• Transactions of the Korean Society of Automotive Engineers
• /
• v.18 no.5
• /
• pp.20-24
• /
• 2010

The position of the automobile's head restraint is very important for the neck injury in rear end collision. This study is about influence of the head restraint height and distance on neck injury during rear end collision. The effects of the position have been evaluated experimentally. The neck injuries are calculated by the relative acceleration between the upper and lower neck. As a result, It is found that the head restraint should be close enough to the back of the head and high enough to the top of the head.

• Proceedings of the Optical Society of Korea Conference
• /
• 1989.02a
• /
• pp.36-38
• /
• 1989

We have developed Magnetic Pulse Compression System to realize repetitive excimer laser excitation. The principle of this system is to use the large change in permiability owing to the nolinear characteristics of ferro-magnetic material (Metglas2605s-2 metal ribon). Prior to the laser operation, the MPC system was tested with a dummy load (5$\Omega$) and laser head. Laser head has a discharge volume of 1.0 (w) x 2.0 (h) x 20.0(1) cm. This MPC system compressed a 6.2us (FWHM), 80 A pulse into a 0.4us(FWHM), 1.3kA pulse.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.10a
• /
• pp.16-16
• /
• 2003

In this study, for a safety assessment of wheelchair occupant in side impact, we used a dynamic sled impact test results. The test was carried out total 6 times and impact speed was 13g$\pm$0.43/28km/h$\pm$0.95, By using EURO SID-1 dummy, head performance criteria(HPC), abdominal peak force, etc. were measured. We evaluated wheelchair occupant safety by motion criteria(MC) which was measured by head, trunk and side deformation change of wheelchair and Head & Neck injury criteria(HNI) measured by using head and neck deformation angle and time relation. When we assumed that the maximum injury value in side impact was 100%, the results of motion criteria(MC) of wheelchair occupant were max 80.3, mim 32.3 and average 60.3%, Head & Neck injury criteria(HNI) value were max 118.4, min 14.5 and average 59.7%.

• The Journal of the Acoustical Society of Korea
• /
• v.24 no.2
• /
• pp.111-116
• /
• 2005

This study deals with a subjective assessment to investigate the preferred acoustic conditions and determine the important acoustical parameters in concert halls. A subjective test was carried out using dummy head recorded sounds made in actual halls in Australia (referred to as Hall A and Hall B) to evaluate the acoustic performance of two halls. The results of subjective tests were then correlated with measured acoustical parameters to investigate the significant determinants for the preference judgements. The listeners show a stronger Preference for seats in the Hall B than those in the Hall A. The low preferences for seats in the Hall A are in agreement with live performance ratings assessed by musicians. It is found that the sound level is the most significant acoustical parameter for evaluating the overall acoustic preference in the two halls.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.572-574
• /
• 2014

Researches on three-dimensional multimedia has been performed actively in recent years. Virtual sound technology corresponding to virtual image should be provided to implement 3D multimedia with high quality. Head-related transfer function (HRTF) plays a key role in this research area. HRTFs measured in changing azimuth, elevation, and distance for each and every subject is necessary for ideal solution. However, it is practically impossible to measure all subjects' HRTFs, so various HRTF databases have been built by many researchers. Because HRTF displays quite different aspects from subject to subject, HRTF of dummy head has been used for generic usage. However, mannequin's HRTF showed much worse performance comparing with individual case so this solution should be improved. From previous work, standardization of HRTF based on tensor-singular value decomposition method has been proposed. For effective extraction of standard HRTF, three different decomposition methods are compared in this paper.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.11a
• /
• pp.616-619
• /
• 2005

An extensive data base of HRTFs (Head Related Transfer Functions) has been established in order to work with high qualifies of 3D acoustic appliances. The basic specifications of the measurement presented are that a spatial resolution of 10$^{\circ}$ in elevation angles (ranging from -40$^{\circ}$ to 90$^{\circ}$) and uniform spatial resolution of 5$^{\circ}$ in azimuth angles. The distance from the measurement sources to the centre of the dummy head is 2m and the sampling frequency is 48 kHz and the quantisation depth is 24-bits. The data is presented for three arrangements of pinna models (large, small and no pinna) which were combined with the open and blocked ear canal cases to give a total of 6 sets of measurements. The data base may contribute to show promise of providing useful applications of 3D sound.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.15 no.5
• /
• pp.125-132
• /
• 2007

In order to provide consumers with safety informations of vehicles according to the Korean New Car Assessment Program(KNCAP), the evaluation results and the star ratings of 21 vehicles for the side impact tests have been reported since 2003. Now, the KNCAP considers changing the side impact dummy from EuroSID-1 to EuroSID-2 near future. The rib deflection of EuroSID-2 is 20-30% higher than that of EuroSID-1 because of the removal of "Flat Tops" effect. In this study, the effect of changing the side impact dummy from EuroSID-1 to EuroSID-2 in the KNCAP side impact evaluation is estimated through the previous KNCAP evaluation results. The results show that the decrease of the star ratings would be one star($\bigstar$) approximately.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.6 no.2
• /
• pp.118-128
• /
• 1998

Finite element analyses are carried out to provide results usable in the design of airbag module that consists of inflater, cushion, cover, mounting plate, etc. In the first phase, a deployment process of airbag module is analyzed to evaluate the pressure waveform of developed airbag and deployment characteristics, and is compared with the test results. Interaction between head form and inflated airbag module is investigated in the second phase. In the last stage, sled test with rigid dummy, airbag midule, driving system and car interior part are simulated to investigate the influence of airbag design factor on the behavior of dummy with seat belt. The procedures can be provided as a guideline for airbag module design and improvement of airbag module performance.

• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.4
• /
• pp.220-225
• /
• 2000

This paper develops a finite element model for studying occupant behavior of a mid-size truck equipped with a driver side airbag. The developed model simulates an occupant behavior using PAM-CRASH/PAM-SAFE in super computer SP2. The model is developed based on a sled test. A 50% hybrid dummy III is used for measuring head and chest accelerations and femur loads, and major injury coefficients such as HIC, CA and femur load. Inferior components such as foot rest, seat, kneebolster, crash pad, etc. are roughly modeled and defined by a rigid material model. And contact type II is used for detecting a contact with dummy. Contact type II definition uses force-deflection relationship of each body Such components as steering column which directly affect on the occupant injuy are modeled in detail and defined by an elastic-plastic material model. Airbag cushion is modeled using rivet elements. Airbag cover groove is modeled using rivet elements. Airbag tether is modeled as nonlinear bar elements. Airbag model has two vent holes to ventilating the exploded gas. Airbag is folded close to the real airbag folding procedure, and folded cautiously in order not to have initial penetration. A vehicle pulse acquired from 31mph frontal barrier test is used as input signal for the simulation. The simulation conditions are tuned to the sled test ones. The measured dummy accelerations and major injury coefficients, and filmed dummy behavior and airbag inflation process using high speed camera are compared to the simulation results to verify the developed finite element model.

• Journal of KSNVE
• /
• v.10 no.2
• /
• pp.269-279
• /
• 2000

This paper deals with the development of biomechanical model on a seat with backrest support in the vertical direction. Four kinds of biomechanical models are discussed to depict human motion. One DOF model mainly describes z-axis motion of hip, two and three DOF models describe z-axis of hip and head, and while nine DOF model suggested in this study represents more motion than the otehr model. Three kinds of experiments were executed to validate these models. The first one was to measure the acceleration of the floor and hip surface in z-axis, the back surface in x-axis, and the head in z-axis under exciter. From this measurement, the transmissiblities of each subject were obtained. The second one was the measurement of the joint position by the device having pointer and the measurement of contact position between the human body and the seat by body pressure distribution. The third one was the measurement of the seat and back cushion by dummy. The biomechanical model parameters were obtained by matching the simulated to the experimental transmissiblities at the hip, back, and head.