• 한국자동차공학회논문집
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• 제25권3호
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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.

• 대한토목학회논문집
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• 제32권4A호
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• pp.197-206
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• 2012

충돌해석 데이터의 확대해석 사례는 미국의 도로안전시설 지침인 MASH(Manual for Assessing Safety Hardware, AASHTO, 2009)에서 2,270 kg 픽업트럭의 충격흡수시설에 대한 충돌시험 데이터로부터 1,500 kg 중형승용차의 안전도를 계산하는 절차에 관한 내용을 최초로 소개하였다. MASH 방법에 따라 1.3 ton 차량의 충돌시험 데이터로부터 0.9 ton 차량의 충돌데이터 및 안전지수를 계산하여 0.9 ton 차량의 충돌실험 데이터와 비교하였다. 비교 결과 MASH방법으로 계산한 0.9 ton 차량의 충돌데이터 및 안전지수가 충돌실험 데이터와 큰 차이를 나타낸다는 것을 확인하였고 그 원인을 분석하여 새로운 확대해석 방법을 개발하였다. 개발된 확대해석 방법은 질량이 큰 차량(1.3 ton)의 충돌시험 데이터로부터 작은 차량(0.9 ton)의 충돌 데이터를 계산할 수 있을 뿐 아니라 작은 차량(0.9 ton)의 충돌 데이터로 부터 큰 차량(1.3 ton)의 데이터를 계산할 수 있다. 개발된 확대해석 방법은 정확도가 MASH에 비하여 월등하고 이론적인 원리가 확실하다. 본 논문은 충돌시험 데이터를 이용하여 새로운 확대해석 방법의 효율성과 정확도를 입증하고 그 원리를 규명하였다.

• 한국자동차공학회논문집
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• 제21권5호
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• pp.136-144
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• 2013

An extensive real world in-depth crash accident data is needed to make a precise occupant injury risk prediction at crash accidents which might be a critical information from the scene of the accident in ACNS(Automatic Crash Notification System). However it is rather unfortunate that there is no such a domestic database unlike other leading countries. Therefore we propose a numerical method, i.e., crash simulation using a sled model to make a virtual database that can substitute car crash database in real world. The proposing crash injury risk prediction is validated against a limited domestic crash accident data.

• Asian Journal of Business Environment
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• 제10권1호
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• pp.19-28
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• 2020

Purpose: This research aims to investigate the impact of corporate integrity on stock price crash risk. Research design, data, and methodology: Taking 1419 firms listed in Shenzhen Stock Exchange in China as a sample, this paper empirically analyzed the relationship between corporate integrity and stock price crash risk. The main integrity data was hand-collected from Shenzhen Stock Exchange Website. Other financial data was collected from CSMAR Database. Results: Findings show that corporate integrity can significantly decrease stock price crash risk. After changing the selection of samples, model estimation methods and the proxy variable of stock price crash risk, the conclusion is still valid. Further research shows that the relationship between corporate integrity and stock price crash risk is only found in firms with weak internal control and firms in poor legal system areas. Conclusions: Results of the study suggest that corporate integrity has a significant influence on behaviors of managers. Business ethics reduces the likelihood of managers to overstate financial performance and hide bad news, which leads to the low likelihood of future stock price crashes. Meanwhile, corporate integrity can supplement internal control and legal system in decreasing stock price crash risks.

• 자동차안전학회지
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• 제12권4호
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• pp.39-47
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• 2020

In this study, crash situations of representative bus crash types were elicited by analyzing a total of 1,416 bus repair record which were collected in 2018~2019. K-means clustering was used as a methodology for this study. Bus repair record contain the information of repair term, type of bus operation, responsibility of accident, weather condition, road surface condition, type of accident, other party, type of road and type of location for each data. Also, by checking collision parts of each bus repair record, each record was classified by types of collision regions. From this, 760 record are classified to frontal type, 363 record are classified to middle-frontal type, 374 record are classified to middle-rear type and 331 record are classified to rear type. As mentioned, k-means clustering was performed on each type of collision parts. As a result, this study analyzed the severity of bus crash based on actual bus accident data which are based on bus repair record not the crash data from the TAAS. Also, this study presented crash situation of representative bus crash types. It is expected that this study can be expanded to analyzing hydrogen bus crash and defining indicators of hydrogen bus safety.

• 대한토목학회논문집
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• 제28권2D호
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• pp.163-170
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• 2008

본 연구에서는 한국도로공사 도로교통기술원에서 수행한 충격흡수시설의 충돌시험 결과 데이터를 분석하여 충격흡수시설 설계법 개발을 위한 유용한 결과를 얻고자 하였다. 분석에 사용된 CC1등급 충격흡수시설 10회, CC2등급 충격흡수시설 24회 총34회의 충돌시험 결과데이터들을 이용하여 국내 지침에 따라 탑승자 충돌속도(THIV)와 탑승자 가속도(PHD)를 계산하였고 총34회의 충돌시험데이터에서 Y축 가속도와 Yaw 각속도를 무시하고 X축 가속도 충돌시험데이터만을 이용해 탑승자 충돌속도(THIV)와 탑승자 가속도(PHD)를 계산하였다. 비교분석 결과 충격흡수시설의 탑승자 안전도가 오차율 2% 미만으로 나타나 X축 가속도 충돌시험데이터만을 이용한 탑승자 안전도 계산의 유효성이 증명되었다. 충돌시험 데이터 중 X축 가속도를 적분하여 얻은 흡수에너지와 초기 충돌차량의 충돌에너지를 비교분석한 결과, 거의 정확히 일치하여 X축 가속도만을 사용한 충격흡수시설의 충돌거동 분석이 가능하였다. 본 논문에서는 충격흡수시설의 실물차량 충돌시험데이터를 이용해 탑승자의 안전도 및 충돌거동을 분석함으로써 일차원을 적용한 충격흡수시설의 설계법 개발의 근간을 마련하였다.

• Journal of East Asia Management
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• 제3권1호
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• pp.25-40
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• 2022

This study investigates the effect of labor union and its power on information opacity. Given that the information opacity ultimately leads to the stock price crash, this study examines the relationship between labor unions and future stock price crash risk. Further, by assuming a strike by labor union as the actual power of the unionization in firms, whether labor union's power subrogated by the activity (i.e., a strike) makes a significant difference in the likelihood of future stock price crash between unionized firms is also examined. The work place survey data provided by Korea Labor Institute is used to test the hypotheses. The data is for the periods of 2004 - 2012 on firms listed on Korea Stock Exchange and KOSDAQ. The results show that while labor unionization has a positive impact on future stock price crash risk, on which labor union's power has a negative impact. This means that the existence of labor union itself might facilitate firm's information to be opaque by tolerating manager opportunism, while its power mitigates the managerial opportunism, which leads to lower future stock price crash risk. This study adds to the literature on the role of labor unions as nonfinancial stakeholders and its power in accounting environment, and also on the determinants of stock price crash. It is also valuable to examine the unions' role in terms of the economic consequences of both presence and power of the labor unions.

• 한국자동차공학회논문집
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• 제11권2호
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• pp.148-156
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• 2003

Many car manufacturers have frequently adopted an aggressive inflator and a lower threshold speed for airbag deployment in order to meet an injury requirement for unbolted occupant at high speed crash test. Consequently, today's occupant safety restraint system has a weakness due to an airbag induced injury at low speed crash event. This paper proposes a new crash algorithm to improve the weakness by suppressing airbag deployment at low speed crash event in case of belted condition. The proposed algorithm consists of two major blocks-crash severity algorithm and deployment logic block. The first block decides crash severity with two levels by means of velocity and crash energy calculation from acceleration signal. The second block implemented by simple AND/OR logic combines the crash severity level and seat belt status information to generate firing commands for airbag and belt pretensioner. Furthermore, it can be extended to adopt additional sensor information from passenger presence detection sensor and safing sensor. A simulation using real crash data for a 1,800cc passenger vehicle has been conducted to verify the performance of proposed algorithm.

• International Journal of Automotive Technology
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• 제7권2호
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• pp.179-185
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• 2006

Airbag deployment has been responsible for huge death, incidental injuries and broken bones due to low crash severity and wrong deployment decision. This misfortune has led the authorities and the industries to pursue uniquely designed airbags incorporating crash-sensing technologies. This paper provides a thorough discussion underlying crash sensing algorithm approaches for the subject matter. Unfortunately, most algorithms used for crash sensing still have some problems. They either deploy at low severity or fail to trigger the airbag on time. In this work, the crash-sensing algorithm is studied by analyzing the data obtained from the variables such as (i) change of velocity, (ii) speed of the vehicle and (iii) acceleration. The change of velocity is used to detect crash while speed of the vehicle provides relevant information for deployment decision. This paper also demonstrates crash severity with respect to the changing speed of the vehicle. Crash sensing simulations were carried out using Simulink, Stateflow, SimMechanics and Virtual Reality toolboxes. These toolboxes are also used to validate the results obtained from the simulated experiments of crash sensing, airbag deployment decision and its crash severity detection of the proposed system.

• 자동차안전학회지
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• 제13권4호
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• pp.66-72
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• 2021

This study was initiated to improve of the defect investigation method using event data recorders (EDR) and suggested a solution through the regulation and system analysis of EDR. The EDR data has been used for various purposes such as the vehicle defect investigation and the traffic accident investigation. However the EDR regulation has not been updated since the implementation in 2012. "Trigger Threshold" can be used to analyze a single accident such as the frontal crash, the side crash, and the rollover. In the case of a complex accident in which a rollover accident and a crash accident occur simultaneously, it is difficult to analyze a complex accident due to current "Trigger Threshold". This study proposed the method of separating the "Trigger Threshold" into a crash accident and a rollover accident so that accidents can be analyzed using the EDR data even when a complex accident occurs. In addition, it proposed the improvement method to quickly use the data of EDR in accident reconstruction software.