• Journal of the Semiconductor & Display Technology
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• v.19 no.3
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• pp.93-99
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• 2020

A majority of car crash is affected by careless driving that causes extensive economic and social costs, as well as injuries and fatalities. Thus, the research of precise crash detection systems is very significant issues in automotive safety. A lot of crash detection algorithms have been developed, but the coverage of these algorithms has been limited to few scenarios. Road scenes and situations need to be considered in order to expand the scope of a collision detection system to include a variety of collision modes. The proposed algorithm effectively handles the x, y, and z axes of the sensor, while considering time and suggests a method suitable for various real worlds. To reduce nuisance and false crash detection events, the algorithm discriminated between driving mode and parking mode. The performance of the suggested algorithm was evaluated under various scenarios, and it successfully discriminated between driving and parking modes, and it adjusted crash detection events depending on the real scenario. The proposed algorithm is expected to efficiently manage the space and lifespan of the storage device by allowing the vehicle's black box system to store only necessary crash event's videos.

• Journal of Auto-vehicle Safety Association
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• v.15 no.3
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• pp.59-65
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• 2023

As advanced driving assistance system (ADAS) and autonomous driving performance continue to improve, existing crash accidents and crash types are changing. Accordingly, the collision angle and the seating posture of the occupant are changed. It is necessary to study how the occupant injury mechanism changes according to these different crash types. In this regard, a representative crash test mode was derived when the automatic emergency braking system (AEB), one of the autonomous driving performance, was applied to the representative car-to-car crash scenario in Korea. The derived crash test mode was used to analyse the mechanisms of collision injuries according to both impact angle and the occupant seating posture (reclined seat-back angle). The results obtained through this study can be utilized as reference data for the development of new crash evaluation methods and improvements in crash restraint systems for enhancing crash safety.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.1
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• pp.136-142
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• 1995

An analysis model is proposed for the performance prediction of typical ball and tube type mechanical crash sensors based upon mass-spring-viscous gas damping idealization. Also a construction of mechanical crash pulse generator is suggested as an experimental tool for calibration and verification of model predictions. A sensor tuning procedure for a particular set of crash pulses is suggested based upon the analysis model and the experimental tools.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.2
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• pp.49-57
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• 2008

The performance of crash cushion systems is certified through the full scale crash tests by the standard for installation and maintenance guidelines for roadside safety appurtenance. The impact severities of impacting vehicles in collision with crash cushion systems are rated by indices THIV and PHD. Crash test results are considered to study the performance of three crash cushion systems. In case of the frontal impact or the offset frontal impact, the results show that THIV values of three systems are very close to the threshold limit for the occupant protection. Also, the results show that PHD would be improper for the occupant protection performance index. In order to improve the occupant protection performance of crash cushions, ASI needs to be included in the impact severity index.

• Journal of the Korean Society for Railway
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• v.5 no.4
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• pp.231-236
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• 2002

Todays, crash safety requirements of the railway vehicle structures become important design criterion according to the increased driving speed and the lightweight construction. Although the crash analysis using computer simulation can be effectively applied to predict the crash performance of the railway vehicles in the early design stage, the optimized design w.r.t the crash safety could be realized by the crash tests with actual prototype vehicles. However, it is very expensive and time-consuming task to perform the crash test of the railway vehicles. As a measure to cope with the problem, in this paper, the scale modeling technique is suggested and experimentally verified to predict the impact energy absorption characteristics of full scale model of aluminum extrusions sub-structures and the high-speed railway vehicle structure.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.163-170
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• 2008

According to the rules, a crash cushion is supposed to set up products that is satisfied with the standard of a performance test after performing the car crash test by road safety facilities and management guide. For development of crash cushion, performance should be estimated through the car crash test eventually. However, there is no reasonable design method which considers passenger's safety and only depend on crash test without an alternative plan. Therefore it incurs a loss materially and takes a lot. Therefore, we are asked to create a systematic design of the crash cushion. This study shows that a scientific basis of applying single degree of freedom when it designs the crash cushion after analyzing vehicle crash test data of crash cushion and also represents design of crash cushion through single degree of freedom response spectrum using calculated by crash test data on crash cushion.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.2
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• pp.205-214
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• 2004

This paper presents design concepts, specifications and performances of a newly developed Black Box, the reconstruction analysis tool with the records, and results of validation tests. The Black Box can detect crash accidents automatically, and record the vehicle's motion and driver's maneuvers during a pre-defined time period before and after the accident. The items of the Black Box included the acceleration, yaw-rate, vehicle speed, engine RPM, braking application, steering and several digital inputs for recording driver's maneuvers. To detect the accident-related-crash, it is important to understand characteristics of the crash signal, which are much different from those of normal driving. Therefore, analytical considerations should be taken in designing pre-filtering circuits and selecting appropriate parameters for identifying crash accidents. And, it is necessary to select proper combination of motion sensors and design proper pre-filtering circuits in order to describe the vehicle's motion. The analysis algorithms were developed and implemented which can perform accurate detection of crash accidents, simulating pre-crash trajectories, and calculating parameters for reconstruction analysis of crash accidents. The developed Black Box was installed on passenger cars and several types of validation tests were conducted. Through the tests, the accuracy of the recorded data and usefulness of the analysis tool for reconstruction have been validated.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.317-325
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• 2017

The EDR(Event Data Recorder) is a part of the ACU(Airbag Control Unit) functions mounted on a vehicle. EDR data have pre-crash data and post-crash data. Pre-crash data are recorded within 5 sec from time zero(AE) with 0.5 sec resolution, and reveal vehicle speed, engine rotation speed, throttle opening, brake pedal operation, acceleration pedal position and steering angle, etc. Using this EDR data, the investigation of a traffic accident can become more objective and scientific. Crash tests of three vehicles equipped with EDR function had been performed successfully. Evaluation of EDR data reliability had also been performed using Vbox and PC-Crash's sequence table function. Based on the results, we could confirm EDR data's reliability and availability for Traffic Accident Analysis by the series of this process.

• The Journal of Asian Finance, Economics and Business
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• v.5 no.4
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• pp.67-72
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• 2018

The purpose of this study is to investigate the effect of quality of management discussion and analysis (MD&A) disclosure on stock price crash risk. The MD&A can be seen to reflect the management's intention on public announcement and reveals directly what the management says to communicate with outside investors. A firm's high-quality MD&A implies the management's commitment to communicating with the market, not allowing the managers to have incentives to hoard unfavorable news, which if revealed to the public, may lead to downward stock price corrections, damaging corporate values. The high-quality MD&A is, thus, likely to reduce the stock price crash risk. We use a logistic regression to test whether MD&A influences crash risk using listed companies in the Korean Stock Exchange (KSE) stock market between 2010 and 2013. Findings of the empirical test show that the higher the quality of MD&A, the less likely crash risk appears, implying that the MD&A disclosed adequately can be one of the factors mitigating firm's stock price crash risk. This study has implications as it presents the MD&A disclosure as a factor influencing stock price crash risk and suggests voluntary disclosure as well as mandatory disclosure acts as a variable that explains the risk of stock price crash.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.2
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• pp.116-129
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• 2001

Traditional occupant analysis has been performed with a pre-determined crash puse which is produced from a test and the involved components are designed based on the analysis resuls. The method has limitations in that the design does not have much freedom. Howrver, if a good crash pulse is proposed, the body structure can be modified to generate the crash pulse. Therefore, it is assumed that the crash pulse can be changed to imptove the occupant crash performance. A preferable crash pulse is determined to minimize the occupant injuty. A constraint is established to keep the phenomena of physics valid. The response surface method(RSM) is adopted for the optimization process. An RSM in a commercial code is utilzed by interfacing with an in-house occupant analysis program called SAFE(Safety Analysis For occupant crash Enviroment). Design of involved components called is carried out through optimization with the RSM. The advantages of the RSM are investigated as opposed to other methods, and the tesults are compared. Also, the design under the new crach pulse is compared with that trom the pre-detetmined pulse.