the adopted event data. In this paper, we report to traffic accident investigators notable points and analysis methods on the basis of thousands of cases and the results of one's own experiment in NFS(National Forensic Service).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7329-7334
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• 2015

This is to analyze of driver behavioral and the accident characteristics in rollover. The study period was January 2011 to May 2014 and the subject of study was 102 person who were drivers visited the emergency room. Research tool includes a damage information of the vehicle, accident mechanism, damage to the patient clinical information with the injury data from the ROAD Traffic Authority. For data analysis, SPSS 18.0 was used for t-test, ANOVA and Chi-square test. Injury Severity Score average score according to the vehicle type is 6.00 points in the smaller vehicle, at high vehicle 11.78 points, from the other vehicle that showed 14.70 points. Significant differences between the three groups did not show (P=.267). Men did not use a seat belt significantly compared to women(P=.007). Vehicle type and weather, this was no correlation with whether or not use the seat belt(P=.755, P=.793). But showed a tendency to smaller size vehicles drivers do not use a seat belt, the weather could see a little more inclined to use a seat belt rather than a sunny day. Finally, in rollover accidents as in other types of accident it was confirmed that the seat belt has a great influence on the damage.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.8
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• pp.64-72
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• 2020

In this study, a stability analysis was conducted through finite element analysis (FEA) of a simplified model of a fire ladder truck by changing the ascending angle, turning angle, and boundary conditions between the outrigger and the ground. The results of the analysis showed that decreasing the angle of the ladder car increases the moment due to the ladder weight, decreasing the safety factor despite being under the same load conditions. In the case of a rotating radius, the stability was found to vary depending on the boundary conditions. A comparative analysis in the future with these results and the experimental values from the actual fire ladder truck may determine the most appropriate boundary conditions based on the analysis program. It is expected to predict the risk of damage and rollover by assessing the stability of aerial ladder vehicles under different conditions.

• The Korean Journal of Financial Management
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• v.22 no.1
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• pp.71-91
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• 2005

The object or this paper is to analyze the rollover effect on KOSPI 200 index option prices. Especially we analyze the implied volatilities of the options that became the near maturity options as the old one expired. For this analysis, a panel data of KOSPI 200 Index Option Prices from year 1999 to year 2001 were used, and following results were obtained. First, after controlling for the underlying index returns, strike prices and other pricing factors, the call option prices tend to decrease while the put option prices tend to increase during the week of expiry. Second, if one concentrates on the daily price changes, call option prices tend to go up on Thursday (as the old options expire), and then experience a price decrease on the following day, while the reverse is true for the put options. These results imply that the option prices are affected by some of the market micro-structure effects such as whether the option is the near maturity option. We conjecture that the reason for this is related to the undervaluation of KOSPI 200 futures. The results from this paper have implications on the timing of option trades. If one wants to buy put options, and/or sell call options, he has better off by executing his intended trades before the old options expire. On the other hand, if one wants to buy call options, and/or sell put options, hi has better off by executing his intended trades after the expiry.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.483-490
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• 2016

Automobile door latch is a fine design and assembly techniques are required in order to produce them in a small component assembly shape such as a spring, injection products, a small-sized motor. The door latch is fixed to not open the door of the car plays an important role it has a direct impact on the driver's safety. In this study, during trimming of the terminals of the connector main components of the car door latch, reduce rollover and conducted a research to find a suitable effective shear surface. Using the Taguchi method with orthogonal array of Finite Element Analysis and optimal Design of Experiments were set up parameters for the shear surface quality of the car door latch connector terminals. The design parameters used in the analysis is the clearance, the radius, and the blank holding force, the material of the connector terminal is a C2600. Trimming process optimum conditions suggested by the analysis has been verified by experiments, the shear surface shape and dimensions of a final product in good agreement with forming analysis results.Taguchi method from the above results in the optimization for the final rollover and effective shear surface improved for a vehicle door latch to the connector terminal can be seen that the applicable and useful for a variety of metal forming processes other than the trimming process is determined to be applicable.