• International journal of advanced smart convergence
• /
• v.9 no.4
• /
• pp.1-7
• /
• 2020

This study is a study on the development of AEBS test scenarios for traffic accidents in Korea, and was compared and analyzed using the Traffic Accident Analysis Program. To ensure the safety of passengers and pedestrians in traffic accidents, the number of cars equipped with ADAS is increasing rapidly at all car manufacturers in each country. For traffic accidents used in this study, the domestic traffic accident database (ACCC) produced by SAMSONG was used. Domestic traffic accidents differ from overseas traffic accidents in terms of road type, signal system, driver's seat location and number of vehicles. ACCC databases, which supplemented and reinforced these differences, built a database based on the PC-CRASH program. In the study, we analyze the types of accidents to develop comparative scenarios for each type of road and collision type of traffic accidents. When the road types of traffic accidents in Korea were divided into five types and the collision types were divided into six, it was confirmed that the most types of FRONT-SIDE crashes appeared at the intersection. It is expected that the frequency of possible traffic accidents and collision types can be predicted according to the road type in the accident database, we that it can be used as an AEBS test scenario development suitable for the domestic road environment.

• International Journal of Automotive Technology
• /
• v.6 no.6
• /
• pp.643-655
• /
• 2005

The frontal crash optimization of S-shaped closed-hat section member using the homogenization method, design of experiment (DOE) and response surface method (RSM) was studied. The optimization to effectively absorb more crash energy was studied to introduce the reinforcement design. The main focus of design was to decide the optimum size and thickness of reinforcement. In this study, the location of reinforcement was decided by homogenization method. Also, the effective size and thickness of reinforcements was studied by design of experiments and response surface method. The effects of various impact velocity for reinforcement design were researched. The high impact velocity reinforcement design showed to absorb the more crash energy than low velocities design. The effect of size and thickness of reinforcement was studied and the sensitivity of size and thickness was different according to base thickness of model. The optimum size and thickness of the reinforcement has shown a direct proportion to the thickness of base model. Also, the thicker the base model was, the effect of optimization using reinforcement was the bigger. The trend curve for effective size and thickness of reinforcement using response surface method was obtained. The predicted size and thickness of reinforcement by RSM were compared with results of DOE. The results of a specific dynamic mean crushing loads for the predicted design by RSM were shown the small difference with the predicted results by RSM and DOE. These trend curves can be used as a basic guideline to find the optimum reinforcement design for S-shaped member.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.18 no.1
• /
• pp.58-63
• /
• 2010

Introduction : Head trauma is the main cause of death in aircraft crash. In a Michigan study of structurally survivable, fatal accidents, 80% of the fatally injured had received head trauma. We tried to develop a new helmet for passengers, and perform its efficiency test. Methods : An aircraft helmet requires an excellent protection against head trauma, lightness, and small volumes. In addition, it must be wearable, fire resistant, and non toxic when it is burning. We developed two new helmets made from silicone foam which met all theses requirements. One was thin (2.5cm), and the other was thick (6.3cm). These looked like a motorcycle helmet and had only a soft silicone as liner material without an outer hard shell. Therefore we can carry them easily inside aircrafts. The standard test for helmet is Snell's drop test. It measures the impact acceleration of head shaped metal wearing helmet during we drop it at certain heights. Impact sites were total 5 sites (front, back, right, left and top) for each helmet. All these sites were impacted twice. Results : The thickness of impact sites varied from 2.5cm to 6.3cm. The impact acceleration of 2.5cm thickness site when it was dropped from 1.0 meter was 379g. But, that of 6.3cm thickness site when it was dropped from 1.5 meter was only 163g. Unfortunately, both helmets didn't meet the Snell Standard for motorcycle helmets. Discussion : If we add suitable outer hard shell, and change its thickness and design, the efficiency will be increased. A study indicated that helmet could reduce the risk of head trauma up to 85%. We made helmet for passengers in aircraft crash for the first time. If we improve its weak points, it will decrease the frequency of head trauma in aircraft craft.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.5
• /
• pp.81-87
• /
• 2012

New car assessment program (NCAP) originated from USNCAP in 1979 has been implemented in several countries or markets, for instance USA, Europe, Korea, Japan, China and Australia. NCAP has contributed greatly to reduce accidental tolls. But recently, NCAP performance has no distinction between cars because manufacturer have been continuously developed to improve NCAP performance. Therefore, NHTSA announced new USNCAP protocol becoming effective from MY2011. NHTSA had carried out many NCAP tests based on the new test protocol and announced these test results. In this paper, USNCAP test results were reviewed by statistical method. This review was focused on passenger cars and frontal crash test results in order to investigate effect of changes in new NCAP protocol. There are two key changes, one is sited female dummy in passenger position, the other is enlarged to 4 scoring body regions in each dummy. Results of this review were summarized as followings. Performance in Passenger (12.5%) is lower than Driver's (50%) for number of 5 star vehicle. Neck injury criterion is dominant to NCAP star rating for both dummies in the mean sense. For standard deviation, chest deflection is showed largest value in driver dummy but neck injury criterion is showed for passenger's. DKAB and PKAB were equipped 28.1% and 6.2%, respectively. Consequently, the countermeasure for new USNCAP frontal crash test is essential to control well dummy kinematics with some safety features including KAB to reduce neck injuries.

• Journal of Korean Society of Transportation
• /
• v.26 no.2
• /
• pp.7-15
• /
• 2008

New Car Assessment Program(NCAP) provides consumers with vehicle safety information, primarily front and side crash rating results, and more recently rollover ratings, to aid consumers in their vehicle purchase decisions. NCAP is a system to improve driver and passenger safety by providing market incentives for vehicle manufacturers to voluntarily design their vehicles to better protect drivers and passengers in a crash and be less susceptible to rollover, rather than by regulatory directives. NCAP have been performed since 1999 in Korea by the government in order to reduce fatalities and injuries caused by traffic accidents. Although as the number of vehicles models increases, more vehicle models are required to be test and NCAP is evaluated as a valuable system for vehicle safety, the expansion of the system is slow. It looks like that the benefit of NCAP quantitatively was not verified. In this study, based on the idea that the benefit of the NCAP is defined as the decrease of traffic accident severity by improving vehicle safety, a methodology to analyze the effectiveness of NCAP quantitatively in terms of traffic safety was developed. According to the developed methodology, the reduced numbers of fatalities and injuries were 1.51 and 466 in 2005.

• Journal of information and communication convergence engineering
• /
• v.8 no.3
• /
• pp.289-294
• /
• 2010

In the vehicle communication system, transferred information is needed to be detected as possible as fast in order to inform car status located in front and rear side. Through the moving vehicle information, we can avoid the crash caused by sudden break of front one or acquire to real time traffic data to check the detour road. To be connecting the wireless communication between the vehicles, fast timing synchronization can be a key factor. Finding out the sync point fast is able to have more marginal time to compensate the distorted signals caused by channel variance. Thus, we introduce the combination method which helps find out the start of frame quickly. It is executed by auto-correlation and cross-correlation simultaneously using only short preambles. With taking the absolute value at the implemented synch block output, the proposed method shows much better system performance to us.

• International Journal of Highway Engineering
• /
• v.15 no.4
• /
• pp.135-146
• /
• 2013

PURPOSES : This study aimed to analyze the impact the operation of pre-signals at 4-leg signalized intersections and present primary environmental factors of roads that need to be considered in the installation of pre-signals. METHODS : Shift of proportions safety effectiveness evaluation method which assesses shifts in proportions of target collision types to determine safety effectiveness was applied to analyze traffic crash by types. Also, Empirical Bayes before/after safety effectiveness evaluation method was adapted to analyze the impact pre-signal installation. Negative binomial regression was conducted to determine SPF(safety performance function). RESULTS : Pre-signals are effective in reducing the number of head on, right angle and sideswipe collisions and both the total number of personal injury crashes and severe crashes. Also, it is deemed that each factor used as an independent variable for the SPF model has strong correlation with the total number of personal injury crashes and severe crashes, and impacts general traffic crashes as a whole. CONCLUSIONS: This study suggests the following should be considered in pre-signal installation on intersections. 1) U-turns allowed in the front and rear 2) A high number of roads that connect to the intersection 3) Many right-turn traffic flows 4) Crosswalks installed in the front and rear 5) Insufficient left-turn lanes compared to left-turn traffic flows or no left-turn-only lane.

• Journal of Auto-vehicle Safety Association
• /
• v.6 no.1
• /
• pp.27-32
• /
• 2014

A study assessing driver acceptance level for various active safety systems against Korean drivers has been conducted. A 2013 Cadillac ATS model vehicle was tested along southern outskirt of Seoul including local roadway and interurban highway. Active safety systems included were FCA(Forward Collision Alert), LDW(Lane Departure Warning), SBZA(Side Blind Zone Alert), FRPA(Front/Rear Park Assist), RCTA(Rear Cross Traffic Alert), ACC(Adaptive Cruise Control), and AEB(Autonomous Emergency Braking). Participants experienced the FRPA, RCTA and AEB features in a controlled parking lot with a dummy vehicle and traffic cones as target obstacles. Remaining features have been tested on the accumulated stretched of 106 km long urban and interurban roadway. Series of questionnaires corresponding to each active safety systems have been conducted. Tentative results revealed that RCTA and SBZA systems received favourable ratings compared to the other ones.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.14 no.1
• /
• pp.85-93
• /
• 2015

Previous studies have estimated crash prediction models with the fixed effect model which assumes the fixed value of coefficients without considering characteristics of each intersections. However the fixed effect model would estimate under estimation of the standard error resulted in over estimation of t-value. In order to overcome these shortcomings, the random effect model can be used with considering heterogeneity of AADT, geometric information and unobserved factors. In this study, data collections from 89 intersections in Daejeon and estimates of crash prediction models were conducted using the random and fixed effect negative binomial regression model for comparison and analysis of two models. As a result of model estimates, AADT, speed limits, number of lanes, exclusive right turn pockets and front traffic signal were found to be significant. For comparing statistical significance of two models, the random effect model could be better statistical significance with -1537.802 of log-likelihood at convergence comparing with -1691.327 for the fixed effect model. Also likelihood ration value was computed as 0.279 for the random effect model and 0.207 for the fixed effect model. This mean that the random effect model can be improved for statistical significance of models comparing with the fixed effect model.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.918-923
• /
• 2011

On AC railway systems, the neutral sections are installed in front of substations and sectioning posts in order to avoid crash between power that have differing phases. In case railway vehicles pass through these neutral sections, it is necessary for them to switch to coasting driving by notch-off. This may reduce speed of the vehicles, resulting lowered train operation efficiency. The usage of automatic power switching systems makes it possible to pass neutral sections at notch-on, enhancing operation efficiency so that it is appropriate for high-speed railway applications. This paper introduces a simulator that assesses efficiency of automatic power switching systems in neutral sections. The is composed of a power supply system, electric railway vehicles, thyristor switches, and traction motors.