• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.3
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• pp.65-77
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• 2013

Recent advanced sensors and communication technologies have been widely applied to advanced safety vehicle (ASV) for reducing traffic accident and injury severity. To apply the advanced safety vehicle technologies, it is important to quantify the safety benefits, which is a fundamental for justifying application. This study proposed a methodology for quantifying the effectiveness of the advanced driver assistant system (ADAS), and applied the methodology to lane departure warning system (LDWS) and automatic emergency braking system (AEBS) which are typical advanced driver assistant systems. When the proposed methodology is applied to 2008-2010 gyeonggi-province crash data, LDWS would reduce about 10~14% of relevant crashes such as head-on, run-off-the road, rollover and fixed-object collisions on the road. In addition, AEBS could potentially prevent about 50% of total rear-end crashes. The outcomes of this study support decision making for developing not only vehicular technology but also relevant safety policies.

• Nuclear Engineering and Technology
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• v.52 no.2
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• pp.417-428
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• 2020

Investigations of the commercial aircraft impact effect on nuclear island infrastructures have been drawing extensive attention, and this paper aims to perform the safety assessment of Generation III nuclear power plant (NPP) buildings subjected to typical commercial aircrafts crash. At present Part III, the local damage of the rigid components of aircraft, e.g., engine and landing gear, impacting the steel concrete (SC) structures of NPP containment is mainly discussed. Two typical SC target panels with the thicknesses of 40 mm and 100 mm, as well as the steel cylindrical projectile with a mass of 2.15 kg and a diameter of 80 mm are fabricated. By using a large-caliber air gas gun, both the projectile penetration and perforation test are conducted, in which the striking velocities were ranged from 96 m/s to 157 m/s. The bulging velocity and the maximal deflection of rear steel plate, as well as penetration depth of projectile are derived, and the local deformation and failure modes of SC panels are assessed experimentally. Then, the commercial finite element program LS-DYNA is utilized to perform the numerical simulations, by comparisons with the experimental and simulated projectile impact process and SC panel damage, the numerical algorithm, constitutive models and the corresponding parameters are verified. The present work can provide helpful references for the evaluation of the local impact resistance of NPP buildings against the aircraft engine.

• Journal of Auto-vehicle Safety Association
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• v.8 no.3
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• pp.10-15
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• 2016

The purpose of this study is to evaluate the injury mechanism of facial injury related to an air-bag's deployment in occupant motor vehicle accident (MVA) by using Hospital Information System (HIS) and reconstruction program, based on the materials related to motor vehicle accidents. Among patients who visited the emergency department of Wonju Severance Christian Hospital due to motor vehicle accidents from August 2012 to February 2014, we collected data on patients with agreement for taking the damaged vehicle's photos. After obtaining the verbal consent from the patient, we asked about the cause of the accident, information on vehicle involved in the accident, and the location of car repair shop. The photos of the damaged vehicle were taken on the basis of front, rear, left side and right side. Damage to the vehicle was presented using the CDC code by analytical study of photo-images of the damaged vehicle, and a trauma score was used for medical examination of the severity of the patient's injury. Among the 309 patients with agreement for an investigation, thirty five (11.3 %) were the severe who had ISS over 15. And also, sixteen (5.2%) derived from the reconstructed data (maximum collision energy, maximum acceleration, delta V) by PC-Crash. As a result, ISS including the facial injuries was affected by the condition. It was high when the number of crash extent, the safety belt was not fastened, and the seating position of occupant and the direction of collision is same. For accurate analysis of the relationship between occupant injury and vehicle damage in MVAs, build-up of an in-depth database through carrying out various policies for motor vehicle accidents is necessary for sure.

• Journal of Platform Technology
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• v.11 no.6
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• pp.47-55
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• 2023

With the goal of ensuring the safety of wheelchair users, this study was conducted using finite element analysis, focusing on the development of a platform that can be used to evaluate safety during the design stage. Safety evaluation criteria for wheelchairs used in vehicles are defined in ANSI/RESNA WC19 and ISO 7176-19. Based on these standards, finite element analysis was performed to assess the sectional forces of each component of the wheelchair and sensitivity analysis was conducted based on the specifications. These results were used to derive equivalent composite loads for the wheelchair's main components, determine the necessary sectional specifications for these main components in the wheelchair design phase, and investigate the process of safety assessment verification. The study showed that member forces vary with changes in the cross-sectional values of the wheelchair frame's main components, with the front and rear lower members, as well as the rear upper and lower members, requiring the highest cross-sectional values for safety design. This study offers a proactive method for evaluating safety in the wheelchair design stage, and in future research, we plan to develop a safety evaluation platform based on these results.

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

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.3
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• pp.52-59
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• 2008

Most accident reconstruction or analysis depend on the coefficient of friction to estimate the vehicle speeds. Skid mark and coefficient of friction are usually utilized to calculate the velocity and behavior of vehicles. For a critical case such as traffic accident reconstruction, however, the initial velocity of the car should be calculated precisely. In this paper, emergency brake tests on ABS and Non-ABS brake system are conducted on the dry pavement asphalt road on speed 40, 60, 80 and 100 km/h respectively. The SWIFT sensor was established in the front wheel and rear wheel at driver side to measure the forces, moments and speeds of revolution of the tires. These tests results can be available to brake tests and accident reconstruction.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.6
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• pp.125-132
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• 2002

Bumpers are structural components to reduce physical damage to the front and rear ends of a passenger motor vehicle from low speed collisions. Damage assessment and the protectiveness are the commonly used designing criteria but in this study, relative displacements of the bumper are examined. To absorb the crash energy without significant damage to the bumper itself, foam material is installed between fascia and beam. However, it is not easy to predict the exact displacements generated in bumper structures through FEM because the compressive stress-strain curve of a foam material depends on strain rates that deviates significantly on each trial. Under this uncertain condition, a range of displacements is calculated and the optimum design is performed using the design of experiments. The result will be used to find the design that minimizes the weight within displacement constraints. The orthogonal array of L9 is introduced to find the optimum of the design variables that considers the thickness of inner beam, outer beam and stay, This study will suggest the design procedure of a front bumper using the uncertain stress-strain curve of a foam material.

• Journal of Auto-vehicle Safety Association
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• v.13 no.4
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• pp.53-59
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• 2021

According to the Korean Traffic Accident Analysis System (TAAS), more than 200,000 traffic accidents occur every year. Also, the statistics including auto insurance companies data show 1.3 million traffic accidents. In the case of TAAS, the types of traffic accidents are simply divided into four; frontal collision, side collision, rear collision, and rollover. However, more detailed information is needed to assess for advanced driver assist systems at intersections. For example, directional information is needed, such as whether the vehicle in the car accident way in a straight or a left turn, etc. This study intends to redefine the type of accident with the more clear driving direction and path by referring to the Negligence standards used in automobile insurance accidents. The standards largely divide five categories of car-to-car/motorcycle /pedestrian/cyclist, and highway, and the each category is classified into dozens of types by status of the traffic signal, conflict situations. In order to present more various accident types for auto insurance accidents, the standards are reclassified driving direction and path of vehicles from crash situations. In results, the car-to-car accidents are classified into 33 accident types, car-to-pedestrian accidents have 19 accident types, car-to-motorcycle accidents have 38 accident types, and car-to-cyclist accidents are derived into 26 types.

• Journal of Auto-vehicle Safety Association
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• v.8 no.1
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• pp.31-37
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• 2016

The Child Occupant Safety Assessment was first introduced and carried out by Euro NCAP in 2003, with the goal of ensuring manufacturers to develop safe vehicles for passengers of all ages; the objective was to evaluate the safety and protection offered by different Child Restraint Systems (CRS) in the event of a crash. In 2013, the formerly used P child dummy series was replaced by newer and more biofidelic Q1.5 and Q3 child dummies, representing 1.5 and 3 year old children respectively. The frontal and side impact dynamic performances of the Q1.5 and Q3 were tested within all classes of vehicles assessed by Euro NCAP at the time. As an extension to that initiative, Q6 and Q10 child dummies were later developed representing children of 6 and 10 years old. Since the protection of larger children during vehicle crashes relies greatly on the interaction of vehicle restraint systems such as seat belt and the CRS, instrumented Q6 and Q10 dummies will be used to assess the protection offered in the event of front and side impact crashes. In this paper, we focused on injury criteria of Q6 and Q10 child dummies at 64 kph 40% offset frontal crash test. The whole procedure was designed with DFSS analysis. The full vehicle sled test results of both dummies were conducted with different restraint systems settled through previous sled test. It showed that several injury criteria and image data were collected as the result of the full vehicle sled test. Based on the results of these investigations, this paper describes which factor is most important and combination shows the best performance when evaluating rear seat occupant protection for Q6 and Q10 child dummies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.843-850
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• 2020

The purpose of this study is to evaluate the structural risk and weakness of a railway tank car through nonlinear collision analysis according to overseas collision safety standards. The goal is to propose a crash safety design guideline for railway tank cars for transporting dangerous goods in Korea. We analyzed the buffer impact test procedure of railway freight cars prescribed in EN 12663-2 and the tank puncture test criteria prescribed in 49CFR179. A nonlinear finite element model according to each standard was modeled using LS-DYNA, a commercial finite element analysis solver. As a result of the buffing impact test simulation, it was predicted that plastic deformation would not occur at a collision speed of 6 km/h or less. However, plastic deformation was detected at the rear of the center sill and at the tank center supporting the structure at a collision speed of 8 km/h or more. As a result of a head-on test simulation of tank puncture, the outer tank shell was destroyed at the corner of the tank head when 4% of the kinetic energy of the impacter was absorbed. The tank shell was destroyed in the area of contact with the impacter in the test mode analysis of tank shell puncture when the kinetic energy of the moving vehicle was reduced by 30%. Therefore, the simulation results of the puncture test show that fracture at the tank shell and leakage of the internal material is expected. Consequently, protection and structural design reinforcement are required on railway tank cars in Korea.